Odds are, you have it. By the age of 40, nearly 90 percent of adults in the United States have been exposed to the herpes simplex virus-1 (HSV1) that causes cold sores. Not everyone who has the virus lurking in their body will have symptoms, but those who do will be annoyed for life by unexpected lip blisters. But now
the secret of how the cold sore virus manages to persist for a lifetime in the human body may have been cracked [BBC News], and researchers say their findings may point the way towards a treatment that could kill the virus once and for all.
The virus is a difficult target. When a cold sore appears, it's easily treatable with a drug that kills the replicating virus, but that drug can't get to the latent versions of the virus that are hiding within nerve cells and waiting to cause the next eruption. Until now, research has generally concentrated on keeping HSV1 inactive — and preventing cold sores from ever showing up. But [Duke University] researchers took the opposite tack: figuring out precisely how to switch the virus from latency to its active stage. That's important, says lead author Dr. Bryan Cullen, professor of molecular genetics and microbiology at Duke, "because unless you activate the virus, you can't kill it" [Time].
Researchers discovered that when the virus is latent it produces a strange kind of RNA, a strand of genetic material that's copied from the virus's DNA. The RNA in most viruses codes for useful proteins, but researchers discovered that in the herpes virus this RNA strand breaks down into small bits that block the production of proteins, keeping the virus from activating. These findings, published in the journal Nature [subscription required], suggest that if researchers can prevent the RNA from breaking down, they can cause all the latent viruses to become activated, and could then kill them all at once. "Once the virus sticks its head up over the fence, you whack it off for good," Cullen says. "Yes, the person has to have one last cold sore, but it'd be worth it to most people to cure them forever"
. Researchers caution that there's a lot of research to be done before anyone can test out a pharmaceutical cure on humans, but say their new understanding of the herpes virus could eventually lead to a host of medical treatments.
[T]he findings could apply to the whole range of herpes viruses, including herpes simplex 2, which causes genital herpes, and the varicella zoster virus, which causes chickenpox and a more chronic, painful condition known as shingles [HealthDay News].