scholarly journals Lectin Site Interaction with Capsular Polysaccharide Mediates Nonimmune Phagocytosis of Type III Group B Streptococci

2000 ◽  
Vol 68 (10) ◽  
pp. 5794-5802 ◽  
Author(s):  
E. A. Albanyan ◽  
M. S. Edwards
Keyword(s):  
Capsular Polysaccharide ◽  
Group B Streptococci ◽  
Type Iii ◽  
Group B

scholarly journals Capsular polysaccharide regulates neutrophil complement receptor interactions with type III group B streptococci.

1993 ◽  
Vol 61 (7) ◽  
pp. 2866-2871 ◽  
Author(s):  
M S Edwards ◽  
M R Wessels ◽  
C J Baker
Keyword(s):  
Capsular Polysaccharide ◽  
Complement Receptor ◽  
Group B Streptococci ◽  
Type Iii ◽  
Receptor Interactions ◽  
Group B

Specificity and Protective Activity of Murine Monoclonal Antibodies Directed Against the Capsular Polysaccharide of Type III Group B Streptococci

Hybridoma ◽  
1992 ◽  
Vol 11 (1) ◽  
pp. 13-22 ◽  
Author(s):  
G. TETI ◽  
M. CALAPAI ◽  
G. CALOGERO ◽  
F. TOMASELLO ◽  
G. MANCUSO ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Capsular Polysaccharide ◽  
Protective Activity ◽  
Group B Streptococci ◽  
Type Iii ◽  
Group B ◽  
Murine Monoclonal Antibodies

scholarly journals Alpha C Protein as a Carrier for Type III Capsular Polysaccharide and as a Protective Protein in Group B Streptococcal Vaccines

1999 ◽  
Vol 67 (5) ◽  
pp. 2491-2496 ◽  
Author(s):  
Claudia Gravekamp ◽  
Dennis L. Kasper ◽  
Lawrence C. Paoletti ◽  
Lawrence C. Madoff
Keyword(s):  
Conjugate Vaccine ◽  
Tetanus Toxoid ◽  
Capsular Polysaccharide ◽  
Protein A ◽  
Surface Protein ◽  
Negative Control ◽  
Group B Streptococci ◽  
C Protein ◽  
Type Iii ◽  
Group B

ABSTRACT The alpha C protein, a protective surface protein of group B streptococci (GBS), is present in most non-type III GBS strains. Conjugate vaccines composed of the alpha C protein and type III capsular polysaccharide (CPS) might be protective against most GBS infections. In this study, the type III CPS was covalently coupled to full-length, nine-repeat alpha C protein (resulting in III-α9r conjugate vaccine) or to two-repeat alpha C protein (resulting in III-α2r conjugate vaccine) by reductive amination. Initial experiments with the III-α9r vaccine showed that it was poorly immunogenic in mice with respect to both vaccine antigens and was suboptimally efficacious in providing protection in mice against challenge with GBS. Therefore, modified vaccination protocols were used with the III-α2r vaccine. Female mice were immunized three times with 0.5, 5, or 20 μg of the III-α2r vaccine with an aluminum hydroxide adjuvant and bred. Ninety-five percent of neonatal mice born to dams immunized with the III-α2r vaccine survived challenge with GBS expressing type III CPS, and 60% survived challenge with GBS expressing wild-type (nine-repeat) alpha C protein; 18 and 17%, respectively, of mice in the negative control groups survived (P, <0.0001). These protection levels did not differ significantly from those obtained with the type III CPS-tetanus toxoid conjugate vaccine and the unconjugated two-repeat alpha C protein, which protected 98 and 58% of neonates from infection with GBS expressing type III CPS or the alpha C protein, respectively. Thus, the two-repeat alpha C protein in the vaccine was immunogenic and simultaneously enhanced the immunogenicity of type III CPS. III-α vaccines may be alternatives to GBS polysaccharide-tetanus toxoid vaccines, eliciting additional antibodies protective against GBS infection.

scholarly journals Nonopsonic Binding of Type III Group B Streptococci to Human Neutrophils Induces Interleukin-8 Release Mediated by the p38 Mitogen-Activated Protein Kinase Pathway

2000 ◽  
Vol 68 (4) ◽  
pp. 2053-2060 ◽  
Author(s):  
Esam A. Albanyan ◽  
Jesus G. Vallejo ◽  
C. Wayne Smith ◽  
Morven S. Edwards
Keyword(s):  
Capsular Polysaccharide ◽  
Kinase Inhibitor ◽  
Interleukin 8 ◽  
Mitogen Activated Protein Kinase ◽  
Human Neutrophils ◽  
Complement Receptor ◽  
Group B Streptococci ◽  
Type Iii ◽  
Mitogen Activated Protein ◽  
Group B

ABSTRACT Nonopsonic interaction of host immune cells with pathogens is an important first line of defense. We hypothesized that nonopsonic recognition between type III group B streptococcus and human neutrophils would occur and that the interaction would be sufficient to trigger neutrophil activation. By using a serum-free system, it was found that heat-killed type III group B streptococci bound to neutrophils in a rapid, stable, and inoculum-dependent manner that did not result in ingestion. Transposon-derived type III strain COH1-13, which lacks capsular polysaccharide, and strain COH1-11 with capsular polysaccharide lacking terminal sialic acid demonstrated increased neutrophil binding, suggesting that capsular polysaccharide masks an underlying binding site. Experiments using monoclonal antibodies to complement receptor 1 and to the I domain or lectin site of complement receptor 3 did not inhibit binding, indicating that the complement receptors used for ingestion of opsonized group B streptococci were not required for nonopsonic binding. Nonopsonic binding resulted in rapid activation of cellular p38 and p44/42 mitogen-activated protein kinases. This interaction was not an effective trigger for superoxide production but did promote release of the proinflammatory cytokine interleukin-8. The release of interleukin-8 was markedly suppressed by the p38 mitogen-activated protein kinase inhibitor SB203580 but was only minimally suppressed by the mitogen-activated protein/extracellular signal-regulated kinase inhibitor PD98059. Thus, nonopsonic binding of type III group B streptococci to neutrophils is sufficient to initiate intracellular signaling pathways and could serve as an arm of innate immunity of particular importance to the immature host.

