Effect of O Acetylation of Neisseria meningitidis Serogroup A Capsular Polysaccharide on Development of Functional Immune Responses

ABSTRACT The importance of O-acetyl groups to the immunogenicity of Neisseria meningitidis serogroup A polysaccharide (PS) was examined in studies using human sera and mouse immunization. In 17 of 18 postimmunization human sera, inhibition enzyme-linked immunosorbent assay indicated that the majority of antibodies binding to serogroup A PS were specific for epitopes involving O-acetyl groups. Studies with mice also showed an essential role for O-acetyl groups, where serum bactericidal titers following immunization with de-O-acetylated (de-O-Ac) conjugate vaccine were at least 32-fold lower than those following immunization with O-Ac PS-conjugate vaccine and 4-fold lower than those following immunization with native capsular PS. Inhibition studies using native and de-O-Ac PS confirmed the specificity of murine antibodies to native PS. The dramatic reduction in immunogenicity associated with removal of O-acetyl groups indicates that O acetylation is essential to the immunogenic epitopes of serogroup A PS. Since levels of bactericidal antibodies are correlated with protection against disease, O-acetyl groups appear to be important in protection.

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Development and Evaluation of a Tetraplex Flow Cytometric Assay for Quantitation of Serum Antibodies to Neisseria meningitidis Serogroups A, C, Y, and W-135

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.11.2.272-279.2004 ◽

2004 ◽

Vol 11 (2) ◽

pp. 272-279 ◽

Cited By ~ 68

Author(s):

Gouri Lal ◽

Paul Balmer ◽

Helen Joseph ◽

Maureen Dawson ◽

Ray Borrow

Keyword(s):

Neisseria Meningitidis ◽

Capsular Polysaccharide ◽

Cross Reactivity ◽

Enzyme Linked Immunosorbent Assay ◽

Capsular Polysaccharides ◽

Simple Method ◽

Serum Dilution ◽

Flow Cytometric ◽

Important Addition ◽

Inhibition Studies

ABSTRACT A rapid and simple method for the simultaneous quantitation of serum immunoglobulin G (IgG) antibodies specific for Neisseria meningitidis serogroups A, C, Y, and W-135 was developed and evaluated. Four bead sets were generated, each conjugated with one of the meningococcal capsular polysaccharides (A, C, Y, or W-135) and serologically assessed by the use of antimeningococcal international reference sera. Cross-reactivity studies demonstrated no inhibition between monoplex and multiplex assays, and the assay was linear over a 24-fold serum dilution range. Inhibition studies demonstrated that the assay is specific, with <25% heterologous inhibition occurring. The assay was also found to have low intra- and interassay variations and limits of detection ≤650 pg/ml. A comparison of the meningococcal bead assay with the standardized meningococcal enzyme-linked immunosorbent assay showed a good correlation between the IgG concentrations obtained by each assay. The tetraplex assay has the potential to be an important addition to the serologic evaluation of meningococcal capsular polysaccharide conjugate vaccines.

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Avidity of the Immunoglobulin G Response to a Neisseria meningitidis Group C Polysaccharide Conjugate Vaccine as Measured by Inhibition and Chaotropic Enzyme-Linked Immunosorbent Assays

Clinical and Vaccine Immunology ◽

10.1128/cvi.00241-06 ◽

2007 ◽

Vol 14 (4) ◽

pp. 397-403 ◽

Cited By ~ 14

Author(s):

Shannon L. Harris ◽

How Tsao ◽

Lindsey Ashton ◽

David Goldblatt ◽

Philip Fernsten

Keyword(s):

Neisseria Meningitidis ◽

Conjugate Vaccine ◽

Capsular Polysaccharide ◽

Geometric Mean ◽

Enzyme Linked Immunosorbent Assay ◽

Primary Immunization ◽

Individual Subject ◽

Antibody Avidity ◽

Booster Immunization ◽

Immunization Series

ABSTRACT Antibody avidity, the strength of the multivalent interaction between antibodies and their antigens, is an important characteristic of protective immune responses. We have developed an inhibition enzyme-linked immunosorbent assay (ELISA) to measure antibody avidity for the capsular polysaccharide (PS) of Neisseria meningitidis group C (MnC) and determined the avidity constants (KD s) for 100 sera from children immunized with an MnC PS conjugate vaccine. The avidity constants were compared to the avidity indices (AI) obtained for the same sera using a chaotropic ELISA protocol. After the primary immunization series, the geometric mean (GM) KD was 674 nM and did not change in the months following immunization. However, the GM avidity did increase after the booster dose (GM KD , 414 nM 1 month after booster immunization). In contrast, the GM AI increased from an initial value of 118 after the primary immunization series to 147 6 months after the completion of the primary immunization series and then further increased to 178 after booster immunization. At the individual subject level, the avidity constant and AI correlated after the primary immunization series and after booster immunization but not prior to boosting. This work suggests that the AI, as measured by the chaotropic ELISA, in contrast to the KD , reflects changes that render antibody populations less susceptible to disruption by chaotropic agents without directly affecting the strength of the binding interactions.

