Ultraviolet-?attenuated?cercariae?of?Schistosoma?japonicum?fail?to?effectively?induce?a?Th1?response?in?spite?of?up-regulating?expression?of?cytotoxicity-related?genes?in?C57BL/6?mice

Objective:?To?better?understand?the?reason?that?Schistosoma?japonicum?(S.?japonicum)?ultraviolet?(UV)-radiated?cercariae?could?not?induce?high?level?of?protection?in?C57BL/6?mice.?Methods:?Microarray?technology?was?performed?to?investigate?the?gene?transcription?profile?in?skin?draining?lymph?nodes?(sdLNs)?at?1?w?after?ex-posure?to?attenuated?cercariae?(AC)?or?normal?cercariae?(NC)?of?S.?japonicum?in?C57BL/6?mice.?The?expressions?of?some?representative?genes?were?further?confirmed?by?real-time?PCR.?Subsequently,?the?expressions?of?Th1/Th2?cytokine?genes,?cytotoxicity-related?genes,?as?well?as?co-stimulator?genes?in?spleens?from?AC-vaccinated?and?NC-infected?mice?were?analyzed?by?real-time?PCR?at?w?3?and?6?post-exposure.?Results:?The?gene?expressions?of?Th1?cytokines,?including?interferon-γ?(IFN-γ),?interleukin?(IL)-12?and?tumor?necrosis?factor-α?(TNF-α)?in?the?sdLNs?were?significantly?lower?in?AC-vaccinated?mice?than?in?NC-infected?mice.?Furthermore,?the?gene?expressions?of?Th1-?and?Th2-?cytokines,?including?IFN-γ,?IL-12,?TNF-α,?IL-4?and?IL-10,?in?the?spleens?from?AC-vaccinated?mice?showed?little?changes?at?w?3?and?6?post-vaccination.?In?addition,?cytotoxicity-related?molecules?including?granzyme?A,?granzyme?B,?granzyme?K,?perforin?1?and?Fas?L?were?up-regulated?from?the?early?stage?of?vaccina-tion,?and?peaked?at?the?3rd?w?after?vaccination?with?UV-AC.?Conclusion:?UV-AC?of?S.?japonicum?could?not?ef-fectively?induce?a?Th1?response?in?C57BL/6?mice,?which?may?be?an?explanation?for?the?low?protection?against?parasite?challenge,?and?the?role?played?by?up-regulated?expression?of?cytotoxicity-related?genes?in?mice?needs?to?be?further?investigated.