uu.seUppsala University Publications
Change search
Refine search result
1 - 13 of 13
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.
    Altschuh, Danièle
    et al.
    Biotechnologie et signalisation cellulaire, Université de Strasbourg, France.
    Björkelund, Hanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Strandgård, John
    Ridgeview Instruments AB, Uppsala, Sweden.
    Chouliera, Laurence
    Biotechnologie et signalisation cellulaire, Université de Strasbourg, France.
    Malmqvist, Magnus
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Andersson, Karl
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Deciphering complex protein interaction kinetics using Interaction Map2012In: Biochemical and Biophysical Research Communications - BBRC, ISSN 0006-291X, E-ISSN 1090-2104, Vol. 428, no 1, p. 74-79Article in journal (Refereed)
    Abstract [en]

    Cellular receptor systems are expected to present complex ligand interaction patterns that cannot beevaluated assuming a simple one ligand:one receptor interaction model. We have previously evaluatedheterogeneous interactions using an alternative method to regression analysis, called Interaction Map(IM). IM decomposes a time-resolved binding curve into its separate components. By replacing the reductionistic,scalar kinetic association rate constant ka and dissociation rate constant kd with a two-dimensionaldistribution of ka and kd, it is possible to display heterogeneous data as a map where each peakcorresponds to one of the components that contribute to the cumulative binding curve. Here we challengethe Interaction Map approach by artificially generating heterogeneous data from two known interactions,on either LigandTracer or Surface Plasmon Resonance devices. We prove the ability of IM toaccurately decompose these man-made heterogeneous binding curves composed of two different interactions.We conclude that the Interaction Map approach is well suited for the analysis of complex bindingdata and forecast that it has a potential to resolve previously uninterpretable data, in particular thosegenerated in cell-based assays.

  • 2.
    Björkelund, Hanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Novel Methods for Analysis of Heterogeneous Protein-Cell Interactions: Resolving How the Epidermal Growth Factor Binds to Its Receptor2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Cells are complex biological units with advanced signalling systems, a dynamic capacity to adapt to its environment, and the ability to divide and grow. In fact, they are of such high level of complexity that it has deemed extremely difficult or even impossible to completely understand cells as complete units. The search for comprehending the cell has instead been divided into small, relatively isolated research fields, in which simplified models are used to explain cell biology. The result produced through these reductionistic investigations is integral for our current description of biology. However, there comes a time when it is possible to go beyond such simplifications and investigate cell biology at a higher level of complexity. That time is now.

    This thesis describes the development of mathematical tools to investigate intricate biological systems, with focus on heterogeneous protein interactions. By the use of simulations, real-time measurements and kinetic fits, standard assays for specificity measurements and receptor quantification were scrutinized in order to find optimal experimental settings and reduce labour time as well as reagent cost. A novel analysis platform, called Interaction Map, was characterized and applied on several types of interactions. Interaction Map decomposes a time-resolved binding curve and presents information on the kinetics and magnitude of each interaction that contributed to the curve. This provides a greater understanding of parallel interactions involved in the same biological system, such as a cell. The heterogeneity of the epidermal growth factor receptor (EGFR) system was investigated with Interaction Map applied on data from the instrument LigandTracer, together with complementing manual assays. By further introducing disturbances to the system, such as tyrosine kinase inhibitors and variation in temperature, information was obtained about dimerization, internalization and degradation rates.

    In the long term, analysis of binding kinetics and combinations of parallel interactions can improve the understanding of complex biomolecular mechanisms in cells and may explain some of the differences observed between cell lines, medical treatments and groups of patients.

    List of papers
    1. Avoiding false negative results in specificity analysis of protein-protein interactions
    Open this publication in new window or tab >>Avoiding false negative results in specificity analysis of protein-protein interactions
    2011 (English)In: Journal of Molecular Recognition, ISSN 0952-3499, E-ISSN 1099-1352, Vol. 24, no 1, p. 81-89Article in journal (Refereed) Published
    Abstract [en]

    The competition measurement using simultaneous incubation of labeled and unlabeled Ligand is a common method to assess the specificity of a biomolecular interaction. In this paper we show that invalid assumptions about the interactions may lead to improper experimental setups which in turn can result in inaccurate conclusions about the specificity. To improve understanding of competition measurements, simulations in MATLAB as well as real-time interaction analysis using LigandTracer have been performed. We show that use of a concentration of unlabeled Ligand of at least 10 × K(D) is necessary for assay accuracy. Increasing the incubation time to assure equilibrium, adding a pre-incubation phase, and a general understanding of the reversibility of an interaction may also improve the reliability of the measurement and the conclusions drawn about specificity. These findings may lower the risk of false negative results as well as reducing the amount of reagent needed.

    Keyword
    specificity, affinity, kinetics, competition assay
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-147025 (URN)10.1002/jmr.1026 (DOI)000289781900008 ()21194119 (PubMedID)
    Available from: 2011-02-23 Created: 2011-02-23 Last updated: 2017-12-11Bibliographically approved
    2. Circumventing the requirement of binding saturation for receptor quantification using interaction kinetic extrapolation
    Open this publication in new window or tab >>Circumventing the requirement of binding saturation for receptor quantification using interaction kinetic extrapolation
    2011 (English)In: Nuclear medicine communications, ISSN 0143-3636, E-ISSN 1473-5628, Vol. 32, no 9, p. 863-867Article in journal (Refereed) Published
    Abstract [en]

    Quantification of the number of receptors per cell (NRPC) is important when assessing whether a tumor surface biomarker is suitable for medical imaging. One common method for NPRC quantification is to use a binding saturation assay, which is time consuming and requires large amounts of reagents. The aim of this study was to evaluate an alternative method based on kinetic extrapolation (KEX) and compare it with the classical manual saturation technique with regard to accuracy as well as time and reagent consumption. Epidermal growth factor receptor (EGFR) and HER2 receptor surface expression were quantified on five tumor cell lines using three (125)I-labeled and (131)I-labeled ligands (cetuximab and EGF for EGFR, trastuzumab for HER2 receptor) for both techniques. The KEX method involved interaction measurements in the LigandTracer, followed by KEX through computerized real-time interaction analysis to correct for nonsaturation on cells. Variability and NRPC estimates of the EGFR and HER2 receptor levels using the KEX method were comparable with the results from the classical saturation technique. However, the ligand consumption for the KEX method was 26-46% of the classical saturation technique. Furthermore, the KEX method reduced the workload radically. From the observations described in this study, we believe that the KEX method enables fast, credible, and easy NRPC quantification with a reduction in reagent consumption.

    Keyword
    kinetics, ligand-receptor interaction, receptor quantification
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-158879 (URN)10.1097/MNM.0b013e3283483e1c (DOI)000294345300015 ()
    Available from: 2011-09-20 Created: 2011-09-19 Last updated: 2017-12-08Bibliographically approved
    3. Deciphering complex protein interaction kinetics using Interaction Map
    Open this publication in new window or tab >>Deciphering complex protein interaction kinetics using Interaction Map
    Show others...
    2012 (English)In: Biochemical and Biophysical Research Communications - BBRC, ISSN 0006-291X, E-ISSN 1090-2104, Vol. 428, no 1, p. 74-79Article in journal (Refereed) Published
    Abstract [en]

    Cellular receptor systems are expected to present complex ligand interaction patterns that cannot beevaluated assuming a simple one ligand:one receptor interaction model. We have previously evaluatedheterogeneous interactions using an alternative method to regression analysis, called Interaction Map(IM). IM decomposes a time-resolved binding curve into its separate components. By replacing the reductionistic,scalar kinetic association rate constant ka and dissociation rate constant kd with a two-dimensionaldistribution of ka and kd, it is possible to display heterogeneous data as a map where each peakcorresponds to one of the components that contribute to the cumulative binding curve. Here we challengethe Interaction Map approach by artificially generating heterogeneous data from two known interactions,on either LigandTracer or Surface Plasmon Resonance devices. We prove the ability of IM toaccurately decompose these man-made heterogeneous binding curves composed of two different interactions.We conclude that the Interaction Map approach is well suited for the analysis of complex bindingdata and forecast that it has a potential to resolve previously uninterpretable data, in particular thosegenerated in cell-based assays.

