Abstract:

Objective To observe the effect of adoptive transferring FTY720-dendritic cells (FTY720-DCs) on the embryo loss rate in the mouse model of spontaneous abortion and explore the mechanism of inducing maternal-fetal immune tolerance. Methods The mouse models of spontaneous abortion (CBA/J×DBA/2) and normal pregnancy (CBA/J×BALB/c) were constructed. Mice were assigned to six groups, i.e. normal pregnancy group (CBA/J×BALB/c),  spontaneous abortion with no intervention group (CBA/J×DBA/2), abortion with DC cells culture medium (DCCM) injection group, abortion with adoptive transferring DC group, abortion with FTY720 injection group, and abortion with adoptive transferring FTY720-DC group. The embryo loss on 12th-14th day of gestation was observed. The proportions of Treg and Th17 cells in peripheral blood mononuclear cells were measured with flow cytometer. Results The embryo lost rate in mice with adoptive transferring FTY720-DC was significantly lower as compared with mice in the spontaneous abortion with no intervention group and the abortion with DCCM injection group (P=0.00), as well as the abortion with adoptive transferring DC group and the abortion with FTY720 injection group (P=0.01). There was no significant difference in the embryo lost rate between the abortion with adoptive transferring FTY720-DC group and the normal pregnancy group (P>0.05). The proportion of peripheral blood Treg cells was remarkably increased and the proportion of Th17 cells was significantly decreased after adoptive transferring FTY720-DC. The differences were statistically significant as compared with the spontaneous abortion with no intervention group and the abortion with DCCM injection group (P=0.00) and the difference was not statistically significant as compared with the normal pregnancy group (P>0.05). Conclusion Adoptive transfer of FTY720-DC can induce immune tolerance in pregnancy and decrease the embryo loss rate in mice of spontaneous abortion model. The mechanism may be associated with the reverse of the imbalance of Treg/Th17 in mice of spontaneous abortion model.

Key words: FTY720-DC； dendritic cell； adoptive transfer； spontaneous abortion, immune tolerance