Dynamic Changes And Immunomodulatory Effects Of Dendritic Cells Of Mice Infected With Schistosoma Japonicum

Obejective To dynamically observe the numbers of splenic and bone marrow dendritic cells(DCs)and their immune function in mice infected with Schistosoma japonicum in days 0,7,28,35 and 63 and it is purposeful to study the immunoregulattion and the immunoregulatory mechanisms of DCs in Sj infection,it is aimed to provide new data to enrich the theory of immunity in sjinfection.Methods The levels of IFN-y,IL-12,IL-10 and IL-4 in serum and the dynamics of the ratios of total DCs and mature DCs in spleens and bone marrow of mice were detected by ELISA method and FCM respectively in different stages of intection;Spleen DCs were sorted at two time points at which the numbers of mouse DCs changes obviously and the whole genome microarray was performed;In vitro,after 50 ?g/ml(SAWA)and soluble egg antigen(SEA)of Sj were co-incubated with DCs respectively,the changes of MHC-II and CD86 on DCs were tested by FCM,the levels of IL-10,IL-12,DC-SIGN,NF-?B P65,MEK1,CD86 and CD83 of DCs were detected by qPCR method;The effects of DCs co-incubated with SAWA or SEA antigens on the proliferation of mouse splenocytes were detected by CCK-8 kit,then the proportions of CD4~+CD25~+Foxp3~+ regulatory T cells in CD4~+CD25~+ T cells were detected in spleenocytes co-cultured with DCs which were stimulated with antigens above and mouse spleen cells via FCM;Finally,anti-IL-10 antibody and anti-TGF-?antibody were used to block DCs respectively,and the proliferation changes of regulatory T cells induced by these DCs were observed.One-way ANOVA method was used to analyze the data between groups,P<0.05 was considered as significant.Results1.The expression levels of IL-12,IL-10 and IL-4 in mouse serum increased in 0-63 days of Sj infection,while the expression of IFN-? decreased;In spleens and bone marrow of infected mice,the percentages of total DCs in CD3e" cells rose first and then reduced,but the ratios of mature DCs in total DCs decreased first and then raised.2.Compared with normal DCs,at different stages of sj infection,spleen DCs of mice not only had specific differentially expressed genes,but also had common differentially expressed genes,the differentially expressed genes were mainly related to cytokines,antigen presentation molecules,costimulatory molecules,receptors and so on.3.The vitro experiments showed SEA could up-regulate the expression levels of MHC-?,CD86,IL-12,IL-10 and down-regulated the expression level of DC-SIGN,and could induce DCs to suppress the proliferation of regulatory T cells in spleen cells;While SAWA could down-regulate the expressions of MHC-?,CD86 and DC-SIGN,but did not affect the expressions of IL-12 and IL-10 obviously and didn't influence DCs to regulate the proliferation of tregs in spleen cells significantly.Both SAWA or SEA could activate the transcriptional factors of DCs including NF-?B P65 and MEK1,when NF-?B inhibitor or MEK1/2 inhibitor was added,the expression levels of CD86 and CD83declined;anti-TGF-? antibody could inhibit the proliferation of spleen tregs by the block of DCs,and the role of IL-10 blocking is not obvious.4.In vivo experiments,it showed that NF-?B and MEK1 were activated in mouse DCs in days 0,28 and 63 after Sj infection,and the expression level of DC-SIGN declined;the ritios of spleen tregs rose in 28-day infected mice,while the proportions of spleen tregs decreased in day 63.Conclusions1.In the process of mouse sj infection,Thl type and Th2 type immune response coexist,due to the combined effect of the two types of cytokines,the immune response shifts from the stronger Thl-type response to the stronger Th2-type response.After infection with Sj,28-day and 63-day DCs showed different immune functions,it is correlated with the numbers and maturation of DCs and it is speculated schistosoma can paly a role in immuoregulation by regulating the numbers and maturation of DCs.2.DCs express specific differentially expressed genes respectively in acute infection or chronic infection,while common differentially expressed genes play a role both in acute and chronic infection,by the analysis of differentially expressed genes,it is speculated schistosoma may modulate immunity by DCs' cytokines,antigen presenting molecules,costimulatory molecules,receptors,apoptosis,etc.3.SAWA can inhibit the maturation of DCs,and SEA can promote the maturity of DCs.It is inferred that different antigens can regulate the maturation of DCs to play an immune regulation role in infection of Sj;SEA can up-regulate or down-regulate the expressions of IL-12,IL-10,DC-SIGN,NF-?B,MEK1/2 of DCs,and the proliferation of CD4~+CD25~+Foxp3~+ tregs to play the role of immune regulation,while SAWA can up-regulate or down-regulate the expressions of DC-SIGN,NF-?B,and the proliferation of CD4~+CD25~+Foxp3~+ tregs to play an immunoregulatory role.