    Keyword
    Real-time analysis, Kinetics, Heterogeneity, LigandTracer, SPR
    National Category
    Medical and Health Sciences
    Research subject
    Molecular Biotechnology
    Identifiers
    urn:nbn:se:uu:diva-183869 (URN)10.1016/j.bbrc.2012.10.008 (DOI)000311523200013 ()
    Available from: 2012-11-05 Created: 2012-11-05 Last updated: 2017-12-07Bibliographically approved
    4. Comparing the epidermal growth factor interaction with four different cell lines: intriguing effects imply strong dependency of cellular context
    Open this publication in new window or tab >>Comparing the epidermal growth factor interaction with four different cell lines: intriguing effects imply strong dependency of cellular context
    2011 (English)In: PLoS ONE, ISSN 1932-6203, Vol. 6, no 1, p. e16536-Article in journal (Refereed) Published
    Abstract [en]

    The interaction of the epidermal growth factor (EGF) with its receptor (EGFR) is known to be complex, and the common over-expression of EGF receptor family members in a multitude of tumors makes it important to decipher this interaction and the following signaling pathways. We have investigated the affinity and kinetics of (125)I-EGF binding to EGFR in four human tumor cell lines, each using four culturing conditions, in real time by use of LigandTracer®.Highly repeatable and precise measurements show that the overall apparent affinity of the (125)I-EGF - EGFR interaction is greatly dependent on cell line at normal culturing conditions, ranging from K(D)≈200 pM on SKBR3 cells to K(D)≈8 nM on A431 cells. The (125)I-EGF - EGFR binding curves (irrespective of cell line) have strong signs of multiple simultaneous interactions. Furthermore, for the cell lines A431 and SKOV3, gefitinib treatment increases the (125)I-EGF - EGFR affinity, in particular when the cells are starved. The (125)I-EGF - EGFR interaction on cell line U343 is sensitive to starvation while as on SKBR3 it is insensitive to gefitinib and starvation.The intriguing pattern of the binding characteristics proves that the cellular context is important when deciphering how EGF interacts with EGFR. From a general perspective, care is advisable when generalizing ligand-receptor interaction results across multiple cell-lines.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-147027 (URN)10.1371/journal.pone.0016536 (DOI)000286834300081 ()21304974 (PubMedID)
    Available from: 2011-02-23 Created: 2011-02-23 Last updated: 2013-02-11Bibliographically approved
    5. Gefitinib Induces Epidermal Growth Factor Receptor Dimers Which Alters the Interaction Characteristics with (125)I-EGF
    Open this publication in new window or tab >>Gefitinib Induces Epidermal Growth Factor Receptor Dimers Which Alters the Interaction Characteristics with (125)I-EGF
    Show others...
    2011 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 6, no 9, p. e24739-Article in journal (Refereed) Published
    Abstract [en]

    The tyrosine kinase inhibitor gefitinib inhibits growth in some tumor types by targeting the epidermal growth factor receptor (EGFR). Previous studies show that the affinity of the EGF-EGFR interaction varies between hosting cell line, and that gefitinib increases the affinity for some cell lines. In this paper, we investigate possible mechanisms behind these observations. Real-time interaction analysis in LigandTracer (R) Grey revealed that the HER2 dimerization preventing antibody pertuzumab clearly modified the binding of (125)I-EGF to EGFR on HER2 overexpressing SKOV3 cells in the presence of gefitinib. Pertuzumab did not affect the binding on A431 cells, which express low levels of HER2. Cross-linking measurements showed that gefitinib increased the amount of EGFR dimers 3.0-3.8 times in A431 cells in the absence of EGF. In EGF stimulated SKOV3 cells the amount of EGFR dimers increased 1.8-2.2 times by gefitinib, but this effect was cancelled by pertuzumab. Gefitinib treatment did not alter the number of EGFR or HER2 expressed in tumor cell lines A431, U343, SKOV3 and SKBR3. Real-time binding traces were further analyzed in a novel tool, Interaction Map, which deciphered the different components of the measured interaction and supports EGF binding to multiple binding sites. EGFR and HER2 expression affect the levels of EGFR monomers, homodimers and heterodimers and EGF binds to the various monomeric/dimeric forms of EGFR with unique binding properties. Taken together, we conclude that dimerization explains the varying affinity of EGF - EGFR in different cells, and we propose that gefitinib induces EGFR dimmers, which alters the interaction characteristics with (125)I-EGF.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-159470 (URN)10.1371/journal.pone.0024739 (DOI)000294803200045 ()
    Available from: 2011-10-04 Created: 2011-10-03 Last updated: 2017-12-08Bibliographically approved
    6. Resolving the EGF-EGFR interaction characteristics through a multiple-temperature, multiple-inhibitor, real-time interaction analysis approach
    Open this publication in new window or tab >>Resolving the EGF-EGFR interaction characteristics through a multiple-temperature, multiple-inhibitor, real-time interaction analysis approach
    2013 (English)In: Molecular and Clinical Oncology, ISSN 2049-9469, Vol. 1, no 2, p. 343-352Article in journal (Refereed) Published
    Abstract [en]

