uu.seUppsala University Publications
Change search
Refine search result
1 - 36 of 36
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Abu Hamdeh, Sami
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Virhammar, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Alafuzoff, Irina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Clinical and experimental pathology.
    Cesarini, Kristina G
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Marklund, Niklas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Brain tissue Aβ42 levels are linked to shunt response in idiopathic normal pressure hydrocephalus2018In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, p. 1-9Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE The authors conducted a study to test if the cortical brain tissue levels of soluble amyloid beta (Aβ) reflect the propensity of cortical Aβ aggregate formation and may be an additional factor predicting surgical outcome following idiopathic normal pressure hydrocephalus (iNPH) treatment. METHODS Highly selective ELISAs (enzyme-linked immunosorbent assays) were used to quantify soluble Aβ40, Aβ42, and neurotoxic Aβ oligomers/protofibrils, associated with Aβ aggregation, in cortical biopsy samples obtained in patients with iNPH (n = 20), sampled during ventriculoperitoneal (VP) shunt surgery. Patients underwent pre- and postoperative (3-month) clinical assessment with a modified iNPH scale. The preoperative CSF biomarkers and the levels of soluble and insoluble Aβ species in cortical biopsy samples were analyzed for their association with a favorable outcome following the VP shunt procedure, defined as a ≥ 5-point increase in the iNPH scale. RESULTS The brain tissue levels of Aβ42 were negatively correlated with CSF Aβ42 (Spearman's r = -0.53, p < 0.05). The Aβ40, Aβ42, and Aβ oligomer/protofibril levels in cortical biopsy samples were higher in patients with insoluble cortical Aβ aggregates (p < 0.05). The preoperative CSF Aβ42 levels were similar in patients responding (n = 11) and not responding (n = 9) to VP shunt treatment at 3 months postsurgery. In contrast, the presence of cortical Aβ aggregates and high brain tissue Aβ42 levels were associated with a poor outcome following VP shunt treatment (p < 0.05). CONCLUSIONS Brain tissue measurements of soluble Aβ species are feasible. Since high Aβ42 levels in cortical biopsy samples obtained in patients with iNPH indicated a poor surgical outcome, tissue levels of Aβ species may be associated with the clinical response to shunt treatment.

  • 2.
    Englund, Hillevi
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Johansson, Ann-Sofi
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Nilsson, Lars N.G.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Gellerfors, Pär
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Paulie, Staffan
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Ekholm Pettersson, Frida
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Sensitive ELISA detection of amyloid-β protofibrils in biological samples2007In: Journal of Neurochemistry, ISSN 0022-3042, E-ISSN 1471-4159, Vol. 103, no 1, p. 334-345Article in journal (Refereed)
    Abstract [en]

    Amyloid-β (Aβ) protofibrils are known intermediates of the in vitro Aβ aggregation process and the protofibrillogenic Arctic mutation (APPE693G) provides clinical support for a pathogenic role of Aβ protofibrils in Alzheimer's disease (AD). To verify their in vivo relevance and to establish a quantitative Aβ protofibril immunoassay, Aβ conformation dependent monoclonal antibodies were generated. One of these antibodies, mAb158 (IgG2a), was used in a sandwich ELISA to specifically detect picomolar concentrations of Aβ protofibrils without interference from Aβ monomers or the amyloid precursor protein (APP). The specificity and biological significance of this ELISA was demonstrated using cell cultures and transgenic mouse models expressing human APP containing the Swedish mutation (APPKN670/671ML), or the Swedish and Arctic mutation in combination. The mAb158 sandwich ELISA analysis revealed presence of Aβ protofibrils in both cell and animal models, proving that Aβ protofibrils are formed not only in vitro, but also in vivo. Furthermore, elevated Aβ protofibril levels in the Arctic-Swedish samples emphasize the usefulness of the Arctic mutation as a model of enhanced protofibril formation. This assay provides a novel tool for investigating the role of Aβ protofibrils in AD and has the potential of becoming an important diagnostic assay.

  • 3.
    Eriksson, Jonas
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Fang, Xiaotian T.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Hultqvist, Greta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Olberg, D. E.
    Univ Oslo, Dept Pharm, Oslo, Norway.
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preparative Medicinal Chemistry.
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Syvänen, Stina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    [F-18]Tetrazine-trans-cyclooctene mediated labelling of antibodies for PET imaging of amyloid-beta2018In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 45, p. S643-S643Article in journal (Other academic)
  • 4.
    Fang, Xiaotian
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences.
    Hultqvist, Greta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Meier, Silvio
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences.
    Syvänen, Stina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences.
    A small bispecific antibody-based construct based on bapineuzumab as a PET tracer for amyloid beta pathology in brain2017In: Meeting abstractArticle in journal (Other academic)
  • 5.
    Fang, Xiaotian T.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET-MRI Platform. PET Centre, Uppsala University Hospital, 751 85 Uppsala, Sweden.
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET-MRI Platform. Uppsala University Hospital, 751 85 Uppsala, SwedenUppsala University Hospital, 751 85 Uppsala, Sweden.
    Yngve, Ulrika
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET-MRI Platform. Uppsala University Hospital, 751 85 Uppsala, SwedenUppsala University Hospital, 751 85 Uppsala, Sweden.
    Cato, Linda
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Syvänen, Stina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Brain mGluR5 in mice with amyloid beta pathology studied with in vivo [(11)C]ABP688 PET imaging and ex vivo immunoblotting2017In: Neuropharmacology, ISSN 0028-3908, E-ISSN 1873-7064, Vol. 113, no Pt A, p. 293-300, article id S0028-3908(16)30459-2Article in journal (Refereed)
    Abstract [en]

    Alzheimer's disease (AD) is characterized by aggregation of amyloid beta (Aβ) into insoluble plaques. Intermediates, Aβ oligomers (Aβo), appear to be the mechanistic cause of disease. The de facto PET AD ligand, [(11)C]PIB, binds and visualizes Aβ plaque load, which does not correlate well with disease severity. Therefore, finding a dynamic target that changes with pathology progression in AD is of great interest. Aβo alter synaptic plasticity, inhibit long-term potentiation, and facilitate long-term depression; key mechanisms involved in memory and learning. In order to convey these neurotoxic effects, Aβo requires interaction with the metabotropic glutamate 5 receptor (mGluR5). The aim was to investigate in vivo mGluR5 changes in an Aβ pathology model using PET. Wild type C57/BL6 (wt) and AβPP transgenic mice (tg-ArcSwe), 4, 8, and 16 months old, were PET scanned with [(11)C]ABP688, which is highly specific to mGluR5, to investigate changes in mGluR5. Mouse brains were extracted postscan and mGluR5 and Aβ protofibril levels were assessed with immunoblotting and ELISA respectively. Receptor-dense brain regions (hippocampus, thalamus, and striatum) displayed higher [(11)C]ABP688 concentrations corresponding to mGluR5 expression pattern. Mice had similar uptake levels of [(11)C]ABP688 regardless of genotype or age. Immunoblotting revealed general decline in mGluR5 expression and elevated levels of mGluR5 in 16 months old tg-ArcSwe compared with wt mice. [(11)C]ABP688 could visualize mGluR5 in the mouse brain. In conclusion, mGluR5 levels were found to decrease with age and tended to be higher in tg-ArcSwe compared with wt mice, however these changes could not be quantified with PET.

  • 6.
    Fang, Xiaotian T.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Hultqvist, Greta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Meier, Silvio R.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET-MRI Platform.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Syvänen, Stina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    High detection sensitivity with antibody-based PET radioligand for amyloid beta in brain2019In: NeuroImage, ISSN 1053-8119, E-ISSN 1095-9572, Vol. 184, p. 881-888Article in journal (Refereed)
    Abstract [en]

    PET imaging of amyloid-beta (A beta) deposits in brain has become an important aid in Alzheimer's disease diagnosis, and an inclusion criterion for patient enrolment into clinical trials of new anti-A beta treatments. Available PET radioligands visualizing A beta bind to insoluble fibrils, i.e. A beta plaques. Levels of prefibrillar A beta forms, e.g. soluble oligomers and protofibrils, correlate better than plaques with disease severity and these soluble species are the neurotoxic form of A beta leading to neurodegeneration. The goal was to create an antibody-based radioligand, recognizing not only fibrillary A beta , but also smaller and still soluble aggregates. We designed and expressed a small recombinant bispecific antibody construct, di-scFv 3D6-8D3, targeting the A beta N-terminus and the transferrin receptor (TfR). Natively expressed at the blood-brain barrier (BBB), TfR could thus be used as a brain-blood shuttle. Di-scFv 3D6-8D3 bound to A beta 1-40 with high affinity and to TfR with moderate affinity. Di-scFv [I-124] 3D6-8D3 was injected in two transgenic mouse models overexpressing human A beta and wild-type control mice and PET scanned at 14, 24 or 72 h after injection. Di-scFv [I-124] 3D6-8D3 was retained in brain of transgenic animals while it was cleared from wild-type lacking A beta . This difference was observed from 24 h onwards, and at 72 h, 18 months old transgenic animals, with high load of A beta pathology, displayed SUVR of 2.2-3.5 in brain while wildtype showed ratios close to unity. A subset of the mice were also scanned with [C-11] PIB. Again wt mice displayed ratios of unity while transgenes showed slightly, non-significantly, elevated SUVR of 1.2, indicating improved sensitivity with novel di-scFv [I-124] 3D6-8D3 compared with [C-11] PIB. Brain concentrations of di-scFv [I-124] 3D6-8D3 correlated with soluble A beta (p < 0.0001) but not with total A beta, i.e. plaque load (p = 0.34). We have successfully created a small bispecific antibody-based radioligand capable of crossing the BBB, subsequently binding to and visualizing intrabrain A beta in vivo. The radioligand displayed better sensitivity compared with [C-11] PIB, and brain concentrations correlated with soluble neurotoxic A beta aggregates.

