Implantation: can immunological parameters of implantation failure be of interest for pre-eclampsia?

The role of the immune system in preeclampsia

“…Previous investigations of the Th1/Th2 immune responses during pregnancy were able to show that a distinct shift towards Th2 type reactions occurs at the fetomaternal interface (Lin et al, 1993;Michimata et al, 2002) and at systemic sites (Krishnan et al, 1996;Saito et al, 1999b;Piccinni et al, 1998), although a quadruple Th2-cytokine-knockout mouse was found to have normal reproductive performance (Fallon et al, 2002), and conflicting data were also reported (Bates et al, 2002;Chaouat, 2003;Chaouat et al, 2003). Anyway, Th2 type immunity might play some important roles in successful pregnancy, at least in part, and predominant Th2 type immunity to Th1 type immunity may regulate the allogeneic immune responses to the fetus and the excessive inflammation in normal pregnancy.…”

Immunological Analogy Between Allograft Rejection, Recurrent Abortion and Pre-Eclampsia – the Same Basic Mechanism?

“…It was also shown, that IL-18 secretion inside placenta, decidua and spleen was decreased in abortionprone mice compared to normal healthy controls. Bidirectional pattern of activity characterized also IL-15, which might boost cytotoxicity of uNK cells' or might play a role of growth factor needed for survival and terminal differentiation of immature uNK cells [152,153]. In IL-15 ablated mice uNK cells failed to develop, which resulted in an improper modification of spiral arteries and decidua.…”

“…Interleukin-12 could play a stimulatory function for synthesis of asymmetric antibodies [142]. An abnormal IL-18 level and IL-12/IL-18 ratio were shown to correlate with unsuccessful pregnancy outcome, which means that not only exaggerated but also depleted cytokine secretion was detrimental for gestation status, and influenced uNK cells activity [153]. Proliferation and inhibition of cytotoxic activity of human decidual uNK CD3Ϫ/CD16ϪCD56ϩ cells was regulated by many genes, and between them some seemed to be IL-15-dependent [172].…”

“…Proliferation and inhibition of cytotoxic activity of human decidual uNK CD3Ϫ/CD16ϪCD56ϩ cells was regulated by many genes, and between them some seemed to be IL-15-dependent [172]. Both lack of uNK cell activation or uNK cell over-activation into cytotoxic pathway caused by disturbed IL-12/-15/-18 tripod, could disturb vascular remodeling and provoke oxydative stress which might lead to clinical signs of abortion, multiple IVF-ET failures or preeclampsia [153,173,174].…”

Trafficking of peripheral blood CD56bright cells to the decidualizing uterus—new tricks for old dogmas?

“…Decidualization of human and murine endometria is associated with the appearance and proliferation of two unique maternal cell types; Natural Killer (NK) cells and immature dendritic cells (DC) (King, 2000;Chaouat et al, 2003;Kammerer et al, 2003;Robertson et al, 2003). These cells emerge in precise microdomains within implantation sites, proliferate and many localize to the spiral arteries.…”