This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Melin, M.
Right arrow Articles by Väkeväinen, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Melin, M.
Right arrow Articles by Väkeväinen, M.

 Previous Article  |  Next Article 

Infection and Immunity, February 2009, p. 676-684, Vol. 77, No. 2
0019-9567/09/$08.00+0     doi:10.1128/IAI.01186-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.

Streptococcus pneumoniae Capsular Serotype 19F Is More Resistant to C3 Deposition and Less Sensitive to Opsonophagocytosis than Serotype 6B{triangledown}

Merit Melin,1* Hanna Jarva,2 Lotta Siira,3 Seppo Meri,2 Helena Käyhty,1 and Merja Väkeväinen1

National Public Health Institute, Department of Vaccines, Helsinki, Finland,1 Haartman Institute, Department of Bacteriology and Immunology, University of Helsinki, Finland, and Helsinki University Central Hospital Laboratory, HUSLAB, Finland,2 National Public Health Institute, Department of Bacterial and Inflammatory Diseases, Helsinki, Finland3

Received 24 September 2008/ Returned for modification 26 October 2008/ Accepted 22 November 2008

The polysaccharide capsule is a major virulence mechanism of Streptococcus pneumoniae, shielding the bacterium from phagocytes. Capsule types may differ in their abilities to resist immune defense. Antibody-mediated complement activation and opsonophagocytosis are crucial in protection against pneumococcus. Conjugate vaccine trials suggest imperfect protection against 19F. We have previously shown that significantly more anti-19F than anti-6B antibody is needed for killing in the opsonophagocytic assay (OPA). In this study, we explored whether the amount of C3 deposited on serotype 6B and 19F pneumococcal strains reflects their sensitivity to opsonophagocytosis. We compared clinical 6B and 19F nasopharyngeal, middle ear, and blood isolates as well as reference OPA strains (n = 16) for their sensitivity to opsonophagocytosis and C3 deposition. Sixfold anticapsular antibody concentrations were required for 50% opsonophagocytic killing of 19F compared to that of 6B strains. Serotype 19F was more resistant to C3 deposition than 6B. Complement deposition and opsonophagocytosis were dependent on the concentration of anticapsular antibodies. Differences between pneumococcal serotypes in antibody-mediated protection may partly be explained by the abilities of the capsules to resist complement deposition. These findings support previous studies suggesting that higher antibody concentrations to the capsular polysaccharide are needed for protection against disease caused by serotype 19F than that caused by 6B.

* Corresponding author. Mailing address: National Public Health Institute (KTL), Department of Vaccines, Mannerheimintie 166, 00300 Helsinki, Finland. Phone: 358-9-4744 8903. Fax: 358-9-4744 8599. E-mail: merit.melin{at}ktl.fi

{triangledown} Published ahead of print on 1 December 2008.

Editor: A. Camilli

Infection and Immunity, February 2009, p. 676-684, Vol. 77, No. 2
0019-9567/09/$08.00+0     doi:10.1128/IAI.01186-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Thurlow, L. R., Thomas, V. C., Fleming, S. D., Hancock, L. E. (2009). Enterococcus faecalis Capsular Polysaccharide Serotypes C and D and Their Contributions to Host Innate Immune Evasion. Infect. Immun. 77: 5551-5557 [Abstract] [Full Text]  
  • Standish, A. J., Weiser, J. N. (2009). Human Neutrophils Kill Streptococcus pneumoniae via Serine Proteases. J. Immunol. 183: 2602-2609 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»