Immune system gene could subdue HIV and hepatitis

In a major development on the front of treatment of HIV and other chronic infections, the researchers have found that a gene protecting the human embryo could possibly treat and subdue chronic infections such as HIV, hepatitis and tuberculosis.

The recently identified gene, called Arih2, is basic to the immune system - making critical decisions about whether to switch it on during an infection or not.

According to the journal Nature Immunology reports, Marc Pellegrini, Greg Ebert and colleagues from the Walter and Eliza Hall Institute of Medical Research's infection and immunity division, Australia, with collaborators from the University of Toronto, Canada, led the research,

Pellegrini who is an infectious disease specialist said that Arih2 is found in dendritic cells, the sentinels of the immune system that play a vital role in raising the alarm about the presence of foreign invaders in the body, says a Walter Eliza Institute statement.

"Arih2 is responsible for the most fundamental and important decision that the immune system has to make - whether the immune response should be initiated and progressed or whether it should be switched off to avoid the development of chronic inflammation or autoimmunity," Pellegrini has been quoted as saying.

"If the wrong decision is made, the organism will either succumb to the infection, or succumb to auto-immunity."

"During evolution, some organisms have evolved ways of exhausting our immune system to the point where the immune system just switches off, and this is what happens in HIV, Hepatitis B and tuberculosis," he added.

"These organisms counter the immune response - exhausting T cells which are stimulated over and over again by the infection and becoming exhausted or paralysed," Pellegrini said.

"With this current discovery, what we should be able to do is circumvent these mechanisms and reinvigorate the immune response temporarily to boost the immune system and help clear these infections," he stated.

Ebert said that his research team was now examining the effect on the immune response of switching off Arih2 for short periods of time during chronic infections.

"We are investigating how manipulating Arih2 and associated pathways promotes immunity in chronic overwhelming infections, where we know the immune response is inadequate," Ebert added.

Pellegrini said that, it would take many years to translate the discovery to a drug that could be used in humans. "We are very excited about this discovery."

--with inputs from IANS