Glutathione-S-transferase of Trichinella spiralis regulates maturation and function of dendritic cells.

Abstract

Immunomodulation by molecules from Trichinella spiralis (T. spiralis) has been widely reported. Glutathione-S-transferase (GST) is a major immune-modulator of the family of detoxification enzymes. Dendritic cells (DCs) are an important target for the regulation of the immune response by T. spiralis. In this study, the recombinant GST of T. spiralis (rTs-GST) was expressed and purified. rTs-GST induced low CD40 expression and moderate CD80, CD86 and MHC-II expressions and inhibited the increase of CD40, CD80 and CD86 on DCs induced by LPS. We showed that rTs-GST decreased the LPS-induced elevated level of pro-inflammatory cytokines of DCs and enhanced the level of regulatory cytokines IL-10 and TGF-β. Furthermore, co-culture of DCs and CD4+ T cells demonstrated that rTs-GST-treated DCs suppressed the proliferation of OVA-specific CD4+ T cells and increased the population of regulatory T cells (Tregs). rTs-GST-treated DCs induced a higher level of IL-4, IL-10 and TGF-β, but inhibited the level of IFN-γ. This indicates that rTs-GST-pulsed DCs induce both Th2-type responses and Tregs. These findings contribute to the current understanding of the immunomodulation of Ts-GST on cellular response and immunomodulation of T. spiralis.