HIV infection of dendritic cells subverts the IFN induction pathway via IRF-1 and inhibits type 1 IFN production

Blood. 2011 Jul 14;118(2):298-308. doi: 10.1182/blood-2010-07-297721. Epub 2011 Mar 16.

Abstract

Many viruses have developed mechanisms to evade the IFN response. Here, HIV-1 was shown to induce a distinct subset of IFN-stimulated genes (ISGs) in monocyte-derived dendritic cells (DCs), without detectable type I or II IFN. These ISGs all contained an IFN regulatory factor 1 (IRF-1) binding site in their promoters, and their expression was shown to be driven by IRF-1, indicating this subset was induced directly by viral infection by IRF-1. IRF-1 and -7 protein expression was enriched in HIV p24 antigen-positive DCs. A HIV deletion mutant with the IRF-1 binding site deleted from the long terminal repeat showed reduced growth kinetics. Early and persistent induction of IRF-1 was coupled with sequential transient up-regulation of its 2 inhibitors, IRF-8, followed by IRF-2, suggesting a mechanism for IFN inhibition. HIV-1 mutants with Vpr deleted induced IFN, showing that Vpr is inhibitory. However, HIV IFN inhibition was mediated by failure of IRF-3 activation rather than by its degradation, as in T cells. In contrast, herpes simplex virus type 2 markedly induced IFNβ and a broader range of ISGs to higher levels, supporting the hypothesis that HIV-1 specifically manipulates the induction of IFN and ISGs to enhance its noncytopathic replication in DCs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cells, Cultured
  • Dendritic Cells / metabolism
  • Dendritic Cells / pathology
  • Dendritic Cells / virology*
  • Down-Regulation / immunology
  • Gene Expression Profiling
  • Gene Expression Regulation / immunology
  • HIV Infections / genetics*
  • HIV Infections / immunology*
  • HIV Infections / metabolism
  • HIV Infections / pathology
  • HIV-1 / physiology*
  • Humans
  • Interferon Regulatory Factor-1 / genetics
  • Interferon Regulatory Factor-1 / metabolism
  • Interferon Regulatory Factor-1 / physiology*
  • Interferon Type I / metabolism*
  • Microarray Analysis
  • Promoter Regions, Genetic
  • Sequence Analysis, DNA
  • Signal Transduction / immunology
  • Signal Transduction / physiology
  • Up-Regulation / genetics
  • Up-Regulation / immunology

Substances

  • Interferon Regulatory Factor-1
  • Interferon Type I