Induction of TNF-alpha mRNA in murine macrophages by virulent and avirulent strains of Salmonella choleraesuis serovar typhimurium and serovar Choleraesuis.
TNF-alpha mRNA induction in murine macrophages by virulent and avirulent Salmonella strains was measured in vitro by RT-PCR method. Virulence plasmid-cured strains of S. choleraesuis serovar Typhimurium and serovar Choleraesuis, and rpoS-defective mutant of S. choleraesuis serovar Typhimurium induced significantly higher level of TNF-alpha mRNA than their parent (virulent) strains in macrophages of C3H/HeN mice. When macrophages of LPS-low responder (C3H/HeJ) mice were used, the difference of the induction level was not observed, indicating that LPS was involved in the enhanced level of TNF-alpha mRNA induction by avirulent Salmonella strains. LPSs from virulent and avirulent strains were analysed, but no difference was found for cytokine-inducing activity, and chemical properties. Those results suggested that avirulent Salmonella strains were damaged more easily, and released more LPS in macrophages to enhance TNF-alpha induction.
Mitsui-Yamaguchi
T
T
Department of Bacteriology, Kitasato Institute, Tokyo, Japan.
Abe
A
A
Danbara
H
H
Kawahara
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K
D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics; D002478:Cells, Cultured; D005260:Female; D008070:Lipopolysaccharides / Q000032:analysis / Q000378:metabolism / Q000494:pharmacology; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D008809:Mice, Inbred C3H; D016254:Mutagenesis, Insertional; D010957:Plasmids; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis*; D012475:Salmonella / Q000378:metabolism*; D012481:Salmonella Infections, Animal / Q000382:microbiology*; D012486:Salmonella typhimurium / Q000378:metabolism* / Q000472:pathogenicity*; D012808:Sigma Factor / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis / Q000096:biosynthesis*; D014774:Virulence
D001426:Bacterial Proteins; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D012808:Sigma Factor; D014409:Tumor Necrosis Factor-alpha; C069567:sigma factor KatF protein, Bacteria