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  • 1.
    Altai, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Varasteh, Zohreh
    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.
    Eek, Annemarie
    Boerman, Otto
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    In Vivo and In Vitro Studies on Renal Uptake of Radiolabeled Affibody Molecules for Imaging of HER2 Expression in Tumors2013In: Cancer Biotherapy and Radiopharmaceuticals, ISSN 1084-9785, E-ISSN 1557-8852, Vol. 28, no 3, p. 187-195Article in journal (Refereed)
    Abstract [en]

    Affibody molecules (6-7 kDa) are a new class of small robust three-helical scaffold proteins. Radiolabeled subnanomolar anti-HER2 affibody Z(HER2:342) was developed for imaging of HER2 expression in tumors, and a clinical study has demonstrated that the In-111- and Ga-68-labeled affibody molecules can efficiently detect HER2 expressing metastases in breast cancer patients. However, a significant renal accumulation of radioactivity after systemic injection of a radiolabeled anti-HER2 affibody conjugate is observed. The aim of this study was to investigate the mechanism of renal reabsorption of anti-HER2 affibody at the molecular level. Renal accumulation of radiolabeled anti-HER2 affibody molecules was studied in a murine model and in vitro using opossum-derived proximal tubule (OK) cells. It was found that kidney reabsorption of affibody molecule was not driven by megalin/cubilin. Amino acids in the target-binding side of affibody molecule were involved in binding to OK cells. On OK cells, two types of receptors for anti-HER2 affibody molecule were found: K-D1 = 0.8 nM, B-max1 = 71,500 and K-D2 = 9.2 nM, B-max2 = 367,000. The results of the present study indicate that affibody molecule and other scaffold-based targeting proteins with a relatively low kidney uptake can be selected using in vitro studies with tubular kidney cells.

  • 2.
    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.

  • 3.
    Andersson, Karl
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Bringing time into molecular and cellular biology2013In: Journal of Analytical Oncology, ISSN 1927-7229, Vol. 2, no 2, p. 65-68Article in journal (Refereed)
    Abstract [en]

    In conjunction with the defense of a doctoral thesis on the deciphering of complex protein interactions on living cells, six scientists shared their view on time in molecular and cellular biology. This brief review takes the form of a conference report and summarizes the contributions of the speakers and the defense. Opportunities and challenges for time resolved assays in molecular and cellular biology were vividly discussed during two days with a pan-European audience. Awareness of biological timeframes and understanding the temporal aspects were claimed critical for analytical applications in biology.

  • 4.
    Andersson, Karl
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Choulier, Laurence
    Hämäläinen, Markku
    van Regenmortel, Marc H. V.
    Altschuh, Danièle
    Malmqvist, Magnus
    Predicting the kinetics of peptide-antibody interactions using a multivariate experimental design of sequence and chemical space2001In: Journal of Molecular Recognition, Vol. 14, p. 62-71Article in journal (Refereed)
  • 5. Barta, P.
    et al.
    Trejtnar, F.
    Andersson, Karl
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Preclinical Evaluation of Ligand-Target Binding Properties Using Competitive Interaction Analysis in Real-Time Radioimmunoassay on Living Cells2013In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 40, no Suppl. 2, p. S323-S324Article in journal (Other academic)
  • 6.
    Barta, Pavel
    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.
    Andersson, Karl
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Circumventing the requirement of binding saturation for receptor quantification using interaction kinetic extrapolation2011In: Nuclear medicine communications, ISSN 0143-3636, E-ISSN 1473-5628, Vol. 32, no 9, p. 863-867Article in journal (Refereed)
    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.

  • 7. Barta, Pavel
    et al.
    Malmberg, Jennie
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Melicharova, Ludmila
    Strandgård, John
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Laznicek, Milan
    Andersson, Karl
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Protein interactions with HER-family receptors can have different characteristics depending on the hosting cell line2012In: International Journal of Oncology, ISSN 1019-6439, Vol. 40, no 5, p. 1677-1682Article in journal (Refereed)
    Abstract [en]

    Cell lines are common model systems in the development of therapeutic proteins and in the research on cellular functions and dysfunctions. In this field, the protein interaction assay is a frequently used tool for assessing the adequacy of a protein for diagnostic and therapeutic purposes. In this study, we investigated the extent to which the interaction characteristics depend on the choice of cell line for HER-family receptors. The interaction characteristics of two therapeutic antibodies (trastuzumab and cetuximab) and one Affibody molecule (ZHER2:342), interacting with the intended receptor were characterized with high precision using an automated real-time interaction method, in different cell lines (HaCaT, A431, HEP-G2, SKOV3, PC3, DU-145). Clear differences in binding affinity and kinetics, up to one order of magnitude, were found for the interaction of the same protein binding to the same receptor on different cells for all three proteins. For HER-family receptors, it is therefore important to refer to the measured affinity for a protein-receptor interaction together with the hosting cell line. The ability to accurately measure affinity and kinetics of a protein-receptor interaction on cell lines of different origins may increase the understanding of underlying receptor biology, and impact the selection of candidates in the development of therapeutic or diagnostic agents.

