It was recently discovered that small number of people are able to naturally cure themselves of an HIV infection. A person referred to as EC2, once had HIV but showed no functional copies of the virus in the 1.5 billion cells analyzed. However, EC2 did still have some nonfunctional copies of HIV left behind. In another person labeled EC1, only 1 of 1 billion cells contained functional copies of HIV. These two people are referred to as "elite controllers" and they are some of the few people to have kept the HIV under control without medication. It has been difficult for researchers to determine the mechanism for how the elite controllers keep functional HIV copies at a minimum. Studies indicate that elite controllers have a genetic variant in their immune system that contributes to their control of viruses. Researchers then inserted the functional HIV into DNA from 64 elite controllers and 41 HIV-infected participants on antiretroviral drugs. The DNA from elite controllers maintained low levels of functional HIV for a median of 9 years. It has been hypothesized that elite controllers were rather lucky when first being infected with HIV because it was stored in the heterochromatin. Therefore, the HIV was most likely to stay inert and not replicate rapidly as if it were in other parts of the human genome. Overall, the suspicion is that the elite controllers' immune system first destroys cells producing functional HIV, which then leaves only fragments of HIV, which is then stored in heterochromatin for containment. The exact mechanism for this process is still under investigation.
C. Jiang et al. Distinct viral reservoirs in individuals with spontaneous control of HIV-1. Nature. August 26, 2020. doi: 10.1038/s41586-020-2651-8
Saey, T. H. (2021, January 30). In a first, a person's immune system fought HIV - and won. Retrieved from https://www.sciencenews.org/article/hiv-immune-system-elite-controllers