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Effect of Antigen Coating Conditions on Enzyme-Linked Immunosorbent Assay for Detection of Immunoglobulin G Antibody to Neisseria meningitidis Serogroup Y and W135 Capsular Polysaccharide Antigens in Serum

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.10.6.1136-1140.2003 ◽

2003 ◽

Vol 10 (6) ◽

pp. 1136-1140 ◽

Cited By ~ 4

Author(s):

Peter C. Giardina ◽

Renee E. Evans ◽

Daniel J. Sikkema ◽

Dace Madore ◽

Stephen W. Hildreth

Keyword(s):

Immunoglobulin G ◽

Capsular Polysaccharide ◽

Enzyme Linked Immunosorbent Assay ◽

Meningococcal Vaccine ◽

Igg Antibody ◽

Human Sera ◽

Polysaccharide Antigens ◽

Reference Serum ◽

Adult Volunteers ◽

Assay Conditions

ABSTRACT Human sera collected from 28 consenting adult volunteers were used to define assay conditions for meningococcal vaccine clinical trial serology. Immunoassay parameters were optimized with these test sera and the standard reference serum, CDC1992. Coating conditions for serogroup Y and W135 polysaccharide antigens were found to influence the predicted serum immunoglobulin G (IgG) antibody concentrations. Sera that displayed IgG antibody binding profiles most unlike that of CDC1992 were influenced the most by coating conditions. Our results suggest that presentation of specific epitopes is influenced by antigen-coating concentrations for serogroup Y and W135 polysaccharides.

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Multicenter comparison of Neisseria meningitidis serogroup C anti-capsular polysaccharide antibody levels measured by a standardized enzyme-linked immunosorbent assay.

Journal of Clinical Microbiology ◽

10.1128/jcm.32.6.1475-1482.1994 ◽

1994 ◽

Vol 32 (6) ◽

pp. 1475-1482 ◽

Cited By ~ 118

Author(s):

L L Gheesling ◽

G M Carlone ◽

L B Pais ◽

P F Holder ◽

S E Maslanka ◽

...

Keyword(s):

Neisseria Meningitidis ◽

Immunosorbent Assay ◽

Capsular Polysaccharide ◽

Enzyme Linked Immunosorbent Assay ◽

Polysaccharide Antibody ◽

Antibody Levels

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Assessment of Antibody Response Elicited by a 7-valent Pneumococcal Conjugate Vaccine in Pediatric Human Immunodeficiency Virus Infection

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.12.1.165-170.2005 ◽

2005 ◽

Vol 12 (1) ◽

pp. 165-170 ◽

Cited By ~ 28

Author(s):

David Tarragó ◽

Julio Casal ◽

Jesús Ruiz-Contreras ◽

J. Tomás Ramos ◽

Pablo Rojo ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Immune Responses ◽

Conjugate Vaccine ◽

Pneumococcal Conjugate Vaccine ◽

Correlation Coefficients ◽

Antibody Responses ◽

Enzyme Linked Immunosorbent Assay ◽

Immunodeficiency Virus ◽

Vaccine Immunogenicity ◽

Functional Antibodies

ABSTRACT We investigated antibody responses against pneumococci of serotypes 6B, 14, and 23F in 56 children and adolescents with perinatal human immunodeficiency virus (HIV) infection who were vaccinated with 7-valent pneumococcal conjugate vaccine. Overall immune responses differed greatly between serotypes. Correlation coefficients between immunoglobulin G (IgG) measured by enzyme-linked immunosorbent assay (ELISA) and functional antibodies measured by a flow cytometry opsonophagocytosis assay (OPA) varied with serotype and time points studied. After 3 months of administering a second PCV7 dose we got the highest correlation (with significant r values of 0.754, 0.414, and 0.593 for serotypes 6B, 14, and 23F, respectively) but no significant increase in IgG concentration and OPA titers compared to the first dose. We defined a responder to a serotype included in the vaccine with two criteria: frequency of at least twofold OPA and ELISA increases for each serotype and frequency of conversion from negative to positive OPA levels. Responders varied from 43.9% to 46.3%, 28.5% to 50.0%, and 38.0% to 50.0% for serotypes 6B, 14, and 23F, respectively, depending on the response criterion. The present research highlights the importance of demonstrating vaccine immunogenicity with suitable immunological endpoints in immunocompromised patients and also the need to define how much antibody is required for protection from different serotypes, since immunogenicity differed significantly between serotypes.

