scholarly journals Both Innate Immunity and Type 1 Humoral Immunity to Streptococcus pneumoniae Are Mediated by MyD88 but Differ in Their Relative Levels of Dependence on Toll-Like Receptor 2

2005 ◽  
Vol 73 (1) ◽  
pp. 298-307 ◽  
Author(s):  
Abdul Q. Khan ◽  
Quanyi Chen ◽  
Zheng-Qi Wu ◽  
James C. Paton ◽  
Clifford M. Snapper
Keyword(s):  
Streptococcus Pneumoniae ◽  
Humoral Immunity ◽  
Protein A ◽  
Surface Protein ◽  
Lethal Challenge ◽  
Humoral Immune ◽  
Extracellular Bacterium

ABSTRACT Little is known regarding the role of Toll-like receptors (TLRs) in regulating protein- and polysaccharide-specific immunoglobulin (Ig) isotype production in response to an in vivo challenge with an extracellular bacterium. In this report we demonstrate that MyD88−/−, but not TLR2−/−, mice are markedly defective in their induction of multiple splenic proinflammatory cytokine- and chemokine-specific mRNAs after intraperitoneal (i.p.) challenge with heat-killed Streptococcus pneumoniae capsular type 14 (S. pneumoniae type 14). This is correlated with analogous responses in splenic cytokine protein release in vitro following addition of S. pneumoniae type 14. Consistent with these data, naïve MyD88−/−, but not TLR2−/−, mice are more sensitive to killing following i.p. challenge with live S. pneumoniae type 14, relative to responses in wild-type mice. However, prior immunization of MyD88−/− mice with heat-killed S. pneumoniae type 14 protects against an otherwise-lethal challenge with live S. pneumoniae type 14. Surprisingly, both MyD88−/− and TLR2−/− mice exhibit striking and equivalent defects in elicitation of type 1 IgG isotypes (IgG3, IgG2b, and IgG2a), but not the type 2 IgG isotype, IgG1, specific for several protein and polysaccharide antigens, in response to i.p. challenge with heat-killed S. pneumoniae type 14. Of note, the type 1 IgG isotype titers specific for pneumococcal surface protein A are reduced in MyD88−/− mice but not TLR2−/− mice. These data suggest that distinct TLRs may differentially regulate innate versus adaptive humoral immunity to intact S. pneumoniae and are the first to implicate a role for TLR2 in shaping an in vivo type 1 IgG humoral immune response to a gram-positive extracellular bacterium.

scholarly journals Pneumococcal Surface Protein A Inhibits Complement Activation by Streptococcus pneumoniae

1999 ◽  
Vol 67 (9) ◽  
pp. 4720-4724 ◽  
Author(s):  
Anh-Hue T. Tu ◽  
Robert L. Fulgham ◽  
Mark A. McCrory ◽  
David E. Briles ◽  
Alexander J. Szalai
Keyword(s):  
Streptococcus Pneumoniae ◽  
Defense Mechanisms ◽  
Alternative Pathway ◽  
Protein A ◽  
Surface Protein ◽  
Serum Complement ◽  
Factor B ◽  
Pneumococcal Surface Protein A

ABSTRACT Pneumococcal surface protein A (PspA) is a surface-exposed protein virulence factor for Streptococcus pneumoniae. In this study, no significant depletion of serum complement was observed for the serum of mice infected with pneumococci that express PspA. In contrast, in mice infected with an isogenic strain of pneumococci lacking PspA, significant activation of serum complement was detected within 30 min after infection. Also, the PspA-deficient strain but not the PspA-expressing strain was cleared from the blood within 6 h. The contribution of PspA to pneumococcal virulence was further investigated by using mice deficient for C5, C3, or factor B. In mice deficient for C3 or factor B, PspA-negative pneumococci became fully virulent. In contrast, in C5-deficient mice as in wild-type mice, PspA-deficient pneumococci were avirulent. These in vivo data suggest that, in nonimmune mice infected with pneumococci, PspA interferes with complement-dependent host defense mechanisms mediated by factor B. Immunoblots of pneumococci opsonized in vitro suggested that more C3b was deposited on PspA-negative than on PspA-positive pneumococci. This was observed with and without anticapsular antibody. Furthermore, processing of the α chain of C3b was reduced in the presence of PspA. We propose that PspA exerts its virulence function by interfering with deposition of C3b onto pneumococci and/or by inhibiting formation of a fully functional alternative pathway C3 convertase. By blocking recruitment of the alternative pathway, PspA reduces the amount of C3b deposited onto pneumococci, thereby reducing the effectiveness of complement receptor-mediated pathways of clearance.