    Overexpression and aberrant activity of the epidermal growth factor (EGF) have been observed in various cancer types, rendering it an important target in oncology research. The interaction between EGF and its receptor (EGFR), as well as subsequent internalization, is complex and may be affected by various factors including tyrosine kinase inhibitors (TKIs). By combining real‑time binding curves produced in LigandTracer® with internalization assays conducted at different temperatures and with different TKIs, the processes of ligand binding, internalization and excretion was visualized. SKOV3 cells had a slower excretion rate compared to A431 and U343 cells, and the tested TKIs (gefitinib, lapatinib, AG1478 and erlotinib) reduced the degree of internalization. The kinetic analysis of the binding curves further demonstrated TKI‑dependent balances of EGFR monomer and dimer populations, where lapatinib promoted the monomeric form, while the other TKIs induced dimers. The dimer levels were found to be associated with the apparent affinity of the EGF‑EGFR interaction, with EGF binding stronger to EGFR dimers compared to monomers. This study analyzed how real‑time molecular interaction analysis may be utilized in combination with perturbations in order to understand the kinetics of a ligand‑receptor interaction, as well as some of its associated intracellular processes. Our multiple‑temperature and ‑inhibitor assay setup renders it possible to follow the EGFR monomer, dimer and internalized populations in a detailed manner, allowing for a new perspective of the EGFR biology.

    Keyword
    epidermal growth factor, tyrosine kinase inhibitors, internalization, kinetics, dimerization, heterogeneity
    National Category
    Medical and Health Sciences
    Research subject
    Medicine; Molecular Biotechnology; Medical Cell Biology
    Identifiers
    urn:nbn:se:uu:diva-183868 (URN)10.3892/mco.2012.37 (DOI)
    Available from: 2012-11-05 Created: 2012-11-05 Last updated: 2013-07-24Bibliographically approved
  • 3.
    Björkelund, Hanna
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Gedda, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Malmqvist, Magnus
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Andersson, Karl
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Resolving the EGF-EGFR interaction characteristics through a multiple-temperature, multiple-inhibitor, real-time interaction analysis approach2013In: Molecular and Clinical Oncology, ISSN 2049-9469, Vol. 1, no 2, p. 343-352Article in journal (Refereed)
    Abstract [en]

    Overexpression and aberrant activity of the epidermal growth factor (EGF) have been observed in various cancer types, rendering it an important target in oncology research. The interaction between EGF and its receptor (EGFR), as well as subsequent internalization, is complex and may be affected by various factors including tyrosine kinase inhibitors (TKIs). By combining real‑time binding curves produced in LigandTracer® with internalization assays conducted at different temperatures and with different TKIs, the processes of ligand binding, internalization and excretion was visualized. SKOV3 cells had a slower excretion rate compared to A431 and U343 cells, and the tested TKIs (gefitinib, lapatinib, AG1478 and erlotinib) reduced the degree of internalization. The kinetic analysis of the binding curves further demonstrated TKI‑dependent balances of EGFR monomer and dimer populations, where lapatinib promoted the monomeric form, while the other TKIs induced dimers. The dimer levels were found to be associated with the apparent affinity of the EGF‑EGFR interaction, with EGF binding stronger to EGFR dimers compared to monomers. This study analyzed how real‑time molecular interaction analysis may be utilized in combination with perturbations in order to understand the kinetics of a ligand‑receptor interaction, as well as some of its associated intracellular processes. Our multiple‑temperature and ‑inhibitor assay setup renders it possible to follow the EGFR monomer, dimer and internalized populations in a detailed manner, allowing for a new perspective of the EGFR biology.

