IFNγ reduces EBOV-GP/rVSV morbidity and mortality.

<p>(A) IFNγ enhances survival of EBOV GP/rVSV infected mice. IFNγ (10 μg) or PBS was administered by i.p. injection to BALB/c IFNAR^-/- mice 24 hours prior to or 2, 6, 12 or 48 hours following EBOV GP/rVSV infection (n≥8/treatment). (B) IFNγ treatment as a 24 hour pre-treatment or a 2 hour post-treatment reduces serum viremia and organ titers of EBOV GP/rVSV-infected mice. Sera and organs were harvested at 48 hours following infection (n≥ 4/treatment) in mice treated with 3.3μg of IFNγ. Viremia and organ virus titers were determined by endpoint dilution of serum or homogenized organ samples on Vero cells. Significance was calculated by Mann-Whitney test compared to PBS control, *<i>p</i> < 0.05, **<i>p</i> < 0.01. ns, not significant. (C) Intraperitoneal IFNγ treatment of mice significantly inhibits EBOV GP/rVSV infection of peritoneal cells. Peritoneal cells were isolated from EBOV GP/rVSV infected mice treated with 3.3μg of IFNγ at times noted prior to or following challenge. Amount of VSV-L RNA was determined by qRT-PCR. Significance was determined by ANOVA with a Tukey post-test, ***<i>p</i> < 0.001. (D) Intramuscular administration of IFNγ increases survival of IFNAR^-/- mice. PBS or IFNγ at the indicated concentration was administered by i.m. injection 24 hours prior to i.p. injection of EBOV GP/rVSV. For A & D, significance was determined by Mantel-Cox Test, **<i>p</i> < 0.01, ***<i>p</i> < 0.001.