scholarly journals 4-1BB (CD137) Differentially Regulates Murine In Vivo Protein- and Polysaccharide-Specific Immunoglobulin Isotype Responses to Streptococcus pneumoniae

2003 ◽  
Vol 71 (1) ◽  
pp. 196-204 ◽  
Author(s):  
Zheng-Qi Wu ◽  
Abdul Q. Khan ◽  
Yi Shen ◽  
Karen M. Wolcott ◽  
Wojciech Dawicki ◽  
...  
Keyword(s):  
T Cells ◽  
Streptococcus Pneumoniae ◽  
Protein A ◽  
Teichoic Acid ◽  
Surface Protein ◽  
Cell Receptor ◽  
Primary Response ◽  
Humoral Immune ◽  
Specific Immunoglobulin

ABSTRACT 4-1BB (CD137) is induced on activated CD4+ and CD8+ T cells and delivers a costimulatory signal upon binding the 4-1BB ligand (4-1BBL) expressed on antigen-presenting cells. Induction of 4-1BB is dependent on activation via the T-cell receptor (TCR) and possibly CD28. It was previously demonstrated that both an in vivo protein (pneumococcal surface protein A [PspA])- and polysaccharide (phosphorylcholine [PC] determinant of teichoic acid)-specific immunoglobulin (Ig) isotype response to Streptococcus pneumoniae was dependent on CD4+ TCRαβ+ T cells and B7-dependent costimulation through CD28. We thus postulated that 4-1BB costimulation would also play a role in regulating the in vivo anti-PspA and anti-PC response to S. pneumoniae. We demonstrate that mice genetically deficient in 4-1BBL elicit a markedly reduced IgM and IgG anti-PC but normal primary and secondary IgG anti-PspA responses to S. pneumoniae relative to those for wild-type mice. However, injection of an agonistic anti-4-1BB monoclonal antibody (MAb), while having no significant effect on the anti-PC response, strongly inhibits the primary anti-PspA response, the generation of PspA-specific memory, and germinal center formation but does not induce a lasting state of tolerance. In contrast, anti-4-1BB MAb has no effect on the anti-PspA response when injected only at the time of secondary immunization. Delay of the addition of anti-4-1BB leads to progressively less inhibition of the primary response up to day 8. This inhibition is independent of CD8+ T cells and is associated with the expansion of CD4+ T cells with an activated phenotype, which is partly dependent on B7-dependent costimulation. These data are the first to suggest a stimulatory role for endogenous 4-1BB-4-1BBL interactions during a humoral immune response to a pathogen and further underscore significant differences in costimulation requirements for an in vivo protein- versus polysaccharide-specific Ig isotype response to an extracellular bacterium.

scholarly journals Pertussis Toxin Improves Immune Responses to a Combined Pneumococcal Antigen and Leads to Enhanced Protection against Streptococcus pneumoniae

2014 ◽  
Vol 21 (7) ◽  
pp. 972-981 ◽  
Author(s):  
Carolina Salcedo-Rivillas ◽  
Anne-Sophie Debrie ◽  
Eliane Namie Miyaji ◽  
Jorge M. C. Ferreira ◽  
Isaías Raw ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Pertussis Toxin ◽  
Protein A ◽  
Passive Immunization ◽  
Surface Protein ◽  
Interleukin 17 ◽  
Adjuvant Activity ◽  
Content Type

