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Characterization of Inflammatory Responses During Intranasal Colonization with Streptococcus pneumoniae
09:12

Characterization of Inflammatory Responses During Intranasal Colonization with Streptococcus pneumoniae

Published on: January 17, 2014

Commonly invasive serotypes of Streptococcus pneumoniae trigger a reduced innate immune response compared with

Thomas S T Burgess1, Aaron F Hirschfeld, Gregory J Tyrrell

  • 1Department of Pediatrics, Division of Infectious and Immunological Diseases, BC Children's Hospital and Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada.

FEMS Immunology and Medical Microbiology
|February 6, 2008
PubMed

Insights

Commonly invasive Streptococcus pneumoniae serotypes trigger a weaker innate immune response, specifically less tumor necrosis factor-alpha (TNF-alpha), than rare serotypes. This suggests the host response may be less effective against common pneumococcal strains.

Area of Science:

  • Immunology
  • Microbiology
  • Infectious Diseases

Background:

  • Streptococcus pneumoniae (pneumococcus) has over 90 serotypes.
  • A small subset of these serotypes causes most invasive pneumococcal infections.
  • The reasons for differential invasiveness among serotypes are not fully understood.

Purpose of the Study:

  • To investigate the human innate immune response to different pneumococcal serotypes.
  • To determine if pneumococcal serotype influences the production of tumor necrosis factor-alpha (TNF-alpha).

Main Methods:

  • Human monocyte-derived macrophages were exposed to clinical isolates of pneumococci.
  • Isolates represented both commonly and rarely invasive serotypes.
  • TNF-alpha production was measured as an indicator of innate immune response.

Main Results:

  • Commonly invasive pneumococcal serotypes induced significantly lower TNF-alpha production compared to rarely invasive serotypes.
  • This difference in TNF-alpha production was statistically significant (P<0.004).

Conclusions:

  • The magnitude of innate immune-mediated TNF-alpha production is a factor in the invasive potential of pneumococcal serotypes.
  • The host's integrated immune response may be less effective against commonly invasive pneumococcal serotypes than against rarely invasive ones.

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