Abstract: Objective： To investigate the effect of transvaginal injected recombinant IL-17 on the pregnancy outcome in the CBA/J mice model （CBA/J×BALB/c） and its role in feto-maternal immune rejection. Methods：Six to eight-week-old female CBA/J and male BALB/c were divided into three different experimental groups. Mice of normal pregnancy（CBA/J×BALB/c） received no treatment were served as control group. 50 μL phosphate-buffered saline（PBS） or 50 μL recombinant IL-17 （rIL-17） was administered in the vaginal vaults of anesthetized pregnant CBA/J mice on Day 1 of pregnancy served as PBS group and rIL-17 group individually. The numbers of surviving and reabsorbed fetuses in each group were counted, and the expression of TGF-β and IL-10 in decidua was assessed by quantitative real-time PCR and western blotting on Day 14 of pregnancy. Ｒｅｓｕｌｔｓ：In this in vivo model of normal pregnancy, exogenous rIL-17 resulted in increased spontaneous resorption of fetuses and decreased expression of TGF-β and IL-１０ （Ｐ＜０．０５）． Ａｎｄ ｔｈｅｒｅ ｗａｓ ｎｏ ｓｔａｔｉｓｔｉｃａｌ ｄｉｆｆｅｒｅｎｃｅ ｂｅｔｗｅｅｎ ＰＢＳ ｇｒｏｕｐ ａｎｄ ｃｏｎｔｒｏｌ ｇｒｏｕｐ （Ｐ＞０．０５）． Ｃｏｎｃｌｕｓｉｏｎｓ：Intravaginal rIL-17 can induce inflammation in feto-maternal interface resulting in abortion in normal pregnant CBA/J mice model.

Key words: Interleukin-10, Interleukin-17, Transforming growth factor beta, Pregnancy, animal