  • 4.
    Bondza, Sina
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science. Ridgeview Instruments AB, Uppsala.
    Björkelund, Hanna
    Ridgeview Instruments AB, Uppsala.
    Nestor, Marika
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Andersson, Karl
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science. Ridgeview Instruments AB, Uppsala.
    Buijs, Jos
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science. Ridgeview Instruments AB, Uppsala.
    Novel Real-Time Proximity Assay for Characterizing Multiple Receptor Interactions on Living Cells2017In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 89, no 24, p. 13212-13218Article in journal (Refereed)
    Abstract [en]

    Cellular receptor activity is often controlled through complex mechanisms involving interactions with multiple molecules, which can be soluble ligands and/or other cell surface molecules. In this study, we combine a fluorescence-based technology for real-time interaction analysis with fluorescence quenching to create a novel time-resolved proximity assay to study protein-receptor interactions on living cells. This assay extracts the binding kinetics and affinity for two proteins if they bind in proximity on the cell surface. One application of real-time proximity interaction analysis is to study relative levels of receptor dimerization. The method was primarily evaluated using the HER2 binding antibodies Trastuzumab and Pertuzumab and two EGFR binding antibodies including Cetuximab. Using Cetuximab and Trastuzumab, proximity of EGFR and HER2 was investigated before and after treatment of cells with the tyrosine-kinase inhibitor Gefitinib. Treated cells displayed 50% increased proximity signal, whereas the binding characteristics of the two antibodies were not significantly affected, implying an increase in the EGFR-HER2 dimer level. These results demonstrate that real-time proximity interaction analysis enables determination of the interaction rate constants and affinity of two ligands while simultaneously quantifying their relative colocalization on living cells.

  • 5.
    Bondza, Sina
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Stenberg, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Nestor, Marika
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Otolaryngology and Head and Neck Surgery.
    Andersson, Karl
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Björkeund, Hanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Conjugation Effects on Antibody-Drug Conjugates: Evaluation of Interaction Kinetics in Real Time on Living Cells2014In: Molecular Pharmaceutics, ISSN 1543-8384, E-ISSN 1543-8392, Vol. 11, no 11, p. 4154-4163Article in journal (Refereed)
    Abstract [en]

    Antibody-drug conjugates (ADC) have shown promising effects in cancer therapy by combining the target specificity of an antibody with the toxicity of a chemotherapeutic drug. As the number of therapeutic antibodies is significantly larger than those used as ADCs, there is unused potential for more effective therapies. However, the conjugation of an additional molecule to an antibody may affect the interaction with its target, altering association rate, dissociation rate, or both. Any changes of the binding kinetics can have subsequent effects on the efficacy of the ADCs, thus the kinetics are important to monitor during ADC development and production. This paper describes a method for the analysis of conjugation effects on antibody binding to its antigen, using the instrument LigandTracer and a fluorescent monovalent anti-IgG binder denoted FIBA, which did not affect the interaction. All measurements were done in real time using living cells which naturally expressed the antigens. With this method the binding profiles of different conjugations of the therapeutic anti-EGFR antibody cetuximab and the anti-CD44v6 antibody fragment AbD15171 were evaluated and compared. Even comparatively small modifications of cetuximab altered the interaction with the epidermal growth factor receptor (EGFR). In contrast, no impact on the AbD15171-CD44v6 interaction was observed upon conjugation. This illustrates the importance to study the binding profile for each ADC combination, as it is difficult to draw any general conclusion about conjugation effects. The modification of interaction kinetics through conjugation opens up new possibilities when optimizing an antibody or an ADC, since the conjugations can be used to create a binding profile more apt for a specific clinical need.

