epitop

Epitop is a term that appears in immunology literature as a variant spelling or translation of the word epitope. An epitope is the specific part of an antigen that is recognized by an antibody, a B-cell receptor, or a T-cell receptor. Epitopes are the functional determinants that drive immune recognition and can vary in their properties and location on an antigen.

There are two broad categories of epitopes. B-cell epitopes are recognized by antibodies and can be linear (continuous amino acid sequences) or conformational (discontinuous sequences brought together in the folded protein). T-cell epitopes are typically short peptides displayed by major histocompatibility complex (MHC) molecules and recognized by T-cell receptors. The immunogenicity of epitopes depends on factors such as accessibility, processing, and the host’s MHC repertoire.

Epitopes are central to many areas of biomedicine. Epitope mapping identifies the precise regions that elicit an immune response, informing vaccine design, diagnostic assays, and therapeutic antibody development. Epitope-focused vaccines aim to trigger protective immunity by presenting key determinant regions, sometimes enhancing specificity and reducing unwanted responses. Epitope data are gathered through methods such as peptide mapping, phage display, peptide microarrays, structural analyses, and mass spectrometry.

In use, the term epitop may appear in non-English texts or as a transliteration, but its meaning aligns with epitopes—the molecular determinants of antigen recognition by the immune system. Related concepts include immunodominance, epitope spreading, and cross-reactivity.