Vpr Promotes Macrophage-Dependent HIV-1 Infection of CD4+ T Lymphocytes

PLoS Pathog. 2015 Jul 17;11(7):e1005054. doi: 10.1371/journal.ppat.1005054. eCollection 2015 Jul.

Abstract

Vpr is a conserved primate lentiviral protein that promotes infection of T lymphocytes in vivo by an unknown mechanism. Here we demonstrate that Vpr and its cellular co-factor, DCAF1, are necessary for efficient cell-to-cell spread of HIV-1 from macrophages to CD4+ T lymphocytes when there is inadequate cell-free virus to support direct T lymphocyte infection. Remarkably, Vpr functioned to counteract a macrophage-specific intrinsic antiviral pathway that targeted Env-containing virions to LAMP1+ lysosomal compartments. This restriction of Env also impaired virological synapses formed through interactions between HIV-1 Env on infected macrophages and CD4 on T lymphocytes. Treatment of infected macrophages with exogenous interferon-alpha induced virion degradation and blocked synapse formation, overcoming the effects of Vpr. These results provide a mechanism that helps explain the in vivo requirement for Vpr and suggests that a macrophage-dependent stage of HIV-1 infection drives the evolutionary conservation of Vpr.

Publication types

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

MeSH terms

  • CD4-Positive T-Lymphocytes / immunology
  • CD4-Positive T-Lymphocytes / virology*
  • HIV-1 / immunology*
  • Humans
  • Interferon-alpha / metabolism
  • Macrophages / metabolism
  • Macrophages / virology*
  • Virion / metabolism
  • vpr Gene Products, Human Immunodeficiency Virus / immunology*

Substances

  • Interferon-alpha
  • vpr Gene Products, Human Immunodeficiency Virus