Antigen-presenting cell and antigen recognition process (APC (for Antigen-presenting cell); no canonical abbreviation for the process itself)

Antigen presentation and recognition by immune cells is not a single molecular target, but rather a critical immunological process in which antigen-presenting cells (APCs) display pieces of protein (antigens), typically bound to MHC molecules, on their surface for recognition by T cell receptors (TCRs) on T lymphocytes[1][2][3][6][7]. Professional APCs—such as dendritic cells, macrophages, and B cells—specialize in presenting antigens via MHC class II to helper T cells (CD4+), while all nucleated cells can present intracellular antigens via MHC class I to cytotoxic T cells (CD8+)[1][2][4][5][8]. This process is essential for initiating adaptive immune responses against pathogens and cancer, but can also be involved in autoimmunity and immune evasion by tumors and certain pathogens[6][7]. The phrase itself refers to an immunological pathway, not a discrete receptor or molecule, so it is not considered a direct therapeutic target in the way that a receptor, enzyme, or transporter would be.

Other names

Antigen presentationAPCaccessory cellprofessional antigen-presenting cellnon-professional antigen-presenting cell