1
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Griffin ME, Klupt S, Espinosa J, Hang HC. Peptidoglycan NlpC/P60 peptidases in bacterial physiology and host interactions. Cell Chem Biol 2023; 30:436-456. [PMID: 36417916 PMCID: PMC10192474 DOI: 10.1016/j.chembiol.2022.11.001] [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: 05/18/2022] [Revised: 09/15/2022] [Accepted: 10/31/2022] [Indexed: 11/23/2022]
Abstract
The bacterial cell wall is composed of a highly crosslinked matrix of glycopeptide polymers known as peptidoglycan that dictates bacterial cell morphology and protects against environmental stresses. Regulation of peptidoglycan turnover is therefore crucial for bacterial survival and growth and is mediated by key protein complexes and enzyme families. Here, we review the prevalence, structure, and activity of NlpC/P60 peptidases, a family of peptidoglycan hydrolases that are crucial for cell wall turnover and division as well as interactions with antibiotics and different hosts. Understanding the molecular functions of NlpC/P60 peptidases should provide important insight into bacterial physiology, their interactions with different kingdoms of life, and the development of new therapeutic approaches.
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Affiliation(s)
- Matthew E Griffin
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA
| | - Steven Klupt
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA
| | - Juliel Espinosa
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, New York, NY 10065, USA
| | - Howard C Hang
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA; Department of Chemistry, Scripps Research, La Jolla, CA 92037, USA.
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2
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Mkaouar H, Mariaule V, Rhimi S, Hernandez J, Kriaa A, Jablaoui A, Akermi N, Maguin E, Lesner A, Korkmaz B, Rhimi M. Gut Serpinome: Emerging Evidence in IBD. Int J Mol Sci 2021; 22:ijms22116088. [PMID: 34200095 PMCID: PMC8201313 DOI: 10.3390/ijms22116088] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 06/01/2021] [Accepted: 06/03/2021] [Indexed: 12/11/2022] Open
Abstract
Inflammatory bowel diseases (IBD) are incurable disorders whose prevalence and global socioeconomic impact are increasing. While the role of host genetics and immunity is well documented, that of gut microbiota dysbiosis is increasingly being studied. However, the molecular basis of the dialogue between the gut microbiota and the host remains poorly understood. Increased activity of serine proteases is demonstrated in IBD patients and may contribute to the onset and the maintenance of the disease. The intestinal proteolytic balance is the result of an equilibrium between the proteases and their corresponding inhibitors. Interestingly, the serine protease inhibitors (serpins) encoded by the host are well reported; in contrast, those from the gut microbiota remain poorly studied. In this review, we provide a concise analysis of the roles of serine protease in IBD physiopathology and we focus on the serpins from the gut microbiota (gut serpinome) and their relevance as a promising therapeutic approach.
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Affiliation(s)
- Héla Mkaouar
- Microbiota Interaction with Human and Animal Team (MIHA), Micalis Institute, AgroParisTech, Université Paris-Saclay, INRAE, 78350 Jouy-en-Josas, France; (H.M.); (V.M.); (S.R.); (A.K.); (A.J.); (N.A.); (E.M.)
| | - Vincent Mariaule
- Microbiota Interaction with Human and Animal Team (MIHA), Micalis Institute, AgroParisTech, Université Paris-Saclay, INRAE, 78350 Jouy-en-Josas, France; (H.M.); (V.M.); (S.R.); (A.K.); (A.J.); (N.A.); (E.M.)
| | - Soufien Rhimi
- Microbiota Interaction with Human and Animal Team (MIHA), Micalis Institute, AgroParisTech, Université Paris-Saclay, INRAE, 78350 Jouy-en-Josas, France; (H.M.); (V.M.); (S.R.); (A.K.); (A.J.); (N.A.); (E.M.)
| | - Juan Hernandez
- Department of Clinical Sciences, Nantes-Atlantic College of Veterinary Medicine and Food Sciences (Oniris), University of Nantes, 101 Route de Gachet, 44300 Nantes, France;
| | - Aicha Kriaa
- Microbiota Interaction with Human and Animal Team (MIHA), Micalis Institute, AgroParisTech, Université Paris-Saclay, INRAE, 78350 Jouy-en-Josas, France; (H.M.); (V.M.); (S.R.); (A.K.); (A.J.); (N.A.); (E.M.)
| | - Amin Jablaoui
- Microbiota Interaction with Human and Animal Team (MIHA), Micalis Institute, AgroParisTech, Université Paris-Saclay, INRAE, 78350 Jouy-en-Josas, France; (H.M.); (V.M.); (S.R.); (A.K.); (A.J.); (N.A.); (E.M.)
| | - Nizar Akermi
- Microbiota Interaction with Human and Animal Team (MIHA), Micalis Institute, AgroParisTech, Université Paris-Saclay, INRAE, 78350 Jouy-en-Josas, France; (H.M.); (V.M.); (S.R.); (A.K.); (A.J.); (N.A.); (E.M.)
| | - Emmanuelle Maguin
- Microbiota Interaction with Human and Animal Team (MIHA), Micalis Institute, AgroParisTech, Université Paris-Saclay, INRAE, 78350 Jouy-en-Josas, France; (H.M.); (V.M.); (S.R.); (A.K.); (A.J.); (N.A.); (E.M.)
| | - Adam Lesner
- Faculty of Chemistry, University of Gdansk, Uniwersytet Gdanski, Chemistry, Wita Stwosza 63, PL80-308 Gdansk, Poland;
| | - Brice Korkmaz
- INSERM UMR-1100, “Research Center for Respiratory Diseases” and University of Tours, 37032 Tours, France;
| | - Moez Rhimi
- Microbiota Interaction with Human and Animal Team (MIHA), Micalis Institute, AgroParisTech, Université Paris-Saclay, INRAE, 78350 Jouy-en-Josas, France; (H.M.); (V.M.); (S.R.); (A.K.); (A.J.); (N.A.); (E.M.)
