HLA class II histocompatibility antigen, DQ(6) alpha chain is a protein that in humans is encoded by the HLA-DQA2 gene. Also known as HLA-DXA or DAAP-381D23.2, it is part of the human leukocyte antigen system. [5]
The protein encoded by this gene is expressed, but unlike HLA-DQA1, it is apparently unable to heterodimerize with HLA class II beta chain paralogues. [6] The low level of HLA-DQA2 expression is apparently due to impaired transcription factor binding to the HLA-DQA2 gene promoter. [7]
Transcriptome analysis of blood immune cells and nasopharyngeal cells before elaborate infection of study participants revealed that heightened expression of HLA-DQA2 correlates to a significantly lower chance of COVID-19 successfully infecting the individual. [8]