The uterus of mammalian species (including humans and model organisms such as mice) contains many immune cells that are critical for a successful pregnancy. In a new paper published in the journal Immunity, Norman Shreeve and colleagues from Francesco Colucci’s group at the Department of Obstetrics and Gynaecology, together with their collaborators, studied the role of the cell receptor NKG2A, which is found on a subset of maternal immune cells called uterine natural killer (uNK) cells. These cells are important for establishing functional placental units during early pregnancy. In pregnant mice that lack this receptor, the offspring were found to be smaller and with abnormal growth patterns. This was associated with poor maternal blood vessel adaptation to pregnancy and abnormal placental gene expression. In humans whose genes do not favour the use of NKG2A, an increased risk of preeclampsia was found. This study helps understanding the immunological mechanisms that underpin normal pregnancy and may also contribute towards the improved identification of those women at risk of preeclampsia.

Shreeve N, Depierreux D, Hawkes D, Traherne JA, Sovio U, Huhn O, Jayaraman J, Horowitz A, Ghadially H, Perry JRB, Moffett A, Sled JG, Sharkey AM, Colucci F. The CD94/NKG2A inhibitory receptor educates uterine NK cells to optimize pregnancy outcomes in humans and mice. Immunity. 2021 Apr 19:S1074-7613(21)00133-3. doi: 10.1016/j.immuni.2021.03.021. Epub ahead of print. PMID: 33887202.