Boosting Body's Immune System Key to HIV Cure

The research team, led by Dr Marc Pellegrini from the Walter and Eliza Hall Institute, showed that a cell signaling hormone called interleukin-7 (IL-7) reinvigorates the immune response to chronic viral infection, allowing the host to completely clear virus.

Pellegrini said the finding could lead to a cure for chronic viral infections such as HIV, hepatitis B and C, and bacterial infections such as tuberculosis, which are significant economic and global health burdens.

The team investigated the role of IL-7, a naturally-occurring immune hormone, in a mouse model of HIV infection. IL-7 is a cytokine (cell signalling hormone) that plays a critical role in immune system development and maintenance.

"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," Pellegrini said.

Further investigations revealed that, at the molecular level, IL-7 switched off a gene called SOCS-3.

"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," Pellegrini said.

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

Preston, who worked on the SOCS-3 studies, said that switching off the SOCS-3 gene boosted the immune system and helped the animals to completely eliminate the infection.

The findings were released in today's edition of the journal Cell.