The Salmonella enterica serotype Typhi regulator TviA reduces interleukin-8 production in intestinal epithelial cells by repressing flagellin secretion

Sebastian E. Winter, Manuela Raffatellu, Paul R. Wilson, Holger Rüssmann, Andreas J Baumler

Research output: Contribution to journalArticle

66 Scopus citations


Unlike non-typhoidal Salmonella serotypes, S. enterica serotype Typhi does not elicit neutrophilic infiltrates in the human intestinal mucosa. The Vi capsule-encoding tviABCDEvexABCDE operon (viaB locus) is a S. Typhi-specific DNA region preventing production of interleukin (IL)-8 during infection of intestinal epithelial cells. We elucidated the mechanism by which the viaB locus reduces IL-8 production in human colonic epithelial (T84) cells. A S. Typhi tviABCDEvexABCDE deletion mutant, but not a tviBCDEvexABCDE deletion mutant, elicited increased IL-8 production, which could be reduced to wild-type levels by introducing the cloned tviA regulatory gene. Thus, IL-8 expression in T84 cells was modulated by the TviA regulatory protein, but not by the Vi capsular antigen. Consistent with previous reports, IL-8 secretion by T84 cells was dependent on the presence of the flagellin protein FliC. TviA reduced expression of flhDC :: lacZ and fliC::lacZ transcriptional fusions and secretion of FliC in S. Typhi. Introduction of tviA into S.enterica serotype Typhimurium reduced flagellin secretion and IL-8 expression. In conclusion, the viaB locus reduces IL-8 production in T84 cells by a TviA-mediated repression of flagellin secretion. Our data suggest that changes in flagella gene regulation played an important role during evolution of the human-adapted S. Typhi.

Original languageEnglish (US)
Pages (from-to)247-261
Number of pages15
JournalCellular Microbiology
Issue number1
StatePublished - Jan 2008


ASJC Scopus subject areas

  • Clinical Biochemistry
  • Microbiology

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