Stiasny

Humans infected with flaviviruses produce antibodies which can confer long-lasting immunity to the infecting virus. The protective effect of antibodies is based on their capacity to bind to the surface of virus particles, thereby neutralizing virus infectivity. Immune responses, however, are heterogeneous, and some antibodies are very potent in preventing infection but others are ineffective. There is strong evidence that poorly neutralizing or non-neutralizing antibodies can even enhance flavivirus infection of certain cells. In this research area, we dissect the specificities and functional activities of antibody populations in human blood after different flavivirus infections or vaccinations and determine the balance between neutralizing and infection-enhancing activity. A strong focus is on antibodies that react with all flaviviruses but are unable to inhibit infectivity. These broadly cross-reactive antibodies also hamper the specific laboratory diagnosis of flavivirus infections. Our studies will therefore not only have implications for our basic understanding of immune responses to flaviviruses but also impact the design of diagnostic tests.

These studies are supported by the Austrian Science Fund FWF (P29928-B30) and by intramural funds of the Center for Virology, Medical University of Vienna.