UVA Research: Nearly Indestructible Virus Yields Tool to Battle DiseasesPosted: Updated:
Scientists at the University of Virginia School of Medicine say they have found a blueprint for battling disease. The discovery of a specific virus' resistance to almost any kind of environment is prompting researchers to see how it can be used to save lives.
The virus is named SIRV2 and even though it was discovered more than a decade ago, UVA scientists have unlocked how it seems to resist nearly every kind and temperature or environment. Researchers say the virus infects microscopic organisms and can survive in boiling acid, extreme subzero temperatures and ultraviolet radiation.
Professor Edward Egelman says the virus' resistance structure makes it a great template to copy when trying to treat diseases. He says normally a sick person's body would fight off foreign DNA that treatments deliver, but if coated with a protective casing like the virus, gene therapy methods could be a reality.
"It contains proteins that we can actually synthesize in the laboratory, and these proteins that we synthesize could then be used to encapsidate DNA for things like drug delivery or it could be used for imaging," Egelman said.
Egelman says one important part of this discovery is that if doctors treated people with forms of this virus, it would not be toxic, even though it infects microscopic life forms.
It is too early to tell what kinds of diseases could be treated with this virus, but scientists are hopeful they'll be able to nail that down in the near future.
University of Virginia News Release:
CHARLOTTESVILLE, Va., May 26, 2015 – By unlocking the secrets of a bizarre virus that survives in nearly boiling acid, scientists at the University of Virginia School of Medicine have found a blueprint for battling human disease using DNA clad in near-indestructible armor.
“What's interesting and unusual is being able to see how proteins and DNA can be put together in a way that's absolutely stable under the harshest conditions imaginable,” said Edward H. Egelman, PhD, of the UVA Department of Biochemistry and Molecular Genetics. “We've discovered what appears to be a basic mechanism of resistance – to heat, to desiccation, to ultraviolet radiation. And knowing that, then, we can go in many different directions, including developing ways to package DNA for gene therapy.”
Packaging DNA to Treat Disease
Finding effective packaging for DNA delivery is important because the human body has many ways to degrade and remove foreign DNA – that's how it combats viruses. But that protective mechanism becomes a major obstacle for doctors seeking to use genes to battle disease. Creating an impenetrable packaging would overcome that problem, and this strange virus offers a promising template.
The virus, SIRV2, infects a microscopic organism known as Sulfolobus islandicus that lives in what Egelman described as “extremely unusual” conditions: acidic hot springs where temperatures top 175 degrees Fahrenheit. The research identified surprising similarities between the SIRV2 virus and the spores bacteria form to survive in inhospitable environments. “Some of these spores are responsible for very, very horrific diseases that are hard to treat, like anthrax. So we show in this paper that this virus actually functions in a similar way to some of the proteins present in bacterial spores,” he said. Spores are also formed by C. difficile, which now accounts for approximately 30,000 deaths per year in the U.S. and has been classified by the Centers for Disease Control and Prevention as having a threat level of “urgent.” “Understanding how these bacterial spores work gives us potentially new abilities to destroy them,” Egelman said. “Having this basic scientific research leads in many, many directions, most of which are impossible to predict, in terms of what the implications are going to be.”
So how does the virus survive such inhospitable conditions? SIRV2, it turns out, forces its DNA into what is called A-form, a structural state identified by pioneering DNA researcher Rosalind Franklin more than a half-century ago. “This is, I think, going to highlight once again the contributions she made, because many people have felt that this A-form of DNA is only found in the laboratory under very non-biological conditions, when DNA is dehydrated or dry,” Egelman said. “Instead, it appears to be a general mechanism in biology for protecting DNA.”
Egelman and his colleagues were able to crack the mystery only because of the remarkable power of UVA's new Titan Krios electron microscope. Buried deep below Fontaine Research Park, the massive microscope is insulated within many tons of concrete to provide the stability needed to examine biological samples in previously impossible detail. The microscope is one of only a few of its kind in the world, and was funded, in part, by the National Institutes of Health. Researchers from far and wide, both at UVA and beyond, are tapping its power.
Published in Science
Egelman's findings are among the first to result from UVA's Titan, but others are expected to follow soon. The discovery has been described in the prestigious scientific journal Science in an article authored by Frank DiMaio, Xiong Yu, Elena Rensen, Mart Krupovic, David Prangishvili and Egelman.
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