Lee SK, et al. Immune Netw. 2015 Feb;15(1):16-26. https://doi.org/10.4110/in.2015.15.1.16

The immune system of pregnant women is tightly controlled to defend against microbial infections and at the same time, to accept an embryo or the fetus, which are expressing semi‐allogenic paternal antigens. Furthermore, inflammation‐like processes are crucial for tissue growth, remodeling, and differentiation of the decidua during pregnancy. Dysregulation of elaborate immune control may lead reproductive failure, such as implantation failure, recurrent pregnancy loss (RPL), preterm birth, intrauterine fetal growth restriction, and preeclampsia. Until recent years, a balance between Th1 and Th2 cells was believed to be the key immune regulatory mechanism of T‐cell immunology especially during pregnancy. Since the identification of regulatory T cells was made, the mechanism of immune regulation has become a major issue in immunologic research. Also, the recent identification of Th17 cells has drawn our attention to a new immune effector. The balance between Th17 and regulatory T cells may explain more about the pathophysiology of reproductive failure. This review will discuss relevant human literature on regulatory T and Th17 cells in normal reproductive physiology and in women with RPL and infertility.

Emerging evidence indicates that aberrant maternal inflammation is associated with several pregnancy-related disorders such as preeclampsia, preterm birth, and intrauterine growth restriction. Sirtuin1 (SIRT1), a class III histone deacetylase, is involved in the regulation of various physiopathological processes including cellular inflammation and metabolism. However, the effect of SIRT1 on the placental proinflammatory environment remains to be elucidated. In this study, we investigated the effect of SIRT1 on lipopolysaccharide (LPS)-induced NLRP3 inflammasome activation and its underlying mechanisms in human first-trimester trophoblasts (Sw.71 and HTR-8/SVneo cells). Treatment with LPS elevated SIRT1 expression and induced NLRP3 inflammasome activation in mouse placental tissues and human trophoblasts. Knockdown of SIRT1 enhanced LPS-induced NLRP3 inflammasome activation, inflammatory signaling, and subsequent interleukin (IL)-1β secretion. Furthermore, knockdown of NLRP3 considerably attenuated the increase of IL-1β secretion in SIRT1-knockdown cells treated with LPS. Moreover, SIRT1 inhibited LPS-induced NLRP3 inflammasome activation by reducing oxidative stress. This study revealed a novel mechanism via which SIRT1 exerts anti-inflammatory effects, suggesting that SIRT1 is a potential therapeutic target for the prevention of inflammation-associated pregnancy-related complications.