Changes in capsular serotype alter the surface exposure of pneumococcal adhesins and impact virulence.
We examined the contribution of serotype on Streptococcus pneumoniae adhesion and virulence during respiratory tract infection using a panel of isogenic TIGR4 (serotype 4) mutants expressing the capsule types 6A (+6A), 7F (+7F) and 23F (+23F) as well as a deleted and restored serotype 4 (+4) control...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2011-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC3197518?pdf=render |
| _version_ | 1819260566612475904 |
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| author | Carlos J Sanchez Cecilia A Hinojosa Pooja Shivshankar Catherine Hyams Emilie Camberlein Jeremy S Brown Carlos J Orihuela |
| author_facet | Carlos J Sanchez Cecilia A Hinojosa Pooja Shivshankar Catherine Hyams Emilie Camberlein Jeremy S Brown Carlos J Orihuela |
| author_sort | Carlos J Sanchez |
| collection | DOAJ |
| description | We examined the contribution of serotype on Streptococcus pneumoniae adhesion and virulence during respiratory tract infection using a panel of isogenic TIGR4 (serotype 4) mutants expressing the capsule types 6A (+6A), 7F (+7F) and 23F (+23F) as well as a deleted and restored serotype 4 (+4) control strain. Immunoblots, bacterial capture assays with immobilized antibody, and measurement of mean fluorescent intensity by flow cytometry following incubation of bacteria with antibody, all determined that the surface accessibility, but not total protein levels, of the virulence determinants Pneumococcal surface protein A (PspA), Choline binding protein A (CbpA), and Pneumococcal serine-rich repeat protein (PsrP) changed with serotype. In vitro, bacterial adhesion to Detroit 562 pharyngeal or A549 lung epithelial cells was modestly but significantly altered for +6A, +7F and +23F. In a mouse model of nasopharyngeal colonization, the number of +6A, +7F, and +23F pneumococci in the nasopharynx was reduced 10 to 100-fold versus +4; notably, only mice challenged with +4 developed bacteremia. Intratracheal challenge of mice confirmed that capsule switch strains were highly attenuated for virulence. Compared to +4, the +6A, +7F, and +23F strains were rapidly cleared from the lungs and were not detected in the blood. In mice challenged intraperitoneally, a marked reduction in bacterial blood titers was observed for those challenged with +6A and +7F versus +4 and +23F was undetectable. These findings show that serotype impacts the accessibility of surface adhesins and, in particular, affects virulence within the respiratory tract. They highlight the complex interplay between capsule and protein virulence determinants. |
| first_indexed | 2024-12-23T19:27:57Z |
| format | Article |
| id | doaj.art-50d819a18c6b4353b5d45c6e3ff32a96 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-23T19:27:57Z |
| publishDate | 2011-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-50d819a18c6b4353b5d45c6e3ff32a962022-12-21T17:34:00ZengPublic Library of Science (PLoS)PLoS ONE1932-62032011-01-01610e2658710.1371/journal.pone.0026587Changes in capsular serotype alter the surface exposure of pneumococcal adhesins and impact virulence.Carlos J SanchezCecilia A HinojosaPooja ShivshankarCatherine HyamsEmilie CamberleinJeremy S BrownCarlos J OrihuelaWe examined the contribution of serotype on Streptococcus pneumoniae adhesion and virulence during respiratory tract infection using a panel of isogenic TIGR4 (serotype 4) mutants expressing the capsule types 6A (+6A), 7F (+7F) and 23F (+23F) as well as a deleted and restored serotype 4 (+4) control strain. Immunoblots, bacterial capture assays with immobilized antibody, and measurement of mean fluorescent intensity by flow cytometry following incubation of bacteria with antibody, all determined that the surface accessibility, but not total protein levels, of the virulence determinants Pneumococcal surface protein A (PspA), Choline binding protein A (CbpA), and Pneumococcal serine-rich repeat protein (PsrP) changed with serotype. In vitro, bacterial adhesion to Detroit 562 pharyngeal or A549 lung epithelial cells was modestly but significantly altered for +6A, +7F and +23F. In a mouse model of nasopharyngeal colonization, the number of +6A, +7F, and +23F pneumococci in the nasopharynx was reduced 10 to 100-fold versus +4; notably, only mice challenged with +4 developed bacteremia. Intratracheal challenge of mice confirmed that capsule switch strains were highly attenuated for virulence. Compared to +4, the +6A, +7F, and +23F strains were rapidly cleared from the lungs and were not detected in the blood. In mice challenged intraperitoneally, a marked reduction in bacterial blood titers was observed for those challenged with +6A and +7F versus +4 and +23F was undetectable. These findings show that serotype impacts the accessibility of surface adhesins and, in particular, affects virulence within the respiratory tract. They highlight the complex interplay between capsule and protein virulence determinants.http://europepmc.org/articles/PMC3197518?pdf=render |
| spellingShingle | Carlos J Sanchez Cecilia A Hinojosa Pooja Shivshankar Catherine Hyams Emilie Camberlein Jeremy S Brown Carlos J Orihuela Changes in capsular serotype alter the surface exposure of pneumococcal adhesins and impact virulence. PLoS ONE |
| title | Changes in capsular serotype alter the surface exposure of pneumococcal adhesins and impact virulence. |
| title_full | Changes in capsular serotype alter the surface exposure of pneumococcal adhesins and impact virulence. |
| title_fullStr | Changes in capsular serotype alter the surface exposure of pneumococcal adhesins and impact virulence. |
| title_full_unstemmed | Changes in capsular serotype alter the surface exposure of pneumococcal adhesins and impact virulence. |
| title_short | Changes in capsular serotype alter the surface exposure of pneumococcal adhesins and impact virulence. |
| title_sort | changes in capsular serotype alter the surface exposure of pneumococcal adhesins and impact virulence |
| url | http://europepmc.org/articles/PMC3197518?pdf=render |
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