Antigen?presenting?cells?may?be?able?to?distinguish?between?normal?and?radiated?Schistosoma?japonicum?cercaria:?an?in?vitro?observation

Objective:?To?observe?the?discrepancies?of?responses?induced?by?Schistosoma?japonicum?(S.?japonicum)?nor-mal?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?(40?μg/mL)?or?UVACA?(40?μg/mL)?in?the?presence?or?absence?of?recombinant?mouse?interferon?gamma?(rmIFN-γ;?4?ng/mL)?for?48?h.?Cell?surface?stain-ing?and?flow?cytometry?were?used?to?assess?the?major?histocompatibility?complex?(MHC)Ⅱ?expression,?and?data?were?expressed?as?mean?fluorescence?intensities?(MFI).?Interleukin?(IL)?-10,?IL-6?and?prostaglandin?E2?(PGE2)?in?cell?culture?supernatant?were?evaluated?by?commercial?enzyme-linked?immunosorbent?assays.?Results:?NCA?significantly?suppressed?IFN-γ-induced?MHCⅡ?expression?on?RAW?264.7?cells.?In?the?presence?of?IFN-γ,?NCA?significantly?promoted?IL-6,?IL-10?and?PGE2?secretion?from?RAW?264.7?cells.?In?the?presence?of?IFN-γ,?UVACA?significantly?promoted?IL-10?but?not?IL-6?and?PGE2?secretion?from?RAW?264.7?cells?and?showed?no?effect?on?IFN-γ-induced?MHC?Ⅱ?expression.?Compared?with?UVACA,?NCA?significantly?suppressed?IFN-γ-induced?MHC?Ⅱ?expression?and?significantly?promoted?IL-6,?PGE2?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?Ⅱ?expression?and?significantly?promote?IL-6,?IL-10?and?PGE2?secretion?from?RAW?264.7?cells?compared?with?UVACA.