Antigen presenting cells may be able to distinguish between normal and radiatedSchistosoma japonicum cercaria:anin vitro observation

摘要： Objective:To observe the discrepancies of responses induced by Schistosoma japonicum(S.japonicum)normal cercaria antigen(NCA)and ultraviolet(UV)-radiation-attenuated cercaria antigen(UVACA)in an in vitro system.Methods:S.japonicum cercariae were collected and UVACA and NCA were prepared.Mouse macro- phage model cells(RAW 264.7)were treated with medium,NCA(40μg/mL)or UVACA(40μg/mL)in the presence or absence of recombinant mouse interferon gamma(rmIFN-γ;4 ng/mL)for 48 h.Cell surface staining and flow cytometry were used to assess the major histocompatibility complex(MHC)Ⅱexpression,and data were expressed as mean fluorescence intensities(MFI).Interleukin(IL)-10,IL-6 and prostaglandin E2(PGE 2 ) in cell culture supernatant were evaluated by commercial enzyme-linked immunosorbent assays.Results:NCA significantly suppressed IFN-γ-induced MHCⅡexpression on RAW 264.7 cells.In the presence of IFN-γ,NCA significantly promoted IL-6,IL-10 and PGE 2 secretion from RAW 264.7 cells.In the presence of IFN-γ,UVACA significantly promoted IL-10 but not IL-6 and PGE 2 secretion from RAW 264.7 cells and showed no effect on IFN-γ-induced MHCⅡexpression.Compared with UVACA,NCA significantly suppressed IFN-γ-induced MHC Ⅱexpression and significantly promoted IL-6,PGE 2 and IL-10 secretion from RAW 264.7 cells.Conclusion: RAW 264.7 cells respond differently to NCA and UVACA.NCA can significantly suppress IFN-γ-induced MHC Ⅱexpression and significantly promote IL-6,IL-10 and PGE 2 secretion from RAW 264.7 cells compared with UVACA. （共7頁）