U.S. researchers pinpoint weakness of HIV virus

by Rich Bowden - Jul 15 2008, 22:43

A team of HIV researchers at the University of Texas Medical School in Houston have discovered what they believe to be a weak spot in the HIV virus.

The team found the weakness in the HIV envelope protein gp120, a component essential for the virus to attach to host cells, which then initiates the infection leading to AIDS.

HIV has resisted attacks from the body's immune system due to the fact that it is a constantly changing and mutating virus. It is also for this reason that a preventative treatment has remained elusive. However University of Texas (UT) researchers have isolated a small stretch of amino acids numbered 421-433 ongp 120, and say, as the virus needs one region to remain constant to attach itself to the cells, this may provide a target for therapeutic intervention.

"Unlike the changeable regions of its envelope, HIV needs at least one region that must remain constant to attach to cells," said Sudhir Paul, Ph.D., pathology professor at the UT Medical School, and senior author of a paper on the subject published in the journal Autoimmunity Reviews.

"If this region changes, HIV cannot infect cells. Equally important, HIV does not want this constant region to provoke the body's defense system. So, HIV uses the same constant cellular attachment site to silence B lymphocytes -- the antibody producing cells," added Paul in a UT press release.

"The result is that the body is fooled into making abundant antibodies to the changeable regions of HIV but not to its cellular attachment site. Immunologists call such regions superantigens. HIV's cleverness is unmatched. No other virus uses this trick to evade the body's defenses."

The team has developed antibodies with enzymatic activity, also known as abzymes, which are designed to attack the weak point of the virus in a very precise way.

"The abzymes recognize essentially all of the diverse HIV forms found across the world. This solves the problem of HIV changeability. The next step is to confirm our theory in human clinical trials," Paul said.

According to a 2007 report released by the World Health Organisation and the United Nations, around 33 million people currently live with AIDS with total deaths numbering 2.1 million. The report outlines that over three quarters of these deaths have occurred in sub-Saharan Africa. 

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