Infected cell antigen

"Infected cell antigen" refers to any molecule (usually a protein or peptide) that is expressed by a cell due to infection with a pathogen and is recognized as foreign by the immune system. Such antigens are presented on the cell surface (commonly via major histocompatibility complex, MHC), where they can be detected by antibodies or T cell receptors, eliciting an immune response. They form the molecular basis of immune recognition of infected cells—for example, a virally infected cell displays viral proteins as antigens, which cytotoxic T lymphocytes or antibodies can recognize and target for destruction. The identity of infected cell antigens varies with the pathogen and cell type. The term is not specific to any one molecule and should not be used as a distinct, structured molecular target in databases. Summary: "Infected cell antigen" is a generic, non-canonical descriptor for antigens originating from infected cells; it is not a specific receptor, enzyme, or drug target and should not be used as a canonical structured entity in molecular databases.

Other names

Infected cell surface antigenPathogen-associated antigen (sometimes used contextually)Viral antigen (in context of viral infection)Bacterial antigen (in context of bacterial infection)

Immune recognition by antibodies or cytotoxic T cells: Antibodies or cytotoxic T cell receptors bind to infected cell antigens, leading to neutralization, opsonization, complement activation, or cell lysis. Mechanisms of action depend entirely on the specific antigen.