Interferon-γ inhibition of Ebola virus infection [Alveolar macrophage]

Episodic Ebola virus (EBOV) outbreaks, such as the current one in West Africa, emphasize the critical need for novel antivirals against this highly pathogenic virus. Here, we demonstrate that interferon gamma (IFNγ) prevents morbidity and mortality associated with EBOV infection when administered to mice either 24 hours prior to or 2 hours following EBOV infection. Microarray studies with IFNγ-stimulated human macrophages identified novel interferon-stimulated genes (ISGs) that inhibit EBOV infection upon ectopic expression. IFNγ treatment reduced viral RNA levels in macrophages to a similar degree as cells treated with the protein synthesis inhibitor, cycloheximide, suggesting that IFNγ treatment inhibits genome replication. As IFNγ treatment robustly protects mice against EBOV infection, we propose that this FDA-approved drug may serve as a useful prophylactic or therapeutic strategy during EBOV outbreaks, contributing to the currently limited arsenal of filovirus antivirals. Total RNA was isolated from alveolar macrophages from healthy individuals. All cells were treated with 50 ng/mL of M-CSF plus or minus 20 ng/mL of IFNg for 24 hours prior to infection.