  • 7.
    Fang, Xiaotian T.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Syvänen, Stina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Hultqvist, Greta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Efficient and inexpensive transient expression of multispecific multivalent antibodies in Expi293 cells2017In: Biological Procedures Online, ISSN 1480-9222, E-ISSN 1480-9222, Vol. 19, article id 11Article in journal (Refereed)
    Abstract [en]

    Background: Immunotherapy is a very fast expanding field within drug discovery and, hence, rapid and inexpensive expression of antibodies would be extremely valuable. Antibodies are, however, difficult to express. Multifunctional antibodies with additional binding domains further complicate the expression. Only few protocols describe the production of tetravalent bispecific antibodies and all with limited expression levels.

    Methods: Here, we describe a protocol that can produce functional tetravalent, bispecific antibodies at around 22 mg protein/l to a low cost. The expression system is based on the Expi293 cells, which have been adapted to grow in denser cultures than HEK293 cells and gives higher expression yields. The new protocol transfects the Expi293 cells with PEI (which has a negligible cost).

    Results: The protocol has been used to generate multiple variants of tetra-and hexavalent bispecific antibodies with yields of around 22 mg protein/l within 10 days. All materials are commercially available and the implementation of the protocol is inexpensive and straightforward. The bispecific antibodies generated in our lab were capable of binding to all antigens with similar affinity as the original antibody. Two of the bispecific antibodies have also been used in transgenic mice as positron emission tomography (PET) ligands to successfully detect amyloid-beta (A beta) aggregates in vivo.

    Conclusions: This protocol is the first describing transfection of the human Expi293 cells with PEI. It can be used to generate functional multi-specific antibodies in high amounts. The use of biological drugs, and in particular multispecific antibodies, is rapidly increasing, hence improved protocols such as the one presented here are highly valuable.

  • 8.
    Gustafsson, Gabriel
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Lööv, Camilla
    Massachusetts Gen Hosp, Dept Neurol, Charlestown, MA 02129 USA; Harvard Med Sch, Neurosci Program, Boston, MA 02115 USA.
    Persson, Emma
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Lázaro, Diana F.
    Univ Med Ctr Gottingen, Dept Expt Neurodegenerat, Gottingen, Germany.
    Takeda, Shuko
    Massachusetts Gen Hosp, Dept Neurol, Charlestown, MA 02129 USA; Harvard Med Sch, Neurosci Program, Boston, MA 02115 USA.
    Bergström, Joakim
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Erlandsson, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Balaj, Leonora
    Massachusetts Gen Hosp, Dept Neurol, Charlestown, MA 02129 USA; Massachusetts Gen Hosp, Dept Radiol, Charlestown, MA 02129 USA; Harvard Med Sch, Neurosci Program, Boston, MA 02115 USA.
    György, Bence
    Massachusetts Gen Hosp, Dept Neurol, Charlestown, MA 02129 USA; Massachusetts Gen Hosp, Dept Radiol, Charlestown, MA 02129 USA; Harvard Med Sch, Neurosci Program, Boston, MA 02115 USA.
    Hallbeck, Martin
    Linkoping Univ, Dept Clin & Expt Med, Dept Pathol, Linkoping, Sweden.
    Outeiro, Tiago F
    Univ Med Ctr Gottingen, Dept Expt Neurodegenerat, Gottingen, Germany; Max Planck Inst Expt Med, Gottingen, Germany; Newcastle Univ, Med Sch, Inst Neurosci, Framlington Pl, Newcastle Upon Tyne NE2 4HH, Tyne & Wear, England.
    Breakefield, Xandra O
    Massachusetts Gen Hosp, Dept Neurol, Charlestown, MA 02129 USA; Massachusetts Gen Hosp, Dept Radiol, Charlestown, MA 02129 USA; Harvard Med Sch, Neurosci Program, Boston, MA 02115 USA.
    Hyman, Bradley T
    Massachusetts Gen Hosp, Dept Neurol, Charlestown, MA 02129 USA; Harvard Med Sch, Neurosci Program, Boston, MA 02115 USA.
    Ingelsson, Martin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics. Massachusetts Gen Hosp, Dept Neurol, Charlestown, MA 02129 USA; Massachusetts Gen Hosp, Dept Radiol, Charlestown, MA 02129 USA; Harvard Med Sch, Neurosci Program, Boston, MA 02115 USA.
    Secretion and uptake of α-synuclein via extracellular vesicles in cultured cells2018In: Cellular and molecular neurobiology, ISSN 0272-4340, E-ISSN 1573-6830, Vol. 38, no 8, p. 1539-1550Article in journal (Refereed)
    Abstract [en]

    In Parkinson’s disease and other Lewy body disorders, the propagation of pathology has been accredited to the spreading of extracellular α-synuclein (α-syn). Although the pathogenic mechanisms are not fully understood, cell-to-cell transfer of α-syn via exosomes and other extracellular vesicles (EVs) has been reported. Here, we investigated whether altered molecular properties of α-syn can influence the distribution and secretion of α-syn in human neuroblastoma cells. Different α-syn variants, including α-syn:hemi-Venus and disease-causing mutants, were overexpressed and EVs were isolated from the conditioned medium. Of the secreted α-syn, 0.1–2% was associated with vesicles. The major part of EV α-syn was attached to the outer membrane of vesicles, whereas a smaller fraction was found in their lumen. For α-syn expressed with N-terminal hemi-Venus, the relative levels associated with EVs were higher than for WT α-syn. Moreover, such EV-associated α-syn:hemi-Venus species were internalized in recipient cells to a higher degree than the corresponding free-floating forms. Among the disease-causing mutants, A53T α-syn displayed an increased association with EVs. Taken together, our data suggest that α-syn species with presumably lost physiological functions or altered aggregation properties may shift the cellular processing towards vesicular secretion. Our findings thus lend further support to the tenet that EVs can mediate spreading of harmful α-syn species and thereby contribute to the pathology in α-synucleinopathies.

  • 9.
    Gustafsson, Sofia
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Gustavsson, Tobias
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Roshanbin, Sahar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Hultqvist, Greta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Syvänen, Stina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Blood-Brain Barrier Integrity in a Mouse Model of Alzheimer’s Disease With or Without Acute 3D6 Immunotherapy2018In: Neuropharmacology, ISSN 0028-3908, E-ISSN 1873-7064, Vol. 143, p. 1-9Article in journal (Refereed)
    Abstract [en]

    The blood-brain barrier (BBB) is suggested to be compromised in Alzheimer's disease (AD). The concomitant presence of vascular amyloid beta (AD) pathology, so called cerebral amyloid angiopathy (CAA), also predisposes impairment of vessel integrity. Additionally, immunotherapy against A beta may lead to further damage of the BBB. To what extent this affects the BBB passage of molecules is debated. The current study aimed to investigate BBB integrity to large molecules in transgenic mice displaying abundant A beta pathology and age matched wild type animals, with or without acute anti-A beta antibody treatment. Animals were administered a single i.v. injection of PBS or 3D6 (10 mg/kg), i.e. the murine version of the clinically investigated A beta antibody bapineuzumab, supplemented with [(125)]3D6. Three days post injections, a 4 kDa FITC and a 150 kDa Antonia Red dextran were administered i.v. to all animals. After termination, fluorescent detection in brain and serum was used for the calculation of dextran brain-to-blood concentration ratios. Further characterization of antibody fate and the presence of CAA were investigated using radioactivity measurements and Congo red staining. BBB passage of large molecules was equally low in wild type and transgenic mice, suggesting an intact BBB despite A beta pathology. Neither was the BBB integrity affected by acute 3D6 treatment. However, CAA was confirmed in the transgenes and local antibody accumulations were observed in the brain, indicating CAA-antibody interactions. The current study shows that independently of A beta pathology or acute 3D6 treatment, the BBB is intact, without extensive permeability to large molecules, including the 3D6 antibody.

  • 10.
    Gustafsson, Sofia
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Lampa, Erik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, UCR-Uppsala Clinical Research Center.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Loryan, Irena
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Heterogeneous drug tissue binding in brain regions of rats, Alzheimer’s patients and controls: impact on translational drug development2019In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, article id 5308Article in journal (Refereed)
    Abstract [en]

    For preclinical and clinical assessment of therapeutically relevant unbound, free, brain concentrations, the pharmacokinetic parameter fraction of unbound drug in brain (fu,brain) is commonly used to compensate total drug concentrations for nonspecific brain tissue binding (BTB). As, homogenous BTB is assumed between species and in health and disease, rat BTB is routinely used. The impact of Alzheimer’s disease (AD) on drug BTB in brain regions of interest (ROI), i.e., fu,brain,ROI, is yet unclear. This study for the first time provides insight into regional drug BTB and the validity of employing rat fu,brain,ROI as a surrogate of human BTB, by investigating five marketed drugs in post-mortem tissue from AD patients (n = 6) and age-matched controls (n = 6). Heterogeneous drug BTB was observed in all within group comparisons independent of disease and species. The findings oppose the assumption of uniform BTB, highlighting the need of case-by-case evaluation of fu,brain,ROI in translational CNS research.