- Correspondence:
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3
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Zaide G, Elia U, Cohen-Gihon I, Israeli M, Rotem S, Israeli O, Ehrlich S, Cohen H, Lazar S, Beth-Din A, Shafferman A, Zvi A, Cohen O, Chitlaru T. Comparative Analysis of the Global Transcriptomic Response to Oxidative Stress of Bacillus anthracis htrA-Disrupted and Parental Wild Type Strains. Microorganisms 2020; 8:microorganisms8121896. [PMID: 33265965 PMCID: PMC7760947 DOI: 10.3390/microorganisms8121896] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 11/26/2020] [Accepted: 11/27/2020] [Indexed: 12/30/2022] Open
Abstract
We previously demonstrated that the HtrA (High Temperature Requirement A) protease/chaperone active in the quality control of protein synthesis, represents an important virulence determinant of Bacillus anthracis. Virulence attenuation of htrA-disrupted Bacillus anthracis strains was attributed to susceptibility of ΔhtrA strains to stress insults, as evidenced by affected growth under various stress conditions. Here, we report a comparative RNA-seq transcriptomic study generating a database of differentially expressed genes in the B. anthracishtrA-disrupted and wild type parental strains under oxidative stress. The study demonstrates that, apart from protease and chaperone activities, HtrA exerts a regulatory role influencing expression of more than 1000 genes under stress. Functional analysis of groups or individual genes exhibiting strain-specific modulation, evidenced (i) massive downregulation in the ΔhtrA and upregulation in the WT strains of various transcriptional regulators, (ii) downregulation of translation processes in the WT strain, and (iii) downregulation of metal ion binding functions and upregulation of sporulation-associated functions in the ΔhtrA strain. These modulated functions are extensively discussed. Fifteen genes uniquely upregulated in the wild type strain were further interrogated for their modulation in response to other stress regimens. Overexpression of one of these genes, encoding for MazG (a nucleoside triphosphate pyrophosphohydrolase involved in various stress responses in other bacteria), in the ΔhtrA strain resulted in partial alleviation of the H2O2-sensitive phenotype.
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4
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Tran SL, Cormontagne D, Vidic J, André-Leroux G, Ramarao N. Structural Modeling of Cell Wall Peptidase CwpFM (EntFM) Reveals Distinct Intrinsically Disordered Extensions Specific to Pathogenic Bacillus cereus Strains. Toxins (Basel) 2020; 12:toxins12090593. [PMID: 32937845 PMCID: PMC7551459 DOI: 10.3390/toxins12090593] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 09/04/2020] [Accepted: 09/09/2020] [Indexed: 12/21/2022] Open
Abstract
The emergence of B. cereus as an opportunistic food-borne pathogen has intensified the need to distinguish strains of public health concern. The heterogeneity of the diseases associated with B. cereus infections emphasizes the versatility of these bacteria strains to colonize their host. Nevertheless, the molecular basis of these differences remains unclear. Several toxins are involved in virulence, particularly in gastrointestinal disorders, but there are currently no biological markers able to differentiate pathogenic from harmless strains. We have previously shown that CwpFM is a cell wall peptidase involved in B. cereus virulence. Here, we report a sequence/structure/function characterization of 39 CwpFM sequences, chosen from a collection of B. cereus with diverse virulence phenotypes, from harmless to highly pathogenic strains. CwpFM is homology-modeled in silico as an exported papain-like endopeptidase, with an N-terminal end composed of three successive bacterial Src Homology 3 domains (SH3b1–3) likely to control protein–protein interactions in signaling pathways, and a C-terminal end that contains a catalytic NLPC_P60 domain primed to form a competent active site. We confirmed in vitro that CwpFM is an endopeptidase with a moderate peptidoglycan hydrolase activity. Remarkably, CwpFMs from pathogenic strains harbor a specific stretch of twenty residues intrinsically disordered, inserted between the SH3b3 and the catalytic NLPC_P60 domain. This strongly suggests this linker as a marker of differentiation between B. cereus strains. We believe that our findings improve our understanding of the pathogenicity of B. cereus while advancing both clinical diagnosis and food safety.
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Affiliation(s)
- Seav-Ly Tran
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France; (S.-L.T.); (D.C.); (J.V.)
| | - Delphine Cormontagne
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France; (S.-L.T.); (D.C.); (J.V.)
| | - Jasmina Vidic
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France; (S.-L.T.); (D.C.); (J.V.)
| | - Gwenaëlle André-Leroux
- MaIAGE, INRAE, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
- Correspondence: (G.A.-L.); (N.R.)
| | - Nalini Ramarao
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France; (S.-L.T.); (D.C.); (J.V.)
- Correspondence: (G.A.-L.); (N.R.)
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5
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Transcriptome Sequencing Data of Bacillus anthracis Vollum Δ htrA and Its Parental Strain, Isolated under Oxidative Stress. Microbiol Resour Announc 2020; 9:9/35/e00618-20. [PMID: 32855245 PMCID: PMC7453281 DOI: 10.1128/mra.00618-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The high-temperature requirement chaperone/protease (HtrA) is involved in the stress response of the anthrax-causing pathogen Bacillus anthracis. Resilience to oxidative stress is essential for the manifestation of B. anthracis pathogenicity. Here, we announce transcriptome data sets detailing global gene expression in B. anthracis wild-type and htrA-disrupted strains following H2O2-induced oxidative stress. The high-temperature requirement chaperone/protease (HtrA) is involved in the stress response of the anthrax-causing pathogen Bacillus anthracis. