scholarly journals Epitopes Recognized by a Nonautoreactive Murine Anti-N-Propionyl Meningococcal Group B Polysaccharide Monoclonal Antibody

2005 ◽  
Vol 73 (4) ◽  
pp. 2123-2128 ◽  
Author(s):  
Gregory R. Moe ◽  
Apurva Dave ◽  
Dan M. Granoff
Keyword(s):  
Monoclonal Antibody ◽  
Capsular Polysaccharide ◽  
Polysialic Acid ◽  
Enzyme Linked Immunosorbent Assay ◽  
Ionization Time ◽  
Protein Carriers ◽  
Protein Conjugate ◽  
Meningococcal Group ◽  
Group B ◽  
Antigenic Targets

ABSTRACT The capsular polysaccharide of Neisseria meningitidis group B (MBPS) is a polymer of alpha (2→8) N-acetyl neuraminic acid. The polysaccharide is chemically identical to an autoantigen, polysialic acid (PSA), and is a poor immunogen, even when conjugated to protein carriers. Immunization of mice with MBPS-protein conjugate vaccines, in which N-acetyl groups have been replaced by propionyl groups (N-Pr MBPS), elicits serum bactericidal antibodies. A subpopulation of these antibodies do not cross-react with human PSA. The reasons for the increased immunogenicity of N-Pr MBPS and the antigenic targets of the bactericidal nonautoreactive antibodies are unknown. In this study, we investigated the antigenic targets of a protective murine monoclonal antibody (MAb) prepared against a N-Pr MBPS-tetanus toxoid conjugate vaccine. Binding of the MAb to N-Pr MBPS (as demonstrated by an enzyme-linked immunosorbent assay) and bactericidal activity were inhibited by de-N-acetylated MBPS and re-N-acetylated MBPS, which indicate that N-propionyl groups are not obligatory determinants for binding. The results of affinity selection from a preparation of N-Pr MBPS and matrix-assisted laser desorption ionization-time of flight mass spectroscopic analysis indicated that the minimal epitope recognized by the MAb is a MBPS disaccharide containing one de-N-acetylated residue. Thus, the bacterial capsular epitope recognized by this bactericidal, nonautoreactive, anti-group-B MAb likely contains de-N-acetyl residues.

scholarly journals Immunohistochemical localization of polysialic acid in tissue sections: differential binding to polynucleotides and DNA of a murine IgG and a human IgM monoclonal antibody.

1990 ◽  
Vol 38 (2) ◽  
pp. 209-215 ◽  
Author(s):  
M Husmann ◽  
J Roth ◽  
E A Kabat ◽  
C Weisgerber ◽  
M Frosch ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Capsular Polysaccharide ◽  
Polysialic Acid ◽  
Immunohistochemical Localization ◽  
Tissue Sections ◽  
Neural Cell Adhesion ◽  
Differential Binding ◽  
Group B ◽  
Unambiguous Detection

For immunolocalization of alpha(2-8)-linked polysialic acid, which forms part of the neural cell adhesion molecule (N-CAM), two monoclonal antibodies, MAb735 and IgMNOV, were employed. Both antibodies have previously been shown to bind the extremely low immunogenic capsular polysaccharide of group B meningococci, which also consists of alpha(2-8) polysialic acid, but not to other, even closely related forms of polysialic acid. Despite the identical polysaccharide specificity of these two MAb, we observed marked differences of the staining pattern in tissue sections. We showed that these differences in immunostaining were due to the crossreactivity of IgMNOV with polynucleotides and DNA. MAb735, however, was shown to react exclusively with alpha(2-8) polysialic acid. Moreover, the specificity of MAb735 proved to be unique among eleven other MAb directed against various bacterial polysaccharides, as it was the only one unreactive with polynucleotides. Thus, MAb735, the only IgG type mouse monoclonal antibody to polysialic acid thus far reported, can be considered a specific probe for the unambiguous detection of alpha(2-8) polysialic acid in tissue sections, and should therefore help to further elucidate the role of polysialic acid in developmental processes.

scholarly journals Modulation of the Lung Inflammatory Response to Serotype 8 Pneumococcal Infection by a Human Immunoglobulin M Monoclonal Antibody to Serotype 8 Capsular Polysaccharide

