Boosting immune response rids HIV in mouse model

Kathleen Blanchard's picture

Researchers have a new idea to cure HIV by boosting levels of cells that are vital to immune function.

Scientists were able to clear HIV in a mouse model by switching off a gene called SOCS-3 that becomes highly activated in the presence of viral infections.

Dr Marc Pellegrini from the Walter and Eliza Hall Institute explains viruses overwhelm the immune system so they just give up. That's why viruses like Hepatitis B and C and HIV become incurable. He says, "Our approach is to discover some of the mechanisms that cause this immune exhaustion, and manipulate host genes to see if we can boost the natural immune response in order to beat infection"

In the study, the researchers investigated IL-7, hormone that occurs naturally and is critical for immune function. They found the hormone cleared the mice from infection.


During their investigation of the hormone, they also found that IL7 switched off the SOC3 gene.

"In an overwhelming infection, 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 Pellegrini said. "In the case of these overwhelming infections, the immune system effectively slams on the brakes too early, and the infection persists."

The key finding, according to Mr Simon Preston from the Ontario Cancer Institute, was figuring out turning off the SOC-3 gene only worked to rid the mice of HIV when it was switched off inside T-cells. "It allowed the immune response to boost the number of virus-specific T cells and have an immune response good enough to eliminate the virus without initiating an immune response that was too large and would make the animal sick."

Current approaches to treating HIV and other chronic infections focus on long-lasting immunity. The researcher say that doesn't always work. Instead, the team is focusing on how to manipulate the immune system to help the body fight infection. Pelligrini says it might be possible to develop drugs that target specific molecules. Switching off genes like SOC3 for short periods of time might invigorate the immune system to fight HIV and other chronic viral infections.

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