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Shanon MR, Al-Marzoqi AH, Hussein HJ. Prototheca spp. co-infections and their virulence factors in human protothecosis in Hillah city, Iraq. GENE REPORTS 2021. [DOI: 10.1016/j.genrep.2020.101009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Swietnicki W, Czarny A, Antkowiak L, Zaczynska E, Kolodziejczak M, Sycz J, Stachowicz L, Alicka M, Marycz K. Identification of a potent inhibitor of type II secretion system from Pseudomonas aeruginosa. Biochem Biophys Res Commun 2019; 513:688-693. [PMID: 30987825 DOI: 10.1016/j.bbrc.2019.04.055] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 04/07/2019] [Indexed: 12/27/2022]
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen infecting human population. The pathogen is becoming a serious health problem due to its ability to evade normal immune response of the host and multiple drug resistance to many antibiotics. The pathogen has 2 major virulence systems of which the type III secretion system (T3SS) is of major concern to humans. A third system, type 2 secretion system (T2SS), is common to bacteria and used to secrete exotoxin A (ExoA) responsible for human cell destruction. To help bypass the drug resistance, a strategy to block the T2SS based on a low similarity between human ATPases and the essential ATPases of the T3SS and T2SS of P. aeruginosa, was used. An in silico-optimized inhibitor of T3SS, made directly from the computer-optimized of previously published compounds and their combinatorial libraries, showed IC50 = 1.3 ± 0.2 μM in the T2SS ExoA secretion blocking test. The compound was non-toxic to human lung epithelial cell line A549 and could block cellular destruction of those cells in a cell infection model at 200 μM for at least 24 h. The compound could be a lead candidate for the development of T2SS virulence blockers of Pseudomonas aeruginosa.
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Affiliation(s)
- Wieslaw Swietnicki
- Department of Immunology of Infectious Diseases, Laboratory of Medical Microbiology, USA.
| | - Anna Czarny
- Department of Immunology of Infectious Diseases, Laboratory of Medical Microbiology, USA
| | - Lukasz Antkowiak
- Faculty of Chemistry, Department of Biochemistry, Technical University of Wroclaw, Ul. C. K. Norwida 4/6, 50-373, Wroclaw, Poland
| | - Ewa Zaczynska
- Department of Experimental Therapy, Laboratory of Immunobiology, Institute of Immunology and Experimental Therapy PAS, 53-114, Wroclaw, Ul. R. Weigla 12, Poland
| | - Monika Kolodziejczak
- Faculty of Chemistry, Department of Biochemistry, Technical University of Wroclaw, Ul. C. K. Norwida 4/6, 50-373, Wroclaw, Poland
| | - Jordan Sycz
- Department of Chemistry, Wroclaw University of Environmental and Life Sciences, Ul. C. K. Norwida 25, 50-375, Wroclaw, Poland
| | - Lukasz Stachowicz
- Department of Pharmacology, Silesian Medical University, Ul. Jednosci 8, 41-200, Sosnowiec, Poland
| | - Michalina Alicka
- Department of Experimental Biology, Wroclaw University of Environmental and Life Sciences, Ul. C. K. Norwida 27B, 50-375, Wroclaw, Poland
| | - Krzysztof Marycz
- Department of Experimental Biology, Wroclaw University of Environmental and Life Sciences, Ul. C. K. Norwida 27B, 50-375, Wroclaw, Poland; Faculty of Veterinary Medicine, Equine Clinic - Equine Surgery, Justus-Liebig-University, 35392, Giessen, Germany
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Little AS, Okkotsu Y, Reinhart AA, Damron FH, Barbier M, Barrett B, Oglesby-Sherrouse AG, Goldberg JB, Cody WL, Schurr MJ, Vasil ML, Schurr MJ. Pseudomonas aeruginosa AlgR Phosphorylation Status Differentially Regulates Pyocyanin and Pyoverdine Production. mBio 2018; 9:e02318-17. [PMID: 29382736 PMCID: PMC5790918 DOI: 10.1128/mbio.02318-17] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 12/18/2017] [Indexed: 12/31/2022] Open
Abstract
Pseudomonas aeruginosa employs numerous, complex regulatory elements to control expression of its many virulence systems. The P. aeruginosa AlgZR two-component regulatory system controls the expression of several crucial virulence phenotypes. We recently determined, through transcriptomic profiling of a PAO1 ΔalgR mutant strain compared to wild-type PAO1, that algZR and hemCD are cotranscribed and show differential iron-dependent gene expression. Previous expression profiling was performed in strains without algR and revealed that AlgR acts as either an activator or repressor, depending on the gene. Thus, examination of P. aeruginosa gene expression from cells locked into different AlgR phosphorylation states reveals greater physiological relevance. Therefore, gene expression from strains carrying algR alleles encoding a phosphomimetic (AlgR D54E) or a phosphoablative (AlgR D54N) form were compared by microarray to PAO1. Transcriptome analyses of these strains revealed 25 differentially expressed genes associated with iron siderophore biosynthesis or heme acquisition or production. The PAO1 algR D54N mutant produced lower levels of pyoverdine but increased expression of the small RNAs prrf1 and prrf2 compared to PAO1. In contrast, the algR D54N mutant produced more pyocyanin than wild-type PAO1. On the other hand, the PAO1 algR D54E mutant produced higher levels of pyoverdine, likely due to increased expression of an iron-regulated gene encoding the sigma factor pvdS, but it had decreased pyocyanin production. AlgR specifically bound to the prrf2 and pvdS promoters in vitro AlgR-dependent pyoverdine production was additionally influenced by carbon source rather than the extracellular iron concentration per se AlgR phosphorylation