Sample records for radiolabeled anthrax toxins

  1. Radiolabeled antibodies to Bacillus anthracis toxins are bactericidal and partially therapeutic in experimental murine anthrax.

    PubMed

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

    2009-11-01

    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 gamma2b and 10F4 gamma1) and lethal factor (MAb 14FA gamma2b) 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 (188)Re or (213)Bi. In vitro, (213)Bi was more efficient than (188)Re in mediating microbicidal activity against B. anthracis. The administration of MAbs [(213)Bi]10F4 gamma1 and [(213)Bi]14FA gamma2b 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. PMID:19704133

  2. Anthrax toxin receptor proteins

    Microsoft Academic Search

    Kenneth A. Bradley; John A. T. Young

    2003-01-01

    Anthrax toxin is a key virulence factor for Bacillus anthracis, the causative agent of anthrax. Here we discuss what is known about the anthrax toxin receptor (ATR), the cellular receptor for anthrax toxin, and how this information is being used to develop treatments for anthrax as well as to understand aspects of cancer. ATR was identified recently as a type

  3. Anthrax toxins.

    PubMed

    Mourez, M

    2004-01-01

    Bacillus anthracis, the etiological agent of anthrax, secretes three polypeptides that assemble into toxic complexes on the cell surfaces of the host it infects. One of these polypeptides, protective antigen (PA), binds to the integrin-like domains of ubiquitously expressed membrane proteins of mammalian cells. PA is then cleaved by membrane endoproteases of the furin family. Cleaved PA molecules assemble into heptamers, which can then associate with the two other secreted polypeptides: edema factor (EF) and/or lethal factor (LF). The heptamers of PA are relocalized to lipid rafts where they are quickly endocytosed and routed to an acidic compartment. The low pH triggers a conformational change in the heptamers, resulting in the formation of cation-specific channels and the translocation of EF/LF. EF is a calcium- and calmodulin-dependent adenylate cyclase that dramatically raises the intracellular concentration of cyclic adenosine monophosphate (cAMP). LF is a zinc-dependent endoprotease that cleaves the amino terminus of mitogen-activated protein kinase kinases (Meks). Cleaved Meks cannot bind to their substrates and have reduced kinase activity, resulting in alterations of the signaling pathways they govern. The structures of PA, PA heptamer, EF, and LF have been solved and much is now known about the molecular details of the intoxication mechanism. The in vivo action of the toxins, on the other hand, is still poorly understood and hotly debated. A better understanding of the toxins will help in the design of much-needed anti-toxin drugs and the development of new toxin-based medical applications. PMID:15549606

  4. Targeted Silencing of Anthrax Toxin Receptors Protects against Anthrax Toxins*

    PubMed Central

    Arévalo, Maria T.; Navarro, Ashley; Arico, Chenoa D.; Li, Junwei; Alkhatib, Omar; Chen, Shan; Diaz-Arévalo, Diana; Zeng, Mingtao

    2014-01-01

    Anthrax spores can be aerosolized and dispersed as a bioweapon. Current postexposure treatments are inadequate at later stages of infection, when high levels of anthrax toxins are present. Anthrax toxins enter cells via two identified anthrax toxin receptors: tumor endothelial marker 8 (TEM8) and capillary morphogenesis protein 2 (CMG2). We hypothesized that host cells would be protected from anthrax toxins if anthrax toxin receptor expression was effectively silenced using RNA interference (RNAi) technology. Thus, anthrax toxin receptors in mouse and human macrophages were silenced using targeted siRNAs or blocked with specific antibody prior to challenge with anthrax lethal toxin. Viability assays were used to assess protection in macrophages treated with specific siRNA or antibody as compared with untreated cells. Silencing CMG2 using targeted siRNAs provided almost complete protection against anthrax lethal toxin-induced cytotoxicity and death in murine and human macrophages. The same results were obtained by prebinding cells with specific antibody prior to treatment with anthrax lethal toxin. In addition, TEM8-targeted siRNAs also offered significant protection against lethal toxin in human macrophage-like cells. Furthermore, silencing CMG2, TEM8, or both receptors in combination was also protective against MEK2 cleavage by lethal toxin or adenylyl cyclase activity by edema toxin in human kidney cells. Thus, anthrax toxin receptor-targeted RNAi has the potential to be developed as a life-saving, postexposure therapy against anthrax. PMID:24742682

  5. Anthrax Toxin Receptor 2Dependent Lethal Toxin Killing In Vivo

    E-print Network

    Sejnowski, Terrence J.

    Anthrax Toxin Receptor 2­Dependent Lethal Toxin Killing In Vivo Heather M. Scobie1,2 , Darran J Jolla, California, United States of America Anthrax toxin receptors 1 and 2 (ANTXR1 and ANTXR2) have by residue D683 of the protective antigen (PA) subunit of anthrax toxin. The receptor-bound metal ion and PA

  6. Probing interactions within anthrax toxin by electron paramagnetic resonance

    E-print Network

    Probing interactions within anthrax toxin by electron paramagnetic resonance Laura D. Jennings of anthrax toxin forms oligomeric pores that translocate the enzymatic moieties of the toxin -- lethal factor

  7. Designing Inhibitors of Anthrax Toxin

    PubMed Central

    Nestorovich, Ekaterina M.; Bezrukov, Sergey M.

    2014-01-01

    Introduction Present-day rational drug design approaches are based on exploiting unique features of the target biomolecules, small- or macromolecule drug candidates, and physical forces that govern their interactions. The 2013 Nobel Prize in chemistry awarded “for the development of multiscale models for complex chemical systems” once again demonstrated the importance of the tailored drug discovery that reduces the role of the trial and error approach to a minimum. The “rational drug design” term is rather comprehensive as it includes all contemporary methods of drug discovery where serendipity and screening are substituted by the information-guided search for new and existing compounds. Successful implementation of these innovative drug discovery approaches is inevitably preceded by learning the physics, chemistry, and physiology of functioning of biological structures under normal and pathological conditions. Areas covered This article provides an overview of the recent rational drug design approaches to discover inhibitors of anthrax toxin. Some of the examples include small-molecule and peptide-based post-exposure therapeutic agents as well as several polyvalent compounds. The review also directs the reader to the vast literature on the recognized advances and future possibilities in the field. Expert opinion Existing options to combat anthrax toxin lethality are limited. With the only anthrax toxin inhibiting therapy (PA-targeting with a monoclonal antibody, raxibacumab) approved to treat inhalational anthrax, in our view, the situation is still insecure. The FDA’s animal rule for drug approval, which clears compounds without validated efficacy studies on humans, creates a high level of uncertainty, especially when a well-characterized animal model does not exist. Besides, unlike PA, which is known to be unstable, LF remains active in cells and in animal tissues for days. Therefore, the effectiveness of the post-exposure treatment of the individuals with anti-PA therapeutics can be time-dependent, requiring coordinated use of membrane permeable small-molecule inhibitors, which block the LF and EF enzymatic activity intracellularly. The desperate search for an ideal anthrax antitoxin allowed researchers to gain important knowledge of the basic principles of small-molecule interactions with their protein targets that could be easily transferred to other systems. At the same time, better identification and validation of anthrax toxin therapeutic targets at the molecular level, which include understanding of the physical forces underlying the target/drug interaction, as well as elucidation of the parameters determining the corresponding therapeutic windows, require further examination. PMID:24447197

  8. Anthrax lethal and edema toxins in anthrax pathogenesis

    PubMed Central

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

    2014-01-01

    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 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

  9. Human genetic variation altering anthrax toxin sensitivity

    E-print Network

    Tang, Hua

    Human genetic variation altering anthrax toxin sensitivity Mikhail Martchenkoa , Sophie I for review October 31, 2011) The outcome of exposure to infectious microbes or their toxins is influenced affecting capillary morphogenesis gene 2 (CMG2), which encodes a host membrane protein exploited by anthrax

  10. Anthrax lethal and edema toxins in anthrax pathogenesis.

    PubMed

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

    2014-06-01

    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

  11. Membrane translocation by anthrax toxin.

    PubMed

    Collier, R John

    2009-12-01

    Much attention has been focused on anthrax toxin recently, both because of its central role in the pathogenesis of Bacillus anthracis and because it has proven to be one of the most tractable toxins for studying how enzymic moieties of intracellularly acting toxins traverse membranes. The Protective Antigen (PA) moiety of the toxin, after being proteolytically activated at the cell surface, self-associates to form a heptameric pore precursor (prepore). The prepore binds up to three molecules of Edema Factor (EF), Lethal Factor (LF), or both, forming a series of complexes that are then endocytosed. Under the influence of acidic pH within the endosome, the prepore undergoes a conformational transition to a mushroom-shaped pore, with a globular cap and 100A-long stem that spans the membrane. Electrophysiological studies in planar bilayers indicate that EF and LF translocate through the pore in unfolded form and in the N- to C-terminal direction. The pore serves as an active transporter, which translocates its proteinaceous cargo across the endosomal membrane in response to DeltapH and perhaps, to a degree, Deltapsi. A ring of seven Phe residues (Phe427) in the lumen of the pore forms a seal around the translocating polypeptide and blocks the passage of ions, presumably preserving the pH gradient. A charge state-dependent Brownian ratchet mechanism has been proposed to explain how the pore translocates EF and LF. This transport mechanism of the pore may function in concert with molecular chaperonins to effect delivery of effector proteins in catalytically active form to the cytosolic compartment of host cells. PMID:19563824

  12. Receptors of anthrax toxin and cell entry.

    PubMed

    van der Goot, Gisou; Young, John A T

    2009-12-01

    Anthrax toxin-receptor interactions are critical for toxin delivery to the host cell cytoplasm. This review summarizes what is known about the molecular details of the protective antigen (PA) toxin subunit interaction with either the ANTXR1 and ANTXR2 cellular receptors, and how receptor-type can dictate the low pH threshold of PA pore formation. The roles played by cellular factors in regulating the endocytosis of toxin-receptor complexes is also discussed. PMID:19732789

  13. Crystallographic studies of the Anthrax lethal toxin. Annual report

    Microsoft Academic Search

    1996-01-01

    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

  14. The roles of anthrax toxin in pathogenesis

    Microsoft Academic Search

    Mahtab Moayeri; Stephen H Leppla

    2004-01-01

    Anthrax lethal toxin is a multi-functional virulence factor that has evolved to target multiple host functions to allow for optimal establishment of Bacillus anthracis infection. The toxin appears to play a role in all stages of infection, from germination to the induction of vascular collapse leading to host death. Early in infection, at sublethal doses, it acts to suppress immune

  15. Anthrax Toxin Receptor 2–Dependent Lethal Toxin Killing In Vivo

    Microsoft Academic Search

    Heather M. Scobie; Darran J. Wigelsworth; John M. Marlett; Diane Thomas; G. Jonah A. Rainey; D. Borden Lacy; Marianne Manchester; R. John Collier; John A. T. Young

    2006-01-01

    Anthrax toxin receptors 1 and 2 (ANTXR1 and ANTXR2) have a related integrin-like inserted (I) domain which interacts with a metal cation that is coordinated by residue D683 of the protective antigen (PA) subunit of anthrax toxin. The receptor-bound metal ion and PA residue D683 are critical for ANTXR1-PA binding. Since PA can bind to ANTXR2 with reduced affinity in

  16. The roles of anthrax toxin in pathogenesis.

    PubMed

    Moayeri, Mahtab; Leppla, Stephen H

    2004-02-01

    Anthrax lethal toxin is a multi-functional virulence factor that has evolved to target multiple host functions to allow for optimal establishment of Bacillus anthracis infection. The toxin appears to play a role in all stages of infection, from germination to the induction of vascular collapse leading to host death. Early in infection, at sublethal doses, it acts to suppress immune cell and cytokine responses, thereby promoting bacterial outgrowth. Later in the disease, lethal levels of toxin induce the cytokine-independent shock-like death associated with anthrax. The understanding of the molecular events induced by anthrax toxin in different target cells at each stage of infection will aid in deciphering the pathogenesis of this bacterium and developing therapies. PMID:15036135

  17. Receptor-specific requirements for anthrax toxin delivery into cells

    E-print Network

    Sejnowski, Terrence J.

    . The current model of anthrax toxin entry invokes (PA63)7 prepore conversion to a 14-stranded -barrel-containingReceptor-specific requirements for anthrax toxin delivery into cells G. Jonah A. Rainey*, Darran J Contributed by R. John Collier, July 12, 2005 The three proteins that constitute anthrax toxin self

  18. Anthrax toxin-induced rupture of artificial lipid bilayer membranes.

    PubMed

    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

    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

  19. Anthrax toxin-induced rupture of artificial lipid bilayer membranes

    PubMed Central

    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.

    2013-01-01

    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

  20. Interactions between anthrax toxin receptors and protective antigen.

    PubMed

    Scobie, Heather M; Young, John A T

    2005-02-01

    Since the anthrax mail attacks of 2001, much has been learned about the interactions between anthrax toxin and its receptors. Two distinct cellular receptors for anthrax toxin have been identified and are designated capillary morphogenesis protein 2 (CMG2) and anthrax toxin receptor/tumor endothelial marker 8 (ATR/TEM8). The molecular details of the toxin-receptor interactions have been revealed through crystallographic, biochemical and genetic studies. In addition, a novel pathway by which anthrax toxin enters cells is starting to be uncovered. PMID:15694864

  1. Cellular and systemic effects of anthrax lethal toxin and edema toxin

    Microsoft Academic Search

    Mahtab Moayeri; Stephen H. Leppla

    2009-01-01

    Anthrax lethal toxin (LT) and edema toxin (ET) are the major virulence factors of anthrax and can replicate the lethality and symptoms associated with the disease. This review provides an overview of our current understanding of anthrax toxin effects in animal models and the cytotoxicity (necrosis and apoptosis) induced by LT in different cells. A brief reexamination of early historic

  2. New insights into the functions of anthrax toxin.

    PubMed

    Banks, David J; Ward, Sabrina C; Bradley, Kenneth A

    2006-01-01

    Anthrax is the disease caused by the Gram-positive bacterium Bacillus anthracis. Two toxins secreted by B. anthracis - lethal toxin (LT) and oedema toxin (OT) - contribute significantly to virulence. Although these toxins have been studied for half a century, recent evidence indicates that LT and OT have several roles during infection not previously ascribed to them. Research on toxin-induced effects other than cytolysis of target cells has revealed that LT and OT influence cell types previously thought to be insensitive to toxin. Multiple host factors that confer sensitivity to anthrax toxin have been identified recently, and evidence indicates that the toxins probably contribute to colonisation and invasion of the host. Additionally, the toxins are now known to cause a wide spectrum of tissue and organ pathophysiologies associated with anthrax. Taken together, these new findings indicate that anthrax-toxin-associated pathogenesis is much more complex than has been traditionally recognised. PMID:16608555

  3. cAMP imaging of cells treated with pertussis toxin, cholera toxin, and anthrax edema toxin

    Microsoft Academic Search

    Federica Dal Molin; Irene Zornetta; Andrea Puhar; Fiorella Tonello; Manuela Zaccolo; Cesare Montecucco

    2008-01-01

    The enzymatic activity of the three most studied bacterial toxins that increase the cytosolic cAMP level: pertussis toxin (PT), cholera toxin (CT), and anthrax edema toxin (ET), was imaged by fluorescence videomicroscopy. Three different cell lines were transfected with a fluorescence resonance energy transfer biosensor based on the PKA regulatory and catalytic subunits fused to CFP and YFP, respectively. Real-time

  4. Ratcheting up protein translocation with anthrax toxin

    PubMed Central

    Feld, Geoffrey K; Brown, Michael J; Krantz, Bryan A

    2012-01-01

    Energy-consuming nanomachines catalyze the directed movement of biopolymers in the cell. They are found both dissolved in the aqueous cytosol as well as embedded in lipid bilayers. Inquiries into the molecular mechanism of nanomachine-catalyzed biopolymer transport have revealed that these machines are equipped with molecular parts, including adjustable clamps, levers, and adaptors, which interact favorably with substrate polypeptides. Biological nanomachines that catalyze protein transport, known as translocases, often require that their substrate proteins unfold before translocation. An unstructured protein chain is likely entropically challenging to bind, push, or pull in a directional manner, especially in a way that produces an unfolding force. A number of ingenious solutions to this problem are now evident in the anthrax toxin system, a model used to study protein translocation. Here we highlight molecular ratchets and current research on anthrax toxin translocation. A picture is emerging of proton-gradient-driven anthrax toxin translocation, and its associated ratchet mechanism likely applies broadly to other systems. We suggest a cyclical thermodynamic order-to-disorder mechanism (akin to a heat-engine cycle) is central to underlying protein translocation: peptide substrates nonspecifically bind to molecular clamps, which possess adjustable affinities; polypeptide substrates compress into helical structures; these clamps undergo proton-gated switching; and the substrate subsequently expands regaining its unfolded state conformational entropy upon translocation. PMID:22374876

  5. Ratcheting up protein translocation with anthrax toxin.

    PubMed

    Feld, Geoffrey K; Brown, Michael J; Krantz, Bryan A

    2012-05-01

    Energy-consuming nanomachines catalyze the directed movement of biopolymers in the cell. They are found both dissolved in the aqueous cytosol as well as embedded in lipid bilayers. Inquiries into the molecular mechanism of nanomachine-catalyzed biopolymer transport have revealed that these machines are equipped with molecular parts, including adjustable clamps, levers, and adaptors, which interact favorably with substrate polypeptides. Biological nanomachines that catalyze protein transport, known as translocases, often require that their substrate proteins unfold before translocation. An unstructured protein chain is likely entropically challenging to bind, push, or pull in a directional manner, especially in a way that produces an unfolding force. A number of ingenious solutions to this problem are now evident in the anthrax toxin system, a model used to study protein translocation. Here we highlight molecular ratchets and current research on anthrax toxin translocation. A picture is emerging of proton-gradient-driven anthrax toxin translocation, and its associated ratchet mechanism likely applies broadly to other systems. We suggest a cyclical thermodynamic order-to-disorder mechanism (akin to a heat-engine cycle) is central to underlying protein translocation: peptide substrates nonspecifically bind to molecular clamps, which possess adjustable affinities; polypeptide substrates compress into helical structures; these clamps undergo proton-gated switching; and the substrate subsequently expands regaining its unfolded state conformational entropy upon translocation. PMID:22374876

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

    PubMed Central

    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

    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. PMID:23607659

  7. Anthrax toxin: structures, functions and tumour targeting.

    PubMed

    Liu, Shihui; Schubert, Rebecca L; Bugge, Thomas H; Leppla, Stephen H

    2003-08-01

    Anthrax toxin, the major virulence factor of Bacillus anthracis, consists of three polypeptides: protective antigen (PrAg), lethal factor (LF) and oedema factor (EF). To intoxicate mammalian cells, PrAg binds to its cellular receptors and is subsequently activated via proteolysis, yielding a carboxyl-terminal fragment which coordinately assembles to form heptamers that bind and translocate LF and EF into the cytosol to exert their cytotoxic effects. Substantial progress has been made in recent years towards the characterisation of the structure and function of anthrax toxin, and this has greatly facilitated rational drug design of antianthrax agents. There is also emerging evidence that toxins can be manipulated for cancer therapy. LF can efficiently inactivate several mitogen-activated protein kinase kinases (MAPKKs) via cleavage of their amino-terminal sequences. Consequently, antitumour effects of wild type lethal toxin were observed after treatment of mitogen-activated protein kinase (MAPK)-dependent tumours such as human melanomas. Modification of the toxin's proteolytic activation site limits its cytotoxicity to certain cell types and creates a versatile method of treatment. One approach that has successfully achieved specific tumour targeting is the alteration of the furin cleavage of PrAg so that it is not activated by furin, but, alternatively, by proteases that are highly expressed by tumour tissues, including matrix metalloproteases and urokinase. PMID:12880383

  8. Cellular and systemic effects of anthrax lethal toxin and edema toxin.

    PubMed

    Moayeri, Mahtab; Leppla, Stephen H

    2009-12-01

    Anthrax lethal toxin (LT) and edema toxin (ET) are the major virulence factors of anthrax and can replicate the lethality and symptoms associated with the disease. This review provides an overview of our current understanding of anthrax toxin effects in animal models and the cytotoxicity (necrosis and apoptosis) induced by LT in different cells. A brief reexamination of early historic findings on toxin in vivo effects in the context of our current knowledge is also presented. PMID:19638283

  9. Anthrax

    MedlinePLUS

    ... the attachment of protective antigen in test-tube experiments, thereby inhibiting all anthrax toxin activity. NIAID-funded ... treat anthrax toxicity. Their study shows that a human gene called LRP6 plays a role in the ...

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

    E-print Network

    Nizet, Victor

    Review New insights into the biological effects of anthrax toxins: linking cellular to organismal, and brain. In this review, we examine the various biological effects of anthrax toxins, focusing The anthrax toxins lethal toxin (LT) and edema toxin (ET) are essential virulence factors produced by Bacillus

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

    Microsoft Academic Search

    Annabel Guichard; Victor Nizet; Ethan Bier

    The anthrax toxins lethal toxin (LT) and edema toxin (ET) are essential virulence factors produced by Bacillus 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

  12. Anthrax Edema Toxin Impairs Clearance in Mice

    PubMed Central

    Sastalla, Inka; Tang, Shixing; Crown, Devorah; Liu, Shihui; Eckhaus, Michael A.; Hewlett, Indira K.; Leppla, Stephen H.

    2012-01-01

    The anthrax edema toxin (ET) of Bacillus anthracis is composed of the receptor-binding component protective antigen (PA) and of the adenylyl cyclase catalytic moiety, edema factor (EF). Uptake of ET into cells raises intracellular concentrations of the secondary messenger cyclic AMP, thereby impairing or activating host cell functions. We report here on a new consequence of ET action in vivo. We show that in mouse models of toxemia and infection, serum PA concentrations were significantly higher in the presence of enzymatically active EF. These higher concentrations were not caused by ET-induced inhibition of PA endocytosis; on the contrary, ET induced increased PA binding and uptake of the PA oligomer in vitro and in vivo through upregulation of the PA receptors TEM8 and CMG2 in both myeloid and nonmyeloid cells. ET effects on protein clearance from circulation appeared to be global and were not limited to PA. ET also impaired the clearance of ovalbumin, green fluorescent protein, and EF itself, as well as the small molecule biotin when these molecules were coinjected with the toxin. Effects on injected protein levels were not a result of general increase in protein concentrations due to fluid loss. Functional markers for liver and kidney were altered in response to ET. Concomitantly, ET caused phosphorylation and activation of the aquaporin-2 water channel present in the principal cells of the collecting ducts of the kidneys that are responsible for fluid homeostasis. Our data suggest that in vivo, ET alters circulatory protein and small molecule pharmacokinetics by an as-yet-undefined mechanism, thereby potentially allowing a prolonged circulation of anthrax virulence factors such as EF during infection. PMID:22104108

  13. Structure of heptameric protective antigen bound to an anthrax toxin receptor: A role for receptor

    E-print Network

    Harrison, Stephen C.

    Structure of heptameric protective antigen bound to an anthrax toxin receptor: A role for receptor of anthrax toxin forms a heptameric prepore. The prepore later undergoes pH-dependent conversion to a pore accomplishes this disruption by secreting a tripartite toxin­ anthrax toxin, consisting of two intracellularly

  14. Anthrax toxin and genetic aspects regulating its expression

    Microsoft Academic Search

    Amy E. Tucker; Jimmy D. Ballard

    Anthrax toxin is a unique, tripartite bacterial toxin, capable of causing edema and lethality through binary combinations of protective antigen (PA) with either edema factor (EF) or lethal factor (LF). The toxin-encoding genes (pagA, lef, cya) are maintained on a ~44 kb pathogenicity island (PAI), found on the large plasmid, pXO1. The toxin encoding genes are subject to inducible expression in

  15. Cytoskeleton as an Emerging Target of Anthrax Toxins

    PubMed Central

    Trescos, Yannick; Tournier, Jean-Nicolas

    2012-01-01

    Bacillus anthracis, the agent of anthrax, has gained virulence through its exotoxins produced by vegetative bacilli and is composed of three components forming lethal toxin (LT) and edema toxin (ET). So far, little is known about the effects of these toxins on the eukaryotic cytoskeleton. Here, we provide an overview on the general effects of toxin upon the cytoskeleton architecture. Thus, we shall discuss how anthrax toxins interact with their receptors and may disrupt the interface between extracellular matrix and the cytoskeleton. We then analyze what toxin molecular effects on cytoskeleton have been described, before discussing how the cytoskeleton may help the pathogen to corrupt general cell processes such as phagocytosis or vascular integrity. PMID:22474568

  16. Cytoskeleton as an emerging target of anthrax toxins.

    PubMed

    Trescos, Yannick; Tournier, Jean-Nicolas

    2012-02-01

    Bacillus anthracis, the agent of anthrax, has gained virulence through its exotoxins produced by vegetative bacilli and is composed of three components forming lethal toxin (LT) and edema toxin (ET). So far, little is known about the effects of these toxins on the eukaryotic cytoskeleton. Here, we provide an overview on the general effects of toxin upon the cytoskeleton architecture. Thus, we shall discuss how anthrax toxins interact with their receptors and may disrupt the interface between extracellular matrix and the cytoskeleton. We then analyze what toxin molecular effects on cytoskeleton have been described, before discussing how the cytoskeleton may help the pathogen to corrupt general cell processes such as phagocytosis or vascular integrity. PMID:22474568

  17. Genetically modified anthrax lethal toxin safely delivers whole HIV protein antigens into the

    E-print Network

    Lieberman, Judy

    , 2000 (received for review January 24, 2000) Bacillus anthrax lethal toxin can be engineered to deliverGenetically modified anthrax lethal toxin safely delivers whole HIV protein antigens compartment of mammalian cells. The engineered anthrax toxin vaccine appears unlikely to induce an antibody

  18. The unfolding story of anthrax toxin translocation.

    PubMed

    Thoren, Katie L; Krantz, Bryan A

    2011-05-01

    The essential cellular functions of secretion and protein degradation require a molecular machine to unfold and translocate proteins either across a membrane or into a proteolytic complex. Protein translocation is also critical for microbial pathogenesis, namely bacteria can use translocase channels to deliver toxic proteins into a target cell. Anthrax toxin (Atx), a key virulence factor secreted by Bacillus anthracis, provides a robust biophysical model to characterize transmembrane protein translocation. Atx is comprised of three proteins: the translocase component, protective antigen (PA) and two enzyme components, lethal factor (LF) and oedema factor (OF). Atx forms an active holotoxin complex containing a ring-shaped PA oligomer bound to multiple copies of LF and OF. These complexes are endocytosed into mammalian host cells, where PA forms a protein-conducting translocase channel. The proton motive force unfolds and translocates LF and OF through the channel. Recent structure and function studies have shown that LF unfolds during translocation in a force-dependent manner via a series of metastable intermediates. Polypeptide-binding clamps located throughout the PA channel catalyse substrate unfolding and translocation by stabilizing unfolding intermediates through the formation of a series of interactions with various chemical groups and ?-helical structure presented by the unfolding polypeptide during translocation. PMID:21443527

  19. cAMP imaging of cells treated with pertussis toxin, cholera toxin, and anthrax edema toxin.

    PubMed

    Dal Molin, Federica; Zornetta, Irene; Puhar, Andrea; Tonello, Fiorella; Zaccolo, Manuela; Montecucco, Cesare

    2008-11-14

    The enzymatic activity of the three most studied bacterial toxins that increase the cytosolic cAMP level: pertussis toxin (PT), cholera toxin (CT), and anthrax edema toxin (ET), was imaged by fluorescence videomicroscopy. Three different cell lines were transfected with a fluorescence resonance energy transfer biosensor based on the PKA regulatory and catalytic subunits fused to CFP and YFP, respectively. Real-time imaging of cells expressing this cAMP biosensor provided time and space resolved pictures of the toxins action. The time course of the PT-induced cAMP increase suggests that its active subunit enters the cytosol more rapidly than that deduced by biochemical experiments. ET generated cAMP concentration gradients decreasing from the nucleus to the cell periphery. On the contrary, CT, which acts on the plasma membrane adenylate cyclase, did not. The potential of imaging methods in studying the mode of entry and the intracellular action of bacterial toxins is discussed. PMID:18793614

  20. Identification of the cellular receptor for anthrax toxin

    NASA Astrophysics Data System (ADS)

    Bradley, Kenneth A.; Mogridge, Jeremy; Mourez, Michael; Collier, R. John; Young, John A. T.

    2001-11-01

    The tripartite toxin secreted by Bacillus anthracis, the causative agent of anthrax, helps the bacterium evade the immune system and can kill the host during a systemic infection. Two components of the toxin enzymatically modify substrates within the cytosol of mammalian cells: oedema factor (OF) is an adenylate cyclase that impairs host defences through a variety of mechanisms including inhibiting phagocytosis; lethal factor (LF) is a zinc-dependent protease that cleaves mitogen-activated protein kinase kinase and causes lysis of macrophages. Protective antigen (PA), the third component, binds to a cellular receptor and mediates delivery of the enzymatic components to the cytosol. Here we describe the cloning of the human PA receptor using a genetic complementation approach. The receptor, termed ATR (anthrax toxin receptor), is a type I membrane protein with an extracellular von Willebrand factor A domain that binds directly to PA. In addition, a soluble version of this domain can protect cells from the action of the toxin.

  1. NANO APTASENSOR FOR PROTECTIVE ANTIGEN TOXIN OF ANTHRAX

    PubMed Central

    Cella, Lakshmi N.; Sanchez, Pablo; Zhong, Wenwan; Myung, Nosang V.; Chen, Wilfred; Mulchandani, Ashok

    2010-01-01

    We demonstrate a highly sensitive nano aptasensor for anthrax toxin through the detection of its polypeptide entity, protective antigen (PA toxin) using a PA toxin ssDNA aptamer functionalized single-walled carbon nanotubes (SWNTs) device. The aptamer was developed in-house by capillary electrophoresis systematic evolution of ligands by exponential enrichment (CE-SELEX) and had a dissociation constant (Kd) of 112 nM. The aptasensor displayed a wide dynamic range spanning up to 800 nM with a detection limit of 1nM. The sensitivity was 0.11 per nM and it was reusable six times. The aptasensor was also highly selective for PA toxin with no interference from human and bovine serum albumin, demonstrating it as a potential tool for rapid and point-of-care diagnosis for anthrax. PMID:20136122

  2. Nano aptasensor for protective antigen toxin of anthrax.

    PubMed

    Cella, Lakshmi N; Sanchez, Pablo; Zhong, Wenwan; Myung, Nosang V; Chen, Wilfred; Mulchandani, Ashok

    2010-03-01

    We demonstrate a highly sensitive nano aptasensor for anthrax toxin through the detection of its polypeptide entity, protective antigen (PA toxin) using a PA toxin ssDNA aptamer functionalized single-walled carbon nanotubes (SWNTs) device. The aptamer was developed in-house by capillary electrophoresis systematic evolution of ligands by exponential enrichment (CE-SELEX) and had a dissociation constant (K(d)) of 112 nM. The aptasensor displayed a wide dynamic range spanning up to 800 nM with a detection limit of 1 nM. The sensitivity was 0.11 per nM, and it was reusable six times. The aptasensor was also highly selective for PA toxin with no interference from human and bovine serum albumin, demonstrating it as a potential tool for rapid and point-of-care diagnosis for anthrax. PMID:20136122

  3. Role of Toxin Functional Domains in Anthrax Pathogenesis

    Microsoft Academic Search

    FABIEN BROSSIER; MARTINE WEBER-LEVY; MICHELE MOCK; JEAN-CLAUDE SIRARD

    2000-01-01

    We investigated the role of the functional domains of anthrax toxins during infection. Three proteins produced by Bacillus anthracis, the protective antigen (PA), the lethal factor (LF), and the edema factor (EF), combine in pairs to produce the lethal (PA1LF) and edema (PA1EF) toxins. A genetic strategy was developed to introduce by allelic exchange specific point mutations or in-frame deletions

  4. Anthrax lethal toxin: a weapon of multisystem destruction

    Microsoft Academic Search

    A. Agrawal; B. Pulendran

    2004-01-01

    Lethal toxin (LT) is a major virulence factor secreted by anthrax bacteria. It is composed of two proteins, PA (protective antigen) and LF (lethal factor). PA transports the LF inside the cell, where LF, a zinc-dependent metalloprotease cleaves the mitogen activated protein kinase kinase (MAPKK) enzymes of the mitogen activated protein kinase (MAPK) signaling pathway, thereby impairing their function. This

  5. Anthrax Toxin: Receptor Binding, Internalization, Pore Formation, and Translocation

    Microsoft Academic Search

    John A. T. Young; R. John Collier

    2007-01-01

    Anthrax toxin consists of three nontoxic proteins that self-assemble at the surface of receptor-bearing mammalian cells or in solution, yielding a series of toxic complexes. Two of the proteins, called Lethal Factor (LF) and Edema Factor (EF), are enzymes that act on cytosolic substrates. The third, termed Protective Antigen (PA), is a multifunctional protein that binds to receptors, orchestrates the

  6. Anthrax Lethal Toxin-Mediated Killing of Human and Murine Dendritic Cells Impairs

    E-print Network

    Brojatsch, Jürgen

    Anthrax Lethal Toxin-Mediated Killing of Human and Murine Dendritic Cells Impairs the Adaptive anthracis interferes with host defenses by releasing anthrax lethal toxin (LT), which inactivates mitogen that anthrax LT impairs adaptive immunity by specifically targeting DCs. This may represent an immune- evasion

  7. Endosomal recycling regulates anthrax toxin receptor 1\\/tumor endothelial marker 8-dependent cell spreading

    Microsoft Academic Search

    Jingsheng Gu; Victor Faundez; Erica Werner

    2010-01-01

    Mechanisms for receptor-mediated anthrax toxin internalization and delivery to the cytosol are well understood. However, far less is known about the fate followed by anthrax toxin receptors prior and after cell exposure to the toxin. We report that Anthrax Toxin Receptor 1\\/Tumor Endothelial Marker 8 (TEM8) localized at steady state in Rab11a-positive and transferrin receptor-containing recycling endosomes. TEM8 followed a

  8. Amiodarone and bepridil inhibit anthrax toxin entry into host cells.

    PubMed

    Sanchez, Ana M; Thomas, Diane; Gillespie, Eugene J; Damoiseaux, Robert; Rogers, Joseph; Saxe, Jonathan P; Huang, Jing; Manchester, Marianne; Bradley, Kenneth A

    2007-07-01

    Anthrax lethal toxin is one of the fundamental components believed to be responsible for the virulence of Bacillus anthracis. In order to find novel compounds with anti-lethal toxin properties, we used a cell-based assay to screen a collection of approximately 500 small molecules. Nineteen compounds that blocked lethal toxin-mediated killing of RAW 264.7 macrophages were identified, and we report here on the characterization of the two most potent antitoxic compounds, amiodarone and bepridil. These drugs are used to treat cardiac arrhythmia or angina in humans at doses similar to those that provide protection against lethal toxin in vitro. Our results support a model whereby the antitoxic properties of both drugs result from their ability to block endosomal acidification, thereby blocking toxin entry. Amiodarone was tested in vivo and found to significantly increase survival of lethal toxin-challenged Fischer rats. PMID:17485504

  9. Crystallographic studies of the Anthrax lethal toxin. Annual report

    SciTech Connect

    Frederick, C.A.

    1996-07-01

    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.

  10. Anthrax Lethal and Edema Toxins Fail to Directly Impair Human Platelet Function

    PubMed Central

    Chauncey, Kassidy M.; Szarowicz, Sarah E.; Sidhu, Gurjit S.; During, Russell L.

    2012-01-01

    Hemorrhage is a prominent clinical manifestation of systemic anthrax. Therefore, we have examined the effects of anthrax lethal and edema toxins on human platelets. We find that anthrax lethal toxin fails to cleave its target, mitogen-activated protein kinase 1, and anthrax edema toxin fails to increase intracellular cyclic adenosine monophosphate. Surface expression of toxin receptors tumor endothelial marker 8 and capillary morphogenesis gene 2, as well as coreceptor low density lipoprotein receptor-related protein 6 (LRP6), are markedly reduced, preventing toxin binding to platelets. Our studies suggest that the hemorrhagic clinical manifestations of systemic anthrax are unlikely to be caused by the direct binding and entry of anthrax toxins into human platelets. PMID:22158563

  11. Anthrax toxin: pathologic effects on the cardiovascular system.

    PubMed

    Golden, Honey B; Watson, Linley E; Lal, Hind; Verma, Suresh K; Foster, Donald M; Kuo, Shu-Ru; Sharma, Avadhesh; Frankel, Arthur; Dostal, David E

    2009-01-01

    Anthrax is a disease caused by infection with spores from the bacteria Bacillus anthracis. After entering the body, the spores germinate into bacteria and secrete a toxin that causes local edema and, in systemic infections, cardiovascular collapse and death. The toxin is a tripartite polypeptide, consisting of protective antigen (PA), lethal factor (LF) and edema factor (EF), which have key roles in the bacterial pathogenesis and disease progression. PA facilitates transfer of LF and EF to the cytosol. Lethal toxin is a zinc metalloproteinase, which has the capacity to inactivate mitogen-activated protein (MAP) kinase kinase (MEK) and stimulates the release of sepsis-related cytokines tumor necrosis factor-alpha and interleukin-1beta. Edema factor is a calmodulin (CaM)-dependent adenylate cyclase, which increases levels of cyclic AMP, causing impaired neutrophil function and disruption of water balance that ultimately results in massive tissue edema. Together, the toxins effectively inhibit host innate and adaptive immune responses, allowing the bacteria to grow unrestrained and overwhelming any resistance. Clinically, inhalational anthrax presents in a biphasic pattern with initial nonspecific "flu-like" symptoms nausea and vomiting 1 to 4 days after exposure, followed by severe illness with dyspnea, high fever and circulatory shock. The latter symptoms represent a terminal stage and treatment is often ineffective when started at that time. Key indicators of early anthrax cardiovascular-related pathogenesis include mediastinal widening in association with pleural effusion and edema. In this review, we describe the current understanding of anthrax toxins on cellular function in the context of cardiovascular function and discuss potential therapeutic strategies. PMID:19273204

  12. Contribution of toxins to the pathogenesis of inhalational anthrax.

    PubMed

    Tournier, Jean-Nicolas; Quesnel-Hellmann, Anne; Cleret, Aurélie; Vidal, Dominique R

    2007-03-01

    Inhalational anthrax is a life-threatening infectious disease of considerable concern, especially as a potential bioterrorism agent. Progress is gradually being made towards understanding the mechanisms used by Bacillus anthracis to escape the immune system and to induce severe septicaemia associated with toxaemia and leading to death. Recent advances in fundamental research have revealed previously unsuspected roles for toxins in various cell types. We summarize here pathological data for animal models and macroscopic histological examination data from recent clinical records, which we link to the effects of toxins. We describe three major steps in infection: (i) an invasion phase in the lung, during which toxins have short-distance effects on lung phagocytes; (ii) a phase of bacillus proliferation in the mediastinal lymph nodes, with local effects of toxins; and (iii) a terminal, diffusion phase, characterized by a high blood bacterial load and by long-distance effects of toxins, leading to host death. The pathophysiology of inhalational anthrax thus involves interactions between toxins and various cell partners, throughout the course of infection. PMID:17223930

  13. Delivery of nucleic acid into mammalian cells by anthrax toxin

    Microsoft Academic Search

    Reetika Gaur; Pradeep K Gupta; Anita Goyal; Winfried Wels; Yogendra Singh

    2002-01-01

    Gene delivery vehicles based on receptor-mediated endocytosis offer an attractive long-term solution as they might overcome the limitations of toxicity and cargo capacity inherent to many viral gene delivery systems. The protective antigen component of anthrax toxin bind to specific receptors and deliver lethal factor or edema factor into the cytosol of mammalian cells. The N-terminal 254 amino acids of

  14. Polyvalent Recognition of Biopolymers:The Design of Potent Inhibitors of Anthrax Toxin

    NASA Astrophysics Data System (ADS)

    Kane, Ravi

    2007-03-01

    Polyvalency -- the simultaneous binding of multiple ligands on one entity to multiple receptors on another -- is a phenomenon that is ubiquitous in nature. We are using a biomimetic approach, inspired by polyvalency, to design potent inhibitors of anthrax toxin. Since the major symptoms and death from anthrax are due primarily to the action of anthrax toxin, the toxin is a prime target for therapeutic intervention. We describe the design of potent polyvalent anthrax toxin inhibitors, and will discuss the role of pattern matching in polyvalent recognition. Pattern-matched polyvalent inhibitors can neutralize anthrax toxin in vivo, and may enable the successful treatment of anthrax during the later stages of the disease, when antibiotic treatment is ineffective.

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

    Microsoft Academic Search

    Susan Welkos; Stephen Little; Arthur Friedlander; David Fritz; Patricia Fellows

    Vaccines which are efficacious against anthrax, such as the human vaccine, Anthrax Vaccine Absorbed (AVA), contain the protective antigen (PA) component of the anthrax toxins as the major protective immunogen. Although AVA protects against inhalational anthrax, the immune responses to and role in protection of PA and possibly other antigens have yet to be fully elucidated. Sera from animals immunized

  16. Impairment of dendritic cells and adaptive immunity by anthrax lethal toxin

    Microsoft Academic Search

    Anshu Agrawal; Jai Lingappa; Stephen H. Leppla; Sudhanshu Agrawal; Abdul Jabbar; Conrad Quinn; Bali Pulendran

    2003-01-01

    Anthrax poses a clear and present danger as an agent of biological terrorism. Infection with Bacillus anthracis, the causative agent of anthrax, if untreated can result in rampant bacteraemia, multisystem dysfunction and death. Anthrax lethal toxin (LT) is a critical virulence factor of B. anthracis, which occurs as a complex of protective antigen and lethal factor. Here we demonstrate that

  17. Direct Inhibition of T-Lymphocyte Activation by Anthrax Toxins In Vivo

    Microsoft Academic Search

    Jason E. Comer; Ashok K. Chopra; Johnny W. Peterson; Rolf Konig

    2005-01-01

    Received 28 June 2005\\/Returned for modification 4 September 2005\\/Accepted 18 September 2005 The causative agent of anthrax, Bacillus anthracis, produces two toxins that contribute in part to its virulence. Lethal toxin is a metalloprotease that cleaves upstream mitogen-activated protein kinase kinases. Edema toxin is a calmodulin-dependent adenylate cyclase. Previous studies demonstrated that the anthrax toxins are important immunomodulators that promote

  18. LRP6 holds the key to the entry of anthrax toxin.

    PubMed

    Bann, James G; Cegelski, Lynette; Hultgren, Scott J

    2006-03-24

    In this issue of Cell, it is demonstrated that the low-density lipoprotein receptor-related protein 6 (LRP6) promotes endocytosis of the anthrax toxin into cells. LRP6 acts as a coreceptor with either TEM8 or CMG2, the two previously identified receptors for anthrax toxin. PMID:16564002

  19. Novel repression of the glucocorticoid receptor by anthrax lethal toxin.

    PubMed

    Webster, Jeanette I; Moayeri, Mahtab; Sternberg, Esther M

    2004-06-01

    Death from anthrax has been reported to occur from systemic shock. The lethal toxin (LeTx) is the major effector of anthrax mortality. Although the mechanism of entry of this toxin into cells is well understood, its actions once inside the cell are not as well understood. LeTx is known to cleave and inactivate MAPKKs. We have recently shown that LeTx represses the glucocorticoid receptor (GR) both in vitro and in vivo. This repression is partial and specific, repressing the glucocorticoid, progesterone, and estrogen receptor alpha, but not the mineralocorticoid or estrogen receptor beta. This toxin does not affect GR ligand or DNA binding, and we have suggested that it may function by removing/inactivating one or more of the many cofactors involved in nuclear hormone receptor signaling. Although the precise involvement of this nuclear hormone receptor repression in LeTx toxicity is unknown, examples of blunted HPA axis and glucocorticoid signaling in numerous autoimmune/inflammatory diseases suggest that such repression of critically important receptors could have deleterious effects on health. PMID:15265771

  20. MICROBIOLOGY: Enhanced: Fighting Anthrax with a Mutant Toxin

    NSDL National Science Digital Library

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

    2008-10-05

    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.

  1. Anthrax Toxin Uptake by Primary Immune Cells as Determined with a Lethal Factor-beta-Lactamase Fusion Protein

    Microsoft Academic Search

    Haijing Hu; Stephen H. Leppla; Adam J. Ratner

    2009-01-01

    BackgroundTo initiate infection, Bacillus anthracis needs to overcome the host innate immune system. Anthrax toxin, a major virulence factor of B. anthracis, impairs both the innate and adaptive immune systems and is important in the establishment of anthrax infections.Methodology\\/Principal FindingsTo measure the ability of anthrax toxin to target immune cells, studies were performed using a fusion of the anthrax toxin

  2. The effects of anthrax lethal toxin on host barrier function.

    PubMed

    Xie, Tao; Auth, Roger D; Frucht, David M

    2011-06-01

    The pathological actions of anthrax toxin require the activities of its edema factor (EF) and lethal factor (LF) enzyme components, which gain intracellular access via its receptor-binding component, protective antigen (PA). LF is a metalloproteinase with specificity for selected mitogen-activated protein kinase kinases (MKKs), but its activity is not directly lethal to many types of primary and transformed cells in vitro. Nevertheless, in vivo treatment of several animal species with the combination of LF and PA (termed lethal toxin or LT) leads to morbidity and mortality, suggesting that LT-dependent toxicity is mediated by cellular interactions between host cells. Decades of research have revealed that a central hallmark of this toxicity is the disruption of key cellular barriers required to maintain homeostasis. This review will focus on the current understanding of the effects of LT on barrier function, highlighting recent progress in establishing the molecular mechanisms underlying these effects. PMID:22069727

  3. Contribution of Lethal Toxin and Edema Toxin to the Pathogenesis of Anthrax Meningitis ?

    PubMed Central

    Ebrahimi, Celia M.; Sheen, Tamsin R.; Renken, Christian W.; Gottlieb, Roberta A.; Doran, Kelly S.

    2011-01-01

    Bacillus anthracis is a Gram-positive spore-forming bacterium that causes anthrax disease in humans and animals. Systemic infection is characterized by septicemia, toxemia, and meningitis, the main neurological complication associated with high mortality. We have shown previously that B. anthracis Sterne is capable of blood-brain barrier (BBB) penetration, establishing the classic signs of meningitis, and that infection is dependent on the expression of both major anthrax toxins, lethal toxin (LT) and edema toxin (ET). Here we further investigate the contribution of the individual toxins to BBB disruption using isogenic toxin mutants deficient in lethal factor, ?LF, and edema factor, ?EF. Acute infection with B. anthracis Sterne and the ?LF mutant resulted in disruption of human brain microvascular endothelial cell (hBMEC) monolayer integrity and tight junction protein zona occludens-1, while the result for cells infected with the ?EF mutant was similar to that for the noninfected control. A significant decrease in bacterial invasion of BBB endothelium in vitro was observed during infection with the ?LF strain, suggesting a prominent role for LT in promoting BBB interaction. Further, treatment of hBMECs with purified LT or chemicals that mimic LT action on host signaling pathways rescued the hypoinvasive phenotype of the ?LF mutant and resulted in increased bacterial uptake. We also observed that toxin expression reduced bacterial intracellular survival by inducing the bulk degradative autophagy pathway in host cells. Finally, in a murine model of anthrax meningitis, mice infected with the ?LF mutant exhibited no mortality, brain bacterial load, or evidence of meningitis compared to mice infected with the parental or ?EF strains. PMID:21518787

  4. [Molecular model of anthrax toxin translocation into target-cells].

