Interferon-? Inhibits Ebola Virus Infection

Rhein, Bethany A.; Powers, Linda S.; Rogers, Kai; Anantpadma, Manu; Singh, Brajesh K.; Sakurai, Yasuteru; Bair, Thomas; Miller-Hunt, Catherine; Sinn, Patrick; Davey, Robert A.; Monick, Martha M.; Maury, Wendy

Mouse peritoneal macrophages treated for 48 hours with either granulocyte-macrophage colony stimulating factor (GM-CSF) or macrophage colony stimulating factor (M-CSF) support robust infection by a recombinant EBOV (formerly Zaire EBOV) that expresses green fluorescent protein (GFP) [20] (Fig 1A) . M-CSF-treated cells were consistently more permissive for EBOV infection than GM-CSF-treated cells. Consequently, M-CSF-treated macrophages were primarily investigated in these studies. We observed that M-CSF-treated peritoneal macrophages cultures that were also pretreated with a combination of IFNγ and TNFα were highly resistant to EBOV infection ( Fig 1A) . The addition of cytokines TNFα and IFNγ to macrophages has been shown to generate a proinflammatory M1 phenotype [14, 15] . Evidence that the combination of these cytokines or IFNγ alone elicited an M1 phenotype of our isolated macrophages included significant increases in expression of proinflammatory genes such as IL-6, TNFα, and CXCL10 in our cells in the presence or absence of EBOV infection (S1 Fig) .