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1

Radiolabeled Antibodies to Bacillus anthracis Toxins Are Bactericidal and Partially Therapeutic in Experimental Murine Anthrax?  

PubMed Central

Bacillus anthracis is a powerful agent for use in biological warfare, and infection with the organism is associated with a high rate of mortality, underscoring the need for additional effective therapies for anthrax. Radioimmunotherapy (RIT) takes advantage of the specificity and affinity of the antigen-antibody interaction to deliver a microbicidal radioactive nuclide to a site of infection. RIT has proven therapeutic in experimental models of viral, bacterial, and fungal infections; but it is not known whether this approach can successfully employ toxin binding monoclonal antibodies (MAbs) for diseases caused by toxigenic bacteria. Indirect immunofluorescence studies with MAbs to protective antigen (MAbs 7.5G ?2b and 10F4 ?1) and lethal factor (MAb 14FA ?2b) revealed the surface expression of toxins on bacterial cells. Scatchard analysis of MAbs revealed high binding constants and numerous binding sites on the bacterial surface. To investigate the microbicidal properties of these MAbs, our group radiolabeled MAbs with either 188Re or 213Bi. In vitro, 213Bi was more efficient than 188Re in mediating microbicidal activity against B. anthracis. The administration of MAbs [213Bi]10F4 ?1 and [213Bi]14FA ?2b prolonged the survival of A/JCr mice infected with B. anthracis Sterne bacterial cells but not B. anthracis Sterne spores. These results indicate that RIT with MAbs that target B. anthracis toxin components can be used to treat experimental anthrax infection and suggest that toxigenic bacteria may be targeted with radiolabeled MAbs.

Rivera, Johanna; Nakouzi, Antonio S.; Morgenstern, Alfred; Bruchertseifer, Frank; Dadachova, Ekaterina; Casadevall, Arturo

2009-01-01

2

In vitro evaluation, biodistribution and scintigraphic imaging in mice of radiolabeled anthrax toxins  

PubMed Central

Introduction There is a lot of interest towards creating therapies and vaccines for Bacillus anthracis, a bacterium which causes anthrax in humans and which spores can be made into potent biological weapons. Systemic injection of lethal factor (LF), edema factor (EF), and protective antigen (PA) in mice produces toxicity and this protocol is commonly used to investigate the efficacy of specific antibodies in passive protection and vaccine studies. Availability of toxins labeled with imagable radioisotopes would allow to demonstrate their tissue distribution after intravenous injection at toxin concentration that are below pharmacologically significant to avoid masking by toxic effects. Methods LF, EF and PA were radiolabeled with 188Re and 99mTc and their performance in vitro was evaluated by macrophages and CHO cells toxicity assays and by binding to macrophages. Scintigraphic imaging and biodistribution of IV injected 99mTc- and 123I-labeled toxins was performed in BALB/c mice. Results Radiolabeled toxins preserved their biological activity. Scatchard-type analysis of the binding of radiolabeled PA to the J774.16 macrophage-like cells revealed 6.6 × 104 binding sites per cell with a dissociation constant of 6.7 nM. Comparative scintigraphic imaging of mice injected intravenously with either 99mTc- or 123I-labeled PA, EF, and LF toxins demonstrated similar biodistribution patterns with early localization of radioactivity in the liver, spleen, intestines and excretion through kidneys. The finding of renal excretion shortly after IV injection strongly suggests that toxins are rapidly degraded which could contribute to the variability of mouse toxigenic assays. Biodistribution studies confirmed that all three toxins concentrated in the liver and the presence of high levels of radioactivity again implied rapid degradation in vivo. Conclusions The availability of 188Re and 99mTc-labeled PA, LF and EF toxins allowed us to confirm the number of PA binding sites per cell, to provide an estimate of the dissociation constant of PA for its receptor, and to demonstrate tissue distribution of toxins in mice after intravenous injection.

Dadachova, Ekaterina; Rivera, Johanna; Revskaya, Ekaterina; Nakouzi, Antonio; Cahill, Sean M.; Blumenstein, Michael; Xiao, Hui; Rykunov, Dmitry; Casadevall, Arturo

2008-01-01

3

Anthrax toxin characterization.  

PubMed

The anthrax toxin comprises three proteins. When they work together, they can kill humans, especially after spores of the bacteria have been inhaled. One anthrax protein, called protective antigen (PA), chaperones the two other toxins into human or animal cells and shields them from the body's immune system. The second, lethal factor (LF), destroys the white blood cells that hosts send in defence. The third toxin molecule, edema factor (EF), hijacks the signaling system in the body. This disrupts the energy balance of cells and leads to them accumulating fluid and complete destroy of cells. PMID:12143109

Patocka, Jirí; Splino, Miroslav

2002-01-01

4

Anthrax lethal and edema toxins in anthrax pathogenesis.  

PubMed

The pathophysiological effects resulting from many bacterial diseases are caused by exotoxins released by the bacteria. Bacillus anthracis, a spore-forming bacterium, is such a pathogen, causing anthrax through a combination of bacterial infection and toxemia. B. anthracis causes natural infection in humans and animals and has been a top bioterrorism concern since the 2001 anthrax attacks in the USA. The exotoxins secreted by B. anthracis use capillary morphogenesis protein 2 (CMG2) as the major toxin receptor and play essential roles in pathogenesis during the entire course of the disease. This review focuses on the activities of anthrax toxins and their roles in initial and late stages of anthrax infection. PMID:24684968

Liu, Shihui; Moayeri, Mahtab; Leppla, Stephen H

2014-06-01

5

Anthrax toxin-induced rupture of artificial lipid bilayer membranes.  

PubMed

We demonstrate experimentally that anthrax toxin complexes rupture artificial lipid bilayer membranes when isolated from the blood of infected animals. When the solution pH is temporally acidified to mimic that process in endosomes, recombinant anthrax toxin forms an irreversibly bound complex, which also destabilizes membranes. The results suggest an alternative mechanism for the translocation of anthrax toxin into the cytoplasm. PMID:23947891

Nablo, Brian J; Panchal, Rekha G; Bavari, Sina; Nguyen, Tam L; Gussio, Rick; Ribot, Wil; Friedlander, Art; Chabot, Donald; Reiner, Joseph E; Robertson, Joseph W F; Balijepalli, Arvind; Halverson, Kelly M; Kasianowicz, John J

2013-08-14

6

Exposure to anthrax toxin alters human leucocyte expression of anthrax toxin receptor 1  

PubMed Central

Anthrax is a toxin-mediated disease, the lethal effects of which are initiated by the binding of protective antigen (PA) with one of three reported cell surface toxin receptors (ANTXR). Receptor binding has been shown to influence host susceptibility to the toxins. Despite this crucial role for ANTXR in the outcome of disease, and the reported immunomodulatory consequence of the anthrax toxins during infection, little is known about ANTXR expression on human leucocytes. We characterized the expression levels of ANTXR1 (TEM8) on human leucocytes using flow cytometry. In order to assess the effect of prior toxin exposure on ANTXR1 expression levels, leucocytes from individuals with no known exposure, those exposed to toxin through vaccination and convalescent individuals were analysed. Donors could be defined as either ‘low’ or ‘high’ expressers based on the percentage of ANTXR1-positive monocytes detected. Previous exposure to toxins appears to modulate ANTXR1 expression, exposure through active infection being associated with lower receptor expression. A significant correlation between low receptor expression and high anthrax toxin-specific interferon (IFN)-? responses was observed in previously infected individuals. We propose that there is an attenuation of ANTXR1 expression post-infection which may be a protective mechanism that has evolved to prevent reinfection.

Ingram, R J; Harris, A; Ascough, S; Metan, G; Doganay, M; Ballie, L; Williamson, E D; Dyson, H; Robinson, J H; Sriskandan, S; Altmann, D M

2013-01-01

7

Beta-cyclodextrin derivatives that inhibit anthrax lethal toxin.  

PubMed

Recently, we demonstrated that simultaneous blocking of bacterial growth by antibiotics and inhibition of anthrax toxin action with antibodies against protective antigen were beneficial for the treatment of anthrax. The present study examined the hypothesis that blocking the pore formed by protective antigen can inhibit the action of anthrax toxin. The potential inhibitors were chosen by a structure-based design using beta-cyclodextrin as the starting molecule. Several beta-cyclodextrin derivatives were evaluated for their ability to protect RAW 264.7 cells from the action of anthrax lethal toxin. Per-substituted aminoalkyl derivatives displayed inhibitory activity and were protective against anthrax lethal toxin action at low micromolar concentrations. These results provide the basis for a structure-based drug discovery program, with the goal of identifying new drug candidates for anthrax treatment. PMID:16169738

Karginov, Vladimir A; Yohannes, Adiamseged; Robinson, Tanisha M; Fahmi, Nour Eddine; Alibek, Kenneth; Hecht, Sidney M

2006-01-01

8

The Receptors that Mediate the Direct Lethality of Anthrax Toxin  

PubMed Central

Tumor endothelium marker-8 (TEM8) and capillary morphogenesis protein-2 (CMG2) are the two well-characterized anthrax toxin receptors, each containing a von Willebrand factor A (vWA) domain responsible for anthrax protective antigen (PA) binding. Recently, a cell-based analysis was used to implicate another vWA domain-containing protein, integrin ?1 as a third anthrax toxin receptor. To explore whether proteins other than TEM8 and CMG2 function as anthrax toxin receptors in vivo, we challenged mice lacking TEM8 and/or CMG2. Specifically, we used as an effector protein the fusion protein FP59, a fusion between the PA-binding domain of anthrax lethal factor (LF) and the catalytic domain of Pseudomonas aeruginosa exotoxin A. FP59 is at least 50-fold more potent than LF in the presence of PA, with 2 ?g PA + 2 ?g FP59 being sufficient to kill a mouse. While TEM8?/? and wild type control mice succumbed to a 5 ?g PA + 5 ?g FP59 challenge, CMG2?/? mice were completely resistant to this dose, confirming that CMG2 is the major anthrax toxin receptor in vivo. To detect whether any toxic effects are mediated by TEM8 or other putative receptors such as integrin ?1, CMG2?/?/TEM8?/? mice were challenged with as many as five doses of 50 ?g PA + 50 ?g FP59. Strikingly, the CMG2?/?/TEM8?/? mice were completely resistant to the 5-dose challenge. These results strongly suggest that TEM8 is the only minor anthrax toxin receptor mediating direct lethality in vivo and that other proteins implicated as receptors do not play this role.

Liu, Shihui; Zhang, Yi; Hoover, Benjamin; Leppla, Stephen H.

2012-01-01

9

Identification of novel anthrax toxin countermeasures using in silico methods.  

PubMed

Anthrax is an acute infectious disease caused by the spore-forming, gram-positive, rod-shaped bacterium Bacillus anthracis. The anthrax toxin lethal factor (LF) is the primary anthrax toxin component responsible for cytotoxicity and host death and has been a heavily researched target for design of postexposure therapeutics in the event of a bioterror attack. Various computer-aided drug design methodologies have proven useful for pinpointing new antianthrax drug scaffolds, optimizing existing leads and probes, and elucidating key mechanisms of action. We present a selection of in silico virtual screening protocols incorporating docking and scoring, shape-based searching, and pharmacophore mapping techniques to identify and prioritize small molecules with potential biological activity against LF. We also recommend screening parameters that have been shown to increase the accuracy and reliability of these computational results. PMID:23568471

Chiu, Ting-Lan; Maize, Kimberly M; Amin, Elizabeth A

2013-01-01

10

Key tissue targets responsible for anthrax-toxin-induced lethality.  

PubMed

Bacillus anthracis, the causative agent of anthrax disease, is lethal owing to the actions of two exotoxins: anthrax lethal toxin (LT) and oedema toxin (ET). The key tissue targets responsible for the lethal effects of these toxins are unknown. Here we generated cell-type-specific anthrax toxin receptor capillary morphogenesis protein-2 (CMG2)-null mice and cell-type-specific CMG2-expressing mice and challenged them with the toxins. Our results show that lethality induced by LT and ET occurs through damage to distinct cell types; whereas targeting cardiomyocytes and vascular smooth muscle cells is required for LT-induced mortality, ET-induced lethality occurs mainly through its action in hepatocytes. Notably, and in contradiction to what has been previously postulated, targeting of endothelial cells by either toxin does not seem to contribute significantly to lethality. Our findings demonstrate that B. anthracis has evolved to use LT and ET to induce host lethality by coordinately damaging two distinct vital systems. PMID:23995686

Liu, Shihui; Zhang, Yi; Moayeri, Mahtab; Liu, Jie; Crown, Devorah; Fattah, Rasem J; Wein, Alexander N; Yu, Zu-Xi; Finkel, Toren; Leppla, Stephen H

2013-09-01

11

Crystallographic studies of the Anthrax lethal toxin. Annual report  

SciTech Connect

The lethal form of Anthrax results from the inhalation of anthrax spores. Death is primarily due to the effects of the lethal toxin (Protective Antigen (PA) + Lethal Factor) from the causative agent, Bacillus anthracis. All the Anthrax vaccines currently in use or under development contain or produce PA, the major antigenic component of anthrax toxin, and there is a clear need for an improved vaccine for human use. In the previous report we described the first atomic resolution structure of PA, revealing that the molecule is composed largely of beta-sheets organized into four domains. This information can be used in the design. of recombinant PA vaccines. In this report we describe additional features of the full-length PA molecule derived from further crystallographic refinement and careful examination of the structure. We compare two crystal forms of PA grown at different pH values and discuss the functional implications. A complete definition of the function of each domain must await the crystal structure of the PA63 heptamer. We have grown crystals of the heptamer under both detergent and detergent-free conditions, and made substantial progress towards the crystal structure. The mechanism of anthrax intoxication in the light of our results is reviewed.

Frederick, C.A.

1996-07-01

12

Calpain-dependent cytoskeletal rearrangement exploited for anthrax toxin endocytosis  

PubMed Central

The protective antigen component of Bacillus anthracis toxins can interact with at least three distinct proteins on the host cell surface, capillary morphogenesis gene 2 (CMG2), tumor endothelial marker 8, and ?1-integrin, and, with the assistance of other host proteins, enters targeted cells by receptor-mediated endocytosis. Using an antisense-based phenotypic screen, we discovered the role of calpains in this process. We show that functions of a ubiquitous Ca2+-dependent cysteine protease, calpain-2, and of the calpain substrate talin-1 are exploited for association of anthrax toxin and its principal receptor, CMG2, with higher-order actin filaments and consequently for toxin entry into host cells. Down-regulated expression of calpain-2 or talin-1, or pharmacological interference with calpain action, did not affect toxin binding but reduced endocytosis and increased the survival of cells exposed to anthrax lethal toxin. Adventitious expression of wild-type talin-1 promoted toxin endocytosis and lethality, whereas expression of a talin-1 mutant (L432G) that is insensitive to calpain cleavage did not. Disruption of talin-1, which links integrin-containing focal adhesion complexes to the actin cytoskeleton, facilitated association of toxin bound to its principal cell-surface receptor, CMG2, with higher-order actin filaments undergoing dynamic disassembly and reassembly during endocytosis. Our results reveal a mechanism by which a bacterial toxin uses constitutively occurring calpain-mediated cytoskeletal rearrangement for internalization.

Jeong, Sun-Young; Martchenko, Mikhail; Cohen, Stanley N.

2013-01-01

13

Induction Of Histamine, Bradykinin And Serotonin Release In Response To Anthrax Lethal Toxin  

Microsoft Academic Search

Background: Anthrax lethal toxin (LeTx) is a major virulence factor in anthrax infection but compelling evidence suggests that it exerts a strong inhibitory effect on macrophage cytokine production. This leaves no definitive explanation as to the etiology of many of the early signs and symptoms, seen in inhalational anthrax infection. Methods: The responses of histamine, bradykinin and serotonin release to

Yue Lydia Li; Darya Alibek; Raymond S. Weinstein; Joseph Shiloach; Qingzhu Zhai; Dustin Schaffner; Kenneth Alibek; Aiguo Wu

2009-01-01

14

Recombinant anthrax toxin receptor-Fc fusion proteins produced in plants protect rabbits against inhalational anthrax.  

PubMed

Inhalational anthrax, a zoonotic disease caused by the inhalation of Bacillus anthracis spores, has a ?50% fatality rate even when treated with antibiotics. Pathogenesis is dependent on the activity of two toxic noncovalent complexes: edema toxin (EdTx) and lethal toxin (LeTx). Protective antigen (PA), an essential component of both complexes, binds with high affinity to the major receptor mediating the lethality of anthrax toxin in vivo, capillary morphogenesis protein 2 (CMG2). Certain antibodies against PA have been shown to protect against anthrax in vivo. As an alternative to anti-PA antibodies, we produced a fusion of the extracellular domain of human CMG2 and human IgG Fc, using both transient and stable tobacco plant expression systems. Optimized expression led to the CMG2-Fc fusion protein being produced at high levels: 730 mg/kg fresh leaf weight in Nicotiana benthamiana and 65 mg/kg in N. tabacum. CMG2-Fc, purified from tobacco plants, fully protected rabbits against a lethal challenge with B. anthracis spores at a dose of 2 mg/kg body weight administered at the time of challenge. Treatment with CMG2-Fc did not interfere with the development of the animals' own immunity to anthrax, as treated animals that survived an initial challenge also survived a rechallenge 30 days later. The glycosylation of the Fc (or lack thereof) had no significant effect on the protective potency of CMG2-Fc in rabbits or on its serum half-life, which was about 5 days. Significantly, CMG2-Fc effectively neutralized, in vitro, LeTx-containing mutant forms of PA that were not neutralized by anti-PA monoclonal antibodies. PMID:20956592

Wycoff, Keith L; Belle, Archana; Deppe, Dorothée; Schaefer, Leah; Maclean, James M; Haase, Simone; Trilling, Anke K; Liu, Shihui; Leppla, Stephen H; Geren, Isin N; Pawlik, Jennifer; Peterson, Johnny W

2011-01-01

15

MICROBIOLOGY: Enhanced: Fighting Anthrax with a Mutant Toxin  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required: There is an urgent need to develop new therapeutics against the microbe causing anthrax, which has the potential to be used in biological warfare. In their Perspective, Olsnes and Wesche discuss a new therapeutic approach designed by Sellman and colleagues. In this approach, a mutant subunit of the toxin prevents correct assembly of wild-type subunits into a pore in the host cell membrane. In this way, lethal bacterial enzymes are prevented from translocating into the host cell.

Sjur Olsnes (Institute for Cancer Research;Department of Biochemistry); Jørgen Wesche (Institute for Cancer Research;Department of Biochemistry)

2008-10-05

16

Synthesis of Potent Inhibitors of Anthrax Toxin Based on Poly-L-Glutamic Acid  

PubMed Central

We report the synthesis of biodegradable polyvalent inhibitors of anthrax toxin based on poly-L-glutamic acid (PLGA). These biocompatible polyvalent inhibitors are at least four orders of magnitude more potent than the corresponding monovalent peptides in vitro and are comparable in potency to polyacrylamide-based inhibitors of anthrax toxin assembly. We have elucidated the influence of peptide density on inhibitory potency and demonstrate that these inhibitory potencies are limited by kinetics, with even higher activities seen when the inhibitors are preincubated with the heptameric receptor-binding subunit of anthrax toxin prior to exposure to cells. These polyvalent inhibitors are also effective at neutralizing anthrax toxin in vivo and represent attractive leads for designing biocompatible anthrax therapeutics.

Joshi, Amit; Saraph, Arundhati; Poon, Vincent; Mogridge, Jeremy; Kane, Ravi S.

2008-01-01

17

Anthrax  

MedlinePLUS

... worried about anthrax germs being grown as a weapon. The issue of laboratory-grown B. anthracis received ... technologically difficult to use anthrax effectively as a weapon on a large scale. Types of Anthrax The ...

18

Three Models of Anthrax Toxin Effects on the MAP-Kinase Pathway and Macrophage Survival.  

National Technical Information Service (NTIS)

Lethal factor (LF), a component of anthrax toxin, is the primary virulence factor that allows Bacillus anthracis to evade the immune response by blocking the activation of mitogen-activated protein kinase (MAPK) enzymes. This research modifies three publi...

D. J. Schneider

2008-01-01

19

Suppressive Effects of Anthrax Lethal Toxin on Megakaryopoiesis  

PubMed Central

Anthrax lethal toxin (LT) is a major virulence factor of Bacillus anthracis. LT challenge suppresses platelet counts and platelet function in mice, however, the mechanism responsible for thrombocytopenia remains unclear. LT inhibits cellular mitogen-activated protein kinases (MAPKs), which are vital pathways responsible for cell survival, differentiation, and maturation. One of the MAPKs, the MEK1/2-extracellular signal-regulated kinase pathway, is particularly important in megakaryopoiesis. This study evaluates the hypothesis that LT may suppress the progenitor cells of platelets, thereby inducing thrombocytopenic responses. Using cord blood-derived CD34+ cells and mouse bone marrow mononuclear cells to perform in vitro differentiation, this work shows that LT suppresses megakaryopoiesis by reducing the survival of megakaryocytes. Thrombopoietin treatments can reduce thrombocytopenia, megakaryocytic suppression, and the quick onset of lethality in LT-challenged mice. These results suggest that megakaryocytic suppression is one of the mechanisms by which LT induces thrombocytopenia. These findings may provide new insights for developing feasible approaches against anthrax.

Lin, Guan-Ling; Wang, Tsung-Pao; Lai, Yi-Ling; Lin, Ting-Kai; Hsieh, Ming-Chun; Kau, Jyh-Hwa; Huang, Hsin-Hsien; Hsu, Hui-Ling; Liao, Chi-Yuan; Sun, Der-Shan

2013-01-01

20

Non-canonical effects of anthrax toxins on haematopoiesis: implications for vaccine development.  

PubMed

Anthrax receptor (ATR) shares similarities with molecules relevant to haematopoiesis. This suggests that anthrax proteins might bind to these mimicking molecules and exert non-specific haematopoietic effects. The haematopoietic system is the site of immune cell development in the adult. As such, ATR ligand, protective antigen (PA) and the other anthrax proteins, lethal factor, edema factor, could be significant to haematopoietic responses against Bacillus anthracis infection. Because haematopoiesis is the process of immune cell development, effects by anthrax proteins could be relevant to vaccine development. Here, we report on effects of anthrax proteins and toxins on early and late haematopoiesis. Flow cytometry shows binding of PA to haematopoietic cells. This binding might be partly specific because flow cytometry and Western blots demonstrate the presence of ATR1 on haematopoietic cell subsets and the supporting stromal cells. Functional studies with long-term initiating cell and clonogenic assays determined haematopoietic suppression by anthrax toxins and stimulation by monomeric proteins. The suppressive effects were not attributed to cell death, but partly through the induction of haematopoietic suppressors, interleukin (IL)-10 and CCL3 (MIP-1alpha). In summary, anthrax proteins affect immune cell development by effects on haematopoiesis. The type of effect, stimulation or suppression, depend on whether the stimulator is a toxin or monomeric protein. The studies show effects of anthrax proteins beginning at the early stage of haematopoiesis, and also show secondary mediators such as IL-10 and CCL3. The roles of other cytokines and additional ATR are yet to be investigated. PMID:18752638

Liu, Katherine; Wong, Elaine W; Schutzer, Steven E; Connell, Nancy D; Upadhyay, Alok; Bryan, Margarette; Rameshwar, Pranela

2009-08-01

21

From structure to solutions: the role of basic research in developing anthrax countermeasures: Microbiology Graduate Program Seminar: Anthrax toxin.  

PubMed

Dr. John Collier traced the discoveries that elucidated the structure and function of the anthrax toxin in his talk "Anthrax Toxin," which was part of the Microbiology Graduate Program Seminar Series at Yale School of Medicine on February 23, 2012. Dr. Collier, Professor of Microbiology and Immunobiology at Harvard University, began by noting the advantages to studying anthrax pathogenesis in a biosafety level-1 lab. This designation does not merely facilitate his research, but also reflects a larger trend of basic research being leveraged to develop translational applications. Basic research on toxin structure has led to the development of a vaccine by Dr. Collier's group. Next-generation prophylactics also may stem from recent discoveries uncovering a role for cellular cofactors that mediate toxin function. Finally, basic research into the toxin substructure has facilitated efforts to change the receptor tropism to target dysregulated cells for therapeutic purposes. The urgency around biodefense agents makes the choice of research priorities a salient issue. As such, this author submits that basic research occupies a unique and lucrative niche driving clinical applications. PMID:22737057

Hardiman, Camille A

2012-06-01

22

New insights into the biological effects of anthrax toxins: linking cellular to organismal responses  

PubMed Central

The anthrax toxins lethal toxin (LT) and edema toxin (ET), are essential virulence factors produced by B. anthracis. These toxins act during two distinct phases of anthrax infection. During the first, prodromal phase, which is often asymptomatic, anthrax toxins act on cells of the immune system to help the pathogen establish infection. Then, during the rapidly progressing (or fulminant) stage of the disease bacteria disseminate via a hematological route to various target tissues and organs, which are typically highly vascularized. As bacteria proliferate in the bloodstream LT and ET begin to accumulate rapidly reaching a critical threshold level that will cause death even when the bacterial proliferation is curtailed by antibiotics. During this final phase of infection the toxins cause an increase in vascular permeability and a decrease in function of target organs including the heart, spleen, kidney, adrenal gland, and brain. In this review, we examine the various biological effects of anthrax toxins, focusing on the fulminant stage of the disease and on mechanisms by which the two toxins may collaborate to cause cardiovascular collapse. We discuss normal mechanisms involved in maintaining vascular integrity and based on recent studies indicating that LT and ET cooperatively inhibit membrane trafficking to cell-cell junctions we explore several potential mechanisms by which the toxins may achieve their lethal effects. We also summarize the effects of other potential virulence factors secreted by B. anthracis and consider the role of toxic factors in the evolutionarily recent emergence of this devastating disease.

Guichard, Annabel; Nizet, Victor; Bier, Ethan

2013-01-01

23

In situ gastrointestinal protection against anthrax edema toxin by single-chain antibody fragment producing lactobacilli  

PubMed Central

Background Anthrax is caused by the bacterium Bacillus anthracis and is regarded as one of the most prominent bioterrorism threats. Anthrax toxicity is induced by the tripartite toxin complex, composed of the receptor-binding anthrax protective antigen and the two enzymatic subunits, lethal factor and edema factor. Recombinant lactobacilli have previously been used to deliver antibody fragments directed against surface epitopes of a variety of pathogens, including Streptococcus mutans, Porphyromonas gingivalis, and rotavirus. Here, we addressed whether or not anthrax toxins could be targeted and neutralised in the gastrointestinal tract by lactobacilli producing recombinant antibody fragments as a model system for toxin neutralisation in the gastrointestinal lumen. Results The neutralising anti-PA scFv, 1H, was expressed in L. paracasei as a secreted protein, a cell wall-anchored protein or both secreted and wall-anchored protein. Cell wall display on lactobacilli and PA binding of the anchored constructs was confirmed by flow cytometry analysis. Binding of secreted or attached scFv produced by lactobacilli to PA were verified by ELISA. Both construct were able to protect macrophages in an in vitro cytotoxicity assay. Finally, lactobacilli producing the cell wall attached scFv were able to neutralise the activity of anthrax edema toxin in the GI tract of mice, in vivo. Conclusion We have developed lactobacilli expressing a neutralising scFv fragment against the PA antigen of the anthrax toxin, which can provide protection against anthrax toxins both in vitro and in vivo. Utilising engineered lactobacilli therapeutically for neutralising toxins in the gastrointestinal tract can potential be expanded to provide protection against a range of additional gastrointestinal pathogens. The ability of lactobacilli to colonise the gastrointestinal tract may allow the system to be used both prophylactically and therapeutically.

2011-01-01

24

Dominant-Negative Mutants of a Toxin Subunit: An Approach to Therapy of Anthrax  

NASA Astrophysics Data System (ADS)

The protective antigen moiety of anthrax toxin translocates the toxin's enzymic moieties to the cytosol of mammalian cells by a mechanism that depends on its ability to heptamerize and insert into membranes. We identified dominant-negative mutants of protective antigen that co-assemble with the wild-type protein and block its ability to translocate the enzymic moieties across membranes. These mutants strongly inhibited toxin action in cell culture and in an animal intoxication model, suggesting that they could be useful in therapy of anthrax.

Sellman, Bret R.; Mourez, Michael; John Collier, R.

2001-04-01

25

Role of chondroitin sulfate C in the action of anthrax toxin.  

PubMed

Anthrax toxin is produced by Bacillus anthracis, the causative agent of anthrax, and is responsible for the majority of disease symptoms. The toxin consists of 3 proteins, protective antigen (PA), lethal factor (LF), and edema factor (EF), which combine to form lethal and edema toxin. Glycosaminoglycans, which are present on the surface of cells, were investigated with regard to their role in toxicity resulting from anthrax toxin exposure. Lethal toxin-induced cytotoxicity of the RAW 264.7 cells was significantly inhibited by the addition of chondroitin sulfate C as determined by the MTT assay. By contrast, several other glycosaminoglycans, including heparin, heparan sulfate, and dermatan sulfate did not show significant levels of inhibition. Studies utilizing fluorescence-labeled PA demonstrated decreased PA binding to RAW 264.7 cells with the addition of chondroitin sulfate C. Formation of PA oligomers at the surface of cells after binding was also inhibited by chondroitin sulfate C. Interestingly, enzymatic degradation of endogenous chondroitin sulfate C from the cell surface with chondroitinase ABC was accompanied by increased sensitivity to the toxin. These findings were further confirmed by pretreating cells with sodium chlorate to reduce the degree of cell surface glycosaminoglycans sulfation. In addition, chondroitin sulfate C effectively inhibits edema toxin-induced cAMP accumulation in cells. Our results indicate that chondroitin sulfate C may play an important role in the toxicity of anthrax toxin. PMID:22503668

Ahn, Hyun Chan; Kim, Na Young; Hur, Gyeung Haeng; Yang, Jai Myung; Shin, Sungho

2012-07-16

26

Bidirectional effect of Wnt signaling antagonist DKK1 on the modulation of anthrax toxin uptake.  

PubMed

LRP6, a co-receptor for the morphogen Wnt, aids endocytosis of anthrax complexes. Here we report that Dickkopf1 (DKK1) protein, a secreted LRP6 ligand and antagonist, is also a modulator of anthrax toxin sensitivity. shRNA-mediated gene silencing or TALEN-mediated gene knockout of DKK1 reduced sensitivity of cells to PA-dependent hybrid toxins. However, unlike the solely inhibitory effect on Wnt signaling, the effects of DKK1 overexpression on anthrax toxicity were bidirectional, depending on its endogenous expression and cell context. Fluorescence microscopy and biochemical analyses showed that DKK1 facilitates internalization of anthrax toxins and their receptors, an event mediated by DKK1-LRP6-Kremen2 complex. Monoclonal antibodies against DKK1 provided dose-dependent protection to macrophages from killing by anthrax lethal toxin (LT). Our discovery that DKK1 forms ternary structure with LRP6 and Kremen2 in promoting PA-mediated toxin internalization provides a paradigm for bacterial exploitation of mechanisms that host cells use to internalize signaling proteins. PMID:24671437

Qian, LiLi; Cai, ChangZu; Yuan, PengFei; Jeong, Sun-Young; Yang, XiaoZhou; Dealmeida, Venita; Ernst, James; Costa, Michael; Cohen, Stanley N; Wei, WenSheng

2014-05-01

27

Anthrax  

Microsoft Academic Search

Anthrax is caused byBacillus anthracis, an encapulated and spore-forming bacillus. The disease is usually contracted through uptake of spores that remain viable\\u000a in the contaminated soil for many years. Anthrax is primarily a disease of herbivorous animals and is uncommon in humans who\\u000a may get the infection through contact with contaminated animals or their products. Anthrax spores germinate after entering

K. K. Datta; Jagvir Singh

2002-01-01

28

Search for cyclodextrin-based inhibitors of anthrax toxins: synthesis, structural features, and relative activities.  

PubMed

Recently, using structure-inspired drug design, we demonstrated that aminoalkyl derivatives of beta-cyclodextrin inhibited anthrax lethal toxin action by blocking the transmembrane pore formed by the protective antigen (PA) subunit of the toxin. In the present study, we evaluate a series of new beta-cyclodextrin derivatives with the goal of identifying potent inhibitors of anthrax toxins. Newly synthesized hepta-6-thioaminoalkyl and hepta-6-thioguanidinoalkyl derivatives of beta-cyclodextrin with alkyl spacers of various lengths were tested for the ability to inhibit cytotoxicity of lethal toxin in cells as well as to block ion conductance through PA channels reconstituted in planar bilayer lipid membranes. Most of the tested derivatives were protective against anthrax lethal toxin action at low or submicromolar concentrations. They also blocked ion conductance through PA channels at concentrations as low as 0.1 nM. The activities of the derivatives in both cell protection and channel blocking were found to depend on the length and chemical nature of the substituent groups. One of the compounds was also shown to block the edema toxin activity. It is hoped that these results will help to identify a new class of drugs for anthrax treatment, i.e., drugs that block the pathway for toxin translocation into the cytosol, the PA channel. PMID:16982795

Karginov, Vladimir A; Nestorovich, Ekaterina M; Yohannes, Adiamseged; Robinson, Tanisha M; Fahmi, Nour Eddine; Schmidtmann, Frank; Hecht, Sidney M; Bezrukov, Sergey M

2006-11-01

29

Protection against anthrax toxin by recombinant antibody fragments correlates with antigen affinity  

Microsoft Academic Search

The tripartite toxin produced by Bacillus anthracis is the key determinant in the etiology of anthrax. We have engineered a panel of toxin-neutralizing antibodies, including single-chain variable fragments (scFvs) and scFvs fused to a human constant ? domain (scAbs), that bind to the protective antigen subunit of the toxin with equilibrium dissociation constants (Kd) between 63 nM and 0.25 nM.

Jennifer A. Maynard; Catharina B. M. Maassen; Stephen H. Leppla; Kathleen Brasky; Jean L. Patterson; Brent L. Iverson; George Georgiou

2002-01-01

30

Anthrax Edema Toxin Modulates PKA and CREB-Dependent Signaling in Two Phases  

Microsoft Academic Search

BackgroundAnthrax edema toxin (EdTx) is an adenylate cyclase which operates in the perinuclear region of host cells. However, the action of EdTx is poorly understood, especially at molecular level. The ability of EdTx to modulate cAMP-dependent signaling was studied in Jurkat T cells and was compared with that of other cAMP-rising agents: Bordetella pertussis adenylate cyclase toxin, cholera toxin and

Andrea Puhar; Federica Dal Molin; Stéphanie Horvath; Daniel Ladants; Cesare Montecucco; Adam J. Ratner

2008-01-01

31

The Potential Contributions of Lethal and Edema Toxins to the Pathogenesis of Anthrax Associated Shock  

PubMed Central

Outbreaks of Bacillus anthracis in the US and Europe over the past 10 years have emphasized the health threat this lethal bacteria poses even for developed parts of the world. In contrast to cutaneous anthrax, inhalational disease in the US during the 2001 outbreaks and the newly identified injectional drug use form of disease in the UK and Germany have been associated with relatively high mortality rates. One notable aspect of these cases has been the difficulty in supporting patients once shock has developed. Anthrax bacilli produce several different components which likely contribute to this shock. Growing evidence indicates that both major anthrax toxins may produce substantial cardiovascular dysfunction. Lethal toxin (LT) can alter peripheral vascular function; it also has direct myocardial depressant effects. Edema toxin (ET) may have even more pronounced peripheral vascular effects than LT, including the ability to interfere with the actions of conventional vasopressors. Additionally, ET also appears capable of interfering with renal sodium and water retention. Importantly, the two toxins exert their actions via quite different mechanisms and therefore have the potential to worsen shock and outcome in an additive fashion. Finally, both toxins have the ability to inhibit host defense and microbial clearance, possibly contributing to the very high bacterial loads noted in patients dying with anthrax. This last point is clinically relevant since emerging data has begun to implicate other bacterial components such as anthrax cell wall in the shock and organ injury observed with infection. Taken together, accumulating evidence regarding the potential contribution of LT and ET to anthrax-associated shock supports efforts to develop adjunctive therapies that target both toxins in patients with progressive shock.

Hicks, Caitlin W.; Cui, Xizhong; Sweeney, Daniel A.; Li, Yan; Barochia, Amisha; Eichacker, Peter Q.

2011-01-01

32

New Developments in Vaccines, Inhibitors of Anthrax Toxins, and Antibiotic Therapeutics for Bacillus anthracis  

PubMed Central

Bacillus anthracis, the causative agent responsible for anthrax infections, poses a significant biodefense threat. There is a high mortality rate associated with untreated anthrax infections; specifically, inhalation anthrax is a particularly virulent form of infection with mortality rates close to 100%, even with aggressive treatment. Currently, a vaccine is not available to the general public and few antibiotics have been approved by the FDA for the treatment of inhalation anthrax. With the threat of natural or engineered bacterial resistance to antibiotics and the limited population for whom the current drugs are approved, there is a clear need for more effective treatments against this deadly infection. A comprehensive review of current research in drug discovery is presented in this article, including efforts to improve the purity and stability of vaccines, design inhibitors targeting the anthrax toxins, and identify inhibitors of novel enzyme targets. High resolution structural information for the anthrax toxins and several essential metabolic enzymes has played a significant role in aiding the structure-based design of potent and selective antibiotics.

Beierlein, J.M.; Anderson, A.C.

2013-01-01

33

New developments in vaccines, inhibitors of anthrax toxins, and antibiotic therapeutics for Bacillus anthracis.  

PubMed

Bacillus anthracis, the causative agent responsible for anthrax infections, poses a significant biodefense threat. There is a high mortality rate associated with untreated anthrax infections; specifically, inhalation anthrax is a particularly virulent form of infection with mortality rates close to 100%, even with aggressive treatment. Currently, a vaccine is not available to the general public and few antibiotics have been approved by the FDA for the treatment of inhalation anthrax. With the threat of natural or engineered bacterial resistance to antibiotics and the limited population for whom the current drugs are approved, there is a clear need for more effective treatments against this deadly infection. A comprehensive review of current research in drug discovery is presented in this article, including efforts to improve the purity and stability of vaccines, design inhibitors targeting the anthrax toxins, and identify inhibitors of novel enzyme targets. High resolution structural information for the anthrax toxins and several essential metabolic enzymes has played a significant role in aiding the structure-based design of potent and selective antibiotics. PMID:22050756

Beierlein, J M; Anderson, A C

2011-01-01

34

Certhrax Toxin, an Anthrax-related ADP-ribosyltransferase from Bacillus cereus*  

PubMed Central

We identified Certhrax, the first anthrax-like mART toxin from the pathogenic G9241 strain of Bacillus cereus. Certhrax shares 31% sequence identity with anthrax lethal factor from Bacillus anthracis; however, we have shown that the toxicity of Certhrax resides in the mART domain, whereas anthrax uses a metalloprotease mechanism. Like anthrax lethal factor, Certhrax was found to require protective antigen for host cell entry. This two-domain enzyme was shown to be 60-fold more toxic to mammalian cells than anthrax lethal factor. Certhrax localizes to distinct regions within mouse RAW264.7 cells by 10 min postinfection and is extranuclear in its cellular location. Substitution of catalytic residues shows that the mART function is responsible for the toxicity, and it binds NAD+ with high affinity (KD = 52.3 ± 12.2 ?m). We report the 2.2 ? Certhrax structure, highlighting its structural similarities and differences with anthrax lethal factor. We also determined the crystal structures of two good inhibitors (P6 (KD = 1.7 ± 0.2 ?m, Ki = 1.8 ± 0.4 ?m) and PJ34 (KD = 5.8 ± 2.6 ?m, Ki = 9.6 ± 0.3 ?m)) in complex with Certhrax. As with other toxins in this family, the phosphate-nicotinamide loop moves toward the NAD+ binding site with bound inhibitor. These results indicate that Certhrax may be important in the pathogenesis of B. cereus.

Visschedyk, Danielle; Rochon, Amanda; Tempel, Wolfram; Dimov, Svetoslav; Park, Hee-Won; Merrill, A. Rod

2012-01-01

35

[Anthrax].  

PubMed

Anthrax is a severe infectious disease by Bacillus anthracis. It can cause massacres among large herbivores, but means also a threat to humans. The latter develop mainly cutaneous anthrax, which they mostly survive. Inhalation can lead to more severe infections which, without medical intervention, are virtually always lethal. At the moment the disease draws much attention since it is thought to be a potential weapon in the hands of bioterrorists. PMID:12784517

Bol, P

2003-05-01

36

Cross-Reactivity of Anthrax and C2 Toxin: Protective Antigen Promotes the Uptake of Botulinum C2I Toxin into Human Endothelial Cells  

Microsoft Academic Search

Binary toxins are among the most potent bacterial protein toxins performing a cooperative mode of translocation and exhibit fatal enzymatic activities in eukaryotic cells. Anthrax and C2 toxin are the most prominent examples for the AB7\\/8 type of toxins. The B subunits bind both host cell receptors and the enzymatic A polypeptides to trigger their internalization and translocation into the

Angelika Kronhardt; Monica Rolando; Christoph Beitzinger; Caroline Stefani; Michael Leuber; Gilles Flatau; Michel R. Popoff; Roland Benz; Emmanuel Lemichez

2011-01-01

37

Computational studies on molecular interactions of 6-thioguanosine analogs with anthrax toxin receptor 1.  

PubMed

Dormant endospores of Bacillus anthracis are the causative agent of anthrax, which is an acute disease for both human and animals. Anthrax has been practised as biological weapon because of two attributes: i) short duration of spore germination, and ii) lethal toxaemia of the vegetative stage. Pathogenesis is caused by the activity of edema toxin and lethal toxin. Protective antigen (PA), is an essential component of both complexes, binds to Anthrax Toxin Receptor (ATR) and mediates the lethality in mammals. The combination of vaccine and antibiotics are preferred to be effective treatment for destruction of the vegetative cell wall but could not be a successive destructor for endospores. So the present study is intended to identify the small molecules as a potential inhibitor for ATR1. 3D structure of Anthrax Toxin Receptor 1 (ATR1) was built by using the crystal structure of Anthrax Toxin Receptor 2 (ATR2) from Homo sapiens as template. Molecular docking of 6-thiogunaosine (6-TG) analogs was performed on the ATR1 model and effective inhibitor was selected based on the docking results. The docking results showed that the three residues in the ATR1 binding pocket (Phe162, Asp160, and Phe22) were essential for making hydrogen bond with the 2-(2-bromo-6-chloro-4H-purin-9(5H)-yl)- 5-(hydroxymethyl) tetrahydrofuran-3,4-diol (C(11)H(13)N(3)O(5)). The data presented here strongly indicate that the interactions of these four residues are necessary for a stronger binding of the ATR1 with C(11)H(13)N(3)O(5). Also, the study proposed C(11)H(13)N(3)O(5) as an effective inhibitor by the comparison of docking energy. PMID:23292691

Singh, Nitin K; Pakkkianathan, Britto C; Kumar, Manish; Daddam, Jayssima R; Jayavel, Sridhar; Kannan, Mani; Pillai, Girinath G; Krishnan, Muthukalingan

2012-09-01

38

Anthrax Toxins Induce Shock in Rats by Depressed Cardiac Ventricular Function  

PubMed Central

Anthrax infections are frequently associated with severe and often irreversible hypotensive shock. The isolated toxic proteins of Bacillus anthracis produce a non-cytokine-mediated hypotension in rats by unknown mechanisms. These observations suggest the anthrax toxins have direct cardiovascular effects. Here, we characterize these effects. As a first step, we administered systemically anthrax lethal toxin (LeTx) and edema toxin (EdTx) to cohorts of three to twelve rats at different doses and determined the time of onset, degree of hypotension and mortality. We measured serum concentrations of the protective antigen (PA) toxin component at various time points after infusion. Peak serum levels of PA were in the µg/mL range with half-lives of 10–20 minutes. With doses that produced hypotension with delayed lethality, we then gave bolus intravenous infusions of toxins to groups of four to six instrumented rats and continuously monitored blood pressure by telemetry. Finally, the same doses used in the telemetry experiments were given to additional groups of four rats, and echocardiography was performed pretreatment and one, two, three and twenty-four hours post-treatment. LeTx and EdTx each produced hypotension. We observed a doubling of the velocity of propagation and 20% increases in left ventricular diastolic and systolic areas in LeTx-treated rats, but not in EdTx-treated rats. EdTx-but not LeTx-treated rats showed a significant increase in heart rate. These results indicate that LeTx reduced left ventricular systolic function and EdTx reduced preload. Uptake of toxins occurs readily into tissues with biological effects occurring within minutes to hours of serum toxin concentrations in the µg/mL range. LeTx and EdTx yield an irreversible shock with subsequent death. These findings should provide a basis for the rational design of drug interventions to reduce the dismal prognosis of systemic anthrax infections.

Watson, Linley E.; Kuo, Shu-ru; Katki, Khurshed; Dang, Tongyun; Park, Seong Kyu; Dostal, David E.; Tang, Wei-Jen; Leppla, Stephen H.; Frankel, Arthur E.

2007-01-01

39

A Human/Murine Chimeric Fab Antibody Neutralizes Anthrax Lethal Toxin In Vitro  

PubMed Central

Human anthrax infection caused by exposure to Bacillus anthracis cannot always be treated by antibiotics. This is mostly because of the effect of the remaining anthrax toxin in the body. Lethal factor (LF) is a component of lethal toxin (LeTx), which is the major virulence of anthrax toxin. A murine IgG monoclonal antibody (mAb) against LF with blocking activity (coded LF8) was produced in a previous study. In this report, a human/murine chimeric Fab mAb (coded LF8-Fab) was developed from LF8 by inserting murine variable regions into human constant regions using antibody engineering to reduce the incompatibility of the murine antibody for human use. The LF8-Fab expressed in Escherichia coli could specifically identify LF with an affinity of 3.46 × 107?L/mol and could neutralize LeTx with an EC50 of 85??g/mL. Even after LeTx challenge at various time points, the LF8-Fab demonstrated protection of J774A.1 cells in vitro. The results suggest that the LF8-Fab might be further characterized and potentially be used for clinical applications against anthrax infection.

Chen, Ximin; Zhu, Jin; Duesbery, Nicholas S.; Cheng, Xunjia; Cao, Brian

2013-01-01

40

Certhrax toxin, an anthrax-related ADP-ribosyltransferase from Bacillus cereus.  

PubMed

We identified Certhrax, the first anthrax-like mART toxin from the pathogenic G9241 strain of Bacillus cereus. Certhrax shares 31% sequence identity with anthrax lethal factor from Bacillus anthracis; however, we have shown that the toxicity of Certhrax resides in the mART domain, whereas anthrax uses a metalloprotease mechanism. Like anthrax lethal factor, Certhrax was found to require protective antigen for host cell entry. This two-domain enzyme was shown to be 60-fold more toxic to mammalian cells than anthrax lethal factor. Certhrax localizes to distinct regions within mouse RAW264.7 cells by 10 min postinfection and is extranuclear in its cellular location. Substitution of catalytic residues shows that the mART function is responsible for the toxicity, and it binds NAD(+) with high affinity (K(D) = 52.3 ± 12.2 ?M). We report the 2.2 ? Certhrax structure, highlighting its structural similarities and differences with anthrax lethal factor. We also determined the crystal structures of two good inhibitors (P6 (K(D) = 1.7 ± 0.2 ?M, K(i) = 1.8 ± 0.4 ?M) and PJ34 (K(D) = 5.8 ± 2.6 ?M, K(i) = 9.6 ± 0.3 ?M)) in complex with Certhrax. As with other toxins in this family, the phosphate-nicotinamide loop moves toward the NAD(+) binding site with bound inhibitor. These results indicate that Certhrax may be important in the pathogenesis of B. cereus. PMID:22992735

Visschedyk, Danielle; Rochon, Amanda; Tempel, Wolfram; Dimov, Svetoslav; Park, Hee-Won; Merrill, A Rod

2012-11-30

41

Toxin-Deficient Mutants of Bacillus anthracis Are Lethal in a Murine Model for Pulmonary Anthrax?  

PubMed Central

Bacillus anthracis, the etiologic agent of anthrax, produces at least three primary virulence factors: lethal toxin, edema toxin, and a capsule. The capsule is absolutely required for dissemination and lethality in a murine model of inhalation anthrax, yet the roles for the toxins during infection are ill-defined. We show in a murine model that when spores of specific toxin-null mutants are introduced into the lung, dissemination and lethality are comparable to those of the parent strain. Mutants lacking one or more of the structural genes for the toxin proteins, i.e., protective antigen, lethal factor, and edema factor, disseminated from the lung to the spleen at rates similar to that of the virulent parental strain. The 50% lethal dose (LD50) and mean time to death (MTD) of the mutants did not differ significantly from those of the parent. The LD50s or MTDs were also unaffected relative to those of the parent strain when mice were inoculated intravenously with vegetative cells. Nonetheless, histopathological examination of tissues revealed subtle but distinct differences in infections by the parent compared to some toxin mutants, suggesting that the host response is affected by toxin proteins synthesized during infection.

Heninger, Sara; Drysdale, Melissa; Lovchik, Julie; Hutt, Julie; Lipscomb, Mary F.; Koehler, Theresa M.; Lyons, C. Rick

2006-01-01

42

Anthrax Lethal Factor Cleaves Mouse Nlrp1b in Both Toxin-Sensitive and Toxin-Resistant Macrophages  

PubMed Central

Anthrax lethal factor (LF) is the protease component of anthrax lethal toxin (LT). LT induces pyroptosis in macrophages of certain inbred mouse and rat strains, while macrophages from other inbred strains are resistant to the toxin. In rats, the sensitivity of macrophages to toxin-induced cell death is determined by the presence of an LF cleavage sequence in the inflammasome sensor Nlrp1. LF cleaves rat Nlrp1 of toxin-sensitive macrophages, activating caspase-1 and inducing cell death. Toxin-resistant macrophages, however, express Nlrp1 proteins which do not harbor the LF cleavage site. We report here that mouse Nlrp1b proteins are also cleaved by LF. In contrast to the situation in rats, sensitivity and resistance of Balb/cJ and NOD/LtJ macrophages does not correlate to the susceptibility of their Nlrp1b proteins to cleavage by LF, as both proteins are cleaved. Two LF cleavage sites, at residues 38 and 44, were identified in mouse Nlrp1b. Our results suggest that the resistance of NOD/LtJ macrophages to LT, and the inability of the Nlrp1b protein expressed in these cells to be activated by the toxin are likely due to polymorphisms other than those at the LF cleavage sites.

Hellmich, Kristina A.; Levinsohn, Jonathan L.; Fattah, Rasem; Newman, Zachary L.; Maier, Nolan; Sastalla, Inka; Liu, Shihui; Leppla, Stephen H.; Moayeri, Mahtab

2012-01-01

43

Select human anthrax protective antigen epitope-specific antibodies provide protection from lethal toxin challenge.  

PubMed

Bacillus anthracis remains a serious bioterrorism concern, and the currently licensed vaccine remains an incomplete solution for population protection from inhalation anthrax and has been associated with concerns regarding efficacy and safety. Thus, understanding how to generate long-lasting protective immunity with reduced immunizations or provide protection through postexposure immunotherapeutics are long-sought goals. Through evaluation of a large military cohort, we characterized the levels of antibodies against protective antigen and found that over half of anthrax vaccinees had low serum levels of in vitro toxin neutralization capacity. Using solid-phase epitope mapping and confirmatory assays, we identified several neutralization-associated humoral epitopes and demonstrated that select antipeptide responses mediated protection in vitro. Finally, passively transferred antibodies specific for select epitopes provided protection in an in vivo lethal toxin mouse model. Identification of these antigenic regions has important implications for vaccine design and the development of directed immunotherapeutics. PMID:20533877

Crowe, Sherry R; Ash, Linda L; Engler, Renata J M; Ballard, Jimmy D; Harley, John B; Farris, A Darise; James, Judith A

2010-07-15

44

Cholera- and Anthrax-Like Toxins Are among Several New ADP-Ribosyltransferases  

PubMed Central

Chelt, a cholera-like toxin from Vibrio cholerae, and Certhrax, an anthrax-like toxin from Bacillus cereus, are among six new bacterial protein toxins we identified and characterized using in silico and cell-based techniques. We also uncovered medically relevant toxins from Mycobacterium avium and Enterococcus faecalis. We found agriculturally relevant toxins in Photorhabdus luminescens and Vibrio splendidus. These toxins belong to the ADP-ribosyltransferase family that has conserved structure despite low sequence identity. Therefore, our search for new toxins combined fold recognition with rules for filtering sequences – including a primary sequence pattern – to reduce reliance on sequence identity and identify toxins using structure. We used computers to build models and analyzed each new toxin to understand features including: structure, secretion, cell entry, activation, NAD+ substrate binding, intracellular target binding and the reaction mechanism. We confirmed activity using a yeast growth test. In this era where an expanding protein structure library complements abundant protein sequence data – and we need high-throughput validation – our approach provides insight into the newest toxin ADP-ribosyltransferases.

Fieldhouse, Robert J.; Turgeon, Zachari; White, Dawn; Merrill, A. Rod

2010-01-01

45

Cholera- and anthrax-like toxins are among several new ADP-ribosyltransferases.  

PubMed

Chelt, a cholera-like toxin from Vibrio cholerae, and Certhrax, an anthrax-like toxin from Bacillus cereus, are among six new bacterial protein toxins we identified and characterized using in silico and cell-based techniques. We also uncovered medically relevant toxins from Mycobacterium avium and Enterococcus faecalis. We found agriculturally relevant toxins in Photorhabdus luminescens and Vibrio splendidus. These toxins belong to the ADP-ribosyltransferase family that has conserved structure despite low sequence identity. Therefore, our search for new toxins combined fold recognition with rules for filtering sequences--including a primary sequence pattern--to reduce reliance on sequence identity and identify toxins using structure. We used computers to build models and analyzed each new toxin to understand features including: structure, secretion, cell entry, activation, NAD+ substrate binding, intracellular target binding and the reaction mechanism. We confirmed activity using a yeast growth test. In this era where an expanding protein structure library complements abundant protein sequence data--and we need high-throughput validation--our approach provides insight into the newest toxin ADP-ribosyltransferases. PMID:21170356

Fieldhouse, Robert J; Turgeon, Zachari; White, Dawn; Merrill, A Rod

2010-01-01

46

Anthrax Lethal Toxin Downregulates Claudin-5 Expression in Human Endothelial Tight Junctions  

PubMed Central

Vascular leakage pathologies such as pleural effusion and hemorrhage are hallmarks of anthrax pathogenesis. We previously reported that anthrax lethal toxin (LT), the major virulence factor of anthrax, reduces barrier function in cultured primary human microvascular endothelial cells. Here, we show that LT-induced barrier dysfunction is accompanied by the reduced expression of the endothelial tight junction (TJ) protein claudin-5 but no change in the expression of other TJ components occludin, ZO-1, ZO-2, or the adherens junction (AJ) protein VE-cadherin. The downregulation of claudin-5 correlated temporally and dose-dependently with the reduction of transendothelial electrical resistance. LT-induced loss of claudin-5 was independent of cell death and preceded the appearance of actin stress fibers and altered AJ morphology. Pharmacological inhibition of MEK-1/2, two kinases that are proteolytically inactivated by LT, showed a similar reduction in claudin-5 expression. We found that LT reduced claudin-5 mRNA levels but did not accelerate the rate of claudin-5 degradation. Mice challenged with LT also showed significant reduction in claudin-5 expression. Together, these findings support a possible role for LT disruption of endothelial TJs in the vascular leakage pathologies of anthrax.

D'Agnillo, Felice; Williams, Matthew C.; Moayeri, Mahtab; Warfel, Jason M.

2013-01-01

47

Cytolethal distending toxin B as a cell-killing component of tumor-targeted anthrax toxin fusion proteins  

PubMed Central

Cytolethal distending toxin (Cdt) is produced by Gram-negative bacteria of several species. It is composed of three subunits, CdtA, CdtB, and CdtC, with CdtB being the catalytic subunit. We fused CdtB from Haemophilus ducreyi to the N-terminal 255 amino acids of Bacillus anthracis toxin lethal factor (LFn) to design a novel, potentially potent antitumor drug. As a result of this fusion, CdtB was transported into the cytosol of targeted cells via the efficient delivery mechanism of anthrax toxin. The fusion protein efficiently killed various human tumor cell lines by first inducing a complete cell cycle arrest in the G2/M phase, followed by induction of apoptosis. The fusion protein showed very low toxicity in mouse experiments and impressive antitumor effects in a Lewis Lung carcinoma model, with a 90% cure rate. This study demonstrates that efficient drug delivery by a modified anthrax toxin system combined with the enzymatic activity of CdtB has great potential as anticancer treatment and should be considered for the development of novel anticancer drugs.

Bachran, C; Hasikova, R; Leysath, C E; Sastalla, I; Zhang, Y; Fattah, R J; Liu, S; Leppla, S H

2014-01-01

48

Assessment of Neutralising Activity of Colostrum-Derived, Polyclonal, Bovine Antibodies: Use of the J774A.1 Anthrax Lethal Toxin Cytototoxity Assay.  

National Technical Information Service (NTIS)

Bacillus anthracis lethal toxin is believed to play an important role in anthrax pathogenesis. Published reports have suggested that antibody therapies with specificity against lethal toxin may improve survival in animal models. Macrophage cell lines such...

A. K. Pickering M. R. Alderton

2005-01-01

49

Studies in Mice Reveal a Role for Anthrax Toxin Receptors in Matrix Metalloproteinase Function and Extracellular Matrix Homeostasis  

PubMed Central

The genes encoding Anthrax Toxin Receptors (ANTXRs) were originally identified based on expression in endothelial cells suggesting a role in angiogenesis. The focus of this review is to discuss what has been learned about the physiological roles of these receptors through evaluation of the Antxr knockout mouse phenotypes. Mice mutant in Antxr genes have defects in extracellular matrix homeostasis. We discuss how knowledge of physiological ANTXR function relates to what is already known about anthrax intoxication.

Reeves, Claire; Charles-Horvath, Pelisa; Kitajewski, Jan

2013-01-01

50

Efficient neutralization of anthrax toxin by chimpanzee monoclonal antibodies against protective antigen.  

PubMed

Four single-chain variable fragments (scFvs) against protective antigen (PA) and 2 scFvs against lethal factor (LF) of anthrax were isolated from a phage display library generated from immunized chimpanzees. Only 2 scFvs recognizing PA (W1 and W2) neutralized the cytotoxicity of lethal toxin in a macrophage lysis assay. Full-length immunoglobulin G (IgG) of W1 and W2 efficiently protected rats from anthrax toxin challenge. The epitope recognized by W1 and W2 was conformational and was formed by C-terminal amino acids 614-735 of PA. W1 and W2 each bound to PA with an equilibrium dissociation constant of 4x10-11 mol/L to 5x10(-11) mol/L, which is an affinity that is 20-100-fold higher than that for the interaction of the receptor and PA. W1 and W2 inhibited the binding of PA to the receptor, suggesting that this was the mechanism of protection. These data suggest that W1 and W2 chimpanzee monoclonal antibodies may serve as PA entry inhibitors for use in the emergency prophylaxis against and treatment of anthrax. PMID:16453257

Chen, Zhaochun; Moayeri, Mahtab; Zhou, Yi-Hua; Leppla, Stephen; Emerson, Suzanne; Sebrell, Andrew; Yu, Fujuan; Svitel, Juraj; Schuck, Peter; St Claire, Marisa; Purcell, Robert

2006-03-01

51

Anthrax toxin protective antigen--Insights into molecular switching from prepore to pore  

PubMed Central

The protective antigen is a key component of the anthrax toxin, as it allows entry of the enzymatic components edema factor and lethal factor into the host cell, through the formation of a membrane spanning pore. This event is absolutely critical for the pathogenesis of anthrax, and although we have yet to understand the mechanism of pore formation, recent developments have provided key insights into how this process may occur. Based on the available data, a model is proposed for the kinetic steps for protective antigen conversion from prepore to pore. In this model, the driving force for pore formation is the formation of the phi (?)-clamp, a region that forms a leak-free seal around the translocating polypeptide. Formation of the ?-clamp elicits movements within the prepore that provide steric freedom for the subsequent conformational changes required to form the membrane spanning pore.

Bann, James G

2012-01-01

52

Characterization of the Native Form of Anthrax Lethal Factor for Use in the Toxin Neutralization Assay  

PubMed Central

The cell-based anthrax toxin neutralization assay (TNA) is used to determine functional antibody titers of sera from animals and humans immunized with anthrax vaccines. The anthrax lethal toxin is a critical reagent of the TNA composed of protective antigen (PA) and lethal factor (LF), which are neutralization targets of serum antibodies. Cytotoxic potency of recombinant LF (rLF) lots can vary substantially, causing a challenge in producing a renewable supply of this reagent for validated TNAs. To address this issue, we characterized a more potent rLF variant (rLF-A) with the exact native LF amino acid sequence that lacks the additional N-terminal histidine and methionine residues present on the commonly used form of rLF (rLF-HMA) as a consequence of the expression vector. rLF-A can be used at 4 to 6 ng/ml (in contrast to 40 ng/ml rLF-HMA) with 50 ng/ml recombinant PA (rPA) to achieve 95 to 99% cytotoxicity. In the presence of 50 ng/ml rPA, both rLF-A and rLF-HMA allowed for similar potencies (50% effective dilution) among immune sera in the TNA. rPA, but not rLF, was the dominant factor in determining potency of serum samples containing anti-PA antibodies only or an excess of anti-PA relative to anti-rLF antibodies. Such anti-PA content is reflected in immune sera derived from most anthrax vaccines in development. These results support that 7- to 10-fold less rLF-A can be used in place of rLF-HMA without changing TNA serum dilution curve parameters, thus extending the use of a single rLF lot and a consistent, renewable supply.

Lu, Hang; Catania, Jason; Baranji, Katalin; Feng, Jie; Gu, Mili; Lathey, Janet; Sweeny, Diane; Sanford, Hannah; Sapru, Kavita; Patamawenu, Terry; Chen, June-Home; Ng, Alan; Fesseha, Zenbework; Kluepfel-Stahl, Stefanie; Minang, Jacob

2013-01-01

53

A Receptor-based Switch that Regulates Anthrax Toxin Pore Formation  

PubMed Central

Cellular receptors can act as molecular switches, regulating the sensitivity of microbial proteins to conformational changes that promote cellular entry. The activities of these receptor-based switches are only partially understood. In this paper, we sought to understand the mechanism that underlies the activity of the ANTXR2 anthrax toxin receptor-based switch that binds to domains 2 and 4 of the protective antigen (PA) toxin subunit. Receptor-binding restricts structural changes within the heptameric PA prepore that are required for pore conversion to an acidic endosomal compartment. The transfer cross-saturation (TCS) NMR approach was used to monitor changes in the heptameric PA-receptor contacts at different steps during prepore-to-pore conversion. These studies demonstrated that receptor contact with PA domain 2 is weakened prior to pore conversion, defining a novel intermediate in this pathway. Importantly, ANTXR2 remained bound to PA domain 4 following pore conversion, suggesting that the bound receptor might influence the structure and/or function of the newly formed pore. These studies provide new insights into the function of a receptor-based molecular switch that controls anthrax toxin entry into cells.

Pilpa, Rosemarie M.; Bayrhuber, Monika; Marlett, John M.; Riek, Roland; Young, John A. T.

2011-01-01

54

Designed Azolopyridinium Salts Block Protective Antigen Pores In Vitro and Protect Cells from Anthrax Toxin  

PubMed Central

Background Several intracellular acting bacterial protein toxins of the AB-type, which are known to enter cells by endocytosis, are shown to produce channels. This holds true for protective antigen (PA), the binding component of the tripartite anthrax-toxin of Bacillus anthracis. Evidence has been presented that translocation of the enzymatic components of anthrax-toxin across the endosomal membrane of target cells and channel formation by the heptameric/octameric PA63 binding/translocation component are related phenomena. Chloroquine and some 4-aminoquinolones, known as potent drugs against Plasmodium falciparium infection of humans, block efficiently the PA63-channel in a dose dependent way. Methodology/Principal Findings Here we demonstrate that related positively charged heterocyclic azolopyridinium salts block the PA63-channel in the µM range, when both, inhibitor and PA63 are added to the same side of the membrane, the cis-side, which corresponds to the lumen of acidified endosomal vesicles of target cells. Noise-analysis allowed the study of the kinetics of the plug formation by the heterocycles. In vivo experiments using J774A.1 macrophages demonstrated that the inhibitors of PA63-channel function also efficiently block intoxication of the cells by the combination lethal factor and PA63 in the same concentration range as they block the channels in vitro. Conclusions/Significance These results strongly argue in favor of a transport of lethal factor through the PA63-channel and suggest that the heterocycles used in this study could represent attractive candidates for development of novel therapeutic strategies against anthrax.

Duscha, Kerstin; Riedl, Zsuzsanna; Huber-Lang, Markus; Benz, Roland; Hajos, Gyorgy; Barth, Holger

2013-01-01

55

Role of macrophage oxidative burst in the action of anthrax lethal toxin.  

PubMed Central

BACKGROUND: Major symptoms and death from systemic Bacillus anthracis infections are mediated by the action of the pathogen's lethal toxin on host macrophages. High levels of the toxin are cytolytic to macrophages, whereas low levels stimulate these cells to produce cytokines (interleukin-1 beta and tumor necrosis factor-alpha), which induce systemic shock and death. MATERIALS AND METHODS: Experiments were performed to assess the possibility that the oxidative burst may be involved in one or both of lethal toxin's effects on macrophages. Toximediated cell lysis, superoxide anion and cytokine production were measured. Effects of antioxidants and macrophage mutations were examined. RESULTS: RAW264.7 murine macrophages treated with high levels of toxin released large amounts of superoxide anion, beginning at about 1 hr, which correlates with the onset of cytolysis. Cytolysis could be blocked with various exogenous antioxidants or with N-acetyl-L-cysteine and methionine, which promote production of the endogenous antioxidant, glutathione. Mutant murine macrophage lines deficient in production of reactive oxygen intermediates (ROIs) were relatively insensitive to the lytic effects of the toxin, whereas a line with increased oxidative burst potential showed elevated sensitivity. Also, cultured blood monocyte-derived macrophages from a patient with Chronic Granulomatous Disease, a disorder in which the phagocyte's oxidative burst is disabled, were totally resistant to toxin, in contrast to control monocytes. CONCLUSIONS: These results imply that the cytolytic effect of the toxin is mediated by ROIs. Additionally, cytokine production and consequent pathologies showed partial dependence on macrophage ROIs. Antioxidants moderately inhibited toxin-induced cytokine production in vitro, and BALB/c mice pretreated with N-acetyl-L-cysteine or mepacrine showed partial protection against lethal toxin. Thus ROIs are involved in both the cytolytic action of anthrax lethal toxin and the overall pathologic process in vivo.

Hanna, P. C.; Kruskal, B. A.; Ezekowitz, R. A.; Bloom, B. R.; Collier, R. J.

1994-01-01

56

Crystallographic studies of the anthrax lethal toxin. Final report, 1 July 1994-31 December 1996  

SciTech Connect

Protective Antigen (PA) is the central component of the three-part protein toxin secreted by Bacillus anthraces, the organism responsible for anthrax. Following proteolytic activation on the host cell surface, PA forms a membrane-inserting heptamer that translocates the toxic enzymes into the cytosol. We have solved the crystal structure of monomeric PA at 2.1 A resolution and the water-soluble heptamer at 4.5 A resolution. The monomer is organized mainly into antiparallel b-sheets and has four domains: an N-terminal domain containing two calcium ions; a heptamerization domain containing a large flexible loop implicated in membrane insertion; a small domain of unknown function; and a C-terminal receptor-binding domain. Removal of a 20 kDa fragment from the N-terminal domain permits assembly of the heptamer, a ring-shaped structure with a negatively charged lumen, and exposes a large hydrophobic surface for binding the toxic enzymes. We present a model of pH-dependent membrane insertion involving formation of a porin-like membrane-spanning b barrel. These studies greatly enhance current understanding of the mechanism of anthrax intoxication, and will be useful in the design of recombinant anthrax vaccines.

Frederick, C.A.

1997-01-01

57

Cross-Reactivity of Anthrax and C2 Toxin: Protective Antigen Promotes the Uptake of Botulinum C2I Toxin into Human Endothelial Cells  

PubMed Central

Binary toxins are among the most potent bacterial protein toxins performing a cooperative mode of translocation and exhibit fatal enzymatic activities in eukaryotic cells. Anthrax and C2 toxin are the most prominent examples for the AB7/8 type of toxins. The B subunits bind both host cell receptors and the enzymatic A polypeptides to trigger their internalization and translocation into the host cell cytosol. C2 toxin is composed of an actin ADP-ribosyltransferase (C2I) and C2II binding subunits. Anthrax toxin is composed of adenylate cyclase (EF) and MAPKK protease (LF) enzymatic components associated to protective antigen (PA) binding subunit. The binding and translocation components anthrax protective antigen (PA63) and C2II of C2 toxin share a sequence homology of about 35%, suggesting that they might substitute for each other. Here we show by conducting in vitro measurements that PA63 binds C2I and that C2II can bind both EF and LF. Anthrax edema factor (EF) and lethal factor (LF) have higher affinities to bind to channels formed by C2II than C2 toxin's C2I binds to anthrax protective antigen (PA63). Furthermore, we could demonstrate that PA in high concentration has the ability to transport the enzymatic moiety C2I into target cells, causing actin modification and cell rounding. In contrast, C2II does not show significant capacity to promote cell intoxication by EF and LF. Together, our data unveiled the remarkable flexibility of PA in promoting C2I heterologous polypeptide translocation into cells.

Beitzinger, Christoph; Stefani, Caroline; Leuber, Michael; Flatau, Gilles; Popoff, Michel R.; Benz, Roland; Lemichez, Emmanuel

2011-01-01

58

Structure-Activity Relationship of Semicarbazone EGA Furnishes Photoaffinity Inhibitors of Anthrax Toxin Cellular Entry.  

PubMed

EGA, 1, prevents the entry of multiple viruses and bacterial toxins into mammalian cells by inhibiting vesicular trafficking. The cellular target of 1 is unknown, and a structure-activity relationship study was conducted in order to develop a strategy for target identification. A compound with midnanomolar potency was identified (2), and three photoaffinity labels were synthesized (3-5). For this series, the expected photochemistry of the phenyl azide moiety is a more important factor than the IC50 of the photoprobe in obtaining a successful photolabeling event. While 3 was the most effective reversible inhibitor of the series, it provided no protection to cells against anthrax lethal toxin (LT) following UV irradiation. Conversely, 5, which possessed weak bioactivity in the standard assay, conferred robust irreversible protection vs LT to cells upon UV photolysis. PMID:24900841

Jung, Michael E; Chamberlain, Brian T; Ho, Chi-Lee C; Gillespie, Eugene J; Bradley, Kenneth A

2014-04-10

59

Engineering Anthrax Toxin Variants That Exclusively Form Octamers and Their Application to Targeting Tumors*  

PubMed Central

Anthrax toxin protective antigen (PA) delivers its effector proteins into the host cell cytosol through formation of an oligomeric pore, which can assume heptameric or octameric states. By screening a highly directed library of PA mutants, we identified variants that complement each other to exclusively form octamers. These PA variants were individually nontoxic and demonstrated toxicity only when combined with their complementary partner. We then engineered requirements for activation by matrix metalloproteases and urokinase plasminogen activator into two of these variants. The resulting therapeutic toxin specifically targeted cells expressing both tumor associated proteases and completely stopped tumor growth in mice when used at a dose far below that which caused toxicity. This scheme for obtaining intercomplementing subunits can be employed with other oligomeric proteins and potentially has wide application.

Phillips, Damilola D.; Fattah, Rasem J.; Crown, Devorah; Zhang, Yi; Liu, Shihui; Moayeri, Mahtab; Fischer, Elizabeth R.; Hansen, Bryan T.; Ghirlando, Rodolfo; Nestorovich, Ekaterina M.; Wein, Alexander N.; Simons, Lacy; Leppla, Stephen H.; Leysath, Clinton E.

2013-01-01

60

Anthrax Lethal Toxin-Induced Gene Expression Changes in Mouse Lung  

PubMed Central

A major virulence factor of Bacillus anthracis is the anthrax Lethal Toxin (LeTx), a bipartite toxin composed of Protective Antigen and Lethal Factor. Systemic administration of LeTx to laboratory animals leads to death associated with vascular leakage and pulmonary edema. In this study, we investigated whether systemic exposure of mice to LeTx would induce gene expression changes associated with vascular/capillary leakage in lung tissue. We observed enhanced susceptibility of A/J mice to death by systemic LeTx administration compared to the C57BL/6 strain. LeTx-induced groups of both up- and down-regulated genes were observed in mouse lungs 6 h after systemic administration of wild type toxin compared to lungs of mice exposed to an inactive mutant form of the toxin. Lungs of the less susceptible C57BL/6 strain showed 80% fewer differentially expressed genes compared to lungs of the more sensitive A/J strain. Expression of genes known to regulate vascular permeability was modulated by LeTx in the lungs of the more susceptible A/J strain. Unexpectedly, the largest set of genes with altered expression was immune specific, characterized by the up-regulation of lymphoid genes and the down-regulation of myeloid genes. Transcripts encoding neutrophil chemoattractants, modulators of tumor regulation and angiogenesis were also differentially expressed in both mouse strains. These studies provide new directions for the investigation of vascular leakage and pulmonary edema induced by anthrax LeTx.

Dumas, Eric K.; Cox, Philip M.; Fullenwider, Charles O'Connor; Nguyen, Melissa; Centola, Michael; Frank, Mark Barton; Dozmorov, Igor; James, Judith A.; Farris, A. Darise

2011-01-01

61

Anthrax vaccines.  

PubMed

Anthrax, an uncommon disease in humans, is caused by a large bacterium, Bacillus anthracis. The risk of inhalation infection is the main indication for anthrax vaccination. Pre-exposure vaccination is provided by an acellular vaccine (anthrax vaccine adsorbed or AVA), which contains anthrax toxin elements and results in protective immunity after 3 to 6 doses. Anthrax vaccine precipitated (AVP) is administered at primovaccination in 3 doses with a booster dose after 6 months. To evoke and maintain protective immunity, it is necessary to administer a booster dose once at 12 months. In Russia, live spore vaccine (STI) has been used in a two-dose schedule. Current anthrax vaccines show considerable local and general reactogenicity (erythema, induration, soreness, fever). Serious adverse reactions occur in about 1% of vaccinations. New second-generation vaccines in current research programs include recombinant live vaccines and recombinant sub-unit vaccines. PMID:15977694

Splino, Miroslav; Patocka, Jiri; Prymula, Roman; Chlibek, Roman

2005-01-01

62

Hijacking multivesicular bodies enables long-term and exosome-mediated long-distance action of anthrax toxin  

PubMed Central

SUMMARY Anthrax Lethal Toxin is a classical AB-toxin comprised of two components, Protective Antigen (PA) and Lethal Factor (LF). Here we show that following assembly and endocytosis, PA forms a channel that translocates LF, not only into the cytosol, but also into the lumen of endosomal intraluminal vesicles (ILVs). These ILVs can fuse and release LF into the cytosol, where LF can proteolyze and disable host targets. We find that LF can persist in ILVs for days, fully sheltered from proteolytic degradation, both in vitro and in vivo. During this time ILV-localized LF can be transmitted to daughter cells upon cell division. In addition, LF-containing ILVs can be delivered to the extracellular medium as exosomes. These can deliver LF to the cytosol of naïve cells in a manner that is independent of the typical anthrax toxin-receptor trafficking pathway, while being sheltered from neutralizing extracellular factors of the immune system.

Abrami, Laurence; Brandi, Lucia; Moayeri, Mahtab; Brown, Michael J.; Krantz, Bryan A.; Leppla, Stephen H.; van der Goot, F. G.

2013-01-01

63

Toll-like receptor 4 knockout protects against anthrax lethal toxin-induced cardiac contractile dysfunction: role of autophagy  

PubMed Central

BACKGROUND AND PURPOSE Anthrax lethal toxin (LeTx) is known to induce circulatory shock and death, although the underlying mechanisms have not been elucidated. This study was designed to evaluate the role of toll-like receptor 4 (TLR4) in anthrax lethal toxin-induced cardiac contractile dysfunction. EXPERIMENTAL APPROACH Wild-type (WT) and TLR4 knockout (TLR?/?) mice were challenged with lethal toxin (2 µg·g?1, i.p.), and cardiac function was assessed 18 h later using echocardiography and edge detection. Small interfering RNA (siRNA) was employed to knockdown TLR4 receptor or class III PI3K in H9C2 myoblasts. GFP–LC3 puncta was used to assess autophagosome formation. Western blot analysis was performed to evaluate autophagy (LC3, Becline-1, Agt5 and Agt7) and endoplasmic reticulum (ER) stress (BiP, eIF2? and calreticulin). KEY RESULTS In WT mice, lethal toxin exposure induced cardiac contractile dysfunction, as evidenced by reduced fractional shortening, peak shortening, maximal velocity of shortening/re-lengthening, prolonged re-lengthening duration and intracellular Ca2+ derangement. These effects were significantly attenuated or absent in the TLR4 knockout mice. In addition, lethal toxin elicited autophagy in the absence of change in ER stress. Knockdown of TLR4 or class III PI3 kinase using siRNA but not the autophagy inhibitor 3-methyladenine significantly attenuated or inhibited lethal toxin-induced autophagy in H9C2 cells. CONCLUSION AND IMPLICATIONS Our results suggest that TLR4 may be pivotal in mediating the lethal cardiac toxicity induced by anthrax possibly through induction of autophagy. These findings suggest that compounds that negatively modulate TLR4 signalling and autophagy could be used to treat anthrax infection-induced cardiovascular complications.

Kandadi, Machender R; Frankel, Arthur E; Ren, Jun

2012-01-01

64

A model of anthrax toxin lethal factor bound to protective antigen  

PubMed Central

Anthrax toxin is made up of three proteins: the edema factor (EF), lethal factor (LF) enzymes, and the multifunctional protective antigen (PA). Proteolytically activated PA heptamerizes, binds the EF/LF enzymes, and forms a pore that allows for EF/LF passage into host cells. Using directed mutagenesis, we identified three LF-PA contact points defined by a specific disulfide crosslink and two pairs of complementary charge-reversal mutations. These contact points were consistent with the lowest energy LF-PA complex found by using Rosetta protein-protein docking. These results illustrate how biochemical and computational methods can be combined to produce reliable models of large complexes. The model shows that EF and LF bind through a highly electrostatic interface, with their flexible N-terminal region positioned at the entrance of the heptameric PA pore and thus poised to initiate translocation in an N- to C-terminal direction.

Lacy, D. Borden; Lin, Henry C.; Melnyk, Roman A.; Schueler-Furman, Ora; Reither, Laura; Cunningham, Kristina; Baker, David; Collier, R. John

2005-01-01

65

Anthrax toxin protective antigen: low-pH-induced hydrophobicity and channel formation in liposomes.  

PubMed

To probe the role of the protective antigen (PA) component of anthrax toxin in toxin entry into animals cells, we examined the membrane channel-forming properties and hydrophobicity of intact and trypsin-cleaved forms of the protein at various pH values. At neutral pH neither form caused release of entrapped K+ from unilamellar lipid vesicles. At pH values below 6.0, however, K+ was rapidly released upon addition of either the nicked PA (PAN) or the 63 kDa tryptic fragment of PA (PA63), which has been implicated in the toxin entry process. Under the same conditions intact PA exhibited only weak channel-forming activity, and PA20, the complementary tryptic fragment, showed no such activity. Both PA and PA63 exhibited enhanced hydrophobicity at acidic pH values, but the enhancement was greater and the pH threshold higher with PA63. Our findings indicate that proteolytic removal of PA20 from intact PA enables the residual protein, PA63, to adopt a conformation at mildly acidic pH values that permits it to insert readily and form channels in membranes. Thus acidic conditions within endocytic vesicles may trigger membrane insertion of PA63, which in turn promotes translocation of ligated effector moieties, edema factor or lethal factor, across the vesicle membrane into the cytosol. PMID:1787799

Koehler, T M; Collier, R J

1991-06-01

66

Expression of either Lethal Toxin or Edema Toxin by Bacillus anthracis Is Sufficient for Virulence in a Rabbit Model of Inhalational Anthrax  

PubMed Central

The development of therapeutics against biothreats requires that we understand the pathogenesis of the disease in relevant animal models. The rabbit model of inhalational anthrax is an important tool in the assessment of potential therapeutics against Bacillus anthracis. We investigated the roles of B. anthracis capsule and toxins in the pathogenesis of inhalational anthrax in rabbits by comparing infection with the Ames strain versus isogenic mutants with deletions of the genes for the capsule operon (capBCADE), lethal factor (lef), edema factor (cya), or protective antigen (pagA). The absence of capsule or protective antigen (PA) resulted in complete avirulence, while the presence of either edema toxin or lethal toxin plus capsule resulted in lethality. The absence of toxin did not influence the ability of B. anthracis to traffic to draining lymph nodes, but systemic dissemination required the presence of at least one of the toxins. Histopathology studies demonstrated minimal differences among lethal wild-type and single toxin mutant strains. When rabbits were coinfected with the Ames strain and the PA? mutant strain, the toxin produced by the Ames strain was not able to promote dissemination of the PA? mutant, suggesting that toxigenic action occurs in close proximity to secreting bacteria. Taken together, these findings suggest that a major role for toxins in the pathogenesis of anthrax is to enable the organism to overcome innate host effector mechanisms locally and that much of the damage during the later stages of infection is due to the interactions of the host with the massive bacterial burden.

Drysdale, Melissa; Koehler, Theresa M.; Hutt, Julie A.; Lyons, C. Rick

2012-01-01

67

Cathepsin B-mediated Autophagy Flux Facilitates the Anthrax Toxin Receptor 2-mediated Delivery of Anthrax Lethal Factor into the Cytoplasm*  

PubMed Central

Anthrax lethal toxin (LeTx) is a virulence factor secreted by Bacillus anthracis and has direct cytotoxic effects on most cells once released into the cytoplasm. The cytoplasmic delivery of the proteolytically active component of LeTx, lethal factor (LF), is carried out by the transporter component, protective antigen, which interacts with either of two known surface receptors known as anthrax toxin receptor (ANTXR) 1 and 2. We found that the cytoplasmic delivery of LF by ANTXR2 was mediated by cathepsin B (CTSB) and required lysosomal fusion with LeTx-containing endosomes. Also, binding of protective antigen to ANXTR1 or -2 triggered autophagy, which facilitated the cytoplasmic delivery of ANTXR2-associated LF. We found that whereas cells treated with the membrane-permeable CTSB inhibitor CA074-Me- or CTSB-deficient cells had no defect in fusion of LC3-containing autophagic vacuoles with lysosomes, autophagic flux was significantly delayed. These results suggested that the ANTXR2-mediated cytoplasmic delivery of LF was enhanced by CTSB-dependent autophagic flux.

Ha, Soon-Duck; Ham, Boram; Mogridge, Jeremy; Saftig, Paul; Lin, Shengcai; Kim, Sung Ouk

2010-01-01

68

CCT chaperonin complex is required for efficient delivery of anthrax toxin into the cytosol of host cells  

PubMed Central

Bacterial toxins have evolved successful strategies for coopting host proteins to access the cytosol of host cells. Anthrax lethal factor (LF) enters the cytosol through pores in the endosomal membrane formed by anthrax protective antigen. Although in vitro models using planar lipid bilayers have shown that translocation can occur in the absence of cellular factors, recent studies using intact endosomes indicate that host factors are required for translocation in the cellular environment. In this study, we describe a high-throughput shRNA screen to identify host factors required for anthrax lethal toxin-induced cell death. The cytosolic chaperonin complex chaperonin containing t-complex protein 1 (CCT) was identified, and subsequent studies showed that CCT is required for efficient delivery of LF and related fusion proteins into the cytosol. We further show that knockdown of CCT inhibits the acid-induced delivery of LF and the fusion protein LFN-Bla (N terminal domain of LF fused to ?-lactamase) across the plasma membrane of intact cells. Together, these results suggest that CCT is required for efficient delivery of enzymatically active toxin to the cytosol and are consistent with a direct role for CCT in translocation of LF through the protective antigen pore.

Slater, Louise H.; Hett, Erik C.; Clatworthy, Anne E.; Mark, Kevin G.; Hung, Deborah T.

2013-01-01

69

Anthrax Lethal Toxin and the Induction of CD4 T Cell Immunity  

PubMed Central

Bacillus anthracis secretes exotoxins which act through several mechanisms including those that can subvert adaptive immunity with respect both to antigen presenting cell and T cell function. The combination of Protective Antigen (PA) and Lethal Factor (LF) forming Lethal Toxin (LT), acts within host cells to down-regulate the mitogen activated protein kinase (MAPK) signaling cascade. Until recently the MAPK kinases were the only known substrate for LT; over the past few years it has become evident that LT also cleaves Nlrp1, leading to inflammasome activation and macrophage death. The predicted downstream consequences of subverting these important cellular pathways are impaired antigen presentation and adaptive immunity. In contrast to this, recent work has indicated that robust memory T cell responses to B. anthracis antigens can be identified following natural anthrax infection. We discuss how LT affects the adaptive immune response and specifically the identification of B. anthracis epitopes that are both immunogenic and protective with the potential for inclusion in protein sub-unit based vaccines.

Ascough, Stephanie; Ingram, Rebecca J.; Altmann, Daniel M.

2012-01-01

70

Solubilization and characterization of the anthrax toxin pore in detergent micelles  

PubMed Central

Proteolytically activated Protective Antigen (PA) moiety of anthrax toxin self-associates to form a heptameric ring-shaped oligomer (the prepore). Acidic pH within the endosome converts the prepore to a pore that serves as a passageway for the toxin's enzymatic moieties to cross the endosomal membrane. Prepore is stable in solution under mildly basic conditions, and lowering the pH promotes a conformational transition to an insoluble pore-like state. N-tetradecylphosphocholine (FOS14) was the only detergent among 110 tested that prevented aggregation without dissociating the multimer into its constituent subunits. FOS14 maintained the heptamers as monodisperse, insertion-competent 440-kDa particles, which formed channels in planar phospholipid bilayers with the same unitary conductance and ability to translocate a model substrate protein as channels formed in the absence of detergent. Electron paramagnetic resonance analysis detected pore-like conformational changes within PA on solubilization with FOS14, and electron micrograph images of FOS14-solubilized pore showed an extended, mushroom-shaped structure. Circular dichroïsm measurements revealed an increase in ? helix and a decrease in ? structure in pore formation. Spectral changes caused by a deletion mutation support the hypothesis that the 2?2-2?3 loop transforms into the transmembrane segment of the ?-barrel stem of the pore. Changes caused by selected point mutations indicate that the transition to ? structure is dependent on residues of the luminal 2?11-2?12 loop that are known to affect pore formation. Stabilizing the PA pore in solution with FOS14 may facilitate further structural analysis and a more detailed understanding of the folding pathway by which the pore is formed.

Vernier, Gregory; Wang, Jie; Jennings, Laura D; Sun, Jianjun; Fischer, Audrey; Song, Likai; Collier, R John

2009-01-01

71

Potent neutralization of anthrax edema toxin by a humanized monoclonal antibody that competes with calmodulin for edema factor binding.  

PubMed

This study describes the isolation and characterization of a neutralizing monoclonal antibody (mAb) against anthrax edema factor, EF13D. EF13D neutralized edema toxin (ET)-mediated cyclic AMP (cAMP) responses in cells and protected mice from both ET-induced footpad edema and systemic ET-mediated lethality. The antibody epitope was mapped to domain IV of EF. The mAb was able to compete with calmodulin (CaM) for EF binding and displaced CaM from EF-CaM complexes. EF-mAb binding affinity (0.05-0.12 nM) was 50- to 130-fold higher than that reported for EF-CaM. This anti-EF neutralizing mAb could potentially be used alone or with an anti-PA mAb in the emergency prophylaxis and treatment of anthrax infection. PMID:19651602

Chen, Zhaochun; Moayeri, Mahtab; Zhao, Huaying; Crown, Devorah; Leppla, Stephen H; Purcell, Robert H

2009-08-11

72

Identification of Novel Host-Targeted Compounds That Protect From Anthrax Lethal Toxin-Induced Cell Death  

PubMed Central

Studying how pathogens subvert the host to cause disease has contributed to the understanding of fundamental cell biology. Bacillus anthracis, the causative agent of anthrax, produces the virulence factor lethal toxin to disarm host immunity and cause pathology. We conducted a phenotypic small molecule screen to identify inhibitors of lethal toxin-induced macrophage cell death and used an ordered series of secondary assays to characterize the hits and determine their effects on cellular function. We identified a structurally diverse set of small molecules that act at various points along the lethal toxin pathway, including inhibitors of endocytosis; natural product inhibitors of organelle acidification (e.g. the botulinum neurotoxin inhibitor, toosendanin); and a novel proteasome inhibitor, 4MNB (4-methoxy-2-[2-(5-methoxy-2-nitrosophenyl)ethyl]-1-nitrosobenzene). Many of the compounds, including three drugs approved for use in humans, also protected against the related Clostridium difficile toxin TcdB, further demonstrating their value as novel tools for perturbation and study of toxin biology and host cellular processes, and highlighting potential new strategies for intervening on toxin-mediated diseases.

Slater, Louise H.; Hett, Erik C.; Mark, Kevin; Chumbler, Nicole M.; Patel, Deepa; Lacy, D. Borden; Collier, R. John; Hung, Deborah T.

2013-01-01

73

Rabbit and Nonhuman Primate Models of Toxin-Targeting Human Anthrax Vaccines  

PubMed Central

The intentional use of Bacillus anthracis, the etiological agent of anthrax, as a bioterrorist weapon in late 2001 made our society acutely aware of the importance of developing, testing, and stockpiling adequate countermeasures against biological attacks. Biodefense vaccines are an important component of our arsenal to be used during a biological attack. However, most of the agents considered significant threats either have been eradicated or rarely infect humans alive today. As such, vaccine efficacy cannot be determined in human clinical trials but must be extrapolated from experimental animal models. This article reviews the efficacy and immunogenicity of human anthrax vaccines in well-defined animal models and the progress toward developing a rugged immunologic correlate of protection. The ongoing evaluation of human anthrax vaccines will be dependent on animal efficacy data in the absence of human efficacy data for licensure by the U.S. Food and Drug Administration.

Phipps, Andrew J.; Premanandan, Christopher; Barnewall, Roy E.; Lairmore, Michael D.

2004-01-01

74

Tumor therapy with a urokinase plasminogen activator-activated anthrax lethal toxin alone and in combination with paclitaxel.  

PubMed

PA-U2, an engineered anthrax protective antigen that is activated by urokinase was combined with wildtype lethal factor in the treatment of Colo205 colon adenocarcinoma in vitro and B16-BL6 mouse melanoma in vitro and in vivo. This therapy was also tested in combination with the small molecule paclitaxel, based on prior reports suggesting synergy between ERK1/2 inhibition and chemotherapeutics. Colo205 was sensitive to PA-U2/LF while B16-BL6 was not. For the combination treatment of B16-BL6, paclitaxel showed a dose response in vitro, but cells remained resistant to PA-U2/LF even in the presence of paclitaxel. In vivo, each therapy slowed tumor progression, and an additive effect between the two was observed. Since LF targets tumor vasculature while paclitaxel is an antimitotic, it is possible the agents were acting against different cells in the stroma, precluding a synergistic effect. The engineered anthrax toxin PA-U2/LF warrants further development and testing, possibly in combination with an antiangiogenesis therapy such as sunitinib or sorafinib. PMID:22843210

Wein, Alexander N; Liu, Shihui; Zhang, Yi; McKenzie, Andrew T; Leppla, Stephen H

2013-02-01

75

Assembly of anthrax toxin pore: Lethal-factor complexes into lipid nanodiscs  

PubMed Central

We have devised a procedure to incorporate the anthrax protective antigen (PA) pore complexed with the N-terminal domain of anthrax lethal factor (LFN) into lipid nanodiscs and analyzed the resulting complexes by negative-stain electron microscopy. Insertion into nanodiscs was performed without relying on primary and secondary detergent screens. The preparations were relatively pure, and the percentage of PA pore inserted into nanodiscs on EM grids was high (?43%). Three-dimensional analysis of negatively stained single particles revealed the LFN-PA nanodisc complex mirroring the previous unliganded PA pore nanodisc structure, but with additional protein density consistent with multiple bound LFN molecules on the PA cap region. The assembly procedure will facilitate collection of higher resolution cryo-EM LFN-PA nanodisc structures and use of advanced automated particle selection methods.

Akkaladevi, N; Hinton-Chollet, L; Katayama, H; Mitchell, J; Szerszen, L; Mukherjee, S; Gogol, E P; Pentelute, B L; Collier, R J; Fisher, M T

2013-01-01

76

The Heart Is an Early Target of Anthrax Lethal Toxin in Mice: A Protective Role for Neuronal Nitric Oxide Synthase (nNOS)  

Microsoft Academic Search

Anthrax lethal toxin (LT) induces vascular insufficiency in experimental animals through unknown mechanisms. In this study, we show that neuronal nitric oxide synthase (nNOS) deficiency in mice causes strikingly increased sensitivity to LT, while deficiencies in the two other NOS enzymes (iNOS and eNOS) have no effect on LT-mediated mortality. The increased sensitivity of nNOS?\\/? mice was independent of macrophage

Mahtab Moayeri; Devorah Crown; David W. Dorward; Don Gardner; Jerrold M. Ward; Yan Li; Xizhong Cui; Peter Eichacker; Stephen H. Leppla

2009-01-01

77

Comparability of ELISA and toxin neutralization to measure immunogenicity of Protective Antigen in mice, as part of a potency test for anthrax vaccines.  

PubMed

Complexities of lethal challenge models have prompted the investigation of immunogenicity assays as potency tests of anthrax vaccines. An ELISA and a lethal toxin neutralization assay (TNA) were used to measure antibody response to Protective Antigen (PA) in mice immunized once with either a commercial or a recombinant PA (rPA) vaccine formulated in-house. Even though ELISA and TNA results showed correlation, ELISA results may not be able to accurately predict TNA results in this single immunization model. PMID:19501205

Parreiras, P M; Sirota, L A; Wagner, L D; Menzies, S L; Arciniega, J L

2009-07-16

78

Anthrax Toxin Receptor 1 / Tumor Endothelial Marker 8: Mutation of Conserved Inserted Domain Residues Overrides Cytosolic Control of Protective Antigen Binding†  

PubMed Central

Anthrax toxin receptor 1 (ANTXR1) / tumor endothelial marker 8 (TEM8) is one of two known proteinaceous cell surface anthrax toxin receptors. A metal ion dependent adhesion site (MIDAS) present in the integrin-like inserted (I) domain of ANTXR1 mediates the binding of the anthrax toxin subunit, protective antigen (PA). Here we provide evidence that single point mutations in the I domain can override regulation of ANTXR1 ligand-binding activity mediated by intracellular signals. A previously reported MIDAS-mutant of ANTXR1 (T118A) was found to retain normal metal ion binding and secondary structure but failed to bind PA, consistent with a locked inactive state. Conversely, mutation of a conserved I domain phenylalanine residue to a tryptophan (F205W) increased the proportion of cell-surface ANTXR1 that bound PA, consistent with a locked active state. Interestingly, the KD and total amount of PA bound by the isolated ANTXR1 I domain was not affected by the F205W mutation, indicating that ANTXR1 is preferentially found in the active state in the absence of inside-out signaling. Circular dichroism (CD) spectroscopy and 1H-15N heteronuclear single quantum coherence (HSQC) nuclear magnetic resonance (NMR) revealed that structural changes between T118A, F205W and WT I domains were minor despite a greater than 103-fold difference in their abilities to bind toxin. Regulation of toxin binding has important implications for the design of toxin inhibitors and for the targeting of ANTXR1 for anti-tumor therapies.

Ramey, Jordan D.; Villareal, Valerie A.; Ng, Charles; Ward, Sabrina; Xiong, Jian-Ping; Clubb, Robert T.; Bradley, Kenneth A.

2010-01-01

79

Three dimensional structure of the anthrax toxin translocon-lethal factor complex by cryo-electron microscopy  

PubMed Central

We have visualized by cryo-electron microscopy (cryo-EM) the complex of the anthrax protective antigen (PA) translocon and the N-terminal domain of anthrax lethal factor (LFN) inserted into a nanodisc model lipid bilayer. We have determined the structure of this complex at a nominal resolution of 16 Å by single-particle analysis and three-dimensional reconstruction. Consistent with our previous analysis of negatively stained unliganded PA, the translocon comprises a globular structure (cap) separated from the nanodisc bilayer by a narrow stalk that terminates in a transmembrane channel (incompletely distinguished in this reconstruction). The globular cap is larger than the unliganded PA pore, probably due to distortions introduced in the previous negatively stained structures. The cap exhibits larger, more distinct radial protrusions, previously identified with PA domain three, fitted by elements of the NMFF PA prepore crystal structure. The presence of LFN, though not distinguished due to the seven-fold averaging used in the reconstruction, contributes to the distinct protrusions on the cap rim volume distal to the membrane. Furthermore, the lumen of the cap region is less resolved than the unliganded negatively stained PA, due to the low contrast obtained in our images of this specimen. Presence of the LFN extended helix and N terminal unstructured regions may also contribute to this additional internal density within the interior of the cap. Initial NMFF fitting of the cryoEM-defined PA pore cap region positions the Phe clamp region of the PA pore translocon directly above an internal vestibule, consistent with its role in toxin translocation.

Gogol, E P; Akkaladevi, N; Szerszen, L; Mukherjee, S; Chollet-Hinton, L; Katayama, H; Pentelute, B L; Collier, R J; Fisher, M T

2013-01-01

80

Biophysical characterization and immunization studies of dominant negative inhibitor (DNI), a candidate anthrax toxin subunit vaccine.  

PubMed

Dominant Negative Inhibitor (DNI) is a translocation-deficient homolog of recombinant protective antigen of Bacillus anthracis that is a candidate for a next generation anthrax vaccine. This study demonstrates that the biophysical characteristics of the DNI protein stored in lyophilized form at 4°C for 8 y were similar to recombinant Protective Antigen (rPA). To provide information on the accelerated stability of DNI, samples in the lyophilized form were subjected to thermal stress (40°C and 70°C for up to 4 weeks) and thoroughly evaluated using various biophysical and chemical characterization techniques. Results demonstrate preserved structural stability of the DNI protein under extreme conditions, suggesting long-term stability can be achieved for a vaccine that employs DNI, as desired for a biodefense countermeasure. Furthermore, the biological activity of the stressed DNI bound to the adjuvant Alhydrogel (®) was evaluated in mice and it was found that the immunogenicity DNI was not affected by thermal stress. PMID:23925275

Iyer, Vidyashankara; Hu, Lei; Schanté, Carole E; Vance, David; Chadwick, Chrystal; Jain, Nishant Kumar; Brey, Robert N; Joshi, Sangeeta B; Volkin, David B; Andra, Kiran K; Bann, James G; Mantis, Nicholas J; Middaugh, C Russell

2013-11-01

81

Hyaline Fibromatosis Syndrome inducing mutations in the ectodomain of anthrax toxin receptor 2 can be rescued by proteasome inhibitors  

PubMed Central

Hyaline Fibromatosis Syndrome (HFS) is a human genetic disease caused by mutations in the anthrax toxin receptor 2 (or cmg2) gene, which encodes a membrane protein thought to be involved in the homeostasis of the extracellular matrix. Little is known about the structure and function of the protein or the genotype–phenotype relationship of the disease. Through the analysis of four patients, we identify three novel mutants and determine their effects at the cellular level. Altogether, we show that missense mutations that map to the extracellular von Willebrand domain or the here characterized Ig-like domain of CMG2 lead to folding defects and thereby to retention of the mutated protein in the endoplasmic reticulum (ER). Mutations in the Ig-like domain prevent proper disulphide bond formation and are more efficiently targeted to ER-associated degradation. Finally, we show that mutant CMG2 can be rescued in fibroblasts of some patients by treatment with proteasome inhibitors and that CMG2 is then properly transported to the plasma membrane and signalling competent, identifying the ER folding and degradation pathway components as promising drug targets for HFS.

Deuquet, Julie; Lausch, Ekkehart; Guex, Nicolas; Abrami, Laurence; Salvi, Suzanne; Lakkaraju, Asvin; Ramirez, Maria Celeste M; Martignetti, John A; Rokicki, Dariusz; Bonafe, Luisa; Superti-Furga, Andrea; van der Goot, Francoise G

2011-01-01

82

HDAC8-Mediated Epigenetic Reprogramming Plays a Key Role in Resistance to Anthrax Lethal Toxin-Induced Pyroptosis in Macrophages.  

PubMed

Macrophages pre-exposed to a sublethal dose of anthrax lethal toxin (LeTx) are refractory to subsequent high cytolytic doses of LeTx, termed toxin-induced resistance (TIR). A small population of TIR cells (2-4%) retains TIR characteristics for up to 5-6 wk. Through studying these long-term TIR cells, we found that a high level of histone deacetylase (HDAC)8 expression was crucial for TIR. Knocking down or inhibition of HDAC8 by small interfering RNAs or the HDAC8-specific inhibitor PCI-34051, respectively, induced expression of the mitochondrial death genes Bcl2 adenovirus E1B 19 kDa-interacting protein 3 (BNIP3), BNIP3-like and metastatic lymph node 64, and resensitized TIR cells to LeTx. Among multiple histone acetylations, histone H3 lysine 27 (H3K27) acetylation was most significantly decreased in TIR cells in an HDAC8-dependent manner, and the association of H3K27 acetylation with the genomic regions of BNIP3 and metastatic lymph node 64, where HDAC8 was recruited to, was diminished in TIR cells. Furthermore, overexpression of HDAC8 or knocking down the histone acetyltransferase CREB-binding protein/p300, known to target H3K27, rendered wild-type cells resistant to LeTx. As in RAW264.7 cells, primary bone marrow-derived macrophages exposed to a sublethal dose of LeTx were resistant to LeTx in an HDAC8-dependent manner. Collectively, this study demonstrates that epigenetic reprogramming mediated by HDAC8 plays a key role in determining the susceptibility of LeTx-induced pyroptosis in macrophages. PMID:24973453

Ha, Soon-Duck; Han, Chae Young; Reid, Chantelle; Kim, Sung Ouk

2014-08-01

83

SELECTION OF ANTHRAX TOXIN PROTECTIVE ANTIGEN VARIANTS THAT DISCRIMINATE BETWEEN THE CELLULAR RECEPTORS TEM8 AND CMG2 AND ACHIEVE TARGETING OF TUMOR CELLS  

PubMed Central

Anthrax toxin, a three-component protein toxin secreted by Bacillus anthracis, assembles into toxic complexes at the surface of receptor-bearing eukaryotic cells. The protective antigen (PA) protein binds to receptors, either tumor endothelial cell marker 8 (TEM8) or capillary morphogenesis protein 2 (CMG2), and orchestrates the delivery of the lethal and edema factors into the cytosol. TEM8 is reported to be over-expressed during tumor angiogenesis, whereas CMG2 is more widely expressed in normal tissues. To extend prior work on targeting of tumor with modified anthrax toxins, we used phage display to select PA variants that preferentially bind to TEM8 as compared to CMG2. Substitutions were randomly introduced into residues 605-729 of PA, within the C-terminal domain 4 of PA, which is the principal region that contacts receptor. Candidates were characterized in cellular cytotoxicity assays with CHO cells expressing either TEM8 or CMG2. A PA mutant having the substitutions R659S and M662R had enhanced specificity toward TEM8 over-expressing CHO cells. This PA variant also displayed broad and potent tumoricidal activity to various human tumor cells, especially to HeLa and A549/ATCC cells. By contrast, the substitution N657Q significantly reduced toxicity to TEM8 but not CMG2 over-expressing CHO cells. Our results indicate that certain amino acid substitutions within PA domain 4 create anthrax toxins that selectively kill human tumor cells. The PA R659S/M662R protein may be useful as a therapeutic agent for cancer treatment.

Chen, Kuang-Hua; Liu, Shihui; Bankston, Laurie A.; Liddington, Robert C.; Leppla, Stephen H.

2008-01-01

84

Combinations of Monoclonal Antibodies to Anthrax Toxin Manifest New Properties in Neutralization Assays  

PubMed Central

Monoclonal antibodies (MAbs) are potential therapeutic agents against Bacillus anthracis toxins, since there is no current treatment to counteract the detrimental effects of toxemia. In hopes of isolating new protective MAbs to the toxin component lethal factor (LF), we used a strain of mice (C57BL/6) that had not been used in previous studies, generating MAbs to LF. Six LF-binding MAbs were obtained, representing 3 IgG isotypes and one IgM. One MAb (20C1) provided protection from lethal toxin (LeTx) in an in vitro mouse macrophage system but did not provide significant protection in vivo. However, the combination of two MAbs to LF (17F1 and 20C1) provided synergistic increases in protection both in vitro and in vivo. In addition, when these MAbs were mixed with MAbs to protective antigen (PA) previously generated in our laboratory, these MAb combinations produced synergistic toxin neutralization in vitro. But when 17F1 was combined with another MAb to LF, 19C9, the combination resulted in enhanced lethal toxicity. While no single MAb to LF provided significant toxin neutralization, LF-immunized mice were completely protected from infection with B. anthracis strain Sterne, which suggested that a polyclonal response is required for effective toxin neutralization. In total, these studies show that while a single MAb against LeTx may not be effective, combinations of multiple MAbs may provide the most effective form of passive immunotherapy, with the caveat that these may demonstrate emergent properties with regard to protective efficacy.

Rivera, Johanna; Nakouzi, Antonio; Chow, Siu-Kei; Casadevall, Arturo

2013-01-01

85

Monitoring the kinetics of the pH-driven transition of the anthrax toxin prepore to the pore by biolayer interferometry and surface plasmon resonance.  

PubMed

Domain 2 of the anthrax protective antigen (PA) prepore heptamer unfolds and refolds during endosome acidification to generate an extended 100 Å ? barrel pore that inserts into the endosomal membrane. The PA pore facilitates the pH-dependent unfolding and translocation of bound toxin enzymic components, lethal factor (LF) and/or edema factor, from the endosome to the cytoplasm. We constructed immobilized complexes of the prepore with the PA-binding domain of LF (LFN) to monitor the real-time prepore to pore kinetic transition using surface plasmon resonance and biolayer interferometry (BLI). The kinetics of this transition increased as the solution pH was decreased from 7.5 to 5.0, mirroring acidification of the endosome. Once it had undergone the transition, the LFN-PA pore complex was removed from the BLI biosensor tip and deposited onto electron microscopy grids, where PA pore formation was confirmed by negative stain electron microscopy. When the soluble receptor domain (ANTRX2/CMG2) binds the immobilized PA prepore, the transition to the pore state was observed only after the pH was lowered to early (pH 5.5) or late (pH 5.0) endosomal pH conditions. Once the pore formed, the soluble receptor readily dissociated from the PA pore. Separate binding experiments with immobilized PA pores and the soluble receptor indicate that the receptor has a weakened propensity to bind to the transitioned pore. This immobilized anthrax toxin platform can be used to identify or validate potential antimicrobial lead compounds capable of regulating and/or inhibiting anthrax toxin complex formation or pore transitions. PMID:23964683

Naik, Subhashchandra; Brock, Susan; Akkaladevi, Narahari; Tally, Jon; McGinn-Straub, Wesley; Zhang, Na; Gao, Phillip; Gogol, E P; Pentelute, B L; Collier, R John; Fisher, Mark T

2013-09-17

86

Development of an in Vitro Potency Assay for Anti-anthrax Lethal Toxin Neutralizing Antibodies  

PubMed Central

Lethal toxin (LT) of Bacillus anthracis reduces the production of a number of inflammatory mediators, including transcription factors, chemokines and cytokines in various human cell lines, leading to down-regulation of the host inflammatory response. Previously we showed that the reduction of interleukin-8 (IL-8) is a sensitive marker of LT-mediated intoxication in human neutrophil-like NB-4 cells and that IL-8 levels are restored to normality when therapeutic monoclonal antibodies (mAb) with toxin-neutralising (TN) activity are added. We used this information to develop cell-based assays that examine the effects of TN therapeutic mAbs designed to treat LT intoxication and here we extend these findings. We present an in vitro assay based on human endothelial cell line HUVEC jr2, which measures the TN activity of therapeutic anti-LT mAbs using IL-8 as a marker for intoxication. HUVEC jr2 cells have the advantage over NB-4 cells that they are adherent, do not require a differentiation step and can be used in a microtitre plate format and therefore can facilitate high throughput analysis. This human cell-based assay provides a valid alternative to the mouse macrophage assay as it is a more biologically relevant model of the effects of toxin-neutralising antibodies in human infection.

Whiting, Gail; Baker, Michael; Rijpkema, Sjoerd

2012-01-01

87

Anthrax Lethal Toxin Impairs IL-8 Expression in Epithelial Cells through Inhibition of Histone H3 Modification  

PubMed Central

Lethal toxin (LT) is a critical virulence factor of Bacillus anthracis, the etiological agent of anthrax, whose pulmonary form is fatal in the absence of treatment. Inflammatory response is a key process of host defense against invading pathogens. We report here that intranasal instillation of a B. anthracis strain bearing inactive LT stimulates cytokine production and polymorphonuclear (PMN) neutrophils recruitment in lungs. These responses are repressed by a prior instillation of an LT preparation. In contrast, instillation of a B. anthracis strain expressing active LT represses lung inflammation. The inhibitory effects of LT on cytokine production are also observed in vitro using mouse and human pulmonary epithelial cells. These effects are associated with an alteration of ERK and p38-MAPK phosphorylation, but not JNK phosphorylation. We demonstrate that although NF-?B is essential for IL-8 expression, LT downregulates this expression without interfering with NF-?B activation in epithelial cells. Histone modifications are known to induce chromatin remodelling, thereby enhancing NF-?B binding on promoters of a subset of genes involved in immune response. We show that LT selectively prevents histone H3 phosphorylation at Ser 10 and recruitment of the p65 subunit of NF-?B at the IL-8 and KC promoters. Our results suggest that B. anthracis represses the immune response, in part by altering chromatin accessibility of IL-8 promoter to NF-?B in epithelial cells. This epigenetic reprogramming, in addition to previously reported effects of LT, may represent an efficient strategy used by B. anthracis for invading the host.

Raymond, Benoit; Batsche, Eric; Boutillon, Florence; Wu, Yong-Zheng; Leduc, Dominique; Balloy, Viviane; Raoust, Eloise; Muchardt, Christian; Goossens, Pierre L.; Touqui, Lhousseine

2009-01-01

88

Sublethal Doses of Anthrax Lethal Toxin on the Suppression of Macrophage Phagocytosis  

PubMed Central

Background Lethal toxin (LT), the major virulence factor produced by Bacillus anthracis, has been shown to suppress the immune system, which is beneficial to the establishment of B. anthracis infections. It has been suggested that the suppression of MEK/MAPK signaling pathways of leukocytes contributes to LT-mediated immunosuppressive effects. However, the involvement of MAPK independent pathways has not been clearly elucidated; nor has the crucial role played by LT in the early stages of infection. Determining whether LT exerts any pathological effects before being enriched to an MEK inhibitory level is an important next step in the furtherance of this field. Methodology/Principal Findings Using a cell culture model, we determined that low doses of LT inhibited phagocytosis of macrophages, without influencing MAPK pathways. Consistent low doses of LT significantly suppressed bacterial clearance and enhanced the mortality of mice with bacteremia, without suppressing the MEK1 of splenic and peripheral blood mononuclear cells. Conclusion/Significance These results suggest that LT suppresses the phagocytes in a dose range lower than that required to suppress MEK1 in the early stages of infection.

Huang, Hsuan-Shun; Lien, Te-Sheng; Huang, Hsin-Hsien; Lin, Hung-Chi; Chang, Hsin-Hou

2010-01-01

89

Anthrax lethal toxin-mediated disruption of endothelial VE-cadherin is attenuated by inhibition of the Rho-associated kinase pathway.  

