By Chris Young
Daily Bruin Reporter
UCLA has long been on the cutting-edge of AIDS research ““
in 1981 it was a UCLA doctor who first identified the disease.
Twenty years later, UCLA has more than 140 faculty working on
projects of the human immunodeficiency virus ““ the virus that
causes AIDS ““ and of the more than 70 clinical trials of HIV
vaccines being tested in the United States, four are at UCLA. As
research on HIV vaccines increases, UCLA scientists predict a
vaccine will be approved by the government in eight to 10
years.
Scientists group vaccines into two types: preventive vaccines
administered to HIV-negative people block infection, and
therapeutic vaccines help boost the immune systems of HIV-positive
people. HIV destroys the body’s natural immune system and
lowers its capacity to fight other diseases.
Currently, UCLA has two therapeutic and two preventive vaccines
in clinical trial phases, and more are in preclinical testing.
Irvin Chen, director of the UCLA AIDS Institute, is developing a
preventive vaccine to kill the HIV but allow the body’s
immune system to build up protection against the virus.
Chen’s team treats the HIV with chemicals that target its
ribonucleic acid genome and proteins used for proper functioning,
making it impossible to reproduce the virus in humans.
The virus has proteins on its outer envelope, called GP120
proteins, that the human immune system detects. As Chen’s
group prepares the vaccination by killing the viral sample, its
normally coiled GP120 proteins unravel, exposing previously hidden
parts that let the immune system better identify HIV.
“By exposing parts of GP120 so the immune system can
detect them, the body makes a better immune response,” Chen
said.
Peter Anton, an associate professor in medicine at UCLA, uses a
virus with only three HIV genes that cannot replicate in
humans.
Anton’s group genetically engineered a virus with only a
few of the genes or proteins of HIV. The body recognizes this
incomplete virus as the real HIV and builds an immune response to
it. But because the virus is incomplete, patients won’t
actually be infected with HIV.
Anton’s Phase I trial will look at whether the site of
injection of a vaccine will change the body’s effectiveness
in fighting the real virus.
These three protein-making genes will hopefully generate B- and
T-cell immune responses in the body. B- and T-cells are two types
of white blood cells that significantly contribute to the immune
system.
Trial subjects will be given a vaccine either in the arm ““
the traditional injection site ““ or the pelvic region. Anton
said vaccinating the pelvic region might be more effective because
the part of the immune system the vaccine affects is located in the
groin, close to the likely location of HIV exposure.
“If the vaccines administered to the arm show a 30-percent
efficacy, for example, researchers may conclude it is not very
effective,” he said. “But if that vaccine is
administered to the groin or thigh, perhaps they would see a 60-
to70-percent efficacy.”
Judith Currier, an associate professor at UCLA, is evaluating an
HIV vaccine that, like Anton’s, uses only parts of HIV that
may allow the immune system to gain resistance against the
virus.
The vaccine, developed by Merck, a pharmaceutical company, is in
Phase I trial to test its safety at 12 sites, including UCLA.
Currier says the vaccine carries an HIV regulatory protein, GAG,
that will hopefully initiate an immune response.
The vaccine is based on research on HIV-positive patients who
did not acquire AIDS and who showed a strong immune response to
GAG, implying that their immune systems detected the protein and
mounted a good immune response against it.
But despite the advances in HIV vaccinations, the public should
not get lulled into a false sense of security that the HIV/AIDS has
been “solved,” Landsman said.
He noted that when protease inhibitors ““ drugs that stop
HIV from replicating in the body ““ were initially approved
and got good results, many started having unprotected sex because
they thought “we had “˜conquered it.'”
“Drugs have some horrible side effects, and vaccines will
come, but they are a ways off,” Landsman said.
“Prevention is more important.”