Tulane Researchers Take a New Approach to Halting HIV Infection

Newswise -- Researchers at the Tulane National Primate Research Center are making strides in the fight against HIV infection, taking a new approach to halting the HIV epidemic. In the 1980s, most HIV vaccine research concentrated on the body's immune system as a whole and HIV transmission through blood. Primate center scientists have shown that major sites for HIV transmission and early viral replication are the mucosal linings of the body - particularly the gastrointestinal tract and vagina. Their research focusing on the mucosal immune system is supported by nine grants, primarily from the National Institutes of Health (NIH), totaling more than $3.5 million for the current year.

About 50 percent of all people living with AIDS are women. Since the epidemic began, 60 million people have been infected with HIV worldwide and an estimated 45 million more people will be infected by 2010, according to the Joint United Nations Programme on HIV/AIDS (UNAIDS).

Tulane faculty members Ronald Veazey, Preston Marx, Louis Martin, Andrew Lackner and Karol Sestak are working together on a variety of projects involving mechanisms of HIV transmission, pathogenesis and vaccines. In addition, Marx and Veazey are conducting research into a topical microbicide that may reduce the risk of transmitting HIV infection from men to women. Veazey and Marx have shown that a topical microbicide - a germ-fighting barrier that would be placed in the vagina before sexual intercourse - prevented SIV infection, the monkey form of HIV, in most of the monkeys in their study. They co-authored a paper about their discovery in the journal Nature Medicine (2003).

"Women are four times more vulnerable to HIV infection than men during sex, because mucosal surfaces contain many of the cells that the virus targets, and women have larger mucosal surfaces that can tear to further facilitate viral infection," Veazey says. "We're working on a molecular barrier, a coating on the cells that would prevent the virus from `seeing' the cells."

In their work to perfect an effective HIV vaccine, the scientists at the primate center are focusing on new strategies that would incorporate their knowledge of the mucosal immune system.

Sestak recently received a two-year, $500,000 grant from the NIH, to collaborate with a vaccine company in Sweden and John Clements, professor and chair of microbiology and immunology at Tulane, who holds a patent on a mucosal adjuvant, which has been shown to boost the immune system.

"So far, the vaccines that are being tested in humans do not target the mucosal immune system," says Lackner, director of the Tulane National Primate Research Center.

"These traditional vaccines have not proven effective. By targeting the mucosal tissues, our hope is to block HIV infection at an earlier stage.

Source: Tulane University