PubMed

Systemic anthrax disease is characterized by vascular leakage pathologies. We previously reported that anthrax lethal toxin (LT) induces human endothelial barrier dysfunction in a cell death-independent manner with actin stress fiber formation and disruption of adherens junctions (AJs). In the present study, we further characterize the molecular changes in the AJ complex and investigate whether AJ structure and barrier function can be preserved by modulating key cytoskeletal signaling pathways. Here, we show that LT reduces total VE-cadherin protein and gene expression but the expression of the key linker protein beta-catenin remained unchanged. The changes in VE-cadherin expression correlated temporally with the appearance of actin stress fibers and a two-fold increase in phosphorylation of the stress fiber-associated protein myosin light chain (p-MLC) and cleavage of Rho-associated kinase-1 (ROCK-1). Co-treatment with ROCK inhibitors (H-1152 and Y27632), but not an inhibitor of MLC kinase (ML-7), blocked LT-induced p-MLC enhancement and stress fiber formation. This was accompanied by the restoration of VE-cadherin expression and membrane localization, and attenuation of the LT-induced increase in monolayer permeability to albumin. Together, these findings suggest the ROCK pathway may be a relevant target for countering LT-mediated endothelial barrier dysfunction. PMID:22069696

Warfel, Jason M; D'Agnillo, Felice

2011-10-01

90

Anthrax Lethal Toxin-Mediated Disruption of Endothelial VE-Cadherin Is Attenuated by Inhibition of the Rho-Associated Kinase Pathway  

PubMed Central

Systemic anthrax disease is characterized by vascular leakage pathologies. We previously reported that anthrax lethal toxin (LT) induces human endothelial barrier dysfunction in a cell death-independent manner with actin stress fiber formation and disruption of adherens junctions (AJs). In the present study, we further characterize the molecular changes in the AJ complex and investigate whether AJ structure and barrier function can be preserved by modulating key cytoskeletal signaling pathways. Here, we show that LT reduces total VE-cadherin protein and gene expression but the expression of the key linker protein beta-catenin remained unchanged. The changes in VE-cadherin expression correlated temporally with the appearance of actin stress fibers and a two-fold increase in phosphorylation of the stress fiber-associated protein myosin light chain (p-MLC) and cleavage of Rho-associated kinase-1 (ROCK-1). Co-treatment with ROCK inhibitors (H-1152 and Y27632), but not an inhibitor of MLC kinase (ML-7), blocked LT-induced p-MLC enhancement and stress fiber formation. This was accompanied by the restoration of VE-cadherin expression and membrane localization, and attenuation of the LT-induced increase in monolayer permeability to albumin. Together, these findings suggest the ROCK pathway may be a relevant target for countering LT-mediated endothelial barrier dysfunction.

Warfel, Jason M.; D'Agnillo, Felice

2011-01-01

91

Specific, Sensitive, and Quantitative Enzyme-Linked Immunosorbent Assay for Human Immunoglobulin G Antibodies to Anthrax Toxin Protective Antigen  

PubMed Central

The bioterrorism-associated human anthrax epidemic in the fall of 2001 highlighted the need for a sensitive, reproducible, and specific laboratory test for the confirmatory diagnosis of human anthrax. The Centers for Disease Control and Prevention developed, optimized, and rapidly qualified an enzyme-linked immunosorbent assay (ELISA) for immunoglobulin G (IgG) antibodies to Bacillus anthracis protective antigen (PA) in human serum. The qualified ELISA had a minimum detection limit of 0.06 µg/mL, a reliable lower limit of detection of 0.09 µg/mL, and a lower limit of quantification in undiluted serum specimens of 3.0 µg/mL anti-PA IgG. The diagnostic sensitivity of the assay was 97.8%, and the diagnostic specificity was 94.2%. A competitive inhibition anti-PA IgG ELISA was also developed to enhance diagnostic specificity to 100%. The anti-PA ELISAs proved valuable for the confirmation of cases of cutaneous and inhalational anthrax and evaluation of patients in whom the diagnosis of anthrax was being considered.

Semenova, Vera A.; Elie, Cheryl M.; Romero-Steiner, Sandra; Greene, Carolyn; Li, Han; Stamey, Karen; Steward-Clark, Evelene; Schmidt, Daniel S.; Mothershed, Elizabeth; Pruckler, Janet; Schwartz, Stephanie; Benson, Robert F.; Helsel, Leta O.; Holder, Patricia F.; Johnson, Scott E.; Kellum, Molly; Messmer, Trudy; Thacker, W. Lanier; Besser, Lilah; Plikaytis, Brian D.; Taylor, Thomas H.; Freeman, Alison E.; Wallace, Kelly J.; Dull, Peter; Sejvar, Jim; Bruce, Erica; Moreno, Rosa; Schuchat, Anne; Lingappa, Jairam R.; Martin, Sandra K.; Walls, John; Bronsdon, Melinda; Carlone, George M.; Bajani-Ari, Mary; Ashford, David A.; Stephens, David S.; Perkins, Bradley A.

2002-01-01

92

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

PubMed Central

Development 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.

Malkevich, Nina V.; Basu, Subhendu; Rudge, Thomas L.; Clement, Kristin H.; Chakrabarti, Ajoy C.; Aimes, Ronald T.; Nabors, Gary S.; Skiadopoulos, Mario H.

2013-01-01

93

Anthrax Toxin-Mediated Delivery of the Pseudomonas Exotoxin A Enzymatic Domain to the Cytosol of Tumor Cells via Cleavable Ubiquitin Fusions  

PubMed Central

ABSTRACT Anthrax toxin proteins from Bacillus anthracis constitute a highly efficient system for delivering cytotoxic enzymes to the cytosol of tumor cells. However, exogenous proteins delivered to the cytosol of cells are subject to ubiquitination on lysines and proteasomal degradation, which limit their potency. We created fusion proteins containing modified ubiquitins with their C-terminal regions fused to the Pseudomonas exotoxin A catalytic domain (PEIII) in order to achieve delivery and release of PEIII to the cytosol. Fusion proteins in which all seven lysines of wild-type ubiquitin were retained while the site cleaved by cytosolic deubiquitinating enzymes (DUBs) was removed were nontoxic, apparently due to rapid ubiquitination and proteasomal degradation. Fusion proteins in which all lysines of wild-type ubiquitin were substituted by arginine had high potency, exceeding that of a simple fusion lacking ubiquitin. This variant was less toxic to nontumor tissues in mice than the fusion protein lacking ubiquitin and was very efficient for tumor treatment in mice. The potency of these proteins was highly dependent on the number of lysines retained in the ubiquitin domain and on retention of the C-terminal ubiquitin sequence cleaved by DUBs. It appears that rapid cytosolic release of a cytotoxic enzyme (e.g., PEIII) that is itself resistant to ubiquitination is an effective strategy for enhancing the potency of tumor-targeting toxins.

Bachran, Christopher; Morley, Thomas; Abdelazim, Suzanne; Fattah, Rasem J.; Liu, Shihui; Leppla, Stephen H.

2013-01-01

94

Anthrax Protective Antigen (PA63) Bound Conformation of a Peptide Inhibitor of the Binding of Lethal Factor to PA63: As Determined by trNOESY NMR and Molecular Modelling.  

National Technical Information Service (NTIS)

Anthrax protective antigen (PA) is one of the three proteins produced by the gram positive bacteria Bacillus anthracis collectively known as the 'anthrax toxin.' The role played by PA in anthrax intoxication is to transport the two enzymes lethal factor (...

R. P. Hicks A. K. Bhattacharjee B. W. Koser D. D. Traficante

2004-01-01

95

Regulation of anthrax toxin activator gene (atxA) expression in Bacillus anthracis: temperature, not CO2/bicarbonate, affects AtxA synthesis.  

PubMed Central

Anthrax toxin gene expression in Bacillus anthracis is dependent on the presence of atxA, a trans-acting regulatory gene located on the resident 185-kb plasmid pXO1. In atxA+ strains, expression of the toxin genes (pag, lef, and cya) is enhanced by two physiologically significant signals: elevated CO2/bicarbonate and temperature. To determine whether increased toxin gene expression in response to these signals is associated with increased atxA expression, we monitored steady-state levels of atxA mRNA and AtxA protein in cells cultured in different conditions. We purified histidine-tagged AtxA [AtxA(His)] from Escherichia coli and used anti-AtxA(His) serum to detect AtxA in protein preparations from B. anthracis cells. AtxA was identified as a protein with an apparent size of 56 kDa in cytoplasmic fractions of B. anthracis cells. Our data indicate that atxA expression is not influenced by CO2/bicarbonate levels. However, the steady-state level of atxA mRNA in cells grown in elevated CO2/bicarbonate at 37 degrees C is five- to sixfold higher than that observed in cells grown in the same conditions at 28 degrees C. A corresponding difference in AtxA protein was also seen at the different growth temperatures. When atxA was cloned on a multicopy plasmid in B. anthracis, AtxA levels corresponding to the atxA gene copy number were observed. However, this strain produced significantly less pag mRNA and protective antigen protein than the parental strain harboring atxA in single copy on pXO1. These results indicate that increased AtxA expression does not lead to a corresponding increase in pag expression. Our data strongly suggest that an additional factor(s) is involved in regulation of pag and that the relative amounts of such a factor(s) and AtxA are important for optimal toxin gene expression.

Dai, Z; Koehler, T M

1997-01-01

96

Cellular Adaptation to Anthrax Lethal Toxin-Induced Mitochondrial Cholesterol Enrichment, Hyperpolarization, and Reactive Oxygen Species Generation through Downregulating MLN64 in Macrophages  

PubMed Central

Cellular adaptation to different stresses related to survival and function has been demonstrated in several cell types. Anthrax lethal toxin (LeTx) induces rapid cell death, termed “pyroptosis,” by activating NLRP1b/caspase-1 in murine macrophages. We and others (S. D. Ha et al., J. Biol. Chem. 282:26275-26283, 2007; I. I. Salles et al., Proc. Natl. Acad. Sci. U. S. A. 100:12426 –12431, 2003) have shown that RAW264.7 cells preexposed to sublethal doses of LeTx become resistant to subsequent high cytolytic doses of LeTx, termed toxin-induced resistance (TIR). To date, the cellular mechanisms of pyroptosis and TIR are largely unknown. We found that LeTx caused NLRP1b/caspase-1-dependent mitochondrial dysfunction, including hyperpolarization and generation of reactive oxygen species, which was distinct from that induced by stimuli such as NLRP3-activating ATP. In TIR cells, these mitochondrial events were not detected, although caspase-1 was activated, in response to LeTx. We identified that downregulation of the late endosomal cholesterol-transferring protein MLN64 in TIR cells was involved in TIR. The downregulation of MLN64 in TIR cells was at least in part due to DNA methyltransferase 1-mediated DNA methylation. In wild-type RAW264.7 cells and primary bone marrow-derived macrophages, LeTx caused NLRP1b/caspase-1-dependent mitochondrial translocation of MLN64, resulting in cholesterol enrichment, membrane hyperpolarization, reactive oxygen species (ROS) generation, and depletion of free glutathione (GSH). This study demonstrates for the first time that MLN64 plays a key role in LeTx/caspase-1-induced mitochondrial dysfunction.

Ha, Soon-Duck; Park, Sangwook; Han, Chae Young; Nguyen, Marilyn L.

2012-01-01

97

Anthrax: Treatment  

MedlinePLUS

... Confirming Anthrax Through the Laboratory Response Network Laboratory Testing - FAQs Collecting Specimens Recommended Specimens Information for Specific Groups Laboratory Professionals People Who Work with Animal Products Exposure to Hides/Drums Treatment of Products ...

98

Anthrax: Prevention  

MedlinePLUS

... Confirming Anthrax Through the Laboratory Response Network Laboratory Testing - FAQs Collecting Specimens Recommended Specimens Information for Specific Groups Laboratory Professionals People Who Work with Animal Products Exposure to Hides/Drums Treatment of Products ...

99

Inhalation Anthrax  

MedlinePLUS

... Confirming Anthrax Through the Laboratory Response Network Laboratory Testing - FAQs Collecting Specimens Recommended Specimens Information for Specific Groups Laboratory Professionals People Who Work with Animal Products Exposure to Hides/Drums Treatment of Products ...

100

Injection Anthrax  

MedlinePLUS

... Confirming Anthrax Through the Laboratory Response Network Laboratory Testing - FAQs Collecting Specimens Recommended Specimens Information for Specific Groups Laboratory Professionals People Who Work with Animal Products Exposure to Hides/Drums Treatment of Products ...

101

Cutaneous Anthrax  

MedlinePLUS

... Confirming Anthrax Through the Laboratory Response Network Laboratory Testing - FAQs Collecting Specimens Recommended Specimens Information for Specific Groups Laboratory Professionals People Who Work with Animal Products Exposure to Hides/Drums Treatment of Products ...

102

Gastrointestinal Anthrax  

MedlinePLUS

... Confirming Anthrax Through the Laboratory Response Network Laboratory Testing - FAQs Collecting Specimens Recommended Specimens Information for Specific Groups Laboratory Professionals People Who Work with Animal Products Exposure to Hides/Drums Treatment of Products ...

103

Anthrax: Symptoms  

MedlinePLUS

... Confirming Anthrax Through the Laboratory Response Network Laboratory Testing - FAQs Collecting Specimens Recommended Specimens Information for Specific Groups Laboratory Professionals People Who Work with Animal Products Exposure to Hides/Drums Treatment of Products ...

104

Anthrax: Diagnosis  

MedlinePLUS

... Confirming Anthrax Through the Laboratory Response Network Laboratory Testing - FAQs Collecting Specimens Recommended Specimens Information for Specific Groups Laboratory Professionals People Who Work with Animal Products Exposure to Hides/Drums Treatment of Products ...

105

Raxibacumab: potential role in the treatment of inhalational anthrax  

PubMed Central

Anthrax is a highly contagious and potentially fatal human disease caused by Bacillus anthracis, an aerobic, Gram-positive, spore-forming rod-shaped bacterium with worldwide distribution as a zoonotic infection in herbivore animals. Bioterrorist attacks with inhalational anthrax have prompted the development of more effective treatments. Antibodies against anthrax toxin have been shown to decrease mortality in animal studies. Raxibacumab is a recombinant human monoclonal antibody developed against inhalational anthrax. The drug received approval after human studies showed its safety and animal studies demonstrated its efficacy for treatment as well as prophylaxis against inhalational anthrax. It works by preventing binding of the protective antigen component of the anthrax toxin to its receptors in host cells, thereby blocking the toxin’s deleterious effects. Recently updated therapy guidelines for Bacillus anthracis recommend the use of antitoxin treatment. Raxibacumab is the first monoclonal antitoxin antibody made available that can be used with the antibiotics recommended for treatment of the disease. When exposure is suspected, raxibacumab should be given with anthrax vaccination to augment immunity. Raxibacumab provides additional protection against inhalational anthrax via a mechanism different from that of either antibiotics or active immunization. In combination with currently available and recommended therapies, raxibacumab should reduce the morbidity and mortality of inhalational anthrax.

Kummerfeldt, Carlos E

2014-01-01

106

Anthrax: pre-publication and special issue  

NSDL National Science Digital Library

This special topics Webpage from Nature contains two pre-publication research papers and a collection of articles, news stories, and commentary from Nature's archive. The two pre-pubs, Bradley et al.'s "Identification of the cellular receptor for anthrax toxin" and "Crystal structure of the anthrax lethal factor" by Pannifer et al., should be useful to researchers and scientists working on treatments for anthrax. The two other feature articles here, "Designing a polyvalent inhibitor of anthrax toxin" by Mourez et al. and "Genomics and future biological weapons: the need for preventive action by the biomedical community," by Fraser et al., come from October issues of Nature Biotechnology and Nature Genetics respectively. Interested members of the general public should find the collection of Nature news stories, which cover a range of issues related to bioweapons and defense, a worthwhile read. All material is available in HTML or .pdf formats.

2001-01-01

107

Kinetics and thermodynamics of binding reactions as exemplified by anthrax toxin channel blockage with a cationic cyclodextrin derivative.  

PubMed

The thermodynamics of binding reactions is usually studied in the framework of the linear van't Hoff analysis of the temperature dependence of the equilibrium constant. The logarithm of the equilibrium constant is plotted versus inverse temperature to discriminate between two terms: an enthalpic contribution that is linear in the inverse temperature, and a temperature-independent entropic contribution. When we apply this approach to a particular case-blockage of the anthrax PA(63) channel by a multicharged cyclodextrin derivative-we obtain a nearly linear behavior with a slope that is characterized by enthalpy of about 1 kcal/mol. In contrast, from blocker partitioning between the channel and the bulk, we estimate the depth of the potential well for the blocker in the channel to be at least 8 kcal/mol. To understand this apparent discrepancy, we use a simple model of particle interaction with the channel and show that this significant difference between the two estimates is due to the temperature dependence of the physical forces between the blocker and the channel. In particular, we demonstrate that if the major component of blocker-channel interaction is van der Waals interactions and/or Coulomb forces in water, the van't Hoff enthalpy of the binding reaction may be close to zero or even negative, including cases of relatively strong binding. The results are quite general and, therefore, of importance for studies of enzymatic reactions, rational drug design, small-molecule binding to proteins, protein-protein interactions, and protein folding, among others. PMID:23100532

Nestorovich, Ekaterina M; Karginov, Vladimir A; Berezhkovskii, Alexander M; Parsegian, V Adrian; Bezrukov, Sergey M

2012-11-01

108

Kinetics and thermodynamics of binding reactions as exemplified by anthrax toxin channel blockage with a cationic cyclodextrin derivative  

PubMed Central

The thermodynamics of binding reactions is usually studied in the framework of the linear van’t Hoff analysis of the temperature dependence of the equilibrium constant. The logarithm of the equilibrium constant is plotted versus inverse temperature to discriminate between two terms: an enthalpic contribution that is linear in the inverse temperature, and a temperature-independent entropic contribution. When we apply this approach to a particular case—blockage of the anthrax PA63 channel by a multicharged cyclodextrin derivative—we obtain a nearly linear behavior with a slope that is characterized by enthalpy of about 1 kcal/mol. In contrast, from blocker partitioning between the channel and the bulk, we estimate the depth of the potential well for the blocker in the channel to be at least 8 kcal/mol. To understand this apparent discrepancy, we use a simple model of particle interaction with the channel and show that this significant difference between the two estimates is due to the temperature dependence of the physical forces between the blocker and the channel. In particular, we demonstrate that if the major component of blocker–channel interaction is van der Waals interactions and/or Coulomb forces in water, the van’t Hoff enthalpy of the binding reaction may be close to zero or even negative, including cases of relatively strong binding. The results are quite general and, therefore, of importance for studies of enzymatic reactions, rational drug design, small-molecule binding to proteins, protein–protein interactions, and protein folding, among others.

Nestorovich, Ekaterina M.; Karginov, Vladimir A.; Berezhkovskii, Alexander M.; Parsegian, V. Adrian; Bezrukov, Sergey M.

2012-01-01

109

Cytotoxicity of Anthrax Lethal Toxin to Human Acute Myeloid Leukemia Cells Is Nonapoptotic and Dependent on Extracellular Signal-Regulated Kinase 1/2 Activity1  

PubMed Central

In this study, we attempt to target the mitogen-activated protein kinase (MAPK) pathway in acute myeloid leukemia (AML) cells using a recombinant anthrax lethal toxin (LeTx). LeTx consists of protective antigen (PrAg) and lethal factor (LF). PrAg binds cells, is cleaved by furin, oligomerizes, binds three to four molecules of LF, and undergoes endocytosis, releasing LF into the cytosol. LF cleaves MAPK kinases, inhibiting the MAPK pathway. We tested potency of LeTx on a panel of 11 human AML cell lines. Seven cell lines showed cytotoxic responses to LeTx. Cytotoxicity of LeTx was mimicked by the specific mitogen-activated protein/extracellular signal-regulated kinase kinase 1/2 (MEK1/2) inhibitor U0126, indicating that LeTx-induced cell death is mediated through the MEK1/2-extracellular signal-regulated kinase (ERK1/2) branch of the MAPK pathway. The four LeTx-resistant cell lines were sensitive to the phosphatidylinositol 3-kinase inhibitor LY294002. Co-treatment of AML cells with both LeTx and LY294002 did not lead to increased sensitivity, showing a lack of additive/synergistic effects when both pathways are inhibited. Flow cytometry analysis of MAPK pathway activation revealed the presence of phospho-ERK1/2 only in LeTx-sensitive cells. Staining for Annexin V/propidium iodide and active caspases showed an increase in double-positive cells and the absence of caspase activation following treatment, indicating that LeTx-induced cell death is caspase-independent and nonapoptotic. We have shown that a majority of AML cell lines are sensitive to the LF-mediated inhibition of the MAPK pathway. Furthermore, we have demonstrated that LeTx-induced cytotoxicity in AML cells is nonapoptotic and dependent on phospho-ERK1/2 levels.

Kassab, Elias; Darwish, Manal; Timsah, Zahra; Liu, ShiHui; Leppla, Stephen H; Frankel, Arthur E; Abi-Habib, Ralph J

2013-01-01

110

Prepositioning Antibiotics for Anthrax.  

National Technical Information Service (NTIS)

Rapid access to antibiotics can prevent people who are exposed to aerosolized Bacillus anthracis from developing anthrax; once symptoms of anthrax emerge, the disease progresses rapidly and can prove fatal. Since the anthrax attack in 2001, the nations pu...

2012-01-01

111

Raxibacumab: potential role in the treatment of inhalational anthrax.  

PubMed

Anthrax is a highly contagious and potentially fatal human disease caused by Bacillus anthracis, an aerobic, Gram-positive, spore-forming rod-shaped bacterium with worldwide distribution as a zoonotic infection in herbivore animals. Bioterrorist attacks with inhalational anthrax have prompted the development of more effective treatments. Antibodies against anthrax toxin have been shown to decrease mortality in animal studies. Raxibacumab is a recombinant human monoclonal antibody developed against inhalational anthrax. The drug received approval after human studies showed its safety and animal studies demonstrated its efficacy for treatment as well as prophylaxis against inhalational anthrax. It works by preventing binding of the protective antigen component of the anthrax toxin to its receptors in host cells, thereby blocking the toxin's deleterious effects. Recently updated therapy guidelines for Bacillus anthracis recommend the use of antitoxin treatment. Raxibacumab is the first monoclonal antitoxin antibody made available that can be used with the antibiotics recommended for treatment of the disease. When exposure is suspected, raxibacumab should be given with anthrax vaccination to augment immunity. Raxibacumab provides additional protection against inhalational anthrax via a mechanism different from that of either antibiotics or active immunization. In combination with currently available and recommended therapies, raxibacumab should reduce the morbidity and mortality of inhalational anthrax. PMID:24812521

Kummerfeldt, Carlos E

2014-01-01

112

Pathophysiology of anthrax  

PubMed Central

Infection by Bacillus anthracis in animals and humans results from accidental or intentional exposure, by oral, cutaneous or pulmonary routes, to spores, which are normally present in the soil. Treatment includes administration of antibiotics, vaccination or treatment with antibody to the toxin. A better understanding of the molecular basis of the processes involved in the pathogenesis of anthrax namely, spore germination in macrophages and biological effects of the secreted toxins on heart and blood vessels will lead to improved management of infected animals and patients. Controlling germination will be feasible by inhibiting macrophage paralysis and cell death. On the other hand, the control of terminal hypotension might be achieved by inhibition of cardiomyocyte mitogen-activated protein kinase and stimulation of vessel cAMP.

Frankel, Arthur E.; Kuo, Shu-Ru; Dostal, David; Watson, Linley; Duesbery, Nicholas S.; Cheng, Che-Ping; Cheng, Heng Jie; Tang, Wei-Jen; Leppla, Stephen H.

2014-01-01

113

Anthrax toxin induces macrophage death by p38 MAPK inhibition but leads to inflammasome activation via ATP leakage  

PubMed Central

Detection of microbial constituents by membrane associated and cytoplasmic pattern recognition receptors is the essence of innate immunity, leading to activation of protective host responses. However, it is still unclear how immune cells specifically respond to pathogenic bacteria. Using virulent and non-virulent strains of Bacillus anthracis, we have shown that secretion of ATP by infected macrophages and the sequential activation of the P2X7 purinergic receptor and nucleotide binding oligomerization domain (NOD)- like receptors are critical for IL-1-dependent host protection from virulent B. anthracis. Importantly, lethal toxin produced by virulent B. anthracis blocked activation of protein kinases, p38 MAPK and AKT, resulting in opening of a connexin ATP release channel and induction of macrophage death. Prevention of cell death or ATP release through constitutive p38 or AKT activation interfered with inflammasome activation and IL-1? production, thereby compromising anti-microbial immunity.

Ali, Syed Raza; Timmer, Anjuli M.; Bilgrami, Sameera; Park, Eek Joong; Eckmann, Lars; Nizet, Victor; Karin, Michael

2012-01-01

114

Neutralizing Antibodies and Persistence of Immunity following Anthrax Vaccination  

Microsoft Academic Search

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.

James F. Hanson; Sarah C. Taft; Alison A. Weiss

2006-01-01

115

Scientists Report New Lead in How Anthrax Kills Cells  

Cancer.gov

For years scientists have known that anthrax bacillus produces a toxin containing a deadly protein called lethal factor. However, researchers have never been able to identify how lethal factor kills cells.

116

Efficient synthetic inhibitors of anthrax lethal factor  

PubMed Central

Inhalation anthrax is a deadly disease for which there is currently no effective treatment. Bacillus anthracis lethal factor (LF) metalloproteinase is an integral component of the tripartite anthrax lethal toxin that is essential for the onset and progression of anthrax. We report here on a fragment-based approach that allowed us to develop inhibitors of LF. The small-molecule inhibitors we have designed, synthesized, and tested are highly potent and selective against LF in both in vitro tests and cell-based assays. These inhibitors do not affect the prototype human metalloproteinases that are structurally similar to LF. Initial in vivo evaluation of postexposure efficacy of our inhibitors combined with antibiotic ciprofloxican against B. anthracis resulted in significant protection. Our data strongly indicate that the scaffold of inhibitors we have identified is the foundation for the development of novel, safe, and effective emergency therapy of postexposure inhalation anthrax.

Forino, Martino; Johnson, Sherida; Wong, Thiang Y.; Rozanov, Dmitri V.; Savinov, Alexei Y.; Li, Wei; Fattorusso, Roberto; Becattini, Barbara; Orry, Andrew J.; Jung, Dawoon; Abagyan, Ruben A.; Smith, Jeffrey W.; Alibek, Ken; Liddington, Robert C.; Strongin, Alex Y.; Pellecchia, Maurizio

2005-01-01

117

Assembly of the small outer capsid protein, Soc, on bacteriophage T4: a novel system for high density display of multiple large anthrax toxins and foreign proteins on phage capsid.  

PubMed

Bacteriophage T4 capsid is a prolate icosahedron composed of the major capsid protein gp23*, the vertex protein gp24*, and the portal protein gp20. Assembled on its surface are 810 molecules of the non-essential small outer capsid protein, Soc (10 kDa), and 155 molecules of the highly antigenic outer capsid protein, Hoc (39 kDa). In this study Soc, a "triplex" protein that stabilizes T4 capsid, is targeted for molecular engineering of T4 particle surface. Using a defined in vitro assembly system, anthrax toxins, protective antigen, lethal factor and their domains, fused to Soc were efficiently displayed on the capsid. Both the N and C termini of the 80 amino acid Soc polypeptide can be simultaneously used to display antigens. Proteins as large as 93 kDa can be stably anchored on the capsid through Soc-capsid interactions. Using both Soc and Hoc, up to 1662 anthrax toxin molecules are assembled on the phage T4 capsid under controlled conditions. We infer from the binding data that a relatively high affinity capsid binding site is located in the middle of the rod-shaped Soc, with the N and C termini facing the 2- and 3-fold symmetry axes of the capsid, respectively. Soc subunits interact at these interfaces, gluing the adjacent capsid protein hexamers and generating a cage-like outer scaffold. Antigen fusion does interfere with the inter-subunit interactions, but these interactions are not essential for capsid binding and antigen display. These features make the T4-Soc platform the most robust phage display system reported to date. The study offers insights into the architectural design of bacteriophage T4 virion, one of the most stable viruses known, and how its capsid surface can be engineered for novel applications in basic molecular biology and biotechnology. PMID:17544446

Li, Qin; Shivachandra, Sathish B; Zhang, Zhihong; Rao, Venigalla B

2007-07-27

118

ANTHRAX TECHNICAL ASSISTANCE DOCUMENT  

EPA Science Inventory

The Anthrax TAD was developed as an Interim Draft Final technical resource in November 2003. It is specifically for response to an actual or suspected terrorist release of anthrax (i.e., it is not intended for response to anthrax in agricultural settings.). The TAD was provided ...

119

Serotherapy of Anthrax.  

National Technical Information Service (NTIS)

The use of serum for anthrax has more justification than the use of neosalvarsan. The anthrax serum should be used in all serious cases. In view of the possibility of sepsis in the median and mild forms of anthrax, it is sometimes necessary to utilize ser...

B. G. Popkova L. A. Abramovich

1968-01-01

120

Serology and anthrax in humans, livestock and Etosha National Park wildlife.  

PubMed Central

Results are presented from a number of epidemiological studies using enzyme immunoassays (EIA) based on the purified anthrax toxin antigens, protective antigen, lethal factor and oedema factor. Studies on sera from a group of 62 human anthrax patients in Turkey and from cattle in Britain following two unrelated outbreaks of anthrax show that EIA using protective antigen can be a useful diagnostic aid and will detect subclinical infections in appropriate circumstances. A serological survey on wildlife in the Etosha National Park, Namibia, where anthrax is endemic, showed that naturally acquired anthrax-specific antibodies are rare in herbivores but common in carnivores; in carnivores, titres appear to reflect the prevalence of anthrax in their ranges. Problems, as yet unresolved, were encountered in studies on sera from pigs following an outbreak of anthrax on a farm in Wales. Clinical details, including treatment, of the human and one of the bovine outbreaks are summarized and discussed in relation to the serological findings.

Turnbull, P. C.; Doganay, M.; Lindeque, P. M.; Aygen, B.; McLaughlin, J.

1992-01-01

121

Biological Terrorism The Anthrax Scare of 2001  

NSDL National Science Digital Library

In the weeks following the September 11, 2001, terrorist attacks on the World Trade Center and the Pentagon, anthrax-laced envelopes were mailed to individuals in government and the news media. Thousands were treated for exposure, and five people were killed. At the same time, scientists solved the last remaining pieces of the anthrax puzzle and the mechanism of infection of the anthrax toxin is now well understood. Developed for a second-semester biochemistry course, this case presents students with a wealth of biochemical, microbiological, and immunological material to analyze. It also explores important societal issues related to national preparedness against bioterrorist attacks, funding for biodefense research, and the use and misuse of antibiotic therapy.

Cornely, Kathleen A.

2005-01-01

122

Use of Recombinant DNA Techniques for the Production of a More Effective Anthrax Vaccine.  

National Technical Information Service (NTIS)

The overall goal of the present research is to construct a safe and effective human anthrax vaccine using recombinant DNA techniques. During the course of this contract, we have isolated and characterized each of the Bacillus anthracis toxin genes. Althou...

D. L. Robertson

1988-01-01

123

Identification of Novel Non-Hydroxamate Anthrax Toxin Lethal Factor Inhibitors by Topomeric Searching, Docking and Scoring, and In Vitro Screening  

PubMed Central

Anthrax is an infectious disease caused by Bacillus anthracis, a Gram-positive, rod-shaped, anaerobic bacterium. The lethal factor (LF) enzyme is secreted by B. anthracis as part of a tripartite exotoxin and is chiefly responsible for anthrax-related cytotoxicity. As LF can remain in the system long after antibiotics have eradicated B. anthracis from the body, the preferred therapeutic modality would be the administration of antibiotics together with an effective LF inhibitor. Although LF has garnered a great deal of attention as an attractive target for rational drug design, relatively few published inhibitors have demonstrated activity in cell-based assays and, to date, no LF inhibitor is available as a therapeutic or preventive agent. Here we present a novel in silico high-throughput virtual screening protocol that successfully identified 5 non-hydroxamic acid small molecules as new, preliminary LF inhibitor scaffolds with low micromolar inhibition against that target, resulting in a 12.8% experimental hit rate. This protocol screened approximately thirty-five million non-redundant compounds for potential activity against LF and comprised topomeric searching, docking and scoring, and drug-like filtering. Among these 5 hit compounds, none of which has previously been identified as a LF inhibitor, three exhibited experimental IC50 values less than 100 µM. These three preliminary hits may potentially serve as scaffolds for lead optimization, as well as templates for probe compounds to be used in mechanistic studies. Notably, our docking simulations predicted that these novel hits are likely to engage in critical ligand-receptor interactions with nearby residues in at least two of the three (S1’, S1–S2 and S2’) subsites in the LF substrate binding area. Further experimental characterization of these compounds is in process. We found that micromolar-level LF inhibition can be attained by compounds with non-hydroxamate zinc-binding groups that exhibit monodentate zinc chelation, as long as key hydrophobic interactions with at least two LF subsites are retained.

Chiu, Ting-Lan; Solberg, Jonathan; Patil, Satish; Geders, Todd W.; Zhang, Xia; Rangarajan, Subhashree; Francis, Rawle; Finzel, Barry C.; Walters, Michael A.; Hook, Derek J.; Amin, Elizabeth A.

2009-01-01

124

Rapid Vascular Responses to Anthrax Lethal Toxin in Mice Containing a Segment of Chromosome 11 from the CAST/Ei Strain on a C57BL/6 Genetic Background  

PubMed Central

Host allelic variation controls the response to B. anthracis and the disease course of anthrax. Mouse strains with macrophages that are responsive to anthrax lethal toxin (LT) show resistance to infection while mouse strains with LT non-responsive macrophages succumb more readily. B6.CAST.11M mice have a region of chromosome 11 from the CAST/Ei strain (a LT responsive strain) introgressed onto a LT non-responsive C57BL/6J genetic background. Previously, B6.CAST.11M mice were found to exhibit a rapid inflammatory reaction to LT termed the early response phenotype (ERP), and displayed greater resistance to B. anthracis infection compared to C57BL/6J mice. Several ERP features (e.g., bloat, hypothermia, labored breathing, dilated pinnae vessels) suggested vascular involvement. To test this, Evan’s blue was used to assess vessel leakage and intravital microscopy was used to monitor microvascular blood flow. Increased vascular leakage was observed in lungs of B6.CAST.11M mice compared to C57BL/6J mice 1 hour after systemic administration of LT. Capillary blood flow was reduced in the small intestine mesentery without concomitant leukocyte emigration following systemic or topical application of LT, the latter suggesting a localized tissue mechanism in this response. Since LT activates the Nlrp1b inflammasome in B6.CAST.11M mice, the roles of inflammasome products, IL-1? and IL-18, were examined. Topical application to the mesentery of IL-1? but not IL-18 revealed pronounced slowing of blood flow in B6.CAST.11M mice that was not present in C57BL/6J mice. A neutralizing anti-IL-1? antibody suppressed the slowing of blood flow induced by LT, indicating a role for IL-1? in the response. Besides allelic differences controlling Nlrp1b inflammasome activation by LT observed previously, evidence presented here suggests that an additional genetic determinant(s) could regulate the vascular response to IL-1?. These results demonstrate that vessel leakage and alterations to blood flow are part of the rapid response in mice resistant to B. anthracis infection.

Weigel, Kelsey J.; Rues, Laura; Doyle, Edward J.; Buchheit, Cassandra L.; Wood, John G.; Gallagher, Ryan J.; Kelly, Laura E.; Radel, Jeffrey D.; Bradley, Kenneth A.; LeVine, Steven M.

2012-01-01

125

Management of anthrax.  

PubMed

From 3 October 2001 through 16 November 2001, in the United States, there were 18 confirmed cases of inhalational and cutaneous anthrax, an additional 4 suspected cases of cutaneous anthrax, and 5 deaths due to inhalational anthrax. Although the number of cases was relatively small, this experience brought bioterrorism and its potential to sharp focus as thousands of people began receiving prophylactic antibiotics after possible exposure to anthrax spores. These events have resulted in a substantial impact on the health care system, including the rewriting of pneumonia guidelines, new emphasis on identification of microbial etiology, substantial infusion of funds for bioterrorism-related research, and a sudden mandate for regional disaster and public health planning. This article provides clinicians with clinically relevant information about the diagnosis and management of anthrax. PMID:12228822

Bartlett, John G; Inglesby, Thomas V; Borio, Luciana

2002-10-01

126

Anthrax toxin protective antigen integrates poly-?-d-glutamate and pH signals to sense the optimal environment for channel formation  

PubMed Central

Many toxins assemble into oligomers on the surface of cells. Local chemical cues signal and trigger critical rearrangements of the oligomer, inducing the formation of a membrane-fused or channel state. Bacillus anthracis secretes two virulence factors: a tripartite toxin and a poly-?-d-glutamic acid capsule (?-DPGA). The toxin’s channel-forming component, protective antigen (PA), oligomerizes to create a prechannel that forms toxic complexes upon binding the two other enzyme components, lethal factor (LF) and edema factor (EF). Following endocytosis into host cells, acidic pH signals the prechannel to form the channel state, which translocates LF and EF into the host cytosol. We report ?-DPGA binds to PA, LF, and EF, exhibiting nanomolar avidity for the PA prechannel oligomer. We show PA channel formation requires the pH-dependent disruption of the intra-PA domain-2–domain-4 (D2-D4) interface. ?-DPGA stabilizes the D2-D4 interface, preventing channel formation both in model membranes and cultured mammalian cells. A 1.9-Å resolution X-ray crystal structure of a D2-D4-interface mutant and corresponding functional studies reveal how stability at the intra-PA interface governs channel formation. We also pinpoint the kinetic pH trigger for channel formation to a residue within PA’s membrane-insertion loop at the inter-PA D2-D4 interface. Thus, ?-DPGA may function as a chemical cue, signaling that the local environment is appropriate for toxin assembly but inappropriate for channel formation.

Kintzer, Alexander F.; Tang, Iok I; Schawel, Adam K.; Brown, Michael J.; Krantz, Bryan A.

2012-01-01

127

Antibodies Against Anthrax: Mechanisms of Action and Clinical Applications  

PubMed Central

B. anthracis is a bioweapon of primary importance and its pathogenicity depends on its lethal and edema toxins, which belong to the A-B model of bacterial toxins, and on its capsule. These toxins are secreted early in the course of the anthrax disease and for this reason antibiotics must be administered early, in addition to other limitations. Antibodies (Abs) may however neutralize those toxins and target this capsule to improve anthrax treatment, and many Abs have been developed in that perspective. These Abs act at various steps of the cell intoxication and their mechanisms of action are detailed in the present review, presented in correlation with structural and functional data. The potential for clinical application is discussed for Abs targeting each step of entry, with four of these molecules already advancing to clinical trials. Paradoxically, certain Abs may also enhance the lethal toxin activity and this aspect will also be presented. The unique paradigm of Abs neutralizing anthrax toxins thus exemplifies how they may act to neutralize A-B toxins and, more generally, be active against infectious diseases.

Froude, Jeffrey W.; Thullier, Philippe; Pelat, Thibaut

2011-01-01

128

The Role of NF-?B and H3K27me3 Demethylase, Jmjd3, on the Anthrax Lethal Toxin Tolerance of RAW 264.7 Cells  

Microsoft Academic Search

BackgroundIn Bacillus anthracis, lethal toxin (LeTx) is a critical virulence factor that causes immune suppression and toxic shock in the infected host. NF-?B is a key mediator of the inflammatory response and is crucial for the plasticity of first level immune cells such as macrophages, monocytes and neutrophils. In macrophages, this inflammatory response, mediated by NF-?B, can regulate host defense

Nando Dulal Das; Kyoung Hwa Jung; Young Gyu Chai

2010-01-01

129

The sepsis model: An emerging hypothesis for the lethality of inhalation anthrax  

PubMed Central

Inhalation anthrax is often described as a toxin-mediated disease. However, the toxemia model does not account for the high mortality of inhalation anthrax relative to other forms of the disease or for the pathology present in inhalation anthrax. Patients with inhalation anthrax consistently show extreme bacteremia and, in contrast to animals challenged with toxin, signs of sepsis. Rather than toxemia, we propose that death in inhalation anthrax results from an overwhelming bacteremia that leads to severe sepsis. According to our model, the central role of anthrax toxin is to permit the vegetative bacteria to escape immune detection. Other forms of B. anthracis infection have lower mortality because their overt symptoms early in the course of disease cause patients to seek medical care at a time when the infection and its sequelae can still be reversed by antibiotics. Thus, the sepsis model explains key features of inhalation anthrax and may offer a more complete understanding of disease pathology for researchers as well as those involved in the care of patients.

Coggeshall, K. Mark; Lupu, Florea; Ballard, Jimmy; Metcalf, Jordan P.; James, Judith A.; Farris, Darise; Kurosawa, Shinichiro

2013-01-01

130

A comparison of non-toxin vaccine adjuvants for their ability to enhance the immunogenicity of nasally-administered anthrax recombinant protective antigen  

PubMed Central

Development of nasal immunization for human use is hindered by the lack of acceptable adjuvants. Although CT is an effective adjuvant, its toxicity will likely prevent its use in nasal vaccines. This study compared non-toxin adjuvants to CT for their ability to induce protective antibody responses with nasal immunization. C3H/HeN and C57BL/6 mice were immunized with rPA formulated with the following adjuvants: CT, IL-1?, LPS, CpG, Pam3CSK4, 3M-019, resiquimod/R848 or c48/80. Serum and nasal wash cytokine concentrations were monitored 6 hours post-vaccination as biomarkers for acute activation of the innate immune system. Not all of the adjuvants induced significant changes in innate serum or nasal wash cytokines, but when changes were observed, the cytokine signatures were unique for each adjuvant. All adjuvants except Pam3CSK4 induced significantly increased anti-rPA serum IgG titers in both strains of mice, while only IL-1?, c48/80 and CpG enhanced mucosal anti-rPA IgA. Pam3CSK4 was the only adjuvant unable to enhance the induction of serum LeTx-neutralizing antibodies in C3H/HeN mice while c48/80 was the only adjuvant to induce increased serum LeTx-neutralizing antibodies in C57BL/6 mice. Only CT enhanced total serum IgE in C3H/HeN mice while IL-1? enhanced total serum IgE in C57BL/6 mice. The adjuvant influenced antigen-specific serum IgG subclass and T cell cytokine profiles, but these responses did not correlate with the induction of LeTx-neutralizing activity. Our results demonstrate the induction of diverse innate and adaptive immune responses by non-toxin nasal vaccine adjuvants that lead to protective humoral immunity comparable to CT and that these responses may be influenced by the host strain.

Gwinn, William M.; Johnson, Brandi T.; Kirwan, Shaun M.; Sobel, Ashley E.; Abraham, Soman N.; Gunn, Michael D.; Staats, Herman F.

2013-01-01

131

Molecular Motions as a Drug Target: Mechanistic Simulations of Anthrax Toxin Edema Factor Function Led to the Discovery of Novel Allosteric Inhibitors  

PubMed Central

Edema Factor (EF) is a component of Bacillus anthracis toxin essential for virulence. Its adenylyl cyclase activity is induced by complexation with the ubiquitous eukaryotic cellular protein, calmodulin (CaM). EF and its complexes with CaM, nucleotides and/or ions, have been extensively characterized by X-ray crystallography. Those structural data allowed molecular simulations analysis of various aspects of EF action mechanism, including the delineation of EF and CaM domains through their association energetics, the impact of calcium binding on CaM, and the role of catalytic site ions. Furthermore, a transition path connecting the free inactive form to the CaM-complexed active form of EF was built to model the activation mechanism in an attempt to define an inhibition strategy. The cavities at the surface of EF were determined for each path intermediate to identify potential sites where the binding of a ligand could block activation. A non-catalytic cavity (allosteric) was found to shrink rapidly at early stages of the path and was chosen to perform virtual screening. Amongst 18 compounds selected in silico and tested in an enzymatic assay, 6 thiophen ureidoacid derivatives formed a new family of EF allosteric inhibitors with IC50 as low as 2 micromolars.

Laine, Elodie; Martinez, Leandro; Ladant, Daniel; Malliavin, Therese; Blondel, Arnaud

2012-01-01

132

Mouse Monoclonal Antibodies to Anthrax Edema Factor Protect against Infection ?  

PubMed Central

Bacillus anthracis is the causative agent of anthrax, and the tripartite anthrax toxin is an essential element of its pathogenesis. Edema factor (EF), a potent adenylyl cyclase, is one of the toxin components. In this work, anti-EF monoclonal antibodies (MAb) were produced following immunization of mice, and four of the antibodies were fully characterized. MAb 3F2 has an affinity of 388 pM, was most effective for EF detection, and appears to be the first antibody reported to neutralize EF by binding to the catalytic CB domain. MAb 7F10 shows potent neutralization of edema toxin activity in vitro and in vivo; it targets the N-terminal protective antigen binding domain. The four MAb react with three different domains of edema factor, and all were able to detect purified edema factor in Western blot analysis. None of the four MAb cross-reacted with the lethal factor toxin component. Three of the four MAb protected mice in both a systemic edema toxin challenge model and a subcutaneous spore-induced foreleg edema model. A combination of three of the MAb also significantly delayed the time to death in a third subcutaneous spore challenge model. This appears to be the first direct evidence that monoclonal antibody-mediated neutralization of EF alone is sufficient to delay anthrax disease progression.

Leysath, Clinton E.; Chen, Kuang-Hua; Moayeri, Mahtab; Crown, Devorah; Fattah, Rasem; Chen, Zhaochun; Das, Suman R.; Purcell, Robert H.; Leppla, Stephen H.

2011-01-01

133

Effect of 2-Fluorohistidine Labeling of the Anthrax Protective Antigen on Stability, Pore Formation, and Translocation †  

Microsoft Academic Search

The action of anthrax toxin relies in part upon the ability of the protective antigen (PA) moiety to form a heptameric pore in the endosomal membrane, providing a portal for entry of the enzymic moieties of the toxin into the cytosol. Pore formation is dependent on a conformational change in the heptameric prepore that occurs in the neutral to mildly

D. Shyamali Wimalasena; John C. Cramer; Blythe E. Janowiak; Stephen J. Juris; Roman A. Melnyk; D. Eric Anderson; Kenneth L. Kirk; R. John Collier; James G. Bann

2007-01-01

134

Nanopore biosensor for label-free and real-time detection of anthrax lethal factor.  

PubMed

We report a label-free real-time nanopore sensing method for the detection of anthrax lethal factor, a component of the anthrax toxin, by using a complementary single-stranded DNA as a molecular probe. The method is rapid and sensitive: sub-nanomolar concentrations of the target anthrax lethal factor DNA could be detected in ?1 min. Further, our method is selective, which can differentiate the target DNA from other single-stranded DNA molecules at the single-base resolution. This sequence-specific detection approach should find useful application in the development of nanopore sensors for the detection of other pathogens. PMID:24806593

Wang, Liang; Han, Yujing; Zhou, Shuo; Wang, Guihua; Guan, Xiyun

2014-05-28

135

Evaluation of Intravenous Anthrax Immune Globulin for Treatment of Inhalation Anthrax  

PubMed Central

Bacillus anthracis toxins can be neutralized by antibodies against protective antigen (PA), a component of anthrax toxins. Anthrivig (human anthrax immunoglobulin), also known as AIGIV, derived from plasma of humans immunized with BioThrax (anthrax vaccine adsorbed), is under development for the treatment of toxemia following exposure to anthrax spores. The pharmacokinetics (PK) of AIGIV was assessed in naive animals and healthy human volunteers, and the efficacy of AIGIV was assessed in animals exposed via inhalation to aerosolized B. anthracis spores. In the clinical study, safety, tolerability, and PK were evaluated in three dose cohorts (3.5, 7.1, and 14.2 mg/kg of body weight of anti-PA IgG) with 30 volunteers per cohort. The elimination half-life of AIGIV in rabbits, nonhuman primates (NHPs), and humans following intravenous infusion was estimated to be approximately 4, 12, and 24 days, respectively, and dose proportionality was observed. In a time-based treatment study, AIGIV protected 89 to 100% of animals when administered 12 h postexposure; however, a lower survival rate of 39% was observed when animals were treated 24 h postexposure, underscoring the need for early intervention. In a separate set of studies, animals were treated on an individual basis upon detection of a clinical sign or biomarker of disease, namely, a significant increase in body temperature (SIBT) in rabbits and presence of PA in the serum of NHPs. In these trigger-based intervention studies, AIGIV induced up to 75% survival in rabbits depending on the dose and severity of toxemia at the time of treatment. In NHPs, up to 33% survival was observed in AIGIV-treated animals. (The clinical study has been registered at ClinicalTrials.gov under registration no. NCT00845650.)

Mytle, Nutan; Hopkins, Robert J.; Malkevich, Nina V.; Basu, Subhendu; Meister, Gabriel T.; Sanford, Daniel C.; Comer, Jason E.; Van Zandt, Kristopher E.; Al-Ibrahim, Mohamed; Kramer, William G.; Howard, Cris; Daczkowski, Nancy; Chakrabarti, Ajoy C.; Ionin, Boris; Nabors, Gary S.

2013-01-01

136

What Is Anthrax?  

MedlinePLUS

... SIL-us an-THRAY-sus). These bacteria make spores , a form of the germ covered by a protective shell. The spores can live for years in the soil, and ... get anthrax if they are exposed to the spores. (Exposed means that a germ that can cause ...

137

Methods for neutralizing anthrax or anthrax spores  

DOEpatents

The present invention concerns methods, compositions and apparatus for neutralizing bioagents, wherein bioagents comprise biowarfare agents, biohazardous agents, biological agents and/or infectious agents. The methods comprise exposing the bioagent to an organic semiconductor and exposing the bioagent and organic semiconductor to a source of energy. Although any source of energy is contemplated, in some embodiments the energy comprises visible light, ultraviolet, infrared, radiofrequency, microwave, laser radiation, pulsed corona discharge or electron beam radiation. Exemplary organic semiconductors include DAT and DALM. In certain embodiments, the organic semiconductor may be attached to one or more binding moieties, such as an antibody, antibody fragment, or nucleic acid ligand. Preferably, the binding moiety has a binding affinity for one or more bioagents to be neutralized. Other embodiments concern an apparatus comprising an organic semiconductor and an energy source. In preferred embodiments, the methods, compositions and apparatus are used for neutralizing anthrax spores.

Sloan, Mark A; Vivekandanda, Jeevalatha; Holwitt, Eric A; Kiel, Johnathan L

2013-02-26

138

Purification of tritium-labeled cholera toxin.  

PubMed Central

Cholera toxin was labeled with tritium by the Wilzbach technique, and highly purified radiolabeled toxin was obtained by Sephadex column chromatography and disc gel electrophoresis. 3H-labeled cholera toxin retained its biological activity and chemical stability and had a specific activity of 405.9 muCi/mumol. The methods utilized in extraction and purification of 3H-labeled toxin may be advantageous for preparation of other biologically active radiolabeled proteins. Images

Banwell, J G; Hanke, D W; Diedrich, D

1978-01-01

139

Prophylaxis against anthrax.  

PubMed

The paper presents fundamental knowledge concerning Bacillus anthracis and its potential terrorist misuse. The basic clinical forms are resumed with emphasis on inhalation infection from inspiration of B. anthracis spores. The AVA vaccine licensed in the United States, primary vaccination, protective efficacy of the vaccine, and adverse events are characterised. Stress is laid on pre-exposure and post-exposure prophylaxis of anthrax. PMID:12515043

Splino, Miroslav; Patocka, Jirí

2002-01-01

140

Small-Molecule Inhibitors of Lethal Factor Protease Activity Protect against Anthrax Infection  

PubMed Central

Bacillus anthracis, the causative agent of anthrax, manifests its pathogenesis through the action of two secreted toxins. The bipartite lethal and edema toxins, a combination of lethal factor or edema factor with the protein protective antigen, are important virulence factors for this bacterium. We previously developed small-molecule inhibitors of lethal factor proteolytic activity (LFIs) and demonstrated their in vivo efficacy in a rat lethal toxin challenge model. In this work, we show that these LFIs protect against lethality caused by anthrax infection in mice when combined with subprotective doses of either antibiotics or neutralizing monoclonal antibodies that target edema factor. Significantly, these inhibitors provided protection against lethal infection when administered as a monotherapy. As little as two doses (10 mg/kg) administered at 2 h and 8 h after spore infection was sufficient to provide a significant survival benefit in infected mice. Administration of LFIs early in the infection was found to inhibit dissemination of vegetative bacteria to the organs in the first 32 h following infection. In addition, neutralizing antibodies against edema factor also inhibited bacterial dissemination with similar efficacy. Together, our findings confirm the important roles that both anthrax toxins play in establishing anthrax infection and demonstrate the potential for small-molecule therapeutics targeting these proteins.

Crown, Devorah; Jiao, Guan-Sheng; Kim, Seongjin; Johnson, Alan; Leysath, Clinton; Leppla, Stephen H.

2013-01-01

141

Anthrax: Who Is at Risk  

MedlinePLUS

... Confirming Anthrax Through the Laboratory Response Network Laboratory Testing - FAQs Collecting Specimens Recommended Specimens Information for Specific Groups Laboratory Professionals People Who Work with Animal Products Exposure to Hides/Drums Treatment of Products ...

142

Detection of anthrax protective antigen (PA) using europium labeled anti-PA monoclonal antibody and time-resolved fluorescence.  

PubMed

Inhalation anthrax is a rare but acute infectious disease following adsorption of Bacillus anthracis spores through the lungs. The disease has a high fatality rate if untreated, but early and correct diagnosis has a significant impact on case patient recovery. The early symptoms of inhalation anthrax are, however, non-specific and current anthrax diagnostics are primarily dependent upon culture and confirmatory real-time PCR. Consequently, there may be a significant delay in diagnosis and targeted treatment. Rapid, culture-independent diagnostic tests are therefore needed, particularly in the context of a large scale emergency response. The aim of this study was to evaluate the ability of monoclonal antibodies to detect anthrax toxin proteins that are secreted early in the course of B. anthracis infection using a time-resolved fluorescence (TRF) immunoassay. We selected monoclonal antibodies that could detect protective antigen (PA), as PA83 and also PA63 and LF in the lethal toxin complex. The assay reliable detection limit (RDL) was 6.63×10(-6)?M (0.551ng/ml) for PA83 and 2.51×10(-5)?M (1.58ng/ml) for PA63. Despite variable precision and accuracy of the assay, PA was detected in 9 out of 10 sera samples from anthrax confirmed case patients with cutaneous (n=7), inhalation (n=2), and gastrointestinal (n=1) disease. Anthrax Immune Globulin (AIG), which has been used in treatment of clinical anthrax, interfered with detection of PA. This study demonstrates a culture-independent method of diagnosing anthrax through the use of monoclonal antibodies to detect PA and LF in the lethal toxin complex. PMID:24857756

Stoddard, Robyn A; Quinn, Conrad P; Schiffer, Jarad M; Boyer, Anne E; Goldstein, Jason; Bagarozzi, Dennis A; Soroka, Stephen D; Dauphin, Leslie A; Hoffmaster, Alex R

2014-06-01

143

Two capsular polysaccharides enable Bacillus cereus G9241 to cause anthrax-like disease  

PubMed Central

Summary Bacillus cereus G9241 causes an anthrax-like respiratory illness in humans, however the molecular mechanisms of disease pathogenesis are not known. Genome sequencing identified two putative virulence plasmids proposed to provide for anthrax toxin (pBCXO1) and/or capsule expression (pBC218). We report here that B. cereus G9241 causes anthrax-like disease in immune-competent mice, which is dependent on each of the two virulence plasmids. pBCXO1 encodes pagA1, the homolog of anthrax protective antigen, as well as hasACB, providing for hyaluronic acid capsule formation, two traits that each contribute to disease pathogenesis. pBC218 harbors bpsX-H, Bacillus cereus exo-polysaccharide, which produce a second capsule. During infection, B. cereus G9241 elaborates both hasACB and bpsX-H capsules, which together are essential for the establishment of anthrax-like disease and the resistance of bacilli to phagocytosis. A single nucleotide deletion causes premature termination of hasA translation in B. anthracis, which is known to escape phagocytic killing by its pXO2 encoded poly-D-?-glutamic acid (PDGA) capsule. Thus, multiple different gene clusters endow pathogenic bacilli with capsular material, provide for escape from innate host immune responses and aid in establishing the pathogenesis of anthrax-like disease.

Oh, So-Young; Budzik, Jonathan M.; Garufi, Gabriella; Schneewind, Olaf

2012-01-01

144

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

PubMed Central

Bacillus anthracis is the causative agent of anthrax. We have developed a novel whole-bacterial-cell anthrax vaccine utilizing B. anthracis that is killed but metabolically active (KBMA). Vaccine strains that are asporogenic and nucleotide excision repair deficient were engineered by deleting the spoIIE and uvrAB genes, rendering B. anthracis extremely sensitive to photochemical inactivation with S-59 psoralen and UV light. We also introduced point mutations into the lef and cya genes, 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. KBMA B. anthracis vaccines were avirulent in mice and induced less injection site inflammation than recombinant PA adsorbed to aluminum hydroxide gel. KBMA B. anthracis-vaccinated animals produced antibodies against numerous anthrax antigens, including high levels of anti-PA and toxin-neutralizing antibodies. Vaccination with KBMA B. anthracis fully 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 KBMA B. anthracis were 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.

Skoble, Justin; Beaber, John W.; Gao, Yi; Lovchik, Julie A.; Sower, Laurie E.; Liu, Weiqun; Luckett, William; Peterson, Johnny W.; Calendar, Richard; Portnoy, Daniel A.; Lyons, C. Rick; Dubensky, Thomas W.

2009-01-01

145

Aerosol Vaccination of Guinea Pigs Against Anthrax.  

National Technical Information Service (NTIS)

Aerosol immunization of guinea pigs against anthrax proved less effective than intradermal vaccination. The method of immunization of animals against anthrax by aerosol vaccination could be used in practice after more extensive experimental tests. (Author...

