uterine natural killer cell 1, human
uterine natural killer cell 1, human
​​A uterine natural killer subset that is present in the endometrial lining during the non-pregnant state (Garcia-Alonso et al., 2021) and in the decidua during pregnancy (Vento-Tormo et al., 2018). It expresses the uterine resident marker CD49a and is distinguished from uNK2 and uNK3 by CD39 expression and the absence of CD103 (Whettlock et al., 2022) and CD160 (Marečková et al., 2024). It also expresses higher levels of killer-cell immunoglobulin-like receptors (KIRs) and leukocyte immunoglobulin-like receptor B1 (LILRB1), which facilitate interaction with human leukocyte antigens (HLAs) on extravillous trophoblast cells, promoting immune tolerance and implantation. Enriched in the endometrium post-ovulation (Marečková et al., 2024) and prominent in early pregnancy (Whettlock et al., 2022), uNK1 regulates trophoblast invasion and spiral artery remodeling (Zhang & Wei, 2021).