Antigen presentation via major histocompatibility complex molecule

Antigen presentation via major histocompatibility complex (MHC) molecules is a **biological process**, rather than a single molecule or therapeutic target. In this process, **MHC class I and MHC class II molecules** display peptide fragments on the cell surface for recognition by T cells. - **MHC class I molecules** (present on all nucleated cells) present endogenous peptides—often from cytosolic proteins or intracellular pathogens like viruses—to CD8+ cytotoxic T lymphocytes[1][5][6]. - **MHC class II molecules** (mainly on specialized antigen-presenting cells such as dendritic cells, B cells, and macrophages) present exogenous peptides, typically from extracellular sources, to CD4+ helper T cells[4][6][8]. This process is critical for initiating adaptive immune responses, distinguishing self from non-self, and orchestrating immune surveillance and defense mechanisms. Because "Antigen presentation via MHC molecules" does not refer to a specific, druggable entity (e.g., a single receptor or protein encoded by a gene), it is not considered a conventional therapeutic target. Instead, the **specific MHC molecules** (such as HLA-A, HLA-B, HLA-DR, etc.) might be targets for diagnostics or immunomodulatory therapies, and defects or variants in this pathway are implicated in immune-related diseases including infections, cancer, and autoimmunity[6][7]. **Note on correctness:** - The entry describes a process rather than a specific molecule, gene, or protein and thus is not suitable as a canonical drug target[4][6][7]. - For structured information as usually required for molecular targets, the canonical forms should be individual MHC molecules (e.g., "Major histocompatibility complex class I, HLA-A") rather than the overall antigen presentation mechanism.

Other names

MHC-mediated antigen presentationAntigen presentation pathwayAntigen processing and presentation