T-cell receptor-Major Histocompatibility Complex interaction (TCR-MHC interaction)

The host allogeneic T-cell response via TCR–MHC allorecognition is the fundamental immunological process responsible for the rejection of transplanted organs and tissues (Nature Reviews Immunology, 2013). It involves the recognition of foreign (allogeneic) Major Histocompatibility Complex (MHC) molecules by the host's T-cell receptors (TCRs), a phenomenon known as allorecognition (Janeway's Immunobiology, 2017). This recognition can occur directly, where T cells bind to intact donor MHC, or indirectly, where donor MHC-derived peptides are presented by host MHC molecules (Frontiers in Immunology, 2018). This interaction triggers robust T-cell activation, leading to the production of inflammatory cytokines and the recruitment of effector cells that cause graft injury (StatPearls, 2023). Therapeutic strategies to modulate this response include the use of calcineurin inhibitors, costimulation blockers, and monoclonal antibodies that target the TCR complex or downstream signaling pathways (PubMed, 2021). While effective at preventing acute rejection, these interventions require lifelong administration and are associated with significant side effects, including nephrotoxicity and increased susceptibility to infections and cancer (NIH, 2022).

Other names

AllorecognitionAlloantigen recognitionHost-versus-graft responseTCR-HLA recognitionAllogeneic T-cell activation

Inhibition of T-cell activation and proliferation by blocking TCR signaling, costimulatory pathways, or downstream cytokine signaling.