effects were also examined in a Drosophila melanogaster feeding, murine acute pneumonia, and punch wound infection models. Abrogation of AlgR phosphorylation attenuated P. aeruginosa virulence in these infection models. These results show that the AlgR phosphorylation state can directly, as well as indirectly, modulate the expression of iron acquisition genes that may ultimately impact the ability of P. aeruginosa to establish and maintain an infection.IMPORTANCE Pyoverdine and pyocyanin production are well-known P. aeruginosa virulence factors that obtain extracellular iron from the environment and from host proteins in different manners. Here, we show that the AlgR phosphorylation state inversely controls pyoverdine and pyocyanin production and that this control is carbon source dependent. P. aeruginosa expressing AlgR D54N, mimicking the constitutively unphosphorylated state, produced more pyocyanin than cells expressing wild-type AlgR. In contrast, a strain expressing an AlgR phosphomimetic (AlgR D54E) produced higher levels of pyoverdine. Pyoverdine production was directly controlled through the prrf2 small regulatory RNA and the pyoverdine sigma factor, PvdS. Abrogating pyoverdine or pyocyanin gene expression has been shown to attenuate virulence in a variety of models. Moreover, the inability to phosphorylate AlgR attenuates virulence in three different models, a Drosophila melanogaster feeding model, a murine acute pneumonia model, and a wound infection model. Interestingly, AlgR-dependent pyoverdine production was responsive to carbon source, indicating that this regulation has additional complexities that merit further study.
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Affiliation(s)
- Alexander S. Little
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Yuta Okkotsu
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Alexandria A. Reinhart
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - F. Heath Damron
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
- Department of Microbiology, Immunology, and Cell Biology, West Virginia University, Morgantown, West Virginia, USA
| | - Mariette Barbier
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
- Department of Microbiology, Immunology, and Cell Biology, West Virginia University, Morgantown, West Virginia, USA
| | - Brandon Barrett
- Department of Biology, University of Dallas, Irving, Texas, USA
| | - Amanda G. Oglesby-Sherrouse
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Joanna B. Goldberg
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA
- Center for Cystic Fibrosis and Airways Disease Research, Children’s Healthcare of Atlanta, Atlanta, Georgia, USA
| | - William L. Cody
- Department of Biology, University of Dallas, Irving, Texas, USA
| | - Michael J. Schurr
- Department of Surgery, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Michael L. Vasil
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Michael J. Schurr
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
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Head BM, Rubinstein E, Meyers AFA. Alternative pre-approved and novel therapies for the treatment of anthrax. BMC Infect Dis 2016; 16:621. [PMID: 27809794 PMCID: PMC5094018 DOI: 10.1186/s12879-016-1951-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 10/22/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Bacillus anthracis, the causative agent of anthrax, is a spore forming and toxin producing rod-shaped bacterium that is classified as a category A bioterror agent. This pathogenic microbe can be transmitted to both animals and humans. Clinical presentation depends on the route of entry (direct contact, ingestion, injection or aerosolization) with symptoms ranging from isolated skin infections to more severe manifestations such as cardiac or pulmonary shock, meningitis, and death. To date, anthrax is treatable if antibiotics are administered promptly and continued for 60 days. However, if treatment is delayed or administered improperly, the patient's chances of survival are decreased drastically. In addition, antibiotics are ineffective against the harmful anthrax toxins and spores. Therefore, alternative therapeutics are essential. In this review article, we explore and discuss advances that have been made in anthrax therapy with a primary focus on alternative pre-approved and novel antibiotics as well as anti-toxin therapies. METHODS A literature search was conducted using the University of Manitoba search engine. Using this search engine allowed access to a greater variety of journals/articles that would have otherwise been restricted for general use. In order to be considered for discussion for this review, all articles must have been published later than 2009. RESULTS The alternative pre-approved antibiotics demonstrated high efficacy against B. anthracis both in vitro and in vivo. In addition, the safety profile and clinical pharmacology of these drugs were already known. Compounds that targeted underexploited bacterial processes (DNA replication, RNA synthesis, and cell division) were also very effective in combatting B. anthracis. In addition, these novel compounds prevented bacterial resistance. Targeting B. anthracis virulence, more specifically the anthrax toxins, increased the length of which treatment could be administered. CONCLUSIONS Several novel and pre-existing antibiotics, as well as toxin inhibitors, have shown increasing promise. A combination treatment that targets both bacterial growth and toxin production would be ideal and probably necessary for effectively combatting this armed bacterium.
