Virion-associated Vpr of human immunodeficiency virus type 1 triggers activation of apoptotic events and enhances fas-induced apoptosis in human t cells

Academic Article


  • Human immunodeficiency virus type 1 (HIV-1) Vpr protein exists in three different forms: soluble, intracellular, and virion associated. Previous studies showed that virion-associated Vpr induces apoptosis in activated peripheral blood mononuclear cells (PBMCs) and Jurkat T cells, but these studies were conducted in the presence of other de novo-expressed HIV proteins that may have had additive proapoptotic effects. In this report, we show that virion-associated Vpr triggers apoptosis through caspases 3/7 and 9 in human T cells independently of other HIV de novo-expressed proteins. In contrast to a previous study, we also detected the activation of caspase 8, the initiator caspase of the death receptor pathway. However, activation of all caspases by virion-associated Vpr was independent of the Fas death receptor pathway. Further analyses showed that virion-associated Vpr enhanced caspase activation in Fas-mediated apoptosis in Jurkat T cells and human activated PBMCs. Thus, our results indicate for the first time that viral particles that contain virion-associated Vpr can cause apoptosis in the absence of other de novo-expressed viral factors and can act in synergy with the Fas receptor pathway, thereby enhancing the apoptotic process in T cells. These findings suggest that virionassociated Vpr can contribute to the depletion of CD4 + lymphocytes either directly or by enhancing Fas-mediated apoptosis during acute HIV-1 infection and in AIDS. Copyright © 2009, American Society for Microbiology. All Rights Reserved.
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    Digital Object Identifier (doi)

    Author List

  • Arokium H; Kamata M; Chen I
  • Start Page

  • 11283
  • End Page

  • 11297
  • Volume

  • 83
  • Issue

  • 21