The run-up to the 20th International AIDS Meeting, scheduled to wrap up on 25 July in Melbourne, Australia, was overshadowed by news that a three-year-old child once thought to be cured of HIV still harbours the virus — and by the horrific crash of Malaysian Airlines flight 17, which claimed the lives of six conference delegates.
Here Nature rounds up three major cure stories that unfolded at the conference.
1. HIV establishes secure hiding places from the immune system extremely early after infection — a huge obstacle to developing a cure for HIV infection, scientists say. Researchers reported in Nature on 20 July that monkeys treated starting three days after infection with simian immunodeficiency virus (SIV) appeared to be free of virus after two years. But after treatment was stopped, the virus escaped from its hiding places, or “reservoirs”, and the infections resurged in the monkeys.
2. Still, finding a way to eliminate such reservoirs seems the only way to a cure, and scientists reported a degree of progress in this direction on 22 July. A team from Aarhus University in Denmark used a cancer drug called romidepsin to re-activate dormant HIV in six infected patients. HIV then surged to detectable levels in five of the patients. The next step in this ‘kick and kill’ strategy is to find a way to eliminate the resurgent virus and the cells that produce it — perhaps by using a therapeutic vaccine to boost the patients’ immune systems.
3. Other researchers are testing gene therapy to cure HIV — for instance, by modifying immune cells so that they become resistant to the virus. A team at the University of New South Wales in Australia is examining whether inducing lab-grown cells to make proteins that target HIV can block infection. Another Australian group infused HIV-infected cells with molecules that prevented cells from becoming activated by drugs such as romidepsin. This raises the possibility of a strategy that reverses the kick-and-kill approach: it would prevent resting cells from leaving their dormant state. Neither strategy is yet being tested in patients, but against this week’s suite of dispiriting news, they offer a reminder that the HIV cure field is far from exhausting all options.