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Wu W, Booth JL, Liang Z, Li G, Metcalf JP. Bacillus anthracis spores are internalized in human lung epithelial cells by Rab GTPase-supported macropinocytosis. Microb Pathog 2023; 183:106305. [PMID: 37586464 DOI: 10.1016/j.micpath.2023.106305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 08/10/2023] [Accepted: 08/12/2023] [Indexed: 08/18/2023]
Abstract
Inhalation anthrax, the deadliest form of the disease, requires inhaled B. anthracis spores to escape from the alveolar space and travel to the mediastinal lymph nodes, from where the vegetative form of the pathogen disseminates, resulting in a rapidly fatal outcome. The role of epithelia in alveolar escape is unclear, but previous work suggests these epithelial cells are involved in this process. Using confocal microscopy, we found that B. anthracis spores are internalized more rapidly by A549 type II alveolar epithelial cells compared to hAELVi type I alveolar epithelial cells. Internalization of spores by alveolar epithelial cells requires cytoskeletal rearrangement evidenced by significant inhibition by cytochalasin D, an actin inhibitor. Chemical inhibitors of macropinocytosis significantly downregulated B. anthracis spore internalization in human alveolar cells, while inhibitors of other endocytosis pathways had minimal effects. Additional studies using a macropinosome marker and electron microscopy confirmed the role of macropinocytosis in spore uptake. By colocalization of B. anthracis spores with four endocytic Rab proteins, we demonstrated that Rab31 played a role in B. anthracis spore macropinocytosis. Finally, we confirmed that Rab31 is involved in B. anthracis spore internalization by enhanced spore uptake in Rab31-overexpressing A549 cells. This is the first report that shows B. anthracis spore internalization by macropinocytosis in human epithelial cells. Several Rab GTPases are involved in the process.
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Affiliation(s)
- Wenxin Wu
- Pulmonary, Critical Care & Sleep Medicine, Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - J Leland Booth
- Pulmonary, Critical Care & Sleep Medicine, Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Zhimin Liang
- Department of Biochemistry and Molecular Biology, Peggy and Charles Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Guangpu Li
- Department of Biochemistry and Molecular Biology, Peggy and Charles Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.
| | - Jordan P Metcalf
- Pulmonary, Critical Care & Sleep Medicine, Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA; Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA; Pulmonary Section, Medicine Service, Veterans Affairs Medical Center, Oklahoma City, OK, 73104, USA.
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2
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Godbold GD, Hewitt FC, Kappell AD, Scholz MB, Agar SL, Treangen TJ, Ternus KL, Sandbrink JB, Koblentz GD. Improved understanding of biorisk for research involving microbial modification using annotated sequences of concern. Front Bioeng Biotechnol 2023; 11:1124100. [PMID: 37180048 PMCID: PMC10167326 DOI: 10.3389/fbioe.2023.1124100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 04/11/2023] [Indexed: 05/15/2023] Open
Abstract
Regulation of research on microbes that cause disease in humans has historically been focused on taxonomic lists of 'bad bugs'. However, given our increased knowledge of these pathogens through inexpensive genome sequencing, 5 decades of research in microbial pathogenesis, and the burgeoning capacity of synthetic biologists, the limitations of this approach are apparent. With heightened scientific and public attention focused on biosafety and biosecurity, and an ongoing review by US authorities of dual-use research oversight, this article proposes the incorporation of sequences of concern (SoCs) into the biorisk management regime governing genetic engineering of pathogens. SoCs enable pathogenesis in all microbes infecting hosts that are 'of concern' to human civilization. Here we review the functions of SoCs (FunSoCs) and discuss how they might bring clarity to potentially problematic research outcomes involving infectious agents. We believe that annotation of SoCs with FunSoCs has the potential to improve the likelihood that dual use research of concern is recognized by both scientists and regulators before it occurs.
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Affiliation(s)
| | | | | | | | - Stacy L. Agar
- Signature Science, LLC, Charlottesville, VA, United States
| | - Todd J. Treangen
- Department of Computer Science, Rice University, Houston, TX, United States
| | | | - Jonas B. Sandbrink
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Gregory D. Koblentz
- Schar School of Policy and Government, George Mason University, Arlington, VA, United States
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3
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Ciaston I, Dobosz E, Potempa J, Koziel J. The subversion of toll-like receptor signaling by bacterial and viral proteases during the development of infectious diseases. Mol Aspects Med 2022; 88:101143. [PMID: 36152458 PMCID: PMC9924004 DOI: 10.1016/j.mam.2022.101143] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 07/29/2022] [Accepted: 09/09/2022] [Indexed: 02/05/2023]
Abstract
Toll-like receptors (TLRs) are pattern recognition receptors (PRRs) that respond to pathogen-associated molecular patterns (PAMPs). The recognition of specific microbial ligands by TLRs triggers an innate immune response and also promotes adaptive immunity, which is necessary for the efficient elimination of invading pathogens. Successful pathogens have therefore evolved strategies to subvert and/or manipulate TLR signaling. Both the impairment and uncontrolled activation of TLR signaling can harm the host, causing tissue destruction and allowing pathogens to proliferate, thus favoring disease progression. In this context, microbial proteases are key virulence factors that modify components of the TLR signaling pathway. In this review, we discuss the role of bacterial and viral proteases in the manipulation of TLR signaling, highlighting the importance of these enzymes during the development of infectious diseases.
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Affiliation(s)
- Izabela Ciaston
- Department of Microbiology Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Ewelina Dobosz
- Department of Microbiology Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Jan Potempa
- Department of Microbiology Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland; Department of Oral Health and Systemic Disease, University of Louisville School of Dentistry, University of Louisville, Louisville, KY, USA.
| | - Joanna Koziel
- Department of Microbiology Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland.