  • 8. Barta, Pavel
    et al.
    Volkova, Marie
    Dascalu, Adrian
    Spiegelberg, Diana
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Trejtnar, Frantisek
    Andersson, Karl
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Determination of receptor protein binding site specificity and relative binding strength using a time-resolved competition assay2014In: Journal of pharmacological and toxicological methods, ISSN 1056-8719, E-ISSN 1873-488X, Vol. 70, no 2, p. 145-151Article in journal (Refereed)
    Abstract [en]

    Introduction: Competitive binding assays can be used to decipher not only the binding kinetics of studied ligands but also the binding site preference. Such assays are an essential step in the characterization of radioligands. However, the currently used competition assays require high concentrations of usually expensive ligands and still provide only binding site preference. By employing the time-resolved competition assay presented in this paper, binding characteristics including binding site preference can be obtained using less ligand. Methods: To demonstrate the appropriateness of the time-resolved competition assay, we developed an assay in which the ligand binding was interrupted with a competitor. Experiments were performed on human carcinoma cell lines expressing epidermal growth factor receptor (EGFR). The targeting of the receptor was performed with radio-iodinated epidermal growth factor (EGF). The employed competitors involved either natural ligand transforming growth factor alpha (TGF-alpha) or anti-EGFR antibodies cetuximab and panitumumab targeting the same EGFR domain. Results: Radio-iodinated EGF bound to EGFR was displaced with either low concentrations of cetuximab or high concentrations of panitumumab. In the case of TGF-alpha, we observed no competitive displacement of bound EGF at either high or low concentrations. When comparing the time-resolved competition assay with a manual competition assay, the resulting data of measured inhibition constants were in agreement. Discussion: The results summarised in this study confirm the appropriateness of the time-resolved competition assay for assessing ligand binding properties. The assay has the potential to complement or replace conventional competition assays for determining binding site preference in the future.  

  • 9.
    Björke, Henrik
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Andersson, Karl
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Automated, high-resolution cellular retention and uptake studies in vitro2006In: Applied Radiation and Isotopes, ISSN 0969-8043, E-ISSN 1872-9800, Vol. 64, no 8, p. 901-905Article in journal (Refereed)
    Abstract [en]

    This report describes an automated method for the measurements of cellular retention and uptake of radiolabeled proteins interacting with cell-surface receptors on intact cancer cells. A complete uptake and retention measurement was performed in one cell dish using a rotating radioimmunoassay (RIA) principle. Compared to common manual measurements, rotating RIA saved both labor time and reagents and provided real-time binding traces with superior time-resolution. The rotating RIA retention profiles for different interactions agreed with retention times reported in the literature.

  • 10.
    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.

  • 11.
    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.

  • 12.
    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, Vange, Sweden.
    Foy, Eleanor
    Univ Leeds, Leeds Inst Rheumat & Musculoskeletal Med, Leeds, W Yorkshire, England..
    Brooks, Jonathan
    Pfizer Inc, Cambridge, MA USA..
    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, Vange, Sweden.
    Robinson, James
    Univ Leeds, Leeds Inst Rheumat & Musculoskeletal Med, Leeds, W Yorkshire, England..
    Richalet, Pascale
    BioRevera LLC, Arlington, MA USA..
    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, Vange, Sweden.
    Real-time Characterization of Antibody Binding to Receptors on Living Immune Cells2017In: Frontiers in Immunology, ISSN 1664-3224, E-ISSN 1664-3224, Vol. 8, article id 455Article in journal (Refereed)
    Abstract [en]

    Understanding molecular interactions on immune cells is crucial for drug development to treat cancer and autoimmune diseases. When characterizing molecular interactions, the use of a relevant living model system is important, as processes such as receptor oligomerization and clustering can influence binding patterns. We developed a protocol to enable time-resolved analysis of ligand binding to receptors on living suspension cells. Different suspension cell lines and weakly adhering cells were tethered to Petri dishes with the help of a biomolecular anchor molecule, and antibody binding was analyzed using LigandTracer. The protocol and assay described in this report were used to characterize interactions involving eight cell lines. Experiments were successfully conducted in three different laboratories, demonstrating the robustness of the protocol. For various antibodies, affinities and kinetic rate constants were obtained for binding to CD20 on both Daudi and Ramos B-cells, the T-cell co-receptor CD3 on Jurkat cells, and the Fc gamma receptor CD32 on transfected HEK293 cells, respectively. Analyzing the binding of Rituximab to B-cells resulted in an affinity of 0.7-0.9 nM, which is similar to values reported previously for living B-cells. However, we observed a heterogeneous behavior for Rituximab interacting with B-cells, which to our knowledge has not been described previously. The understanding of complex interactions will be facilitated with the possibility to characterize binding processes in real-time on living immune cells. This provides the chance to broaden the understanding of how binding kinetics relate to biological function.

