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At least 19 recordsLinked to original sources

PubMed2004

Human anti-anthrax protective antigen neutralizing monoclonal antibodies derived from donors vaccinated with anthrax vaccine adsorbed.

BACKGROUND: Potent anthrax toxin neutralizing human monoclonal antibodies were generated from peripheral blood lymphocytes obtained from Anthrax Vaccine Adsorbed (AVA) immune donors. The anti-anthrax toxin human monoclonal antibodies were evaluated for neutralization of anthrax lethal toxin in vivo in the Fisher 344 rat bolus toxin challenge model. METHODS: Human peripheral blood lymphocytes from AVA immunized donors were engrafted into severe combined immunodeficient (SCID) mice. Vaccination with anthrax protective antigen and lethal factor produced a significant increase in antigen specific human IgG in the mouse serum. The antibody producing lymphocytes were immortalized by hybridoma formation. The genes encoding the protective antibodies were rescued and stable cell lines expressing full-length human immunoglobulin were established. The antibodies were characterized by; (1) surface plasmon resonance; (2) inhibition of toxin in an in vitro mouse macrophage cell line protection assay and (3) in vivo in a Fischer 344 bolus lethal toxin challenge model. RESULTS: The range of antibodies generated were diverse with evidence of extensive hyper mutation, and all were of very high affinity for PA83~1 x 10-10-11M. Moreover all the antibodies were potent inhibitors of anthrax lethal toxin in vitro. A single IV dose of AVP-21D9 or AVP-22G12 was found to confer full protection with as little as 0.5x (AVP-21D9) and 1x (AVP-22G12) molar equivalence relative to the anthrax toxin in the rat challenge prophylaxis model. CONCLUSION: Here we describe a powerful technology to capture the recall antibody response to AVA vaccination and provide detailed molecular characterization of the protective human monoclonal antibodies. AVP-21D9, AVP-22G12 and AVP-1C6 protect rats from anthrax lethal toxin at low dose. Aglycosylated versions of the most potent antibodies are also protective in vivo, suggesting that lethal toxin neutralization is not Fc effector mediated. The protective effect of AVP-21D9 persists for at least one week in rats. These potent fully human anti-PA toxin-neutralizing antibodies are attractive candidates for prophylaxis and/or treatment against Anthrax Class A bioterrorism toxins.

Journal Article↗

PubMed2002

Symptoms associated with anthrax exposure: suspected "aborted" anthrax.

Anthrax is a naturally occurring organism with a low incidence of infection. There are no known cases of human-to-human transmission. Bioterrorism-related anthrax in the United States has been seen in three high-risk groups: (1) postal workers, (2) politicians and their staffs, and (3) the press. It appears as though the bioterrorism-related anthrax cases of fall 2001 have been transmitted through the US Postal Service. The authors present a case in which a person at high risk for anthrax exposure was inadequately treated and had symptoms that do not fall into any specific category of disease. It emphasizes the need for someone who has been started on prophylaxis for anthrax to complete a full 60-day course of treatment. It also shows the effectiveness of antibiotic therapy, even in those with high exposure to weaponized anthrax. Further, we would like to suggest that there may exist a new clinical entity of "aborted anthrax infection."

Adult↗

PubMed2003

Calls about anthrax to the Texas Poison Center Network in relation to the anthrax bioterrorism attack in 2001.

Between October 4, 2001 and November 20, 2001, 22 cases of anthrax were identified in a bioterrorism attack on the US. This study examined the patterns of anthrax calls before and after the bioterrorist attack based on calls received by poison centers in Texas, a state that reported no anthrax cases as a result of the attack. During 1998-2002, 553 calls about anthrax were received. The majority of the anthrax calls occurred in 2001 (n = 489, 88.4%) and 2002 (n = 52, 9.4%). The number of calls increased greatly in the days after October 4, 2001, reaching a peak of 31 anthrax calls in 1 d and then declining sharply in succeeding months. However, by December 2002 the number of calls about anthrax still had not returned to pre-attack levels. This study demonstrated the value of poison centers in documenting public need for information on biological agents used in a terrorist attack, even if the attack did not occur in the area serviced by the poison center. Poison centers may expect to receive calls regarding a bioterrorist attack shortly after the public became aware of the attack and will continue to receive related calls for months afterward. Poison centers need to be prepared with appropriate information prior to such attacks to provide to the public upon request.

