Scientists Develop Novel Approach to Fighting AIDS Virus
http://www.redorbit.com/news/health/1690719/scientists_develop_novel_approach_to_fighting_aids_virus/
Posted on: Monday, 18 May 2009, 12:05 CDT
Scientists are testing a new approach that involves the insertion of a gene into muscle tissue that will allow the body to produce antibodies that fight off the HIV/AIDS virus.
Reporting in the online edition of the journal Nature Medicine, Dr. Philip R. Johnson of the Children’s Hospital of Philadelphia and his team of researchers said the approach has already been in mice and monkeys with reported success, but they admit it could be years before a vaccine for humans arises.
“Six of nine immunized monkeys were protected against infection by the SIV challenge, and all nine were protected from AIDS,” Johnson and colleagues wrote.
AIDS has impacted populations worldwide, with more than 20 million dead from the virus and an estimated 33 million currently living with HIV, according to the International AIDS Vaccine Initiative.
Previous attempts to develop an effective vaccine have fallen short . The
human body is not able to make antibodies against the virus. Johnson and colleagues developed a synthetic immune system molecule that would make artificial antibodies, or antibody-like proteins or immunoadhesins.
“We used a leapfrog strategy, bypassing the natural immune system response that was the target of all previous HIV and SIV vaccine candidates,” Johnson told the Associated Press.
“Some years ago I came to the conclusion that HIV was different from other viruses for which we were trying to develop vaccines and we and might not ever be able to use traditional approaches.”
Researchers used adeno-associated virus, or AAV, to deliver the engineered DNA into the muscles of the monkeys. As a result, the muscles began to produce the proteins.
Researchers said one month after receiving the AAV insertion, the nine monkeys were injected with SIV, which is very closely related to HIV.
Six of the monkeys never became infected, the other three never developed AIDS, said researchers.
To ultimately succeed, more and better molecules that work against HIV, including human monoclonal antibodies, will be needed,” researchers wrote.
Dr. Peggy Johnston, head of the HIV Vaccine Research Branch at the National Institute of Allergy and Infectious Diseases, which funded the study, told Reuters that the study’s findings were “very promising.â€Â
“We need to make the genes as humanized as possible so that the human body doesn’t react to that,” she added.