  • 13.
    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.

  • 14.
    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.

  • 15.
    Encarnacao, Joao Crispim
    et al.
    Ridgeview Instruments AB, Skillsta 4, S-74020 Uppsala, Sweden..
    Barta, Pavel
    Charles Univ Prague, Fac Pharm, Dept Biophys & Phys Chem, Hradec Kralove 50005, Czech Republic..
    Fornstedt, Torgny
    Karlstad Univ, Dept Engn & Chem Sci, S-65188 Karlstad, Sweden..
    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, Skillsta 4, S-74020 Uppsala, Sweden.
    Impact of assay temperature on antibody binding characteristics in living cells: A case study2017In: BIOMEDICAL REPORTS, ISSN 2049-9434, Vol. 7, no 5, p. 400-406Article in journal (Refereed)
    Abstract [en]

    Kinetic and thermodynamic studies of ligand-receptor interactions are essential for increasing the understanding of receptor activation mechanisms and drug behavior. The characterization of molecular interactions on living cells in real-time goes beyond most current binding assays, and provides valuable information about the dynamics and underlying mechanism of the molecules in a living system. The effect of temperature on interactions in cell-based assays is, however, rarely discussed. In the present study, the effect of temperature on binding of monoclonal antibodies, cetuximab and pertuzumab to specific receptors on living cancer cells was evaluated, and the affinity and kinetics of the interactions were estimated at selected key temperatures. Changes in the behavior of the interactions, particularly in the on- and off-rates were observed, leading to greatly extended time to reach the equilibrium at 21 degrees C compared with at 37 degrees C. However, the observed changes in kinetic characteristics were less than a factor of 10. It was concluded that it is possible to conduct real-time measurements with living cells at different temperatures, and demonstrated that influences of the ambient temperature on the interaction behavior are likely to be less than one order of magnitude.

  • 16.
    Encarnacao, Joao Crispim
    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, Vange, Sweden.
    Schulte, Tim
    Karolinska Inst, Dept Med Solna, Sci Life Lab, Solna, Sweden;Karolinska Univ Hosp, Dept Infect Dis, Solna, Sweden.
    Achour, Adnane
    Karolinska Inst, Dept Med Solna, Sci Life Lab, Solna, Sweden;Karolinska Univ Hosp, Dept Infect Dis, Solna, Sweden.
    Bjorkelund, Hanna
    Ridgeview Instruments AB, Vange, Sweden.
    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, Vange, Sweden.
    Detecting ligand interactions in real time on living bacterial cells2018In: Applied Microbiology and Biotechnology, ISSN 0175-7598, E-ISSN 1432-0614, Vol. 102, no 9, p. 4193-4201Article in journal (Refereed)
    Abstract [en]

    Time-resolved analysis assays of receptor-ligand interactions are fundamental in basic research and drug discovery. Adequate methods are well developed for the analysis of recombinant proteins such as antibody-antigen interactions. However, assays for time-resolved ligand-binding processes on living cells are still rare, in particular within microbiology. In this report, the real-time cell-binding assay (RT-CBA) technology LigandTracerA (R), originally designed for mammalian cell culture, was extended to cover Gram-positive and Gram-negative bacteria. This required the development of new immobilization methods for bacteria, since LigandTracer depends on cells being firmly attached to a Petri dish. The evaluated Escherichia coli CJ236 and BL21 as well as Staphylococcus carnosus TM300 strains were immobilized to plastic Petri dishes using antibody capture, allowing us to depict kinetic binding traces of fluorescently labeled antibodies directed against surface-displayed bacterial proteins for as long as 10-15 h. Interaction parameters, such as the affinity and kinetic constants, could be estimated with high precision (coefficient of variation 9-44%) and the bacteria stayed viable for at least 16 h. The other tested attachment protocols were inferior to the antibody capture approach. Our attachment protocol is generic and could potentially also be applied to other assays and purposes.

  • 17.
    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.

