Schistosoma Japonicum Protein Peroxiredoxin-Ⅰ: Expression, Purification And Induction Of Th2 Responses

Background:Schistosomiasis, an infectious parasitic disease and also called bilharziasis, can be divided into intestinal schistosomiasis and urogenital schistosomiasis. According to whether an emergency condition of Schistosomiasis is existed and the distribution location of schistosome eggs in tissues, clinical manifestation vary in several types, including intolerance of cold, fever, emaciation, lymphadenectasis, hepatosplenomegaly, etc. The schistosomiasis contains various species including three human-infectious types, bilharzia haematobia, schistosoma mansoni as well as schistosoma japonicum. The major epidemic in our country is schistosoma japonicum. Th1 response polarization is appeared in the early infectious phase of schistosomiasis. Schistosome worms produce eggs after 6 weeks since first infected with schistosome cercaria, meanwhile Th2 response polarization is appeared in the host and peaks 8-9 weeks later, when levels of Th1 and Th2 cytokines are declined. After 12 weeks, the schistosoma miracidium in eggs died and the SEA will also be reduced and disappeared. Local fibrosis will be formed along with The volume decrease of granuloma. According to the theory of Th1/Th2 immune deviation, we can realize that the Th2 response induced by schistosome infection can suppress autoimmune diseases mediated by Th1. The Th1 response polarization will turn into Th2 response polarization in later period of schistosome infection and schistosomiasis will become chronic, implying Th2 response can suppress Th1 response, which is of great value to autoimmune diseases mediated by Th1. Accumulating researches showed that parasitic infection mainly with Th2 responses can temper numerous autoimmune diseases mediated by Th1. The antioxidant, Prx, was found, based on the murine model infected with Fasciola hepatica and schistosoma mansoni. Electron in glutathione and thioredoxin can be transferred into H2O2 by Prx. Therefore, Prx plays an important role in dissociation of H2O2, implying that Prx is a significant cytokine in detoxication and also a potential therapeutic targets. Objective:By the expression,purification,infection in mice and stimulates cells of the SjPrxⅠ,to study the related mechanism of the SjPrxⅠ in the induction of Th2 immune response in vivo and in vitro,thus further reveal the molecular mechanism of the insect body immune escape,host immune tolerance,immune deviation,etc Methods:At first, we find the SjPrxⅠ sequence in Gen Bank and design primers for PCR amplification. We successfully built the prokaryotic expression plasmid. After the identification of proteins with western blotting, we get a large number of expressing protein. We use the high purity SjPrxⅠ protein and LPS to inject mice. Cytokines of spleen cells were investigated by using ELISA. For SjPrxⅠprotein induced Th2 immune mechanism to conduct a comprehensive analysis. Results:(1) We obtain The 0.8mg¤ml purified SjPrxⅠprotein.(3) The protein was injected into mice from day zero(First day) and subsequently at Three days intervals for six days(A total of 3 times). Conclusions:SjPrxⅠstimulate mouse spleen cell suspension changes tend to Th2, however for the mice injected by LPS and protein at the same time, still bias Th1 cytokine changes.