Email updates

Keep up to date with the latest news and content from BMC Microbiology and BioMed Central.

Open Access Highly Accessed Research article

Streptococcal collagen-like surface protein 1 promotes adhesion to the respiratory epithelial cell

Shih-Ming Chen1, Yau-Sheng Tsai2, Chin-Ming Wu3, Shuen-Kuei Liao1, Ling-Chia Wu4, Cherng-Shyang Chang5, Ya-Hui Liu5 and Pei-Jane Tsai45*

Author Affiliations

1 Graduate Institute of Clinical Medical Sciences, Chang Gung University, Taoyuan, Taiwan ROC

2 Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan ROC

3 Department of Cell Biology and Anatomy, College of Medicine, National Cheng Kung University, Tainan, Taiwan ROC

4 Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan, Taiwan ROC

5 Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan ROC

For all author emails, please log on.

BMC Microbiology 2010, 10:320  doi:10.1186/1471-2180-10-320

Published: 15 December 2010

Abstract

Background

Collagen-like surface proteins Scl1 and Scl2 on Streptococcus pyogenes contain contiguous Gly-X-X triplet amino acid motifs, the characteristic structure of human collagen. Although the potential role of Scl1 in adhesion has been studied, the conclusions may be affected by the use of different S. pyogenes strains and their carriages of various adhesins. To explore the bona fide nature of Scl1 in adherence to human epithelial cells without the potential interference of other streptococcal surface factors, we constructed a scl1 isogenic mutant from the Scl2-defective S. pyogenes strain and a Scl1-expressed Escherichia coli.

Results

Loss of Scl1 in a Scl2-defective S. pyogenes strain dramatically decreased the adhesion of bacteria to HEp-2 human epithelial cells. Expression of Scl1 on the surface of the heterologous bacteria E. coli significantly increased adhesion to HEp-2. The increase in adhesion was nullified when Scl1-expressed E. coli was pre-incubated with proteases or antibodies against recombinant Scl1 (rScl1) protein. Treatment of HEp-2 cells with rScl protein or pronase drastically reduced the binding capability of Scl1-expressed E. coli. These findings suggest that the adhesion is mediated through Scl1 on bacterial surface and protein receptor(s) on epithelial cells. Further blocking of potential integrins revealed significant contributions of α2 and β1 integrins in Scl1-mediated binding to epithelial cells.

Conclusions

Together, these results underscore the importance of Scl1 in the virulence of S. pyogenes and implicate Scl1 as an adhesin during pathogenesis of streptococcal infection.