  • 18.
    Hamalainen, Markku D.
    et al.
    Kontigo Care AB, Dragarbrunnsgatan 35, S-75320 Uppsala, Sweden.
    Zetterstrom, Andreas
    Kontigo Care AB, Dragarbrunnsgatan 35, S-75320 Uppsala, Sweden.
    Winkvist, Maria
    Kontigo Care AB, Dragarbrunnsgatan 35, S-75320 Uppsala, Sweden.
    Soderquist, Marcus
    Kontigo Care AB, Dragarbrunnsgatan 35, S-75320 Uppsala, Sweden.
    Karlberg, Elin
    Akad Sjukhuset, Innovat Akad, S-75185 Uppsala, Sweden.
    Ohagen, Patrik
    Uppsala Clin Res Ctr, Dag Hammarskjoldsvag 14 B,Uppsala Sci Pk, S-75183 Uppsala, Sweden.
    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, Skillsta 4, S-74020 Vange, Sweden.
    Nyberg, Fred
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Real-time Monitoring Using a Breathalyzer-Based eHealth System Can Identify Lapse/Relapse Patterns in Alcohol Use Disorder Patients2018In: Alcohol and Alcoholism, ISSN 0735-0414, E-ISSN 1464-3502, Vol. 53, no 4, p. 368-375Article in journal (Refereed)
    Abstract [en]

    Aim: We introduce a new remote real-time breathalyzer-based method for monitoring and early identification of lapse/relapse patterns for alcohol use disorder (AUD) patients using a composite measure of sobriety, the Addiction Monitoring Index (AMI). Methods: We constructed AMI from (a) obtained test results and (b) the pattern of ignored tests using data from the first 30 patients starting in the treatment arms of two on-going clinical trials. The patients performed 2-4 scheduled breath alcohol content (BrAC)-tests per day presented as blood alcohol content (BAC) data. In total, 10,973 tests were scheduled, 7743 were performed and 3230 were ignored during 3982 patient days. Results: AMI-time profiles could be used to monitor the daily trends of alcohol consumption and detect early signs of lapse and relapses. The pattern of ignored tests correlates with the onset of drinking. AMI correlated with phosphatidyl ethanol (n = 61, F-ratio = 34.6, P < 0.0001, R = -0.61). The recognition of secret drinking could further be improved using a low alcohol detection threshold (BrAC = 0.025 mg/l, BAC(Swe) = 0.05% or US = 0.0053 g/dl), in addition to the legal Swedish traffic limit (BrAC = 0.1 mg/l, BAC(Swe) = 0.2% or US = 0.021 g/dl). Nine out of 10 patients who dropped out from the study showed early risk signs as reflected in the level and pattern in AMI before the actual dropout. Conclusions: AMI-time profiles from an eHealth system are useful for monitoring the recovery process and for early identification of lapse/relapse patterns. High-resolution monitoring of sobriety enables new measurement-based treatment methods for proactive personalized long-term relapse prevention and treatment of AUD patients. Clinical Trial Registration: The data used for construction of AMI was from two clinical trials approved by the Regional Ethics Committee of Uppsala, Sweden and performed in accordance with the Declaration of Helsinki. Written informed consent was obtained from all participating subjects. The study was registered at ClinicalTrials.gov (NCT03195894).

  • 19.
    Hillerdal, Victoria
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Clinical Immunology.
    Boura, Vanessa F.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Clinical Immunology.
    Björkelund, Hanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Clinical Immunology. Ridgeview Instruments AB, Vange, Sweden..
    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, Vange, Sweden..
    Essand, Magnus
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Clinical Immunology.
    Avidity characterization of genetically engineered T-cells with novel and established approaches2016In: BMC Immunology, ISSN 1471-2172, E-ISSN 1471-2172, Vol. 17, article id 23Article in journal (Refereed)
    Abstract [en]

    Background: Adoptive transfer of genetically engineered autologous T-cells is becoming a successful therapy for cancer. The avidity of the engineered T-cells is of crucial importance for therapy success. We have in the past cloned a T-cell receptor (TCR) that recognizes an HLA-A2 (MHC class I)-restricted peptide from the prostate and breast cancer- associated antigen TARP. Herein we perform a side-by-side comparison of the TARP-specific TCR (TARP-TCR) with a newly cloned TCR specific for an HLA-A2-restricted peptide from the cytomegalovirus (CMV) pp65 antigen. Results: Both CD8(+) T-cells and CD4(+) T-cells transduced with the HLA-A2-restricted TARP-TCR could readily be detected by multimer analysis, indicating that the binding is rather strong, since binding occured also without the CD8 co-receptor of HLA-A2. Not surprisingly, the TARP-TCR, which is directed against a self-antigen, had weaker binding to the HLA-A2/peptide complex than the CMV pp65-specific TCR (pp65-TCR), which is directed against a viral epitope. Higher peptide concentrations were needed to achieve efficient cytokine release and killing of target cells when the TARP- TCR was used. We further introduce the LigandTracer technology to study cell-cell interactions in real time by evaluating the interaction between TCR-engineered T-cells and peptide-pulsed cancer cells. We were able to successfully detect TCR-engineered T-cell binding kinetics to the target cells. We also used the xCELLigence technology to analyzed cell growth of target cells to assess the killing potency of the TCR-engineered T-cells. T-cells transduced with the pp65 - TCR exhibited more pronounced cytotoxicity, being able to kill their targets at both lower effector to target ratios and lower peptide concentrations. Conclusion: The combination of binding assay with functional assays yields data suggesting that TARP- TCR-engineered T-cells bind to their target, but need more antigen stimulation compared to the pp65-TCR to achieve full effector response. Nonetheless, we believe that the TARP- TCR is an attractive candidate for immunotherapy development for prostate and/or breast cancer.

