Transcriptional profiling of human decidual CD45RA+ and CD45RA- primed CD8 T cells by bulk RNA-seq

Here, we identify a conserved subset of effector-like memory CD8⁺ T cells that are preferentially infiltrate in the decidua of both humans and mice, via the CX3CL1–CX3CR1 axis. Murine decidual CX3CR1⁺ memory CD8⁺ T cells and human decidual CD45RA⁺ CD8⁺ T cells share transcriptional and functional programs, characterized by reduced cytokine output but enhanced cytotoxic granule production.

We show that decidual stromal cells upregulate CX3CL1 during decidualization, which recruits CX3CR1⁺ cells via receptor engagement and internalization. Functionally, these cells mediate enhanced local protection against Listeria monocytogenes infection at the fetal-maternal interface in a CX3CL1-dependent manner, without contributing to fetal damage. These findings define a conserved mechanism by which decidual tissues selectively enrich effector-like memory CD8⁺ T cells, enabling localized pathogen surveillance while maintaining maternal–fetal tolerance.