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Affiliation(s)
- Breanne M. Head
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB R3E 0J9 Canada
| | - Ethan Rubinstein
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB R3E 0J9 Canada
| | - Adrienne F. A. Meyers
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB R3E 0J9 Canada
- National Laboratory for HIV Immunology, JC Wilt Infectious Disease Research Centre, Public Health Agency of Canada, Winnipeg, Canada
- Department of Medical Microbiology, University of Nairobi, Nairobi, Kenya
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Golpasha ID, Mousavi SF, Owlia P, Siadat SD, Irani S. Immunization with 3-oxododecanoyl-L-homoserine lactone-r-PcrV conjugate enhances survival of mice against lethal burn infections caused by Pseudomonas aeruginosa. Bosn J Basic Med Sci 2015; 15:15-24. [PMID: 26042508 DOI: 10.17305/bjbms.2015.292] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 02/04/2015] [Accepted: 02/08/2015] [Indexed: 01/22/2023] Open
Abstract
Quorum Sensing and type III secretion system play an important role in the virulence of Pseudomonas (P.) aeruginosa in burn wound infections. We aimed to explore the feasibility of using 3-oxo-C₁₂-HSL-r-PcrV conjugate as a candidate vaccine against P. aeruginosa caused infections. 3-oxo-C₁₂-HSL-r-PcrV conjugate was prepared and used for immunization of mice (10 μg, subcutaneous, three times, at 2-week intervals). Mice were divided into five groups: I: PcrV; II: 3-oxo-C₁₂-HSL-r-PcrV (10 μg); III: 3-oxo-C₁₂-HSL-r-PcrV (20 μg); IV: 3-oxo-C₁₂-HSL; and V: PBS receiving groups. After each shot of immunization, total and isotype antibody responses against corresponding antigen were measured to determine the immunization efficacy. One month after the last immunization, all groups were burned and challenged subeschar with P. aeruginosa PAO1. Survival rate and bacterial quantity in the skin and internal organs (liver and spleen) were evaluated 25-hr after burn infection. Immunization with 3-oxo-C₁₂-HSL-r-PcrV significantly increased total IgG and specific subclass antibodies (IgG₁, IgG₂a, IgG₂b, and IgM) in the serum of the groups II and III compared to the control group (p<0.001). While all the control mice (PBS injected group) died within 2 days after bacterial challenge, 64% of the group I, 78% of group II, and 86% of group III, survived within 14 days after challenge. Interestingly, bacterial burden in the liver and spleen of 3-oxo-C₁₂-HSL-r-PcrV injected group (III) was significantly lower than the control group (p<0.001). The present study proposed two-component vaccine to inhibit Pseudomonas infections in burned mouse.
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Affiliation(s)
- Isar Dejban Golpasha
- Department of Biology, Science and Research branch, Islamic Azad University, Tehran, Iran.
