During pregnancy, the fetus is presented with a safe environment within the mother’s womb and is supplied with nutrition essential for its growth. This means that what exists in the womb during pregnancy contributes to regulated fetus growth. Yet, little was known about the function of natural killer (NK) cells within the uterine microenvironment until a recent discovery by the Columbia University Medical Center (CUMC).
Researchers in CUMC discovered that uterine NK cells work as an immune system by eliminating intracellular pathogens. They also demonstrated how NK cells facilitates fetal growth by promoting the production of pleiotrophin, osteoglycin, and osteopontin, all of which are growth-promoting factors, in mice. Fetal growth involves processes such as cell expansion, cellular specialization, and generation of specific organs in a chronological order. Hence, regulation of the growth factors is crucial. When the NK cells were removed from a mother’s fetus, it led to defective fetal development at best and miscarriage at worst. The discovery is significant as it can lead to providing a safer fetal environment during pregnancy.