The Study On Regulatory B Cells In Mice Infected With Echinoccus Granulosus

Objective:To observe the phenotype changes and expressions of regulatory B cells and its related molecules in BALB/c mice infected with Echinococcus granulosus and relationship between them and infection focus,in order to reaserch the relationship between regulatory B cells and its related molecules in Echinococcus granulosus infection and to reaserch the function of regulatory B cells to Echinococcus granulosus infection.Methods:96 female BALB/c mice were randomly divided into infection group and control group.The infection group was injected protoscoles of Echinococcus granulosus by intraperitoneally vena portae.The control group was received corresponding volume of physiology saline.And then eight mice in infection group and eight mice in control group were sacrificed on 2 days,8 days,30 days,90 days,180 days and 270 days post inoculate.Flow cytometry was used to analyze the rate of CD1d^hiCD5⁺CD19^hii B cells and CD1d^hiCD5⁺CD19^hiIL-10⁺B cells in spleen;The expressions of IL-10 and TGF-β1 mRNA were analyzed by qRT-PCR;The level of liver pathological alteration was observed by HE staining;The protein expression and location of IL-10 and TGF-β1 were analyzed by immuhistochemistry respectively;we measured the serum levels of IL-10 and TGF-β1 in each group by ELISA.Results:1)Flow cytometry results showed that compared with control,the ratio of CD1d^hiCD5⁺CD19^hii cells and CD1d^hiCD5⁺CD19^hii IL-10⁺cells in spleen infected mice was significantly higher from 90 days to 270 days after infection（p<0.05）.2)qRT-PCR demonstrated that in the early stages of the infection,the expressions of IL-10 and TGF-β1 mRNA were not obviously difference,but significantly increased in the middle and late stages of the infection（p<0.05）.3)HE staining reveals that the erosion of livers was getting worse during the infection.Liver cells emerge into edema,bile duct hyperplasia,liver structural damage and can not distinguish lobular,vacuolar degeneration of liver cells infections with advanced lymphocytic infiltration.4)IL-10 and TGF-β1 only observed in hepatic sinusoid,hyalomitome,fiber organization,focus germinal layer surrounding in infected group.Compared with control,during early stages,the expressions of IL-10 and TGF-β1 both remain low or non,but they were both significantly increased in the late stages of infection（p<0.05）.5)CBA and ELISA results showed that compared with control,during early stages,the serum of IL-10and TGF-β1 both remain low or non.In the late stages of the infection,the levels of IL-10and TGF-β1 in serum both significantly increased（p<0.05）.Conclusion:CD1d^hiCD5⁺CD19^hiregulatory B cells may be the one reason of leading Echinococcus granulosus infection immune suppress.In the early stages of Echinococcus granulosus infection,CD1d^hiCD5⁺CD19^hii regulatory B cells and CD1d^hiCD5⁺CD19^hiIL-10⁺regulatory B cells in mice spleen were not obviously difference.In the middle and late stages,but significantly increased in the middle and late stages of the infection.Regulatory B cells in mice spleen participate in Echinococcus granulosus infection development.In the infection,regulatory B cells by secreting IL-10 and TGF-βplay inhibit function.Furthermore,the high expressions of regulatory B cells related molecules IL-10 and TGF-β1 are disadvantage of host clearancing livers Echinococcus granulosus infection and promote Echinococcus granulosus developing.