Pancreatic islet antigen–Major Histocompatibility Complex complex (Islet pMHC)

Pancreatic islet antigen–Major Histocompatibility Complex (MHC) complexes are molecular assemblies formed by the binding of peptides derived from beta-cell-specific proteins—such as insulin, glutamic acid decarboxylase 65 (GAD65), and zinc transporter 8 (ZnT8)—to MHC molecules (Human Leukocyte Antigen or HLA in humans) [PMID: 30104655]. These complexes are displayed on the surface of pancreatic beta cells and professional antigen-presenting cells, serving as the primary signal for T-cell recognition via the T-cell receptor (TCR) [PMID: 29438510]. In the context of Type 1 Diabetes (T1D), a breakdown in immune tolerance leads to the activation of CD4+ and CD8+ T cells that specifically recognize these islet pMHC complexes, culminating in the progressive autoimmune destruction of insulin-producing cells [PMID: 31213547]. Because these complexes are the specific triggers for the disease-causing immune response, they represent high-precision therapeutic targets. Current drug development efforts, such as IMCY-0098, utilize modified islet peptides to induce regulatory T cells (Tregs) that can specifically suppress the autoimmune attack without compromising the rest of the immune system [PMID: 33465234].

Other names

Islet peptide-MHC complexBeta-cell antigen-HLA complexIslet autoantigen-MHC complexpMHC

Antigen-specific immunotherapy, Induction of antigen-specific regulatory T cells, Inhibition of autoreactive T-cell activation