epitopen

Epitopen is the Dutch term for epitopes, the specific parts of an antigen that are recognized by the immune system. In immunology, an epitoop or antigenic determinant is the precise molecular motif that an antibody or a T-cell receptor binds. Epitopen can be derived from proteins, polysaccharides, lipids, or other macromolecules and may be displayed on the surface of pathogens or presented by host cells.

There are two broad functional classes. B-cell epitopen are recognized by antibodies and can be linear or conformational, depending on the three‑dimensional structure of the antigen. T-cell epitopen are presented by major histocompatibility complex (MHC) molecules as short peptide fragments, typically 8–10 amino acids for CD8+ T cells and longer peptides for CD4+ T cells, and are recognized by T-cell receptors. The immune response to an antigen often involves multiple epitopen, with different immune receptors targeting distinct determinants.

Epitopen are central to vaccine design, diagnostics, and research into immune responses. Epitope mapping identifies which determinants are recognized, informing antigen selection and the development of epitope-based vaccines or diagnostic tests. Epitope data also contribute to understanding autoimmune diseases, where self-epitopes may trigger harmful responses.

Methods to identify epitopen include overlapping peptide libraries, phage display, mutational analyses, structural techniques such as X-ray crystallography or cryo-electron microscopy, and computational predictions that integrate sequence, structure, and binding data.