New protective antigen of group A streptococci

Dale, James B.; Chiang, Edna Y.; Liu, Shaoyou; Courtney, Harry S.; Hasty, David L.

doi:10.1172/jci5118

Cited by 70 publications

(69 citation statements)

References 30 publications

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“…n et al, 1984). Searches of databases for homologies to the amino acid sequence of the putative IgG-binding domain of FgBP reveals significant similarities only with (a) a new protective antigen (Spa) of group A streptococci which shows a curious and remarkable (98 %) homology with S. equi FgBP over the C-terminal half of the molecule (Dale et al, 1999 ; GenBank accession no. AF0876813), and (b) the central regions of the Fg\IgG-binding protein DemA from S. dysgalactiae.…”

Section: Fgbp Contributes To Virulence In Micementioning

confidence: 99%

The fibrinogen-binding protein (FgBP) of Streptococcus equi subsp. equi additionally binds IgG and contributes to virulence in a mouse model

et al. 2001

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The major cell-wall-associated protein of the equine pathogen Streptococcus equi subsp. equi is an M-like fibrinogen-binding protein (FgBP) which binds equine fibrinogen (Fg) avidly, through residues located at the extreme Nterminus of the molecule. In this study, it is shown that FgBP additionally binds equine IgG-Fc. When tested against polyclonal IgG from ten other animal species, it was found that FgBP binds human, rabbit, pig and cat IgG, but does not bind mouse, rat, goat, sheep, cow or chicken IgG. Through the use of a panel of recombinant FgBP truncates containing defined deletions of sequence, it was shown that residues in the central regions of FgBP are important in IgG binding. An fbp knockout mutant which does not express FgBP on the cell surface was also constructed. Mutant cells failed to autoaggregate, bound no detectable equine Fg or IgG-Fc, were rapidly killed in horse blood, and showed greatly decreased virulence in a mouse model. Results suggest that FgBP is the major surface structure responsible for binding either Fg or IgG, that the molecule has pronounced antiphagocytic properties, and that it is a likely factor contributing to the virulence of wild-type S. equi subsp. equi.

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Section: Fgbp Contributes To Virulence In Micementioning

confidence: 99%

The fibrinogen-binding protein (FgBP) of Streptococcus equi subsp. equi additionally binds IgG and contributes to virulence in a mouse model

et al. 2001

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“…More than 50 extracellular proteins with this motif have been described in Gram-positive bacteria, and many of them are virulence factors (38). For example, in GAS this motif is present in M protein, M-like proteins, C5a peptidase, GRAB protein, serum opacity factor, a fibronectin-binding protein, streptococcal protective antigen, and two collagen-like proteins (13,43,(47)(48)(49). All of these proteins are expressed on the GAS cell surface.…”

Section: Implications For Pathogenesis and Development Of Therapeuticsmentioning

confidence: 99%

Multilocus analysis of extracellular putative virulence proteins made by group A Streptococcus: Population genetics, human serologic response, and gene transcription

Reid

Green

Buss

et al. 2001

Proc. Natl. Acad. Sci. U.S.A.

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Species of pathogenic microbes are composed of an array of evolutionarily distinct chromosomal genotypes characterized by diversity in gene content and sequence (allelic variation). The occurrence of substantial genetic diversity has hindered progress in developing a comprehensive understanding of the molecular basis of virulence and new therapeutics such as vaccines. To provide new information that bears on these issues, 11 genes encoding extracellular proteins in the human bacterial pathogen group A Streptococcus identified by analysis of four genomes were studied. Eight of the 11 genes encode proteins with a LPXTG(L) motif that covalently links Gram-positive virulence factors to the bacterial cell surface. Sequence analysis of the 11 genes in 37 geographically and phylogenetically diverse group A Streptococcus strains cultured from patients with different infection types found that recent horizontal gene transfer has contributed substantially to chromosomal diversity. Regions of the inferred proteins likely to interact with the host were identified by molecular population genetic analysis, and Western immunoblot analysis with sera from infected patients confirmed that they were antigenic. Real-time reverse transcriptase-PCR (TaqMan) assays found that transcription of six of the 11 genes was substantially up-regulated in the stationary phase. In addition, transcription of many genes was influenced by the covR and mga trans-acting gene regulatory loci. Multilocus investigation of putative virulence genes by the integrated approach described herein provides an important strategy to aid microbial pathogenesis research and rapidly identify new targets for therapeutics research.

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“…In this regard, there are studies showing that immunization with proteases such as C5a peptidase and streptococcal cysteine protease elicit a non-type-specific immunity irrespective of the M serotype (20,22). More recently, several cell surface proteins have been reported to induce protective immune responses in mice (8,13,39). However, it is still unclear whether these proteins induce protective immune responses to different M serotypes.…”

mentioning

confidence: 99%

“…The opsonization assay was done, with minor modifications, as described previously (8). Briefly, 80 l of heparinized whole blood was mixed with 10 l of bacteria (ϳ5 ϫ 10 6 CFU) and 20 l of rabbit anti-FBP54 serum or nonimmunized serum for 5 to 10 min at 37°C.…”

mentioning

confidence: 99%

Systemic and Mucosal Immunizations with Fibronectin-Binding Protein FBP54 Induce Protective Immune Responses againstStreptococcus pyogenesChallenge in Mice

et al. 2001

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The purpose of this study was to examine the suitability of fibronectin-binding protein FBP54 as a putative vaccine for Streptococcus pyogenes infections. When the distribution of the fbp54 gene among the clinical isolates representing various M serotypes was tested by PCR and Southern blot assays, it was found that all of the strains possess this gene. Furthermore, a significant increase in immunoglobulin G (IgG) antibody titers against FBP54 was observed in sera from patients with S. pyogenes infections compared with those from healthy volunteers (P < 0.005). Mice were immunized with FBP54 subcutaneously, orally, or nasally. An enzyme-linked immunosorbent assay revealed that antigen-specific IgG antibodies were induced in the sera of immunized mice, while high salivary levels of IgA antibodies were detected after oral and nasal immunizations. Mice subcutaneously or orally immunized with FBP54 survived significantly longer following the challenge with S. pyogenes than did nonimmunized mice (P < 0.001). These results indicate that FBP54 is a promising vaccine for the prevention of S. pyogenes infections.

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New protective antigen of group A streptococci

Cited by 70 publications

References 30 publications

The fibrinogen-binding protein (FgBP) of Streptococcus equi subsp. equi additionally binds IgG and contributes to virulence in a mouse model

The fibrinogen-binding protein (FgBP) of Streptococcus equi subsp. equi additionally binds IgG and contributes to virulence in a mouse model

Multilocus analysis of extracellular putative virulence proteins made by group A Streptococcus: Population genetics, human serologic response, and gene transcription

Systemic and Mucosal Immunizations with Fibronectin-Binding Protein FBP54 Induce Protective Immune Responses againstStreptococcus pyogenesChallenge in Mice

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