BIRC2/cIAP1 Is a Negative Regulator of HIV-1 Transcription and Can Be Targeted by Smac Mimetics to Promote Reversal of Viral Latency

Cell Host Microbe. 2015 Sep 9;18(3):345-53. doi: 10.1016/j.chom.2015.08.009.

Abstract

Combination antiretroviral therapy (ART) is able to suppress HIV-1 replication to undetectable levels. However, the persistence of latent viral reservoirs allows for a rebound of viral load upon cessation of therapy. Thus, therapeutic strategies to eradicate the viral latent reservoir are critically needed. Employing a targeted RNAi screen, we identified the ubiquitin ligase BIRC2 (cIAP1), a repressor of the noncanonical NF-κB pathway, as a potent negative regulator of LTR-dependent HIV-1 transcription. Depletion of BIRC2 through treatment with small molecule antagonists known as Smac mimetics enhanced HIV-1 transcription, leading to a reversal of latency in a JLat latency model system. Critically, treatment of resting CD4+ T cells isolated from ART-suppressed patients with the histone deacetylase inhibitor (HDACi) panobinostat together with Smac mimetics resulted in synergistic activation of the latent reservoir. These data implicate Smac mimetics as useful agents for shock-and-kill strategies to eliminate the latent HIV reservoir.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • CD4-Positive T-Lymphocytes / drug effects
  • CD4-Positive T-Lymphocytes / virology
  • Cells, Cultured
  • Gene Expression Regulation, Viral*
  • HIV-1 / physiology*
  • Host-Pathogen Interactions*
  • Humans
  • Hydroxamic Acids / metabolism
  • Indoles / metabolism
  • Inhibitor of Apoptosis Proteins / antagonists & inhibitors
  • Inhibitor of Apoptosis Proteins / metabolism*
  • Oligopeptides / metabolism
  • Panobinostat
  • Transcription, Genetic / drug effects*
  • Ubiquitin-Protein Ligases / antagonists & inhibitors
  • Ubiquitin-Protein Ligases / metabolism*
  • Virus Activation / drug effects*
  • Virus Latency / drug effects*

Substances

  • Hydroxamic Acids
  • Indoles
  • Inhibitor of Apoptosis Proteins
  • Oligopeptides
  • SMAC peptide
  • Panobinostat
  • BIRC2 protein, human
  • Ubiquitin-Protein Ligases