scholarly journals The Proline-Rich Region of Pneumococcal Surface Proteins A and C Contains Surface-Accessible Epitopes Common to All Pneumococci and Elicits Antibody-Mediated Protection against Sepsis

2010 ◽  
Vol 78 (5) ◽  
pp. 2163-2172 ◽  
Author(s):  
Calvin C. Daniels ◽  
Patricia Coan ◽  
Janice King ◽  
Joanetha Hale ◽  
Kimberly A. Benton ◽  
...  
Keyword(s):  
Protein A ◽  
Pneumococcal Infection ◽  
Passive Immunization ◽  
Surface Protein ◽  
Helical Structure ◽  
Structural Similarity ◽  
Cross Reactivity ◽  
Surface Proteins ◽  
Structure Characteristic ◽  
Protective Antibodies

ABSTRACTPneumococcal surface protein A (PspA) and PspC ofStreptococcus pneumoniaeare surface virulence proteins that interfere with complement deposition and elicit protective immune responses. The C-terminal halves of PspA and PspC have some structural similarity and contain highly cross-reactive proline-rich (PR) regions. In many PR regions of PspA and PspC, there exists an almost invariant nonproline block (NPB) of about 33 amino acids. Neither the PR regions nor their NPB exhibit the alpha-helical structure characteristic of much of the protection-eliciting N-terminal portions of PspA and PspC. Prior studies of PspA and PspC as immunogens focused primarily on the alpha-helical regions of these molecules that lack the PR and NPB regions. This report shows that immunization with recombinant PR (rPR) molecules and passive immunization with monoclonal antibodies reactive with either NPB or PR epitopes are protective against infection in mice. PR regions of both PspA and PspC were antibody accessible on the pneumococcal surface. Our results indicate that while PspA could serve as a target of these protective antibodies in invasive infections, PspC might not. When antibody responses to rPR immunogens were evaluated by using flow cytometry to measure antibody binding to live pneumococci, it was observed that the mice that survived subsequent challenge produced significantly higher levels of antibodies reactive with exposed PR epitopes than the mice that became moribund. Due to their conservation and cross-reactivity, the PR regions and NPB regions represent potential vaccine targets capable of eliciting cross-protection immunity against pneumococcal infection.

scholarly journals Group B Streptococcal Surface Proteins as Targets for Protective Antibodies: Identification of Two Novel Proteins in Strains of Serotype V

1999 ◽  
Vol 67 (12) ◽  
pp. 6350-6357 ◽  
Author(s):  
Thomas Areschoug ◽  
Margaretha Stålhammar-Carlemalm ◽  
Charlotte Larsson ◽  
Gunnar Lindahl
Keyword(s):  
Vaccine Development ◽  
Group B Streptococcus ◽  
Surface Protein ◽  
Cross Reactivity ◽  
Active Immunization ◽  
Surface Proteins ◽  
Protective Antibodies ◽  
Group B ◽  
Different Strains ◽  
Type V

ABSTRACT Strains of group B streptococcus (GBS) express surface proteins that confer protective immunity. In particular, most strains of the four classical capsular serotypes (Ia, Ib, II, and III) express either of the Rib and α proteins, two members of the same protein family. Here, we report a study of surface proteins expressed by strains of serotype V, which has recently emerged as an important serotype among GBS strains causing serious disease. Two novel GBS proteins were identified, purified, and characterized. One of these proteins, designated Fbs, was immunologically unrelated to other GBS surface proteins. This ∼110-kDa protein was found in 15 of 49 (31%) type V isolates but in few strains of other serotypes. The Fbs proteins expressed by different strains showed limited variation in size. The most common surface protein among type V strains, found in 29 of 49 (59%) isolates, was designated Rib-like, since it cross-reacted with Rib but was not immunologically identical to Rib. Characterization of this Rib-like protein showed that the N-terminal sequence (12 residues) was identical to that of α, although these two proteins lacked cross-reactivity. The biochemical and immunological properties of the Rib-like GBS protein indicate that it is closely related to the R28 protein of Streptococcus pyogenes. Importantly, passive and active immunization experiments with mice showed that the Fbs and Rib-like proteins are targets for protective antibodies. These two proteins are therefore of interest for analysis of pathogenic mechanisms and for vaccine development.

scholarly journals A Novel, Multiple-Antigen Pneumococcal Vaccine Protects against LethalStreptococcus pneumoniaeChallenge

2018 ◽  
Vol 87 (3) ◽  
Author(s):  
Win-Yan Chan ◽  
Claire Entwisle ◽  
Giuseppe Ercoli ◽  
Elise Ramos-Sevillano ◽  
Ann McIlgorm ◽  
...  
Keyword(s):  
Heat Shock ◽  
Protein A ◽  
Surface Protein ◽  
Surface Proteins ◽  
Rabbit Serum ◽  
Protein Antigens ◽  
Content Type ◽  
Multiple Antigen ◽  
Bacterial Lysates ◽  
Chromatography Step