  • 11.
    Hultqvist, Greta
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Syvänen, Stina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Fang, Xiaotian T.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Bivalent Brain Shuttle Increases Antibody Uptake by Monovalent Binding to the Transferrin Receptor2017In: Theranostics, ISSN 1838-7640, E-ISSN 1838-7640, Vol. 7, no 2, p. 308-318Article in journal (Refereed)
    Abstract [en]

    The blood-brain barrier (BBB) is an obstacle for antibody passage into the brain, impeding the development of immunotherapy and antibody-based diagnostics for brain disorders. In the present study, we have developed a brain shuttle for active transport of antibodies across the BBB by receptor-mediated transcytosis. We have thus recombinantly fused two single-chain variable fragments (scFv) of the transferrin receptor (TfR) antibody 8D3 to the light chains of mAb158, an antibody selectively binding to A beta protofibrils, which are involved in the pathogenesis of Alzheimer's disease (AD). Despite the two TfR binders, a monovalent interaction with TfR was achieved due to the short linkers that sterically hinder bivalent binding to the TfR dimer. The design enabled efficient receptor-mediated brain uptake of the fusion protein. Two hours after administration, brain concentrations were 2-3% of the injected dose per gram brain, comparable to small molecular drugs and 80-fold higher than unmodified mAb158. After three days, fusion protein concentrations in AD transgenic mouse brains were 9-fold higher than in wild type mice, demonstrating high in vivo specificity. Thus, our innovative recombinant design markedly increases mAb158 brain uptake, which makes it a strong candidate for improved Aa immunotherapy and as a PET radioligand for early diagnosis and evaluation of treatment effect in AD. Moreover, this approach could be applied to any target within the brain.

  • 12.
    Kamali-Moghaddam, Masood
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Genetics and Pathology, Molecular tools.
    Ekholm Pettersson, Frida
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Wu, Di
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Genetics and Pathology, Molecular tools.
    Englund, Hillevi
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Darmanis, Spyros
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Genetics and Pathology, Molecular tools.
    Lord, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Tavoosidana, Gholamreza
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Genetics and Pathology, Molecular tools.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Gustafsdottir, Sigrun
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Genetics and Pathology, Molecular tools.
    Nilsson, Lars N. G.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Landegren, Ulf
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Genetics and Pathology, Molecular tools.
    Sensitive detection of A beta protofibrils by proximity ligation: relevance for Alzheimer's disease2010In: BMC neuroscience (Online), ISSN 1471-2202, E-ISSN 1471-2202, Vol. 11, p. 124-Article in journal (Refereed)
    Abstract [en]

    Background: Protein aggregation plays important roles in several neurodegenerative disorders. For instance, insoluble aggregates of phosphorylated tau and of A beta peptides are cornerstones in the pathology of Alzheimer's disease. Soluble protein aggregates are therefore potential diagnostic and prognostic biomarkers for their cognate disorders. Detection of the aggregated species requires sensitive tools that efficiently discriminate them from monomers of the same proteins. Here we have established a proximity ligation assay (PLA) for specific and sensitive detection of A beta protofibrils via simultaneous recognition of three identical determinants present in the aggregates. PLA is a versatile technology in which the requirement for multiple target recognitions is combined with the ability to translate signals from detected target molecules to amplifiable DNA strands, providing very high specificity and sensitivity. Results: For specific detection of A beta protofibrils we have used a monoclonal antibody, mAb158, selective for A beta protofibrils in a modified PLA, where the same monoclonal antibody was used for the three classes of affinity reagents required in the assay. These reagents were used for detection of soluble Ab aggregates in solid- phase reactions, allowing detection of just 0.1 pg/ml A beta protofibrils, and with a dynamic range greater than six orders of magnitude. Compared to a sandwich ELISA setup of the same antibody the PLA increases the sensitivity of the Ab protofibril detection by up to 25- fold. The assay was used to measure soluble Ab aggregates in brain homogenates from mice transgenic for a human allele predisposing to A beta aggregation. Conclusions: The proximity ligation assay is a versatile analytical technology for proteins, which can provide highly sensitive and specific detection of A beta aggregates - and by implication other protein aggregates of relevance in Alzheimer's disease and other neurodegenerative disorders.

  • 13.
    Kaya, Ibrahim
    et al.
    Univ Gothenburg, Sahlgrenska Acad, Dept Psychiat & Neurochem, S-43180 Molndal, Sweden..
    Brinet, Dimitri
    Univ Gothenburg, Sahlgrenska Acad, Dept Psychiat & Neurochem, S-43180 Molndal, Sweden.;Univ Gothenburg, Dept Chem & Mol Biol, S-41296 Gothenburg, Sweden..
    Michno, Wojciech
    Univ Gothenburg, Sahlgrenska Acad, Dept Psychiat & Neurochem, S-43180 Molndal, Sweden..
    Syvänen, Stina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Zetterberg, Henrik
    Univ Gothenburg, Sahlgrenska Acad, Dept Psychiat & Neurochem, S-43180 Molndal, Sweden.;Sahlgrens Univ Hosp, Clin Neurochem Lab, S-43180 Molndal, Sweden.;UCL, Inst Neurol, Dept Mol Neurosci, London WC1N 3BG, England..
    Blennow, Kaj
    Univ Gothenburg, Sahlgrenska Acad, Dept Psychiat & Neurochem, S-43180 Molndal, Sweden.;Sahlgrens Univ Hosp, Clin Neurochem Lab, S-43180 Molndal, Sweden..
    Hanrieder, Jorg
    Univ Gothenburg, Sahlgrenska Acad, Dept Psychiat & Neurochem, S-43180 Molndal, Sweden.;UCL, Inst Neurol, Dept Mol Neurosci, London WC1N 3BG, England.;Chalmers, Dept Chem & Chem Engn, S-41296 Gothenburg, Sweden..
    Delineating Amyloid Plaque Associated Neuronal Sphingolipids in Transgenic Alzheimer's Disease Mice (tgArcSwe) Using MALDI Imaging Mass Spectrometry2017In: ACS Chemical Neuroscience, ISSN 1948-7193, E-ISSN 1948-7193, Vol. 8, no 2, p. 347-355Article in journal (Refereed)
    Abstract [en]

    The major pathological hallmarks of Alzheimer's disease (AD) are the progressive aggregation and accumulation of beta-amyloid (A beta) and hyperphosphorylated tau protein into neurotoxic deposits. A beta aggregation has been suggested as the critical early inducer, driving the disease progression. However, the factors that promote neurotoxic A beta aggregation remain elusive. Imaging mass spectrometry (IMS) is a powerful technique to comprehensively elucidate the spatial distribution patterns of lipids, peptides, and proteins in biological tissue sections. In the present study, matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS)-based imaging was used on transgenic Alzheimer's disease mouse (tgArcSwe) brain tissue to investigate the sphingolipid microenvironment of individual A beta plaques and elucidate plaque-associated sphingolipid alterations. Multivariate data analysis was used to interrogate the IMS data for identifying pathologically relevant, anatomical features based on their lipid chemical profile. This approach revealed sphingolipid species that distinctly located to cortical and hippocampal deposits, whose A beta identity was further verified using fluorescent amyloid staining and immunohistochemistry. Subsequent multivariate statistical analysis of the spectral data revealed significant localization of gangliosides and ceramides species to A beta positive plaques, which was accompanied by distinct local reduction of sulfatides. These plaque-associated changes in sphingolipid levels implicate a functional role of sphingolipid metabolism in A beta plaque pathology and AD pathogenesis. Taken together, the presented data highlight the potential of imaging mass spectrometry as a powerful approach for probing A beta plaque-associated lipid changes underlying AD pathology.

  • 14.
    Lannfelt, Lars
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Moller, Christer
    Basun, Hans
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Osswald, Gunilla
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Satlin, Andrew
    Logovinsky, Veronika
    Gellerfors, Par
    Perspectives on future Alzheimer therapies: amyloid-beta protofibrils - a new target for immunotherapy with BAN2401 in Alzheimer's disease2014In: ALZHEIMERS RES THER, ISSN 1758-9193, Vol. 6, no 2, p. 16-Article, review/survey (Refereed)
    Abstract [en]

    The symptomatic drugs currently on the market for Alzheimer's disease (AD) have no effect on disease progression, and this creates a large unmet medical need. The type of drug that has developed most rapidly in the last decade is immunotherapy: vaccines and, especially, passive vaccination with monoclonal antibodies. Antibodies are attractive drugs as they can be made highly specific for their target and often with few side effects. Data from recent clinical AD trials indicate that a treatment effect by immunotherapy is possible, providing hope for a new generation of drugs. The first anti-amyloid-beta (anti-A beta) vaccine developed by Elan, AN1792, was halted in phase 2 because of aseptic meningoencephalitis. However, in a follow-up study, patients with antibody response to the vaccine demonstrated reduced cognitive decline, supporting the hypothesis that A beta immunotherapy may have clinically relevant effects. Bapineuzumab (Elan/Pfizer Inc./Johnson & Johnson), a monoclonal antibody targeting fibrillar A beta, was stopped because the desired clinical effect was not seen. Solanezumab (Eli Lilly and Company) was developed to target soluble, monomeric A beta. In two phase 3 studies, Solanezumab did not meet primary endpoints. When data from the two studies were pooled, a positive pattern emerged, revealing a significant slowing of cognitive decline in the subgroup of mild AD. The Arctic mutation has been shown to specifically increase the formation of soluble A beta protofibrils, an A beta species shown to be toxic to neurons and likely to be present in all cases of AD. A monoclonal antibody, mAb158, was developed to target A beta protofibrils with high selectivity. It has at least a 1,000-fold higher selectivity for protofibrils as compared with monomers of A beta, thus targeting the toxic species of the peptide. A humanized version of mAb158, BAN2401, has now entered a clinical phase 2b trial in a collaboration between BioArctic Neuroscience and Eisai without the safety concerns seen in previous phase 1 and 2a trials. Experiences from the field indicate the importance of initiating treatment early in the course of the disease and of enriching the trial population by improving the diagnostic accuracy. BAN2401 is a promising candidate for A beta immunotherapy in early AD. Other encouraging efforts in immunotherapy as well as in the small-molecule field offer hope for new innovative therapies for AD in the future.

