Figure 1.

Progesterone receptor signaling in maternal FOXP3+ cells protects against fetal wastage

(A) Percent fetal wastage, number of live pups in utero, and concepti in FOXP3-WT (black), FOXP3-PRKO [FOXP3^Cre/CrePR^flox/flox] (red), and FOXP3-Cre/Cre (blue) female mice at mid-gestation (E11.5) during allogeneic pregnancies sired by Balb/c-2W1S/OVA (H-2^d) male mice.

(B) Percent fetal wastage and number of live pups for FOXP3-PRKO female mice at mid-gestation (E11.5) during allogeneic pregnancies sired by Balb/c-2W1S/OVA (H-2^d) male mice, including those adoptively transferred PR-sufficient Treg from FOXP3^DTR donor mice prior to mating (squares) and whether or not DT was administered to selectively eliminate donor FOXP3+ Tregs (open).

(C) Frequency of FOXP3+ and number of FOXP3+ and FOXP3− CD4+ T cells with I-A^b:2W1S_55-68 specificity in the spleen and pooled peripheral lymph nodes for mice described in panel A.

(D) CTLA-4 expression (gMFI) after cell-surface + intracellular staining among I-A^b:2W1S_55-68-specific (filled) or bulk (open) CD4+ T cells in the spleen and pooled peripheral lymph nodes for mice described in panel A.

(E) Percent fetal wastage and number of live pups 2 days following administration of RU486 (red) or vehicle (black) in allogeneic pregnant female mice.

(F) Representative FACS plots and summary data showing number of I-A^b:2W1S_55-68 CD4+ T cells and frequency of FOXP3+ Treg cells in the spleen and pooled peripheral lymph nodes for mice described in panel E. Data are from at least three independent experiments each with similar results, with each point representing data from an individual mouse. Bar, mean ± SEM. ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.005, ∗∗∗∗p < 0.001.