  • 20.
    Honarvar, Hadis
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Jokilaakso, Nima
    Andersson, Karl
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Malmberg, Jennie
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Rosik, Daniel
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Karlstrom, Amelie Eriksson
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Jarver, Peter
    Evaluation of backbone-cyclized HER2-binding 2-helix Affibody molecule for In Vivo molecular imaging2013In: Nuclear Medicine and Biology, ISSN 0969-8051, E-ISSN 1872-9614, Vol. 40, no 3, p. 378-386Article in journal (Refereed)
    Abstract [en]

    Introduction

    Affibody molecules, small scaffold proteins, have demonstrated an appreciable potential as imaging probes. Affibody molecules are composed of three alpha-helices. Helices 1 and 2 are involved in molecular recognition, while helix 3 provides stability. The size of Affibody molecules can be reduced by omitting the third alpha-helix and cross-linking the two remaining, providing a smaller molecule with better extravasation and quicker clearance of unbound tracer. The goal of this study was to develop a novel 2-helix Affibody molecule based on backbone cyclization by native chemical ligation (NCL).

    Methods

    The HER2-targeting NCL-cyclized Affibody molecule ZHER2:342min has been designed, synthesized and site-specifically conjugated with a DOTA chelator. DOTA-ZHER2:342min was labeled with 111In and 68 Ga. The binding affinity of DOTA-ZHER2:342min was evaluated in vitro. The targeting properties of 111In- and 68 Ga-DOTA-ZHER2:342min were evaluated in mice bearing SKOV-3 xenografts and compared with the properties of 111In- and 68 Ga-labeled PEP09239, a DOTA-conjugated 2-helix Affibody analogue cyclized by a homocysteine disulfide bridge.

    Results

    The dissociation constant (KD) for DOTA-ZHER2:342min binding to HER2 was 18 nM according to SPR measurements. DOTA-ZHER2:342min was labeled with 111In and 68 Ga. Both conjugates demonstrated bi-phasic binding kinetics to HER2-expressing cells, with KD1 in low nanomolar range. Both variants demonstrated specific uptake in HER2-expressing xenografts. Tumor-to-blood ratios at 2 h p.i. were 6.1 ± 1.3 for 111In- DOTA-ZHER2:342min and 4.6 ± 0.7 for 68 Ga-DOTA-ZHER2:342min. However, the uptake of DOTA-ZHER2:342min in lung, liver and spleen was appreciably higher than the uptake of PEP09239-based counterparts.

    Conclusions

    Native chemical ligation enables production of a backbone-cyclized HER2-binding 2-helix Affibody molecule (ZHER2:342min) with low nanomolar target affinity and specific tumor uptake.

  • 21.
    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.

  • 22. McGrath, T. F.
    et al.
    Andersson, Karl
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Campbell, K.
    Fodey, T. L.
    Elliott, C. T.
    Development of a rapid low cost fluorescent biosensor for the detection of food contaminants2013In: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 41, no 1, p. 96-102Article in journal (Refereed)
    Abstract [en]

    A prototype fluorescent based biosensor has been developed for the antibody based detection of food related contaminants. Its performance was characterised and showed a typical antibody binding signal of 200-2000. mV, a short term noise of 9.1. mV, and baseline slope of -0.016. mV/s over 4. h. Bulk signal detection repeatability (n=23) and reproducibility (n=3) were less than 2.4%CV. The biosensor detection unit was evaluated using two food related model systems proving its ability to monitor both binding using commercial products and inhibition through the development of an assay. This assay development potential was evaluated by observing the biosensor's performance whilst appraising several labelled antibody and glass slide configurations. The molecular interaction between biotin and an anti-biotin antibody was shown to be inhibited by 41% due to the presence of biotin in a sample. A food toxin (domoic acid) calibration curve was produced, with %CVs ranging from 2.7 to 7.8%, and a midpoint of approximately 17. ng/ml with further optimisation possible. The ultimate aim of this study was to demonstrate the working principles of this innovative biosensor as a potential portable tool with the opportunity of interchangeable assays. The biosensor design is applicable for the requirements of routine food contaminant analysis, with respect to performance, functionality and cost.