ABSTRACTPneumococcal surface protein A (PspA) is a candidate antigen for the composition of protein-based vaccines againstStreptococcus pneumoniae. While searching for efficient adjuvants for PspA-based vaccines, our group has described the potential of combining PspA with the whole-cell pertussis vaccine (wP). When given to mice through the nasal route, a formulation composed of PspA from clade 5 (PspA5) and wP (PspA5-wP) induced high levels of antibodies and protection against challenges with different pneumococcal strains. PspA5-wP also induced the secretion of interleukin 17 (IL-17) by splenocytes and the infiltration of leukocytes in the lungs after challenge. Here, we show that protection against a pneumococcal invasive challenge was completely abrogated in μMT−/−mice, which are deficient in the maturation of B cells, illustrating the importance of antibodies in the survival elicited by the PspA5-wP vaccine. Moreover, passive immunization showed that IgG purified from the sera of mice immunized with PspA5-wP conferred significant protection to naive mice, whereas the respective F(ab′)2did not. Additionally,in vivodepletion of complement abolished protection against the pneumococcal challenge. The combination of PspA5 with wild-type or mutantBordetella pertussisstrains or with purified components showed that the pertussis toxin (PT)-containing formulations induced the highest levels of antibodies and protection. This suggests that the adjuvant activity of wP in the PspA5 model is mediated at least in part by PT. The sera from mice immunized with such formulations displayed high IgG binding and induction of complement deposition on the pneumococcal surfacein vitro, which is consistent with thein vivoresults.

scholarly journals PneumococcalSurface Protein A Is Expressed In Vivo, and Antibodies to PspA AreEffective for Therapy in a Murine Model of PneumococcalSepsis

2003 ◽  
Vol 71 (12) ◽  
pp. 7149-7153 ◽  
Author(s):  
E. Swiatlo ◽  
J. King ◽  
G. S. Nabors ◽  
B. Mathews ◽  
D. E. Briles
Keyword(s):  
Northern Blot Analysis ◽  
Lethal Dose ◽  
Protein A ◽  
Surface Protein ◽  
Immune Serum ◽  
Invasive Infection ◽  
Pneumococcal Infections ◽  
Type 3

ABSTRACT Pneumococcal surface protein A (PspA) is an immunogenic protein expressed on the surface of all strains of Streptococcus pneumoniae (pneumococcus) and induces antibodies which protect against invasive infection in mice. Pneumococci used for infectious challenge in protection studies are typically collected from cultures grown in semisynthetic medium in vitro. The purpose of these studies is to confirm that PspA is expressed by pneumococci during growth in vivo at a level sufficient for antibodies to PspA to be protective. Mice were actively immunized with purified PspA or by passive transfer of monoclonal antibody (MAb) and challenged with a capsular type 3 strain in diluted whole blood from bacteremic mice. All were protected against challenge with 10 times the 50% lethal dose (LD50), and mice challenged with 1,000 times the LD50 had increased survival compared with controls. Additionally, nonimmune mice treated with MAbs to PspA or PspA immune serum at 6 and 12 h after infection with 10 times the LD50 also showed increased survival. Northern blot analysis of RNA from pneumococci grown either in vitro or in vivo showed similar levels of PspA mRNA. These results demonstrate that PspA is expressed in vivo in a mouse model and that immunization with PspA induces antibodies to an antigen which is expressed during the course of invasive infection. Immunotherapy with antibodies to PspA may have some utility in treating pneumococcal infections in humans.

scholarly journals Induction of a Specific Humoral Immune Response by Nasal Delivery of Bcla2ctd of Clostridioides difficile

2020 ◽  
Vol 21 (4) ◽  
pp. 1277 ◽  
Author(s):  
Ana Raquel Maia ◽  
Rodrigo Reyes-Ramírez ◽  
Marjorie Pizarro-Guajardo ◽  
Anella Saggese ◽  
Pablo Castro-Córdova ◽  
...  
Keyword(s):  
Immune Response ◽  
Humoral Immune Response ◽  
Surface Protein ◽  
Developed Countries ◽  
Nasal Delivery ◽  
Experimental Conditions ◽  
Humoral Immune ◽  
Clostridioides Difficile

Clostridioides difficile, formerly known as Clostridium difficile, is a spore-forming bacterium considered as the most common cause of nosocomial infections in developed countries. The spore of C. difficile is involved in the transmission of the pathogen and in its first interaction with the host; therefore, a therapeutic approach able to control C. difficile spores would improve the clearance of the infection. The C-terminal (CTD) end of BclA2, a spore surface protein of C. difficile responsible of the interaction with the host intestinal cells, was selected as a putative mucosal antigen. The BclA2 fragment, BclA2CTD, was purified and used to nasally immunize mice both as a free protein and after adsorption to the spore of Bacillus subtilis, a well-established mucosal delivery vehicle. While the adsorption to spores increased the in vitro stability of BclA2CTD, in vivo both free and spore-adsorbed BclA2CTD were able to induce a similar, specific humoral immune response in a murine model. Although in the experimental conditions utilized the immune response was not protective, the induction of specific IgG indicates that free or spore-bound BclA2CTD could act as a putative mucosal antigen targeting C. difficile spores.