M. Chajkowski

1968-01-01

146

Anthrax: A Guide for Biology Teachers.  

ERIC Educational Resources Information Center

Presents facts about anthrax so that biology teachers can communicate them to others. Defines anthrax and the nature of bacterial spores. Discusses transmission and clinical presentation as well as prevention, diagnosis, and treatment. Explores the use of anthrax as a biological warfare agent. (Contains 27 references.) (DDR)

Simon, Eric J.

2002-01-01

147

Correlation between Lethal Toxin-Neutralizing Antibody Titers and Protection from Intranasal Challenge with Bacillus anthracis Ames Strain Spores in Mice after Transcutaneous Immunization with Recombinant Anthrax Protective Antigen  

PubMed Central

Transcutaneous immunization of mice with recombinant protective antigen (rPA) of Bacillus anthracis resulted in significantly higher lethal toxin-neutralizing antibody titers than did intramuscular injection of alum-adsorbed rPA. Immunized mice were partially protected against intranasal challenge with 235,000 (10 50% lethal doses) Ames strain B. anthracis spores. A highly significant correlation was observed between toxin-neutralizing antibody titer and survival after challenge. Future experiments with rabbits and nonhuman primates should confirm the significance of protection by this vaccine strategy.

Peachman, Kristina K.; Rao, Mangala; Alving, Carl R.; Burge, Robert; Leppla, Stephen H.; Rao, Venigalla B.; Matyas, Gary R.

2006-01-01

148

Neutralizing Antibodies and Persistence of Immunity following Anthrax Vaccination  

PubMed Central

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.

Hanson, James F.; Taft, Sarah C.; Weiss, Alison A.

2006-01-01

149

Airing Out Anthrax  

NASA Technical Reports Server (NTRS)

The AiroCide TiO2 is an air-purifier that kills 93.3 percent of airborne pathogens that pass through it, including Bacillus anthraci, more commonly known as anthrax. It is essentially a spinoff of KES Science & Technology, Inc.'s Bio-KES system, a highly effective device used by the produce industry for ethylene gas removal to aid in preserving the freshness of fruits, vegetables, and flowers. The TiO2-based ethylene removal technology that is incorporated into the company's AiroCide TiO2 and Bio-KES products was first integrated into a pair of plant-growth chambers known as ASTROCULTURE(TM) and ADVANCED ASTROCULTURE(TM). Both chambers have housed commercial plant growth experiments in space on either the Space Shuttle or the International Space Station. The AiroCide TiO2 also has a proven record of destroying 98 percent of other airborne pathogens, such as microscopic dust mites, molds, and fungi. Moreover, the device is a verified killer of Influenza A (flu), E. coli, Staphylococcus aureas, Streptococcus pyogenes, and Mycoplasma pneumoniae, among many other harmful viruses.

2002-01-01

150

[Production and characteristics of monoclonal antibodies to the diphtheria toxin].  

PubMed

Monoclonal antibodies to the diphtheria toxin were produced without cross reactivity with the thermolabile toxin (LT) from Escherichia coli; ricin; choleraic toxin; the SeA, SeB, SeE, SeI, and SeG toxins of staphylococcus; the lethal factor of the anthrax toxin; and the protective antigen of the anthrax toxin. A pair of antibodies for the quantitative determination of the diphtheria toxin in the sandwich variation of enzyme-linked immunosorbent assay (ELISA) was chosen. The determination limit of the toxin was 0.7 ng/ml in plate and 1.6 ng/ml in microchip ELISA. The presence of a secretion from the nasopharynx lavage did not decrease the sensitivity of the toxin determination by sandwich ELISA. The immunization of mice with the diphtheria toxin and with a conjugate of the diphtheria toxin with polystyrene microspheres demonstrated that the conjugate immunization resulted in the formation of hybridoma clones which produced antibodies only to the epitopes of the A fragment of the diphtheria toxin. The immunization with the native toxin caused the production of hybridoma clones which predominantly produced antibodies to the epitopes of the B fragment. PMID:19915639

Valiakina, T I; Lakhtina, O E; Komaleva, R L; Simonova, M A; Samokhvalova, L V; Shoshina, N S; Kalinina, N A; Rubina, A Iu; Filippova, M A; Vertiev, Iu V; Grishin, E V

2009-01-01

151

Serological Correlate of Protection in Guinea Pigs for a Recombinant Protective Antigen Anthrax Vaccine Produced from Bacillus brevis  

PubMed Central

Objective Recombinant protective antigen (rPA) is the active pharmaceutical ingredient of a second generation anthrax vaccine undergoing clinical trials both in Korea and the USA. By using the rPA produced from Bacillus brevis pNU212 expression system, correlations of serological immune response to anthrax protection efficacy were analyzed in a guinea pig model. Methods Serological responses of rPA anthrax vaccine were investigated in guinea pigs that were given single or two injections (interval of 4 weeks) of various amounts of rPA combined with aluminumhydroxide adjuvant. Guinea pigs were subsequently challenged by the intramuscular injection with 30 half-lethal doses (30LD50) of virulent Bacillus anthracis spores. Serumantibody titerswere determined by anti-PA IgGELISA and the ability of antibodies to neutralize the cytotoxicity of lethal toxin on J774A.1 cell was measured through the toxin neutralizing antibody (TNA) assay. Results To examine correlations between survival rate and antibody titers, correlation between neutralizing antibody titers and the extent of protection was determined. Toxin neutralization titers of at least 1176 were sufficient to confer protection against a dose of 30LD50 of virulent anthrax spores of the H9401 strain. Such consistency in the correlation was not observed from those antibody titers determined by ELISA. Conclusion Neutralizing-antibody titers can be used as a surrogate marker.

Chun, Jeong-Hoon; Choi, On-Jee; Cho, Min-Hee; Hong, Kee-Jong; Seong, Won Keun; Oh, Hee-Bok; Rhie, Gi-Eun

2012-01-01

152

Preparedness for an anthrax attack.  

PubMed

Bacillus anthracis is a long-known bacterial organism with a uniquely stable spore stage. Its stability and the lethal disease which results when the spore is inhaled made it a favorite of state-sponsored biological weapons programs throughout the Cold War era. It is also believed to be high on the list of candidate microbial agents which could be used by terrorist groups or lone actors. Its unique characteristics make protection of humans, especially civilians, from an intentional biological attack very difficult. The author argues that an all-hazards/public health approach - which would also be needed for any natural or deliberate outbreak, no matter the agent - should serve as a foundation of preparation for the specific anthrax countermeasures. Because B. anthracis is a unique organism, specific countermeasures for anthrax detection, diagnostics, prophylaxis and therapy, should be developed in nations or regions where the threat of biological attack is believed to warrant such preparation. Other considerations for a nation interested in anthrax preparedness are discussed. PMID:19619577

Franz, David R

2009-12-01

153

Treatment of Anthrax Disease Frequently Asked Questions  

SciTech Connect

This document provides a summary of Frequently Asked Questions (FAQs) on the treatment of anthrax disease caused by a wide-area release of Bacillus anthracis spores as an act bioterrorism. These FAQs are intended to provide the public health and medical community, as well as others, with guidance and communications to support the response and long-term recovery from an anthrax event.

Judd, Kathleen S.; Young, Joan E.; Lesperance, Ann M.; Malone, John D.

2010-05-14

154

Anthrax Vaccine: What You Need to Know  

MedlinePLUS

... fatigue. Up to 20% of these cases are fatal if untreated. Gastrointestinal anthrax . This form of anthrax can result from eating raw or undercooked infected meat. Symptoms can include fever, nausea, vomiting, sore throat, abdominal pain and swelling, and swollen lymph glands. Gastrointestinal ...

155

Metabolism of the cyclic peptide HC-toxin, a host-specific toxin, by resistant (R) and susceptible (S) maize  

Microsoft Academic Search

Cochliobolus carbonum (race 1) and the toxin it produces, HC-toxin, affect only maize that is homozygous recessive at the nuclear locus, Hm. Radiolabeled HC-toxin was purified after controlled feeding of D,L-(³H)-alanine to the fungus and used to study metabolism as a basis for its host-selectivity. A single HC-toxin metabolite was recovered from maize leaves exposed to (³H)-HC-toxin. The 8-keto group

R. Meeley; J. D. Walton

1990-01-01

156

Anthrax in America 2001-2003.  

PubMed Central

Anthrax caused by Bacillus anthracis in humans is rare. Two recent outbreaks that were intentionally caused occurred among postal employees, politicians, and journalists in the United States. This has caused tremendous fear, and our experience with these "anthrax incidents" has changed our views on the natural history of this disease in people. In this paper, we review the lifecycle and biology of this micro-organism. Anthrax that occurs from a weaponized form of this micro-organism has a specific clinical presentation that requires a suspicion of anthrax exposure to be diagnosed. New methods of testing for anthrax have been developed and may simplify diagnosis in the future. The range of illness caused by B. anthracis from the molecular level to the clinical symptoms is discussed. We also review the diagnostic criteria and differential diagnosis as well as treatment of this condition.

Joshi, Shivang G.; Cymet, Holly Berkovits; Kerkvliet, Gary; Cymet, Tyler

2004-01-01

157

Serum adenosine deaminase activity in cutaneous anthrax  

PubMed Central

Background Adenosine deaminase (ADA) activity has been discovered in several inflammatory conditions; however, there are no data associated with cutaneous anthrax. The aim of this study was to investigate serum ADA activity in patients with cutaneous anthrax. Material/Methods Sixteen patients with cutaneous anthrax and 17 healthy controls were enrolled. We measured ADA activity; peripheral blood leukocyte, lymphocyte, neutrophil, and monocyte counts; erythrocyte sedimentation rate; and C reactive protein levels. Results Serum ADA activity was significantly higher in patients with cutaneous anthrax than in the controls (p<0.001). A positive correlation was observed between ADA activity and lymphocyte counts (r=0.589, p=0.021) in the patient group. Conclusions This study suggests that serum ADA could be used as a biochemical marker in cutaneous anthrax.

Sunnetcioglu, Mahmut; Karadas, Sevdegul; Aslan, Mehmet; Ceylan, Mehmet Resat; Demir, Halit; Oncu, Mehmet Resit; Karahocagil, Mustafa Kas?m; Sunnetcioglu, Aysel; Aypak, Cenk

2014-01-01

158

Serum adenosine deaminase activity in cutaneous anthrax.  

PubMed

Background Adenosine deaminase (ADA) activity has been discovered in several inflammatory conditions; however, there are no data associated with cutaneous anthrax. The aim of this study was to investigate serum ADA activity in patients with cutaneous anthrax. Material and Methods Sixteen patients with cutaneous anthrax and 17 healthy controls were enrolled. We measured ADA activity; peripheral blood leukocyte, lymphocyte, neutrophil, and monocyte counts; erythrocyte sedimentation rate; and C reactive protein levels. Results Serum ADA activity was signi?cantly higher in patients with cutaneous anthrax than in the controls (p<0.001). A positive correlation was observed between ADA activity and lymphocyte counts (r=0.589, p=0.021) in the patient group. Conclusions This study suggests that serum ADA could be used as a biochemical marker in cutaneous anthrax. PMID:24997584

Sunnetcioglu, Mahmut; Karadas, Sevdegul; Aslan, Mehmet; Ceylan, Mehmet Resat; Demir, Halit; Oncu, Mehmet Resit; Karahocagil, Mustafa Kas?m; Sunnetcioglu, Aysel; Aypak, Cenk

2014-01-01

159

Stable dry powder formulation for nasal delivery of anthrax vaccine.  

PubMed

There is a current biodefense interest in protection against anthrax. Here, we developed a new generation of stable and effective anthrax vaccine. We studied the immune response elicited by recombinant protective antigen (rPA) delivered intranasally with a novel mucosal adjuvant, a mast cell activator compound 48/80 (C48/80). The vaccine formulation was prepared in a powder form by spray-freeze-drying (SFD) under optimized conditions to produce particles with a target size of D(50) = 25 ?m, suitable for delivery to the rabbit nasal cavity. Physicochemical properties of the powder vaccines were characterized to assess their delivery and storage potential. Structural stability of rPA was confirmed by circular dichroism and attenuated total reflectance-Fourier transform infrared spectroscopy, whereas functional stability of rPA and C48/80 was monitored by cell-based assays. Animal study was performed using a unit-dose powder device for direct nasal application. Results showed that C48/80 provided effective mucosal adjuvant activity in rabbits. Freshly prepared SFD powder vaccine formulations or powders stored for over 2 years at room temperature elicited significantly elevated serum PA-specific and lethal toxin neutralization antibody titers that were comparable to that induced by intramuscular immunization with rPA. Nasal delivery of this vaccine formulation may be a viable alternative to the currently licensed vaccine or an attractive vaccine platform for other mucosally transmitted diseases. PMID:21905034

Wang, Sheena H; Kirwan, Shaun M; Abraham, Soman N; Staats, Herman F; Hickey, Anthony J

2012-01-01

160

Anthrax--update on diagnosis and management.  

PubMed

Human anthrax is difficult to contain. This is primarily because it is a zoonotic disease and the disease has never been contained in the livestock of India due to lack of adequate vaccination facilities. Animal anthrax is very common in many parts of India. The problem of anthrax is further compounded by lack of awareness on the part of village folk who unwittingly handle the hide and share the dead animal meat and this causes cutaneous and gastrointestinal forms of anthrax respectively. Hemorrhagic meningitis and pulmonary anthrax, the other forms of anthrax, carry a risk of nearly cent percent mortality. Characteristic gram positive rods abundantly found in the smear of the cerebrospinal fluid, blood etc. make diagnosis certain in most of the cases. Resistance to penicillin, the drug of choice, now being occasionally reported, may become a confounding factor while attempting successful control of the disease. Other antibiotics which are found to be very effective are doxycycline and ciprofloxacin. Fear of use of anthrax spores as a biological weapon has also given a new dimension to the problem. PMID:22334971

Dutta, T K; Sujatha, S; Sahoo, R K

2011-09-01

161

Targeting HER2-positive cancer cells with receptor-redirected anthrax protective antigen  

PubMed Central

Targeted therapeutics have emerged in recent years as an attractive approach to treating various types of cancer. One approach is to modify a cytocidal protein toxin to direct its action to a specific population of cancer cells. We created a targeted toxin in which the receptor-binding and pore-forming moiety of anthrax toxin, termed Protective Antigen (PA), was modified to redirect its receptor specificity to HER2, a marker expressed at the surface of a significant fraction of breast and ovarian tumors. The resulting fusion protein (mPA-ZHER2) delivered cytocidal effectors specifically into HER2-positive tumor cells, including a trastuzumab-resistant line, causing death of the cells. No off-target killing of HER2-negative cells was observed, either with homogeneous populations or with mixtures of HER2-positive and HER2-negative cells. A mixture of mPA variants targeting different receptors mediated killing of cells bearing either receptor, without affecting cells devoid of these receptors. Anthrax toxin may serve as an effective platform for developing therapeutics to ablate cells bearing HER2 or other tumor-specific cell-surface markers.

McCluskey, Andrew J.; Olive, Andrew J.; Starnbach, Michael N.; Collier, R. John

2012-01-01

162

Anthrax Vaccine Induced Antibodies Provide Cross-Species Prediction of Survival to Aerosol Challenge  

PubMed Central

Because clinical trials to assess the efficacy of vaccines against anthrax are not ethical or feasible, licensure for new anthrax vaccines will likely involve the Food and Drug Administration’s “Animal Rule,” a set of regulations that allow approval of products based on efficacy data only in animals combined with immunogenicity and safety data in animals and humans. US government sponsored animal studies have shown anthrax vaccine efficacy in a variety of settings. We examined data from 21 of those studies to determine if an immunological bridge based on lethal toxin neutralization activity assay (TNA) can predict survival against an inhalation anthrax challenge within and across species and genera. The 21 studies were classified into 11 different settings, each of which had the same animal species, vaccine type and formulation, vaccination schedule, time of TNA measurement, and challenge time. Logistic regression models determined the contribution of vaccine dilution dose and TNA on prediction of survival. For most settings, logistic models using only TNA explained more than 75% of the survival effect of the models with dose additionally included. Cross species survival predictions using TNA were compared to the actual survival and shown to have good agreement (Cohen’s ? ranged from 0.55 to 0.78). In one study design, cynomolgus macaque data predicted 78.6% survival in rhesus macaques (actual survival 83.0%) and 72.6% in rabbits (actual survival, 64.6%). These data add support for the use of TNA as an immunological bridge between species to extrapolate data in animals to predict anthrax vaccine effectiveness in humans.

Fay, Michael P.; Follmann, Dean A.; Lynn, Freyja; Schiffer, Jarad M.; Stark, Greg; Kohberge, Robert; Quinn, Conrad P.; Nuzum, Edwin O.

2013-01-01

163

Laboratory Testing for Anthrax: Frequently Asked Questions  

MedlinePLUS

... Confirming Anthrax Through the Laboratory Response Network Laboratory Testing - FAQs Collecting Specimens Recommended Specimens Information for Specific Groups Laboratory Professionals People Who Work with Animal Products Exposure to Hides/Drums Treatment of Products ...

164

Anthrax: Exposure to Hides/Drums  

MedlinePLUS

... Confirming Anthrax Through the Laboratory Response Network Laboratory Testing - FAQs Collecting Specimens Recommended Specimens Information for Specific Groups Laboratory Professionals People Who Work with Animal Products Exposure to Hides/Drums Treatment of Products ...

165

Anthrax vaccines: present status and future prospects.  

PubMed

The management of anthrax remains a top priority among the biowarfare/bioterror agents. It was the Bacillus anthracis spore attack through the US mail system after the September 11, 2001, terrorist attacks in the USA that highlighted the potential of B. anthracis as a bioterrorism agent and the threat posed by its deliberate dissemination. These attacks invigorated the efforts toward understanding the anthrax pathogenesis and development of more comprehensive medical intervention strategies for its containment in case of both natural disease and manmade, accidental or deliberate infection of a non-suspecting population. Currently, efforts are directed toward the development of safe and efficacious vaccines as well as intervention tools for controlling the disease in the advanced fulminant stage when toxemia has already developed. This work presents an overview of the current understanding of anthrax pathogenesis and recent advances made, particularly after 2001, for the successful management of anthrax and outlines future perspectives. PMID:23984963

Kaur, Manpreet; Singh, Samer; Bhatnagar, Rakesh

2013-08-01

166

Air Force Surgeon General Speaks on Anthrax.  

National Technical Information Service (NTIS)

Presentation covers the AFNEWS story 14 June 1999, on Anthrax Virus Vaccine. The Air Force Surgeon General, Lieutenant General Charles Rodman, speaking at Dover Air Force Base, Delaware Commander's Call, talks about the importance of being vaccinated agai...

1999-01-01

167

Gastrointestinal anthrax: clinical experience in 5 cases  

PubMed Central

Background: Bacillus anthracis may usually cause three forms of anthrax: inhalation, gastrointestinal and cutaneous. The gastrointestinal (GI) anthrax develops after eating contaminated meat. Thus, in this paper were report 5 cases of intestinal anthrax. Case Presentation: We report a case series of intestinal anthrax, with history of consumption of raw or poorly cooked liver of sheep. One patient was female and 4 were males with the age range between 17 and 26 years. All patients were admitted with abdominal pain, nausea, and vomiting. Examination revealed abdominal distention on the right lower quadrant or diffuse tenderness. Laboratory examination in all patients showed leukocytosis with polymorphonuclear of >80%. Because of the unclear and questionable diagnosis, exploratory laparotomy was performed on several patients, invariably showing an abundant yellowish and thick ascitic fluid, soft hypertrophied mesenteric lymph nodes (3-5 cm) mostly in the ileocecal region, and substantial edema involving one segment of small bowel, cecum or ascending colon. Anthrax was diagnosed on the epidemiologic basis (ingestion history of half cooked liver of sheep) or microbiologic (microscopy with bacterial culture) and pathologic testing (post surgery in four patients or autopsy in one patient). With appropriate treatment, 4 survived and one patient died. Conclusion: Gastrointestinal anthrax is characterized by rapid onset, fever, ascitis and septicemia. The symptoms can mimic those seen in an acute surgical abdomen. Rapid diagnosis and prompt initiation of antibiotic therapy and then exploratory laparotomy (right hemicolectomy) are keys to survival.

Maddah, Ghodratollah; Abdollahi, Abbas; Katebi, Mehrdad

2013-01-01

168

Anthrax Vaccine Powder Formulations for Nasal Mucosal Delivery.  

National Technical Information Service (NTIS)

Anthrax remains a serious threat worldwide as a bioterror agent. A second-generation anthrax vaccine currently under clinical evaluation consists of a recombinant Protective Antigen (rPA) of Bacillus anthracis. We have previously demonstrated that complet...

G. E. Jiang S. B. Joshi L. J. Peek D. T. Brandau J. Huang

2005-01-01

169

No CDC Lab Workers Seem Sickened by Anthrax  

MedlinePLUS

... JavaScript. No CDC Lab Workers Seem Sickened by Anthrax: Report Breakdown in safety procedures last month led ... staff Tuesday, July 1, 2014 Related MedlinePlus Page Anthrax TUESDAY, July 1, 2014 (HealthDay News) -- None of ...

170

In vitro and in vivo activities of recombinant anthrax protective antigen co-expressed with thioredoxin in Escherichia coli.  

PubMed

Because of the central role it plays in the formation of lethal toxin and edema toxin, protective antigen (PA) is the principal target for the development of vaccines against anthrax. In the present study, we explored and compared the in vitro and in vivo activities of recombinant anthrax protective antigen (rPA) and receptor binding domain of protective antigen (PA4). As a result, the fully soluble rPA and PA4 proteins were successfully expressed in Escherichia coli by co-expression with thioredoxin (Trx), and the rPA was active in forming cytotoxic lethal toxins, indicating that the rPA protein retains a functionally biological activity. Furthermore, immunization with rPA protein induced stronger PA-specific immune responses in mice than PA4 protein. The protection elicited by immunization with PA4 suggests the presence of common neutralizing epitopes between rPA and PA4, but the immunization with rPA protein induced stronger neutralizing antibodies and protective levels against challenge with the B. anthracis strain A16R than the PA4 protein. The sera neutralizing antibodies titers correlated well with anti-PA group ELISA antibodies titers and the in vivo protective potency. Based on the results of cell cytotoxicity assays and the observed immune responses and protective potency, we concluded that the soluble rPA protein retains the in vitro and in vivo functionally biological activity and can be developed into a highly effective human subunit vaccine candidate against anthrax. PMID:23880942

Ma, Yao; Yu, Yun-Zhou; Zhu, Yu-Feng; Xu, Qing; Sun, Zhi-Wei

2013-11-01

171

Mapping the lethal factor and edema factor binding sites on oligomeric anthrax protective antigen  

PubMed Central

Assembly of anthrax toxin complexes at the mammalian cell surface involves competitive binding of the edema factor (EF) and lethal factor (LF) to heptameric oligomers and lower order intermediates of PA63, the activated carboxyl-terminal 63-kDa fragment of protective antigen (PA). We used sequence differences between PA63 and homologous PA-like proteins to delineate a region within domain 1? of PA that may represent the binding site for these ligands. Substitution of alanine for any of seven residues in or near this region (R178, K197, R200, P205, I207, I210, and K214) strongly inhibited ligand binding. Selected mutations from this set were introduced into two oligomerization-deficient PA mutants, and the mutants were used in various combinations to map the single ligand site within dimeric PA63. The site was found to span the interface between two adjacent subunits, explaining the dependence of ligand binding on PA oligomerization. The locations of residues comprising the site suggest that a single ligand molecule sterically occludes two adjacent sites, consistent with the finding that the PA63 heptamer binds a maximum of three ligand molecules. These results elucidate the process by which the components of anthrax toxin, and perhaps other binary bacterial toxins, assemble into toxic complexes.

Cunningham, Kristina; Lacy, D. Borden; Mogridge, Jeremy; Collier, R. John

2002-01-01

172

pH-dependent permeabilization of the plasma membrane of mammalian cells by anthrax protective antigen.  

PubMed

Protective antigen (PA) of anthrax toxin forms ion-conductive channels in planar lipid bilayers and liposomes under acidic pH conditions. We show here that PA has a similar permeabilizing action on the plasma membranes of CHO-K1 and three other mammalian cell lines (J774A.1, RAW264.7 and Vero). Changes in membrane permeability were evaluated by measuring the efflux of the K+ analogue, 86Rb+, from prelabelled cells, and the influx of 22Na+. The permeabilizing activity of PA was limited to a proteolytically activated form (PAN) and was dependent on acidic pH for membrane insertion (optimal at pH 5.0), but not for sustained ion flux. The flux was reduced in the presence of several known channel blockers: tetrabutyl-, tetrapentyl-, and tetrahexylammonium bromides. PAN facilitated the membrane translocation of anthrax edema factor under the same conditions that induced changes in membrane permeability to ions. These results indicate that PAN permeabilizes cellular membranes under conditions that are believed to prevail in the endosomal compartment of toxin-sensitive cells; and they provide a basis for more detailed studies of the relationship between channel formation and translocation of toxin effector moieties in vivo. PMID:7968541

Milne, J C; Collier, R J

1993-11-01

173

Anthrax  

MedlinePLUS Videos and Cool Tools

... guidelines. For further information, contact your departments of public health and public safety. 1. Place the envelope, letter ... results, medical attention should be sought and the public health department should be contacted. Follow medical advice; do ...

174

Antiinflammatory cAMP signaling and cell migration genes co-opted by the anthrax bacillus  

PubMed Central

Bacillus anthracis, the etiologic agent of anthrax, avoids immune surveillance and commandeers host macrophages as a vehicle for lymphatic spreading. Here, we show that B. anthracis edema toxin (ET), via its adenylyl cyclase activity, dramatically increases the motility of infected macrophages and the expression of vascular endothelial growth factor. The transcription factor CREB and the syndecan-1 gene, a CREB target, play crucial roles in ET-induced macrophage migration. These molecular and cellular responses occur in macrophages engaged in antiinflammatory G protein-coupled receptor activation, thus illustrating a common signaling circuitry controlling resolution of inflammation and host cell hijacking by B. anthracis.

Kim, Chun; Wilcox-Adelman, Sarah; Sano, Yasuyo; Tang, Wei-Jen; Collier, R. John; Park, Jin Mo

2008-01-01

175

Chimeric toxins  

US Patent & Trademark Office Database

A chimeric toxin is disclosed. In a preferred embodiment, the chimeric toxin comprises a botulinal neurotoxin heavy chain and non-clostridial toxin chain. A method of creating a chimeric toxin is also disclosed. The chimeric toxin will have utility for pharmacological treatment of neurological disorders.

2003-04-08

176

Capsule synthesis by Bacillus anthracis is required for dissemination in murine inhalation anthrax  

PubMed Central

Bacillus anthracis, the agent of anthrax, produces a poly-D-glutamic acid capsule that has been implicated in virulence. Many strains missing pXO2 (96 kb), which harbors the capsule biosynthetic operon capBCAD, but carrying pXO1 (182 kb) that harbors the anthrax toxin genes, are attenuated in animal models. Also, noncapsulated strains are readily phagocytosed by macrophage cell lines, whereas capsulated strains are resistant to phagocytosis. We show that a strain carrying both virulence plasmids but deleted specifically for capBCAD is highly attenuated in a mouse model for inhalation anthrax. The parent strain and capsule mutant initiated germination in the lungs, but the capsule mutant did not disseminate to the spleen. A mutant harboring capBCAD but deleted for the cap regulators acpA and acpB was also significantly attenuated, in agreement with the capsule-negative phenotype during in vitro growth. Surprisingly, an acpB mutant, but not an acpA mutant, displayed an elevated LD50 and reduced ability to disseminate, indicating that acpA and acpB are not true functional homologs and that acpB may play a larger role in virulence than originally suspected.

Drysdale, Melissa; Heninger, Sara; Hutt, Julie; Chen, Yahua; Lyons, C Rick; Koehler, Theresa M

2005-01-01

177

Anthrax countermeasures: current status and future needs.  

PubMed

The U.S. government does not yet have the range of medical countermeasures needed to protect its citizens from anthrax and other potential bioweapons. In the event of an anthrax attack, treatment interventions in addition to antibiotics would be needed so that very ill patients can be treated and clean-up crews can be better protected, especially if an engineered strain is used. This article describes specific anthrax countermeasures that are in development, barriers to development, and potential mechanisms the government could use to accelerate the movement of these countermeasures through the pipeline. A key challenge will be to encourage the transition of promising leads from basic research to the product development stage, when they may qualify for BioShield funds. PMID:16000041

Borio, Luciana L; Gronvall, Gigi Kwik

2005-01-01

178

Targeting the inflammasome and adenosine type-3 receptors improves outcome of antibiotic therapy in murine anthrax  

PubMed Central

AIM: To establish whether activation of adenosine type-3 receptors (A3Rs) and inhibition of interleukin-1?-induced inflammation is beneficial in combination with antibiotic therapy to increase survival of mice challenged with anthrax spores. METHODS: DBA/2 mice were challenged with Bacillus anthracis spores of the toxigenic Sterne strain 43F2. Survival of animals was monitored for 15 d. Ciprofloxacin treatment (50 mg/kg, once daily, intraperitoneally) was initiated at day +1 simultaneously with the administration of inhibitors, and continued for 10 d. Two doses (2.5 mg/kg and 12.5 mg/kg) of acetyl-tyrosyl-valyl-alanyl-aspartyl-chloromethylketone (YVAD) and three doses (0.05, 0.15 and 0.3 mg/kg) of 1-[2-Chloro-6-[[(3-iodophenyl) methyl]amino]-9H-purin-9-yl]-1-deoxy-N-methyl-?-D- ribofuranuronamide (Cl-IB-MECA) were tested. Animals received YVAD on days 1-4, and Cl-IB-MECA on days 1-10 once daily, subcutaneously. Human lung epithelial cells in culture were challenged with spores or edema toxin and the effects of IB-MECA on phosphorylation of AKT and generation of cAMP were tested. RESULTS: We showed that the outcome of antibiotic treatment in a murine anthrax model could be substantially improved by co-administration of the caspase-1/4 inhibitor YVAD and the A3R agonist Cl-IB-MECA. Combination treatment with these substances and ciprofloxacin resulted in up to 90% synergistic protection. All untreated mice died, and antibiotic alone protected only 30% of animals. We conclude that both substances target the aberrant host signaling that underpins anthrax mortality. CONCLUSION: Our findings suggest new possibilities for combination therapy of anthrax with antibiotics, A3R agonists and caspase-1 inhibitors.

Popov, Serguei G; Popova, Taissia G; Kashanchi, Fatah; Bailey, Charles

2011-01-01

179

A single immunization with a dry powder anthrax vaccine protects rabbits against lethal aerosol challenge.  

PubMed

Here we confirm that intranasal (IN) dry powder anthrax vaccine formulations are able to protect rabbits against aerosol challenge 9 weeks after a single immunization. The optimum dose of rPA in our dry powder anthrax vaccine formulation in rabbits was experimentally determined to be 150microg and therefore was chosen as the target dose for all subsequent experiments. Rabbits received a single dose of either 150microg rPA, 150microg rPA+150microg of a conjugated 10-mer peptide representing the Bacillus anthracis capsule (conj), or 150microg of conj alone. All dry powder formulations contained MPL and chitosan (ChiSys). Significant anti-rPA titers and anthrax lethal toxin neutralizing antibody (TNA) levels were seen with both rPA containing vaccines, although rPA-specific IgG and TNA levels were reduced in rabbits immunized with rPA plus conj. Nine weeks after immunization, rabbits were exposed to a mean aerosol challenge dose of 278 LD50 of Ames spores. Groups immunized with rPA or with rPA+conj had significant increases in survivor proportions compared to the negative control group by Logrank test (p=0.0001 and 0.003, respectively), and survival was not statistically different for the rPA and rPA+conj immunized groups (p=0.63). These data demonstrate that a single immunization with our dry powder anthrax vaccine can protect against a lethal aerosol spore challenge 9 weeks later. PMID:18703110

Klas, S D; Petrie, C R; Warwood, S J; Williams, M S; Olds, C L; Stenz, J P; Cheff, A M; Hinchcliffe, M; Richardson, C; Wimer, S

2008-10-01

180

Serodiagnosis of Human Cutaneous Anthrax in India Using an Indirect Anti-Lethal Factor IgG Enzyme-Linked Immunosorbent Assay  

PubMed Central

Anthrax, caused by Bacillus anthracis, is primarily a zoonotic disease. Being a public health problem also in several developing countries, its early diagnosis is very important in human cases. In this study, we describe the use of an indirect enzyme-linked immunosorbent assay (ELISA) for detection of anti-lethal factor (anti-LF) IgG in human serum samples. A panel of 203 human serum samples consisting of 50 samples from patients with confirmed cutaneous anthrax, 93 samples from healthy controls from areas of India where anthrax is nonendemic, 44 samples from controls from an area of India where anthrax is endemic, and 16 patients with a disease confirmed not to be anthrax were evaluated with an anti-LF ELISA. The combined mean anti-LF ELISA titer for the three control groups was 0.136 ELISA unit (EU), with a 95% confidence interval (CI) of 0.120 to 0.151 EU. The observed sensitivity and specificity of the ELISA were 100% (95% CI, 92.89 to 100%) and 97.39% (95% CI, 93.44 to 99.28%), respectively, at a cutoff value of 0.375 EU, as decided by receiver operating characteristic (ROC) curve analysis. The likelihood ratio was found to be 49.98. The positive predictive value (PPV), negative predictive value (NPV), efficiency, and Youden's index (J) for reliability of the assay were 92.5%, 100%, 98.02%, and 0.97, respectively. The false-positive predictive rate and false-negative predictive rate of the assay were 2.61% and 0%. The assay could be a very useful tool for early diagnosis of cutaneous anthrax cases, as antibodies against LF appear much earlier than those against other anthrax toxins in human serum samples.

Ghosh, N.; Tomar, I.; Lukka, H.

2013-01-01

181

Generation of protective immune response against anthrax by oral immunization with protective antigen plant-based vaccine.  

PubMed

In concern with frequent recurrence of anthrax in endemic areas and inadvertent use of its spores as biological weapon, the development of an effective anthrax vaccine suitable for both human and veterinary needs is highly desirable. A simple oral delivery through expression in plant system could offer promising alternative to the current methods that rely on injectable vaccines extracted from bacterial sources. In the present study, we have expressed protective antigen (PA) gene in Indian mustard by Agrobacterium-mediated transformation and in tobacco by plastid transformation. Putative transgenic lines were verified for the presence of transgene and its expression by molecular analysis. PA expressed in transgenic lines was biologically active as evidenced by macrophage lysis assay. Intraperitoneal (i.p.) and oral immunization with plant PA in murine model indicated high serum PA specific IgG and IgA antibody titers. PA specific mucosal immune response was noted in orally immunized groups. Further, antibodies indicated lethal toxin neutralizing potential in-vitro and conferred protection against in-vivo toxin challenge. Oral immunization experiments demonstrated generation of immunoprotective response in mice. Thus, our study examines the feasibility of oral PA vaccine expressed in an edible plant system against anthrax. PMID:24548460

Gorantala, Jyotsna; Grover, Sonam; Rahi, Amit; Chaudhary, Prerna; Rajwanshi, Ravi; Sarin, Neera Bhalla; Bhatnagar, Rakesh

2014-04-20

182

Anthrax Lethal Factor Cleavage of Nlrp1 Is Required for Activation of the Inflammasome  

PubMed Central

NOD-like receptor (NLR) proteins (Nlrps) are cytosolic sensors responsible for detection of pathogen and danger-associated molecular patterns through unknown mechanisms. Their activation in response to a wide range of intracellular danger signals leads to formation of the inflammasome, caspase-1 activation, rapid programmed cell death (pyroptosis) and maturation of IL-1? and IL-18. Anthrax lethal toxin (LT) induces the caspase-1-dependent pyroptosis of mouse and rat macrophages isolated from certain inbred rodent strains through activation of the NOD-like receptor (NLR) Nlrp1 inflammasome. Here we show that LT cleaves rat Nlrp1 and this cleavage is required for toxin-induced inflammasome activation, IL-1 ? release, and macrophage pyroptosis. These results identify both a previously unrecognized mechanism of activation of an NLR and a new, physiologically relevant protein substrate of LT.

Hellmich, Kristina A.; Fattah, Rasem; Getz, Matthew A.; Liu, Shihui; Sastalla, Inka; Leppla, Stephen H.; Moayeri, Mahtab

2012-01-01

183

Cationic polyamines inhibit anthrax lethal factor protease  

Microsoft Academic Search

BACKGROUND: Anthrax is a human disease that results from infection by the bacteria, Bacillus anthracis and has recently been used as a bioterrorist agent. Historically, this disease was associated with Bacillus spore exposure from wool or animal carcasses. While current vaccine approaches (targeted against the protective antigen) are effective for prophylaxis, multiple doses must be injected. Common antibiotics that block

Mark Evan Goldman; Lynne Cregar; Dominique Nguyen; Ondrej Simo; Sean O'Malley; Tom Humphreys

2006-01-01

184

Inhalation Anthrax: Dose Response and Risk Analysis  

PubMed Central

The notion that inhalation of a single Bacillus anthracis spore is fatal has become entrenched nearly to the point of urban legend, in part because of incomplete articulation of the scientific basis for microbial risk assessment, particularly dose-response assessment. Risk analysis (ie, risk assessment, risk communication, risk management) necessitates transparency: distinguishing scientific facts, hypotheses, judgments, biases in interpretations, and potential misinformation. The difficulty in achieving transparency for biothreat risk is magnified by misinformation and poor characterization of both dose-response relationships and the driving mechanisms that cause susceptibility or resistance to disease progression. Regrettably, this entrenchment unnecessarily restricts preparedness planning to a single response scenario: decontaminate until no spores are detectable in air, water, or on surfaces—essentially forcing a zero-tolerance policy inconsistent with the biology of anthrax. We present evidence about inhalation anthrax dose-response relationships, including reports from multiple studies documenting exposures insufficient to cause inhalation anthrax in laboratory animals and humans. The emphasis of the article is clarification about what is known from objective scientific evidence for doses of anthrax spores associated with survival and mortality. From this knowledge base, we discuss the need for future applications of more formal risk analysis processes to guide development of alternative non-zero criteria or standards based on science to inform preparedness planning and other risk management activities.

Thran, Brandolyn; Morse, Stephen S.; Hugh-Jones, Martin; Massulik, Stacey

2008-01-01

185

Anthrax Attack! A Case on Bioterrorism  

NSDL National Science Digital Library

This case study presents a fictitious bio-terrorist plan to release anthrax in the United States. Students are assigned character roles and, through research, role-playing, and teamwork, develop a plan to minimize or avert the attack. The case is appropriate for courses designed for health professionals, general biology courses, and social science courses.

Mergenhagen, Kari A.

2003-01-01

186

Clinical application of radiolabelled platelets  

SciTech Connect

This book presents papers on the clinical applications of radiolabelled platelets. The papers are grouped into six sections on platelet labelling techniques, radiolabelled platelets in cardiology, monitoring of antiplatelet therapy, platelet scintigraphy in stroke patients, platelet scintigraphy in angiology, and platelet scintigraphy in hematology and other clinical applications, including renal transplant rejection.

Kessler, C. (Medical Univ. Lubeck, Lubeck (DE))

1990-01-01

187

Pharmacophore Selection and Redesign of Non-nucleotide Inhibitors of Anthrax Edema Factor  

PubMed Central

Antibiotic treatment may fail to protect individuals, if not started early enough, after infection with Bacillus anthracis, due to the continuing activity of toxins that the bacterium produces. Stable and easily stored inhibitors of the edema factor toxin (EF), an adenylyl cyclase, could save lives in the event of an outbreak, due to natural causes or a bioweapon attack. The toxin’s basic activity is to convert ATP to cAMP, and it is thus in principle a simple phosphatase, which means that many mammalian enzymes, including intracellular adenylcyclases, may have a similar activity. While nucleotide based inhibitors, similar to its natural substrate, ATP, were identified early, these compounds had low activity and specificity for EF. We used a combined structural and computational approach to choose small organic molecules in large, web-based compound libraries that would, based on docking scores, bind to residues within the substrate binding pocket of EF. A family of fluorenone-based inhibitors was identified that inhibited the release of cAMP from cells treated with EF. The lead inhibitor was also shown to inhibit the diarrhea caused by enterotoxigenic E. coli (ETEC) in a murine model, perhaps by serving as a quorum sensor. These inhibitors are now being tested for their ability to inhibit Anthrax infection in animal models and may have use against other pathogens that produce toxins similar to EF, such as Bordetella pertussis or Vibrio cholera.

Schein, Catherine H.; Chen, Deliang; Ma, Lili; Kanalas, John J.; Gao, Jian; Jimenez, Maria Estrella; Sower, Laurie E.; Walter, Mary A.; Gilbertson, Scott R.; Peterson, Johnny W.

2012-01-01

188

Binding of ATP by pertussis toxin and isolated toxin subunits  

SciTech Connect

The binding of ATP to pertussis toxin and its components, the A subunit and B oligomer, was investigated. Whereas, radiolabeled ATP bound to the B oligomer and pertussis toxin, no binding to the A subunit was observed. The binding of ({sup 3}H)ATP to pertussis toxin and the B oligomer was inhibited by nucleotides. The relative effectiveness of the nucleotides was shown to be ATP > GTP > CTP > TTP for pertussis toxin and ATP > GTP > TTP > CTP for the B oligomer. Phosphate ions inhibited the binding of ({sup 3}H)ATP to pertussis toxin in a competitive manner; however, the presence of phosphate ions was essential for binding of ATP to the B oligomer. The toxin substrate, NAD, did not affect the binding of ({sup 3}H)ATP to pertussis toxin, although the glycoprotein fetuin significantly decreased binding. These results suggest that the binding site for ATP is located on the B oligomer and is distinct from the enzymatically active site but may be located near the eukaryotic receptor binding site.

Hausman, S.Z.; Manclark, C.R.; Burns, D.L. (Center for Biologics Evaluation and Research, Bethesda, MD (USA))

1990-07-03

189

Radiolabeling of platelets  

SciTech Connect

The radiolabeling of platelets has been studied for many years, both with megakaryocytes labeled in vivo and with direct platelet labels in vitro. The major aim of this work has been to evaluate platelet interactions in vivo. This has been made possible with indium-111-labeled platelets. The radionuclide is easily imaged and can be incorporated into platelets with ease. Unfortunately, the lipophilic complex used is not platelet-specific and must be exposed only to the isolated cell population for specific labeling. This requires isolation of platelets from whole blood followed by one of many variations of differential centrifugation, buffer washes, and resuspension techniques that have been reported. The major differences in these techniques are the resuspension media, the incubation time, and the ligand used. These variations are discussed with emphasis on known platelet characteristics and specific responses to these modifications.

Mathias, C.J.; Welch, M.J.

1984-04-01

190

Bioterrorism-Related Anthrax Surveillance, Connecticut, September-December, 2001  

PubMed Central

On November 19, 2001, a case of inhalational anthrax was identified in a 94-year-old Connecticut woman, who later died. We conducted intensive surveillance for additional anthrax cases, which included collecting data from hospitals, emergency departments, private practitioners, death certificates, postal facilities, veterinarians, and the state medical examiner. No additional cases of anthrax were identified. The absence of additional anthrax cases argued against an intentional environmental release of Bacillus anthracis in Connecticut and suggested that, if the source of anthrax had been cross-contaminated mail, the risk for anthrax in this setting was very low. This surveillance system provides a model that can be adapted for use in similar emergency settings.

Williams, Alcia A.; Stoica, Adrian; Ridzon, Renee; Kirschke, David L.; Meyer, Richard F.; McClellan, Jennifer; Fischer, Marc; Nelson, Randy; Cartter, Matt; Hadler, James L.; Jernigan, John A.; Mast, Eric E.; Swerdlow, David L.

2002-01-01

191

Use of the Bacillus Species to Express the Bacillus Anthracis Toxin Genes for Vaccine Studies.  

National Technical Information Service (NTIS)

We have constructed vectors for the high-level expression of the anthrax toxin genes. We have cloned the T7 RNA polymerase gene downstream from the IPTG-inducible promoter from pSI-1. IPTG induces expression of the T7 RNA polymerase when the 1acI represso...

D. Robinson E. Woolley

1995-01-01

192

Directed killing of anthrax spores by microwave-induced cavitation  

Microsoft Academic Search

High-power pulsed-microwave radiation damages anthrax spores by apparent sonoluminescence in aqueous solutions containing the organic semiconductor diazoluminomelanin (DALM). DALM biosynthesized by JM109 E. coli, containing the plasmid pIC2ORNR1.1, had a higher affinity for spores of Sterne strain anthrax when compared to several other species of bacilli and enhanced the effect. Upon exposure to pulsed-microwave radiation, anthrax spores showed a maximum

Johnathan L. Kiel; Richard E. Sutter; Patrick A. Mason; Jill E. Parker; Pedro J. Morales; Lucille J. V. Stribling; John L. Alls; Eric A. Holwitt; Ronald L. Seaman; Satnam P. Mathur

2002-01-01

193

Toxin-Independent Virulence of Bacillus anthracis in Rabbits  

PubMed Central

The accepted paradigm states that anthrax is both an invasive and toxinogenic disease and that the toxins play a major role in pathogenicity. In the guinea pig (GP) model we have previously shown that deletion of all three toxin components results in a relatively moderate attenuation in virulence, indicating that B. anthracis possesses an additional toxin-independent virulence mechanism. To characterize this toxin-independent mechanism in anthrax disease, we developed a new rabbit model by intravenous injection (IV) of B. anthracis encapsulated vegetative cells, artificially creating bacteremia. Using this model we were able to demonstrate that also in rabbits, B. anthracis mutants lacking the toxins are capable of killing the host within 24 hours. This virulent trait depends on the activity of AtxA in the presence of pXO2, as, in the absence of the toxin genes, deletion of either component abolishes virulence. Furthermore, this IV virulence depends mainly on AtxA rather than the whole pXO1. A similar pattern was shown in the GP model using subcutaneous (SC) administration of spores of the mutant strains, demonstrating the generality of the phenomenon. The virulent strains showed higher bacteremia levels and more efficient tissue dissemination; however our interpretation is that tissue dissemination per se is not the main determinant of virulence whose exact nature requires further elucidation.

Levy, Haim; Glinert, Itai; Weiss, Shay; Sittner, Assa; Schlomovitz, Josef; Altboum, Zeev; Kobiler, David

2014-01-01

194

Anthrax: a continuing concern in the era of bioterrorism  

PubMed Central

Anthrax, a potentially fatal infection, is a virulent and highly contagious disease. It is caused by a gram-positive, toxigenic, spore-forming bacillus: Bacillus anthracis. For centuries, anthrax has caused disease in animals and, although uncommonly, in humans throughout the world. Descriptions of this naturally occurring disease begin in antiquity. Anthrax is primarily a disease of herbivores, which are infected by ingestion of spores from the soil. With the advent of modern microbiology, Pasteur developed the first successful anthrax vaccine in 1881. The incidence of the disease has continually decreased since the late 19th century, and animal vaccination programs drastically reduced the animal mortality from the disease. However, anthrax spores continue to be documented in soil samples from throughout the world. Research on anthrax as a biological weapon began more than 80 years ago, and today at least 17 nations are believed to have offensive biological weapons programs that include anthrax. Recent events in the USA have shown how society is affected by both hoax and real threats of anthrax bioweapons. This fourth article in the series on weapons of biowarfare/bioterrorism summarizes the historical background of anthrax as well as clinical and laboratory information useful for bioterrorism preparedness.

2005-01-01

195

Mass spectrometric detection of protein-based toxins.  

PubMed

This review focuses on mass spectrometric detection of protein-based toxins, which are among the most toxic substances known. Special emphasis is given to the bacterial toxins botulinum neurotoxin from Clostridium botulinum and anthrax toxins from Bacillus anthracis as well as the plant toxin ricin produced by Ricinus communis. A common feature, apart from their extreme toxicity, is that they are composed of 2 polypeptide chains, one of which is responsible for cell uptake and another that has enzymatic function with the ability to destroy basic cellular functions. These toxins pose a threat, both regarding natural spread and from a terrorism perspective. In order for public health and emergency response officials to take appropriate action in case of an outbreak, whether natural or intentional, there is a need for fast and reliable detection methods. Traditionally, large molecules like proteins have been detected using immunological techniques. Although sensitive, these methods suffer from some drawbacks, such as the risk of false-positives due to cross-reactions and detection of inactive toxin. This article describes recently developed instrumental methods based on mass spectrometry for the reliable detection of botulinum neurotoxins, anthrax toxins, and ricin. Unequivocal identification of a protein toxin can be carried out by mass spectrometry-based amino acid sequencing. Furthermore, in combination with antibody affinity preconcentration and biochemical tests with mass spectrometric detection demonstrating the toxin's enzymatic activity, very powerful analytical methods have been described. In conclusion, the advent of sensitive, easily operated mass spectrometers provides new possibilities for the detection of protein-based toxins. PMID:23971809

Tevell Åberg, Annica; Björnstad, Kristian; Hedeland, Mikael

2013-09-01

196

Cutaneous anthrax in a school teacher.  

PubMed

Cutaneous anthrax is an infection of the skin caused by Bacillus anthracis. This is a report of a case of cutaneous anthrax attending outpatients of Mymensingh Medical College Hospital in October, 2010. The infected person was a retired school teacher with a very good body build. He reported to handle cow flesh about 4-5 days ago, developed few painless papules over shin of right leg, which gradually became large bullae and blackish eschar developed over the lesion. Smears from the lesions were investigated which confirmed the causative agent B. anthracis. The patient was treated with oral Ciprofloxacin (500mg) twice daily for seven days which cured the infection as observed on his subsequent follow up visits on 7 and 14 days later. Oral Ciprofloxacin is found effective as recommended by the World Health Organization. PMID:24858169

Nandi, A K; Kamal, M M; Alam, M A; Rahman, F; Uddin, M J; Baidya, N R; Mostafa, S M

2014-04-01

197

Clinical microbiologists facing an anthrax alert.  

PubMed

Microbiological war and terrorist attacks are made to weaken populations by transmitting pathogenic and epidemic microorganisms. These bacteria or viruses are often difficult to diagnose. Anthrax alerts following September 2001 showed that most clinical microbiology laboratories were not adequately prepared, using obsolete diagnostic methods or being too slow to use accurate tools when facing a major threat. Following this period, most microbiology laboratories were prepared for bioterrorism alerts, in order to provide accurate and rapid results, although such events are rare and unexpected. In this review, we describe the organization and preparedness of our clinical microbiology laboratory regarding bioterrorism risk, although its main task is to perform routine diagnostic microbiology tests. To illustrate the difficulties, we briefly describe an anthrax alert. PMID:24845109

Jaton, K; Greub, G

2014-06-01

198

Bacillus anthracis and the Pathogenesis of Anthrax  

Microsoft Academic Search

\\u000a Bacillus anthracis is the causative agent of anthrax, a disease of animals that is transmissible to humans. Because B. anthracis forms spores that can be aerosolized and sprayed with the intent to kill, this pathogen can also be viewed as an agent of\\u000a biological warfare and bioterrorism (1). The accidental release of spores into the air in Sverdlosk, Russia, and

Dominique M. Missiakas; Olaf Schneewind

199

Anthrax phylogenetic structure in Northern Italy  

PubMed Central

Background Anthrax has almost disappeared from mainland Europe, except for the Mediterranean region where cases are still reported. In Central and South Italy, anthrax is enzootic, but in the North there are currently no high risk areas, with only sporadic cases having been registered in the last few decades. Regional genetic and molecular characterizations of anthrax in these regions are still lacking. To investigate the potential molecular diversity of Bacillus anthracis in Northern Italy, canonical Single nucleotide polymorphism (canSNP) and Multilocus variable number tandem repeat analysis (MLVA) genotyping was performed against all isolates from animal outbreaks registered in the last twenty years in the region. Findings Six B. anthracis strains were analyzed. The canSNP analysis indicates the presence of three sublineages/subgroups each of which belong to one of the 12 worldwide CanSNP genotypes: B.Br.CNEVA (3 isolates), A.Br.005/006 (1 isolates) and A.008/009 (2 isolate). The latter is the dominant canSNP genotype in Italy. The 15-loci MLVA analysis revealed five different genotypes among the isolates. Conclusions The major B branch and the A.Br.005/006 were recovered in the Northeast region. The genetic structure of anthrax discovered in this area differs from the rest of the country, suggesting the presence of a separate and independent B. anthracis molecular evolution niche. Although the isolates analyzed in this study are limited in quantity and representation, these results indicate that B. anthracis genetic diversity changes around the Alps.

2011-01-01

200

A FRET-based high throughput screening assay to identify inhibitors of anthrax protective antigen binding to capillary morphogenesis gene 2 protein.  

PubMed

Anti-angiogenic therapies are effective for the treatment of cancer, a variety of ocular diseases, and have potential benefits in cardiovascular disease, arthritis, and psoriasis. We have previously shown that anthrax protective antigen (PA), a non-pathogenic component of anthrax toxin, is an inhibitor of angiogenesis, apparently as a result of interaction with the cell surface receptors capillary morphogenesis gene 2 (CMG2) protein and tumor endothelial marker 8 (TEM8). Hence, molecules that bind the anthrax toxin receptors may be effective to slow or halt pathological vascular growth. Here we describe development and testing of an effective homogeneous steady-state fluorescence resonance energy transfer (FRET) high throughput screening assay designed to identify molecules that inhibit binding of PA to CMG2. Molecules identified in the screen can serve as potential lead compounds for the development of anti-angiogenic and anti-anthrax therapies. The assay to screen for inhibitors of this protein-protein interaction is sensitive and robust, with observed Z' values as high as 0.92. Preliminary screens conducted with a library of known bioactive compounds identified tannic acid and cisplatin as inhibitors of the PA-CMG2 interaction. We have confirmed that tannic acid both binds CMG2 and has anti-endothelial properties. In contrast, cisplatin appears to inhibit PA-CMG2 interaction by binding both PA and CMG2, and observed cisplatin anti-angiogenic effects are not mediated by interaction with CMG2. This work represents the first reported high throughput screening assay targeting CMG2 to identify possible inhibitors of both angiogenesis and anthrax intoxication. PMID:22768167

Rogers, Michael S; Cryan, Lorna M; Habeshian, Kaiane A; Bazinet, Lauren; Caldwell, Thomas P; Ackroyd, P Christine; Christensen, Kenneth A

2012-01-01

201

Reported Anthrax Disease in Costa Rica - Is it Accurate?  

Microsoft Academic Search

Recently, the potential use of anthrax spores as a biological weapon has increased awareness and increased interest in this potentially deadly bacteria (3). The purpose of this research project was to perform an extensive critical investigation using qualitative data that focuses on the accuracy of the reporting of cutaneous anthrax disease in Costa Rica. This issue of accurate reporting of

Brian Walls; Mario Tristán

202

Identification of anthrax-specific signature sequence from Bacillus anthracis  

Microsoft Academic Search

The primary objective was to identify and clone novel chromosomal DNA fragments for use as B. anthracis-specific markers. Towards this goal, 300 random primers (RAPD technology, randomly amplified polymorphic DNA) were screened to identify polymorphic loci on the anthrax chromosome. Five such DNA fragments uniquely amplifying from anthrax chromosome were identified and isolated. These fragments were cloned in pCR vector

Vipin K. Rastogi; Tu-chen Cheng

2001-01-01

203

Epidemiologic Investigations of Bioterrorism-Related Anthrax, New Jersey, 2001  

Microsoft Academic Search

At least four Bacillus anthracis-containing envelopes destined for New York City and Washington, D.C. were processed at the Trenton Processing and Distribution Center (PDC) on September 18 and October 9, 2001. When cutaneous anthrax was confirmed in a Trenton postal worker, the PDC was closed. Four cutaneous and two inhalational anthrax cases were identified. Five patients were hospitalized; none died.

Carolyn M. Greene; Jennita Reefhuis; Christina Tan; Anthony E. Fiore; Susan Goldstein; Michael J. Beach; Stephen C. Redd; David Valiante; Gregory Burr; James Buehler; Robert W. Pinner; Eddy Bresnitz; Beth P. Bell

2002-01-01

204

Anthrax in transit; practical experience and intellectual exchange.  