Anthrax↗

PubMed2005

Cerebral diffusional changes in the early phase of anthrax: is cutaneous anthrax only limited to skin?

OBJECTIVES: Characteristics of cerebral diffusion in the acute period of the anthrax infection were investigated to understand the pathophysiology of the disease. METHODS: Six cutaneous anthrax patients (mean age: 33.3, SD: 18.1) and six healthy control subjects (mean age: 33.7, SS: 19.6) were examined at the acute phase of the infection with diffusion weighted imaging on 1.5 T scanner. ADC values were measured from five different cerebral locations. T-tests, logistic regression and ROC curves were used. RESULTS: Anthrax patients were significantly different than controls regarding cortical ADC values (p<0.05). Logistic regression model accurately classified five out of the six anthrax cases (83.3%). A cut-off value of 574 mm2/s x 10(-3) was found by using ROC curve coordinates. A sensitivity of 100% and a specificity of 67% were attained by means of this value. CONCLUSIONS: This study shows the existence of cerebral parenchymal changes at microstructural level in cutaneous anthrax without neurological findings. These changes are possibly related to the components of the toxin. Our results support the general but unproven opinion that anthrax treatment does not change the existence and the effects of the toxin. Pathophysiological mechanisms towards classification should therefore be reviewed.

Adolescent↗

PubMed2005

Molecular dynamics simulations of complexes between wild-type and mutant anthrax protective antigen variants and a model anthrax toxin receptor.

Bacillus anthracis, a spore-forming infectious bacterium, produces a toxin consisting of three proteins: lethal factor (LF), edema factor (EF), and protective antigen (PA). LF and EF possess intracellular enzymatic functions, the net effect of which is to severely compromise host innate immunity. During an anthrax infection PA plays the critical role of facilitating entry of both EF and LF toxins into host cell cytoplasm. Crystal structures of all three of the anthrax toxins have been determined, as well as the crystal structure of the (human) von Willebrand factor A (integrin VWA/I domain) -- an anthrax toxin receptor. A theoretical structure of the complex between VWA/I and PA has also been reported. Here we report on the results of 1,000 psec molecular dynamics (MD) simulations carried out on complexes between the Anthrax Protective Antigen Domain 4 (PA-D4) and the von Willebrand Factor A (VWA/I). MD simulations (using Insight II software) were carried out for complexes containing wild-type (WT) PA-D4, as well as for complexes containing three different mutants of PA-D4, one containing three substitutions in the PA-D4 "small loop" (residues 679-693) (D683A/L685E/Y688C), one containing a single substitution at a key site at the PA-D4 -- receptor interface (K679A) and another containing a deletion of eleven residues at the C-terminus of PA (Delta724-735). All three sets of PA mutations have been shown experimentally to result in serious deficiencies in PA function. Our MD results are consistent with these findings. Major disruptions in interactions were observed between the mutant PA-D4 domains and the anthrax receptor during the MD simulations. Many secondary structural features in PA-D4 are also severely compromised when VWA complexes with mutant variants of PA-D4 are subjected to MD simulations. These MD simulation results clearly indicate the importance of the mutated PA-D4 residues in both the "small loop" and at the carboxyl terminus in maintaining a PA conformation that is capable of effective interaction with the anthrax toxin receptor.

Antigens, Bacterial↗

PubMed2006

Analysis of anti-protective antigen IgG subclass distribution in recipients of anthrax vaccine adsorbed (AVA) and patients with cutaneous and inhalation anthrax.

The anti-PA IgG1, IgG2, IgG3, and IgG4 subclass responses to clinical anthrax and to different numbers of anthrax vaccine adsorbed (AVA, BioThrax) injections were determined in a cross-sectional study of sera from 63 vaccinees and 13 clinical anthrax patients. The data show that both vaccination with three AVA injections and clinical anthrax elicit anti-PA IgG1, IgG2, and IgG3 subclass responses. An anti-PA IgG4 response was detected in AVA recipients after the fourth injection. The anthrax lethal toxin (LTx) neutralization efficacy of sera from recipients who received 4 to > or =10 AVA injections did not vary significantly in relation to changes in distribution of anti-PA IgG1 and IgG4 subclasses.

Adult↗

PubMed1998

Comparative efficacy of experimental anthrax vaccine candidates against inhalation anthrax in rhesus macaques.