  • 6. Borzecka, Kinga
    et al.
    Plociennikowska, Agnieszka
    Björkelund, Hanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Sobota, Andrzej
    Kwiatkowska, Katarzyna
    CD14 Mediates Binding of High Doses of LPS but Is Dispensable for TNF-alpha Production2013In: Mediators of Inflammation, ISSN 0962-9351, E-ISSN 1466-1861, p. 824919-Article in journal (Refereed)
    Abstract [en]

    Activation of macrophages with lipopolysaccharide (LPS) involves a sequential engagement of serum LPS-binding protein (LBP), plasma membrane CD14, and TLR4/MD-2 signaling complex. We analyzed participation of CD14 in TNF-alpha production stimulated with 1-1000 ng/mL of smooth or rough LPS (sLPS or rLPS) and in sLPS binding to RAW264 and J744 cells. CD14 was indispensable for TNF-alpha generation induced by a low concentration, 1 ng/mL, of sLPS and rLPS. At higher doses of both LPS forms (100-1000 ng/mL), TNF-alpha release required CD14 to much lower extent. Among the two forms of LPS, rLPS-induced TNF-alpha production was less CD14-dependent and could proceed in the absence of serumas an LBP source. On the other hand, the involvement of CD14 was crucial for the binding of 1000 ng/mL of sLPS judging from an inhibitory effect of the anti-CD14 antibody. The binding of sLPS was also strongly inhibited by dextran sulfate, a competitive ligand of scavenger receptors (SR). In the presence of dextran sulfate, sLPS-induced production of TNF-alpha was upregulated about 1.6-fold. The data indicate that CD14 together with SR participates in the binding of high doses of sLPS. However, CD14 contribution to TNF-alpha production induced by high concentrations of sLPS and rLPS can be limited.

  • 7.
    Dubois, Louise
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Andersson, Karl
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Asplund, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Björkelund, Hanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Evaluating real-time immunohistochemistry on multiple tissue samples, multiple targets and multiple antibody labeling methods2013In: BMC Research Notes, ISSN 1756-0500, E-ISSN 1756-0500, Vol. 6, p. 542-Article in journal (Refereed)
    Abstract [en]

    Background

    Immunohistochemistry (IHC) is a well-established method for the analysis of protein expression in tissue specimens and constitutes one of the most common methods performed in pathology laboratories worldwide. However, IHC is a multi-layered method based on subjective estimations and differences in staining and interpretation has been observed between facilities, suggesting that the analysis of proteins on tissue would benefit from protocol optimization and standardization. Here we describe how the emerging and operator independent tool of real-time immunohistochemistry (RT-IHC) reveals a time resolved description of antibody interacting with target protein in formalin fixed paraffin embedded tissue. The aim was to understand the technical aspects of RT-IHC, regarding generalization of the concept and to what extent it can be considered a quantitative method.

    Results

    Three different antibodies labeled with fluorescent or radioactive labels were applied on nine different tissue samples from either human or mouse, and the results for all RT-IHC analyses distinctly show that the method is generally applicable. The collected binding curves showed that the majority of the antibody-antigen interactions did not reach equilibrium within 3 hours, suggesting that standardized protocols for immunohistochemistry are sometimes inadequately optimized. The impact of tissue size and thickness as well as the position of the section on the glass petri dish was assessed in order for practical details to be further elucidated for this emerging technique. Size and location was found to affect signal magnitude to a larger extent than thickness, but the signal from all measurements were still sufficient to trace the curvature. The curvature, representing the kinetics of the interaction, was independent of thickness, size and position and may be a promising parameter for the evaluation of e.g. biopsy sections of different sizes.

    Conclusions

    It was found that RT-IHC can be used for the evaluation of a number of different antibodies and tissue types, rendering it a general method. We believe that by following interactions over time during the development of conventional IHC assays, it becomes possible to better understand the different processes applied in conventional IHC, leading to optimized assay protocols with improved sensitivity.

  • 8.
    Gedda, Lars
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Björkelund, Hanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Lebel, Lena
    Asplund, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Molecular and Morphological Pathology.
    Dubois, Louise
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Wester, Kenneth
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Clinical Immunology.
    Penagos, Nelly
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Molecular and Morphological Pathology.
    Malmqvist, Magnus
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Andersson, Karl
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Evaluation of Real-Time Immunohistochemistry and Interaction Map as an Alternative Objective Assessment of HER2 Expression in Human Breast Cancer Tissue2013In: Applied immunohistochemistry & molecular morphology (Print), ISSN 1541-2016, E-ISSN 1533-4058, Vol. 21, no 6, p. 497-505Article in journal (Refereed)
    Abstract [en]

    Immunohistochemical study (IHC) is a critical tool in the clinical diagnosis of breast cancer. One common assessment is the expression level of the HER2 receptor in breast cancer tissue samples with the aim of stratifying patients for applicability of the therapeutic antibody Herceptin. In this study, we aimed to investigate whether a novel assay, real-time IHC combined with Interaction Map analysis, offers the possibility of objective assessment of HER2 expression. Interaction Map presents real-time interaction data as a collection of peaks on a surface, and it was performed on 20 patient tissue samples previously scored for HER2 expression. The result shows that the relative weight of the peaks in the maps contains novel information that could discriminate between high and low HER2 expression in an operator-independent manner (P<0.001). We conclude that the real-time IHC assay has a promising potential to complement conventional IHC and may improve the precision in the future clinical diagnostics of breast cancer.

  • 9.
    Huijbers, Elisabeth J M
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Femel, Julia
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Andersson, Karl
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Björkelund, Hanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Hellman, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology.
    Olsson, Anna-Karin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    The non-toxic and biodegradable adjuvant Montanide ISA 720/CpG can replace Freund's in a cancer vaccine targeting ED-B-a prerequisite for clinical development2012In: Vaccine, ISSN 0264-410X, E-ISSN 1873-2518, Vol. 30, no 2, p. 225-230Article in journal (Refereed)
    Abstract [en]

    We have recently shown that immunization against the extra domain-B (ED-B) of fibronectin, using Freund's adjuvant, reduces tumor growth in mice by 70%. In the present study we compare the immune response generated against ED-B using the non-toxic and biodegradable adjuvant Montanide ISA 720/CpG with the response elicited by Freund's adjuvant. Montanide ISA 720/CpG induced anti-ED-B antibodies with higher avidity and less variable levels between individuals than Freund's. Moreover, the duration of the immune response was longer and the generation of anti-ED-B antibodies in naïve mice was faster, when Montanide ISA 720/CpG was used. We conclude that it is possible to replace the mineral oil based adjuvant Freund's with an adjuvant acceptable for human use, which is a prerequisite for transfer of the ED-B vaccine to the clinic.

  • 10. Nilvebrant, J.
    et al.
    Kuku, G.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science.
    Björkelund, Hanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Nestor, Marika
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Otolaryngology and Head and Neck Surgery.
    Selection and characterisation of human CD44v6-binding antibody fragments for specific targeting of head and neck squamous cell carcinoma2012In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 39, no S2, p. S418-S418Article in journal (Other academic)
  • 11. Nilvebrant, Johan
    et al.
    Kuku, Gamze
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Björkelund, Hanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Nestor, Marika
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Otolaryngology and Head and Neck Surgery.
    Selection and in vitro characterization of human CD44v6-binding antibody fragments2012In: Biotechnology and applied biochemistry, ISSN 0885-4513, E-ISSN 1470-8744, Vol. 59, no 5, p. 367-380Article in journal (Refereed)
    Abstract [en]

    The cluster of differentiation (CD) 44v6 antigen has been suggested to be involved in tumor formation, invasion, and metastasis formation, and has been observed in a majority of primary and metastatic squamous cell carcinomas of the head and neck. Probes specifically binding to this region may be utilized as tools for the challenging tasks of early detection and targeted treatments of small residual disease. In this project, an epitope-guided phage display selection of human fragment antigen-binding (Fab) fragments with affinity to the v6 sequence was performed. A selected set of Fab fragments was shown to specifically recognize increasingly complex forms of the target sequence, both in the form of a short synthetic or recombinant peptide and in the context of a purified extracellular domain of CD44. The binding was independent of known v6-sequence variation and posttranslational modifications that are common in the CD44 protein family. Furthermore, real-time interaction measurements on antibody fragments labeled with 125I showed specific and high-affinity binding to the antigen present on cultured head and neck squamous cell carcinoma cells. There was no cross-reactivity toward cells that lack the target protein. As hypothesized, characterization of the interaction between Fab fragments and the targets using the mathematical tool Interaction Map revealed more heterogeneous interactions on cells than with pure proteins analyzed by surface plasmon resonance. One main candidate Fab fragment with optimal affinity for all forms of the target sequence was identified. The flexible recombinant source of the Fab fragments might aid the development of tailored molecules adapted for therapeutic or diagnostic applications in the future.

