Inflammatory responses to a Clostridium perfringens type A strain and α-toxin in primary intestinal epithelial cells of chicken embryos

Avian Pathol. 2015;44(2):81-91. doi: 10.1080/03079457.2015.1005573.

Abstract

The causative pathogen of necrotic enteritis is the Gram-positive bacterium Clostridium perfringens. Its main cell wall component, peptidoglycan (PGN), can be recognized by Toll-like receptor 2 and nucleotide-binding oligomerization domain (NOD). Consequently, the immune response is initiated via activation of nuclear factor kappa B (NF-κB) signalling pathway. An in vitro study was conducted to investigate chicken intestinal inflammatory responses to C. perfringens type A and one of its virulence factors, α-toxin. In primary intestinal epithelial cells, C. perfringens as well as commercially available PGN and α-toxin challenge upregulated mRNA expression of interleukin (IL)-6, IL-8 and inducible nitric oxide synthase (iNOS) with a dosage-dependent manner at 3 h post infection (p.i.; P ≤ 0.001). Time-course effects of three stimulators at high concentration were further examined. C. perfringens infection elevated IL-6, IL-8 and iNOS levels from 1 h to 9 h p.i., while PGN treatment increased IL-6 and IL-8 expression at 1 h and 3 h p.i. (P < 0.05). Bacterial and PGN treatments induced NOD1 expression at 6 h p.i. and only bacterial infection boosted NF-κB p65 expression at 6 h and 9 h p.i. (P < 0.05). α-Toxin treatment upregulated IL-6 and IL-8 expression throughout infection, as well as iNOS, TNF-α and NF-κB p65 expression at later hours p.i. (P < 0.05). In conclusion, both C. perfringens and α-toxin challenge induced intense cytokine expression associated with NF-κB activation in chicken intestinal epithelial cells. The receptors for the recognition of PGN component of C. perfringens need further investigation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacterial Toxins / toxicity*
  • Calcium-Binding Proteins / toxicity*
  • Chick Embryo
  • Clostridium perfringens / immunology*
  • Epithelial Cells / drug effects*
  • Epithelial Cells / immunology*
  • Epithelial Cells / microbiology
  • Gene Expression Regulation / drug effects
  • Gene Expression Regulation / immunology*
  • In Vitro Techniques
  • Interleukin-6 / metabolism
  • Interleukin-8 / metabolism
  • Intestinal Mucosa / cytology*
  • NF-kappa B / immunology
  • Nitric Oxide Synthase Type II / metabolism
  • Signal Transduction / immunology*
  • Type C Phospholipases / toxicity*

Substances

  • Bacterial Toxins
  • Calcium-Binding Proteins
  • Interleukin-6
  • Interleukin-8
  • NF-kappa B
  • Nitric Oxide Synthase Type II
  • Type C Phospholipases
  • alpha toxin, Clostridium perfringens