AUTHOR=Chen Pengfei , Zhou Liying , Chen Jiying , Lu Ying , Cao Chaoxia , Lv Shuangli , Wei Zhihong , Wang Liping , Chen Jiao , Hu Xinglin , Wu Zijing , Zhou Xiaohua , Su Danna , Deng Xuefeng , Zeng Changchun , Wang Huiyun , Pu Zuhui , Diao Ruiying , Mou Lisha TITLE=The Immune Atlas of Human Deciduas With Unexplained Recurrent Pregnancy Loss JOURNAL=Frontiers in Immunology VOLUME=12 YEAR=2021 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2021.689019 DOI=10.3389/fimmu.2021.689019 ISSN=1664-3224 ABSTRACT=

Recurrent pregnancy loss (RPL) is a common fertility problem that affects 1%-2% of couples all over the world. Despite exciting discoveries regarding the important roles of the decidual natural killer cell (dNK) and regulatory T cell in pregnancy, the immune heterogeneity in patients with unexplained recurrent pregnancy loss (URPL) remains elusive. Here, we profiled the transcriptomes of 13,953 CD45+ cells from three normal and three URPL deciduas. Based on our data, the cellular composition revealed three major populations of immune cells including dNK cell, T cell, and macrophage, and four minor populations including monocytes, dendritic cell (DC), mast cell, and B cell. Especially, we identified a subpopulation of CSF1+ CD59+ KIRs-expressing dNK cells in normal deciduas, while the proportion of this subpopulation was decreased in URPL deciduas. We also identified a small subpopulation of activated dDCs that were accumulated mainly in URPL deciduas. Furthermore, our data revealed that in decidua at early pregnancy, CD8+ T cells exhibited cytotoxic properties. The decidual macrophages expressed high levels of both M1 and M2 feature genes, which made them unique to the conventional M1/M2 classification. Our single-cell data revealed the immune heterogeneity in decidua and the potentially pathogenic immune variations in URPL.