Some people have a genetic tweak that gives them a natural immunity to HIV, allowing them to live without any symptoms of infection. Now researchers are trying to pinpoint exactly how they manage this. In a paper published in the journal Science Immunology, scientists have taken tentative steps in that direction.
Despite the continued stigma surrounding HIV, the development of treatments to fight the virus is actually one of the greatest achievements of modern medicine. Rather than being the death sentence it was when the virus was first identified, people today with HIV that receive treatment have a life expectancy no different than the general population. Not only that, but we even have drugs that can prevent someone from being infected in the first place.
The main problem, however, is that anyone receiving treatment has to take medicine every single day. While clearly inconvenient, this isn’t too much of a problem for people in the West. But for those who have been diagnosed with or are at risk of contracting HIV in the developing world, taking drugs every day for the rest of their lives is simply an impossibility, due largely to access and cost.
So researchers have turned their attention to the tiny proportion of people known as HIV “elite controllers”. These are people who are infected with the virus but show no symptoms of HIV for decades, even without the use of medication. How they manage this has remained unknown, but many are now desperately trying to figure it out in order to produce similar results in non-elite controller patients.
When HIV infects the body, it heads for the immune cells known as T cells. While much of previous research has focused on how the virus affects these cells as they circulate in the blood – due largely to the ease at which this is sampled – the latest team looked instead at what happens when the infected T cells return to the lymphoid tissue that forms part of the immune system.
While elite controllers have CD8 T cells that are more efficient at killing HIV-infected cells in the blood, the majority of the virus is not found in the blood but the tissue. Here, elite controllers, seem to have a unique adaptation too. Unlike most patients, the T cells of elite controllers move into the lymphoid tissue and stay there, expressing different genes and making different proteins to help fight off the HIV that's infecting the tissue.
How they do this – and how scientists can replicate it – is the next step in fully understanding the ability of HIV elite controllers, but hopefully this research will form the foundations for future studies.
[H/T: New Scientist]