The authors examined the efficacy of Bacillus anthracis protective antigen (PA) combined with adjuvants as vaccines against an aerosol challenge of virulent anthrax spores in rhesus macaques. Adjuvants tested included i) aluminum hydroxide (Alhydrogel), ii) saponin QS-21 and iii) monophosphoryl lipid A (MPL) in squalene/lecithin/Tween 80 emulsion (SLT). Animals were immunized once with either 50 micrograms of recombinant PA plus adjuvant, or with Anthrax Vaccine Adsorbed (AVA), the licensed human anthrax vaccine. The serological response to PA was measured by enzyme linked immunosorbent assay. Lymphocyte proliferation and serum neutralization of in vitro lethal toxin cytotoxicity were also assayed. In all vaccine groups, anti-PA IgM and IgG titers peaked at 2 weeks and 4-5 weeks postimmunization, respectively. Five weeks postimmunization, animals in all vaccine groups demonstrated PA-specific lymphocyte proliferation and sera that neutralized in vitro cytotoxicity. Six weeks after immunization, the animals were challenged by aerosol with approximately 93 LD50 of virulent anthrax spores. Animals were bled daily for 1 week to monitor bacteremia, and deaths were recorded. Anti-PA ELISA titers in all groups of immunized animals were substantially increased 2 weeks after challenge. One dose of each vaccine provided significant protection (> 90%) against inhalation anthrax in the rhesus macaques.

Administration, Inhalation↗

PubMed2003

Serious adverse events among participants in the Centers for Disease Control and Prevention's Anthrax Vaccine and Antimicrobial Availability Program for persons at risk for bioterrorism-related inhalational anthrax.

On 20 December 2001, the Centers for Disease Control and Prevention (CDC) initiated the Anthrax Vaccine and Antibiotic Availability Program (hereafter, the "Program") under an investigational new drug application with the US Food and Drug Administration. This Program provided options for additional preventive treatment for persons at risk for inhalation anthrax as a result of recent bioterrorism attacks who had concluded or were concluding a 60-day course of antimicrobial prophylaxis. Participants were offered an additional 40 days of antibiotic therapy (with ciprofloxacin, doxycycline, or amoxicillin) or antibiotic therapy plus 3 doses of anthrax vaccine. By 11 February 2002, a total of 5420 persons had received standardized education about the Program and 1727 persons (32%) had enrolled. Twelve participants have been identified as having serious adverse events (SAEs). One SAE, which occurred in a participant with ciprofloxacin-induced allergic interstitial nephritis, was considered to be probably associated with treatment received in the Program. No SAEs were associated with anthrax vaccine. CDC will continue to monitor Program participants during the next 2 years.

Adverse Drug Reaction Reporting Systems↗

PubMed2001

The role of antibodies to Bacillus anthracis and anthrax toxin components in inhibiting the early stages of infection by anthrax spores.

Vaccines which are efficacious against anthrax, such as the human vaccine, Anthrax Vaccine Absorbed (AVA), contain the protective antigen (PA) component of the anthrax toxins as the major protective immunogen. Although AVA protects against inhalational anthrax, the immune responses to and role in protection of PA and possibly other antigens have yet to be fully elucidated. Sera from animals immunized with a toxin-producing, unencapsulated live vaccine strain of Bacillus anthracis have been reported to have anti-spore activities associated with the antitoxin humoral response. The authors performed studies to determine whether anti-PA antibody (Ab)-containing preparations stimulated spore uptake by phagocytes and suppressed the germination of spores in vitro. AVA- and PA-immune sera from several species enhanced the phagocytosis by murine peritoneal macrophages of spores of the virulent Ames and the Sterne vaccine strains. Antitoxin Abs appeared to contribute significantly, although not solely, to the enhanced uptake. Rabbit antisera to PA purified from either Sterne or a PA-producing pX01-cured recombinant, affinity-purified anti-PA IgG, and monkey antisera to AVA were used to assess the role of anti-PA ABS: Rabbit anti-PA Abs promoted the uptake of spores of the PA-producing strains Sterne, Ames and RP42, a mutant of Sterne producing only PA, but not of the pX01-Sterne-1 strain, Ames strain, or RP4, a mutant of Sterne with deletions in the loci encoding PA and the oedema factor (EF) toxin component and producing only the lethal factor toxin component. Rabbit anti-PA and monkey anti-AVA Abs also significantly inhibited spore germination in vitro compared to preimmune serum or medium. Spore-associated proteins recognized by anti-PA Abs were detected by electron microscopy and confirmed by immunoblotting of spore coat extracts. Thus, the anti-PA Ab-specific immunity induced by AVA has anti-spore activity and might have a role in impeding the early stages of infection with B. anthracis spores.

