The hormone that holds key to HIV cure and other long-term infections, including hepatitis B and C

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The hormone that holds key to HIV cure

By GATONYE GATHURA gathura@...

Posted Saturday, February 5 2011

Scientists have discovered a treatment that could eliminate the Aids-causing

virus from the system and allow the body to cure itself.

It has been known that HIV’s persistent attack on the body overwhelms the

defence or the immune system, eventually wearing down the white blood cells.

White blood cells or T-cells are primarily responsible for fighting off foreign

organisms that enter the body.

Like an army

Just like in an army that is constantly at war, the solders, in this case the

white blood cells, can become exhausted and give up, leaving the body

defenceless and open to opportunistic infections.

In such a case, the military commander, knowing that he is fighting a losing

war, may decide to surrender to avoid more damage. The body has a similar

mechanism.

Scientists have also discovered that overproduction and excitement of white

blood cells can damage some other body tissues and sometimes lead to leukaemia,

a type of blood cancer.

The overproduction of white blood cells or an overworked immune system in people

with HIV and other chronic infections has been associated with the possible

development of cancers and heart disease.

Now Australian scientists at the Walter and Eliza Hall Institute have

manipulated this mechanism to ensure the production and activation of white

blood cells does not stop but goes on until HIV and other viruses have been

eliminated from the body.

In a press statement released by the institute on Friday, the researchers said

they manipulated the gene SOCS-3, which orders the “surrender” of white blood

cells, with a hormone called IL-7.

When the researchers increased levels of the hormone IL-7, the gene SOCS-3

“switched off” and the trial mice were able to gradually eliminate the HIV from

their bodies, says the main study published in the February 4 issue of the

journal Cell.

Overwhelming infection

“In an overwhelming infection like HIV, SOCS-3 becomes highly activated and

suppresses the immune response, probably as a natural precaution to prevent ‘out

of control’ responses that cause collateral damage to body tissue,” Dr Marc

Pellegrini, the lead researcher, said in the statement.

“In the case of these overwhelming infections, the immune system effectively

slams on the brakes too early, and the infection persists.”

Switching off the SOCS-3 gene made sure the white cells remained active and

helped the lab mice completely eliminate the infection.

The switch off and immune boost were timed to be long and strong enough to

eliminate the virus without causing damage to other body tissues.

Dr Pellegrini said the research had provided excellent ideas for new treatments

that could target and boost immune cells to fight disease, rather than targeting

the disease itself.

“The findings could help to develop drugs that target some of these host

molecules, such as SOCS-3, and turn them off for very short, defined periods of

time to reinvigorate the T-cells, allowing them to regroup to fight infection,”

he said.

The researchers say their work raises a real possibility for a possible cure not

only for HIV but for other long-term infections, including hepatitis B and C and

tuberculosis.

Despite tremendous efforts, long-lived immune responses for some of these

viruses are ineffective because the body is so overrun by the virus that the

immune system gives up trying to battle the infection.

Anti-retroviral treatment

An estimated 1.5 million Kenyans are infected with HIV, of which about a third

are on antiretroviral treatment. Antiretrovirals work by suppressing the

replication of the virus in the body and are a life-long treatment.

Like most other medicines for chronic diseases, they sometimes cause serious

side effects, and a patient is advised to be in constant communication with a

qualified clinician.