This item requires the Flash plug-in (version 8 or higher). JavaScript must also be enabled in your browser.
Please download the latest version of the free Flash plug-in.
Hans-George Krausslich/University of Heiderlberg
Posted on 03/08/2010 8:41:04 PM PST by neverdem
Powerful anti-HIV drugs have come tantalizingly close to eradicating the virus from people, driving the blood level of HIV so low that standard tests cannot detect it. But no one has been cured: the virus comes roaring back in everyone who stops taking the drugs. A new study has identified one of HIV's main hideaways, raising intriguing possibilities about how to remove it.
The work addresses a mystery first reported in 2006 by the lab of Robert Siliciano, a virologist at Johns Hopkins University in Baltimore, Maryland, who has developed the most sensitive test to find HIV. Siliciano's group first isolated HIV from treated people who had been "undetectable" for at least 6 months. The team then sequenced the genetic material from these viruses and tracked down the infected cells that produced them. The researchers identified some white blood cells with CD4 receptors-the conductor of the immune system's orchestra and the main target of the virus—that held identical HIV sequences in their chromosomes. But in most people they studied, the virus in the blood did not match the sequence in the CD4 cells, indicating that HIV was hiding elsewhere.
This item requires the Flash plug-in (version 8 or higher). JavaScript must also be enabled in your browser.
Please download the latest version of the free Flash plug-in.
A team led by virologist Kathleen Collins of the University of Michigan, Ann Arbor, now has evidence that HIV hangs out inside bone marrow. Specifically, they found the virus in hematopoietic progenitor cells (HPCs)—the mother of all immune system cells.
Collins and colleagues first established that HPCs could be infected with HIV. Using HPCs from umbilical cords and commercial labs, the researchers demonstrated in test-tube experiments that the virus not only infected the cells but also could remain latent. This means that the virus does not copy itself, a capability key to forming what's called a reservoir. The virus in latently infected cells, Collins explains, does not trigger an immune response and remains impervious to anti-HIV drugs.
To determine whether HPCs actually harbor the virus in infected people, Collins's team worked with a hematologist who removed HPCs from the bone marrow of 15 HIV-infected volunteers. The researchers report today in Nature Medicine that they found the virus in HPCs from all six people with high levels of HIV in their blood. And of the nine people who had undetectable levels of virus for at least 6 months, four carried HIV-infected HPCs. Collins says she suspects that the other five people also had latently infected HPCs, but the test was not sensitive enough to detect the virus because it infects few cells and they only had small samples from each person.
"Eradication efforts will only be successful if all of the reservoirs for HIV are identified and eliminated," says Siliciano. The new study helps solve the mystery of where HIV hides out, he says, although there may be other undetected reservoirs.
Collins says the hope now is to develop drugs that specifically rattle latent HPCs, forcing them to produce virus, which will lead to their death and, eventually, drain this reservoir. "The challenge is certainly daunting," says Collins. "But what's more likely, a vaccine or eradication? I used to think it was a vaccine. Right now, I'm not so sure."
micro ping
People coexist with many dormant viruses for much of their lives, viruses that can flare up but don’t necessarily have to. If buggery would stop, so would virtually all HIV transmission. Short of that, the best that probably can be hoped is coexistence with the virus by agents that keep it permanently dormant.
Am i the only one seeing the possibles of wiping out all retrovirus infections?
Ping...(Thanks, neverdem!)
Thanks for the ping!
They may not have a cure now, but something is really happening here. How about a guess that within the next 15 years there will be a cure?
Perhaps not.
Although the vast majority of the sufferers of this particular retroviral disease happen to engage in acts I consider immoral and/or unnatural, not all do.
The further implications of identifying reservoir mechanisms for virii in humans may be more effective cures for viral ailments of any stripe, and possibly may have implications in erradicating cancer.
You’re Welcome, Alamo-Girl!
Actually, many have been ‘cured’ but the standard retort of denial that is issued prevails: They never were infected, previous results were in error.
That is the kind of junk that passes for ‘science’ in the age of hoaxes.
I sympathize with the need to make a political case for the funding of scientific research. Believe me, I've seen lots of the results of this phenomenon over decades of working in the sector. Once it was sickle cell, then cancer, then aids funding. Melvin Calvin got his own lab at Berkeley and had his account at NSF. Peter Duesberg, a brilliant scientist, recruited from the Max Plank Institute, lost all his NSF funding because he suggested testing of alternative hypothesis - because he put truth first.
Science has suffered because its funding is largely government controlled. That is the reason for the junk science of global warming and for the junk medicine surrounding HIV, and for the junk science policy of John Holdren and his fellow Marxists. We are headed down the path of T.D. Lysenko, whose dialectically correct genetic principles set Soviet genetic science back fifty years. There may be some science being done by scientists getting HIV funding, but it isn't likely to have any impact on AIDS. I too know how to write the grant proposals likely to get funding. We do what we must to do science, but it is a poor substitute for the real thing.
One of the ironies is that many in gay support groups, I know of Act Up in particular, know the truth and have modified their life styles, forsaken the drugs including prophylactic antibiotics, and live healthy lives, like Magic Johnson, with occasional bouts of cold sores and HIV infections just like the rest of us. Magic is probably only alive because some very knowledgeable people warned him away from antiviral treatment.
Thanks for the Ping.
Silly me. I always thought they were hiding that virus up their butt.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.