scholarly journals Induction of Neutralizing Antibodies against Diphtheria Toxin by Priming with Recombinant Mycobacterium bovis BCG Expressing CRM197, a Mutant Diphtheria Toxin

2001 ◽  
Vol 69 (2) ◽  
pp. 869-874 ◽  
Author(s):  
Eliane N. Miyaji ◽  
Rogerio P. Mazzantini ◽  
Waldely O. Dias ◽  
Ana L. T. O. Nascimento ◽  
Rugimar Marcovistz ◽  
...  
Keyword(s):  
Mycobacterium Bovis ◽  
Diphtheria Toxin ◽  
Neutralizing Antibodies ◽  
Humoral Response ◽  
Diphtheria Toxoid ◽  
Mycobacterium Fortuitum ◽  
Adjuvant Effect ◽  
Shuttle Vectors ◽  
Tetanus Vaccine ◽  
Conventional Vaccine

ABSTRACT BCG, the attenuated strain of Mycobacterium bovis, has been widely used as a vaccine against tuberculosis and is thus an important candidate as a live carrier for multiple antigens. With the aim of developing a recombinant BCG (rBCG) vaccine against diphtheria, pertussis, and tetanus (DPT), we analyzed the potential of CRM197, a mutated nontoxic derivative of diphtheria toxin, as the recombinant antigen for a BCG-based vaccine against diphtheria. Expression of CRM197 in rBCG was achieved usingEscherichia coli-mycobacterium shuttle vectors under the control of pBlaF*, an upregulated β-lactamase promoter from Mycobacterium fortuitum. Immunization of mice with rBCG-CRM197 elicited an anti-diphtheria toxoid antibody response, but the sera of immunized mice were not able to neutralize diphtheria toxin (DTx) activity. On the other hand, a subimmunizing dose of the conventional diphtheria-tetanus vaccine, administered in order to mimic an infection, showed that rBCG-CRM197 was able to prime the induction of a humoral response within shorter periods. Interestingly, the antibodies produced showed neutralizing activity only when the vaccines had been given as a mixture in combination with rBCG expressing tetanus toxin fragment C (FC), suggesting an adjuvant effect of rBCG-FC on the immune response induced by rBCG-CRM197. Isotype analysis of the anti-diphtheria toxoid antibodies induced by the combined vaccines, but not rBCG-CRM197alone, showed an immunoglobulin G1-dominant profile, as did the conventional vaccine. Our results show that rBCG expressing CRM197 can elicit a neutralizing humoral response and encourage further studies on the development of a DPT vaccine with rBCG.

scholarly journals Transcutaneous Immunization with Cross-Reacting Material CRM197 of Diphtheria Toxin Boosts Functional Antibody Levels in Mice Primed Parenterally with Adsorbed Diphtheria Toxoid Vaccine

2008 ◽  
Vol 76 (4) ◽  
pp. 1766-1773 ◽  
Author(s):  
Paul Stickings ◽  
Marisa Peyre ◽  
Laura Coombes ◽  
Sylviane Muller ◽  
Rino Rappuoli ◽  
...  
Keyword(s):  
Immune Responses ◽  
Diphtheria Toxin ◽  
Neutralizing Antibodies ◽  
Time Course ◽  
Herd Immunity ◽  
Neutralizing Antibody ◽  
Diphtheria Toxoid ◽  
Booster Immunization ◽  
Transcutaneous Immunization ◽  
Antibody Levels

ABSTRACT Transcutaneous immunization (TCI) capitalizes on the accessibility and immunocompetence of the skin, elicits protective immunity, simplifies vaccine delivery, and may be particularly advantageous when frequent boosting is required. In this study we examined the potential of TCI to boost preexisting immune responses to diphtheria in mice. The cross-reacting material (CRM197) of diphtheria toxin was used as the boosting antigen and was administered alone or together with either one of two commonly used mucosal adjuvants, cholera toxin (CT) and a partially detoxified mutant of heat-labile enterotoxin of Escherichia coli (LTR72). We report that TCI with CRM197 significantly boosted preexisting immune responses elicited after parenteral priming with aluminum hydroxide-adsorbed diphtheria toxoid (DTxd) vaccine. In the presence of LTR72 as an adjuvant, toxin-neutralizing antibody titers were significantly higher than those elicited by CRM197 alone and were comparable to the functional antibody levels induced after parenteral booster immunization with the adsorbed DTxd vaccine. Time course study showed that high levels of toxin-neutralizing antibodies persisted for at least 14 weeks after the transcutaneous boost. In addition, TCI resulted in a vigorous antigen-specific proliferative response in all groups of mice boosted with the CRM197 protein. These findings highlight the promising prospect of using booster administrations of CRM197 via the transcutaneous route to establish good herd immunity against diphtheria.

