Development of a Pentacistronic Ebola Virus Minigenome System

Ebola virus (EBOV) causes severe disease outbreaks in humans with high case fatality rates. EBOV requires adaptation to cause lethal disease in mice by acquiring single mutations in both the nucleoprotein (NP) and VP24 genes. As an attempt to model mouse-adapted EBOV (MA-EBOV), we engineered novel pentacistronic minigenomes (5xMG) containing a reporter gene, VP40, and glycoprotein genes as well as the NP and VP24 genes from either EBOV or MA-EBOV. The 5xMGs were constructed and optimized, and the produced transcription- and replication-competent virus-like particles (trVLPs) were demonstrated to infect several cell lines. Introduction of the mouse-adaptation mutations did not significantly impact the replication and transcription of the 5xMG or the relative infectivity of the trVLPs in vitro. This work demonstrates the development of the 5xMG system as a new versatile tool to study EBOV biology.