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Antibodies found in lupus and some hemophilia patients may prove to be a potent preventative against HIV transmission and progression, according to researchers who presented two new studies yesterday at the 17th International AIDS Conference in Mexico City.

The antibodies act on a particular part of HIV protein called gp120, which is the target of a vaccine that has failed to deliver any preventative effect as demonstrated in a large clinical trial. Gp120 is known to help HIV invade human cells.

The antibodies can be used as a microbicide to block infection during sexual intercourse. Also it is possible to make a vaccine that targets at the particular stretch of the protein to trigger the human body to produce these antibodies to have a protective effect.

Every human being produces certain amounts of these anti-HIV antibodies, but the level is not enough to prevent the infection and stop progression of HIV into full blown AIDS except in some people who can survive the HIV/AIDS for much longer than expected.

The antibodies attack a small but important region with 13 amino acids of the protein, which is constructed with 500 amino acids, to prevent the virus from binding to its main prey, immune-system cells known as lymphocytes.

These antibodies have been found in people with lupus in whom HIV infection is rarely seen and also in HIV carriers who can survive for a long term including three people with the blood disease called hemophilia, according to the researchers.

The protein gp120 has been known for more than a decade and an unsuccessful vaccine was just based on a large dose of purified gp120 protein, Washington Post reported.

The reported two studies by Stephanie Planque and Sudhir Paul at the University of Texas Medical School in Houston focused on the 13 unit stretch of the 500 unit protein where the HIV virus attaches to the cells' receptors. This small portion of the gp120 protein is identical in all strains of HIV.

For the studies, the researchers went through a library of antibodies made by lupus patients and identified those with catalytic activity against the 13-unit stretch of the gp120 protein.

Planque said at the AIDS conference that the antibodies from lupus patients killed HIV samples from five HIV clades or families. The antibody isolates from three hemophilia patients who carried HIV but have lived for more than 17 years were also highly effective at killing HIV virus.

The discoveries may lead to a new drug, a microbicide with antibodies or a vaccine, to help people prevent HIV infection and or stop HIV from progressing to cause AIDS.

Paul was cited by Washington Post as speculating that a microbicide might be affordable even for people in the developing world because of a small dose of short-lived antibodies are needed to protect against sexual transmission. He said, cited by the post, that it would be much harder to develop a vaccine to target the particular section of the gp120 protein.

Source:foodconsumer.com