Major histocompatibility complex, class II, DO alpha chain (HLA-DOA)

Major histocompatibility complex, class II, DO alpha chain (HLA-DOA) is a non-classical MHC class II alpha chain predominantly expressed in B cells and some dendritic cells[2][4][6]. It forms a heterodimer with HLA-DOB, creating the HLA-DO complex, which localizes in lysosomes of antigen-presenting cells. HLA-DOA, through its complex with HLA-DOB, acts as a regulator of antigen presentation by modulating HLA-DM-mediated peptide exchange on MHC class II molecules. By inhibiting or fine-tuning the peptide exchange activity of HLA-DM, HLA-DOA impacts the repertoire of peptides presented to CD4+ T cells, influencing immune response quality, disease susceptibility, and immune tolerance. Unlike classical HLA class II molecules, HLA-DOA shows minimal sequence diversity at the protein level[4][6][2]. Variations in HLA-DOA expression or function have been associated with susceptibility to autoimmunity and infection, likely through effects on antigen presentation and downstream immune activation[2][6][8].

Other names

HLA-DOAHLA class II histocompatibility antigen DO alpha chainHLA-DNAHLA-DZAHLADZHLA-D0-alphaMHC DN-alphaMHC DZ alphaMHC class II antigen DOAlymphocyte antigenmajor histocompatibility complex class II DN alpha