The Inlfuence Of Antigenb In E.g Of Proportion On Treg Cell In The BALB/c Mice’ Spleen Cells And PBMC In Vitro

Objective: To mimick the infection of CE in vitro, spleen cells were separated fromBALB/c mice`and cultured with Echinococcus granulosus fluid; to observe theexpression of Foxp3and Smad4in the spleen of BABL/c mice treated with Echinococcusgranulosus Fluid(EgF); To explore the role of AgB on Treg cell differentiation in immuneevasion due to Echinococcus granulosus infection. Methods: Spleen cells of BABL/cmice were separated by grinding and randomLy divided into experimental group (treatedwith EgF) and the control group, total RNA was extracted at1,3,6and12h, cDNA wassynthesized and the gene expression of Foxp3and Smad4was detected by qRT-PCR (realtime quantitative PCR).25cases, from First Affiliated Hospital of Xinjiang MedicalUniversity, were divided into healthy control group (HC)(10cases), cystic echinococcosis(CE)group(15cases). PBMCs were isolated from peripheral blood by Ficoll densitygradient centrifugation, the proportion of Treg cells was detected by flow cytometry(FCM). In vitro experiments, both normal and patients’ PBMCs were separated andincubated with low(2μg/mL) and high(5μg/mL) concentration of AgB. The proportionof Treg cell was detected by flow cytometry (FCM) at96,120,144h after incubation.Paired T test was used to compare the differences between groups, and Pearson’s rho wasused to analyze the correlation coefficient. Results: qRT-PCR results showed that theexpression of Foxp3was significantly decreased at1h,(9.274±0.451,4.577±0.317); butthe expression of Foxp3was higher at3h and12h {(8.517±0.978,3.297±0.408);(7.406±0.822,2.464±0.328)}. The expression of Smad4was significantly increased(3.862±1.417,1.689±0.221) but decreased at12h (1.690±0.248,3.600±1.081). Itshowed negative correlation between Foxp3and Smad4(P＜0.05). Compared to those inthe HC group(0.800±0.470), the proportion of Treg cell were significantly higher in CEpatients(2.540±1.130,P＝0.026). And it showed a positive correlation with AgB(r＝ 0.739，P＜0.05). In vitro, compared to control,the proportion of Treg cells marklyincreased after incubation120h and144h with low concentration of AgB group(0.800±0.082, t＝2.820;2.200±0.819, t＝2.529，P＜0.01). The proportion of Treg cellsdramatically decreased after incubation120h and144h with high concentration of AgB(0.333±0.115, t＝2.598;0.833±0.551, t＝2.836, P＜0.05). Conclusion: The expressionof Foxp3increased significantly, with an abnormal lower expression of Smad4aftertreatment with EgF, suggest that Treg may be negatively regulated by TGF-β signalingpathway,and thus play an important role in immune evasion during Echinococcusgranulosus infection. Both in vivo and in vitro experiments showed a significantcorrelation between AgB and Treg cells. The differential effect between low and highconcentration of AgB in the in vitro experiments suggests a fine tuning of the generationof Tregs which could be involved in immunosuppressive properties due to E. granulosusinfection.