Antigenic determinant

classification of blood types

An epitope, also known as antigenic determinant, is the part of an antigen that is recognized by the immune system, specifically by antibodies, B cells, or T cells. The part of an antibody that binds to the epitope is called a paratope. Although epitopes are usually non-self proteins, sequences derived from the host that can be recognized (as in the case of autoimmune diseases) are also epitopes.

Any mechanism of immune avoidance that directly affects the host immune system, e.g. blocking any stage in host MHC class I and II presentation. The host is defined as the larger of the organisms involved in a symbiotic interaction.