Immunomodulatory effects of Trichinella spiralis excretory-secretory antigens on macrophages

Helminths and their products can suppress the host immune response and other immunopathologies which may benefit parasite survival. Parasitic nematode Trichinella spiralis (T. spiralis) exert immunomodulatory effect on the host immune response through excretory-secretory (ES) products. However, the immunomodulatory mechanism is not yet completely understood or defined. Macrophages play a key role in modulating the host immune response to helminth parasite infection. Here, we focus on the effect of T. spiralis ES antigens on the immune response by studying the effect of ES antigens on RAW264.7 macrophages in vitro. RAW264.7 macrophages were incubated with ES antigens either alone or in combination with LPS. The cytokine production (TNF-α, IL-10 and IL-12 p70) and the expression of TLR were measured. Moreover, the nuclear translocation of MyD88 and NF-кB was assessed by Western blot analysis. Results indicate that ES products had impacts on reducing the expression of TLRs in LPS-induced macrophages. In addition, ES products inhibited the cytokine production of IL-12 p70 and TNF-α and alone boosted the expression of cytokine IL-10 in RAW264.7 macrophages. In conclusion, our results implied that T. spiralis ES antigens may regulate host immune response at the macrophages level in vitro.