AIDS Study Focuses on 'Elite Controllers'

An international team that is seeking elite controllers will scan their genomes for small variations called "single-nucleotide polymorphisms." This will cost about $10,000 per subject, said Rafick-Pierre Sekaly, a researcher at Hospital Saint-Luc in Montreal, where 12 subjects have been identified.

Walker said he has enrolled about 100 through his research group, and 50 have been identified by physicians on the West Coast. Since a recent newspaper article appeared in the Los Angeles Times, he's been getting 10 calls a week. Some of the early subjects surfaced through a mention in Poz, a magazine whose target audience is HIV-positive people.

That is how Loreen Willenberg, 52, a landscape designer from a town in Northern California, found out about it. She said that in 1992 she had a dream that she was infected, went to the health department the next day and was tested. She was right.

Since then she has been entirely healthy. She enrolled in the elite-controller project last year, and a week ago she revealed her HIV status to her friends and neighbors in Diamond Springs.

"I felt that 14 years was long enough to live in the closet," she told a news conference Wednesday. "If I've been blessed by this good health and this unique status, it is my obligation to speak for those who cannot or will not," she said.

Walker emphasized that participants in the story do not need to reveal their status publicly.

Over the next six months, he and his collaborators hope to enroll 1,000 elite controllers and 1,000 "viremic controllers" -- people who have kept their viral load between 50 and 2,000 viruses per milliliter.

That second group is considered important because people taking AIDS drugs who are able to keep their viral load below 2,000 have a very low rate of disease progression and of infecting others through sexual activity.

A vaccine that kept the infection that much in check would be highly useful. It would keep people well and would lead to few new infections. It would be "a recipe for the contraction of the epidemic," Walker said.

The problem is that researchers do not know how such a vaccine would need to stimulate the immune system.

"What are we aiming for? Well, nobody really knows. But there is a reasonable chance that we will come up with something with this effort," he said.

Other researchers here talked about other emerging insights into natural resistance to HIV infection.

Shehzad Iqbal, a graduate student at the University of Manitoba, said he and his collaborators had found a substance called trappin-2 in the vaginal fluid of a small number of prostitutes in Nairobi, Kenya, who have not been infected by HIV despite hundreds of exposures.

The women have been the subjects of close study by a team of Canadian researchers since they were identified in 1984. What cells make the substance and how it works are not known, but "it may be a good candidate for a microbicide" -- a vaginal gel that a woman could use to prevent infection, Iqbal said.

A researcher from Mount Sinai School of Medicine, Arevik Mosoian, described a substance called prothymosyn alpha that is produced by certain immune-system cells and that appears to suppress HIV's ability to replicate.

She said it is uncertain whether this is the same substance, called CAF, that Jay Levy at the University of California at San Francisco found years ago and which has eluded complete identification since then.

Nicole Lund of the University of Toronto described another molecule, called globotriaosyl ceramide (GB3), that appears to make it more difficult for HIV to attach to a cell, which is the first step of infection.

Cells lacking GB3 are highly susceptible to infection. Something that enhanced or mimicked GB3's action could offer a new way to prevent infection.