ABSTRACTCurrent vaccination againstStreptococcus pneumoniaeuses vaccines based on capsular polysaccharides from selected serotypes and has led to nonvaccine serotype replacement disease. We have investigated an alternative serotype-independent approach, using multiple-antigen vaccines (MAV) prepared fromS. pneumoniaeTIGR4 lysates enriched for surface proteins by a chromatography step after culture under conditions that induce expression of heat shock proteins (Hsp; thought to be immune adjuvants). Proteomics and immunoblot analyses demonstrated that, compared to standard bacterial lysates, MAV was enriched with Hsps and contained several recognized protective protein antigens, including pneumococcal surface protein A (PspA) and pneumolysin (Ply). Vaccination of rodents with MAV induced robust antibody responses to multiple serotypes, including nonpneumococcal conjugate vaccine serotypes. Homologous and heterologous strains ofS. pneumoniaewere opsonized after incubation in sera from vaccinated rodents. In mouse models, active vaccination with MAV significantly protected against pneumonia, while passive transfer of rabbit serum from MAV-vaccinated rabbits significantly protected against sepsis caused by both homologous and heterologousS. pneumoniaestrains. Direct comparison of MAV preparations made with or without the heat shock step showed no clear differences in protein antigen content and antigenicity, suggesting that the chromatography step rather than Hsp induction improved MAV antigenicity. Overall, these data suggest that the MAV approach may provide serotype-independent protection againstS. pneumoniae.

scholarly journals Recognition of pneumococcal isolates by antisera raised against PspA fragments from different clades

2008 ◽  
Vol 57 (3) ◽  
pp. 273-278 ◽  
Author(s):  
Michelle Darrieux ◽  
Adriana T. Moreno ◽  
Daniela M. Ferreira ◽  
Fabiana C. Pimenta ◽  
Ana Lúcia S. S. de Andrade ◽  
...  
Keyword(s):  
Animal Models ◽  
Vaccine Candidate ◽  
Protein A ◽  
Surface Protein ◽  
Structural Diversity ◽  
Cross Reactivity ◽  
Terminal Region ◽  
Hybrid Protein ◽  
Pneumococcal Infections ◽  
Clade 1

Pneumococcal surface protein A (PspA) is an important vaccine candidate against pneumococcal infections, capable of inducing protection in different animal models. Based on its structural diversity, it has been suggested that a PspA-based vaccine should contain at least one fragment from each of the two major families (family 1, comprising clades 1 and 2, and family 2, comprising clades 3, 4 and 5) in order to elicit broad protection. This study analysed the recognition of a panel of 35 pneumococcal isolates bearing different PspAs by antisera raised against the N-terminal regions of PspA clades 1 to 5. The antiserum to PspA clade 4 was found to show the broadest cross-reactivity, being able to recognize pneumococcal strains containing PspAs of all clades in both families. The cross-reactivity of antibodies elicited against a PspA hybrid including the N-terminal region of clade 1 fused to a shorter and more divergent fragment (clade-defining region, or CDR) of clade 4 (PspA1–4) was also tested, and revealed a strong recognition of isolates containing clades 1, 4 and 5, and weaker reactions with clades 2 and 3. The analysis of serum reactivity against different PspA regions further revealed that the complete N-terminal region rather than just the CDR should be included in an anti-pneumococcal vaccine. A PspA-based vaccine is thus proposed to be composed of the whole N-terminal region of clades 1 and 4, which could also be expressed as a hybrid protein.

Serogroups of the beer spoilage bacterium Megasphaera cerevisiae correlate with the molecular weight of the major EDTA-extractable surface protein

2000 ◽  
Vol 46 (2) ◽  
pp. 95-100 ◽  
Author(s):  
Barry Ziola ◽  
Lori Gee ◽  
Nancy N Berg ◽  
Sun Y Lee
Keyword(s):  
Ethylenediaminetetraacetic Acid ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Surface Protein ◽  
Cross Reactivity ◽  
Surface Reactivity ◽  
Surface Proteins ◽  
Bacterial Surface ◽  
Spoilage Bacteria ◽  
Beer Spoilage

