We've all been hearing this kind of news for years and it never seems
to pan out. And frankly, I see a fly in the ointment with this theory
already. Still, it's worth hearing about and you just never know..
Thought you might tuck this away in your "Might be of interest
someday" file but don't get overly optimistic about it just yet.

New approach offers chance to finally kill herpes
<http://news.yahoo.com/s/nm/20080702/hl_nm/herpes_treatment_dc_1>

By Maggie Fox, Health and Science Editor Wed Jul 2, 5:39 PM ET

WASHINGTON (Reuters) - U.S. researchers reported on Wednesday they may
have found a way to flush out herpes viruses from hiding -- offering a
potential way to cure pesky and painful conditions from cold sores to
shingles.

They discovered that a mysterious gene carried by the herpes simplex-1
virus -- the one that causes cold sores -- allows the virus to lay low
in the nerves it infects.

It does so via microRNAs, little pieces of genetic material that
regulate the activity of many viruses, the researchers report in the
journal Nature.

It may be possible to "wake up" the virus and then kill it with
standard antiviral drugs such as acyclovir, said Jennifer Lin Umbach
of Duke University in North Carolina, who worked on the study.

"We are trying to go into animal trials," Umbach said in a telephone
interview.

The Duke team is discussing a potential collaboration with Regulus
Therapeutics LLC, a joint venture between Alnylam Pharmaceuticals, Inc
and Isis Pharmaceuticals, Inc that specializes in microRNAs.

Herpes viruses cause permanent infections. They head straight to nerve
cells, where they stay latent for the life of an animal or person,
often causing periodic outbreaks.

Herpes simplex 1 or HSV-1 causes cold sores, HSV-2 causes genital
herpes, while varicella causes chicken pox and returns in middle or
old age as herpes zoster to cause shingles.

Acyclovir and related drugs can suppress symptoms but only when the
virus is active.

IMPOSSIBLE TO KILL

"Inactive virus is completely untouchable by any treatment we have.
Unless you activate the virus, you can't kill it," said Bryan Cullen,
who oversaw the research.

Umbach said that for still unknown reasons, viruses infecting
different neurons in the same body activate at different times, making
it impossible to eradicate an infection.

Her team found that a gene called LAT controls microRNAs that turn off
other genes in the virus.

"The presence of these active microRNAs keep the virus dormant,"
Umbach said. "When the virus is activated by stress like UV
(ultraviolet) light or a wound, production of (other) genes goes up."

Then LAT is overwhelmed and unable to keep the virus in check. It
wakes up and causes an outbreak.

A drug that would turn off the microRNAs could drive the virus out of
hiding and allow all copies of the virus to be killed with acyclovir,
she said.

"You would have one cold sore but you would get rid of it," she said.
Curing something more painful, such as shingles, might be a little
trickier, she added.

One class of drug called an antagomir might work, Umbach said. These
chemically engineered oligonucleotides are short segments of RNA that
can be made into mirror images of a targeted bit of genetic material
-- such as the herpes microRNAs. They would attach and "silence" the
microRNA.

The potential market is large. An estimated one in five Americans have
genital herpes, according to the U.S. Centers for Disease Control and
Prevention, while 100 million have the HSV-1 virus that causes cold
sores.

The CDC estimates there are a million cases of shingles every year in
the United States alone.