The effects of miR-10a on the immune function of splenic CD4+CD25+ Treg cells in septic mice / 中华急诊医学杂志

ABSTRACT

Objective To investigate the role of miR-10a in CD4+CD25+Treg-mediated immunosuppression during sepsis and its potential role in immunotherapy for sepsis.Methods Sepsis mouse model was established by cecal ligation and puncture(CLP).Balb/c mice of clean grade were sacrificed 1,3,5,and 7 days after operation.Blood as well as spleen samples were harvested at given intervals.The splenic CD4+CD25+Treg cells and CD4+T cells were isolated by MACS microbeads.Cells were cultured,and phenotypes were analyzed by flow cytometry.The miR-10a expressed in Treg cells were detected by Real-time PCR.After administration of LV-mmu-miR-10a-5p-inhibition,the immunosuppressive function have been detected.Statistical analyses were performed using one-way analysis of variance (SPSS 19.0,Chicago,USA) test followed by Dunnett-t test to compare among three or more groups or by Student's t-test to compare between two groups.Results The percentages of splenic Tregs (CD4+CD25+/CD4+T) was (7.34±1.2)％ in normal group,and the increase in percentage of Tregs in spleen has been observed in septic mice (P＜0.05).The mean fluorescence intensity (MFI) of Foxp3+Treg was increased in septic mice compared with sham group (P＜0.05).The expression of miR-10a was significantly elevated on CLP 1-7 day (P＜0.05).After down-regulation of miR-10a in septic mice,the percentages of Tregs (CD4+CD25+/CD4+T) was significantly increased in septic mice (P＜0.05),the MFI of Foxp3+Treg was increased in septic mice compared with control group (P＜0.05).The CD4+T cell proliferative activity in CLP-induced mice was significantly suppressed on CLP 3 day compared with sham group (P＜0.05).After down-regulation of miR-10a in septic mice,the CD4+T cell proliferative activity was significantly suppressed compared with control group (P＜0.05).Conclusions Treg plays a critical role in immunosuppression in septic mice.Inhibition of miR-10a in vivo could enhence immunesuppression of CD4+CD25+Treg.Therefore miR-10a may participate in the regulation of CD4+CD25+Treg immunosuppression in sepsis and become the target for immunotherapy.