Expansion of decidual CD45RO+ T cells with high expression of CEACAM1 in the early stage of pregnancy

Abstract

The aim of the present study was to investigate the mechanism involved in the expansion of CD45RO+ T cells in the decidual microenvironment, and in the expression of the inhibitory carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) on the surface of decidual CD45RO+ T cells. Twenty-one healthy nonpregnant females and seventeen healthy pregnant females in the first trimester were included in the study. Peripheral blood samples from nonpregnant and pregnant females, and decidual tissues from pregnant females following elective abortion, were obtained and analyzed by flow cytometry. The percentages of CD45RO+ T cells and CEACAM1-expressing CD45RO+ T cells were significantly higher in first trimester human decidua than in the peripheral blood. Conditioned medium from the coculture of monocytes and the human trophoblast HTR8/SVneo cell line (MHM) was added to the model for the generation of CD45RO+ T cells in vitro. MHM caused an increase in the percentage of CD45RO+ T cells in a monocyte chemoattractant protein-1 (MCP-1)-dependent manner and an increase in the percentage of CEACAM1-expressing CD4+CD45RO+ T cells in the model. In conclusion, our results implied that trophoblast cells and monocytes may be involved in the increase of decidual CD45RO+ T cells and the high expression of CEACAM1 on their surfaces.