Characterization of the adaptive immune response of donors receiving live anthrax vaccine

Live anthrax vaccine containing spores from attenuated strains STI-1 of Bacillus anthracis is used in Russia and former CIS (Commonwealth of Independent States) to prevent anthrax. In this paper we studied the duration of circulation of antibodies specific to spore antigens, the protective antigen (PA), the lethal factor (LF) and their domains (D) in donors’ blood at different times after their immunization with live anthrax vaccine. The relationship between the toxin neutralization activity level and the level of antibodies to PA, LF and their domains was tested. The effect of age, gender and number of vaccinations on the level of adaptive post-vaccination immune response has been studied. It was shown that antibodies against PA-D1 circulate in the blood of donors for 1 year or more after immunization with live anthrax vaccine. Antibodies against all domains of LF and PA-D4 were detected in 11 months after vaccination. Antibodies against the spores were detected in 8 months after vaccination. A moderate positive correlation was found between the titers of antibodies to PA, LF, or their domains, and the TNA of the samples of blood serum from the donors.

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Is the Prevalence of Leishmania infantum Linked to Breeds in Dogs? Characterization of Seropositive Dogs in Ibiza

Animals ◽

10.3390/ani11092579 ◽

2021 ◽

Vol 11 (9) ◽

pp. 2579

Author(s):

Maria Edo ◽

Pablo Jesús Marín-García ◽

Lola Llobat

Keyword(s):

Immune Response ◽

Leishmania Infantum ◽

Protozoan Parasite ◽

Disease Stage ◽

Doberman Pinscher ◽

Th2 Immune Response ◽

Mediterranean Island ◽

Antibody Titers ◽

The Relationship

Leishmaniosis is an important zoonotic protozoan disease primarily spread to the Mediterranean region by Leishmania infantum, the predominant protozoan species, which accounts for the majority of cases. Development of disease depends on the immune response of the definitive host and, predictably, their genetic background. Recent studies have revealed breed-typical haplotypes that are susceptible to the spread of the protozoan parasite. The objective of this study was to analyze the prevalence of leishmaniosis on a Mediterranean island and determine the relationship between disease prevalence and breed. In addition, information on seropositive animals was recorded to characterize animals affected by the disease. To study the prevalence, a total of 3141 dogs were analyzed. Of these, the 149 infected animals were examined for age, sex, antibody titer, and disease stage. We observed a prevalence of 4.74%, which varied between breeds (p < 0.05). The Doberman Pinscher and Boxer breeds had the highest prevalence of leishmaniosis. Significant differences were observed between breeds with common ancestors, emphasizing the important genetic component. Finally, regarding the characterization of seropositive animals, the distribution is similar to other studies. We discovered a relationship (p < 0.05) between the number of antibody titers and the clinical disease stage, which was also present in Leishmania infantum, suggesting that the development of the disease depends on the humoral or Th2 immune response with ineffective antibodies.

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Binding of the von Willebrand Factor A Domain of Capillary Morphogenesis Protein 2 to Anthrax Protective Antigen Vaccine Reduces Immunogenicity in Mice

mSphere ◽

10.1128/msphere.00556-19 ◽

2020 ◽

Vol 5 (1) ◽

Author(s):

Fabiana Freire Mendes de Oliveira ◽

Sireesha Mamillapalli ◽

Srinivas Gonti ◽

Robert N. Brey ◽

Han Li ◽

...

Keyword(s):