Megasphaera cerevisiae is a Gram-negative obligate anaerobe that causes turbidity and off-flavour and aroma in beer. Seven isolates of M. cerevisiae were obtained worldwide, and their extractable surface antigens were focused upon to determine if there is more than one serogroup of this bacterium. Sodium dodecyl sulphate polyacrylamide gel electrophoresis of ethylenediaminetetraacetic acid (EDTA) bacterial extracts revealed a predominant protein with apparent molecular weights of 46 000, 45 000, and 43 000 for three, two, and two isolates, respectively. When mouse antiserum generated against any of the EDTA extracts was reacted with denatured bacterial proteins in immunoblots, all bacterial isolates exhibited extensive cross-reactivity involving three antigens, one being the major EDTA-extractable protein. In contrast, when the sera were tested for surface reactivity with intact bacteria, three cross-reactivity groups were observed, with the groups individually comprised of bacteria having the same size major EDTA-extractable surface protein. When BALB/c mice immunized with a bacterium from each of the three serogroups were used for monoclonal antibody (Mab) hybridoma production, bacterial surface-reactive Mabs were obtained whose reactivities parallel the three polyclonal antibody-defined serogroups. Through combining these surface-reactive Mabs, it will be possible to rapidly detect and identify beer contamination by M. cerevisiae belonging to any serogroup. Key words: beer spoilage bacteria, Megasphaera cerevisiae, monoclonal antibodies, surface proteins, serogroups.

scholarly journals Broadly reactive human monoclonal antibodies targeting the pneumococcal histidine triad protein protect against fatal pneumococcal infection

2021 ◽  
Author(s):  
Jiachen Huang ◽  
Aaron D. Gingerich ◽  
Fredejah Royer ◽  
Amy V. Paschall ◽  
Alma Pena-Briseno ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Disease Prevention ◽  
Disease Incidence ◽  
Protein A ◽  
Pneumococcal Infection ◽  
Surface Protein ◽  
Human Monoclonal Antibodies ◽  
Human Mabs ◽  
Prevention And Treatment ◽  
Pneumococcal Serotype

AbstractStreptococcus pneumoniae remains a leading cause of bacterial pneumonia despite the widespread use of vaccines. While vaccines are effective at reducing the incidence of most vaccine-included serotypes, a rise in infection due to non-vaccine serotypes, and moderate efficacy against some vaccine included serotypes have contributed to high disease incidence. Additionally, numerous isolates of S. pneumoniae are antibiotic or multi-drug resistant. Several conserved pneumococcal proteins prevalent in the majority of serotypes have been examined as vaccines in preclinical and clinical trials. An additional, yet unexplored tool for disease prevention and treatment is the use of human monoclonal antibodies (mAbs) targeting conserved pneumococcal proteins. Here, we isolate the first human mAbs (PhtD3, PhtD6, PhtD7, PhtD8, PspA16) against the pneumococcal histidine triad protein (PhtD), and the pneumococcal surface protein A (PspA), two conserved and protective antigens. mAbs to PhtD target diverse epitopes on PhtD, and mAb PspA16 targets the N-terminal segment of PspA. The PhtD-specific mAbs bind to multiple serotypes, while mAb PspA16 serotype breadth is limited. mAbs PhtD3 and PhtD8 prolong the survival of mice infected with pneumococcal serotype 3. Furthermore, mAb PhtD3 prolongs the survival of mice in intranasal and intravenous infection models with pneumococcal serotype 4, and in mice infected with pneumococcal serotype 3 when administered 24 hours after pneumococcal infection. All PhtD and PspA mAbs demonstrate opsonophagocytic activity, suggesting a potential mechanism of protection. Our results provide new human mAbs for pneumococcal disease prevention and treatment, and identify epitopes on PhtD and PspA recognized by human B cells.

scholarly journals Genetic Immunization with the Region Encoding the α-Helical Domain of PspA Elicits Protective Immunity againstStreptococcus pneumoniae

2001 ◽  
Vol 69 (9) ◽  
pp. 5456-5463 ◽  
Author(s):  
Joseph R. Bosarge ◽  
James M. Watt ◽  
D. Olga McDaniel ◽  
Edwin Swiatlo ◽  
Larry S. McDaniel
Keyword(s):  
Protein A ◽  
Survival Rates ◽  
Serum Antibody ◽  
Pneumococcal Infection ◽  
Surface Protein ◽  
Eukaryotic Expression ◽  
Dependent Manner ◽  
Genetic Immunization ◽  
Helical Domain ◽  
Dose Dependent

ABSTRACT Pneumococcal surface protein A (PspA) is a pneumococcal virulence factor capable of eliciting protection against pneumococcal infection in mice. Previous studies have demonstrated that the protection is antibody mediated. Here we examined the ability ofpspA to elicit a protective immune response following genetic immunization of mice. Mice were immunized by intramuscular injections with a eukaryotic expression vector encoding the α-helical domain of PspA/Rx1. Immunization induced a PspA-specific serum antibody response, and immunized mice survived pneumococcal challenge. Survival and antibody responses occurred in a dose-dependent manner, the highest survival rates being seen with doses of 10 μg or greater. The ability of genetic immunization to elicit cross-protection was demonstrated by the survival of immunized mice challenged with pneumococcal strains differing in capsule and PspA types. Also, immunized mice were protected from intravenous and intratracheal challenges with pneumococci. Similar to the results seen with immunization with PspA, the survival of mice genetically immunized with pspA was antibody mediated. There was no decline in the level of protection 7 months after immunization. These results support the use of genetic immunization to elicit protective immune responses against extracellular pathogens.

