The Roles Of Memory T Follicular Helper Cells And CCR7 In Recurrent Spontaneous Abortion

Aims T follicular helper(Tfh)cells have a central role in the regulation of immune response,Chemokine receptor type 7(CCR7)mediates cell migration and invasion.However,the true physiological characteristics of Tfh cells and CCR7 in recurrent spontaneous abortion(RSA)remain unclear.In this study,we investigated the phenotype and mechanism of Tfh cells and CCR7 in RSA.Methods The expression of Tfh cell subtypes in peripheral blood and decidua of patients with RSA and the women(8-10 weeks of gestation)undergoing induced abortion with nonmedical causes as control group were detected by flow cytometry,and the correlation between the CD4+CXCR5+PD1+ICOS+ memory Tfh cell and B cell was analyzed.The m RNA and protein expression of CCR7 in villous specimens were observed by q RT-PCR and Western Blot.We utilized JEG-3 and JAR cell lines to conduct scratch-wound assay and Transwell assay to examine the effect of CCR7 on trophoblast migration and invasion.Then we used JEG-3 and JAR cells to have analysis further.Small interfering(si)RNA knocking down and adding CCR7 ligand agonists CCL19 were used to change the expression of CCR7.Finally,the expression of the downstream molecules at the level of m RNA and protein was verified by q RTPCR and Western Blot in the villous of RSA and control group.Results 1.The expression of CD4+CXCR5+memory Tfh cells,CD4+CXCR5+PD-1+memory Tfh cells,CD4+CXCR3-CCR6-memory Tfh cells,CD4+CXCR5+PD1+CCR7-memory Tfh cells and CD4+CXCR5+PD-1+ICOS+memory Tfh cells in decidual tissue of RSA patients were significantly higher than those of the normal control group patients.2.RSA patients were divided into positive and negative groups according to the expression of antibodies.Compared with negative RSA group,the expression of CD4+CXCR5+PD1+ICOS+memory Tfh cells in decidua tissue of positive RSA group was significantly increased,which was closely related to the expression of B cells.3.Compared with the the normal control group patients,the levels of CCR7 m RNA and protein in villous of RSA patients decreased significantly.4.In JEG-3 and JAR cells,after knocking down CCR7,the expression of GATA2 and MMP2 was decreased by down-regulating AKT pathway,and the migration and invasion ability of cells was inhibited.On the contrary,CCL19 up-regulated the expression of GATA2 and MMP2 by activating CCR7-AKT pathway to enhance the migration and invasion ability of the cells.5.The expression levels of p-AKT,GATA2 and MMP2 in villous of RSA patients were significantly lower than those of the normal control group patients.Conclusions The abnormal expression of Tfh cell subtypes in decidua may be one of the factors leading to maternal-fetal immune imbalance and recurrent spontaneous abortion.CCR7 regulates GATA2 expression through AKT pathway,thereby affecting MMP2 expression,and ultimately changes the migration and invasion ability of trophoblasts,which may be one of the factors leading to the failure of embryo implantation and recurrent spontaneous abortion.The down-regulation of CCR7 and its downstream molecules in villous of RSA patients provide a new theoretical basis for the pathogenesis of RSA,CCL19 can reverse the miscarriage caused by CCR7 downregulationand which provides a new target for the prevention and treatment of RSA.