scholarly journals Rapid seroconversion and persistent functional IgG antibodies in severe COVID-19 patients correlates with an IL-12p70 and IL-33 signature

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ariel Munitz ◽  
L. Edry-Botzer ◽  
M. Itan ◽  
R. Tur-Kaspa ◽  
D. Dicker ◽  
...  
Keyword(s):  
Nucleocapsid Protein ◽  
Neutralizing Antibodies ◽  
Host Response ◽  
Humoral Response ◽  
Rapid Onset ◽  
Response Analysis ◽  
Receptor Binding Domain ◽  
Igg Antibodies ◽  
Viral Receptor ◽  
Iga Antibodies

AbstractDespite ongoing efforts to characterize the host response toward SARS-CoV-2, a major gap in our knowledge still exists regarding the magnitude and duration of the humoral response. Analysis of the antibody response in mild versus moderate/severe patients, using our new developed quantitative electrochemiluminescent assay for detecting IgM/IgA/IgG antibodies toward SARS-CoV-2 antigens, revealed a rapid onset of IgG/IgA antibodies, specifically in moderate/severe patients. IgM antibodies against the viral receptor binding domain, but not against nucleocapsid protein, were detected at early stages of the disease. Furthermore, we observed a marked reduction in IgM/IgA antibodies over-time. Adapting our assay for ACE2 binding-competition, demonstrated that the presence of potentially neutralizing antibodies is corelated with IgG/IgA. Finally, analysis of the cytokine profile in COVID-19 patients revealed unique correlation of an IL-12p70/IL33 and IgG seroconversion, which correlated with disease severity. In summary, our comprehensive analysis has major implications on the understanding and monitoring of SARS-CoV-2 infections.

scholarly journals A longitudinal study of SARS-CoV-2-infected patients reveals a high correlation between neutralizing antibodies and COVID-19 severity

2021 ◽  
Author(s):  
Vincent Legros ◽  
Solène Denolly ◽  
Manon Vogrig ◽  
Bertrand Boson ◽  
Eglantine Siret ◽  
...  
Keyword(s):  
Intensive Care ◽  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
Surface Protein ◽  
Humoral Response ◽  
Neutralizing Antibody ◽  
Rapid Decline ◽  
Serum Samples ◽  
Immune Correlates ◽  
Human Coronaviruses

AbstractUnderstanding the immune responses elicited by SARS-CoV-2 infection is critical in terms of protection against reinfection and, thus, for public health policy and vaccine development for COVID-19. In this study, using either live SARS-CoV-2 particles or retroviruses pseudotyped with the SARS-CoV-2 S viral surface protein (Spike), we studied the neutralizing antibody (nAb) response in serum samples from a cohort of 140 SARS-CoV-2 qPCR-confirmed infections, including patients with mild symptoms and also more severe forms, including those that required intensive care. We show that nAb titers correlated strongly with disease severity and with anti-spike IgG levels. Indeed, patients from intensive care units exhibited high nAb titers; conversely, patients with milder disease symptoms had heterogeneous nAb titers, and asymptomatic or exclusive outpatient-care patients had no or low nAbs. We found that nAb activity in SARS-CoV-2-infected patients displayed a relatively rapid decline after recovery compared to individuals infected with other coronaviruses. Moreover, we found an absence of cross-neutralization between endemic coronaviruses and SARS-CoV-2, indicating that previous infection by human coronaviruses may not generate protective nAbs against SARS-CoV-2. Finally, we found that the D614G mutation in the spike protein, which has recently been identified as the current major variant in Europe, does not allow neutralization escape. Altogether, our results contribute to our understanding of the immune correlates of SARS-CoV-2-induced disease, and rapid evaluation of the role of the humoral response in the pathogenesis of SARS-CoV-2 is warranted.

scholarly journals Titers of Neutralizing Antibodies against SARS-CoV-2 Are Independent of Symptoms of Non-Severe COVID-19 in Young Adults

