Here is the full blown article.
October 24, 1997
Researchers Find a Molecule
That Protects Cells From HIV
Associated Press
WASHINGTON -- Researchers have identified a natural molecule that
prevents HIV from infecting cells, a basic discovery they say could lead
eventually to powerful new types of AIDS drugs or even a vaccine.
The molecule, discovered by a Maryland-based team led by famed AIDS
researcher Robert Gallo, works against HIV by physically blocking the
portal used by the virus to invade lymphocytes and other types of blood
cells. The study by Mr. Gallo and his team will be published Friday in the
journal Science.
Mr. Gallo's team at the Institute of Human Virology at the University of
Maryland-Baltimore, earlier identified three similar molecules, all called
chemokines. But the new molecule is much more effective because it
protects all the cell types attacked by HIV, Mr. Gallo said.
Flooding the body with these
chemokines could create a
barrier between HIV and its
target cells, and, thus, prevent
the virus from spreading its
deadly infection, Mr. Gallo said.
"Its breadth of activity and its potency will make it more important than
any of the other chemokines found so far," Mr. Gallo said in an interview.
But he emphasized that before chemokines can be tried against HIV in
humans, the molecules must be extensively tested in monkeys against a
related virus called simian immunodeficiency virus. Such testing could take
several years.
Discovery of the new chemokine comes just as doctors report that some
AIDS virus is developing a resistance to the three-drug combination that
has successfully suppressed HIV in thousands of patients. That
combination of reverse transcriptase and protease inhibitors works against
the virus inside the target cell.
Chemokines would work against HIV by preventing the virus from
entering those cells. The virus is thought to be less able to develop a
resistance against this blocking action.
The discovery "sounds very promising" as a new type of treatment against
the disease, said Patricia D'Souza, an AIDS researcher at the National
Institute of Allergy and Infectious Diseases.
"This chemokine appears to inhibit the viruses that appear early, as well as
those that develop later," Ms. D'Souza said. "It might be really valuable in
preventing infection, as well as preventing the progression of the disease."
Chemokines have been the subject of intense study by AIDS researchers
since the discovery a decade ago that the molecules somehow work to
suppress HIV, and are secreted by immune-system blood cells in
response to HIV infection.
Their natural function is to attach to white blood cells, which are the body's
major disease fighters, and guide those cells to the site of an infection.
Earlier research showed that chemokines attached to white blood cell
surfaces at the same points, called receptors, that were used by the HIV
virus. The scientists also found that some strains of HIV concentrated on
one type of receptor, while other strains targeted other receptors.
Mr. Gallo and his team earlier identified three chemokines that were able
to block an HIV strain that mainly attacked macrophages, one type of
blood cell.
The new chemokine is able to block not only the HIV strains that attack
macrophages, but also the virus that attacks T-cells, the principal warrior
of the immune system and the primary target of HIV, Mr. Gallo said.
"This chemokine is so broad that it also blocks SIV," or simian
immunodeficiency virus, the monkey equivalent of HIV, human
immunodeficiency virus, Mr. Gallo said. "That means we can go right into
testing on monkeys. This is a major step forward."
If the chemokines prove effective, he said, it may be possible to control
HIV infection with periodic injections of a "cocktail" of several types of
chemokines.
"It would be like using insulin shots to control diabetes," Mr. Gallo said.
It may also be possible to create a vaccine that prompts the body to
produce high amounts of the HIV-specific chemokines. That, in theory,
could prevent the initial HIV infection. |
