Dendritic Cells Bearing HLA-G Inhibit T-Cell Activation in Type 1 Diabetes

HLA-G is normally expressed on human trophoblast cells. It is a non-classical MHC molecule class I b. The role of HLA-G in diabetic type 1 is not known. We investigated the role of IFN-β in induction HLA-G expression on the monocyte derived dendritic cells (DC) in diabetes type 1. Treatment of dendritic cell with IFN-β in vitro from diabetic patients (n=20) and normal subjects (n=20) resulted to the production and expression of HLA-G on these cells from both groups. However, comparison of DC from the diabetic patients with DC from the controls revealed lower levels of HLA-G molecules in DC from diabetic patients. Using mixed lymphocyte reaction (MLR), it was found that DC expressing HLA-G mediated the inhibition of autologous T cell activation. It is concluded that IFN-β can increase HLA-G in DC from diabetic patients; subsequently it may prevent the immune regularly pathway in the diabetic pathogenesis.