Friday, July 30, 2010

Stem Cells Could Fight HIV

An alternative for patients who can’t use antivirals

A novel stem cell therapy that arms the immune system with an intrinsic defense against HIV could be a powerful strategy to tackle the disease. This new approach could dramatically improve the quality of life and life expectancy for HIV sufferers in whom antiviral drugs are no longer effective, said Ben Berkhout, PhD, head of the Laboratory of Experimental Virology at the University of Amsterdam. He discussed his research at the recent spring meeting of the Society for General Microbiology in Edinburgh, Scotland.

In the absence of an effective vaccine, daily administration of antiretroviral drugs is the most effective treatment for HIV. However, low patient compliance rates, combined with the virus’s ability to easily mutate, have led to the emergence of drug-resistant strains that are difficult to treat.

This therapy would offer an alternative for HIV-infected patients that can no longer be treated with regular antivirals.
—Ben Berkhout, PhD, University of Amsterdam

Dr. Berkhout is investigating a novel gene therapy with long-lasting effects even after a single treatment. This therapy arms patients against viral infection by delivering antiviral DNA to their own immune cells. “This therapy would offer an alternative for HIV infected patients that can no longer be treated with regular antivirals,” he said in a statement.

The therapy involves extracting and purifying blood stem cells from a patient’s bone marrow. Antiviral DNA is transferred to the cells in the laboratory, after which the cells are re-injected into the body. The DNA encodes small RNAs that are the mirror image of key viral genes used by HIV to cause disease. The small RNAs float around inside the immune cell until they encounter viral genes to which they can firmly attach. This RNA interference approach can block the production of key viral components from these genes.

Transferring the antiviral DNA to stem cells would help to restore a large part of the patient’s immune system. The group hopes to start clinical trials of the therapy within three years. “So far, very promising results have been obtained in the laboratory, and we are now testing the safety and efficacy in a pre-clinical mouse model,” Dr. Berkhout said.

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