Infection-sensing minigenome as a novel therapeutic approach against Ebola virus

We describe here a molecular therapy that uses the virus's own proteins to combat itself. In this approach, infection-sensing RNAs encoding therapeutic genes are flanked by viral promoters and packaging signals in negative-sense orientation. These therapeutic minigenome RNAs do not express the transgene and remain silent in the absence of a viral infection. In contrast, if the cell is infected, the virus acts as a helper virus, providing viral proteins <i>in trans</i> to transcribe, replicate, and package the therapeutic minigenomes. Proof of concept for this therapeutic approach is demonstrated here using Ebola virus (EBOV) minigenomes expressing two antiviral transgenes: a short-hairpin (sh) RNA targeting the EBOV viral protein VP24 and an open-reading frame expressing a host peptide from the retinoblastoma-binding protein 6 (RBBP6). By using an EBOV tetracistronic-minigenome as a virus life cycle modeling system, we show here that both therapeutic minigenomes suppressed viral RNA replication and viral protein production, and a more than 50% reduction in the reporter signal was observed when cells were challenged with EBOV transcription/replication-competent virus-like particles. These findings highlight the therapeutic potential of infection-sensing minigenome to combat EBOV and perhaps other viral pathogens.