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Updated: Aug 15, 2026

High-throughput Assay to Phenotype Salmonella enterica Typhimurium Association, Invasion, and Replication in Macrophages
11:10

High-throughput Assay to Phenotype Salmonella enterica Typhimurium Association, Invasion, and Replication in Macrophages

Published on: August 11, 2014

CsgA is a pathogen-associated molecular pattern of Salmonella enterica serotype Typhimurium that is recognized by

Cagla Tükel1, Manuela Raffatellu, Andrea D Humphries

  • 1Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, One Shields Avenue, Davis, CA 95616-8645, USA.

Molecular Microbiology
|September 17, 2005
PubMed

Insights

Salmonella Typhimurium fimbriae, specifically CsgA, act as pathogen-associated molecular patterns (PAMPs). These PAMPs are recognized by Toll-like receptor 2 (TLR2), initiating innate immune responses and inflammation.

Area of Science:

  • Microbiology
  • Immunology
  • Pathogenesis

Background:

  • Understanding microbial triggers of innate immunity is crucial for inflammatory disease research.
  • Pathogen-associated molecular patterns (PAMPs) are key microbial molecules recognized by the host immune system.

Purpose of the Study:

  • To investigate Salmonella enterica serotype Typhimurium fimbriae as potential PAMPs.
  • To identify the specific microbial component and the host receptor involved in initiating inflammatory pathways.

Main Methods:

  • Screening of Salmonella Typhimurium fimbrial mutants for enteropathogenicity in a calf ileal loop model.
  • Investigating cytokine production (IL-8, IL-6) in human cell lines and murine macrophages using purified fimbriae and fusion proteins.
  • Utilizing Toll-like receptor (TLR) transfected cells to determine receptor specificity.

Main Results:

  • A Salmonella Typhimurium csgBA mutant showed reduced enteropathogenicity and inflammatory mediator expression.
  • Purified thin curled fimbriae (CsgA) induced IL-8 production via TLR2/CD14 signaling.
  • GST-CsgA fusion protein stimulated IL-6 production in a TLR2-dependent manner in mouse macrophages.

Conclusions:

  • Salmonella Typhimurium CsgA fimbriae function as PAMPs.
  • CsgA is recognized by Toll-like receptor 2 (TLR2), initiating innate immune responses.
  • This TLR2-mediated recognition contributes to the pathogenesis of Salmonella-induced inflammation.

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