London, January 11 : Scientists have identified more than 250 human proteins that aid in the spreading of HIV throughout the body.
Stephen Elledge, a geneticist at Harvard Medical School in Boston, Massachusetts, says that these proteins may lead to the development of reasonably effective HIV drugs.
The researcher says that HIV might be stopped in its tracks if drugs could deactivate these proteins, without having too drastic an impat on the patient.
"If you could inhibit a host protein that is necessary for HIV progression, HIV would have to develop a new ability. And in the number games, that doesn't happen. That's why host proteins could make tremendously good drug targets," Nature magazine quoted him as saying.
Scientists were aware of only a few human proteins that are exploited by HIV before this study.
With an eye on finding more of them, Elledge's team used RNA interference to block the expression of a single gene in each of some 21,000 pools of human cells, thereby creating 'knockout' cells for every gene in the human genome.
The researchers then treated the pools of cells with HIV. They also examined the pools for two signs of HIV progression - the presence of an HIV-protein called Gag on the surface of the human cells, and the ability of the cells to infect new, uninfected human cells.
It was found that 273 of the gene knockouts were lacking one or both of these signs of HIV progression, suggesting that the proteins encoded by such genes are important to HIV.
The researchers said that only 36 of such genes had previously been implicated in helping HIV.
"There are certainly lots of proteins that no one would have ever guessed are involved in HIV infection," Nature magazine quoted Elledge as reporting in the journal Science.
Martin Hirsch, another expert at Harvard Medical School, said that the new finding might eventually spur new therapeutic approaches against HIV, but pointed out that drugs that interact with human proteins could be toxic.
"Many previous investigators have gone this route over the past 20 years, with minimal success," he said.
Elledge said that minimizing toxicity of medicines could be achieved if they were programmed to interfere with several of the proteins, without knocking any of them out completely.
He says that this way the critical functions of the proteins could be preserved for the patient, while wiping out a critical function for HIV.
"The cell may not depend on these pathways for a single function, but the virus could," he said.
Elledge's team are now planning to study how these human proteins interact with HIV.