Human Immunodeficiency Virus Type 1 Can Establish Latent Infection in Resting CD4+T Cells in the Absence of Activating Stimuli

ABSTRACT Resting CD4 + T cells are the best-defined reservoir of latent human immunodeficiency virus type 1 (HIV-1) infection, but how the reservoir is formed is unclear. Understanding how the reservoir of latently infected cells forms is critical because it is a major barrier to curing HIV infection. The system described here may provide an in vitro model of latent HIV-1 infection in resting CD4 + T cells. We demonstrated that HIV-1 integrates into the genomes of in vitro-inoculated resting CD4 + T cells that have not received activating stimuli and have not entered cell cycle stage G 1b . A percentage of the resting CD4 + T cells that contain integrated DNA produce virus upon stimulation, i.e., are latently infected. Our results show that latent HIV-1 infection occurs in unstimulated resting CD4 + T cells and suggest a new route for HIV-1 reservoir formation.