  • 15.
    Lord, Anna
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Gumucio, Astrid
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Englund, Hillevi
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Sundquist, Valentina Screpanti
    Söderberg, Linda
    Möller, Christer
    Gellerfors, Pär
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Pettersson, Frida Ekholm
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Nilsson, Lars N G
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    An amyloid-beta protofibril-selective antibody prevents amyloid formation in a mouse model of Alzheimer's disease2009In: Neurobiology of Disease, ISSN 0969-9961, E-ISSN 1095-953X, Vol. 36, no 3, p. 425-434Article in journal (Refereed)
    Abstract [en]

    Human genetics link Alzheimer's disease pathogenesis to excessive accumulation of amyloid-beta (Abeta) in brain, but the symptoms do not correlate with senile plaque burden. Since soluble Abeta aggregates can cause synaptic dysfunctions and memory deficits, these species could contribute to neuronal dysfunction and dementia. Here we explored selective targeting of large soluble aggregates, Abeta protofibrils, as a new immunotherapeutic strategy. The highly protofibril-selective monoclonal antibody mAb158 inhibited in vitro fibril formation and protected cells from Abeta protofibril-induced toxicity. When the mAb158 antibody was administered for 4 months to plaque-bearing transgenic mice with both the Arctic and Swedish mutations (tg-ArcSwe), Abeta protofibril levels were lowered while measures of insoluble Abeta were unaffected. In contrast, when treatment began before the appearance of senile plaques, amyloid deposition was prevented and Abeta protofibril levels diminished. Therapeutic intervention with mAb158 was however not proven functionally beneficial, since place learning depended neither on treatment nor transgenicity. Our findings suggest that Abeta protofibrils can be selectively cleared with immunotherapy in an animal model that display highly insoluble Abeta deposits, similar to those of Alzheimer's disease brain.

  • 16.
    Magnusson, Kristina
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Syvänen, Stina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Svedberg, Marie M.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Philipson, Ola
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Soderberg, Linda
    Tegerstedt, Karin
    Holmquist, Mats
    Gellerfors, Pär
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Hall, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Nilsson, Lars N. G.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Specific Uptake of an Amyloid-beta Protofibril-Binding Antibody-Tracer in A beta PP Transgenic Mouse Brain2013In: Journal of Alzheimer's Disease, ISSN 1387-2877, E-ISSN 1875-8908, Vol. 37, no 1, p. 29-40Article in journal (Refereed)
    Abstract [en]

    Evidence suggests that amyloid-beta (A beta) protofibrils/oligomers are pathogenic agents in Alzheimer's disease (AD). Unfortunately, techniques enabling quantitative estimates of these species in patients or patient samples are still rather limited. Here we describe the in vitro and ex vivo characteristics of a new antibody-based radioactive ligand, [I-125]mAb158, which binds to A beta protofibrils with high affinity. [I-125]mAb158 was specifically taken up in brain of transgenic mice expressing amyloid-beta protein precursor (A beta PP) as shown ex vivo. This was in contrast to [I-125]mAb-Ly128 which does not bind to A beta. The uptake of intraperitoneally-administered [I-125]mAb158 into the brain was age- and time-dependent, and saturable in A beta PP transgenic mice with modest A beta deposition. Brain uptake was also found in young A beta PP transgenic mice that were devoid of A beta deposits, suggesting that [I-125]mAb158 targets soluble A beta protofibrils. The radioligand was diffusely located in the parenchyma, sometimes around senile plaques and only occasionally colocalized with cerebral amyloid angiopathy. A refined iodine-124-labeled version of mAb158 with much improved blood-brain barrier passage and a shorter plasma half-life might be useful for PET imaging of A beta protofibrils.

  • 17.
    Meier, Silvio R.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Syvänen, Stina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Hultqvist, Greta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Fang, Xiaotian T.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Roshanbin, Sahar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics. BioArctic AB, Stockholm, Sweden.
    Neumann, Ulf
    Novartis Inst BioMed Res, Neurosci Res, Basel, Switzerland.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Antibody-Based In Vivo PET Imaging Detects Amyloid-beta Reduction in Alzheimer Transgenic Mice After BACE-1 Inhibition2018In: Journal of Nuclear Medicine, ISSN 0161-5505, E-ISSN 1535-5667, Vol. 59, no 12, p. 1885-1891Article in journal (Refereed)
    Abstract [en]

    Visualization of amyloid-beta (A beta) pathology with PET has become an important tool for making a specific clinical diagnosis of Alzheimer disease (AD). However, the available amyloid PET radioligands, such as C-11-Pittsburgh compound B, reflect levels of insoluble A beta plaques but do not capture soluble and protofibrillar A beta forms. Furthermore, the plaque load appears to be fairly static during clinical stages of AD and may not be affected by A beta-reducing treatments. The aim of the present study was to investigate whether a novel PET radioligand based on an antibody directed toward soluble aggregates of A beta can be used to detect changes in A beta levels during disease progression and after treatment with a beta-secretase (BACE-1) inhibitor. Methods: One set of transgenic mice (tg-ArcSwe, a model of A beta pathology) aged between 7 and 16 mo underwent PET with the A beta protofibril-selective radioligand I-124-RmAb158-scFv8D3 (where RmAb is recombinant mouse monoclonal antibody and scFv is single-chain variable fragment) to follow progression of A beta pathology in the brain. A second set of tg-ArcSwe mice, aged 10 mo, were treated with the BACE-1 inhibitor NB-360 for 3 mo and compared with an untreated control group. A third set of tg-ArcSwe mice, also aged 10 mo, underwent PET as a baseline group. Brain tissue was isolated after PET to determine levels of A beta by ELISA and immunohistochemistry. Results: The concentration of I-124-RmAb158-scFv8D3, as measured in vivo with PET, increased with age and corresponded well with the ex vivo autoradiography and A beta immunohistochemistry results. Mice treated with NB-360 showed significantly lower in vivo PET signals than untreated animals and were similar to the baseline animals. The decreased I-124-RmAb158-scFv8D3 concentrations in NB-360-treated mice, as quantified with PET, corresponded well with the decreased A beta levels measured in postmortem brain. Conclusion: Several treatments for AD are in phase 2 and 3 clinical trials, but the possibility of studying treatment effects in vivo on the important, nonfibrillar, forms of A beta is limited. This study demonstrated the ability of the A beta protofibril-selective radioligand I-124-RmAb158-scFv8D3 to follow disease progression and detect treatment effects with PET imaging in tg-ArcSwe mice.

  • 18.
    Michno, Wojciech
    et al.
    Univ Gothenburg, Sahlgrenska Acad, Dept Psychiat & Neurochem, S-43180 Molndal, Sweden.
    Nyström, Sofie
    Linkoping Univ, Dept Phys Chem & Biol, S-58183 Linkoping, Sweden.
    Wehrli, Patrick
    Univ Gothenburg, Sahlgrenska Acad, Dept Psychiat & Neurochem, S-43180 Molndal, Sweden.
    Lashley, Tammaryn
    UCL, Dept Neurodegenerat Dis, UCL Queen Sq Inst Neurol, London WC1N 3BG, England.
    Brinkmalm, Gunnar
    Univ Gothenburg, Sahlgrenska Acad, Dept Psychiat & Neurochem, S-43180 Molndal, Sweden.
    Guerard, Laurent
    Univ Gothenburg, Sahlgrenska Acad, Ctr Cellular Imaging, S-41390 Gothenburg, Sweden.
    Syvänen, Stina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Kaya, Ibrahim
    Univ Gothenburg, Sahlgrenska Acad, Dept Psychiat & Neurochem, S-43180 Molndal, Sweden.
    Brinet, Dimitri
    Univ Gothenburg, Sahlgrenska Acad, Dept Psychiat & Neurochem, S-43180 Molndal, Sweden.
    Nilsson, K. Peter R.
    Linkoping Univ, Dept Phys Chem & Biol, S-58183 Linkoping, Sweden.
    Hammarström, Per
    Linkoping Univ, Dept Phys Chem & Biol, S-58183 Linkoping, Sweden.
    Blennow, Kaj
    Univ Gothenburg, Sahlgrenska Acad, Dept Psychiat & Neurochem, S-43180 Molndal, Sweden;Sahlgrens Univ Hosp, Clin Neurochem Lab, S-43180 Molndal, Sweden.
    Zetterberg, Henrik
    Univ Gothenburg, Sahlgrenska Acad, Dept Psychiat & Neurochem, S-43180 Molndal, Sweden;UCL, Dept Neurodegenerat Dis, UCL Queen Sq Inst Neurol, London WC1N 3BG, England;Sahlgrens Univ Hosp, Clin Neurochem Lab, S-43180 Molndal, Sweden;UCL, UK Dementia Res Inst, London WC1E 6BT, England.
    Hanrieder, Jörg
    Univ Gothenburg, Sahlgrenska Acad, Dept Psychiat & Neurochem, S-43180 Molndal, Sweden;UCL, Dept Neurodegenerat Dis, UCL Queen Sq Inst Neurol, London WC1N 3BG, England.
    Pyroglutamation of amyloid-βx-42 (Aβx-42) followed by Aβ1–40 deposition underlies plaque polymorphism in progressing Alzheimer's disease pathology2019In: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 294, no 17, p. 6719-6732Article in journal (Refereed)
    Abstract [en]

    Amyloid- (A) pathology in Alzheimer's disease (AD) is characterized by the formation of polymorphic deposits comprising diffuse and cored plaques. Because diffuse plaques are predominantly observed in cognitively unaffected, amyloid-positive (CU-AP) individuals, pathogenic conversion into cored plaques appears to be critical to AD pathogenesis. Herein, we identified the distinct A species associated with amyloid polymorphism in brain tissue from individuals with sporadic AD (s-AD) and CU-AP. To this end, we interrogated A polymorphism with amyloid conformation-sensitive dyes and a novel in situ MS paradigm for chemical characterization of hyperspectrally delineated plaque morphotypes. We found that maturation of diffuse into cored plaques correlated with increased A1-40 deposition. Using spatial in situ delineation with imaging MS (IMS), we show that A1-40 aggregates at the core structure of mature plaques, whereas A1-42 localizes to diffuse amyloid aggregates. Moreover, we observed that diffuse plaques have increased pyroglutamated Ax-42 levels in s-AD but not CU-AP, suggesting an AD pathology-related, hydrophobic functionalization of diffuse plaques facilitating A1-40 deposition. Experiments in tgAPP(Swe) mice verified that, similar to what has been observed in human brain pathology, diffuse deposits display higher levels of A1-42 and that A plaque maturation over time is associated with increases in A1-40. Finally, we found that A1-40 deposition is characteristic for cerebral amyloid angiopathy deposition and maturation in both humans and mice. These results indicate that N-terminal Ax-42 pyroglutamation and A1-40 deposition are critical events in priming and maturation of pathogenic A from diffuse into cored plaques, underlying neurotoxic plaque development in AD.

