Major histocompatibility complex pathway (MHC pathway)

The **major histocompatibility complex (MHC) pathway** refers to the cellular and molecular processes responsible for the presentation of peptide antigens to T cells, a central mechanism in adaptive immunity. MHC class I molecules present endogenous antigens (including viral or tumor antigens) to **CD8+ cytotoxic T cells**, whereas MHC class II molecules present exogenous antigens to **CD4+ helper T cells**. This pathway determines immune recognition of self and non-self, impacts organ transplant compatibility, and is a critical modulator of both autoimmunity and anti-tumor immunity[1][3][5][7][8]. Therapies targeting the MHC pathway aim to enhance or suppress antigen presentation, to modulate the immune response in cancer immunotherapy or autoimmune diseases[2][4][6][8]. However, the "MHC pathway" is a **biological process, not a single molecular target**, and includes multiple proteins (e.g., MHC class I/II, TAP, chaperones), so this entry is semantically not a proper molecular target. **Note:** - "MHC pathway" is not a molecular entity but a pathway/process, so the entry is technically incorrect for a target database and should be flagged as such. - Canonical targets would include "MHC class I molecule," "MHC class II molecule," or specific HLA gene products, rather than the pathway itself[1][5][7].

Other names

Major histocompatibility complex antigen presentation pathwayMHC antigen presentation pathway

Modulate or restore antigen presentation Block antigen presentation (e.g., glatiramer acetate competes for MHC binding to block autoantigen presentation) Epigenetic reprogramming to upregulate MHC expression Targeting MHC-peptide complexes with therapeutic antibodies or cell therapies