Reverse Engineering Influenza A Virus Assembly and Transmission

Dr. Michael Vahey (host: Mukherji), Department of Biomedical Engineering, Washington University in St. Louis

Influenza A virus (IAV) - a major cause of the seasonal flu - decorates its surface with proteins that have competing activities.  While one of these proteins (hemagglutinin, or HA) binds to the viral receptor, sialic acid, to promote entry into cells, the other (neuraminidase, or NA) destroys this same receptor to promote viral release.  Although the balance between these competing activities is central in determining virulence, the mechanisms governing how this plays out across virus populations as well as on the surface of individual viral particles remain poorly understood.  In this talk, I will describe our efforts to understand this balance using a strain of IAV amenable to quantitative, site-specific fluorescent labeling of viral proteins. With this tool, we are able to measure distributions of HA and NA both across virus populations as well as on the surface of individual particles, and to connect these measurements directly to functional characteristics of the virus.  I will describe the insight these experiments provide into how aspects of virus assembly and organization contribute to the persistence and transmission of infection.