  • 19.
    Nikitidou, Elisabeth
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics. Rudbeck Lab, Mol Geriatr, Uppsala, Sweden..
    Söllvander, Sofia
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics. Rudbeck Lab, Mol Geriatr, Uppsala, Sweden..
    Zyśk, Marlena
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences. Rudbeck Lab, Mol Geriatr, Uppsala, Sweden..
    Söderberg, L.
    BioArctic Neurosci, Stockholm, Sweden..
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics. Rudbeck Lab, Mol Geriatr, Uppsala, Sweden..
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics. Rudbeck Lab, Mol Geriatr, Uppsala, Sweden..
    Erlandsson, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics. Rudbeck Lab, Mol Geriatr, Uppsala, Sweden..
    The A beta protofibril selective antibody mAb158 prevents accumulation of A beta in astrocytes and rescues neurons from A beta induced apoptosis2017In: Glia, ISSN 0894-1491, E-ISSN 1098-1136, Vol. 65, no S1, p. E170-E170Article in journal (Other academic)
  • 20.
    O'Callaghan, Paul
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences.
    Noborn, Fredrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences.
    Li, Jin-ping
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences.
    Lindahl, Ulf
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Zhang, Xiao
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Pharmacology.
    Apolipoprotein E increases cell association of amyloid-β 40 through heparan sulfate and LRP1 dependent pathways2014In: Amyloid: Journal of Protein Folding Disorders, ISSN 1350-6129, E-ISSN 1744-2818, Vol. 21, no 2, p. 76-87Article in journal (Refereed)
  • 21.
    Olsen, Malin
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Aguilar, Ximena
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Fang, Xiaotian T.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET-MRI Platform.
    Erlandsson, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Syvänen, Stina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Astroglial Responses to Amyloid-Beta Progression in a Mouse Model of Alzheimer's Disease2018In: Molecular Imaging and Biology, ISSN 1536-1632, E-ISSN 1860-2002, Vol. 20, no 4, p. 605-614Article in journal (Refereed)
    Abstract [en]

    Alzheimer's disease (AD) is a neurodegenerative disorder characterized by amyloid-beta (A beta) deposition, hyperphosphorylation of tau, and neuroinflammation. Astrocytes, the most abundant glial cell type in the nervous system, respond to neurodegenerative disorders through astrogliosis, i.e., converting to a reactive inflammatory state. The aim of this study was to investigate how in vivo quantification of astrogliosis using positron emission tomography (PET) radioligand deuterium-l-[C-11]deprenyl ([C-11]DED), binding to enzyme monoamine oxidase-B (MAO-B) which is overexpressed in reactive astrocytes during AD, corresponds to expression of glial fibrillary acidic protein (GFAP) and vimentin, i.e., two well-established markers of astrogliosis, during A beta pathology progression. APP(ArcSwe) mice (n = 37) and wild-type (WT) control mice (n = 23), 2-16-month old, were used to investigate biomarkers of astrogliosis. The radioligand, [C-11]DED, was used as an in vivo marker while GFAP, vimentin, and MAO-B were used to investigate astrogliosis and macrophage-associated lectin (Mac-2) to investigate microglia/macrophage activation by immunohistochemistry of the mouse brain. A beta and GFAP levels were also measured with ELISA in brain homogenates. The intrabrain levels of aggregated A beta and reactive astrocytes were found to be elevated in APP(ArcSwe) compared with WT mice. GFAP and vimentin expression increased with age, i.e., with A beta pathology, in the APP(ArcSwe) mice. This was not the case for in vivo marker [C-11]DED that showed elevated binding of the same magnitude in APP(ArcSwe) mice compared with WT mice at both 8 and 16 months. Further, immunohistochemistry indicated that there was limited co-expression of MAO-B and GFAP. MAO-B levels are increased early in A beta pathology progression, while GFAP and vimentin appear to increase later, most likely as a consequence of abundant A beta plaque formation. Thus, [C-11]DED is a useful PET radioligand for the detection of changes in MAO-B at an early stage of AD progression but does not measure the total extent of astrogliosis at advanced stages of A beta pathology.

  • 22.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Aβ Conformation Dependent Antibodies and Alzheimer's Disease2010Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Soluble intermediates of the amyloid-β (Aβ) aggregation process are suggested to play a central role in the pathogenesis of Alzheimer’s disease (AD) by causing synaptic dysfunction and neuronal loss. In this thesis, soluble Aβ aggregates have been studied with a particular focus on the Aβ protofibril, which has served as the antigen for developing conformation dependent monoclonal antibodies.

    Antibodies generated from mice immunized with Aβ protofibrils were characterized regarding Aβ binding properties and the amino acid sequences of their antigen binding sites. A conformation dependent IgG antibody, mAb158, was further characterized and found to bind to Aβ protofibrils with a 200-fold higher affinity than to monomeric Aβ without affinity for soluble amyloid-β precursor protein (AβPP) or other amyloidogenic proteins. A sandwich enzyme-linked immunosorbent assay (ELISA) based on mAb158 was used to measure soluble Aβ protofibrils in brain extracts from AβPP-transgenic mice. Low levels of protofibrils could also be detected in human AD brain. However, positive signals generated from measurements in AD and control CSF samples were attributed to interference from heterophilic antibodies (HA), generating false positive signals by cross-binding the assay antibodies; consequently, a study on HA interference in Aβ oligomer ELISAs was initiated. A large set of plasma and CSF samples from AD and non-AD subjects were analyzed with and without measures taken to block HA interference, revealing that virtually all signals above the assay limit of detection were false and generated by HA interference.

    Many types of soluble Aβ aggregates have been described and suggested to impair neuron and synapse function. To investigate the soluble Aβ pool, synthetic Aβ and brain extracts from AβPP-transgenic mice and AD patients were ultracentrifuged on a density gradient to separate Aβ by size under native conditions. Four distinct gradient fractions were defined based on the appearance of synthetic Aβ in atomic force microscopy (AFM) and immunoreactivity in our protofibril specific sandwich ELISA. Interestingly, most Aβ from AD patients and AβPP-transgenic mice separated in the same fraction as toxic synthetic protofibrils.

    List of papers
    1. Heavy-Chain Complementarity-Determining Regions Determine Conformation Selectivity of Anti-A beta Antibodies
    Open this publication in new window or tab >>Heavy-Chain Complementarity-Determining Regions Determine Conformation Selectivity of Anti-A beta Antibodies
    Show others...
    2011 (English)In: Neurodegenerative Diseases, ISSN 1660-2854, Vol. 8, no 3, p. 117-123Article in journal (Refereed) Published
    Abstract [en]

    Background/Aims: Amyloid-beta (Abeta) protofibrils are neurotoxic soluble intermediates in the Abeta aggregation process eventually forming senile plaques in Alzheimer's disease. This Abeta species is a potential biomarker for Alzheimer's disease and also a promising target for immunotherapy. In this study, we investigated the characteristics of conformation-dependent Abeta antibodies specific for Abeta protofibrils. Methods: Mice were immunized with Abeta protofibrils to generate hybridomas producing Abeta-specific monoclonal antibodies. Binding of antibodies to different Abeta conformations was investigated with inhibition ELISA. The antibodies' complementarity-determining region (CDR) sequences were determined and compared. Results: A majority of the antibodies were of the IgM class, all selectively binding to aggregated Abeta. Two IgG antibodies were generated: one with selective affinity for Abeta protofibrils and the other bound Abeta in all conformations. A high degree of similarity between the heavy-chain CDRs of the conformation-dependent antibodies was found, and all high-affinity Abeta antibodies displayed a high degree of sequence similarity in the light-chain CDRs. Conclusion: Sequence similarity in the heavy-chain CDRs is associated with conformation selectivity of the antibodies, while sequence similarity in the light-chain CDRs correlates with the affinity for Abeta.