  • 23.
    Multia, Evgen
    et al.
    Univ Helsinki, Dept Chem, Analyt Chem Lab, POB 55, FI-00014 Helsinki, Finland..
    Sirén, Heli
    Univ Helsinki, Dept Chem, Analyt Chem Lab, POB 55, FI-00014 Helsinki, Finland..
    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, SE-74020 Vange, Sweden..
    Samuelsson, Jörgen
    Karlstad Univ, Dept Engn & Chem Sci, SE-65188 Karlstad, Sweden..
    Forssén, Patrik
    Karlstad Univ, Dept Engn & Chem Sci, SE-65188 Karlstad, Sweden..
    Fornstedt, Torgny
    Karlstad Univ, Dept Engn & Chem Sci, SE-65188 Karlstad, Sweden..
    Öörni, Katariina
    Wihuri Res Inst, Haartmaninkatu 8, FI-00290 Helsinki, Finland..
    Jauhiainen, Matti
    Biomedicum, Genom & Biomarkers Unit, Natl Inst Hlth & Welf, FI-00290 Helsinki, Finland..
    Riekkola, Marja-Liisa
    Univ Helsinki, Dept Chem, Analyt Chem Lab, POB 55, FI-00014 Helsinki, Finland..
    Thermodynamic and kinetic approaches for evaluation of monoclonal antibody - Lipoprotein interactions2017In: Analytical Biochemistry, ISSN 0003-2697, E-ISSN 1096-0309, Vol. 518, p. 25-34Article in journal (Refereed)
    Abstract [en]

    Two complementary instrumental techniques were used, and the data generated was processed with advanced numerical tools to investigate the interactions between anti-human apoB-100 monoclonal antibody (anti-apoB-100 Mab) and apoB-100 containing lipoproteins. Partial Filling Affinity Capillary Electrophoresis (PF-ACE) combined with Adsorption Energy Distribution (AED) calculations provided information on the heterogeneity of the interactions without any a priori model assumptions. The AED calculations evidenced a homogenous binding site distribution for the interactions. Quartz Crystal Microbalance (QCM) studies were used to evaluate thermodynamics and kinetics of the Low-Density Lipoprotein (LDL) and anti-apoB-100 Mab interactions. High affinity and selectivity were observed, and the emerging data sets were analysed with so called Interaction Maps. In thermodynamic studies, the interaction between LDL and anti-apoB-100 Mab was found to be predominantly enthalpy driven. Both techniques were also used to study antibody interactions with Intermediate-Density (IDL) and Very Low Density (VLDL) Lipoproteins. By screening affinity constants for IDL-VLDL sample in a single injection we were able to distinguish affinity constants for both subpopulations using the numerical Interaction Map tool.

  • 24.
    Orlova, Anna
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Hofström, Camilla
    Strand, Joanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Varasteh, Zohreh
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Sandström, Mattias
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Medical Physics.
    Andersson, Karl
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Gräslund, Torbjörn
    [99mTc(CO)3]+-(HE)3-ZIGF1R:4551, a new Affibody conjugate for visualization of insulin-like growth factor-1 receptor expression in malignant tumours2013In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 40, no 3, p. 439-449Article in journal (Refereed)
    Abstract [en]

    Purpose

    Radionuclide imaging of insulin-like growth factor type 1 receptor (IGF-1R) expression in tumours might be used for selection of patients who would benefit from IGF-1R-targeted therapy. We have previously shown the feasibility of IGF-1R imaging using the Affibody molecule 111In-DOTA-His6-ZIGF1R:4551. The use of 99mTc instead of 111In should improve sensitivity and resolution of imaging, and reduce the dose burden to patients. We hypothesized that inclusion of a HEHEHE tag instead of a His6 tag in ZIGF1R:4551 would permit its convenient purification using IMAC, enable labelling with [99mTc(CO)3]+, and improve its biodistribution.

    Methods

    ZIGF1R:4551 was expressed with a HEHEHE tag in the N terminus. The resulting (HE)3-ZIGF1R:4551 construct was labelled with [99mTc(CO)3]+. Targeting of IGF-1R-expressing cells using [99mTc(CO)3]+-(HE)3-ZIGF1R:4551 was evaluated in vitro and in vivo.