scholarly journals Immunization with C5a Peptidase or Peptidase-Type III Polysaccharide Conjugate Vaccines Enhances Clearance of Group B Streptococci from Lungs of Infected Mice

2002 ◽  
Vol 70 (11) ◽  
pp. 6409-6415 ◽  
Author(s):  
Qi Cheng ◽  
Steven Debol ◽  
Hong Lam ◽  
Ron Eby ◽  
Lorri Edwards ◽  
...  
Keyword(s):  
Tetanus Toxoid ◽  
Capsular Polysaccharide ◽  
Vaccine Development ◽  
Surface Protein ◽  
Histological Evaluation ◽  
Group B Streptococci ◽  
Type Iii ◽  
Rapid Clearance ◽  
Group B ◽  
The Impact

ABSTRACT Group B streptococci (GBS) are among the most common causes of life-threatening neonatal infections. Vaccine development since the late 1970s has focused on the capsular polysaccharides, but a safe, effective product is still not available. Our quest for a vaccine turned to the streptococcal C5a peptidase (SCPB). This surface protein is antigenically conserved across most if not all serotypes. A murine model was used to assess the impact of SCPB on clearance of GBS from the lungs of intranasally infected animals. Mutational inactivation of SCPB resulted in more-rapid clearance of streptococci from the lung. Immunization with recombinant SCPB alone or SCPB conjugated to type III capsular polysaccharide produced serotype-independent protection, which was evidenced by more-rapid clearance of the serotype VI strain from the lungs. Immunization of mice with tetanus toxoid-type III polysaccharide conjugate did not produce protection, confirming that protection induced by SCPB conjugates was independent of type III polysaccharide antigen. Histological evaluation of lungs from infected mice revealed that pathology in animals immunized with SCPB or SCPB conjugates was significantly less than that in animals immunized with a tetanus toxoid-polysaccharide conjugate. These experiments suggest that inclusion of C5a peptidase in a vaccine will both add another level to and broaden the spectrum of the protection of a polysaccharide vaccine.

scholarly journals Group B streptococci invade endothelial cells: type III capsular polysaccharide attenuates invasion.

1993 ◽  
Vol 61 (2) ◽  
pp. 478-485 ◽  
Author(s):  
R L Gibson ◽  
M K Lee ◽  
C Soderland ◽  
E Y Chi ◽  
C E Rubens
Keyword(s):  
Endothelial Cells ◽  
Capsular Polysaccharide ◽  
Group B Streptococci ◽  
Type Iii ◽  
Group B

scholarly journals Prevention of C3 deposition by capsular polysaccharide is a virulence mechanism of type III group B streptococci.

1992 ◽  
Vol 60 (10) ◽  
pp. 3986-3993 ◽  
Author(s):  
M B Marques ◽  
D L Kasper ◽  
M K Pangburn ◽  
M R Wessels
Keyword(s):  
Capsular Polysaccharide ◽  
Group B Streptococci ◽  
Type Iii ◽  
Group B

scholarly journals Sialylation of Group B Streptococcal Capsular Polysaccharide Is Mediated by cpsK and Is Required for Optimal Capsule Polymerization and Expression

2005 ◽  
Vol 187 (13) ◽  
pp. 4615-4626 ◽  
Author(s):  
D. O. Chaffin ◽  
L. M. Mentele ◽  
C. E. Rubens
Keyword(s):  
Sialic Acid ◽  
Cell Surface ◽  
High Performance ◽  
Capsular Polysaccharide ◽  
Immunoblot Analysis ◽  
Enzyme Linked Immunosorbent Assay ◽  
Group B Streptococci ◽  
Type Iii ◽  
Self Recognition ◽  
Group B

ABSTRACT Several bacterial pathogens have evolved the means to escape immune detection by mimicking host cell surface carbohydrates that are crucial for self/non-self recognition. Sialic acid, a terminal residue on these carbohydrates, inhibits activation of the alternate pathway of complement by recruiting the immune modulating molecule factors H, I, and iC3b. Sialylation of capsular polysaccharide (CPS) is important for virulence of group B streptococci (GBS), a significant human pathogen. We previously reported that cpsK, a gene within the cps locus of type III GBS, could complement a sialyltransferase deficient lst mutant of Haemophilus ducreyi, implicating its role in sialylation of the GBS capsule. To explore the function of cpsK in GBS capsule production, we created a mutant in cpsK. Immunoblot analysis and enzyme-linked immunosorbent assay using anti-type III CPS antisera demonstrated that the mutant CPS did not contain sialic acid. This was confirmed by high-performance liquid chromatography after mild acid hydrolysis of the CPS. Although increased CPS chain length was seen for this strain, CPS production was <20% of the parental isolate. An episomal cpsK copy restored synthesis of sialo-CPS to wild-type levels. These data support our hypothesis that cpsK encodes the GBS CPS sialyltransferase and provide further evidence that lack of CPS oligosaccharide sialylation reduces the amount of CPS expressed on the cell surface. These observations also imply that one or more of the components involved in synthesis or transport of oligosaccharide repeating units requires a sialo-oligosaccharide for complete activity.

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