2005 ◽  
Vol 73 (8) ◽  
pp. 4530-4538 ◽  
Author(s):  
Tamika Burns ◽  
Maria Abadi ◽  
Liise-anne Pirofski
Keyword(s):  
Monoclonal Antibody ◽  
Inflammatory Response ◽  
Capsular Polysaccharide ◽  
Human Monoclonal Antibody ◽  
Pneumococcal Infection ◽  
Immunoglobulin M ◽  
Enzyme Linked Immunosorbent Assay ◽  
Necrosis Factor Alpha ◽  
Monocyte Chemoattractant Protein 1

ABSTRACT The human monoclonal antibody to serotype 8 pneumococcal capsular polysaccharide D11 [immunoglobulin M(κ)] protects wild-type and complement component 4 knockout (C4 KO) mice against lethal intratracheal challenge with serotype 8 pneumococcus, but it does not promote polymorphonuclear leukocyte (PMN)-mediated pneumococcal killing in vitro. In this study, we investigated the effect of D11 on the blood and lung bacterial burdens and the serum and lung expression of inflammatory chemokines and cytokines in an intratracheal challenge model with serotype 8 pneumococcus in C4 KO mice. Pneumococcus was not detected in the blood of D11-treated mice, whereas control mice had high-grade bacteremia with >107 CFU. Control mice had a >5-log increase in lung CFU and D11-treated mice manifested a nearly 3-log increase in lung CFU compared to the original inoculum 24 h after infection. Serum and lung levels of soluble macrophage inflammatory protein 2 (MIP-2) and interleulin-6 (IL-6) as measured by an enzyme-linked immunosorbent assay were lower in D11-treated mice than in control mice 24 h after infection. Real-time PCR was performed to examine lung mRNA chemokine and cytokine expression. The results showed that D11-treated mice had significantly less gamma interferon, MIP-2, IL-12, monocyte chemoattractant protein 1/JE, and tumor necrosis factor alpha expression than control mice 24 h after infection. Histopathology and immunohistochemical staining of lung tissues revealed that D11-treated mice had less inflammation, fewer PMNs, and less myeloperoxidase staining than control mice 24 h after infection. These findings suggest that the efficacy of certain serotype-specific antibodies against pneumococcal pneumonia could be associated with modulation of the lung inflammatory response and a reduction in host damage.

Serological and conformational properties of E. coli K92 capsular polysaccharide and its N-propionylated derivative both illustrate that induced antibody does not recognize extended epitopes of polysialic acid: Implications for a comprehensive conjugate vaccine against groups B and C N. meningitidis

2002 ◽  
Vol 80 (8) ◽  
pp. 1055-1063 ◽  
Author(s):  
Robert A Pon ◽  
Nam Huan Khieu ◽  
Qing-Ling Yang ◽  
Jean-Robert Brisson ◽  
Harold J Jennings
Keyword(s):  
Molecular Dynamics ◽  
Immune Response ◽  
Conjugate Vaccine ◽  
Capsular Polysaccharide ◽  
Competitive Inhibition ◽  
Polysialic Acid ◽  
E Coli ◽  
Protective Epitope ◽  
Conformational Properties ◽  
Group B

The capsular polysaccharide of E. coli K92 (K92P) contains elements in common with the capsular polysaccharides of both groups B and C N. meningitidis, and may therefore form the basis of a bivalent vaccine. In an attempt to augment the cross-protective immune response to group B meningococci, the N-acetyl groups of the K92P were replaced by N-propionyl groups (NPrK92P) and conjugated to protein. This strategy had previously been applied with success to the poorly immunogenic capsular polysaccharide of group B meningococcus (GBMP), and the bactericidal epitope was found to be exclusively mimicked by extended helical segments of the NPrGBMP. The NPrK92P-conjugate, in relation to a K92P-conjugate, failed to enhance the response to GBMP but did generate a measurable response to NPrGBMP, but only at the expense of a greatly reduced GCMP response. Despite the presence of an immune response to NPrGBMP, the anti-NPrK92 serum was not bactericidal. Competitive inhibition studies with NPrGBMP oligosaccharides suggested the NPrK92 antibodies could not cross-react with the protective epitope on group B meningococci, as defined by extended helical segments of the NPrGBMP, but only recognized short non-bactericidal NPrGBMP epitopes. This hypothesis was supported from the conformational and molecular dynamics studies of the K92P, which demonstrated a lack of extended conformations that resemble the GBMP extended epitope. Indeed, the conformational properties of the K92P more closely resembled those of the GCMP, thereby explaining the observed moderate cross-protection of the K92P antiserum towards group C meningococci. Thus, on the basis of these results, it can be concluded that K92P, regardless of N-propionyl modification, will not serve as an effective single vaccine component against both groups B and C meningococci.Key words: conjugate vaccine, Neisseria meningitidis, polysialic acid, NMR, molecular dynamics.