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Immunogenicity of a Heptavalent Conjugate Pneumococcal Vaccine Administered Concurrently with a Combination Diphtheria, Tetanus, Five-Component Acellular Pertussis, Inactivated Polio, and Haemophilus influenzae Type b Vaccine and a Meningococcal Group C Conjugate Vaccine at 2, 3, and 4 Months of Age

Clinical and Vaccine Immunology ◽

10.1128/cvi.00315-09 ◽

2009 ◽

Vol 17 (3) ◽

pp. 311-316 ◽

Cited By ~ 14

Author(s):

S. J. Moss ◽

A. C. Fenton ◽

J. Toomey ◽

A. Grainger ◽

R. Borrow ◽

...

Keyword(s):

Immune Responses ◽

Haemophilus Influenzae ◽

Conjugate Vaccine ◽

Capsular Polysaccharide ◽

Geometric Mean ◽

Haemophilus Influenzae Type ◽

Type B ◽

Term Infants ◽

Meningococcal Group ◽

Pneumococcal Serotype

ABSTRACT The immunogenicities of conjugate pneumococcal vaccines have been demonstrated when they are administered at 2, 3, and 4 months of age. There is a paucity of data on the immunogenicity of this vaccine when it is administered concurrently with other vaccines in the primary immunization schedule of the United Kingdom. We immunized 55 term infants at 2, 3, and 4 months of age with the seven-valent pneumococcal conjugate vaccine (PCV7), the meningococcal group C conjugate (MCC) vaccine, and the diphtheria, tetanus, five-component acellular pertussis, inactivated polio, and Haemophilus influenzae type b (DTaP5/IPV/Hib-TT) vaccine. The immune responses to the H. influenzae type b (Hib), MCC, and tetanus vaccines were measured at 2, 5, and 12 months of age; and the immune responses to PCV7 were measured at 2 and 5 months and then either at 12 months or following a 4th dose of PCV7. There were increases in the geometric mean concentrations (GMCs) of all antigens postimmunization. Greater than or equal to 90% of the infants achieved putatively protective levels postimmunization for all vaccine antigens except pneumococcal serotype 6B and Hib. The GMCs of the PCV7 serotypes increased following a 4th dose, although one infant had not reached putative levels of protection against serotype 6B. In conclusion, when infants were vaccinated according to the schedule described above, they had lower postprimary immunization responses to Hib, meningococcus group C capsular polysaccharide, and pneumococcal serotype 6B than the responses demonstrated by use of the other schedules. Despite this finding, there was a good response following a 4th dose of PCV7.

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Estimation of Group B Streptococcus Type III Polysaccharide-Specific Antibody Concentrations in Human Sera Is Antigen Dependent

Infection and Immunity ◽

10.1128/iai.66.12.5848-5853.1998 ◽

1998 ◽

Vol 66 (12) ◽

pp. 5848-5853 ◽

Cited By ~ 17

Author(s):

Reva Bhushan ◽

Bascom F. Anthony ◽

Carl E. Frasch

Keyword(s):

Human Serum Albumin ◽

Serum Albumin ◽

Human Serum ◽

Conjugate Vaccine ◽

Group B Streptococcus ◽

Antigenic Specificity ◽

Enzyme Linked Immunosorbent Assay ◽

Type Iii ◽

Human Sera ◽

Group B

ABSTRACT The presence of immunoglobulin G (IgG) antibodies against group B streptococcus (GBS) type III polysaccharide (PS) has been correlated with protection against GBS disease. The GBS type III PS is structurally similar to the pneumococcal type 14 PS, differing only in the presence of sialic acid residues. Four different preparations of GBS type III PS were evaluated for their specificity in enzyme-linked immunosorbent assay (ELISA): free PS, free PS mixed with methylated human serum albumin (mHSA), PS conjugated to biotin and PS conjugated to human serum albumin. Three groups of human sera were used to evaluate these PS preparations: sera from recipients of a GBS PS vaccine, sera from women receiving a GBS type III PS-tetanus toxoid conjugate vaccine, and sera from nonimmunized healthy women of childbearing age. Estimated antibody concentrations were different depending on the PS preparation used. Using any of the four preparations, we were able to measure ≤0.05 μg of IgG antibody to the GBS type III PS per ml. The specificity of the assay was determined by competitive inhibition with homologous and heterologous PS. The pneumococcal type 14 PS did not inhibit binding of antibody to the native GBS type III PS in sera from adults receiving the GBS PS vaccine or in sera from nonimmunized adults (except serum G9). The pneumococcal type 14 PS inhibited 50% in sera from recipients of GBS type III conjugate vaccine and in serum G9 when GBS type III PS conjugated to biotin or to HSA was used as antigen in ELISA. These data show that free GBS type III PS or PS mixed with mHSA is a sensitive and specific antigen for ELISA and that conjugation can alter the antigenic specificity of a PS.

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A stabilized glycomimetic conjugate vaccine inducing protective antibodies against Neisseria meningitidis serogroup A

Nature Communications ◽

10.1038/s41467-020-18279-x ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Jacopo Enotarpi ◽

Marta Tontini ◽

Cristiana Balocchi ◽

Daan van der Es ◽

Ludovic Auberger ◽

...

Keyword(s):

Neisseria Meningitidis ◽

Shelf Life ◽

Conjugate Vaccine ◽

Capsular Polysaccharide ◽

Antibody Binding ◽

Liquid Formulation ◽

In Vivo Testing ◽

Protective Antibodies ◽

Polyclonal Serum

AbstractNeisseria meningitidis serogroup A capsular polysaccharide (MenA CPS) consists of (1 → 6)-2-acetamido-2-deoxy-α-D-mannopyranosyl phosphate repeating units, O-acetylated at position C3 or C4. Glycomimetics appear attractive to overcome the CPS intrinsic lability in physiological media, due to cleavage of the phosphodiester bridge, and to develop a stable vaccine with longer shelf life in liquid formulation. Here, we generate a series of non-acetylated carbaMenA oligomers which are proven more stable than the CPS. An octamer (DP8) inhibits the binding of a MenA specific bactericidal mAb and polyclonal serum to the CPS, and is selected for further in vivo testing. However, its CRM197 conjugate raises murine antibodies towards the non-acetylated CPS backbone, but not the natural acetylated form. Accordingly, random O-acetylation of the DP8 is performed, resulting in a structure (Ac-carbaMenA) showing improved inhibition of anti-MenA CPS antibody binding and, after conjugation to CRM197, eliciting anti-MenA protective murine antibodies, comparably to the vaccine benchmark.

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Antibody Persistence in Young Children 5 Years after Vaccination with a Combined Haemophilus influenzae Type b-Neisseria meningitidis Serogroup C Conjugate Vaccine Coadministered with Diphtheria-Tetanus-Acellular Pertussis-Based and Pneumococcal Conjugate Vaccines

Clinical and Vaccine Immunology ◽

10.1128/cvi.00057-16 ◽

2016 ◽

Vol 23 (7) ◽

pp. 555-563

Author(s):

Juan Carlos Tejedor ◽

Jerzy Brzostek ◽

Ryszard Konior ◽

Detlef Grunert ◽

Devayani Kolhe ◽

...

Keyword(s):

Haemophilus Influenzae ◽

Neisseria Meningitidis ◽

Conjugate Vaccine ◽

Pneumococcal Conjugate Vaccine ◽

Booster Vaccination ◽

Haemophilus Influenzae Type ◽

Enzyme Linked Immunosorbent Assay ◽

Type B ◽

Content Type ◽

Antibody Persistence

We evaluated antibody persistence in children up to 5 years after administration of a combinedHaemophilus influenzaetype b (Hib)-Neisseria meningitidisserogroup C (MenC)-tetanus toxoid (TT) conjugate vaccine coadministered with a pneumococcal conjugate vaccine. This is the follow-up study of a randomized trial (ClinicalTrials.gov registration no. NCT00334334/00463437) in which healthy children were vaccinated (primary vaccinations at 2, 4, and 6 months of age and booster vaccination at 11 to 18 months of age) with Hib-MenC-TT or a control MenC conjugate vaccine, coadministered with diphtheria-tetanus-acellular pertussis (DTPa)-based combination vaccines (DTPa/Hib for control groups) and a pneumococcal conjugate vaccine (10-valent pneumococcal nontypeableH. influenzaeprotein D conjugate vaccine [PHiD-CV] or 7-valent cross-reacting material 197 [CRM197] conjugate vaccine [7vCRM]). MenC antibody titers were measured with a serum bactericidal antibody (SBA) assay using rabbit complement (i.e., rabbit SBA [rSBA]), and antibodies against Hib polyribosylribitol phosphate (PRP) were measured with an enzyme-linked immunosorbent assay. Antibody persistence up to 5 years after booster vaccination is reported for 530 children ∼6 years of age. The percentages of children with seroprotective rSBA-MenC titers were between 24.2% and 40.1% in all groups approximately 5 years after booster vaccination. More than 98.5% of children in each group retained seroprotective anti-PRP concentrations. No vaccine-related serious adverse events and no events related to a lack of vaccine efficacy were reported. Approximately 5 years after booster vaccination, the majority of children retained seroprotective anti-PRP antibody concentrations. The percentage of children retaining seroprotective rSBA-MenC titers was low (≤40%), suggesting that a significant proportion of children may be unprotected against MenC disease. (This study has been registered at ClinicalTrials.gov under registration no. NCT00891176.)

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