Study the role of regulatory T cells in the mechanism of immune tolerance in chronic HBV infection

Objective To investigate the role of pDCs and CD4+ CD25+ Treg cells in the mechanism of immune-tolerant chronic HBV infection. Methods 12 patients with immune-tolerant chronic HBV infection and 6 patients in recovery period of acute hepatitis B were examined. Frequencies and expression of CD80/CD83/CD86 of pDCs and Frequencies of Treg cells in peripheral blood were detected by flow cytometry. Plasma cytokines IFN-α2, IFN- gamma, TGF- alpha, FLT-3L, IL-10, IL-6, IL-17A were measured by Luminex. Results Frequencies and expression of CD80/CD83/CD86 of pDCs in immune tolerance group were similar to the resolved acute HBV infection group, but the level of plasma IFN- alpha 2 was significantly higher than that in acute hepatitis B recovery group.Frequencies of Treg cells and cytokines IL-10 in immune-tolerant group was also significantly higher than that in acute hepatitis B recovery group. Conclusion The number and function of pDCs in chronic HBV infection immune tolerance group was normal, while Treg cells and IL-10 with a significant increase. Key words: Hepatitis B; Dendritic cells; T-Lympha cytes; Interloukin-10; Interferon-alpha