Fig. 4

Increased ZIKV infection in the vagina of progesterone-treated OVX Ifnlr1^−/− and hSTAT2 KI Ifnlr1^−/− mice. Six week-old WT, Ifnlr1^−/−, hSTAT2 KI, or hSTAT2 KI Ifnlr1^−/− OVX mice were given a hormone replacement regimen of estradiol, progesterone, estradiol and progesterone, or vehicle. WT and Ifnlr1^−/− mice were treated with 1 mg of anti-Ifnar1 mAb at day −1. On day 0, mice were inoculated via intravaginal route with 10⁶ FFU of ZIKV (Dakar 41525). At 7 dpi, ZIKV RNA was stained using ISH on vaginal tissue (WT and Ifnlr1^−/−, a; hSTAT2KI and hSTAT2 KI Ifnlr1^−/−, b). Images are representative of two or three experiments. Low magnification scale bar = 500 μm, high magnification scale bar = 50 μm. Numbers of mice analyzed: Vehicle: WT + anti-Ifnar1, n = 10; Ifnlr1^−/− + anti-Ifnar1, n = 7. Progesterone: WT + anti-Ifnar1, n = 16; Ifnlr1^−/− + anti-Ifnar1, n = 11; hSTAT2 KI, n = 7; or hSTAT2 KI Ifnlr1^−/−, n = 5. Estradiol: WT + anti-Ifnar1, n = 10; Ifnlr1^−/− + anti-Ifnar1, n = 6. Estradiol and progesterone: WT + anti-Ifnar1, n = 9; Ifnlr1^−/− + anti-Ifnar1, n = 13