Intracellular activities of Salmonella enterica in murine dendritic cells

Cell Microbiol. 2003 Dec;5(12):933-45. doi: 10.1046/j.1462-5822.2003.00334.x.

Abstract

Dendritic cells (DC) efficiently phagocytose invading bacteria, but fail to kill intracellular pathogens such as Salmonella enterica serovar Typhimurium (S. Typhimurium). We analysed the intracellular fate of Salmonella in murine bone marrow-derived DC (BM-DC). The intracellular proliferation and subcellular localization were investigated for wild-type S. Typhimurium and mutants deficient in Salmonella pathogenicity island 2 (SPI2), a complex virulence factor that is essential for systemic infections in the murine model and intracellular survival and replication in macrophages. Using a segregative plasmid to monitor intracellular cell division, we observed that, in BM-DC, S. Typhimurium represents a static, non-dividing population. In BM-DC, S. Typhimurium resides in a membrane-bound compartment that has acquired late endosomal markers. However, these bacteria respond to intracellular stimuli, because induction of SPI2 genes was observed. S. Typhimurium within DC are also able to translocate a virulence protein into their host cells. SPI2 function was not required for intracellular survival in DC, but we observed that the maturation of the Salmonella-containing vesicle is different in DC infected with wild-type bacteria and a strain deficient in SPI2. Our observations indicate that S. Typhimurium in DC are able to modify normal processes of their host cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Bacterial Proteins / physiology
  • Cell Culture Techniques
  • Colony Count, Microbial
  • Dendritic Cells / microbiology*
  • Dendritic Cells / ultrastructure
  • Endosomes / microbiology
  • Gene Expression Regulation, Bacterial
  • Genes, Bacterial
  • Genes, Reporter
  • Genomic Islands / genetics
  • Genomic Islands / physiology
  • Green Fluorescent Proteins
  • Luminescent Proteins / genetics
  • Luminescent Proteins / metabolism
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism
  • Mice
  • Molecular Chaperones / genetics
  • Molecular Chaperones / metabolism
  • Mutagenesis, Insertional
  • Mutation
  • Promoter Regions, Genetic
  • Protein Transport
  • Recombinant Fusion Proteins / metabolism
  • Salmonella typhimurium / genetics
  • Salmonella typhimurium / growth & development
  • Salmonella typhimurium / pathogenicity*
  • Virulence Factors / genetics
  • Virulence Factors / metabolism
  • Virulence Factors / physiology

Substances

  • Bacterial Proteins
  • Luminescent Proteins
  • Membrane Proteins
  • Molecular Chaperones
  • Recombinant Fusion Proteins
  • SPI-2 protein, Salmonella
  • SseA protein, Salmonella typhimurium
  • Virulence Factors
  • Green Fluorescent Proteins