    PubMed

    Noskov, A N

    2014-01-01

    Anthrax toxin is formed from three components: protective antigen (PA), lethal (LF) and edema (EF) factors. PA83 is cleaved by cell surface protease furin to produce a 63-kDa fragment (PA63). PA63 and LF/EF molecules are assembled to anthrax toxin complexes: oligomer PA63 x 7 + LF/EF x 3. Assembly is occurred during of binding with cellular receptor or near surface of target-cell. This toxin complex forms pore and induces receptor-mediated endocytosis. Formed endosome consists extracellular liquid with LF/EF and membrane-associated ferments (H+ and K+/Na+-ATPases) and proteins (receptors and others). H+ concentration is increased into endosome as result of K/Na-ATPase-dependent- activity of H+-ATPase. Difference of potentials (between endosome and intracellular liquid) is increased and LF/EF molecules are moved to pore and bound with PA63-oligomer to PA63 x 7 + LF/EF x 7 and full block pore (ion-selective channel). Endosome is increased in volume and induces increasing of PA63-oligomer pore to.size of effector complex: LF/EF x 7 + PAl7 x 7 = 750 kDa. Effector complex is translocated from endosome to cytosol by means high difference of potentials (H+) and dissociates from PA47 x 7 complex after cleavage of FFD315-sait by intracellular chymotrypsin-like proteases in all 7 molecules PA63. PA47 x 7 complex (strongly fixed in membrane with debris of hydrophobic loops) return into endosome and pore is destroyed. Endosome pH is decreased rapidly and PA47 x 7 complex is destroyed by endosomal/lysosomal proteases. Receptor-mediated endocytosis is ended by endosome recycling in cell-membrane. PMID:25898749

  5. A Role for PACE4 in the Proteolytic Activation of Anthrax Toxin Protective Antigen

    Microsoft Academic Search

    VALERY M. GORDON; ALNAWAZ REHEMTULLA; STEPHEN H. LEPPLA

    1997-01-01

    Several bacterial protein toxins require activation by eukaryotic proteases. Previous studies have shown that anthrax toxin protective antigen (PA), Pseudomonas exotoxin A (PE), and diphtheria toxin (DT) are cleaved by furin C-terminal to the sequences RKKR, RQPR, and RVRR, respectively. Because furin-deficient cells retain some sensitivity to PA and DT, it is evident that other cellular proteases can activate these

  6. Anthrax vaccine design: strategies to achieve comprehensive protection against spore, bacillus, and toxin

    Microsoft Academic Search

    Julia Y Wang; Michael H Roehrl

    2005-01-01

    The successful use of Bacillus anthracis as a lethal biological weapon has prompted renewed research interest in the development of more effective vaccines against anthrax. The disease consists of three critical components: spore, bacillus, and toxin, elimination of any of which confers at least partial protection against anthrax. Current remedies rely on postexposure antibiotics to eliminate bacilli and pre- and

  7. The medicinal chemistry of botulinum, ricin and anthrax toxins.

    PubMed

    Hicks, Rickey P; Hartell, Mark G; Nichols, Daniel A; Bhattacharjee, Apurba K; van Hamont, John E; Skillman, Donald R

    2005-01-01

    The potential use of weapons of mass destruction (nuclear, biological or chemical) by terrorist organizations represents a major threat to world peace and safety. Only a limited number of vaccines are available to protect the general population from the medical consequences of these weapons. In addition there are major health concerns associated with a pre-exposure mass vaccination of the general population. To reduce or eliminate the impact of these terrible threats, new drugs must be developed to safely treat individuals exposed to these agents. A review of all therapeutic agents under development for the treatment of the illnesses and injuries that result from exposure to nuclear, biological or chemical warfare agents is beyond the scope of any single article. The intent here is to provide a focused review for medicinal and organic chemists of three widely discussed and easily deployed biological warfare agents, botulinum neurotoxin and ricin toxins and the bacteria Bacillus anthracis. Anthrax will be addressed because of its similarity in both structure and mechanism of catalytic activity with botulinum toxin. The common feature of these three agents is that they exhibit their biological activity via toxin enzymatic hydrolysis of a specific bond in their respective substrate molecules. A brief introduction to the history of each of the biological warfare agents is presented followed by a discussion on the mechanisms of action of each at the molecular level, and a review of current potential inhibitors under investigation. PMID:15790305

  8. A model of anthrax toxin lethal factor bound to protective antigen

    E-print Network

    Baker, David

    translocation in an N- to C-terminal direction. computation docking electrostatic Bacillus anthracis), and lethal factor (LF), that are collectively referred to as anthrax toxin (1). After its proteolytic

  9. Atomic structure of anthrax protective antigen pore elucidates toxin translocation.

    PubMed

    Jiang, Jiansen; Pentelute, Bradley L; Collier, R John; Zhou, Z Hong

    2015-05-28

    Anthrax toxin, comprising protective antigen, lethal factor, and oedema factor, is the major virulence factor of Bacillus anthracis, an agent that causes high mortality in humans and animals. Protective antigen forms oligomeric prepores that undergo conversion to membrane-spanning pores by endosomal acidification, and these pores translocate the enzymes lethal factor and oedema factor into the cytosol of target cells. Protective antigen is not only a vaccine component and therapeutic target for anthrax infections but also an excellent model system for understanding the mechanism of protein translocation. On the basis of biochemical and electrophysiological results, researchers have proposed that a phi (?)-clamp composed of phenylalanine (Phe)427 residues of protective antigen catalyses protein translocation via a charge-state-dependent Brownian ratchet. Although atomic structures of protective antigen prepores are available, how protective antigen senses low pH, converts to active pore, and translocates lethal factor and oedema factor are not well defined without an atomic model of its pore. Here, by cryo-electron microscopy with direct electron counting, we determine the protective antigen pore structure at 2.9-Å resolution. The structure reveals the long-sought-after catalytic ?-clamp and the membrane-spanning translocation channel, and supports the Brownian ratchet model for protein translocation. Comparisons of four structures reveal conformational changes in prepore to pore conversion that support a multi-step mechanism by which low pH is sensed and the membrane-spanning channel is formed. PMID:25778700

  10. Suppressive Effects of Anthrax Lethal Toxin on Megakaryopoiesis

    PubMed Central

    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

    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. PMID:23555687

  11. Anthrax toxin: receptor binding, internalization, pore formation, and translocation.

    PubMed

    Young, John A T; Collier, R John

    2007-01-01

    Anthrax toxin consists of three nontoxic proteins that self-assemble at the surface of receptor-bearing mammalian cells or in solution, yielding a series of toxic complexes. Two of the proteins, called Lethal Factor (LF) and Edema Factor (EF), are enzymes that act on cytosolic substrates. The third, termed Protective Antigen (PA), is a multifunctional protein that binds to receptors, orchestrates the assembly and internalization of the complexes, and delivers them to the endosome. There, the PA moiety forms a pore in the endosomal membrane and promotes translocation of LF and EF to the cytosol. Recent advances in understanding the entry process include insights into how PA recognizes its two known receptors and its ligands, LF and EF; how the PA:receptor interaction influences the pH-dependence of pore formation; and how the pore functions in promoting translocation of LF and EF across the endosomal membrane. PMID:17335404

  12. Evidence against a Human Cell-Specific Role for LRP6 in Anthrax Toxin Entry

    Microsoft Academic Search

    Patricia L. Ryan; John A. T. Young; Debbie Fox

    2008-01-01

    The role of the cellular protein LRP6 in anthrax toxin entry is controversial. Previous studies showed that LRP6 was important for efficient intoxication of human M2182 prostate carcinoma cells but other studies performed with cells from gene-knockout mice demonstrated no role for either LRP6 or the related LRP5 protein in anthrax toxin entry. One possible explanation for this discrepancy is

  13. Potent antitumor activity of a urokinase-activated engineered anthrax toxin

    PubMed Central

    Liu, Shihui; Aaronson, Hannah; Mitola, David J.; Leppla, Stephen H.; Bugge, Thomas H.

    2003-01-01

    The acquisition of cell-surface urokinase plasminogen activator activity is a hallmark of malignancy. We generated an engineered anthrax toxin that is activated by cell-surface urokinase in vivo and displays limited toxicity to normal tissue but broad and potent tumoricidal activity. Native anthrax toxin protective antigen, when administered with a chimeric anthrax toxin lethal factor, Pseudomonas exotoxin fusion protein, was extremely toxic to mice, causing rapid and fatal organ damage. Replacing the furin activation sequence in anthrax toxin protective antigen with an artificial peptide sequence efficiently activated by urokinase greatly attenuated toxicity to mice. In addition, the mutation conferred cell-surface urokinase-dependent toxin activation in vivo, as determined by using a panel of plasminogen, plasminogen activator, plasminogen activator receptor, and plasminogen activator inhibitor-deficient mice. Surprisingly, toxin activation critically depended on both urokinase plasminogen activator receptor and plasminogen in vivo, showing that both proteins are essential cofactors for the generation of cell-surface urokinase. The engineered toxin displayed potent tumor cell cytotoxicity to a spectrum of transplanted tumors of diverse origin and could eradicate established solid tumors. This tumoricidal activity depended strictly on tumor cell-surface plasminogen activation. The data show that a simple change of protease activation specificity converts anthrax toxin from a highly lethal to a potent tumoricidal agent. PMID:12525700

  14. Potent antitumor activity of a urokinase-activated engineered anthrax toxin

    NASA Astrophysics Data System (ADS)

    Liu, Shihui; Aaronson, Hannah; Mitola, David J.; Leppla, Stephen H.; Bugge, Thomas H.

    2003-01-01

    The acquisition of cell-surface urokinase plasminogen activator activity is a hallmark of malignancy. We generated an engineered anthrax toxin that is activated by cell-surface urokinase in vivo and displays limited toxicity to normal tissue but broad and potent tumoricidal activity. Native anthrax toxin protective antigen, when administered with a chimeric anthrax toxin lethal factor, Pseudomonas exotoxin fusion protein, was extremely toxic to mice, causing rapid and fatal organ damage. Replacing the furin activation sequence in anthrax toxin protective antigen with an artificial peptide sequence efficiently activated by urokinase greatly attenuated toxicity to mice. In addition, the mutation conferred cell-surface urokinase-dependent toxin activation in vivo, as determined by using a panel of plasminogen, plasminogen activator, plasminogen activator receptor, and plasminogen activator inhibitor-deficient mice. Surprisingly, toxin activation critically depended on both urokinase plasminogen activator receptor and plasminogen in vivo, showing that both proteins are essential cofactors for the generation of cell-surface urokinase. The engineered toxin displayed potent tumor cell cytotoxicity to a spectrum of transplanted tumors of diverse origin and could eradicate established solid tumors. This tumoricidal activity depended strictly on tumor cell-surface plasminogen activation. The data show that a simple change of protease activation specificity converts anthrax toxin from a highly lethal to a potent tumoricidal agent.

  15. Tumor Endothelium Marker8 Based Decoys Exhibit Superiority over Capillary Morphogenesis Protein2 Based Decoys as Anthrax Toxin Inhibitors

    Microsoft Academic Search

    Chenguang Cai; Jinjing Che; Long Xu; Qiang Guo; Yirong Kong; Ling Fu; Junjie Xu; Yuanguo Cheng; Wei Chen

    2011-01-01

    Anthrax toxin is the major virulence factor produced by Bacillus anthracis. The toxin consists of three protein subunits: protective antigen (PA), lethal factor, and edema factor. Inhibition of PA binding to its receptors, tumor endothelium marker-8 (TEM8) and capillary morphogenesis protein-2 (CMG2) can effectively block anthrax intoxication, which is particularly valuable when the toxin has already been overproduced at the

  16. Binding of anthrax toxin to its receptor is similar to alpha integrin-ligand interactions.

    PubMed

    Bradley, Kenneth A; Mogridge, Jeremy; Jonah, G; Rainey, A; Batty, Sarah; Young, John A T

    2003-12-01

    The secreted protein toxin produced by Bacillus anthracis contributes to virulence of this pathogen and can cause many of the symptoms seen during an anthrax infection, including shock and sudden death. The cell-binding component of anthrax toxin, protective antigen, mediates entry of the toxin into cells by first binding directly to the extracellular integrin-like inserted (I) domain of the cellular anthrax toxin receptor, ATR. Here we report that this interaction requires an intact metal ion-dependent adhesion site (MIDAS) in the receptor as well as the presence of specific divalent cations. Also, we demonstrate that the toxin-receptor interaction is critically dependent on the Asp-683 carboxylate group of protective antigen, which projects from the receptor binding surface. We propose that this carboxylate group completes the coordination of the MIDAS metal of ATR, mimicking integrin-ligand interactions. PMID:14507921

  17. Anthrax vaccine design: strategies to achieve comprehensive protection against spore, bacillus, and toxin.

    PubMed

    Wang, Julia Y; Roehrl, Michael H

    2005-03-24

    The successful use of Bacillus anthracis as a lethal biological weapon has prompted renewed research interest in the development of more effective vaccines against anthrax. The disease consists of three critical components: spore, bacillus, and toxin, elimination of any of which confers at least partial protection against anthrax. Current remedies rely on postexposure antibiotics to eliminate bacilli and pre- and postexposure vaccination to target primarily toxins. Vaccines effective against toxin have been licensed for human use, but need improvement. Vaccines against bacilli have recently been developed by us and others. Whether effective vaccines will be developed against spores is still an open question. An ideal vaccine would confer simultaneous protection against spores, bacilli, and toxins. One step towards this goal is our dually active vaccine, designed to destroy both bacilli and toxin. Existing and potential strategies towards potent and effective anthrax vaccines are discussed in this review. PMID:15790405

  18. Manipulation of host signalling pathways by anthrax toxins.

    PubMed

    Turk, Benjamin E

    2007-03-15

    Infectious microbes face an unwelcoming environment in their mammalian hosts, which have evolved elaborate multicelluar systems for recognition and elimination of invading pathogens. A common strategy used by pathogenic bacteria to establish infection is to secrete protein factors that block intracellular signalling pathways essential for host defence. Some of these proteins also act as toxins, directly causing pathology associated with disease. Bacillus anthracis, the bacterium that causes anthrax, secretes two plasmid-encoded enzymes, LF (lethal factor) and EF (oedema factor), that are delivered into host cells by a third bacterial protein, PA (protective antigen). The two toxins act on a variety of cell types, disabling the immune system and inevitably killing the host. LF is an extraordinarily selective metalloproteinase that site-specifically cleaves MKKs (mitogen-activated protein kinase kinases). Cleavage of MKKs by LF prevents them from activating their downstream MAPK (mitogen-activated protein kinase) substrates by disrupting a critical docking interaction. Blockade of MAPK signalling functionally impairs cells of both the innate and adaptive immune systems and induces cell death in macrophages. EF is an adenylate cyclase that is activated by calmodulin through a non-canonical mechanism. EF causes sustained and potent activation of host cAMP-dependent signalling pathways, which disables phagocytes. Here I review recent progress in elucidating the mechanisms by which LF and EF influence host signalling and thereby contribute to disease. PMID:17313374

  19. Anthrax lethal toxin: a weapon of multisystem destruction.

    PubMed

    Agrawal, A; Pulendran, B

    2004-11-01

    Lethal toxin (LT) is a major virulence factor secreted by anthrax bacteria. It is composed of two proteins, PA (protective antigen) and LF (lethal factor). PA transports the LF inside the cell, where LF, a zinc-dependent metalloprotease cleaves the mitogen activated protein kinase kinase (MAPKK) enzymes of the mitogen activated protein kinase (MAPK) signaling pathway, thereby impairing their function. This disruption of the MAPK pathway, which serves essential functions such as proliferation, survival and inflammation in all cell types, results in multisystem dysfunction in the host. The inactivation of the MAPK pathway in both macrophages and dendritic cells leads to inhibition of proinflammatory cytokine secretion, downregulation of costimulatory molecules such as CD80 and CD86, and ineffective T cell priming. The net result is an impaired innate and adaptive immune response. Endothelial cells of the vascular system undergo apoptosis upon LT exposure, also likely due to inactivation of the MAPK pathway. The activity of various hormone receptors such as glucocorticoids, progesterone and estrogen is also blocked, due to inhibition of p38 MAPK phosphorylation, thus affecting the body's response to stress. The present review summarizes the various disarming effects of Bacillus anthracis through the use of a single weapon, the lethal toxin. PMID:15558214

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

    PubMed Central

    Guichard, Annabel; Nizet, Victor; Bier, Ethan

    2013-01-01

    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. PMID:21930233

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

    PubMed

    Guichard, Annabel; Nizet, Victor; Bier, Ethan

    2012-02-01

    The anthrax toxins lethal toxin (LT) and edema toxin (ET) are essential virulence factors produced by Bacillus 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. PMID:21930233

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

    PubMed Central

    2011-01-01

    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. PMID:22185669

  3. Antibodies to anthrax toxin in humans and guinea pigs and their relevance to protective immunity

    Microsoft Academic Search

    P. C. B. Turnbull; S. H. Leppla; M. G. Broster; C. P. Quinn; J. Malling

    1988-01-01

    A forerunning study on the relationship between antibodies to the protective antigen (PA) and lethal factor (LF) components of anthrax toxin and protective immunity has been expanded and extended to include the third toxin component, the edema factor (EF). It was found that protection against the “vaccine resistant” Ames strain was possible in the absence of detectable anti-LF and anti-EF

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

    Microsoft Academic Search

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

    2001-01-01

    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 mem- branes. These mutants

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

    NASA Astrophysics Data System (ADS)

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

    2001-04-01

    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.

  6. Immune system paralysis by anthrax lethal toxin: the roles of innate and adaptive immunity.

    PubMed

    Fukao, Taro

    2004-03-01

    Since the deliberate use of anthrax as a bioweapon in the USA in 2001, an enormous amount of attention has been focused on the biology of Bacillus anthracis, the causative bacterium of anthrax. Fatal systemic anthrax involves massive bacteraemia and toxaemia with non-descript early symptoms until the onset of shock and sudden death. The outbreak of fatal symptoms after the incubation period of B anthracis suggests an impairment of the host immune system against this pathogen. Thus, it is likely that B anthracis will possess certain strategies to escape from the host immune system. However, the mechanisms of such immune-evasion strategies are not fully characterised yet. Given the critical role of B anthracis toxins in anthrax pathogenesis, much effort has been made to understand the pathological nature of the toxins. Recent studies have shown the pleiotropic actions of anthrax lethal toxin on host innate immune cells, and that several effects of anthrax lethal toxin may directly account for the mechanism of immune intervention by B anthracis. PMID:14998502

  7. Control of Anthrax Toxin Gene Expression by the Transition State Regulator abrB

    Microsoft Academic Search

    Elke Saile; Theresa M. Koehler

    2002-01-01

    Bacillus anthracis produces the anthrax toxin proteins protective antigen (PA), lethal factor (LF), and edema factor (EF) in a growth phase-dependent manner when cultured in liquid medium. Expression of the toxin genes pagA, lef, and cya peaks in late log phase, and steady-state levels of the toxin proteins are highest during the transition into stationary phase. Here we show that

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

    Microsoft Academic Search

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

    2002-01-01

    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.

  9. Delayed Toxicity Associated with Soluble Anthrax Toxin Receptor Decoy-Ig Fusion Protein Treatment

    Microsoft Academic Search

    Diane Thomas; John Naughton; Christopher Cote; Susan Welkos; Marianne Manchester; John A. T. Young

    2012-01-01

    Soluble receptor decoy inhibitors, including receptor-immunogloubulin (Ig) fusion proteins, have shown promise as candidate anthrax toxin therapeutics. These agents act by binding to the receptor-interaction site on the protective antigen (PA) toxin subunit, thereby blocking toxin binding to cell surface receptors. Here we have made the surprising observation that co-administration of receptor decoy-Ig fusion proteins significantly delayed, but did not

  10. 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 ...

  11. Consequences and utility of the zinc-dependent metalloprotease activity of anthrax lethal toxin.

    PubMed

    Bromberg-White, Jennifer; Lee, Chih-Shia; Duesbery, Nicholas

    2010-05-01

    Anthrax is caused by the gram-positive bacterium Bacillus anthracis. The pathogenesis of this disease is dependent on the presence of two binary toxins, edema toxin (EdTx) and lethal toxin (LeTx). LeTx, the major virulence factor contributing to anthrax, contains the effector moiety lethal factor (LF), a zinc-dependent metalloprotease specific for targeting mitogen-activated protein kinase kinases. This review will focus on the protease-specific activity and function of LF, and will include a discussion on the implications and consequences of this activity, both in terms of anthrax disease, and how this activity can be exploited to gain insight into other pathologic conditions. PMID:22069624

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

    Microsoft Academic Search

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

    2011-01-01

    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

  13. Development of receptor-based inhibitory RNA aptamers for anthrax toxin neutralization.

    PubMed

    Lee, Sang-Choon; Gedi, Vinayakumar; Ha, Na-Reum; Cho, Jun-Haeng; Park, Hae-Chul; Yoon, Moon-Young

    2015-06-01

    Anthrax toxin excreted by Bacillus anthracis is the key causative agent of infectious anthrax disease. In the present study, we targeted the binding of PA to the ATR/TEM8 Von Willebrand factor type A (VWA) domain, which we cloned into Escherichia coli and purified to homogeneity under denaturing conditions. To develop an anthrax toxin inhibitor, we selected and identified short single strand RNA aptamers (approximately 30mer) consisting of different sequences of nucleic acids with a high binding affinity in the 100 nanomolar range against the recombinant ATR/TEM8 VWA domain using systematic evolution of ligands by exponential enrichment (SELEX). Five candidate aptamers were further characterized by several techniques including secondary structural analysis. The inhibitor efficiency (IC50) of one of the aptamers toward anthrax toxin was approximately 5?M in macrophage RAW 264.7 cells, as determined from cytotoxicity analysis by MTT assay. We believe that the candidate aptamers should be useful for blocking the binding of PA to its receptor in order to neutralize anthrax toxin. PMID:25841381

  14. The potential contributions of lethal and edema toxins to the pathogenesis of anthrax associated shock.

    PubMed

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

    2011-09-01

    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. PMID:22069762

  15. Role of anthrax toxins in dissemination, disease progression, and induction of protective adaptive immunity in the mouse aerosol challenge model.

    PubMed

    Loving, Crystal L; Khurana, Taruna; Osorio, Manuel; Lee, Gloria M; Kelly, Vanessa K; Stibitz, Scott; Merkel, Tod J

    2009-01-01

    Anthrax toxins significantly contribute to anthrax disease pathogenesis, and mechanisms by which the toxins affect host cellular responses have been identified with purified toxins. However, the contribution of anthrax toxin proteins to dissemination, disease progression, and subsequent immunity after aerosol infection with spores has not been clearly elucidated. To better understand the role of anthrax toxins in pathogenesis in vivo and to investigate the contribution of antibody to toxin proteins in protection, we completed a series of in vivo experiments using a murine aerosol challenge model and a collection of in-frame deletion mutants lacking toxin components. Our data show that after aerosol exposure to Bacillus anthracis spores, anthrax lethal toxin was required for outgrowth of bacilli in the draining lymph nodes and subsequent progression of infection beyond the lymph nodes to establish disseminated disease. After pulmonary exposure to anthrax spores, toxin expression was required for the development of protective immunity to a subsequent lethal challenge. However, immunoglobulin (immunoglobulin G) titers to toxin proteins, prior to secondary challenge, did not correlate with the protection observed upon secondary challenge with wild-type spores. A correlation was observed between survival after secondary challenge and rapid anamnestic responses directed against toxin proteins. Taken together, these studies indicate that anthrax toxins are required for dissemination of bacteria beyond the draining lymphoid tissue, leading to full virulence in the mouse aerosol challenge model, and that primary and anamnestic immune responses to toxin proteins provide protection against subsequent lethal challenge. These results provide support for the utility of the mouse aerosol challenge model for the study of inhalational anthrax. PMID:18955474

  16. Tumor Endothelium Marker-8 Based Decoys Exhibit Superiority over Capillary Morphogenesis Protein-2 Based Decoys as Anthrax Toxin Inhibitors

    PubMed Central

    Xu, Long; Guo, Qiang; Kong, Yirong; Fu, Ling; Xu, Junjie; Cheng, Yuanguo; Chen, Wei

    2011-01-01

    Anthrax toxin is the major virulence factor produced by Bacillus anthracis. The toxin consists of three protein subunits: protective antigen (PA), lethal factor, and edema factor. Inhibition of PA binding to its receptors, tumor endothelium marker-8 (TEM8) and capillary morphogenesis protein-2 (CMG2) can effectively block anthrax intoxication, which is particularly valuable when the toxin has already been overproduced at the late stage of anthrax infection, thus rendering antibiotics ineffectual. Receptor-like agonists, such as the mammalian cell-expressed von Willebrand factor type A (vWA) domain of CMG2 (sCMG2), have demonstrated potency against the anthrax toxin. However, the soluble vWA domain of TEM8 (sTEM8) was ruled out as an anthrax toxin inhibitor candidate due to its inferior affinity to PA. In the present study, we report that L56A, a PA-binding-affinity-elevated mutant of sTEM8, could inhibit anthrax intoxication as effectively as sCMG2 in Fisher 344 rats. Additionally, pharmacokinetics showed that L56A and sTEM8 exhibit advantages over sCMG2 with better lung-targeting and longer plasma retention time, which may contribute to their enhanced protective ability in vivo. Our results suggest that receptor decoys based on TEM8 are promising anthrax toxin inhibitors and, together with the pharmacokinetic studies in this report, may contribute to the development of novel anthrax drugs. PMID:21674060

  17. Anthrax.

    PubMed

    Wenner, Kimberly A; Kenner, Julie R

    2004-07-01

    Anthrax is an ancient disease associated with the plagues in biblical Egypt and modern bioterrorism. Three clinical syndromes result from exposure to anthrax spores: cutaneous,inhalational, and gastrointestinal. Cutaneous anthrax is the most common naturally occurring syndrome; inhalational anthrax is most likely to result from airborne release of spores. Prophylactic and early treatment can improve the mortality from inhalational anthrax. A vaccine is available, but has many limitations. New vaccines are currently being developed. PMID:15207306

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

    PubMed Central

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

    2013-01-01

    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

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

    PubMed

    Beierlein, J M; Anderson, A C

    2011-01-01

    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

  20. Nasal immunization with a dual antigen anthrax vaccine induced strong mucosal and systemic immune responses against toxins and bacilli.

    PubMed

    Sloat, Brian R; Cui, Zhengrong

    2006-09-29

    Anthrax-vaccine-adsorbed (AVA), the only anthrax vaccine licensed in the U.S., suffers from many major drawbacks. Therefore, there is a need to develop new generation anthrax vaccines that can be easily administered and induce strong immune responses not only against the anthrax toxins, but also against the toxin-producing vegetative anthrax bacilli. In the present study, we evaluated the feasibility of inducing strong mucosal and systemic immune responses against both anthrax toxins and bacilli after nasal immunization using a synthetic double-stranded RNA (dsRNA), polyriboinosinic-polyribocytidylic acid (poly(I:C) or pI:C), as the adjuvant. We have shown that the capsular poly-gamma-D-glutamic acid (PGA) from bacillus was immunogenic when conjugated to a carrier protein and dosed intranasally to mice. We further demonstrated that nasal immunization with the PGA-carrier protein conjugate in combination with the anthrax protective antigen (PA) protein induced both anti-PGA and anti-PA immune responses in mouse sera and lung mucosal secretions. The anti-PA antibody (Ab) response was shown to have anthrax lethal toxin neutralization activity; and the anti-PGA Abs induced were able to activate complement and kill PGA-producing bacteria. These findings demonstrated that it is feasible to develop a novel dual-action nasal anthrax vaccine. PMID:16828937

  1. Proteasomes Control Caspase-1 Activation in Anthrax Lethal Toxin-mediated Cell Killing*S

    E-print Network

    Brojatsch, Jürgen

    Proteasomes Control Caspase-1 Activation in Anthrax Lethal Toxin-mediated Cell Killing*S Received, MAPKK cleavage is insufficient for LT killing and is possibly not even required for this process (17). In the mouse model, the susceptibility of antigen-presenting cells to LT killing is strain

  2. Cryo-electron microscopy study of bacteriophage T4 displaying anthrax toxin proteins

    Microsoft Academic Search

    Andrei Fokine; Valorie D. Bowman; Anthony J. Battisti; Qin Li; Paul R. Chipman; Venigalla B. Rao; Michael G. Rossmann

    2007-01-01

    The bacteriophage T4 capsid contains two accessory surface proteins, the small outer capsid protein (Soc, 870 copies) and the highly antigenic outer capsid protein (Hoc, 155 copies). As these are dispensable for capsid formation, they can be used for displaying proteins and macromolecular complexes on the T4 capsid surface. Anthrax toxin components were attached to the T4 capsid as a

  3. Cytotoxic T-Lymphocyte Epitopes Fused to Anthrax Toxin Induce Protective Antiviral Immunity

    Microsoft Academic Search

    AMY M. DOLING; JIMMY D. BALLARD; HAO SHEN; KAJA MURALI KRISHNA; RAFI AHMED; R. JOHN COLLIER; MICHAEL N. STARNBACH

    1999-01-01

    We have investigated the use of the protective antigen (PA) and lethal factor (LF) components of anthrax toxin as a system for in vivo delivery of cytotoxic T-lymphocyte (CTL) epitopes. During intoxication, PA directs the translocation of LF into the cytoplasm of mammalian cells. Here we demonstrate that antiviral immunity can be induced in BALB\\/c mice immunized with PA plus

  4. LETTER doi:10.1038/nature09446 Anthrax toxins cooperatively inhibit endocytic

    E-print Network

    Nizet, Victor

    Sorge2 *, Victor Nizet2,4 & Ethan Bier1 Bacillus anthracis is the causative agent of anthrax in humans to toxin-dependent barrier disruption and vascular dysfunction during B. anthracis infection. B. anthracis is whether LF and EF, which are both required individually for the pathogenicity of B. anthracis, also

  5. Anthrax uses a receptor on the surface of cells to inject its lethal toxins. However, the physiological function of this receptor, named

    E-print Network

    Loewith, Robbie

    Anthrax uses a receptor on the surface of cells to inject its lethal toxins. However, the physiological function of this receptor, named Anthrax Toxin Receptor 2a (Antxr2a), remained unknown until now. Anthrax is a particularly virulent germ once a person is infected by inhaling its spores. The severity

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

    PubMed Central

    Koya, Vijay; Moayeri, Mahtab; Leppla, Stephen H.; Daniell, Henry

    2005-01-01

    The currently available human vaccine for anthrax, derived from the culture supernatant of Bacillus anthracis, contains the protective antigen (PA) and traces of the lethal and edema factors, which may contribute to adverse side effects associated with this vaccine. Therefore, an effective expression system that can provide a clean, safe, and efficacious vaccine is required. In an effort to produce anthrax vaccine in large quantities and free of extraneous bacterial contaminants, PA was expressed in transgenic tobacco chloroplasts by inserting the pagA gene into the chloroplast genome. Chloroplast integration of the pagA gene was confirmed by PCR and Southern analysis. Mature leaves grown under continuous illumination contained PA as up to 14.2% of the total soluble protein. Cytotoxicity measurements in macrophage lysis assays showed that chloroplast-derived PA was equal in potency to PA produced in B. anthracis. Subcutaneous immunization of mice with partially purified chloroplast-derived or B. anthracis-derived PA with adjuvant yielded immunoglobulin G titers up to 1:320,000, and both groups of mice survived (100%) challenge with lethal doses of toxin. An average yield of about 150 mg of PA per plant should produce 360 million doses of a purified vaccine free of bacterial toxins edema factor and lethal factor from 1 acre of land. Such high expression levels without using fermenters and the immunoprotection offered by the chloroplast-derived PA should facilitate development of a cleaner and safer anthrax vaccine at a lower production cost. These results demonstrate the immunogenic and immunoprotective properties of plant-derived anthrax vaccine antigen. PMID:16299323

  7. Molecular Dynamics Simulations of Complexes Between Wild-Type and Mutant Anthrax Protective Antigen Variants and a Model Anthrax Toxin Receptor

    Microsoft Academic Search

    Linsey Stiles; Donald J. Nelson

    2005-01-01

    Bacillus anthracis, a spore-forming infectious bacterium, produces a toxin consisting of three proteins: lethal factor (LF), edema factor (EF), and protective antigen (PA). LF and EF possess intracellular enzymatic functions, the net effect of which is to severely compromise host innate immunity. During an anthrax infection PA plays the critical role of facilitating entry of both EF and LF toxins

  8. Anthrax 

    E-print Network

    Lawhorn, D. Bruce

    2001-08-09

    Anthrax is a very destructive animal disease found worldwide. This publication describes anthrax symptoms in livestock, deer and people, and explains how a diagnosis is made. There is important information about prevention, control and actions...

  9. Anthrax

    MedlinePLUS

    Anthrax is a disease caused by Bacillus anthracis, a germ that lives in soil. Many people know ... bioterror attacks. In the attacks, someone purposely spread anthrax through the U.S. mail. This killed five people ...

  10. Anthrax Toxin Receptor Drives Protective Antigen Oligomerization and Stabilizes the Heptameric and Octameric Oligomer by a Similar Mechanism

    Microsoft Academic Search

    Alexander F. Kintzer; Harry J. Sterling; Iok I. Tang; Evan R. Williams; Bryan A. Krantz; Andreas Hofmann

    2010-01-01

    BackgroundAnthrax toxin is comprised of protective antigen (PA), lethal factor (LF), and edema factor (EF). These proteins are individually nontoxic; however, when PA assembles with LF and EF, it produces lethal toxin and edema toxin, respectively. Assembly occurs either on cell surfaces or in plasma. In each milieu, PA assembles into a mixture of heptameric and octameric complexes that bind

  11. An Anthrax Lethal Factor-Neutralizing Monoclonal Antibody Protects Rats before and after Challenge with Anthrax Toxin

    Microsoft Academic Search

    Nam-Kyu Lim; Jung-Hwan Kim; Mee Sook Oh; Sangyoon Lee; Se-Yeon Kim; Keun-Soo Kim; Hyun-jung Kang; Hyo Jeong Hong

    2005-01-01

    Lethal factor (LF) is a component of anthrax lethal toxin (LeTx). We generated anti-LF murine monoclonal antibodies (MAbs) that show LeTx-neutralizing activity in vitro and in vivo. Anti-LF MAbs were generated by immunization with recombinant LF, and the MAbs showing LeTx-neutralizing activity in vitro were selected. Two MAbs with the highest affinities, 5B13B1 (dissociation constant (Kd), 2.62 nM) and 3C16C3

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

    PubMed Central

    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

    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. PMID:23152930

  13. Anti-toxin antibodies in prophylaxis and treatment of inhalation anthrax.

    PubMed

    Schneemann, Anette; Manchester, Marianne

    2009-02-01

    The CDC recommend 60 days of oral antibiotics combined with a three-dose series of the anthrax vaccine for prophylaxis after potential exposure to aerosolized Bacillus anthracis spores. The anthrax vaccine is currently not licensed for anthrax postexposure prophylaxis and has to be made available under an Investigational New Drug protocol. Postexposure prophylaxis based on antibiotics can be problematic in cases where the use of antibiotics is contraindicated. Furthermore, there is a concern that an exposure could involve antibiotic-resistant strains of B. anthracis. Availability of alternate treatment modalities that are effective in prophylaxis of inhalation anthrax is therefore highly desirable. A major research focus toward this end has been on passive immunization using polyclonal and monoclonal antibodies against B. anthracis toxin components. Since 2001, significant progress has been made in isolation and commercial development of monoclonal and polyclonal antibodies that function as potent neutralizers of anthrax lethal toxin in both a prophylactic and therapeutic setting. Several new products have completed Phase I clinical trials and are slated for addition to the National Strategic Stockpile. These rapid advances were possible because of major funding made available by the US government through programs such as Bioshield and the Biomedical Advanced Research and Development Authority. Continued government funding is critical to support the development of a robust biodefense industry. PMID:19207098

  14. ANTHRAX

    Microsoft Academic Search

    Michele Mock; Agnes Fouet

    2001-01-01

    Anthrax is an ancient bacterial infection capable of infecting nearly all warm-blooded animals. It has existed since early-recorded history as a disease of both human beings and their livestock. However, recent exposures to anthrax due to bioterrorism have turned anthrax and its mechanisms of infection into an important topic of inquiry. As new information is obtained, more effective treatments for

  15. The Design of Potent Liposome-Based Inhibitors of Anthrax Toxin

    NASA Astrophysics Data System (ADS)

    Rai, Prakash; Padala, Chakradhar; Poon, Vincent; Saraph, Arundhati; Basha, Saleem; Kate, Sandesh; Tao, Kevin; Mogridge, Jeremy; Kane, Ravi

    2006-03-01

    Several biological processes involve the recognition of a specific pattern of binding sites on a target surface. Theoreticians have predicted that endowing synthetic biomimetic structures with statistical pattern matching capabilities may impact the development of sensors and separation processes. We demonstrated for the first time that statistical pattern matching significantly enhances the potency of a polyvalent therapeutic -- an anthrax toxin inhibitor. We functionalized liposomes with an inhibitory peptide at different densities and observed a transition in potency at an inter-peptide separation that matches the distance between ligand-binding sites on the heptameric subunit of anthrax toxin. Pattern-matched polyvalent liposomes neutralized anthrax toxin in vitro at concentrations four orders of magnitude lower than the corresponding monovalent peptide. We also showed that polyvalent liposome-based inhibitors can neutralize a microbial toxin in vivo. Statistical pattern matching represents a facile strategy to enhance the potency of therapeutics targeting toxins or pathogens. Our results also illuminate other fundamental aspects of polyvalent recognition --specifically we found that the efficiency of polyvalent inhibition is influenced by the competition between the rates of ligand dissociation and diffusion.

  16. Anthrax toxin: the long and winding road that leads to the kill.

    PubMed

    Abrami, Laurence; Reig, Nuria; van der Goot, F Gisou

    2005-02-01

    The past five years have led to a tremendous increase in our molecular understanding of the mode of action of the anthrax toxin, one of the two main virulence factors produced by Bacillus anthracis. The structures of each of the three components of the toxin--lethal factor (LF), edema factor (EF) and protective antigen (PA)--have been solved not only in their monomeric forms but, depending on the subunit, in a heptameric form, bound to their substrate, co-factor or receptor. The endocytic route followed by the toxin has also been unraveled and the enzymatic mechanisms of EF and LF elucidated. PMID:15680766

  17. Crystal structure of the von Willebrand factor A domain of human capillary morphogenesis protein 2: An anthrax toxin receptor

    Microsoft Academic Search

    D. Borden Lacy; Darran J. Wigelsworth; Heather M. Scobie; John A. T. Young; R. John Collier

    2004-01-01

    Anthrax toxin is released from Bacillus anthracis as three monomeric proteins, which assemble into toxic complexes at the surface of receptor-bearing host cells. One of the proteins, protective antigen (PA), binds to receptors and orchestrates the delivery of the other two (the lethal and edema factors) into the cytosol. PA has been shown to bind to two cellular receptors: anthrax

  18. Detection of Anthrax Toxin in the Serum of Animals Infected with Bacillus anthracis by Using Engineered Immunoassays

    PubMed Central

    Mabry, Robert; Brasky, Kathleen; Geiger, Robert; Carrion, Ricardo; Hubbard, Gene B.; Leppla, Stephen; Patterson, Jean L.; Georgiou, George; Iverson, B. L.

    2006-01-01

    Several strategies that target anthrax toxin are being developed as therapies for infection by Bacillus anthracis. Although the action of the tripartite anthrax toxin has been extensively studied in vitro, relatively little is known about the presence of toxins during an infection in vivo. We developed a series of sensitive sandwich enzyme-linked immunosorbent assays (ELISAs) for detection of both the protective antigen (PA) and lethal factor (LF) components of the anthrax exotoxin in serum. The assays utilize as capture agents an engineered high-affinity antibody to PA, a soluble form of the extracellular domain of the anthrax toxin receptor (ANTXR2/CMG2), or PA itself. Sandwich immunoassays were used to detect and quantify PA and LF in animals infected with the Ames or Vollum strains of anthrax spores. PA and LF were detected before and after signs of toxemia were observed, with increasing levels reported in the late stages of the infection. These results represent the detection of free PA and LF by ELISA in the systemic circulation of two animal models exposed to either of the two fully virulent strains of anthrax. Simple anthrax toxin detection ELISAs could prove useful in the evaluation of potential therapies and possibly as a clinical diagnostic to complement other strategies for the rapid identification of B. anthracis infection. PMID:16760326

  19. Anthrax, toxins and vaccines: a 125-year journey targeting Bacillus anthracis.

    PubMed

    Tournier, Jean-Nicolas; Ulrich, Robert G; Quesnel-Hellmann, Anne; Mohamadzadeh, Mansour; Stiles, Bradley G

    2009-03-01

    Bacillus anthracis is the causative agent of anthrax, a disease that plagues both humans and various animal species. Effective vaccines are available, but those approved for human use are crude culture supernatants that require multiple injections and a yearly boost. Many experts agree that it is now time for the next generation of human vaccines against anthrax. Accordingly, this review will succinctly focus upon: pathogenesis of B. anthracis, with particular emphasis upon the immune system; the pertinent biophysical nature of protective antigen, which includes how the protein toxin component affords protection as a vaccine target; alternative methods for improving protective antigen as an immunogen; and additional B. anthracis antigens that might further sustain protective titers in humans. In addition to a better understanding of the disease process elicited by B. anthracis, which will logically lead to better vaccines (and therapeutics), there also needs to be the same level of open-mindedness applied to the politics of anthrax. PMID:19254170

  20. Heterodimeric integrin complexes containing ?1-integrin promote internalization and lethality of anthrax toxin

    PubMed Central

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

    2010-01-01

    To kill macrophages, the lethal factor component of Bacillus anthracis toxin binds to a carrier protein (PA), which then interacts with the CMG2 receptor protein on the cell surface and is endocytosed into the cytoplasm. CMG2, as well as TEM8, a second PA receptor not present on macrophages, contain a von Willebrand A domain that is crucial for toxin binding. Here we report that integrin ?1, another cell surface von Willebrand A domain protein, can mediate and potentiate anthrax toxin endocytosis. By using microarray-based analysis to globally correlate gene expression profiles with toxin sensitivity, we associated toxin effects with the integrin-activating proteins osteopontin and CD44. Further study showed that PA binds to ?4?1– and ?5?1–integrin complexes, leading to their conjoint endocytosis, and also interacts—weakly relative to CMG2 but comparably to TEM8—with purified ?5?1 complex in vitro. Monoclonal antibody directed against ?1-integrin or its ? integrin partners reduced PA/integrin endocytosis and anthrax toxin lethality, and hyaluronic acid—which interferes with CD44-mediated integrin activation—had similar effects. Remarkably, whereas deficiency of CMG2 protected macrophages from rapid killing by large toxin doses (>50 ng/mL), by 24 h the toxin-treated cells were dead. Such late killing of CMG2-deficient cells by high dose toxin as well as the late death observed during exposure of CMG2-producing macrophages to low-dose toxin (<1 ng/mL), was dependent on integrin function. Effects of inactivating both CMG2 and integrin were synergistic. Collectively, our findings argue strongly that ?1-integrin can both potentiate CMG2-mediated endocytosis and serve independently as a low-affinity PA receptor. PMID:20713715

  1. Anthrax toxins: A paradigm of bacterial immune suppression.

    PubMed

    Baldari, Cosima T; Tonello, Fiorella; Paccani, Silvia Rossi; Montecucco, Cesare

    2006-09-01

    Several species of microorganism have developed immune evasion and/or immunosuppression strategies. Bacillus anthracis secretes two toxins, edema toxin and lethal toxin, that enter the cytosol of almost every cell type, including the cells of the innate and adaptive immune systems, and subvert cell signaling. Edema toxin causes a consistent elevation of cyclic adenosine monophosphate, whereas lethal toxin cleaves most isoforms of mitogen-activated protein kinase kinases. In a concerted manner, these toxins alter major signaling pathways involved in the development of immune-cell effector functions, with the inhibition of bacterial clearance by phagocytes and of B. anthracis-specific responses. Thus, B. anthracis can invade the host, with ensuing massive bacteremia and toxemia. Here, we review the specific effects of B. anthracis on neutrophils, macrophages, dendritic cells, T- and B-lymphocytes. PMID:16861036

  2. Anthrax.

    PubMed

    Kalamas, Alicia Gruber

    2004-09-01

    Anthrax is an often fatal bacterial infection that occurs when Bacillus anthracis endospores enter the body through one of three major routes: inhalational, cutaneous, or gastrointestinal. Before the anthrax terrorist attacks in the United States in 2001, there was very little interest in anthrax as a serious human pathogen; anthrax was viewed mainly as a veterinarian problem of minor importance, with most cases attributed to occupational exposure. However, this cavalier attitude toward anthrax changed following the 2001 terrorist attacks. Although the number of cases was relatively small, the attacks have heightened concern about the feasibility of large-scale aerosol bioweapons attacks by terrorist groups. Many, if not most patients, would require some degree of critical care in the form of ventilator or hemodynamic support. It is for this reason that anesthesiologists and other critical care physicians have specific knowledge of the diagnosis, treatment, and prevention of anthrax. PMID:15325717

  3. Cryo-electron microscopy study of bacteriophage T4 displaying anthrax toxin proteins

    SciTech Connect

    Fokine, Andrei; Bowman, Valorie D.; Battisti, Anthony J. [Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, IN 47907-2054 (United States); Li Qin [Department of Biology, Catholic University of America, 620 Michigan Avenue NE, Washington, DC 20064 (United States); Chipman, Paul R. [Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, IN 47907-2054 (United States); Rao, Venigalla B. [Department of Biology, Catholic University of America, 620 Michigan Avenue NE, Washington, DC 20064 (United States); Rossmann, Michael G. [Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, IN 47907-2054 (United States)], E-mail: mr@purdue.edu

    2007-10-25

    The bacteriophage T4 capsid contains two accessory surface proteins, the small outer capsid protein (Soc, 870 copies) and the highly antigenic outer capsid protein (Hoc, 155 copies). As these are dispensable for capsid formation, they can be used for displaying proteins and macromolecular complexes on the T4 capsid surface. Anthrax toxin components were attached to the T4 capsid as a fusion protein of the N-terminal domain of the anthrax lethal factor (LFn) with Soc. The LFn-Soc fusion protein was complexed in vitro with Hoc{sup -}Soc{sup -}T4 phage. Subsequently, cleaved anthrax protective antigen heptamers (PA63){sub 7} were attached to the exposed LFn domains. A cryo-electron microscopy study of the decorated T4 particles shows the complex of PA63 heptamers with LFn-Soc on the phage surface. Although the cryo-electron microscopy reconstruction is unable to differentiate on its own between different proposed models of the anthrax toxin, the density is consistent with a model that had predicted the orientation and position of three LFn molecules bound to one PA63 heptamer.

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

    Microsoft Academic Search

    1997-01-01

    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

  5. Proteasome Activity Is Required for Anthrax Lethal Toxin To Kill Macrophages

    Microsoft Academic Search

    GUANGQING TANG; STEPHEN H. LEPPLA

    1999-01-01

    Anthrax lethal toxin (LeTx), consisting of protective antigen (PA) and lethal factor (LF), rapidly kills primary mouse macrophages and macrophage-like cell lines such as RAW 264.7. LF is translocated by PA into the cytosol of target cells, where it acts as a metalloprotease to cleave mitogen-activated protein kinase kinase 1 (MEK1) and possibly other proteins. In this study, we show

  6. Anthrax Lethal Toxin Triggers the Formation of a Membrane-Associated Inflammasome Complex in Murine Macrophages

    Microsoft Academic Search

    Adel M. Nour; Laura Santambrogio; Eric D. Boyden; E. Richard Stanley; Jurgen Brojatsch

    2009-01-01

    Multiple microbial components trigger the formation of an inflammasome complex that contains pathogen- specific nucleotide oligomerization and binding domain (NOD)-like receptors (NLRs), caspase-1, and in some cases the scaffolding protein ASC. The NLR protein Nalp1b has been linked to anthrax lethal toxin (LT)- mediated cytolysis of murine macrophages. Here we demonstrate that in unstimulated J774A.1 macrophages, caspase-1 and Nalp1b are

  7. New insights into the pathogenesis and treatment of anthrax toxin-induced shock.

    PubMed

    Li, Yan; Sherer, Kevin; Cui, Xizhong; Eichacker, Peter Q

    2007-06-01

    Inhalational Bacillus anthracis infection is a leading bioterrorist health threat in the US today. Lethal (LeTx) and edema toxin production are key to the virulent effects of this lethal bacteria. Recent insights into the structure and function of these toxins have increased the understanding of both the pathogenesis and treatment of anthrax. These are binary type toxins comprised of protective antigen necessary for their cellular uptake and either lethal or edema factors, the toxigenic moieties. Primary cellular receptors for protective antigen have been identified and the processing of the completed toxins clarified. Consistent with the ability of lethal factor to cleave mitogen activated protein kinase kinases, the evidence indicates that an excessive inflammatory response does not contribute to shock with LeTx. Rather, the immunosuppressive effects of LeTx could promote infection; however, direct endothelial dysfunction may have an important role in shock due to LeTx. Recent studies show that edema factor, a potent adenyl cyclase, may have a major role in shock during anthrax and that it may also be immunosuppresive. Therapies under development which target several steps in the cellular uptake and function of these two toxins have been effective in both in vitro and in vivo systems. Understanding how best to apply these agents in combination with conventional treatments should be a goal of future research. PMID:17555370

  8. Emergence of anthrax edema toxin as a master manipulator of macrophage and B cell functions.

    PubMed

    Gnade, Bryan T; Moen, Scott T; Chopra, Ashok K; Peterson, Johnny W; Yeager, Linsey A

    2010-07-01

    Anthrax edema toxin (ET), a powerful adenylyl cyclase, is an important virulence factor of Bacillus anthracis. Until recently, only a modest amount of research was performed to understand the role this toxin plays in the organism's immune evasion strategy. A new wave of studies have begun to elucidate the effects this toxin has on a variety of host cells. While efforts have been made to illuminate the effect ET has on cells of the adaptive immune system, such as T cells, the greatest focus has been on cells of the innate immune system, particularly the macrophage. Here we discuss the immunoevasive activities that ET exerts on macrophages, as well as new research on the effects of this toxin on B cells. PMID:22069663

  9. Anthrax toxins: a weapon to systematically dismantle the host immune defenses.

    PubMed

    Tournier, Jean-Nicolas; Rossi Paccani, Silvia; Quesnel-Hellmann, Anne; Baldari, Cosima T

    2009-12-01

    Successful colonization of the host by bacterial pathogens relies on their capacity to evade the complex and powerful defenses opposed by the host immune system, at least in the initial phases of infection. The two toxins of Bacillus anthracis, lethal toxin and edema toxin, appear to have been shaped by evolution to assist the microorganism in this crucial function, in addition to act as general toxins acting on almost all cell types. Edema toxin causes a consistent elevation of cAMP, an important second messenger the production of which is normally strictly controlled in mammalian cells, whereas lethal toxin cleaves most isoforms of mitogen-activated protein kinase kinases. By disrupting or subverting central modules common to all the principal signaling networks which control immune cell activation, effector function and migration, the anthrax toxins effectively and systematically dismantle both the innate and the adaptive immune defenses of the host. Here, we review the specific effects of the lethal and edema toxins of B. anthracis on the activation and function of phagocytes, dendritic cells and lymphocytes. We also discuss some open issues which should be addressed to gain a comprehensive insight into the complex relationship that B. anthracis establishes with the host. PMID:19560486

  10. Glycogen Synthase Kinase 3 Activation Is Important for Anthrax Edema Toxin-Induced Dendritic Cell Maturation and Anthrax Toxin Receptor 2 Expression in Macrophages ?

