Antigenic Determinants
Antigenic Determinants - Related Videos
15:27
Determination of High-affinity Antibody-antigen Binding Kinetics Using Four Biosensor Platforms
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Cited by 30 •
2017
We describe here protocols for the measurement of antibody-antigen binding affinity and kinetics using four commonly used biosensor platforms.
06:57
Development of an Antigen-driven Colitis Model to Study Presentation of Antigens by Antigen Presenting Cells to T Cells
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Cited by 9 •
2016
In this antigen-driven colitis model, OT-II CD4+ T cells expressing a red fluorescent protein were adoptively transferred into RAG-/- mice that express a green fluorescent protein in mononuclear phagocytes (MPs). The hosts were challenged with Escherichia coli (E.coli) expressing the ovalbumin protein (OVA) fused to a cyan fluorescent protein (CFP).
07:39
Determining Binding Affinity (KD) of Radiolabeled Antibodies to Immobilized Antigens
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2022
Here, a method is described to determine the binding affinity (KD) of radiolabeled antibodies to immobilized antigens. KD is the equilibrium dissociation constant that can be determined from a saturation binding experiment by measuring the total, specific, and nonspecific binding of a radiolabeled antibody at various concentrations to its antigen.
10:17
Rapid Determination of Antibody-Antigen Affinity by Mass Photometry
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Cited by 14 •
2021
We describe a single-molecule approach to antigen-antibody affinity measurements using mass photometry (MP). The MP-based protocol is fast, accurate, uses a very small amount of material, and does not require protein modification.
08:37
In Situ MHC-tetramer Staining and Quantitative Analysis to Determine the Location, Abundance, and Phenotype of Antigen-specific CD8 T Cells in Tissues
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Cited by 11 •
2017
Here, we describe a method that combines in situ MHC-tetramer staining with immunohistochemistry to determine localization, phenotype, and quantity of antigen-specific T cells in tissues. This protocol is used to determine the spatial and phenotypic characteristics of antigen-specific CD8 T cells relative to other cell type and structures in tissues.
FAQs
Recognition reflects more than an antigen’s overall identity. Amino acid sequence can contribute directly, while three-dimensional shape determines whether the relevant surface has the right molecular arrangement. Charge and physical accessibility also influence contact with an antibody or presentation for receptor recognition. Consequently, changes that alter structure, surface exposure, or local chemistry may change immune recognition.
These two recognition modes assess related but not identical molecular information. B-cell epitopes are contacted directly by antibodies, so exposed three-dimensional features, charge, and accessibility are especially relevant. T-cell epitopes are typically presented as peptides bound to major histocompatibility complex molecules before T-cell receptor recognition. This distinction matters when interpreting immune-response data or designing epitope-focused studies.
Shared molecular features can allow an antibody or receptor response directed at one antigenic determinant to recognize another, providing a basis for cross-reactivity. Conversely, differences in determinant sequence, shape, charge, or accessibility can reduce recognition. Examining these properties helps researchers relate molecular variation to immune evasion and distinguish a broadly shared response from a highly specific one.
Epitope mapping links immune recognition to particular regions and molecular features rather than treating an antigen as a single uniform target. It can show whether responses focus on antibody-accessible surfaces or on peptides displayed for T-cell recognition, and whether distinct samples recognize overlapping or different determinants. These results help interpret specificity, cross-reactivity, and variation in responses to infections or therapeutic proteins.
In vaccine design, identifying relevant determinants helps connect candidate antigen structure with the immune specificities it is intended to elicit. In diagnostic assay development, determinant analysis helps assess which antigen regions can support selective detection of an immune response. The same framework can clarify whether recognition is likely to be shared across related antigens or restricted to a particular target.
Antibody engineering can use determinant information to focus on the molecular regions and properties associated with recognition, including sequence, shape, charge, and accessibility. For therapeutic proteins, analyzing recognized determinants helps evaluate how the immune system may respond to the protein and whether recognition overlaps with responses to other antigens. This supports more informed interpretation of specificity and cross-reactivity.