Analysis of interactions of salmonella type three secretion mutants with 3-D intestinal epithelial cells

Andrea L. Radtke, James W. Wilson, Shameema Sarker, Cheryl Nickerson

Research output: Contribution to journalArticle

39 Citations (Scopus)

Abstract

The prevailing paradigm of Salmonella enteropathogenesis based on monolayers asserts that Salmonella pathogenicity island-1 Type Three Secretion System (SPI-1 T3SS) is required for bacterial invasion into intestinal epithelium. However, little is known about the role of SPI-1 in mediating gastrointestinal disease in humans. Recently, SPI-1 deficient nontyphoidal Salmonella strains were isolated from infected humans and animals, indicating that SPI-1 is not required to cause enteropathogenesis and demonstrating the need for more in vivo-like models. Here, we utilized a previously characterized 3-D organotypic model of human intestinal epithelium to elucidate the role of all characterized Salmonella enterica T3SSs. Similar to in vivo reports, the Salmonella SPI-1 T3SS was not required to invade 3-D intestinal cells. Additionally, Salmonella strains carrying single (SPI-1 or SPI-2), double (SPI-1/2) and complete T3SS knockout (SPI-1/SPI-2: flhDC) also invaded 3-D intestinal cells to wildtype levels. Invasion of wildtype and TTSS mutants was a Salmonella active process, whereas noninvasive bacterial strains, bacterial size beads, and heat-killed Salmonella did not invade 3-D cells. Wildtype and T3SS mutants did not preferentially target different cell types identified within the 3-D intestinal aggregates, including M-cells/Mlike cells, enterocytes, or Paneth cells. Moreover, each T3SS was necessary for substantial intracellular bacterial replication within 3-D cells. Collectively, these results indicate that T3SSs are dispensable for Salmonella invasion into highly differentiated 3-D models of human intestinal epithelial cells, but are required for intracellular bacterial growth, paralleling in vivo infection observations and demonstrating the utility of these models in predicting in vivo-like pathogenic mechanisms.

Original languageEnglish (US)
Article numbere15750
JournalPLoS One
Volume5
Issue number12
DOIs
StatePublished - 2010

Fingerprint

type III secretion system
Salmonella
epithelial cells
Epithelial Cells
secretion
mutants
cells
Somatostatin-Secreting Cells
Intestinal Mucosa
intestinal mucosa
Paneth Cells
pathogenicity islands
Genomic Islands
Salmonella enterica
Enterocytes
Gastrointestinal Diseases
enterocytes
cell aggregates
digestive system diseases
microbial growth

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Medicine(all)

Cite this

Analysis of interactions of salmonella type three secretion mutants with 3-D intestinal epithelial cells. / Radtke, Andrea L.; Wilson, James W.; Sarker, Shameema; Nickerson, Cheryl.

In: PLoS One, Vol. 5, No. 12, e15750, 2010.

Research output: Contribution to journalArticle

Radtke, Andrea L. ; Wilson, James W. ; Sarker, Shameema ; Nickerson, Cheryl. / Analysis of interactions of salmonella type three secretion mutants with 3-D intestinal epithelial cells. In: PLoS One. 2010 ; Vol. 5, No. 12.
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