scholarly journals Catabolite Control Protein A (CcpA) Contributes to Virulence and Regulation of Sugar Metabolism in Streptococcus pneumoniae

2005 ◽  
Vol 187 (24) ◽  
pp. 8340-8349 ◽  
Author(s):  
Ramkumar Iyer ◽  
Nitin S. Baliga ◽  
Andrew Camilli
Keyword(s):  
Streptococcus Pneumoniae ◽  
Protein A ◽  
Sugar Metabolism ◽  
Invasive Disease ◽  
Sugar Uptake ◽  
Catabolite Control Protein A ◽  
Control Protein ◽  
Catabolite Control

ABSTRACT We characterized the role of catabolite control protein A (ccpA) in the physiology and virulence of Streptococcus pneumoniae. S. pneumoniae has a large percentage of its genome devoted to sugar uptake and metabolism, and therefore, regulation of these processes is likely to be crucial for fitness in the nasopharynx and may play a role during invasive disease. In many bacteria, carbon catabolite repression (CCR) is central to such regulation, influencing hierarchical sugar utilization and growth rates. CcpA is the major transcriptional regulator in CCR in several gram-positive bacteria. We show that CcpA functions in CCR of lactose-inducible β-galactosidase activity in S. pneumoniae. CCR of maltose-inducible α-glucosidase, raffinose-inducible α-galactosidase, and cellobiose-inducible β-glucosidase is unaffected in the ccpA strain, suggesting that other regulators, possibly redundant with CcpA, control these systems. The ccpA strain is severely attenuated for nasopharyngeal colonization and lung infection in the mouse, establishing its role in fitness on these mucosal surfaces. Comparison of the cell wall fraction of the ccpA and wild-type strains shows that CcpA regulates many proteins in this compartment that are involved in central and intermediary metabolism, a subset of which are required for survival and multiplication in vivo. Both in vitro and in vivo defects were complemented by providing ccpA in trans. Our results demonstrate that CcpA, though not a global regulator of CCR in S. pneumoniae, is required for colonization of the nasopharynx and survival and multiplication in the lung.

scholarly journals Immunization with Pneumococcal Surface Protein K of Nonencapsulated Streptococcus pneumoniae Provides Protection in a Mouse Model of Colonization

2015 ◽  
Vol 22 (11) ◽  
pp. 1146-1153 ◽  
Author(s):  
Lance E. Keller ◽  
Xiao Luo ◽  
Justin A. Thornton ◽  
Keun-Seok Seo ◽  
Bo Youn Moon ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Mouse Model ◽  
Pneumococcal Disease ◽  
Surface Protein ◽  
Antibody Isotype ◽  
Content Type ◽  
Mouse Immunization ◽  
Escape Mutants

ABSTRACTCurrent vaccinations are effective against encapsulated strains ofStreptococcus pneumoniae, but they do not protect against nonencapsulatedStreptococcus pneumoniae(NESp), which is increasing in colonization and incidence of pneumococcal disease. Vaccination with pneumococcal proteins has been assessed for its ability to protect against pneumococcal disease, but several of these proteins are not expressed by NESp. Pneumococcal surface protein K (PspK), an NESp virulence factor, has not been assessed for immunogenic potential or host modulatory effects. Mammalian cytokine expression was determined in anin vivomouse model and in anin vitrocell culture system. Systemic and mucosal mouse immunization studies were performed to determine the immunogenic potential of PspK. Murine serum and saliva were collected to quantitate specific antibody isotype responses and the ability of antibody and various proteins to inhibit epithelial cell adhesion. Host cytokine response was not reduced by PspK. NESp was able to colonize the mouse nasopharynx as effectively as encapsulated pneumococci. Systemic and mucosal immunization provided protection from colonization by PspK-positive (PspK+) NESp. Anti-PspK antibodies were recovered from immunized mice and significantly reduced the ability of NESp to adhere to human epithelial cells. A protein-based pneumococcal vaccine is needed to provide broad protection against encapsulated and nonencapsulated pneumococci in an era of increasing antibiotic resistance and vaccine escape mutants. We demonstrate that PspK may serve as an NESp target for next-generation pneumococcal vaccines. Immunization with PspK protected against pneumococcal colonization, which is requisite for pneumococcal disease.