    PubMed Central

    Larabee, Jason L.; Maldonado-Arocho, Francisco J.; Pacheco, Sergio; France, Bryan; DeGiusti, Kevin; Shakir, Salika M.; Bradley, Kenneth A.; Ballard, Jimmy D.

    2011-01-01

    Anthrax edema toxin (ET) is one of two binary toxins produced by Bacillus anthracis that contributes to the virulence of this pathogen. ET is an adenylate cyclase that generates high levels of cyclic AMP (cAMP), causing alterations in multiple host cell signaling pathways. We previously demonstrated that ET increases cell surface expression of the anthrax toxin receptors (ANTXR) in monocyte-derived cells and promotes dendritic cell (DC) migration toward the lymph node-homing chemokine MIP-3?. In this work, we sought to determine if glycogen synthase kinase 3 (GSK-3) is important for ET-induced modulation of macrophage and DC function. We demonstrate that inhibition of GSK-3 dampens ET-induced maturation and migration processes of monocyte-derived dendritic cells (MDDCs). Additional studies reveal that the ET-induced expression of ANTXR in macrophages was decreased when GSK-3 activity was disrupted with chemical inhibitors or with small interfering RNA (siRNA) targeting GSK-3. Further examination of the ET induction of ANTXR revealed that a dominant negative form of CREB could block the ET induction of ANTXR, suggesting that CREB or a related family member was involved in the upregulation of ANTXR. Because CREB and GSK-3 activity appeared to be important for ET-induced ANTXR expression, the impact of GSK-3 on ET-induced CREB activity was examined in RAW 264.7 cells possessing a CRE-luciferase reporter. As with ANTXR expression, the ET induction of the CRE reporter was decreased by reducing GSK-3 activity. These studies not only provide insight into host pathways targeted by ET but also shed light on interactions between GSK-3 and CREB pathways in host immune cells. PMID:21576335

  11. Disulfide Bonds in the Ectodomain of Anthrax Toxin Receptor 2 Are Required for the Receptor-Bound Protective-Antigen Pore to Function

    Microsoft Academic Search

    Jianjun Sun; R. John Collier; Adam J. Ratner

    2010-01-01

    BackgroundCell-surface receptors play essential roles in anthrax toxin action by providing the toxin with a high-affinity anchor and self-assembly site on the plasma membrane, mediating the toxin entry into cells through endocytosis, and shifting the pH threshold for prepore-to-pore conversion of anthrax toxin protective antigen (PA) to a more acidic pH, thereby inhibiting premature pore formation. Each of the two

  12. Immunization of Mice with Anthrax Protective Antigen Limits Cardiotoxicity but Not Hepatotoxicity Following Lethal Toxin Challenge.

    PubMed

    Devera, T Scott; Prusator, Dawn K; Joshi, Sunil K; Ballard, Jimmy D; Lang, Mark L

    2015-01-01

    Protective immunity against anthrax is inferred from measurement of vaccine antigen-specific neutralizing antibody titers in serum samples. In animal models, in vivo challenges with toxin and/or spores can also be performed. However, neither of these approaches considers toxin-induced damage to specific organ systems. It is therefore important to determine to what extent anthrax vaccines and existing or candidate adjuvants can provide organ-specific protection against intoxication. We therefore compared the ability of Alum, CpG DNA and the CD1d ligand ?-galactosylceramide (?GC) to enhance protective antigen-specific antibody titers, to protect mice against challenge with lethal toxin, and to block cardiotoxicity and hepatotoxicity. By measurement of serum cardiac Troponin I (cTnI), and hepatic alanine aminotransferase (ALT), and aspartate aminotransferase (AST), it was apparent that neither vaccine modality prevented hepatic intoxication, despite high Ab titers and ultimate survival of the subject. In contrast, cardiotoxicity was greatly diminished by prior immunization. This shows that a vaccine that confers survival following toxin exposure may still have an associated morbidity. We propose that organ-specific intoxication should be monitored routinely during research into new vaccine modalities. PMID:26120785

  13. A microfluidic live cell assay to study anthrax toxin induced cell lethality assisted by conditioned medium.

    PubMed

    Shen, Jie; Cai, Changzu; Yu, Zhilong; Pang, Yuhong; Zhou, Ying; Qian, Lili; Wei, Wensheng; Huang, Yanyi

    2015-01-01

    It is technically challenging to investigate the function of secreted protein in real time by supply of conditioned medium that contains secreted protein of interest. The internalization of anthrax toxin is facilitated by a secreted protein Dickkopf-1 (DKK1) and its receptor, and eventually leads to cell lethality. To monitor the dynamic interplay between these components in live cells, we use an integrated microfluidic device to perform the cell viability assays with real-time controlled culture microenvironment in parallel. Conditioned medium, which contains the secreted proteins from specific cell lines, can be continuously pumped towards the cells that exposed to toxin. The exogenous DKK1 secreted from distant cells is able to rescue the sensitivity to toxin for those DKK1-knocked-down cells. This high-throughput assay allows us to precisely quantify the dynamic interaction between key components that cause cell death, and provide independent evidence of the function of DKK1 in the complex process of anthrax toxin internalization. PMID:25731605

  14. Anthrax

    MedlinePLUS

    ... is a disease caused by the bacterium Bacillus anthracis, a bacterium that has the ability to form ... would be inhalational anthrax. Who's At Risk B. anthracis is a very rare bacterium, and it causes ...

  15. Anthrax

    MedlinePLUS

    ... an infectious disease due to a bacterium called Bacillus anthracis . Infection in humans most often involves the skin, ... Saunders; 2011:chap 302. Martin GJ, Friedlander Am. Bacillus anthracis (anthrax). In: Mandell GL, Bennett JE, Dolin R, ...

  16. Erythropoiesis Suppression Is Associated with Anthrax Lethal Toxin-Mediated Pathogenic Progression

    PubMed Central

    Chang, Hsin-Hou; Wang, Tsung-Pao; Chen, Po-Kong; Lin, Yo-Yin; Liao, Chih-Hsien; Lin, Ting-Kai; Chiang, Ya-Wen; Lin, Wen-Bin; Chiang, Chih-Yu; Kau, Jyh-Hwa; Huang, Hsin-Hsien; Hsu, Hui-Ling; Liao, Chi-Yuan; Sun, Der-Shan

    2013-01-01

    Anthrax is a disease caused by the bacterium Bacillus anthracis, which results in high mortality in animals and humans. Although some of the mechanisms are already known such as asphyxia, extensive knowledge of molecular pathogenesis of this disease is deficient and remains to be further investigated. Lethal toxin (LT) is a major virulence factor of B. anthracis and a specific inhibitor/protease of mitogen-activated protein kinase kinases (MAPKKs). Anthrax LT causes lethality and induces certain anthrax-like symptoms, such as anemia and hypoxia, in experimental mice. Mitogen-activated protein kinases (MAPKs) are the downstream pathways of MAPKKs, and are important for erythropoiesis. This prompted us to hypothesize that anemia and hypoxia may in part be exacerbated by erythropoietic dysfunction. As revealed by colony-forming cell assays in this study, LT challenges significantly reduced mouse erythroid progenitor cells. In addition, in a proteolytic activity-dependent manner, LT suppressed cell survival and differentiation of cord blood CD34+-derived erythroblasts in vitro. Suppression of cell numbers and the percentage of erythroblasts in the bone marrow were detected in LT-challenged C57BL/6J mice. In contrast, erythropoiesis was provoked through treatments of erythropoietin, significantly ameliorating the anemia and reducing the mortality of LT-treated mice. These data suggested that suppressed erythropoiesis is part of the pathophysiology of LT-mediated intoxication. Because specific treatments to overcome LT-mediated pathogenesis are still lacking, these efforts may help the development of effective treatments against anthrax. PMID:23977125

  17. Anthrax

    Microsoft Academic Search

    Philip S. Brachman; Arnold F. Kaufmann

    \\u000a Anthrax, a zoonotic disease of herbivorous animals transmissible from animals to man, occurs primarily in three forms: cutaneous,\\u000a inhalational, and gastrointestinal. Meningitis and septicemia occur but are secondary to one of the primary forms; occasionally,\\u000a cases of anthrax meningitis are reported in which a primary focus is not identified. The etiologic agent is Bacillus anthracis, a gram-positive organism that in

  18. Anthrax

    Microsoft Academic Search

    Peter C. B. Turnbull

    \\u000a Microbiologists are generally familiar with the statement that anthrax has been well recognized from earliest recorded history.\\u000a In the absence of any understanding of the microbial aetiology of infectious diseases prior to about the mid-1800s, the belief\\u000a in the age-old recognition of anthrax has to be based on clinical descriptions in earlier writings commensurate with today’s\\u000a case definitions of the

  19. T cell targeting by anthrax toxins: two faces of the same coin.

    PubMed

    Paccani, Silvia Rossi; Baldari, Cosima T

    2011-06-01

    Bacillus anthracis, similar to other bacterial pathogens, has evolved effective immune evasion strategies to prolong its survival in the host, thus ensuring the unchecked spread of the infection. This function is subserved by lethal (LT) and edema (ET) toxins, two exotoxins produced by vegetative anthrax bacilli following germination of the spores. The structure of these toxins and the mechanism of cell intoxication are topics covered by other reviews in this issue. Here we shall discuss how B. anthracis uses LT and ET to suppress the immune defenses of the host, focusing on T lymphocytes, the key players in adaptive immunity. We shall also summarize recent findings showing that, depending on its concentration, ET has the ability not only to suppress T cell activation but also to promote the polarization of CD4(+) T cells to the Th2 and Th17 subsets, highlighting the potential use of this toxin as an immunomodulator. PMID:22069732

  20. Role of the Protective Antigen Octamer in the Molecular Mechanism of Anthrax Lethal Toxin Stabilization in Plasma

    Microsoft Academic Search

    Alexander F. Kintzer; Harry J. Sterling; Iok I. Tang; Ali Abdul-Gader; Andrew J. Miles; B. A. Wallace; Evan R. Williams; Bryan A. Krantz

    2010-01-01

    Anthrax is caused by strains of Bacillus anthracis that produce two key virulence factors, anthrax toxin (Atx) and a poly-?-D-glutamic acid capsule. Atx is comprised of three proteins: protective antigen (PA) and two enzymes, lethal factor (LF) and edema factor (EF). To disrupt cell function, these components must assemble into holotoxin complexes, which contain either a ring-shaped homooctameric or homoheptameric

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

    PubMed Central

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

    2013-01-01

    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. PMID:23389402

  2. Studies in mice reveal a role for anthrax toxin receptors in matrix metalloproteinase function and extracellular matrix homeostasis.

    PubMed

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

    2013-02-01

    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. PMID:23389402

  3. Anthrax toxin protective antigen--insights into molecular switching from prepore to pore.

    PubMed

    Bann, James G

    2012-01-01

    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. PMID:22095644

  4. Anthrax toxin protective antigen—Insights into molecular switching from prepore to pore

    PubMed Central

    Bann, James G

    2012-01-01

    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. PMID:22095644

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

    PubMed Central

    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

    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. PMID:23637044

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

    PubMed Central

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

    2011-01-01

    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. PMID:21850257

  7. The Disulfide Bond Cys255-Cys279 in the Immunoglobulin-Like Domain of Anthrax Toxin Receptor 2 Is Required for Membrane Insertion of Anthrax Protective Antigen Pore

    PubMed Central

    Boone, Kyle; Altiyev, Agamyrat; Puschhof, Jens; Sauter, Roland; Arigi, Emma; Ruiz, Blanca; Peng, Xiuli; Almeida, Igor; Sherman, Michael; Xiao, Chuan; Sun, Jianjun

    2015-01-01

    Anthrax toxin receptors act as molecular clamps or switches that control anthrax toxin entry, pH-dependent pore formation, and translocation of enzymatic moieties across the endosomal membranes. We previously reported that reduction of the disulfide bonds in the immunoglobulin-like (Ig) domain of the anthrax toxin receptor 2 (ANTXR2) inhibited the function of the protective antigen (PA) pore. In the present study, the disulfide linkage in the Ig domain was identified as Cys255-Cys279 and Cys230-Cys315. Specific disulfide bond deletion mutants were achieved by replacing Cys residues with Ala residues. Deletion of the disulfide bond C255-C279, but not C230-C315, inhibited the PA pore-induced release of the fluorescence dyes from the liposomes, suggesting that C255-C279 is essential for PA pore function. Furthermore, we found that deletion of C255-C279 did not affect PA prepore-to-pore conversion, but inhibited PA pore membrane insertion by trapping the PA membrane-inserting loops in proteinaceous hydrophobic pockets. Fluorescence spectra of Trp59, a residue adjacent to the PA-binding motif in von Willebrand factor A (VWA) domain of ANTXR2, showed that deletion of C255-C279 resulted in a significant conformational change on the receptor ectodomain. The disulfide deletion-induced conformational change on the VWA domain was further confirmed by single-particle 3D reconstruction of the negatively stained PA-receptor heptameric complexes. Together, the biochemical and structural data obtained in this study provides a mechanistic insight into the role of the receptor disulfide bond C255-C279 in anthrax toxin action. Manipulation of the redox states of the receptor, specifically targeting to C255-C279, may become a novel strategy to treat anthrax. PMID:26107617

  8. Frequency and Domain Specificity of Toxin-Neutralizing Paratopes in the Human Antibody Response to Anthrax Vaccine Adsorbed?

    PubMed Central

    Reason, Donald; Liberato, Justine; Sun, Jinying; Keitel, Wendy; Zhou, Jianhui

    2009-01-01

    Protective antigen (PA) is the cell surface recognition unit of the binary anthrax toxin system and the primary immunogenic component in both the current and proposed “next-generation” anthrax vaccines. Several studies utilizing animal models have indicated that PA-specific antibodies, acquired by either active or passive immunization, are sufficient to protect against infection with Bacillus anthracis. To investigate the human antibody response to anthrax immunization, we have established a large panel of human PA-specific monoclonal antibodies derived from multiple individuals vaccinated with the currently approved anthrax vaccine BioThrax. We have determined that although these antibodies bind PA in standard binding assays such as enzyme-linked immunosorbent assay, Western blotting, capture assays, and dot blots, less than 25% are capable of neutralizing lethal toxin (LT) in vitro. Nonneutralizing antibodies also fail to neutralize toxin when present in combination with other nonneutralizing paratopes. Although neutralizing antibodies recognize determinants throughout the PA monomer, they are significantly less common among those paratopes that bind to the immunodominant amino-terminal portion of the molecule. These findings demonstrate that PA binding alone is not sufficient to neutralize LT and suggest that for an antibody to effectively block PA-mediated toxicity, it must bind to PA such that one of the requisite toxin functions is disrupted. A vaccine design strategy that directed a higher percentage of the antibody response toward neutralizing epitopes may result in a more efficacious vaccine for the prevention of anthrax infection. PMID:19223482

  9. Frequency and domain specificity of toxin-neutralizing paratopes in the human antibody response to anthrax vaccine adsorbed.

    PubMed

    Reason, Donald; Liberato, Justine; Sun, Jinying; Keitel, Wendy; Zhou, Jianhui

    2009-05-01

    Protective antigen (PA) is the cell surface recognition unit of the binary anthrax toxin system and the primary immunogenic component in both the current and proposed "next-generation" anthrax vaccines. Several studies utilizing animal models have indicated that PA-specific antibodies, acquired by either active or passive immunization, are sufficient to protect against infection with Bacillus anthracis. To investigate the human antibody response to anthrax immunization, we have established a large panel of human PA-specific monoclonal antibodies derived from multiple individuals vaccinated with the currently approved anthrax vaccine BioThrax. We have determined that although these antibodies bind PA in standard binding assays such as enzyme-linked immunosorbent assay, Western blotting, capture assays, and dot blots, less than 25% are capable of neutralizing lethal toxin (LT) in vitro. Nonneutralizing antibodies also fail to neutralize toxin when present in combination with other nonneutralizing paratopes. Although neutralizing antibodies recognize determinants throughout the PA monomer, they are significantly less common among those paratopes that bind to the immunodominant amino-terminal portion of the molecule. These findings demonstrate that PA binding alone is not sufficient to neutralize LT and suggest that for an antibody to effectively block PA-mediated toxicity, it must bind to PA such that one of the requisite toxin functions is disrupted. A vaccine design strategy that directed a higher percentage of the antibody response toward neutralizing epitopes may result in a more efficacious vaccine for the prevention of anthrax infection. PMID:19223482

  10. A Receptor-based Switch that Regulates Anthrax Toxin Pore Formation

    PubMed Central

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

    2011-01-01

    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. PMID:22174672

  11. Retrocyclins Kill Bacilli and Germinating Spores of Bacillus anthracis and Inactivate Anthrax Lethal Toxin*

    PubMed Central

    Wang, Wei; Mulakala, Chandrika; Ward, Sabrina C.; Jung, Grace; Luong, Hai; Pham, Duy; Waring, Alan J.; Kaznessis, Yiannis; Lu, Wuyuan; Bradley, Kenneth A.; Lehrer, Robert I.

    2008-01-01

    ?-defensins are cyclic octadecapeptides encoded by the modified ?-defensin genes of certain nonhuman primates. The recent demonstration that human ?-defensins could prevent deleterious effects of anthrax lethal toxin in vitro and in vivo led us to examine the effects of ?-defensins on Bacillus anthracis (Sterne). We tested rhesus ?-defensins 1–3, retrocyclins 1–3, and several analogues of RC-1. Low concentrations of ?-defensins not only killed vegetative cells of B. anthracis (Sterne) and rendered their germinating spores nonviable, they also inactivated the enzymatic activity of anthrax lethal factor and protected murine RAW-264.7 cells from lethal toxin, a mixture of lethal factor and protective antigen. Structure-function studies indicated that the cyclic backbone, intramolecular tri-disulfide ladder, and arginine residues of ?-defensins contributed substantially to these protective effects. Surface plasmon resonance studies showed that retrocyclins bound the lethal factor rapidly and with high affinity. Retrocyclin-mediated inhibition of the enzymatic activity of lethal factor increased substantially if the enzyme and peptide were preincubated before substrate was added. The temporal discrepancy between the rapidity of binding and the slowly progressive extent of lethal factor inhibition suggest that post-binding events, perhaps in situ oligomerization, contribute to the antitoxic properties of retrocyclins. Overall, these findings suggest that ?-defensins provide molecular templates that could be used to create novel agents effective against B. anthracis and its toxins. PMID:16790431

  12. Retrocyclins kill bacilli and germinating spores of Bacillus anthracis and inactivate anthrax lethal toxin.

    PubMed

    Wang, Wei; Mulakala, Chandrika; Ward, Sabrina C; Jung, Grace; Luong, Hai; Pham, Duy; Waring, Alan J; Kaznessis, Yiannis; Lu, Wuyuan; Bradley, Kenneth A; Lehrer, Robert I

    2006-10-27

    Theta-defensins are cyclic octadecapeptides encoded by the modified alpha-defensin genes of certain nonhuman primates. The recent demonstration that human alpha-defensins could prevent deleterious effects of anthrax lethal toxin in vitro and in vivo led us to examine the effects of theta-defensins on Bacillus anthracis (Sterne). We tested rhesus theta-defensins 1-3, retrocyclins 1-3, and several analogues of RC-1. Low concentrations of theta-defensins not only killed vegetative cells of B. anthracis (Sterne) and rendered their germinating spores nonviable, they also inactivated the enzymatic activity of anthrax lethal factor and protected murine RAW-264.7 cells from lethal toxin, a mixture of lethal factor and protective antigen. Structure-function studies indicated that the cyclic backbone, intramolecular tri-disulfide ladder, and arginine residues of theta-defensins contributed substantially to these protective effects. Surface plasmon resonance studies showed that retrocyclins bound the lethal factor rapidly and with high affinity. Retrocyclin-mediated inhibition of the enzymatic activity of lethal factor increased substantially if the enzyme and peptide were preincubated before substrate was added. The temporal discrepancy between the rapidity of binding and the slowly progressive extent of lethal factor inhibition suggest that post-binding events, perhaps in situ oligomerization, contribute to the antitoxic properties of retrocyclins. Overall, these findings suggest that theta-defensins provide molecular templates that could be used to create novel agents effective against B. anthracis and its toxins. PMID:16790431

  13. Anthrax

    NSDL National Science Digital Library

    Patient Education Institute

    This patient education program explains the causes and types of anthrax. It also reviews the symptoms, diagnosis, treatment, and prevention of anthrax through vaccination and awareness of bioterrorism. This resource is a MedlinePlus Interactive Health Tutorial from the National Library of Medicine, designed and developed by the Patient Education Institute. NOTE: This tutorial requires a special Flash plug-in, version 4 or above. If you do not have Flash, you will be prompted to obtain a free download of the software before you start the tutorial. You will also need an Acrobat Reader, available as a free download, in order to view the Reference Summary.

  14. Monitoring of ELISA-reactive antibodies against anthrax protective antigen (PA), lethal factor (LF), and toxin-neutralising antibodies in serum of individuals vaccinated against anthrax with the PA-based UK anthrax vaccine

    Microsoft Academic Search

    Roland Grunow; Mustafa Porsch-Özcürümez; Wolf Splettstoesser; Arno Buckendahl; Ulrike Hahn; Wolfgang Beyer; Reinhard Böhm; Maria Huber; Ulrich vd Esche; Wolfgang Bessler; Dimitrios Frangoulidis; Ernst-Jürgen Finke

    2007-01-01

    The human anthrax vaccines currently licensed contain the protective antigen (PA) of Bacillus anthracis as main antigen together with traces of some other bacillus components, e.g. lethal factor (LF). The present study aimed at monitoring the course of specific antibody titres against PA and LF by enzyme linked immunosorbent assays (ELISA), as well as the levels of toxin-neutralising antibodies, in

  15. Cardiac-specific catalase overexpression rescues anthrax lethal toxin-induced cardiac contractile dysfunction: role of oxidative stress and autophagy

    PubMed Central

    2012-01-01

    Background Lethal and edema toxins secreted by Bacillus anthracis during anthrax infection were found to incite serious cardiovascular complications. However, the underlying mechanisms in anthrax lethal toxin-induced cardiac anomalies remain unknown. This study was designed to evaluate the impact of antioxidant enzyme catalase in anthrax lethal toxin-induced cardiomyocyte contractile dysfunction. Methods Wild type (WT) and cardiac-specific catalase overexpression mice were challenged with lethal toxin (2 ?g/g, intraperotineally (i.p.)). Cardiomyocyte contractile and intracellular Ca2+ properties were assessed 18 h later using an IonOptix edge-detection system. Proteasome function was assessed using chymotrypsin-like and caspase-like activities. GFP-LC3 puncta and Western blot analysis were used to evaluate autophagy and protein ubiquitination. Results Lethal toxin exposure suppressed cardiomyocyte contractile function (suppressed peak shortening, maximal velocity of shortening/re-lengthening, prolonged duration of shortening/re-lengthening, and impaired intracellular Ca2+ handling), the effects of which were alleviated by catalase. In addition, lethal toxin triggered autophagy, mitochondrial and ubiquitin-proteasome defects, the effects of which were mitigated by catalase. Pretreatment of cardiomyocytes from catalase mice with the autophagy inducer rapamycin significantly attenuated or ablated catalase-offered protection against lethal toxin-induced cardiomyocyte dysfunction. On the other hand, the autophagy inhibitor 3-MA ablated or significantly attenuated lethal toxin-induced cardiomyocyte contractile anomalies. Conclusions Our results suggest that catalase is protective against anthrax lethal toxin-induced cardiomyocyte contractile and intracellular Ca2+ anomalies, possibly through regulation of autophagy and mitochondrial function. PMID:23134810

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

    PubMed

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

    2014-04-10

    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

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

    PubMed Central

    2014-01-01

    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

  18. Anthrax Toxin-Mediated Delivery In Vivo and In Vitro of a Cytotoxic T-Lymphocyte Epitope from Ovalbumin

    Microsoft Academic Search

    JIMMY D. BALLARD; AMY M. DOLING; KATHRYN BEAUREGARD; R. JOHN COLLIER; MICHAEL N. STARNBACH

    1998-01-01

    We reported earlier that a nontoxic form of anthrax toxin was capable of delivering a cytotoxic T-lymphocyte (CTL) epitope in vivo, such that a specific CTL response was primed against the epitope. The epitope, of bacterial origin, was fused to an N-terminal fragment (LFn) from the lethal-factor component of the toxin, and the fusion protein was injected, together with the

  19. Stable peptide inhibitors prevent binding of lethal and oedema factors to protective antigen and neutralize anthrax toxin in vivo

    PubMed Central

    Pini, Alessandro; Runci, Ylenia; Falciani, Chiara; Lelli, Barbara; Brunetti, Jlenia; Pileri, Silvia; Fabbrini, Monica; Lozzi, Luisa; Ricci, Claudia; Bernini, Andrea; Tonello, Fiorella; Dal Molin, Federica; Neri, Paolo; Niccolai, Neri; Bracci, Luisa

    2006-01-01

    The lethal and oedema toxins produced by Bacillus anthracis, the aetiological agent of anthrax, are made by association of protective antigen with lethal and oedema factors and play a major role in the pathogenesis of anthrax. In the present paper, we describe the production of peptide-based specific inhibitors in branched form which inhibit the interaction of protective antigen with lethal and oedema factors and neutralize anthrax toxins in vitro and in vivo. Anti-protective antigen peptides were selected from a phage library by competitive panning with lethal factor. Selected 12-mer peptides were synthesized in tetra-branched form and were systematically modified to obtain peptides with higher affinity and inhibitory efficiency. PMID:16398644

  20. Anthrax Lethal Toxin-Mediated Killing of Human and Murine Dendritic Cells Impairs the Adaptive Immune Response

    Microsoft Academic Search

    Abdelkrim Alileche; Evan R. Serfass; Stefan M. Muehlbauer; Steven A. Porcelli; Jürgen Brojatsch

    2005-01-01

    Many pathogens have acquired strategies to combat the immune response. Bacillus anthracis interferes with host defenses by releasing anthrax lethal toxin (LT), which inactivates mitogen-activated protein kinase pathways, rendering dendritic cells (DCs) and T lymphocytes nonresponsive to immune stimulation. However, these cell types are considered resistant to killing by LT. Here we show that LT kills primary human DCs in

  1. Induction of Protective Immunity to Anthrax Lethal Toxin with a Nonhuman Primate Adenovirus-Based Vaccine in the Presence of Preexisting Anti-Human Adenovirus Immunity

    Microsoft Academic Search

    Masahiko Hashimoto; Julie L. Boyer; Neil R. Hackett; James M. Wilson; Ronald G. Crystal

    2005-01-01

    Prevention or therapy for bioterrorism-associated anthrax infections requires rapidly acting effective vac- cines. We recently demonstrated (Y. Tan, N. R. Hackett, J. L. Boyer, and R. G. Crystal, Hum. Gene Ther. 14:1673-1682, 2003) that a single administration of a recombinant serotype 5 adenovirus (Ad) vector express- ing anthrax protective antigen (PA) provides rapid protection against anthrax lethal toxin challenge. However,

  2. Expression and purification of functional human anthrax toxin receptor (ATR/TEM8) binding domain from Escherichia coli.

    PubMed

    Ding, Zhiping; Bradley, Kenneth A; Amin Arnaout, M; Xiong, Jian-Ping

    2006-09-01

    Anthrax is caused by the gram-positive, spore-forming bacterium, Bacillus anthracis. Anthrax receptors play a crucial role in the pathogenesis of the anthrax disease. Anthrax toxin receptor ATR/TEM8 VWA domain is responsible for the binding of protective antigen (PA) of B. anthracis, and thus an attractive target for structure-based drug therapies. However, the production of soluble and functional ATR/TEM8 VWA domain currently requires the use of mammalian expression systems. In this work, we expressed the ATR/TEM8 VWA domain as a fusion protein in Escherichia coli. Recombinant ATR/TEM8 VWA domain has been purified to homogeneity, and its identity has been verified by both N-terminal protein microsequencing and mass spectrometry. The purified ATR/TEM8 VWA domain exhibits very high affinity to PA based on BIAcore assay. Moreover, like the domain expressed in mammalian system, the bacterially expressed ATR/TEM8 VWA domain can block cytotoxicity induced by anthrax toxins, suggesting that the bacterially expressed ATR/TEM8 VWA domain is properly folded and fully functional. PMID:16798009

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

    PubMed Central

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

    2013-01-01

    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. PMID:24239351

  4. The Protective Antigen Component of Anthrax Toxin Forms Functional Octameric Complexes

    PubMed Central

    Kintzer, Alexander F.; Thoren, Katie L.; Sterling, Harry J.; Dong, Ken C.; Feld, Geoffrey K.; Tang, Iok I.; Zhang, Teri T.; Williams, Evan R.; Berger, James M.; Krantz, Bryan A.

    2009-01-01

    The assembly of bacterial toxins and virulence factors is critical to their function, but the regulation of assembly during infection has not been studied. We begin to address this question using anthrax toxin as a model. The protective antigen (PA) component of the toxin assembles into ring-shaped homooligomers that bind the two other enzyme components of the toxin, lethal factor (LF) and edema factor (EF), to form toxic complexes. To disrupt the host, these toxic complexes are endocytosed, such that the PA oligomer forms a membrane-spanning channel that LF and EF translocate through to enter the cytosol. We show using single-channel electrophysiology that PA channels contain two populations of conductance states, which correspond with two different PA pre-channel oligomers observed by electron microscopy—the well-described heptamer and a novel octamer. Mass spectrometry demonstrates that the PA octamer binds four LFs, and assembly routes leading to the octamer are populated with even-numbered, dimeric and tetrameric, PA intermediates. Both heptameric and octameric PA complexes can translocate LF and EF with similar rates and efficiencies. Here we also report a 3.2-Å crystal structure of the PA octamer. The octamer comprises ?20?30% of the oligomers on cells, but outside of the cell, the octamer is more stable than the heptamer under physiological pH. Thus the PA octamer is a physiological, stable, and active assembly state capable of forming lethal toxins that may withstand the hostile conditions encountered in the bloodstream. This assembly mechanism may provide a novel means to control cytotoxicity. PMID:19627991

  5. Disruption of Anthrax Toxin Binding with the Use of Human Antibodies and Competitive Inhibitors

    PubMed Central

    Cirino, Nick M.; Sblattero, Daniele; Allen, David; Peterson, Scott R.; Marks, James D.; Jackson, Paul J.; Bradbury, Andrew; Lehnert, Bruce E.

    1999-01-01

    The protective antigen (PA83) of Bacillus anthracis is integral to the mechanism of anthrax toxicity. We have isolated a human single-chain Fv antibody fragment (scFv) that blocks binding of a fluorescently tagged protective antigen (PA) moiety to cell surface receptors. Several phage-displayed scFv were isolated from a naive library biopanned against PA83. Soluble, monomeric scFv were characterized for affinity and screened for their capacity to disrupt receptor-mediated binding of PA. Four unique scFv bound to PA83, as determined by surface plasmon resonance, the tightest binder exhibiting a Kd of 50 nM. Two scFv had similar affinities for natural PA83 and a novel, recombinant, 32-kDa carboxy-terminal PA fragment (PA32). Binding of scFv to green fluorescent protein fused to the amino-terminal 32-kDa fragment of B. anthracis edema factor, EGFP-EF32, was used to confirm specificity. Fusion of EGFP to PA32 facilitated development of a novel flow cytometric assay that showed that one of the scFv disrupted PA receptor binding. This method can now be used as a rapid assay for small molecule inhibitors of PA binding to cell receptors. The combined data presented suggest the potential utility of human scFv as prophylactics against anthrax poisoning. Moreover, recombinant PA32 may also be useful as a therapeutic agent to compete with anthrax toxins for cellular receptors during active infection. PMID:10338505

  6. Anthrax lethal toxin suppresses high glucose induced VEGF over secretion through a post-translational mechanism

    PubMed Central

    Zhang, Wei-Wei; Wang, Xin; Xie, Ping; Yuan, Song-Tao; Liu, Qing-Huai

    2015-01-01

    AIM To prove anthrax lethal toxin (LeTx) blocks the mitogen activated protein kinases (MAPKs) activation by degrading the MAPK/ERK kinases (MEKs) to suppress vascular endothelial growth factor (VEGF) secretion. METHODS Human adult retinal pigmented epithelium (ARPE) cells were cultured and treated with normal glucose, high glucose or high glucose with LeTx for additional 24, 48 or 72h for viable cell count. Total RNA from the ARPE was isolated for reverse transcription polymerase chain reaction (RT-PCR). The conditioned medium of ARPE cells treated in different group for 48h was filtered and diluted to detect the concentration of VEGF by enzyme-linked immunosorbant assays. Evaluate the role of MEK/MAPK pathway in the secretion of VEGF by immunoblotting. RESULTS In this study, we proved high glucose induced activation of the MAPK extracellular signal-regulated kinase (ERK1/2) and p38 in the ARPE cell line was blocked by anthrax LeTx. LeTx also inhibited high glucose induced ARPE cell over proliferation. CONCLUSION LeTx suppressed high glucose induced VEGF over secretion in the ARPE cells, mainly through a post-translational mechanism. PMID:26085990

  7. Anthrax Lethal Toxin Disrupts Intestinal Barrier Function and Causes Systemic Infections with Enteric Bacteria

    PubMed Central

    Sun, Chen; Fang, Hui; Xie, Tao; Auth, Roger D.; Patel, Nayana; Murray, Patrick R.; Frucht, David M.

    2012-01-01

    A variety of intestinal pathogens have virulence factors that target mitogen activated protein kinase (MAPK) signaling pathways, including Bacillus anthracis. Anthrax lethal toxin (LT) has specific proteolytic activity against the upstream regulators of MAPKs, the MAPK kinases (MKKs). Using a murine model of intoxication, we show that LT causes the dose-dependent disruption of intestinal epithelial integrity, characterized by mucosal erosion, ulceration, and bleeding. This pathology correlates with an LT-dependent blockade of intestinal crypt cell proliferation, accompanied by marked apoptosis in the villus tips. C57BL/6J mice treated with intravenous LT nearly uniformly develop systemic infections with commensal enteric organisms within 72 hours of administration. LT-dependent intestinal pathology depends upon its proteolytic activity and is partially attenuated by co-administration of broad spectrum antibiotics, indicating that it is both a cause and an effect of infection. These findings indicate that targeting of MAPK signaling pathways by anthrax LT compromises the structural integrity of the mucosal layer, serving to undermine the effectiveness of the intestinal barrier. Combined with the well-described immunosuppressive effects of LT, this disruption of the intestinal barrier provides a potential mechanism for host invasion via the enteric route, a common portal of entry during the natural infection cycle of Bacillus anthracis. PMID:22438953

  8. Detection of protective antigen, an anthrax specific toxin in human serum by using surface plasmon resonance.

    PubMed

    Ghosh, Neha; Gupta, Nidhi; Gupta, Garima; Boopathi, Mannan; Pal, Vijay; Goel, Ajay Kumar

    2013-09-01

    In this study, surface plasmon resonance (SPR) technology was used for the sensitive detection of protective antigen (PA), an anthrax specific toxin in spiked human serum samples. A monoclonal antibody raised against Bacillus anthracis PA was immobilized on carboxymethyldextran-modified gold chip, and its interaction with PA was characterized in situ by SPR. By using kinetic evaluation software, KD (equilibrium constant) and Bmax (maximum binding capacity of analyte) were found to be 20 fM and 18.74 m°, respectively. The change in Gibb's free energy (?G= -78.04 kJ/mol) confirmed the spontaneous interaction between antigen and antibody. The assay could detect 1 pg/mL purified PA. In PA-spiked human serum samples, 10 pg/mL of PA could be detected. Presence of PA in blood samples serves as an important early diagnostic marker for B. anthracis infections. Thus, SPR test can be a sensitive assay for detection of anthrax at early stages of infection. PMID:23773677

  9. Regulation of Anthrax Toxin-Specific Antibody Titers by Natural Killer T Cell-Derived IL4 and IFN?

    Microsoft Academic Search

    T. Scott Devera; Sunil K. Joshi; Lindsay M. Aye; Gillian A. Lang; Jimmy D. Ballard; Mark L. Lang

    2011-01-01

    Activation of Natural Killer-like T cells (NKT) with the CD1d ligand ?-GC leads to enhanced production of anthrax toxin protective Ag (PA)-neutralizing Abs, yet the underlying mechanism for this adjuvant effect is not known. In the current study we examined the role of Th1 and Th2 type responses in NKT-mediated enhancement of antibody responses to PA. First, the contribution of

  10. Protection against Anthrax Lethal Toxin Challenge by Genetic Immunization with a Plasmid Encoding the Lethal Factor Protein

    Microsoft Academic Search

    BRIAN M. PRICE; ADRIANE L. LINER; STEPHEN H. LEPPLA; ALFRED MATECZUN; DARRELL R. GALLOWAY

    2001-01-01

    The ability of genetic vaccination to protect against a lethal challenge of anthrax toxin was evaluated. BALB\\/c mice were immunized via gene gun inoculation with eucaryotic expression vector plasmids encoding either a fragment of the protective antigen (PA) or a fragment of lethal factor (LF). Plasmid pCLF4 contains the N-terminal region (amino acids (aa) 10 to 254) of Bacillus anthracis

  11. The lethal and edema factors of anthrax toxin bind only to oligomeric forms of the protective antigen

    Microsoft Academic Search

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

    2002-01-01

    The three proteins that comprise anthrax toxin, edema factor (EF), lethal factor (LF), and protective antigen (PA), assemble at the mammalian cell surface into toxic complexes. After binding to its receptor, PA is proteolytically activated, yielding a carboxyl-terminal 63-kDa fragment (PA63) that coordinates assembly of the complexes, promotes their endocytosis, and translocates EF and LF to the cytosol. PA63 spontaneously

  12. Synthesis and assembly of anthrax lethal factor-cholera toxin B-subunit fusion protein in transgenic potato

    Microsoft Academic Search

    Tae-Geum Kim; Darrell R. Galloway; William H. R. Langridge

    2004-01-01

    A DNA encoding the 27-kDa domain I of anthrax lethal factor protein (LF), was linked to the carboxyl terminus of the cholera\\u000a toxin B-subunit (CTB-LF). The CTB-LF fusion gene was transferred into Solanum tuberosum cells by Agrobacterium tumefaciens-mediated in vivo transformation methods and antibiotic-resistant plants were regenerated. The CTB-LF fusion gene was detected\\u000a in transformed potato leaf genomic DNA by

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

    PubMed Central

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

    2013-01-01

    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. PMID:23716698

  14. Anthrax vaccines.

    PubMed

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

    2005-01-01

    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

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

    Microsoft Academic Search

    Vijay Koya; Mahtab Moayeri; Stephen H. Leppla; Henry Daniell

    2005-01-01

    The currently available human vaccine for anthrax, derived from the culture supernatant of Bacillus anthracis, contains the protective antigen (PA) and traces of the lethal and edema factors, which may contribute to adverse side effects associated with this vaccine. Therefore, an effective expression system that can provide a clean, safe, and efficacious vaccine is required. In an effort to produce

  16. Regulation of Anthrax Toxin Activator Gene (atxA) Expression in Bacillus anthracis: Temperature, Not CO 2 \\/Bicarbonate, Affects AtxA Synthesis

    Microsoft Academic Search

    ZHIHAO DAI; THERESA M. KOEHLER

    1997-01-01

    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 1 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

  17. Anthrax Lethal Toxin Impairs Innate Immune Functions of Alveolar Macrophages and Facilitates Bacillus anthracis Survival

    PubMed Central

    Ribot, Wilson J.; Panchal, Rekha G.; Brittingham, Katherine C.; Ruthel, Gordon; Kenny, Tara A.; Lane, Douglas; Curry, Bob; Hoover, Timothy A.; Friedlander, Arthur M.; Bavari, Sina

    2006-01-01

    Alveolar macrophages (AM) are very important for pulmonary innate immune responses against invading inhaled pathogens because they directly kill the organisms and initiate a cascade of innate and adaptive immune responses. Although several factors contribute to inhalational anthrax, we hypothesized that unimpeded infection of Bacillus anthracis is directly linked to disabling the innate immune functions contributed by AM. Here, we investigated the effects of lethal toxin (LT), one of the binary complex virulence factors produced by B. anthracis, on freshly isolated nonhuman primate AM. Exposure of AM to doses of LT that killed susceptible macrophages had no effect on the viability of AM, despite complete MEK1 cleavage. Intoxicated AM remained fully capable of B. anthracis spore phagocytosis. However, pretreatment of AM with LT resulted in a significant decrease in the clearance of both the Sterne strain and the fully virulent Ames strain of B. anthracis, which may have been a result of impaired AM secretion of proinflammatory cytokines. Our data imply that cytolysis does not correlate with MEK1 cleavage, and this is the first report of LT-mediated impairment of nonhuman primate AM bactericidal activity against B. anthracis. PMID:16926394

  18. Differential dependence on N-glycosylation of anthrax toxin receptors CMG2 and TEM8.

    PubMed

    Friebe, Sarah; Deuquet, Julie; van der Goot, F Gisou

    2015-01-01

    ANTXR 1 and 2, also known as TEM8 and CMG2, are two type I membrane proteins, which have been extensively studied for their role as anthrax toxin receptors, but with a still elusive physiological function. Here we have analyzed the importance of N-glycosylation on folding, trafficking and ligand binding of these closely related proteins. We find that TEM8 has a stringent dependence on N-glycosylation. The presence of at least one glycan on each of its two extracellular domains, the vWA and Ig-like domains, is indeed necessary for efficient trafficking to the cell surface. In the absence of any N-linked glycans, TEM8 fails to fold correctly and is recognized by the ER quality control machinery. Expression of N-glycosylation mutants reveals that CMG2 is less vulnerable to sugar loss. The absence of N-linked glycans in one of the extracellular domains indeed has little impact on folding, trafficking or receptor function of the wild type protein expressed in tissue culture cells. N-glycans do, however, seem required in primary fibroblasts from human patients. Here, the presence of N-linked sugars increases the tolerance to mutations in cmg2 causing the rare genetic disease Hyaline Fibromatosis Syndrome. It thus appears that CMG2 glycosylation provides a buffer towards genetic variation by promoting folding of the protein in the ER lumen. PMID:25781883

  19. Ion conductance of the stem of the anthrax toxin channel during lethal factor translocation.

    PubMed

    Schiffmiller, Aviva; Finkelstein, Alan

    2015-03-27

    The tripartite anthrax toxin consists of protective antigen, lethal factor (LF), and edema factor. PA63 (the 63-kDa, C-terminal part of protective antigen) forms heptameric channels in cell membranes that allow for the transport of LF and edema factor into the cytosol. These channels are mushroom shaped, with a ring of seven phenylalanine residues (known as the phenylalanine clamp) lining the junction between the cap and the stem. It is known that when LF is translocated through the channel, the phenylalanine clamp creates a seal that causes an essentially complete block of conduction. In order to examine ion conductance in the stem of the channel, we used Venus yellow fluorescent protein as a molecular stopper to trap LFN (the 30-kDa, 263-residue N-terminal segment of LF), as well as various truncated constructs of LFN, in mutant channels in which the phenylalanine clamp residues were mutated to alanines. Here we present evidence that ion movement occurs within the channel stem (but is stopped, of course, at the phenylalanine clamp) during protein translocation. Furthermore, we also propose that the lower region of the stem plays an important role in securing peptide chains during translocation. PMID:24996036

  20. Anthrax lethal toxin and the induction of CD4 T cell immunity.

    PubMed

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

    2012-10-01

    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. PMID:23162703

  1. Differential Dependence on N-Glycosylation of Anthrax Toxin Receptors CMG2 and TEM8

    PubMed Central

    Friebe, Sarah; Deuquet, Julie; van der Goot, F. Gisou

    2015-01-01

    ANTXR 1 and 2, also known as TEM8 and CMG2, are two type I membrane proteins, which have been extensively studied for their role as anthrax toxin receptors, but with a still elusive physiological function. Here we have analyzed the importance of N-glycosylation on folding, trafficking and ligand binding of these closely related proteins. We find that TEM8 has a stringent dependence on N-glycosylation. The presence of at least one glycan on each of its two extracellular domains, the vWA and Ig-like domains, is indeed necessary for efficient trafficking to the cell surface. In the absence of any N-linked glycans, TEM8 fails to fold correctly and is recognized by the ER quality control machinery. Expression of N-glycosylation mutants reveals that CMG2 is less vulnerable to sugar loss. The absence of N-linked glycans in one of the extracellular domains indeed has little impact on folding, trafficking or receptor function of the wild type protein expressed in tissue culture cells. N-glycans do, however, seem required in primary fibroblasts from human patients. Here, the presence of N-linked sugars increases the tolerance to mutations in cmg2 causing the rare genetic disease Hyaline Fibromatosis Syndrome. It thus appears that CMG2 glycosylation provides a buffer towards genetic variation by promoting folding of the protein in the ER lumen. PMID:25781883

  2. Cell entry and cAMP imaging of anthrax edema toxin.

    PubMed

    Dal Molin, Federica; Tonello, Fiorella; Ladant, Daniel; Zornetta, Irene; Zamparo, Ilaria; Di Benedetto, Giulietta; Zaccolo, Manuela; Montecucco, Cesare

    2006-11-15

    The entry and enzymatic activity of the anthrax edema factor (EF) in different cell types was studied by monitoring EF-induced changes in intracellular cAMP with biochemical and microscopic methods. cAMP was imaged in live cells, transfected with a fluorescence resonance energy transfer biosensor based on the protein kinase A regulatory and catalytic subunits fused to CFP and YFP, respectively. The cAMP biosensor was located either in the cytosol or was membrane-bound owing to the addition of a tag determining its myristoylation/palmitoylation. Real-time imaging of cells expressing the cAMP biosensors provided the time course of EF catalytic activity and an indication of its subcellular localization. Bafilomycin A1, an inhibitor of the vacuolar ATPase proton pump, completely prevented EF activity, even when added long after the toxin. The time course of appearance of the adenylate cyclase activity and of bafilomycin A1 action suggests that EF enters the cytosol from late endosomes. EF remains associated to these compartments and its activity shows a perinuclear localization generating intracellular cAMP concentration gradients from the cell centre to the periphery. PMID:17082768

  3. Cell entry and cAMP imaging of anthrax edema toxin

    PubMed Central

    Dal Molin, Federica; Tonello, Fiorella; Ladant, Daniel; Zornetta, Irene; Zamparo, Ilaria; Di Benedetto, Giulietta; Zaccolo, Manuela; Montecucco, Cesare

    2006-01-01

    The entry and enzymatic activity of the anthrax edema factor (EF) in different cell types was studied by monitoring EF-induced changes in intracellular cAMP with biochemical and microscopic methods. cAMP was imaged in live cells, transfected with a fluorescence resonance energy transfer biosensor based on the protein kinase A regulatory and catalytic subunits fused to CFP and YFP, respectively. The cAMP biosensor was located either in the cytosol or was membrane-bound owing to the addition of a tag determining its myristoylation/palmitoylation. Real-time imaging of cells expressing the cAMP biosensors provided the time course of EF catalytic activity and an indication of its subcellular localization. Bafilomycin A1, an inhibitor of the vacuolar ATPase proton pump, completely prevented EF activity, even when added long after the toxin. The time course of appearance of the adenylate cyclase activity and of bafilomycin A1 action suggests that EF enters the cytosol from late endosomes. EF remains associated to these compartments and its activity shows a perinuclear localization generating intracellular cAMP concentration gradients from the cell centre to the periphery. PMID:17082768

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

    PubMed Central

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

    2009-01-01

    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

  5. High-sensitivity MALDI-TOF MS quantification of anthrax lethal toxin for diagnostics and evaluation of medical countermeasures.

