Fig. 2.
The progesterone-PGR axis is required for efficient innate antiviral response in vivo. a Effects of progesterone on virus-induced IFN-β production in the sera of mice. Mice (male, n = 6 in each group) were injected intravenously with the indicated doses of P4 for half an hour, and then infected with SeV or EMCV (1 × 108 pfu) for 6 h before measurement of serum IFN-β by ELISA assays. b Effects of progesterone on viral replication in mice. Mice (8-week-old male, n = 3) were intraperitoneally (i.p.) treated with a neutralizing antibody (nAb) against IFNAR-1 (500 μg/mouse) or PBS, and then injected intravenously with DMSO or P4 (30 μg/kg) for half an hour, followed by intraperitoneal injection of SeV or EMCV (1 × 108 pfu) and repeated antibody treatments as described in the Materials and Methods section. Viral genomic copy numbers in the spleens of SeV-infected mice or the brains of EMCV-infected mice were quantified by qPCR. c Effects of progesterone on virus-induced death of mice. Mice (8-week-old male, n = 6) were injected intravenously with DMSO or P4 (30 μg/kg) for half an hour, and then infected intraperitoneally with EMCV (1 × 107 pfu). The survival rates were monitored for twelve days. d Effects of Pgr-deficiency on virus-induced production of serum cytokines. Pgr+/+ and Pgr−/− male mice were infected intravenously with SeV (n = 6 mice in each group) or EMCV (1 × 108 pfu, n = 4 mice in each group) for 6 h before serum cytokines were measured by ELISA. e Effects of Pgr-deficiency on EMCV-induced death of mice. Pgr+/+ and Pgr−/− mice (n = 8 per strain, 8-week-old male) were infected intraperitoneally with EMCV (1 × 107 pfu per mice), and the survival rates of mice were monitored for ten days. f Progesterone levels in pregnant mice. Sera from control and two-week pregnant female mice (n = 4 in each group) were collected for progesterone measurement by ELISA assays. g Levels of serum IFN-β and CXCL10 in virus-infected pregnant mice. The control and two-week pregnant female mice (n = 4 in each group) were infected intravenously with SeV for the indicated times before serum IFN-β and CXCL10 were measured by ELISA assays. h The mRNA levels of antiviral genes in different tissues of virus-infected pregnant mice. The control and two-week pregnant female mice (n = 4 in each group) were infected intravenously with SeV for 6 h, and then the indicated tissues were collected for qPCR analysis of mRNA levels of the indicated genes. *P < 0.05; **P < 0.01; ***P < 0.001; ns not significant