Scientists have identified a new HIV reservoir in the body where HIV persists despite treatment. This discovery has major implications for cure research.
Current HIV cure research has focused on clearing the virus from a type of white blood cells, called T cells, which is an essential part of the immune system. However, investigations have found the virus persists in another type of white blood cells called macrophages. Macrophages are large white blood cells found in tissues throughout the body including the liver, lung, bone marrow and brain. The discovery of this other HIV reservoir has significant implications for HIV cure research. These findings were published in Nature Medicine on Monday, April 17.
“These results are paradigm changing because they demonstrate that any possible therapeutic intervention to eradicate HIV might have to target two very different types of cells,” said Jenna Honeycutt, Ph.D., lead-author and postdoctoral research associate.
Garcia and his team showed that ART drugs strongly suppress the multiplication of HIV virus in tissue macrophages. Yet when HIV treatment was interrupted, viral levels bounced back in one third of the study animals. This is consistent with the establishment of a HIV reservoir in tissue macrophages.
“This is the first report demonstrating that tissue macrophages can be infected and that they respond to antiretroviral therapy,” Honeycutt said. “In addition, we show that infected macrophages can persist despite treatment; and most importantly, that they can restart and sustain infection upon interrupting treatment even in the absence of T cells — the major target of HIV infection.”
Now that Garcia and his team know HIV persists in macrophages, the next step will be to determine what regulates HIV persistence in tissue macrophages, where in the body persistently infected macrophages reside during HIV treatment and how macrophages respond to possible therapeutic interventions aimed at eradicating HIV from the body.