Australian scientists may have discovered a vital key to curing HIV and other immune related illnesses by boosting the body’s immune response. A team of researchers led by Dr. Marc Pellegrini from the Walter and Eliza Hall Institute, successfully cured a HIV-like infection from mice by boosting the function of cells vital to their immune system.

Dr Pellegrini, from the institute’s Infection and Immunity unit is confident that the study’s findings offer a superior solution to current attempts at curing chronic infections that focus on long-lived immune responses.

“Viruses such as HIV and hepatitis B and C overwhelm the immune system, leading to establishment of chronic infections that are lifelong and incurable,” said Dr Pellegrini. “Despite tremendous efforts, long-lived immune responses for some of these viruses are ineffective, because the body is so overrun by virus that the immune system, in particular T cells, just give up trying to battle the infection. Some people have coined the phrase ‘immune exhaustion’ to explain the phenomenon. 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.”

The research focused on interleukin-7 (IL-7) – a naturally occurring hormone that stimulates the immune responses. The team illustrated how the IL-7 hormone can stimulate the body’s immune response to successfully clear chronic infections and viruses.

“We found that IL-7 boosted the immune response in a pretty profound fashion, such that animals were able to gradually clear the virus without too much collateral tissue damage,” added Dr Pellegrini. Further investigation also highlighted that at the molecular level, the IL-7 hormone switched off a gene called SOCS-3. By switching off the SOCS-3 gene, the mice maintained a stimulated immune system that helped eliminate the infection.

“The key for us was figuring out that turning off SOCS-3 only really worked when it was within T cells,” explained Mr Preston, one of the study’s researchers. “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.”

The study provides great promise in helping find a cure for chronic infections such as HIV, hepatitis B and C, and bacterial infections such as tuberculosis. The findings have been published in the online journal, Cell.