In Vitro Transplantation Of Schistosoma Japonicum Larvae And Immune Response Of Mice Which Was Infected With Schistosoma Before And After Treatment With Praziquantel

This paper aimed to explore a new method of in vitro cultivation of Schistosoma japonicum larvae,transdermal delivery efficacy of praziquantel,the immune response of the host of Schistosoma japonicum and after treatment with praziquantel. Not only provided a new method of in vitro manipulation of Schistosoma japonicum larvae, but also provided a more convenience therapeutic approach for the treatment of schistosomiasis, explored the relationship between praziquantel and inflammation, in order to provide some theoretical basis for studying the mechanism of praziquantel.Several BALB / c mouse`s livers were removed aseptic which were infected by Schistosoma japonicum after 42 days, homogenated by tissue homogenate instrument, incubated miracidium with constant temperature, the miracidium co-cultivated with Spodoptera frugiperda ovary cells (sf9 cells) in constant temperature Cell incubator. The pictures of miracidia were recorded after co-cultivation for 1 h, 12 h, 24 h and 3 d. The co-cultivated for 3 days mother sporocysts injected in the head and foot of negative snails, after 80 days, observed whether cercariae could be obtained or not. The experiment repeated three times, the survival rates of snails in three experiments were 24.72%, 28.23 % and 57.89% respectively while the positive rates of cercariae were 4.55%, 8.57% and 14.29% respectively. The related gene characteristics of cercariae were identified by histochemical examination and PCR method.BALB / c mice were infected with Schistosoma japonicum cercariae 40±2.After 35 days, mice were treated with different concentration of PZQ transdermal agent, 800mg/kg, 480mg/kg, 240mg/kg individually, and treated with different times of PZQ transdermal agent, 240mg / kg once and three times individually.percutaneous treatment of abdominal After one week, mice were dissected, statistical of worm reduction rate, egg reduction rate and hatch of egg reduction rate and so on. By treating with 800mg/kg of PZQ transdermal agent, worm reduction rate up to 50%, egg reduction rate up to 70%, and each group of female reduction rate was 100%, miracidia reduction rate up to 50%. Meanwhile, BALB/c mice were experimental animal models. BALB / c mice were infected with cercariae 30±2. After 28 days and 35 days of infection, some of mice were treated with praziquantel with quantitative (900mg/kg) by oral approach. After one week or two weeks of treatment, the ratio of CD4+, CD8+ lymphocyte subsets, and the expression levels of cytokines IL-4, IFN -γ, IL-17 were detected by flow cytometry in mice.Animal experiments showed that the cercariae released from artificial cultivation of positive snails were infectiuous and had the same gene characteristics of Schistosoma japonicum. Sf9 cells could be feeder cells for in vitro-coltivation of miracidia and positive snails could be obtained by in vitro micro-injection of cercariae thus to provide a new approach for in vitro operation of Schistosoma japonicum larvae. The effect on Schistosoma was depended on dose and times of praziquantel transdermal agent, the better treatment effect was more times and low dose, each group reached the effective of separating the male and female worms. After praziquantel treatment, a series of inflammatory reactions were caused by the death of worm, induced a mixed immune response with Th1/Th2 type, which mainly was Th2 type immune response. Th17 cells also played an important role in the inflammatory response. Praziquantel could inhibit the inflammatory response.