The Immune Atlas of Human Deciduas With Unexplained Recurrent Pregnancy Loss

Front Immunol. 2021 Jun 7;12:689019. doi: 10.3389/fimmu.2021.689019. eCollection 2021.


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.

Keywords: human decidua; immune heterogeneity; scRNA decidual nature killer cell; single-cell RNA sequencing; the immune atlas; unexplained recurrent pregnancy loss.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abortion, Habitual / immunology*
  • CD8-Positive T-Lymphocytes / immunology
  • Decidua / cytology
  • Decidua / immunology*
  • Dendritic Cells / immunology
  • Female
  • Humans
  • Killer Cells, Natural / immunology
  • Macrophages / immunology
  • RNA-Seq