scholarly journals Structural Properties of Group B Streptococcal Type III Polysaccharide Conjugate Vaccines That Influence Immunogenicity and Efficacy

1998 ◽  
Vol 66 (5) ◽  
pp. 2186-2192 ◽  
Author(s):  
Michael R. Wessels ◽  
Lawrence C. Paoletti ◽  
Hilde-Kari Guttormsen ◽  
Francis Michon ◽  
Anello J. D’Ambra ◽  
...  
Keyword(s):  
Capsular Polysaccharide ◽  
Protective Efficacy ◽  
Molecular Size ◽  
Cross Linking ◽  
Opsonic Activity ◽  
Conjugate Vaccines ◽  
Type Iii ◽  
Protein Conjugate ◽  
Group B ◽  
Protein Cross Linking

ABSTRACT In this study, we tested the hypothesis that the immunogenicity and protective efficacy of polysaccharide-protein conjugate vaccines are influenced by three variables: (i) molecular size of the conjugate, (ii) molecular size of the polysaccharide used for conjugation, and (iii) extent of polysaccharide-to-protein cross-linking. Type III group B Streptococcus capsular polysaccharide was linked by reductive amination at multiple sites to tetanus toxoid to create a polysaccharide-protein conjugate (III-TT). A single lot of III-TT was fractionated into small, medium, and large M rpools. Whereas all three conferred protection in a maternal immunization-neonatal challenge model in mice, the smallestM r conjugate evoked less polysaccharide-specific immunoglobulin G (IgG) than the two largerM r conjugates. To test whether the molecular size of the polysaccharide used for conjugation also affected the immunogenicity of the conjugate, vaccines were synthesized using capsular polysaccharides with M rs of 38,000, 105,000, and 349,000. Polysaccharide-specific IgG responses in mice increased with the M r of the polysaccharides, and protective efficacy was lower for the smallest polysaccharide conjugate compared to the other two vaccines. Immunogenicity testing of a series of vaccines prepared with different degrees of polysaccharide-to-protein cross-linking demonstrated higher polysaccharide-specific antibody responses as the extent of cross-linking increased. However, opsonic activity was greatest in mouse antiserum raised to a moderately cross-linked conjugate, suggesting that some antibodies evoked by highly cross-linked conjugates were directed to a nonprotective epitope. We conclude that conjugate size, polysaccharide size, and degree of polysaccharide-protein cross-linking influence the immunogenicity and protective efficacy of III-TT conjugate vaccines.

scholarly journals Current status of meningococcal group B vaccine candidates: capsular or noncapsular?

1994 ◽  
Vol 7 (4) ◽  
pp. 559-575 ◽  
Author(s):  
J Diaz Romero ◽  
I M Outschoorn
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Capsular Polysaccharide ◽  
Outer Membrane Proteins ◽  
Immunoglobulin A ◽  
Current Status ◽  
Short Term ◽  
Meningococcal Group ◽  
Life Threatening ◽  
Group B

Meningococcal meningitis is a severe, life-threatening infection for which no adequate vaccine exists. Current vaccines, based on the group-specific capsular polysaccharides, provide short-term protection in adults against serogroups A and C but are ineffective in infants and do not induce protection against group B strains, the predominant cause of infection in western countries, because the purified serogroup B polysaccharide fails to elicit human bactericidal antibodies. Because of the poor immunogenicity of group B capsular polysaccharide, different noncapsular antigens have been considered for inclusion in a vaccine against this serogroup: outer membrane proteins, lipooligosaccharides, iron-regulated proteins, Lip, pili, CtrA, and the immunoglobulin A proteases. Alternatively, attempts to increase the immunogenicity of the capsular polysaccharide have been made by using noncovalent complexes with outer membrane proteins, chemical modifications, and structural analogs. Here, we review the strategies employed for the development of a vaccine for Neisseria meningitidis serogroup B; the difficulties associated with the different approaches are discussed.

scholarly journals Primary and Booster Mucosal Immune Responses to Meningococcal Group A and C Conjugate and Polysaccharide Vaccines Administered to University Students in the United Kingdom