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4
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Godbole NM, Chowdhury AA, Chataut N, Awasthi S. Tight Junctions, the Epithelial Barrier, and Toll-like Receptor-4 During Lung Injury. Inflammation 2022; 45:2142-2162. [PMID: 35779195 DOI: 10.1007/s10753-022-01708-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 05/31/2022] [Accepted: 06/13/2022] [Indexed: 11/25/2022]
Abstract
Lung epithelium is constantly exposed to the environment and is critically important for the orchestration of initial responses to infectious organisms, toxins, and allergic stimuli, and maintenance of normal gaseous exchange and pulmonary function. The integrity of lung epithelium, fluid balance, and transport of molecules is dictated by the tight junctions (TJs). The TJs are formed between adjacent cells. We have focused on the topic of the TJ structure and function in lung epithelial cells. This review includes a summary of the last twenty years of literature reports published on the disrupted TJs and epithelial barrier in various lung conditions and expression and regulation of specific TJ proteins against pathogenic stimuli. We discuss the molecular signaling and crosstalk among signaling pathways that control the TJ structure and function. The Toll-like receptor-4 (TLR4) recognizes the pathogen- and damage-associated molecular patterns released during lung injury and inflammation and coordinates cellular responses. The molecular aspects of TLR4 signaling in the context of TJs or the epithelial barrier are not fully known. We describe the current knowledge and possible networking of the TLR4-signaling with cellular and molecular mechanisms of TJs, lung epithelial barrier function, and resistance to treatment strategies.
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Affiliation(s)
- Nachiket M Godbole
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Oklahoma Health Sciences Center, 1110 N. Stonewall Avenue, Oklahoma City, OK, 73117, USA
| | - Asif Alam Chowdhury
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Oklahoma Health Sciences Center, 1110 N. Stonewall Avenue, Oklahoma City, OK, 73117, USA
| | - Neha Chataut
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Oklahoma Health Sciences Center, 1110 N. Stonewall Avenue, Oklahoma City, OK, 73117, USA
| | - Shanjana Awasthi
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Oklahoma Health Sciences Center, 1110 N. Stonewall Avenue, Oklahoma City, OK, 73117, USA.
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Rougeaux C, Becher F, Goossens PL, Tournier JN. Very Early Blood Diffusion of the Active Lethal and Edema Factors of Bacillus anthracis After Intranasal Infection. J Infect Dis 2020; 221:660-667. [PMID: 31574153 PMCID: PMC6996859 DOI: 10.1093/infdis/jiz497] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 09/30/2019] [Indexed: 11/22/2022] Open
Abstract
Background Lethal and edema toxins are critical virulence factors of Bacillus anthracis. Few data are available on their presence in the early stage of intranasal infection. Methods To investigate the diffusion of edema factor (EF) and lethal factor (LF), we use sensitive quantitative methods to measure their enzymatic activities in mice intranasally challenged with a wild-type B anthracis strain or with an isogenic mutant deficient for the protective antigen. Results One hour after mouse challenge, although only 7% of mice presented bacteremia, LF and EF were detected in the blood of 100% and 42% of mice, respectively. Protective antigen facilitated the diffusion of LF and EF into the blood compartment. Toxins played a significant role in the systemic dissemination of B anthracis in the blood, spleen, and liver. A mouse model of intoxination further confirmed that LT and ET could diffuse rapidly in the circulation, independently of bacteria. Conclusions In this inhalational model, toxins have disseminated rapidly in the blood, playing a significant and novel role in the early systemic diffusion of bacteria, demonstrating that they may represent a very early target for the diagnosis and the treatment of anthrax.
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Affiliation(s)
- Clémence Rougeaux
- Unité Biothérapies Anti-Infectieuses et Immunité, Institut de Recherche Biomédicale des Armées, Brétigny-sur-Orge, France.,Pathogénie des Toxi-Infections Bactériennes, Institut Pasteur, Paris, France
| | - François Becher
- Service de Pharmacologie et d'Immunoanalyse, Laboratoire d'Etude du Métabolisme des Médicaments, Commissariat à l'Energie Atomique et aux Energies Alternatives, Institut National de la Recherche Agronomique, Université Paris Saclay, Gif-sur-Yvette, France
| | - Pierre L Goossens
- Pathogénie des Toxi-Infections Bactériennes, Institut Pasteur, Paris, France
| | - Jean-Nicolas Tournier
- Unité Biothérapies Anti-Infectieuses et Immunité, Institut de Recherche Biomédicale des Armées, Brétigny-sur-Orge, France.,Pathogénie des Toxi-Infections Bactériennes, Institut Pasteur, Paris, France.,Ecole du Val-de-Grâce, Paris, France.,Centre National de Référence-Laboratoire Expert Charbon, Institut de Recherche Biomédicale des Armées, Brétigny-sur-Orge, France
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6
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Shi L, Liu BY, Wang X, Zhu MJ, Chen L, Zhou MY, Gu YJ, Cheng L, Wang Y. RUNX3-dependent oxidative epithelial-to-mesenchymal transition in methamphetamine-induced chronic lung injury. Cell Stress Chaperones 2020; 25:793-802. [PMID: 32681471 PMCID: PMC7479662 DOI: 10.1007/s12192-020-01133-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 06/22/2020] [Accepted: 06/25/2020] [Indexed: 12/18/2022] Open
Abstract
Lung toxicity is the main cause of the death from methamphetamine (MA) abuse, but its mechanism has remained unclear. The purpose of our study was to investigate if MA can induce epithelial-to-mesenchymal transition (EMT) and if RUNX3 is involved in oxidative EMT in MA-induced chronic lung injury. The rats were divided into the control group and MA group. Extracted lungs were used for morphological measurements and Western blot. The alveolar epithelial cells were cultured or transfected and then treated with MA or/and N-acetyl cysteine (NAC) followed by flow cytometry, Western blot, and immunohistochemistry. Chronic exposure to MA resulted in the lower growth ratio of weight, increased right ventricular index, thickened alveolar walls, and reduced number of alveolar sacs. Long-term administration with MA caused oxidative stress and pulmonary EMT. NAC increased RUNX3 and alleviated EMT. However, after knockdown of RUNX3, reactive oxygen species (ROS) levels were significantly upregulated, indicating that RUNX3 was closely related to oxidative stress. Knockdown of RUNX3 aggravated MA-induced EMT by activating RUNX3-dependent TGF-β signaling. Therefore, RUNX3 may be the key to oxidative EMT in methamphetamine-induced chronic lung injury.
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Affiliation(s)
- Lin Shi
- Department of Clinical Pharmacology, School of Pharmacy, China Medical University, No.77 Puhe Road, Shenyang North New Area, Shenyang, 110122, Liaoning, People's Republic of China
| | - Bing-Yang Liu
- Department of Endocrinology, Shengjing Hospital of China Medical University, Shenyang, 110004, Liaoning, People's Republic of China
| | - Xin Wang
- Department of Clinical Pharmacology, School of Pharmacy, China Medical University, No.77 Puhe Road, Shenyang North New Area, Shenyang, 110122, Liaoning, People's Republic of China
| | - Mei-Jia Zhu
- Department of Clinical Pharmacology, School of Pharmacy, China Medical University, No.77 Puhe Road, Shenyang North New Area, Shenyang, 110122, Liaoning, People's Republic of China
| | - Lei Chen
- Department of Clinical Pharmacology, School of Pharmacy, China Medical University, No.77 Puhe Road, Shenyang North New Area, Shenyang, 110122, Liaoning, People's Republic of China
| | - Ming-Yuan Zhou
- Department of Clinical Pharmacology, School of Pharmacy, China Medical University, No.77 Puhe Road, Shenyang North New Area, Shenyang, 110122, Liaoning, People's Republic of China
| | - Ying-Jian Gu
- Department of Clinical Pharmacology, School of Pharmacy, China Medical University, No.77 Puhe Road, Shenyang North New Area, Shenyang, 110122, Liaoning, People's Republic of China
| | - Lin Cheng
- Department of Clinical Pharmacology, School of Pharmacy, China Medical University, No.77 Puhe Road, Shenyang North New Area, Shenyang, 110122, Liaoning, People's Republic of China
| | - Yun Wang
- Department of Clinical Pharmacology, School of Pharmacy, China Medical University, No.77 Puhe Road, Shenyang North New Area, Shenyang, 110122, Liaoning, People's Republic of China.
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7
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Structural Integrity of the Alveolar-Capillary Barrier in Cynomolgus Monkeys Challenged with Fully Virulent and Toxin-Deficient Strains of Bacillus anthracis. THE AMERICAN JOURNAL OF PATHOLOGY 2020; 190:2095-2110. [PMID: 32598882 DOI: 10.1016/j.ajpath.2020.06.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 05/27/2020] [Accepted: 06/09/2020] [Indexed: 11/21/2022]
Abstract
Inhalational anthrax, a disease caused by inhaling Bacillus anthracis spores, leads to respiratory distress, vascular leakage, high-level bacteremia, and often death within days. Anthrax lethal toxin and edema toxin, which are composed of protective antigen (PA) plus either lethal factor (LF) or edema factor (EF), respectively, play an important yet incompletely defined role in the pulmonary pathophysiology. To better understand their contribution, we examined the structural integrity of the alveolar-capillary barrier in archival formalin-fixed lungs of cynomolgus monkeys challenged with the fully virulent B. anthracis Ames wild-type strain or the isogenic toxin-deficient mutants ΔEF, ΔLF, and ΔPA. Pulmonary spore challenge with the wild-type strain caused high mortality, intra-alveolar hemorrhages, extensive alveolar septal sequestration of bacteria and neutrophils, diffuse destabilization of epithelial and endothelial junctions, increased markers of coagulation and complement activation (including tissue factor and C5a), and multifocal intra-alveolar fibrin deposition. ΔEF challenge was lethal and showed similar alveolar-capillary alterations; however, intra-alveolar hemorrhages, bacterial deposition, and markers of coagulation or complement were absent or markedly lower. In contrast, ΔLF or ΔPA challenges were nonlethal and showed no signs of alveolar bacterial deposition or alveolar-capillary changes. These findings provide evidence that lethal toxin plays a determinative role in bacterial dissemination and alveolar-capillary barrier dysfunction, and edema toxin may significantly exacerbate pulmonary pathologies in a systemic infection.
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8
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Mondoñedo JR, Bartolák-Suki E, Bou Jawde S, Nelson K, Cao K, Sonnenberg A, Obrochta WP, Imsirovic J, Ram-Mohan S, Krishnan R, Suki B. A High-Throughput System for Cyclic Stretching of Precision-Cut Lung Slices During Acute Cigarette Smoke Extract Exposure. Front Physiol 2020; 11:566. [PMID: 32655401 PMCID: PMC7326018 DOI: 10.3389/fphys.2020.00566] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 05/07/2020] [Indexed: 12/31/2022] Open
Abstract
Rationale Precision-cut lung slices (PCLSs) are a valuable tool in studying tissue responses to an acute exposure; however, cyclic stretching may be necessary to recapitulate physiologic, tidal breathing conditions. Objectives To develop a multi-well stretcher and characterize the PCLS response following acute exposure to cigarette smoke extract (CSE). Methods A 12-well stretching device was designed, built, and calibrated. PCLS were obtained from male Sprague-Dawley rats (N = 10) and assigned to one of three groups: 0% (unstretched), 5% peak-to-peak amplitude (low-stretch), and 5% peak-to-peak amplitude superimposed on 10% static stretch (high-stretch). Lung slices were cyclically stretched for 12 h with or without CSE in the media. Levels of Interleukin-1β (IL-1β), matrix metalloproteinase (MMP)-1 and its tissue inhibitor (TIMP1), and membrane type-MMP (MT1-MMP) were assessed via western blot from tissue homogenate. Results The stretcher system produced nearly identical normal Lagrangian strains (Exx and Eyy, p > 0.999) with negligible shear strain (Exy < 0.0005) and low intra-well variability 0.127 ± 0.073%. CSE dose response curve was well characterized by a four-parameter logistic model (R2 = 0.893), yielding an IC50 value of 0.018 cig/mL. Cyclic stretching for 12 h did not decrease PCLS viability. Two-way ANOVA detected a significant interaction between CSE and stretch pattern for IL-1β (p = 0.017), MMP-1, TIMP1, and MT1-MMP (p < 0.001). Conclusion This platform is capable of high-throughput testing of an acute exposure under tightly-regulated, cyclic stretching conditions. We conclude that the acute mechano-inflammatory response to CSE exhibits complex, stretch-dependence in the PCLS.
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Affiliation(s)
- Jarred R Mondoñedo
- Department of Biomedical Engineering, College of Engineering, Boston University, Boston, MA, United States.,Boston University School of Medicine, Boston, MA, United States
| | - Elizabeth Bartolák-Suki
- Department of Biomedical Engineering, College of Engineering, Boston University, Boston, MA, United States
| | - Samer Bou Jawde
- Department of Biomedical Engineering, College of Engineering, Boston University, Boston, MA, United States
| | - Kara Nelson
- Department of Biomedical Engineering, College of Engineering, Boston University, Boston, MA, United States
| | - Kun Cao
- Department of Biomedical Engineering, College of Engineering, Boston University, Boston, MA, United States
| | - Adam Sonnenberg
- Department of Systems Engineering, College of Engineering, Boston University, Boston, MA, United States
| | - Walter Patrick Obrochta
- Department of Biomedical Engineering, College of Engineering, Boston University, Boston, MA, United States
| | - Jasmin Imsirovic
- Department of Biomedical Engineering, College of Engineering, Boston University, Boston, MA, United States
| | - Sumati Ram-Mohan
- Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
| | - Ramaswamy Krishnan
- Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
| | - Béla Suki
- Department of Biomedical Engineering, College of Engineering, Boston University, Boston, MA, United States
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Lucas R, Hadizamani Y, Gonzales J, Gorshkov B, Bodmer T, Berthiaume Y, Moehrlen U, Lode H, Huwer H, Hudel M, Mraheil MA, Toque HAF, Chakraborty T, Hamacher J. Impact of Bacterial Toxins in the Lungs. Toxins (Basel) 2020; 12:toxins12040223. [PMID: 32252376 PMCID: PMC7232160 DOI: 10.3390/toxins12040223] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/30/2020] [Accepted: 03/31/2020] [Indexed: 12/13/2022] Open
Abstract
Bacterial toxins play a key role in the pathogenesis of lung disease. Based on their structural and functional properties, they employ various strategies to modulate lung barrier function and to impair host defense in order to promote infection. Although in general, these toxins target common cellular signaling pathways and host compartments, toxin- and cell-specific effects have also been reported. Toxins can affect resident pulmonary cells involved in alveolar fluid clearance (AFC) and barrier function through impairing vectorial Na+ transport and through cytoskeletal collapse, as such, destroying cell-cell adhesions. The resulting loss of alveolar-capillary barrier integrity and fluid clearance capacity will induce capillary leak and foster edema formation, which will in turn impair gas exchange and endanger the survival of the host. Toxins modulate or neutralize protective host cell mechanisms of both the innate and adaptive immunity response during chronic infection. In particular, toxins can either recruit or kill central players of the lung's innate immune responses to pathogenic attacks, i.e., alveolar macrophages (AMs) and neutrophils. Pulmonary disorders resulting from these toxin actions include, e.g., acute lung injury (ALI), the acute respiratory syndrome (ARDS), and severe pneumonia. When acute infection converts to persistence, i.e., colonization and chronic infection, lung diseases, such as bronchitis, chronic obstructive pulmonary disease (COPD), and cystic fibrosis (CF) can arise. The aim of this review is to discuss the impact of bacterial toxins in the lungs and the resulting outcomes for pathogenesis, their roles in promoting bacterial dissemination, and bacterial survival in disease progression.
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Affiliation(s)
- Rudolf Lucas
- Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Department of Medicine and Division of Pulmonary Critical Care Medicine, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Correspondence: (R.L.); (J.H.); Tel.: +41-31-300-35-00 (J.H.)
| | - Yalda Hadizamani
- Lungen-und Atmungsstiftung, Bern, 3012 Bern, Switzerland;
- Pneumology, Clinic for General Internal Medicine, Lindenhofspital Bern, 3012 Bern, Switzerland
| | - Joyce Gonzales
- Department of Medicine and Division of Pulmonary Critical Care Medicine, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Boris Gorshkov
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Thomas Bodmer
- Labormedizinisches Zentrum Dr. Risch, Waldeggstr. 37 CH-3097 Liebefeld, Switzerland;
| | - Yves Berthiaume
- Department of Medicine, Faculty of Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada;
| | - Ueli Moehrlen
- Pediatric Surgery, University Children’s Hospital, Zürich, Steinwiesstrasse 75, CH-8032 Zürch, Switzerland;
| | - Hartmut Lode
- Insitut für klinische Pharmakologie, Charité, Universitätsklinikum Berlin, Reichsstrasse 2, D-14052 Berlin, Germany;
| | - Hanno Huwer
- Department of Cardiothoracic Surgery, Voelklingen Heart Center, 66333 Voelklingen/Saar, Germany;
| | - Martina Hudel
- Justus-Liebig-University, Biomedical Research Centre Seltersberg, Schubertstr. 81, 35392 Giessen, Germany; (M.H.); (M.A.M.); (T.C.)
| | - Mobarak Abu Mraheil
- Justus-Liebig-University, Biomedical Research Centre Seltersberg, Schubertstr. 81, 35392 Giessen, Germany; (M.H.); (M.A.M.); (T.C.)
| | - Haroldo Alfredo Flores Toque
- Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Trinad Chakraborty
- Justus-Liebig-University, Biomedical Research Centre Seltersberg, Schubertstr. 81, 35392 Giessen, Germany; (M.H.); (M.A.M.); (T.C.)
| | - Jürg Hamacher
- Lungen-und Atmungsstiftung, Bern, 3012 Bern, Switzerland;
- Pneumology, Clinic for General Internal Medicine, Lindenhofspital Bern, 3012 Bern, Switzerland
- Medical Clinic V-Pneumology, Allergology, Intensive Care Medicine and Environmental Medicine, Faculty of Medicine, Saarland University, University Medical Centre of the Saarland, D-66421 Homburg, Germany
- Institute for Clinical & Experimental Surgery, Faculty of Medicine, Saarland University, D-66421 Homburg, Germany
- Correspondence: (R.L.); (J.H.); Tel.: +41-31-300-35-00 (J.H.)
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10
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Cui X, Xu W, Neupane P, Weiser-Schlesinger A, Weng R, Pockros B, Li Y, Moayeri M, Leppla SH, Fitz Y, Eichacker PQ. Bacillus anthracis lethal toxin, but not edema toxin, increases pulmonary artery pressure and permeability in isolated perfused rat lungs. Am J Physiol Heart Circ Physiol 2019; 316:H1076-H1090. [PMID: 30767685 DOI: 10.1152/ajpheart.00685.2018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Although lethal toxin (LT) and edema toxin (ET) contribute to lethality during Bacillus anthracis infection, whether they increase vascular permeability and the extravascular fluid accumulation characterizing this infection is unclear. We employed an isolated perfused Sprague-Dawley rat lung model to investigate LT and ET effects on pulmonary vascular permeability. Lungs (n ≥ 6 per experimental group) were isolated, ventilated, suspended from a force transducer, and perfused. Lung weight and pulmonary artery (Ppa) and left atrial pressures were measured over 4 h, after which pulmonary capillary filtration coefficients (Kf.c) and lung wet-to-dry weight ratios (W/D) were determined. When compared with controls, LT increased Ppa over 4 h and Kf.c and W/D at 4 h (P < 0.0001). ET decreased Ppa in a significant trend (P = 0.09) but did not significantly alter Kf.c or W/D (P ≥ 0.29). Edema toxin actually blocked LT increases in Ppa but not LT increases in Kf.c and W/D. When Ppa was maintained at control levels, LT still increased Kf.c and W/D (P ≤ 0.004). Increasing the dose of each toxin five times significantly increased and a toxin-directed monoclonal antibody decreased the effects of each toxin (P ≤ 0.05). Two rho-kinase inhibitors (GSK269962 and Y27632) decreased LT increases in Ppa (P ≤ 0.02) but actually increased Kf.c and W/D in LT and control lungs (P ≤ 0.05). A vascular endothelial growth factor receptor inhibitor (ZM323881) had no significant effect (P ≥ 0.63) with LT. Thus, LT but not ET can increase pulmonary vascular permeability independent of increased Ppa and could contribute to pulmonary fluid accumulation during anthrax infection. However, pulmonary vascular dilation with ET could disrupt protective hypoxic vasoconstriction. NEW & NOTEWORTHY The most important findings from the present study are that Bacillus anthracis lethal toxin increases pulmonary artery pressure and pulmonary permeability independently in the isolated rat lung, whereas edema toxin decreases the former and does not increase permeability. Each effect could be a basis for organ dysfunction in patients with this lethal infection. These findings further support the need for adjunctive therapies that limit the effects of both toxins during infection.
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Affiliation(s)
- Xizhong Cui
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Wanying Xu
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Pranita Neupane
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Andie Weiser-Schlesinger
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Ray Weng
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Benjamin Pockros
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Yan Li
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Mahtab Moayeri
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Bethesda, Maryland
| | - Stephen H Leppla
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Bethesda, Maryland
| | - Yvonne Fitz
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Peter Q Eichacker
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
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11
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Booth JL, Duggan ES, Patel VI, Wu W, Burian DM, Hutchings DC, White VL, Coggeshall KM, Dozmorov MG, Metcalf JP. Gene expression profiling of primary human type I alveolar epithelial cells exposed to Bacillus anthracis spores reveals induction of neutrophil and monocyte chemokines. Microb Pathog 2018; 121:9-21. [PMID: 29704667 DOI: 10.1016/j.micpath.2018.04.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 02/12/2018] [Accepted: 04/22/2018] [Indexed: 11/18/2022]
Abstract
The lung is the entry site for Bacillus anthracis in inhalation anthrax, the most deadly form of the disease. Spores must escape through the alveolar epithelial cell (AEC) barrier and migrate to regional lymph nodes, germinate and enter the circulatory system to cause disease. Several mechanisms to explain alveolar escape have been postulated, and all these tacitly involve the AEC barrier. In this study, we incorporate our primary human type I AEC model, microarray and gene enrichment analysis, qRT-PCR, multiplex ELISA, and neutrophil and monocyte chemotaxis assays to study the response of AEC to B. anthracis, (Sterne) spores at 4 and 24 h post-exposure. Spore exposure altered gene expression in AEC after 4 and 24 h and differentially expressed genes (±1.3 fold, p ≤ 0.05) included CCL4/MIP-1β (4 h), CXCL8/IL-8 (4 and 24 h) and CXCL5/ENA-78 (24 h). Gene enrichment analysis revealed that pathways involving cytokine or chemokine activity, receptor binding, and innate immune responses to infection were prominent. Microarray results were confirmed by qRT-PCR and multiplex ELISA assays. Chemotaxis assays demonstrated that spores induced the release of biologically active neutrophil and monocyte chemokines, and that CXCL8/IL-8 was the major neutrophil chemokine. The small or sub-chemotactic doses of CXCL5/ENA-78, CXCL2/GROβ and CCL20/MIP-3α may contribute to chemotaxis by priming effects. These data provide the first whole transcriptomic description of the human type I AEC initial response to B. anthracis spore exposure. Taken together, our findings contribute to an increased understanding of the role of AEC in the pathogenesis of inhalational anthrax.
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Affiliation(s)
- J Leland Booth
- Pulmonary and Critical Care Division of the Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Elizabeth S Duggan
- Pulmonary and Critical Care Division of the Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Vineet I Patel
- Pulmonary and Critical Care Division of the Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Wenxin Wu
- Pulmonary and Critical Care Division of the Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Dennis M Burian
- Civil Aerospace Medical Institute, Office of Aviation Medicine, Federal Aviation Administration, Oklahoma City, OK 73169, USA.
| | | | - Vicky L White
- Civil Aerospace Medical Institute, Office of Aviation Medicine, Federal Aviation Administration, Oklahoma City, OK 73169, USA.
| | - K Mark Coggeshall
- Immunobiology and Cancer Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA.
| | - Mikhail G Dozmorov
- Department of Biostatistics, Virginia Commonwealth University, Richmond, VA 23298, USA.
| | - Jordan P Metcalf
- Pulmonary and Critical Care Division of the Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
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12
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Celentano A, Mignogna MD, McCullough M, Cirillo N. Pathophysiology of the Desmo-Adhesome. J Cell Physiol 2016; 232:496-505. [PMID: 27505028 DOI: 10.1002/jcp.25515] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 08/08/2016] [Indexed: 01/18/2023]
Abstract
Advances in our understanding of desmosomal diseases have provided a clear demonstration of the key role played by desmosomes in tissue and organ physiology, highlighting the importance of their dynamic and finely regulated structure. In this context, non-desmosomal regulatory molecules have acquired increasing relevance in the study of this organelle resulting in extending the desmosomal interactome, named the "desmo-adhesome." Spatiotemporal changes in the expression and regulation of the desmo-adhesome underlie a number of genetic, infectious, autoimmune, and malignant conditions. The aim of the present article was to examine the structural and functional relationship of the desmosome, by providing a comprehensive, yet focused overview of the constituents targeted in human disease. The inclusion of the novel regulatory network in the desmo-adhesome pathophysiology opens new avenues to a deeper understanding of desmosomal diseases, potentially unveiling pathogenic mechanisms waiting to be explored. J. Cell. Physiol. 232: 496-505, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Antonio Celentano
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University Federico II of Naples, Naples, Italy.,Melbourne Dental School, University of Melbourne, Carlton, Victoria, Australia
| | - Michele Davide Mignogna
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University Federico II of Naples, Naples, Italy
| | - Michael McCullough
- Melbourne Dental School, University of Melbourne, Carlton, Victoria, Australia.,Oral Health Cooperative Research Centre (CRC), University of Melbourne, Carlton, Victoria, Australia
| | - Nicola Cirillo
- Melbourne Dental School, University of Melbourne, Carlton, Victoria, Australia.,Oral Health Cooperative Research Centre (CRC), University of Melbourne, Carlton, Victoria, Australia
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13
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Booth JL, Duggan ES, Patel VI, Langer M, Wu W, Braun A, Coggeshall KM, Metcalf JP. Bacillus anthracis spore movement does not require a carrier cell and is not affected by lethal toxin in human lung models. Microbes Infect 2016; 18:615-626. [PMID: 27320392 PMCID: PMC5534360 DOI: 10.1016/j.micinf.2016.06.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Revised: 05/04/2016] [Accepted: 06/08/2016] [Indexed: 01/29/2023]
Abstract
The lung is the entry site for Bacillus anthracis in inhalation anthrax, the most deadly form of the disease. Spores escape from the alveolus to regional lymph nodes, germinate and enter the circulatory system to cause disease. The roles of carrier cells and the effects of B. anthracis toxins in this process are unclear. We used a human lung organ culture model to measure spore uptake by antigen presenting cells (APC) and alveolar epithelial cells (AEC), spore partitioning between these cells, and the effects of B. anthracis lethal toxin and protective antigen. We repeated the study in a human A549 alveolar epithelial cell model. Most spores remained unassociated with cells, but the majority of cell-associated spores were in AEC, not in APC. Spore movement was not dependent on internalization, although the location of internalized spores changed in both cell types. Spores also internalized in a non-uniform pattern. Toxins affected neither transit of the spores nor the partitioning of spores into AEC and APC. Our results support a model of spore escape from the alveolus that involves spore clustering with transient passage through intact AEC. However, subsequent transport of spores by APC from the lung to the lymph nodes may occur.
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Affiliation(s)
- J Leland Booth
- Pulmonary and Critical Care Division of the Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Elizabeth S Duggan
- Pulmonary and Critical Care Division of the Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Vineet I Patel
- Pulmonary and Critical Care Division of the Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Marybeth Langer
- Immunobiology and Cancer Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA.
| | - Wenxin Wu
- Pulmonary and Critical Care Division of the Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Armin Braun
- Fraunhofer Institute for Toxicology and Experimental Medicine, D-30625, Hannover, Germany.
| | - K Mark Coggeshall
- Immunobiology and Cancer Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA.
| | - Jordan P Metcalf
- Pulmonary and Critical Care Division of the Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
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14
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Celentano A, Cirillo N. Desmosomes in disease: a guide for clinicians. Oral Dis 2016; 23:157-167. [PMID: 27329525 DOI: 10.1111/odi.12527] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 06/18/2016] [Indexed: 12/24/2022]
Abstract
The large number of diseases occurring when desmosome constituents are impaired provides striking evidence for the key role of desmosomes in maintaining tissue integrity. A detailed understanding of the molecular alterations causing desmosomal dysfunction has, in turn, underpinned the development of novel diagnostic tools. This has salient clinical implications for dentists and oral medicine practitioners because the majority of desmosomal diseases affect the oral cavity. In the present article, we review the autoimmune, infectious, genetic, and neoplastic diseases that target the desmosome, with particular emphasis on clinical manifestations, diagnostic pathways, and relevant laboratory investigations.
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Affiliation(s)
- A Celentano
- Melbourne Dental School and Oral Health CRC, University of Melbourne, Melbourne, Vic., Australia.,Department of Neurosciences, Reproductive and Odontostomatological Sciences, Federico II University of Naples, Naples, Italy
| | - N Cirillo
- Melbourne Dental School and Oral Health CRC, University of Melbourne, Melbourne, Vic., Australia
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15
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Goossens PL, Tournier JN. Crossing of the epithelial barriers by Bacillus anthracis: the Known and the Unknown. Front Microbiol 2015; 6:1122. [PMID: 26500645 PMCID: PMC4598578 DOI: 10.3389/fmicb.2015.01122] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 09/28/2015] [Indexed: 12/15/2022] Open
Abstract
Anthrax, caused by Bacillus anthracis, a Gram-positive spore-forming bacterium, is initiated by the entry of spores into the host body. There are three types of human infection: cutaneous, inhalational, and gastrointestinal. For each form, B. anthracis spores need to cross the cutaneous, respiratory or digestive epithelial barriers, respectively, as a first obligate step to establish infection. Anthrax is a toxi-infection: an association of toxemia and rapidly spreading infection progressing to septicemia. The pathogenicity of Bacillus anthracis mainly depends on two toxins and a capsule. The capsule protects bacilli from the immune system, thus promoting systemic dissemination. The toxins alter host cell signaling, thereby paralyzing the immune response of the host and perturbing the endocrine and endothelial systems. In this review, we will mainly focus on the events and mechanisms leading to crossing of the respiratory epithelial barrier, as the majority of studies have addressed inhalational infection. We will discuss the critical gaps of knowledge that need to be addressed to gain a comprehensive view of the initial steps of inhalational anthrax. We will then discuss the few data available on B. anthracis crossing the cutaneous and digestive epithelia.
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Affiliation(s)
- Pierre L Goossens
- Pathogénie des Toxi-Infections Bactériennes, Institut Pasteur , Paris, France
| | - Jean-Nicolas Tournier
- Pathogénie des Toxi-Infections Bactériennes, Institut Pasteur , Paris, France ; Unité Interactions Hôte-Agents Pathogènes, Institut de Recherche Biomédicale des Armées , Brétigny-sur-Orge, France ; Ecole du Val-de-Grâce , Paris, France
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16
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Wu W, Zhang W, Duggan ES, Booth JL, Zou MH, Metcalf JP. RIG-I and TLR3 are both required for maximum interferon induction by influenza virus in human lung alveolar epithelial cells. Virology 2015; 482:181-8. [PMID: 25880109 PMCID: PMC4461467 DOI: 10.1016/j.virol.2015.03.048] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 03/23/2015] [Accepted: 03/24/2015] [Indexed: 02/01/2023]
Abstract
Pattern recognition receptors, such as retinoic acid-inducible protein I (RIG-I), Toll-like receptors 3 and 7 (TLR3 and 7), and nucleotide-binding oligomerization domain containing protein 2 (NOD2), play important roles in the recognition of influenza A virus (IAV), but their role in interferon (IFN) induction is still unclear, particularly in human lung. We investigated IFN induction by IAV in the A549 cell line as well as in primary human alveolar epithelial cells (AEC). TLR3/7, NOD2, RIG-I, and IFN expression levels were measured by qRT-PCR and ELISA in cells infected with IAV PR8. We found that TLR7 and NOD2 were not involved in IFN induction by IAV in these cells. Neither RIG-I nor TLR3 siRNA alone completely blocked IFN induction. However, double knockdown of RIG-I and TLR3 completely inhibited IFN induction by influenza. Thus, signaling through both RIG-I and TLR3 is important for IFN induction by IAV in human lung AEC.
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Affiliation(s)
- Wenxin Wu
- Pulmonary and Critical Care Division, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Wei Zhang
- Pulmonary and Critical Care Division, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Elizabeth S Duggan
- Pulmonary and Critical Care Division, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - J Leland Booth
- Pulmonary and Critical Care Division, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Ming-Hui Zou
- Section of Molecular Medicine, Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA; Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Jordan P Metcalf
- Pulmonary and Critical Care Division, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA; Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA; Veterans Affairs Medical Center, Oklahoma City, OK, USA.
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17
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Abstract
Anthrax is caused by the spore-forming, gram-positive bacterium Bacillus anthracis. The bacterium's major virulence factors are (a) the anthrax toxins and (b) an antiphagocytic polyglutamic capsule. These are encoded by two large plasmids, the former by pXO1 and the latter by pXO2. The expression of both is controlled by the bicarbonate-responsive transcriptional regulator, AtxA. The anthrax toxins are three polypeptides-protective antigen (PA), lethal factor (LF), and edema factor (EF)-that come together in binary combinations to form lethal toxin and edema toxin. PA binds to cellular receptors to translocate LF (a protease) and EF (an adenylate cyclase) into cells. The toxins alter cell signaling pathways in the host to interfere with innate immune responses in early stages of infection and to induce vascular collapse at late stages. This review focuses on the role of anthrax toxins in pathogenesis. Other virulence determinants, as well as vaccines and therapeutics, are briefly discussed.
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Affiliation(s)
- Mahtab Moayeri
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892; , , , ,
| | - Stephen H Leppla
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892; , , , ,
| | - Catherine Vrentas
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892; , , , ,
| | - Andrei P Pomerantsev
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892; , , , ,
| | - Shihui Liu
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892; , , , ,
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18
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Abstract
Desmosomes are cell-cell junctions that mediate adhesion and couple the intermediate filament cytoskeleton to sites of cell-cell contact. This architectural arrangement integrates adhesion and cytoskeletal elements of adjacent cells. The importance of this robust adhesion system is evident in numerous human diseases, both inherited and acquired, which occur when desmosome function is compromised. This review focuses on autoimmune and infectious diseases that impair desmosome function. In addition, we discuss emerging evidence that desmosomal genes are often misregulated in cancer. The emphasis of our discussion is placed on the way in which human diseases can inform our understanding of basic desmosome biology and in turn, the means by which fundamental advances in the cell biology of desmosomes might lead to new treatments for acquired diseases of the desmosome.
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19
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Khavrutskii IV, Legler PM, Friedlander AM, Wallqvist A. A reaction path study of the catalysis and inhibition of the Bacillus anthracis CapD γ-glutamyl transpeptidase. Biochemistry 2014; 53:6954-67. [PMID: 25334088 DOI: 10.1021/bi500623c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The CapD enzyme of Bacillus anthracis is a γ-glutamyl transpeptidase from the N-terminal nucleophile hydrolase superfamily that covalently anchors the poly-γ-D-glutamic acid (pDGA) capsule to the peptidoglycan. The capsule hinders phagocytosis of B. anthracis by host cells and is essential for virulence. The role CapD plays in capsule anchoring and remodeling makes the enzyme a promising target for anthrax medical countermeasures. Although the structure of CapD is known, and a covalent inhibitor, capsidin, has been identified, the mechanisms of CapD catalysis and inhibition are poorly understood. Here, we used a computational approach to map out the reaction steps involved in CapD catalysis and inhibition. We found that the rate-limiting step of either CapD catalysis or inhibition was a concerted asynchronous formation of the tetrahedral intermediate with a barrier of 22-23 kcal/mol. However, the mechanisms of these reactions differed for the two amides. The formation of the tetrahedral intermediate with pDGA was substrate-assisted with two proton transfers. In contrast, capsidin formed the tetrahedral intermediate in a conventional way with one proton transfer. Interestingly, capsidin coupled a conformational change in the catalytic residue of the tetrahedral intermediate to stretching of the scissile amide bond. Furthermore, capsidin took advantage of iminol-amide tautomerism of its diacetamide moiety to convert the tetrahedral intermediate to the acetylated CapD. As evidence of the promiscuous nature of CapD, the enzyme cleaved the amide bond of capsidin by attacking it on the opposite side compared to pDGA.
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Affiliation(s)
- Ilja V Khavrutskii
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Materiel Command , Fort Detrick, Maryland 21702, United States
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20
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Simon NC, Barbieri JT. Bacillus cereus Certhrax ADP-ribosylates vinculin to disrupt focal adhesion complexes and cell adhesion. J Biol Chem 2014; 289:10650-10659. [PMID: 24573681 DOI: 10.1074/jbc.m113.500710] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Bacillus cereus is often associated with mild to moderate gastroenteritis; however, some recent isolates cause inhalational anthrax-like diseases and death. These potential emerging human pathogens express multiple virulence factors. B. cereus strain G9241 expresses anthrax toxin, several polysaccharide capsules, and the novel ADP-ribosyltransferase, Certhrax. In this study, we show that Certhrax ADP-ribosylates Arg-433 of vinculin, a protein that coordinates actin cytoskeleton and extracellular matrix interactions. ADP-ribosylation of vinculin disrupted focal adhesion complexes and redistributed vinculin to the cytoplasm. Exogenous vinculin rescued these phenotypes. This provides a mechanism for strain G9241 to breach host barrier defenses and promote bacterial growth and spread. Certhrax is the first bacterial toxin to add a post-translational modification to vinculin to disrupt the actin cytoskeleton.
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Affiliation(s)
- Nathan C Simon
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Joseph T Barbieri
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin 53226.
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21
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Bacillus anthracis has two independent bottlenecks that are dependent on the portal of entry in an intranasal model of inhalational infection. Infect Immun 2013; 81:4408-20. [PMID: 24042112 DOI: 10.1128/iai.00484-13] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Bacillus anthracis can cause inhalational anthrax. Murine inhalational B. anthracis infections have two portals of entry, the nasal mucosa-associated lymphoid tissue (NALT) and the lumen of the lungs. Analysis of the dissemination from these sites is hindered because infections are asynchronous and asymptomatic until the hosts near death. To further understand and compare how B. anthracis disseminates from these two different environments, clonal analysis was employed using a library of equally virulent DNA-tagged clones of a luminescent Sterne strain. Luminescence was used to determine the origin of the infection and monitor the dissemination in vivo. The number of clones and their proportions in the portals of entry, lymph nodes draining the portals, and kidneys were analyzed. Clonal analysis indicated a bottleneck for both portals of entry, yet the extent and location of the reduction in represented clones differed between the routes. In NALT-based infections, all clones were found to germinate in the NALT, but they underwent a bottleneck as the infection spread to the cervical lymph node. However, lung-based infections underwent a bottleneck in a focal region of growth within the lung lumen and did not need to spread through the mediastinal lymph nodes to cause a systemic infection. Further, the average number of clones found in the kidney and the rate at which genetic drift was affecting the disseminated populations were significantly higher in lung-based infections. Collectively, the data suggested that differences in the host environment alter dissemination of B. anthracis depending on the site of initial colonization and growth.
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22
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Coggeshall KM, Lupu F, Ballard J, Metcalf JP, James JA, Farris D, Kurosawa S. The sepsis model: an emerging hypothesis for the lethality of inhalation anthrax. J Cell Mol Med 2013; 17:914-20. [PMID: 23742651 PMCID: PMC3729634 DOI: 10.1111/jcmm.12075] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Accepted: 03/29/2013] [Indexed: 01/19/2023] Open
Abstract
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.
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Affiliation(s)
- Kenneth Mark Coggeshall
- Immunobiology and Cancer Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA.
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