Enhancement of Immune Effector Functions by Modulating IgG’s Intrinsic Affinity for Target Antigen
| Autor: | M. Jack Borrok, Chunning Yang, William Dall'acqua, Herren Wu, Yariv Mazor, Karen Aherne, Joanne Ayriss |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Physiology Receptor ErbB-2 Cytotoxicity Antibody Affinity lcsh:Medicine Toxicology Pathology and Laboratory Medicine Biochemistry Immunoglobulin G White Blood Cells Binding Analysis 0302 clinical medicine Spectrum Analysis Techniques Animal Cells Genes Reporter Immune Physiology Medicine and Health Sciences Protein Isoforms Receptor lcsh:Science Multidisciplinary Immune System Proteins biology Effector T Cells Flow Cytometry Antigenic Variation Endocytosis Cell biology Antibody opsonization ErbB Receptors Spectrophotometry 030220 oncology & carcinogenesis CD4 Antigens Cytophotometry Antibody Cellular Types Cell Binding Assay Research Article Cell Binding Cell Physiology Immune Cells Immunology Research and Analysis Methods Antibodies 03 medical and health sciences Immune system Antigen Cell Line Tumor Antigenic variation Humans Antigens Chemical Characterization Blood Cells lcsh:R Receptors IgG Antibody-Dependent Cell Cytotoxicity Biology and Life Sciences Proteins Cell Biology Molecular biology 030104 developmental biology biology.protein lcsh:Q |
| Zdroj: | PLoS ONE PLoS ONE, Vol 11, Iss 6, p e0157788 (2016) |
| ISSN: | 1932-6203 |
| Popis: | Antibody-mediated immune effector functions play an essential role in the anti-tumor efficacy of many therapeutic mAbs. While much of the effort to improve effector potency has focused on augmenting the interaction between the antibody-Fc and activating Fc-receptors expressed on immune cells, the role of antibody binding interactions with the target antigen remains poorly understood. We show that antibody intrinsic affinity to the target antigen clearly influences the extent and efficiency of Fc-mediated effector mechanisms, and report the pivotal role of antibody binding valence on the ability to regulate effector functions. More particularly, we used an array of affinity modulated variants of three different mAbs, anti-CD4, anti-EGFR and anti-HER2 against a panel of target cell lines expressing disparate levels of the target antigen. We found that at saturating antibody concentrations, IgG variants with moderate intrinsic affinities, similar to those generated by the natural humoral immune response, promoted superior effector functions compared to higher affinity antibodies. We hypothesize that at saturating concentrations, effector function correlates most directly with the amount of Fc bound to the cell surface. Thus, high affinity antibodies exhibiting slow off-rates are more likely to interact bivalently with the target cell, occupying two antigen sites with a single Fc. In contrast, antibodies with faster off-rates are likely to dissociate each binding arm more rapidly, resulting in a higher likelihood of monovalent binding. Monovalent binding may in turn increase target cell opsonization and lead to improved recruitment of effector cells. This unpredicted relationship between target affinity and effector function potency suggests a careful examination of antibody design and engineering for the development of next-generation immunotherapeutics. |
| Databáze: | OpenAIRE |
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