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

 Previous Article  |  Next Article 

Infect. Immun., 04 1997, 1462-1467, Vol 65, No. 4
Copyright © 1997, American Society for Microbiology

Characterization of two distinct opsonic and protective epitopes within the alpha C protein of the group B Streptococcus

DE Kling, C Gravekamp, LC Madoff and JL Michel
Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, USA.

Group B Streptococcus (GBS) is a major cause of neonatal sepsis, meningitis in early infancy, postpartum endometritis, and serious invasive infections in adults in the United States. We previously cloned, sequenced, and characterized the alpha antigen gene, bca, and showed that the alpha C protein of GBS is a trypsin-resistant, surface- associated polypeptide that contains a signal sequence, a unique N terminus, nine identical tandem repeats, and a C-terminal membrane anchor structure. Polyclonal antiserum raised to the recombinant alpha C protein and an opsonic monoclonal antibody, 4G8, raised to the native protein from GBS have been shown to be protective in a mouse model. The binding site of 4G8 has now been localized to the tandem repeat region of the alpha C protein. To determine whether the N terminus of the alpha C protein contains additional opsonic and/or protective epitopes, the sequence corresponding to the alpha C protein N terminus was subcloned into a pET vector, the expressed peptide from Escherichia coli was purified by Ni2+ affinity chromatography, and rabbit polyclonal antibodies were raised to the purified recombinant peptide. Antibodies to the alpha C protein N terminus were shown to be opsonic by an in vitro opsonophagocytosis assay. In addition, 69% of newborn mouse pups from mothers passively immunized with the antiserum to the recombinant N-terminal polypeptide of the alpha C protein were protected against lethal challenge with GBS A909. These data indicate that at least two distinct regions of the alpha C protein, the N terminus and the tandem repeat region, contain opsonic and protective epitopes.

This article has been cited by other articles:

• Bolduc, G. R., Madoff, L. C. (2007). The group B streptococcal alpha C protein binds {alpha}1 1-integrin through a novel KTD motif that promotes internalization of GBS within human epithelial cells. Microbiology 153: 4039-4049 [Abstract] [Full Text]  
• Baron, M. J., Filman, D. J., Prophete, G. A., Hogle, J. M., Madoff, L. C. (2007). Identification of a Glycosaminoglycan Binding Region of the Alpha C Protein That Mediates Entry of Group B Streptococci into Host Cells. J. Biol. Chem. 282: 10526-10536 [Abstract] [Full Text]  
• Auperin, T. C., Bolduc, G. R., Baron, M. J., Heroux, A., Filman, D. J., Madoff, L. C., Hogle, J. M. (2005). Crystal Structure of the N-terminal Domain of the Group B Streptococcus Alpha C Protein. J. Biol. Chem. 280: 18245-18252 [Abstract] [Full Text]  
• Seepersaud, R., Hanniffy, S. B., Mayne, P., Sizer, P., Le Page, R., Wells, J. M. (2005). Characterization of a Novel Leucine-Rich Repeat Protein Antigen from Group B Streptococci That Elicits Protective Immunity. Infect. Immun. 73: 1671-1683 [Abstract] [Full Text]  
• Lindahl, G., Stalhammar-Carlemalm, M., Areschoug, T. (2005). Surface Proteins of Streptococcus agalactiae and Related Proteins in Other Bacterial Pathogens. Clin. Microbiol. Rev. 18: 102-127 [Abstract] [Full Text]  
• Baron, M. J., Bolduc, G. R., Goldberg, M. B., Auperin, T. C., Madoff, L. C. (2004). Alpha C Protein of Group B Streptococcus Binds Host Cell Surface Glycosaminoglycan and Enters Cells by an Actin-dependent Mechanism. J. Biol. Chem. 279: 24714-24723 [Abstract] [Full Text]  
• Moyo, S. R., Maeland, J. A., Mudzori, J. (2001). Antibodies against Streptococcus agalactiae Proteins calpha and R4 in Sera from Pregnant Women from Norway and Zimbabwe. CVI 8: 1110-1114 [Abstract] [Full Text]  
• Puopolo, K. M., Hollingshead, S. K., Carey, V. J., Madoff, L. C. (2001). Tandem Repeat Deletion in the Alpha C Protein of Group B Streptococcus Is recA Independent. Infect. Immun. 69: 5037-5045 [Abstract] [Full Text]  
• Brodeur, B. R., Boyer, M., Charlebois, I., Hamel, J., Couture, F., Rioux, C. R., Martin, D. (2000). Identification of Group B Streptococcal Sip Protein, Which Elicits Cross-Protective Immunity. Infect. Immun. 68: 5610-5618 [Abstract] [Full Text]  
• MAELAND, J.A., BRAKSTAD, O.G., BEVANGER, L., KROKSTAD, S. (2000). Distribution and expression of bca, the gene encoding the c alpha protein, by Streptococcus agalactiae. J Med Microbiol 49: 193-198 [Abstract] [Full Text]  
• Li, J., Kasper, D. L., Ausubel, F. M., Rosner, B., Michel, J. L. (1997). Inactivation of the alpha  C protein antigen gene, bca, by a novel shuttle/suicide vector results in attenuation of virulence and immunity in group B Streptococcus. Proc. Natl. Acad. Sci. USA 94: 13251-13256 [Abstract] [Full Text]