Unusual intracellular trafficking of Salmonella typhimurium in human melanoma cells

Cell Microbiol. 2001 Jun;3(6):407-16. doi: 10.1046/j.1462-5822.2001.00123.x.

Abstract

Salmonella spp. are enterobacteria capable of invading and replicating in both professional and non-professional phagocytes. Here, we investigate the fate of S. typhimurium in human melanoma MelJuSo cells. The bacterium entered MelJuSo cells by a trigger mechanism and resided within a unique organelle, the Salmonella-containing vacuole (SCV). The SCV acquired early endosomal markers transiently and then underwent a series of membrane modifications. In HeLa cells, vacuole maturation is characterized by the simultaneous acquisition of the lysosomal membrane glycoproteins (Lgps) Lamp1, CD63 and vacuolar (v)-ATPase; in MelJuSo cells, however, acquisition of CD63 and v-ATPase preceded that of Lamp1. A very striking event in MelJuSo cells was the arrest of bacterial septation starting from 8 h after infection. Bacteria nevertheless continued to elongate, remained morphologically intact and viable and were eventually exocytosed. This original feature was observed in several skin-related cells including melanocytes, suggesting that it may provide the basis for an efficient host defence mechanism against Salmonella infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Division
  • HeLa Cells
  • Humans
  • Melanoma, Experimental / microbiology*
  • Models, Biological
  • Phagocytosis
  • Salmonella typhimurium / cytology
  • Salmonella typhimurium / pathogenicity*
  • Skin / cytology
  • Skin / microbiology*
  • Vacuoles / microbiology