Animals↗

PubMed2005

Plant-based vaccine: mice immunized with chloroplast-derived anthrax protective antigen survive anthrax lethal toxin challenge.

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.

Animals↗

PubMed2003

Lymphocytic vasculitis associated with the anthrax vaccine: case report and review of anthrax vaccination.

Anthrax is caused by the spore-forming bacteria Bacillus anthracis. It occurs naturally, but recently has been manufactured as a biological warfare agent. This makes prophylaxis for anthrax an urgent concern and efforts are ongoing for the production of an efficient and safe vaccine. Side effects to the current anthrax vaccine are usually minor and mainly consist of local skin reactions. Occasionally an unusual complication may occur; a case of a patient with lymphocytic vasculitis temporally associated with the anthrax vaccine is reported.

Anthrax Vaccines↗

PubMed1980

Anthrax. William Smith Greenfield, M.D., F.R.C.P., Professor Superintendent, the Brown Animal Sanatory Institution (1878-81). Concerning the priority due to him for the production of the first vaccine against anthrax.

The purpose of this paper is to draw attention to the fact that W. S. Greenfield, working at the Brown Animal Sanatory Institution in London, prepared an effective vaccine against anthrax and described his results some months before the experiment of Pasteur at Pouilly-le-fort. Partly through lack of financial support and partly due to opposition by the antivivisectionists, Greenfield was forced to confine his experiments to a small number of animals, but his results were nevertheless conclusive. He showed that by continuous subculture in a fluid medium that the anthrax bacillus progressively lost its virulence, until it was harmless even to the most susceptible animal, the mouse. The injection of suitably attenuated organisms into cattle rendered them immune to the subsequent injection of virulent anthrax bacilli. Greenfield's work has been overlooked or neglected, and he has never received the credit due him. It is only fitting that his work should be acknowledged in the centenary of the year in which it was described. The following account is composed primarily of quotations from his published papers. For additional information on Greenfield, reference may be made to the series of papers by Wilson (1979 a, b). It may be pointed out that the method of attenuating the virulence of bacilli recorded by Pasteur in relation to the bacillus of fowl cholera was, like that of anthrax vaccine, anticipated by Greenfield.

Anthrax↗

PubMed2005

Combining anthrax vaccine and therapy: a dominant-negative inhibitor of anthrax toxin is also a potent and safe immunogen for vaccines.

Anthrax is caused by the unimpeded growth of Bacillus anthracis in the host and the secretion of toxins. The currently available vaccine is based on protective antigen (PA), a central component of anthrax toxin. Vaccination with PA raises no direct immune response against the bacilli and, being a natural toxin component, PA might be hazardous when used immediately following exposure to B. anthracis. Thus, we have sought to develop a vaccine or therapeutic agent that is safe and eliminates both secreted toxins and bacilli. To that end, we have previously developed a dually active vaccine by conjugating the capsular poly-gamma-d-glutamate (PGA) with PA to elicit the production of antibodies specific for both bacilli and toxins. In the present report, we describe the improved potency of anthrax vaccines through the use of a dominant-negative inhibitory (DNI) mutant to replace PA in PA or PA-PGA vaccines. When tested in mice, DNI alone is more immunogenic than PA, and DNI-PGA conjugate elicits significantly higher levels of antibodies against PA and PGA than PA-PGA conjugate. To explain the enhanced immunogenicity of DNI, we propose that the two point mutations in DNI may have improved epitopes of PA allowing better antigen presentation to helper T cells. Alternatively, these mutations may enhance the immunological processing of PA by altering endosomal trafficking of the toxin in antigen-presenting cells. Because DNI has previously been demonstrated to inhibit anthrax toxin, postexposure use of DNI-based vaccines, including conjugate vaccines, may provide improved immunogenicity and therapeutic activity simultaneously.

Animals↗

PubMed2005

Identification of a protein subset of the anthrax spore immunome in humans immunized with the anthrax vaccine adsorbed preparation.