Immune Response ◽

Von Willebrand Factor ◽

Neutralizing Antibodies ◽

Protective Antigen ◽

Antibody Responses ◽

Anthrax Toxin ◽

Anthrax Vaccine ◽

Capillary Morphogenesis ◽

Von Willebrand ◽

Willebrand Factor

ABSTRACT Protective antigen (PA) is a component of anthrax toxin that can elicit toxin-neutralizing antibody responses. PA is also the major antigen in the current vaccine to prevent anthrax, but stability problems with recombinant proteins have complicated the development of new vaccines containing recombinant PA. The relationship between antigen physical stability and immunogenicity is poorly understood, but there are theoretical reasons to think that this parameter can affect immune responses. We investigated the immunogenicity of anthrax PA, in the presence and absence of the soluble von Willebrand factor A domain of the human form of receptor capillary morphogenesis protein 2 (sCMG2), to elicit antibodies to PA in BALB/c mice. Prior studies showed that sCMG2 stabilizes the 83-kDa PA structure to pH, chemical denaturants, temperature, and proteolysis and slows the hydrogen-deuterium exchange rate of histidine residues far from the binding interface. In contrast to a vaccine containing PA without adjuvant, we found that mice immunized with PA in stable complex with sCMG2 showed markedly reduced antibody responses to PA, including toxin-neutralizing antibodies and antibodies to domain 4, which correlated with fewer toxin-neutralizing antibodies. In contrast, mice immunized with PA in concert with a nonbinding mutant of sCMG2 (D50A) showed anti-PA antibody responses similar to those observed with PA alone. Our results suggest that addition of sCMG2 to a PA vaccine formulation is likely to result in a significantly diminished immune response, but we discuss the multitude of factors that could contribute to reduced immunogenicity. IMPORTANCE The anthrax toxin PA is the major immunogen in the current anthrax vaccine (anthrax vaccine adsorbed). Improving the anthrax vaccine for avoidance of a cold chain necessitates improvements in the thermodynamic stability of PA. We address how stabilizing PA using sCMG2 affects PA immunogenicity in BALB/c mice. Although the stability of PA is increased by binding to sCMG2, PA immunogenicity is decreased. This study emphasizes that, while binding of a ligand retains or improves conformational stability without affecting the native sequence, epitope recognition or processing may be affected, abrogating an effective immune response.

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Vaccination of Rhesus Macaques with the Anthrax Vaccine Adsorbed Vaccine Produces a Serum Antibody Response That Effectively Neutralizes Receptor-Bound Protective Antigen In Vitro

Clinical and Vaccine Immunology ◽

10.1128/cvi.00174-10 ◽

2010 ◽

Vol 17 (11) ◽

pp. 1753-1762 ◽

Cited By ~ 8

Author(s):

Kristin H. Clement ◽

Thomas L. Rudge ◽

Heather J. Mayfield ◽

Lena A. Carlton ◽

Arelis Hester ◽

...

Keyword(s):

Cell Surface ◽

Neutralizing Antibodies ◽

Protective Antigen ◽

Rhesus Macaques ◽

Lethal Factor ◽

Serum Antibody ◽

Target Cells ◽

Furin Cleavage ◽

Anthrax Vaccine

ABSTRACT Anthrax toxin (ATx) is composed of the binary exotoxins lethal toxin (LTx) and edema toxin (ETx). They have separate effector proteins (edema factor and lethal factor) but have the same binding protein, protective antigen (PA). PA is the primary immunogen in the current licensed vaccine anthrax vaccine adsorbed (AVA [BioThrax]). AVA confers protective immunity by stimulating production of ATx-neutralizing antibodies, which could block the intoxication process at several steps (binding of PA to the target cell surface, furin cleavage, toxin complex formation, and binding/translocation of ATx into the cell). To evaluate ATx neutralization by anti-AVA antibodies, we developed two low-temperature LTx neutralization activity (TNA) assays that distinguish antibody blocking before and after binding of PA to target cells (noncomplexed [NC] and receptor-bound [RB] TNA assays). These assays were used to investigate anti-PA antibody responses in AVA-vaccinated rhesus macaques (Macaca mulatta) that survived an aerosol challenge with Bacillus anthracis Ames spores. Results showed that macaque anti-AVA sera neutralized LTx in vitro, even when PA was prebound to cells. Neutralization titers in surviving versus nonsurviving animals and between prechallenge and postchallenge activities were highly correlated. These data demonstrate that AVA stimulates a myriad of antibodies that recognize multiple neutralizing epitopes and confirm that change, loss, or occlusion of epitopes after PA is processed from PA83 to PA63 at the cell surface does not significantly affect in vitro neutralizing efficacy. Furthermore, these data support the idea that the full-length PA83 monomer is an appropriate immunogen for inclusion in next-generation anthrax vaccines.

