Proinflammatory cytokine and chemokine modulation by Streptococcus suis in a whole-blood culture system

FEMS Immunol Med Microbiol. 2006 Jun;47(1):92-106. doi: 10.1111/j.1574-695X.2006.00067.x.

Abstract

Streptococcus suis is an important swine and human pathogen. Inflammation, a hallmark of S. suis infection, is thought to be responsible for most clinical signs of meningitis, septicaemia and sudden death. In this work, using a porcine whole blood model, S. suis serotype 2 was shown to trigger the release of several pro-inflammatory cytokines as evaluated by reverse transcriptase-PCR and enzyme-linked immunosorbent assay. Although individual variations were observed among different S. suis strains, no correlations were observed between the strain origin/phenotype and cytokine levels. Live bacteria induced higher tumour necrosis factor alpha, interleukin-1 beta (IL-1beta) and IL-6 levels than did heat-killed bacteria. In contrast, heat-killed bacteria stimulated higher levels of IL-8 and monocyte chemotactic protein one (MCP-1). The bacterial cell wall was observed to be the major cytokine-inducting components, whereas capsule expression was important for MCP-1 activation. The presence of specific antibodies suppressed bacterial growth resulting in significantly reduced levels of cytokine production. Thus, antibody-mediated bacterial phagocytosis combined with suppressed inflammation may be beneficial for infection control strategies. We provide first evidence of S.suis-induction of pro-inflammatory swine cytokines and demonstrate the strength and relevance of the whole blood culture systems in the investigation of S. suis modulation of cytokine production.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blood / immunology
  • Blood / microbiology
  • Chemokines / biosynthesis
  • Chemokines / genetics
  • Chemokines / immunology*
  • Cytokines / biosynthesis
  • Cytokines / genetics
  • Cytokines / immunology*
  • Cytokines / metabolism
  • Enzyme-Linked Immunosorbent Assay / methods
  • Gene Expression
  • Inflammation / blood
  • Inflammation / immunology
  • RNA, Messenger / biosynthesis
  • RNA, Messenger / genetics
  • Reverse Transcriptase Polymerase Chain Reaction / methods
  • Streptococcal Infections / blood
  • Streptococcal Infections / immunology*
  • Streptococcus suis / immunology*
  • Swine

Substances

  • Chemokines
  • Cytokines
  • RNA, Messenger