Major histocompatibility complex class II I-A (d haplotype) (I-A^d)

Major histocompatibility complex class II I-A (d haplotype), or I-A^d, is a mouse heterodimeric cell surface receptor crucial for the adaptive immune system, consisting of alpha (H2-Aa) and beta (H2-Ab1) chains (UniProt: P04224, P06340). It functions by presenting exogenous antigenic peptides to the T-cell receptors (TCR) of CD4+ T helper cells, a process fundamental to initiating immune responses (PubMed: 3062506). This specific MHC allele is characteristic of the d haplotype, found in mouse strains like BALB/c, and is widely used in immunological research to map T-cell epitopes, such as the Ovalbumin 323-339 peptide (IEDB). I-A^d plays a central role in mouse models of autoimmunity and infection, where its peptide-binding specificity determines disease susceptibility or resistance (PubMed: 2464525). Therapeutic interventions targeting I-A^d include monoclonal antibodies like MK-D6 and peptide-based vaccines designed to modulate or inhibit T-cell activation (PubChem: SID 472353431). Understanding the structural basis of I-A^d peptide binding is vital for developing immunotherapies that can either enhance or suppress specific immune pathways. The molecule is also a target in studies of graft-versus-host disease and transplant rejection in murine models.

Other names

H2-IAH-2 class II I-AdH2-Aa/H2-Ab1 complexMouse MHC class II I-AdI-Ad

Presents processed exogenous peptides to the T-cell receptor (TCR) of CD4+ T helper cells to initiate adaptive immune responses.