Porcine reproductive and respiratory syndrome virus modulates apoptosis during replication in alveolar macrophages

Arch Virol. 2008;153(8):1453-65. doi: 10.1007/s00705-008-0135-5. Epub 2008 Jun 19.

Abstract

Different viruses have evolved strategies that inhibit apoptosis of the host cell early in infection and/or induce apoptosis in the host cell late in infection. In this study, it was investigated if and when porcine reproductive and respiratory syndrome virus (PRRSV) modulates apoptosis in PRRSV-infected macrophages. The PRRSV replication cycle in macrophages was completed within 12 h post-inoculation (hpi). PRRSV-infected macrophages, treated with staurosporine at 4, 5, 6 and 8 hpi, were significantly protected against staurosporine-induced apoptosis, but PRRSV-infected macrophages, treated with staurosporine at 12 hpi, were not. In contrast, starting from 12 hpi, all PRRSV-infected macrophages died by caspase-dependent apoptosis, which culminated in secondary necrosis. Treatment of PRRSV-infected macrophages with Z-Val-DL-Asp-fluoromethylketone indicated that apoptosis late in infection was not essential for efficient virus release. Anti- and pro-apoptotic activities were also observed in PRRSV-infected Marc-145 cells. In conclusion, this study shows that PRRSV stimulates anti-apoptotic pathways in macrophages early in infection and that PRRSV-infected macrophages die by apoptosis late in infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / immunology
  • Apoptosis / physiology*
  • Macrophages, Alveolar / drug effects
  • Macrophages, Alveolar / immunology
  • Macrophages, Alveolar / virology*
  • Porcine Reproductive and Respiratory Syndrome / immunology*
  • Porcine Reproductive and Respiratory Syndrome / pathology
  • Porcine respiratory and reproductive syndrome virus / pathogenicity*
  • Staurosporine / pharmacology
  • Swine Diseases / pathology
  • Swine Diseases / virology
  • Virus Replication / physiology*

Substances

  • Staurosporine