Experimental Topical Microbicide Offers Long-Lasting Protection Against Genital Herpes Libraries
News Jan 23, 2009
A topical microbicide that silences two genes can safely protect against genital herpes infection for as long as one week, according to a joint study by researchers at the Albert Einstein College of Medicine of Yeshiva University and Harvard Medical School.
The study, carried out in mice and published in Cell Host & Microbe, represents a major step toward developing a vaginal microbicide that offers women convenient, long-lasting protection against herpes infection. Such a microbicide might also help in controlling the AIDS epidemic, since the blisters caused by genital herpes make people more susceptible to HIV infection.
The study’s principal investigators were Deborah Palliser, Ph.D., assistant professor of microbiology & immunology at Einstein and Judy Lieberman, M.D., Ph.D., professor of pediatrics, Harvard Medical School.
An estimated one in five American adults is infected with herpes simplex virus 2 (HSV-2), which causes the sexually transmitted disease known as genital herpes.
The most effective way to prevent the transmission of HSV-2 is to avoid sexual contact during an active outbreak and to use condoms for sexual contact between outbreaks. When an outbreak occurs, promptly taking the suppressive antiviral drug valacyclovir can help minimize symptoms and reduce the risk of transmitting the virus.
The microbicide in this study is based on RNA interference (RNAi), a mechanism cells use to protect their genetic machinery from viruses and other threats. RNAi employs short, double-stranded RNAs called small interfering RNAs, or siRNAs. In 2001, scientists discovered that synthetic siRNAs can induce RNA interference in mammalian cells - a finding that has triggered interest in harnessing this strategy for biomedical research and drug development.
The HSV-2 microbicide used in this study inactivates two genes via RNA interference. One siRNA targets a viral gene, thereby silencing virus immediately following application, but suppression lasts for only a couple of days. The second siRNA - specific for a cell-surface protein used by HSV-2 to dock onto cells it infects - takes a few days to silence the gene, but then confers suppression for a week.
By combining the fast-acting-but-short-lived RNAi with the slower-acting-but-long-lived RNAi, the researchers created a vaginal microbicide offering protection that was both immediate (even warding off an HSV-2 “challenge” given shortly before the microbicide was applied) and sustained (protecting against HSV-2 challenge for a week after application).
“A good microbicide for a sexually transmitted disease must offer long-term protection—compliance will be problematic if it has to be applied immediately before sexual intercourse,” says Dr. Palliser.
She continued, “Our microbicide, with its two siRNAs, provided sustained and uninterrupted protection against HSV-2 infection. And equally important, we achieved these results without causing inflammation of vaginal tissue—a side effect observed with other siRNAs that also risks neutralizing a microbicide’s benefits. We’re hopeful that this experimental microbicide can be turned into a cost-effective therapy for use in developing countries where up to 80 percent of the population is infected with HSV-2.”
The researchers are currently working to refine the microbicide and as yet have no plans for clinical trials.
Early Life-Changing Experiences Also Change Your GenesNews
Factors in early life such as maternal care influence the number and modifications of certain 'jumping genes' - a finding that ties together nature and nurture.READ MORE
Genetic Identity of Atacama "Alien" Skeleton RevealedNews
A mysterious six-inch skeleton found in the Chilean desert was thought to be the answer to extraterrestrial life. Instead, it may provide solutions to some very human questions about mutation.READ MORE
Comments | 1 ADD COMMENT
bella sandra | Mar 08, 2018
it was a greatest surprise to me that i was cured from herpes virus by a powerful herbal doctor, it was just like a dream to me i taught that their is no cure for herpes because for about six years i spent so much of my money in hospital but no improvement i was confuse in life until a friend of mine introduce me to this herbal doctor i contacted him firstname.lastname@example.org if their can be any help and he promise to help me, he prepared a herbal medicine for me i followed his instruction after 14 days i went to hospital for test but i was cured it was a greatest surprise to me so i decide to share this testimony. a very big thanks to this herbal doctor who save my life, please if you have this kind of sickness or any disease do not give up you can contact him https://web.facebook.com/Dr-Herbal-Solution-Home-222978621567048/reviews/ or whatsapp him on +2348064438762..