HIV antiviral therapy lets infected people live relatively healthy lives for many years, but the virus doesn’t go away completely. If treatment stops, the virus multiplies again from hidden reservoirs in the body. Now, investigators from the Harvard-affiliated Massachusetts General Hospital (MGH) and the Ragon Institute of MGH, MIT, and Harvard may have found HIV’s viral hiding place — in a small group of recently identified T cells with stem cell-like properties.
“Most human cells are short-lived, so it has been unclear how HIV manages to stick around for decades in spite of very effective antiviral treatment,” said Mathias Lichterfeld of the MGH Infectious Disease Division, an assistant professor at Harvard Medical School and corresponding author of a report on the findings receiving advance online publication in Nature Medicine.
Though HIV normally attacks immune system cells called T cells, those cells are short-lived. The virus’ ability to survive years of therapy caused researchers to wonder whether it might also infect stem cells, regenerative cells that are the longest-lasting in the body, Lichterfeld said. The problem with that idea is that organ-specific stem cells are resistant to HIV infection.
“We have discovered that a new group of T cells, called T memory stem cells, are susceptible to HIV and likely represent the longest-lasting cellular niche for the virus,” Lichterfeld said.