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 284
Author(s):  
Hulda R. Jonsdottir ◽  
Michel Bielecki ◽  
Denise Siegrist ◽  
Thomas W. Buehrer ◽  
Roland Züst ◽  
...  
Keyword(s):  
Young Adults ◽  
Neutralizing Antibodies ◽  
Severe Disease ◽  
Humoral Response ◽  
Neutralizing Antibody ◽  
Neutralization Assay ◽  
Asymptomatic Infection ◽  
Homogeneous Population ◽  
Humoral Immune ◽  
Antibody Titers

Neutralizing antibodies are an important part of the humoral immune response to SARS-CoV-2. It is currently unclear to what extent such antibodies are produced after non-severe disease or asymptomatic infection. We studied a cluster of SARS-CoV-2 infections among a homogeneous population of 332 predominantly male Swiss soldiers and determined the neutralizing antibody response with a serum neutralization assay using a recombinant SARS-CoV-2-GFP. All patients with non-severe COVID-19 showed a swift humoral response within two weeks after the onset of symptoms, which remained stable for the duration of the study. One month after the outbreak, titers in COVID-19 convalescents did not differ from the titers of asymptomatically infected individuals. Furthermore, symptoms of COVID-19 did not correlate with neutralizing antibody titers. Therefore, we conclude that asymptomatic infection can induce the same humoral immunity as non-severe COVID-19 in young adults.

scholarly journals Improved Specificity of a Multiplex Immunoassay for Quantitation of Anti-Diphtheria Toxin Antibodies with the Use of Diphtheria Toxoid

2011 ◽  
Vol 18 (7) ◽  
pp. 1183-1186 ◽  
Author(s):  
Pieter G. M. van Gageldonk ◽  
Christina von Hunolstein ◽  
Fiona R. M. van der Klis ◽  
Guy A. M. Berbers
Keyword(s):  
Diphtheria Toxin ◽  
Neutralization Test ◽  
Diphtheria Toxoid ◽  
Inhibition Assay ◽  
Nonspecific Binding ◽  
Serum Samples ◽  
Multiplex Immunoassay ◽  
Toxin Binding ◽  
Binding Inhibition ◽  
Binding Inhibition Assay

ABSTRACTA nonspecific binding of antibodies to diphtheria toxin, especially in adult serum samples, was observed in our diphtheria-tetanus-pertussis multiplex immunoassay (DTaP4 MIA). This can be significantly reduced by the use of diphtheria toxoid, achieving a good correlation with the Vero cell neutralization test and the toxin binding inhibition assay.

scholarly journals Neutralization Assessments Reveal High Cardiothoracic Ratio and Old Age as Independent Predictors of Low Neutralizing Antibody Titers in Hemodialysis Patients Receiving a Single Dose of COVID-19 Vaccine

2022 ◽  
Vol 12 (1) ◽  
pp. 68
Author(s):  
Chun-Yu Chen ◽  
Kuan-Ting Liu ◽  
Shin-Ru Shih ◽  
Jung-Jr Ye ◽  
Yih-Ting Chen ◽  
...  
Keyword(s):  
Single Dose ◽  
Old Age ◽  
Neutralizing Antibodies ◽  
Additive Model ◽  
Humoral Response ◽  
Neutralizing Antibody ◽  
Enzyme Linked Immunosorbent Assay ◽  
Healthy Controls ◽  
Neutralization Titer ◽  
Cardiothoracic Ratio

Background: Data are lacking regarding predictors of quantification of neutralizing antibodies (nAbs) based on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) 50% neutralization titer (NT50) after a single dose of COVID-19 vaccine in hemodialysis (HD) patients. Methods: This prospective single-center study enrolled 200 HD patients and 82 healthy subjects to estimate antibodies against the SARS-CoV-2 viral spike protein 1 and receptor-binding domain after a first dose of a COVID-19 vaccine (ChAdOx1 or mRNA-1273), measured by enzyme-linked immunosorbent assay and applied spline-based generalized additive model regression analysis to predict NT50 converted to international units. Results: After the first dose of ChAdOx1, multiple linear regression showed that age (p = 0.011) and cardiothoracic ratio (p = 0.002) were negatively associated with NT50. Older age (OR = 0.958, p = 0.052) and higher cardiothoracic ratio (OR < 0.001, p = 0.037) could predict negative humoral response (NT50 < 35.13 IU/mL). NT50 was lower in HD patients compared with healthy controls receiving ChAdOx1 (10.68 vs. 43.01 IU/m, p < 0.001) or mRNA-1273 (36.39 vs. 262.2 IU/mL, p < 0.001). ChAdOx1 elicited lower GMTs than mRNA-1273 in the HD cohort (10.68 vs. 36.39 IU/mL, p < 0.001) and in healthy controls (43.01 vs. 262.22 IU/mL, p < 0.001). Conclusion: High cardiothoracic ratio and old age could independently predict a decline in nAb titers in an HD cohort vaccinated with a single dose of ChAdOx1.

