THREE people with drug-resistant strains of HIV have become the first to undergo a new form of gene therapy designed to block the virus.
The idea is to use a modified form of HIV to deliver an "antisense" gene to the immune cells that HIV infects. This is integrated into the cells' genome, and stays there until a cell is infected. Then it is switched on, and produces RNA complementary to the "sense" RNA encoding a viral protein. In theory, the RNAs should bind together, blocking viral replication.
Lab tests by the Maryland-based company VIRxSYS showed viral replication is at least 100 times lower in treated cells. So in July last year the company started treating patients by filtering immune cells from their blood, exposing the cells to very low doses of the modified virus, and then putting them back into the body.
Like existing antiretroviral drugs, the approach will not completely eliminate HIV from the body. But because the antisense RNA fragment is very long, HIV should never be able to mutate enough to become resistant to it, Boro Dropulic, chief scientific officer of VIRxSYS, told the RNAi 2004 meeting in Boston last week.
It is the first time that this has been attempted with modified HIV, and Dropulic says the results so far are encouraging. But Richard Sutton of Baylor College of Medicine in Houston is sceptical, saying the many problems inherent in gene therapy for HIV have led others to give up on the approach. "A lot of people, including large pharma, have seen the writing on the wall," he says.
Author: Jenny Hogan, Boston
New Scientist issue: 15 MAY 2004
PLEASE MENTION NEW SCIENTIST AS THE SOURCE OF THIS STORY AND, IF PUBLISHING ONLINE, PLEASE CARRY A HYPERLINK TO: http://www.newscientist.com.
"These articles are posted on this site to give advance access to other authorised media who may wish to quote extracts as part of fair dealing with this copyrighted material. Full attribution is required, and if publishing online a link to http://www.newscientist.com is also required. Advance permission is required before any and every reproduction of each article in full - please contact firstname.lastname@example.org.
Please note that all material is copyright of Reed Business Information Limited and we reserve the right to take such action as we consider appropriate to protect such copyright."
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
Published on PsychCentral.com. All rights reserved.
We teach people how to remember, we never teach them how to grow.
-- Oscar Wilde