Top Story

Mechanical properties of viral DNA determine the course of infection

A new study reveals a previously unknown mechanism that governs whether viruses that infect bacteria will quickly kill their hosts or remain latent inside the cell. The discovery also may apply to viruses that infect humans and other animals. After injecting their DNA into a cell, viruses tend to follow one of two major pathways, called "lytic” or "latent” infections. In the lytic pathway, viral DNA quickly commandeers the host cell's own resources to make hundreds of copies of itself. The new viruses then kill the cell and go on to repeat the cycle in other cells. Latent viral infections follow a different course: Once inside the cell, the viral DNA incorporates itself into the host genome; when the cell divides, the viral DNA also gets duplicated; as long as the infection remains latent, there is little evidence of it in the host. The problem with latent viral infections is that, in times of stress for the host, the virus can suddenly turn lytic, taking over the cell and killing it after a mad bout of reproduction.

Visit Website | Image credit: Alex Evilevitch and Ting Liu/University of Illinois Urbana-Champaign