Major Histocompatibility Complex Molecule Presentation Pathway (MHC Presentation Pathway)

The major histocompatibility complex (MHC) molecule presentation pathway is a fundamental component of the adaptive immune system. Its primary function is to bind peptide fragments derived from pathogens or self-proteins and display them on the cell surface for recognition by T cells. This process enables the immune system to distinguish between self and non-self, facilitating targeted immune responses against infections and abnormal cells. MHC Class I presents intracellular antigens to CD8+ T cells, while MHC Class II presents extracellular antigens to CD4+ T cells. The pathway is highly polymorphic, influencing disease susceptibility, transplant rejection, and immune responses to cancer and infection.

Other names

MHC Class I PresentationMHC Class II PresentationAntigen Presentation PathwayHLA System

Varies depending on the specific drug; immunosuppressants often target T-cell activation pathways downstream of MHC presentation; checkpoint inhibitors block inhibitory signals that prevent T-cell activation.