scholarly journals Rapid and Broad Immune Efficacy of a Recombinant Five-Antigen Vaccine against Staphylococcus aureus Infection in Animal Models

Vaccines ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 134 ◽  
Author(s):  
Hao Zeng ◽  
Feng Yang ◽  
Qiang Feng ◽  
Jinyong Zhang ◽  
Jiang Gu ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Severe Disease ◽  
Lethal Dose ◽  
Protein A ◽  
Surface Proteins ◽  
Staphylococcal Protein A ◽  
Humoral Immune ◽  
Aureus Infection

Staphylococcus aureus (S. aureus) is a leading cause of both healthcare-and community-associated infections globally, which result in severe disease and readily developing antibiotic resistance. Developing an efficacious vaccine against S. aureus is urgently required. In the present study, we selected five conserved antigens, including the secreted factors α-hemolysin (Hla), staphylococcal enterotoxin B (SEB) and the three surface proteins staphylococcal protein A (SpA), iron surface determinant B N2 domain (IsdB-N2) and manganese transport protein C (MntC). They were all well-characterized virulence factor of S. aureus and developed a recombinant five-antigen S. aureus vaccine (rFSAV), rFSAV provided consistent protection in S. aureus lethal sepsis and pneumonia mouse models, and it showed broad immune protection when challenged with a panel of epidemiologically relevant S. aureus strains. Meanwhile, rFSAV immunized mice were able to induce comprehensive cellular and humoral immune responses to reduce bacterial loads, inflammatory cytokine expression, inflammatory cell infiltration and decrease pathology after challenge with a sub-lethal dose of S. aureus. Moreover, the importance of specific antibodies in protection was demonstrated by antibody function tests in vitro and in vivo. Altogether, our data demonstrate that rFSAV is a potentially promising vaccine candidate for defensing against S. aureus infection.

scholarly journals Evaluation of a Vaccine Formulation against Streptococcus pneumoniae Based on Choline-Binding Proteins

2014 ◽  
Vol 22 (2) ◽  
pp. 213-220 ◽  
Author(s):  
Eliane N. Miyaji ◽  
Cintia F. M. Vadesilho ◽  
Maria Leonor S. Oliveira ◽  
André Zelanis ◽  
David E. Briles ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Binding Proteins ◽  
Choline Chloride ◽  
Protein A ◽  
Surface Protein ◽  
Mass Spectrometry Analysis ◽  
Effective Vaccine ◽  
Lethal Challenge ◽  
Content Type ◽  
Spectrometry Analysis

ABSTRACTStreptococcus pneumoniaehas proteins that are attached to its surface by binding to phosphorylcholine of teichoic and lipoteichoic acids. These proteins are known as choline-binding proteins (CBPs). CBPs are an interesting alternative for the development of a cost-effective vaccine, and PspA (pneumococcal surface protein A) is believed to be the most important protective component among the different CBPs. We sought to use CBPs eluted from pneumococci as an experimental vaccine. Since PspA shows variability between isolates, we constructed strains producing different PspAs. We used the nonencapsulated Rx1 strain, which produces PspA from clade 2 (PspA2), to generate apspA-knockout strain (Rx1 ΔpspA) and strains expressing PspA from clade 1 (Rx1pspA1) and clade 4 (Rx1pspA4). We grew Rx1, Rx1 ΔpspA, Rx1pspA1, and Rx1pspA4in Todd-Hewitt medium containing 0.5% yeast extract and washed cells in 2% choline chloride (CC). SDS-PAGE analysis of the proteins recovered by a CC wash showed few bands, and the CBPs PspA and PspC (pneumococcal surface protein C) were identified by mass spectrometry analysis. Subcutaneous immunization of mice with these full-length native proteins without adjuvant led to significantly higher rates of survival than immunization with diluent after an intranasal lethal challenge with two pneumococcal strains and also after a colonization challenge with one strain. Importantly, immunization with recombinant PspA4 (rPspA4) without adjuvant did not elicit significant protection.

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