A recent study conducted by a team of researchers at the Karolinska Institutet in Sweden and the University of Pennsylvania suggests that a new method of treating HIV may be just as effective at combating the disease; one that doesn’t involve killing infected cells but suppressing the HIV virus and preventing replication.
A small percentage of individuals infected with HIV do not go on to develop AIDS, even if they receive no treatment. These individuals are known as elite controllers. They are able, without any medications, to control the infection and prevent HIV from replicating, according to the study.
For all but elite controllers, infection with the HIV virus will gradually lead to the loss of white blood cell called CD4+ T cells. These cells, in conjunction with CD8+ T cells, attack foreign material in the body and kill cells infected with viruses. In patients with HIV, the lower the number of CD4+ cells, the worse the symptoms of HIV will be as infected cells are not killed off in sufficient numbers.
Elite controllers have stable CD4+ T cell counts and undetectable HIV viremia and do not require treatment for the infection. These individuals were found to have much more effective CD8+ T cells than the majority of other people infected with HIV.
To determine how the CD8+ T cells differed in elite controllers, the researchers studied blood samples and lymph node tissue from 51 HIV+ patients, 12 of whom were elite controllers. The researchers performed single-cell RNA sequencing analyses and found higher numbers of CD8+ T cells in samples of lymphoid tissue taken from the elite controllers than the other patients. However, those cells were non-cytolytic CD8+ T cells, so they were not capable of killing infected cells. Further analyses revealed they had a distinct transcriptional profile and, through increased ribosomal function, they were more effective at building proteins from amino acids. This allowed a much greater variety of cytokines to be produced and in much greater numbers, which boosted the polyfunctionality of the cells.
Killing cells infected with HIV is only one way that the disease can be controlled. This research strongly suggests that killing infected cells is not necessary to stop the progression of HIV to AIDS. Viral suppression could be just as effective a treatment for HIV. While it would not eradicate the virus, it could serve as an effective functional cure.
You can read more about the study in the paper – Elite control of HIV is associated with distinct functional and transcriptional signatures in lymphoid tissue CD8+ T cells – was recently published in the journal Science Translational Medicine. DOI: 10.1126/scitranslmed.aax4077