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Roy V, Ghani K, Caruso M. A dominant-negative approach that prevents diphthamide formation confers resistance to Pseudomonas exotoxin A and diphtheria toxin. PLoS One 2010; 5:e15753. [PMID: 21203470 PMCID: PMC3009735 DOI: 10.1371/journal.pone.0015753] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Accepted: 11/23/2010] [Indexed: 11/25/2022] Open
Abstract
Diphtheria toxin (DT), Pseudomonas aeruginosa Exotoxin A (ETA) and cholix toxin from Vibrio cholerae share the same mechanism of toxicity; these enzymes ADP-rybosylate elongation factor-2 (EF-2) on a modified histidine residue called diphthamide, leading to a block in protein synthesis. Mutant Chinese hamster ovary cells that are defective in the formation of diphthamide have no distinct phenotype except their resistance to DT and ETA. These observations led us to predict that a strategy that prevents the formation of diphthamide to confer DT and ETA resistance is likely to be safe. It is well documented that Dph1 and Dph2 are involved in the first biochemical step of diphthamide formation and that these two proteins interact with each other. We hypothesized that we could block diphthamide formation with a dominant negative mutant of either Dph1 or Dph2. We report in this study the first cellular-targeted strategy that protects against DT and ETA toxicity. We have generated Dph2(C-), a dominant-negative mutant of Dph2, that could block very efficiently the formation of diphthamide. Cells expressing Dph2(C-) were 1000-fold more resistant to DT than parental cells, and a similar protection against Pseudomonas exotoxin A was also obtained. The targeting of a cellular component with this approach should have a reduced risk of generating resistance as it is commonly seen with antibiotic treatments.
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Affiliation(s)
- Vincent Roy
- Le Centre de Recherche en Cancérologie de l'Université Laval, L'Hôtel Dieu de Québec, Centre Hospitalier Universitaire de Québec, Québec, Canada
| | - Karim Ghani
- Le Centre de Recherche en Cancérologie de l'Université Laval, L'Hôtel Dieu de Québec, Centre Hospitalier Universitaire de Québec, Québec, Canada
| | - Manuel Caruso
- Le Centre de Recherche en Cancérologie de l'Université Laval, L'Hôtel Dieu de Québec, Centre Hospitalier Universitaire de Québec, Québec, Canada
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Abstract
OBJECTIVE Although most reviews of Pseudomonas aeruginosa therapeutics focus on antibiotics currently in use or in the pipeline, we review evolving translational strategies aimed at using virulence factor antagonists as adjunctive therapies. DATA SOURCE Current literature regarding P. aeruginosa virulence determinants and approaches that target them, with an emphasis on type III secretion, quorum-sensing, biofilms, and flagella. DATA EXTRACTION AND SYNTHESIS P. aeruginosa remains one of the most important pathogens in nosocomial infections, with high associated morbidity and mortality. Its predilection to develop resistance to antibiotics and expression of multiple virulence factors contributes to the frequent ineffectiveness of current therapies. Among the many P. aeruginosa virulence determinants that impact infections, type III secretion, quorum sensing, biofilm formation, and flagella have been the focus on much recent investigation. Here we review how increased understanding of these important bacterial structures and processes has enabled the development of novel approaches to inhibit each. These promising translational strategies may lead to the development of adjunctive therapies capable of improving outcomes. CONCLUSIONS Adjuvant therapies directed against virulence factors have the potential to improve outcomes in P. aeruginosa infections.
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Manafi A, Kohanteb J, Mehrabani D, Japoni A, Amini M, Naghmachi M, Zaghi AH, Khalili N. Active immunization using exotoxin A confers protection against Pseudomonas aeruginosa infection in a mouse burn model. BMC Microbiol 2009; 9:23. [PMID: 19183501 PMCID: PMC2644702 DOI: 10.1186/1471-2180-9-23] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2007] [Accepted: 02/01/2009] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND Pseudomonas aeruginosa is an important cause of nosocomial infection and may lead to septicemia and death. We evaluated the immunogenicity of semi-purified exotoxin A from the bacterium in a mouse burn model. METHODS The toxoid was prepared from exotoxin A taken from toxigenic strains of P. aeruginosa (PA 103). 50 mice were immunized with the toxoid, burned with hot metal and infected with 1 x 10(8) CFU of toxigenic strains of P. aeruginosa (experimental group); 25 non-immunized mice were also burned and infected (control group). The mortality rate and presence of any exotoxin and P. aeruginosa in the sera, liver and spleen were determined. RESULTS In the experimental group, 2 mice died before the burns were administered and were excluded from the study. The remainder (48 mice) were challenged with a lethal dose of P. aeruginosa and followed for 70 days. 3 of these mice died. Neither P. aeruginosa nor exotoxin A was not detected in the liver, spleen or sera of the surviving mice. The protective efficacy of toxoid vaccination was therefore 93.8%. In the control group, all mice died from bacteremia and septicemia, most (80%) within 6 days, and P. aeruginosa and exotoxin A were isolated from sera, spleen and liver. CONCLUSION Active immunization of mice using a semi-purified exotoxin A derived from P. aeruginosa was 93.8% effective at protecting mice from subsequent P. aeruginosa infections in a mouse burn model.
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Affiliation(s)
- Ali Manafi
- Department of Plastic Surgery, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Jamshid Kohanteb
- Department of Medical Microbiology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Davood Mehrabani
- Gastroenterohepatology Research Center, Nemazee Hospital, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Aziz Japoni
- Professor Alborzi Clinical Microbiology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Masoud Amini
- Department of Surgery, Shiraz University of Medical Sciences, Shiraz, Iran
| | | | - Ahmad Hosseinzadeh Zaghi
- Department of Plastic Surgery, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Nazanin Khalili
- School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran
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Kipnis E, Sawa T, Wiener-Kronish J. Targeting mechanisms of Pseudomonas aeruginosa pathogenesis. Med Mal Infect 2006; 36:78-91. [PMID: 16427231 DOI: 10.1016/j.medmal.2005.10.007] [Citation(s) in RCA: 198] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2005] [Accepted: 10/18/2005] [Indexed: 01/08/2023]
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen responsible for ventilator-acquired pneumonia, acute lower respiratory tract infections in immunocompromised patients and chronic respiratory infections in cystic fibrosis patients. High incidence, infection severity and increasing resistance characterize P. aeruginosa infections, highlighting the need for new therapeutic options. One such option is to target the many pathogenic mechanisms conferred to P. aeruginosa by its large genome encoding many different virulence factors. This article reviews the pathogenic mechanisms and potential therapies targeting these mechanisms in P. aeruginosa respiratory infections.
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Affiliation(s)
- E Kipnis
- Department of Anesthesia and Perioperative Care, University of California San Francisco, 513 Parnassus Avenue, Room s-261, Medical Science Building, Box 0542, San Francisco, CA 94143, USA.
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Hsieh JC, Tham DM, Feng W, Huang F, Embaie S, Liu K, Dean D, Hertle R, Fitzgerald DJ, Mrsny RJ. Intranasal immunization strategy to impede pilin-mediated binding of Pseudomonas aeruginosa to airway epithelial cells. Infect Immun 2005; 73:7705-17. [PMID: 16239575 PMCID: PMC1273878 DOI: 10.1128/iai.73.11.7705-7717.2005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2005] [Revised: 07/13/2005] [Accepted: 08/10/2005] [Indexed: 11/20/2022] Open
Abstract
Prevention of pulmonary Pseudomonas aeruginosa infections represents a critical unmet medical need for cystic fibrosis (CF) patients. We have examined the tenet that a mucosal immunization approach can reduce interactions of a piliated form of this opportunistic pathogen with respiratory epithelial cells. Vaccinations were performed using ntPEpilinPAK, a protein chimera composed of a nontoxic form of P. aeruginosa exotoxin A (ntPE), where the C-terminal loop amino acid sequence of the PAK strain pilin protein was inserted in place of the ntPE Ib domain. Intranasal (i.n.) immunization of BALB/c mice with ntPEpilinPAK generated both serum and saliva immune responses. A series of in vitro studies showed that diluted samples of saliva obtained from immunized mice reduced pilin-dependent P. aeruginosa binding to polarized human tracheal epithelial cells, protected human pulmonary epithelial cells from cytotoxic actions associated with bacterial challenge, and reduced exotoxin A toxicity. Overall, i.n. administration of ntPEpilinPAK induced mucosal and systemic immune responses that may be beneficial for blocking early stage adhesion and/or infection events of epithelial cell-P. aeruginosa interactions at oropharyngeal surfaces.
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Affiliation(s)
- Jennifer C Hsieh
- Trinity BioSystems, Inc., 1455 Adams Dr., Suite 1317, Menlo Park, CA 94025-1438, USA
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Yunus TM, Molina RM, Prevatt AR, Gajewski BJ, Sedwick JD, Antonelli PJ. Hearing loss with semicircular canal fistula in exotoxin A-deficient Pseudomonas otitis media. Otolaryngol Head Neck Surg 2004; 130:430-6. [PMID: 15100639 DOI: 10.1016/j.otohns.2003.12.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
OBJECTIVE The study goal was to compare the severity of hearing loss with semicircular canal injury in the presence of otitis media (OM) due to an exotoxin A-producing strain of Pseudomonas aeruginosa (PA+) and an exotoxin A-deficient daughter strain (PA-). METHODS PA+ or PA- was injected bilaterally into guinea pig ears. Three days later, unilateral lateral semicircular canal transection was performed. Hearing was tested before and after transection. RESULTS PA OM was induced in all injected ears. Significant elevation of click and 12-kHz thresholds (P < 0.0001) were encountered in PA+-infected ears. No significant threshold elevations were encountered in PA--infected ears. CONCLUSION Hearing loss resulting from canal injury in the presence of Pseudomonas OM may be mediated by exotoxin A. SIGNIFICANCE Treatment to neutralize the effects of exotoxin A may minimize the risk of hearing loss with canal fistula in chronic OM.
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Affiliation(s)
- Tariq M Yunus
- Department of Otolaryngology,University of Florida, Gainseville, FL 32610-0264, USA
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Karginov VA, Robinson TM, Riemenschneider J, Golding B, Kennedy M, Shiloach J, Alibek K. Treatment of anthrax infection with combination of ciprofloxacin and antibodies to protective antigen of Bacillus anthracis. ACTA ACUST UNITED AC 2004; 40:71-4. [PMID: 14734189 DOI: 10.1016/s0928-8244(03)00302-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Currently there is no effective treatment for inhalational anthrax beyond administration of antibiotics shortly after exposure. There is need for new, safe and effective treatments to supplement traditional antibiotic therapy. Our study was based on the premise that simultaneous inhibition of lethal toxin action with antibodies and blocking of bacterial growth by antibiotics will be beneficial for the treatment of anthrax. In this study, we tested the effects of a combination treatment using purified rabbit or sheep anti-protective antigen (PA) antibodies and the antibiotic ciprofloxacin in a rodent anthrax model. In mice infected with a dose of Bacillus anthracis Sterne strain corresponding to 10 LD(50), antibiotic treatment with ciprofloxacin alone only cured 50% of infected animals. Administration of anti-PA IgG in combination with ciprofloxacin produced 90-100% survival. These data indicate that a combination of antibiotic/immunoglobulin therapy is more effective than antibiotic treatment alone in a rodent anthrax model.
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Huang YT, Jeng CR, Cheng CH, Chueh LL, Liu JJ, Pang VF. Morphological and immunological evidence of a unique selective production and endoplasmic reticular accumulation of interleukin-1alpha in rat peritoneal macrophages induced by Pseudomonas aeruginosa exotoxin A. Cell Immunol 2003; 221:143-56. [PMID: 12747956 DOI: 10.1016/s0008-8749(03)00076-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The immunotoxicity of Pseudomonas aeruginosa exotoxin A (ETA) on macrophages was evaluated by incubating rat peritoneal macrophages (RPM) with 1-100 ng/ml ETA for 3-60 h. Although the overall changes in cell viability and DNA, RNA, and protein synthesis of the ETA-treated RPM (E-RPM) were reduced in a dose- and time-dependent manner, there was a transient but evident rebound in RNA and/or protein synthesis at 24-36 h post-incubation (HPI) at 1-50 ng/ml ETA. However, a more apparent enhancement appeared in RNA and protein synthesis at 36-48 HPI in 10 and 50 ng/ml E-RPM after normalized on the basis of viable cell. Most 50-100 ng/ml E-RPM underwent necrosis/apoptosis before 24 HPI. By 36 HPI, 41% of 10 ng/ml E-RPM remained viable but were full of cytoplasmic granules due to the accumulation of glycoprotein in segmentally dilated endoplasmic reticulum. Immunological staining of the granules revealed strong IL-1alpha but weak or no signals for IL-1beta, IL-1 receptor antagonist, IL-6, and TNF-alpha. A time-dependent increase in IL-1alpha but no IL-1beta was detected in cell lysate of 10 ng/ml E-RPM; however, neither IL-1alpha nor IL-1beta was detected in culture supernatant. Thus, besides cytopathic and functional effects, ETA could induce a unique selective production and endoplasmic reticular accumulation of IL-1alpha in RPM.
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Affiliation(s)
- Yen-Te Huang
- Graduate Institute of Veterinary Medicine, National Taiwan University, 106, ROC, Taipei, Taiwan
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Barekzi NA, Felts AG, Poelstra KA, Slunt JB, Grainger DW. Locally delivered polyclonal antibodies potentiate intravenous antibiotic efficacy against gram-negative infections. Pharm Res 2002; 19:1801-7. [PMID: 12523657 DOI: 10.1023/a:1021481122011] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE Comparison of the anti-microbial efficacy of locally delivered antibodies in tandem with conventional systemic administration of ceftazidime antibiotic therapy in two lethal gram-negative animal infection models. METHODS Previously published lethal E. coli-induced closed peritonitis and Klebsiella-induced burn wound infections were generated in outbred female CF-1 mice cohorts. Pooled human polyclonal antibodies were injected locally into sites of infection in these mice simultaneously with intravenous infusions of the broad-spectrum antibiotic, ceftazidime. Mouse survival was compared in sham control cohorts vs. both ceftazidime-alone or antibody-alone systemically infused cohorts as well as local antibody-systemic ceftazidime combination therapy cohorts. Microbial burdens in blood and tissue samples (by agar plating), as well as interleukin-6 cytokine levels (using ELISA) correlated with sepsis, were monitored in sacrificed animals as a function of antimicrobial treatment regimen. RESULTS Local delivery of human polyclonal antibodies to infection sites was shown to produce synergistic therapeutic efficacy in combination with systemic antibiotic administration in these lethal wound infection models in mice. Enhanced benefits of the unique combination therapy included host survival, bacterial burden both locally and systemically, and IL-6 levels in host serum. CONCLUSIONS Commercial pooled human antibodies contain a broad spectrum of antimicrobial activity against gram-negative pathogens. Prevention of systemization of infection correlates with host survival in these models. Local control of infection using doses of local, high-titer polyclonal antibodies can enhance traditional approaches to curb systemic spread of infection using intravenous antibiotics. Antibodies provide antimicrobial efficacy independent of known pathogen resistance mechanisms.
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Affiliation(s)
- Nazir A Barekzi
- Anthony G. Gristina Institute for Biomedical Research, 520 Huntmar Park Drive, Herndon, Virginia 20170, USA
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15
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Hertle R, Mrsny R, Fitzgerald DJ. Dual-function vaccine for Pseudomonas aeruginosa: characterization of chimeric exotoxin A-pilin protein. Infect Immun 2001; 69:6962-9. [PMID: 11598071 PMCID: PMC100076 DOI: 10.1128/iai.69.11.6962-6969.2001] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2001] [Accepted: 08/07/2001] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas aeruginosa is the major infectious agent of concern for cystic fibrosis patients. Strategies to prevent colonization by this bacterium and/or neutralize its virulence factors are clearly needed. Here we characterize a dual-function vaccine designed to generate antibodies to reduce bacterial adherence and to neutralize the cytotoxic activity of exotoxin A. To construct the vaccine, key sequences from type IV pilin were inserted into a vector encoding a nontoxic (active-site deletion) version of exotoxin A. The chimeric protein, termed PE64Delta553pil, was expressed in Escherichia coli, refolded to a near-native conformation, and then characterized by various biochemical and immunological assays. PE64Delta553pil bound specifically to asialo-GM1, and, when injected into rabbits, produced antibodies that reduced bacterial adherence and neutralized the cell-killing activity of exotoxin A. Results support further evaluation of this chimeric protein as a vaccine to prevent Pseudomonas colonization in susceptible individuals.
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Affiliation(s)
- R Hertle
- Biotherapy Section, Laboratory of Molecular Biology, CCR, National Cancer Institute, Bethesda, Maryland 20892-4255, USA
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16
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Schümann J, Bluethmann H, Tiegs G. Synergism of Pseudomonas aeruginosa exotoxin A with endotoxin, superantigen, or TNF results in TNFR1- and TNFR2-dependent liver toxicity in mice. Immunol Lett 2000; 74:165-72. [PMID: 10996392 DOI: 10.1016/s0165-2478(00)00240-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Pseudomonas aeruginosa is a potentially dangerous Gram-negative nosocomial pathogen, causing bacteremia in debilitated patients, and a prominent cause of bacterial cholangitis. Opportunistic infections with other nosocomial pathogens, e.g. Staphylococcus aureus, are common. Hence, multi-intoxication with P. aeruginosa exotoxin A (PEA) and other bacterial toxins, including endotoxin (LPS) and the superantigen S. aureus enterotoxin B (SEB), is very likely. Here we show that PEA synergistically interacted with LPS, SEB, or recombinant murine tumor necrosis factor alpha (rmuTNF) in mice, resulting in severe liver injury. Enhanced and prolonged circulation of cytokines, including TNF, which depended on the presence of T cells, was a remarkable feature of synergistic PEA/LPS- or PEA/SEB-induced hepatotoxicity. PEA/LPS-, PEA/SEB- or PEA/rmuTNF-induced liver injury was mediated by both TNF receptors (TNFRs), i.e. TNFR1 and TNFR2. In view of the fact that TNFR1, but not TNFR2, signaling is unequivocally required for host defense, our results suggest that anti-TNFR2 strategies might be beneficial to protect the liver from inflammatory damage caused by synergistic interactions of PEA with other TNF-inducing bacterial toxins.
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Affiliation(s)
- J Schümann
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Erlangen-Nürnberg, Fahrstr. 17, Universitatsstrasse 22, D-91054, Erlangen, Germany.
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17
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Rojas IA, Slunt JB, Grainger DW. Polyurethane coatings release bioactive antibodies to reduce bacterial adhesion. J Control Release 2000; 63:175-89. [PMID: 10640591 DOI: 10.1016/s0168-3659(99)00195-9] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This study describes the formulation of a biomedical grade polyurethane hydrogel coating containing solid dispersed bioactive antibodies cast from an organic solvent onto a model polymer biomaterial substrate. A prepolymer dispersion in anhydrous isopropanol containing a uniformly distributed slurry of 22 microm sieved commercial lyophilized polyclonal pooled human immunoglobulin G (IgG) solids was coated onto polymer substrates by simple immersion. Maximum antibody release was approximately 50 microg/cm(2) from a 15% w/w IgG polymer coating. In vitro antimicrobial studies utilized Escherichia coli to compare performance of bare uncoated tubing, hydrogel-coated tubing with added aqueous phase antibodies, and antibody-dispersed hydrogel-coated tubing. Bacterial adhesion was reduced significantly (p<0.05) in the presence of antibodies with the greatest reduction seen with the antibody releasing coating. The presence of antibody also significantly enhanced the killing of the bacteria in an in vitro opsonophagocytic assay using freshly isolated blood neutrophils over 2 h indicating that antibody bioactivity is maintained. This controlled release polyurethane hydrogel coating imparts infection resistance by exploiting the low adhesive properties of the biomedical grade hydrogel and the intrinsic bioactive role of the antibodies to reduce bacterial adhesion and promote clearance via natural immune mechanisms.
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Affiliation(s)
- I A Rojas
- The Anthony G. Gristina Institute for Biomedical Research, Herndon, VA 20170, USA
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18
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Barekzi NA, Poelstra KA, Felts AG, Rojas IA, Slunt JB, Grainger DW. Efficacy of locally delivered polyclonal immunoglobulin against Pseudomonas aeruginosa peritonitis in a murine model. Antimicrob Agents Chemother 1999; 43:1609-15. [PMID: 10390211 PMCID: PMC89332 DOI: 10.1128/aac.43.7.1609] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/1998] [Accepted: 04/23/1999] [Indexed: 11/20/2022] Open
Abstract
Infectious peritonitis results from bacterial contamination of the abdominal cavity. Conventional antibiotic treatment is complicated both by the emergence of antibiotic-resistant bacteria and by increased patient populations intrinsically at risk for nosocomial infections. To complement antibiotic therapies, the efficacy of direct, locally applied pooled human immunoglobulin G (IgG) was assessed in a murine model (strains CF-1, CD-1, and CFW) of peritonitis caused by intraperitoneal inoculations of 10(6) or 10(7) CFU of Pseudomonas aeruginosa (strains IFO-3455, M-2, and MSRI-7072). Various doses of IgG (0.005 to 10 mg/mouse) administered intraperitoneally simultaneously with local bacterial challenge significantly increased survival in a dose-dependent manner. Local intraperitoneal application of 10 mg of IgG increased animal survival independent of either the P. aeruginosa or the murine strains used. A local dose of 10 mg of IgG administered up to 6 h prophylactically or at the time of bacterial challenge resulted in 100% survival. Therapeutic 10-mg IgG treatment given up to 12 h postinfection also significantly increased survival. Human IgG administered to the mouse peritoneal cavity was rapidly detected systemically in serum. Additionally, administered IgG in peritoneal lavage fluid samples actively opsonized and decreased the bacterial burden via phagocytosis at 2 and 4 h post-bacterial challenge. Tissue microbial quantification studies showed that 1.0 mg of locally applied IgG significantly reduced the bacterial burden in the liver, peritoneal cavity, and blood and correlated with reduced levels of interleukin-6 in serum.
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Affiliation(s)
- N A Barekzi
- Anthony G. Gristina Institute for Biomedical Research (formerly Medical Sciences Research Institute), Inc., Herndon, Virginia 20170, USA
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