2001 ◽  
Vol 69 (7) ◽  
pp. 4337-4341 ◽  
Author(s):  
Q. Zhang ◽  
R. Lakshman ◽  
R. Burkinshaw ◽  
S. Choo ◽  
J. Everard ◽  
...  
Keyword(s):  
Young Adults ◽  
Immune Responses ◽  
University Students ◽  
Capsular Polysaccharide ◽  
Primary Vaccination ◽  
Enzyme Linked Immunosorbent Assay ◽  
Meningococcal Group ◽  
Group A ◽  
Mucosal Immune Responses ◽  
To Receive

ABSTRACT Meningococcal group A+C capsular polysaccharide (PS) conjugate vaccines may prime for serum immunoglobulin G (IgG) memory responses to meningococcal capsular PS. It is not known whether these vaccines induce immunological memory at the mucosal level, which may be important in reducing nasopharyngeal carriage. Mucosal immune responses to meningococcal conjugate and PS vaccines in young adults were investigated. Healthy university students were randomized to receive either a groups A+C meningococcal conjugate vaccine (MACconj,n = 100) or a group A+C meningococcal PS vaccine (MACPS, n = 95). One year after the primary immunization, both groups were randomized again to receive a MACconj or a MACPS booster vaccination. Saliva samples were collected before and 1 month after the primary and booster vaccinations. Anti-meningococcal A (MenA) and C (MenC) PS IgA and IgG antibody levels were measured by a standard enzyme-linked immunosorbent assay. After the primary vaccination, salivary MenA and MenC IgG and MenA IgA concentrations were significantly increased after immunization with both MACconj and MACPS vaccines, but the salivary Men C IgA level was increased only after MACPS vaccine (P < 0.01). IgA responses to both serogroups were greater for MACPS than MACconj vaccine (P < 0.05), whereas no significant differences were seen for IgG responses. MenA IgG titers were higher after the MACPS booster in MACconj-primed subjects than after the MACPS primary vaccination, suggesting the presence of IgG memory. Antibody responses to a dose of either MACPS or MACconj were not significantly reduced in those previously given MACPS compared to the primary responses to those vaccines. Meningococcal A+C conjugate and PS vaccines induce significant mucosal responses in young adults. MACconj priming may induce IgG memory at the mucosal level, which is likely to be a reflection of an anamnestic serum IgG response. No evidence of mucosal hyporesponsiveness was observed after MACPS priming in this study.

scholarly journals How the Knowledge of Interactions between Meningococcus and the Human Immune System Has Been Used to Prepare EffectiveNeisseria meningitidisVaccines

2015 ◽  
Vol 2015 ◽  
pp. 1-26 ◽  
Author(s):  
R. Gasparini ◽  
D. Panatto ◽  
N. L. Bragazzi ◽  
P. L. Lai ◽  
A. Bechini ◽  
...  
Keyword(s):  
Immune System ◽  
Capsular Polysaccharide ◽  
Infectious Agent ◽  
Adaptive Responses ◽  
Human Immune System ◽  
New Horizons ◽  
Genomics And Proteomics ◽  
Meningococcal Group ◽  
Human Immune ◽  
Group B

In the last decades, tremendous advancement in dissecting the mechanisms of pathogenicity ofNeisseria meningitidisat a molecular level has been achieved, exploiting converging approaches of different disciplines, ranging from pathology to microbiology, immunology, and omics sciences (such as genomics and proteomics). Here, we review the molecular biology of the infectious agent and, in particular, its interactions with the immune system, focusing on both the innate and the adaptive responses. Meningococci exploit different mechanisms and complex machineries in order to subvert the immune system and to avoid being killed. Capsular polysaccharide and lipooligosaccharide glycan composition, in particular, play a major role in circumventing immune response. The understanding of these mechanisms has opened new horizons in the field of vaccinology. Nowadays different licensed meningococcal vaccines are available and used: conjugate meningococcal C vaccines, tetravalent conjugate vaccines, an affordable conjugate vaccine against theN. menigitidisserogroup A, and universal vaccines based on multiple antigens each one with a different and peculiar function against meningococcal group B strains.

scholarly journals A Phase 2, Randomized, Control Trial of Group B Streptococcus (GBS) Type III Capsular Polysaccharide-tetanus Toxoid (GBS III-TT) Vaccine to Prevent Vaginal Colonization With GBS III

