Repulsion of Superinfecting Virions: A Mechanism for Rapid Virus Spread

Abstract

Viral Superspreaders Viruses are thought to spread across a lawn of cells by an iterative process of infection, replication, and release. If this were the case, the rate of spread would be limited by the viral replication kinetics. Now, Doceul et al. (p. 873 , published online 21 January; see the Perspective by Pickup ) describe a spreading mechanism used by vaccinia virus that is not restricted by viral replication kinetics and that causes a dramatic acceleration of spread. Early after infection, vaccinia virus proteins A33 and A36 are expressed as a complex on the cell surface. This marks the cell as infected and causes superinfecting virions to be repelled by the formation of actin projections beneath the virus particle. Virions are repelled from infected cells repeatedly until an uninfected cell is reached and are thus pushed further away from the origin of infection to accelerate dissemination.