scholarly journals A modular protein subunit vaccine candidate produced in yeast confers protection against SARS-CoV-2 in non-human primates

2021 ◽  
Author(s):  
Neil C Dalvie ◽  
Lisa H Tostanoski ◽  
Sergio A Rodriguez-Aponte ◽  
Kawaljit Kaur ◽  
Sakshi Bajoria ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Cellular Response ◽  
Subunit Vaccine ◽  
Hepatitis B Surface Antigen ◽  
Low Cost ◽  
Humoral Response ◽  
High Volume ◽  
Developed Countries ◽  
Protein Subunit ◽  
Middle Income

Vaccines against SARS-CoV-2 have been distributed at massive scale in developed countries, and have been effective at preventing COVID-19. Access to vaccines is limited, however, in low- and middle-income countries (LMICs) due to insufficient supply, high costs, and cold storage requirements. New vaccines that can be produced in existing manufacturing facilities in LMICs, can be manufactured at low cost, and use widely available, proven, safe adjuvants like alum, would improve global immunity against SARS-CoV-2. One such protein subunit vaccine is produced by the Serum Institute of India Pvt. Ltd. and is currently in clinical testing. Two protein components, the SARS-CoV-2 receptor binding domain (RBD) and hepatitis B surface antigen virus-like particles (VLPs), are each produced in yeast, which would enable a low-cost, high-volume manufacturing process. Here, we describe the design and preclinical testing of the RBD-VLP vaccine in cynomolgus macaques. We observed titers of neutralizing antibodies (>104) above the range of protection for other licensed vaccines in non-human primates. Interestingly, addition of a second adjuvant (CpG1018) appeared to improve the cellular response while reducing the humoral response. We challenged animals with SARS-CoV-2, and observed a ~3.4 and ~2.9 log10 reduction in median viral loads in bronchoalveolar lavage and nasal mucosa, respectively, compared to sham controls. These results inform the design and formulation of current clinical COVID-19 vaccine candidates like the one described here, and future designs of RBD-based vaccines against variants of SARS-CoV-2 or other betacoronaviruses.

scholarly journals Improvement of bovine tuberculosis diagnosis

2021 ◽  
pp. 261-265
Author(s):  
M. O. Baratov
Keyword(s):  
Red Blood Cells ◽  
Mycobacterium Bovis ◽  
Blood Cells ◽  
Bovine Tuberculosis ◽  
Intradermal Test ◽  
Mycobacterium Fortuitum ◽  
Post Mortem ◽  
Post Mortem Examination ◽  
Antibody Titers ◽  
Specific Reactions

Detection of animals with non-specific reactions to tuberculin is one of the major problems in bovine tuberculosis (TB) diagnosis. There is a need to find and improve methods for detection of the sensitization causes. This paper presents the results of comparative studies of different ways to stabilize red blood cells in order to obtain diagnosticums for indirect hemagglutination (IHA) test. The article describes the stages of red blood cells stabilization and sensitization and demonstrates the diagnostic significance of Fili stabilization method using formaldehyde as a fixative. The highest antibody titers (1:3000 and 1:4000) were received in hyperimmune sera of rabbits immunized with Mycobacterium bovis using a homologous diagnosticum. Practical importance of the sensitins homologous to the infection is shown during testing of 1,911 serum samples collected from animals of different categories (diseased; healthy and reacting to tuberculin; healthy and not reacting to tuberculin) with IHA test using diagnosticums produced from Mycobacterium bovis and Mycobacterium fortuitum. Based on the positive results of the IHA test, TB was diagnosed in 87.5% of animals originating from an infected farm during post-mortem examination. The results of the IHA test agreed with those of the intradermal tuberculin test in 37.7% of cases. Diagnostic antibody titers were found in 206 TB infected animals with no reaction to the intradermal test. However, the post-mortem examination revealed TB changes in internal organs. The obtained data suggest a possibility to use the IHA test to detect TB infected animals with non-specific reactions to tuberculin.

