Cell Cycle Arrest by Vpr in HIV-1 Virions and Insensitivity to Antiretroviral Agents

Abstract

Expression of human immunodeficiency virus–type 1 (HIV-1) Vpr after productive infection of T cells induces cell cycle arrest in the G 2 phase of the cell cycle. In the absence of de novo expression, HIV-1 Vpr packaged into virions still induced cell cycle arrest. Naturally noninfectious virus or virus rendered defective for infection by reverse transcriptase or protease inhibitors were capable of inducing Vpr-mediated cell cycle arrest. These results suggest a model whereby both infectious and noninfectious virions in vivo, such as those surrounding follicular dendritic cells, participate in immune suppression.