Piece of HIV Puzzle Put in Place
March 16, 2000 (Atlanta) -- A common gene links the very uncommon people who
are infected with HIV but seem to remain invulnerable to developing full-blown
AIDS. These individuals, who remain healthy for many years after being infected
with HIV, may point the way to effective vaccines and treatments, according to
a study in the March 14 issue of Proceedings of the National Academy of
The research team that conducted the study searched high and low for people
who not only remained healthy and had a normal immune system after years of HIV
infection, but also had extremely low levels of the virus in their blood. Years
of search turned up 13 of these people. Eleven of the 13 carried a protective
gene. What complicates the issue -- and points to even more important findings
-- is the fact that the gene also occurs in about 10% of people who do
go on to develop AIDS.
Lead investigator Mark Connors, PhD, tells WebMD that this means that
additional factors are involved -- and that the search for these factors may
lead to breakthroughs in AIDS research. "This is the important piece that
we don't understand, and it means there has to be a second piece of this
puzzle," says Connors, senior clinical investigator at the National
Institute of Allergy and Infectious Disease Laboratory of Immunoregulation.
Other researchers have found a protective effect for this gene, although not
nearly as strong as that seen in this current study. Mary Carrington, PhD,
senior scientist at NCI-Frederick, tells WebMD that genetic studies in her
laboratory show that people with this gene have significantly slower HIV
This looks like a protective gene, says Carrington, who was not involved in
the study. In a recent study performed by Carrington and colleagues, she tells
WebMD they found that half of the HIV-infected people with this gene developed
AIDS within 14 years compared to half of people without the gene who developed
AIDS sooner -- within 10 years. As of now, researchers are unable to explain
how the gene is protective in HIV positive patients.
Connors suggests that further research will point the way to effective AIDS
vaccines and/or treatments. Researchers hope to figure out how the gene works
and then harness that power for those who don't carry the gene. However,
Connors says if they never find out what makes this gene tick, "even so,
these patients have been incredibly useful in telling us ... what can be done
against the virus. So now we are comparing them to progressors to understand
what it is that is helping them."
- Researchers believe they can learn about developing AIDS vaccines and
treatments by studying the few people who have low levels of HIV in their blood
and do not go on to develop the disease.
- Eleven of 13 people studied had a common gene that seems to be a protector
against developing AIDS. But scientists know 1 in 10 AIDS patients also has the
gene. This makes researchers think there still is a missing piece to the
- Scientists say more research is needed to find out just how the gene
protects some people before any treatments can be developed.