The Role Of Th17Cell In Productive Immunity Of Host Induced By NP30of Schistosoma Japonica

The monoclonal anti-idiotypic antibody NP30of Schistosoma japonica, belonging to anti-idiotypic antibody of gut associated antigen (GAA) internal image with a function of imitating antigen, could be used as immunodiagnosis and vaccine study of schistosomiasis instead of insect source antigen. NP30could be applied for active immunity on Kunming mice, C57BL/6, BALB/c mice and goats, inducing the protection of50.46%、42.05%、39.53%�'�42.86%when facing the challenge infection of cercaria.Thl7cell is a newly-discovered CD/T-cell subset. Research has illustrated that the main expression product IL-17of Th17cell plays an important role in infection immunity of schistosomiasis. At the early stage of host attack conducted by schistosoma mansoni, Th17cell is activated and secrete large numbers of IL-17which could stimulate to secrete inflammation related cell factors of different kinds; when in serious infection with a lack of targeted cure or low immunity of hosts, the load of schistosomiasis increases, inducing more Th17cells to differentiate, thus immunopathology of hosts being seriously changed; at the later stage, Th17cells and the secreted IL-17also participated in the formulation of egg granuloma in liver, which implies that immunopathology damage led by eggs, to a large degree, is induced by Th17cells. Therefore, the assumption is formed that Th17cell also makes vital contribution to immunity of host infected by schistosoma japonica.PurposeDue to the close relation between IL-17and schistosomiasis, supposal could be conducted that productive immunity of host induced by NP30is related to the IL-17secreted by Th17cells, and therefore, study purpose is determined:1. To illustrate the relationship between Th17and productive immunity of host induced by the monoclonal anti-idiotypic antibodyNP30of schistosoma japonica.2. To provide theoretical basis for improving immunity protection function of the monoclonal anti-idiotypic antibody NP30of schistosoma japonica.Methodology1. In vitro culture and identification of the bone marrow-derived dendritic cells (DCs) of mice.By GM-CSF(10ng/ml) and IL-4(5ng/ml) inducement, the normal BALB/c mice were taken to cultivate DCs, which should be observed under inverted micro-scopes. Flow cytometry was used to detect the surface markers.2. The variation of IFN-γ、IL-4、IL-6、IL-17、IL-23and TGF-βstimulated by NP30with in vitro detectionSpleen lymphocytes of normal BALB/c mice were taken to separate and select the CD4+T-cell. NP30, SEA and DCs+CD4+T-cell of different concentration were co-cultivated with a reference group of PBS. After72h cultivation, supernatant of cell was collected from which level of secreted cell factors were detected for each groups, preliminary screening NP30related cell factors.3. Detection of level of relevant cell factors of infected bone marrow-derived DCs and CD4+-cells after NP30immunityThirty BALB/c mice of6-year-old were taken to be separated into three groups with ten ones each:NP30group (after3times NP30immunity, infected by40±2cercaria of schistosoma japonica); SEA group (after3times SEA immunity, infected by40±2cercaria of schistosoma japonica); reference group (after injection of PBS, infected by40±2cercaria of schistosoma japonica). bone marrow-derived DCs and spleen cells should be taken out respectively after5w,8w and incubated by different antigens to detect the change of cell factors in IFN-y, IL-4, IL-6, IL-17, IL-23and TGF-p.Results1. The high purity DCs (87.37%) used for experiments has been induced and cultivated from bone-marrow cells of mice; NP30stimulate more high expression co-stimulate molecular CD40and CD86than the control of PBS;2. In vitro experiments suggest that NP30could stimulate DCs+CD4+T-cell to secrete high level TGF-β, but the level of IL-6and IL-23is obviously lower than that of SEA group; NP30could stimulate DCs+CD4+T-cell to secrete IL-17and Th17cells related cell differentiation factors is higher than PBS group but lower than SEA group.3. In vivo experiments suggest that DCs of NP30immunity group secrete IL-6and TGF-β is lower than SEA immunity group when fected5w; NP30could stimulate Spleen sources of CD4+T-cell to secrete TGF-β higher than SEA immunity group, but the level of IL-17is lower than SEA immunity group; CD4+T-cell of NP30immunity group secrete IL-17is obviously lower than other group when infected8w.Conclusion1. Th17cell plays an important role in schistosoma japonica infection2. Implies that inducement of host’s protective immunity by NP30is related to the regulation of Th17reaction。3. It through probably the following two mechanisms:①By changing the level or type of the relative factors of Th17cell secreted by DCs;②By improving Treg cells to differentiate and regulate polarization of Th17.