PubMed

Focusing on three Anglo-American outbreaks of industrial anthrax, this essay engages the question of how local circumstances influenced the transmission of scientific knowledge in the late nineteenth century. Walpole (Massachusetts), Glasgow, and Bradford (Yorkshire) served as important nodes of transnational investigation into anthrax. Knowledge about the morphology and behavior of Bacillus anthracis changed little while in transit between these nodes, even during complex debates about the nature of bacterial morphology, disease causation, and spontaneous generation. Working independently of their more famous counterparts (Robert Koch and Louis Pasteur), Anglo-American anthrax investigators used visual representations of anthrax bacilli to persuade their peers that a specific, identifiable cause produced all forms of anthrax-malignant pustule (cutaneous anthrax), intestinal anthrax, and woolsorter's disease (pneumonic anthrax). By the late 1870s, this point of view also supported what we would today call an ecological notion of the disease's origins in the interactions of people, animals, and microorganisms in the context of global commerce. PMID:18959192

Jones, Susan D; Teigen, Philip M

2008-09-01

205

GRP78(BiP) facilitates the cytosolic delivery of anthrax lethal factor (LF) in vivo and functions as an unfoldase in vitro  

PubMed Central

Summary Anthrax toxin is an A/B bacterial protein toxin which is composed of the enzymatically active Lethal Factor (LF) and/or Oedema Factor (EF) bound to Protective Antigen 63 (PA63) which functions as both the receptor binding and transmembrane domains. Once the toxin binds to its cell surface receptors it is internalized into the cell and traffics through Rab5- and Rab7-associated endosomal vesicles. Following acidification of the vesicle lumen, PA63 undergoes a dynamic change forming a beta-barrel that inserts into and forms a pore through the endosomal membrane. It is widely recognized that LF, and the related fusion protein LFnDTA, must be completely denatured in order to transit through the PA63 formed pore and enter the eukaryotic cell cytosol. We demonstrate by protease protection assays that the molecular chaperone GRP78 mediates the unfolding of LFnDTA and LF at neutral pH and thereby converts these proteins from a trypsin resistant to sensitive conformation. We have used immuno-electron microscopy and gold-labeled antibodies to demonstrate that both GRP78 and GRP94 chaperones are present in the lumen of endosomal vesicles. Finally, we have used siRNA to demonstrate that knock down of GRP78 results in the emergence of resistance to anthrax lethal toxin and edema toxin action.

Tamayo, Alfred G.; Slater, Louise; Taylor-Parker, Julian; Bharti, Ajit; Harrison, Robert; Hung, Deborah T.; Murphy, John R.

2011-01-01

206

Intranasal administration of dry powder anthrax vaccine provides protection against lethal aerosol spore challenge.  

PubMed

The use of an aerosolizable form of anthrax as a biological weapon is considered to be among the most serious bioterror threats. Intranasal (IN) delivery of a dry powder anthrax vaccine could provide an effective and non-invasive administration alternative to traditional intramuscular (IM) or subcutaneous (SC) injection. We evaluated a dry powder vaccine based on the recombinant Protective Antigen (rPA) of Bacillus anthracis for vaccination against anthrax via IN immunization in a rabbit model. rPA powders were formulated and administered IN using a prototype powder delivery device. We compared serum IgG and toxin neutralizing antibody (TNA) titers of rabbits immunized IN with 10 microg rPA of a powder formulation with those immunized with the same dose of liquid rPA vaccine, delivered either IN or by IM injection. In addition, each group was tested for survival after aerosol spore challenge. Our results showed that IN vaccination with rPA powders elicited serum PA-specific IgG and TNA titers that were equivalent to those raised by liquid rPA administered IN. Serum PA-specific IgG and TNA titers after IN delivery were lower than for IM injection, however, after aerosol spore challenge, rabbits immunized IN with powders displayed 100% protection versus 63% for the group immunized IN with the liquid vaccine and 86% for the group immunized by IM injection. The results suggest that an IN powder vaccine based on rPA is at least as protective as a liquid delivered by IM injection. PMID:17375001

Huang, Joanne; Mikszta, John A; Ferriter, Matthew S; Jiang, Ge; Harvey, Noel G; Dyas, Beverly; Roy, Chad J; Ulrich, Robert G; Sullivan, Vincent J

2007-01-01

207

The Effect of Anthrax Bioterrorism on Emergency Department Presentation  

PubMed Central

Study Objective: From September through December 2001, 22 Americans were diagnosed with anthrax, prompting widespread national media attention and public concern over bioterrorism. The purpose of this study was to determine the effect of the threat of anthrax bioterrorism on patient presentation to a West Coast emergency department (ED). Methods: This survey was conducted at an urban county ED in Oakland, CA between December 15, 2001 and February 15, 2002. During random 8-hour blocks, all adult patients presenting for flu or upper respiratory infection (URI) symptoms were surveyed using a structured survey instrument that included standard visual numerical and Likert scales. Results: Eighty-nine patients were interviewed. Eleven patients (12%) reported potential exposure risk factors. Eighty percent of patients watched television, read the newspaper, or listened to the radio daily, and 83% of patients had heard about anthrax bioterrorism. Fifty-five percent received a chest x-ray, 10% received either throat or blood cultures, and 28% received antibiotics. Twenty-one percent of patients surveyed were admitted to the hospital. Most patients were minimally concerned that they may have contracted anthrax (mean=3.3±3.3 where 0=no concern and 10=extremely concerned). Patient concern about anthrax had little influence on their decision to visit the ED (mean=2.8±3.0 where 0=no influence and 10=greatly influenced). Had they experienced their same flu or URI symptoms one year prior to the anthrax outbreak, 91% of patients stated they would have sought medical attention. Conclusions: After considerable exposure to media reports about anthrax, most patients in this urban West Coast ED population were not concerned about anthrax infection. Fear of anthrax had little effect on decisions to come to the ED, and most would have sought medical help prior to the anthrax outbreak.

Rodriguez, Robert M.; Reeves, Jabari; Houston, Sherard; McClung, Christian

2005-01-01

208

Identification of small molecules that inhibit the interaction of TEM8 with anthrax protective antigen using a FRET assay  

PubMed Central

Tumor marker endothelial 8 (TEM8) is a receptor for the Protective Antigen (PA) component of anthrax toxin. TEM8 is upregulated on endothelial cells lining the blood vessels within tumors, compared to normal blood vessels. A number of studies have demonstrated a pivotal role for TEM8 in developmental and tumor angiogenesis. We have also shown that targeting the anthrax receptors with a mutated form of PA inhibits angiogenesis and tumor formation in vivo. Here we describe the development and testing of a high-throughput fluorescence resonance energy transfer assay to identify molecules that strongly inhibit the interaction of PA and TEM8. The assay we describe is sensitive and robust, with a Z-prime value of 0.8. A preliminary screen of 2310 known bioactive library compounds identified ebselen and thimerosal as inhibitors of the TEM8-PA interaction. These molecules each contain a cysteine-reactive transition metal, and complimentary studies indicate that their inhibition of interaction is due to modification of a cysteine residue in the TEM8 extracellular domain. This is the first demonstration of a high-throughput screening assay that identifies inhibitors of TEM8, with potential application for anti-anthrax and anti-angiogenic diseases.

Cryan, Lorna M.; Habeshian, Kaiane A.; Caldwell, Thomas P.; Morris, Meredith T.; Ackroyd, P. Christine; Christensen, Kenneth A.; Rogers, Michael S.

2013-01-01

209

Bacillus cereus G9241 S-Layer Assembly Contributes to the Pathogenesis of Anthrax-Like Disease in Mice  

PubMed Central

Bacillus cereus G9241, the causative agent of anthrax-like disease, harbors virulence plasmids encoding anthrax toxins as well as hyaluronic acid (HA) and B. cereus exopolysaccharide (BPS) capsules. B. cereus G9241 also harbors S-layer genes, including homologs of Bacillus anthracis surface array protein (Sap), extractable antigen 1 (EA1), and the S-layer-associated proteins (BSLs). In B. anthracis, S-layer proteins and BSLs attach via their S-layer homology domains (SLH) to the secondary cell wall polysaccharide (SCWP) in a manner requiring csaB, a predicted ketalpyruvate transferase. Here we used a genetic approach to analyze B. cereus G9241 S-layer assembly and function. Variants lacking the csaB gene synthesized SCWP but failed to retain Sap, EA1, and BSLs in the bacterial envelope. The B. cereus G9241 csaB mutant assembled capsular polysaccharides but displayed an increase in chain length relative to the wild-type strain. This phenotype is likely due to its inability to deposit BslO murein hydrolase at divisional septa. During growth under capsule-inducing conditions, B. cereus G9241 assembled BSLs (BslA and BslO) and the Sap S-layer protein, but not EA1, in the envelope. Finally, csaB-mediated assembly of S-layer proteins and BSLs in B. cereus G9241 contributes to the pathogenesis of anthrax-like disease in mice.

Wang, Ya-Ting; Oh, So-Young; Hendrickx, Antoni P. A.; Lunderberg, J. M.

2013-01-01

210

Cholera toxin can catalyze ADP-ribosylation of cytoskeletal proteins  

SciTech Connect

Cholera toxin catalyzes transfer of radiolabel from (/sup 32/P)NAD/sup +/ to several peptides in particulate preparations of human foreskin fibroblasts. Resolution of these peptides by two-dimensional gel electrophoresis allowed identification of two peptides of M/sub r/ = 42,000 and 52,000 as peptide subunits of a regulatory component of adenylate cyclase. The radiolabeling of another group of peptides (M/sub r/ = 50,000 to 65,000) suggested that cholera toxin could catalyze ADP-ribosylation of cytoskeletal proteins. This suggestion was confirmed by showing that incubation with cholera toxin and (/sup 32/P)NAD/sup +/ caused radiolabeling of purified microtubule and intermediate filament proteins.

Kaslow, H.R.; Groppi, V.E.; Abood, M.E.; Bourne, H.R.

1981-11-01

211

Ultrasensitive detection of protein translocated through toxin pores in droplet-interface bilayers  

PubMed Central

Many bacterial toxins form proteinaceous pores that facilitate the translocation of soluble effector proteins across cellular membranes. With anthrax toxin this process may be monitored in real time by electrophysiology, where fluctuations in ionic current through these pores inserted in model membranes are used to infer the translocation of individual protein molecules. However, detecting the minute quantities of translocated proteins has been a challenge. Here, we describe use of the droplet-interface bilayer system to follow the movement of proteins across a model membrane separating two submicroliter aqueous droplets. We report the capture and subsequent direct detection of as few as 100 protein molecules that have translocated through anthrax toxin pores. The droplet-interface bilayer system offers new avenues of approach to the study of protein translocation.

Fischer, Audrey; Holden, Matthew A.; Pentelute, Brad L.; Collier, R. John

2011-01-01

212

Towards a human oral vaccine for anthrax: the utility of a Salmonella Typhi Ty21a-based prime-boost immunization strategy.  

PubMed

We previously demonstrated the ability of an orally administered attenuated Salmonella enterica serovar Typhimurium strain expressing the protective antigen (PA) of Bacillus anthracis to confer protection against lethal anthrax aerosol spore challenge [Stokes MG, Titball RW, Neeson BN, et al. Oral administration of a Salmonella enterica-based vaccine expressing Bacillus anthracis protective antigen confers protection against aerosolized B. anthracis. Infect Immun 2007;75(April (4)):1827-34]. To extend the utility of this approach to humans we constructed variants of S. enterica serovar Typhi Ty21a, an attenuated typhoid vaccine strain licensed for human use, which expressed and exported PA via two distinct plasmid-based transport systems: the Escherichia coli HlyA haemolysin and the S. Typhi ClyA export apparatus. Murine immunogenicity studies confirmed the ability of these constructs, especially Ty21a expressing the ClyA-PA fusion protein, to stimulate strong PA-specific immune responses following intranasal immunization. These responses were further enhanced by a subsequent boost with either parenterally delivered recombinant PA or the licensed US human alum-adsorbed anthrax vaccine (AVA). Anthrax toxin neutralizing antibody responses using this prime-boost regimen were rapid, vigorous and broad in nature. The results of this study demonstrate the feasibility of employing a mucosal prime with a licensed Salmonella Typhi vaccine strain followed by a parenteral protein boost to stimulate rapid protective immunity against anthrax. PMID:18805452

Baillie, Leslie W J; Rodriguez, Ana L; Moore, Stephen; Atkins, Helen S; Feng, Chiguang; Nataro, James P; Pasetti, Marcela F

2008-11-11

213

Rapid generation of an anthrax immunotherapeutic from goats using a novel non-toxic muramyl dipeptide adjuvant  

PubMed Central

Background There is a clear need for vaccines and therapeutics for potential biological weapons of mass destruction and emerging diseases. Anthrax, caused by the bacterium Bacillus anthracis, has been used as both a biological warfare agent and bioterrorist weapon previously. Although antibiotic therapy is effective in the early stages of anthrax infection, it does not have any effect once exposed individuals become symptomatic due to B. anthracis exotoxin accumulation. The bipartite exotoxins are the major contributing factors to the morbidity and mortality observed in acute anthrax infections. Methods Using recombinant B. anthracis protective antigen (PA83), covalently coupled to a novel non-toxic muramyl dipeptide (NT-MDP) derivative we hyper-immunized goats three times over the course of 14 weeks. Goats were plasmapheresed and the IgG fraction (not affinity purified) and F(ab')2 derivatives were characterized in vitro and in vivo for protection against lethal toxin mediated intoxication. Results Anti-PA83 IgG conferred 100% protection at 7.5 ?g in a cell toxin neutralization assay. Mice exposed to 5 LD50 of Bacillus anthracis Ames spores by intranares inoculation demonstrated 60% survival 14 d post-infection when administered a single bolus dose (32 mg/kg body weight) of anti-PA83 IgG at 24 h post spore challenge. Anti-PA83 F(ab')2 fragments retained similar neutralization and protection levels both in vitro and in vivo. Conclusion The protection afforded by these GMP-grade caprine immunotherapeutics post-exposure in the pilot murine model suggests they could be used effectively to treat post-exposure, symptomatic human anthrax patients following a bioterrorism event. These results also indicate that recombinant PA83 coupled to NT-MDP is a potent inducer of neutralizing antibodies and suggest it would be a promising vaccine candidate for anthrax. The ease of production, ease of covalent attachment, and immunostimulatory activity of the NT-MDP indicate it would be a superior adjuvant to alum or other traditional adjuvants in vaccine formulations.

Kelly, Cassandra D; O'Loughlin, Chris; Gelder, Frank B; Peterson, Johnny W; Sower, Laurie E; Cirino, Nick M

2007-01-01

214

The seminal literature of anthrax research.  

PubMed

A chronically weak area in research papers, reports, and reviews is the complete identification of seminal background documents that formed the building blocks for these papers. A method for systematically determining these seminal references is presented. Citation-Assisted Background (CAB) is based on the assumption that seminal documents tend to be highly cited. Application of CAB to the field of Anthrax research is presented. While CAB is a highly systematic approach for identifying seminal references, it is not a substitute for the judgment of the researchers, and serves as a supplement. PMID:17653986

Kostoff, Ronald N; Morse, Stephen A; Oncu, Serkan

2007-01-01

215

Anthrax Edema Factor Toxicity Is Strongly Mediated by the N-end Rule  

PubMed Central

Anthrax edema factor (EF) is a calmodulin-dependent adenylate cyclase that converts adenosine triphosphate (ATP) into 3’–5’-cyclic adenosine monophosphate (cAMP), contributing to the establishment of Bacillus anthracis infections and the resulting pathophysiology. We show that EF adenylate cyclase toxin activity is strongly mediated by the N-end rule, and thus is dependent on the identity of the N-terminal amino acid. EF variants having different N-terminal residues varied by more than 100-fold in potency in cultured cells and mice. EF variants having unfavorable, destabilizing N-terminal residues showed much greater activity in cells when the E1 ubiquitin ligase was inactivated or when proteasome inhibitors were present. Taken together, these results show that EF is uniquely affected by ubiquitination and/or proteasomal degradation.

Leysath, Clinton E.; Phillips, Damilola D.; Crown, Devorah; Fattah, Rasem J.; Moayeri, Mahtab; Leppla, Stephen H.

2013-01-01

216

Epidemic Anthrax in the Eighteenth Century, the Americas  

PubMed Central

Anthrax has been described as a veterinary disease of minor importance to clinical medicine, causing occasional occupational infections in single cases or clusters. Its potential for rapid and widespread epidemic transmission under natural circumstances has not been widely appreciated. A little-known 1770 epidemic that killed 15,000 people in Saint-Domingue (modern Haiti) was probably intestinal anthrax. The epidemic spread rapidly throughout the colony in association with consumption of uncooked beef. Large-scale, highly fatal epidemics of anthrax may occur under unusual but natural circumstances. Historical information may not only provide important clues about epidemic development but may also raise awareness about bioterrorism potential.

Morens, David M.

2002-01-01

217

Cutaneous anthrax resulting in renal failure with generalized tissue damage.  

PubMed

Anthrax is a zoonotic infection caused by Bacillus anthracis which can be clinically present in a cutaneous, gastrointestinal or inhalational form depending on the entry site of the agent. The most frequent clinical type with the mildest clinical course is cutaneous anthrax. In this report, a patient with cutaneous anthrax which begins at the dorsal hand and progresses up to the proximal forearm resulting in massive tissue damage is presented. Prerenal azotemia developed due to massive tissue damage and patient was sent to hemodialysis twice. PMID:23431997

Akdeniz, Necmettin; Calka, Omer; Uce Ozkol, Hatice; Akdeniz, Hayrettin

2013-10-01

218

Anthrax Lethal Factor Activates K+ Channels To Induce IL-1? Secretion in Macrophages  

PubMed Central

Anthrax lethal toxin (LeTx) is a virulence factor of Bacilillus anthracis that is a bivalent toxin, containing lethal factor (LF) and protective Ag proteins, which causes cytotoxicity and altered macrophage function. LeTx exposure results in early K+ efflux from macrophages associated with caspase-1 activation and increased IL-1? release. The mechanism of this toxin-induced K+ efflux is unknown. The goals of the current study were to determine whether LeTx-induced K+ efflux from macrophages is mediated by toxin effects on specific K+ channels and whether altered K+-channel activity is involved in LeTx-induced IL-1? release. Exposure of macrophages to LeTx induced a significant increase in the activities of two types of K+ channels that have been identified in mouse macrophages: Ba2+-sensitive inwardly rectifying K+ (Kir) channels and 4-aminopyridine–sensitive outwardly rectifying voltage-gated K+ (Kv) channels. LeTx enhancement of both Kir and Kv required the proteolytic activity of LF, because exposure of macrophages to a mutant LF-protein (LFE687C) combined with protective Ag protein had no effect on the currents. Furthermore, blocking Kir and Kv channels significantly decreased LeTx-induced release of IL-1?. In addition, retroviral transduction of macrophages with wild-type Kir enhanced LeTx-induced release of IL-1?, whereas transduction of dominant-negative Kir blocked LeTx-induced release of IL-1?. Activation of caspase-1 was not required for LeTx-induced activation of either of the K+ channels. These data indicate that a major mechanism through which LeTx stimulates macrophages to release IL-1? involves an LF-protease effect that enhances Kir and Kv channel function during toxin stimulation.

Thomas, Johnson; Epshtein, Yulia; Chopra, Arun; Ordog, Balazs; Ghassemi, Mahmood; Christman, John W.; Nattel, Stanley; Cook, James L.; Levitan, Irena

2012-01-01

219

[Epidemiology studies regarding anthrax epidemic in Romania].  

PubMed

Antrax infection, a major bacterial zoonosis caused by B. anthracis, affects animals, particulary the herbivores. The infection can be accidentally transmitted to man, in whom it has two forms. Cutaneous anthrax, more frequently encountered (95%), the transmission being favoured by the contact with contaminated animal or, after the sacrifice of the animal, with various contaminated products (skin, wool, hair, especially of goat, as well as bones, meat, blood); the evolution is favourable following treatment. Internal (visceral)--pulmonary, gastro-intestinal, meningo-encephalytic--anthrax causes quasi-total mortality, despite treatment. Transmission is conditioned by the presence of sporulated forms. The bacteriological diagnosis is based on the detection of the germ on smears or cultures for various pathological specimens (skin lesions, blood, tissues, exudates, c.s.f., sputum, etc), rapid results being obtained by immunofluorescence. The serological diagnosis is indicated by the elevated titer of antibodies, detectable by immunological methods (ELISA). 81 pathological specimens and 16 soil samples suspected of B. anthracis were received by our laboratory in 2000 and were investigated for their morpho-cultural characteristics, under the microscope and using pathogenecity tests. Of the total number of samples investigated, B. anthracis was confirmed in 12 (12.37%) cases. PMID:15085606

Negu?, M; Caplan, Dana Magdalena

2002-01-01

220

Characterization of a multi-component anthrax vaccine designed to target the initial stages of infection as well as toxaemia  

PubMed Central

Current vaccine approaches to combat anthrax are effective; however, they target only a single protein [the protective antigen (PA) toxin component] that is produced after spore germination. PA production is subsequently increased during later vegetative cell proliferation. Accordingly, several aspects of the vaccine strategy could be improved. The inclusion of spore-specific antigens with PA could potentially induce protection to initial stages of the disease. Moreover, adding other epitopes to the current vaccine strategy will decrease the likelihood of encountering a strain of Bacillus anthracis (emerging or engineered) that is refractory to the vaccine. Adding recombinant spore-surface antigens (e.g. BclA, ExsFA/BxpB and p5303) to PA has been shown to augment protection afforded by the latter using a challenge model employing immunosuppressed mice challenged with spores derived from the attenuated Sterne strain of B. anthracis. This report demonstrated similar augmentation utilizing guinea pigs or mice challenged with spores of the fully virulent Ames strain or a non-toxigenic but encapsulated ?Ames strain of B. anthracis, respectively. Additionally, it was shown that immune interference did not occur if optimal amounts of antigen were administered. By administering the toxin and spore-based immunogens simultaneously, a significant adjuvant effect was also observed in some cases. Thus, these data further support the inclusion of recombinant spore antigens in next-generation anthrax vaccine strategies.

Cote, C. K.; Kaatz, L.; Reinhardt, J.; Bozue, J.; Tobery, S. A.; Bassett, A. D.; Sanz, P.; Darnell, S. C.; Alem, F.; O'Brien, A. D.

2012-01-01

221

Pertussis toxin  

SciTech Connect

This book contains 13 selections. Some of the titles are: Genetic and Functional Studies of Pertussis Toxin Substrates; Effect of Pertussis Toxin on the Hormonal Responsiveness of Different Tissues; Extracellular Adenylate Cyclase of Bordetella pertussis; and GTP-Regulatory Proteins are Introcellular Messagers: A Model for Hormone Action.

Sekura, R.D.; Moss, J.; Vaughan, M.

1985-01-01

222

Novel chimpanzee/human monoclonal antibodies that neutralize anthrax lethal factor, and evidence for possible synergy with anti-protective antigen antibody.  

PubMed

Three chimpanzee Fabs reactive with lethal factor (LF) of anthrax toxin were isolated and converted into complete monoclonal antibodies (MAbs) with human gamma1 heavy-chain constant regions. In a macrophage toxicity assay, two of the MAbs, LF10E and LF11H, neutralized lethal toxin (LT), a complex of LF and anthrax protective antigen (PA). LF10E has the highest reported affinity for a neutralizing MAb against LF (dissociation constant of 0.69 nM). This antibody also efficiently neutralized LT in vitro, with a 50% effective concentration (EC(50)) of 0.1 nM, and provided 100% protection of rats against toxin challenge with a 0.5 submolar ratio relative to LT. LF11H, on the other hand, had a slightly lower binding affinity to LF (dissociation constant of 7.4 nM) and poor neutralization of LT in vitro (EC(50) of 400 nM) and offered complete protection in vivo only at an equimolar or higher ratio to toxin. Despite this, LF11H, but not LF10E, provided robust synergistic protection when combined with MAb W1, which neutralizes PA. Epitope mapping and binding assays indicated that both LF10E and LF11H recognize domain I of LF (amino acids 1 to 254). Although domain I is responsible for binding to PA, neither MAb prevented LF from binding to activated PA. Although two unique MAbs could protect against anthrax when used alone, even more efficient and broader protection should be gained by combining them with anti-PA MAbs. PMID:19528217

Chen, Zhaochun; Moayeri, Mahtab; Crown, Devorah; Emerson, Suzanne; Gorshkova, Inna; Schuck, Peter; Leppla, Stephen H; Purcell, Robert H

2009-09-01

223

Search for a New-Generation Human Anthrax Vaccine,  

National Technical Information Service (NTIS)

Anthrax is a disease primarily of herbivores, but humans can become infected through contact with infected animals or animal products. The etiological agent, Bacillus anthracis, possesses two primary virulence factors: a poly-D-glumatic acid capsule and a...

B. E. Ivins

1987-01-01

224

[Anthrax meningoencephalitis: A case following a cutaneous lesion in Morocco].  

PubMed

Anthrax meningoencephalitis is very rare especially following skin location. We report a case of meningoencephalitis secondary to skin lesion. The diagnosis is based on clinical presentation and confirmed by microbiological tests. Its evolution remains fatal despite aggressive resuscitation. PMID:24784916

Ziadi, A; Hachimi, A; Soraa, N; Tassi, N; Nejmi, H; Elkhayari, M; Samkaoui, M A

2014-05-01

225

Identification of anthrax-specific signature sequence from Bacillus anthracis  

NASA Astrophysics Data System (ADS)

The primary objective was to identify and clone novel chromosomal DNA fragments for use as B. anthracis-specific markers. Towards this goal, 300 random primers (RAPD technology, randomly amplified polymorphic DNA) were screened to identify polymorphic loci on the anthrax chromosome. Five such DNA fragments uniquely amplifying from anthrax chromosome were identified and isolated. These fragments were cloned in pCR vector and sequenced. Database (genebank) analysis of one of the cloned probe, VRTC899, revealed the presence of specific chromosomal DNA probe, Ba813 from anthrax. This prove also contains flanking DNA with no homology to known sequences. Availability of signature DNA probes for detection of antrax-causing agent in environmental samples is critical for field application of DNA-based sensor technologies. In conclusion, we have demonstrated application of RAPD technology for identification of anthrax-specific signature sequences. This strategy can be extended to identify signature sequences from other BW agents.

Rastogi, Vipin K.; Cheng, Tu-chen

2001-08-01

226

[Anthrax meningoencephalitis: a case report and review of Turkish literature].  

PubMed

The incidence of anthrax is decreasing in Turkey, however, it is still endemic in some regions of the country. Although central nervous system involvement is rare in cases with anthrax, high mortality rates are significant. Here, we report a 46-years old woman who was anthrax meningoencephalitis. The patient was from Yozgat located in Central Anatolia, Turkey. Her history revealed that following peeling the skin of sheeps and consuming their meat a week ago, a lesion developed in her left forearm and she had been treated with penicilin G with the diagnosis of cutaneous anthrax in a local health center. The patient was admitted to the emergency room of our hospital due to increased headache and loss of conciousness and diagnosed as anthrax meningitis. Crytallized penicilin G (24 MU/day IV) and vancomycin (2 g/day IV) were initiated. The macroscopy of cerebrospinal fluid (CSF) sample was haemorrhagic, white blood cell count was 40/mm3 (80% of neutrophil) and Gram staining of CSF yielded abundant gram-positive bacilli. The diagnosis was confirmed by the isolation of Bacillus anthracis from CSF culture. Although the isolate was susceptible to penicillin and dexamethasone was added to the treatment, the patient died. Review of the Turkish literature revealed seven cases of anthrax with central nervous system involvement between 1980-2008. One of the patients was an 11-years old boy and the others were adults aged between 19 and 64 years. The source of the infection was skin in four patients and inhalation in one patient. The most common findings in all of the patients were inhabitance in rural area, haemorrhagic CSF and loss of all patients despite appropriate antibiotic therapy. In conclusion, anthrax meningitis and meningoencephalitis should be considered in the differential diagnosis of haemorrhagic meningitis in areas where anthrax is endemic and high rate of mortality despite appropriate therapy should always be kept in mind. PMID:20084923

Metan, Gökhan; Uysal, Burcu; Co?kun, Ramazan; Perçin, Duygu; Do?anay, Mehmet

2009-10-01

227

Biodistribution of radiolabeled lymphocytes. [Rats  

SciTech Connect

Factors that might affect the biodistribution and clinical utility of radiolabeled lymphocytes were evaluated in experimental animals. Indium-111 (In-111) labeled lymphocytes obtained from peripheral blood, lymph node, or spleen were found in significant amounts in the lymphoid tissues of Lewis rats as early as 3 hours after infusion. A progressive increase in nodal activity with concomitant fall of activity in other organs followed, indicating active recirculation of the lymphocytes. In vitro irradiation of the In-111 labeled lymphocytes resulted in no detectable lymphocyte recirculation and/or reduced localization in lymphoid tissue. Splenectomized animals and those sensitized to an organ allograft before cell infusion showed increased activity in their bone marrow. These results suggest that the source of the injected cells, cell irradiation dose level and host sensitization should be considered when radiolabeled lymphocytes are being prepared for use in clinical diagnosis and therapy.

Fawwaz, R.A.; Oluwole, S.; Wang, T.S.; Kuromoto, N.; Iga, C.; Hardy, M.A.; Alderson, P.O.

1985-05-01

228

Botulinum toxin.  

PubMed

Botulinum toxin is regarded as the most lethal substance known. It is estimated that the human LD50 for inhalation botulism is 1 to 3 nanograms of toxin/kilogram body mass. Although only three cases of inhalational botulism have been described, an understanding of the pathophysiology of food-borne outbreaks, wound botulism, and infant botulism, and their therapies, enables the medical community to plan treatment in the event of an aerosol release of botulinum toxin. Antitoxin, vaccine, and F(ab')2 immune fragment therapies are discussed as adjuncts to supportive therapy. PMID:16168317

Horowitz, B Zane

2005-10-01

229

Anthrax Vaccine as a Component of the Strategic National Stockpile: A Dilemma for Homeland Security.  

National Technical Information Service (NTIS)

The author explains how past problems with the Defense Department anthrax vaccine currently affect Department of Homeland Security and Department of Health and Human Service policy. The departments included the BioThrax(Registered) anthrax vaccine in the ...

T. L. Rempfer

2009-01-01

230

Military Hospitalizations among Deployed US Service Members Following Anthrax Vaccination, 1998-2001.  

National Technical Information Service (NTIS)

Safety concerns have confronted the Department of Defense Anthrax Vaccine Immunization Program since its inception in 1998. To determine if anthrax vaccination was associated with an increased risk of hospitalization, a historical cohort study utilizing p...

T. S. Wells P. A. Sato T. C. Smith L. Z. Wang R. J. Reed

2006-01-01

231

Military Hospitalizations Among Deployed US Service Members Following Anthrax Vaccination, 1998-2001.  

National Technical Information Service (NTIS)

Safety concerns have confronted the Department of Defense Anthrax Vaccine Immunization Program since inception in 1998. To determine if anthrax vaccination was associated with an increased risk of hospitalization, a historical cohort study utilizing pre- ...

L. Z. Wang P. A. Sato R. J. Reed T. C. Smith T. S. Wells

2006-01-01

232

Short-Course Postexposure Antibiotic Prophylaxis Combined with Vaccination Protects Against Experimental Inhalational Anthrax.  

National Technical Information Service (NTIS)

Prevention of inhalational anthrax after Bacillus anthracis spore exposure requires a prolonged course of antibiotic prophylaxis. In response to the 2001 anthrax attack in the United States, approximately 10,000 people were offered 60 days of antibiotic p...

B. K. Purcell E. K. Leffel J. V. Lawler N. J. Vietri P. Rico

2006-01-01

233

Short-Course Postexposure Antibiotic Prophylaxis Combined with Vaccination Protects Against Experimental Inhalational Anthrax.  

National Technical Information Service (NTIS)

Prevention of inhalational anthrax after Bacillus anthracis spore exposure requires a prolonged course of antibiotic prophylaxis. In response to the 2001 anthrax attack in the United States, 10,000 people were offered 60 days of antibiotic prophylaxis to ...

N. J. Vietri B. K. Purcell J. V. Lawler E. K. Leffel P. Rico

2006-01-01

234

Clinical Presentation of Inhalational Anthrax Following Bioterrorism Exposure Report of 2 Surviving Patients  

Microsoft Academic Search

The use of anthrax as a weapon of biological terrorism has moved from theory to reality in recent weeks. Following processing of a letter containing anthrax spores that had been mailed to a US senator, 5 cases of inhalational anthrax have occurred among postal workers employed at a major postal facility in Wash- ington, DC. This report details the clinical

Thom A. Mayer; Susan Bersoff-Matcha; Cecele Murphy; James Earls; Scott Harper; Denis Pauze; Michael Nguyen; Jonathan Rosenthal; Donald Cerva; Glenn Druckenbrod; Dan Hanfling; Naaz Fatteh; Anthony Napoli; Ashna Nayyar; Elise L. Berman

235

Laboratory Aspects of Bioterrorism-related Anthrax - from Identification to Molecular Subtyping to Microbial Forensics  

Microsoft Academic Search

During the bioterrorism-associated anthrax investigation of 2001 in the United States, 11 patients were diagnosed with inhalational anthrax and 11 more with the cutaneous forms of the disease. Over 125,000 specimens were processed at laboratories of the Laboratory Response Network including those at the Centers for Disease Control and Prevention. Although the 2001 anthrax investigation initially began as a public

Tanja Popoviæ; Mindy Glass

2003-01-01

236

The ecology of anthrax spores: tough but not invincible.  

PubMed Central

Bacillus anthracis is the causative agent of anthrax, a serious and often fatal disease of wild and domestic animals. Central to the persistence of anthrax in an area is the ability of B. anthracis to form long-lasting, highly resistant spores. Understanding the ecology of anthrax spores is essential if one hopes to control epidemics. Studies on the ecology of anthrax have found a correlation between the disease and specific soil factors, such as alkaline pH, high moisture, and high organic content. Researchers initially suggested that these factors influenced vegetative anthrax bacilli. However, subsequent research has shown that vegetative cells of B. anthracis have very specific nutrient and physiological requirements and are unlikely to survive outside a host. Review of the properties of spores of B. anthracis and other Bacillus species suggests that the specific soil factors linked to epidemic areas reflect important environmental conditions that aid the anthrax spores in causing epidemics. Specifically, high levels of calcium in the soil may help to maintain spore vitality for prolonged periods, thereby increasing the chance of spores encountering and infecting a new host. Cycles of runoff and evaporation may collect spores dispersed from previous epidemics into storage areas, thereby concentrating them. Uptake of large doses of viable spores from storage areas by susceptible animals, via altered feeding or breeding behavior, may then allow the bacterium to establish infection and cause a new epidemic. Literature search for this review was done by scanning the Life Sciences Collection 1982-1994 using the keywords "anthrax" and "calcium and spore." Images Figure 1.

Dragon, D C; Rennie, R P

1995-01-01

237

Antibody radiolabeling techniques to optimize cellular retention.  

PubMed

Radiolabeling of antibodies and antibody fragments facilitates the development of new targeted therapeutics or tracking and validation of biosimilars. The typical metal ion chelators that can be used for radiolabeling reactions have residualizing properties in tissues/tumors. A team at Genentech has developed an elegant new technique for combining iodine radiolabeling with an azamacrocyclic chelator to confer residualizing properties on the radioiodine metabolites. Robust protocols, such as this example, are required for the future development of protein based drugs. PMID:24283797

Archibald, Stephen J

2013-12-12

238

Neuromodulators (Botulinum Toxin Therapy)  

MedlinePLUS

... at the corners of the eyes. What is botulinum toxin? Botulinum toxin is a purified toxin and, when ... needed for expression and important functions like eating. Botulinum toxin therapy Treatment involves injection of very small amounts ...

239

Clinical uses of radiolabeled platelets  

SciTech Connect

Platelets were first successfully radiolabeled in 1953. At that time, investigators were primarily interested in developing a technique to accurately measure platelet life span in both normal and thrombocytopenic patients. Studies using platelets labeled with /sup 51/Cr have shown shortened platelet survival times in a number of diseases including idiopathic thrombocytopenic purpura, coronary artery disease, and diabetes mellitus. More recently, labels such as /sup 111/In have been developed that allow in vivo imaging of platelets. Indium-111 platelets are being used to better understand the pathophysiology of atherosclerosis, thrombophlebitis, pulmonary embolism and clotting disorders, and to improve the clinical diagnosis of these diseases.

Datz, F.L.; Christian, P.E.; Baker, W.J.

1985-12-01

240

BOTULINUM TOXIN  

PubMed Central

Botulinum toxin, one of the most poisonous biological substances known, is a neurotoxin produced by the bacterium Clostridium botulinum. C. botulinum elaborates eight antigenically distinguishable exotoxins (A, B, C1, C2, D, E, F and G). All serotypes interfere with neural transmission by blocking the release of acetylcholine, the principal neurotransmitter at the neuromuscular junction, causing muscle paralysis. The weakness induced by injection with botulinum toxin A usually lasts about three months. Botulinum toxins now play a very significant role in the management of a wide variety of medical conditions, especially strabismus and focal dystonias, hemifacial spasm, and various spastic movement disorders, headaches, hypersalivation, hyperhidrosis, and some chronic conditions that respond only partially to medical treatment. The list of possible new indications is rapidly expanding. The cosmetological applications include correction of lines, creases and wrinkling all over the face, chin, neck, and chest to dermatological applications such as hyperhidrosis. Injections with botulinum toxin are generally well tolerated and side effects are few. A precise knowledge and understanding of the functional anatomy of the mimetic muscles is absolutely necessary to correctly use botulinum toxins in clinical practice.

Nigam, P K; Nigam, Anjana

2010-01-01

241

Reduced Expression of CD45 Protein-tyrosine Phosphatase Provides Protection against Anthrax Pathogenesis*S?  

PubMed Central

The modulation of cellular processes by small molecule inhibitors, gene inactivation, or targeted knockdown strategies combined with phenotypic screens are powerful approaches to delineate complex cellular pathways and to identify key players involved in disease pathogenesis. Using chemical genetic screening, we tested a library of known phosphatase inhibitors and identified several compounds that protected Bacillus anthracis infected macrophages from cell death. The most potent compound was assayed against a panel of sixteen different phosphatases of which CD45 was found to be most sensitive to inhibition. Testing of a known CD45 inhibitor and antisense phosphorodiamidate morpholino oligomers targeting CD45 also protected B. anthracis-infected macrophages from cell death. However, reduced CD45 expression did not protect anthrax lethal toxin (LT) treated macrophages, suggesting that the pathogen and independently added LT may signal through distinct pathways. Subsequent, in vivo studies with both gene-targeted knockdown of CD45 and genetically engineered mice expressing reduced levels of CD45 resulted in protection of mice after infection with the virulent Ames B. anthracis. Intermediate levels of CD45 expression were critical for the protection, as mice expressing normal levels of CD45 or disrupted CD45 phosphatase activity or no CD45 all succumbed to this pathogen. Mechanism-based studies suggest that the protection provided by reduced CD45 levels results from regulated immune cell homeostasis that may diminish the impact of apoptosis during the infection. To date, this is the first report demonstrating that reduced levels of host phosphatase CD45 modulate anthrax pathogenesis.

Panchal, Rekha G.; Ulrich, Ricky L.; Bradfute, Steven B.; Lane, Douglas; Ruthel, Gordon; Kenny, Tara A.; Iversen, Patrick L.; Anderson, Arthur O.; Gussio, Rick; Raschke, William C.; Bavari, Sina

2009-01-01

242

Rapid homogenous time-resolved fluorescence (HTRF) immunoassay for anthrax detection.  

PubMed

Infection with Bacillus anthracsis spores induces an acute anthrax disease that can cause casualties and death in untreated cases. Thus rapid diagnosis of anthrax at early stage of the disease is essential to allow an effective treatment. Here we present the development of rapid and sensitive homogenous time-resolved fluorescence (HTRF) immunoassays based on the energy transfer process of europium cryptate (EuK) donor to AlexaFluor647 acceptor. The energy transfer process is limited to d?toxin, a serological marker that correlates with bacteremia in infected hosts, using two monoclonal anti-PA antibodies that specifically recognize two different epitopes on the PA molecule. The assay was sensitive enabling detection of 2 ng/ml PA in the serum of B. anthracsis-infected rabbits in only 15 min assay. Additionally, HTRF assay was developed for the detection of bacterial spores using polyclonal anti-spore antibodies that recognize many epitopes on the bacterial surface. The assay enabled the detection of 2?×?10(6) spores/ml in 30 min assay and was specific, showing no cross reactivity with closely related non-virulent bacillus cereus strain. This study describes the use of the HTRF assay for the detection of both singled-epitope (proteins) and multi-epitope (particles) as rapid, simple and sensitive method that can be used at the time that fast results are needed to allow an effective medical care. PMID:24515915

Cohen, Noam; Mechaly, Adva; Mazor, Ohad; Fisher, Morly; Zahavy, Eran

2014-05-01

243

Clostridial toxins  

PubMed Central

The current global outbreak of Clostridium difficile infection exemplifies the major public health threat posed by clostridial glucosylating toxins. In the western world, C. difficile infection is one of the most prolific causes of bacterial-induced diarrhea and potentially fatal colitis. Two pathogenic enterotoxins, TcdA and TcdB, cause the disease. Vancomycin and metronidazole remain readily available treatment options for C. difficile infection, but neither is fully effective as is evident by high clinical relapse and fatality rates. Thus, there is an urgent need to find an alternative therapy that preferentially targets the toxins and not the drug-resistant pathogen. Recently, we addressed these critical issues in a Nature Medicine letter, describing a novel host defense mechanism for subverting toxin virulence that we translated into prototypic allosteric therapy for C. difficile infection. In this addendum article, we provide a continued perspective of this antitoxin mechanism and consider the broader implications of therapeutic allostery in combating gut microbial pathogenesis.

Oezguen, Numan; Power, Trevor D.; Urvil, Petri; Feng, Hanping; Pothoulakis, Charalabos; Stamler, Jonathan S.; Braun, Werner; Savidge, Tor C.

2012-01-01

244

Antimicrobial Postexposure Prophylaxis for Anthrax: Adverse Events and Adherence  

PubMed Central

We collected data during postexposure antimicrobial prophylaxis campaigns and from a prophylaxis program evaluation 60 days after start of antimicrobial prophylaxis involving persons from six U.S. sites where Bacillus anthracis exposures occurred. Adverse events associated with antimicrobial prophylaxis to prevent anthrax were commonly reported, but hospitalizations and serious adverse events as defined by Food and Drug Administration criteria were rare. Overall adherence during 60 days of antimicrobial prophylaxis was poor (44%), ranging from 21% of persons exposed in the Morgan postal facility in New York City to 64% of persons exposed at the Brentwood postal facility in Washington, D.C. Adherence was highest among participants in an investigational new drug protocol to receive additional antibiotics with or without anthrax vaccine—a likely surrogate for anthrax risk perception. Adherence of <60 days was not consistently associated with adverse events.

Soriano-Gabarro, Montse; Zell, Elizabeth R.; Hayslett, James; Lukacs, Susan; Goldstein, Susan; Factor, Stephanie; Jones, Joshua; Ridzon, Renee; Williams, Ian; Rosenstein, Nancy

2002-01-01

245

Anthrax Postexposure Prophylaxis in Postal Workers, Connecticut, 2001  

PubMed Central

After inhalational anthrax was diagnosed in a Connecticut woman on November 20, 2001, postexposure prophylaxis was recommended for postal workers at the regional mail facility serving the patient’s area. Although environmental testing at the facility yielded negative results, subsequent testing confirmed the presence of Bacillus anthracis. We distributed questionnaires to 100 randomly selected postal workers within 20 days of initial prophylaxis. Ninety-four workers obtained antibiotics, 68 of whom started postexposure prophylaxis and 21 discontinued. Postal workers who stopped or never started taking prophylaxis cited as reasons disbelief regarding anthrax exposure, problems with adverse events, and initial reports of negative cultures. Postal workers with adverse events reported predominant symptoms of gastrointestinal distress and headache. The influence of these concerns on adherence suggests that communication about risks of acquiring anthrax, education about adverse events, and careful management of adverse events are essential elements in increasing adherence.

Noviello, Stephanie S.; Griffith, Kevin S.; Wurtzel, Heather; Hamborsky, Jennifer; Perz, Joseph F.; Williams, Ian T.; Hadler, James L.; Swerdlow, David L.; Ridzon, Renee

2002-01-01

246

Further Insights into Brevetoxin Metabolism by de Novo Radiolabeling  

PubMed Central

The toxic dinoflagellate Karenia brevis, responsible for early harmful algal blooms in the Gulf of Mexico, produces many secondary metabolites, including potent neurotoxins called brevetoxins (PbTx). These compounds have been identified as toxic agents for humans, and they are also responsible for the deaths of several marine organisms. The overall biosynthesis of these highly complex metabolites has not been fully ascertained, even if there is little doubt on a polyketide origin. In addition to gaining some insights into the metabolic events involved in the biosynthesis of these compounds, feeding studies with labeled precursors helps to discriminate between the de novo biosynthesis of toxins and conversion of stored intermediates into final toxic products in the response to environmental stresses. In this context, the use of radiolabeled precursors is well suited as it allows working with the highest sensitive techniques and consequently with a minor amount of cultured dinoflagellates. We were then able to incorporate [U-14C]-acetate, the renowned precursor of the polyketide pathway, in several PbTx produced by K. brevis. The specific activities of PbTx-1, -2, -3, and -7, identified by High-Resolution Electrospray Ionization Mass Spectrometer (HRESIMS), were assessed by HPLC-UV and highly sensitive Radio-TLC counting. We demonstrated that working at close to natural concentrations of acetate is a requirement for biosynthetic studies, highlighting the importance of highly sensitive radiolabeling feeding experiments. Quantification of the specific activity of the four, targeted toxins led us to propose that PbTx-1 and PbTx-2 aldehydes originate from oxidation of the primary alcohols of PbTx-7 and PbTx-3, respectively. This approach will open the way for a better comprehension of the metabolic pathways leading to PbTx but also to a better understanding of their regulation by environmental factors.

Calabro, Kevin; Guigonis, Jean-Marie; Teyssie, Jean-Louis; Oberhansli, Francois; Goudour, Jean-Pierre; Warnau, Michel; Dechraoui Bottein, Marie-Yasmine; Thomas, Olivier P.

2014-01-01

247

Further insights into brevetoxin metabolism by de novo radiolabeling.  

PubMed

The toxic dinoflagellate Karenia brevis, responsible for early harmful algal blooms in the Gulf of Mexico, produces many secondary metabolites, including potent neurotoxins called brevetoxins (PbTx). These compounds have been identified as toxic agents for humans, and they are also responsible for the deaths of several marine organisms. The overall biosynthesis of these highly complex metabolites has not been fully ascertained, even if there is little doubt on a polyketide origin. In addition to gaining some insights into the metabolic events involved in the biosynthesis of these compounds, feeding studies with labeled precursors helps to discriminate between the de novo biosynthesis of toxins and conversion of stored intermediates into final toxic products in the response to environmental stresses. In this context, the use of radiolabeled precursors is well suited as it allows working with the highest sensitive techniques and consequently with a minor amount of cultured dinoflagellates. We were then able to incorporate [U-14C]-acetate, the renowned precursor of the polyketide pathway, in several PbTx produced by K. brevis. The specific activities of PbTx-1, -2, -3, and -7, identified by High-Resolution Electrospray Ionization Mass Spectrometer (HRESIMS), were assessed by HPLC-UV and highly sensitive Radio-TLC counting. We demonstrated that working at close to natural concentrations of acetate is a requirement for biosynthetic studies, highlighting the importance of highly sensitive radiolabeling feeding experiments. Quantification of the specific activity of the four, targeted toxins led us to propose that PbTx-1 and PbTx-2 aldehydes originate from oxidation of the primary alcohols of PbTx-7 and PbTx-3, respectively. This approach will open the way for a better comprehension of the metabolic pathways leading to PbTx but also to a better understanding of their regulation by environmental factors. PMID:24918358

Calabro, Kevin; Guigonis, Jean-Marie; Teyssié, Jean-Louis; Oberhänsli, François; Goudour, Jean-Pierre; Warnau, Michel; Bottein, Marie-Yasmine Dechraoui; Thomas, Olivier P

2014-01-01

248

Structural and Immunological Analysis of Anthrax Recombinant Protective Antigen Adsorbed to Aluminum Hydroxide Adjuvant  

PubMed Central

New anthrax vaccines currently under development are based on recombinant protective antigen (rPA) and formulated with aluminum adjuvant. Because long-term stability is a desired characteristic of these vaccines, an understanding of the effects of adsorption to aluminum adjuvants on the structure of rPA is important. Using both biophysical and immunological techniques, we compared the structure and immunogenicity of freshly prepared rPA-Alhydrogel formulations to that of formulations stored for 3 weeks at either room temperature or 37°C in order to assess the changes in rPA structure that might occur upon long-term storage on aluminum adjuvant. Intrinsic fluorescence emission spectra of tryptophan residues indicated that some tertiary structure alterations of rPA occurred during storage on Alhydrogel. Using anti-PA monoclonal antibodies to probe specific regions of the adsorbed rPA molecule, we found that two monoclonal antibodies that recognize epitopes located in domain 1 of PA exhibited greater reactivity to the stored formulations than to freshly prepared formulations. Immunogenicity of rPA-Alhydrogel formulations in mice was assessed by measuring the induction of toxin-neutralizing antibodies, as well as antibodies reactive to 12-mer peptides spanning the length of PA. Mice immunized with freshly prepared formulations developed significantly higher toxin-neutralizing antibody titers than mice immunized with the stored preparations. In contrast, sera from mice immunized with stored preparations exhibited increased reactivity to nine 12-mer peptides corresponding to sequences located throughout the rPA molecule. These results demonstrate that storage of rPA-Alhydrogel formulations can lead to structural alteration of the protein and loss of the ability to elicit toxin-neutralizing antibodies.

Wagner, Leslie; Verma, Anita; Meade, Bruce D.; Reiter, Karine; Narum, David L.; Brady, Rebecca A.; Little, Stephen F.

2012-01-01

249

Wanted, an Anthrax vaccine: Dead or Alive?  

PubMed Central

It has been more than 100 years since the realization that microbes are capable of causing disease. In that time, we have learned a great deal as to how each organism has adapted to the immune system so as to avoid elimination. As well, we have also learned an immense amount since Louis Pasteur first proposed that the solution to infectious diseases was to culture the microbes and attenuate their virulence, so as to use them as vaccines. From the optimism and promise of the 19th century and immunization as the ultimate answer to the invasion by the microbial world, to the scientific realities of the 21st century, it is of interest to retrace the steps of the earliest microbiologists cum immunologists, to realize how far we've come, as well as how far we yet have to go. This editorial focuses on the history of anthrax as a microbial disease, and the earliest efforts at producing a vaccine for its prevention.

Smith, Kendall A

2005-01-01

250

LYSINE DEFICIENCY AND HOST RESISTANCE TO ANTHRAX  

PubMed Central

1. Lysine deficiency has been produced in rats by placing the weanling animals on an experimental diet in which gluten replaced the casein of the control diet. Both diets were complete in all other known requirements. 2. The resistance of the deficient animals to a subcutaneous challenge of several concentrations of B. anthracis spores, was decreased. Deaths occurred within 2 days post inoculation. 3. When lysine was added to the gluten diet to bring the total concentration to that of the control diet, the growth rate of the animals was maintained but a decrease in resistance remained, although not as great as on the gluten diet. 4. Changes in the tissues associated with lysine deficiency are reported. 5. It is not unreasonable to state that within the time frame of our experiments, the decreased ability of the RES of the host to clear the invading organism from the tissues and subsequently to break down the organism is a major factor of the decreased resistance of the lysine-deficient rats to anthrax.

Gray, Irving

1963-01-01

251

Sverdlovsk Anthrax Outbreak: An Educational Case Study  

NASA Astrophysics Data System (ADS)

In April and May of 1979 an Anthrax epidemic broke out in the city of Sverdlovsk (now Ekaterinburg) in the former Soviet Union. Sixty-four people were reported to have died from the outbreak, although there is still debate concerning the actual number of victims. While Soviet officials initially attributed this outbreak to contaminated meat, the US Government maintained that the outbreak was due to a leakage from a biological weapons facility. We have created and implemented an undergraduate educational exercise based on the forensic analysis of this event. Students were provided case data of the victims, area satellite images and meteorological data. One goal of the exercise was for students to reconstruct the most probable scenario of events through valid inference based on the limited information and uncertainties associated with the data set. Another goal was to make students sensitive to issues of biological weapons and bioterrorism. The exercise was highly rated by students even before the events of September 11. There is a clear need to educate students, particularly in the sciences, to be aware of the signatures of terrorist activities. Evidence of terrorist activities is more likely to appear from unintended discoveries than from active intelligence gathering. We believe our national security can be enhanced by sensitizing those that monitor the natural environment to the signatures of terrorist activities through the types of educational exercises that we have developed.

Steele, S. J.; van der Vink, G.

2002-05-01

252

Identification of small molecules that inhibit the interaction of TEM8 with anthrax protective antigen using a FRET assay.  

PubMed

Tumor marker endothelial 8 (TEM8) is a receptor for the protective antigen (PA) component of anthrax toxin. TEM8 is upregulated on endothelial cells lining the blood vessels within tumors, compared with normal blood vessels. A number of studies have demonstrated a pivotal role for TEM8 in developmental and tumor angiogenesis. We have also shown that targeting the anthrax receptors with a mutated form of PA inhibits angiogenesis and tumor formation in vivo. Here we describe the development and testing of a high-throughput fluorescence resonance energy transfer assay to identify molecules that strongly inhibit the interaction of PA and TEM8. The assay we describe is sensitive and robust, with a Z' value of 0.8. A preliminary screen of 2310 known bioactive library compounds identified ebselen and thimerosal as inhibitors of the TEM8-PA interaction. These molecules each contain a cysteine-reactive transition metal, and complementary studies indicate that their inhibition of interaction is due to modification of a cysteine residue in the TEM8 extracellular domain. This is the first demonstration of a high-throughput screening assay that identifies inhibitors of TEM8, with potential application for antianthrax and antiangiogenic diseases. PMID:23479355

Cryan, Lorna M; Habeshian, Kaiane A; Caldwell, Thomas P; Morris, Meredith T; Ackroyd, P Christine; Christensen, Kenneth A; Rogers, Michael S

2013-07-01

253

Radionuclide therapy of cancer with radiolabeled antibodies.  

PubMed

Radioimmunotherapy (RIT) using radiolabeled monoclonal antibodies (MAbs) directed against tumor-associated antigens has evolved from an appealing concept to one of the standard treatment options for patients with non-Hodgkin's lymphoma (NHL). Inefficient localization of radiolabeled MAbs to nonhematological cancers due to various tumor-related factors, however, limits the therapeutic efficacy of RIT in solid tumors. Still, small volume or minimal residual disease has been recognized as a potentially suitable target for radiolabeled antibodies. Several strategies are being explored aimed at improving the targeting of radiolabeled MAbs to solid tumors thus improving their therapeutic efficacy. In this review, various aspects of the application of radiolabeled MAbs as anti-cancer agents are discussed, and the clinical results of RIT in patients with hematological and various solid cancers (colorectal, ovarian, breast and renal carcinomas) are reviewed. PMID:17504159

Boerman, Otto C; Koppe, Manuel J; Postema, E J; Corstens, Frans H; Oyen, Wim J

2007-05-01

254

Transient Co-Expression of Post-Transcriptional Gene Silencing Suppressors for Increased in Planta Expression of a Recombinant Anthrax Receptor Fusion Protein  

PubMed Central

Potential epidemics of infectious diseases and the constant threat of bioterrorism demand rapid, scalable, and cost-efficient manufacturing of therapeutic proteins. Molecular farming of tobacco plants provides an alternative for the recombinant production of therapeutics. We have developed a transient production platform that uses Agrobacterium infiltration of Nicotiana benthamiana plants to express a novel anthrax receptor decoy protein (immunoadhesin), CMG2-Fc. This chimeric fusion protein, designed to protect against the deadly anthrax toxins, is composed of the von Willebrand factor A (VWA) domain of human capillary morphogenesis 2 (CMG2), an effective anthrax toxin receptor, and the Fc region of human immunoglobulin G (IgG). We evaluated, in N. benthamiana intact plants and detached leaves, the expression of CMG2-Fc under the control of the constitutive CaMV 35S promoter, and the co-expression of CMG2-Fc with nine different viral suppressors of post-transcriptional gene silencing (PTGS): p1, p10, p19, p21, p24, p25, p38, 2b, and HCPro. Overall, transient CMG2-Fc expression was higher on intact plants than detached leaves. Maximum expression was observed with p1 co-expression at 3.5 days post-infiltration (DPI), with a level of 0.56 g CMG2-Fc per kg of leaf fresh weight and 1.5% of the total soluble protein, a ten-fold increase in expression when compared to absence of suppression. Co-expression with the p25 PTGS suppressor also significantly increased the CMG2-Fc expression level after just 3.5 DPI.

Arzola, Lucas; Chen, Junxing; Rattanaporn, Kittipong; Maclean, James M.; McDonald, Karen A.

