Differential expression of HLA-DQA1 and HLA-DQB1 gene alleles was analysed in three different cell populations isolated from peripheral bloodB lymphocytes, monocytes and whole-blood cells. Interallelic differences in mRNA levels were observed: DQA1*03 alleles were among the most expressed in all cell types, whereas DQA1*05 alleles were least expressed in whole blood and monocytes and among the most expressed in B cells.
For DQB1 gene, DQB1*06 group of alleles were the most expressed, and DQB1*02 group the least expressed within all cell populations examined. In comparison with the rest alleles, DQB1*06 and DQB1*05:02 alleles have higher expression in monocytes than in B cells, professional antigen-presenting cells.
Cell type-specific regulation of expression was observed as well, with higher and more balanced expression of alleles in B lymphocytes compared to monocytes.