title: A doubly fluorescent HIV-1 reporter shows that the majority of integrated HIV-1 is latent shortly after infection.
abstract: HIV-1 latency poses a major barrier to viral eradication. Canonically, latency is thought to arise from progressive epigenetic silencing of active infections. However, little is known about when and how long terminal repeat (LTR)-silent infections arise since the majority of the current latency models cannot differentiate between initial (LTR-silent) and secondary (progressive silencing) latency. In this study, we constructed and characterized a novel, double-labeled HIV-1 vector (Red-Green-HIV-1 [RGH]) that allows for detection of infected cells independently of LTR activity. Infection of Jurkat T cells and other cell lines with RGH suggests that the majority of integrated proviruses were LTR-silent early postinfection. Furthermore, the LTR-silent infections were transcriptionally competent, as the proviruses could be reactivated by a variety of T cell signaling agonists. Moreover, we used the double-labeled vector system to compare LTRs from seven different subtypes with respect to LTR silencing and reactivation. These experiments indicated that subtype D and F LTRs were more sensitive to silencing, whereas the subtype AE LTR was largely insensitive. Lastly, infection of activated human primary CD4(+) T cells yielded LTR-silent as well as productive infections. Taken together, our data, generated using the newly developed RGH vector as a sensitive tool to analyze HIV-1 latency on a single-cell level, show that the majority of HIV-1 infections are latent early postinfection.
authors: Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada.
authors: Matthew S
authors: MS
authors: Dahabieh
authors: Marcel
authors: M
authors: Ooms
authors: Viviana
authors: V
authors: Simon
authors: Ivan
authors: I
authors: Sadowski
mesh_terms: D017930:Genes, Reporter; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D019169:Jurkat Cells; D013194:Staining and Labeling / Q000379:methods; D013601:T-Lymphocytes / Q000821:virology; D014773:Virology / Q000379:methods; D017735:Virus Latency