Comprehensive RNA expression profile analysis of gamma delta T cells from peripheral blood and decidual tissues in normal pregnancy (NP) donors and patients with recurrent pregnancy loss (RPL)

Recurrent pregnancy loss (RPL) is a significant adverse pregnancy complication. The loss of immune tolerance has been proposed in the pathogenesis of RPL, however, the role of gamma delta T cells in RPL is still controversial. In this study, the gene expression patterns of circulated and decidual tissue-resident gamma delta T cells from normal pregnancy donors and patients with RPL were analyzed by SMART-seq. We demonstrate that the transcriptional expression profile of different subsets of gamma delta T cells in peripheral blood and decidual tissue is strikingly different. V delta 2 gamma delta T cells, as the major cytotoxic subset, are found to be enriched considerably, and the potential cytotoxicity of this subset is further enhanced in the decidua of RPL patients may be due to detrimental ROS reduction, enhanced metabolic activity, downregulation of immunosuppressive molecules expression in resident gamma delta T cells. Time-series Expression Miner (STEM) analysis of transcriptome indicates complex changes in gene expression in decidual gamma delta T cells over time from NP and RPL patients. Taken together, our work identifies high heterogeneity of gene signature in gamma delta T cells from NP and RPL patients between peripheral blood and decidua, which will be a useful resource for further studies of the critical roles of gamma delta T cells in RPL.