Research shows viral DNA infects cells by changing from solid to fluid-like state

Many double-stranded DNA viruses infect cells by ejecting their genetic information into a host cell. But how does the usually rigid DNA packaged inside a virus' shell flow from the virus to the cell?

In two separate studies, Carnegie Mellon University biophysicist Alex Evilevitch has shown that in viruses that infect both bacteria and humans, a phase transition at the temperature of infection allows the DNA to change from a rigid crystalline structure into a fluid-like structure that facilitates infection.

The findings, published in Nature Chemical Biology and the Proceedings of the National Academy of Sciences (PNAS), provide a promising new target for antiviral therapies. Most antiviral drugs work by deactivating viral proteins, but viruses often evolve and become drug resistant.

Evilevitch believes that researchers now have a possible new way to prevent infection—blocking the phase transition. Such a therapy could be generalizable across all types of Herpes viruses, and wouldn't be prone to developing resistance.

"The exciting part of this is that the physical properties of packaged DNA play a very important role in the spread of a viral infection, and those properties are universal," said Evilevitch, an associate professor in Carnegie Mellon's Department of Physics. "This could lead to a therapy that isn't linked to the virus' gene sequence or protein structure, which would make developing resistance to the therapy highly unlikely."