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The Humoral Immune Response to Various Domains of Protective Antigen of Bacillus anthracis in Cutaneous Anthrax Cases in India

Defence Science Journal ◽

10.14429/dsj.66.10805 ◽

2016 ◽

Vol 66 (6) ◽

pp. 645 ◽

Cited By ~ 3

Author(s):

Anshul Varshney ◽

Nidhi Puranik ◽

M. Kumar ◽

A.K. Goel

Keyword(s):

Immune Response ◽

Bacillus Anthracis ◽

Humoral Immune Response ◽

Vaccine Development ◽

Protective Antigen ◽

Lethal Factor ◽

Serum Samples ◽

Public Health Importance ◽

Humoral Immune ◽

Cutaneous Anthrax

Anthrax, caused by Bacillus anthracis is known to occur globally since antiquity. Besides being an important biothreat agent, it is an important public health importance pathogen also in countries like India. B. anthracis secretes three distinct toxins, namely protective antigen (PA), lethal factor (LF) and edema factor (EF). PA is the central moiety of the anthrax toxin complex and therefore has been a molecule of choice for vaccine development. PA has four different domains with different functions. In this study, the major domains of PA were cloned and expressed in bacterial system. The purified recombinant proteins were used to determine the humoral immune response by ELISA using 43 human cutaneous anthrax serum samples. The maximum immunoreactivity was observed with the whole PA protein followed by domain 2, 4 and 1. The study corroborated that in addition to full PA, individual domain 2 and 4 can also be good target for vaccine development as well as for serodiagnostic assays for cutaneous anthrax

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Effect of Anthrax Immune Globulin on Response to BioThrax (Anthrax Vaccine Adsorbed) in New Zealand White Rabbits

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00460-13 ◽

2013 ◽

Vol 57 (11) ◽

pp. 5693-5696 ◽

Cited By ~ 12

Author(s):

Nina V. Malkevich ◽

Subhendu Basu ◽

Thomas L. Rudge ◽

Kristin H. Clement ◽

Ajoy C. Chakrabarti ◽

...

Keyword(s):

Immune Response ◽

New Zealand ◽

Immune Globulin ◽

Neutralizing Antibodies ◽

Protective Antigen ◽

Anthrax Vaccine ◽

New Zealand White Rabbits ◽

Anthrax Toxins

ABSTRACTDevelopment of anthrax countermeasures that may be used concomitantly in a postexposure setting requires an understanding of the interaction between these products. Anthrax immune globulin intravenous (AIGIV) is a candidate immunotherapeutic that contains neutralizing antibodies against protective antigen (PA), a component of anthrax toxins. We evaluated the interaction between AIGIV and BioThrax (anthrax vaccine adsorbed) in rabbits. While pharmacokinetics of AIGIV were not altered by vaccination, the vaccine-induced immune response was abrogated in AIGIV-treated animals.

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Plant-Based Vaccine: Mice Immunized with Chloroplast-Derived Anthrax Protective Antigen Survive Anthrax Lethal Toxin Challenge

Infection and Immunity ◽

10.1128/iai.73.12.8266-8274.2005 ◽

2005 ◽

Vol 73 (12) ◽

pp. 8266-8274 ◽

Cited By ~ 147

Author(s):

Vijay Koya ◽

Mahtab Moayeri ◽

Stephen H. Leppla ◽

Henry Daniell

Keyword(s):

Protective Antigen ◽

Expression System ◽

Lethal Factor ◽

Vaccine Antigen ◽

Total Soluble Protein ◽

Continuous Illumination ◽

Anthrax Lethal Toxin ◽

Anthrax Vaccine ◽

Edema Factor ◽

Subcutaneous Immunization

ABSTRACT The currently available human vaccine for anthrax, derived from the culture supernatant of Bacillus anthracis, contains the protective antigen (PA) and traces of the lethal and edema factors, which may contribute to adverse side effects associated with this vaccine. Therefore, an effective expression system that can provide a clean, safe, and efficacious vaccine is required. In an effort to produce anthrax vaccine in large quantities and free of extraneous bacterial contaminants, PA was expressed in transgenic tobacco chloroplasts by inserting the pagA gene into the chloroplast genome. Chloroplast integration of the pagA gene was confirmed by PCR and Southern analysis. Mature leaves grown under continuous illumination contained PA as up to 14.2% of the total soluble protein. Cytotoxicity measurements in macrophage lysis assays showed that chloroplast-derived PA was equal in potency to PA produced in B. anthracis. Subcutaneous immunization of mice with partially purified chloroplast-derived or B. anthracis-derived PA with adjuvant yielded immunoglobulin G titers up to 1:320,000, and both groups of mice survived (100%) challenge with lethal doses of toxin. An average yield of about 150 mg of PA per plant should produce 360 million doses of a purified vaccine free of bacterial toxins edema factor and lethal factor from 1 acre of land. Such high expression levels without using fermenters and the immunoprotection offered by the chloroplast-derived PA should facilitate development of a cleaner and safer anthrax vaccine at a lower production cost. These results demonstrate the immunogenic and immunoprotective properties of plant-derived anthrax vaccine antigen.

