Home » General » Talk » A New Use for HIV
 A New Use for HIV [message #1148319] |
Fri, 06 November 2009 13:48  |
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From Yahoo! and the Associated Press:
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New gene therapy halts 2 boys' rare brain disease
By LAURAN NEERGAARD, AP Medical Writer Lauran Neergaard, Ap Medical Writer – Thu Nov 5, 5:12 pm ET
WASHINGTON – French scientists mixed gene therapy and bone marrow transplants in two boys to seemingly halt a brain disease that can kill by adolescence. The surprise ingredient: They disabled the HIV virus so it couldn't cause AIDS, and then used it to carry in the healthy new gene.
The experiment marks the first time researchers have tried that long-contemplated step in people — and the first effective gene therapy against a severe brain disease, said lead researcher Dr. Patrick Aubourg of the University Paris-Descartes.
Although it's a small, first-step study, it has "exciting implications" for other blood and immune disorders that had been feared beyond gene therapy's reach, said Dr. Kenneth Cornetta, president of the American Society of Gene and Cell Therapy.
"This study shows the power of combining gene therapy and cell therapy," added Cornetta, whose own lab at Indiana University has long researched how to safely develop gene delivery using lentiviruses, HIV's family.
The research was published in Friday's edition of the journal Science.
In 20 years of gene therapy research, there have been few home runs and some headline-making setbacks — including a risk of leukemia caused by otherwise successful gene therapy for another rare disorder, "bubble boy disease." That's a risk that specialists hope a lentivirus-based gene therapy will eliminate.
Best known from the movie "Lorenzo's Oil", adrenoleukodystrophy, or ALD, is a rare genetic disease that, in its most devastating form, destroys the coating of nerve fibers in boys' brains. Without that coating, called myelin, the neurological system breaks down. The disease typically strikes between the ages of four and 10, leading to blindness, deafness, dementia and loss of muscle control, and killing them within a few years.
Bone marrow transplants can halt ALD by letting new myelin-forming stem cells take root. But it's difficult to find a matching marrow donor, and the transplant itself is very risky.
So what if stem cells from the boys' own bone marrow could be genetically corrected, eliminating the ALD mutation? To do that, Aubourg's team had to overcome a technical hurdle: Gene therapy works when scientists harness deliver a healthy new gene by attaching to a virus that can harmlessly infect cells. But none of today's so-called gene therapy "vectors" could penetrate enough of the stem cells needed for an ALD treatment to work.
Unlike most viruses, HIV can penetrate stem cells, and it sticks permanently. So Aubourg's team removed the genetic parts of HIV that make it dangerous, leaving basically a scaffolding to carry the new therapeutic gene.
Then they culled stem cells from two 7-year-old boys in the early stages of ALD, and mixed in the healthy gene. The boys underwent bone marrow-destroying chemotherapy and then had their genetically corrected stem cells reinserted.
Two years later, the boys have shown no sign of worsening brain damage and are functioning well with 15 percent of their blood cells producing the healthy protein, said Aubourg, who plans to test the experimental procedure in more patients. An advocacy group, the Stop ALD Foundation, is working to raise money for a similar U.S. study.
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On the Net:
Science Web site: http://www.sciencemag.org
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| Re: A New Use for HIV [message #1148332] |
Sat, 07 November 2009 18:08  |
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Wow, that is amazing. Reminds me of the mice, and it relates to me. I know it does nothing for HIV, but it does deal with bone marrow like in the article. It's pretty exciting since it will be a cure for my eyes. (Previously, there are no cure.)
| UF scientists program blood stem cells to become vision cells |
John Pastor
07/30/2009
Maria B. Grant, M.D., a professor of pharmacology and therapeutics at UF’s College of Medicine
Photo available in the Recent News Gallery or direct download high res image or media mail image
University of Florida researchers were able to program bone marrow stem cells to repair damaged retinas in mice, suggesting a potential treatment for one of the most common causes of vision loss in older people.
The success in repairing a damaged layer of retinal cells in mice implies that blood stem cells taken from bone marrow can be programmed to restore a variety of cells and tissues, including ones involved in cardiovascular disorders such as atherosclerosis and coronary artery disease.
"To our knowledge, this is the first report using targeted gene manipulation to specifically program an adult stem cell to become a new cell type," said Maria B. Grant, M.D., a professor of pharmacology and therapeutics at UF's College of Medicine. "Although we used genes, we also suggest you can do the same thing with drugs — but ultimately you would not give the drugs to the patient, you would give the drugs to their cells. Take the cells out, activate certain chemical pathways, and put the cells back into the patient."
In a paper slated to appear in the September issue of the journal Molecular Therapy, scientists describe how they used a virus carrying a gene that gently pushed cultured adult stem cells from mice toward a fate as retinal cells. Only after the stem cells were reintroduced into the mice did they completely transform into the desired type of vision cells, apparently taking environmental cues from the damaged retinas.
After studying the cell-transformation process, scientists were able to bypass the gene manipulation step entirely and instead use chemical compounds that mirrored environmental conditions in the body, thus pointing the stem cells toward their ultimate identities as vision cells.
"First we were able to show you can overexpress a protein unique to a retinal cell type and trick the stem cell into thinking it is that kind of cell," said Grant, who collaborated with Edward Scott, Ph.D., the director of the Program in Stem Cell Biology and Regenerative Medicine at UF's McKnight Brain Institute. "As we proceeded, we found we could activate the stem cells by mimicking the body's natural signaling channels with chemicals. This implies a whole new field of stem cell research that uses drug manipulation rather than genetic manipulation to send these immature cells along new pathways."
Scientists chose to build retinal pigment epithelial cells, which form the outer barrier of the retina. In addition to being very specialized and easy to identify, RPE cells are faulty in many retinal diseases, including age-related macular degeneration, which affects nearly 2 million people in the United States, and some forms of blindness related to diabetes.
"This work applies to 85 percent of patients who have age-related macular degeneration," Grant said. "There are no therapies for this devastating disease."
The work was supported by the National Eye Institute. Researchers removed blood stem cells from the bone marrow of mice, modified the cells in cultures, and injected them back into the animals' circulatory systems. From there, the stem cells were able to home in on the eye injury and become retinal cells.
At 28 days after receiving the modified stem cells, mice that had previously demonstrated no retinal function were no different than normal mice in electrical measures of their response to light.
Grant and UF have patented some technology involved in the research.
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| Re: A New Use for HIV (And other medical break throughs) [message #1148334] |
Sat, 07 November 2009 19:10 |
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I think this thread will be about the new use for HIV and other medical break throughs.
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| Re: A New Use for HIV [message #1148344] |
Sat, 07 November 2009 22:29 |
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Actually, you know what, when I read the article over, I saw that it also used a dead virus as a carrier, like the original article did for HIV. It's good that we can use the viruses that hurt or kill us and turn it around to help us in these research.
Something is boring
But can you believe I can
Write a haiku here?
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| Re: A New Use for HIV [message #1148348] |
Sat, 07 November 2009 22:31 |
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Yes, I would hope to see more of that good use go around more often.
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