Infected cell killing by HIV-1 protease promotes NF-kappaB dependent HIV-1 replication

PLoS One. 2008 May 7;3(5):e2112. doi: 10.1371/journal.pone.0002112.

Abstract

Acute HIV-1 infection of CD4 T cells often results in apoptotic death of infected cells, yet it is unclear what evolutionary advantage this offers to HIV-1. Given the independent observations that acute T cell HIV-1 infection results in (1) NF-kappaB activation, (2) caspase 8 dependent apoptosis, and that (3) caspase 8 directly activates NF-kappaB, we questioned whether these three events might be interrelated. We first show that HIV-1 infected T cell apoptosis, NF-kappaB activation, and caspase 8 cleavage by HIV-1 protease are coincident. Next we show that HIV-1 protease not only cleaves procaspase 8, producing Casp8p41, but also independently stimulates NF-kappaB activity. Finally, we demonstrate that the HIV protease cleavage of caspase 8 is necessary for optimal NF-kappaB activation and that the HIV-1 protease specific cleavage fragment Casp8p41 is sufficient to stimulate HIV-1 replication through NF-kappaB dependent HIV-LTR activation both in vitro as well as in cells from HIV infected donors. Consequently, the molecular events which promote death of HIV-1 infected T cells function dually to promote HIV-1 replication, thereby favoring the propagation and survival of HIV-1.

Publication types

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

MeSH terms

  • Alstrom Syndrome
  • Apoptosis
  • CD4-Positive T-Lymphocytes / cytology
  • CD4-Positive T-Lymphocytes / virology
  • Caspase 8 / genetics
  • Cell Survival*
  • Enzyme Activation
  • Genes, Reporter
  • HIV Long Terminal Repeat / genetics
  • HIV Protease / metabolism*
  • HIV-1 / enzymology
  • HIV-1 / genetics
  • HIV-1 / physiology*
  • Humans
  • Jurkat Cells
  • NF-kappa B / physiology*
  • Plasmids
  • T-Lymphocytes / virology
  • Transfection
  • Virus Replication*

Substances

  • NF-kappa B
  • Caspase 8
  • HIV Protease
  • p16 protease, Human immunodeficiency virus 1