Scientists find new cellular receptor for HIV

In another landmark discovery, U.S. government scientists identified a potential method human immunodeficiency virus (HIV) uses to attack a human body, the New York Times reported on Monday.

The latest findings could provide a new ray of hope for the development of additional therapies to stop the lethal and so far incurable virus, the report said.

The discovery is the identification of a new human receptor for H.I.V that helps guide the virus to the intestines after it gains entry to the body, where it replicates and eventually destroys the body's lymph tissue.

A team of scientists headed by veteran HIV researcher Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID), said they found a human receptor, a molecule called integrin alpha-4 beta-7, that naturally directs immune cells to the intestines also serves as a receptor for HIV.

Dr. Fauci and colleagues said they discovered a protein on the outer shell of HIV sticks itself to the receptor molecule integrin alpha-4 beta-7 that is linked to the way T cells find the digestive tract.

"The gut is where the virus really takes hold," said Elena Martinelli, a co-researcher of the latest study. "We found that integrin alpha 4 beta 7, whose natural function is to direct T cells to the GALT, is also a receptor for HIV. It is very unlikely that this is a coincidence."

Scientists have known for years that the virus rapidly invades the lymph nodes and lymph tissues found in the intestines, which becomes the key location where HIV replicates. After HIV replicates in the intestines, the virus then goes on to deplete the lymph tissue of the immune system cells, or lymphocytes, known as CD4 T-cells.

Now, the latest study explains how it gets into the intestines, where it hides out and multiplies for a full assault on the body.

The team that reported their findings on Sunday in the online edition of journal Nature Immunology also found that the binding of HIV to the molecule provokes activation of another molecule, LFA-1, which helps spread the virus from one cell to another, eventually leading to the destruction of lymph tissue, the Times said.

"It is a homing receptor for lymphocytes to get to the gut. It is the very molecule that steers lymphocytes to the gut and keeps them there," Dr. Fauci said in a telephone interview. "It is not only important in that it is a homing receptor to the gut. But it also can play a role in enhancing the ability of HIV to spread in the body," he continued.

The global pandemic, HIV AIDS is spreading like forest fire worldwide, affecting more than 33 million people globally. There is no cure and the virus has killed 25 million people around the world. The infectious disease is transmitted mostly during sex between a man and a woman.

Hopes of finding a preventative tool to stop the spread of AIDS dealt a severe blow last year in September when Merck & Co., Inc.'s experimental HIV prevention vaccine failed to show protection against global pandemic, HIV/AIDS.