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

The ability of IFNγ, but not TNFα, to inhibit virus infection was also demonstrated in human macrophages. In these studies, six-day M-CSF matured human monocyte derived macrophages (hMDMs) were treated for 24 hours prior to infection with TNFα and/or IFNγ. Similar to our murine macrophages findings, M-CSF-matured hMDMs were highly permissive for EBOV GP/rVSV infection and human IFNγ, but not TNFα, effectively and profoundly blocked the number of cells infected by our recombinant virus (Fig 1C) . In a dose-dependent manner, 200 pg/mL reduced EBOV GP/rVSV replication by about 10-fold and 20 ng/mL reduced titers as assessed by end point dilution by more than four orders of magnitude ( Fig 1D) . In addition, we determined if human IFNγ inhibits EBOV GP/rVSV infection of an in vivo matured macrophage population, human alveolar macrophages. These cells were isolated by bronchial lavage and phenotyped as previously described [26, 27] . Similar to the MDM cultures, M-CSF-treated cells were permissive for virus, whereas the addition of IFNγ prevented infection of these cells (Fig 1E) .