TNF-α production and apoptosis in hepatocytes after Listeria monocytogenes and Salmonella Typhimurium invasion

Rev Inst Med Trop Sao Paulo. 2011 Mar-Apr;53(2):107-12. doi: 10.1590/s0036-46652011000200009.

Abstract

Invasion of hepatocytes by Listeria monocytogenes (LM) and Salmonella Typhimurium (ST) can stimulate tumor necrosis factor alpha (TNF-α) release and induce apoptosis. In this study, we compared the behavior of hepatocytes invaded by three L. monocytogenes serotypes (LM-4a, LM-4b and LM-1/2a) and by ST to understand which bacterium is more effective in the infectious process. We quantified TNF-α release by ELISA, apoptosis rates by annexin V (early apoptosis) and TUNEL (late apoptosis) techniques. The cell morphology was studied too. TNF-α release rate was highest in ST-invaded hepatocytes. ST and LM-1/2a induced the highest apoptosis production rates evaluated by TUNEL. LM-4b produced the highest apoptosis rate measured by annexin. Invaded hepatocytes presented various morphological alterations. Overall, LM-4b and LM-1/2a proved to be the most efficient at cell invasion, although ST adapted faster to the environment and induced earlier hepatocyte TNF-α release.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Newborn
  • Apoptosis / physiology*
  • Female
  • Flow Cytometry
  • Hepatocytes / immunology
  • Hepatocytes / microbiology*
  • Hepatocytes / ultrastructure
  • Listeria monocytogenes / pathogenicity
  • Listeria monocytogenes / physiology*
  • Microscopy, Electron
  • Rats
  • Rats, Wistar
  • Salmonella typhimurium / pathogenicity
  • Salmonella typhimurium / physiology*
  • Time Factors
  • Tumor Necrosis Factor-alpha / biosynthesis*

Substances

  • Tumor Necrosis Factor-alpha