Investigators in the Division of Infectious Diseases at the University of North Carolina (UNC) School of Medicine have found that macrophages, in addition to T cells, act as a reservoir for the human immunodeficiency virus (HIV). These findings could potentially shift the focus from clearing the virus from T cells to also eradicating it from macrophage-large white blood cells found throughout the body, including the liver, bone marrow, lung, and brain.
Published in Nature Medicine, the study, “HIV Persistence in Tissue Macrophages of Humanized Myeloid-Only Mice During Antiretroviral Therapy,” focused on how macrophages would respond to antiretroviral therapy (ART). Led by J. Victor Garcia, PhD, professor of medicine, microbiology and immunology at UNC School of Medicine, researchers used a mouse model lacking T cells to show that ART suppressed HIV replication in tissue macrophages. Viral rebound occurred in one third of the subject animals when HIV treatment was interrupted, according to the study.
“This is the first report demonstrating that tissue macrophages can be infected, and that they respond to antiretroviral therapy,” notes Jenna Honeycutt, PhD, the study’s lead author and postdoctoral research associate in the UNC Division of Infectious Diseases. “In addition, it shows that productively infected macrophages can persist despite ART — and, most importantly, that they can reinitiate and sustain infection upon therapy interruption, even in the absence of T cells — the major target of HIV infection.”