In addition to fetal tissue tolerance, T cells and NK cells also play a role in fetal-maternal metabolic homeostasis.
Immune system adaptations in the maternal-fetal environment are essential for a successful pregnancy. When this adaptation is hindered or inadequate, infertility, miscarriage, pregnancy complications, and adverse fetal outcomes can occur. Specific immune cells have been studied to better understand their role in pregnancy and to know what this information can provide overall regarding the development of new immunotherapeutic approaches for disease states.
The most-studied cells of the immune system associated with the fetal-uterine environment are T cells and natural killer (NK) cells. Natural killer cells are abundant and very well-characterized cells of the immune system. In addition to responding to many types of pathogens, they are involved in metabolic homeostasis. Seventy percent of the leukocytes of the uterine decidua are NK cells during the first trimester, but they make up 30% by mid-gestation. One role determined for uterine NK cells is in assisting the early stages of vascular remodeling in the decidua.
Memory T cells in pregnancy are thought to play an important, but positive, role in fetal-maternal tolerance. However, there is increasing evidence that supports the role of regulatory T cells in the induction of feto-maternal tolerance. Maldistribution and functional impairment of regulatory T cells have been implicated in implantation failure and miscarriage in humans. Therefore, dynamic changes in the maternal immune system are crucial to maintain fetal tolerance during pregnancy.
In addition to the role of T and NK cells in fetal tissue tolerance, they play a role in fetal-maternal metabolic homeostasis. There is significant interaction between metabolic processes and immune function. The immune system requires energy in the form of protein, glucose, and fatty acids to function, and shifts in how this energy is used during pregnancy determines pregnancy success. Study of the interaction between metabolic and immune processes and how these are modified during pregnancy can provide information on how this interaction can be exploited to develop immunotherapeutic strategies for different disease states.
Resource: How pregnancy changes women's metabolism and immune systems. (2019). Medicalxpress.com. Retrieved 6 November 2019, from https://medicalxpress.com/news/2019-09-pregnancy-women-metabolism-immune.html