2011-01-01

255

Epidemiologic Investigations of Bioterrorism-Related Anthrax, New Jersey, 2001  

PubMed Central

At least four Bacillus anthracis–containing envelopes destined for New York City and Washington, D.C., were processed at the Trenton Processing and Distribution Center (PDC) on September 18 and October 9, 2001. When cutaneous anthrax was confirmed in a Trenton postal worker, the PDC was closed. Four cutaneous and two inhalational anthrax cases were identified. Five patients were hospitalized; none died. Four were PDC employees; the others handled or received mail processed there. Onset dates occurred in two clusters following envelope processing at the PDC. The attack rate among the 170 employees present when the B. anthracis–containing letters were sorted on October 9 was 1.2%. Of 137 PDC environmental samples, 57 (42%) were positive. Five (10%) of 50 local post offices each yielded one positive sample. Cutaneous or inhalational anthrax developed in four postal employees at a facility where B. anthracis–containing letters were processed. Cross-contaminated mail or equipment was the likely source of infection in two other case-patients with cutaneous anthrax.

Reefhuis, Jennita; Tan, Christina; Fiore, Anthony E.; Goldstein, Susan; Beach, Michael J.; Redd, Stephen C.; Valiante, David; Burr, Gregory; Buehler, James; Pinner, Robert W.; Bresnitz, Eddy; Bell, Beth P.

2002-01-01

256

Anthrax in Wuerttemberg. A Statistical and Epidemiological Study.  

National Technical Information Service (NTIS)

Today Anthrax is limited to foci in Goeppingen and Ludwigsburg Countries, and to isolated cases throughout the state. As seen especially well in the Murr valley, the communities situated on rivers below tanneries were menaced by spore-containing sludge fr...

A. Braun

1966-01-01

257

[Four cases of cutaneous anthrax in Diyarbakir, Turkey].  

PubMed

Anthrax which is a rare disease in developed countries, is still a serious public health problem in countries like Turkey where livestock is common. In this report, four cases of cutaneous anthrax detected in Kirkira village of Diyarbakir, Southeast Anatolia, Turkey, were presented. Three female and one male patients were admitted to our hospital with the complaints of skin lesions and high fever lasting for 10 days. Their history indicated that they injured their fingers during slaughtering of a dead cow meat. All patients had irregular edged necrotic vesiculobullous lesions on the erythematous and edematous base on their hand fingers, developed in 1 week following the contact. There was no systemic finding and the laboratory findings were within normal limits. Typical bamboo cane shaped gram-positive bacilli were observed on the Gram stained smears prepared from the vesicular lesions. Aerobic cultures in blood agar media revealed typical R type colonies, gray in color, creased, granulated and 2-3 mm in diameter within 24 hours of incubation. In one patient although the lesion was typical and characteristic gram-positive bacilli were detected in the Gram stained smears, no growth was seen in the cultures. The isolates (n= 3) were identified as Bacillus anthracis by conventional microbiological methods, and also confirmed by Vitek 2 (BioMerieux, France) automated identification system. Antibiotic susceptibility tests were performed by disc diffusion method according to the CLSI guidelines. The isolates were found susceptible to penicillin G, ampicillin, erythromycin, amikacin, chloramphenicol, tetracycline, vancomycin and ciprofloxacin. All of the patients were treated successfully with penicillin or ciprofloxacin accompanied by topical wound care. In the last years several case series of anthrax were reported especially from the East and Southeastern Anatolia regions of Turkey. These four cutaneous anthrax cases from Diyarbakir, Turkey were reported to withdraw attention to anthrax in that specific area. It was concluded that in areas where anthrax is endemic to educate people under risk, to take the necessary preventive measures and to rule out anthrax in the differential diagnosis of cases presenting with typical ulcers and had contact with animals or their products, are of crucial importance for the early initiation of appropriate treatment which would decrease related morbidity and mortality. PMID:23971932

Turhano?lu, Nezire Mine; Bay?nd?r Bilman, Fulya; Kutlu Yürüker, Safiye

2013-07-01

258

Pathology of inhalation anthrax in cynomolgus monkeys (Macaca fascicularis).  

PubMed

Anthrax is considered a serious biowarfare and bioterrorism threat because of its high lethality, especially by the inhalation route. Rhesus macaques (Macaca mulatta) are the most commonly used nonhuman primate model of human inhalation anthrax exposure. The nonavailability of rhesus macaques necessitated development of an alternate model for vaccine testing and immunologic studies. This report describes the median lethal dose (LD(50)) and pathology of inhalation anthrax in cynomolgus macaques (Macaca fascicularis). Gross and microscopic tissue changes were reviewed in 14 cynomolgus monkeys that died or were killed after aerosol exposure of spores of Bacillus anthracis (Ames strain). The LD(50) and 95% confidence intervals were 61800 (34000 to 110000) colony-forming units. The most common gross lesions were mild splenomegaly, lymph node enlargement, and hemorrhages in various organs, particularly involving the meninges and the lungs. Mediastinitis, manifested as hemorrhage or edema, affected 29% of the monkeys. Microscopically, lymphocytolysis occurred in the intrathoracic lymph nodes and spleens of all animals, and was particularly severe in the spleen and in germinal centers of lymph nodes. Hemorrhages were common in lungs, bronchial lymph nodes, meninges, gastrointestinal tract, and mediastinum. These results demonstrate that the Ames strain of B. anthracis is lethal by the inhalation route in the cynomolgus macaque. The LD(50) of the Ames strain of B. anthracis was within the expected experimental range of previously reported values in the rhesus monkey in an aerosol challenge. The gross and microscopic pathology of inhalation anthrax in the cynomolgus monkey is remarkably similar to that reported in rhesus monkeys and humans. The results of this study are important for the establishment of an alternative nonhuman primate model for evaluation of medical countermeasures against inhalational anthrax. PMID:12920249

Vasconcelos, Daphne; Barnewall, Roy; Babin, Michael; Hunt, Robert; Estep, James; Nielsen, Carl; Carnes, Robert; Carney, John

2003-08-01

259

Recent developments in monoclonal antibody radiolabeling techniques  

SciTech Connect

Monoclonal antibodies (MAbs) have shown the potential to serve as selective carriers of radionuclides to specific in vivo antigens. Accordingly, there has been an intense surge of research activity in an effort to develop and evaluate MAb-based radiopharmaceuticals for tumor imaging (radioimmunoscintigraphy) and therapy (radioimmunotherapy), as well as for diagnosing nonmalignant diseases. A number of problems have recently been identified, related to the MAbs themselves and to radiolabeling techniques, that comprise both the selectivity and the specificity of the in vivo distribution of radiolabeled MAbs. This paper will address some of these issues and primarily discuss recent developments in the techniques for radiolabeling monoclonal antibodies that may help resolve problems related to the poor in vivo stability of the radiolabel and may thus produce improved biodistribution. Even though many issues are identical with therapeutic radionuclides, the discussion will focus mainly on radioimmunoscintigraphic labels. 78 refs., 6 tabs.

Srivastava, S.C.; Mease, R.C.

1989-01-01

260

Localization of tumors by radiolabelled antibodies  

Microsoft Academic Search

A method of utilizing radiolabelled antibodies to carcinoembryonic antigens for determining the site of tumors which produce or are associated with carcinoembryonic antigen is disclosed. 3 claims, no drawings.

H. J. Hansen; F. J. Primus

1975-01-01

261

[The return of anthrax. From bioterrorism to the zoonotic cluster of Sciacca district].  

PubMed

Anthrax is a disease caused by Bacillus anthracis which affects herbivorous animals. Humans acquire the disease incidentally by exposure to infected animals, animal products or spores on soil. The infection is still endemic in many regions in developing countries. In Italy animal clusters are very rare and human cases are exceptional. Bacillus anthrax is also a potential source for acts of bioterrorism. In the natural human infection, cutaneous anthrax is the most widespread, while the other two, pulmonary and gastrointestinal anthrax, are very rare forms. We describe the first case of human anthrax occurring in western Sicily in the last twenty years. The cutaneous lesion healed without significant scarring after antibiotic treatment with tigecycline, rifampin and ciprofloxacin. Following our diagnosis, a cluster of bovine anthrax was detected in the district of Sciacca, causing the death of 13 animals. A larger outbreak was avoided by the vaccination of over 5000 herbivores. PMID:20610930

Scarlata, Francesco; Colletti, Pietro; Bonura, Silvia; Trizzino, Marcello; Giordano, Salvatore; Titone, Lucina

2010-06-01

262

Evaluation of the House Fly Musca domestica as a Mechanical Vector for an Anthrax  

PubMed Central

Anthrax is a disease of human beings and animals caused by the encapsulated, spore-forming, Bacillus anthracis. The potential role of insects in the spread of B. anthracis to humans and domestic animals during an anthrax outbreak has been confirmed by many studies. Among insect vectors, the house fly Musca domestica is considered a potential agent for disease transmission. In this study, laboratory-bred specimens of Musca domestica were infected by feeding on anthrax-infected rabbit carcass or anthrax contaminated blood, and the presence of anthrax spores in their spots (faeces and vomitus) was microbiologically monitored. It was also evaluated if the anthrax spores were able to germinate and replicate in the gut content of insects. These results confirmed the role of insects in spreading anthrax infection. This role, although not major, given the huge size of fly populations often associated with anthrax epidemics in domestic animals, cannot be neglected from an epidemiological point of view and suggest that fly control should be considered as part of anthrax control programs.

Fasanella, Antonio; Scasciamacchia, Silvia; Garofolo, Giuliano; Giangaspero, Annunziata; Tarsitano, Elvira; Adone, Rosanna

2010-01-01

263

Metabolism of the cyclic peptide HC-toxin, a host-specific toxin, by resistant (R) and susceptible (S) maize  

SciTech Connect

Cochliobolus carbonum (race 1) and the toxin it produces, HC-toxin, affect only maize that is homozygous recessive at the nuclear locus, Hm. Radiolabeled HC-toxin was purified after controlled feeding of D,L-({sup 3}H)-alanine to the fungus and used to study metabolism as a basis for its host-selectivity. A single HC-toxin metabolite was recovered from maize leaves exposed to ({sup 3}H)-HC-toxin. The 8-keto group of the epoxy-containing amino acid, AOE, was reduced to the corresponding alcohol. the identity of this compound was determined by FAB-MS, and by co-elution on HPLC and TLC with synthetically reduced HC-toxin. This synthetic derivative was previously proven to be biologically inactive. Metabolism of the epoxide group was not detected. Reduction of the 8-keto group was also catalyzed enzymatically by cell-free maize extracts. The reaction required NADPH and was inhibited by p-hydroxymercuribenzoate. Cell-free extracts from R (Hm/hm) and S (hm/hm) maize catalyzed the reduction of HC-toxin equally well, and the process was also found to occur in spinach and barley leaf segments. Thus, detoxification of HC-toxin occurs in maize, but appears to have no relationship to host-selectivity.

Meeley, R.; Walton, J.D. (Michigan State Univ., East Lansing (USA))

1990-05-01

264

[Radiolabeled antibodies for cancer treatment].  

PubMed

The first treatment ever by radio-immunotherapy (RIT) was performed by William H. Beierwaltes in 1951 and was a success. Fifty years later, the main question is to find ways of extending the success of radiolabelled anti-CD20 antibodies in indolent non-Hodgkin's lymphoma to other forms of cancer. Solid tumours are much more radioresistant than lymphomas, but they respond to RIT if the lesions are small. Clinical situations of residual or minimal disease are thus the most likely to benefit from RIT in the adjuvant or consolidation settings. For disseminated disease, like leukemias or myelomas, the problem is different: beta- particles emitted by the radioactive atoms classically used for cancer treatment (iodine-131 or yttrium-90) disperse their energy in large volumes (ranges 1 mm to 1 cm) and are not very effective against isolated cells. Advances in RIT progress in two directions. One is the development of pretargeting strategies in which the antibody is not labelled but used to provide binding sites to small molecular weight radioactivity vectors (biotin, haptens). These techniques have been shown to increase tumour to non-target uptake ratios and anti-tumour efficacy has been demonstrated in the clinic. The other approach is the use of radionuclides adapted to the various clinical situations. Lutetium-177 or copper-67, because of the lower energy of their emission, their relatively long half-life and good gamma emission, may significantly improve RIT efficacy and acceptability. Beyond that, radionuclides emitting particles such as alpha particles or Auger electrons, much more efficient to kill isolated tumour cells, are being tested for RIT in the clinic. Finally, RIT should be integrated with other cancer treatment approaches in multimodality protocols. Thus RIT, now a mature technology, should enter a phase of well designed and focused clinical developments that may be expected to afford significant therapeutic advances. PMID:20035676

Barbet, Jacques; Chatal, Jean-François; Kraeber-Bodéré, Françoise

2009-12-01

265

A specific binding protein from Manduca sexta for the insecticidal toxin of Bacillus thuringiensis subsp. berliner.  

PubMed

Biopesticides based on the bacterium Bacillus thuringiensis have attracted wide attention as safe alternatives to chemical pesticides. In this paper, we report, for the first time, the identification and purification of a single binding protein from a lepidopteran insect, Manduca sexta, that is specific for a cryIA toxin of B. thuringiensis. The purified protein appeared as a single band of 210 kDa on a two-dimensional gel, had a pI of approximately 5.5, and stained with Schiff's reagent. The band material was sensitive to proteolytic digestion and was rich with acidic amino acids, indicating its protein nature. Radiolabeled toxin bound to the protein with a Kd value of 708 pM and could be specifically blocked by unlabeled toxin but not by toxins from other subspecies of B. thuringiensis. This study lays the groundwork to clone the toxin binding protein and to determine the molecular mechanism(s) of toxin action. PMID:8509372

Vadlamudi, R K; Ji, T H; Bulla, L A

1993-06-15

266

Risk factors associated with anthrax in cattle on smallholdings.  

PubMed

SUMMARY Unprecedented high rates of anthrax outbreaks have been observed recently in cattle and humans in Bangladesh, with 607 human cases in 2010. By enrolling 15 case and 15 control cattle smallholdings in the spatial zone in July-September 2010, we conducted a case-control study, data of which were analysed by matched-pair analysis and multivariable conditional logistic regression. Feeding animals with uprooted and unwashed grass [odds ratio (OR) 41·2, 95% confidence interval (CI) 3·7-458·8, P=0·003], and feeding water hyacinth (Eichhornia crassipes) (OR 22·2, 95% CI 1·2-418·7, P=0·039) were independent risk factors for anthrax in cattle. PMID:22123521

Biswas, P K; Islam, M Z; Shil, S K; Chakraborty, R K; Ahmed, S S U; Christensen, J P

2012-10-01

267

Public response to an anthrax attack: a multiethnic perspective.  

PubMed

The 2001 anthrax attacks emphasized the need to develop outreach that would more effectively support racial/ethnic minority populations during a bioterrorism incident. Given the importance of antibiotic prophylaxis in a future anthrax attack, it should be a priority to better support racial/ethnic minorities in mass dispensing programs. To examine the needs and perspectives of racial/ethnic minorities, this study used a nationally representative poll of 1,852 adults, including 1,240 whites, 261 African Americans, and 282 Hispanics. The poll examined public reactions to a ''worst-case scenario'' in which cases of inhalation anthrax are discovered without an identified source and the entire population of a city or town is asked to receive antibiotic prophylaxis within 48 hours. Findings suggest willingness across all racial/ethnic groups to comply with recommendations to seek prophylaxis at dispensing sites. However, findings also indicate possible barriers for racial/ethnic minorities, including greater concern about pill safety and multiple attacks as well as lesser knowledge about inhalation anthrax. Across all racial/ethnic groups, roughly half would prefer to receive antibiotics at mass dispensing sites rather than through the US Postal Service. People in racial/ethnic minority groups were more likely to say this preference stems from a desire to speak with staff or to exchange medication formulation or type. Findings suggest the need for tailored outreach to racial/ethnic minorities through, for example, emphasis on key messages and enhanced understandability in communications, increased staff for answering questions in relevant dispensing sites, and long-term trust building with racial/ethnic minority communities. PMID:23244501

Steelfisher, Gillian K; Blendon, Robert J; Brulé, Amanda S; Ben-Porath, Eran N; Ross, Laura J; Atkins, Bret M

2012-12-01

268

SNR analysis: molecular investigation of an anthrax epidemic  

PubMed Central

Background In Italy, anthrax is endemic but occurs sporadically. During the summer of 2004, in the Pollino National Park, Basilicata, Southern Italy, an anthrax epidemic consisting of 41 outbreaks occurred; it claimed the lives of 124 animals belonging to different mammal species. This study is a retrospective molecular epidemiological investigation carried out on 53 isolates collected during the epidemic. A 25-loci Multiple Locus VNTR Analysis (MLVA) MLVA was initially performed to define genetic relationships, followed by an investigation of genetic diversity between epidemic strains through Single Nucleotide Repeat (SNR) analysis. Results 53 Bacillus anthracis strains were isolated. The 25-loci MLVA analysis identified all of them as belonging to a single genotype, while the SNR analysis was able to detect the existence of five subgenotypes (SGTs), allowing a detailed epidemic investigation. SGT-1 was the most frequent (46/53); SGTs 2 (4/53), 3 (1/53) 4 (1/53) and 5 (1/53) were detected in the remaining seven isolates. Conclusions The analysis revealed the prevalent spread, during this epidemic, of a single anthrax clone. SGT-1 - widely distributed across the epidemic area and present throughout the period in question - may, thus, be the ancestral form. SGTs 2, 3 and 4 differed from SGT-1 at only one locus, suggesting that they could have evolved directly from the latter during the course of this epidemic. SGT-5 differed from the other SGTs at 2-3 loci. This isolate, thus, appears to be more distantly related to SGT-1 and may not be a direct descendant of the lineage responsible for the majority of cases in this epidemic. These data confirm the importance of molecular typing and subtyping methods for in-depth epidemiological analyses of anthrax epidemics.

2010-01-01

269

Economic Impacts of a Wide Area Release of Anthrax  

SciTech Connect

This analysis explores economic impacts that might result from a wide-area release of anthrax. The intent is not to provide a quantitative analysis of such a disaster, but to: 1. Define the general categories of economic impacts that the region should be concerned about; and, 2. Explore what types of private sector businesses or industries, if any, may have the greatest impact on speeding the economic recovery of the region.

Judd, Kathleen S.; Olson, Jarrod; Stein, Steven L.; Lesperance, Ann M.

2009-05-29

270

HEPA/Vaccine Plan for Indoor Anthrax Remediation  

PubMed Central

We developed a mathematical model to compare 2 indoor remediation strategies in the aftermath of an outdoor release of 1.5 kg of anthrax spores in lower Manhattan. The 2 strategies are the fumigation approach used after the 2001 postal anthrax attack and a HEPA/vaccine plan, which relies on HEPA vacuuming, HEPA air cleaners, and vaccination of reoccupants. The HEPA/vaccine approach leads to few anthrax cases among reoccupants if applied to all but the most heavily contaminated buildings, and recovery is much faster than under the decades-long fumigation plan. Only modest environmental sampling is needed. A surge capacity of 10,000 to 20,000 Hazmat workers is required to perform remediation within 6 to 12 months and to avoid permanent mass relocation. Because of the possibility of a campaign of terrorist attacks, serious consideration should be given to allowing or encouraging voluntary self-service cleaning of lightly contaminated rooms by age-appropriate, vaccinated, partially protected (through masks or hoods) reoccupants or owners.

Liu, Yifan; Leighton, Terrance J.

2005-01-01

271

Interactions between Bacillus anthracis and Plants May Promote Anthrax Transmission.  

PubMed

Environmental reservoirs are essential in the maintenance and transmission of anthrax but are poorly characterized. The anthrax agent, Bacillus anthracis was long considered an obligate pathogen that is dormant and passively transmitted in the environment. However, a growing number of laboratory studies indicate that, like some of its close relatives, B. anthracis has some activity outside of its vertebrate hosts. Here we show in the field that B. anthracis has significant interactions with a grass that could promote anthrax spore transmission to grazing hosts. Using a local, virulent strain of B. anthracis, we performed a field experiment in an enclosure within a grassland savanna. We found that B. anthracis increased the rate of establishment of a native grass (Enneapogon desvauxii) by 50% and that grass seeds exposed to blood reached heights that were 45% taller than controls. Further we detected significant effects of E. desvauxii, B. anthracis, and their interaction on soil bacterial taxa richness and community composition. We did not find any evidence for multiplication or increased longevity of B. anthracis in bulk soil associated with grass compared to controls. Instead interactions between B. anthracis and plants may result in increased host grazing and subsequently increased transmission to hosts. PMID:24901846

Ganz, Holly H; Turner, Wendy C; Brodie, Eoin L; Kusters, Martina; Shi, Ying; Sibanda, Heniritha; Torok, Tamas; Getz, Wayne M

2014-06-01

272

Improvement of a Potential Anthrax Therapeutic by Computational Protein Design*  

PubMed Central

Past anthrax attacks in the United States have highlighted the need for improved measures against bioweapons. The virulence of anthrax stems from the shielding properties of the Bacillus anthracis poly-?-d-glutamic acid capsule. In the presence of excess CapD, a B. anthracis ?-glutamyl transpeptidase, the protective capsule is degraded, and the immune system can successfully combat infection. Although CapD shows promise as a next generation protein therapeutic against anthrax, improvements in production, stability, and therapeutic formulation are needed. In this study, we addressed several of these problems through computational protein engineering techniques. We show that circular permutation of CapD improved production properties and dramatically increased kinetic thermostability. At 45 °C, CapD was completely inactive after 5 min, but circularly permuted CapD remained almost entirely active after 30 min. In addition, we identify an amino acid substitution that dramatically decreased transpeptidation activity but not hydrolysis. Subsequently, we show that this mutant had a diminished capsule degradation activity, suggesting that CapD catalyzes capsule degradation through a transpeptidation reaction with endogenous amino acids and peptides in serum rather than hydrolysis.

Wu, Sean J.; Eiben, Christopher B.; Carra, John H.; Huang, Ivan; Zong, David; Liu, Peixian; Wu, Cindy T.; Nivala, Jeff; Dunbar, Josef; Huber, Tomas; Senft, Jeffrey; Schokman, Rowena; Smith, Matthew D.; Mills, Jeremy H.; Friedlander, Arthur M.; Baker, David; Siegel, Justin B.

2011-01-01

273

Interactions between Bacillus anthracis and Plants May Promote Anthrax Transmission  

PubMed Central

Environmental reservoirs are essential in the maintenance and transmission of anthrax but are poorly characterized. The anthrax agent, Bacillus anthracis was long considered an obligate pathogen that is dormant and passively transmitted in the environment. However, a growing number of laboratory studies indicate that, like some of its close relatives, B. anthracis has some activity outside of its vertebrate hosts. Here we show in the field that B. anthracis has significant interactions with a grass that could promote anthrax spore transmission to grazing hosts. Using a local, virulent strain of B. anthracis, we performed a field experiment in an enclosure within a grassland savanna. We found that B. anthracis increased the rate of establishment of a native grass (Enneapogon desvauxii) by 50% and that grass seeds exposed to blood reached heights that were 45% taller than controls. Further we detected significant effects of E. desvauxii, B. anthracis, and their interaction on soil bacterial taxa richness and community composition. We did not find any evidence for multiplication or increased longevity of B. anthracis in bulk soil associated with grass compared to controls. Instead interactions between B. anthracis and plants may result in increased host grazing and subsequently increased transmission to hosts.

Ganz, Holly H.; Turner, Wendy C.; Brodie, Eoin L.; Kusters, Martina; Shi, Ying; Sibanda, Heniritha; Torok, Tamas; Getz, Wayne M.

2014-01-01

274

Anthrax Lethal Factor as an Immune Target in Humans and Transgenic Mice and the Impact of HLA Polymorphism on CD4+ T Cell Immunity  

PubMed Central

Bacillus anthracis produces a binary toxin composed of protective antigen (PA) and one of two subunits, lethal factor (LF) or edema factor (EF). Most studies have concentrated on induction of toxin-specific antibodies as the correlate of protective immunity, in contrast to which understanding of cellular immunity to these toxins and its impact on infection is limited. We characterized CD4+ T cell immunity to LF in a panel of humanized HLA-DR and DQ transgenic mice and in naturally exposed patients. As the variation in antigen presentation governed by HLA polymorphism has a major impact on protective immunity to specific epitopes, we examined relative binding affinities of LF peptides to purified HLA class II molecules, identifying those regions likely to be of broad applicability to human immune studies through their ability to bind multiple alleles. Transgenics differing only in their expression of human HLA class II alleles showed a marked hierarchy of immunity to LF. Immunogenicity in HLA transgenics was primarily restricted to epitopes from domains II and IV of LF and promiscuous, dominant epitopes, common to all HLA types, were identified in domain II. The relevance of this model was further demonstrated by the fact that a number of the immunodominant epitopes identified in mice were recognized by T cells from humans previously infected with cutaneous anthrax and from vaccinated individuals. The ability of the identified epitopes to confer protective immunity was demonstrated by lethal anthrax challenge of HLA transgenic mice immunized with a peptide subunit vaccine comprising the immunodominant epitopes that we identified.

Ascough, Stephanie; Ingram, Rebecca J.; Chu, Karen K.; Reynolds, Catherine J.; Musson, Julie A.; Doganay, Mehmet; Metan, Gokhan; Ozkul, Yusuf; Baillie, Les; Sriskandan, Shiranee; Moore, Stephen J.; Gallagher, Theresa B.; Dyson, Hugh; Williamson, E. Diane; Robinson, John H.; Maillere, Bernard; Boyton, Rosemary J.; Altmann, Daniel M.

2014-01-01

275

Anthrax lethal factor as an immune target in humans and transgenic mice and the impact of HLA polymorphism on CD4+ T cell immunity.  

PubMed

Bacillus anthracis produces a binary toxin composed of protective antigen (PA) and one of two subunits, lethal factor (LF) or edema factor (EF). Most studies have concentrated on induction of toxin-specific antibodies as the correlate of protective immunity, in contrast to which understanding of cellular immunity to these toxins and its impact on infection is limited. We characterized CD4+ T cell immunity to LF in a panel of humanized HLA-DR and DQ transgenic mice and in naturally exposed patients. As the variation in antigen presentation governed by HLA polymorphism has a major impact on protective immunity to specific epitopes, we examined relative binding affinities of LF peptides to purified HLA class II molecules, identifying those regions likely to be of broad applicability to human immune studies through their ability to bind multiple alleles. Transgenics differing only in their expression of human HLA class II alleles showed a marked hierarchy of immunity to LF. Immunogenicity in HLA transgenics was primarily restricted to epitopes from domains II and IV of LF and promiscuous, dominant epitopes, common to all HLA types, were identified in domain II. The relevance of this model was further demonstrated by the fact that a number of the immunodominant epitopes identified in mice were recognized by T cells from humans previously infected with cutaneous anthrax and from vaccinated individuals. The ability of the identified epitopes to confer protective immunity was demonstrated by lethal anthrax challenge of HLA transgenic mice immunized with a peptide subunit vaccine comprising the immunodominant epitopes that we identified. PMID:24788397

Ascough, Stephanie; Ingram, Rebecca J; Chu, Karen K; Reynolds, Catherine J; Musson, Julie A; Doganay, Mehmet; Metan, Gökhan; Ozkul, Yusuf; Baillie, Les; Sriskandan, Shiranee; Moore, Stephen J; Gallagher, Theresa B; Dyson, Hugh; Williamson, E Diane; Robinson, John H; Maillere, Bernard; Boyton, Rosemary J; Altmann, Daniel M

2014-05-01

276

Structure-based redesign of an edema toxin inhibitor  

PubMed Central

Edema Factor toxin (EF) of Bacillus anthracis (NIAID category A), and several other toxins from NIAID category B Biodefense target bacteria are adenylyl cyclases or adenylyl cyclase agonists that catalyze the conversion of ATP to 3?,5?-cyclic adenosine monophosphate (cAMP). We previously identified compound 1 (3-[(9-Oxo-9H-fluorene-1-carbonyl)-amino]-benzoic acid), that inhibits EF activity in cultured mammalian cells, and reduces diarrhea caused by enterotoxigenic Escherichia coli (ETEC) at an oral dosage of 15 ?g/mouse. Here, molecular docking was used to predict improvements in potency and solubility of new derivatives of compound 1 in inhibiting edema toxin-(ET) catalyzed stimulation of cyclic AMP production in murine monocyte-macrophage cells (RAW 264.7). Structure-activity relationship (SAR) analysis of the bioassay results for 22 compounds indicated positions important for activity. Several derivatives demonstrated superior pharmacological properties compared to our initial lead compound, and are promising candidates to treat anthrax infections and diarrheal diseases induced by toxin-producing bacteria.

Chen, Deliang; Ma, Lili; Kanalas, John J.; Gao, Jian; Pawlik, Jennifer; Jimenez, Maria Estrella; Walter, Mary A.; Peterson, Johnny W.; Gilbertson, Scott R.; Schein, Catherine H.

2011-01-01

277

Cationic PAMAM Dendrimers as Pore-Blocking Binary Toxin Inhibitors.  

PubMed

Dendrimers are unique highly branched macromolecules with numerous groundbreaking biomedical applications under development. Here we identified poly(amido amine) (PAMAM) dendrimers as novel blockers for the pore-forming B components of the binary anthrax toxin (PA63) and Clostridium botulinum C2 toxin (C2IIa). These pores are essential for delivery of the enzymatic A components of the internalized toxins from endosomes into the cytosol of target cells. We demonstrate that at low ?M concentrations cationic PAMAM dendrimers block PA63 and C2IIa to inhibit channel-mediated transport of the A components, thereby protecting HeLa and Vero cells from intoxication. By channel reconstitution and high-resolution current recording, we show that the PAMAM dendrimers obstruct transmembrane PA63 and C2IIa pores in planar lipid bilayers at nM concentrations. These findings suggest a new potential role for the PAMAM dendrimers as effective polyvalent channel-blocking inhibitors, which can protect human target cells from intoxication with binary toxins from pathogenic bacteria. PMID:24954629

Förstner, Philip; Bayer, Fabienne; Kalu, Nnanya; Felsen, Susanne; Förtsch, Christina; Aloufi, Abrar; Ng, David Y W; Weil, Tanja; Nestorovich, Ekaterina M; Barth, Holger

2014-07-14

278

An approach to characterizing single-subunit mutations in multimeric prepores and pores of anthrax protective antigen  

PubMed Central

Heptameric pores formed by the protective antigen (PA) moiety of anthrax toxin translocate the intracellular effector moieties of the toxin across the endosomal membrane to the cytosol of mammalian cells. We devised a protocol to characterize the effects of individual mutations in a single subunit of heptameric PA prepores (pore precursors) or pores. We prepared monomeric PA containing a test mutation plus an innocuous Cys-replacement mutation at a second residue (Lys563, located on the external surface of the prepore). The introduced Cys was biotinylated, and the protein was allowed to cooligomerize with a 20-fold excess of wild-type PA. Finally, biotinylated prepores were freed from wild-type prepores by avidin affinity chromatography. For the proof of principle, we examined single-subunit mutations of Asp425 and Phe427, two residues where Ala replacements have been shown to cause strong inhibitory effects. The single-subunit D425A mutation inhibited pore formation by >104 and abrogated activity of PA almost completely in our standard cytotoxicity assay. The single-subunit F427A mutation caused ?100-fold inhibition in the cytotoxicity assay, and this effect was shown to result from a combination of strong inhibition of translocation and smaller effects on pore formation and ligand affinity. Our results show definitively that replacing a single residue in one subunit of the heptameric PA prepore can inhibit the transport activity of the oligomer almost completely—and by different mechanisms, depending on the specific residue mutated.

Janowiak, Blythe E; Finkelstein, Alan; Collier, R John

2009-01-01

279

Anthrax Vaccine does not affect semen Parameters, Embryo Quality, or Pregnancy Outcome in Couples with a Vaccinated Male Military Service Member.  

National Technical Information Service (NTIS)

Anthrax vaccination has been used in an effort to prevent infection should anthrax be used as a biological weapon, and widespread use has been considered in the event of another anthrax attack on American soil, but the long-term impact of anthrax vaccinat...

A. James C. Murdock K. Polson L. Scott R. Alvero

2005-01-01

280

Identification of a Protein Subset of the Anthrax Spore Immunome in Humans Immunized with the Anthrax Vaccine Adsorbed Preparation  

PubMed Central

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.

Kudva, Indira T.; Griffin, Robert W.; Garren, Jeonifer M.; Calderwood, Stephen B.; John, Manohar

2005-01-01

281

News Note: A new dual vaccine for protection against both smallpox and anthrax  

Cancer.gov

Scientists have developed and tested a new protective vaccine against smallpox and anthrax, two agents of bioterrorism, in animal models. Liyanage P. Perera, Ph.D., NCI, and colleagues made the enhanced dual vaccine by inserting the genes for protective parts of anthrax and the immune-boosting chemical, interleukin-15, into the backbone of the licensed smallpox vaccine, ACAM2000.

282

Key aspects of the molecular and cellular basis of inhalational anthrax.  

PubMed

Bacillus anthracis is the etiologic agent of the disease inhalational anthrax, an acute systemic infection initiated by inhaling spores, which if not rapidly detected and treated, results in death. Decades of research have elucidated novel aspects of anthrax pathogenesis but there are many issues left unresolved. PMID:21816231

Cote, Christopher K; Welkos, Susan L; Bozue, Joel

2011-12-01

283

A Three-Dose Intramuscular Injection Schedule of Anthrax Vaccine Adsorbed Generates Sustained Humoral and Cellular Immune Responses to Protective Antigen and Provides Long-Term Protection against Inhalation Anthrax in Rhesus Macaques  

PubMed Central

A 3-dose (0, 1, and 6 months) intramuscular (3-IM) priming series of a human dose (HuAVA) and dilutions of up to 1:10 of anthrax vaccine adsorbed (AVA) provided statistically significant levels of protection (60 to 100%) against inhalation anthrax for up to 4 years in rhesus macaques. Serum anti-protective antigen (anti-PA) IgG and lethal toxin neutralization activity (TNA) were detectable following a single injection of HuAVA or 1:5 AVA or following two injections of diluted vaccine (1:10, 1:20, or 1:40 AVA). Anti-PA and TNA were highly correlated (overall r2 = 0.89 for log10-transformed data). Peak responses were seen at 6.5 months. In general, with the exception of animals receiving 1:40 AVA, serum anti-PA and TNA responses remained significantly above control levels at 28.5 months (the last time point measured for 1:20 AVA), and through 50.5 months for the HuAVA and 1:5 and 1:10 AVA groups (P < 0.05). PA-specific gamma interferon (IFN-?) and interleukin-4 (IL-4) CD4+ cell frequencies and T cell stimulation indices were sustained through 50.5 months (the last time point measured). PA-specific memory B cell frequencies were highly variable but, in general, were detectable in peripheral blood mononuclear cells (PBMC) by 2 months, were significantly above control levels by 7 months, and remained detectable in the HuAVA and 1:5 and 1:20 AVA groups through 42 months (the last time point measured). HuAVA and diluted AVA elicited a combined Th1/Th2 response and robust immunological priming, with sustained production of high-avidity PA-specific functional antibody, long-term immune cell competence, and immunological memory (30 months for 1:20 AVA and 52 months for 1:10 AVA). Vaccinated animals surviving inhalation anthrax developed high-magnitude anamnestic anti-PA IgG and TNA responses.

Sabourin, Carol L.; Niemuth, Nancy A.; Li, Han; Semenova, Vera A.; Rudge, Thomas L.; Mayfield, Heather J.; Schiffer, Jarad; Mittler, Robert S.; Ibegbu, Chris C.; Wrammert, Jens; Ahmed, Rafi; Brys, April M.; Hunt, Robert E.; Levesque, Denyse; Estep, James E.; Barnewall, Roy E.; Robinson, David M.; Plikaytis, Brian D.; Marano, Nina

2012-01-01

284

Recombinant Vaccine Displaying the Loop-Neutralizing Determinant from Protective Antigen Completely Protects Rabbits from Experimental Inhalation Anthrax  

PubMed Central

We previously showed that a multiple antigenic peptide (MAP) vaccine displaying amino acids (aa) 304 to 319 from the 2?2-2?3 loop of protective antigen was capable of protecting rabbits from an aerosolized spore challenge with Bacillus anthracis Ames strain. Antibodies to this sequence, referred to as the loop-neutralizing determinant (LND), are highly potent at neutralizing lethal toxin yet are virtually absent in rabbit and human protective antigen (PA) antiserum. While the MAP vaccine was protective against anthrax, it contains a single heterologous helper T cell epitope which may be suboptimal for stimulating an outbred human population. We therefore engineered a recombinant vaccine (Rec-LND) containing two tandemly repeated copies of the LND fused to maltose binding protein, with enhanced immunogenicity resulting from the p38/P4 helper T cell epitope from Schistosoma mansoni. Rec-LND was found to be highly immunogenic in four major histocompatibility complex (MHC)-diverse strains of mice. All (7/7) rabbits immunized with Rec-LND developed high-titer antibody, 6 out of 7 developed neutralizing antibody, and all rabbits were protected from an aerosolized spore challenge of 193 50% lethal doses (LD50) of the B. anthracis Ames strain. Survivor serum from Rec-LND-immunized rabbits revealed significantly increased neutralization titers and specific activity compared to prechallenge levels yet lacked PA or lethal factor (LF) antigenemia. Control rabbits immunized with PA, which were also completely protected, appeared sterilely immune, exhibiting significant declines in neutralization titer and specific activity compared to prechallenge levels. We conclude that Rec-LND may represent a prototype anthrax vaccine for use alone or potentially combined with PA-containing vaccines.

Yu, Fen; Jacobs, Jana L.; Cease, Kemp B.

2013-01-01

285

Phase I Study of Safety and Immunogenicity of an Escherichia coli-Derived Recombinant Protective Antigen (rPA) Vaccine to Prevent Anthrax in Adults  

PubMed Central

Background The fatal disease caused by Bacillus anthracis is preventable with a prophylactic vaccine. The currently available anthrax vaccine requires a lengthy immunization schedule, and simpler and more immunogenic options for protection against anthrax are a priority for development. In this report we describe a phase I clinical trial testing the safety and immunogenicity of an anthrax vaccine using recombinant Escherichia coli-derived, B. anthracis protective antigen (rPA). Methodology/Principal Findings A total of 73 healthy adults ages 18–40 were enrolled and 67 received 2 injections separated by 4 weeks of either buffered saline placebo, or rPA formulated with or without 704 µg/ml Alhydrogel® adjuvant in increasing doses (5, 25, 50, 100 µg) of rPA. Participants were followed for one year and safety and immunologic data were assessed. Tenderness and warmth were the most common post-injection site reactions. No serious adverse events related to the vaccine were observed. The most robust humoral immune responses were observed in subjects receiving 50 µg of rPA formulated with Alhydrogel® with a geometric mean concentration of anti-rPA IgG antibodies of 283 µg/ml and a toxin neutralizing geometric 50% reciprocal geometric mean titer of 1061. The highest lymphoproliferative peak cellular response (median Lymphocyte Stimulation Index of 29) was observed in the group receiving 25 µg Alhydrogel®-formulated rPA. Conclusions/Significance The vaccine was safe, well tolerated and stimulated a robust humoral and cellular response after two doses. Trial Registration ClinicalTrials.gov NCT00057525

Brown, Bruce K.; Cox, Josephine; Gillis, Anita; VanCott, Thomas C.; Marovich, Mary; Milazzo, Mark; Antonille, Tanya Santelli; Wieczorek, Lindsay; McKee, Kelly T.; Metcalfe, Karen; Mallory, Raburn M.; Birx, Deborah; Polonis, Victoria R.; Robb, Merlin L.

2010-01-01

286

Radiolabeled lipid nanoparticles for diagnostic imaging.  

PubMed

Background: Nanoparticles are increasingly being incorporated into the design of diagnostic imaging agents. Significant research efforts have been conducted with one class of lipid nanoparticle (liposomes) radiolabeled with gamma-emitting radionuclides as radiopharmaceuticals for scintigraphic imaging of cancer, inflammation/infection and sentinel lymph node detection. Objective: This article reviews the current literature with special emphasis on the clinical studies performed with liposome radiopharmaceuticals for detection of tumors, infectious/inflammatory sites or metastatic lymph nodes. Future uses of liposome radiopharmaceuticals are also described. Methods: Characteristics required of the radionuclide, liposome formulation and radiolabeling method for an effective radiopharmaceutical are discussed. A description of the procedures and instrumentation for conducting an imaging study with liposome radiopharmaceutical is included. Clinical studies using liposome radiopharmaceuticals are summarized. Future imaging applications of first- and second-generation radiolabeled liposomes for chemodosimetry and the specific targeting of a disease process are also described. Results/conclusion: The choice of radionuclide, liposome formulation and radiolabeling method must be carefully considered during the design of a liposome radiopharmaceutical for a given application. After-loading and surface chelation methods are the most efficient and practical. Clinical studies with liposome radiopharmaceuticals demonstrated that a wide variety of tumors could be detected with good sensitivity and specificity. Liposome radiopharmaceuticals could also clearly detect various soft tissue and bone inflammatory/infectious lesions, and performed equal to or better than infection imaging agents that are approved at present. Yet, despite these favorable results, no liposome radiopharmaceutical has been approved for any indication. Some of the reasons for this can be attributed to reports of an unexpected infusion-related adverse reaction in two studies, the requirement of more complex liposome manufacturing procedures, and the adoption of other competing imaging procedures. Continued research of liposome radiopharmaceutical design based on a better understanding of liposome biology, improved radiolabeling methodologies and advances in gamma camera technology is warranted. PMID:23495822

Goins, Beth A

2008-07-01

287

Shared binding sites in Lepidoptera for Bacillus thuringiensis Cry1Ja and Cry1A toxins.  

PubMed

Bacillus thuringiensis toxins act by binding to specific target sites in the insect midgut epithelial membrane. The best-known mechanism of resistance to B. thuringiensis toxins is reduced binding to target sites. Because alteration of a binding site shared by several toxins may cause resistance to all of them, knowledge of which toxins share binding sites is useful for predicting cross-resistance. Conversely, cross-resistance among toxins suggests that the toxins share a binding site. At least two strains of diamondback moth (Plutella xylostella) with resistance to Cry1A toxins and reduced binding of Cry1A toxins have strong cross-resistance to Cry1Ja. Thus, we hypothesized that Cry1Ja shares binding sites with Cry1A toxins. We tested this hypothesis in six moth and butterfly species, each from a different family: Cacyreus marshalli (Lycaenidae), Lobesia botrana (Tortricidae), Manduca sexta (Sphingidae), Pectinophora gossypiella (Gelechiidae), P. xylostella (Plutellidae), and Spodoptera exigua (Noctuidae). Although the extent of competition varied among species, experiments with biotinylated Cry1Ja and radiolabeled Cry1Ac showed that Cry1Ja and Cry1Ac competed for binding sites in all six species. A recent report also indicates shared binding sites for Cry1Ja and Cry1A toxins in Heliothis virescens (Noctuidae). Thus, shared binding sites for Cry1Ja and Cry1A occur in all lepidopteran species tested so far. PMID:11722929

Herrero, S; González-Cabrera, J; Tabashnik, B E; Ferré, J

2001-12-01

288

Shared Binding Sites in Lepidoptera for Bacillus thuringiensis Cry1Ja and Cry1A Toxins  

PubMed Central

Bacillus thuringiensis toxins act by binding to specific target sites in the insect midgut epithelial membrane. The best-known mechanism of resistance to B. thuringiensis toxins is reduced binding to target sites. Because alteration of a binding site shared by several toxins may cause resistance to all of them, knowledge of which toxins share binding sites is useful for predicting cross-resistance. Conversely, cross-resistance among toxins suggests that the toxins share a binding site. At least two strains of diamondback moth (Plutella xylostella) with resistance to Cry1A toxins and reduced binding of Cry1A toxins have strong cross-resistance to Cry1Ja. Thus, we hypothesized that Cry1Ja shares binding sites with Cry1A toxins. We tested this hypothesis in six moth and butterfly species, each from a different family: Cacyreus marshalli (Lycaenidae), Lobesia botrana (Tortricidae), Manduca sexta (Sphingidae), Pectinophora gossypiella (Gelechiidae), P. xylostella (Plutellidae), and Spodoptera exigua (Noctuidae). Although the extent of competition varied among species, experiments with biotinylated Cry1Ja and radiolabeled Cry1Ac showed that Cry1Ja and Cry1Ac competed for binding sites in all six species. A recent report also indicates shared binding sites for Cry1Ja and Cry1A toxins in Heliothis virescens (Noctuidae). Thus, shared binding sites for Cry1Ja and Cry1A occur in all lepidopteran species tested so far.

Herrero, Salvador; Gonzalez-Cabrera, Joel; Tabashnik, Bruce E.; Ferre, Juan

2001-01-01

289

*CYANOBACTERIA AND THEIR TOXINS  

EPA Science Inventory

Cyanobacteria, or blue-green algae, are naturally-occurring contaminants of surface waters worldwide. These photosynthesizing prokaryotes thrive in warm, shallow, nutrient-rich waters. Many produce potent toxins as secondary metabolites. Cyanobacteria toxins have been document...

290

Swab protocol for rapid laboratory diagnosis of cutaneous anthrax.  

PubMed

The clinical laboratory diagnosis of cutaneous anthrax is generally established by conventional microbiological methods, such as culture and directly straining smears of clinical specimens. However, these methods rely on recovery of viable Bacillus anthracis cells from swabs of cutaneous lesions and often yield negative results. This study developed a rapid protocol for detection of B. anthracis on clinical swabs. Three types of swabs, flocked-nylon, rayon, and polyester, were evaluated by 3 extraction methods, the swab extraction tube system (SETS), sonication, and vortex. Swabs were spiked with virulent B. anthracis cells, and the methods were compared for their efficiency over time by culture and real-time PCR. Viability testing indicated that the SETS yielded greater recovery of B. anthracis from 1-day-old swabs; however, reduced viability was consistent for the 3 extraction methods after 7 days and nonviability was consistent by 28 days. Real-time PCR analysis showed that the PCR amplification was not impacted by time for any swab extraction method and that the SETS method provided the lowest limit of detection. When evaluated using lesion swabs from cutaneous anthrax outbreaks, the SETS yielded culture-negative, PCR-positive results. This study demonstrated that swab extraction methods differ in their efficiency of recovery of viable B. anthracis cells. Furthermore, the results indicated that culture is not reliable for isolation of B. anthracis from swabs at ? 7 days. Thus, we recommend the use of the SETS method with subsequent testing by culture and real-time PCR for diagnosis of cutaneous anthrax from clinical swabs of cutaneous lesions. PMID:23035192

Dauphin, Leslie A; Marston, Chung K; Bhullar, Vinod; Baker, Daniel; Rahman, Mahmudur; Hossain, M Jahangir; Chakraborty, Apurba; Khan, Salah Uddin; Hoffmaster, Alex R

2012-12-01

291

Swab Protocol for Rapid Laboratory Diagnosis of Cutaneous Anthrax  

PubMed Central

The clinical laboratory diagnosis of cutaneous anthrax is generally established by conventional microbiological methods, such as culture and directly straining smears of clinical specimens. However, these methods rely on recovery of viable Bacillus anthracis cells from swabs of cutaneous lesions and often yield negative results. This study developed a rapid protocol for detection of B. anthracis on clinical swabs. Three types of swabs, flocked-nylon, rayon, and polyester, were evaluated by 3 extraction methods, the swab extraction tube system (SETS), sonication, and vortex. Swabs were spiked with virulent B. anthracis cells, and the methods were compared for their efficiency over time by culture and real-time PCR. Viability testing indicated that the SETS yielded greater recovery of B. anthracis from 1-day-old swabs; however, reduced viability was consistent for the 3 extraction methods after 7 days and nonviability was consistent by 28 days. Real-time PCR analysis showed that the PCR amplification was not impacted by time for any swab extraction method and that the SETS method provided the lowest limit of detection. When evaluated using lesion swabs from cutaneous anthrax outbreaks, the SETS yielded culture-negative, PCR-positive results. This study demonstrated that swab extraction methods differ in their efficiency of recovery of viable B. anthracis cells. Furthermore, the results indicated that culture is not reliable for isolation of B. anthracis from swabs at ?7 days. Thus, we recommend the use of the SETS method with subsequent testing by culture and real-time PCR for diagnosis of cutaneous anthrax from clinical swabs of cutaneous lesions.

Marston, Chung K.; Bhullar, Vinod; Baker, Daniel; Rahman, Mahmudur; Hossain, M. Jahangir; Chakraborty, Apurba; Khan, Salah Uddin; Hoffmaster, Alex R.

2012-01-01

292

Exogenous Interferon-? and Interferon-? Increase Lethality of Murine Inhalational Anthrax  

PubMed Central

Background Bacillus anthracis, the etiologic agent of inhalational anthrax, is a facultative intracellular pathogen. Despite appropriate antimicrobial therapy, the mortality from inhalational anthrax approaches 45%, underscoring the need for better adjuvant therapies. The variable latency between exposure and development of disease suggests an important role for the host's innate immune response. Type I and Type II Interferons (IFN) are prominent members of the host innate immune response and are required for control of intracellular pathogens. We have previously described a protective role for exogenous Type I and Type II IFNs in attenuating intracellular B.anthracis germination and macrophage cell death in vitro. Methodology and Principal Findings We sought to extend these findings in an in vivo model of inhalational anthrax, utilizing the Sterne strain (34F2) of B.anthracis. Mice devoid of STAT1, a component of IFN-? and IFN-? signaling, had a trend towards increased mortality, bacterial germination and extrapulmonary spread of B.anthracis at 24 hrs. This was associated with impaired IL-6, IL-10 and IL-12 production. However, administration of exogenous IFN-?, and to a lesser extent IFN-?, at the time of infection, markedly increased lethality. While IFNs were able to reduce the fraction of germinated spores within the lung, they increased both the local and systemic inflammatory response manifest by increases in IL-12 and reductions in IL-10. This was associated with an increase in extrapulmonary dissemination. The mechanism of IFN mediated inflammation appears to be in part due to STAT1 independent signaling. Conclusions In conclusion, while endogenous IFNs are essential for control of B.anthracis germination and lethality, administration of exogenous IFNs appear to increase the local inflammatory response, thereby increasing mortality.

Gold, Jeffrey A.; Hoshino, Yoshihiko; Jones, Marcus B.; Hoshino, Satomi; Nolan, Anna; Weiden, Michael D.

2007-01-01

293

The effect of seasonal variation on anthrax epidemiology in the upper Zambezi floodplain of western Zambia  

PubMed Central

Anthrax has become endemic throughout the upper Zambezi floodplain located in the Western Province of Zambia over the recent years. To date, no comprehensive study has been carried out to determine whether recurrence of anthrax outbreaks may be linked to differences in precipitation and human activities. Retrospective data for the period 1999 to 2007 showed that a total of 1,216 bovine cases of anthrax were reported. During the same period, 1,790 human anthrax cases and a corresponding case fatality rate of 4.63% (83/1,790) was documented in the upper Zambezi floodplain. Occurrence of human cases was highly correlated with cattle outbreaks (r = 0.94, p < 0.001). Differences in precipitation were significantly associated with the occurrence of anthrax outbreaks (?2 = 4.75, p < 0.03), indicating that the likelihood of outbreaks occurring was higher during the dry months when human occupancy of the floodplain was greater compared to the flooding months when people and livestock moved out of this region. Human dependency on the floodplain was shown to significantly influence the epidemiology of anthrax in the upper Zambezi floodplain of western Zambia. Methods for mitigating anthrax outbreaks by disrupting the cycle of transmission are herein highlighted.

Banda, Fredrick; Siamudaala, Victor Mukulule; Munyeme, Musso; Kasanga, Christopher Jacob; Hamududu, Byman

2012-01-01

294

Plague and anthrax bacteria cell ultra structure 3D images  

NASA Astrophysics Data System (ADS)

The vast majority of information about cells and cell organelle structure were obtained by means of transmission electron microscopy investigation of cells serial thin sections. However often it is very difficult to derive information about 3D structure of specimens from such electron micrographs. A new program restoring 3D image of cells from the serial thin sections micrographs have been developed in our lab. The program makes it possible to visualize a 3D image of cell and obtain image of inner cell structure in arbitrary plane. The plague bacteria and anthrax cells with spore were visualized with resolution about 70 nm by means of the program.

Volkov, Uryi P.; Konnov, Nikolai P.; Novikova, Olga V.; Yakimenko, Roman A.

2002-07-01

295

Detection of the sentinel anthrax case in the United States.  

PubMed

First-hand knowledge of the detection of the first bioweapon in modern United States history is described in this article. The method by which the presumptive diagnosis of anthrax meningitis was made within 13 hours of the patient presenting to the emergency department is described using pre-analytic, analytic, and post-analytic phases. The lessons learned from this process are briefly presented so that other laboratories may learn from our experience: how to prepare; how to quickly analyze a potential bioweapon; how to communicate with staff and local, regional, and national authorities; and how to deal with disruptive media attention. PMID:14531222

Beall, Anne; Cooke, William; Trout, Joanne; Robb, James A

2003-01-01

296

Keeping the Air Clean and Safe: An Anthrax Smoke Detector  

NASA Technical Reports Server (NTRS)

Scientists at work in the Planetary Protection division at NASA s Jet Propulsion Laboratory (JPL) sterilize everything before blasting it to the Red Planet. They take great pains to ensure that all spacecraft are void of bacterial life, especially the microscopic bacteria that can live hundreds of years in their spore states. No one is quite sure what Earthly germs would do on Mars, but scientists agree that it is safest to keep the Martian terrain as undisturbed as possible. Errant Earth germs would also render useless the instruments placed on exploration rovers to look for signs of life, as the life that they registered would be life that came with them from Earth. A team at JPL, headed by Dr. Adrian Ponce, developed a bacterial spore-detection system that uses a simple and robust chemical reaction that visually alerts Planetary Protection crews. It is a simple air filter that traps micron-sized bacterial spores and then submits them to the chemical reaction. When the solution is then viewed under an ultraviolet light, the mixture will glow green if it is contaminated by bacteria. Scientists can then return to the scrubbing and cleaning stages of the sterilization process to remove these harmful bacteria. The detection system is the space-bound equivalent of having your hands checked for cleanliness before being allowed to the table; and although intended to keep terrestrial germs from space, this technology has awesome applications here on Mother Earth. The bacterial spore-detection unit can recognize anthrax and other harmful, spore-forming bacteria and alert people of the impending danger. As evidenced in the anthrax mailings of fall 2001 in the United States, the first sign of anthrax exposure was when people experienced flu-like symptoms, which unfortunately, can take as much as a week to develop after contamination. Anthrax cost 5 people their lives and infected 19 others; and the threat of bioterrorism became a routine concern, with new threats popping up nearly everyday. The attacks threatened the safety that so many Americans took for granted, as the very air that people breathed became suspect. Any building with a circulation system, where large groups congregate, was now a potential target.

2005-01-01

297

Receptor-directed chimeric toxins created by sortase-mediated protein fusion.  

PubMed

Chimeric protein toxins that act selectively on cells expressing a designated receptor may serve as investigational probes and/or antitumor agents. Here, we report use of the enzyme sortase A (SrtA) to create four chimeric toxins designed to selectively kill cells bearing the tumor marker HER2. We first expressed and purified: (i) a receptor recognition-deficient form of diphtheria toxin that lacks its receptor-binding domain and (ii) a mutated, receptor-binding-deficient form of anthrax-protective antigen. Both proteins carried at the C terminus the sortase recognition sequence LPETGG and a H? affinity tag. Each toxin protein was mixed with SrtA plus either of two HER2-recognition proteins--a single-chain antibody fragment or an Affibody--both carrying an N-terminal G? tag. With wild-type SrtA, the fusion reaction between the toxin and receptor-recognition proteins approached completion only after several hours, whereas with an evolved form of the enzyme, SrtA*, the reaction was virtually complete within 5 minutes. The four fusion toxins were purified and shown to kill HER2-positive cells in culture with high specificity. Sortase-mediated ligation of binary combinations of diverse natively folded proteins offers a facile way to produce large sets of chimeric proteins for research and medicine. PMID:23945077

McCluskey, Andrew J; Collier, R John

2013-10-01

298

Risk practices for animal and human anthrax in Bangladesh: an exploratory study  

PubMed Central

Introduction From August 2009 to October 2010, International Centre for Diarrheal Disease Research, Bangladesh and the Institute of Epidemiology, Disease Control and Research together investigated 14 outbreaks of anthrax which included 140 animal and 273 human cases in 14 anthrax-affected villages. Our investigation objectives were to explore the context in which these outbreaks occurred, including livestock rearing practices, human handling of sick and dead animals, and the anthrax vaccination program. Methods Field anthropologists used qualitative data-collection tools, including 15 hours of unstructured observations, 11 key informant interviews, 32 open-ended interviews, and 6 group discussions in 5 anthrax-affected villages. Results Each cattle owner in the affected communities raised a median of six ruminants on their household premises. The ruminants were often grazed in pastures and fed supplementary rice straw, green grass, water hyacinth, rice husk, wheat bran, and oil cake; lactating cows were given dicalcium phosphate. Cattle represented a major financial investment. Since Islamic law forbids eating animals that die from natural causes, when anthrax-infected cattle were moribund, farmers often slaughtered them on the household premises while they were still alive so that the meat could be eaten. Farmers ate the meat and sold it to neighbors. Skinners removed and sold the hides from discarded carcasses. Farmers discarded the carcasses and slaughtering waste into ditches, bodies of water, or open fields. Cattle in the affected communities did not receive routine anthrax vaccine due to low production, poor distribution, and limited staffing for vaccination. Conclusion Slaughtering anthrax-infected animals and disposing of butchering waste and carcasses in environments where ruminants live and graze, combined with limited vaccination, provided a context that permitted repeated anthrax outbreaks in animals and humans. Because of strong financial incentives, slaughtering moribund animals and discarding carcasses and waste products will likely continue. Long-term vaccination coverage for at-risk animal populations may reduce anthrax infection.