    PubMed

    Boyer, Anne E; Gallegos-Candela, Maribel; Quinn, Conrad P; Woolfitt, Adrian R; Brumlow, Judith O; Isbell, Katherine; Hoffmaster, Alex R; Lins, Renato C; Barr, John R

    2015-04-01

    Inhalation anthrax has a rapid progression and high fatality rate. Pathology and death from inhalation of Bacillus anthracis spores are attributed to the actions of secreted protein toxins. Protective antigen (PA) binds and imports the catalytic component lethal factor (LF), a zinc endoprotease, and edema factor (EF), an adenylyl cyclase, into susceptible cells. PA-LF is termed lethal toxin (LTx) and PA-EF, edema toxin. As the universal transporter for both toxins, PA is an important target for vaccination and immunotherapeutic intervention. However, its quantification has been limited to methods of relatively low analytic sensitivity. Quantification of LTx may be more clinically relevant than LF or PA alone because LTx is the toxic form that acts on cells. A method was developed for LTx-specific quantification in plasma using anti-PA IgG magnetic immunoprecipitation of PA and quantification of LF activity that co-purified with PA. The method was fast (<4 h total time to detection), sensitive at 0.033 ng/mL LTx in plasma for the fast analysis (0.0075 ng/mL LTx in plasma for an 18 h reaction), precise (6.3-9.9% coefficient of variation), and accurate (0.1-12.7%error; n???25). Diagnostic sensitivity was 100% (n?=?27 animal/clinical cases). Diagnostic specificity was 100% (n?=?141). LTx was detected post-antibiotic treatment in 6/6 treated rhesus macaques and 3/3 clinical cases of inhalation anthrax and as long as 8 days post-treatment. Over the course of infection in two rhesus macaques, LTx was first detected at 0.101 and 0.237 ng/mL at 36 h post-exposure and increased to 1147 and 12,107 ng/mL in late-stage anthrax. This demonstrated the importance of LTx as a diagnostic and therapeutic target. This method provides a sensitive, accurate tool for anthrax toxin detection and evaluation of PA-directed therapeutics. PMID:25673244

  6. Anthrax infection.

    PubMed

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

    2011-12-15

    Bacillus anthracis infection is rare in developed countries. However, recent outbreaks in the United States and Europe and the potential use of the bacteria for bioterrorism have focused interest on it. Furthermore, although anthrax was known to typically occur as one of three syndromes related to entry site of (i.e., cutaneous, gastrointestinal, or inhalational), a fourth syndrome including severe soft tissue infection in injectional drug users is emerging. Although shock has been described with cutaneous anthrax, it appears much more common with gastrointestinal, inhalational (5 of 11 patients in the 2001 outbreak in the United States), and injectional anthrax. Based in part on case series, the estimated mortalities of cutaneous, gastrointestinal, inhalational, and injectional anthrax are 1%, 25 to 60%, 46%, and 33%, respectively. Nonspecific early symptomatology makes initial identification of anthrax cases difficult. Clues to anthrax infection include history of exposure to herbivore animal products, heroin use, or clustering of patients with similar respiratory symptoms concerning for a bioterrorist event. Once anthrax is suspected, the diagnosis can usually be made with Gram stain and culture from blood or surgical specimens followed by confirmatory testing (e.g., PCR or immunohistochemistry). Although antibiotic therapy (largely quinolone-based) is the mainstay of anthrax treatment, the use of adjunctive therapies such as anthrax toxin antagonists is a consideration. PMID:21852539

  7. Anthrax Infection

    PubMed Central

    Sweeney, Daniel A.; Hicks, Caitlin W.; Cui, Xizhong; Li, Yan

    2011-01-01

    Bacillus anthracis infection is rare in developed countries. However, recent outbreaks in the United States and Europe and the potential use of the bacteria for bioterrorism have focused interest on it. Furthermore, although anthrax was known to typically occur as one of three syndromes related to entry site of (i.e., cutaneous, gastrointestinal, or inhalational), a fourth syndrome including severe soft tissue infection in injectional drug users is emerging. Although shock has been described with cutaneous anthrax, it appears much more common with gastrointestinal, inhalational (5 of 11 patients in the 2001 outbreak in the United States), and injectional anthrax. Based in part on case series, the estimated mortalities of cutaneous, gastrointestinal, inhalational, and injectional anthrax are 1%, 25 to 60%, 46%, and 33%, respectively. Nonspecific early symptomatology makes initial identification of anthrax cases difficult. Clues to anthrax infection include history of exposure to herbivore animal products, heroin use, or clustering of patients with similar respiratory symptoms concerning for a bioterrorist event. Once anthrax is suspected, the diagnosis can usually be made with Gram stain and culture from blood or surgical specimens followed by confirmatory testing (e.g., PCR or immunohistochemistry). Although antibiotic therapy (largely quinolone-based) is the mainstay of anthrax treatment, the use of adjunctive therapies such as anthrax toxin antagonists is a consideration. PMID:21852539

  8. Human capillary morphogenesis protein 2 functions as an anthrax toxin receptor

    E-print Network

    Sejnowski, Terrence J.

    , MA, February 24, 2003 (received for review February 7, 2003) Bacillus anthracis secretes two useful for the treatment of anthrax. Anthrax is caused by the spore-forming organism Bacillus anthracis the deliberate mailing of B. anthracis spores via the U.S. postal system resulted in the deaths of five people (1

  9. Regulatory mechanisms of anthrax toxin receptor 1-dependent vascular and connective tissue homeostasis.

    PubMed

    Besschetnova, Tatiana Y; Ichimura, Takaharu; Katebi, Negin; St Croix, Brad; Bonventre, Joseph V; Olsen, Bjorn R

    2015-03-01

    It is well known that angiogenesis is linked to fibrotic processes in fibroproliferative diseases, but insights into pathophysiological processes are limited, due to lack of understanding of molecular mechanisms controlling endothelial and fibroblastic homeostasis. We demonstrate here that the matrix receptor anthrax toxin receptor 1 (ANTXR1), also known as tumor endothelial marker 8 (TEM8), is an essential component of these mechanisms. Loss of TEM8 function in mice causes reduced synthesis of endothelial basement membrane components and hyperproliferative and leaky blood vessels in skin. In addition, endothelial cell alterations in mutants are almost identical to those of endothelial cells in infantile hemangioma lesions, including activated VEGF receptor signaling in endothelial cells, increased expression of the downstream targets VEGF and CXCL12, and increased numbers of macrophages and mast cells. In contrast, loss of TEM8 in fibroblasts leads to increased rates of synthesis of fiber-forming collagens, resulting in progressive fibrosis in skin and other organs. Compromised interactions between TEM8-deficient endothelial and fibroblastic cells cause dramatic reduction in the activity of the matrix-degrading enzyme MMP2. In addition to insights into mechanisms of connective tissue homeostasis, our data provide molecular explanations for vascular and connective tissue abnormalities in GAPO syndrome, caused by loss-of-function mutations in ANTXR1. Furthermore, the loss of MMP2 activity suggests that fibrotic skin abnormalities in GAPO syndrome are, in part, the consequence of pathophysiological mechanisms underlying syndromes (NAO, Torg and Winchester) with multicentric skin nodulosis and osteolysis caused by homozygous loss-of-function mutations in MMP2. PMID:25572963

  10. Anthrax Toxin Receptor 2 Promotes Human Uterine Smooth Muscle Cell Viability, Migration and Contractility

    PubMed Central

    VINK, Joy Y.; CHARLES-HORVATH, Pelisa C.; KITAJEWSKI, Jan K.; REEVES, Claire V.

    2014-01-01

    Objective Previously we demonstrated anthrax toxin receptor 2 knockout (Antxr2?/?) mice are fertile but fail to deliver their pups at term. This parturition defect is associated with over-accumulation of extracellular matrix (ECM) proteins and decreased myometrial cell content in the uterus. Myometrial cell loss in Antxr2?/? uterine tissue prompted us to evaluate if ANTXR2 is essential for human uterine smooth muscle cell (HUSMC) viability and function. Study Design We subjected HUSMC to lentiviral-mediated knock down (R2KD) or retroviral-mediated over-expression (R2OE) of ANTXR2. Flow cytometry confirmed R2KD or R2OE in cell lines vs control (CTL). Cell behavior and function in CTL, R2KD and R2OE cells were evaluated for apoptosis via TUNEL assay, migration via Boyden chamber assay and with oxytocin-mediated collagen contraction assays. Matrix metalloproteinase (MMP) activity was evaluated using gelatin zymography. Cell lines and samples were run in duplicate. Student t-test was used for statistical analysis. Results ANTXR2 is expressed by HUSMC. HUMSC-R2KD cells exhibited increased apoptosis (p<0.05) and decreased migration (p<0.05) while HUSMC-R2OE cells exhibited no change in apoptosis (p=0.91) and increased migration (p=0.05) vs CTL. HUMSC-R2KD cells contracted significantly less than CTL while HUSMC-R2OE cells showed no difference in contractility vs CTL. MMP2 activity appeared slightly decreased in HUMSC-R2KD cells and increased in HUSMC-R2OE cells vs CTL. Conclusion ANTXR2 is expressed by HUSMC and appears important for normal HUSMC viability, migration and contractility. Further studies are needed to delineate if ANTXR2 is important for normal and abnormal labor patterns. PMID:24060446

  11. Anthrax Lethal Toxin Induces Acute Diastolic Dysfunction in Rats Through Disruption of the Phospholamban Signaling Network

    PubMed Central

    Golden, Honey B.; Watson, Linley E.; Nizamutdinov, Damir; Feng, Hao; Gerilechaogetu, Fnu; Lal, Hind; Verma, Suresh K.; Mukhopadhyay, Swagoto; Foster, Donald M.; Dillmann, Wolfgang H.; Dostal, D.E.

    2013-01-01

    Background Anthrax lethal toxin (LT), secreted by Bacillus anthracis, causes severe cardiac dysfunction by unknown mechanisms. LT specifically cleaves the docking domains of MAPKK (MEKs); thus, we hypothesized that LT directly impairs cardiac function through dysregulation of MAPK signaling mechanisms. Methods and Results In a time-course study of LT toxicity, echocardiography revealed acute diastolic heart failure accompanied by pulmonary regurgitation and left atrial dilation in adult Sprague-Dawley rats at time points corresponding to dysregulated JNK, phospholamban (PLB) and protein phosphatase 2A (PP2A) myocardial signaling. Using isolated rat ventricular myocytes, we identified the MEK7-JNK1-PP2A-PLB signaling axis to be important for regulation of intracellular calcium (Ca2+i) handling, PP2A activation and targeting of PP2A-B56? to Ca2+i handling proteins, such as PLB. Through a combination of gain-of-function and loss-of-function studies, we demonstrated that over-expression of MEK7 protects against LT-induced PP2A activation and Ca2+i dysregulation through activation of JNK1. Moreover, targeted phosphorylation of PLB-Thr17 by Akt improved sarcoplasmic reticulum Ca2+i release and reuptake during LT toxicity. Co-immunoprecipitation experiments further revealed the pivotal role of MEK7-JNK-Akt complex formation for phosphorylation of PLB-Thr17 during acute LT toxicity. Conclusions Our findings support a cardiogenic mechanism of LT-induced diastolic dysfunction, by which LT disrupts JNK1 signaling and results in Ca2+i dysregulation through diminished phosphorylation of PLB by Akt and increased dephosphorylation of PLB by PP2A. Integration of the MEK7-JNK1 signaling module with Akt represents an important stress-activated signalosome that may confer protection to sustain cardiac contractility and maintain normal levels of Ca2+i through PLB-T17 phosphorylation. PMID:23907041

  12. Genetically modified anthrax lethal toxin safely delivers whole HIV protein antigens into the cytosol to induce T cell immunity

    PubMed Central

    Lu, Yichen; Friedman, Rachel; Kushner, Nicholas; Doling, Amy; Thomas, Lawrence; Touzjian, Neal; Starnbach, Michael; Lieberman, Judy

    2000-01-01

    Bacillus anthrax lethal toxin can be engineered to deliver foreign proteins to the cytosol for antigen presentation to CD8 T cells. Vaccination with modified toxins carrying 8–9 amino acid peptide epitopes induces protective immunity in mice. To evaluate whether large protein antigens can be used with this system, recombinant constructs encoding several HIV antigens up to 500 amino acids were produced. These candidate HIV vaccines are safe in animals and induce CD8 T cells in mice. Constructs encoding gag p24 and nef stimulate gag-specific CD4 proliferation and a secondary cytotoxic T lymphocyte response in HIV-infected donor peripheral blood mononuclear cells in vitro. These results lay the foundation for future clinical vaccine studies. PMID:10884430

  13. Erythrocytic Mobilization Enhanced by the Granulocyte Colony-Stimulating Factor Is Associated with Reduced Anthrax-Lethal-Toxin-Induced Mortality in Mice

    PubMed Central

    Chang, Hsin-Hou; Chiang, Ya-Wen; Lin, Ting-Kai; Lin, Guan-Ling; Lin, You-Yen; Kau, Jyh-Hwa; Huang, Hsin-Hsien; Hsu, Hui-Ling; Wang, Jen-Hung; Sun, Der-Shan

    2014-01-01

    Anthrax lethal toxin (LT), one of the primary virulence factors of Bacillus anthracis, causes anthrax-like symptoms and death in animals. Experiments have indicated that levels of erythrocytopenia and hypoxic stress are associated with disease severity after administering LT. In this study, the granulocyte colony-stimulating factor (G-CSF) was used as a therapeutic agent to ameliorate anthrax-LT- and spore-induced mortality in C57BL/6J mice. We demonstrated that G-CSF promoted the mobilization of mature erythrocytes to peripheral blood, resulting in a significantly faster recovery from erythrocytopenia. In addition, combined treatment using G-CSF and erythropoietin tended to ameliorate B. anthracis-spore-elicited mortality in mice. Although specific treatments against LT-mediated pathogenesis remain elusive, these results may be useful in developing feasible strategies to treat anthrax. PMID:25384016

  14. Anthrax Toxin Receptor 2 Functions in ECM Homeostasis of the Murine Reproductive Tract and Promotes MMP Activity

    PubMed Central

    Reeves, Claire V.; Wang, Xing; Charles-Horvath, Pelisa C.; Vink, Joy Y.; Borisenko, Valeriya Y.; Young, John A. T.; Kitajewski, Jan K.

    2012-01-01

    Anthrax Toxin Receptor proteins function as receptors for anthrax toxin, however physiological activity remains unclear. To evaluate the biological role of Antxr2, we generated Antxr2?/? mice. Antxr2?/? mice were viable, however Antxr2 is required for parturition in young females and for preserving fertility in older female mice. Histological analysis of the uterus and cervix revealed aberrant deposition of extracellular matrix proteins such as type I collagen, type VI collagen and fibronectin. A marked disruption of both the circular and longitudinal myometrial cell layers was evident in Antxr2?/? mice. These changes progressed as the mice aged, resulting in a thickened, collagen dense, acellular stroma and the disappearance of normal uterine architecture. To investigate the molecular mechanism underlying the uterine fibrosis we performed immunoblotting for MMP2 using uterine lysates and zymography using conditioned medium from Antxr2?/? mouse embryonic fibroblasts and found reduced levels of activated MMP2 in both. This prompted us to investigate MT1-MMP status, as MMP2 processing is regulated by MT1-MMP. We found MT1-MMP activity, as measured by MMP2 processing and activation, was enhanced by expression of either ANTXR1 or ANTXR2. We identified an ANTXR2/MT1-MMP complex and demonstrated that MT1-MMP activity is dependent on ANTXR2 expression levels in cells. Thus, we have discovered that ANTXR1 and ANTXR2 function as positive regulators of MT1-MMP activity. PMID:22529944

  15. Structure-based inhibitor discovery against adenylyl cyclase toxins from pathogenic bacteria that cause anthrax and whooping cough.

    PubMed

    Soelaiman, Sandriyana; Wei, Binqing Q; Bergson, Pamela; Lee, Young-Sam; Shen, Yuequan; Mrksich, Milan; Shoichet, Brian K; Tang, Wei-Jen

    2003-07-11

    Edema factor (EF) and CyaA are adenylyl cyclase toxins secreted by pathogenic bacteria that cause anthrax and whooping cough, respectively. Using the structure of the catalytic site of EF, we screened a data base of commercially available, small molecular weight chemicals for those that could specifically inhibit adenylyl cyclase activity of EF. From 24 compounds tested, we have identified one quinazoline compound, ethyl 5-aminopyrazolo[1,5-a]quinazoline-3-carboxylate, that specifically inhibits adenylyl cyclase activity of EF and CyaA with approximately 20 microm Ki. This compound neither affects the activity of host resident adenylyl cyclases type I, II, and V nor exhibits promiscuous inhibition. The compound is a competitive inhibitor, consistent with the prediction that it binds to the adenine portion of the ATP binding site on EF. EF is activated by the host calcium sensor, calmodulin. Surface plasmon resonance spectroscopic analysis shows that this compound does not affect the binding of calmodulin to EF. This compound is dissimilar from a previously described, non-nucleoside inhibitor of host adenylyl cyclase. It may serve as a lead to design antitoxins to address the role of adenylyl cyclase toxins in bacterial pathogenesis and to fight against anthrax and whooping cough. PMID:12676933

  16. Symmetry complementarity-guided design of anthrax toxin inhibitors based on ?-cyclodextrin: Synthesis and relative activities of face-selective functionalized polycationic clusters.

    PubMed

    Díaz-Moscoso, Alejandro; Méndez-Ardoy, Alejandro; Ortega-Caballero, Fernando; Benito, Juan M; Ortiz Mellet, Carmen; Defaye, Jacques; Robinson, Tanisha M; Yohannes, Adiamseged; Karginov, Vladimir A; García Fernández, José M

    2011-01-01

    Three new series of potential anthrax toxin inhibitors based on the ?-cyclodextrin (?CD) scaffold were developed by exploiting face-selective Cu(I)-catalyzed azide-alkyne 1,3-cycloadditions, amine-isothiocyanate coupling, and allyl group hydroboration-oxidation/hydroxy ? amine replacement reactions. The molecular design follows the "symmetry-complementarity" concept between homogeneously functionalized polycationic ?CD derivatives and protective antigen (PA), a component of anthrax toxin known to form C?-symmetric pores on the cell membrane used by lethal and edema factors to gain access to the cytosol. The synthesis and antitoxin activity of a collection of ?CD derivatives differing in the number, arrangement, and face location of the cationic elements are reported herein. These results set the basis for a structure-activity relationship development program of new candidates to combat the anthrax threat. PMID:21140396

  17. The Serological Relationship between Purified Prepara- tions of Factors I and I1 of the Anthrax Toxin Produced In uiuo and In uitro

    Microsoft Academic Search

    K. SARGEANT; J. L. STANLEY; H. SMITH

    SUMMARY: A serological comparison on gel-diffusion plates of purified preparations of factors I and I1 of the anthrax toxin obtained in vitro and in Wive indicated that all but one (factor I from in Witro sources) of these preparations contained at least two major serological components. At least three serological components were involved in the total system: A (associated with

  18. Rabbit and nonhuman primate models of toxin-targeting human anthrax vaccines.

    PubMed

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

    2004-12-01

    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. PMID:15590776

  19. Anthrax and the inflammasome

    PubMed Central

    Moayeri, Mahtab; Sastalla, Inka; Leppla, Stephen H.

    2012-01-01

    Anthrax lethal toxin (LT), a major virulence determinant of anthrax disease, induces vascular collapse in mice and rats. LT activates the Nlrp1 inflammasome in macrophages and dendritic cells, resulting in caspase-1 activation, IL-1? and IL-18 maturation and a rapid cell death (pyroptosis). This review presents the current understanding of LT-induced activation of Nlrp1 in cells, and its consequences for toxin-mediated effects in rodent toxin and spore challenge models. PMID:22207185

  20. Anthrax and the inflammasome.

    PubMed

    Moayeri, Mahtab; Sastalla, Inka; Leppla, Stephen H

    2012-05-01

    Anthrax lethal toxin (LT), a major virulence determinant of anthrax disease, induces vascular collapse in mice and rats. LT activates the Nlrp1 inflammasome in macrophages and dendritic cells, resulting in caspase-1 activation, IL-1? and IL-18 maturation and a rapid cell death (pyroptosis). This review presents the current understanding of LT-induced activation of Nlrp1 in cells and its consequences for toxin-mediated effects in rodent toxin and spore challenge models. PMID:22207185

  1. Anthrax toxins: A weapon to systematically dismantle the host immune defenses

    Microsoft Academic Search

    Jean-Nicolas Tournier; Silvia Rossi Paccani; Anne Quesnel-Hellmann; Cosima T. Baldari

    2009-01-01

    Successful colonization of the host by bacterial pathogens relies on their capacity to evade the complex and powerful defenses opposed by the host immune system, at least in the initial phases of infection. The two toxins of Bacillus anthracis, lethal toxin and edema toxin, appear to have been shaped by evolution to assist the microorganism in this crucial function, in

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

    PubMed Central

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

    2013-01-01

    PA-U2, an engineered anthrax protective antigen that is activated by urokinase was combined with wild-type 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 anti-mitotic, 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 anti-angiogenesis therapy such as sunitinib or sorafinib. PMID:22843210

  3. Statistical analysis, optimization, and prioritization of virtual screening parameters for zinc enzymes including the anthrax toxin lethal factor.

    PubMed

    Maize, Kimberly M; Zhang, Xia; Amin, Elizabeth Ambrose

    2014-01-01

    The anthrax toxin lethal factor (LF) and matrix metalloproteinase-3 (MMP-3, stromelysin-1) are popular zinc metalloenzyme drug targets, with LF primarily responsible for anthrax-related toxicity and host death, while MMP-3 is involved in cancer- and rheumatic disease-related tissue remodeling. A number of in silico screening techniques, most notably docking and scoring, have proven useful for identifying new potential drug scaffolds targeting LF and MMP-3, as well as for optimizing lead compounds and investigating mechanisms of action. However, virtual screening outcomes can vary significantly depending on the specific docking parameters chosen, and systematic statistical significance analyses are needed to prioritize key parameters for screening small molecules against these zinc systems. In the current work, we present a series of chi-square statistical analyses of virtual screening outcomes for cocrystallized LF and MMP-3 inhibitors docked into their respective targets, evaluated by predicted enzyme-inhibitor dissociation constant and root-mean-square deviation (RMSD) between predicted and experimental bound configurations, and we present a series of preferred parameters for use with these systems in the industry-standard Surflex-Dock screening program, for use by researchers utilizing in silico techniques to discover and optimize new scaffolds. PMID:25373478

  4. Anthrax Toxin Induces Macrophage Death by p38 MAPK Inhibition but Leads to

    E-print Network

    Nizet, Victor

    of Bacillus anthracis, we have shown that secretion of ATP by infected macro- phages and the sequential of the Gram-positive bacterial pathogen Bacillus anthracis, the causative agent of anthrax (Tournier et al)-like receptors are critical for IL-1-dependent host protection from virulent B. anthracis. Importantly, lethal

  5. Affinity binding of antibodies to supermacroporous cryogel adsorbents with immobilized protein A for removal of anthrax toxin protective antigen.

    PubMed

    Ingavle, Ganesh C; Baillie, Les W J; Zheng, Yishan; Lis, Elzbieta K; Savina, Irina N; Howell, Carol A; Mikhalovsky, Sergey V; Sandeman, Susan R

    2015-05-01

    Polymeric cryogels are efficient carriers for the immobilization of biomolecules because of their unique macroporous structure, permeability, mechanical stability and different surface chemical functionalities. The aim of the study was to demonstrate the potential use of macroporous monolithic cryogels for biotoxin removal using anthrax toxin protective antigen (PA), the central cell-binding component of the anthrax exotoxins, and covalent immobilization of monoclonal antibodies. The affinity ligand (protein A) was chemically coupled to the reactive hydroxyl and epoxy-derivatized monolithic cryogels and the binding efficiencies of protein A, monoclonal antibodies to the cryogel column were determined. Our results show differences in the binding capacity of protein A as well as monoclonal antibodies to the cryogel adsorbents caused by ligand concentrations, physical properties and morphology of surface matrices. The cytotoxicity potential of the cryogels was determined by an in vitro viability assay using V79 lung fibroblast as a model cell and the results reveal that the cryogels are non-cytotoxic. Finally, the adsorptive capacities of PA from phosphate buffered saline (PBS) were evaluated towards a non-glycosylated, plant-derived human monoclonal antibody (PANG) and a glycosylated human monoclonal antibody (Valortim(®)), both of which were covalently attached via protein A immobilization. Optimal binding capacities of 108 and 117 mg/g of antibody to the adsorbent were observed for PANG attached poly(acrylamide-allyl glycidyl ether) [poly(AAm-AGE)] and Valortim(®) attached poly(AAm-AGE) cryogels, respectively, This indicated that glycosylation status of Valortim(®) antibody could significantly increase (8%) its binding capacity relative to the PANG antibody on poly(AAm-AGE)-protien-A column (p < 0.05). The amounts of PA which remained in the solution after passing PA spiked PBS through PANG or Valortim bound poly(AAm-AGE) cryogel were significantly (p < 0.05) decreased relative to the amount of PA remained in the solution after passing through unmodified as well as protein A modified poly(AAm-AGE) cryogel columns, indicates efficient PA removal from spiked PBS over 60 min of circulation. The high adsorption capacity towards anthrax toxin PA of the cryogel adsorbents indicated potential application of these materials for treatment of Bacillus anthracis infection. PMID:25736504

  6. Distinct Regions of NLRP1B Are Required To Respond to Anthrax Lethal Toxin and Metabolic Inhibition

    PubMed Central

    Neiman-Zenevich, Jana; Liao, Kuo-Chieh

    2014-01-01

    Pattern recognition receptors monitor for signs of infection or cellular dysfunction and respond to these events by initiating an immune response. NLRP1B is a receptor that upon activation recruits multiple copies of procaspase-1, which promotes cytokine processing and a proinflammatory form of cell death termed pyroptosis. NLRP1B detects anthrax lethal toxin when the toxin cleaves an amino-terminal fragment from the protein. In addition, NLRP1B is activated when cells are deprived of glucose or treated with metabolic inhibitors, but the mechanism by which the resulting reduction in cytosolic ATP is sensed by NLRP1B is unknown. Here, we addressed whether these two activating signals of NLRP1B converge on a common sensing system. We show that an NLRP1B mutant lacking the amino-terminal region exhibits some spontaneous activity and fails to be further activated by lethal toxin. This mutant was still activated in cells depleted of ATP, however, indicating that the amino-terminal region is not the sole sensing domain of NLRP1B. Mutagenesis of the leucine-rich repeat domain of NLRP1B provided evidence that this domain is involved in autoinhibition of the receptor, but none of the mutants tested was specifically defective at sensing activating signals. Comparison of two alleles of NLRP1B that differed in their response to metabolic inhibitors, but not to lethal toxin, led to the finding that a repeated sequence in the function to find domain (FIIND) that arose from exon duplication facilitated detection of ATP depletion. These results suggest that distinct regions of NLRP1B detect activating signals. PMID:24935976

  7. A heterodimer of a VHH (variable domains of camelid heavy chain-only) antibody that inhibits anthrax toxin cell binding linked to a VHH antibody that blocks oligomer formation is highly protective in an anthrax spore challenge model.

    PubMed

    Moayeri, Mahtab; Leysath, Clinton E; Tremblay, Jacqueline M; Vrentas, Catherine; Crown, Devorah; Leppla, Stephen H; Shoemaker, Charles B

    2015-03-01

    Anthrax disease is caused by a toxin consisting of protective antigen (PA), lethal factor, and edema factor. Antibodies against PA have been shown to be protective against the disease. Variable domains of camelid heavy chain-only antibodies (VHHs) with affinity for PA were obtained from immunized alpacas and screened for anthrax neutralizing activity in macrophage toxicity assays. Two classes of neutralizing VHHs were identified recognizing distinct, non-overlapping epitopes. One class recognizes domain 4 of PA at a well characterized neutralizing site through which PA binds to its cellular receptor. A second neutralizing VHH (JKH-C7) recognizes a novel epitope. This antibody inhibits conversion of the PA oligomer from "pre-pore" to its SDS and heat-resistant "pore" conformation while not preventing cleavage of full-length 83-kDa PA (PA83) by cell surface proteases to its oligomer-competent 63-kDa form (PA63). The antibody prevents endocytosis of the cell surface-generated PA63 subunit but not preformed PA63 oligomers formed in solution. JKH-C7 and the receptor-blocking VHH class (JIK-B8) were expressed as a heterodimeric VHH-based neutralizing agent (VNA2-PA). This VNA displayed improved neutralizing potency in cell assays and protected mice from anthrax toxin challenge with much better efficacy than the separate component VHHs. The VNA protected virtually all mice when separately administered at a 1:1 ratio to toxin and protected mice against Bacillus anthracis spore infection. Thus, our studies show the potential of VNAs as anthrax therapeutics. Due to their simple and stable nature, VNAs should be amenable to genetic delivery or administration via respiratory routes. PMID:25564615

  8. Anthrax toxin-neutralizing antibody reconfigures the protective antigen heptamer into a supercomplex

    PubMed Central

    Radjainia, Mazdak; Hyun, Jae-Kyung; Leysath, Clinton E.; Leppla, Stephen H.; Mitra, Alok K.

    2010-01-01

    The tripartite protein exotoxin secreted by Bacillus anthracis, a major contributor to its virulence and anthrax pathogenesis, consists of binary complexes of the protective antigen (PA) heptamer (PA63h), produced by proteolytic cleavage of PA, together with either lethal factor or edema factor. The mouse monoclonal anti-PA antibody 1G3 was previously shown to be a potent antidote that shares FC domain dependency with the human monoclonal antibody MDX-1303 currently under clinical development. Here we demonstrate that 1G3 instigates severe perturbation of the PA63h structure and creates a PA supercomplex as visualized by electron microscopy. This phenotype, produced by the unconventional mode of antibody action, highlights the feasibility for optimization of vaccines based on analogous structural modification of PA63h as an additional strategy for future remedies against anthrax. PMID:20660775

  9. Detection of Anthrax Toxin by an Ultrasensitive Immunoassay Using Europium Nanoparticles

    Microsoft Academic Search

    Shixing Tang; Mahtab Moayeri; Zhaochun Chen; Harri Harma; Jiangqin Zhao; Haijing Hu; Robert H. Purcell; Stephen H. Leppla; Indira K. Hewlett

    2009-01-01

    We developed a europium nanoparticle-based immunoassay (ENIA) for the sensitive detection of anthrax protective antigen (PA). The ENIA exhibited a linear dose-dependent pattern within the detection range of 0.01 to 100 ng\\/ml and was approximately 100-fold more sensitive than enzyme-linked immunosorbent assay (ELISA). False-positive results were not observed with serum samples from healthy adults, mouse plasma without PA, or plasma

  10. Cell entry and cAMP imaging of anthrax edema toxin

    Microsoft Academic Search

    Federica Dal Molin; Fiorella Tonello; Daniel Ladant; Irene Zornetta; Ilaria Zamparo; Giulietta Di Benedetto; Manuela Zaccolo; Cesare Montecucco

    2006-01-01

    The entry and enzymatic activity of the anthrax edema factor (EF) in different cell types was studied by moni- toring EF-induced changes in intracellular cAMP with biochemical and microscopic methods. cAMP was imaged in live cells, transfected with a fluorescence resonance energy transfer biosensor based on the protein kinase A regulatory and catalytic subunits fused to CFP and YFP, respectively.

  11. Detection of Anthrax Toxin by an Ultrasensitive Immunoassay Using Europium Nanoparticles?

    PubMed Central

    Tang, Shixing; Moayeri, Mahtab; Chen, Zhaochun; Harma, Harri; Zhao, Jiangqin; Hu, Haijing; Purcell, Robert H.; Leppla, Stephen H.; Hewlett, Indira K.

    2009-01-01

    We developed a europium nanoparticle-based immunoassay (ENIA) for the sensitive detection of anthrax protective antigen (PA). The ENIA exhibited a linear dose-dependent pattern within the detection range of 0.01 to 100 ng/ml and was approximately 100-fold more sensitive than enzyme-linked immunosorbent assay (ELISA). False-positive results were not observed with serum samples from healthy adults, mouse plasma without PA, or plasma samples collected from mice injected with anthrax lethal factor or edema factor alone. For the detection of plasma samples spiked with PA, the detection sensitivities for ENIA and ELISA were 100% (11/11 samples) and 36.4% (4/11 samples), respectively. The assay exhibited a linear but qualitative correlation between the PA injected and the PA detected in murine blood (r = 0.97731; P < 0.0001). Anthrax PA was also detected in the circulation of mice infected with spores from a toxigenic Sterne-like strain of Bacillus anthracis, but only in the later stages of infection. These results indicate that the universal labeling technology based on europium nanoparticles and its application may provide a rapid and sensitive testing platform for clinical diagnosis and laboratory research. PMID:19129473

  12. Anthrax Toxin as a Molecular Tool for Stimulation of Cytotoxic T Lymphocytes: Disulfide-Linked Epitopes, Multiple Injections, and Role of CD41 Cells

    Microsoft Academic Search

    JIMMY D. BALLARD; R. JOHN COLLIER; MICHAEL N. STARNBACH

    We have previously demonstrated that anthrax toxin-derived proteins, protective antigen (PA) and the amino-terminal portion of lethal factor (LFn), can be used in combination to deliver heterologous molecules to the cytosol of mammalian cells. In this study we examined the ability of an LFn-peptide disulfide-linked heterodimer to prime cytotoxic T lymphocytes (CTL) in the presence of PA. A mutant of

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

    PubMed Central

    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

    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. PMID:23494942

  14. Anthrax--an overview.

    PubMed

    Oncü, Serkan; Oncü, Selcen; Sakarya, Serhan

    2003-11-01

    Anthrax, a disease of mammals (including humans), is caused by a spore-forming Gram-positive bacilli called Bacillus anthracis. Anthrax is one of the oldest threats to humanity, and remains endemic in animals in many parts of the world. The incidence of anthrax has decreased in developed countries, but it remains a considerable health problem in developing countries. The disease is transmitted to humans by contact with sick animals or their products, such as wool, skin, meat etc. Capsular polypeptide and anthrax toxin are the principal virulence factors of B. anthracis. Anthrax toxin consists of three proteins called protective antigen, edema factor, and lethal factor, each of which is nontoxic but acts synergistically. Human anthrax has three major clinical forms: cutaneous, inhalational, and gastrointestinal. The diagnosis is easily established in cutaneous cases, characterized by black eschar. Severe intoxication and collapse during the course of bronchopneumonia or hemorrhagic enteritis should prompt suspicion of anthrax. Treatment with antibiotics is mandatory. If untreated, anthrax in all forms can lead to septicemia and death. Recently, considerable attention has been focused on the potential for B. anthracis to be used in acts of biological terrorism. The ease of laboratory production and its dissemination via aerosol led to its adoption by terrorists, as shown by recent events in the USA. A good knowledge of anthrax, its epidemiology, pathogenesis, clinical forms and potential as a biological weapon is essential for timely prevention and treatment. This review summarizes the current knowledge on anthrax. PMID:14586293

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

    PubMed Central

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

    2013-01-01

    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. PMID:23509144

  16. Anthrax Lethal Toxin Inhibits Translation of Hypoxia-inducible Factor 1? and Causes Decreased Tolerance to Hypoxic Stress*

    PubMed Central

    Ouyang, Weiming; Torigoe, Chikako; Fang, Hui; Xie, Tao; Frucht, David M.

    2014-01-01

    Hypoxia is considered to be a contributor to the pathology associated with administration of anthrax lethal toxin (LT). However, we report here that serum lactate levels in LT-treated mice are reduced, a finding inconsistent with the anaerobic metabolism expected to occur during hypoxia. Reduced lactate levels are also observed in the culture supernatants of LT-treated cells. LT inhibits the accumulation of hypoxia-inducible factor (HIF)-1?, a subunit of HIF-1, the master regulator directing cellular responses to hypoxia. The toxin has no effect on the transcription or protein turnover of HIF-1?, but instead it acts to inhibit HIF-1? translation. LT treatment diminishes phosphorylation of eIF4B, eIF4E, and rpS6, critical components of the intracellular machinery required for HIF-1? translation. Moreover, blockade of MKK1/2-ERK1/2, but not p38 or JNK signaling, lowers HIF-1? protein levels in both normoxic and hypoxic conditions, consistent with a role for MKK1 and MKK2 as the major targets of LT responsible for the inhibition of HIF-1? translation. The physiological importance of the LT-induced translation blockade is demonstrated by the finding that LT treatment decreases the survival of hepatocyte cell lines grown in hypoxic conditions, an effect that is overcome by preinduction of HIF-1?. Taken together, these data support a role for LT in dysregulating HIF-1? and thereby disrupting homeostatic responses to hypoxia, an environmental characteristic of certain tissues at baseline and/or during disseminated infection with Bacillus anthracis. PMID:24366872

  17. Two independent replicons can support replication of the anthrax toxin-encoding plasmid pXO1 of Bacillus anthracis

    PubMed Central

    Akhtar, Parvez; Khan, Saleem A.

    2014-01-01

    The large pXO1 plasmid (181.6 kb) of Bacillus anthracis encodes the anthrax toxin proteins. Previous studies have shown that two separate regions of pXO1 can support replication of pXO1 miniplasmids when introduced into plasmid-less strains of this organism. No information is currently available on the ability of the above two replicons, termed RepX and ORFs 14/16 replicons, to support replication of the full-length pXO1 plasmid. We generated mutants of the full-length pXO1 plasmid in which either the RepX or the ORFs 14/16 replicon was inactivated by TargeTron insertional mutagenesis. Plasmid pXO1 derivatives containing only the RepX or the ORFs 14/16 replicon were able to replicate when introduced into a plasmid-less B. anthracis strain. Plasmid copy number analysis showed that the ORFs 14/16 replicon is more efficient than the RepX replicon. Our studies demonstrate that both the RepX and ORFs 14/16 replicons can independently support the replication of the full-length pXO1 plasmid. PMID:22239982

  18. ANTHRAX TOXIN BLOCKS PRIMING OF NEUTROPHILS BY LIPOPOLYSACCHARIDE AND BY MURAMYL DIPEPTIDE

    Microsoft Academic Search

    GEORGE G. WRIGHT; GERALD L. MANDELL

    . (10) presented evidence that the toxin was antiphagocytic and antibactericidal by virtue of an action on phagocytic cells . Despite thesignificance of these effects for the further understanding of pathogenesis, only recently have efforts been made to elucidate their mechanism. By analogy with other bacterial adenylate cyclases, we anticipated that PA plus EF would inhibit chemotaxis ofPMN; we found

  19. 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

    Microsoft Academic Search

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

    2012-01-01

    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

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

    PubMed Central

    Whiting, Gail; Baker, Michael; Rijpkema, Sjoerd

    2012-01-01

    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. PMID:22347621

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

    PubMed Central

    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.

    2013-01-01

    Domain 2 of the anthrax protective antigen (PA) prepore heptamer unfolds and refolds during endosome acidification to generate an extended 100 Å beta 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 (EF), from the endosome into 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 (SPR) and bio-layer interferometry (BLI). The kinetics of this transition increased as the solution pH was decreased from pH 7.5 to pH 5.0, mirroring acidification of the endosome. Once transitioned, the LFN-PA pore complex was removed from the BLI biosensor tip and deposited onto EM grids, where the 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 or late endosomal pH conditions (5.5 to 5.0 respectively). Once the pore formed, the soluble receptor readily dissociated from the PA pore. Separate binding experiments with immobilized PA pores and 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

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

    PubMed

    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

    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

  3. Development of antibodies to protective antigen and lethal factor components of anthrax toxin in humans and guinea pigs and their relevance to protective immunity.

    PubMed Central

    Turnbull, P C; Broster, M G; Carman, J A; Manchee, R J; Melling, J

    1986-01-01

    A competitive inhibition enzyme-linked immunosorbent assay (ELISA) was developed to detect antibodies in serum to the protective antigen (PA) and lethal factor (LF) components of anthrax toxin. Current human vaccination schedules with an acellular vaccine induce predictable and lasting antibody titers to PA and, when present in the vaccine, to LF. Live spore vaccine administered to guinea pigs in a single dose conferred significantly better protection than the human vaccines (P less than 0.001), although they elicited significantly lower (P less than 0.0005) anti-PA and anti-LF titers at time of challenge with virulent Bacillus anthracis. Substantial anti-PA and anti-LF titers may not, therefore, indicate solid protective immunity against anthrax infection. The ELISA system was also shown to be capable of detecting anti-PA and anti-LF antibodies in the sera of individuals with histories of clinical anthrax. The advantage of ELISA over the Ouchterlony gel diffusion test and indirect microhemagglutination assay are demonstrated. There was a highly significant degree of correlation between ELISA and the indirect microhemagglutination assay (P less than 0.0005); but ELISA was markedly superior in terms of reproducibility, reliability, specificity, and simplicity in performance and stability of the bound antigen. PMID:3084381

  4. Expression and purification of the functional ectodomain of human anthrax toxin receptor 2 in Escherichia coli Origami B cells with assistance of bacterial Trigger Factor.

    PubMed

    Jacquez, Pedro; Lei, Ningjing; Weigt, David; Xiao, Chuan; Sun, Jianjun

    2014-03-01

    The ectodomain of anthrax toxin receptor 2 (ANTXR2) is composed of a von Willebrand factor A (VWA) domain that binds to anthrax toxin protective antigen (PA) and a newly defined immunoglobulin-like (Ig) domain, in which the disulfide bonds are required for PA pore formation and for the folding of ANTXR2. While the VWA domain has been well characterized, the structure and function of the whole ectodomain (VWA-Ig) are poorly defined, which is mainly due to the limited production of the soluble recombinant protein of the ectodomain. In the present study, the ANTXR2 ectodomain was fused to the C-terminus of bacterial Trigger Factor (TF), a chaperone that mediates the ribosome-associated, co-translational folding of newly synthesized polypeptides in Escherichia coli. Under the control of a cold shock promoter, the fusion protein was overly expressed as a dominant soluble protein at a low temperature in the oxidative cytoplasm of Origami B cells, where formation of the disulfide bonds is favored. Through a series of chromatography, the ANTXR2 ectodomain was purified into homogeneity. The purified ectodomain is functional in binding to PA and mediating PA pore formation on the liposomal membranes, and the yield is applicable for future biochemical and structural characterization. PMID:24380801

  5. Expression and purification of the functional ectodomain of human anthrax toxin receptor 2 in E. coli Origami B cells with assistance of bacterial Trigger Factor

    PubMed Central

    Jacquez, Pedro; Lei, Ningjing; Weigt, David; Xiao, Chuan; Sun, Jianjun

    2014-01-01

    The ectodomain of anthrax toxin receptor 2 (ANTXR2) is composed of a von Willebrand factor A (VWA) domain that binds to anthrax toxin protective antigen (PA) and a newly defined immunoglobulin-like (Ig) domain, in which the disulfide bonds are required for PA pore formation and for the folding of ANTXR2. While the VWA domain has been well characterized, the structure and function of the whole ectodomain (VWA-Ig) are poorly defined, which is mainly due to the limited production of the soluble recombinant protein of the ectodomain. In the present study, the ANTXR2 ectodomain was fused to the C-terminus of bacterial Trigger Factor (TF), a chaperone that mediates the ribosome-associated, co-translational folding of newly synthesized polypeptides in E. coli. Under the control of a cold shock promoter, the fusion protein was overly expressed as a dominant soluble protein at a low temperature in the oxidative cytoplasm of Origami B cells, where formation of the disulfide bonds is favored. Through a series of chromatography, the ANTXR2 ectodomain was purified into homogeneity. The purified ectodomain is functional in binding to PA and mediating PA pore formation on the liposomal membranes, and the yield is applicable for future biochemical and structural characterization. PMID:24380801

  6. Development of a Comprehensive, Validated Pharmacophore Hypothesis for Anthrax Toxin Lethal Factor (LF) Inhibitors Using Genetic Algorithms, Pareto Scoring, and Structural Biology

    PubMed Central

    Chiu, Ting-Lan; Amin, Elizabeth A.

    2012-01-01

    Anthrax is an acute infectious disease caused by the spore-forming bacterium Bacillus anthracis. The anthrax toxin lethal factor (LF), an 89-kDa zinc hydrolase secreted by the bacilli, is the toxin component chiefly responsible for pathogenesis and has been a popular target for rational and structure-based drug design. Although hundreds of small-molecule compounds have been designed to target the LF active site, relatively few reported inhibitors have exhibited activity in cell-based assays and no LF inhibitor is currently available to treat or prevent anthrax. This study presents a new pharmacophore map assembly, validated by experiment, designed to rapidly identify and prioritize promising LF inhibitor scaffolds from virtual compound libraries. The new hypothesis incorporates structural information from all five available LF enzyme-inhibitor complexes deposited in the Protein Data Bank (PDB) and is the first LF pharmacophore map reported to date that includes features representing interactions involving all three key subsites of the LF catalytic binding region. In a wide-ranging validation study on all 546 compounds for which published LF biological activity data exist, this model displayed strong selectivity toward nanomolar-level LF inhibitors, successfully identifying 72.1% of existing nanomolar-level compounds in an unbiased test set, while rejecting 100% of weakly active (>100 µM) compounds. In addition to its capabilities as a database searching tool, this comprehensive model points to a number of key design principles and previously unidentified ligand-receptor interactions that are likely to influence compound potency. PMID:22697455

  7. The Structure of Tumor Endothelial Marker 8 (TEM8) Extracellular Domain and Implications for Its Receptor Function for Recognizing Anthrax Toxin

    PubMed Central

    Cai, Chenguang; Zhao, Ying; Wu, Yang; Li, Yuanyuan; Xu, Junjie; Zhang, Xuejun C.; Xu, Long; Chen, Wei; Rao, Zihe

    2010-01-01

    Anthrax toxin, which is released from the Gram-positive bacterium Bacillus anthracis, is composed of three proteins: protective antigen (PA), lethal factor (LF), and edema factor (EF). PA binds a receptor on the surface of the target cell and further assembles into a homo-heptameric pore through which EF and LF translocate into the cytosol. Two distinct cellular receptors for anthrax toxin, TEM8/ANTXR1 and CMG2/ANTXR2, have been identified, and it is known that their extracellular domains bind PA with low and high affinities, respectively. Here, we report the crystal structure of the TEM8 extracellular vWA domain at 1.7 Å resolution. The overall structure has a typical integrin fold and is similar to that of the previously published CMG2 structure. In addition, using structure-based mutagenesis, we demonstrate that the putative interface region of TEM8 with PA (consisting of residues 56, 57, and 154–160) is responsible for the PA-binding affinity differences between the two receptors. In particular, Leu56 was shown to be a key factor for the lower affinity of TEM8 towards PA compared with CMG2. Because of its high affinity for PA and low expression in normal tissues, an isolated extracellular vWA domain of the L56A TEM8 variant may serve as a potent antitoxin and a potential therapeutic treatment for anthrax infection. Moreover, as TEM8 is often over-expressed in tumor cells, our TEM8 crystal structure may provide new insights into how to design PA mutants that preferentially target tumor cells. PMID:20585457

  8. The structure of tumor endothelial marker 8 (TEM8) extracellular domain and implications for its receptor function for recognizing anthrax toxin.