    Results

    (HE)3-ZIGF1R:4551 was stably labelled with 99mTc with preserved specific binding to IGF-1R-expressing DU-145 prostate cancer cells in vitro. In mice, [99mTc(CO)3]+-(HE)3-ZIGF1R:4551 accumulated in IGF-1R-expressing organs (pancreas, stomach, lung and salivary gland). [99mTc(CO)3]+-(HE)3-ZIGF1R:4551 demonstrated 3.6-fold lower accumulation in the liver and spleen than 111In-DOTA-ZIGF1R:4551. In NMRI nu/nu mice with DU-145 prostate cancer xenografts, the tumour uptake was 1.32 ± 0.11 %ID/g and the tumour-to-blood ratio was 4.4 ± 0.3 at 8 h after injection. The xenografts were visualized using a gamma camera 6 h after injection.

    Conclusion

    99mTc(CO)3]+-(HE)3-ZIGF1R:4551 is a promising candidate for visualization of IGF-1R expression in malignant tumours.

  • 25. Peng, Zhuochun
    et al.
    Andersson, Karl
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Lindholm, Johan
    Bodin, Inger
    Pramana, Setia
    Pawitan, Yudi
    Nister, Monica
    Nilsson, Sten
    Li, Chunde
    Operator Dependent Choice of Prostate Cancer Biopsy Has Limited Impact on a Gene Signature Analysis for the Highly Expressed Genes IGFBP3 and F3 in Prostate Cancer Epithelial Cells2014In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, no 10, p. e109610-Article in journal (Refereed)
    Abstract [en]

    Background: Predicting the prognosis of prostate cancer disease through gene expression analysis is receiving increasing interest. In many cases, such analyses are based on formalin-fixed, paraffin embedded (FFPE) core needle biopsy material on which Gleason grading for diagnosis has been conducted. Since each patient typically has multiple biopsy samples, and since Gleason grading is an operator dependent procedure known to be difficult, the impact of the operator's choice of biopsy was evaluated. Methods: Multiple biopsy samples from 43 patients were evaluated using a previously reported gene signature of IGFBP3, F3 and VGLL3 with potential prognostic value in estimating overall survival at diagnosis of prostate cancer. A four multiplex one-step qRT-PCR test kit, designed and optimized for measuring the signature in FFPE core needle biopsy samples was used. Concordance of gene expression levels between primary and secondary Gleason tumor patterns, as well as benign tissue specimens, was analyzed. Results: The gene expression levels of IGFBP3 and F3 in prostate cancer epithelial cell-containing tissue representing the primary and secondary Gleason patterns were high and consistent, while the low expressed VGLL3 showed more variation in its expression levels. Conclusion: The assessment of IGFBP3 and F3 gene expression levels in prostate cancer tissue is independent of Gleason patterns, meaning that the impact of operator's choice of biopsy is low.

  • 26.
    Persson, Mikael
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Andersson, Karl
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Gedda, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Sandström, Mattias
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Carlsson, Jörgen
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    [(177)Lu]pertuzumab: experimental studies on targeting of HER-2 positive tumour cells2005In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 32, no 12, p. 1457-62Article in journal (Refereed)
    Abstract [en]

    PURPOSE: The new antibody pertuzumab (Omnitarg) targets the dimerisation subdomain of HER-2. The purpose of this study was to analyse whether pertuzumab retains HER-2 targeting capacity after labelling with the therapeutically interesting beta emitter (177)Lu and to make initial characterizations in vitro and in vivo. METHODS: Pertuzumab was conjugated with isothiocyanate-benzyl-CHX-A''-DTPA and chelated to (177)Lu. Immunoreactivity, affinity, cellular retention and internalisation were analysed using SKOV-3 cells. The affinity of non-radioactive pertuzumab was measured using a surface plasmon resonance biosensor. In vivo targeting and specific binding were assessed in Balb/c (nu/nu) mice carrying SKOV-3 xenografts. The biodistribution of (177)Lu was determined 1, 3 and 7 days after [(177)Lu]pertuzumab administration. Gamma camera images were taken after 3 days. RESULTS: The immunoreactivity of [(177)Lu]pertuzumab was 85.8+/-1.3%. The affinity of non-radioactive pertuzumab was 1.8+/-1.1 nM, and that of [(177)Lu]pertuzumab, 4.1+/-0.7 nM. The cellular retention after 5 h pre-incubation was 90+/-2% at 20 h. The targeting was HER-2 specific both in vitro and in vivo, since excess amounts of non-labelled antibody inhibited the uptake of labelled antibody (p<0.0001 and p<0.01, respectively). The biodistribution and gamma camera images of (177)Lu showed extensive tumour uptake. Normal tissues had a surprisingly low uptake. CONCLUSION: Pertuzumab was efficiently labelled with (177)Lu and showed good intracellular retention and HER-2 specific binding both in vitro and in vivo. The gamma camera images and the biodistribution study gave excellent tumour targeting results. Thus, [(177)Lu]pertuzumab is of interest for further studies aimed at radionuclide therapy.

  • 27.
    Reijmar, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Edwards, Katarina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    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, Skillsta 4, 740 20 Vänge, Sweden.
    Agmo Hernández, Víctor
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Characterizing and controlling the loading and release of cationic amphiphilic peptides onto and from PEG-stabilized lipodisks2016In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 32, no 46, p. 12091-12099Article in journal (Refereed)
    Abstract [en]

    Recent studies have identified PEG-stabilized lipid nanodisks (lipodisks) as promising carriers for cationic amphiphilic peptides with antimicrobial and anticancer activity. Using fluorimetric and nanogravimetric methods, we have in this work characterized the parameters describing and controlling the binding of three selected peptides (melittin, LL37, and magainin 2) onto lipodisks. It was found that the affinity of melittin for lipodisks is independent of the disk size and rim charge. On the other hand, the number of binding sites is strongly dependent on both parameters, with the highest loading being obtained for small disks with a negatively charged rim. An optimized composition of the lipodisks was utilized to study the loading of antimicrobial peptides magainin 2 and human LL37. It was observed that although magainin 2 can be loaded in large amounts, it is released very fast upon dilution, which limits future therapeutic applications. In contrast, LL37 can be loaded at relevant concentrations and the formulation is stable. This opens up for applications of LL37-loaded lipodisks as antibiotics and in anticancer treatments.

  • 28.
    Tolmachev, Vladimir
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    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.
    Methods for radiolabelling of monoclonal antibodies2014In: Human Monoclonal Antibodies: Methods and Protocols / [ed] Michael Steinitz, Humana Press, 2014, p. 309-330Chapter in book (Refereed)
    Abstract [en]

    The use of radionuclide labels allows to study the pharmacokinetics of monoclonal antibodies, to control the specificity of their targeting and to monitor the response to an antibody treatment with high accuracy. Selection of label depends on the processing of an antibody after binding to an antigen, and on the character of information to be derived from the study (distribution of antibody in the extracellular space, target occupancy or determination of sites of metabolism). This chapter provides protocols for labelling of antibodies with iodine-125 (suitable also for other radioisotopes of iodine) and with indium-111. Since radiolabelling might damage and reduce the immunoreactive fraction and/or affinity of an antibody, the methods for assessment of these characteristics of an antibody are provided for control.

  • 29. 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.

  • 30.
    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.

  • 31.
    Zetterström, Andreas
    et al.
    Kontigo Care AB, Pavel Snickares Grand 12, S-75320 Uppsala, Sweden.
    Hämäläinen, Markku D.
    Kontigo Care AB, Pavel Snickares Grand 12, S-75320 Uppsala, Sweden.
    Karlberg, Elin
    Uppsala Univ Hosp, Innovat Akad, S-75185 Uppsala, Sweden.
    Winkvist, Maria
    Kontigo Care AB, Pavel Snickares Grand 12, S-75320 Uppsala, Sweden.
    Söderquist, Marcus
    Kontigo Care AB, Pavel Snickares Grand 12, S-75320 Uppsala, Sweden.
    Öhagen, Patrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, UCR-Uppsala Clinical Research Center.
    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, Skillsta 4, S-74020 Vange, Sweden.
    Nyberg, Fred
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Maximum Time Between Tests: A Digital Biomarker to Detect Therapy Compliance and Assess Schedule Quality in Measurement-Based eHealth Systems for Alcohol Use Disorder2019In: Alcohol and Alcoholism, ISSN 0735-0414, E-ISSN 1464-3502, Vol. 54, no 1, p. 70-72Article in journal (Refereed)
    Abstract [en]

    Aim: To evaluate, in a breathalyzer-based eHealth system, whether the time-based digital biomarker maximum time between tests' (MTBT) brings valuable information on alcohol consumption patterns as confirmed by correlation with blood phosphatidyl ethanol (PEth), serum carbohydrate deficient transferrin (CDT) and timeline follow-back data.

    Method: Data on 54 patients in follow-up for treatment of alcohol use disorder were analysed.

    Results: The model of weekly averages of 24-log transformed MTBT adequately described timeline follow-back data (P < 0.0001, R = 0.27-0.38, n = 650). Significant correlations were noted between MTBT and PEth (P < 0.0001, R = 0.41, n = 148) and between MTBT and CDT (P < 0.0079, R = 0.22, n = 120).

    Conclusions: The time-based digital biomarker maximum time between tests' described here has the potential to become a generally useful metric for all scheduled measurement-based eHealth systems to monitor test behaviour and compliance, factors important for dosing' of eHealth systems and for early prediction and interventions of lapse/relapse.

1 - 31 of 31
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