Within a virus's tiny exterior is a store of energy waiting to be unleashed. When the virus encounters a host cell, this pent-up energy is released, propelling the viral DNA into the cell and turning it into a virus factory.
For the first time, Carnegie Mellon University physicist Alex Evilevitch has directly measured the energy associated with the expulsion of viral DNA, a pivotal discovery toward fully understanding the physical mechanisms that control viral infection and designing drugs to interfere with the process.
"We are studying the physics of viruses, not the biology of viruses," said Evilevitch, associate professor of physics who recently came to Carnegie Mellon as part of the department's biological physics initiative. "By treating viruses as physical objects, we can identify physical properties and mechanisms of infection that are common to a variety of viruses, regardless of their biological makeup, which could lead to the development of broad spectrum antiviral drugs."
Current antiviral medications are highly specialized. They target molecules essential to the replication cycle of specific viruses, such as HIV or influenza, limiting the drugs' use to specific diseases. Additionally, viruses mutate over time and may become less susceptible to the medication.
Evilevitch's work in the burgeoning field of physical virology stands to provide tools for the rational design of less-specialized antiviral drugs that will have the ability to treat a broad range of viruses by interrupting the release of viral genomes into cells.
Evilevitch's current findings also have the potential to improve the development of gene therapy, which uses viruses to deliver functional genes directly to human cells to replace defective genes that are causing disease.
Gene therapy takes advantage of viruses' modus operandi — injecting genetic material into cells. But instead of forcing in harmful, viral DNA, gene therapy delivers helpful, functional genes. Controlled packaging of the functional genes into the viral delivery system is one of the key factors involved in developing a successful gene therapy.
Pictured: A 3D reconstruction of bacteriophage lambda with (left) and without (right) DNA.