Ex Vivo Bioactivity and HIV-1 Latency Reversal by Ingenol Dibenzoate and Panobinostat in Resting CD4(+) T Cells from Aviremic Patients

Antimicrob Agents Chemother. 2015 Oct;59(10):5984-91. doi: 10.1128/AAC.01077-15. Epub 2015 Jul 13.


The human immunodeficiency virus type 1 (HIV-1) latent reservoir in resting CD4(+) T cells represents a major barrier to viral eradication. Small compounds capable of latency reversal have not demonstrated uniform responses across in vitro HIV-1 latency cell models. Characterizing compounds that demonstrate latency-reversing activity in resting CD4(+) T cells from aviremic patients ex vivo will help inform pilot clinical trials aimed at HIV-1 eradication. We have optimized a rapid ex vivo assay using resting CD4(+) T cells from aviremic HIV-1(+) patients to evaluate both the bioactivity and latency-reversing potential of candidate latency-reversing agents (LRAs). Using this assay, we characterize the properties of two candidate compounds from promising LRA classes, ingenol 3,20-dibenzoate (a protein kinase C agonist) and panobinostat (a histone deacetylase inhibitor), in cells from HIV-1(+) antiretroviral therapy (ART)-treated aviremic participants, including the effects on cellular activation and cytotoxicity. Ingenol induced viral release at levels similar to those of the positive control (CD3/28 receptor stimulation) in cells from a majority of participants and represents an exciting LRA candidate, as it combines a robust viral reactivation potential with a low toxicity profile. At concentrations that blocked histone deacetylation, panobinostat displayed a wide range of potency among participant samples and consistently induced significant levels of apoptosis. The protein kinase C agonist ingenol 3,20-dibenzoate demonstrated significant promise in a rapid ex vivo assay using resting CD4(+) T cells from treated HIV-1-positive patients to measure latent HIV-1 reactivation.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Anti-HIV Agents / therapeutic use*
  • Antiretroviral Therapy, Highly Active
  • CD4-Positive T-Lymphocytes / drug effects
  • CD4-Positive T-Lymphocytes / pathology
  • CD4-Positive T-Lymphocytes / virology
  • Case-Control Studies
  • DNA, Viral / antagonists & inhibitors
  • DNA, Viral / biosynthesis
  • Diterpenes / pharmacology*
  • Enzyme Activators / pharmacology
  • Female
  • HIV Infections / drug therapy*
  • HIV Infections / pathology
  • HIV Infections / virology
  • HIV-1 / drug effects*
  • HIV-1 / enzymology
  • HIV-1 / genetics
  • Histone Deacetylase Inhibitors / pharmacology
  • Humans
  • Hydroxamic Acids / pharmacology*
  • Indoles / pharmacology*
  • Male
  • Middle Aged
  • Panobinostat
  • Primary Cell Culture
  • Protein Kinase C / metabolism
  • Viral Load / drug effects
  • Virus Activation / drug effects*
  • Virus Latency / drug effects*


  • Anti-HIV Agents
  • DNA, Viral
  • Diterpenes
  • Enzyme Activators
  • Histone Deacetylase Inhibitors
  • Hydroxamic Acids
  • Indoles
  • ingenol dibenzoate
  • Panobinostat
  • Protein Kinase C