Abstract: Objective To explore the effect of rmu-IFN-γ on the change of T cell subsets and natural killer cells of pregnant mice infected with T. gondii. Methods Early pregnant mice infected with T. gondii were administered with different doses（1 U/g or 10 U/g） of rmu-IFN-γ for three days before euthanasia. The numbers of splenic CD4+ and CD8+ T cells and natural killer cells were detected by flow cytometry. Results Compared with the infected mice that were not treated， the level of splenic CD4+ T cells in mice administered with two doses of rmu-IFN-γ increased on the day 10， 12， 14 of gestation， while the level of CD8+ T cells decreased on the day 10， 14 of gestation. The ratio of CD4+/CD8+ T cells increased significantly on the day 10， 12， 14 of gestation. Survival days of the two administered groups were longer than those of the infected group. Conclusion A proper dose of rmu-IFN-γ can reverse the decline of the ratio of T cell subsets， improve the proliferation of NK cells， and so increase the level of peripheral cellular immunity of pregnant mice.

Key words: Toxoplasma gondii, rmu-IFN-γ, Mouse, Pregnancy, T cell subsets, Natural killer cell