The fetal trophoblast cell marker HLA-G activates a type I interferon response in primary NK cells through the receptor KIR2DL4

NK cells and that ISG expression was similar in both NK cell subsets. Comparison of our data with scRNA-seq data from the early maternal-fetal interface revealed that HLA-G induced the transcription of genes that distinguish decidual NK cells from maternal blood NK cells. Thus, ISG transcription, which is inducible by HLA-G, is detected in early pregnancy and may underlie intrinsic antipathogen resistance of NK cells in the maternal decidua.