Major Histocompatibility Complex antigen presentation pathway (MHC pathway)

The Major Histocompatibility Complex (MHC) antigen presentation pathway is a fundamental immunological process by which antigen-presenting cells (APCs) process proteins into small peptides for display on the cell surface (StatPearls, 2023). MHC Class I molecules typically present endogenous antigens to CD8+ cytotoxic T cells, while MHC Class II molecules present exogenous antigens to CD4+ helper T cells (Janeway's Immunobiology, 2017). This pathway is a critical therapeutic target in oncology, where tumors often downregulate MHC expression to evade immune detection, and in autoimmunity, where the pathway may inappropriately present self-antigens. Drugs such as proteasome inhibitors (e.g., Bortezomib) interact with this pathway by preventing the generation of peptides required for MHC Class I loading, while Interferon-gamma is used to upregulate the expression of MHC components (NIH, 2024). Understanding the spatial and temporal regulation of this pathway is essential for the development of effective vaccines and immunotherapies (Nature Reviews Immunology, 2021).

Other names

Antigen processing and presentationHLA presentation pathwayMHC Class I and II presentationAntigen-presenting cell membrane pathway

Modulation of the proteasomal degradation of intracellular proteins to alter peptide supply for MHC Class I, or induction of MHC molecule and transporter expression via cytokine signaling to enhance immune recognition.