The specific surface patch on an antigen that an antibody binds — often a folded shape, not the short HLA-presented peptide seen by T cells.
An antibody epitope is the exact part of an antigen recognized by an antibody. It can be linear, meaning a continuous stretch of amino acids, or conformational, meaning a three-dimensional surface made by residues that are far apart in sequence but close together in the folded protein.
This is different from the peptide epitopes used in most neoantigen-vaccine pipelines. T-cell epitopes are short peptides presented by HLA molecules; antibody epitopes are exposed surfaces on intact proteins. The prediction problems, assays, and therapeutic uses are therefore different.
Antibody-epitope prediction still matters to the field because cancer vaccines, bispecifics, ADCs, and immune monitoring all ask related targeting questions: which molecular surface is visible, specific, and safe enough to aim an immune response at?
An antibody epitope is a surface feature on an intact antigen that an antibody binds directly. A T-cell epitope is usually a short peptide displayed by HLA/MHC and recognized by a T-cell receptor. Neoantigen vaccines mostly target T-cell epitopes, not antibody epitopes.
No. Some are linear stretches of amino acids, but many important antibody epitopes are conformational surfaces formed by the folded 3D structure of a protein.