Toll-like receptor 2 promotes T helper 17 cells response in hepatitis B virus infection.

PURPOSE: Innate and adaptive immune responses play vital roles in initiating and maintaining the immunological homeostasis in both physiological and pathological processes. However, the expression and function of the important cells and molecules as well as their interaction in hepatitis B virus (HBV) infection has not been well elucidated. The aim of the current study was to determine the pattern of Toll-like receptor 2 (TLR2) in T cells in HBV infection and the function of TLR2 in regulation of T helper 17 (Th17) cells response.

METHODS

Thirty-four patients with HBV infection (ten acute and twenty-four chronic) were enrolled. HBV-specific and -nonspecific Th17 cells and TLR2 expression in T cells were analyzed by flow cytometry. The function of TLR2 agonist for induction of IL-17 production was also determined.

RESULTS

HBV-specific and -nonspecific IL-17 secretion in CD4(+) (Th17 cells) and CD8(+) T cells was significantly elevated in chronic HBV infection. Viral-specific TLR2 expression in CD4(+), CD8(+), and Th17 cells was also remarkably increased in patients with chronic hepatitis B. Moreover, TLR2 agonist Pam3Csk4 directly activated Th17 cells response without antigen stimulation in HBV infection.

CONCLUSION

TLR2, which traditionally associated with innate immunity, might also promote Th17 cells response in HBV infection. The function of TLRs in regulation of adaptive immune response in HBV infection, which might play an important role in persistent HBV infection.