Articles by Ari Watt in JoVE
Modeling The Lifecycle Of Ebola Virus Under Biosafety Level 2 Conditions With Virus-like Particles Containing Tetracistronic Minigenomes Thomas Hoenen1, Ari Watt1, Anita Mora2, Heinz Feldmann1 1Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 2Research Technology Branch, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health Work with infectious Ebola viruses is restricted to biosafety level 4 laboratories. Tetracistronic minigenome-containing replication and transcription-competent virus like particles (trVLPs) represent a lifecycle modeling system that allows us to safely model multiple infectious cycles under biosafety level 2 conditions, relying exclusively on Ebola virus components.
Other articles by Ari Watt on PubMed
A Novel Life Cycle Modeling System for Ebola Virus Shows a Genome Length-Dependent Role of VP24 in Virus Infectivity Journal of Virology. Sep, 2014 | Pubmed ID: 24965473 Work with infectious Ebola viruses is restricted to biosafety level 4 (BSL4) laboratories, presenting a significant barrier for studying these viruses. Life cycle modeling systems, including minigenome systems and transcription- and replication-competent virus-like particle (trVLP) systems, allow modeling of the virus life cycle under BSL2 conditions; however, all current systems model only certain aspects of the virus life cycle, rely on plasmid-based viral protein expression, and have been used to model only single infectious cycles. We have developed a novel life cycle modeling system allowing continuous passaging of infectious trVLPs containing a tetracistronic minigenome that encodes a reporter and the viral proteins VP40, VP24, and GP1,2. This system is ideally suited for studying morphogenesis, budding, and entry, in addition to genome replication and transcription. Importantly, the specific infectivity of trVLPs in this system was ∼500-fold higher than that in previous systems. Using this system for functional studies of VP24, we showed that, contrary to previous reports, VP24 only very modestly inhibits genome replication and transcription when expressed in a regulated fashion, which we confirmed using infectious Ebola viruses. Interestingly, we also discovered a genome length-dependent effect of VP24 on particle infectivity, which was previously undetected due to the short length of monocistronic minigenomes and which is due at least partially to a previously unknown function of VP24 in RNA packaging. Based on our findings, we propose a model for the function of VP24 that reconciles all currently available data regarding the role of VP24 in nucleocapsid assembly as well as genome replication and transcription.