scholarly journals Regions of PspA/EF3296 Best Able To Elicit Protection against Streptococcus pneumoniae in a Murine Infection Model

2003 ◽  
Vol 71 (3) ◽  
pp. 1033-1041 ◽  
Author(s):  
Hazeline Roche ◽  
Anders Håkansson ◽  
Susan K. Hollingshead ◽  
David E. Briles
Keyword(s):  
Amino Acids ◽  
Streptococcus Pneumoniae ◽  
Protein A ◽  
Surface Protein ◽  
Cross Protection ◽  
Infection Model ◽  
Helical Domain ◽  
Protective Antibodies ◽  
Terminal Amino ◽  
Helical Region

ABSTRACT Pneumococcal surface protein A (PspA) can elicit protection against Streptococcus pneumoniae in mouse infection models. PspA is classified by serology and amino acid sequence into two major families that are divided by sequence into five clades. The most variable portion of the molecule is the α-helical domain, which comprises the N-terminal half of PspA. Prior studies of a family 1 PspA protein observed that protective antibodies are reactive with epitopes in the α-helical domain and that most cross-protective epitopes mapped to the 108 most C-terminal amino acids of the α-helical region. In these studies, we have used six overlapping recombinant fragments of family 2, clade 3 PspA/EF3296 to map the protection-eliciting regions of its α-helical domain. The three fragments, which included the 104 most C-terminal amino acids of the α-helical domain (314 to 418), could each elicit protection against EF3296. A fragment comprising amino acids 75 to 305 failed to elicit significant protection. A fragment containing amino acids 1 to 115 elicited protection against EF3296 in BALB/c mice but not in CBA/N mice. All three fragments containing amino acids 314 to 418 were able to elicit cross-protection against pneumococci expressing PspA proteins of clades 2, 3, 4, and 5. Cross-protection elicited by these three fragments was easier to demonstrate in CBA/N mice than in BALB/c mice. The 1-to-115 fragment, however, elicited some cross-protection against clades 2 and 4 in BALB/c mice but not in CBA/N mice. These studies provide support for the importance of the C-terminal 104 and N-terminal 115 amino acids of the α-helical region of PspA in the elicitation of cross-protection.

scholarly journals The Putative Proteinase Maturation Protein A ofStreptococcus pneumoniae Is a Conserved Surface Protein with Potential To Elicit Protective Immune Responses

2000 ◽  
Vol 68 (7) ◽  
pp. 4180-4188 ◽  
Author(s):  
K. Overweg ◽  
A. Kerr ◽  
M. Sluijter ◽  
M. H. Jackson ◽  
T. J. Mitchell ◽  
...  
Keyword(s):  
Protein Fraction ◽  
Pathogenic Bacteria ◽  
Protein A ◽  
Surface Protein ◽  
Cross Reactivity ◽  
Two Dimensional Gel Electrophoresis ◽  
Hyperimmune Serum ◽  
Maturation Protein ◽  
Species Specific

ABSTRACT Surface-exposed proteins often play an important role in the interaction between pathogenic bacteria and their host. We isolated a pool of hydrophobic, surface-associated proteins of Streptococcus pneumoniae. The opsonophagocytic activity of hyperimmune serum raised against this protein fraction was high and species specific. Moreover, the opsonophagocytic activity was independent of the capsular type and chromosomal genotype of the pneumococcus. Since the opsonophagocytic activity is presumed to correlate with in vivo protection, these data indicate that the protein fraction has the potential to elicit species-specific immune protection with cross-protection against various pneumococcal strains. Individual proteins in the extract were purified by two-dimensional gel electrophoresis. Antibodies raised against three distinct proteins contributed to the opsonophagocytic activity of the serum. The proteins were identified by mass spectrometry and N-terminal amino acid sequencing. Two proteins were the previously characterized pneumococcal surface protein A and oligopeptide-binding lipoprotein AmiA. The third protein was the recently identified putative proteinase maturation protein A (PpmA), which showed homology to members of the family of peptidyl-prolyl cis/trans isomerases. Immunoelectron microscopy demonstrated that PpmA was associated with the pneumococcal surface. In addition, PpmA was shown to elicit species-specific opsonophagocytic antibodies that were cross-reactive with various pneumococcal strains. This antibody cross-reactivity was in line with the limited sequence variation of ppmA. The importance of PpmA in pneumococcal pathogenesis was demonstrated in a mouse pneumonia model. Pneumococcal ppmA-deficient mutants showed reduced virulence. The properties of PpmA reported here indicate its potential for inclusion in multicomponent protein vaccines.

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