A novel mechanism of antibody-mediated enhancement of flavivirus infection

Author summary Antibodies are an important component of antiviral host responses and their binding to the surface of virus particles usually leads to neutralization of viral infectivity. In some instances, however, antibodies at sub-neutralizing concentrations can enhance infection of certain cells, because they facilitate the uptake of infectious virus-antibody complexes through interactions with antibody-specific cellular receptors (Fcγ receptors). This mechanism is designated antibody-dependent enhancement of infection and implicated in the pathogenesis of dengue and possibly Zika virus infections, both mosquito-transmitted flaviviruses. Here we describe a novel mechanism of infection enhancement by antibodies that is independent of interactions with Fcγ receptors, using another important human-pathogenic flavivirus, tick-borne encephalitis virus. We demonstrate that binding of a specific antibody to the envelope protein E at the viral surface promotes the exposure of a structural element that interacts with the lipids of the cellular plasma membrane, thus increasing infection. Our study provides new insights into mechanisms that potentially modulate the antiviral effects of antibody populations present in post-infection sera.See it on Scoop.it, via Viruses and Bioinformatics from Virology.uvic.ca
A novel mechanism of antibody-mediated enhancement of flavivirus infection
Source: Viral Bioinformatics