Major Histocompatibility Complex Class I Antigen Presentation Pathway (MHC Class I Pathway)

The major histocompatibility complex (MHC) class I antigen presentation pathway is a fundamental component of the adaptive immune system. Its primary function is to present peptide fragments derived from intracellular proteins on the surface of all nucleated cells, allowing cytotoxic CD8+ T cells to monitor and eliminate infected or abnormal cells. The pathway involves protein degradation by the proteasome, peptide transport into the ER by TAP, peptide loading onto MHC class I molecules with the help of chaperones, and surface expression for T cell recognition. This pathway underpins cellular immunity against viruses and some intracellular bacteria while also playing roles in tumor surveillance and autoimmunity when dysregulated.

Other names

MHC-I Antigen Presentation PathwayClass I Antigen Processing PathwayHLA Class I Pathway