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Killed but Metabolically Active Bacillus anthracis Vaccines Induce Broad and Protective Immunity against Anthrax

Infection and Immunity ◽

10.1128/iai.00530-08 ◽

2009 ◽

Vol 77 (4) ◽

pp. 1649-1663 ◽

Cited By ~ 24

Author(s):

Justin Skoble ◽

John W. Beaber ◽

Yi Gao ◽

Julie A. Lovchik ◽

Laurie E. Sower ◽

...

Keyword(s):

Bacillus Anthracis ◽

Neutralizing Antibodies ◽

Protective Immunity ◽

Protective Antigen ◽

Excision Repair ◽

Uv Light ◽

Lethal Factor ◽

Point Mutations ◽

Anthrax Vaccine ◽

Edema Factor

ABSTRACTBacillus anthracisis the causative agent of anthrax. We have developed a novel whole-bacterial-cell anthrax vaccine utilizingB. anthracisthat is killed but metabolically active (KBMA). Vaccine strains that are asporogenic and nucleotide excision repair deficient were engineered by deleting thespoIIEanduvrABgenes, renderingB. anthracisextremely sensitive to photochemical inactivation with S-59 psoralen and UV light. We also introduced point mutations into thelefandcyagenes, which allowed inactive but immunogenic toxins to be produced. Photochemically inactivated vaccine strains maintained a high degree of metabolic activity and secreted protective antigen (PA), lethal factor, and edema factor. KBMAB. anthracisvaccines were avirulent in mice and induced less injection site inflammation than recombinant PA adsorbed to aluminum hydroxide gel. KBMAB. anthracis-vaccinated animals produced antibodies against numerous anthrax antigens, including high levels of anti-PA and toxin-neutralizing antibodies. Vaccination with KBMAB. anthracisfully protected mice against challenge with lethal doses of toxinogenic unencapsulated Sterne 7702 spores and rabbits against challenge with lethal pneumonic doses of fully virulent Ames strain spores. Guinea pigs vaccinated with KBMAB. anthraciswere partially protected against lethal Ames spore challenge, which was comparable to vaccination with the licensed vaccine anthrax vaccine adsorbed. These data demonstrate that KBMA anthrax vaccines are well tolerated and elicit potent protective immune responses. The use of KBMA vaccines may be broadly applicable to bacterial pathogens, especially those for which the correlates of protective immunity are unknown.

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Neutralizing Antibodies and Persistence of Immunity following Anthrax Vaccination

Clinical and Vaccine Immunology ◽

10.1128/cvi.13.2.208-213.2006 ◽

2006 ◽

Vol 13 (2) ◽

pp. 208-213 ◽

Cited By ~ 17

Author(s):

James F. Hanson ◽

Sarah C. Taft ◽

Alison A. Weiss

Keyword(s):

Neutralizing Antibodies ◽

Protective Antigen ◽

Colorimetric Assay ◽

Lethal Factor ◽

Neutralization Activity ◽

Anthrax Vaccine ◽

Edema Factor ◽

Low Levels ◽

Antibody Levels ◽

Toxic Components

ABSTRACT Anthrax toxin consists of protective antigen (PA) and two toxic components, lethal factor (LF) and edema factor (EF). PA binds to mammalian cellular receptors and delivers the toxic components to the cytoplasm. PA is the primary antigenic component of the current anthrax vaccine. Immunity is due to the generation of antibodies that prevent the PA-mediated internalization of LF and EF. In this study, we characterized sera obtained from vaccinated military personnel. Anthrax vaccine is administered in a series of six injections at 0, 2, and 4 weeks and 6, 12, and 18 months, followed by annual boosters. The vaccination histories of the subjects were highly varied; many subjects had not completed the entire series, and several had not received annual boosters. We developed a simple colorimetric assay using alamarBlue dye to assess the antibody-mediated neutralization of LF-mediated toxicity to the J774A.1 murine macrophage cell line. Recently vaccinated individuals had high antibody levels and neutralizing activity. One individual who had not been boosted for 5 years had low immunoglobulin G antibody levels but a detectable neutralization activity, suggesting that this individual produced low levels of very active antibodies.

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