MHC class II antigen presentation of proinsulin-derived peptides (MHCII-proinsulin pathway)

The MHC class II antigen presentation pathway for proinsulin-derived peptides is a central mechanism in the development of Type 1 Diabetes (T1D). In this pathway, proinsulin (specifically Proinsulin II in murine models, encoded by the Ins2 gene) is processed by antigen-presenting cells into immunodominant peptides, such as the B:9-23 fragment (Nakayama et al., 2005, Nature). These peptides are loaded onto MHC class II molecules, such as HLA-DQ8 or HLA-DR4 in humans (or I-Ag7 in mice), and presented to CD4+ T cells (Michels et al., 2011, Journal of Autoimmunity). This interaction triggers the activation and expansion of autoreactive T cells that target and destroy pancreatic beta cells. Therapeutic interventions targeting this pathway aim to induce immune tolerance or block the specific TCR-MHC-peptide interaction to prevent or delay the onset of T1D (Vaidya et al., 2022, Frontiers in Immunology). Current research focuses on peptide-based vaccines, such as C19-A3, and DNA vaccines like NNC0361-0027 to reprogram the immune system's response to these self-antigens. By specifically targeting the presentation of proinsulin peptides, these therapies seek to preserve beta-cell function without causing broad immunosuppression.

Other names

Proinsulin peptide-MHC II complexHLA-DQ8-proinsulin peptide complexInsulin B:9-23 presentationMHCII-Ins2 pathwayMHC class II antigen presentation pathway for proinsulin II-derived peptides

Induction of antigen-specific immune tolerance through the modulation of T-cell receptor (TCR) recognition of the MHC-peptide complex.