    Keywords
    Alzheimer's disease, Amyloid-beta, Conformation dependent antibodies, Complementarity determining region
    National Category
    Medical and Health Sciences
    Research subject
    Geriatrics
    Identifiers
    urn:nbn:se:uu:diva-132722 (URN)10.1159/000316530 (DOI)000289100800003 ()20714111 (PubMedID)
    Available from: 2010-10-26 Created: 2010-10-26 Last updated: 2011-04-19Bibliographically approved
    2. Sensitive ELISA detection of amyloid-β protofibrils in biological samples
    Open this publication in new window or tab >>Sensitive ELISA detection of amyloid-β protofibrils in biological samples
    Show others...
    2007 (English)In: Journal of Neurochemistry, ISSN 0022-3042, E-ISSN 1471-4159, Vol. 103, no 1, p. 334-345Article in journal (Refereed) Published
    Abstract [en]

    Amyloid-β (Aβ) protofibrils are known intermediates of the in vitro Aβ aggregation process and the protofibrillogenic Arctic mutation (APPE693G) provides clinical support for a pathogenic role of Aβ protofibrils in Alzheimer's disease (AD). To verify their in vivo relevance and to establish a quantitative Aβ protofibril immunoassay, Aβ conformation dependent monoclonal antibodies were generated. One of these antibodies, mAb158 (IgG2a), was used in a sandwich ELISA to specifically detect picomolar concentrations of Aβ protofibrils without interference from Aβ monomers or the amyloid precursor protein (APP). The specificity and biological significance of this ELISA was demonstrated using cell cultures and transgenic mouse models expressing human APP containing the Swedish mutation (APPKN670/671ML), or the Swedish and Arctic mutation in combination. The mAb158 sandwich ELISA analysis revealed presence of Aβ protofibrils in both cell and animal models, proving that Aβ protofibrils are formed not only in vitro, but also in vivo. Furthermore, elevated Aβ protofibril levels in the Arctic-Swedish samples emphasize the usefulness of the Arctic mutation as a model of enhanced protofibril formation. This assay provides a novel tool for investigating the role of Aβ protofibrils in AD and has the potential of becoming an important diagnostic assay.

    Keywords
    Alzheimer's disease, Amyloid-β protofibril, Conformation-dependent antibody, Protofibril-specific ELISA
    National Category
    Medical and Health Sciences
    Research subject
    Geriatrics
    Identifiers
    urn:nbn:se:uu:diva-98511 (URN)10.1111/j.1471-4159.2007.04759.x (DOI)000249949700030 ()17623042 (PubMedID)
    Available from: 2009-02-24 Created: 2009-02-24 Last updated: 2017-12-13Bibliographically approved
    3. Interference from Heterophilic Antibodies in Amyloid-beta Oligomer ELISAs
    Open this publication in new window or tab >>Interference from Heterophilic Antibodies in Amyloid-beta Oligomer ELISAs
    Show others...
    2010 (English)In: Journal of Alzheimer's Disease, ISSN 1387-2877, E-ISSN 1875-8908, Vol. 21, no 4, p. 1295-1301Article in journal (Refereed) Published
    Abstract [en]

    Amyloid-beta (Abeta) oligomers of different sizes and forms have recently been the focus for many Alzheimer's disease (AD) researchers. Various immunoassays have been used to detect low concentrations of these elusive Abeta species in different forms of human samples using little or no sample dilutions. However, the possibility that positive results may be caused by interference from heterophilic antibodies (HA) is often overlooked. HA, which recognize immunoglobulins from other species, are present in human plasma and cerebrospinal fluid (CSF) and may cause interference in sandwich immunoassays like enzyme-linked immunosorbent assays (ELISAs) by cross-binding the capture and detection antibodies of the assay. They thus may generate a false positive signal. Here we show that when assessing the Abeta oligomer content in plasma samples from 44 individuals with a sandwich ELISA, none of the 21 positive signals remained when the assay was repeated in the presence of factors blocking HA. Similarly, in CSF samples from 104 individuals, the signals from the 22 positive samples were strongly reduced when analyzed after anti-HA treatment. Taken together, HA interference is a problem that needs to be addressed when measuring low levels of an antigen in human plasma and CSF samples.

    Place, publisher, year, edition, pages
    IOS Press, 2010
    Keywords
    Alzheimer's disease, Heterophilic antibodies, ELISA
    National Category
    Neurology
    Research subject
    Geriatrics
    Identifiers
    urn:nbn:se:uu:diva-132732 (URN)10.3233/JAD-2010-100609 (DOI)000283049700021 ()20693634 (PubMedID)
    Note

    Title also written as: Interference from Heterophilic Antibodies in Amyloid-β Oligomer ELISAs

    Available from: 2010-10-26 Created: 2010-10-26 Last updated: 2017-12-12Bibliographically approved
    4. Large Aggregates Are the Major Soluble Ab Species in AD Brain Fractionated with Density Gradient Ultracentrifugation
    Open this publication in new window or tab >>Large Aggregates Are the Major Soluble Ab Species in AD Brain Fractionated with Density Gradient Ultracentrifugation
    Show others...
    2012 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 2, article id e32014Article in journal (Refereed) Published
    Abstract [en]

    Soluble amyloid-β (Aβ) aggregates of various sizes, ranging from dimers to large protofibrils, have been associated with neurotoxicity and synaptic dysfunction in Alzheimer's Disease (AD). To investigate the properties of biologically relevant Aβ species, brain extracts from amyloid β protein precursor (AβPP) transgenic mice and AD patients as well as synthetic Aβ preparations were separated by size under native conditions with density gradient ultracentrifugation. The fractionated samples were then analyzed with atomic force microscopy (AFM), ELISA, and MTT cell viability assay. Based on AFM appearance and immunoreactivity to our protofibril selective antibody mAb158, synthetic Aβ42 was divided in four fractions, with large aggregates in fraction 1 and the smallest species in fraction 4. Synthetic Aβ aggregates from fractions 2 and 3 proved to be most toxic in an MTT assay. In AβPP transgenic mouse brain, the most abundant soluble Aβ species were found in fraction 2 and consisted mainly of Aβ40. Also in AD brains, Aβ was mainly found in fraction 2 but primarily as Aβ42. All biologically derived Aβ from fraction 2 was immunologically discriminated from smaller species with mAb158. Thus, the predominant species of biologically derived soluble Aβ, natively separated by density gradient ultracentrifugation, were found to match the size of the neurotoxic, 80–500 kDa synthetic Aβ protofibrils and were equally detected with mAb158.

    Keywords
    Alzheimer's disease, amyloid-beta, aggregates, protofibrils
    National Category
    Medical and Health Sciences Engineering and Technology
    Research subject
    Geriatrics
    Identifiers
    urn:nbn:se:uu:diva-132734 (URN)10.1371/journal.pone.0032014 (DOI)000302741300108 ()
    Available from: 2010-10-26 Created: 2010-10-26 Last updated: 2017-12-12Bibliographically approved
  • 23.
    Sehlin, Dag
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Englund, Hillevi
    Simu, Barbro
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Ingelsson, Martin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Nikolajeff, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Pettersson, Frida Ekholm
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Large Aggregates Are the Major Soluble Ab Species in AD Brain Fractionated with Density Gradient Ultracentrifugation2012In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 2, article id e32014Article in journal (Refereed)
    Abstract [en]

    Soluble amyloid-β (Aβ) aggregates of various sizes, ranging from dimers to large protofibrils, have been associated with neurotoxicity and synaptic dysfunction in Alzheimer's Disease (AD). To investigate the properties of biologically relevant Aβ species, brain extracts from amyloid β protein precursor (AβPP) transgenic mice and AD patients as well as synthetic Aβ preparations were separated by size under native conditions with density gradient ultracentrifugation. The fractionated samples were then analyzed with atomic force microscopy (AFM), ELISA, and MTT cell viability assay. Based on AFM appearance and immunoreactivity to our protofibril selective antibody mAb158, synthetic Aβ42 was divided in four fractions, with large aggregates in fraction 1 and the smallest species in fraction 4. Synthetic Aβ aggregates from fractions 2 and 3 proved to be most toxic in an MTT assay. In AβPP transgenic mouse brain, the most abundant soluble Aβ species were found in fraction 2 and consisted mainly of Aβ40. Also in AD brains, Aβ was mainly found in fraction 2 but primarily as Aβ42. All biologically derived Aβ from fraction 2 was immunologically discriminated from smaller species with mAb158. Thus, the predominant species of biologically derived soluble Aβ, natively separated by density gradient ultracentrifugation, were found to match the size of the neurotoxic, 80–500 kDa synthetic Aβ protofibrils and were equally detected with mAb158.

  • 24.
    Sehlin, Dag
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Fang, Xiaotian T.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Cato, Linda
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Syvänen, Stina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Antibody-based PET imaging of amyloid beta in mouse models of Alzheimer's disease2016In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 7, article id 10759Article in journal (Refereed)
    Abstract [en]

    Owing to their specificity and high-affinity binding, monoclonal antibodies have potential as positron emission tomography (PET) radioligands and are currently used to image various targets in peripheral organs. However, in the central nervous system, antibody uptake is limited by the blood-brain barrier (BBB). Here we present a PET ligand to be used for diagnosis and evaluation of treatment effects in Alzheimer's disease. The amyloid beta (A beta) antibody mAb158 is radiolabelled and conjugated to a transferrin receptor antibody to enable receptor-mediated transcytosis across the BBB. PET imaging of two different mouse models with Ab pathology clearly visualize A beta in the brain. The PET signal increases with age and correlates closely with brain A beta levels. Thus, we demonstrate that antibody-based PET ligands can be successfully used for brain imaging.

