Epitope

An **epitope** (also called an antigenic determinant) is the specific part of an antigen that is recognized by the immune system, either through binding by antibodies (such as IgG) or recognition by T cell receptors on T cells[1][7]. B cell epitopes are recognized by antibodies or B cell receptors and are typically conformational (dependent on 3D structure) or linear segments of proteins. T cell epitopes are presented on the surface of antigen-presenting cells bound to major histocompatibility complex (MHC) molecules, chiefly as short peptides (8–11 amino acids for MHC I, 13–17 for MHC II)[1][5]. Some epitopes in IgG, known as **Tregitopes**, have regulatory properties, activating natural T regulatory cells and promoting immune tolerance[2][3][4]. Epitopes can be exploited in immunotherapy, vaccine design, allergy treatment, and in understanding immune responses in various diseases. However, "IgG/T-cell epitopes" is not a standardized or canonical target name and should not be treated as a single molecular entity but rather as a functional immune feature shared by many antigens[1][5][7].

Other names

antigenic determinantT cell epitopeB cell epitopeIgG epitope