    PubMed

    Fu, Sheng; Tong, Xiaohang; Cai, Chenguang; Zhao, Ying; Wu, Yang; Li, Yuanyuan; Xu, Junjie; Zhang, Xuejun C; Xu, Long; Chen, Wei; Rao, Zihe

    2010-01-01

    Anthrax toxin, which is released from the gram-positive bacterium Bacillus anthracis, is composed of three proteins: protective antigen (PA), lethal factor (LF), and edema factor (EF). PA binds a receptor on the surface of the target cell and further assembles into a homo-heptameric pore through which EF and LF translocate into the cytosol. Two distinct cellular receptors for anthrax toxin, TEM8/ANTXR1 and CMG2/ANTXR2, have been identified, and it is known that their extracellular domains bind PA with low and high affinities, respectively. Here, we report the crystal structure of the TEM8 extracellular vWA domain at 1.7 A resolution. The overall structure has a typical integrin fold and is similar to that of the previously published CMG2 structure. In addition, using structure-based mutagenesis, we demonstrate that the putative interface region of TEM8 with PA (consisting of residues 56, 57, and 154-160) is responsible for the PA-binding affinity differences between the two receptors. In particular, Leu56 was shown to be a key factor for the lower affinity of TEM8 towards PA compared with CMG2. Because of its high affinity for PA and low expression in normal tissues, an isolated extracellular vWA domain of the L56A TEM8 variant may serve as a potent antitoxin and a potential therapeutic treatment for anthrax infection. Moreover, as TEM8 is often over-expressed in tumor cells, our TEM8 crystal structure may provide new insights into how to design PA mutants that preferentially target tumor cells. PMID:20585457

  9. [Anthrax and carbuncle].

    PubMed

    Arrese, J E; Piérard-Franchimont, C; Piérard, G E

    2001-10-01

    Anthrax is a name given in French language to two distinct infectious diseases. One corresponds to carbuncle which is a collection of boils. The other one corresponds to the English term anthrax. This condition has a clinical presentation and an outcome that vary according to the inoculation site being cutaneous, pulmonary or digestive, and to the bacterial and toxin spread in the body. PMID:11765578

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

    Microsoft Academic Search

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

    The bioterrorism-associated human anthrax epidemic in the fall of 2001 highlighted the need for a sensi- tive, reproducible, and specific laboratory test for the confirmatory diagnosis of human anthrax. The Cen- ters 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 anti- gen (PA) in

  11. MICROBIOLOGY: A Binding Contract for Anthrax

    NSDL National Science Digital Library

    James J. Bull (University of Texas; Section of Integrative Biology and Institute for Cellular and Molecular Biology)

    2002-07-12

    Access to the article is free, however registration and sign-in are required. As the anthrax bioterrorism attacks demonstrated last year, individuals infected with the causative organism, Bacillus anthracis, may still die even after successful antibiotic treatment because of the production of large amounts of the anthrax toxin. In their Perspective, Bull and Parrish discuss new work published elsewhere that identifies an antitoxin antibody that could be used to passively immunize infected individuals and neutralize the anthrax toxin.

  12. Anthrax Vaccine

    MedlinePLUS

    ... humans. It is caused by bacteria called Bacillus anthracis. People can get anthrax from contact with infected ... Anthrax. This form of anthrax occurs when B. anthracis is inhaled, and is very serious. The first ...

  13. Potent inhibition of tumor angiogenesis by the matrix metalloproteinase-activated anthrax lethal toxin: implications for broad anti-tumor efficacy.

    PubMed

    Alfano, Randall W; Leppla, Stephen H; Liu, Shihui; Bugge, Thomas H; Duesbery, Nicholas S; Frankel, Arthur E

    2008-03-15

    Angiogenesis is a critical step in solid tumor progression. The mitogen-activated protein kinase (MAPK) signaling pathways are central to this process, and thus present attractive targets for angiogenesis inhibition. Anthrax Lethal Toxin (LeTx), secreted from the gram positive Bacillus anthracis, demonstrates potent MAPK pathway inhibition. In vivo efficacy studies revealed that LeTx has broad anti-tumor efficacy via the targeting of angiogenesis. However, specificity in animal models was limited due to the presence of receptors on many normal tissues and the ubiquitous expression of furin in tissues. Further, half-life of LeTx was short due to circulating furin-like proteases. Gelatinases are expressed on tumor angiogenic sprouts and only to a limited extent in normal tissues or blood. In order to circumvent nonspecific LeTx activation, enhance tumor vascular targeting, and improve plasma half-life, a substrate preferably cleaved by gelatinases was substituted for the furin LeTx activation site. The MMP-activated LeTx showed potent angiogenic inhibition in vivo in the absence of systemic toxicity. Based on these studies, this attenuated toxin has clinical potential as a broad anti-tumor agent. PMID:18245947

  14. Nano Aptasensor for Protective Antigen Toxin of Lakshmi N. Cella,,,|

    E-print Network

    Chen, Wilfred

    Nano Aptasensor for Protective Antigen Toxin of Anthrax Lakshmi N. Cella,,,| Pablo Sanchez of California, Riverside, California 92521 We demonstrate a highly sensitive nano aptasensor for anthrax toxin, demonstrating it as a potential tool for rapid and point-of-care diagnosis for anthrax. Anthrax is a disease

  15. Prophylaxis and Therapy of Inhalational Anthrax by a Novel Monoclonal Antibody to Protective Antigen That Mimics Vaccine-Induced Immunity

    Microsoft Academic Search

    Laura Vitale; Diann Blanset; Israel Lowy; Thomas O'Neill; Joel Goldstein; Stephen F. Little; Gerard P. Andrews; Gary Dorough; Ronald K. Taylor; Tibor Keler

    2006-01-01

    The neutralizing antibody response to the protective antigen (PA) component of anthrax toxin elicited by approved anthrax vaccines is an accepted correlate for vaccine-mediated protection against anthrax. We reasoned that a human anti-PA monoclonal antibody (MAb) selected on the basis of superior toxin neutral- ization activity might provide potent protection against anthrax. The fully human MAb (also referred to as

  16. The Anthrax Toxin Activator Gene atxA Is Associated with CO2Enhanced Non-Toxin Gene Expression in Bacillus anthracis

    Microsoft Academic Search

    ALEX R. HOFFMASTER; THERESA M. KOEHLER

    1997-01-01

    tions from atxA1 and atxA isolates grown in 5% CO2 and in air were examined by two-dimensional electro- phoresis. Comparison of the resulting protein patterns indicated that synthesis of non-toxin proteins is influenced by growth in elevated CO2 and the toxin gene regulator, atxA. Second, we generated random transcriptional lacZ fusions in B. anthracis with transposon Tn917-LTV3. Transposon-insertion libraries were

  17. Molecular determinants for a cardiovascular collapse in anthrax.

    PubMed

    Brojatsch, Jurgen; Casadevall, Arturo; Goldman, David L

    2014-01-01

    Bacillus anthracis releases two bipartite proteins, lethal toxin and edema factor, that contribute significantly to the progression of anthrax-associated shock. As blocking the anthrax toxins prevents disease, the toxins are considered the main virulence factors of the bacterium. The anthrax bacterium and the anthrax toxins trigger multi-organ failure associated with enhanced vascular permeability, hemorrhage and cardiac dysfunction in animal challenge models. A recent study using mice that either lacked the anthrax toxin receptor in specific cells and corresponding mice expressing the receptor in specific cell types demonstrated that cardiovascular cells are critical for disease mediated by anthrax lethal toxin. These studies are consistent with involvement of the cardiovascular system, and with an increase of cardiac failure markers observed in human anthrax and in animal models using B. anthracis and anthrax toxins. This review discusses the current state of knowledge regarding the pathophysiology of anthrax and tries to provide a mechanistic model and molecular determinants for the circulatory shock in anthrax. PMID:24389148

  18. Molecular determinants for a cardiovascular collapse in anthrax

    PubMed Central

    Brojatsch, Jurgen; Casadevall, Arturo; Goldman, David L.

    2015-01-01

    Bacillus anthracis releases two bipartite proteins, lethal toxin and edema factor, that contribute significantly to the progression of anthrax-associated shock. As blocking the anthrax toxins prevents disease, the toxins are considered the main virulence factors of the bacterium. The anthrax bacterium and the anthrax toxins trigger multiorgan failure associated with enhanced vascular permeability, hemorrhage and cardiac dysfunction in animal challenge models. A recent study using mice that either lacked the anthrax toxin receptor in specific cells and corresponding mice expressing the receptor in specific cell types demonstrated that cardiovascular cells are critical for disease mediated by anthrax lethal toxin. These studies are consistent with involvement of the cardiovascular system, and with an increase of cardiac failure markers observed in human anthrax and in animal models using B. anthracis and anthrax toxins. This review discusses the current state of knowledge regarding the pathophysiology of anthrax and tries to provide a mechanistic model and molecular determinants for the circulatory shock in anthrax. PMID:24389148

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

    PubMed Central

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

    2012-01-01

    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. PMID:23028046

  20. Ultra-fast pg/ml anthrax toxin (protective antigen) detection assay based on microwave-accelerated metal-enhanced fluorescence.

    PubMed

    Dragan, Anatoliy I; Albrecht, Mark T; Pavlovic, Radmila; Keane-Myers, Andrea M; Geddes, Chris D

    2012-06-01

    Rapid presymptomatic diagnosis of Bacillus anthracis at early stages of infection plays a crucial role in prompt medical intervention to prevent rapid disease progression and accumulation of lethal levels of toxin. To detect low levels of the anthrax protective antigen (PA) exotoxin in biological fluids, we have developed a metal-enhanced fluorescence (MEF)-PA assay using a combination of the MEF effect and microwave-accelerated PA protein surface absorption. The assay is based on a modified version of our "rapid catch and signal" (RCS) technology previously designed for the ultra-fast and sensitive analysis of genomic DNA sequences. Technologically, the proposed MEF-PA assay uses standard 96-well plastic plates modified with silver island films (SiFs) grown within the wells. It is shown that the fluorescent probe, covalently attached to the secondary antibody, plays a crucial role of indicating complex formation (i.e., shows a strong MEF response to the recognition event). Microwave irradiation rapidly accelerates PA deposition onto the surface ("rapid catch"), significantly speeding up the MEF-PA assay and resulting in a total assay run time of less than 40 min with an analytical sensitivity of less than 1 pg/ml PA. PMID:22406431

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

    E-print Network

    Paris-Sud XI, Université de

    Abstract Lethal toxin (LT) is a critical virulence factor of Bacillus anthracis, the etiological agent of host defense against invading pathogens. We report here that intranasal instillation of a B. anthracis, instillation of a B. anthracis strain expressing active LT represses lung inflammation. The inhibitory effects

  2. Interactions of anthrax lethal factor with protective antigen defined by site-directed spin labeling

    E-print Network

    McQuade, D. Tyler

    , 2010 (sent for review October 29, 2010) The protective antigen (PA) moiety of anthrax toxin forms oligoInteractions of anthrax lethal factor with protective antigen defined by site-directed spin the PA pore. Anthrax toxin, in addition to its importance in regard to the pathogenesis of Bacillus

  3. Low molecular weight inhibitors of the protease anthrax lethal factor.

    PubMed

    Dalkas, Georgios A; Papakyriakou, Athanasios; Vlamis-Gardikas, Alexios; Spyroulias, Georgios A

    2008-03-01

    Anthrax Lethal Factor (LF) is a zinc-dependent metalloprotease that together with the protective antigen constitute the anthrax lethal toxin, the most prominent virulence factor of the disease anthrax. This review summarizes the current knowledge on anthrax toxicity and defense in relation to LF. Particular emphasis is placed on the structural aspects of LF, the properties of its substrates and the achievements in the design of low molecular weight inhibitors of the catalytic activity of the metalloenzyme. PMID:18336349

  4. Effect of anthrax immune globulin on response to BioThrax (anthrax vaccine adsorbed) in New Zealand white rabbits.

    PubMed

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

    2013-11-01

    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. PMID:23979740

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

    PubMed Central

    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

    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. PMID:23979740

  6. Anthrax lethal toxin and Salmonella elicit the common cell death pathway of caspase-1-dependent pyroptosis via distinct mechanisms

    Microsoft Academic Search

    Susan L. Fink; Tessa Bergsbaken; Brad T. Cookson

    2008-01-01

    Caspase-1 cleaves the inactive IL-1beta and IL-18 precursors into active inflammatory cytokines. In Salmonella-infected macrophages, caspase-1 also mediates a pathway of proinflammatory programmed cell death termed ``pyroptosis.'' We demonstrate active caspase-1 diffusely distributed in the cytoplasm and localized in discrete foci within macrophages responding to either Salmonella infection or intoxication by Bacillus anthracis lethal toxin (LT). Both stimuli triggered caspase-1-dependent

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

    PubMed Central

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

    2012-01-01

    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. PMID:23100532

  8. 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

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

    2013-01-01

    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. PMID:23418614

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

    PubMed Central

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

    2012-01-01

    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. PMID:21683629

  10. STRUCTURE BASED DESIGN OF PROTEIN LIGANDS: A STUDY OF ANTIBODY-LIKE SCAFFOLDS TARGETED AGAINST THE ANTHRAX TOXIN

    SciTech Connect

    P. SHIFLETT; E. HONG-GELLER; ET AL

    2000-12-01

    We have adopted structure-based approaches to enhance the affinities of two single chain antibodies, scFv1 and scFv4, that bind to two different epitopes on the Protective Antigen (PA), a toxin from Bacillus anthracis. In one approach, we have modified scFv4 and re-engineered a novel antibody-like scaffold in which we have placed V{sub L} on the N terminus and V{sub H} on the C-terminus and joined them by a 10 amino-acid-long linker. This scaffold preserves the native V{sub L}-V{sub H} contact interface and the dispositions of the CDR loops. It binds to PA with 10 fold higher affinity than scFv4. In a second approach, we have created a bispecific ligand by covalently joining scFv1 and scFv4 by a flexible linker that supports simultaneous and synergistic binding of the two scFvs to PA. This bispecific scFv1-linker-scFv4 binds to PA with 10 fold higher affinity than the individual scFvs. The newly re-engineered antibody-like scaffold of scFv4 and scFv1-linker-scFv4 are expected to be potent inhibitors of PA binding to the host cells.

  11. Anthrax lethal toxin and Salmonella elicit the common cell death pathway of caspase-1-dependent pyroptosis via distinct mechanisms.

    PubMed

    Fink, Susan L; Bergsbaken, Tessa; Cookson, Brad T

    2008-03-18

    Caspase-1 cleaves the inactive IL-1beta and IL-18 precursors into active inflammatory cytokines. In Salmonella-infected macrophages, caspase-1 also mediates a pathway of proinflammatory programmed cell death termed "pyroptosis." We demonstrate active caspase-1 diffusely distributed in the cytoplasm and localized in discrete foci within macrophages responding to either Salmonella infection or intoxication by Bacillus anthracis lethal toxin (LT). Both stimuli triggered caspase-1-dependent lysis in macrophages and dendritic cells. Activation of caspase-1 by LT required binding, uptake, and endosome acidification to mediate translocation of lethal factor (LF) into the host cell cytosol. Catalytically active LF cleaved cytosolic substrates and activated caspase-1 by a mechanism involving proteasome activity and potassium efflux. LT activation of caspase-1 is known to require the inflammasome adapter Nalp1. In contrast, Salmonella infection activated caspase-1 through an independent pathway requiring the inflammasome adapter Ipaf. These distinct mechanisms of caspase-1 activation converged on a common pathway of caspase-1-dependent cell death featuring DNA cleavage, cytokine activation, and, ultimately, cell lysis resulting from the formation of membrane pores between 1.1 and 2.4 nm in diameter and pathological ion fluxes that can be blocked by glycine. These findings demonstrate that distinct activation pathways elicit the conserved cell death effector mechanism of caspase-1-mediated pyroptosis and support the notion that this pathway of proinflammatory programmed cell death is broadly relevant to cell death and inflammation invoked by diverse stimuli. PMID:18337499

  12. Anthrax Attacks

    NSDL National Science Digital Library

    Science Netlinks

    2002-05-05

    This Science NetLinks lesson focuses on the bacterial disease known as Anthrax. Anthrax has always been identified as a disease that infects cattle, but there are known cases of people contracting this disease directly from handling infected cattle. In this online lesson the students will research the disease and its impact on human health.

  13. Inhalational anthrax.

    PubMed

    Cuneo, Brian M

    2004-03-01

    Anthrax remains a real threat. In a spore form, it is highly infectious and dispersible. The initial symptoms are similar to those of influenza, and the early stage of inhalational anthrax may not be recognized. Early antibiotic treatment is important to achieving a good outcome. Contrary to historical experience. many patients with even advanced anthrax can be saved with aggressive medical care. Prevention of anthrax infections requires vigilant infection control methods as well as a rational prophylactic plan. All health care providers should be familiar with the symptoms and treatment of this disease. It is hoped that future research will clarify tests for early diagnosis, the best methods of prophylaxis, and the most effective treatments. Unfortunately the threat of bioterrorism, and anthrax in particular, is unlikely to go away. PMID:15062228

  14. Cutaneous anthrax (image)

    MedlinePLUS

    Anthrax is caused by the bacteria Bacillus anthracis . While anthrax commonly affects hoofed animals such as sheep and goats, humans may get sick from anthrax, too. The most common type of anthrax infection ...

  15. Raxibacumab: potential role in the treatment of inhalational anthrax

    PubMed Central

    Kummerfeldt, Carlos E

    2014-01-01

    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

  16. Anthrax: pre-publication and special issue

    NSDL National Science Digital Library

    2001-01-01

    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.

  17. Novel approaches to the treatment of systemic anthrax.

    PubMed

    Artenstein, Andrew W; Opal, Steven M

    2012-04-01

    Anthrax continues to generate concern as an agent of bioterrorism and as a natural cause of sporadic disease outbreaks. Despite the use of appropriate antimicrobial agents and advanced supportive care, the mortality associated with the systemic disease remains high. This is primarily due to the pathogenic exotoxins produced by Bacillus anthracis as well as other virulence factors of the organism. For this reason, new therapeutic strategies that target events in the pathogenesis of anthrax and may potentially augment antimicrobials are being investigated. These include anti-toxin approaches, such as passive immune-based therapies; non-antimicrobial drugs with activity against anthrax toxin components; and agents that inhibit binding, processing, or assembly of toxins. Adjunct therapies that target spore germination or downstream events in anthrax intoxication are also under investigation. In combination, these modalities may enhance the management of systemic anthrax. PMID:22438345

  18. Monoclonal Antibody Therapies against Anthrax

    PubMed Central

    Chen, Zhaochun; Moayeri, Mahtab; Purcell, Robert

    2011-01-01

    Anthrax is a highly lethal infectious disease caused by the spore-forming bacterium Bacillus anthracis. It not only causes natural infection in humans but also poses a great threat as an emerging bioterror agent. The lethality of anthrax is primarily attributed to the two major virulence factors: toxins and capsule. An extensive effort has been made to generate therapeutically useful monoclonal antibodies to each of the virulence components: protective antigen (PA), lethal factor (LF) and edema factor (EF), and the capsule of B. anthracis. This review summarizes the current status of anti-anthrax mAb development and argues for the potential therapeutic advantage of a cocktail of mAbs that recognize different epitopes or different virulence factors. PMID:22069754

  19. Monoclonal antibody therapies against anthrax.

    PubMed

    Chen, Zhaochun; Moayeri, Mahtab; Purcell, Robert

    2011-08-01

    Anthrax is a highly lethal infectious disease caused by the spore-forming bacterium Bacillus anthracis. It not only causes natural infection in humans but also poses a great threat as an emerging bioterror agent. The lethality of anthrax is primarily attributed to the two major virulence factors: toxins and capsule. An extensive effort has been made to generate therapeutically useful monoclonal antibodies to each of the virulence components: protective antigen (PA), lethal factor (LF) and edema factor (EF), and the capsule of B. anthracis. This review summarizes the current status of anti-anthrax mAb development and argues for the potential therapeutic advantage of a cocktail of mAbs that recognize different epitopes or different virulence factors. PMID:22069754

  20. Pathophysiology of anthrax.

    PubMed

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

    2009-01-01

    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. PMID:19273366

  1. Raxibacumab: potential role in the treatment of inhalational anthrax.

    PubMed

    Kummerfeldt, Carlos E

    2014-01-01

    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

  2. Effect of X-irradiation on the course of experimental vaccine anthrax

    Microsoft Academic Search

    J. Van?u?ík

    1964-01-01

    The author studied the course of vaccine anthrax infection in irradiated rabbits. The experiments show that infection of irradiated\\u000a rabbits with a vaccine strain can give rise to a disease bacteriologically, clinically, histologically and biochemically identical\\u000a with typical anthrax and that anthrax toxin can be demonstrated in the plasma of dead rabbits. The main cause of anthrax sepsis\\u000a is not

  3. Rapid Purification of Recombinant Anthrax-Protective Antigen under Nondenaturing Conditions

    Microsoft Academic Search

    Nidhi Ahuja; Praveen Kumar; Rakesh Bhatnagar

    2001-01-01

    Anthrax-protective antigen is the central moiety of the anthrax toxin complex that mediates the entry of the other two toxin components, lethal factor and edema factor into the cells. It is also the main immunogen of the cell-free vaccine against anthrax. However, in addition to PA, the vaccine contains trace amounts of other culture-derived proteins that contribute to the side

  4. Neutron-based sterilization of anthrax contamination.

    PubMed

    Liu, Bin; Wang, Qingfei

    2006-05-01

    With the anthrax threat becoming a reality, it is very important to have an effective way to sterilize areas contaminated by anthrax. Anthrax spores are the dormant form of the anthrax bacteria. They can germinate in tissues, producing new bacteria that release lethal toxins. Neutrons can be a powerful tool in our defense against anthrax contamination. Neutrons are elementary particles that have no charge, which allows them to be very penetrating, killing the anthrax spores on the surface and inside the containers. So neutrons have an advantage over other forms of radiation if deep penetration is required to kill biological organisms. A Cf neutron source allows for a low cost method of decontamination. It emits most neutrons in the 100 keV to 2 MeV energy regions, and a neutron in this energy region is 20 times more deadly than electrons or gamma rays in killing anthrax spores. If we just consider the first neutron collision with anthrax spores and that all the anthrax spores will not survive at the dose level above 2.0 x 10 Gy, our calculations show that a 0.5-g Cf neutron source within 20 min can generate 1.11 x 10 m fluence neutrons, which is good enough to kill the anthrax spores on the sample. An experimental confirmation of the above results may prove that to achieve 1.11 x 10 m fluence neutrons on the anthrax spore sample, the neutron irradiation time may be reduced dramatically or the Cf neutron source reduced to 0.1 g level or even less. The aim of this paper is to evaluate a feasible way to sterilize the anthrax contamination by using a Cf neutron source. Presently, we are mainly concentrating on the theoretical estimation of neutron fluence to see if the Cf neutron source can deliver enough neutron irradiation dose to kill the anthrax spores. Our future work will focus on experimental confirmation and Monte Carlo simulation by using Geant4 or MCNP codes. At that time, we will consider the effects of the real experimental setup, the shielding materials, the exact chemical components, and the biological structures of anthrax spores. We also need to consider the ways of carrying the anthrax spores, and this includes surface contamination, inside an envelope, or hidden in sealed metal containers and luggage. PMID:16607173

  5. Bioterrorism Preparedness--Anthrax 

    E-print Network

    Lawhorn, D. Bruce

    2002-04-24

    This publication explains how people can prepare for a terrorist attack that uses anthrax. It discusses the reasons anthrax might be used in a bioterrorist attack and lists symptoms of anthrax infection in people and signs ...

  6. Anthrax mounts a nuclear attack on glucocorticoid signaling.

    PubMed

    Kliewer, Steven A

    2003-11-01

    Anthrax causes profound inflammation and systemic shock. A recent study has shown that anthrax lethal toxin represses the transcriptional activity of the glucocorticoid receptor, which is a crucial component of the body's defenses against inflammation. The study reports evidence that lethal toxin blocks the glucocorticoid receptor by inhibiting the p38 mitogen-activated protein kinase pathway. Thus, these findings suggest that glucocorticoid receptor inactivation contributes to anthrax toxicity and raise the possibility of developing new strategies to combat this deadly disease. PMID:14607073

  7. Recent Developments in Anti-dotes Against Anthrax.

    PubMed

    Dhasmana, Neha; Singh, Lalit K; Bhaduri, Asani; Misra, Richa; Singh, Yogendra

    2014-01-01

    The etiologic agent of disease anthrax, Bacillus anthracis, causes recurrent outbreaks among the livestock and intermittent infections in humans across the world. Controlling animal infections by vaccination can minimize the incidence of disease in humans. Prevention of anthrax in occupationally exposed personnel is achieved through vaccination with either live spores or precipitates of culture supernatants from attenuated strains of B. anthracis. However, anthrax vaccination of the large human population is impractical as well as inappropriate. Broad-range antibiotics like amoxicillin, ciprofloxacin, clindamycin, streptomycin, and penicillin G are recommended for the treatment of human anthrax infections, but the threat of antibiotic resistant strains always remains. Moreover, in the absence of any specific symptom (s) during early infection, the diagnosis of anthrax is delayed causing elevated levels of anthrax toxin component which could be fatal. For these reasons, there is a need to develop new antimicrobial agents against virulent B. anthracis to effectively combat this fatal pathogen. Over the last two decades, extensive studies have been carried out to develop specific inhibitors against virulence factors of B. anthracis such as capsule, protective antigen, lethal factor and edema factor. Research has also been focused in developing inhibitors of anthrax toxin receptors (including the use of receptor decoys) and host furin endoproteases which are required for activation of toxin. This review highlights the recent progress made in developing the diverse countermeasures for anthrax infections targeting B. anthracis virulence factors and their counterparts in host. PMID:25174439

  8. Efficient synthetic inhibitors of anthrax lethal factor

    PubMed Central

    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

    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. PMID:15983377

  9. Substrate specificity of the anthrax lethal factor

    Microsoft Academic Search

    M. Yu. Zakharova; S. A. Dubiley; D. M. Chudakov; A. G. Gabibov; I. G. Shemyakin; A. V. Kolesnikov

    2008-01-01

    The lethal factor (LF), a high-specific metalloprotease, is a subunit of the B. anthracis toxin. In susceptible cells, LF has a toxic effect due to inactivation of MKK-family kinases (mitogen-activated serine?threonine kinase kinases) and presumably of some other proteins. To develop an approach to neutralization of the anthrax toxin effect, the entire pattern of LF cell targets should be determined.

  10. ForPeerReview Modeling the structure of mAb 14B7 bound to the anthrax protective

    E-print Network

    Gray, Jeffrey J.

    ForPeerReview Modeling the structure of mAb 14B7 bound to the anthrax protective antigen Journal 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 #12;ForPeerReview 2 Abstract The anthrax protective, Department of Chemical Engineering and Materials Science Key Words: affinity maturation, anthrax toxin

  11. Molecular basis for improved anthrax vaccines.

    PubMed

    Brey, Robert N

    2005-06-17

    The current vaccine for anthrax has been licensed since 1970 and was developed based on the outcome of human trials conducted in the 1950s. This vaccine, known as anthrax vaccine adsorbed (AVA), consists of a culture filtrate from an attenuated strain of Bacillus anthracis adsorbed to aluminum salts as an adjuvant. This vaccine is considered safe and effective, but is difficult to produce and is associated with complaints about reactogenicity among users of the vaccine. Much of the work in the past decade on generating a second generation vaccine is based on the observation that antibodies to protective antigen (PA) are crucial in the protection against exposure to virulent anthrax spores. Antibodies to PA are thought to prevent binding to its cellular receptor and subsequent binding of lethal factor (LF) and edema factor (EF), which are required events for the action of the two toxins: lethal toxin (LeTx) and edema toxin (EdTx). The bacterial capsule as well as the two toxins are virulence factors of B. anthracis. The levels of antibodies to PA must exceed a certain minimal threshold in order to induce and maintain protective immunity. Immunity can be generated by vaccination with purified PA, as well as spores and DNA plasmids that express PA. Although antibodies to PA address the toxemia component of anthrax disease, antibodies to additional virulence factors, including the capsule or somatic antigens in the spore, may be critical in development of complete, sterilizing immunity to anthrax exposure. The next generation anthrax vaccines will be derived from the thorough understanding of the interaction of virulence factors with human and animal hosts and the role the immune response plays in providing protective immunity. PMID:15935874

  12. Inhalational anthrax.

    PubMed

    Frazier, Aletta Ann; Franks, Teri J; Galvin, Jeffrey R

    2006-11-01

    Inhalational anthrax is a lethal infection acquired from the inhalation of Bacillus anthracis, a pathogen classified as a Category A bioterrorist agent by the Centers for Disease Control and Prevention. The recent 2001 attack in which weaponized spores were delivered by mail to several US cities exposed our vulnerability to bioterrorism, and taught us important lessons in the timely diagnosis of this devastating disease. It is clear that patient mortality is significantly decreased by early recognition and immediate administration of antibiotic therapy. Unfortunately, the nonspecific clinical presentation is often misinterpreted as a flu-like illness and confirmatory microbiologic tests may take up to 24 hours. Radiologic manifestations, however, are distinctive and may prove essential in directing appropriate clinical care in the critical early hours of inhalational anthrax. PMID:17110848

  13. The 2? 2–2? 3 loop of anthrax protective antigen contains a dominant neutralizing epitope

    Microsoft Academic Search

    Jun Zhang; Junjie Xu; Guanlin Li; Dayong Dong; Xiaohong Song; Qiang Guo; Jian Zhao; Ling Fu; Wei Chen

    2006-01-01

    Anthrax toxin consists of three proteins, protective antigen (PA), lethal factor, and edema factor. PA is the major component in the current anthrax vaccine, but the antigenic epitopes on it are not well-defined. We generated a pool of toxin-neutralizing anti-PA monoclonal antibodies (MAbs) to analyze the neutralizing epitopes of PA. Nine toxin-neutralizing MAbs obtained were found bound to three different

  14. Anthrax biosensor, protective antigen ion channel asymmetric blockade.

    PubMed

    Halverson, Kelly M; Panchal, Rekha G; Nguyen, Tam L; Gussio, Rick; Little, Stephen F; Misakian, Martin; Bavari, Sina; Kasianowicz, John J

    2005-10-01

    The significant threat posed by biological agents (e.g. anthrax, tetanus, botulinum, and diphtheria toxins) (Inglesby, T. V., O'Toole, T., Henderson, D. A., Bartlett, J. G., Ascher, M. S., Eitzen, E., Friedlander, A. M., Gerberding, J., Hauer, J., Hughes, J., McDade, J., Osterholm, M. T., Parker, G., Perl, T. M., Russell, P. K., and Tonat, K. (2002) J. Am. Med. Assoc. 287, 2236-2252) requires innovative technologies and approaches to understand the mechanisms of toxin action and to develop better therapies. Anthrax toxins are formed from three proteins secreted by fully virulent Bacillus anthracis, protective antigen (PA, 83 kDa), lethal factor (LF, 90 kDa), and edema factor (EF, 89 kDa). Here we present electrophysiological measurements demonstrating that full-length LF and EF convert the current-voltage relationship of the heptameric PA63 ion channel from slightly nonlinear to highly rectifying and diode-like at pH 6.6. This effect provides a novel method for characterizing functional toxin interactions. The method confirms that a previously well characterized PA63 monoclonal antibody, which neutralizes anthrax lethal toxin in animals in vivo and in vitro, prevents the binding of LF to the PA63 pore. The technique can also detect the presence of anthrax lethal toxin complex from plasma of infected animals. The latter two results suggest the potential application of PA63 nanopore-based biosensors in anthrax therapeutics and diagnostics. PMID:16087661

  15. Purification of tritium-labeled cholera toxin.

    PubMed Central

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

    1978-01-01

    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 PMID:689738

  16. Vaccines: countering anthrax: vaccines and immunoglobulins.

    PubMed

    Grabenstein, John D

    2008-01-01

    Anthrax spores rank as the leading threat among bioweapons. This article reviews the accumulated evidence for immunization, either active or passive, to counter the malicious release of anthrax spores. The key protective factor in current anthrax vaccines for humans is a protein called protective antigen, which allows ingress of toxins into cells. The US vaccine is licensed to prevent anthrax, regardless of the route of exposure. Its dosing schedule is cumbersome and somewhat painful (shortcomings that may be resolved by ongoing clinical studies). It can be prescribed with the confidence commensurate with dozens of human safety studies and experience in 1.8 million recent vaccinees. For post-exposure prophylaxis, combining antibiotic prophylaxis and active immunization before illness onset may offer the best combination of prompt and sustained protection, especially for people who inhale large doses of spores. To treat anthrax infection, passive immunization using a polyclonal or monoclonal antibody product may offer important clinical benefit, especially if the anthrax bacteria are resistant to multiple antibiotics. PMID:18171228

  17. Recent progress in the development of anthrax vaccines.

    PubMed

    Kaur, Manpreet; Bhatnagar, Rakesh

    2011-12-01

    Bacillus anthracis is the etiological agent of anthrax. Although anthrax is primarily an epizootic disease; humans are at risk for contracting anthrax. The potential use of B. anthracis spores as biowarfare agent has led to immense attention. Prolonged vaccination schedule of current anthrax vaccine and variable protection conferred; often leading to failure of therapy. This highlights the need for alternative anthrax countermeasures. A number of approaches are being investigated to substitute or supplement the existing anthrax vaccines. These relied on expression of Protective antigen (PA), the key protective immunogen; in bacterial or plant systems; or utilization of attenuated strains of B. anthracis for immunization. Few studies have established potential of domain IV of PA for immunization. Other targets including the spore, capsule, S-layer and anthrax toxin components have been investigated for imparting protective immunity. It has been shown that co-immunization of PA with domain I of lethal factor that binds PA resulted in higher antibody responses. Of the epitope based vaccines, the loop neutralizing determinant, in particular; elicited robust neutralizing antibody response and conferred 97% protection upon challenge. DNA vaccination resulted in varying degree of protection and seems a promising approach. Additionally, the applicability of monoclonal and therapeutic antibodies in the treatment of anthrax has also been demonstrated. The recent progress in the direction of anthrax prophylaxis has been evaluated in this review. PMID:22360464

  18. The clinical aspects of anthrax

    Microsoft Academic Search

    A. B. Christie

    1973-01-01

    Cutaneous anthrax is usually easy to diagnose provided the doctor thinks of anthrax. The lesion most likely to be confused with anthrax is accidental vaccinia. Orf lacks the characteristic central eschar. Cutaneous anthrax responds to antibiotic therapy: rare complications are meningitis and hypoxic hypertension. Pulmonary anthrax is highly fatal: its incidence is related to the number and size of anthrax-containing

  19. 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

    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

    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. PMID:22792226

  20. Comparison of a Multiplexed Fluorescent Covalent Microsphere Immunoassay and an Enzyme-Linked Immunosorbent Assay for Measurement of Human Immunoglobulin G Antibodies to Anthrax Toxins

    PubMed Central

    Biagini, Raymond E.; Sammons, Deborah L.; Smith, Jerome P.; MacKenzie, Barbara A.; Striley, Cynthia A. F.; Semenova, Vera; Steward-Clark, Evelen; Stamey, Karen; Freeman, Alison E.; Quinn, Conrad P.; Snawder, John E.

    2004-01-01

    Recently, the Centers for Disease Control and Prevention reported an accurate, sensitive, specific, reproducible, and quantitative enzyme-linked immunosorbent assay (ELISA) for immunoglobulin G (IgG) antibodies to Bacillus anthracis protective antigen (PA) in human serum (C. P. Quinn, V. A. Semenova, C. M. Elie et al., Emerg. Infect. Dis. 8:1103-1110, 2002). The ELISA had a minimum detectable concentration (MDC) of 0.06 ?g/ml, which, when dilution adjusted, yielded a whole-serum MDC of 3.0 ?g of anti-PA IgG per ml. The reliable detection limit (RDL) was 0.09 ?g/ml, while the dynamic range was 0.06 to 1.7 ?g/ml. The diagnostic sensitivity of the assay was 97.6% and the diagnostic specificity was 94.2% for clinically verified cases of anthrax. A competitive inhibition anti-PA IgG ELISA was also developed to enhance the diagnostic specificity to 100%. We report a newly developed fluorescence covalent microbead immunosorbent assay (FCMIA) for B. anthracis PA which was Luminex xMap technology. The FCMIA MDC was 0.006 ?g of anti-PA IgG per ml, the RDL was 0.016 ?g/ml, and the whole-serum equivalent MDC was 1.5 ?g/ml. The dynamic range was 0.006 to 6.8 ?g/ml. Using this system, we analyzed 20 serum samples for anti-PA IgG and compared our results to those measured by ELISA in a double-masked analysis. The two methods had a high positive correlation (r2 = 0.852; P < 0.001). The FCMIA appears to have benefits over the ELISA for the measurement of anti-PA IgG, including greater sensitivity and speed, enhanced dynamic range and reagent stability, the use of smaller sample volumes, and the ability to be multiplexed (measurement of more than one analyte simultaneously), as evidenced by the multiplexed measurement in the present report of anti-PA and anti-lethal factor IgG in serum from a confirmed clinical anthrax infection. PMID:14715544

  1. Involvement of Domain II in Toxicity of Anthrax Lethal Factor*S Received for publication, August 9, 2004, and in revised form, September 23, 2004

    E-print Network

    Involvement of Domain II in Toxicity of Anthrax Lethal Factor*S Received for publication, August 9-1201 Anthrax lethal factor (LF) is a Zn2 -metalloprotease that cleaves and inactivates mitogen in the association of LF into productive com- plex with MEKs. Anthrax toxin is derived from an exotoxin produced

  2. The anthrax vaccine: no new tricks for an old dog.

    PubMed

    Bienek, Diane R; Loomis, Lawrence J; Biagini, Raymond E

    2009-03-01

    The original license for production of the anthrax vaccine, Anthrax Vaccine Adsorbed (AVA), was issued in 1970. Since that time, over 8 million AVA immunizations have been administered to 2+ million individuals. In 2002, the National Academy of Sciences, Institute of Medicine, reviewed the safety and efficacy of AVA. They concluded that the vaccine is acceptably safe and effective in protecting humans against anthrax. The vaccine should protect people against all known strains of anthrax bacteria, as well as against any strains that might be created by potential terrorists or others. Although the Institute of Medicine concluded that AVA was reasonably safe, they noted that it is fairly common for people to experience local reactions (e.g., redness and swelling at the injection site) and for a smaller number to experience systemic reactions such as fever and malaise, within hours or days of vaccination. Results of animal studies done previously and subsequent to this report are generally in agreement. For instance, AVA vaccination increases the level of anthrax anti-protective antigen IgG (anti-PA IgG), which is thought to be one possible correlate of protection (although absolute protective concentrations have not been identified in humans). Anthrax lethal factor neutralization has also been identified as possibly being an important additional correlate of immunity. Future vaccine research efforts include developing a recombinant anthrax vaccine and anthrax monoclonal antibodies to block the anthrax toxin(s). It is projected that the next-generation vaccine will elicit a markedly increased anti-anthrax immune response within a shorter time period and consequently, will enable the easier inoculations of individuals working within high-risk areas. PMID:19270504

  3. Observations on Experimental Anthrax: Demonstration of a Specific Lethal Factor produced in vivo by Bacillus anthracis

    Microsoft Academic Search

    H. Smith; J. Keppie

    1954-01-01

    AN enigma in the study of the cause of death in anthrax has been that no lethal endo- or exo-toxin has been found in cultures of the organism1-3. Recently, we have been able to demonstrate a factor in the plasma of guinea pigs dying of anthrax which is not only lethal but also specifically neutralized by anthrax antiserum. This communication

  4. Biological Terrorism The Anthrax Scare of 2001

    NSDL National Science Digital Library

    Kathleen A. Cornely

    2005-01-01

    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.

  5. Anthrax - blood test

    MedlinePLUS

    ... Antibody test for anthrax; Serologic test for B. anthracis ... An abnormal result means antibodies to B. anthracis have been detected and you may have anthrax disease. However, some people come in contact with the bacteria and do not develop the ...

  6. An overview of anthrax infection including the recently identified form of disease in injection drug users

    PubMed Central

    Hicks, Caitlin W.; Sweeney, Daniel A.; Cui, Xizhong; Li, Yan

    2012-01-01

    Purpose Bacillus anthracis infection (anthrax) can be highly lethal. Two recent outbreaks related to contaminated mail in the USA and heroin in the UK and Europe and its potential as a bioterrorist weapon have greatly increased concerns over anthrax in the developed world. Methods This review summarizes the microbiology, pathogenesis, diagnosis, and management of anthrax. Results and conclusions Anthrax, a gram-positive bacterium, has typically been associated with three forms of infection: cutaneous, gastrointestinal, and inhalational. However, the anthrax outbreak among injection drug users has emphasized the importance of what is now considered a fourth disease form (i.e., injectional anthrax) that is characterized by severe soft tissue infection. While cutaneous anthrax is most common, its early stages are distinct and prompt appropriate treatment commonly produces a good outcome. However, early symptoms with the other three disease forms can be nonspecific and mistaken for less lethal conditions. As a result, patients with gastrointestinal, inhalational, or injectional anthrax may have advanced infection at presentation that can be highly lethal. Once anthrax is suspected, the diagnosis can usually be made with gram stain and culture from blood or tissue followed by confirmatory testing (e.g., PCR). While antibiotics are the mainstay of anthrax treatment, use of adjunctive therapies such as anthrax toxin antagonists are a consideration. Prompt surgical therapy appears to be important for successful management of injectional anthrax. PMID:22527064

  7. Acid induced unfolding of anthrax protective antigen

    Microsoft Academic Search

    Pradeep K Gupta; Raj K Kurupati; Harish Chandra; Reetika Gaur; Vibha Tandon; Yogendra Singh; Kapil Maithal

    2003-01-01

    Acidic pH plays an important role in the membrane insertion of protective antigen (PA) of anthrax toxin leading to the translocation of the catalytic moieties. The structural transitions occurring in PA as a consequence of change in pH were investigated by fluorescence and circular dichroism measurements. Our studies revealed the presence of two intermediates on-pathway of acid induced unfolding; one

  8. Quantitative high throughput screening identifies inhibitors of anthrax-induced cell death

    PubMed Central

    Zhu, Ping Jun; Hobson, Peyton; Southall, Noel; Qiu, Cunping; Thomas, Craig J.; Lu, Jiamo; Inglese, James; Zheng, Wei; Leppla, Stephen H.; Bugge, Thomas H.; Austin, Christopher P.; Liu, Shihui

    2009-01-01

    Here, we report the results of a quantitative high-throughput screen (qHTS) measuring the endocytosis and translocation of a ?-lactamase-fused-lethal factor and the identification of small molecules capable of obstructing the process of anthrax toxin internalization. Several small molecules protect RAW264.7 macrophages and CHO cells from anthrax lethal toxin and protected cells from an LF-Pseudomonas exotoxin fusion protein and diphtheria toxin. Further efforts demonstrated that these compounds impaired the PA heptamer pre-pore to pore conversion in cells expressing the CMG2 receptor, but not the related TEM8 receptor, indicating that these compounds likely interfere with toxin internalization. PMID:19540764

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

    PubMed Central

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

    2013-01-01

    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. PMID:23352329

  10. Antibodies against anthrax: mechanisms of action and clinical applications.

    PubMed

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

    2011-11-01

    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. PMID:22174979

  11. Development of a simple method for the rapid identification of organisms causing anthrax by coagglutination test.

    PubMed

    Sumithra, T G; Chaturvedi, V K; Gupta, P K; Siju, S J; Susan, C; Bincy, J; Laxmi, U; Sunita, S C; Rai, A K

    2014-11-01

    A protective antigen (PA) based coagglutination test was optimized in the present study for the specific and sensitive identification of bacteria causing anthrax in a cost effective and less risky manner. The test showed 100% specificity and sensitivity up to 9 × 10(3) formalinized vegetative cells or 11 ng of PA. The optimized test also detected anthrax toxin directly from the serum as well as blood of anthrax infected animals indicating the potential application for direct diagnosis of anthrax under field conditions. PMID:25151655

  12. Molecular motions as a drug target: mechanistic simulations of anthrax toxin edema factor function led to the discovery of novel allosteric inhibitors.

    PubMed

    Laine, Elodie; Martínez, Leandro; Ladant, Daniel; Malliavin, Thérèse; Blondel, Arnaud

    2012-08-01

    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. PMID:23012649

  13. Patent prospects toward therapeutics and diagnostics of anthrax.

    PubMed

    Chauhan, Rashi; Wadhwa, Gulshan; Sharma, Sanjeev K; Jain, Chakresh K

    2014-01-01

    Anthrax is one of the deadly infectious disease as documented in the CDC website. In spite of the availability of appropriate antimicrobial agents, the mortality related with the anthrax remains high. The pathogenicity of B. anthracis is mainly accredited to the two foremost components: toxins and capsule. Virulence component of B. anthracis includes protective antigen (PA) which plays a vital role in pathogenesis, virulence protein edema factor (EF) and lethal factor (LF). This search for novel therapeutic strategies that attack the proteins involved in the pathogenesis of anthrax and may potentially supplement antimicrobials being investigated. Currently, extensive attempts are in progress to develop novel helpful therapies to all of the virulence components: lethal factor, protective antigen, edema factor and the capsule of B. anthracis. This review discusses the potential anthrax therapeutic, prophylactic measures and diagnostic applications based on recent patents' prospects. PMID:25145329

  14. Anthrax lethal factor inhibitors as potential countermeasure of the infection.

    PubMed

    Kumar, B V S Suneel; Malik, Siddharth; Grandhi, Pradeep; Dayam, Raveendra; Sarma, J A R P

    2014-01-01

    Anthrax Lethal Factor (LF) is a zinc-dependent metalloprotease, one of the virulence factor of anthrax infection. Three forms of the anthrax infection have been identified: cutaneous (through skin), gastrointestinal (through alimentary tract), and pulmonary (by inhalation of spores). Anthrax toxin is composed of protective antigen (PA), lethal factor (LF), and edema factor (EF). Protective antigen mediates the entry of Lethal Factor/Edema Factor into the cytosol of host cells. Lethal factor (LF) inactivates mitogen-activated protein kinase kinase inducing cell death, and EF is an adenylyl cyclase impairing host defenses. In the past few years, extensive studies are undertaken to design inhibitors targeting LF. The current review focuses on the small molecule inhibitors targeting LF activity and its structure activity relationships (SAR). PMID:25262802

  15. Identification of Residues Lining the Anthrax Protective Antigen Channel †

    Microsoft Academic Search

    Ericka L. Benson; Paul D. Huynh; Alan Finkelstein; R. John Collier

    1998-01-01

    In its activated 63 kDa form, the protective antigen (PA) component of anthrax toxin forms a heptameric prepore, which converts to a pore (channel) in endosomal membranes at low pH and mediates translocation of the toxin's enzymic moieties to the cytosol. It has been proposed that the prepore-to- pore conversion involves a conformational rearrangement of a disordered amphipathic loop (D2L2;

  16. Anthrax: an update.

    PubMed

    Kamal, S M; Rashid, A K M M; Bakar, M A; Ahad, M A

    2011-12-01

    Anthrax is a zoonotic disease caused by Bacillus anthracis. It is potentially fatal and highly contagious disease. Herbivores are the natural host. Human acquire the disease incidentally by contact with infected animal or animal products. In the 18th century an epidemic destroyed approximately half of the sheep in Europe. In 1900 human inhalational anthrax occured sporadically in the United States. In 1979 an outbreak of human anthrax occured in Sverdlovsk of Soviet Union. Anthrax continued to represent a world wide presence. The incidence of the disease has decreased in developed countries as a result of vaccination and improved industrial hygiene. Human anthrax clinically presents in three forms, i.e. cutaneous, gastrointestinal and inhalational. About 95% of human anthrax is cutaneous and 5% is inhalational. Gastrointestinal anthrax is very rare (less than 1%). Inhalational form is used as a biological warefare agent. Penicillin, ciprofloxacin (and other quinolones), doxicyclin, ampicillin, imipenem, clindamycin, clarithromycin, vancomycin, chloramphenicol, rifampicin are effective antimicrobials. Antimicrobial therapy for 60 days is recommended. Human anthrax vaccine is available. Administration of anti-protective antigen (PA) antibody in combination with ciprofloxacin produced 90%-100% survival. The combination of CPG-adjuvanted anthrax vaccine adsorbed (AVA) plus dalbavancin significantly improved survival. PMID:23569822

  17. Development of novel vaccines against anthrax in man

    Microsoft Academic Search

    A. V. Stepanov; L. I. Marinin; A. P. Pomerantsev; N. A. Staritsin

    1996-01-01

    It has been shown that antianthrax immunity induced by the novel vaccine proposed has not only antitoxic, but also antispore character. The whole complex of antigens, namely surface spore antigens, surface antigens of cell wall and toxin components is required for the induction of strong and stable immunity against anthrax. The STI-1 vaccine strain with introduced resistance to several antibiotics

  18. The history of anthrax

    Microsoft Academic Search

    George Sternbach

    2003-01-01

    Anthrax, a potentially fatal infection, is a virulent and highly contagious disease. Descriptions of this disease begin in antiquity, with the best ancient account being by the Roman poet Virgil. During the 19th century, anthrax was the infection involved in several important medical developments. It served as the prototype for Koch’s postulates regarding the causation of infectious disease. The first

  19. Anthrax vaccination strategies

    Microsoft Academic Search

    Robert J. Cybulski Jr.; Patrick Sanz; Alison D. O’Brien

    2009-01-01

    The biological attack conducted through the US postal system in 2001 broadened the threat posed by anthrax from one pertinent mainly to soldiers on the battlefield to one understood to exist throughout our society. The expansion of the threatened population placed greater emphasis on the reexamination of how we vaccinate against Bacillus anthracis. The currently-licensed Anthrax Vaccine, Adsorbed (AVA) and

  20. Mucosal Immunity Against Anthrax

    Microsoft Academic Search

    Prosper N. Boyaka; Alexandra Duverger; Estelle Cormet-Boyaka; Jean-Nicolas Tournier

    Anthrax has recently gained much attention due to the potential use of Bacillus anthracis spores as an agent of biowarfare. In the event of intentional dissemination of Bacillus anthracis spores, the most likely routes of infection are through the nasopharyngeal and gastrointestinal tracts. Since inhalational\\u000a and gastrointestinal anthrax are the most severe and potentially lethal forms of the disease, appropriate

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

    Microsoft Academic Search

    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

    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

  2. The sepsis model: an emerging hypothesis for the lethality of inhalation anthrax

    PubMed Central

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

    2013-01-01

    Inhalation anthrax is often described as a toxin-mediated disease. However, the toxaemia 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 bacteraemia and, in contrast to animals challenged with toxin, signs of sepsis. Rather than toxaemia, we propose that death in inhalation anthrax results from an overwhelming bacteraemia 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. PMID:23742651

  3. Anthrax-associated shock.

    PubMed

    Goldman, David L; Casadevall, Arturo

    2008-01-01

    Recent events have brought attention to the potential of Bacillus anthracis as an agent of bioterrorism. The shock like state of anthrax is invariably associated with high mortality, despite anti-microbial and supportive therapy. Multi-system dysfunction is typical, including: enhanced vascular permeability, hemorrhage and inflammation. Important questions concerning the pathophysiology of anthrax-associated shock remain unanswered, including the effects of B. anthracis infection on cardiac function. This review discusses the current state of knowledge regarding the pathophysiology of anthrax-associated shock. PMID:18508494

  4. DNA vaccines against anthrax.

    PubMed

    Galloway, Darrell R; Baillie, Les

    2004-10-01

    DNA vaccination is vaccination at its simplest. Due to renewed interest in vaccination against anthrax and other biothreat agents, a genetic immunisation approach offers attractive possibilities for rapid, responsive vaccine development. DNA vaccination against anthrax is an active area of research showing promising results at present, which in the short-term and in the future could form the basis for new advances in multi-agent vaccine development. The anthrax 'model' constitutes an important experimental system for genetic immunisation technology development. PMID:15461577

  5. What Is Anthrax?

    MedlinePLUS

    ... The spores can live for years in the soil, and they cause anthrax when they enter the ... The Nemours Foundation, iStock, Getty Images, Corbis, Veer, Science Photo Library, Science Source Images, Shutterstock, and Clipart. ...

  6. ANTHRAX REMEDIATION RESEARCH NEEDS

    EPA Science Inventory

    The Environmental Protection Agency has initiated a research program to respond to the immediate needs arising from the recent Bacillus anthracis bioterrorism events. Although the program has a strong emphasis on anthrax, other pathogens and chemical agents, including toxic indu...

  7. Anthrax vaccine: a review.

    PubMed

    Grabenstein, John D

    2003-11-01

    Anthrax can be a deadly disease if treatment does not begin early in the course of infection. An effective vaccine has been available in the United States since 1970, although it was not used widely until 1998. A comprehensive, peer-reviewed evaluation by the National Academy of Sciences affirmed the findings of multiple previous independent panels that found that the US-licensed anthrax vaccine is safe and effective. PMID:14753388

  8. Anthrax vaccination strategies

    PubMed Central

    Cybulski, Robert J.; Sanz, Patrick; O'Brien, Alison D.

    2009-01-01

    The biological attack conducted through the U.S. postal system in 2001 broadened the threat posed by anthrax from one pertinent mainly to soldiers on the battlefield to one understood to exist throughout our society. The expansion of the threatened population placed greater emphasis on the reexamination of how we vaccinate against Bacillus anthracis. The currently-licensed Anthrax Vaccine, Adsorbed (AVA) and Anthrax Vaccine, Precipitated (AVP) are capable of generating a protective immune response but are hampered by shortcomings that make their widespread use undesirable or infeasible. Efforts to gain U.S. Food and Drug Administration (FDA) approval for licensure of a second generation recombinant protective antigen (rPA)-based anthrax vaccine are ongoing. However, this vaccine's reliance on the generation of a humoral immune response against a single virulence factor has led a number of scientists to conclude that the vaccine is likely not the final solution to optimal anthrax vaccine design. Other vaccine approaches, which seek a more comprehensive immune response targeted at multiple components of the B. anthracis organism, are under active investigation. This review seeks to summarize work that has been done to build on the current PA-based vaccine methodology and to evaluate the search for future anthrax prophylaxis strategies. PMID:19729034

  9. Anthrax vaccination strategies.

    PubMed

    Cybulski, Robert J; Sanz, Patrick; O'Brien, Alison D

    2009-12-01

    The biological attack conducted through the US postal system in 2001 broadened the threat posed by anthrax from one pertinent mainly to soldiers on the battlefield to one understood to exist throughout our society. The expansion of the threatened population placed greater emphasis on the reexamination of how we vaccinate against Bacillus anthracis. The currently-licensed Anthrax Vaccine, Adsorbed (AVA) and Anthrax Vaccine, Precipitated (AVP) are capable of generating a protective immune response but are hampered by shortcomings that make their widespread use undesirable or infeasible. Efforts to gain US Food and Drug Administration (FDA) approval for licensure of a second generation recombinant protective antigen (rPA)-based anthrax vaccine are ongoing. However, this vaccine's reliance on the generation of a humoral immune response against a single virulence factor has led a number of scientists to conclude that the vaccine is likely not the final solution to optimal anthrax vaccine design. Other vaccine approaches, which seek a more comprehensive immune response targeted at multiple components of the B. anthracis organism, are under active investigation. This review seeks to summarize work that has been done to build on the current PA-based vaccine methodology and to evaluate the search for future anthrax prophylaxis strategies. PMID:19729034

  10. Nanopore Biosensor for Label-Free and Real-Time Detection of Anthrax Lethal Factor

    PubMed Central

    2015-01-01

    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

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

    PubMed

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

    2014-05-28

    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

  12. New Treatment for Anthrax Approved

    MedlinePLUS

    ... medlineplus/news/fullstory_151670.html New Treatment for Anthrax Approved FDA cites preparedness for intentional release of ... States for the potential release of deadly inhalational anthrax has been approved by the U.S. Food and ...

  13. Development of a Competitive Enzyme Linked Immunosorbent Assay to Identify Epitope Specific Antibodies in Recipients of the U.S. Licensed Anthrax Vaccine

    Microsoft Academic Search

    Michael J. Gubbins; Lisa Schmidt; Raymond S. Tsang; Jody D. Berry; Amin Kabani; Donald I. H. Stewart

    2007-01-01

    Vaccination with anthrax vaccine adsorbed (AVA) results in the production of protective antigen (PA) specific antibodies, which play an important protective role against anthrax toxins. Analyzing the specificity of serum antibodies generated in response to AVA vaccination can provide insight into the mechanisms of protective immunity against this important pathogen. The goal of this study was to develop a competitive

  14. Anthrax of the Gastrointestinal Tract

    Microsoft Academic Search

    Thira Sirisanthana; Arthur E. Brown

    When swallowed, anthrax spores may cause lesions from the oral cavity to the cecum. Gastrointestinal anthrax is greatly underreported in rural disease-endemic areas of the world. The apparent paucity of this form of anthrax reflects the lack of facilities able to make the diagnosis in these areas. The spectrum of disease, ranging from subclinical infection to death, has not been

  15. Evaluation of Intravenous Anthrax Immune Globulin for Treatment of Inhalation Anthrax

    PubMed Central

    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

    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.) PMID:23979731

  16. Discovery and development of anthrax lethal factor metalloproteinase inhibitors.

    PubMed

    Turk, Benjamin E

    2008-02-01

    Anthrax is caused by infection with Bacillus anthracis, a spore forming, rod-shaped, encapsulated gram positive bacteria. The disease manifests itself in distinct ways depending on the route of entry of infective bacterial spores: cutaneous, inhalational, and gastrointestinal. Though rare in humans, inhalational anthrax has become a major concern due to the capacity for spores to be weaponized. The limited success of antibiotic therapy has motivated investigation of complementary therapeutic strategies that target the bacteria's secreted toxin. The zinc-dependent metalloproteinase lethal factor (LF) is a critical component of anthrax toxin and an important potential target for small molecule drugs. In the past few years, a number of approaches have been taken to identify LF inhibitors, from generating conventional metal chelating substrate analogs to random screening of diverse compound libraries. These efforts have produced several different classes of specific nanomolar range inhibitors. Some compounds have fared well in animal models for anthrax toxemia and infection, and these inhibitors and their derivatives may form the basis for future therapies to treat the disease in humans. PMID:18289054

  17. Management of anthrax meningitis.

    PubMed

    Sejvar, James J; Tenover, Fred C; Stephens, David S

    2005-05-01

    Meningitis due to infection with Bacillus anthracis is considered an infrequent manifestation of the disease but one associated with high mortality. The bioterrorism event in the USA in the autumn of 2001 demonstrated our need for a better understanding of anthrax meningitis, as well as management and antimicrobial therapy. However, human clinical trials are not possible and animal experiments to guide such therapy are limited. An approach to the treatment of anthrax meningitis, based on the pathogenicity of B anthracis, the pharmacokinetics and pharmacodynamics of individual antimicrobial agents, studies of anthrax post-exposure prophylaxis in non-human primates, experience with antimicrobial susceptibility patterns of the 2001 outbreak strain, and the clinical experience with inhalational anthrax cases during the 2001 outbreak is presented. These outbreak data, the failure of previous single-drug regimens, the concerns of resistance, and the need for coverage for other causes of bacterial mengingitis suggest initial treatment of suspected anthrax meningitis should anchor on an intravenous fluoroquinolone and should include one or two other agents with activity against B anthracis and good penetration into the central nervous system. Such other agents include penicillin, ampicillin, meropenem, vancomycin, and rifampicin. PMID:15854884

  18. Conformational fluctuations in anthrax protective antigen: a possible role of calcium in the folding pathway of the protein

    Microsoft Academic Search

    Pradeep K Gupta; Harish Chandra; Reetika Gaur; Raj K Kurupati; Shantanu Chowdhury; Vibha Tandon; Yogendra Singh; Kapil Maithal

    2003-01-01

    Protective antigen (PA) is the central receptor binding component of anthrax toxin, which translocates catalytic components of the toxin into the cytosol of mammalian cells. Ever since the crystal structure of PA was solved, there have been speculations regarding the possible role of calcium ions present in domain I of the protein. We have carried out a systematic study to

  19. Protective-antigen (PA) based anthrax vaccines confer protection against inhalation anthrax by precluding the establishment of a systemic infection

    PubMed Central

    Merkel, Tod J; Perera, Pin-Yu; Lee, Gloria M; Verma, Anita; Hiroi, Toyoko; Yokote, Hiroyuki; Waldmann, Thomas A; Perera, Liyanage P

    2013-01-01

    An intense effort has been launched to develop improved anthrax vaccines that confer rapid, long lasting protection preferably with an extended stability profile amenable for stockpiling. Protective antigen (PA)-based vaccines are most favored as immune responses directed against PA are singularly protective, although the actual protective mechanism remains to be unraveled. Herein we show that contrary to the prevailing view, an efficacious PA-based vaccine confers protection against inhalation anthrax by preventing the establishment of a toxin-releasing systemic infection. Equally importantly, antibodies measured by the in vitro lethal toxin neutralization activity assay (TNA) that is considered as a reliable correlate of protection, especially for PA protein-based vaccines adjuvanted with aluminum salts appear to be not absolutely essential for this protective immune response. PMID:23787486

  20. Protective-antigen (PA) based anthrax vaccines confer protection against inhalation anthrax by precluding the establishment of a systemic infection.

    PubMed

    Merkel, Tod J; Perera, Pin-Yu; Lee, Gloria M; Verma, Anita; Hiroi, Toyoko; Yokote, Hiroyuki; Waldmann, Thomas A; Perera, Liyanage P

    2013-09-01

    An intense effort has been launched to develop improved anthrax vaccines that confer rapid, long lasting protection preferably with an extended stability profile amenable for stockpiling. Protective antigen (PA)-based vaccines are most favored as immune responses directed against PA are singularly protective, although the actual protective mechanism remains to be unraveled. Herein we show that contrary to the prevailing view, an efficacious PA-based vaccine confers protection against inhalation anthrax by preventing the establishment of a toxin-releasing systemic infection. Equally importantly, antibodies measured by the in vitro lethal toxin neutralization activity assay (TNA) that is considered as a reliable correlate of protection, especially for PA protein-based vaccines adjuvanted with aluminum salts appear to be not absolutely essential for this protective immune response. PMID:23787486

  1. Human Monoclonal Antibodies against Anthrax Lethal Factor and Protective Antigen Act Independently To Protect against Bacillus anthracis Infection and Enhance Endogenous Immunity to Anthrax

    Microsoft Academic Search

    Mark T. Albrecht; Han Li; E. Diane Williamson; Chris S. LeButt; Helen C. Flick-Smith; Conrad P. Quinn; Hans Westra; Darrell Galloway; Alfred Mateczun; Stanley Goldman; Herman Groen; Les W. J. Baillie

    2007-01-01

    The unpredictable nature of bioterrorism and the absence of real-time detection systems have highlighted the need for an efficient postexposure therapy for Bacillus anthracis infection. One approach is passive immunization through the administration of antibodies that mitigate the biological action of anthrax toxin. We isolated and characterized two protective fully human monoclonal antibodies with specificity for protective antigen (PA) and

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

    PubMed

    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

    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

  3. Added benefit of raxibacumab to antibiotic treatment of inhalational anthrax.

    PubMed

    Migone, Thi-Sau; Bolmer, Sally; Zhong, John; Corey, Al; Vasconcelos, Daphne; Buccellato, Matthew; Meister, Gabriel

    2015-02-01

    Although antibiotics treat bacteremia in inhalational anthrax, pathogenesis is mainly driven by bacterial exotoxins. Raxibacumab, an IgG1 monoclonal antibody, binds the protective antigen (PA) of Bacillus anthracis, thus blocking toxin effects and leading to improved survival in the rabbit and monkey models of inhalational anthrax. To assess raxibacumab's added benefit over levofloxacin (LVX) alone, rabbits surviving to 84 h after a challenge with 200 times the median (50%) lethal dose of B. anthracis spores were randomized to receive 3 daily intragastric LVX doses of 50 mg/kg of body weight, with the first LVX dose administered just prior to administration of a single intravenous dose of placebo or 40 mg/kg raxibacumab. The percentages of animals alive at 28 days following the last LVX dose were compared between the 2 treatment groups using a two-sided likelihood-ratio chi-square test. The 82% survival rate for the LVX-raxibacumab combination was higher than the 65% survival rate for LVX alone (P=0.0874). There were nearly 2-fold fewer deaths for the combination (7 deaths; n=39) than for LVX alone (13 deaths; n=37), and the survival time was prolonged for the combination (P=0.1016). Toxin-neutralizing-activity titers were similar for both treatment groups, suggesting that survivors in both groups were able to mount a toxin-neutralizing immune response. Microscopic findings considered consistent with anthrax were present in animals that died or became moribund on study in both treatment groups, and there were no anthrax-related findings in animals that survived. Overall, raxibacumab provided a meaningful benefit over antibiotic alone when administered late in the disease course. PMID:25487792

  4. Dr. Jekyll and Mr. Hyde: a short history of anthrax.

    PubMed

    Schwartz, Maxime

    2009-12-01

    The anthrax letters crisis, following the discovery of a major bacterial warfare program in the USSR and the realization that Irak had been on the verge of using anthrax as a weapon during the first Gulf war, had the consequence of putting anthrax back on the agenda of scientists. Fortunately, although it was mostly unknown by the public before these events, it was far from unknown by microbiologists. Already mentioned in the bible as a disease of herbivores, it remained a major cause of death for animals all over the planet until the end of the 19th century, with occasional, sometimes extensive, contamination of human beings. The aetiological agent, Bacillus anthracis, was identified by French and German scientists in the 1860s and 1870s. This was the first time that a disease could be attributed to a specific microorganism. The discovery by Koch that this bacterium formed spores greatly contributed to the understanding of the disease epidemiology. Studies on the pathophysiology of anthrax led to the identification of two major virulence factors, the capsule, protecting the bacilli against phagocytosis, and a tripartite toxin. The latter consists of two toxins with a common component (protecting antigen, PA) that allows the binding to and penetration into cells of two enzymes, the oedema factor EF, a calmodulin dependent adenylate cyclase, and the lethal factor LF, a specific zinc metalloprotease. The primary targets of these toxins would seem to be cells of innate immunity that would otherwise impair multiplication of the bacilli. If detected early enough, B. anthracis infections can be stopped by using antibiotics such as ciprofloxacin. Infection of animals can be prevented by the administration of vaccines, the first of which was developed by Pasteur after an historical testing at Pouilly-le-Fort which marked the beginning of the science of vaccines. PMID:19577591

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

    PubMed Central

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

    2013-01-01

    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. PMID:23774434

  6. Pediatric Anthrax Clinical Management

    PubMed Central

    Bradley, John S.; Peacock, Georgina; Krug, Steven E.; Bower, William A.; Cohn, Amanda C.; Meaney-Delman, Dana; Pavia, Andrew T.

    2015-01-01

    Anthrax is a zoonotic disease caused by Bacillus anthracis, which has multiple routes of infection in humans, manifesting in different initial presentations of disease. Because B anthracis has the potential to be used as a biological weapon and can rapidly progress to systemic anthrax with high mortality in those who are exposed and untreated, clinical guidance that can be quickly implemented must be in place before any intentional release of the agent. This document provides clinical guidance for the prophylaxis and treatment of neonates, infants, children, adolescents, and young adults up to the age of 21 (referred to as “children”) in the event of a deliberate B anthracis release and offers guidance in areas where the unique characteristics of children dictate a different clinical recommendation from adults. PMID:24777226

  7. Anthrax undervalued zoonosis.

    PubMed

    Fasanella, Antonio; Galante, Domenico; Garofolo, Giuliano; Jones, Martin Hugh

    2010-01-27

    Anthrax is a non-contagious disease, known since ancient times. However, it became a matter of global public interest after the bioterrorist attacks in the U.S.A. during the autumn of 2001. The concern of politicians and civil authorities everywhere towards this emergency necessitated a significant research effort and the prevention of new bioterrorist acts. Anthrax is primarily a disease that affects livestock and wildlife; its distribution is worldwide; and it can represent a danger to humans but especially more so when it occurs in areas considered to be free and in atypical seasons and climatic conditions. The atypicality of the phenomenon may lead health workers to misdiagnose and, consequently, an inappropriately manage of affected carcasses with a consequent and inevitable increase in the risk of human infection. This article emphasises the importance of paying increasing attention to this zoonosis. The biggest risk is its underestimation. PMID:19747785

  8. Anthrax in animals.

    PubMed

    Beyer, W; Turnbull, P C B

    2009-12-01

    Anthrax is the archetype zoonosis; no other infectious disease affects such a wide range of species, including humans, although most susceptible are herbivorous mammals. Although the disease appears to have been recognized for centuries, it has yet to be established scientifically how animals contract it. While primarily a disease of warmer regions, it has long been spread to cooler zones through the trade of infected animals or contaminated animal products. Today it is still endemic in many countries of Africa and Asia and non-endemic countries must remain alert to the possibility of imports from such endemic areas resulting in outbreaks in their own livestock. The epidemiology of anthrax is becoming understood better with new systems coming on stream for distinguishing different genotypes and this is covered in detail. Clinical signs and pathology in animals are described. PMID:19723532

  9. MODELING THE SPREAD OF ANTHRAX IN BUILDINGS

    Microsoft Academic Search

    RG Sextro; DM Lorenzetti; TL Thatcher

    2002-01-01

    The recent contamination of several U.S. buildings by letters containing anthrax demonstrates the need to understand better the transport and fate of anthrax spores within buildings. We modeled the spread of anthrax for a hypothetical office suite and estimated the distribution of mass and resulting occupant exposures. Based on our modeling assumptions, more than 90% of the anthrax released remains

  10. Anthrax: in Taiwan versus in Western World

    Microsoft Academic Search

    Chiu-Mei Lin; Tzong-Leun Wang; Hang Chang

    2002-01-01

    After the events that began last September, the threatening of terrorism was attacked again, have heightened awareness of and concern about anthrax in the western world. The initial reports documented some cases of clinical anthrax in United Status. These cases included inhalational anthrax and cutaneous anthrax, the serologic testing performed and confirmed by health officials of U.S., but newspaper reported

  11. Bacillus anthracis Lethal Toxin Reduces Human Alveolar Epithelial Barrier Function

    PubMed Central

    Langer, Marybeth; Duggan, Elizabeth Stewart; Booth, John Leland; Patel, Vineet Indrajit; Zander, Ryan A.; Silasi-Mansat, Robert; Ramani, Vijay; Veres, Tibor Zoltan; Prenzler, Frauke; Sewald, Katherina; Williams, Daniel M.; Coggeshall, Kenneth Mark; Awasthi, Shanjana; Lupu, Florea; Burian, Dennis; Ballard, Jimmy Dale; Braun, Armin

    2012-01-01

    The lung is the site of entry for Bacillus anthracis in inhalation anthrax, the deadliest form of the disease. Bacillus anthracis produces virulence toxins required for disease. Alveolar macrophages were considered the primary target of the Bacillus anthracis virulence factor lethal toxin because lethal toxin inhibits mouse macrophages through cleavage of MEK signaling pathway components, but we have reported that human alveolar macrophages are not a target of lethal toxin. Our current results suggest that, unlike human alveolar macrophages, the cells lining the respiratory units of the lung, alveolar epithelial cells, are a target of lethal toxin in humans. Alveolar epithelial cells expressed lethal toxin receptor protein, bound the protective antigen component of lethal toxin, and were subject to lethal-toxin-induced cleavage of multiple MEKs. These findings suggest that human alveolar epithelial cells are a target of Bacillus anthracis lethal toxin. Further, no reduction in alveolar epithelial cell viability was observed, but lethal toxin caused actin rearrangement and impaired desmosome formation, consistent with impaired barrier function as well as reduced surfactant production. Therefore, by compromising epithelial barrier function, lethal toxin may play a role in the pathogenesis of inhalation anthrax by facilitating the dissemination of Bacillus anthracis from the lung in early disease and promoting edema in late stages of the illness. PMID:23027535

  12. Anthrax Spores under a microscope

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Anthrax spores are inactive forms of Bacillus anthracis. They can survive for decades inside a spore's tough protective coating; they become active when inhaled by humans. A result of NASA- and industry-sponsored research to develop small greenhouses for space research is the unique AiroCide TiO2 system that kills anthrax spores and other pathogens.

  13. Anthrax: a disease in waiting?

    PubMed

    Doganay, L; Dognany, L; Welsby, P D

    2006-11-01

    Anthrax was a relatively unknown disease in the Western world until 2001, when spores were maliciously mailed in the US, causing five deaths. The mortality of the disease, the stability of its spores and the subsequent lack of person-to-person spread make anthrax an attractive biological weapon for terrorists with a desire for targeted mass destruction. PMID:17099096

  14. Advances in the development of next-generation anthrax vaccines.

    PubMed

    Friedlander, Arthur M; Little, Stephen F

    2009-11-01

    Anthrax, a disease of herbivores, only rarely infects humans. However, the threat of using Bacillus anthracis, the causative agent, to intentionally produce disease has been the impetus for development of next-generation vaccines. Two licensed vaccines have been available for human use for several decades. These are composed of acellular culture supernatants containing the protective antigen (PA) component of the anthrax toxins. In this review we summarize the various approaches used to develop improved vaccines. These efforts have included the use of PA with newer adjuvants and delivery systems, including bacterial and viral vectors and DNA vaccines. Attempts to broaden the protection afforded by PA-based vaccines have focused on adding other B. anthracis components, including spore and capsule antigens. PMID:19837282

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

    PubMed Central

    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

    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. PMID:19168734

  16. Killed but metabolically active Bacillus anthracis vaccines induce broad and protective immunity against anthrax.

    PubMed

    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

    2009-04-01

    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. PMID:19168734

  17. Progress and novel strategies in vaccine development and treatment of anthrax.

    PubMed

    Chitlaru, Theodor; Altboum, Zeev; Reuveny, Shaul; Shafferman, Avigdor

    2011-01-01

    The lethal anthrax disease is caused by spores of the gram-positive Bacillus anthracis, a member of the cereus group of bacilli. Although the disease is very rare in the Western world, development of anthrax countermeasures gains increasing attention due to the potential use of B. anthracis spores as a bio-terror weapon. Protective antigen (PA), the non-toxic subunit of the bacterial secreted exotoxin, fulfills the role of recognizing a specific receptor and mediating the entry of the toxin into the host target cells. PA elicits a protective immune response and represents the basis for all current anthrax vaccines. Anti-PA neutralizing antibodies are useful correlates for protection and for vaccine efficacy evaluation. Post exposure anti-toxemic and anti-bacteremic prophylactic treatment of anthrax requires prolonged antibiotic administration. Shorter efficient postexposure treatments may require active or passive immunization, in addition to antibiotics. Although anthrax is acknowledged as a toxinogenic disease, additional factors, other than the bacterial toxin, may be involved in the virulence of B. anthracis and may be needed for the long-lasting protection conferred by PA immunization. The search for such novel factors is the focus of several high throughput genomic and proteomic studies that are already leading to identification of novel targets for therapeutics, for vaccine candidates, as well as biomarkers for detection and diagnosis. PMID:21198675

  18. From Structure to Solutions: The Role of Basic Research in Developing Anthrax Countermeasures

    PubMed Central

    Hardiman, Camille A.

    2012-01-01

    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

  19. [Anthrax as a bioweapon].

    PubMed

    Szafraniec, Sylwia; Grzesiowski, Pawe?; Hryniewicz, Waleria

    2004-01-01

    The risk of biological and chemical terrorism is growing according to availability of modern biotechnologies and financial resources. The most potent biological weapon mentioned in the last decade is anthrax. The number of naturally acquired infections in humans is constantly reduced, however endemic areas are located in South and Middle Americas, South Europe, Asia and Africa. In any case of infection laboratory confirmation is indicated. Primary basic testing is available in all microbiology laboratories. In the current situation the medical and epidemiological infrastructure and microbiology diagnostics must be prepared for early and rapid coordinated action in order to detect and respond to biological and chemical attacks. PMID:15518328

  20. The adenylyl cyclase activity of anthrax edema factor.

    PubMed

    Tang, Wei-Jen; Guo, Qing

    2009-12-01

    Bacillus anthracis, the etiologic agent for anthrax, secretes edema factor (EF) to disrupt intracellular signaling pathways. Upon translocation into host cells and association with a calcium sensor, calmodulin (CaM), EF becomes a highly active adenylyl cyclase (AC) that raises the intracellular concentration of cyclic AMP (cAMP). Growing evidence shows that EF plays a key role in anthrax pathogenesis by affecting cellular functions vital for host defense. This strategy is also used by Bordetella pertussis, a bacterium that causes whooping cough. Pertussis bacteria secrete the bifunctional toxin CyaA which raises the intracellular cAMP. Here, we discuss recent advances from structural analyses that reveal the molecular basis of the conserved mechanism of activation and catalysis of EF and CyaA by CaM even though these two toxins use the completely different sequences to bind CaM. Comparison of the biochemical and structural characteristics of these two AC toxins with host ACs reveal that they have diverse strategies of catalytic activation, yet use the same two-metal-ion catalytic mechanism. PMID:19560485

  1. Chloroplast-derived anthrax and other vaccine antigens: their immunogenic and immunoprotective properties.

    PubMed

    Kamarajugadda, Sushama; Daniell, Henry

    2006-12-01

    Transgenic plants offer many advantages, including low cost of production (by elimination of fermenters), storage and transportation, heat stability, absence of human pathogens, protection of antigens in the stomach through bioencapsulation (when delivered orally), elimination of the need for expensive purification and sterile injections and generation of both systemic and mucosal immunity. Recent studies have demonstrated that chloroplast-derived anthrax-protective antigen elicits effective immune responses, develops neutralizing antibodies, confers complete protection against anthrax lethal toxin challenge and produces 360 million doses of vaccine in one acre of transgenic plants. Chloroplast-derived vaccine antigens are efficacious against bacterial, fungal, viral and protozoan pathogens. PMID:17184221

  2. Anthrax eTool: Protecting the Worksite against Terrorism

    MedlinePLUS

    ... Anthrax Credits What is anthrax? What is Bacillus anthracis ? How can I be exposed to Bacillus anthracis ? What are the symptoms of anthrax? What are ... I prevent anthrax infection? Additional information on Bacillus anthracis and anthrax Who is at risk? Anthrax Risk ...

  3. Anthrax: a systematic review of atypical presentations.

    PubMed

    Holty, Jon-Erik C; Kim, Rebecca Y; Bravata, Dena M

    2006-08-01

    During the 2001 US anthrax attacks, mortality from inhalational anthrax was significantly lower than had been reported historically, which was attributed in part to early identification and timely treatment. During future attacks, clinicians will rely on published descriptions of the clinical features of inhalational anthrax to rapidly diagnose patients and institute appropriate treatment. Published descriptions of typical inhalation anthrax usually include patients presenting with cough, dyspnea, or chest pain and found to have abnormal lung examination results with pleural effusions or enlarged mediastinum. The purpose of this article is to evaluate whether atypical presentations of inhalational anthrax occur and to describe the features of these presentations. We define atypical presentations as those in patients with confirmed anthrax infection who do not have known cutaneous, gastrointestinal, or inhalational ports of entry. We reviewed the case reports of 42 patients with atypical anthrax (published between 1900 and 2004) that may have had an inhalational source of infection to evaluate whether their clinical presentations differed from the typical findings of inhalational anthrax. Patients with atypical anthrax were less likely to have cough, chest pain, or abnormal lung examination results than patients with typical inhalational anthrax (P<.05 for all comparisons). A previously published screening protocol for patients with suspected anthrax correctly identified 91% of patients with atypical presentations. We conclude that although uncommon, atypical presentations of inhalational anthrax likely occur. Timely diagnosis and treatment of patients with inhalational anthrax require clinical awareness of the full spectrum of signs and symptoms associated with inhalational anthrax. PMID:16857469

  4. Inflammasome Sensor Nlrp1b-Dependent Resistance to Anthrax Is Mediated by Caspase1, IL1 Signaling and Neutrophil Recruitment

    Microsoft Academic Search

    Mahtab Moayeri; Devorah Crown; Zachary L. Newman; Shu Okugawa; Michael Eckhaus; Christophe Cataisson; Shihui Liu; Inka Sastalla; Stephen H. Leppla

    2010-01-01

    Bacillus anthracis infects hosts as a spore, germinates, and disseminates in its vegetative form. Production of anthrax lethal and edema toxins following bacterial outgrowth results in host death. Macrophages of inbred mouse strains are either sensitive or resistant to lethal toxin depending on whether they express the lethal toxin responsive or non-responsive alleles of the inflammasome sensor Nlrp1b (Nlrp1bS\\/S or

  5. Development of anthrax DNA vaccines.

    PubMed

    Ferrari, Marilyn E; Hermanson, Gary; Rolland, Alain

    2004-10-01

    Over 120 years ago, Pasteur and Greenfield developed an in vitro procedure for producing a live-attenuated Bacillus anthracis bacterial culture capable of protecting livestock from anthrax disease. Since then, anthrax has become one of the best characterized bacterial pathogens with regard to mechanism of toxicity and vaccine development. Most developments have used live-attenuated strains, bacterial supernatants or protein subunit approaches. Recently, novel plasmid DNA (pDNA) approaches to a safe and effective anthrax vaccine have been proposed. This review summarizes the history of anthrax, the need for new vaccines and recent developments in pDNA-based vaccines, leading to the initiation of a human phase I clinical trial in a significantly shorter timeframe than in traditional vaccine development. PMID:15537052

  6. Laboratory Testing for Anthrax: Frequently Asked Questions

    MedlinePLUS

    ... Questions Which laboratories can test specimens for the bacteria that cause anthrax? Laboratories that are a part ... patient specimens for Bacillus anthracis , the type of bacteria that causes anthrax. LRN labs are strategically located ...

  7. The Alternative Sigma Factor  H Is Required for Toxin Gene Expression by Bacillus anthracis

    Microsoft Academic Search

    Maria Hadjifrangiskou; Yahua Chen; Theresa M. Koehler

    2007-01-01

    Expression of the structural genes for the anthrax toxin proteins is coordinately controlled by host-related signals, such as elevated CO2, and the trans-acting positive regulator AtxA. In addition to these requirements, toxin gene expression is under growth phase regulation. The transition state regulator AbrB represses atxA expression to influence toxin synthesis. During the late exponential phase of growth, when AbrB

  8. Anthrax vaccine and public health policy.

    PubMed

    Weiss, Martin Meyer; Weiss, Peter D; Weiss, Joseph B

    2007-11-01

    The Centers for Disease Control and Prevention has classified Bacillus anthracis, the causative organism of anthrax, as a category A potential bioterrorism agent. There are critical shortcomings in the US anthrax vaccine program. Rather than depending on the private sector, the government must assume direct production of anthrax vaccine. The development of a capacity capable of preemptive immunization of the public against anthrax should be considered. PMID:17901434

  9. Distinct interactions of 2?- and 3?- O-( N-methyl)anthraniloyl-isomers of ATP and GTP with the adenylyl cyclase toxin of Bacillus anthracis, edema factor

    Microsoft Academic Search

    Srividya Suryanarayana; Jenna L. Wang; Mark Richter; Yuequan Shen; Wei-Jen Tang; Gerald H. Lushington; Roland Seifert

    2009-01-01

    Anthrax disease is caused by the spore-forming bacterium, Bacillus anthracis. B. anthracis produces a calmodulin-activated adenylyl cyclase (AC) toxin, edema factor (EF). Through excessive cAMP accumulation EF disrupts host defence. In a recent study [Taha HM, Schmidt J, Göttle M, Suryanarayana S, Shen Y, Tang WJ, et al. Molecular analysis of the interaction of anthrax adenylyl cyclase toxin, edema factor,

  10. LIST OF CONTRACTORS TO SUPPORT ANTHRAX REMEDIATION

    E-print Network

    LIST OF CONTRACTORS TO SUPPORT ANTHRAX REMEDIATION May 2010 Prepared for the Interagency Biological by the Northwest Regional Technology Center for Homeland Security List of Contractors to Support Anthrax of Contractors to Support Anthrax Remediation During August 2008, the Pacific Northwest National Laboratory (PNNL

  11. Anthrax: A Guide for Biology Teachers.

    ERIC Educational Resources Information Center

    Simon, Eric J.

    2002-01-01

    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)

  12. Investigation of Inhalation Anthrax Case, United States

    PubMed Central

    Blaney, David; Shadomy, Sean; Lehman, Mark; Pesik, Nicki; Tostenson, Samantha; Delaney, Lisa; Tiller, Rebekah; DeVries, Aaron; Gomez, Thomas; Sullivan, Maureen; Blackmore, Carina; Stanek, Danielle; Lynfield, Ruth

    2014-01-01

    Inhalation anthrax occurred in a man who vacationed in 4 US states where anthrax is enzootic. Despite an extensive multi-agency investigation, the specific source was not detected, and no additional related human or animal cases were found. Although rare, inhalation anthrax can occur naturally in the United States. PMID:24447835

  13. GASTROINTESTINAL ANTHRAX: REVIEW OF NINE PATIENTS

    Microsoft Academic Search

    Shohreh Beheshti; Gholam-Reza Rezaian; Sasan Afifi; Sheema Rezaian

    2003-01-01

    Background - Gastrointestinal anthrax is quite rare and often fatal. Here we report the clinical presentation and outcome of nine patients with this disease. Methods - The medical records of all patients with documented anthrax admitted to our university hospitals from 1975 to 2000 were reviewed. Nine patients were found to have gastrointestinal anthrax. Data regarding the clinical presentation, incubation

  14. Anthrax protective antigen delivered by Salmonella enterica serovar Typhi Ty21a protects mice from a lethal anthrax spore challenge.

    PubMed

    Osorio, Manuel; Wu, Yanping; Singh, Sunil; Merkel, Tod J; Bhattacharyya, Siba; Blake, Milan S; Kopecko, Dennis J

    2009-04-01

    Bacillus anthracis, the etiological agent of anthrax disease, is a proven weapon of bioterrorism. Currently, the only licensed vaccine against anthrax in the United States is AVA Biothrax, which, although efficacious, suffers from several limitations. This vaccine requires six injectable doses over 18 months to stimulate protective immunity, requires a cold chain for storage, and in many cases has been associated with adverse effects. In this study, we modified the B. anthracis protective antigen (PA) gene for optimal expression and stability, linked it to an inducible promoter for maximal expression in the host, and fused it to the secretion signal of the Escherichia coli alpha-hemolysin protein (HlyA) on a low-copy-number plasmid. This plasmid was introduced into the licensed typhoid vaccine strain, Salmonella enterica serovar Typhi strain Ty21a, and was found to be genetically stable. Immunization of mice with three vaccine doses elicited a strong PA-specific serum immunoglobulin G response with a geometric mean titer of 30,000 (range, 5,800 to 157,000) and lethal-toxin-neutralizing titers greater than 16,000. Vaccinated mice demonstrated 100% protection against a lethal intranasal challenge with aerosolized spores of B. anthracis 7702. The ultimate goal is a temperature-stable, safe, oral human vaccine against anthrax infection that can be self-administered in a few doses over a short period of time. PMID:19179420

  15. Clinical application of radiolabelled platelets

    SciTech Connect

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

    1990-01-01

    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.

  16. AMPD3 is involved in anthrax LeTx-induced macrophage cell death

    Microsoft Academic Search

    Sangun Lee; Yanhai Wang; Sung Ouk Kim; Jiahuai Han

    2011-01-01

    The responses of macrophages to Bacillus anthracis infection are important for the survival of the host, since macrophages are required for the germination of B. anthracis spores in lymph nodes, and macrophage death exacerbates anthrax lethal toxin (LeTx)-induced organ collapse. To elucidate\\u000a the mechanism of macrophage cell death induced by LeTx, we performed a genetic screen to search for genes

  17. Genetic Vaccines for Anthrax Based on Recombinant Adeno-associated Virus Vectors

    Microsoft Academic Search

    Te-Hui Liu; Jon Oscherwitz; Bruce Schnepp; Jana Jacobs; Fen Yu; Kemp B Cease; Philip R Johnson

    2009-01-01

    Bacillus anthracis represents a formidable bioterrorism and biowarfare threat for which new vaccines are needed with improved safety and efficacy over current options. Toward this end, we created recombinant adeno-associated virus type 1 (rAAV1) vectors containing synthetic genes derived from the protective antigen (PA) or lethal factor (LF) of anthrax lethal toxin (LeTx) and tested them for immunogenicity and induction

  18. Anthrax in animals and humans in Mongolia.

    PubMed

    Odontsetseg, N; Sh, Tserendorj; Adiyasuren, Z; Uuganbayar, D; Mweene, A S

    2007-12-01

    Anthrax is endemic throughout Mongolia, except in the semi-desert and desert areas of the south. The prevalence of anthrax in Mongolia had drastically decreased since the 1950s due to the use of anthrax antiserum and vaccines, but the privatisation of the animal husbandry sector and changes in the structures of the veterinary and medical delivery systems in Mongolia over the last decade have resulted in challenges for disease control. Animal and human anthrax has become an increasing problem since the mid-1990s. Human cutaneous anthrax is common in Mongolia as a result of exposure to infected animals. In this paper, the authors identify potential causes forthe increase of anthrax in Mongolia. The current prevention efforts may not be adequate. Anthrax surveillance and control must be intensified, particularly in areas of high prevalence. PMID:18293618

  19. Airing Out Anthrax

    NASA Technical Reports Server (NTRS)

    2002-01-01

    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.

  20. Topical immunization onto mouse skin using a microemulsion incorporated with an anthrax protective antigen protein-encoding plasmid.

    PubMed

    Cui, Zhengrong; Sloat, Brian R

    2006-07-24

    The current anthrax vaccine in the U.S., the anthrax vaccine adsorbed, has several serious drawbacks, most notably the very lengthy and complicated dosing schedule. Thus, there is a critical need to develop an alternative anthrax vaccine with a simplified immunization schedule. To address this need, we evaluated the feasibility of topically priming or boosting onto the skin using an anthrax protective antigen (PA) protein-encoding DNA vaccine. To this end, we have shown that topical immunization of mice onto their skin with a perflubron-based microemulsion incorporated with a PA63-encoding plasmid, pGPA, led to significant PA-specific antibody responses, which have anthrax lethal toxin-neutralization activity. Moreover, topical boosting of mice primed with PA protein with the pGPA-incorporated, perflubron-based microemulsion significantly enhanced the anti-PA antibody responses induced. This topical anthrax DNA vaccine has the potential to be combined with a vaccine, such as the current AVA, to produce a simplified and more convenient dosing schedule. PMID:16730934

  1. Apoptosis and melanogenesis in human melanoma cells induced by anthrax lethal factor inactivation of mitogen-activated protein kinase kinase

    NASA Astrophysics Data System (ADS)

    Koo, Han-Mo; Vanbrocklin, Matt; McWilliams, Mary Jane; Leppla, Stephan H.; Duesbery, Nicholas S.; Vande Woude, George F.

    2002-03-01

    Lethal factor, the principal virulence factor of Bacillus anthracis, inhibits mitogen-activated protein kinase (MAPK) signaling by proteolytically cleaving MAPK kinases. Edema factor, another component of anthrax toxin, is an adenylate cyclase, which increases intracellular cAMP. Inhibition of MAPK signaling with either anthrax lethal toxin (LeTx) or small molecule MAPK kinase inhibitors triggers apoptosis in human melanoma cells. Normal melanocytes do not undergo apoptosis in response to MAPK inhibition but arrest in the G1 phase of the cell cycle. Importantly, in vivo treatment of human melanoma xenograft tumors in athymic nude mice with LeTx results in significant or complete tumor regression without apparent side effects, suggesting that inhibiting the MAPK signaling pathway may be a useful strategy for treating melanoma. Additionally, interrupting MAPK signaling with LeTx and elevating cAMP with anthrax edema toxin in both melanoma cells and melanocytes lead to dramatic melanin production, perhaps explaining the formation of blackened eschars in cutaneous anthrax.

  2. Cholera toxin can catalyze ADP-ribosylation of cytoskeletal proteins

    SciTech Connect

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

    1981-11-01

    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.

  3. ECONOMIC IMPACTS OF A WIDE AREA RELEASE OF ANTHRAX

    E-print Network

    ECONOMIC IMPACTS OF A WIDE AREA RELEASE OF ANTHRAX May 2009 Prepared Regional Technology Center for Homeland Security Economic Impacts of a Wide Area Release of Anthrax KS. ................................................................. 2 Figure 2.Framework for analyzing government costs from an anthrax incident

  4. Electronic Anthrax DNA Biosensor Review

    Microsoft Academic Search

    Tim Damrow; Brent Hagemeyer; Hassan Ismail; Ryan Oldham

    We introduce preliminary design specifications for an electronic anthrax deoxyribonucleic acid (DNA) biosensor using the principle of DNA displacement. Upon hybridization, the sample DNA displaces a ferrocene-marked signal probe, which induces an increased redox current that is amperometrically measured and relayed. I. INTRODUCTION The purpose of this article is to propose a design of a Lab- On-Chip DNA biosensor that

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

    Microsoft Academic Search

    Antonio E Muñiz

    2003-01-01

    Anthrax is caused by the spore-forming bacteria Bacillus anthracis. It occurs naturally, but recently has been manufactured as a biological warfare agent. This makes prophylaxis for anthrax an urgent concern and efforts are ongoing for the production of an efficient and safe vaccine. Side effects to the current anthrax vaccine are usually minor and mainly consist of local skin reactions.

  6. Anthrax in the Gambia: an epidemiological study

    Microsoft Academic Search

    B Heyworth; M E Ropp; U G Voos; H I Meinel; H M Darlow

    1975-01-01

    Epidemiological data on 448 cases of human cutaneous anthrax from the Gambia showed that this particular strain of anthrax bacillus causes widespread morbidity and some mortality with, at the same time, subclinical infection. Analysis also showed that anthrax is not an occupationally related disease in the Gambia.The possibility of human-to-human spread, affecting all age groups and both sexes, by means

  7. Cutaneous anthrax: conservative or surgical treatment?

    PubMed

    Godyn, Janusz J; Reyes, Luis; Siderits, Richard; Hazra, Anup

    2005-04-01

    This article summarizes the diagnostic features and treatment recommendations for cutaneous anthrax, exemplified by a case report of nontypical cutaneous anthrax. The treatment of choice is medical, with ciprofloxacin or doxycycline the preferred antibiotics. However, surgical biopsy may be used if the clinical setting and microbiologic examination of swabs are not diagnostically conclusive. Histopathologic findings explain the clinical observation that most cutaneous anthrax lesions heal without scar formation. PMID:15840983

  8. [Use of anthrax as biological weapon].

    PubMed

    Rizzo, G

    2004-01-01

    We describe the epidemiology of anthrax and the several human disease aspect, by spores penetration through the skin or by inhalation or ingestion, and the action of exotoxin secreted by B. anthracis. We detail pulmonary anthrax that could derive from intentional release of endospore as biological weapon. Laboratory diagnosis of Cereus group with cultural, FDA and PCR methods are reported. Environment disinfection, vaccination, antibiotic prophylaxis, passive antibody administration and treatment of anthrax are reported. PMID:15366519

  9. Mass spectrometric detection of protein-based toxins.

    PubMed

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

    2013-09-01

    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

  10. Multiagent vaccines vectored by Venezuelan equine encephalitis virus replicon elicits immune responses to Marburg virus and protection against anthrax and botulinum neurotoxin in mice

    Microsoft Academic Search

    John S. Lee; Jennifer L. Groebner; Angela G. Hadjipanayis; Diane L. Negley; Alan L. Schmaljohn; Susan L. Welkos; Leonard A. Smith; Jonathan F. Smith

    2006-01-01

    The development of multiagent vaccines offers the advantage of eliciting protection against multiple diseases with minimal inoculations over a shorter time span. We report here the results of using formulations of individual Venezuelan equine encephalitis (VEE) virus replicon-vectored vaccines against a bacterial disease, anthrax; a viral disease, Marburg fever; and against a toxin-mediated disease, botulism. The individual VEE replicon particles

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

    PubMed Central

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

    2012-01-01

    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. PMID:23290417

  12. Anthrax vaccines: a development update.

    PubMed

    Little, Stephen F

    2005-01-01

    The current human anthrax vaccines licensed in the US and UK consist of aluminum hydroxide-adsorbed or alum-precipitated culture supernatant material from fermentor cultures of toxigenic noncapsulated strains of Bacillus anthracis. The threat of B. anthracis being used as a biowarfare agent has led to a wider usage of these vaccines, which has heightened concerns regarding the need for frequent boosters and the occasional local reactogenicity associated with vaccination. These concerns have provided the impetus for the development of better characterized vaccines. This review summarizes the work of numerous laboratories in the search for alternative vaccines against anthrax that are well tolerated, provide long-lasting immunity, and are efficacious. PMID:16128606

  13. Small Molecule Inhibitors of Anthrax Lethal Factor Toxin

    PubMed Central

    Williams, John D.; Khan, Atiyya R.; Cardinale, Steven C.; Butler, Michelle M.; Bowlin, Terry L.; Peet, Norton P.

    2014-01-01

    This manuscript describes the preparation of new small molecule inhibitors of Bacillus anthracis lethal factor. Our starting point was the symmetrical, bis-quinolinyl compound 1 (NSC 12155). Optimization of one half of this molecule led to new LF inhibitors that were desymmetrized to afford more drug-like compounds. PMID:24290062

  14. Purification and biophysical characterization of the core protease domain of anthrax lethal factor

    SciTech Connect

    Gkazonis, Petros V.; Dalkas, Georgios A.; Chasapis, Christos T. [Department of Pharmacy, University of Patras, GR-26504 Patras (Greece)] [Department of Pharmacy, University of Patras, GR-26504 Patras (Greece); Vlamis-Gardikas, Alexios [Department of Biochemistry, Foundation for Biomedical Research (BRFAA), Academy of Athens, GR-11527 Athens (Greece)] [Department of Biochemistry, Foundation for Biomedical Research (BRFAA), Academy of Athens, GR-11527 Athens (Greece); Bentrop, Detlef [Institute of Physiology II, University of Freiburg, D-79108 Freiburg (Germany)] [Institute of Physiology II, University of Freiburg, D-79108 Freiburg (Germany); Spyroulias, Georgios A., E-mail: G.A.Spyroulias@upatras.gr [Department of Pharmacy, University of Patras, GR-26504 Patras (Greece)

    2010-06-04

    Anthrax lethal toxin (LeTx) stands for the major virulence factor of the anthrax disease. It comprises a 90 kDa highly specific metalloprotease, the anthrax lethal factor (LF). LF possesses a catalytic Zn{sup 2+} binding site and is highly specific against MAPK kinases, thus representing the most potent native biomolecule to alter and inactivate MKK [MAPK (mitogen-activated protein kinase) kinases] signalling pathways. Given the importance of the interaction between LF and substrate for the development of anti-anthrax agents as well as the potential treatment of nascent tumours, the analysis of the structure and dynamic properties of the LF catalytic site are essential to elucidate its enzymatic properties. Here we report the recombinant expression and purification of a C-terminal part of LF (LF{sub 672-776}) that harbours the enzyme's core protease domain. The biophysical characterization and backbone assignments ({sup 1}H, {sup 13}C, {sup 15}N) of the polypeptide revealed a stable, well folded structure even in the absence of Zn{sup 2+}, suitable for high resolution structural analysis by NMR.

  15. Stable dry powder formulation for nasal delivery of anthrax vaccine.

    PubMed

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

    2012-01-01

    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

  16. Stable Dry Powder Formulation for Nasal Delivery of Anthrax Vaccine

    PubMed Central

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

    2013-01-01

    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 rPA delivered intranasally with a novel mucosal adjuvant, a mast cell activator Compound 48/80. 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 D50=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 CD and ATR-FTIR, while functional stability of rPA and C48/80 was monitored by cell-based assays. Animal study was performed using a unitdose 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 two years at room temperature elicited significantly elevated serum PA-specific and lethal toxin neutralization antibody titers that were comparable to that induced by IM 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

  17. Estimating aerosol hazards from an anthrax letter

    Microsoft Academic Search

    J. Ho; S. Duncan

    2005-01-01

    Events following the anthrax letter incidences in 2001 changed many previously held assumptions regarding biological aerosol hazards. As there were significant fatalities resulting from the sorting of a single anthrax letter, it suggests there is a need to reevaluate how best to measure biological aerosols and to use the information to make accurate predictions. This paper describes the biological aerosol

  18. Human Cutaneous Anthrax, Georgia 2010–2012

    PubMed Central

    Kracalik, Ian; Malania, Lile; Tsertsvadze, Nikoloz; Manvelyan, Julietta; Bakanidze, Lela; Imnadze, Paata; Tsanava, Shota

    2014-01-01

    We assessed the occurrence of human cutaneous anthrax in Georgia during 2010–-2012 by examining demographic and spatial characteristics of reported cases. Reporting increased substantially, as did clustering of cases near urban centers. Control efforts, including education about anthrax and livestock vaccination, can be directed at areas of high risk. PMID:24447721

  19. Anthrax vaccine associated deaths in miniature horses.

    PubMed

    Wobeser, Bruce K

    2015-04-01

    During a widespread anthrax outbreak in Canada, miniature horses were vaccinated using a live spore anthrax vaccine. Several of these horses died from an apparent immune-mediated vasculitis temporally associated with this vaccination. During the course of the outbreak, other miniature horses from different regions with a similar vaccination history, clinical signs, and necropsy findings were found. PMID:25829553

  20. Molecular basis for improved anthrax vaccines

    Microsoft Academic Search

    Robert N. Brey

    2005-01-01

    The current vaccine for anthrax has been licensed since 1970 and was developed based on the outcome of human trials conducted in the 1950s. This vaccine, known as anthrax vaccine adsorbed (AVA), consists of a culture filtrate from an attenuated strain of Bacillus anthracis adsorbed to aluminum salts as an adjuvant. This vaccine is considered safe and effective, but is

  1. [Evaluation of anthrax vaccination in Denmark].

    PubMed

    Bork, Kristian Hveysel; Heegaard, Erik Deichmann; Nielsen, Jesper; Kogutowska, Ewa; Heegaard, Nils Henrik Helweg

    2005-09-01

    The aim of this short review is to present the Danish experience with the U.K. anthrax vaccine as compared with international reviews regarding the immunological response, efficiency, safety and adverse reactions of the U.K. and U.S. anthrax vaccines. PMID:16159489

  2. Treatment of Anthrax Disease Frequently Asked Questions

    SciTech Connect

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

    2010-05-14

    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.

  3. Anthrax Outbreaks in Bangladesh, 2009–2010

    PubMed Central

    Chakraborty, Apurba; Khan, Salah Uddin; Hasnat, Mohammed Abul; Parveen, Shahana; Islam, M. Saiful; Mikolon, Andrea; Chakraborty, Ranjit Kumar; Ahmed, Be-Nazir; Ara, Khorsed; Haider, Najmul; Zaki, Sherif R.; Hoffmaster, Alex R.; Rahman, Mahmudur; Luby, Stephen P.; Hossain, M. Jahangir

    2012-01-01

    During August 2009–October 2010, a multidisciplinary team investigated 14 outbreaks of animal and human anthrax in Bangladesh to identify the etiology, pathway of transmission, and social, behavioral, and cultural factors that led to these outbreaks. The team identified 140 animal cases of anthrax and 273 human cases of cutaneous anthrax. Ninety one percent of persons in whom cutaneous anthrax developed had history of butchering sick animals, handling raw meat, contact with animal skin, or were present at slaughtering sites. Each year, Bacillus anthracis of identical genotypes were isolated from animal and human cases. Inadequate livestock vaccination coverage, lack of awareness of the risk of anthrax transmission from animal to humans, social norms and poverty contributed to these outbreaks. Addressing these challenges and adopting a joint animal and human health approach could contribute to detecting and preventing such outbreaks in the future. PMID:22492157

  4. Serum adenosine deaminase activity in cutaneous anthrax

    PubMed Central

    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

    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. PMID:24997584

  5. Anthrax in America 2001-2003.

    PubMed

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

    2004-03-01

    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. PMID:15040516

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

    PubMed Central

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

    2013-01-01

    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. PMID:22972844

  7. Evaluation of Immunogenicity and Efficacy of Anthrax Vaccine Adsorbed for Postexposure Prophylaxis

    PubMed Central

    Ionin, Boris; Hopkins, Robert J.; Pleune, Brett; Sivko, Gloria S.; Reid, Frances M.; Clement, Kristin H.; Rudge, Thomas L.; Stark, Gregory V.; Innes, Alison; Sari, Suha; Guina, Tina; Howard, Cris; Smith, Jeffrey; Swoboda, M. Lisa; Vert-Wong, Ekaterina; Johnson, Virginia; Nabors, Gary S.

    2013-01-01

    Antimicrobials administered postexposure can reduce the incidence or progression of anthrax disease, but they do not protect against the disease resulting from the germination of spores that may remain in the body after cessation of the antimicrobial regimen. Such additional protection may be achieved by postexposure vaccination; however, no anthrax vaccine is licensed for postexposure prophylaxis (PEP). In a rabbit PEP study, animals were subjected to lethal challenge with aerosolized Bacillus anthracis spores and then were treated with levofloxacin with or without concomitant intramuscular (i.m.) vaccination with anthrax vaccine adsorbed (AVA) (BioThrax; Emergent BioDefense Operations Lansing LLC, Lansing, MI), administered twice, 1 week apart. A significant increase in survival rates was observed among vaccinated animals compared to those treated with antibiotic alone. In preexposure prophylaxis studies in rabbits and nonhuman primates (NHPs), animals received two i.m. vaccinations 1 month apart and were challenged with aerosolized anthrax spores at day 70. Prechallenge toxin-neutralizing antibody (TNA) titers correlated with animal survival postchallenge and provided the means for deriving an antibody titer associated with a specific probability of survival in animals. In a clinical immunogenicity study, 82% of the subjects met or exceeded the prechallenge TNA value that was associated with a 70% probability of survival in rabbits and 88% probability of survival in NHPs, which was estimated based on the results of animal preexposure prophylaxis studies. The animal data provide initial information on protective antibody levels for anthrax, as well as support previous findings regarding the ability of AVA to provide added protection to B. anthracis-infected animals compared to antimicrobial treatment alone. PMID:23658392

  8. Modified anthrax fusion proteins deliver HIV antigens through MHC Class I and II pathways.

    PubMed

    McEvers, K; Elrefaei, M; Norris, P; Deeks, S; Martin, J; Lu, Y; Cao, H

    2005-07-14

    T cell-based HIV vaccine candidates have focused on eliciting both CD4- and CD8-mediated responses. One challenge in vaccine development is the successful introduction and presentation of exogenous antigen to elicit an immune response. Modified bacterial toxins have been studied extensively as intracellular delivery agents because of their unique capability to translocate antigen across the cell membrane without affecting cell viability. Modified anthrax toxin lethal factor (LFn) fusion protein is able to effectively induce anti-HIV cytotoxic T lymphocytes in the absence of protective antigen (PA) and is being evaluated as a vaccine candidate. Here we describe, for the first time, the processing and presentation of LFn fusion proteins by the MHC Class II pathway. The ability of LFn--HIV to induce both CD8- and CD4-mediated responses may have relevance in current approaches to vaccine design. Furthermore, the translocation and presentation of antigens occurs in the absence of PA, which proposes a modified molecular mechanism of antigen presentation by the anthrax toxin model. Additionally, we found that LFn--HIV is specific and sensitive in detecting HIV-specific CD4(+) and CD8(+) T cell responses in T cell assays, further broadening the value of this antigen delivery system as a useful immunologic tool. PMID:15964481

  9. Targeting the anthrax receptors, TEM-8 and CMG-2, for anti-angiogenic therapy.

    PubMed

    Cryan, Lorna M; Rogers, Michael S

    2011-01-01

    The anthrax toxin receptors tumor endothelial marker-8 (TEM-8) and capillary morphogenesis gene-2 (CMG-2) are responsible for allowing entry of anthrax toxin into host cells. These receptors were first discovered due to their enhanced expression on endothelial cells undergoing blood vessel growth or angiogenesis in model systems. Inhibition of angiogenesis is an important strategy for current anti-cancer therapies and treatment of retinal diseases. Functional roles for TEM-8 and CMG-2 in angiogenesis have recently emerged. TEM-8 appears to regulate endothelial cell migration and tubule formation whereas a role for CMG-2 in endothelial proliferation has been documented. TEM-8 and CMG-2 bind differentially to extracellular matrix proteins including collagen I, collagen IV and laminin and these properties may be responsible for their apparent roles in regulating endothelial cell behavior during angiogenesis. TEM-8-binding moieties have also been suggested to be useful in selectively targeting anti-angiogenic and anti-tumorigenic therapies to tumor endothelium. Additionally, studies of modified forms of lethal toxin (LeTx) have demonstrated that targeted inhibition of MAPKs within tumor vessels may represent an efficacious anti-angiogenic strategy. PMID:21196249

  10. Botulinum Toxin Therapy

    MedlinePLUS

    ... Z Diseases and treatments A - D Botulinum toxin Botulinum toxin therapy Also called botulinum rejuvenation Brand names: Botox® ... out what your policy covers. Learn more about botulinum toxin therapy: Is botulinum toxin therapy the right choice ...

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

    PubMed

    Muñiz, Antonio E

    2003-10-01

    Anthrax is caused by the spore-forming bacteria Bacillus anthracis. It occurs naturally, but recently has been manufactured as a biological warfare agent. This makes prophylaxis for anthrax an urgent concern and efforts are ongoing for the production of an efficient and safe vaccine. Side effects to the current anthrax vaccine are usually minor and mainly consist of local skin reactions. Occasionally an unusual complication may occur; a case of a patient with lymphocytic vasculitis temporally associated with the anthrax vaccine is reported. PMID:14585454

  12. Gastrointestinal anthrax: review of the literature.

    PubMed

    Beatty, Mark E; Ashford, David A; Griffin, Patricia M; Tauxe, Robert V; Sobel, Jeremy

    2003-11-10

    Recent events have drawn attention to cases of inhalational and cutaneous anthrax associated with contaminated mail. Gastrointestinal anthrax, the disease caused by ingestion of Bacillus anthracis organisms, has rarely been reported in the United States. This review provides background information on the gastrointestinal form of the disease. We describe the clinical course of gastrointestinal anthrax, outline current therapy, review the microbiology of B anthracis, examine the epidemiology of natural outbreaks, discuss considerations regarding deliberate contamination, and summarize existing literature on the inactivation of spores present in food and water. PMID:14609791

  13. BOTULINUM TOXIN

    PubMed Central

    Nigam, P K; Nigam, Anjana

    2010-01-01

    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. PMID:20418969

  14. [Molecular aspects of anthrax pathogenesis].

    PubMed

    Noskov, A N

    2014-01-01

    A model of anthrax infection with the role determined for main pathogenicity factors of Bacillus anthracis exotoxin and capsule is presented. After spore phagocytosis by macrophages, synthesis of the main exotoxin component begins - a protective antigen that in oligomeric form disrupts phagosome membrane. This accelerates the transition of the pathogen from phagosome into the macrophage cytoplasm. Poly-D-glutamine capsule synthesized by the pathogen triggers the exit (exocytosis) of vegetative cells from macrophages and protects them from re-phagocytosis in lymphatic node lumen. The vegetative cells, that actively and freely replicate in lymphatic node, secret an exotoxin that disrupts endothelial septum between lymph and blood due to cytotoxic activity. As a result the vegetative cells get into blood and bacteremia develops. Pathogenetic pattern during anthrax (multiple hemorrhages in various organs etc.) is associated with local microcirculation disorders of various organs caused by the effect of bacterial exoproteases via activation of Willebrand factor. This results in a rapid local increase of microbial mass and consequent powerful cytotoxic effect of exotoxin on the tissue cells of the affected organ. Death of the infected organism takes place at the final stage of infec- tion due to toxic shock caused by the exotoxin. A reduction of body temperature takes place after death and the process of spore formation begins in the dead animal: capsule depolymerization, chain shortening, peptidoglycan cortex formation. Spores in this form are the prolonged source of infectious agent conservation and spread of infection in nature. PMID:25286538

  15. The anthrax lethal factor and its MAPK kinase-specific metalloprotease activity.

    PubMed

    Tonello, Fiorella; Montecucco, Cesare

    2009-12-01

    The anthrax lethal factor is a multi-domain protein toxin released by Bacillus anthracis which enters cells in a process mediated by the protective antigen and specific cell receptors. In the cytosol, the lethal factor cleaves the N-terminal tail of many MAPK kinases, thus deranging a major cell signaling pathway. The structural features at the basis of these activities of LF are reviewed here with particular attention to the proteolytic activity and to the identification of specific inhibitors. A significant similarity between the metalloprotease domain of the lethal factor and of that of the clostridial neurotoxins has been noted and is discussed. PMID:19665472

  16. Anthrax vaccines: present status and future prospects.

    PubMed

    Kaur, Manpreet; Singh, Samer; Bhatnagar, Rakesh

    2013-08-01

    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

  17. Anthrax vaccines: Pasteur to the present.

    PubMed

    Scorpio, A; Blank, T E; Day, W A; Chabot, D J

    2006-10-01

    Anthrax has been a major cause of death in grazing animals and an occasional cause of death in humans for thousands of years. Since the late 1800s there has been an exceptional international history of anthrax vaccine development. Due to animal vaccinations, the rate of infection has dropped dramatically. Anthrax vaccines have progressed from uncharacterized whole-cell vaccines in 1881, to pXO2-negative spores in the 1930s, to culture filtrates absorbed to aluminum hydroxide in 1970, and likely to recombinant protective antigen in the near future. Each of these refinements has increased safety without significant loss of efficacy. The threat of genetically engineered, antibiotic and vaccine resistant strains of Bacillus anthracis is fueling hypothesis-driven research and global techniques--including genomics, proteomics and transposon site hybridization--to facilitate the discovery of novel vaccine targets. This review highlights historical achievements and new developments in anthrax vaccine research. PMID:16964578

  18. List of Contractors to Support Anthrax Remediation

    SciTech Connect

    Judd, Kathleen S.; Lesperance, Ann M.

    2010-05-14

    This document responds to a need identified by private sector businesses for information on contractors that may be qualified to support building remediation efforts following a wide-area anthrax release.

  19. Platelet-activating Factor Contributes to Bacillus anthracis Lethal Toxin-associated Damage*

    PubMed Central

    Rivera, Johanna; Sellers, Rani S.; Zeng, Wangyong; van Rooijen, Nico; Casadevall, Arturo; Goldman, David L.

    2014-01-01

    The lethal toxin (LeTx) of Bacillus anthracis plays a central role in the pathogenesis of anthrax-associated shock. Platelet-activating factor (PAF) is a potent lipid mediator that has been implicated in endotoxin-associated shock. In this study, we examined the contribution of PAF to the manifestations of lethal toxin challenge in WT mice. LeTx challenge resulted in transient increase in serum PAF levels and a concurrent decrease in PAF acetylhydrolase activity. Inhibition of PAF activity using PAF antagonists or toxin challenge of PAF receptor negative mice reversed or ameliorated many of the pathologic features of LeTx-induced damage, including changes in vascular permeability, hepatic necrosis, and cellular apoptosis. In contrast, PAF inhibition had minimal effects on cytokine levels. Findings from these studies support the continued study of PAF antagonists as potential adjunctive agents in the treatment of anthrax-associated shock. PMID:24478317

  20. Generation and Characterization of Human Monoclonal Antibodies Targeting Anthrax Protective Antigen following Vaccination with a Recombinant Protective Antigen Vaccine.

    PubMed

    Chi, Xiangyang; Li, Jianmin; Liu, Weicen; Wang, Xiaolin; Yin, Kexin; Liu, Ju; Zai, Xiaodong; Li, Liangliang; Song, Xiaohong; Zhang, Jun; Zhang, Xiaopeng; Yin, Ying; Fu, Ling; Xu, Junjie; Yu, Changming; Chen, Wei

    2015-05-01

    The anthrax protective antigen (PA) is the central component of the three-part anthrax toxin, and it is the primary immunogenic component in the approved AVA anthrax vaccine and the "next-generation" recombinant PA (rPA) anthrax vaccines. Animal models have indicated that PA-specific antibodies (AB) are sufficient to protect against infection with Bacillus anthracis. In this study, we investigated the PA domain specificity, affinity, mechanisms of neutralization, and synergistic effects of PA-specific antibodies from a single donor following vaccination with the rPA vaccine. Antibody-secreting cells were isolated 7 days after the donor received a boost vaccination, and 34 fully human monoclonal antibodies (hMAb) were identified. Clones 8H6, 4A3, and 22F1 were able to neutralize lethal toxin (LeTx) both in vitro and in vivo. Clone 8H6 neutralized LeTx by preventing furin cleavage of PA in a dose-dependent manner. Clone 4A3 enhanced degradation of nicked PA, thereby interfering with PA oligomerization. The mechanism of 22F1 is still unclear. A fourth clone, 2A6, that was protective only in vitro was found to be neutralizing in vivo in combination with a toxin-enhancing antibody, 8A7, which binds to domain 3 of PA and PA oligomers. These results provide novel insights into the antibody response elicited by the rPA vaccine and may be useful for PA-based vaccine and immunotherapeutic cocktail design. PMID:25787135

  1. Gastrointestinal anthrax: clinical experience in 5 cases

    PubMed Central

    Maddah, Ghodratollah; Abdollahi, Abbas; Katebi, Mehrdad

    2013-01-01

    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. PMID:24009958

  2. Laboratories Face Crackdown in Wake of Anthrax Scare.

    ERIC Educational Resources Information Center

    Southwick, Ron

    2001-01-01

    Explores the after-effects on college laboratories of the anthrax mail scare; scientists say the anthrax scare justifies tougher rules on biological agents, but some fear that Congress may go too far. (EV)

  3. FINANCIAL SUPPORT FOR THE PRIVATE SECTOR AFTER AN ANTHRAX BIOTERRORISM

    E-print Network

    FINANCIAL SUPPORT FOR THE PRIVATE SECTOR AFTER AN ANTHRAX BIOTERRORISM INCIDENT September Bioterrorism Incident KS Judd AM Lesperance September 30, 2009 #12; DISCLAIMER This report was prepared; 1 FINANCIAL SUPPORT FOR THE PRIVATE SECTOR AFTER AN ANTHRAX BIOTERRORISM INCIDENT Through

  4. A Novel Chimeric Anti-PA Neutralizing Antibody for Postexposure Prophylaxis and Treatment of Anthrax.

    PubMed

    Xiong, Siping; Tang, Qi; Liang, Xudong; Zhou, Tingting; Yang, Jin; Liu, Peng; Chen, Ya; Wang, Changjun; Feng, Zhenqing; Zhu, Jin

    2015-01-01

    Anthrax is a highly lethal infectious disease caused by the bacterium Bacillus anthracis, and the associated shock is closely related to the lethal toxin (LeTx) produced by the bacterium. The central role played by the 63?kDa protective antigen (PA63) region of LeTx in the pathophysiology of anthrax makes it an excellent therapeutic target. In the present study, a human/murine chimeric IgG mAb, hmPA6, was developed by inserting murine antibody variable regions into human constant regions using antibody engineering technology. hmPA6 expressed in 293F cells could neutralize LeTx both in vitro and in vivo. At a dose of 0.3?mg/kg, it could protect all tested rats from a lethal dose of LeTx. Even administration of 0.6?mg/kg hmPA6 48?h before LeTx challenge protected all tested rats. The results indicate that hmPA6 is a potential candidate for clinical application in anthrax treatment. PMID:26134518

  5. A Novel Chimeric Anti-PA Neutralizing Antibody for Postexposure Prophylaxis and Treatment of Anthrax

    PubMed Central

    Xiong, Siping; Tang, Qi; Liang, Xudong; Zhou, Tingting; Yang, Jin; Liu, Peng; Chen, Ya; Wang, Changjun; Feng, Zhenqing; Zhu, Jin

    2015-01-01

    Anthrax is a highly lethal infectious disease caused by the bacterium Bacillus anthracis, and the associated shock is closely related to the lethal toxin (LeTx) produced by the bacterium. The central role played by the 63?kDa protective antigen (PA63) region of LeTx in the pathophysiology of anthrax makes it an excellent therapeutic target. In the present study, a human/murine chimeric IgG mAb, hmPA6, was developed by inserting murine antibody variable regions into human constant regions using antibody engineering technology. hmPA6 expressed in 293F cells could neutralize LeTx both in vitro and in vivo. At a dose of 0.3?mg/kg, it could protect all tested rats from a lethal dose of LeTx. Even administration of 0.6?mg/kg hmPA6 48?h before LeTx challenge protected all tested rats. The results indicate that hmPA6 is a potential candidate for clinical application in anthrax treatment. PMID:26134518

  6. [Recombinant antibodies for medical protection against bioterrorism agents: the example of anthrax].

    PubMed

    Thullier, Philippe; Pelat, Thibault; Paucod, Jean-Charles; Vidal, Dominique

    2010-01-01

    Recombinant antibodies are a highly successful class of therapeutic molecules, they are well adapted for use against bio-weapons (BW) as they act immediately, are often synergistic with other therapeutic molecules, have a long half-life and are well tolerated. Anthrax is regarded at high risk of being used as BW, and its pathogenic properties depend on toxins, which might be neutralized by antibodies. These toxins are made of three different types of sub-units (PA, LF, EF). Several anti-PA have been developed, including an original approach by our team. We have developed an anti-LF, as recommended by experts. Our anti-PA antibody, and to a lesser extend our anti-LF antibody, will be presented here. PMID:20950579

  7. Further Insights into Brevetoxin Metabolism by de Novo Radiolabeling

    PubMed Central

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

    2014-01-01

    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

  8. Public health vaccination policies for containing an anthrax outbreak

    Microsoft Academic Search

    Ron Brookmeyer; Elizabeth Johnson; Robert Bollinger

    2004-01-01

    Concern about biological weapons has raised questions about the most effective public health policies to contain an anthrax outbreak. We developed a probability model to predict the impact of different anthrax antibiotic and vaccination policies. An anthrax outbreak can be significantly contained by minimizing the delay until initiation of antibiotic prophylaxis. However, even if mass distribution of antibiotics is completed

  9. Anthrax: has the clinical milieu changed since 2001?

    PubMed Central

    Adalja, Amesh A.

    2012-01-01

    Since the anthrax attacks of 2001 (Amerithrax), several important improvements in the knowledge of Bacillus anthracis and the clinical condition it causes have occurred. While much remains to be known about the optimal management of anthrax patients, several approaches that were not widely utilized, available, or known in 2001 would be used in the treatment of critically ill anthrax patients in 2012. PMID:23882372

  10. A brief review of anthrax in domestic animals

    Microsoft Academic Search

    I. M. Smith

    1973-01-01

    Although there exists in the U.K. a high degree of control of industrial and agricultural anthrax in man and anthrax in animals originating either from animal products or from materials contaminated by contact with them, total control of anthrax in this country seems unlikely to follow until the disease is eliminated from livestock in the enzootic areas abroad. This view

  11. Diagnostic performance characteristics of a rapid field test for anthrax in cattle.

    PubMed

    Muller, Janine; Gwozdz, Jacek; Hodgeman, Rachel; Ainsworth, Catherine; Kluver, Patrick; Czarnecki, Jill; Warner, Simone; Fegan, Mark

    2015-07-01

    Although diagnosis of anthrax can be made in the field with a peripheral blood smear, and in the laboratory with bacterial culture or molecular based tests, these tests require either considerable experience or specialised equipment. Here we report on the evaluation of the diagnostic sensitivity and specificity of a simple and rapid in-field diagnostic test for anthrax, the anthrax immunochromatographic test (AICT). The AICT detects the protective antigen (PA) component of the anthrax toxin present within the blood of an animal that has died from anthrax. The test provides a result in 15min and offers the advantage of avoiding the necessity for on-site necropsy and subsequent occupational risks and environmental contamination. The specificity of the test was determined by testing samples taken from 622 animals, not infected with Bacillus anthracis. Diagnostic sensitivity was estimated on samples taken from 58 animals, naturally infected with B. anthracis collected over a 10-year period. All samples used to estimate the diagnostic sensitivity and specificity of the AICT were also tested using the gold standard of bacterial culture. The diagnostic specificity of the test was estimated to be 100% (99.4-100%; 95% CI) and the diagnostic sensitivity was estimated to be 93.1% (83.3-98.1%; 95% CI) (Clopper-Pearson method). Four samples produced false negative AICT results. These were among 9 samples, all of which tested positive for B. anthracis by culture, where there was a time delay between collection and testing of >48h and/or the samples were collected from animals that were >48h post-mortem. A statistically significant difference (P<0.001; Fishers exact test) was found between the ability of the AICT to detect PA in samples from culture positive animals <48h post-mortem, 49 of 49, Se=100% (92.8-100%; 95% CI) compared with samples tested >48h post-mortem 5 of 9 Se=56% (21-86.3%; 95% CI) (Clopper-Pearson method). Based upon these results a post hoc cut-off for use of the AICT of 48h post-mortem was applied, Se=100% (92.8-100%; 95% CI) and Sp=100% (99.4-100%; 95% CI). The high diagnostic sensitivity and specificity and the simplicity of the AICT enables it to be used for active surveillance in areas with a history of anthrax, or used as a preliminary tool in investigating sudden, unexplained death in cattle. PMID:25956134

  12. The Glucocorticoid Receptor: A Revisited Target for Toxins

    PubMed Central

    Marketon, Jeanette I. Webster; Sternberg, Esther M.

    2010-01-01

    The hypothalamic-pituitary-adrenal (HPA) axis activation and glucocorticoid responses are critical for survival from a number of bacterial, viral and toxic insults, demonstrated by the fact that removal of the HPA axis or GR blockade enhances mortality rates. Replacement with synthetic glucocorticoids reverses these effects by providing protection against lethal effects. Glucocorticoid resistance/insensitivity is a common problem in the treatment of many diseases. Much research has focused on the molecular mechanism behind this resistance, but an area that has been neglected is the role of infectious agents and toxins. We have recently shown that the anthrax lethal toxin is able to repress glucocorticoid receptor function. Data suggesting that the glucocorticoid receptor may be a target for a variety of toxins is reviewed here. These studies have important implications for glucocorticoid therapy. PMID:22069642

  13. Validation of an anti-PA-ELISA for the potency testing of anthrax vaccine in mice.

    PubMed

    Pombo, María; Berthold, Inge; Gingrich, Elise; Jaramillo, María; Leef, Mary; Sirota, Lev; Hsu, Henry; Arciniega, Juan

    2004-09-01

    The potency test for the anthrax vaccine currently licensed for human use in the United States (Anthrax Vaccine Adsorbed) involves the protection of actively immunized guinea pigs from a lethal challenge with a virulent strain of Bacillus anthracis. Lethal challenge tests entail the use of specialized containment facilities for the safe and secure handling of the challenge strain. This potential difficulty, plus humane considerations, have prompted us to investigate non-lethal, alternative immunogenicity assays that could be considered as potency tests not only for the current vaccine, but also for vaccines under development. Immunogenicity tests will require suitable measurement of an antibody response to relevant antigens, by methods such as enzyme linked immunosorbent assay (ELISA) or a toxin neutralization assay. Any assay chosen for this purpose should be adequately validated and reproducible by other laboratories. Validation of an analytical procedure requires the demonstration that the assay is suitable for its intended purpose. The objective of this work was to study the performance of an anti-PA-ELISA designed to assess the antibody response to anthrax vaccines in mice. Validation studies were performed according to the guidelines of the International Conference of Harmonization (ICH), and we have established the working range of the assay (37-1159 EU/mL) on the bases of the following parameters: linearity (20-1159 EU/mL; r2=0.99; p-value=0.21), accuracy (91-118% recovery), precision (< or =20%CV, repeatability; < or =9 and < or =21%CV, intermediate precision per day and per analyst, respectively), detection limit (5 EU/mL), and quantification limit (37 EU/mL). We believe that assay specificity and the above characteristics are adequate to allow this ELISA to be considered for use in a mouse immunogenicity (potency) test of anthrax vaccines, and for the standardization of reagents. PMID:15536047

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

    PubMed Central

    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.

    2009-01-01

    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 150 ?g and therefore was chosen as the target dose for all subsequent experiments. Rabbits received a single dose of either 150 ?g rPA, 150 ?g rPA + 150 ?g of a conjugated 10-mer peptide representing the B. anthracis capsule (conj), or 150 ?g 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

  15. Is new always better than old?: The development of human vaccines for anthrax.

    PubMed

    Baillie, Leslie W

    2009-12-01

    Anthrax is caused by a Gram-positive aerobic spore-forming bacillus called Bacillus anthracis. Although primarily a disease of animals, it can also infect man, sometimes with fatal consequences. As a result of concerns over the illicit use of this organism, considerable effort is focused on the development of therapies capable of conferring protection against anthrax. while effective concerns over the toxicity of the current vaccines have driven the development of second-generation products. Recombinant Protective Antigen (rPA), the nontoxic cell-binding component of anthrax lethal toxin, is the principal immunogen of the vaccines currently undergoing human clinical trials. While these new vaccines are likely to show reduced side effects they will still require multiple needle based dosing and the inclusion of the adjuvant alum which will make them expensive to administer and stockpile. To address these issues, researchers are seeking to develop vaccine formulations capable of stimulating rapid protection following needle-free injection which are stable at room temperature to facilitate stockpiling and mass vaccination programs. Recent concerns over the potential use of molecular biology to engineer vaccine resistant strains has prompted investigators to identify additional vaccine targets with which to extend the spectrum of protection conferred by rPA. While the injection of research dollars has seen a dramatic expansion of the anthrax vaccine field it is sobering to remember that work to develop the current second generation vaccines began around the time of the first gulf war. Almost two decades and millions of dollars later we still do not have a replacement vaccine and even when we do some argue that the spectrum of protection that it confers will not be as broad as the vaccine it replaces. If we are to respond effectively to emerging biological threats we need to develop processes that generate protective vaccines in a meaningful time frame and yield products in months not decades! PMID:19786839

  16. Pathology of inhalational anthrax animal models.

    PubMed

    Twenhafel, N A

    2010-09-01

    Anthrax is a lethal disease caused by the bacterium Bacillus anthracis. There are three principal forms of the disease in humans-cutaneous, gastrointestinal, and inhalational-depending on the route of exposure. Of these, inhalational anthrax is the most dangerous; it is rapidly fatal; and it has been used as a deadly biological warfare agent in the last decade. Suitable animal models of inhalational anthrax have been utilized to study pathogenesis of disease, investigate bacterial characteristics such as virulence, and test effectiveness of vaccines and therapeutics. To date, mice, guinea pigs, rabbits, and nonhuman primates are the principal animal species used to study inhalational anthrax. Mice are valuable in studying early pathogenesis and bacterial characteristics. Few pathologic changes occur in the mouse models but may include marked bacteremia and lymphocyte destruction in the spleen and mediastinal lymph nodes. Rabbits and guinea pigs rapidly develop fulminate systemic disease, and pathologic findings often include necrotizing lymphadenitis; splenitis; pneumonia; vasculitis; and hemorrhage, congestion, and edema in multiple tissues. Nonhuman primates consistently develop the full range of classic lesions of human inhalational anthrax, including meningitis; lymphadenitis; splenitis; mediastinitis; pneumonia; vasculitis; and hemorrhage, congestion, and edema in multiple tissues. This review focuses on basic characteristics of the bacterium and its products, key aspects of pathogenesis, and the pathologic changes commonly observed in each animal model species. PMID:20656900

  17. A femtomol range FRET biosensor reports exceedingly low levels of cell surface furin: implications for the processing of anthrax protective antigen.

    PubMed

    Gawlik, Katarzyna; Remacle, Albert G; Shiryaev, Sergey A; Golubkov, Vladislav S; Ouyang, Mingxing; Wang, Yingxiao; Strongin, Alex Y

    2010-01-01

    Furin, a specialized endoproteinase, transforms proproteins into biologically active proteins. Furin function is important for normal cells and also in multiple pathologies including malignancy and anthrax. Furin is believed to cycle between the Golgi compartment and the cell surface. Processing of anthrax protective antigen-83 (PA83) by the cells is considered thus far as evidence for the presence of substantial levels of cell-surface furin. To monitor furin, we designed a cleavage-activated FRET biosensor in which the Enhanced Cyan and Yellow Fluorescent Proteins were linked by the peptide sequence SNSRKKR / STSAGP derived from anthrax PA83. Both because of the sensitivity and selectivity of the anthrax sequence to furin proteolysis and the FRET-based detection, the biosensor recorded the femtomolar levels of furin in the in vitro reactions and cell-based assays. Using the biosensor that was cell-impermeable because of its size and also by other relevant methods, we determined that exceedingly low levels, if any, of cell-surface furin are present in the intact cells and in the cells with the enforced furin overexpression. This observation was in a sharp contrast with the existing concepts about the furin presentation on cell surfaces and anthrax disease mechanism. We next demonstrated using cell-based tests that PA83, in fact, was processed by furin in the extracellular milieu and that only then the resulting PA63 bound the anthrax toxin cell-surface receptors. We also determined that the biosensor, but not the conventional peptide substrates, allowed continuous monitoring of furin activity in cancer cell extracts. Our results suggest that there are no physiologically-relevant levels of cell-surface furin and, accordingly, that the mechanisms of anthrax should be re-investigated. In addition, the availability of the biosensor is a foundation for non-invasive monitoring of furin activity in cancer cells. Conceptually, the biosensor we developed may serve as a prototype for other proteinase-activated biosensors. PMID:20585585

  18. A Femtomol Range FRET Biosensor Reports Exceedingly Low Levels of Cell Surface Furin: Implications for the Processing of Anthrax Protective Antigen

    PubMed Central

    Gawlik, Katarzyna; Remacle, Albert G.; Shiryaev, Sergey A.; Golubkov, Vladislav S.; Ouyang, Mingxing; Wang, Yingxiao; Strongin, Alex Y.

    2010-01-01

    Furin, a specialized endoproteinase, transforms proproteins into biologically active proteins. Furin function is important for normal cells and also in multiple pathologies including malignancy and anthrax. Furin is believed to cycle between the Golgi compartment and the cell surface. Processing of anthrax protective antigen-83 (PA83) by the cells is considered thus far as evidence for the presence of substantial levels of cell-surface furin. To monitor furin, we designed a cleavage-activated FRET biosensor in which the Enhanced Cyan and Yellow Fluorescent Proteins were linked by the peptide sequence SNSRKKR?STSAGP derived from anthrax PA83. Both because of the sensitivity and selectivity of the anthrax sequence to furin proteolysis and the FRET-based detection, the biosensor recorded the femtomolar levels of furin in the in vitro reactions and cell-based assays. Using the biosensor that was cell-impermeable because of its size and also by other relevant methods, we determined that exceedingly low levels, if any, of cell-surface furin are present in the intact cells and in the cells with the enforced furin overexpression. This observation was in a sharp contrast with the existing concepts about the furin presentation on cell surfaces and anthrax disease mechanism. We next demonstrated using cell-based tests that PA83, in fact, was processed by furin in the extracellular milieu and that only then the resulting PA63 bound the anthrax toxin cell-surface receptors. We also determined that the biosensor, but not the conventional peptide substrates, allowed continuous monitoring of furin activity in cancer cell extracts. Our results suggest that there are no physiologically-relevant levels of cell-surface furin and, accordingly, that the mechanisms of anthrax should be re-investigated. In addition, the availability of the biosensor is a foundation for non-invasive monitoring of furin activity in cancer cells. Conceptually, the biosensor we developed may serve as a prototype for other proteinase-activated biosensors. PMID:20585585

  19. Efficacy of ETI-204 monoclonal antibody as an adjunct therapy in a New Zealand white rabbit partial survival model for inhalational anthrax.

    PubMed

    Biron, Bethany; Beck, Katie; Dyer, David; Mattix, Marc; Twenhafel, Nancy; Nalca, Aysegul

    2015-04-01

    Inhalational anthrax is characterized by extensive bacteremia and toxemia as well as nonspecific to mild flu-like symptoms, until the onset of hypotension, shock, and mortality. Without treatment, the mortality rate approaches 100%. Antibiotic treatment is not always effective, and alternative treatments are needed, such as monotherapy for antibiotic-resistant inhalational anthrax or as an adjunct therapy in combination with antibiotics. The Bacillus anthracis antitoxin monoclonal antibody (MAb) ETI-204 is a high-affinity chimeric deimmunized antibody which targets the anthrax toxin protective antigen (PA). In this study, a partial protection New Zealand White (NZW) rabbit model was used to evaluate the protective efficacy of the adjunct therapy with the MAb. Following detection of PA in the blood, NZW rabbits were administered either an antibiotic (doxycycline) alone or the antibiotic in conjunction with ETI-204. Survival was evaluated to compare the efficacy of the combination adjunct therapy with that of an antibiotic alone in treating inhalational anthrax. Overall, the results from this study indicate that a subtherapeutic regimen consisting of an antibiotic in combination with an anti-PA MAb results in increased survival compared to the antibiotic alone and would provide an effective therapeutic strategy against symptomatic anthrax in nonvaccinated individuals. PMID:25645849

  20. Immunogenicity of Recombinant Protective Antigen and Efficacy against Aerosol Challenge with Anthrax

    PubMed Central

    Williamson, E. D.; Hodgson, I.; Walker, N. J.; Topping, A. W.; Duchars, M. G.; Mott, J. M.; Estep, J.; LeButt, C.; Flick-Smith, H. C.; Jones, H. E.; Li, H.; Quinn, C. P.

    2005-01-01

    Immunization with a recombinant form of the protective antigen (rPA) from Bacillus anthracis has been carried out with rhesus macaques. Rhesus macaques immunized with 25 ?g or more of B. subtilis-expressed rPA bound to alhydrogel had a significantly increased immunoglobulin G (IgG) response to rPA compared with macaques receiving the existing licensed vaccine from the United Kingdom (anthrax vaccine precipitated [AVP]), although the isotype profile was unchanged, with bias towards the IgG1 and IgG2 subclasses. Immune macaque sera from all immunized groups contained toxin-neutralizing antibody and recognized all the domains of PA. While the recognition of the N terminus of PA (domains 1 to 3) was predominant in macaques immunized with the existing vaccines (AVP and the U.S. vaccine anthrax vaccine adsorbed), macaques immunized with rPA recognized the N- and C-terminal domains of PA. Antiserum derived from immunized macaques protected macrophages in vitro against the cytotoxic effects of lethal toxin. Passive transfer of IgG purified from immune macaque serum into naive A/J mice conferred protection against challenge with B. anthracis in a dose-related manner. The protection conferred by passive transfer of 500 ?g macaque IgG correlated significantly (P = 0.003; r = 0.4) with the titers of neutralizing antibody in donor macaques. Subsequently, a separate group of rhesus macaques immunized with 50 ?g of Escherichia coli-derived rPA adsorbed to alhydrogel was fully protected against a target dose of 200 50% lethal doses of aerosolized B. anthracis. These data provide some preliminary evidence for the existence of immune correlates of protection against anthrax infection in rhesus macaques immunized with rPA. PMID:16113318

  1. When bioterrorism strikes: diagnosis and management of inhalational anthrax.

    PubMed

    Shafazand, Shirin

    2003-09-01

    In October and November, 2001, reports of patients with inhalational anthrax reacquainted the public with this ancient disease and introduced the harsh reality of a bioterrorist act. Bacillus anthracis, a rod-shaped, spore-forming bacterium, primarily infects herbivores. Humans traditionally have acquired the disease from occupational or agricultural exposure to infected animals and animal products. Recent events saw the intentional release of anthrax spores, using the U.S. postal system as an unlikely and unwilling agent. Cutaneous disease, pulmonary disease, and gastrointestinal anthrax are the known clinical manifestations of anthrax. Inhalational anthrax has the highest mortality and is the main focus of this report. PMID:14505276

  2. Sverdlovsk revisited: Modeling human inhalation anthrax

    PubMed Central

    Wilkening, Dean A.

    2006-01-01

    Several models have been proposed for the dose–response function and the incubation period distribution for human inhalation anthrax. These models give very different predictions for the severity of a hypothetical bioterror attack, when an attack might be detected from clinical cases, the efficacy of medical intervention and the requirements for decontamination. Using data from the 1979 accidental atmospheric release of anthrax in Sverdlovsk, Russia, and limited nonhuman primate data, this paper eliminates two of the contending models and derives parameters for the other two, thereby narrowing the range of models that accurately predict the effects of human inhalation anthrax. Dose–response functions that exhibit a threshold for infectivity are contraindicated by the Sverdlovsk data. Dose-dependent incubation period distributions explain the 10-day median incubation period observed at Sverdlovsk and the 1- to 5-day incubation period observed in nonhuman primate experiments. PMID:16679412

  3. [Selected research problems of anthrax vaccine development].

    PubMed

    Zakowska, Dorota; Kocik, Janusz; Bartoszcze, Micha?

    2009-01-01

    The threat of bioterrorism with B. anthracis against civilian population is one of major concern. After successful bioterroristic attack in 2001 in US renewed research interest has prompted in the development of new and more effective vaccine against anthrax. There are two licensed vaccines against anthrax--AVA-Bio-Thrax US and UK--sterile culture filtrate prepared by alum precipitation. Both vaccines are based on PA antigen. There are several concerns regarding PA based vaccines. They require six sc injections and yearly booster, high rates of local reaction after vaccination is observed, the immunity is not long lasting, vaccination do not protect animals against different strains of B. anthracis. New strategies in the development of anthrax vaccines have been presented (recombinant PA, subunits vaccine, mutants, conjugated). Using proteomic approaches new antigens have been also identified as candidates for future vaccines. More effective and easy to perform methods of vaccination have been reviewed. PMID:20120948

  4. Demand for Prophylaxis after Bioterrorism-Related Anthrax Cases, 2001

    PubMed Central

    Kieke, Burney; Lynfield, Ruth; Davis, Jeffrey P.; Besser, Richard E.

    2005-01-01

    Media reports suggested increased public demand for anthrax prophylaxis after the intentional anthrax cases in 2001, but the magnitude of anthrax-related prescribing in unaffected regions was not assessed. We surveyed a random sample of 400 primary care clinicians in Minnesota and Wisconsin to assess requests for and provision of anthrax-related antimicrobial agents. The survey was returned by 239 (60%) of clinicians, including 210 in outpatient practice. Fifty-eight (28%) of those in outpatient practice received requests for anthrax-related antimicrobial agents, and 9 (4%) dispensed them. Outpatient fluoroquinolone use in both states was also analyzed with regression models to compare predicted and actual use in October and November 2001. Fluoroquinolone use as a proportion of total antimicrobial use was not elevated, and anthrax concerns accounted for an estimated 0.3% of all fluoroquinolone prescriptions. Most physicians in Minnesota and Wisconsin managed anthrax-related requests without dispensing antimicrobial agents. PMID:15705321

  5. [Vaccination strategies for anthrax prevention].

    PubMed

    Beyer, Wolfgang

    2004-01-01

    Apart from live spore vaccines with a certain amount of residual virulence for various animal species, there are two acellular protein vaccines for immunoprophylaxis against anthrax in humans. For ethical reasons there are no experimental data available on the efficacy and duration of the immunity they induce in men. Their efficacy was evaluated in laboratory animals, mainly rabbits and rhesus monkeys. Furthermore, it is well known that these vaccines elicit only partial protection in guinea pigs and almost no protection in mice against a challenge with fully virulent spores of Bacillus (B.) anthracis. Other disadvantages are the high amount of boosters necessary to elicit and to maintain a protective immune response, the variability in the composition of bacterial culture supernatants used for production, and the appearance of clinically relevant side effects. Therefore, there is ongoing work worldwide to improve the existing vaccines by substitution with recombinant antigens and to develop new vaccines on the basis of recombinant bacterial or viral live vectors, DNA-vectors, and by addition of new adjuvants. Special attention is given to supplementing the existing toxoid-vaccines with an anti-bacterial component. PMID:15584433

  6. [Progress on the vaccine for anthrax].

    PubMed

    Zhan, De-wen; Wang, Peng; Wang, Ling-chun; Zhang, Zhao-shan

    2005-02-01

    Bacillus anthracis is the causative organism of the potentially fatal disease anthrax, and the used vaccines have some disadvantages. There are new developments appeared for the Bacillus anthracis in recent years, such as anti-PA antibody kills the spore of Bacillus anthracis, mucosal immunization induces immune responses in both systemic and secretory immune compartments, Poly (gamma-D-PGA) protein induce IgG antibodies to the vegetative bacteria, new pathogens were found by genomic analysis. The DNA vaccine and live vector vaccine will be the next generation vaccines for anthrax. It will have a shorter immunization schedule and will be greater protective efficacy than before. PMID:15847185

  7. Bacillus anthracis’ lethal toxin induces broad transcriptional responses in human peripheral monocytes

    PubMed Central

    2012-01-01

    Background Anthrax lethal toxin (LT), produced by the Gram-positive bacterium Bacillus anthracis, is a highly effective zinc dependent metalloprotease that cleaves the N-terminus of mitogen-activated protein kinase kinases (MAPKK or MEKs) and is known to play a role in impairing the host immune system during an inhalation anthrax infection. Here, we present the transcriptional responses of LT treated human monocytes in order to further elucidate the mechanisms of LT inhibition on the host immune system. Results Western Blot analysis demonstrated cleavage of endogenous MEK1 and MEK3 when human monocytes were treated with 500?ng/mL LT for four hours, proving their susceptibility to anthrax lethal toxin. Furthermore, staining with annexin V and propidium iodide revealed that LT treatment did not induce human peripheral monocyte apoptosis or necrosis. Using Affymetrix Human Genome U133 Plus 2.0 Arrays, we identified over 820 probe sets differentially regulated after LT treatment at the p <0.001 significance level, interrupting the normal transduction of over 60 known pathways. As expected, the MAPKK signaling pathway was most drastically affected by LT, but numerous genes outside the well-recognized pathways were also influenced by LT including the IL-18 signaling pathway, Toll-like receptor pathway and the IFN alpha signaling pathway. Multiple genes involved in actin regulation, signal transduction, transcriptional regulation and cytokine signaling were identified after treatment with anthrax LT. Conclusion We conclude LT directly targets human peripheral monocytes and causes multiple aberrant gene responses that would be expected to be associated with defects in human monocyte’s normal signaling transduction pathways and function. This study provides further insights into the mechanisms associated with the host immune system collapse during an anthrax infection, and suggests that anthrax LT may have additional downstream targets outside the well-known MAPK pathway. PMID:22747600

  8. Pharmacophore selection and redesign of non-nucleotide inhibitors of anthrax edema factor.

    PubMed

    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

    2012-11-01

    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. PMID:23202316

  9. A specific binding protein from Tenebrio molitor for the insecticidal toxin of Bacillus thuringiensis subsp. tenebrionis.

    PubMed

    Belfiore, C J; Vadlamudi, R K; Osman, Y A; Bulla, L A

    1994-04-15

    Biopesticides based on the bacterium Bacillus thuringiensis have attracted wide attention as safe alternatives to chemical insecticides. In this paper, we report, for the first time, the identification of a single binding protein from a coleopteran insect, Tenebrio molitor, that is specific for the cryIII toxin of B. thuringiensis. The protein appeared as a single band of 144 kDa on radioligand and immunoblots of total proteins extracted from brush border membrane vesicles of the midgut of T. molitor. Radiolabelled cryIIIA toxin bound to the protein with a Kd value of 17.5 nM and could be specifically blocked by unlabelled toxin but not by toxins from other subspecies of B. thuringiensis. This study lays the groundwork to clone the cryIIIA toxin binding protein and to determine the molecular mechanism(s) of toxin action. PMID:8166706

  10. Application Track: Emerging Application Title: Optimizing Anthrax Outbreak Detection Methods Using Reinforcement Learning

    E-print Network

    Verbrugge, Clark

    Application Track: Emerging Application Title: Optimizing Anthrax Outbreak Detection Methods Using makes developing effective detection methods essential for public health. In the case of anthrax attack Processes (POMDPs) on outbreak detection mechanism for improving alarm function in anthrax outbreak

  11. Localization of tumors by radiolabelled antibodies

    Microsoft Academic Search

    H. J. Hansen; F. J. Primus

    1975-01-01

    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.

  12. Crystal structure of the anthrax lethal factor

    Microsoft Academic Search

    Andrew D. Pannifer; Thiang Yian Wong; Robert Schwarzenbacher; Martin Renatus; Carlo Petosa; Jadwiga Bienkowska; D. Borden Lacy; R. John Collier; Stephen H. Leppla; Philip Hanna; Robert C. Liddington

    2001-01-01

    Lethal factor (LF) is a protein (relative molecular mass 90,000) that is critical in the pathogenesis of anthrax. It is a highly specific protease that cleaves members of the mitogen-activated protein kinase kinase (MAPKK) family near to their amino termini, leading to the inhibition of one or more signalling pathways. Here we describe the crystal structure of LF and its

  13. WASTE DISPOSAL WORKSHOPS: ANTHRAX CONTAMINATED WASTE

    E-print Network

    left intentionally blank.] #12;Prepared for the U.S. Department of Energy PNNL-SA-69994 under Contract #12;#12;PNNL-SA-69994 Waste Disposal Workshops: Anthrax- Contaminated Waste AM Lesperance JF Upton SL Pacific Northwest National Laboratory Richland, Washington 99352 #12;#12;PNNL-SA-69994 iii Summary In 2006

  14. Inhalation Anthrax: Dose Response and Risk Analysis

    PubMed Central

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

    2008-01-01

    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. PMID:18582166

  15. The Sverdlovsk Anthrax Outbreak of 1979

    Microsoft Academic Search

    Matthew Meselson; Jeanne Guillemin; Martin Hugh-Jones; Alexander Langmuir; Ilona Popova; Alexis Shelokov; Olga Yampolskaya

    1994-01-01

    In April and May 1979, an unusual anthrax epidemic occurred in Sverdlovsk, Union of Soviet Socialist Republics. Soviet officials attributed it to consumption of contaminated meat. U.S. agencies attributed it to inhalation of spores accidentally released at a military microbiology facility in the city. Epidemiological data show that most victims worked or lived in a narrow zone extending from the

  16. The Seminal Literature of Anthrax Research

    Microsoft Academic Search

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

    2007-01-01

    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

  17. Visualizing 60 Years of Anthrax Research

    Microsoft Academic Search

    Steven A. Morris; Kevin W. Boyack

    2005-01-01

    Using a collection of 2472 papers covering 60 years of anthrax research, we demonstrate three techniques for visualizing and mapping knowledge in a scientific specialty. Timelines, maps of clusters of papers by time, reveal the temporal changes in the specialty. Crossmaps, maps of the correspondence of groups of entities of different entity-types, reveal overlapping relations among sub-specialties within the specialty.

  18. Radiolabeled antibodies in gynecologic tumors

    SciTech Connect

    Hardy, J.G.; Perkins, A.C.; Symonds, E.M.; Wastie, M.L.; Pimm, M.V.

    1984-01-01

    A monoclonal antibody has been raised against an osteogenic sarcoma cell line and radiolabeled with iodine-131. The antibody was administered to 12 patients with suspected ovarian tumors, two with recurrent carcinoma of the cervix and one with carcinoma of the body of the uterus. Each patient received an intravenous dose of 70 MBq I-131-labeled antibody and was imaged either 24 or 48 hours later. Image enhancement was achieved by subtraction of background activity using Tc-99m-labeled red blood cells and pertechnetate. In eleven patients with ovarian malignancies antibody uptake was detected at the suspected tumor sites, and agreed with the operative findings in the eight patients who subsequently underwent surgery. The patient in whom the antibody failed to localize was found to have a benign lesion. Uptake of antibody was seen at the tumor sites in the patients with carcinoma of the cervix and body of the uterus. The localization of tumor sites using I-131-labeled antibodies is difficult due to background activity, particularly from radioiodine in the bladder. In only five cases could the abnormal antibody concentration be identified on the iodine images alone. This problem was overcome by the use of background subtraction techniques. Immunoscintigraphy is proving useful for the assessment of tumor recurrence and as an aid to radiotherapy treatment planning.

  19. Antibiotics cure anthrax in animal models.

    PubMed

    Weiss, Shay; Kobiler, David; Levy, Haim; Pass, Avi; Ophir, Yakir; Rothschild, Nili; Tal, Arnon; Schlomovitz, Josef; Altboum, Zeev

    2011-04-01

    Respiratory anthrax, in the absence of early antibiotic treatment, is a fatal disease. This study aimed to test the efficiency of antibiotic therapy in curing infected animals and those sick with anthrax. Postexposure prophylaxis (24 h postinfection [p.i.]) of guinea pigs infected intranasally with Bacillus anthracis Vollum spores with doxycycline, ofloxacin, imipenem, and gentamicin conferred protection. However, upon termination of treatment, the animals died from respiratory anthrax. Combined treatment with antibiotics and active vaccination with a protective antigen-based vaccine leads to full protection even after cessation of treatment. Delaying the initiation of antibiotic administration to over 24 h p.i. resulted in treatment of animals with anthrax exhibiting various degrees of bacteremia and toxemia. Treatment with doxycycline or ciprofloxacin cured sick guinea pigs and rabbits exhibiting bacteremia levels up to 10(5) CFU/ml. Addition of anti-protective antigen (PA) antibodies augmented the efficiency of protection, allowing the cure of guinea pigs and rabbits with 10- to 20-fold-higher bacteremia levels, up to 7 × 10(5) CFU/ml and 2 × 10(6) CFU/ml, respectively. Treatment with ciprofloxacin and a monoclonal anti-PA antibody rescued rabbits with bacteremia levels up to 4 × 10(6) CFU/ml. During antibiotic administration, all surviving animals developed a protective immune response against development of a fatal disease and subcutaneous challenge with Vollum spores. In conclusion, these results demonstrate that antibiotic treatment can prevent the development of fatal disease in respiratory-anthrax-infected animals and can cure animals after disease establishment. A therapeutic time window of 40 h to 48 h from infection to initiation of efficient antibiotic-mediated cure was observed. PMID:21263056

  20. Bacillus anthracis Lethal Toxin Represses MMTV Promoter Activity through Transcription Factors

    Microsoft Academic Search

    Zhigang Kang; Jeanette I. Webster Marketon; Antoinette Johnson; Esther M. Sternberg

    2009-01-01

    We have recently shown that the anthrax lethal toxin (LeTx) selectively represses nuclear hormone receptors. In this study, we found that LeTx repressed the activation of the mouse mammary tumor virus promoter related to overexpression of the transcription factors hepatocyte nuclear factor 3, octamer-binding protein 1, and c-Jun. LeTx transcriptional repression was associated with a decrease in the protein levels

  1. A FRET-Based High Throughput Screening Assay to Identify Inhibitors of Anthrax Protective Antigen Binding to Capillary Morphogenesis Gene 2 Protein

    PubMed Central

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

    2012-01-01

    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

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

    PubMed

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

    2012-01-01

    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

  3. Bioterrorism-related anthrax surveillance, Connecticut, September-December, 2001.

    PubMed

    Williams, Alcia A; Parashar, Umesh D; 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

    2002-10-01

    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. PMID:12396919

  4. Bioterrorism-Related Anthrax Surveillance, Connecticut, September–December, 2001

    PubMed Central

    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

    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. PMID:12396919

  5. Evaluation of the immune response induced by a nasal anthrax vaccine based on the protective antigen protein in anaesthetized and non-anaesthetized mice.

    PubMed

    Sloat, Brian R; Cui, Zhengrong

    2006-04-01

    To better protect against inhalational anthrax infection, a nasal anthrax vaccine based on the protective antigen (PA) protein of Bacillus anthracis could be an attractive alternative to the current Anthrax-Vaccine-Adsorbed (AVA), which was licensed for cutaneous anthrax prevention. Previously, we have demonstrated that an anti-PA immune response comparable with that in mice subcutaneously immunized with PA protein adjuvanted with aluminium hydroxide was induced in both the systemic compartment and the mucosal secretions of the nose and lung of anaesthetized mice when they were nasally immunized with PA protein incorporated into previously reported LPD (Liposome-Protamine-DNA) particles. In this study, we evaluated the anti-PA immune response induced by the nasal PA/LPD particles in non-anaesthetized mice and compared it with that in anaesthetized mice. Our data showed that the anti-PA antibody response and the anthrax lethal toxin-neutralization activity induced by the nasal PA/LPD in non-anaesthetized mice was relatively weaker than that in anaesthetized mice. However, the splenocytes isolated from the nasally immunized mice, anaesthetized and non-anaesthetized, proliferated comparably after in-vitro re-stimulation. By evaluating the uptake of fluorescence-labelled LPD particles by phagocytes in the nasal and broncho-alveolar lavages of mice after the nasal administration, we concluded that the relatively weaker anti-PA immune response in the non-anaesthetized mice might be partially attributed to the reduced retention of the PA/LPD particles in the nasal cavity of the non-anaesthetized mice. Data collected in this study are expected to be useful for future anthrax nasal vaccine studies when mice are used as a model. PMID:16597361

  6. Directed killing of anthrax spores by microwave-induced cavitation

    Microsoft Academic Search

    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

    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

  7. Human anthrax in Turkey from 1990 to 2007.

    PubMed

    Doganay, Mehmet; Metan, Gokhan

    2009-04-01

    Anthrax is an endemic disease in Turkey, among other countries of the world. The potential of Bacillus anthracis as a bioterrorism agent makes anthrax an important global issue. The aim of the present study was to review human anthrax in Turkey during the last decade. Human anthrax cases recorded from 1990 to 2005 were obtained from the website of the Turkish Ministry of Health, and those recorded between 1995 and 2005 were plotted on a map of Turkey. Papers on anthrax published from Turkey between 1990 and 2007 were collected and reviewed. Most cases were recorded from the central and eastern parts of Turkey. Three of the reports appeared in international journals prior to 1990, 10 reports appeared in the 1990s, and 24 reports appeared after the anthrax events of 2001 in the United States of America. These reports included 926 cases, 426 of which could be reviewed: 413 (96.9%) cases of cutaneous anthrax, 8 (1.9%) cases of gastrointestinal anthrax, and 5 (1.2%) cases of anthrax meningitis. Of all the affected patients, 95.2% had contact with contaminated materials. All human origin isolates were sensitive to penicillin and did not produce beta-lactamase. Most of the patients (88.7%) had received penicillin G. Total mortality was 2.8%. Anthrax is an endemic disease in Turkey, and acquisition of infection is generally through contact with ill or dying animals or animal products. Sheep and cattle are generally involved. Most clinical disease in humans is cutaneous anthrax, although other clinical forms are seen and have a greater mortality. Penicillin remains the drug of choice in treating the disease. Controlling anthrax in humans depends on controlling the infection in animals. PMID:18945187

  8. Anthrax: a continuing concern in the era of bioterrorism

    PubMed Central

    2005-01-01

    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. PMID:16200179

  9. Human anthrax as a re-emerging disease.

    PubMed

    Doganay, Mehmet; Demiraslan, Hayati

    2015-01-01

    Anthrax is primarily a disease of herbivores and the etiological agent is B. anthracis which is a gram-positive, aerobic, spore-forming, and rod shaped bacterium. Bacillus anthracis spores are highly resistant to heat, pressure, ultraviolet and ionizing radiation, chemical agents and disinfectants. For these reasons, B. anthracis spores are an attractive choice as biological agents for the use of bioweapon and/or bioterrorism. Soil is the main reservoir for the infectious agent. The disease most commonly affects wild and domestic mammals. Human are secondarily infected by contact with infected animals and contaminated animal products or directly expose to B. anthracis spores. Anthrax occurs worldwide. This infection is still endemic or hyperendemic in both animals and humans in some part of areas of the world; particularly in Middle East, West Africa, Central Asia, some part of India, South America. However, some countries are claiming free of anthrax, and anthrax has become a re-emerging disease in western countries with the intentional outbreak. Currently, anthrax is classified according to its setting as (1) naturally occurring anthrax, (2) bioterrorism-related anthrax. Vast majority of human anthrax are occurring as naturally occurring anthrax in the world. It is also a threaten disease for western countries. The aim of this paper is to review the relevant patents, short historical perspective, microbiological and epidemiological features, clinical presentations and treatment. PMID:25851429

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

    PubMed Central

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

    2012-01-01

    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. PMID:21421849

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

    PubMed Central

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

    2013-01-01

    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. PMID:23204457

  12. Anthrax Vaccine Antigen-Adjuvant Formulations Completely Protect New Zealand White Rabbits against Challenge with Bacillus anthracis Ames Strain Spores

    PubMed Central

    Peachman, Kristina K.; Li, Qin; Matyas, Gary R.; Shivachandra, Sathish B.; Lovchik, Julie; Lyons, Rick C.; Alving, Carl R.; Rao, Venigalla B.

    2012-01-01

    In an effort to develop an improved anthrax vaccine that shows high potency, five different anthrax protective antigen (PA)-adjuvant vaccine formulations that were previously found to be efficacious in a nonhuman primate model were evaluated for their efficacy in a rabbit pulmonary challenge model using Bacillus anthracis Ames strain spores. The vaccine formulations include PA adsorbed to Alhydrogel, PA encapsulated in liposomes containing monophosphoryl lipid A, stable liposomal PA oil-in-water emulsion, PA displayed on bacteriophage T4 by the intramuscular route, and PA mixed with Escherichia coli heat-labile enterotoxin administered by the needle-free transcutaneous route. Three of the vaccine formulations administered by the intramuscular or the transcutaneous route as a three-dose regimen induced 100% protection in the rabbit model. One of the formulations, liposomal PA, also induced significantly higher lethal toxin neutralizing antibodies than PA-Alhydrogel. Even 5 months after the second immunization of a two-dose regimen, rabbits vaccinated with liposomal PA were 100% protected from lethal challenge with Ames strain spores. In summary, the needle-free skin delivery and liposomal formulation that were found to be effective in two different animal model systems appear to be promising candidates for next-generation anthrax vaccine development. PMID:22089245

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

    PubMed Central

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

    2013-01-01

    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. PMID:23479355

  14. Surface Plasmon Resonance Biosensor for Detection of Bacillus anthracis, the Causative Agent of Anthrax from Soil Samples Targeting Protective Antigen.

    PubMed

    Ghosh, N; Gupta, G; Boopathi, M; Pal, V; Singh, A K; Gopalan, N; Goel, A K

    2013-03-01

    Bacillus anthracis, the causative agent of anthrax is one of the most important biological warfare agents. In this study, surface plasmon resonance (SPR) technology was used for indirect detection of B. anthracis by detecting protective antigen (PA), a common toxin produced by all live B. anthracis bacteria. For development of biosensor, a monoclonal antibody raised against B. anthracis PA was immobilized on carboxymethyldextran modified gold chip and its interaction with PA was characterized in situ by SPR and electrochemical impedance spectroscopy. By using kinetic evaluation software, KD (equilibrium constant) and Bmax (maximum binding capacity of analyte) were found to be 20 fM and 18.74, respectively. The change in Gibb's free energy (?G = -78.04 kJ/mol) confirmed the spontaneous interaction between antigen and antibody. The assay could detect 12 fM purified PA. When anthrax spores spiked soil samples were enriched, PA produced in the sample containing even a single spore of B. anthracis could be detected by SPR. PA being produced only by the vegetative cells of B. anthracis, confirms indirectly the presence of B. anthracis in the samples. The proposed method can be a very useful tool for screening and confirmation of anthrax suspected environmental samples during a bio-warfare like situation. PMID:24426078

  15. Challenges in disposing of anthrax waste.

    PubMed

    Lesperance, Ann M; Stein, Steve; Upton, Jaki F; Toomey, Chris

    2011-09-01

    Disasters often create large amounts of waste that must be managed as part of both immediate response and long-term recovery. While many federal, state, and local agencies have debris management plans, these plans often do not address chemical, biological, and radiological contamination. The Interagency Biological Restoration Demonstration's (IBRD) purpose was to holistically assess all aspects of an anthrax incident and assist in the development of a plan for long-term recovery. In the case of wide-area anthrax contamination and the follow-on response and recovery activities, a significant amount of material would require decontamination and disposal. Accordingly, IBRD facilitated the development of debris management plans to address contaminated waste through a series of interviews and workshops with local, state, and federal representatives. The outcome of these discussions was the identification of 3 primary topical areas that must be addressed: planning, unresolved research questions, and resolving regulatory issues. PMID:21882972

  16. New insights into gastrointestinal anthrax infection.

    PubMed

    Owen, Jennifer L; Yang, Tao; Mohamadzadeh, Mansour

    2015-03-01

    Bacterial infections are the primary cause of gastrointestinal (GI) disorders in both developing and developed countries, and are particularly dangerous for infants and children. Bacillus anthracis is the 'archetype zoonotic' pathogen; no other infectious disease affects such a broad range of species, including humans. Importantly, there are more case reports of GI anthrax infection in children than inhalational disease. Early diagnosis is difficult and widespread systemic disease develops rapidly. This review highlights new findings concerning the roles of the gut epithelia, commensal microbiota, and innate lymphoid cells (ILCs) in initiation of disease and systemic dissemination in animal models of GI anthrax, the understanding of which is crucial to designing alternative therapies that target the establishment of infection. PMID:25577136

  17. Clinical microbiologists facing an anthrax alert.

    PubMed

    Jaton, K; Greub, G

    2014-06-01

    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

  18. Intramuscular Delivery of Adenovirus Serotype 5 Vector Expressing Humanized Protective Antigen Induces Rapid Protection against Anthrax That May Bypass Intranasally Originated Preexisting Adenovirus Immunity

    PubMed Central

    Wu, Shipo; Zhang, Zhe; Yu, Rui; Zhang, Jun; Liu, Ying; Song, Xiaohong; Yi, Shaoqiong; Liu, Ju; Chen, Jianqin; Yin, Ying; Xu, Junjie

    2014-01-01

    Developing an effective anthrax vaccine that can induce a rapid and sustained immune response is a priority for the prevention of bioterrorism-associated anthrax infection. Here, we developed a recombinant replication-deficient adenovirus serotype 5-based vaccine expressing the humanized protective antigen (Ad5-PAopt). A single intramuscular injection of Ad5-PAopt resulted in rapid and robust humoral and cellular immune responses in Fisher 344 rats. Animals intramuscularly inoculated with a single dose of 108 infectious units of Ad5-PAopt achieved 100% protection from challenge with 10 times the 50% lethal dose (LD50) of anthrax lethal toxin 7 days after vaccination. Although preexisting intranasally induced immunity to Ad5 slightly weakened the humoral and cellular immune responses to Ad5-PAopt via intramuscular inoculation, 100% protection was achieved 15 days after vaccination in Fisher 344 rats. The protective efficacy conferred by intramuscular vaccination in the presence of preexisting intranasally induced immunity was significantly better than that of intranasal delivery of Ad5-PAopt and intramuscular injection with recombinant PA and aluminum adjuvant without preexisting immunity. As natural Ad5 infection often occurs via the mucosal route, the work here largely illuminates that intramuscular inoculation with Ad5-PAopt can overcome the negative effects of immunity induced by prior adenovirus infection and represents an efficient approach for protecting against emerging anthrax. PMID:24307239

  19. Unusual cause of fatal anthrax meningitis.

    PubMed

    Parlak, Emine; Parlak, Mehmet; Atli, Seval Bilgiç

    2015-03-01

    We report the case of fatal anthrax meningoencephalitis in the province of Mu? located in eastern Anatolia, Turkey. The organism isolated from cerebrospinal fluid was identified as Bacillus anthracis. The patient was treated with crystallized penicillin G (24 MU/day IV) and ciprofloxacin (2 × 400/day IV), but died 5 days after hospitalization. Although it is a rare case, we consider that the patients who have skin, respiratory and neurological systems might also have hemorrhagic meningitis. PMID:24678752

  20. Bacillus anthracis and the Pathogenesis of Anthrax

    Microsoft Academic Search

    Dominique M. Missiakas; Olaf Schneewind

    \\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

  1. Emergency response to an anthrax attack

    Microsoft Academic Search

    Lawrence M. Wein; David L. Craft; Edward H. Kaplan

    2003-01-01

    We developed a mathematical model to compare various emergency responses in the event of an airborne anthrax attack. The system consists of an atmospheric dispersion model, an age-dependent dose-response model, a disease progression model, and a set of spatially distributed two-stage queueing systems consisting of antibiotic distribution and hospital care. Our results underscore the need for the extremely aggressive and

  2. The anthrax attacks 10 years later.

    PubMed

    Bush, Larry M; Perez, Maria T

    2012-01-01

    Ten years ago, just weeks after the September 11 attacks, the United States experienced a deliberate act of bioterrorism. Through use of the postal service, anthrax spores were widely disseminated, including to homes, the Senate, and major newsrooms, resulting in morbidity and mortality and effectively disrupting our way of life and revealing our vulnerability. Even though such attacks had been the subject of much writing and had been planned for, detection of and the appropriate response to an attack with an agent from the so-called "Category 'A' List" had only been considered in theoretical terms. What transpired during the following difficult weeks, including how public health and federal government agencies performed, has been both praised and criticized. An intertwined epidemiologic and criminal investigation of such magnitude was unprecedented in U.S. history. To address the question of whether we as a nation are now better prepared for future threats involving biologic agents, it is important to learn from the lessons of the 2001 anthrax attacks, including the critical role of clinicians in surveillance. As physicians involved in diagnosing anthrax in the index case and alerting authorities, we offer our perspective on these events a decade after their occurrence. PMID:21969275

  3. Inhibition of anthrax lethal factor by curcumin and chemically modified curcumin derivatives

    PubMed Central

    Zhang, Yu; Golub, Lorne M.; Johnson, Francis; Simon, Sanford R.

    2014-01-01

    Curcuma longa Curcumin (diferuloylmethane), the active ingredient in the eastern spice turmeric (Curcuma longa), has been shown to inhibit the activities of numerous enzymes and signaling molecules involved in cancer, bacterial and viral infections and inflammatory diseases. We have investigated the inhibitory activities of curcumin and chemically modified curcumin (CMC) derivatives toward lethal factor (LF), the proteolytic component of anthrax toxin produced by the bacterium Bacillus anthracis. Curcumin (Compound 1) appears to inhibit the catalytic activity of LF through a mixture of inhibitory mechanisms, without significant compromise to the binding of oligopeptide substrates, and one CMC derivative in particular, Compound 3 (4-phenylaminocarbonylbis-demethoxycurcumin), is capable of inhibiting LF with potency comparable with the parent compound, while also showing improved solubility and stability. The quantitative reduction in catalytic activity achieved by the different CMC derivatives appears to be a function of the proportion of the multiple mechanisms through which they inhibit the enzyme. PMID:24102525

  4. Inhibition of anthrax lethal factor by curcumin and chemically modified curcumin derivatives.

    PubMed

    Antonelli, Anthony C; Zhang, Yu; Golub, Lorne M; Johnson, Francis; Simon, Sanford R

    2014-10-01

    Curcumin (diferuloylmethane), the active ingredient in the eastern spice turmeric (Curcuma longa), has been shown to inhibit the activities of numerous enzymes and signaling molecules involved in cancer, bacterial and viral infections and inflammatory diseases. We have investigated the inhibitory activities of curcumin and chemically modified curcumin (CMC) derivatives toward lethal factor (LF), the proteolytic component of anthrax toxin produced by the bacterium Bacillus anthracis. Curcumin (Compound 1) appears to inhibit the catalytic activity of LF through a mixture of inhibitory mechanisms, without significant compromise to the binding of oligopeptide substrates, and one CMC derivative in particular, Compound 3 (4-phenylaminocarbonylbis-demethoxycurcumin), is capable of inhibiting LF with potency comparable with the parent compound, while also showing improved solubility and stability. The quantitative reduction in catalytic activity achieved by the different CMC derivatives appears to be a function of the proportion of the multiple mechanisms through which they inhibit the enzyme. PMID:24102525

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

    PubMed Central

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

    2013-01-01

    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. PMID:24015319

  6. MONITORING METHOD OF COW ANTHRAX BASED ON GIS AND SPATIAL STATISTICAL

    E-print Network

    Boyer, Edmond

    MONITORING METHOD OF COW ANTHRAX BASED ON GIS AND SPATIAL STATISTICAL ANALYSIS Lin Li 1 , Yong Yang of the animal disease. In this paper, we analyzed the cow anthrax spatial distribution characteristics of the cow anthrax in this district in combination of spatial statistical analysis and GIS. The Cow anthrax

  7. Catastrophic Incident Recovery: Long-Term Recovery from an Anthrax Event Symposium

    E-print Network

    Bethesda, Maryland, reviewed his medical supervision during the 2001 anthrax event; and Dr. Carol NorthAnthrax Symposium Catastrophic Incident Recovery: Long-Term Recovery from an Anthrax Event. The Catastrophic Incident Recovery: Long-Term Recovery from an Anthrax Event Symposium was held on March 19, 2008

  8. Integrated MOSFET-Embedded-Cantilever-Based Biosensor Characteristic for Detection of Anthrax Simulant

    Microsoft Academic Search

    Salwa Mostafa; Ida Lee; Syed K. Islam; Sazia A. Eliza; Gajendra Shekhawat; Vinayak P. Dravid; Fahmida S. Tulip

    2011-01-01

    In this work, MOSFET-embedded cantilevers are configured as microbial sensors for detection of anthrax simu- lants, Bacillus thuringiensis. Anthrax simulants attached to the chemically treated gold-coated cantilever cause changes in the MOSFET drain current due to the bending of the cantilever which indicates the detection of anthrax simulant. Electrical properties of the anthrax simulant are also responsible for the change

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

    PubMed Central

    Clement, Kristin H.; Rudge, Thomas L.; Mayfield, Heather J.; Carlton, Lena A.; Hester, Arelis; Niemuth, Nancy A.; Sabourin, Carol L.; Brys, April M.; Quinn, Conrad P.

    2010-01-01

    Anthrax toxin (ATx) is composed of the binary exotoxins lethal toxin (LTx) and edema toxin (ETx). They have separate effector proteins (edema factor and lethal factor) but have the same binding protein, protective antigen (PA). PA is the primary immunogen in the current licensed vaccine anthrax vaccine adsorbed (AVA [BioThrax]). AVA confers protective immunity by stimulating production of ATx-neutralizing antibodies, which could block the intoxication process at several steps (binding of PA to the target cell surface, furin cleavage, toxin complex formation, and binding/translocation of ATx into the cell). To evaluate ATx neutralization by anti-AVA antibodies, we developed two low-temperature LTx neutralization activity (TNA) assays that distinguish antibody blocking before and after binding of PA to target cells (noncomplexed [NC] and receptor-bound [RB] TNA assays). These assays were used to investigate anti-PA antibody responses in AVA-vaccinated rhesus macaques (Macaca mulatta) that survived an aerosol challenge with Bacillus anthracis Ames spores. Results showed that macaque anti-AVA sera neutralized LTx in vitro, even when PA was prebound to cells. Neutralization titers in surviving versus nonsurviving animals and between prechallenge and postchallenge activities were highly correlated. These data demonstrate that AVA stimulates a myriad of antibodies that recognize multiple neutralizing epitopes and confirm that change, loss, or occlusion of epitopes after PA is processed from PA83 to PA63 at the cell surface does not significantly affect in vitro neutralizing efficacy. Furthermore, these data support the idea that the full-length PA83 monomer is an appropriate immunogen for inclusion in next-generation anthrax vaccines. PMID:20739500

  10. Toxines botuliques : utilisation pratique

    Microsoft Academic Search

    A Durand; G Serment

    2003-01-01

    Botulinum toxins (A and B) are neurotoxins derived from Clostridium botulinum. Clostridium are anaerobic bacteria. C. botulinum produces exotoxins (A to G) with distinct antigenicities. The neurotoxins inhibit the release of the neurotransmitter acetylcholine from the axon terminals of motor neurons. Botulinum toxin is officially used in clinic for the treatment of muscular hyperactivity (strabismus, blepharospam, cervical dystonia). Botulinum toxins

  11. Absence of Mycoplasma Contamination in the Anthrax Vaccine

    PubMed Central

    Hart, Mary Kate; Del Giudice, Richard A.

    2002-01-01

    Mycoplasma contamination of the licensed anthrax vaccine administered to military personnel has been suggested as a possible cause of Persian Gulf illness. Vaccine samples tested by nonmilitary laboratories were negative for viable mycoplasma and mycoplasma DNA and did not support its survival. Mycoplasma contamination of anthrax vaccine should not be considered a possible cause of illness. PMID:11840996

  12. Protective antigen composite nanofibers as a transdermal anthrax vaccine

    Microsoft Academic Search

    Kevin E. Knockenhauer; Katarzyna M. Sawicka; Elizabeth J. Roemer; Sanford R. Simon

    2008-01-01

    Anthrax, a disease caused by the gram positive bacteria Bacillus anthracis, has become an increasing threat to public health in the last several years, due to its use as an agent of biological warfare. The currently utilized human anthrax vaccine, which confers immunity through the host antibody recognition of protective antigen (PA), requires a three dose regimen and annual booster

  13. Identification of anthrax-specific signature sequence from Bacillus anthracis

    Microsoft Academic Search

    Vipin K. Rastogi; Tu-chen Cheng

    2001-01-01

    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

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

    Microsoft Academic Search

    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

    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.

  15. Immunologic Response of Unvaccinated Workers Exposed to Anthrax, Belgium

    PubMed Central

    Govaerts, Marc; Frangoulidis, Dimitrios; Fretin, David; Kissling, Esther; Van Hessche, Mieke; China, Bernard; Poncin, Martine; Pirenne, Yvo; Hanquet, Germaine

    2009-01-01

    To determine immunologic reactivity to Bacillus anthrax antigens, we conducted serologic testing of workers in a factory that performed scouring of wool and goat hair. Of 66 workers, ?10% had circulating antibodies or T lymphocytes that reacted with anthrax protective antigen. Individual immunity varied from undetectable to high. PMID:19861061

  16. Pathology of Inhalation Anthrax in Cynomolgus Monkeys (Macaca fascicularis)

    Microsoft Academic Search

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

    2003-01-01

    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

  17. Reported Anthrax Disease in Costa Rica - Is it Accurate?

    Microsoft Academic Search

    Brian Walls; Mario Tristán

    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

  18. Emergency response to an anthrax attack Lawrence M. Wein*

    E-print Network

    Li, Fei-Fei

    Emergency response to an anthrax attack Lawrence M. Wein* , David L. Craft , and Edward H. Kaplan, Princeton University, Princeton, NJ, and approved January 28, 2003 (received for review November 11, 2002 of an airborne anthrax attack. The system consists of an atmospheric dispersion model, an age- dependent dose

  19. Advances in the development of next-generation anthrax vaccines

    Microsoft Academic Search

    Arthur M. Friedlander; Stephen F. Little

    2009-01-01

    Anthrax, a disease of herbivores, only rarely infects humans. However, the threat of using Bacillus anthracis, the causative agent, to intentionally produce disease has been the impetus for development of next-generation vaccines. Two licensed vaccines have been available for human use for several decades. These are composed of acellular culture supernatants containing the protective antigen (PA) component of the anthrax

  20. A review of cutaneous anthrax and its outcome

    Microsoft Academic Search

    Mehmet Doganay; Gokhan Metan; Emine Alp

    2010-01-01

    Anthrax is still an endemic disease in some countries in the world and has become a re-emerging disease in western countries with recent intentional outbreak. The aim of this study was to review our clinical experience with cutaneous anthrax cases. From the patient's files, transmission of the diseases, clinical findings and severity of infection, treatment and outcome of patients were

  1. Effects of metalloprotease anthrax lethal factor on its peptide-based inhibitor R9LF-1.

    PubMed

    Kong, Qingsheng; Song, Yuezhang; Mu, Minlei; Han, Xiaolin; Si, Chuanping; Li, Feng

    2015-08-01

    The metalloprotease lethal factor (LF) from Bacillus anthracis plays a vital role in anthrax toxin action, and thus becomes a target for anti-anthrax therapy. Following the guidelines based on existing metalloprotease inhibitors, we designed a 'first-generation' LF inhibitor R9LF-1. This inhibitor was shown to be very stable by itself in a wide range of pH and temperature and able to inhibit LF activity in vitro. However, as we reported previously in the presence of LF, this inhibitor was degraded to a small molecular weight species, resulting in a significantly decreased ability to protect MAPKK from cleavage by LF as well as to protect murine macrophages from lethal toxin. In order to elucidate this unusual phenomenon to build solid basis for high-efficiency LF inhibitor development, we performed extensive research to study the effect of LF on its peptide-based inhibitor. Effects of temperature and incubation period of time on generation of the smaller peptide (short version R9LF-1) by LF as well as its catalytic domain were analyzed. We found that LF degraded R9LF-1 with maximum efficiency in the pH range of 7.0-8.5, which correlates well with the range of LF enzymatic activity with its native substrate. The degradation showed a deviation from normal hyperbolic kinetics but a similarity to the kinetics profile of an enzyme-catalyzed reaction with positive cooperativity. The short version R9LF-1 had decreased inhibitory activity toward LF; surprisingly, BIAcore results suggested a better affinity for its binding to LF. In addition, R9LF-1 was not hydrolyzed by other common proteases, such as chymotrypsin and pepsin, suggesting hydrolysis of the bond between amino acid and hydroxamate groups is unique to LF. This study calls for caution when designing peptide-based LF inhibitors and when interpreting effects of these types of inhibitors. PMID:25981534

  2. Anthrax threat: a review of clinical and diagnostic measures.

    PubMed

    Alqurashi, Abdelrahman Mohammad

    2013-04-01

    Anthrax is the plague of the ancient world and its existence is confirmed by the Roman poet Virgil. Also it is a threat in the modern world as it can be used in biological wars and bioterrorism. Anthrax is caused by Bacillus anthracis an unmovable, aerobic, gram-positive rod. It forms spores, which can survive for years in the environment. Three clinical forms result after exposure to anthrax spores: cutaneous, respiratory, and gastro- intestinal. The cutaneous anthrax commonly prevails among humans. The respiratory form occurs most likely due to inhalation of the bacterial spores, whereas the gastrointestinal form happens after spores' ingestion. Prophylactic, early diagnosis and proper treatment will reduce mortalities of anthrax. Thus, the physicians, senior nurses and individuals at risk should be aware of the danger of this disease. PMID:23697023

  3. Anthrax Protective Antigen Delivered by Salmonella enterica Serovar Typhi Ty21a Protects Mice from a Lethal Anthrax Spore Challenge

    Microsoft Academic Search

    Manuel Osorio; Yanping Wu; Sunil Singh; Tod J. Merkel; Siba Bhattacharyya; Milan S. Blake; Dennis J. Kopecko

    2009-01-01

    Bacillus anthracis, the etiological agent of anthrax disease, is a proven weapon of bioterrorism. Currently, the only licensed vaccine against anthrax in the United States is AVA Biothrax, which, although efficacious, suffers from several limitations. This vaccine requires six injectable doses over 18 months to stimulate protective immunity, requires a cold chain for storage, and in many cases has been

  4. The Effect of Anthrax Bioterrorism on Emergency Department Presentation

    PubMed Central

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

    2005-01-01

    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. PMID:20847852

  5. Bioterrorism: toxins as weapons.

    PubMed

    Anderson, Peter D

    2012-04-01

    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

  6. Generation and characterization of radiolabeled diesel exhaust.

    PubMed

    Dutcher, J S; Sun, J D; Lopez, J A; Wolf, I; Wolff, R K; McClellan, R O

    1984-07-01

    To evaluate the potential health risks associated with increased use of diesel engines, information is needed on the biological fate of inhaled diesel exhaust components. Appropriately radiolabeled exhaust produced by burning radiolabeled fuel could be used to gain this information. The purpose of this study was to characterize different radiolabeled diesel exhausts with respect to their potential use in studies of the biological fate of exhaust carbon particles and particle-associated organic compounds (particle extracts). A single-cylinder diesel engine was used to burn diesel fuel containing trace amounts of 14C-labeled hexadecane, dotriacontane, benzene, phenanthrene or benzo(a)pyrene. Greater than 98% of the 14C in all additives was converted to volatile materials upon combustion. The remainder was distributed in varying amounts between the carbon particles and particle extracts. Aromatic additives labeled carbon particles more efficiently than aliphatic additives. Column chromatography of the particle extracts showed that, in most cases, the majority of the radioactivity eluted in fractions identical to the specific fuel additive employed, suggesting that a large amount of the particle-associated organic compounds consisted of uncombusted fuel constituents. Applying an electrical load to the engine-electrical generator increased carbon particle radioactivity, but had variable effects on the amount of radioactivity in the particle extracts. 67Ga-tetramethylheptanedione was also studied as a fuel additive to label carbon particles. 67Ga was incorporated into the exhaust particles and lung deposition of particles in rats was found to be approximately 10%. However, the 67Ga-radiolabel was found to separate from the particles in vivo, making it an unsuitable radiolabel for studying the long-term lung retention of diesel exhaust carbonaceous particles. PMID:6205579

  7. Structure-based redesign of an edema toxin inhibitor

    PubMed Central

    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

    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. PMID:22154558

  8. Cationic PAMAM Dendrimers as Pore-Blocking Binary Toxin Inhibitors

    PubMed Central

    2015-01-01

    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

  9. The seminal literature of anthrax research.

    PubMed

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

    2007-01-01

    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

  10. A case of fatal gastrointestinal anthrax in north eastern iran.

    PubMed

    Hashemi, Seyed Ahmad; Azimian, Amir; Nojumi, Sara; Garivani, Tahereh; Safamanesh, Saghar; Ghafouri, Majid

    2015-01-01

    Background. Bacillus species are aerobic or facultative anaerobic, gram-positive, or gram-variable spore-forming rods. They are ubiquitous in the environmental sources. Bacillus anthracis may usually cause three forms of anthrax: inhalation, gastrointestinal, and cutaneous. The gastrointestinal (GI) anthrax develops after eating contaminated meat. In this paper we report septic intestinal anthrax. Case Presentation. We report an isolation of Bacillus anthracis from blood culture of patient with intestinal anthrax. Bacillus anthracis was isolated from a blood culture of a 34-year-old man who had a history of severe abdominal pain, bloody diarrhea, nausea, vomiting, fever, sweating, and lethargy within 4 to 5 days after eating the meat of domestic goat. He had evidence of severe infection and septic shock and did not respond to treatments and subsequently expired 9 hours after hospitalization. Conclusion. Gastrointestinal anthrax is characterized by rapid onset, fever, and septicemia. Rapid diagnosis and prompt initiation of antibiotic therapy can help in survival. Most of previous cases of septicemic anthrax were related to injection drug users but, in our case, septicemia occurred after gastrointestinal anthrax. PMID:25918652

  11. A Case of Fatal Gastrointestinal Anthrax in North Eastern Iran

    PubMed Central

    Hashemi, Seyed Ahmad; Nojumi, Sara; Garivani, Tahereh; Safamanesh, Saghar; Ghafouri, Majid

    2015-01-01

    Background. Bacillus species are aerobic or facultative anaerobic, gram-positive, or gram-variable spore-forming rods. They are ubiquitous in the environmental sources. Bacillus anthracis may usually cause three forms of anthrax: inhalation, gastrointestinal, and cutaneous. The gastrointestinal (GI) anthrax develops after eating contaminated meat. In this paper we report septic intestinal anthrax. Case Presentation. We report an isolation of Bacillus anthracis from blood culture of patient with intestinal anthrax. Bacillus anthracis was isolated from a blood culture of a 34-year-old man who had a history of severe abdominal pain, bloody diarrhea, nausea, vomiting, fever, sweating, and lethargy within 4 to 5 days after eating the meat of domestic goat. He had evidence of severe infection and septic shock and did not respond to treatments and subsequently expired 9 hours after hospitalization. Conclusion. Gastrointestinal anthrax is characterized by rapid onset, fever, and septicemia. Rapid diagnosis and prompt initiation of antibiotic therapy can help in survival. Most of previous cases of septicemic anthrax were related to injection drug users but, in our case, septicemia occurred after gastrointestinal anthrax. PMID:25918652

  12. Conference report on public health and clinical guidelines for anthrax.

    PubMed

    Stern, Eric Jacob; Uhde, Kristin Broome; Shadomy, Sean Vincent; Messonnier, Nancy

    2008-04-01

    On March 13-14, 2006, a meeting on anthrax, sponsored by the Centers for Disease Control and Prevention (CDC) in collaboration with the Southeastern Center for Emerging Biologic Threats, was held at Emory University in Atlanta, Georgia, USA. The meeting's agenda included discussion of postexposure prophylaxis (PEP), screening and evaluation, and treatment of the various manifestations of human anthrax. The goal was to convene subject matter experts for a review of research developments and clinical experience with anthrax prophylaxis and treatment and to make consensus recommendations for updating guidelines for PEP, treatment, and clinical evaluation of patients with anthrax. A 2001 conference on guidelines for anthrax has previously been summarized in this journal. This article summarizes the meeting's presentations and discussion. Consensus recommendations are summarized in the Table. Updated CDC guidelines for treatment and prophylaxis of anthrax will be published in detail in other CDC publications and are available on CDC's website at http://www.bt.cdc.gov/agent/anthrax/index.asp. PMID:18394267

  13. A review of cutaneous anthrax and its outcome.

    PubMed

    Doganay, Mehmet; Metan, Gokhan; Alp, Emine

    2010-01-01

    Anthrax is still an endemic disease in some countries in the world and has become a re-emerging disease in western countries with recent intentional outbreak. The aim of this study was to review our clinical experience with cutaneous anthrax cases. From the patient's files, transmission of the diseases, clinical findings and severity of infection, treatment and outcome of patients were recorded. Twenty-two cases were diagnosed as cutaneous anthrax in the last 7 years. Of these cases, 10 cases were severe form of cutaneous anthrax, 10 cases were mild form and 2 cases were toxemic shock due to cutaneous anthrax. The incubation period was between 1 and 17 days. The main clinical characteristics of the cases with severe cutaneous anthrax were fever, hemorrhagic bullous lesions surrounded by an extensive erythema and edema, and leukocytosis. Two cases with toxemic shock had low systolic blood pressure, apathy and toxemic appearance, leukocytosis, hypoalbuminemia & hyponatremia. Penicillin G was given in 15 cases, amoxicillin in 4 and other antibiotics in 3 cases for 3-10 days. Skin lesion left deep tissue scar in 4 cases and were grafted. Physicians working in endemic areas and also in western countries should be aware of all clinical forms of anthrax. PMID:20869669

  14. Injectional anthrax - new presentation of an old disease.

    PubMed

    Berger, T; Kassirer, M; Aran, A A

    2014-01-01

    Bacillus anthracis infection (anthrax) has three distinct clinical presentations depending on the route of exposure: cutaneous, gastrointestinal and inhalational anthrax. Each of these can lead to secondary bacteraemia and anthrax meningitis. Since 2009,anthrax has emerged among heroin users in Europe,presenting a novel clinical manifestation, 'injectional anthrax', which has been attributed to contaminated heroin distributed throughout Europe; before 2009 only one case was reported. During 2012 and 2013,new cases of injectional anthrax were diagnosed in Denmark, France, Germany, and the United Kingdom.Here we present a comprehensive review of the literature and information derived from different reporting systems until 31 December 2013. Overall 70 confirmed cases were reported, with 26 fatalities (37% case fatality rate).The latest two confirmed cases occurred in March 2013. Thirteen case reports have been published,describing 18 confirmed cases. Sixteen of these presented as a severe soft tissue infection that differed clinically from cutaneous anthrax, lacked the characteristic epidemiological history of animal contact and ten cases required complimentary surgical debridement. These unfamiliar characteristics have led to delays of three to 12 days in diagnosis, inadequate treatment and a high fatality rate. Clinicians' awareness of this recently described clinical entity is key for early 'and successful management of patients. PMID:25139073

  15. 9 CFR 309.7 - Livestock affected with anthrax; cleaning and disinfection of infected livestock pens and driveways.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...biologicals which do not contain living anthrax organisms, may be slaughtered and...No anthrax vaccine (live organisms) shall be used on the premises...with anthrax vaccines (live organisms) within 6 weeks, and...

  16. 9 CFR 309.7 - Livestock affected with anthrax; cleaning and disinfection of infected livestock pens and driveways.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...biologicals which do not contain living anthrax organisms, may be slaughtered and...No anthrax vaccine (live organisms) shall be used on the premises...with anthrax vaccines (live organisms) within 6 weeks, and...

  17. 9 CFR 309.7 - Livestock affected with anthrax; cleaning and disinfection of infected livestock pens and driveways.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...biologicals which do not contain living anthrax organisms, may be slaughtered and...No anthrax vaccine (live organisms) shall be used on the premises...with anthrax vaccines (live organisms) within 6 weeks, and...

  18. 9 CFR 309.7 - Livestock affected with anthrax; cleaning and disinfection of infected livestock pens and driveways.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...biologicals which do not contain living anthrax organisms, may be slaughtered and...No anthrax vaccine (live organisms) shall be used on the premises...with anthrax vaccines (live organisms) within 6 weeks, and...

  19. Epidemic Anthrax in the Eighteenth Century, the Americas

    PubMed Central

    Morens, David M.

    2002-01-01

    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. PMID:12396933

  20. The danger of lime use in agricultural anthrax disinfection procedures: the potential role of calcium in the preservation of anthrax spores.

    PubMed

    Himsworth, Chelsea G

    2008-12-01

    Previously, lime (calcium oxide) was recommended by the Canadian Food Inspection Agency (CFIA) as an anthrax disinfectant. However, a recent scientific review of the subject has found evidence to suggest that exposure of anthrax spores to calcium may aid in their survival and viability. For this reason, the CFIA no longer recommends the use of lime for agricultural anthrax disinfection. PMID:19252713