Human leukocyte antigen-G expression on dendritic cells induced by transforming growth factor-beta1 and CD4+ T cells proliferation.

BACKGROUND During antigen capture and processing, mature dendritic cells (DC) express large amounts of peptide-MHC complexes and accessory molecules on their surface. DC are antigen-presenting cells that have an important role in tolerance and autoimmunity. The transforming growth factor-beta1 (TGF-Beta1) cytokine has a regulatory role on the immune and non-immune cells. The aim of this study is to evaluate the effect of TGF-Beta1 on the induction of human leukocyte antigen-G (HLA-G) expression on the DC which is derived from monocyte. METHODS In this study, we evaluated the effect of TGF-Beta1 in induction HLA-G expression on the monocyte-derived DC by flowcytometry and then CD4+ T cell proliferative responses in the presence of DC-treated TGF-Beta1 was studied. RESULTS The results of this study showed that DC bearing HLA-G down-regulated activation of CD4+ T cells and production of IL-6 and IL-17 in comparison with control (P<0.05). CONCLUSION It is concluded that TGF-Beta1 has an important regulatory role in CD4+ T cell proliferation by increasing HLA-G on DC and these cells can probably prevent unexpected immune responses in vivo.