  • 12. Wang, Ellen
    et al.
    Björkelund, Hanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Mihaylova, Dessislava
    Hagemann, Urs B.
    Karlsson, Jenny
    Malmqvist, Magnus
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Buijs, Jos
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Abrahmsen, Lars
    Andersson, Karl
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Automated functional characterization of radiolabeled antibodies: a time-resolved approach2014In: Nuclear medicine communications, ISSN 0143-3636, E-ISSN 1473-5628, Vol. 35, no 7, p. 767-776Article in journal (Refereed)
    Abstract [en]

    Background The number of radiolabeled monoclonal antibodies (mAbs) used for medical imaging and cancer therapy is increasing. The required chemical modification for attaching a radioactive label and all associated treatment may lead to a damaged mAb subpopulation. This paper describes a novel method, concentration through kinetics (CTK), for rapid assessment of the concentration of immunoreactive mAb and the specific radioactivity, based on monitoring binding kinetics. Methods The interaction of radiolabeled mAb with either the antigen or a general mAb binder such as Protein A was monitored in real time using the instrument LigandTracer. As the curvature of the binding trace has a distinct shape based on the interaction kinetics and concentration of the functional mAb, the immunoreactive mAb concentration could be calculated through reverse kinetic fitting of the binding curves, using software developed for this project. The specific activity, describing the degree of radioactive labeling, was determined through the use of calibrated signal intensities. Results The performance of the CTK assay was evaluated on the basis of various mAb-based interaction systems and assay formats, and it was shown that the assay can provide accurate and repeatable results for immunoreactive concentration and specific activity, with both accuracy and relative SD values below 15%. Conclusion By applying reverse kinetics on real-time binding traces it is possible to estimate the functional concentration and specific activity of radiolabeled mAb. The CTK assay may in the future be included as a complement to current quality assessment methods of radiolabeled mAbs.

  • 13.
    Xu, Bo
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Pharmacology.
    Varasteh, Zohreh
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Andersson, Karl
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Larhammar, Dan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Pharmacology.
    Björkelund, Hanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Detecting ligand interactions with G protein-coupled receptors in real-time on living cells2013In: Biochemical and Biophysical Research Communications - BBRC, ISSN 0006-291X, E-ISSN 1090-2104, Vol. 441, no 4, p. 820-824Article in journal (Refereed)
    Abstract [en]

    G protein-coupled receptors (GPCRs) are a large group of receptors of great biological and clinical relevance. Despite this, the tools for a detailed analysis of ligand-GPCR interactions are limited. The aim of this paper was to demonstrate how ligand binding to GPCRs can be followed in real-time on living cells. This was conducted using two model systems, the radiolabeled porcine peptide YY (pPYY) interacting with transfected human Y2 receptor (hY2R) and the bombesin antagonist RM26 binding to the naturally expressed gastrin-releasing peptide receptor (GRPR). By following the interaction over time, the affinity and kinetic properties such as association and dissociation rate were obtained. Additionally, data were analyzed using the Interaction Map method, which can evaluate a real-time binding curve and present the number of parallel interactions contributing to the curve. It was found that pPYY binds very slowly with an estimated time to equilibrium of approximately 12 h. This may be problematic in standard end-point assays where equilibrium is required. The RM26 binding showed signs of heterogeneity, observed as two parallel interactions with unique kinetic properties. In conclusion, measuring binding in real-time using living cells opens up for a better understanding of ligand interactions with GPCRs.

1 - 13 of 13
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