Islam, Md. Saiful; Hossain, M. Jahangir; Mikolon, Andrea; Parveen, Shahana; Khan, M. Salah Uddin; Haider, Najmul; Chakraborty, Apurba; Titu, Abu Mohammad Naser; Rahman, M. Waliur; Sazzad, Hossain M. S.; Rahman, Mahmudur; Gurley, Emily S.; Luby, Stephen P.

2013-01-01

299

Bioterrorism: toxins as weapons.  

PubMed

The potential for biological weapons to be used in terrorism is a real possibility. Biological weapons include infectious agents and toxins. Toxins are poisons produced by living organisms. Toxins relevant to bioterrorism include ricin, botulinum, Clostridium perfrigens epsilson toxin, conotoxins, shigatoxins, saxitoxins, tetrodotoxins, mycotoxins, and nicotine. Toxins have properties of biological and chemical weapons. Unlike pathogens, toxins do not produce an infection. Ricin causes multiorgan toxicity by blocking protein synthesis. Botulinum blocks acetylcholine in the peripheral nervous system leading to muscle paralysis. Epsilon toxin damages cell membranes. Conotoxins block potassium and sodium channels in neurons. Shigatoxins inhibit protein synthesis and induce apoptosis. Saxitoxin and tetrodotoxin inhibit sodium channels in neurons. Mycotoxins include aflatoxins and trichothecenes. Aflatoxins are carcinogens. Trichothecenes inhibit protein and nucleic acid synthesis. Nicotine produces numerous nicotinic effects in the nervous system. PMID:22523138

Anderson, Peter D

2012-04-01

300

A New Murine Model for Gastrointestinal Anthrax Infection  

PubMed Central

The scientific community has been restricted by the lack of a practical and informative animal model of gastrointestinal infection with vegetative Bacillus anthracis. We herein report the development of a murine model of gastrointestinal anthrax infection by gavage of vegetative Sterne strain of Bacillus anthracis into the complement-deficient A/J mouse strain. Mice infected in this manner developed lethal infections in a dose-dependent manner and died 30 h-5 d following gavage. Histological findings were consistent with penetration and growth of the bacilli within the intestinal villi, with subsequent dissemination into major organs including the spleen, liver, kidney and lung. Blood cultures confirmed anthrax bacteremia in all moribund animals, with approximately 1/3 showing co-infection with commensal enteric organisms. However, no evidence of immune activation was observed during infection. Time-course experiments revealed early compromise of the intestinal epithelium, characterized by villus blunting and ulceration in the ileum and jejunum. A decrease in body temperature was most predictive of near-term lethality. Antibiotic treatment of infected animals 24 h following high-dose bacterial gavage protected all animals, demonstrating the utility of this animal model in evaluating potential therapeutics.

Xie, Tao; Sun, Chen; Uslu, Kadriye; Auth, Roger D.; Fang, Hui; Ouyang, Weiming; Frucht, David M.

2013-01-01

301

Anthrax Vaccine: Preliminary Results of GAO's Survey of Guard/Reserve Pilots and Aircrew Members.  

National Technical Information Service (NTIS)

While many factors can influence an individual's decision to leave the military, surveyed Guard and Reserve pilots and aircrew members cited the anthrax immunization as a key reason for leaving or otherwise changing their military status. Since September ...

K. Chan

2000-01-01

302

2011 Risk/Benefit Analysis of the Anthrax Vaccine Immunization Program.  

National Technical Information Service (NTIS)

Safety, efficacy, and legal concerns surrounded the Department of Defense (DoD) Anthrax Vaccine Immunization Program (AVIP) in the early and mid- 2000s. Production capacity, patient refusals, and legal injunctions limited vaccine delivery during this time...

K. L. Davis

2011-01-01

303

Classification and management of animal anthrax outbreaks based on the source of infection.  

PubMed

Anthrax is a non-contagious infectious disease; it primarily affects herbivores, but all mammals, including humans, can be affected. Humans may contract anthrax directly or indirectly from infected animals. Veterinary surveillance systems, providing information about animal and human cases, should increase the efficacy of the animal anthrax management in order to protect population. Any aspect of the disease should be carefully monitored to implement effective prevention and control strategies. In this paper we propose a new, detailed classification of anthrax outbreaks, based on the source of the infection and the risk level for humans. We describe three different types of animal outbreaks and suggest the most effective procedures for their management and prevention. PMID:24968920

Fasanella, Antonio; Adone, Rosanna; Hugh-Jones, Martin

2014-01-01

304

Inhibitions of the translocation pore of Clostridium botulinum C2 toxin by tailored azolopyridinium salts protects human cells from intoxication.  

PubMed

C2 toxin from Clostridium botulinum represents the prototype of clostridial binary actin ADP-ribosylating toxins which destroy the actin-cytoskeleton of mammalian cells and cause severe enteric diseases in humans and animals. After receptor-mediated endocytosis of the C2 toxin complex, the binding/translocation component C2IIa forms a heptameric transmembrane pore in membranes of acidified endosomal vesicles. The separate ADP-ribosyltransferase component C2I translocates through this C2IIa-pore from the endosomal lumen into the cytosol. Here we demonstrate that positively charged heterocyclic azolopyridinium salts which were developed as pore blockers for the anthrax toxins, efficiently protect cultured mammalian cells from intoxication with C2 toxin. The inhibitors had no effects on enzyme activity of C2I or receptor binding of C2 toxin but inhibited the pH-dependent membrane translocation of C2I in living cells, most likely by blocking the C2IIa-translocation pores. In vitro, the substances blocked C2IIa-pores in black lipid bilayer membranes when applied to the cis-side of the membrane which corresponds to the endosomal lumen of cells. Thus, heterocyclic azolopyridinium salts could represent lead compounds for development of novel therapeutics against binary clostridial toxins. PMID:24394545

Bronnhuber, Anika; Maier, Elke; Riedl, Zsuzsanna; Hajós, György; Benz, Roland; Barth, Holger

2014-02-28

305

Anthrax control and research, with special reference to national programme development in Africa: memorandum from a WHO meeting.  

PubMed Central

The prevalence of anthrax in both animal and human populations has been increasing in Africa. It was therefore appropriate for this WHO meeting to be convened in an endemic area of the Western Province of Zambia in 1992. The participants reviewed anthrax epidemiology and control in some African countries, elaborated national anthrax control and research programmes in Africa, discussed international cooperation and work plans, and elaborated recommendations for anthrax control in Africa. The discussions centred on anthrax surveillance and reporting systems, diagnosis, vaccine production and immunization, disinfection and decontamination, carcass disposal, treatment of human cases, health systems, as well as intersectorial cooperation between public health services, veterinary services and other services such as wildlife conservation, so that national control programmes could take full account of the conditions prevailing in epidemic situations in Africa. The recommendations are applicable in other regions where anthrax poses similar problems in public, animal and environmental health.

1994-01-01

306

Lessons for Control of Heroin-Associated Anthrax in Europe from 2009-2010 Outbreak Case Studies, London, UK.  

PubMed

Outbreaks of serious infections associated with heroin use in persons who inject drugs (PWIDs) occur intermittently and require vigilance and rapid reporting of individual cases. Here, we give a firsthand account of the cases in London during an outbreak of heroin-associated anthrax during 2009-2010 in the United Kingdom. This new manifestation of anthrax has resulted in a clinical manifestation distinct from already recognized forms. During 2012-13, additional cases of heroin-associated anthrax among PWIDs in England and other European countries were reported, suggesting that anthrax-contaminated heroin remains in circulation. Antibacterial drugs used for serious soft tissue infection are effective against anthrax, which may lead to substantial underrecognition of this novel illness. The outbreak in London provides a strong case for ongoing vigilance and the use of serologic testing in diagnosis and serologic surveillance schemes to determine and monitor the prevalence of anthrax exposure in the PWID community. PMID:24959910

Abbara, Aula; Brooks, Tim; Taylor, Graham P; Nolan, Marianne; Donaldson, Hugo; Manikon, Maribel; Holmes, Alison

2014-07-01

307

Lessons for Control of Heroin-Associated Anthrax in Europe from 2009-2010 Outbreak Case Studies, London, UK  

PubMed Central

Outbreaks of serious infections associated with heroin use in persons who inject drugs (PWIDs) occur intermittently and require vigilance and rapid reporting of individual cases. Here, we give a firsthand account of the cases in London during an outbreak of heroin-associated anthrax during 2009–2010 in the United Kingdom. This new manifestation of anthrax has resulted in a clinical manifestation distinct from already recognized forms. During 2012–13, additional cases of heroin-associated anthrax among PWIDs in England and other European countries were reported, suggesting that anthrax-contaminated heroin remains in circulation. Antibacterial drugs used for serious soft tissue infection are effective against anthrax, which may lead to substantial underrecognition of this novel illness. The outbreak in London provides a strong case for ongoing vigilance and the use of serologic testing in diagnosis and serologic surveillance schemes to determine and monitor the prevalence of anthrax exposure in the PWID community.

Abbara, Aula; Brooks, Tim; Taylor, Graham P.; Nolan, Marianne; Donaldson, Hugo; Manikon, Maribel

2014-01-01

308

Information on which to base assessments of risk from environments contaminated with anthrax spores.  

PubMed Central

Although there has been a considerable amount of research conducted into Bacillus anthracis, the causative agent of anthrax, the data are widely disseminated in the scientific literature and are therefore not always easy to assimilate. In view of continuing concern about potential anthrax contamination in environmental materials and sites, this review brings together the currently available information relating to the health hazards from B. anthracis. The relevance of the available information for risk assessment purposes is assessed.

Watson, A.; Keir, D.

1994-01-01

309

Pathology and Pathophysiology of Inhalational Anthrax in a Guinea Pig Model  

PubMed Central

Nonhuman primates (NHPs) and rabbits are the animal models most commonly used to evaluate the efficacy of medical countermeasures against anthrax in support of licensure under the FDA's “Animal Rule.” However, a need for an alternative animal model may arise in certain cases. The development of such an alternative model requires a thorough understanding of the course and manifestation of experimental anthrax disease induced under controlled conditions in the proposed animal species. The guinea pig, which has been used extensively for anthrax pathogenesis studies and anthrax vaccine potency testing, is a good candidate for such an alternative model. This study was aimed at determining the median lethal dose (LD50) of the Bacillus anthracis Ames strain in guinea pigs and investigating the natural history, pathophysiology, and pathology of inhalational anthrax in this animal model following nose-only aerosol exposure. The inhaled LD50 of aerosolized Ames strain spores in guinea pigs was determined to be 5.0 × 104 spores. Aerosol challenge of guinea pigs resulted in inhalational anthrax with death occurring between 46 and 71 h postchallenge. The first clinical signs appeared as early as 36 h postchallenge. Cardiovascular function declined starting at 20 h postexposure. Hematogenous dissemination of bacteria was observed microscopically in multiple organs and tissues as early as 24 h postchallenge. Other histopathologic findings typical of disseminated anthrax included suppurative (heterophilic) inflammation, edema, fibrin, necrosis, and/or hemorrhage in the spleen, lungs, and regional lymph nodes and lymphocyte depletion and/or lymphocytolysis in the spleen and lymph nodes. This study demonstrated that the course of inhalational anthrax disease and the resulting pathology in guinea pigs are similar to those seen in rabbits and NHPs, as well as in humans.

Savransky, Vladimir; Sanford, Daniel C.; Syar, Emily; Austin, Jamie L.; Tordoff, Kevin P.; Anderson, Michael S.; Stark, Gregory V.; Barnewall, Roy E.; Briscoe, Crystal M.; Lemiale-Bierinx, Laurence; Park, Sukjoon; Ionin, Boris

2013-01-01

310

Surveillance for Anthrax Cases Associated with Contaminated Letters, New Jersey, Delaware, and Pennsylvania, 2001  

PubMed Central

In October 2001, two inhalational anthrax and four cutaneous anthrax cases, resulting from the processing of Bacillus anthracis–containing envelopes at a New Jersey mail facility, were identified. Subsequently, we initiated stimulated passive hospital-based and enhanced passive surveillance for anthrax-compatible syndromes. From October 24 to December 17, 2001, hospitals reported 240,160 visits and 7,109 intensive-care unit admissions in the surveillance area (population 6.7 million persons). Following a change to reporting criteria on November 8, the average of possible inhalational anthrax reports decreased 83% from 18 to 3 per day; the proportion of reports requiring follow-up increased from 37% (105/286) to 41% (47/116). Clinical follow-up was conducted on 214 of 464 possible inhalational anthrax patients and 98 possible cutaneous anthrax patients; 49 had additional laboratory testing. No additional cases were identified. To verify the limited scope of the outbreak, surveillance was essential, though labor-intensive. The flexibility of the system allowed interim evaluation, thus improving surveillance efficiency.

Sandhu, Hardeep S.; Crawford, Dana C.; Redd, Stephen C.; Beach, Michael J.; Buehler, James; Bresnitz, Eddy A.; Pinner, Robert W.; Bell, Beth P.

2002-01-01

311

Current status of immunization against anthrax: old vaccines may be here to stay for a while.  

PubMed

Anthrax vaccination has become a 'hot' topic. On the one hand, fears that Iraq holds secret caches of anthrax-based weaponry, that other countries may be developing or may have developed similar devices, or that hard-line groups may make their own anthrax-based devices for bioterrorist attacks have focused official attention on the need for means of protection, principally, though, for the military. On the other hand, the unsolved issues of the Gulf War illnesses have left elements of doubt in the minds of some as to the possible role of anthrax (among other) vaccines in this syndrome, and have drawn attention to the shortage of pre-clinical, clinical, pharmacological and safety data on the existing UK and US anthrax vaccines. In the middle are those hotly debating the US and Canadian policies of mandatory anthrax immunization for military personnel or, in the case of the UK policy of voluntary immunization, simply voting with their feet. Compounding matters have been the publicized failures of the US vaccine production facility and the less publicized UK problems of supply. Meanwhile, those in genuine at-risk occupations are left unsure whether, if they can get the vaccine at all, they really want it. Despite two decades of elegant science aimed at formulating alternative vaccines to overcome all the problems of efficacy, safety and supply, such an alternative is at least five years away, and the current status is that we must live with the old vaccines or not vaccinate. PMID:11964777

Turnbull, Peter C.B.

2000-04-01

312

Periocular cutaneous anthrax in Jimma Zone, Southwest Ethiopia: a case series  

PubMed Central

Background Anthrax is a zoonotic disease caused by Bacillus anthracis. Naturally occurring human infection is rare and is generally the result of contact with anthrax-infected animals or animal products. Case presentation We examined three patients who had contact with presumed anthrax-infected animal and/or its product and presented with preseptal cellulitis with a localized itchy erythematous papule of the eyelid and non-pitting periorbital edema, followed by ulceration and dark eschar formation. All the three patients responded to intravenous antibiotics, and the lesion resolved leaving scars which caused cicatricial ectropion in all cases. Conclusion Anthrax is a rare disease but should be considered in the differential diagnosis of ulcerative (and eschar forming) preseptal cellulitis with a history of contact with anthrax-infected animals or animal products. Furthermore, cicatrization of the eyelids, one of the sequelae of periocular cutaneous anthrax, should be addressed. Urgent case report to the local zoonotic disease and infection control body and other responsible authorities is recommended.

2013-01-01

313

Ecology and epidemiology of anthrax in cattle and humans in Zambia.  

PubMed

Anthrax is endemic in Western and North-western Provinces of Zambia. The disease occurs throughout the year and impacts negatively on the economy of the livestock industry and public health in Zambia. During 1989-1995, there were 1626 suspected cases of anthrax in cattle in Western province and of these 51 were confirmed. There were 220 cases of human anthrax cases in 1990 alone and 248 cases during 1991-1998 with 19.1% and 7.7% case fatality rates, respectively. Interplay of the ecology of affected areas and anthropogenic factors seem to trigger anthrax epidemics. Anthrax has drawn considerable attention in recent years due to its potential use as a biological weapon. In this paper, the history, current status and approaches towards the control of the disease in Zambia are discussed. Quarantine measures restrict trade of livestock and exchange of animals for draught power resulting in poor food security at household levels. Challenges of anthrax control are complex and comprise of socio-political, economical, environmental and cultural factors. Inadequate funding, lack of innovative disease control strategies and lack of cooperation from stakeholders are the major constraints to the control of the disease. It is hoped that the information provided here will stimulate continued awareness for the veterinary and medical authorities to maintain their surveillance and capabilities against the disease. This may lead to a culminating positive impact on livestock and human health in the southern African region. PMID:16786974

Siamudaala, Victor M; Bwalya, John M; Munang'andu, Hetron M; Munag'andu, Hetron M; Sinyangwe, Peter G; Banda, Fred; Mweene, Aaron S; Takada, Ayato; Kida, Hiroshi

2006-05-01

314

The Physiologic Responses of Dutch Belted Rabbits Infected with Inhalational Anthrax  

PubMed Central

Bacillus anthracis, the causative agent of anthrax, is a category A priority pathogen that causes extensive damage in humans. For this reason, B. anthracis has been the focus of numerous studies using various animal models. In this study, we explored physiologic parameters in Dutch belted rabbits with inhalation anthrax to characterize the disease progression in this model. To this end, we infected Dutch belted rabbits with 100 LD50 B. anthracis Ames spores by nasal instillation and continuously recorded various physiologic parameters by using telemetry. In addition, samples were collected at selected times for serum chemistry, hematology, and blood gas analysis. The animals exhibited hemodynamic and respiratory changes that coincided with those reported in human cases of inhalational anthrax infection, including hypotension, altered heart rate, and respiratory distress. Likewise, hematology, serum chemistry, and blood gas analysis revealed trends comparable to human anthrax-related pathophysiology. The Dutch belted rabbit model of inhalational anthrax exhibited most of the physiologic, hematologic, and biochemical sequelae noted in human cases. Therefore, this rabbit model fulfills several of the criteria of a useful animal model for studying disease pathogenesis and evaluating therapeutics during inhalational anthrax.

Lawrence, William S; Hardcastle, Jason M; Brining, Douglas L; Weaver, Lori E; Ponce, Cindy; Whorton, Elbert B; Peterson, Johnny W

2009-01-01

315

Empirical valence bond simulations of the chemical mechanism of ATP to cAMP conversion by anthrax edema factor.  

PubMed

The two-metal catalysis by the adenylyl cyclase domain of the anthrax edema factor toxin was simulated using the empirical valence bond (EVB) quantum mechanical/molecular mechanical approach. These calculations considered the energetics of the nucleophile deprotonation and the formation of a new P-O bond in aqueous solution and in the enzyme-substrate complex present in the crystal structure models of the reactant and product states of the reaction. Our calculations support a reaction pathway that involves metal-assisted transfer of a proton from the nucleophile to the bulk aqueous solution followed by subsequent formation of an unstable pentavalent intermediate that decomposes into cAMP and pyrophosphate (PPi). This pathway involves ligand exchange in the first solvation sphere of the catalytic metal. At 12.9 kcal/mol, the barrier for the last step of the reaction, the cleavage of the P-O bond to PPi, corresponds to the highest point on the free energy profile for this reaction pathway. However, this energy is too close to the value of 11.4 kcal/mol calculated for the barrier of the nucleophilic attack step to reach a definitive conclusion about the rate-limiting step. The calculated reaction mechanism is supported by reasonable agreement between the experimental and calculated catalytic rate constant decrease caused by the mutation of the active site lysine 346 to arginine. PMID:23480863

Mones, Letif; Tang, Wei-Jen; Florián, Jan

2013-04-16

316

EVB Simulations of the Chemical Mechanism of ATP to cAMP Conversion by Anthrax Edema Factor$  

PubMed Central

The two-metal catalysis by the adenylyl cyclase domain of the anthrax edema factor toxin was simulated using the empirical valence bond (EVB) quantum mechanical/molecular mechanical approach. These calculations considered the energetics of the nucleophile deprotonation and a new PO bond formation in the aqueous solution and in the enzyme-substrate complex present in the crystal structure models of the reactant and product state of the reaction. Our calculations support reaction pathway that involves metal-assisted proton transfer from the nucleophile to bulk aqueous solution followed by subsequent formation of an unstable pentavalent intermediate that decomposes into cAMP and pyrophosphate (PPi). This pathway involves ligand exchange in the first solvation sphere of the catalytic metal. The last step of the reaction – the cleavage of the PO bond to PPi – has the highest activation barrier of 13.9 kcal/mol but this barrier height is too close to 12.5 kcal/mol calculated for the nucleophilic attack step to make a definitive conclusion about the rate-limiting step. The calculated reaction mechanism is supported by reasonable agreement between the experimental and calculated catalytic rate constant decrease due to the mutation of the active site lysine 346 to arginine.

Mones, Letif; Tang, Wei-Jen; Florian, Jan

2014-01-01

317

Evidence that histidine protonation of receptor-bound anthrax protective antigen is a trigger for pore formation  

PubMed Central

The protective antigen (PA) component of the anthrax toxin forms pores within the low pH environment of host endosomes, through mechanisms that are poorly understood. It has been proposed that pore formation is dependent on histidine protonation. In previous work, we biosynthetically incorporated 2-fluorohistidine (2-FHis), an isosteric analog of histidine with a significantly reduced pKa (~1), into PA, and showed that the pH-dependent conversion from the soluble prepore to a pore was unchanged. However, we also observed that 2-FHisPA was non-functional in the ability to mediate cytotoxicity of CHO-K1 cells by LFN-DTA, and was defective in translocation through planar lipid bilayers. Here, we show that the defect in cytotoxicity is due to both a defect in translocation and, when bound to the host cellular receptor, an inability to undergo low pH-induced pore formation. Combining X-ray crystallography with hydrogen-deuterium (H-D) exchange mass spectrometry, our studies lead to a model in which hydrogen bonds to the histidine ring are strengthened by receptor binding. The combination of both fluorination and receptor binding is sufficient to block low pH-induced pore formation.

Wimalasena, D. Shyamali; Janowiak, Blythe E.; Lovell, Scott; Miyagi, Masaru; Sun, Jianjun; Zhou, Haiying; Hajduch, Jan; Pooput, Chaya; Kirk, Kenneth L.; Battaile, Kevin P.; Bann, James G.

2010-01-01

318

Ante- and postmortem diagnostic techniques for anthrax: rethinking pathogen exposure and the geographic extent of the disease in wildlife.  

PubMed

Although antemortem approaches in wildlife disease surveillance are common for most zoonoses, they have been used infrequently in anthrax surveillance. Classically, anthrax is considered a disease with extremely high mortality. This is because anthrax outbreaks are often detected ex post facto through wildlife or livestock fatalities or spillover transmission to humans. As a result, the natural prevalence of anthrax infection in animal populations is largely unknown. However, in the past 20 yr, antemortem serologic surveillance in wildlife has indicated that not all species exposed succumb to infection, and anthrax exposure may be more widespread than originally appreciated. These studies brought about a multitude of new questions, many of which can be addressed by increased antemortem serologic surveillance in wildlife populations. To fully understand anthrax transmission dynamics and geographic extent, it is important to identify exposure in wildlife hosts and associated factors and, in turn, understand how these influences may drive environmental reservoir dynamics and concurrent disease risk in livestock and humans. Here we review our current understanding of the serologic response to anthrax among wildlife hosts and serologic diagnostic assays used to augment traditional postmortem anthrax surveillance strategies. We also provide recommendations for the use of serology and sentinel species surveillance approaches in anthrax research and management. PMID:24502707

Bagamian, Karoun H; Alexander, Kathleen A; Hadfield, Ted L; Blackburn, Jason K

2013-10-01

319

Self-Assembled Peptide Monolayers as a Toxin Sensing Mechanism within Arrayed Microchannels  

PubMed Central

A sensor for the lethal bacterial enzyme, botulinum neurotoxin type A (BoNT/A), was developed using self-assembled monolayers (SAMs). SAMs consisting of an immobilized synthetic peptide that mimicked the toxin’s in vivo SNAP-25 protein substrate were formed on Au and interfaced with arrayed microfluidic channels. Efforts to optimize SAM composition and assay conditions for greatest reaction efficiency and sensitivity are described in detail. Channel design provided facile fluid manipulation, sample incubation, analyte concentration, and fluorescence detection all within a single microfluidic channel, thus avoiding sample transfer and loss. Peptide SAMs were exposed to varying concentrations of BoNT/A or its catalytic light chain (ALC), resulting in enzymatic cleavage of the peptide substrate from the surface. Fluorescence detection was achieved down to 20 pg/mL ALC and 3 pg/ mL BoNT/A in 3 h. Toxin sensing was also accomplished in vegetable soup, demonstrating practicality of the method. The modular design of this microfluidic SAM platform allows for extension to sensing other toxins that operate via enzymatic cleavage, such as the remaining BoNT serotypes B–G, anthrax, and tetanus toxin.

Frisk, Megan L.; Tepp, William H.; Johnson, Eric A.; Beebe, David J.

2009-01-01

320

Radiolabeled antibodies in renal cell carcinoma.  

PubMed

Renal cell carcinoma (RCC) is a radio- and chemotherapy resistant tumor, which has a very high morbidity and mortality when metastasized. The current treatment options demonstrate limited efficacy and severe side-effects. Therefore, there is a need for new therapeutic strategies for RCC. As for other malignancies, monoclonal antibodies (mAbs) targeting tumor-associated antigens have been developed for RCC. One of these, mAb G250, targets the MN/CAIX/G250 antigen, which is ubiquitously expressed in clear cell RCC (ccRCC). ccRCC is the most common form of RCC with a prevalence of 80%. Expression of G250 in normal tissue is restricted to the gastrointestinal mucosa and related structures, thereby making it a suitable candidate for targeting ccRCC. In several clinical studies the efficient accumulation of mAb G250 in ccRCC has been demonstrated, resulting in high contrast images. G250-imaging could prove to be a valuable tool in diagnosing metastases in patients with a G250-antigen positive primary tumor and/or in the differential diagnosis of suspect kidney lesions. Furthermore, the therapeutic efficacy of radiolabeled G250 has been investigated in a series of studies. Thus far, most efforts have been devoted to G250 labeled with high doses of 131I. Other radionuclides which may enhance the therapeutic index of this radiolabeled mAb are currently under investigation. In our institution, an activity dose escalation study is currently ongoing to investigate the therapeutic potential of 177Lu-labeled G250 in metastatic ccRCC patients. In this review, the current status of the diagnostic and therapeutic properties of radiolabeled antibodies in RCC is described. PMID:18055291

Stillebroer, Alexander B; Oosterwijk, Egbert; Oyen, Wim J G; Mulders, Peter F A; Boerman, Otto C

2007-01-01

321

Toxin-antitoxin systems  

PubMed Central

Toxin–antitoxin (TA) systems are small genetic elements composed of a toxin gene and its cognate antitoxin. The toxins of all known TA systems are proteins while the antitoxins are either proteins or non-coding RNAs. Based on the molecular nature of the antitoxin and its mode of interaction with the toxin the TA modules are currently grouped into five classes. In general, the toxin is more stable than the antitoxin but the latter is expressed to a higher level. If supply of the antitoxin stops, for instance under special growth conditions or by plasmid loss in case of plasmid encoded TA systems, the antitoxin is rapidly degraded and can no longer counteract the toxin. Consequently, the toxin becomes activated and can act on its cellular targets. Typically, TA toxins act on crucial cellular processes including translation, replication, cytoskeleton formation, membrane integrity, and cell wall biosynthesis. TA systems and their components are also versatile tools for a multitude of purposes in basic research and biotechnology. Currently, TA systems are frequently used for selection in cloning and for single protein expression in living bacterial cells. Since several TA toxins exhibit activity in yeast and mammalian cells they may be useful for applications in eukaryotic systems. TA modules are also considered as promising targets for the development of antibacterial drugs and their potential to combat viral infection may aid in controlling infectious diseases.

Unterholzner, Simon J; Poppenberger, Brigitte; Rozhon, Wilfried

2013-01-01

322

[Botulinum toxins for pain].  

PubMed

We review the evidence of botulinum toxins in the treatment of pain. Main indications of botulinum toxin treatment, dystonia and spasticity, involve pain. Increasing evidence suggests direct analgesic effects of botulinum. Botulinum inhibits release of pain mediators (substance P, CGRP, excitatory amino acids, ATP, noradrenaline). Clinical trials have consistently shown analgesic effect of botulinum toxin in post-stroke shoulder pain, bladder dysfunction, chronic migraine, neuropathic pain, bruxism and lateral epicondylitis. Other pain conditions have been studied with yet uncertain results. It seems that the number of patients who would benefit from botulinum toxin treatment will increase considerably in the future. PMID:22238920

Soinila, Seppo; Haanpää, Maija

2011-01-01

323

Leukocidal toxins of staphylococci.  

PubMed

Leukocidal toxins (synergohymenotropic toxin) are cytotoxins produced by staphylococci (S. aureus and S. intermedius) and consist of two separate components. The toxic effect depends on the synergistic action of two proteins. One of them belongs to class F (e.g. LukF-PV, LukF-R, LukF-I, LukM, HlgB) and the other, to class S (e.g. LukS-PV, LukS-R, LukS-I, HlgA, HlgC). Best known are the toxins produced by S. aureus: gamma-haemolysins, HlgA/HlgB and HlgC/HlgB and leukocidin Panton-Valentine, LukS-PV/LukF-PV (Luk-PV, PVL). Very few data are available concerning the relationship between the production of these toxins and the pathology of staphylococcal infections, because little is known about local and general effects of these leukocidal products in vivo. Frequent isolations of staphylococcal strains producing leukocidal toxins from necrotic skin lesions and furuncles suggest a role of these toxins in the virulence of staphylococci, at least in cutaneous infections. Recent data on mechanisms of cytotoxic effects of staphylococcal leukocidal toxins in vitro as well as effects of leukocidal toxins in vitro are discussed. Cell membranes appear to be a primary target for triggering the lysis of phagocytic cells caused by staphylococcal leukocidal toxins. PMID:10360319

Szmigielski, S; Prévost, G; Monteil, H; Colin, D A; Jeljaszewicz, J

1999-04-01

324

Monitoring Anthrax Vaccine Safety in US Military Service Members on Active Duty: Surveillance of Hospitalizations in Temporal Association with Immunization 1998.  

National Technical Information Service (NTIS)

We studied military medical hospitalizations for possible temporal associations with anthrax immunization in U.S. military personnel on active duty in 1998. Anthrax immunization, demographic, and hospitalization data were linked and analyzed using Cox pro...

P. A. Sato R. J. Reed T. C. Smith L. Wang

2000-01-01

325

Determination of benzethonium chloride in anthrax vaccine adsorbed by HPLC.  

PubMed

A novel and sensitive HPLC method for the determination of benzethonium chloride (BZC) in anthrax vaccine was developed. Adjuvant Alhydrogel was removed by syringe filter after a simple sample pretreatment - acidification prior to injection. Chromatography was performed by isocratic reverse phase separation with methanol/262 mM ammonium acetate (80/20, v/v) on an endcapped C18 column with diode array detector (DAD). The method showed excellent recovery (100+/-1.5%). The results indicated that this method could accurately determine BZC at the limit of detection (LOD) of 0.5 ppm and the limit of quantitation (LOQ) of 1.5 ppm with dynamic range up to 100 ppm. The comparison of analysis between new HPLC and old titrimetric methods is also reported. The HPLC method is proven to be more accurate and precise with much less vaccine sample and human labor required. PMID:16492397

Wang, Hsiaoling; Del Grosso, Alfred V; May, Joan C

2006-12-01

326

Fluorescent detection of an anthrax biomarker based on PVA film.  

PubMed

Due to the dangerous nature of anthrax, the development of a cost-effective, sensitive and field-portable sensor for the anthrax biomarker--calcium dipicolinate (CaDPA)--is of exceptional significance for both military and civilian use. Herein, a flexible polymer-film-based ratiometric sensor for detecting CaDPA was demonstrated. A reference dye and a probe ligand were covalently immobilized onto the film surface through a highly selective and efficient "click chemistry" reaction. The reference dye, whose fluorescence intensity does not change with varying amounts of CaDPA, offers a non-interfering internal calibration. The ethylenediaminetetraacetic acid (EDTA)-based ligand binds with Eu(III) and serves as the probe. In the absence of CaDPA, the film sensor exhibited almost no red fluorescence because the Eu(III) ions themselves give no emission without sensitization by CaDPA owing to the small molar absorption coefficients of Eu(III) ions. The presence of CaDPA induces a significantly enhanced emission intensity of the sensor, and thereby enables the film as a ratiometric sensor for CaDPA. This sensor can selectively detect CaDPA in water with a detection limit of 100 nM. Moreover, this sensor exhibited strong anti-interfering capability, it can not only be used in milieus that contain various amino acids and some biologically-abundant cations, but can also be usable in some biological fluids such as urine and serum. This test-paper-like film sensor is suitable for portable field analysis and needs no extra protective measures during transport due to its flexibility, and it can easily be separated from the analyte solution after the detection. PMID:21796290

Ma, Boling; Zeng, Fang; Zheng, Fangyuan; Wu, Shuizhu

2011-09-21

327

Metastatic Insulinoma Managed with Radiolabeled Somatostatin Analog  

PubMed Central

Insulinoma is a rare pancreatic neuroendocrine tumor. Overproduction of insulin and associated hypoglycemia are hallmark features of this disease. Diagnosis can be made through demonstration of hypoglycemia and elevated plasma levels of insulin or C-Peptide. Metastatic disease can be detected through computerized tomography (CT) scans, magnetic resonance imaging (MRI), and positron emission tomography (PET)/CT. Somatostatin receptor scintigraphy can be used not only to document metastatic disease but also as a predictive marker of the benefit from therapy with radiolabeled somatostatin analog. Unresectable metastatic insulinomas may present as a major therapeutic challenge for the treating physician. When feasible, resection is the mainstay of treatment. Prevention of hypoglycemia is a crucial goal of therapy for unresectable/metastatic tumors. Diazoxide, hydrochlorothiazide, glucagon, and intravenous glucose infusions have been used for glycemic control yielding temporary and inconsistent results. Sandostatin and its long-acting depot forms have occasionally been used in the treatment of Octreoscan-positive insulinomas. Herein, we report a case of metastatic insulinoma with very difficult glycemic control successfully treated with the radiolabeled somatostatin analog lutetium (177LU).

Costa, Ricardo; Bacchi, Carlos E.; Almeida Filho, Paulo

2013-01-01

328

Metastatic insulinoma managed with radiolabeled somatostatin analog.  

PubMed

Insulinoma is a rare pancreatic neuroendocrine tumor. Overproduction of insulin and associated hypoglycemia are hallmark features of this disease. Diagnosis can be made through demonstration of hypoglycemia and elevated plasma levels of insulin or C-Peptide. Metastatic disease can be detected through computerized tomography (CT) scans, magnetic resonance imaging (MRI), and positron emission tomography (PET)/CT. Somatostatin receptor scintigraphy can be used not only to document metastatic disease but also as a predictive marker of the benefit from therapy with radiolabeled somatostatin analog. Unresectable metastatic insulinomas may present as a major therapeutic challenge for the treating physician. When feasible, resection is the mainstay of treatment. Prevention of hypoglycemia is a crucial goal of therapy for unresectable/metastatic tumors. Diazoxide, hydrochlorothiazide, glucagon, and intravenous glucose infusions have been used for glycemic control yielding temporary and inconsistent results. Sandostatin and its long-acting depot forms have occasionally been used in the treatment of Octreoscan-positive insulinomas. Herein, we report a case of metastatic insulinoma with very difficult glycemic control successfully treated with the radiolabeled somatostatin analog lutetium ((177)LU). PMID:24455330

Costa, Ricardo; Costa, Rubens; Bacchi, Carlos E; Almeida Filho, Paulo

2013-01-01

329

Radiolabeled regulatory peptides for imaging and therapy  

PubMed Central

Purpose of review The purpose of the present review is to describe new, innovative strategies of diagnosing and treating specific human cancers using a cadre of radiolabeled regulatory peptides. Recent findings Peptide receptor-targeted radionuclide therapy is a method of site-directed radiotherapy that specifically targets human cancers expressing a cognate receptor-subtype in very high numbers. Ideally, the procedure targets only the primary or metastatic disease and is minimally invasive, with little radiation damage to normal, collateral tissues. For treatment strategies of this type to be effective, it is critical to evaluate the toxicity of the treatment protocol, the radiation dosimetry of the therapeutic regimen, and the biological profile of the radiopharmaceutical, including biodistribution and pharmacokinetics of the drug. Site-directed molecular imaging procedures via ?-scintigraphy can address many of the critical issues associated with peptide receptor-targeted radionuclide therapy and it is, therefore, necessary to describe the effective balance between the clinical benefits and risks of this treatment strategy. Summary Continued development in the design or chemical structure of radiolabeled, biologically active peptides could do much to improve the targeting ability of these drugs, thereby creating new and innovative strategies for diagnosis or treatment of human cancers.

Nanda, Prasant K.; Lane, Stephanie R.; Retzloff, Lauren B.; Pandey, Usha S.; Smith, Charles Jeffrey

2010-01-01

330

Awareness and attitude toward zoonoses with particular reference to anthrax among cattle owners in selected rural communities of Zimbabwe.  

PubMed

We conducted a cross-sectional study to assess cattle owners' awareness, perceptions, and attitudes toward zoonoses, with particular emphasis regarding anthrax. Data on awareness of zoonoses, clinical signs of anthrax in animals and human, its routes of transmission and methods of prevention, the families' consumption habits of anthrax-infected carcasses, and other family activities that increase exposure to anthrax were collected using an interviewer-administered questionnaire. A total of 41.4% (135/326) of the farmers were from high-anthrax-risk districts, whereas 28.5% and 30.1% were from medium- and low-risk districts, respectively. Overall, the level of awareness amongst the farmers for the named zoonoses were rabies (88.7%), anthrax (71.5%), and brucellosis (20.9%). Except for anthrax, awareness of other zoonoses did not differ significantly (p>0.05) among the district categories. Farmers from anthrax high-risk districts were significantly more aware of anthrax compared to those from moderate- (p=0.000) and low- (p=0.000) risk districts. All of the farmers were aware that anthrax occurs in cattle, and 73% indicated the presence of unclotting blood oozing from natural orifices as a consistent finding in cattle that died of anthrax, whereas 86.7% of them indicated the presence of skin lesions as the most common sign of the disease in humans. The good efficacy of human anthrax treatment (58.3%), slaughter of moribund cattle and selling of meat from cattle found dead to unsuspecting consumers (59.8%), reluctance to lose animals (47.9%), and forgetting about anthrax (41.1%) were cited as the major reasons for consuming anthrax-infected carcasses. Given that 75.2% of cattle owners indicated that they would not consume meat from cattle found dead, because they were discouraged by veterinary authorities, introducing meat inspection services is likely to have a positive impact in preventing human anthrax outbreaks in Zimbabwe. PMID:23421887

Chikerema, S M; Matope, G; Pfukenyi, D M

2013-04-01

331

Mechanism of Lethal Toxin Neutralization by a Human Monoclonal Antibody Specific for the PA20 Region of Bacillus anthracis Protective Antigen  

PubMed Central

The primary immunogenic component of the currently approved anthrax vaccine is the protective antigen (PA) unit of the binary toxin system. PA-specific antibodies neutralize anthrax toxins and protect against infection. Recent research has determined that in humans, only antibodies specific for particular determinants are capable of effecting toxin neutralization, and that the neutralizing epitopes recognized by these antibodies are distributed throughout the PA monomer. The mechanisms by which the majority of these epitopes effect neutralization remain unknown. In this report we investigate the process by which a human monoclonal antibody specific for the amino-terminal domain of PA neutralizes lethal toxin in an in vitro assay of cytotoxicity, and find that it neutralizes LT by blocking the requisite cleavage of the amino-terminal 20 kD portion of the molecule (PA20) from the remainder of the PA monomer. We also demonstrate that the epitope recognized by this human monoclonal does not encompass the 166RKKR169 furin recognition sequence in domain 1 of PA.

Reason, Donald; Liberato, Justine; Sun, Jinying; Camacho, Jessica; Zhou, Jianhui

2011-01-01

332

Monte Carlo N-particle simulation of neutron-based sterilisation of anthrax contamination  

PubMed Central

Objective To simulate the neutron-based sterilisation of anthrax contamination by Monte Carlo N-particle (MCNP) 4C code. Methods Neutrons are elementary particles that have no charge. They are 20 times more effective than electrons or ?-rays in killing anthrax spores on surfaces and inside closed containers. Neutrons emitted from a 252Cf neutron source are in the 100 keV to 2 MeV energy range. A 2.5 MeV D–D neutron generator can create neutrons at up to 1013 n s?1 with current technology. All these enable an effective and low-cost method of killing anthrax spores. Results There is no effect on neutron energy deposition on the anthrax sample when using a reflector that is thicker than its saturation thickness. Among all three reflecting materials tested in the MCNP simulation, paraffin is the best because it has the thinnest saturation thickness and is easy to machine. The MCNP radiation dose and fluence simulation calculation also showed that the MCNP-simulated neutron fluence that is needed to kill the anthrax spores agrees with previous analytical estimations very well. Conclusion The MCNP simulation indicates that a 10 min neutron irradiation from a 0.5 g 252Cf neutron source or a 1 min neutron irradiation from a 2.5 MeV D–D neutron generator may kill all anthrax spores in a sample. This is a promising result because a 2.5 MeV D–D neutron generator output >1013 n s?1 should be attainable in the near future. This indicates that we could use a D–D neutron generator to sterilise anthrax contamination within several seconds.

Liu, B; Xu, J; Liu, T; Ouyang, X

2012-01-01

333

The dissemination of anthrax from imported wool: Kidderminster 1900-14  

PubMed Central

Background: A century ago anthrax was a continuing health risk in the town of Kidderminster. The distribution of cases in people and in animals provides an indication of the routes by which spores were disseminated. The response to these cases provides an insight into attitudes to an occupational and environmental risk at the time and can be compared with responses in more recent times. Aims: To assess the distribution of anthrax cases associated with the use of contaminated wool and to review the response to them. Methods: The area studied was Kidderminster, Worcestershire, England, from 1900 to 1914. Data sources were national records of the Factory Inspectorate and local records from the infirmary, Medical Officer of Health and inquest reports, and county agricultural records, supplemented by contemporary and later review articles. Case reports and summary data were analysed, and discussions and actions taken to improve precautions reviewed. Results: There were 36 cases of anthrax, with five deaths, one of which was the sole case of the internal form of the disease. Cases of cutaneous anthrax were most frequently found in those handling raw wool, but they also occurred in workers at later stages of the spinning process and in people with little or no recorded exposure to contaminated wool. Limited precautionary measures were in place at the start of the study period. Some improvements were made, especially in the treatment of infections, but wool with a high risk of anthrax contamination continued to be used and cases continued to arise. Major changes were made to the disposal of waste and to agricultural practice in contaminated areas to curtail outbreaks in farm animals. Conclusions: The introduction of anthrax as a contaminant of imported wool led not only to cases in the highly exposed groups of workers but also to cases in other members of the population and in farm animals. The measures taken during the study period reduced fatalities from cutaneous anthrax but did not eliminate the disease. Public concern about the cases was muted.

Carter, T

2004-01-01

334

Radiolabeled dimethyl branched long chain fatty acid for heart imaging  

DOEpatents

A radiolabeled long chain fatty acid for heart imaging that has dimethyl branching at one of the carbons of the chain which inhibits the extent to which oxidation can occur. The closer to the carboxyl the branching is positioned, the more limited the oxidation, thereby resulting in prolonged retention of the radiolabeled compound in the heart.

Knapp, Jr., Furn F. (Oak Ridge, TN); Goodman, Mark M. (Knoxville, TN); Kirsch, Gilbert (Woippy, FR)

1988-08-16

335

Reducing renal uptake of radiolabeled peptides using albumin fragments  

Microsoft Academic Search

In most types of peptide receptor radionuclide therapy, the maximum activity dose that can be administered is limited by high and persistent renal retention of the radiolabeled peptides, which is, at least partly, mediated by the megalin receptor. Several agents that interfere with renal reabsorption of radiolabeled peptides have been identified (e.g., lysine, arginine, succinylated gelatin solution), but none of

E. Vegt; J. E. M. van Eerd; A. Eek; W. J. G. Oyen; J. F. M. Wetzels; M. de Jong; F. G. M. Russel; R. Masereeuw; M. Gotthardt; O. C. Boerman

2008-01-01

336

Localisation and mechanism of renal retention of radiolabelled somatostatin analogues  

Microsoft Academic Search

Purpose: Radiolabelled somatostatin analogues, such as octreotide and octreotate, are used for tumour scin- tigraphy and radionide therapy. The kidney is the most important critical organ during such therapy owing to the re- absorption and retention of radiolabelled peptides. The aim of this study was to investigate in a rat model both the localisation and the mechanism of renal uptake

Marleen Melis; Eric P. Krenning; Bert F. Bernard; Raffaella Barone; Theo J. Visser; Marion de Jong

2005-01-01

337

Muscarinic toxins from the venom of Dendroaspis snakes with agonist-like actions  

Microsoft Academic Search

The venom of some Dendroaspis snakes contains small proteins (7500 mol. wt) that inhibit the binding of radiolabelled muscarinic antagonist to brain synaptomal membranes. There were no peptides described among muscarinic ligands until Adem et al. (Biochim. biophys. Acta968, 340–345, 1988) reported that muscarinic toxins (MTxs), MTx1 and 2 were able to inhibit 3H-QNB binding to rat brain membranes. Since

Diana Jerusalinsky; Edgar Kornisiuk; Ramón Bernabeu; Ivan Izquierdo; Carlos Cerveñansky

1995-01-01

338

Radiolabeled antagonistic bombesin peptidomimetics for tumor targeting.  

PubMed

The replacement of amide bonds in the backbone of peptides by proteolytically stable?1,2,3-triazole isosteres can provide novel peptidomimetics with promising properties for the development of tumor-targeting radiopeptides. On the basis of our previous work with radiolabeled agonistic bombesin (BBN) derivatives of the sequence [Nle(14) ]BBN(7-14), we substituted selected amide bonds of the structurally closely related antagonistic peptide analog JMV594. With the exception of the C-terminal modification, amide-to-triazole substitutions tolerated by [Nle(14) ]BBN(7-14) without loss of biological function led to abolished receptor affinity in the case of JMV594. These findings provide an additional piece of evidence for the currently disputed differences in the modes of action of agonistic and antagonistic gastrin-releasing peptide receptor (GRPR)-targeting radiopeptides. PMID:24327435

Valverde, Ibai E; Huxol, Elena; Mindt, Thomas L

2014-04-01

339

Autodecomposition of radiolabeled human growth hormone  

SciTech Connect

Human growth hormone (hGH) was radiolabeled with /sup 125/I, using a gentle lactoperoxidase technique. The stability and decomposition products of this tracer were studied by frequent periodic analysis by Sephadex G-100 chromatography on a long column. Monomeric /sup 125/I-hGH showed an exponential decline, with a half-life of 61 days. The main radioactive degradation product was iodide, which appeared with a fractional appearance rate of 0.01136 per day. Secondary degradation products were a series of radioactive oligomers of hGH, which appeared with an overall fractional rate of 0.00525 per day. The kinetic data obtained should provide guidelines for the shelf-life and repurification schedule of radioiodinated polypeptides.

Baumann, G.; Amburn, K.

1986-01-01

340

Cell Surface-Exposed Tetanus Toxin Fragment C Produced by Recombinant Bacillus anthracis Protects against Tetanus Toxin  

PubMed Central

Bacillus anthracis, the causal agent of anthrax, synthesizes two surface layer (S-layer) proteins, EA1 and Sap, which account for 5 to 10% of total protein and are expressed in vivo. A recombinant B. anthracis strain was constructed by integrating into the chromosome a translational fusion harboring the DNA fragments encoding the cell wall-targeting domain of the S-layer protein EA1 and tetanus toxin fragment C (ToxC). This construct was expressed under the control of the promoter of the S-layer component gene. The hybrid protein was stably expressed on the cell surface of the bacterium. Mice were immunized with bacilli of the corresponding strain, and the hybrid protein elicited a humoral response to ToxC. This immune response was sufficient to protect mice against tetanus toxin challenge. Thus, the strategy developed in this study may make it possible to generate multivalent live veterinary vaccines, using the S-layer protein genes as a cell surface display system.

Mesnage, Stephane; Weber-Levy, Martine; Haustant, Michel; Mock, Michele; Fouet, Agnes

1999-01-01

341

Responding to the threat of bioterrorism: a microbial ecology perspective--the case of anthrax.  

PubMed

Anthrax is a disease of herbivores caused by the gram-positive bacterium Bacillus anthracis. It can affect cattle, sheep, swine, horses and various species of wildlife. The routes for the spread among wildlife are reviewed. There are three kinds of human anthrax--inhalation, cutaneous, and intestinal anthrax--which differ in their routes of infection and outcomes. In the United States, confirmation of cases is made by the isolation of B. anthracis and by biochemical tests. Vaccination is not recommended for the general public; civilians who should be vaccinated include those who, in their work places, come in contact with products potentially contaminated with B. anthracis spores, and people engaged in research or diagnostic activities. After September 11, 2001, there were bioterrorism anthrax attacks in the United States: anthrax-laced letters sent to multiple locations were the source of infectious B. anthracis. The US Postal Service issued recommendations to prevent the danger of hazardous exposure to the bacterium. B. anthracis spores can spread easily and persist for very long times, which makes decontamination of buildings very difficult. Early detection, rapid diagnosis, and well-coordinated public health response are the key to minimizing casualties. The US Government is seeking new ways to deter bioterrorism, including a tighter control of research on infectious agents, even though pathogens such as B. anthracis are widely spread in nature and easy to grow. It is necessary to define the boundary between defensive and offensive biological weapons research. Deterring bioterrorism should not restrict critical scientific research. PMID:12497181

Atlas, R M

2002-12-01

342

Vaccine Protection against Bacillus cereus-Mediated Respiratory Anthrax-Like Disease in Mice  

PubMed Central

Bacillus cereus strains harboring a pXO1-like virulence plasmid cause respiratory anthrax-like disease in humans, particularly in welders. We developed mouse models for intraperitoneal as well as aerosol challenge with spores of B. cereus G9241, harboring pBCXO1 and pBC218 virulence plasmids. Compared to wild-type B. cereus G9241, spores with a deletion of the pBCXO1-carried protective antigen gene (pagA1) were severely attenuated, whereas spores with a deletion of the pBC218-carried protective antigen homologue (pagA2) were not. Anthrax vaccine adsorbed (AVA) immunization raised antibodies that bound and neutralized the pagA1-encoded protective antigen (PA1) but not the PA2 orthologue encoded by pagA2. AVA immunization protected mice against a lethal challenge with spores from B. cereus G9241 or B. cereus Elc4, a strain that had been isolated from a fatal case of anthrax-like disease. As the pathogenesis of B. cereus anthrax-like disease in mice is dependent on pagA1 and PA-neutralizing antibodies provide protection, AVA immunization may also protect humans from respiratory anthrax-like death.

Oh, So-Young; Maier, Hannah; Schroeder, Jay; Richter, G. Stefan; Elli, Derek; Musser, James M.; Quenee, Lauriane E.; Missiakas, Dominique M.

2013-01-01

343

The Ustilago maydis killer toxins  

Microsoft Academic Search

Killer toxins are small proteins secreted by a number of fungi that are lethal to susceptible cells (generally fungi of the same or related species). They bear some similarity to other families of protein toxins, which are ubiquitous in nature. The three known Ustilago maydis killer toxins typify, in many respects, the class of killer toxins. Two of them appear

Jeremy Bruenn

344

An Adenovirus-Vectored Nasal Vaccine Confers Rapid and Sustained Protection against Anthrax in a Single-Dose Regimen  

PubMed Central

Bacillus anthracis is the causative agent of anthrax, and its spores have been developed into lethal bioweapons. To mitigate an onslaught from airborne anthrax spores that are maliciously disseminated, it is of paramount importance to develop a rapid-response anthrax vaccine that can be mass administered by nonmedical personnel during a crisis. We report here that intranasal instillation of a nonreplicating adenovirus vector encoding B. anthracis protective antigen could confer rapid and sustained protection against inhalation anthrax in mice in a single-dose regimen in the presence of preexisting adenovirus immunity. The potency of the vaccine was greatly enhanced when codons of the antigen gene were optimized to match the tRNA pool found in human cells. In addition, an adenovirus vector encoding lethal factor can confer partial protection against inhalation anthrax and might be coadministered with a protective antigen-based vaccine.

Jex, Edward; Feng, Tsungwei; Sivko, Gloria S.; Baillie, Leslie W.; Goldman, Stanley; Van Kampen, Kent R.; Tang, De-chu C.

2013-01-01

345

Selective inhibitor of endosomal trafficking pathways exploited by multiple toxins and viruses  

PubMed Central

Pathogenic microorganisms and toxins have evolved a variety of mechanisms to gain access to the host-cell cytosol and thereby exert virulent effects upon the host. One common mechanism of cellular entry requires trafficking to an acidified endosome, which promotes translocation across the host membrane. To identify small-molecule inhibitors that block this process, a library of 30,000 small molecules was screened for inhibitors of anthrax lethal toxin. Here we report that 4-bromobenzaldehyde N-(2,6-dimethylphenyl)semicarbazone, the most active compound identified in the screen, inhibits intoxication by lethal toxin and blocks the entry of multiple other acid-dependent bacterial toxins and viruses into mammalian cells. This compound, which we named EGA, also delays lysosomal targeting and degradation of the EGF receptor, indicating that it targets host-membrane trafficking. In contrast, EGA does not block endosomal recycling of transferrin, retrograde trafficking of ricin, phagolysosomal trafficking, or phagosome permeabilization by Franciscella tularensis. Furthermore, EGA does not neutralize acidic organelles, demonstrating that its mechanism of action is distinct from pH-raising agents such as ammonium chloride and bafilomycin A1. EGA is a powerful tool for the study of membrane trafficking and represents a class of host-targeted compounds for therapeutic development to treat infectious disease.

Gillespie, Eugene J.; Ho, Chi-Lee C.; Balaji, Kavitha; Clemens, Daniel L.; Deng, Gang; Wang, Yao E.; Elsaesser, Heidi J.; Tamilselvam, Batcha; Gargi, Amandeep; Dixon, Shandee D.; France, Bryan; Chamberlain, Brian T.; Blanke, Steven R.; Cheng, Genhong; de la Torre, Juan Carlos; Brooks, David G.; Jung, Michael E.; Colicelli, John; Damoiseaux, Robert; Bradley, Kenneth A.

2013-01-01

346

Transport of protein toxins into cells: pathways used by ricin, cholera toxin and Shiga toxin  

Microsoft Academic Search

Ricin, cholera, and Shiga toxin belong to a family of protein toxins that enter the cytosol to exert their action. Since all three toxins are routed from the cell surface through the Golgi apparatus and to the endoplasmic reticulum (ER) before translocation to the cytosol, the toxins are used to study different endocytic pathways as well as the retrograde transport

Kirsten Sandvig; Bo van Deurs

2002-01-01

347

Preparation and biodistribution of radiolabeled fullerene C60 nanocrystals.  

