krn-7000 and Abortion--Spontaneous

Pregnancy loss is the commonest complication of pregnancy. The causes of pregnancy loss are poorly understood. It has been reported that stimulation of invariant natural killer T (iNKT) cells using α-galactosylceramide (αGC) induces pregnancy loss in mice. Here we investigated the mechanisms, especially the role of regulatory T (Treg) cells, in iNKT cell-mediated pregnancy loss. We found that injection of αGC rapidly induced fetal resorption, activated decidual iNKT cells, decreased the percentage of decidual Treg cells and their interleukin (IL)-10 and transforming growth factor (TGF)-β production, and upregulated the levels of interferon (IFN)-γ, tumor necrosis factor-α, IL-4, and IL-10 in serum. Adoptive transfer of iNKT cells from wild-type (WT) and IL-4

Topics: Abortion, Spontaneous; Adoptive Transfer; Animals; Cells, Cultured; Coculture Techniques; Decidua; Female; Galactosylceramides; Interferon-gamma; Interleukin-4; Lymphocyte Activation; Mice; Mice, Inbred C57BL; Mice, Knockout; Natural Killer T-Cells; Pregnancy; T-Lymphocytes, Regulatory

Innate immunity, which is unable to discriminate self from allo-antigens, is thought to be important players in the induction of miscarriages. Here, we show that the administration of IL-12 to syngeneic-mated C57BL/6 mice on gestation day 7.5 (Gd 7.5), drives significant miscarriages in pregnant females. Furthermore, the administration on Gd 7.5 of α-galactosylceramide (α-GalCer), which is known to activate invariant natural killer T (iNKT) cells, induced miscarriages in both syngeneic-mated C57BL/6 mice and allogeneic-mated mice (C57BL/6 (♀) × BALB/c (♂)). Surprisingly, the percentages of both DEC-205(+) DCs and CD1d-restricted NK1.1(+) iNKT cells were higher in the myometrium of pregnant mice treated i.p. with α-GalCer than in the decidua. IL-12 secreted from α-GalCer-activated DEC-205(+) DCs stimulated the secretion of cytokines, including IL-2, IL-4, IFN-γ, TNF-α, perforin, and granzyme B, from the NK1.1(+) iNKT cells in the myometrium, leading to fetal loss in pregnant mice. Finally, the i.p. administration of IL-12 and/or α-GalCer in iNKT-deficient Jα18(-/-) (Jα18 KO) mice did not induce miscarriages. This study provides a new perspective on the importance of the myometrium, rather than the decidua, in regulating pregnancy and a mechanism of miscarriage mediated by activated DEC-205(+) DCs and NK1.1(+) iNKT cells in the myometrium of pregnant mice.

Topics: Abortion, Spontaneous; Animals; Cytokines; Dendritic Cells; Female; Galactosylceramides; Injections, Intraperitoneal; Interleukin-12; Lymphocyte Activation; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Myometrium; Natural Killer T-Cells; Pregnancy