Major histocompatibility complex, class II, DQ beta 2 chain (HLA-DQB2)

Major histocompatibility complex, class II, DQ beta 2 chain (HLA-DQB2) is a beta polypeptide that forms a heterodimer with alpha chains (HLA-DQA), anchoring in the membrane of antigen-presenting cells, primarily B lymphocytes, dendritic cells, and macrophages. This molecule plays a central role in the immune system by presenting peptides derived from extracellular proteins for recognition by CD4+ T cells, thus enabling adaptive immune responses. The binding cleft of the complex accommodates peptides typically generated by lysosomal processing of endocytosed antigens. Although polymorphism in HLA-DQB2 exists, and evidence of protein expression is found, this gene is not routinely genotyped for transplantation, nor is its effect on such clinical outcomes established. There is conflicting evidence regarding the protein-coding capacity of HLA-DQB2, and it may be less clinically relevant than its paralog HLA-DQB1, which is a primary marker typed in transplantation and autoimmunity.

Other names

HLA-DQB2HLA-DXBHLA class II histocompatibility antigen, DQ beta 2 chainHLA class II histocompatibility antigen, DX beta chainMHC class II antigen DQB2DV19.1 (major histocompatibility complex, class II, DQ beta 2 (HLA-DXB))DQB2HLA-DQB1 (sometimes mistakenly used, but is a distinct, more clinically significant paralog)

For drugs affecting antigen presentation broadly: inhibition or modulation of MHC class II-mediated peptide presentation (immunosuppressive effect)