Role of uterine NK cells in pregnancy complication.

Remodeling of blood vessels and angiogenesis play a critical role in the pregnancy process, particularly at the implantation site. Both the innate and adaptive immune systems, especially uterine natural killer (uNK) cells, are involved in this process. During the first trimester, uNK cells constitute approximately 70 % of decidual leukocytes and are differentiated from CD34+ progenitor cells. In comparison to peripheral blood NK cells, uNK cells secrete specific cytokines that promote tissue remodeling while exhibiting lower cytotoxic activity. Any disturbance in the function of uNK cells or dysregulation of their receptors can lead to reproductive failures. This review focuses on the role of uNK cells in pregnancy disorders such as preeclampsia, recurrent pregnancy loss, and endometriosis. The findings of this research will assist researchers in targeting specific checkpoints to address pregnancy disorders in clinical settings. SIGNIFICANCE STATEMENT: In this study, we highlight the evidence that NK cells play a pivotal role in pregnancy disorders and appropriate phenotype and normal expression of receptors on uNK cells affected pregnancy outcomes. In summary, arterial remodeling and correct implantation are related to the presence of various cytokines and factors in the uterine microenvironment. Collectively, it seems that the result of this study can be helpful in clinic. In the other word, specialist can use appropriate drugs in infertility.