aids virus functioning

[Guest guest]

Hi everyone,

I think this is pbly similar to some of our infections and if only

researchers would look as hard with as much money behind them as AIDS

researchers we might get places

Nelly

05:07 PM ET 11/11/99

Study: HIV Hides in Inactive WBC

Study: HIV Hides in Inactive WBC

By PAUL RECER=

AP Science Writer=

WASHINGTON (AP) _ A short time after it invades the body, the

virus that causes AIDS creates a reservoir of silent infection that

cannot be stamped out by current anti-viral drugs and may resist

vaccines, a study shows.

The study, to be published Friday in the journal Science, sheds

new light on how quickly HIV, the virus that causes AIDS, is able

to establish a chronic, drug-resistant infection.

Earlier studies have shown that HIV establishes a reservoir of

silent infection. The new research shows that this disease pool is

created almost immediately after the virus is transmitted.

``These chronically infected cells are important because they

allow the virus to persist below the radar screen of the immune

system, particularly at the time of the transmission,'' said Dr.

T. Haase, an HIV researcher at the University of Minnesota

and the senior author of the study.

Haase said the study shows that a short time after the sexual

transmission of the AIDS virus, there is an infection established

in what are known as resting T-cells. These are white blood cells

that are not actively participating in the body's immune response

to the virus and are resistant to anti-viral drugs.

The finding is contrary to the belief that HIV first infects two

other targets, macrophages and dendritic cells, and then spreads to

active T-cells.

Instead, said Haase, the virus quickly moves in about equal

proportions into both the resting and the active T-cells.

Dr. Tony Fauci, director of the National Institute of Allergy

and Infectious Diseases at the National Institutes of Health, said

the Haase study ``was a nice piece of work'' that gives important

new insight into the early stages of HIV infection.

By quickly infecting the resting T-cells, said Fauci, the virus

``gives itself some insurance of survival.'' Virus in resting

T-cells is a much more difficult target for both the immune system

and for anti-viral drugs, he said.

Fauci said the finding also is ``bad news for vaccines'' because

it makes it more difficult to inoculate the body against HIV

infection.

In the study, Haase and his colleagues first studied the

step-by-step progress of AIDS virus infection in monkeys. The

animals were vaginally infected with SIV, the simian form of HIV.

Researchers then took specimens to trace the disease progress.

They found that just three days after infection, the virus was

in both activated and resting T-cells. In the following days, it

spread faster and faster into the resting T-cells.

Haase said his group then looked at specimens from patients

recently infected with HIV and found a similar pattern. The virus

was present about equally in both resting and activated T-cells, he

said.

Virus in the resting T-cells is reproducing at a very, very low

level, said Haase. This makes the cells less obvious to the immune

system. It also creates a powerful defense against anti-virals

because these drugs attack HIV only when the virus is actively

reproducing.

The finding suggests that the current drugs never will

completely eradicate the virus, he said.

Haase said it is believed that the resting T-cells can persist

in the body for years, perhaps decades. This means that the HIV in

these cells would remain a threat even though the drugs reduce

virus in the blood stream to an undetectable level.