2018 ◽  
Vol 68 (12) ◽  
pp. 2079-2086 ◽  
Author(s):  
Sharon L Hillier ◽  
Patricia Ferrieri ◽  
Morven S Edwards ◽  
Marian Ewell ◽  
Daron Ferris ◽  
...  
Keyword(s):  
Tetanus Toxoid ◽  
Capsular Polysaccharide ◽  
Geometric Mean ◽  
Group B Streptococcus ◽  
Fold Increase ◽  
Enzyme Linked Immunosorbent Assay ◽  
Type Iii ◽  
Maternal Immunization ◽  
Young Infants ◽  
Group B

Abstract Background Group B Streptococcus (GBS) frequently colonizes pregnant women and can cause sepsis and meningitis in young infants. If colonization was prevented through maternal immunization, a reduction in perinatal GBS disease might be possible. A GBS type III capsular polysaccharide (CPS)-tetanus toxoid conjugate (III-TT) vaccine was evaluated for safety and efficacy in preventing acquisition of GBS colonization. Methods Healthy, nonpregnant women aged 18–40 years and screened to be GBS III vaginal and rectal culture negative were randomized to receive III-TT conjugate or tetanus diphtheria toxoid vaccine in a multicenter, observer-blinded trial. GBS vaginal and rectal cultures and blood were obtained bimonthly over 18 months. Serum concentrations of GBS III CPS-specific antibodies were determined using enzyme-linked immunosorbent assay. Results Among 1525 women screened, 650 were eligible for the intent-to-treat analysis. For time to first acquisition of vaginal GBS III, vaccine efficacy was 36% (95% confidence interval [CI], 1%–58%; P = .044), and for first rectal acquisition efficacy was 43% (95% CI, 11% to 63%; P = .014). Two months post-immunization, geometric mean concentrations of serum GBS type III CPS-specific immunoglobulin G were 12.6 µg/mL (95% CI, 9.95 to 15.81) in GBS III-TT recipients, representing a 4-fold increase from baseline in 95% of women, which persisted. Both vaccines were well tolerated. Conclusions GBS CPS III-TT conjugate vaccine significantly delayed acquisition of vaginal and rectal GBS III colonization. In addition to its use for maternal immunization to passively protect infants with maternally derived antibodies, a multivalent vaccine might also serve to reduce fetal and neonatal exposure to GBS. Clinical Trials Registration NCT00128219.

scholarly journals Activity and Cross-Reactivity of Antibodies Induced in Mice by Immunization with a Group B Meningococcal Conjugate

2001 ◽  
Vol 69 (11) ◽  
pp. 7130-7139 ◽  
Author(s):  
D. Coquillat ◽  
J. Bruge ◽  
B. Danve ◽  
M. Latour ◽  
C. Hurpin ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Capsular Polysaccharide ◽  
Polysialic Acid ◽  
Cell Lysis ◽  
Cross Reactivity ◽  
Candidate Vaccine ◽  
Live Cells ◽  
Tissue Sections ◽  
Neural Cell Adhesion ◽  
Group B

ABSTRACT The capsular polysaccharide of group BNeisseria meningitidis is composed of a linear homopolymer of α(2-8) N-acetyl neuraminic acid or polysialic acid (PSA) that is also carried by isoforms of the mammalian neural cell adhesion molecule (NCAM), which is especially expressed on brain cells during development. Here we analyzed the ability of antibodies induced by the candidate vaccineN-propionyl polysaccharide tetanus toxoid conjugate to recognize PSA-NCAM. We hyperimmunized mice to produce a pool of antisera and a series of immunoglobulin G monoclonal antibodies and evaluated their self-reactivity profile by using a battery of tests (immunoprecipitation, immunoblotting, and immunofluorescence detection on live cells and human tissue sections) chosen for their sensitivity and specificity to detect PSA-NCAM in various environments. We also searched for the effects of the vaccine-induced antibodies in two functional assays involving cell lysis or cell migration. Although they were highly bactericidal, all the antibodies tested showed very low or no recognition of PSA-NCAM, in contrast to PSA-specific monoclonal antibodies used as controls. Different patterns of cross-reactions were revealed by the tests used, likely due to affinity and specificity differences among the populations of induced antibodies. Furthermore, neither cell lysis nor perturbation of migration was observed in the presence of the tested antibodies. Importantly, we showed that whereas enzymatic removal of PSA groups from the surfaces of live cells perturbed their migration, blocking them with PSA-specific antibodies was not functionally detrimental. Taken together, our data indicated that this candidate vaccine induced antibodies that could not demonstrate an immunopathologic effect.

Sign in / Sign up

Export Citation Format

Share Document