title: Reactivation of HIV-1 proviruses in immune-compromised mice engrafted with human VOA-negative CD4+ T cells.
abstract: BACKGROUND
  HIV-1 infection remains incurable on antiretroviral therapy (ART) due to virus latency. To date, enhanced co-culture assays, including viral outgrowth assays (VOA), are commonly used to measure HIV-1 latent reservoirs and evaluate latency-reversing agents (LRAs). However, VOA can only reactivate a small fraction of intact proviruses.
  
  
  METHODS
  To explore the utility of NOD scid gamma (NSG) mice as anin vivomodel to reactivate HIV-1 proviruses from VOA-negative CD4+ T cells, resting CD4+ T cells from an HIV-1 latently infected individual were isolated and the human CD4+ T cells corresponding to VOA-positive and VOA-negative CD4+ T cells were engrafted into NSG mice. Plasma viral load (pVL) and human CD4+ T cells were quantified every other week using qRT-PCR and flow cytometry.
  
  
  RESULTS
  We found that NSG mice reactivated latently infected HIV-1 from VOA-positive CD4+ T cells as well as VOA-negative CD4+ T cells. Engrafted CD4+ T cells proliferated considerablyin vivo, peaked prior to provirus reactivation, and lasted for up to 14 weeks. Sequence analyses revealed that reactivated proviruses in VOA-positive and VOA-negative CD4+ T cells are different.
  
  
  CONCLUSIONS
  Taken together, NSG mice can support long-term engraftment of human CD4+ T cells and reactivate VOA-positive and VOA-negative proviruses. Therefore, thisin vivomodel has the potential to be used to study the underlying mechanisms of HIV-1 latency and reactivation.
authors.affiliation: Nebraska Center for Virology, School of Biological Sciences , University of Nebraska-Lincoln , Lincoln , NE , USA.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Yuan
authors.affiliation: Nebraska Center for Virology, School of Biological Sciences , University of Nebraska-Lincoln , Lincoln , NE , USA.
authors.forename: Guobin
authors.initials: G
authors.lastname: Kang
authors.affiliation: Nebraska Center for Virology, School of Biological Sciences , University of Nebraska-Lincoln , Lincoln , NE , USA.
authors.forename: Wuxun
authors.initials: W
authors.lastname: Lu
authors.affiliation: Nebraska Center for Virology, School of Biological Sciences , University of Nebraska-Lincoln , Lincoln , NE , USA.
authors.forename: Qingsheng
authors.initials: Q
authors.lastname: Li
keywords: HIV-1 latency; clonal expansion; immune-compromised mice; in vivo provirus reactivation; resting CD4+ T cells; viral outgrowth assay