The immunosuppressive effects of CD4+ CD25+ regulatory T cells on dendritic cells in patients with chronic hepatitis B.

The characteristics and functions of CD4+ CD25+ regulatory T cells (Tregs) have been well defined in murine and human systems. However, the interaction or crosstalk between CD4+ CD25+ Tregs and dendritic cells (DCs) remains controversial. In this study, the effects of chronic hepatitis B (CHB) CD4+ CD25+ Tregs on the maturation and function of monocyte-derived DCs were examined. The results showed that CD4+ CD25+ render the DCs inefficient as antigen-presenting cells (APCs) despite prestimulation with CD40 ligand. This effect was marginally reverted by applying neutralizing antibodies (Abs) to IL-10 and TGF-β. There were an increased IL-10 and TGF-β secretion and reduced expression of costimulatory molecules in DC. Thus, in addition to a direct suppressor effect on CD4+ T cells, CD4+ CD25+ may modulate the immune response through DCs in CHB patients.