In vitro reactivation of human immunodeficiency virus 1 from latently infected, resting CD4(+) T cells after bacterial stimulation

Microbial coinfections have been associated with transient bursts of human immunodeficiency virus (HIV) viremia in patients. In this study, we have in vestigated whether microbial coinfections can induce replication of HIV-1 i n latently infected CD4(+) T cells derived from HIV-infected patients who a re receiving highly active antiretroviral therapy and in whom plasma viremi a is undetectable by sensitive assays. We demonstrate that supernatants fro m macrophages exposed to the bacterial product lipopolysaccharide can induc e in vitro activation of HIV-1 from latently infected, resting CD4(+) T cel ls obtained from HIV-infected individuals, Depletion of proinflammatory cyt okines from the supernatant markedly reduced-whereas depletion of beta chem okines increased-the ability of the supernatant to induce replication of HI V-1. Our results suggest that coinfection with microbial pathogens such as bacteria may induce viral replication in the latent viral reservoirs in viv o.