We identified spore targets of Anthrax Vaccine Adsorbed (AVA)-induced immunity in humans by screening recombinant clones of a previously generated, limited genomic Bacillus anthracis Sterne (pXO1(+), pXO2(-)) expression library of putative spore surface (spore-associated [SA]) proteins with pooled sera from human adults immunized with AVA (immune sera), the anthrax vaccine currently approved for use by humans in the United States. We identified 69 clones that reacted specifically with pooled immune sera but not with pooled sera obtained from the same individuals prior to immunization. Positive clones expressed proteins previously identified as localized on the anthrax spore surface, proteins highly expressed during spore germination, orthologs of proteins of diverse pathogens under investigation as drug targets, and orthologs of proteins contributing to the virulence of both gram-positive and gram-negative pathogens. Among the reactive clones identified by this immunological screen was one expressing a 15.2-kDa hypothetical protein encoded by a gene with no significant homology to sequences contained in databases. Further studies are required to define the subset of SA proteins identified in this study that contribute to the virulence of this pathogen. We hypothesize that optimal delivery of a subset of SA proteins identified by such studies to the immune system in combination with protective antigen (PA), the principal immunogen in AVA, might facilitate the development of defined, nonreactogenic, more-efficacious PA-based anthrax vaccines. Future studies might also facilitate the identification of SA proteins with potential to serve as targets for drug design, spore inactivation, or spore detection strategies.

Adult↗

PubMed2006

Generalized cutaneous reactions to the anthrax vaccine: preliminary results of anthrax vaccine-specific cell mediated immunity and cytokine profiles.

Over two years, the Vaccine Adverse Event Reporting System reported that 0.042% of all anthrax vaccine (Biothrax, Bioport Corporation) doses administered were associated with cutaneous reactions, half of which were eczematous. This case series attempts to immunologically detail this eczematous reaction in four patients by measuring anthrax vaccine-specific cell mediated immunity (ASCMI), profiling TH1 and TH2 cytokine response to the anthrax vaccine in vitro, and analyzing of skin biopsy specimens. Results demonstrated that (1) ASCMI was variable and likely unrelated to this reaction; (2) a lack of TH1 cytokine response to anthrax vaccine may be associated with an increased risk of this eczematous reaction; and (3) skin biopsy findings were nonspecific but supportive of a clinical diagnosis of eczema. Future studies with more patients may yield data to further characterize the ASCMI response and cytokine profiles among patients with this type of reaction.

Adult↗

PubMed1993

An enzyme-linked immunosorbent assay for detecting anthrax antibody in white-tailed deer (Odocoileus virginianus): evaluation of anthrax vaccination and sera from free-ranging deer.

An enzyme-linked immunosorbent assay for anthrax antibody in white-tailed deer (Odocoileus virginianus) was developed and used to evaluate a vaccination study and compare sera from hunter-killed deer in anthrax endemic and non-endemic areas. Deer subcutaneously vaccinated with anthrax avirulent spore vaccine developed specific antibody to protective antigen (PA) which was significantly higher than the non-vaccinated controls at 30, 60, 90, and 240 days post-vaccination. There was no difference between the levels of antibody to PA between deer in anthrax endemic and non-endemic areas.

Animals↗

PubMed2001

Update: Investigation of bioterrorism-related anthrax and interim guidelines for clinical evaluation of persons with possible anthrax.

Since October 3, 2001, CDC and state and local public health authorities have been investigating cases of bioterrorism-related anthrax. This report updates findings as of October 31, and includes interim guidelines for the clinical evaluation of persons with possible anthrax. A total of 21 cases (16 confirmed and five suspected) of bioterrorism-related anthrax have been reported among persons who worked in the District of Columbia, Florida, New Jersey, and New York City (Figure 1). Until the source of these intentional exposures is eliminated, clinicians and laboratorians should be alert for clinical evidence of Bacillus anthracis infection. Epidemiologic investigation of these cases and surveillance to detect new cases of bioterrorism-associated anthrax continues.

Adult↗

PubMed1985

[Evaluation of penicillin alone and penicillin combined with anti-anthrax serum in experimental anthrax in mice].

In this study penicillin alone versus penicillin combined with anti-anthrax serum were compared in the treatment of experimental anthrax of mice. Three groups of mice were inoculated intraperitoneally with the same suspension of Bacillus anthracis. Ten hours after the onset of infection the control group received no treatment, to the second group penicillin-G was injected every day, and the 3 rd group received penicillin-G plus anti-anthrax serum. The survival rate of the latter two groups was significantly higher than that of the control group. But, there was no difference in the survival of mice and the distribution of the bacilli in various tissues between the penicillin treated mice and the penicillin plus anti-anthrax serum treated group of mice.

Animals↗