Nejvíce citovaný článek - PubMed ID 16584815
Attenuated aroA Salmonella enterica serovar Typhimurium does not induce inflammatory response and early protection of gnotobiotic pigs against parental virulent LT2 strain
Salmonella Typhimurium is a Gram-negative bacterium that causes enterocolitis in humans and pigs. Lipopolysaccharide (LPS) is a component of the outer leaflet of Gram-negative bacteria that provokes endotoxin shock. LPS can be synthesized completely or incompletely and creates S (smooth) or R (rough) chemotypes. Toll-like receptors (TLR) 2, 4, and 9 initiate an inflammatory reaction to combat bacterial infections. We associated/challenged one-week-old gnotobiotic piglets with wild-type S. Typhimurium with S chemotype or its isogenic ∆rfa mutants with R chemotype LPS. The wild-type S. Typhimurium induced TLR2 and TLR4 mRNA expression but not TLR9 mRNA expression in the ileum and colon of one-week-old gnotobiotic piglets 24 h after challenge. The TLR2 and TLR4 stimulatory effects of the S. Typhimurium ∆rfa mutants were related to the completeness of their LPS chain. The transcription of IL-12/23 p40, IFN-γ, and IL-6 in the intestine and the intestinal and plasmatic levels of IL-12/23 p40 and IL-6 but not IFN-γ were related to the activation of TLR2 and TLR4 signaling pathways. The avirulent S. Typhimurium ∆rfa mutants are potentially useful for modulation of the TLR2 and TLR4 signaling pathways to protect the immunocompromised gnotobiotic piglets against subsequent infection with the virulent S. Typhimurium.
- Klíčová slova
- Salmonella Typhimurium, chemotype, endotoxin, germ-free, gnotobiotic, lipopolysaccharide, piglet, toll-like receptor 4, ∆rfa mutant,
- MeSH
- gnotobiologické modely fyziologie MeSH
- ileum metabolismus mikrobiologie MeSH
- kolon metabolismus mikrobiologie MeSH
- miniaturní prasata MeSH
- mutace fyziologie MeSH
- prasata MeSH
- Salmonella typhimurium genetika izolace a purifikace MeSH
- salmonelóza genetika metabolismus patologie MeSH
- toll-like receptor 4 metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- toll-like receptor 4 MeSH
Salmonella Typhimurium is an enteric pathogen that causes acute and chronic infections in humans and animals. One-week-old germ-free piglets were orally colonized/infected with the Salmonella Typhimurium LT2 strain or its isogenic rough ΔrfaL, ΔrfaG or ΔrfaC mutants with exactly defined lipopolysaccharide (LPS) defects. After 24 h, the piglets were euthanized and the colonization of the small intestine, translocations into the mesenteric lymph nodes, liver, spleen, lungs, and bacteremia, along with changes in the ileum histology, and transcription levels of the tight junction proteins claudin-1, claudin-2, and occludin were all assessed. Additionally, transcription levels of IL-8, TNF-α, and IL-10 in the terminal ileum, and their local and systemic protein levels were evaluated. Wild-type Salmonella Typhimurium showed the highest translocation, histopathological changes, upregulation of claudins and downregulation of occludin, transcription of the cytokines, intestinal IL-8 and TNF-α levels, and systemic TNF-α and IL-10 levels. Depending on the extent of the incompleteness of the LPS, the levels of the respective elements decreased, or no changes were observed at all in the piglets colonized/infected with Δrfa mutants. Intestinal IL-10 and systemic IL-8 levels were not detected in any piglet groups. This study provided foundational data on the gnotobiotic piglet response to colonization/infection with the exactly defined rough Salmonella Typhimurium LT2 isogenic mutants.
- Klíčová slova
- Salmonella Typhimurium, cytokines, germ-free piglet, gnotobiotic, lipopolysaccharide, tight junction proteins, Δrfa mutant,
- MeSH
- cytokiny imunologie MeSH
- gnotobiologické modely * MeSH
- játra mikrobiologie MeSH
- lipopolysacharidy toxicita MeSH
- lymfatické uzliny mikrobiologie MeSH
- mutace MeSH
- plíce mikrobiologie MeSH
- prasata MeSH
- Salmonella typhimurium genetika fyziologie MeSH
- salmonelóza imunologie mikrobiologie patologie MeSH
- slezina mikrobiologie MeSH
- tenké střevo imunologie mikrobiologie patologie MeSH
- virulence * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- cytokiny MeSH
- lipopolysacharidy MeSH
Innate immunity is shaped by a complex of redundant and pleiotropic factors that ensure recognition, alert and suppression of pathogens. Innate immune responses in the gut are complicated by the requirement of parallel tolerance to commensal microflora predominating in cell numbers and species. In normal individuals, the intestinal mucosa together with relevant lymph nodes represents a robust barrier against systemic spread of non-typhoid Salmonella. Contemporary insights into these defense mechanisms are reviewed.
- MeSH
- gastrointestinální trakt imunologie MeSH
- lidé MeSH
- přirozená imunita * MeSH
- Salmonella imunologie MeSH
- salmonelóza imunologie MeSH
- slizniční imunita * MeSH
- střevní sliznice imunologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
In this study we characterized aro mutants of Salmonella enterica serovars Enteritidis and Typhimurium, which are frequently used as live oral vaccines. We found that the aroA, aroD, and aroC mutants were sensitive to blood serum, albumen, EDTA, and ovotransferrin, and this defect could be complemented by an appropriate aro gene cloned in a plasmid. Subsequent microarray analysis of gene expression in the aroD mutant in serovar Typhimurium indicated that the reason for this sensitivity might be the upregulation of murA. To confirm this, we artificially overexpressed murA from a multicopy plasmid, and this overexpression caused sensitivity of the strain to albumen and EDTA but not to serum and ovotransferrin. We concluded that attenuation of aro mutants is caused not only by their inability to synthesize aromatic metabolites but also by their defect in cell wall and outer membrane functions associated with decreased resistance to components of innate immune response.
- MeSH
- albuminy farmakologie MeSH
- alkyltransferasy a aryltransferasy genetika MeSH
- aminokyseliny aromatické biosyntéza genetika MeSH
- antibakteriální látky farmakologie MeSH
- bakteriální geny * MeSH
- bakteriální léková rezistence genetika MeSH
- buněčná membrána účinky léků genetika MeSH
- buněčná stěna účinky léků genetika MeSH
- EDTA farmakologie MeSH
- fosfoenolpyruvát metabolismus MeSH
- klonování DNA MeSH
- komplement farmakologie MeSH
- mutace MeSH
- ovotransferin farmakologie MeSH
- plazmidy genetika MeSH
- Salmonella enteritidis účinky léků enzymologie genetika MeSH
- Salmonella typhimurium účinky léků enzymologie genetika MeSH
- sekvenční analýza hybridizací s uspořádaným souborem oligonukleotidů MeSH
- sérum MeSH
- testy genetické komplementace MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- albuminy MeSH
- alkyltransferasy a aryltransferasy MeSH
- aminokyseliny aromatické MeSH
- antibakteriální látky MeSH
- EDTA MeSH
- fosfoenolpyruvát MeSH
- komplement MeSH
- ovotransferin MeSH
- UDP-N-acetylglucosamine 1-carboxyvinyltransferase MeSH Prohlížeč