Effect and expression of costimulatory molecules on regulating Th1/Th2 polarization on mice infected with Schistosoma japonicum

In order to observe the effect of different costimulatory molecules from murine spleen CD+4T lymphocyte mediating Th1/Th2 polarization,costimulatory molecules were detected in vivoand in vitroat different stages of infection.At week 4,7,12,16,20 after infection,murine spleen CD+4 T lymphocyte were collected from infected and non-infected mice respectively.Meantime,cultured supernatants of SEA induced lymphocytes were also collected 72 hours after the collections.Expression of costimulatory molecules including CD80,CD86,ICOS,CD40,OX40,4-1BB and PD1 on the surface of CD+4 T lymphocytes were analyzed by flow cytometry.At the same time,the cytokines IFN-γ from Th1 and IL-4,IL-5,IL-10 and IL-13 from Th2 in cultured supernatants were detected by ELISA on different stages of infection.Results showed that the expression levels of CD86,ICOS,CD40 and OX40 on CD+4 T lymphocyte of mice infected with Schistosoma japonicumhave increased with infection time,especially the levels of ICOS and CD86 in vivo(P0.01).Furthermore,expression levels of these 2 costimulatory molecules were dramatically up-regulated after spleen CD+4 T lymphocyte was stimulated by SEA for 72 hours in vitro.The expression level of IFN-γwas higher at week 4 after infection and began to decrease at week 7.Whereas,the expression levels of IL-4,IL-5,IL-10 and IL-13 rose sharply at week 7.The peak value of IL-5 appeared at week 12 after infection and the others did at week 16,then they remained at a high level until week 20.These findings show that the expression levels of costimulatory molecules on CD+4 T lymphocyte of mice infected with Schistosoma japonicumwere closely related to immune deviation of Th1/Th2.Moreover,ICOS and CD86 might play a key role in modulating polarization of Th2.