scholarly journals Impaired Humoral Response to Vaccines among HIV-Exposed Uninfected Infants

2011 ◽  
Vol 18 (9) ◽  
pp. 1406-1409 ◽  
Author(s):  
Beatriz Mariana Abramczuk ◽  
Taís Nitsch Mazzola ◽  
Yara Maria Franco Moreno ◽  
Tatiane Queiroz Zorzeto ◽  
Wagner Quintilio ◽  
...  
Keyword(s):  
Hepatitis B ◽  
Immune Responses ◽  
Neutralizing Antibodies ◽  
Geometric Mean ◽  
Humoral Response ◽  
Vaccine Response ◽  
Serum Samples ◽  
Hiv Exposed ◽  
Exposed Uninfected

ABSTRACTLittle is known about the vaccine protective response for infants born from HIV-infected mothers. We evaluated the antibody response to hepatitis B, tetanus, and diphtheria vaccine in vertically HIV-exposed uninfected infants and compared them to those of control infants not exposed to the virus. The quantitative determination of specific neutralizing antibodies against hepatitis B, diphtheria, and tetanus were performed blindly on serum samples. The results showed that 6.7% of the HIV-exposed uninfected individuals were nonresponders to hepatitis B vaccine (anti-HBs titer, <10 mIU/ml), and 64.4% were very good responders (anti-HBs titer, ≥1,000 mIU/ml), whereas only 3.6% of the nonexposed infants were nonresponders (χ2=10.93; 1 df). The HIV-exposed uninfected infants showed protective titers for diphtheria and tetanus but lower geometric mean anti-tetanus titers compared to those of the HIV-unexposed infants. Our data point to the necessity of evaluating vaccine immune responses in these children and reinforced that alterations in lymphocyte numbers and functions reported for newborns from HIV-infected mothers interfere with the vaccine response.

scholarly journals Characterization of Neutralizing Antibodies and Identification of Neutralizing Epitope Mimics on the Clostridium botulinum Neurotoxin Type A

2001 ◽  
Vol 67 (7) ◽  
pp. 3201-3207 ◽  
Author(s):  
Han-Chung Wu ◽  
Chia-Tsui Yeh ◽  
Yue-Ling Huang ◽  
Lih-Jeng Tarn ◽  
Chien-Cheng Lung
Keyword(s):  
Monoclonal Antibodies ◽  
Neutralizing Antibodies ◽  
Clostridium Botulinum ◽  
Neuromuscular Junctions ◽  
Competitive Inhibition ◽  
Lethal Dose ◽  
Humoral Response ◽  
Type A ◽  
Phage Clone ◽  
Neutralizing Epitopes

ABSTRACT Clostridium botulinum neurotoxin type A (BTx-A) is known to inhibit the release of acetylcholine at the neuromuscular junctions and synapses and to cause neuroparalysis and death. In this study, we have identified two monoclonal antibodies, BT57-1 and BT150-3, which protect ICR mice against lethal doses of BTx-A challenge. The neutralizing activities for BT57-1 and BT150-3 were 103 and 104 times the 50% lethal dose, respectively. Using immunoblotting analysis, BT57-1 was recognized as a light chain and BT150-3 was recognized as a heavy chain of BTx-A. Also, applying the phage display method, we investigated the antibodies' neutralizing B-cell epitopes. These immunopositive phage clones displayed consensus motifs, Asp-Pro-Leu for BT57-1 and Cys-X-Asp-Cys for BT150. The synthetic peptide P4M (KGTFDPLQEPRT) corresponded to the phage-displayed peptide selected by BT57-1 and was able to bind the antibodies specifically. This peptide was also shown by competitive inhibition assay to be able to inhibit phage clone binding to BT57-1. Aspartic acid (D5) in P4M was crucial to the binding of P4M to BT57-1, since its binding activity dramatically decreased when it was changed to lysine (K5). Finally, immunizing mice with the selected phage clones elicited a specific humoral response against BTx-A. These results suggest that phage-displayed random-peptide libraries are useful in identifying the neutralizing epitopes of monoclonal antibodies. In the future, the identification of the neutralizing epitopes of BTx-A may provide important information for the identification of the BTx-A receptor and the design of a BTx-A vaccine.

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