Human leukocyte antigen DQ2 and DQ8 (HLA-DQ2/8)

Human leukocyte antigen DQ2 and DQ8 (HLA-DQ2/8) are major histocompatibility complex (MHC) class II heterodimeric surface receptors primarily expressed on professional antigen-presenting cells such as dendritic cells, macrophages, and B cells. These molecules play a critical role in the adaptive immune system by binding exogenous peptides and presenting them to CD4+ T cells to initiate immune responses. In celiac disease, HLA-DQ2 and HLA-DQ8 are the central genetic determinants, as their specific binding pockets have a high affinity for deamidated gluten peptides, triggering a T-cell mediated inflammatory cascade that leads to intestinal mucosal damage. Beyond celiac disease, HLA-DQ8 is a significant risk factor for Type 1 Diabetes, where it presents autoantigens like insulin to autoreactive T cells. Therapeutic interventions targeting HLA-DQ2/8 aim to disrupt this presentation axis through various modalities, including monoclonal antibodies that neutralize the peptide-HLA complex, small molecules that block the binding groove, and tolerogenic platforms designed to reprogram the immune system's response to the presented antigens. These approaches represent a major frontier in developing non-dietary treatments for celiac disease and preventing the progression of other HLA-associated autoimmune conditions.

Other names

HLA-DQ2HLA-DQ8MHC class II DQMajor histocompatibility complex, class II, DQHLA-DQ2.5HLA-DQ8.1

Therapeutic agents targeting HLA-DQ2/8 function through several distinct mechanisms: neutralizing antibodies (e.g., DONQ52) bind to the peptide-HLA complex to prevent T-cell recognition; small molecules (e.g., methyldopa) competitively inhibit the peptide-binding groove to block antigen loading; and tolerogenic platforms (e.g., TAK-101, KAN-101) utilize the HLA presentation axis to induce antigen-specific immune tolerance by presenting peptides in a non-inflammatory context.