HLA class II histocompatibility antigen, DRB1-4 beta chain (HLA-DRB1*04)

HLA class II histocompatibility antigen, DRB1-4 beta chain is a highly polymorphic protein that forms part of the HLA-DR heterodimer, a cell surface receptor primarily expressed on professional antigen-presenting cells such as B lymphocytes, dendritic cells, and macrophages. Its fundamental biological role is to bind exogenous peptides and present them to CD4+ T-helper cells, thereby triggering the adaptive immune response [UniProt P01911]. The DRB1*04 allele group is of significant clinical interest due to its strong association with the 'shared epitope,' a specific amino acid sequence in the peptide-binding groove that predisposes individuals to severe, erosive rheumatoid arthritis and other autoimmune conditions like type 1 diabetes [PubMed: 24507777]. In therapeutic contexts, this molecule is targeted by immunomodulators like glatiramer acetate, which acts as a decoy peptide to block the MHC II groove and shift the immune profile from a pro-inflammatory Th1 state to a regulatory Th2 state [DrugBank DB00073]. Furthermore, modern drug discovery efforts focus on developing small molecules or peptide mimetics that can selectively inhibit the presentation of arthritogenic self-antigens by this specific HLA variant without causing broad immunosuppression [PubMed: 30108117].

Other names

HLA-DRB1MHC class II antigen DRB1*04DR4Human leukocyte antigen DRB1DR beta-1 chainMajor histocompatibility complex, class II, DR beta 1

Drugs interacting with this target typically function by competitively binding to the peptide-binding groove to prevent the presentation of autoantigenic peptides, or by modulating the downstream T-cell signaling and activation pathways to induce immune tolerance.