  • 25.
    Sehlin, Dag
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Fang, Xiaotian T.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Meier, Silvio R.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Jansson, Malin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Syvänen, Stina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Pharmacokinetics, biodistribution and brain retention of a bispecific antibody-based PET radioligand for imaging of amyloid-beta2017In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, article id 17254Article in journal (Refereed)
    Abstract [en]

    Monoclonal antibodies (mAbs) have not been used as positron emission tomography (PET) ligands for in vivo imaging of the brain because of their limited passage across the blood-brain barrier (BBB). However, due to their high affinity and specificity, mAbs may be an attractive option for brain PET if their brain distribution can be facilitated. In the present study, a F(ab')(2) fragment of the amyloidbeta (A beta) protofibril selective mAb158 was chemically conjugated to the transferrin receptor (TfR) antibody 8D3 to enable TfR mediated transcytosis across the BBB. The generated bispecific protein, 8D3-F(ab')(2)-h158, was subsequently radiolabeled and used for microPET imaging of A beta pathology in two mouse models of AD. [124I]8D3-F(ab')(2)-h158 was distributed across the BBB several fold more than unmodified mAbs in general and its accumulation in the brain reflected disease progression, while its concentration in blood and other organs remained stable across all age groups studied. Cerebellum was largely devoid of 8D3-F(ab')(2)-h158 in young and middle aged mice, while mice older than 18 months also showed some accumulation in cerebellum. In a longer perspective, the use of bispecific antibodies as PET ligands may enable in vivo 'immunohistochemistry' also of other proteins in the brain for which PET radioligands are lacking.

  • 26.
    Sehlin, Dag
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Hedlund, Marie
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Lord, Anna
    Englund, Hillevi
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Gellerfors, Pär
    Paulie, Staffan
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Pettersson, Frida Ekholm
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Heavy-Chain Complementarity-Determining Regions Determine Conformation Selectivity of Anti-A beta Antibodies2011In: Neurodegenerative Diseases, ISSN 1660-2854, Vol. 8, no 3, p. 117-123Article in journal (Refereed)
    Abstract [en]

    Background/Aims: Amyloid-beta (Abeta) protofibrils are neurotoxic soluble intermediates in the Abeta aggregation process eventually forming senile plaques in Alzheimer's disease. This Abeta species is a potential biomarker for Alzheimer's disease and also a promising target for immunotherapy. In this study, we investigated the characteristics of conformation-dependent Abeta antibodies specific for Abeta protofibrils. Methods: Mice were immunized with Abeta protofibrils to generate hybridomas producing Abeta-specific monoclonal antibodies. Binding of antibodies to different Abeta conformations was investigated with inhibition ELISA. The antibodies' complementarity-determining region (CDR) sequences were determined and compared. Results: A majority of the antibodies were of the IgM class, all selectively binding to aggregated Abeta. Two IgG antibodies were generated: one with selective affinity for Abeta protofibrils and the other bound Abeta in all conformations. A high degree of similarity between the heavy-chain CDRs of the conformation-dependent antibodies was found, and all high-affinity Abeta antibodies displayed a high degree of sequence similarity in the light-chain CDRs. Conclusion: Sequence similarity in the heavy-chain CDRs is associated with conformation selectivity of the antibodies, while sequence similarity in the light-chain CDRs correlates with the affinity for Abeta.

  • 27.
    Sehlin, Dag
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Hultqvist, Greta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Gumucio, Astrid
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Laudon, H.
    BioArctic AB, Biochem, Stockholm, Sweden.
    Söderberg, L.
    BioArctic AB, Biochem, Stockholm, Sweden.
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Syvänen, Stina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Efficient clearance of Amyloid-beta protofibrils in APP-transgenic mice treated with a brain penetrating bifunctional antibody2017In: Journal of Cerebral Blood Flow and Metabolism, ISSN 0271-678X, E-ISSN 1559-7016, Vol. 37, p. 415-416Article in journal (Other academic)
  • 28.
    Sehlin, Dag
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Söllvander, Sofia
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Paulie, Staffan
    Brundin, RoseMarie
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Ingelsson, Martin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Pettersson, Frida Ekholm
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Englund, Hillevi
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Interference from Heterophilic Antibodies in Amyloid-beta Oligomer ELISAs2010In: Journal of Alzheimer's Disease, ISSN 1387-2877, E-ISSN 1875-8908, Vol. 21, no 4, p. 1295-1301Article in journal (Refereed)
    Abstract [en]

    Amyloid-beta (Abeta) oligomers of different sizes and forms have recently been the focus for many Alzheimer's disease (AD) researchers. Various immunoassays have been used to detect low concentrations of these elusive Abeta species in different forms of human samples using little or no sample dilutions. However, the possibility that positive results may be caused by interference from heterophilic antibodies (HA) is often overlooked. HA, which recognize immunoglobulins from other species, are present in human plasma and cerebrospinal fluid (CSF) and may cause interference in sandwich immunoassays like enzyme-linked immunosorbent assays (ELISAs) by cross-binding the capture and detection antibodies of the assay. They thus may generate a false positive signal. Here we show that when assessing the Abeta oligomer content in plasma samples from 44 individuals with a sandwich ELISA, none of the 21 positive signals remained when the assay was repeated in the presence of factors blocking HA. Similarly, in CSF samples from 104 individuals, the signals from the 22 positive samples were strongly reduced when analyzed after anti-HA treatment. Taken together, HA interference is a problem that needs to be addressed when measuring low levels of an antigen in human plasma and CSF samples.

  • 29.
    Syvänen, Stina
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Edén, Desireé
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Chemistry.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Cationization increases brain distribution of an amyloid-beta protofibril selective F(ab')2 fragment2017In: Biochemical and Biophysical Research Communications - BBRC, ISSN 0006-291X, E-ISSN 1090-2104, Vol. 493, no 1, p. 120-125Article in journal (Refereed)
    Abstract [en]

    Antibodies and fragments thereof are, because of high selectivity for their targets, considered as potential therapeutics and biomarkers for several neurological disorders. However, due to their large molecular size, antibodies/fragments do not easily penetrate into the brain. The aim of the present study was to improve the brain distribution via adsorptive-mediated transcytosis of an amyloid-beta (A beta) protofibril selective F(ab')2 fragment (F(ab')2-h158). F(ab')2-h158 was cationized to different extents and the specific and unspecific binding was studied in vitro. Next, cationized F(ab')2-h158 was labelled with iodine-125 and its brain distribution and pharmacokinetics was studied in mice. Cationization did not alter the in vitro affinity to A beta protofibrils, but increased the unspecific binding somewhat. Ex vivo experiments revealed a doubling of brain concentrations compared with unmodified F(ab')2-h158 and in vivo imaging with single photon emission computed tomography (SPECT) showed that the cationized F(ab')2-h158, but not the unmodified F(ab')2-h158 could be visualized in the brain. To conclude, cationization is a means to increase brain concentrations of therapeutic antibodies or fragments and may facilitate the use of antibodies/fragments as imaging biomarkers in the brain.

  • 30.
    Syvänen, Stina
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Fang, Xiaotian T.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Hultqvist, Greta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Falting, J.
    BioArctic AB..
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging. Uppsala Univ Hosp, PET Ctr..
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics. Uppsala Univ, Uppsala, Sweden..
    Antibody-based PET radioligands for imaging of amyloid-beta protofibrils2017In: Journal of Cerebral Blood Flow and Metabolism, ISSN 0271-678X, E-ISSN 1559-7016, Vol. 37, p. 84-84Article in journal (Other academic)
  • 31.
    Syvänen, Stina
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Fang, Xiaotian T.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Hultqvist, Greta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Meier, Silvio R.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    A bispecific Tribody PET radioligand for visualization of amyloid-beta protofibrils - a new concept for neuroimaging2017In: NeuroImage, ISSN 1053-8119, E-ISSN 1095-9572, Vol. 148, p. 55-63Article in journal (Refereed)
    Abstract [en]

    Antibodies are highly specific for their target molecules, but their poor brain penetrance has restricted their use as PET ligands for imaging of targets within the CNS. The aim of this study was to develop an antibody-based radioligand, using the Tribody(TM) format, for PET imaging of soluble amyloid-beta (All) protofibrils, which are suggested to cause neurodegeneration in Alzheimer's disease. Antibodies, even when expressed in smaller engineered formats, are large molecules that do not enter the brain in sufficient amounts for imaging purposes. Hence, their transport across the blood-brain barrier (BBB) needs to be facilitated, for example through interaction with the transferrin receptor (TfR). Thus, a Fab fragment of the TfR antibody 8D3 was fused with two single chain variable fragments (scFv) of the A beta protofibril selective antibody mAb158. Five Tribody proteins (A1-A5) were generated with different linkers between the Fab-8D3 and scFv-158. All proteins bound to TfR and All protofibrils in vitro. Three of the proteins (A1-A3) were radiolabeled with iodine-125 and studied ex vivo in wild-type (wt) and transgenic mice overexpressing human All. The systemic pharmacokinetics were similar with half-lives in blood of around 9 h for all three ligands. Brain concentrations at 2 h were around 1% of the injected dose per gram brain tissue, which is similar to what is observed for small molecular radioligands and at least 10-fold higher than antibodies in general. At 72 h, transgenic mice showed higher concentrations of radioactivity in the brain than wt mice (12, 15- and 16-fold for Al, A2 and A3 respectively), except in the cerebellum, an area largely devoid of A beta pathology. A3 was then labelled with iodine-124 for in vivo positron emission tomography (PET) imaging. Brain concentrations were quantified in six different regions showing a clear distinction both quantitatively and visually between wt and transgenic mice and a good correlation with A beta pathology. We have thus produced a recombinant, bispecific protein, actively transported into the brain, for PET imaging within the CNS. In a longer perspective, this technique may enable imaging of other proteins involved in neurodegenerative diseases for which imaging agents are completely lacking today.

