Major histocompatibility complex class II I-A(s) (I-A^s)

Major histocompatibility complex class II I-A(s) is a mouse MHC class II molecule belonging to the s-haplotype, primarily expressed on professional antigen-presenting cells such as dendritic cells and B cells (UniProt P06339, P04228). It functions as a heterodimeric cell surface receptor that presents exogenous peptide fragments to CD4+ T helper cells, a critical step in the initiation of adaptive immune responses (PubMed: 2561432). This specific MHC variant is highly significant in biomedical research as the primary restriction element for the encephalitogenic proteolipid protein (PLP) 139-151 peptide in SJL mice, which serves as a standard model for Experimental Autoimmune Encephalomyelitis (EAE) and human Multiple Sclerosis (PubMed: 8423345). Therapeutic strategies targeting I-A(s) focus on antigen-specific immunotherapy, utilizing altered peptide ligands or nanoparticle-delivered antigens to induce immunological tolerance rather than activation (PubMed: 23303620). By modulating the interaction between I-A(s) and T cell receptors, these drugs aim to suppress neuroinflammation and promote the expansion of regulatory T cells to treat autoimmune conditions (PubMed: 15123770).

Other names

H-2 class II antigen I-A(s)H2-AsI-AsMouse MHC class II I-A s-haplotypeH2-Aa/H2-Ab1 (s haplotype)

Antigen-specific immune modulation through competitive binding to the MHC groove or induction of immune tolerance via regulatory T cell expansion (PubMed: 23303620).