Chaeoglobosin Fex inhibits poly(I:C)-induced activation of bone marrow-derived dendritic cells.

Dendritic cells (DCs) are implicated in the induction of autoimmune diseases and exist in lesions associated with several autoimmune inflammatory diseases. Chaeoglobosin Fex (Cha Fex), a cytochalasan-based alkaloid, was isolated from marine-derived endophytic fungus Chaetomium globosum QEN-14. In the present study, we evaluated the effect of Cha Fex on poly(I:C)-induced bone marrow-derived DCs. The results showed that Cha Fex attenuated the production of IFN-β both at the mRNA and protein level in poly(I:C)-induced DCs. Cha Fex markedly inhibited the maturation and function of the DCs with a reduced capacity to uptake antigens and low level of expression of costimulatory molecules. Moreover, Cha Fex abrogated the ability of poly(I:C)-induced DCs to promotion of T cell proliferation, Furthermore, Cha Fex inhibited the phosphorylation of IκB-α and IRF-3 in poly(I:C)-induced DCs. Cha Fex also reduced the phosphorylation of p38 and JNK, without affecting ERK1/2. These data demonstrate that that Cha Fex can exhibit an immunosuppressive effect on mouse bone marrow-derived DCs (BMDCs) via TLR3 signaling, which suggests potential application of Cha Fex in the treatment of autoimmune inflammatory diseases.