  • 32.
    Syvänen, Stina
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Hultqvist, Greta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Gustavsson, Tobias
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Gumucio, Astrid
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Laudon, Hanna
    BioArctic AB, Stockholm, Sweden.
    Söderberg, Linda
    BioArctic AB, Stockholm, Sweden.
    Ingelsson, Martin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics. BioArctic AB, Stockholm, Sweden.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Efficient clearence of A beta protofibrils in A beta PP-transgenic mice treated with a brain-penetrating bifunctional antibody2018In: Alzheimer's Research & Therapy, E-ISSN 1758-9193, Vol. 10, article id 49Article in journal (Refereed)
    Abstract [en]

    Background: Amyloid-beta (A beta) immunotherapy is one of the most promising disease-modifying strategies for Alzheimer's disease (AD) Despite recent progress targeting aggregated forms of A beta, low antibody brain penetrance remains a challenge In the piesent study, we used transferrin receptor (TfR)-mediated transcytosis to facilitate brain uptake of our previously developed A beta protofibril-selective mAb158, with the aim of increasing the efficacy of immunotherapy directed toward soluble A beta protofibills. Methods: A beta protein precursor (A beta PP)-transgenic mice (tg-ArcSwe) were given a single dose of mAb158, modified for TfR-mediated transcytosis (RmAb158-scFvSDB), in companson with an equimolar dose or a tenfold higher dose of unmodified recombinant mAb158 (RmAb158) Soluble A beta protofibrills and total A beta in the brain were measured by enzyme-linked immunosorbent assay (ELISA) Brain distribution of radiolabeled antibodies was visualized by positron emission tomography (PET) and ex vivo autoiadiography. Results: ELISA analysis of Tris-buffered saline brain extracts demonstrated a 40% reduction of soluble A beta protofibrils in both RmAb158-scFv8D3- and high-dose RmAb158-treated mice, whereas there was no A beta protofibril reduction in mice treated with a low dose of RmAb158. Further, ex vivo autoradiography and PET imaging revealed diffeient brain distribution patterns of RmAb158-scFv8D3 and RmAb158, suggesting that these antibodies may affect A beta levels by different mechanisms. Conclusions: With a combination of biochemical and imaging analyses, this study demonstrates that antibodies engineered to be transported across the blood brain barrier can be used to increase the efficacy of A beta immunotherapy. This strategy may allow for decreased antibody doses and thereby reduced side effects and treatment costs.

  • 33.
    Söllvander, Sofia
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Ekholm-Pettersson, Frida
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Brundin, Rose-Marie
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Westman, Gabriel
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Infectious Diseases.
    Kilander, Lena
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Paulie, Staffan
    Mabtech AB, Nacka Strand, Sweden..
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics. Uppsala Univ, Rudbeck Lab, Dept Publ Hlth & Caring Sci Mol Geriatr, S-75185 Uppsala, Sweden..
    Increased Number of Plasma B Cells Producing Autoantibodies Against A beta(42) Protofibrils in Alzheimer's Disease2015In: Journal of Alzheimer's Disease, ISSN 1387-2877, E-ISSN 1875-8908, Vol. 48, no 1, p. 63-72Article in journal (Refereed)
    Abstract [en]

    The Alzheimer's disease (AD)-related peptide amyloid-beta (A beta) has a propensity to aggregate into various assemblies including toxic soluble A beta protofibrils. Several studies have reported the existence of anti-A beta antibodies in humans. However, it is still debated whether levels of anti-A beta antibodies are altered in AD patients compared to healthy individuals. Formation of immune complexes with plasma A beta makes it difficult to reliably measure the concentration of circulating anti-A beta antibodies with certain immunoassays, potentially leading to an underestimation. Here we have investigated anti-A beta antibody production on a cellular level by measuring the amount of anti-A beta antibody producing cells instead of the plasma level of anti-A beta antibodies. To our knowledge, this is the first time the anti-A beta antibody response in plasma has been compared in AD patients and age-matched healthy individuals using the enzyme-linked immunospot (ELISpot) technique. Both AD patients and healthy individuals had low levels of B cells producing antibodies binding A beta(40) monomers, whereas the number of cells producing antibodies toward A beta(42) protofibrils was higher overall and significantly higher in AD compared to healthy controls. This study shows, by an alternative and reliable method, that there is a specific immune response to the toxic A beta protofibrils, which is significantly increased in AD patients.

  • 34.
    Söllvander, Sofia
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Nikitidou, Elisabeth
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Brolin, Robin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Soderberg, Linda
    BioArctic Neurosci AB, Warfvinges Vag 35, SE-11251 Stockholm, Sweden..
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Erlandsson, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Accumulation of amyloid-beta by astrocytes result in enlarged endosomes and microvesicle-induced apoptosis of neurons2016In: Molecular Neurodegeneration, ISSN 1750-1326, E-ISSN 1750-1326, Vol. 11, article id 38Article in journal (Refereed)
    Abstract [en]

    Background: Despite the clear physical association between activated astrocytes and amyloid-beta (A beta) plaques, the importance of astrocytes and their therapeutic potential in Alzheimer's disease remain elusive. Soluble A beta aggregates, such as protofibrils, have been suggested to be responsible for the widespread neuronal cell death in Alzheimer's disease, but the mechanisms behind this remain unclear. Moreover, ineffective degradation is of great interest when it comes to the development and progression of neurodegeneration. Based on our previous results that astrocytes are extremely slow in degrading phagocytosed material, we hypothesized that astrocytes may be an important player in these processes. Hence, the aim of this study was to clarify the role of astrocytes in clearance, spreading and neuronal toxicity of A beta. Results: To examine the role of astrocytes in A beta pathology, we added A beta protofibrils to a co-culture system of primary neurons and glia. Our data demonstrates that astrocytes rapidly engulf large amounts of A beta protofibrils, but then store, rather than degrade the ingested material. The incomplete digestion results in a high intracellular load of toxic, partly N-terminally truncated A beta and severe lysosomal dysfunction. Moreover, secretion of microvesicles containing N-terminally truncated A beta, induce apoptosis of cortical neurons. Conclusions: Taken together, our results suggest that astrocytes play a central role in the progression of Alzheimer's disease, by accumulating and spreading toxic A beta species.

  • 35.
    Söllvander, Sofia
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Nikitidou, Elisabeth
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Gallasch, Linn
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Zysk, Marlena
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Söderberg, Linda
    BioArctic AB, Warfvinges Vag 35, SE-11251 Stockholm, Sweden.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Erlandsson, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    The A beta protofibril selective antibody mAb158 prevents accumulation of A beta in astrocytes and rescues neurons from A beta-induced cell death2018In: Journal of Neuroinflammation, ISSN 1742-2094, E-ISSN 1742-2094, Vol. 15, article id 98Article in journal (Refereed)
    Abstract [en]

    Background: Currently, several amyloid beta (A beta) antibodies, including the protofibril selective antibody BAN2401, are in clinical trials. The murine version of BAN2401, mAb158, has previously been shown to lower the levels of pathogenic A beta and prevent A beta deposition in animal models of Alzheimer's disease (AD). However, the cellular mechanisms of the antibody's action remain unknown. We have recently shown that astrocytes effectively engulf A beta(42) protofibrils, but store rather than degrade the ingested A beta aggregates. In a co-culture set-up, the incomplete degradation of A beta(42) protofibrils by astrocytes results in increased neuronal cell death, due to the release of extracellular vesicles, containing N-truncated, neurotoxic A beta. Methods: The aim of the present study was to investigate if the accumulation of A beta in astrocytes can be affected by the A beta protofibril selective antibody mAb158. Co-cultures of astrocytes, neurons, and oligodendrocytes, derived from embryonic mouse cortex, were exposed to A beta(42) protofibrils in the presence or absence of mAb158. Results: Our results demonstrate that the presence of mAb158 almost abolished A beta accumulation in astrocytes. Consequently, mAb158 treatment rescued neurons from A beta-induced cell death. Conclusion: Based on these findings, we conclude that astrocytes may play a central mechanistic role in anti-A beta immunotherapy.

  • 36.
    Westman, Gabriel
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Infectious Diseases.
    Berglund, David
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Clinical Immunology.
    Widen, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Ingelsson, Martin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Korsgren, Olle
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Clinical Immunology.
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Lidehall, Anna-Karin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology.
    Eriksson, Britt-Marie
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Infectious Diseases.
    Increased Inflammatory Response in Cytomegalovirus Seropositive Patients with Alzheimer's Disease2014In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, no 5, p. e96779-Article in journal (Refereed)
    Abstract [en]

    Alzheimer's disease (AD) has been associated with increased local inflammation in the affected brain regions, and in some studies also with elevated levels of proinflammatory cytokines in peripheral blood. Cytomegalovirus (CMV) is known to promote a more effector-oriented phenotype in the T-cell compartment, increasing with age. The aim of this study was to investigate the inflammatory response of peripheral blood mononuclear cells (PBMCs) from AD patients and non-demented (ND) controls. Using a multiplex Luminex xMAP assay targeting GM-CSF, IFN-gamma, IL-1 beta, IL-2, IL-4, IL-5, IL-6, IL-8, IP-10 and TNF-alpha, cytokine profiles from PBMCs were analysed after stimulation with anti-CD3/CD28 beads, CMV pp65 peptide mix or amyloid beta (A beta) protofibrils, respectively. CMV seropositive AD subjects presented with higher IFN-gamma levels after anti-CD3/ CD28 and CMV pp65 but not after Ab stimulation, compared to CMV seropositive ND controls. When analysing IFN-gamma response to anti-CD3/CD28 stimulation on a subgroup level, CMV seropositive AD subjects presented with higher levels compared to both CMV seronegative AD and CMV seropositive ND subjects. Taken together, our data from patients with clinically manifest AD suggest a possible role of CMV as an inflammatory promoter in AD immunology. Further studies of AD patients at earlier stages of disease, could provide better insight into the pathophysiology.

1 - 36 of 36
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf