PBMCs miR-29c在肺炎支原体肺炎患儿中的表达及与Th17/Treg失衡的关系

Expression of PBMCs miR-29c in children with Mycoplasma pneumoniae pneumonia and its relationship with Th17/Treg imbalance

目的探究外周血单个核细胞(PBMCs)miR-29c在肺炎支原体肺炎(MPP)患儿中的表达及Th17/Treg失衡的关系。方法2019年8月至2021年4月在我院儿科共纳入108例MPP患儿,包括58例大环内酯类抗菌药物敏感的MPP患儿(MSMP组)和50例难治性MPP(RMPP组)患儿。另外选择50例健康体检儿童作为对照组。采集入院时的血液样本。采用流式细胞术检测外周血Th17、Treg细胞百分比,酶联免疫吸附法测定血清白细胞介素17(IL-17)和转化生长因子β1(TGF-β1)水平。实时荧光定量PCR法检测PBMCs miR-29c表达。结果与对照组相比,MSMP组和RMPP组CD4^(+)Th17细胞百分比、CD4^(+)Treg细胞百分比、Th17/Treg比值以及血清IL-17水平升高,同时PBMCs miR-29c相对表达量降低(P<0.05);而且RMPP组患儿CD4^(+)Th17细胞百分比、CD4^(+)Treg细胞百分比、Th17/Treg比值以及血清IL-17水平高于MSMP组,PBMCs miR-29c相对表达量低于MSMP组(P<0.05)。对于所有MPP患儿,无论是MSMP组还是RMPP组,PBMCs miR-29c相对表达量与循环Th17细胞%、Th17/Treg比值、血清IL-17水平均呈负相关性(P<0.05)。经受试者工作特征曲线分析,PBMCs miR-29c预测RMPP的AUC为0.932(95%CI:0.888~0.976),最佳临界值为0.67。经多因素Logistic回归分析,PBMCs miR-29c是影响RMPP进展的独立影响因子,PBMCs miR-29c≥0.67患儿进展为RMPP风险较低(P<0.05)。结论MPP患儿中PBMCs miR-29c低表达可诱导Th17细胞分化,进而促进Th17/Treg失衡,这可能是导致RMPP进展的重要机制之一。

Objective To investigate the relationship between the expression of miR-29c in peripheral blood mononuclear cells(PBMCs)and the imbalance of Th17/Treg in children with Mycoplasma pneumoniae pneumonia(MPP).Methods From August 2019 to April 2021,a total of 108 MPP pediatric patients were enrolled in our department,including 58 Macrolide sensitive MPP patients(MSMP group)and 50 refractory MPP patients(RMPP group).In addition,50 healthy children were selected as the control group.The blood samples at administration were obtained and used to detect the percentage of Th17 and Treg cells in peripheral blood by Flow cytometry,and the levels of serum Interleukin 17(IL-17)and transforming growth factor beta1(TGF-β1)were determined by enzyme-linked immunosorbent assay.miR-29c expression in PBMCs was detected by real-time fluorescent quantitative PCR.Results Compared with the control group,the percentage of CD4^(+)Th17 cells,the percentage of CD4^(+)Treg cells,the ratio of Th17/Treg and the level of serum IL-17 were increased in MSMP group and RMPP group,while the relative expression of miR-29c in PBMCs was decreased(P<0.05).Moreover,the percentage of CD4^(+)Th17 cells,CD4^(+)Treg cells,Th17/Treg ratio and serum IL-17 level in RMPP group were higher than those in MSMP group,and the relative expression of miR-29c in PBMCs was lower than that in MSMP group(P<0.05).In all MPP patients,the relative expression of PBMCs miR-29c was negatively correlated with circulating Th17 cell%,Th17/Treg ratio and serum IL-17 level(P<0.05).Receiver operating characteristic curve analysis results showed that the AUC of PBMCs miR-29c for predicting RMPP was 0.932(95%CI:0.888-0.976)and the optimal cut-off value was 0.67.By multiple Logistic regression analysis,PBMCs miR-29c was an independent factor affecting the progression of RMPP.The risk of progression to RMPP of PBMCs miR-29c≥0.67 was lower(P<0.05).Conclusion Low PBMCs miR-29c could induce Th17 cell differentiation and promote Th17/Treg imbalance in children with MPP,which may be one of the important mechanisms of RMPP progression.