PubMed

The present study describes for the first time a procedure for the radiolabeling of fullerene (C(60)) nanocrystals (nanoC(60)) with Na (125)I, as well as the biodistribution of radiolabeled nanoC(60) ((125)I-nanoC(60)). The solvent exchange method with tetrahydrofuran was used to make colloidal water suspensions of radiolabeled nanoC(60) particles. The radiolabeling procedure with the addition of Na (125)I to tetrahydrofuran during dissolution of C(60) gave a higher radiochemical yield of radiolabeled nanoC(60) particles in comparison to the second option, in which Na (125)I was added after C(60) was dissolved. Using photon correlation spectroscopy and transmission electron microscopy, (125)I-nanoC(60) particles were found to have a crystalline structure and a mean diameter of 200-250 nm. The (125)I-nanoC(60) had a particularly high affinity for human serum albumin, displaying 95% binding efficiency after 1 h. Biodistribution studies of (125)I-nanoC(60) in rats indicated significant differences in tissue accumulation of (125)I-nanoC(60) and the radioactive tracer Na (125)I. The higher accumulation of radiolabeled nanoC(60) was observed in liver and spleen, while accumulation in thyroid, stomach, lungs and intestines was significantly lower in comparison to Na (125)I. In addition to being useful for testing the biological distribution of nanoC(60), the described radiolabeling procedure might have possible applications in cancer radiotherapy. PMID:19713574

Nikoli?, Nadezda; Vranjes-Ethuri?, Sanja; Jankovi?, Drina; Ethoki?, Divna; Mirkovi?, Marija; Bibi?, Natasa; Trajkovi?, Vladimir

2009-09-23

348

Epidemiologic Responses to Anthrax Outbreaks: A Review of Field Investigations, 1950-2001  

PubMed Central

We used unpublished reports, published manuscripts, and communication with investigators to identify and summarize 49 anthrax-related epidemiologic field investigations conducted by the Centers for Disease Control and Prevention from 1950 to August 2001. Of 41 investigations in which Bacillus anthracis caused human or animal disease, 24 were in agricultural settings, 11 in textile mills, and 6 in other settings. Among the other investigations, two focused on building decontamination, one was a response to bioterrorism threats, and five involved other causes. Knowledge gained in these investigations helped guide the public health response to the October 2001 intentional release of B. anthracis, especially by addressing the management of anthrax threats, prevention of occupational anthrax, use of antibiotic prophylaxis in exposed persons, use of vaccination, spread of B. anthracis spores in aerosols, clinical diagnostic and laboratory confirmation methods, techniques for environmental sampling of exposed surfaces, and methods for decontaminating buildings.

Bales, Michael E.; Brachman, Philip S.; Kaufmann, Arnold F.; Klatsky, Peter C.; Ashford, David A.

2002-01-01

349

An immuno-diffusion assay to assess the protective antigen content of anthrax vaccine.  

PubMed

The UK anthrax vaccine uses the culture supernatant of toxigenic non-encapsulated Bacillus anthracis as a crude source for protective antigen (PA). The precise amount of PA is not known. We developed a single radial immuno-diffusion (SRD) assay and an indirect ELISA to measure PA in desorbed anthrax vaccines. Based on 23 batches, the PA contents varied from 19.1 to 88.8 microgml(-1), with an average of 39.6 microgml(-1). Analysis of four batches by ELISA revealed considerably lower levels of PA. This discrepancy can be explained by competition of other proteins for binding sites, which results in an artificially low amount of bound PA per well. We conclude that the SRD assay is a reproducible method for the measurement of PA and this assay will contribute to quality control and improve the specifications of current anthrax vaccines. PMID:15908061

Adams, Trudy; Osborn, Sancha; Rijpkema, Sjoerd

2005-08-22

350

Cutaneous anthrax associated with drum making using goat hides from West Africa--Connecticut, 2007.  

PubMed

On August 29, 2007, the Connecticut Department of Public Health was notified by a physician of suspect cutaneous anthrax involving a drum maker and one of his three children. The drum maker had been working with untreated goat hides from Guinea in West Africa. This report summarizes results of the joint epidemiologic and environmental investigation conducted by public health officials, environmental agencies, and law enforcement authorities. The investigation revealed that the drum maker was exposed while working with a contaminated goat hide from Guinea and that his workplace and home were contaminated with anthrax. His child was most likely exposed from cross-contamination of the home. The findings underscore the potential hazard of working with untreated animal hides from areas with epizootic anthrax and the potential for secondary cases from environmental contamination. PMID:18551098

2008-06-13

351

Mechanistic aspects of the deoxyribonuclease activity of diphtheria toxin.  

PubMed

Here we examined the intrinsic nuclease activity of diphtheria toxin (DTx) to determine the mechanism by which it catalyzes DNA degradation. Results show that DTx degrades double-stranded DNA (dsDNA) by non-processive, endonucleolytic attack, without apparent specificity for nucleotide sequence. Moreover, divalent cation composition determines whether supercoiled dsDNA is cleaved by the introduction of single-strand nicks or double-strand breaks. Circular single-stranded DNA (ssDNA) is also a substrate for endonucleolytic attack. Pre-incubation of DTx with a 2000-fold excess of NAD, the natural substrate for the toxin's ADP-ribosyltransferase (ADPrT) activity, inhibited the transfer of radiolabeled ADP-ribose to elongation factor 2 but had no effect on the degradation of radiolabeled DNA. Based on this result and the fact that compounds known to inhibit the ADPrT activity of DTx had no effect on its nuclease activity and pre-incubation of DTx with DNA had no effect on ADPrT activity, we conclude that the ADPrT and nuclease active sites of DTx are functionally and spatially distinct. Moreover, studies with an ADPrT-inactivated form of DTx indicate that nuclease activity alone can lead to target cell lysis. PMID:15680246

Lee, Jason W; Nakamura, Lawrence T; Chang, Michael P; Wisnieski, Bernadine J

2005-02-14

352

Anthrax Sampling and Decontamination: Technology Trade-Offs  

SciTech Connect

The goal of this project was to answer the following questions concerning response to a future anthrax release (or suspected release) in a building: 1. Based on past experience, what rules of thumb can be determined concerning: (a) the amount of sampling that may be needed to determine the extent of contamination within a given building; (b) what portions of a building should be sampled; (c) the cost per square foot to decontaminate a given type of building using a given method; (d) the time required to prepare for, and perform, decontamination; (e) the effectiveness of a given decontamination method in a given type of building? 2. Based on past experience, what resources will be spent on evaluating the extent of contamination, performing decontamination, and assessing the effectiveness of the decontamination in abuilding of a given type and size? 3. What are the trade-offs between cost, time, and effectiveness for the various sampling plans, sampling methods, and decontamination methods that have been used in the past?

Price, Phillip N.; Hamachi, Kristina; McWilliams, Jennifer; Sohn, Michael D.

2008-09-12

353

Dissemination Bottleneck in a Murine Model of Inhalational Anthrax  

PubMed Central

Inhalational anthrax is caused by the sporulating bacterium Bacillus anthracis. A current model for progression in mammalian hosts includes inhalation of bacterial spores, phagocytosis of spores in the nasal mucosa-associated lymphoid tissue (NALT) and lungs by macrophages and dendritic cells, trafficking of phagocytes to draining lymph nodes, germination of spores and multiplication of vegetative bacteria in the NALT and lymph nodes, and dissemination of bacteria via the bloodstream to multiple organs. In previous studies, the kinetics of infection varied greatly among mice, leading us to hypothesize the existence of a bottleneck past which very few spores (perhaps only one) progress to allow the infection to proceed. To test this hypothesis, we engineered three strains of B. anthracis Sterne, each marked with a different fluorescent protein, enabling visual differentiation of strains grown on plates. Mice were infected with a mixture of the three strains, the infection was allowed to proceed, and the strains colonizing the organs were identified. Although the inoculum consisted of approximately equal numbers of each of the three strains, the distal organs were consistently colonized by a majority of only one of the three strains, with the dominant strain varying among animals. Such dominance of one strain over the other two was also found at early time points in the cervical lymph nodes but not in the mediastinal lymph nodes. These results support the existence of a bottleneck in the infectious process.

Plaut, Roger D.; Kelly, Vanessa K.; Lee, Gloria M.; Stibitz, Scott

2012-01-01

354

Molecular imaging and therapy of cancer with radiolabeled nanoparticles  

PubMed Central

Summary This review summarizes the current state-of-the-art of radiolabeled nanoparticles for molecular imaging and internal radiotherapy applications targeting cancer. With the capacity to provide enormous flexibility, radiolabeled nanoparticles have the potential to profoundly impact disease diagnosis and patient management in the near future. Currently, the major challenges facing the research on radiolabeled nanoparticles are desirable (tumor) targeting efficacy, robust chemistry for both radionuclide encapsulation/incorporation and targeting ligand conjugation, favorable safety profile, as well as certain commercial and regulatory hurdles.

Hong, Hao; Zhang, Yin; Sun, Jiangtao; Cai, Weibo

2009-01-01

355

In vitro binding of anthrax protective antigen on bacteriophage T4 capsid surface through Hoc-capsid interactions: A strategy for efficient display of large full-length proteins  

SciTech Connect

An in vitro binding system is described to display large full-length proteins on bacteriophage T4 capsid surface at high density. The phage T4 icosahedral capsid features 155 copies of a nonessential highly antigenic outer capsid protein, Hoc, at the center of each major capsid protein hexon. Gene fusions were engineered to express the 83-kDa protective antigen (PA) from Bacillus anthracis fused to the N-terminus of Hoc and the 130-kDa PA-Hoc protein was expressed in Escherichia coli and purified. The purified PA-Hoc was assembled in vitro on hoc {sup -} phage particles. Binding was specific, stable, and of high affinity. This defined in vitro system allowed manipulation of the copy number of displayed PA and imposed no significant limitation on the size of the displayed antigen. In contrast to in vivo display systems, the in vitro approach allows all the capsid binding sites to be occupied by the 130-kDa PA-Hoc fusion protein. The PA-T4 particles were immunogenic in mice in the absence of an adjuvant, eliciting strong PA-specific antibodies and anthrax lethal toxin neutralizing antibodies. The in vitro display on phage T4 offers a novel platform for potential construction of customized vaccines against anthrax and other infectious diseases.

Shivachandra, Sathish B. [Department of Biology, 103 McCort Ward Hall, Catholic University of America, 620 Michigan Ave., NE, Washington, DC 20064 (United States); Rao, Mangala [Division of Retrovirology, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910 (United States); Janosi, Laszlo [Division of Retrovirology, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910 (United States); Sathaliyawala, Taheri [Department of Biology, 103 McCort Ward Hall, Catholic University of America, 620 Michigan Ave., NE, Washington, DC 20064 (United States); Matyas, Gary R. [Division of Retrovirology, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910 (United States); Alving, Carl R. [Division of Retrovirology, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910 (United States); Leppla, Stephen H. [Bacterial Toxins and Therapeutics Section, National Institute of Allergy and Infectious Diseases, NIH, 30 Convent Dr., Bethesda, MD 20892 (United States); Rao, Venigalla B. [Department of Biology, 103 McCort Ward Hall, Catholic University of America, 620 Michigan Ave., NE, Washington, DC 20064 (United States)]. E-mail: rao@cua.edu

2006-02-05

356

PemK Toxin of Bacillus anthracis Is a Ribonuclease  

PubMed Central

Bacillus anthracis genome harbors a toxin-antitoxin (TA) module encoding pemI (antitoxin) and pemK (toxin). This study describes the rPemK as a potent ribonuclease with a preference for pyrimidines (C/U), which is consistent with our previous study that demonstrated it as a translational attenuator. The in silico structural modeling of the PemK in conjunction with the site-directed mutagenesis confirmed the role of His-59 and Glu-78 as an acid-base couple in mediating the ribonuclease activity. The rPemK is shown to form a complex with the rPemI, which is in line with its function as a TA module. This rPemI-rPemK complex becomes catalytically inactive when both the proteins interact in a molar stoichiometry of 1. The rPemI displays vulnerability to proteolysis but attains conformational stability only upon rPemK interaction. The pemI-pemK transcript is shown to be up-regulated upon stress induction with a concomitant increase in the amount of PemK and a decline in the PemI levels, establishing the role of these modules in stress. The artificial perturbation of TA interaction could unleash the toxin, executing bacterial cell death. Toward this end, synthetic peptides are designed to disrupt the TA interaction. The peptides are shown to be effective in abrogating TA interaction in micromolar range in vitro. This approach can be harnessed as a potential antibacterial strategy against anthrax in the future.

Agarwal, Shivangi; Mishra, Neeraj Kumar; Bhatnagar, Sonika; Bhatnagar, Rakesh

2010-01-01

357

Suspect vector transmission of human cutaneous anthrax during an animal outbreak in Southern Italy.  

PubMed

During an outbreak of sheep anthrax in Basilicata, southern Italy, the owner of a flock located about 3?km away from the affected farm developed skin lesions attributable to cutaneous anthrax. The DNA extracted from the human scabs confirmed the diagnosis, and a 15-loci multiple locus variable number tandem repeat (VNTR) analysis (MLVA) following single-nucleotide repeat (SNR) analysis yielded the same genotype as that found in the dead sheep. The breeder, who had not had contact with infected or dead animals, reported having been stung by gadflies. PMID:23808978

Fasanella, Antonio; Garofolo, Giuliano; Galella, Michelangelo; Troiano, Pasquale; De Stefano, Carlo; Pace, Lorenzo; Aceti, Angela; Serrecchia, Luigina; Adone, Rosanna

2013-10-01

358

Two anthrax cases with soft tissue infection, severe oedema and sepsis in Danish heroin users  

PubMed Central

Background Anthrax had become extremely rare in Europe, but in 2010 an outbreak of anthrax among heroin users in Scotland increased awareness of contaminated heroin as a source of anthrax. We present the first two Danish cases of injectional anthrax and discuss the clinical presentations, which included both typical and more unusual manifestations. Case presentations The first patient, a 55-year old man with HIV and hepatitis C virus co-infection, presented with severe pain in the right thigh and lower abdomen after injecting heroin into the right groin. Computed tomography and ultrasonographic examination of the abdomen and right thigh showed oedematous thickened peritoneum, distended oedematous mesentery and subcutaneous oedema of the right thigh. At admission the patient was afebrile but within 24 hours he progressed to severe septic shock and abdominal compartment syndrome. Cultures of blood and intraperitoneal fluid grew Bacillus anthracis. The patient was treated with meropenem, clindamycin, ciprofloxacin and metronidazole. Despite maximum supportive care including mechanical ventilation, vasopressor treatment and continuous veno-venous hemodiafiltration the patient died on day four. The second patient, a 39-year old man with chronic hepatitis C virus infection, presented with fever and a swollen right arm after injecting heroin into his right arm. The arm was swollen from the axilla to the wrist with tense and discoloured skin. He was initially septic with low blood pressure but responded to crystalloids. During the first week, swelling progressed and the patient developed massive generalised oedema with a weight gain of 40 kg. When blood cultures grew Bacillus anthracis antibiotic treatment was changed to meropenem, moxifloxacin and metronidazole, and on day 7 hydroxycloroquin was added. The patient responded to treatment and was discharged after 29 days. Conclusions These two heroin-associated anthrax cases from Denmark corroborate that heroin contaminated with anthrax spores may be a continuous source of injectional anthrax across Europe. Clinicians and clinical microbiologists need to stay vigilant and suspect anthrax in patients with a history of heroin use who present with soft tissue or generalised infection. Marked swelling of affected soft tissue or unusual intra-abdominal oedema should strengthen clinical suspicion.

2013-01-01

359

Lung Epithelial Injury by B. Anthracis Lethal Toxin Is Caused by MKK-Dependent Loss of Cytoskeletal Integrity  

PubMed Central

Bacillus anthracis lethal toxin (LT) is a key virulence factor of anthrax and contributes significantly to the in vivo pathology. The enzymatically active component is a Zn2+-dependent metalloprotease that cleaves most isoforms of mitogen-activated protein kinase kinases (MKKs). Using ex vivo differentiated human lung epithelium we report that LT destroys lung epithelial barrier function and wound healing responses by immobilizing the actin and microtubule network. Long-term exposure to the toxin generated a unique cellular phenotype characterized by increased actin filament assembly, microtubule stabilization, and changes in junction complexes and focal adhesions. LT-exposed cells displayed randomly oriented, highly dynamic protrusions, polarization defects and impaired cell migration. Reconstitution of MAPK pathways revealed that this LT-induced phenotype was primarily dependent on the coordinated loss of MKK1 and MKK2 signaling. Thus, MKKs control fundamental aspects of cytoskeletal dynamics and cell motility. Even though LT disabled repair mechanisms, agents such as keratinocyte growth factor or dexamethasone improved epithelial barrier integrity by reducing cell death. These results suggest that co-administration of anti-cytotoxic drugs may be of benefit when treating inhalational anthrax.

Lehmann, Mandy; Noack, Deborah; Wood, Malcolm; Perego, Marta; Knaus, Ulla G.

2009-01-01

360

Internal radiation dosimetry for clinical testing of radiolabeled monoclonal antibodies.  

National Technical Information Service (NTIS)

In gauging the efficacy of radiolabeled monoclonal antibodies in cancer treatment, it is important to know the amount of radiation energy absorbed by tumors and normal tissue per unit administered activity. This paper describes methods for estimating abso...

D. R. Fisher J. S. Durham T. E. Hui R. L. Hill

1990-01-01

361

Strategies to reduce uptake of radiolabeled peptides in the kidneys  

Microsoft Academic Search

Neuroendocrine tumors overexpressing somatostatin receptors can be treated with peptide-receptor radionuclide therapy (PRRT) using 90Y-DOTATOC or 177Lu-DOTATATE. Several other radiolabeled peptides are studied for use in imaging and therapy of other tumors. However, the maximum activity dose that can safely be administered is limited by renal retention of radiolabeled peptides, which can cause kidney failure. The kidney radiation dose can

E. Vegt

2011-01-01

362

Antimicrobial Peptides as Infection Imaging Agents: Better Than Radiolabeled Antibiotics  

PubMed Central

Nuclear medicine imaging techniques offer whole body imaging for localization of number and site of infective foci inspite of limitation of spatial resolution. The innate human immune system contains a large member of important elements including antimicrobial peptides to combat any form of infection. However, development of antibiotics against bacteria progressed rapidly and gained popularity over antimicrobial peptides but even powerful antimicrobials failed to reduce morbidity and mortality due to emergence of mutant strains of bacteria resulting in antimicrobial resistance. Differentiation between infection and inflammation using radiolabeled compounds with nuclear medicine techniques has always been a dilemma which is still to be resolved. Starting from nonspecific tracers to specific radiolabeled tracers, the question is still unanswered. Specific radiolabeled tracers included antibiotics and antimicrobial peptides which bind directly to the bacteria for efficient localization with advanced nuclear medicine equipments. However, there are merits and demerits attributed to each. In the current paper, radiolabeled antibiotics and radiolabeled peptides for infection localization have been discussed starting with the background of primitive nonspecific tracers. Radiolabeled antimicrobial peptides have certain merits compared with labeled antibiotics which make them superior agents for localization of infective focus.

Akhtar, Muammad Saeed; Imran, Muhammad Babar; Nadeem, Muhammad Afzal; Shahid, Abubaker

2012-01-01

363

Use of radiolabeled acetate to evaluate the rate of clearance of cerebral oxidative metabolites  

Microsoft Academic Search

Radiolabel derived from glucose (GLC) has been shown to have different cerebral retention kinetics than radiolabel derived from deoxyglucose (DG). In particular, activated structures with high metabolic rates have more rapid loss of GLC-derived radiolabel than DG-derived radiolabel. Because GLC-derived radiolabel can be lost from the brain glycolytically through lactate or oxidatively through COâ, the cause of the difference between

J. L. Lear; R. Kasliwal; R. A. Duryea

1994-01-01

364

Structural Characterizations of Protein Antigens for The Next- Generation Vaccines Against Anthrax and Plague.  

National Technical Information Service (NTIS)

Two recombinant protein antigens called rPA and F1-V are recommended by the U.S. Army as active pharmaceutical ingredients (API) for the next- generation vaccines to protect the warfighter against aerosolized anthrax and plague. Separate candidate vaccine...

B. Powell W. Ribot J. Adamovicz G. Andrews J. Enama

2004-01-01

365

The Selection of Anthrax Bacilli from Liquids Grossly Contaminated with E. Coli.  

National Technical Information Service (NTIS)

The procedure described is based on the fact that polymyxin B is added in a corresponding concentration to a synthetic medium which permits the growth of E. coli but inhibits the germination of anthrax spores. The antibiotic kills the multiplying E. coli ...

G. Gillissen H. G. Scholz

1965-01-01

366

The Secret Life of the Anthrax Agent Bacillus anthracis: Bacteriophage-Mediated Ecological Adaptations  

Microsoft Academic Search

Ecological and genetic factors that govern the occurrence and persistence of anthrax reservoirs in the environment are obscure. A central tenet, based on limited and often conflicting studies, has long held that growing or vegetative forms of Bacillus anthracis survive poorly outside the mammalian host and must sporulate to survive in the environment. Here, we present evidence of a more

Raymond Schuch; Vincent A. Fischetti; Ramy K. Aziz

2009-01-01

367

Bioterrorism-Related Inhalational Anthrax: Can Extrapolated Adult Guidelines Be Applied to A Pediatric Population?  

Microsoft Academic Search

Objective: Since the 2001 anthrax attacks, an extensive body of literature has evolved, but there has been a limited focus on the management of pediatric-specific issues. We looked at the symptom complexes of all pediatric patients presenting to the emergency department of our hospital during this period and examined whether their presentations would likely allow cur- rent guidelines to be

Dan Hanfling; John M. Howell; Thom A. Mayer

2007-01-01

368

Vaccine-induced protection against anthrax in cheetah ( Acinonyx jubatus) and black rhinoceros ( Diceros bicornis)  

Microsoft Academic Search

Institution of a policy of vaccination in endangered species with a vaccine not previously administered to it cannot be undertaken lightly. This applies even more in the case of cheetah (Acinonyx jubatus) with their unusually monomorphic gene pool and the potential restrictions this places on their immune responses. However, the recently observed mortalities from anthrax in these animals in the

P. C. B Turnbull; B. W Tindall; J. D Coetzee; C. M Conradie; R. L Bull; P. M Lindeque; O. J. B Huebschle

2004-01-01

369

Modeling the optimum duration of antibiotic prophylaxis in an anthrax outbreak  

Microsoft Academic Search

A critical consideration in effective and measured public health responses to an outbreak of inhalational anthrax is the optimum duration of antibiotic prophylaxis. We develop a competing-risks model to address the duration of antibiotic prophylaxis and the incubation period that accounts for the risks of spore germination and spore clearance. The model predicts the incubation period distribution, which is confirmed

Ron Brookmeyer; Elizabeth Johnson; Robert Bollinger

2003-01-01

370

9 CFR 311.10 - Anaplasmosis, anthrax, babesiosis, bacillary hemoglobinuria in cattle, blackleg, bluetongue...  

Code of Federal Regulations, 2010 CFR

9 Ç Animals and Animal Products Ç 2 Ç 2013-01-01 Ç 2013-01-01 Ç false Ç Anaplasmosis, anthrax, babesiosis, bacillary hemoglobinuria in cattle, blackleg, bluetongue, hemorrhagic septicemia, icterohematuria in sheep, infectious bovine rhinotracheitis, leptospirosis, malignant epizootic...

2013-01-01

371

9 CFR 311.10 - Anaplasmosis, anthrax, babesiosis, bacillary hemoglobinuria in cattle, blackleg, bluetongue...  

Code of Federal Regulations, 2013 CFR

9 Ç Animals and Animal Products Ç 2 Ç 2014-01-01 Ç 2014-01-01 Ç false Ç Anaplasmosis, anthrax, babesiosis, bacillary hemoglobinuria in cattle, blackleg, bluetongue, hemorrhagic septicemia, icterohematuria in sheep, infectious bovine rhinotracheitis, leptospirosis, malignant epizootic...

2014-01-01

372

9 CFR 311.10 - Anaplasmosis, anthrax, babesiosis, bacillary hemoglobinuria in cattle, blackleg, bluetongue...  

Code of Federal Regulations, 2010 CFR

9 Ç Animals and Animal Products Ç 2 Ç 2007-01-01 Ç 2007-01-01 Ç false Ç Anaplasmosis, anthrax, babesiosis, bacillary hemoglobinuria in cattle, blackleg, bluetongue, hemorrhagic septicemia, icterohematuria in sheep, infectious bovine rhinotracheitis, leptospirosis, malignant epizootic...

2007-01-01

373

Comprehensive systematic surveillance for adverse effects of Anthrax Vaccine Adsorbed, US Armed Forces, 1998–2000  

Microsoft Academic Search

Routine vaccinations of US military personnel with Anthrax Vaccine Adsorbed began in 1998. To systematically identify clinical diagnoses reported more frequently after vaccination than before, all military personnel were retrospectively assigned to pre- or post-vaccination cohorts. Cohort assignments were based on vaccination statuses each day of the 3-year surveillance period. For each cohort, rates of hospitalizations and ambulatory visits for

Jeffrey L. Lange; Sandra E. Lesikar; Mark V. Rubertone; John F. Brundage

2003-01-01

374

ACOG committee opinion #268. management of asymptomatic pregnant or lactating women exposed to anthrax  

Microsoft Academic Search

Anthrax infections are diagnosed by isolating Bacillus anthracis from body fluids or by measuring specific antibodies in the blood of persons suspected to have the disease. It is recommended that asymptomatic pregnant and lactating women who have been exposed to a confirmed environmental contamination or a high-risk source as determined by the local Department of Health (not the women's health

2002-01-01

375

Protective Immunization Against Inhalational Anthrax: A Comparison of Minimally Invasive Delivery Platforms.  

National Technical Information Service (NTIS)

A new anthrax vaccine under clinical investigation is based on recombinant Bacillus anthracis protective antigen (rPA). Here, we investigated microneedle-based cutaneous and nasal mucosal delivery of rPA in mice and rabbits. In mice, intradermal (id) deli...

J. A. Mikszta V. J. Sullivan C. Dean A. M. Waterston J. B. Alarcon

2004-01-01

376

Death due to bioterrorism-related inhalational anthrax: report of 2 patients.  

PubMed

On October 9, 2001, a letter containing anthrax spores was mailed from New Jersey to Washington, DC. The letter was processed at a major postal facility in Washington, DC, and opened in the Senate's Hart Office Building on October 15. Between October 19 and October 26, there were 5 cases of inhalational anthrax among postal workers who were employed at that major facility or who handled bulk mail originating from that facility. The cases of 2 postal workers who died of inhalational anthrax are reported here. Both patients had nonspecific prodromal illnesses. One patient developed predominantly gastrointestinal symptoms, including nausea, vomiting, and abdominal pain. The other patient had a "flulike" illness associated with myalgias and malaise. Both patients ultimately developed dyspnea, retrosternal chest pressure, and respiratory failure requiring mechanical ventilation. Leukocytosis and hemoconcentration were noted in both cases prior to death. Both patients had evidence of mediastinitis and extensive pulmonary infiltrates late in their course of illness. The durations of illness were 7 days and 5 days from onset of symptoms to death; both patients died within 24 hours of hospitalization. Without a clinician's high index of suspicion, the diagnosis of inhalational anthrax is difficult during nonspecific prodromal illness. Clinicians have an urgent need for prompt communication of vital epidemiologic information that could focus their diagnostic evaluation. Rapid diagnostic assays to distinguish more common infectious processes from agents of bioterrorism also could improve management strategies. PMID:11722269

Borio, L; Frank, D; Mani, V; Chiriboga, C; Pollanen, M; Ripple, M; Ali, S; DiAngelo, C; Lee, J; Arden, J; Titus, J; Fowler, D; O'Toole, T; Masur, H; Bartlett, J; Inglesby, T

2001-11-28

377

Enhancement of the Anthrax AVA Vaccine with CpG ODN's.  

National Technical Information Service (NTIS)

A clinical study 'Phase 1/2, Proof-of-Concept, Double-Blind, Randomized, Controlled Trial Assessing the Immunogenicity and Safety of Anthrax Vaccine Adsorbed (BioThrax), Combined with CPG 7909 in Normal Volunteers,' was completed and presented at the 2005...

A. M. Krieg I. Sim

2005-01-01

378

Ciguatera Toxin Information Website  

NSDL National Science Digital Library

This website provides information about the marine toxin disease Ciguatera, which is caused by the consumption of fish that have accumulated ciguatoxin in their tissues. The toxin is produced by a microscopic dinoflagellate (Gambierdiscus toxicus) that lives on the surfaces of macroalgae in coral reef ecosystems. The dinoflagellates are inadvertently consumed by herbivorous fish during grazing and the toxins bioaccumulate in the food chain, attaining highest levels in carnivores. The site includes an introduction to ciguatera, information about the symptoms with links to reported cases and medical treatments, non-medical solutions, an education section, list of retailers, news releases, related links, and more. The site is published by ToxiTech, suppliers of Cigua-CheckÃ, which is a commercially available test kit for screening fish for ciguatoxin prior to consumption.

Toxitech; Oceanit

379

Killer toxin of Hanseniaspora uvarum  

Microsoft Academic Search

The yeast Hanseniaspora uvarum liberates a killer toxin lethal to sensitive strains of the species Saccharomyces cerevisiae. Secretion of this killer toxin was inhibited by tunicamycin, an inhibitor of N-glycosylation, although the mature killer protein did not show any detectable carbohydrate structures. Culture supernatants of the killer strain were concentrated by ultrafiltration and the extracellular killer toxin was precipitated with

F. Radler; M. J. Schmitt; Brigitte Meyer

1990-01-01

380

Toxin plasmids of Clostridium perfringens.  

PubMed

In both humans and animals, Clostridium perfringens is an important cause of histotoxic infections and diseases originating in the intestines, such as enteritis and enterotoxemia. The virulence of this Gram-positive, anaerobic bacterium is heavily dependent upon its prolific toxin-producing ability. Many of the ?16 toxins produced by C. perfringens are encoded by large plasmids that range in size from ?45 kb to ?140 kb. These plasmid-encoded toxins are often closely associated with mobile elements. A C. perfringens strain can carry up to three different toxin plasmids, with a single plasmid carrying up to three distinct toxin genes. Molecular Koch's postulate analyses have established the importance of several plasmid-encoded toxins when C. perfringens disease strains cause enteritis or enterotoxemias. Many toxin plasmids are closely related, suggesting a common evolutionary origin. In particular, most toxin plasmids and some antibiotic resistance plasmids of C. perfringens share an ?35-kb region containing a Tn916-related conjugation locus named tcp (transfer of clostridial plasmids). This tcp locus can mediate highly efficient conjugative transfer of these toxin or resistance plasmids. For example, conjugative transfer of a toxin plasmid from an infecting strain to C. perfringens normal intestinal flora strains may help to amplify and prolong an infection. Therefore, the presence of toxin genes on conjugative plasmids, particularly in association with insertion sequences that may mobilize these toxin genes, likely provides C. perfringens with considerable virulence plasticity and adaptability when it causes diseases originating in the gastrointestinal tract. PMID:23699255

Li, Jihong; Adams, Vicki; Bannam, Trudi L; Miyamoto, Kazuaki; Garcia, Jorge P; Uzal, Francisco A; Rood, Julian I; McClane, Bruce A

2013-06-01

381

Toxin Plasmids of Clostridium perfringens  

PubMed Central

SUMMARY In both humans and animals, Clostridium perfringens is an important cause of histotoxic infections and diseases originating in the intestines, such as enteritis and enterotoxemia. The virulence of this Gram-positive, anaerobic bacterium is heavily dependent upon its prolific toxin-producing ability. Many of the ?16 toxins produced by C. perfringens are encoded by large plasmids that range in size from ?45 kb to ?140 kb. These plasmid-encoded toxins are often closely associated with mobile elements. A C. perfringens strain can carry up to three different toxin plasmids, with a single plasmid carrying up to three distinct toxin genes. Molecular Koch's postulate analyses have established the importance of several plasmid-encoded toxins when C. perfringens disease strains cause enteritis or enterotoxemias. Many toxin plasmids are closely related, suggesting a common evolutionary origin. In particular, most toxin plasmids and some antibiotic resistance plasmids of C. perfringens share an ?35-kb region containing a Tn916-related conjugation locus named tcp (transfer of clostridial plasmids). This tcp locus can mediate highly efficient conjugative transfer of these toxin or resistance plasmids. For example, conjugative transfer of a toxin plasmid from an infecting strain to C. perfringens normal intestinal flora strains may help to amplify and prolong an infection. Therefore, the presence of toxin genes on conjugative plasmids, particularly in association with insertion sequences that may mobilize these toxin genes, likely provides C. perfringens with considerable virulence plasticity and adaptability when it causes diseases originating in the gastrointestinal tract.

Li, Jihong; Adams, Vicki; Bannam, Trudi L.; Miyamoto, Kazuaki; Garcia, Jorge P.; Uzal, Francisco A.; Rood, Julian I.

2013-01-01

382

Identification of Toxin A-Negative, Toxin B-Positive Clostridium difficile by PCR  

Microsoft Academic Search

Toxigenic strains of Clostridium difficile have been reported to produce both toxins A and B nearly always, and nontoxigenic strains have been reported to produce neither of these toxins. Recent studies indicate that it is not always true. We established a PCR assay to differentiate toxin A-negative, toxin B-positive (toxin A2, toxin B1) strains from both toxin-positive (toxin A1, toxin

HARU KATO; NAOKI KATO; KUNITOMO WATANABE; NAOICHI IWAI; HARUHI NAKAMURA; TOSHINOBU YAMAMOTO; KANZO SUZUKI; SHIN-MOO KIM; YUNSOP CHONG; EDDY BAGUS WASITO

1998-01-01

383

9 CFR 310.9 - Anthrax; carcasses not to be eviscerated; disposition of affected carcasses; hides, hoofs, horns...  

Code of Federal Regulations, 2010 CFR

Anthrax; carcasses not to be eviscerated; disposition of affected carcasses; hides, hoofs, horns, hair, viscera and contents, and fat; handling of blood and scalding vat water; general cleanup and disinfection. 310.9 Section 310.9 Animals and Animal...

2006-01-01

384

Disease-enhancing antibodies improve the efficacy of bacterial toxin-neutralizing antibodies  

PubMed Central

SUMMARY During infection, humoral immunity produces a polyclonal response with various immunoglobulins recognizing different epitopes within the microbe or toxin. Despite this diverse response, the biological activity of an antibody (Ab) is usually assessed by the action of a monoclonal population. We demonstrate that a combination of monoclonal antibodies (mAbs) that are individually disease-enhancing or neutralizing to Bacillus anthracis protective antigen (PA), a component of anthrax toxin, results in significantly augmented protection against the toxin. This boosted protection is Fc gamma receptor (Fc?R)-dependent and involves the formation of stoichiometrically defined mAb-PA complexes that requires immunoglobulin bivalence and simultaneous interaction between PA and the two mAbs. The formation of these mAb-PA complexes inhibits PA oligomerization, resulting in protection. These data suggest that functional assessments of single Abs may inaccurately predict how the same Abs will operate in polyclonal preparations and imply that potentially therapeutic mAbs may be overlooked in single Ab screens.

Chow, Siu-Kei; Smith, Cameron; MacCarthy, Thomas; Pohl, Mary Ann; Bergman, Aviv; Casadevall, Arturo

2013-01-01

385

Bacillus anthracis lethal toxin induces TNF-?-independent hypoxia-mediated toxicity in mice  

PubMed Central

Bacillus anthracis lethal toxin (LT) is the major virulence factor of anthrax and reproduces most of the laboratory manifestations of the disease in animals. We studied LT toxicity in BALB/cJ and C57BL/6J mice. BALB/cJ mice became terminally ill earlier and with higher frequency than C57BL/6J mice. Timed histopathological analysis identified bone marrow, spleen, and liver as major affected organs in both mouse strains. LT induced extensive hypoxia. Crisis was due to extensive liver necrosis accompanied by pleural edema. There was no evidence of disseminated intravascular coagulation or renal dysfunction. Instead, analyses revealed hepatic dysfunction, hypoalbuminemia, and vascular/oxygenation insufficiency. Of 50 cytokines analyzed, BALB/cJ mice showed rapid but transitory increases in specific factors including KC, MCP-1/JE, IL-6, MIP-2, G-CSF, GM-CSF, eotaxin, FasL, and IL-1?. No changes in TNF-? occurred. The C57BL/6J mice did not mount a similar cytokine response. These factors were not induced in vitro by LT treatment of toxin-sensitive macrophages. The evidence presented shows that LT kills mice through a TNF-?–independent, FasL-independent, noninflammatory mechanism that involves hypoxic tissue injury but does not require macrophage sensitivity to toxin.

Moayeri, Mahtab; Haines, Diana; Young, Howard A.; Leppla, Stephen H.

2003-01-01

386

De novo asymmetric synthesis of oligo-rhamno di- and tri-saccharides related to the anthrax tetrasaccharide  

PubMed Central

An asymmetric synthesis of the di- and trisaccharide portion of the naturally occurring anthrax tetrasaccharide from acetylfuran has been developed. The construction of the di- and trisaccharide subunits is based upon our previously disclosed route to anthrax tetrasaccharide. The approach uses iterative diastereoselective palladium-catalyzed glycosylations, Luche reductions, diastereoselective dihydroxylations, and regioselective protections for the assembly of the rhamno- di- and tri-saccharide. The route was also modified for the preparation of the mixed D-/L-disaccharide analogue.

Wang, Hua-Yu Leo; Guo, Haibing; O'Doherty, George A.

2013-01-01

387

[Advances in botulinum toxin applications].  

PubMed

Botulinum toxin type A is one of the seven serotype /A-G/ produced by the anerobic bacterium Clostridium botulinum. It is one of the most potent toxins available. Botulinum toxin binds to the motor nerve end-plate and prevents acetylcholin release, causing presynaptic neuromuscular blockade. The toxin is being increasingly used in the treatment of several form of disorders characterized by excessive or inappropriate muscle contraction, including stroke, cerebral palsy, multiple sclerosis. Botulinum toxin type A has brought a new approach to the effective treatment of dystonias. It has demonstrated additional analgesic effect. Among recently describes applications are the treatment of tics, tremors, hyperhydrosis, myoclonus, etc. PMID:10598494

Zaleski, P

1999-09-01

388

Uremia Toxin Assay.  

National Technical Information Service (NTIS)

The purpose of the research was to find assay systems which could be used in attempts to isolate the supposed toxins of uremia. A total of 14 enzyme assay systems were tested against fractions of plasma, dialysate, and urine from both uremic subjects unde...

C. E. Cook

1970-01-01

389

Diffusion of Botulinum Toxins  

PubMed Central

Background It is generally agreed that diffusion of botulinum toxin occurs, but the extent of the spread and its clinical importance are disputed. Many factors have been suggested to play a role but which have the most clinical relevance is a subject of much discussion. Methods This review discusses the variables affecting diffusion, including protein composition and molecular size as well as injection factors (e.g., volume, dose, injection method). It also discusses data on diffusion from comparative studies in animal models and human clinical trials that illustrate differences between the available botulinum toxin products (onabotulinumtoxinA, abobotulinumtoxinA, incobotulinumtoxinA, and rimabotulinumtoxinB). Results Neither molecular weight nor the presence of complexing proteins appears to affect diffusion; however, injection volume, concentration, and dose all play roles and are modifiable. Both animal and human studies show that botulinum toxin products are not interchangeable, and that some products are associated with greater diffusion and higher rates of diffusion-related adverse events than others. Discussion Each of the botulinum toxins is a unique pharmacologic entity. A working knowledge of the different serotypes is essential to avoid unwanted diffusion-related adverse events. In addition, clinicians should be aware that the factors influencing diffusion may range from properties intrinsic to the drug to accurate muscle selection as well as dilution, volume, and dose injected.

Brodsky, Matthew A.; Swope, David M.; Grimes, David

2012-01-01

390

CYANOBACTERIA AND THEIR TOXINS.  

EPA Science Inventory

Science Questions Harmful algal blooms (HAB) of cyanobacteria, also known as blue-green algae, have recently become more spatially and temporally prevalent in the US and worldwide. Cyanobacteria and their highly potent toxins are a significant hazard for human health and ...

391

CYANOBACTERIA AND THEIR TOXINS  

EPA Science Inventory

Science Questions Harmful algal blooms (HAB) of cyanobacteria, also known as blue-green algae, have recently become more spatially and temporally prevalent in the US and worldwide. Cyanobacteria and their highly potent toxins are a significant hazard for human health and ...

392

[Cytolethal distending toxins].  

PubMed

Cytolethal distending toxins (CDT) are intracellularly acting proteins which interfere with the eukaryotic cell cycle. They are produced by Gram-negative bacteria with affinity to mucocutaneous surfaces and could play a role in the pathogenesis of various mammalian diseases. The functional toxin is composed of three proteins: CdtB entering the nucleus and by its nuclease activity inducing nuclear fragmentation and chromatin disintegration, CdtA, and CdtC, the two latter being responsible for toxin attachment to the surface of the target cell. Cytotoxic effect of CDT leads to the cell cycle arrest before the cell enters mitosis and to further changes (cell distension and death, apoptosis) depending on the cell type. Thus, CDT may function as a virulence factor in pathogenic bacteria that produce it and thus may contribute to the initiation of certain diseases. Most important are inflammatory bowel diseases caused by intestinal bacteria, periodontitis with Aggregatibacter actinomycetemcomitans as the aetiologic agent and ulcus molle where Haemophilus ducreyi is the causative agent. Keywords: cytolethal distending toxin - CDT - virulence factor - Gram-negative bacteria. PMID:25025680

Curová, K; Kme?ová, M; Siegfried, L

2014-01-01

393

A High-Affinity Monoclonal Antibody to Anthrax Protective Antigen Passively Protects Rabbits before and after Aerosolized Bacillus anthracis Spore Challenge  

Microsoft Academic Search

We have developed a therapeutic for the treatment of anthrax using an affinity-enhanced monoclonal antibody (ETI-204) to protective antigen (PA), which is the central cell-binding component of the anthrax exotoxins. ETI-204 administered preexposure by a single intravenous injection of a dose of between 2.5 and 10 mg per animal significantly protected rabbits from a lethal aerosolized anthrax spore challenge (60

Nehal Mohamed; Michelle Clagett; Juan Li; Steven Jones; Steven Pincus; Giovanni D'Alia; Linda Nardone; Michael Babin; George Spitalny; Leslie Casey

2005-01-01

394

Changing Patterns of Human Anthrax in Azerbaijan during the Post-Soviet and Preemptive Livestock Vaccination Eras.  

PubMed

We assessed spatial and temporal changes in the occurrence of human anthrax in Azerbaijan during 1984 through 2010. Data on livestock outbreaks, vaccination efforts, and human anthrax incidence during Soviet governance, post-Soviet governance, preemptive livestock vaccination were analyzed. To evaluate changes in the spatio-temporal distribution of anthrax, we used a combination of spatial analysis, cluster detection, and weighted least squares segmented regression. Results indicated an annual percent change in incidence of +11.95% from 1984 to 1995 followed by declining rate of -35.24% after the initiation of livestock vaccination in 1996. Our findings also revealed geographic variation in the spatial distribution of reporting; cases were primarily concentrated in the west early in the study period and shifted eastward as time progressed. Over twenty years after the dissolution of the Soviet Union, the distribution of human anthrax in Azerbaijan has undergone marked changes. Despite decreases in the incidence of human anthrax, continued control measures in livestock are needed to mitigate its occurrence. The shifting patterns of human anthrax highlight the need for an integrated "One Health" approach that takes into account the changing geographic distribution of the disease. PMID:25032701

Kracalik, Ian; Abdullayev, Rakif; Asadov, Kliment; Ismayilova, Rita; Baghirova, Mehriban; Ustun, Narmin; Shikhiyev, Mazahir; Talibzade, Aydin; Blackburn, Jason K

2014-07-01

395

Changing Patterns of Human Anthrax in Azerbaijan during the Post-Soviet and Preemptive Livestock Vaccination Eras  

PubMed Central

We assessed spatial and temporal changes in the occurrence of human anthrax in Azerbaijan during 1984 through 2010. Data on livestock outbreaks, vaccination efforts, and human anthrax incidence during Soviet governance, post-Soviet governance, preemptive livestock vaccination were analyzed. To evaluate changes in the spatio-temporal distribution of anthrax, we used a combination of spatial analysis, cluster detection, and weighted least squares segmented regression. Results indicated an annual percent change in incidence of +11.95% from 1984 to 1995 followed by declining rate of ?35.24% after the initiation of livestock vaccination in 1996. Our findings also revealed geographic variation in the spatial distribution of reporting; cases were primarily concentrated in the west early in the study period and shifted eastward as time progressed. Over twenty years after the dissolution of the Soviet Union, the distribution of human anthrax in Azerbaijan has undergone marked changes. Despite decreases in the incidence of human anthrax, continued control measures in livestock are needed to mitigate its occurrence. The shifting patterns of human anthrax highlight the need for an integrated “One Health” approach that takes into account the changing geographic distribution of the disease.

Kracalik, Ian; Abdullayev, Rakif; Asadov, Kliment; Ismayilova, Rita; Baghirova, Mehriban; Ustun, Narmin; Shikhiyev, Mazahir; Talibzade, Aydin; Blackburn, Jason K.

2014-01-01

396

Binding of a radiolabeled sea anemone cytolysin to erythrocyte membranes.  

PubMed

Stichodactyla helianthus cytolysin III, a 17 kDa basic polypeptide isolated from a Caribbean sea anemone, is one of the most potent hemolysins yet found in a living organism. This toxin has been reported to form new ion channels in artificial lipid bilayer membranes. The ability of this toxin to attack cell membranes is greatly enhanced by the presence of sphingomyelin. In order to investigate the mechanism by which the cytolysin causes cell lysis, we have prepared a highly active [3H]cytolysin derivative by reductive methylation with sodium cyanoborohydride and [3H]formaldehyde. A dimethylated toxin derivative was used to investigate the basis for the differential lytic activity of this polypeptide upon erythrocytes from six mammalian species. Using both direct [3H]toxin binding and indirect (Thron method) binding techniques, we found that the interspecies differences are due to variable membrane susceptibilities toward the bound toxin, rather than to differences in membrane affinity for the toxin. Similarly, we showed the enhanced lytic activity of the toxin for rat erythrocytes at elevated pH to be caused by enhanced activity of the bound toxin. PMID:2574996

Doyle, J W; Kem, W R

1989-12-28

397

Mechanisms of NK Cell-Macrophage Bacillus anthracis Crosstalk: A Balance between Stimulation by Spores and Differential Disruption by Toxins  

PubMed Central

NK cells are important immune effectors for preventing microbial invasion and dissemination, through natural cytotoxicity and cytokine secretion. Bacillus anthracis spores can efficiently drive IFN-? production by NK cells. The present study provides insights into the mechanisms of cytokine and cellular signaling that underlie the process of NK-cell activation by B. anthracis and the bacterial strategies to subvert and evade this response. Infection with non-toxigenic encapsulated B. anthracis induced recruitment of NK cells and macrophages into the mouse draining lymph node. Production of edema (ET) or lethal (LT) toxin during infection impaired this cellular recruitment. NK cell depletion led to accelerated systemic bacterial dissemination. IFN-? production by NK cells in response to B. anthracis spores was: i) contact-dependent through RAE-1-NKG2D interaction with macrophages; ii) IL-12, IL-18, and IL-15-dependent, where IL-12 played a key role and regulated both NK cell and macrophage activation; and iii) required IL-18 for only an initial short time window. B. anthracis toxins subverted both NK cell essential functions. ET and LT disrupted IFN-? production through different mechanisms. LT acted both on macrophages and NK cells, whereas ET mainly affected macrophages and did not alter NK cell capacity of IFN-? secretion. In contrast, ET and LT inhibited the natural cytotoxicity function of NK cells, both in vitro and in vivo. The subverting action of ET thus led to dissociation in NK cell function and blocked natural cytotoxicity without affecting IFN-? secretion. The high efficiency of this process stresses the impact that this toxin may exert in anthrax pathogenesis, and highlights a potential usefulness for controlling excessive cytotoxic responses in immunopathological diseases. Our findings therefore exemplify the delicate balance between bacterial stimulation and evasion strategies. This highlights the potential implication of the crosstalk between host innate defences and B. anthracis in initial anthrax control mechanisms.

Klezovich-Benard, Maria; Corre, Jean-Philippe; Jusforgues-Saklani, Helene; Fiole, Daniel; Burjek, Nick; Tournier, Jean-Nicolas; Goossens, Pierre L.

2012-01-01

398

Environmental Technology Verification Report: Tetracore Inc., Anthrax, Botulinum Toxin, and Ricin Enzyme-Linked Immunosorbent Assay (ELISA).  

National Technical Information Service (NTIS)

The U.S. Environmental Protection Agency (EPA) supports the Environmental Technology Verification (ETV) Program to facilitate the deployment of innovative environmental technologies through performance verification and dissemination of information. The go...

A. Dindal K. Riggs R. James Z. Willenberg

2004-01-01

399

AN ENVIRONMENTAL TECHNOLOGY VERIFICATION (ETV) TESTING OF THREE IMMUNOASSAY TEST KITS FOR ANTHRAX, BOTULINUM TOXIN AND RICIN  

EPA Science Inventory

Immunoassay test kits are based on immunoassay methods, where specific antibodies are used to detect and measure the contaminants of interest. Immunoassay test kits rely on the reaction of a contaminant or antigen with a selective antibody to give a product that can be measures....

400

Thioamide Hydroxypyrothiones Supersede Amide Hydroxypyrothiones in Potency Against Anthrax Lethal Factor  

PubMed Central

Anthrax lethal factor (LF) is a critical virulence factor in the pathogenesis of anthrax. A structure-activity relationship (SAR) of potential lethal factor inhibitors (LFi) is presented in which the zinc-binding group (ZBG), linker, and backbone moieties for a series of hydroxypyrone-based compounds were systematically varied. It was found that hydroxypyrothione ZBGs generate more potent inhibitors than hydroxypyrone ZBGs. Furthermore, coupling the hydroxypyrothione to a backbone group via a thioamide bond improves potency when compared to an amide linker. QM/MM studies show that the thioamide bond in these inhibitors allows for the formation of two additional hydrogen bonds with the protein active site. In both types of hydroxypyrothione compounds, ligand efficiencies of 0.29-0.54 kcal mol-1 per heavy atom were achieved. The results highlight the need for a better understanding to optimize the interplay between the ZBG, linker, and backbone to get improved LFi.

Agrawal, Arpita; de Oliveira, Cesar Augusto F.; Cheng, Yuhui; Jacobsen, Jennifer A.; McCammon, J. Andrew; Cohen, Seth M.

2009-01-01

401

The Anthrax Vaccine Program: an analysis of the CDC's recommendations for vaccine use.  

PubMed

The anthrax vaccine was never proved to be safe and effective. It is one cause of Gulf War illnesses, and recent vaccinees report symptoms resembling Gulf War illnesses. The vaccine's production has been substandard. Without adequate evaluation, the Food and Drug Administration recently approved (retrospectively) significant changes made to the vaccine's composition since 1990. The vaccine's mandatory use for inhalation anthrax is "off-label." A skewed review of the vaccine literature by the Centers for Disease Control and Prevention (CDC) led to remunerative collaborative research with the army, involving civilian volunteers. Despite acknowledging possible fetal harm, the CDC offered the vaccine to children and pregnant women. New trends could weaken prelicensure efficacy and safety review of medical products intended for biodefense and avoid manufacturer liability for their use. PMID:11988433

Nass, Meryl

2002-05-01

402

The Anthrax Vaccine Program: An Analysis of the CDC's Recommendations for Vaccine Use  

PubMed Central

The anthrax vaccine was never proved to be safe and effective. It is one cause of Gulf War illnesses, and recent vaccinees report symptoms resembling Gulf War illnesses. The vaccine's production has been substandard. Without adequate evaluation, the Food and Drug Administration recently approved (retrospectively) significant changes made to the vaccine's composition since 1990. The vaccine's mandatory use for inhalation anthrax is “off-label.” A skewed review of the vaccine literature by the Centers for Disease Control and Prevention (CDC) led to remunerative collaborative research with the army, involving civilian volunteers. Despite acknowledging possible fetal harm, the CDC offered the vaccine to children and pregnant women. New trends could weaken prelicensure efficacy and safety review of medical products intended for biodefense and avoid manufacturer liability for their use.

Nass, Meryl

2002-01-01

403

Special Considerations for Prophylaxis for and Treatment of Anthrax in Pregnant and Postpartum Women  

PubMed Central

In August 2012, the Centers for Disease Control and Prevention, in partnership with the Association of Maternal and Child Health Programs, convened a meeting of national subject matter experts to review key clinical elements of anthrax prevention and treatment for pregnant, postpartum, and lactating (P/PP/L) women. National experts in infectious disease, obstetrics, maternal fetal medicine, neonatology, pediatrics, and pharmacy attended the meeting, as did representatives from professional organizations and national, federal, state, and local agencies. The meeting addressed general principles of prevention and treatment for P/PP/L women, vaccines, antimicrobial prophylaxis and treatment, clinical considerations and critical care issues, antitoxin, delivery concerns, infection control measures, and communication. The purpose of this meeting summary is to provide updated clinical information to health care providers and public health professionals caring for P/PP/L women in the setting of a bioterrorist event involving anthrax.

Zotti, Marianne E.; Creanga, Andreea A.; Misegades, Lara K.; Wako, Etobssie; Treadwell, Tracee A.; Messonnier, Nancy E.; Jamieson, Denise J.

2014-01-01

404

Catastrophic Incident Recovery: Long-Term Recovery from an Anthrax Event Symposium  

SciTech Connect

On March 19, 2008, policy makers, emergency managers, and medical and Public Health officials convened in Seattle, Washington, for a workshop on Catastrophic Incident Recovery: Long-Term Recovery from an Anthrax Event. The day-long symposium was aimed at generating a dialogue about restoration and recovery through a discussion of the associated challenges that impact entire communities, including people, infrastructure, and critical systems.

Lesperance, Ann M.

2008-06-30

405

Randomized, Double-Blind, Placebo-Controlled, Safety and Immunogenicity Study of 4 Formulations of Anthrax Vaccine Adsorbed Plus CPG 7909 (AV7909) in Healthy Adult Volunteers  

PubMed Central

A new anthrax vaccine that could accelerate the immune response and possibly reduce the number of injections needed for protection would be desirable in a post-exposure setting. This Phase 1 study compared the safety and immunogenicity of 2 IM doses (Days 0 and 14) of 4 formulations of AV7909 (AVA plus CPG 7909) with 2 IM doses of BioThrax® (Anthrax Vaccine Adsorbed) and 2 IM doses of saline placebo administered on Days 0 and 14. A total of 105 healthy adults 18 to 50 years of age were randomized to 1 of 6 study groups: BioThrax (0.5 mL), AV7909 Formulation 1 (0.5 mL AVA + 0.5 mg CPG 7909), AV7909 Formulation 2 (0.5 mL AVA + 0.25 mg CPG 7909), AV7909 Formulation 3 (0.25 mL AVA + 0.5 mg CPG 7909), AV7909 Formulation 4 (0.25 mL AVA + 0.25 mg CPG 7909), or saline placebo (0.5 mL). All randomized subjects received at least 1 vaccination, and 100 subjects completed the trial. After 2 doses, mean peak normalized toxin neutralizing antibody responses (TNA NF50) in the AV7909 groups were higher than in the BioThrax group. Differences among the 4 AV7909 groups were not statistically significant. Subjects who received AV7909 reached peak titers on Day 28 vs. Day 35 in the BioThrax group. The most common adverse events (AEs) in the BioThrax and AV7909 groups assessed as related to vaccination were injection site reactions. Transient lymphopenia was observed after the first dose in each AV7909 group. Frequencies of injection site and systemic reactions recorded by subjects in diaries for 7 days after each injection were highest with AV7909 Formulation 1. No AEs of special interest (autoimmune events) were observed in the study. Further studies of doses and dosing regimens are planned to assess the immunogenicity and reactogenicity of AV7909.

Hopkins, Robert J.; Daczkowski, Nancy F.; Kaptur, Paulina E.; Muse, Derek; Sheldon, Eric; LaForce, Craig; Sari, Suha; Rudge, Thomas L.; Bernton, Edward

2013-01-01

406

Advancing role of radiolabeled antibodies in the therapy of cancer  

Microsoft Academic Search

This review focuses on the use of radiolabeled antibodies in the therapy of cancer, termed radioimmunotherapy (RAIT). Basic problems concerned with the choice of antibody, radionuclide, and physiology of the tumor and host are discussed, followed by a review of the pertinent clinical publications of various radioantibody constructs in the treatment of hematopoietic and solid tumors of diverse histopathology, grade,

David M. Goldenberg

2003-01-01

407

Radiolabelled peptides for tumour therapy: current status and future directions  

Microsoft Academic Search

On their plasma membranes, cells express receptor proteins with high affinity for regulatory peptides, such as somatostatin. Changes in the density of these receptors during disease, e.g. overexpression in many tumours, provide the basis for new imaging methods. The first peptide analogues successfully applied for visualisation of receptor-positive tumours were radiolabelled somatostatin analogues. The next step was to label these

Marion de Jong; Dik Kwekkeboom; Roelf Valkema; Eric P. Krenning

2003-01-01