Major histocompatibility complex, class II, DQ alpha 2 chain (HLA-DQA2)

Major histocompatibility complex, class II, DQ alpha 2 chain (HLA-DQA2) is a protein encoded by the *HLA-DQA2* gene, part of the human leukocyte antigen (HLA) system. This molecule is predominantly expressed on antigen-presenting cells (APCs) and forms part of the MHC class II complex, vital for presentation of exogenous peptide antigens to CD4+ T-cells, thereby modulating adaptive immunity and influencing susceptibility to autoimmune, inflammatory, and infectious diseases. Unlike the closely related HLA-DQA1, HLA-DQA2 exhibits comparatively low expression due to promoter-deficient transcription, and may not efficiently heterodimerize with the usual HLA-DQB chain. Variants at this locus have been linked to protection from narcolepsy, modulation of asthma risk, and lower susceptibility to COVID-19.

Other names

HLA class II histocompatibility antigen, DQ alpha 2 chainHLA-DXADX alpha chainHLA class II histocompatibility antigen, DQ(6) alpha chainDC-alphaHLA-DCAHLADQA2

For general MHC class II targeting: Blocking or modulating antigen presentation; Altering T-cell activation or tolerance