Recurrent pregnancy loss (RPL) is a multifactorial disorder, associated with immunologic abnormalities. During pregnancy, the maternal immune system uses different tolerance mechanisms to deal with a semi-allogenic fetus. The expression of immune checkpoints and their related miRNAs in immune cells can ensure pregnancy at the feto-maternal interface by modulating immune responses. This study aims to evaluate the expression of the immune checkpoint molecules PD-1 and Tim-3 on circulating T cells by flow cytometry, that of mir-138 and mir-155 in PBMCs by Real-time PCR, and the concentrations of TGF-β and IP-10 in the sera of women suffering from RPL as well as of gestational age-matched healthy pregnant women by ELISA. The percentage of PD-1 or Tim-3 expressing CD8 T cells was significantly lower in RPL patients compared to the controls, while there was no significant difference in Tim-3 expression of CD4 T cells between the two groups. The mRNA of both the PD-1 and Tim-3 genes were downregulated in PBMCs of RPL patients compared to controls, however, the difference was not statistically significant for Tim-3. The concentration of TGF-β was significantly lower and that of IP-10 was significantly higher in the sera of RPL patients than in those of the controls. The relative expression of mir-138 and miR-155 were significantly lower, in PBMCs of RPL patients than in those of healthy pregnant women. These data confirm that by affecting cytokine production, immune checkpoints, and microRNAs play a role in establishing the appropriate local immune environment for successful pregnancy. The wider analysis of immune checkpoints may also yield new biomarkers for the diagnosis and prevention of RPL.

中文翻译：

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复发性流产妇女PBMCs中PD-1和Tim-3及其相关miRNA表达的评估

复发性妊娠丢失（RPL）是一种多因素疾病，与免疫异常相关。在怀孕期间，母体免疫系统使用不同的耐受机制来应对半同种异体胎儿。免疫细胞中免疫检查点及其相关miRNA的表达可以通过调节免疫反应来确保母胎界面的妊娠。本研究旨在通过流式细胞术评估循环T细胞中免疫检查点分子PD-1和Tim-3的表达，通过实时PCR评估PBMC中mir-138和mir-155的表达，以及TGF-β的浓度。通过 ELISA 检测患有 RPL 的女性以及孕龄匹配的健康孕妇血清中的 β 和 IP-10。与对照组相比，RPL患者表达PD-1或Tim-3的CD8 T细胞的百分比显着降低，而两组之间CD4 T细胞的Tim-3表达没有显着差异。与对照组相比，RPL 患者的 PBMC 中 PD-1 和 Tim-3 基因的 mRNA 均下调，但 Tim-3 的差异不具有统计学意义。RPL患者血清中TGF-β浓度显着低于对照组，IP-10浓度显着高于对照组。RPL患者PBMC中mir-138和miR-155的相对表达量显着低于健康孕妇。这些数据证实，通过影响细胞因子的产生，免疫检查点和 microRNA 在为成功妊娠建立适当的局部免疫环境方面发挥着作用。对免疫检查点的更广泛分析也可能产生用于诊断和预防 RPL 的新生物标志物。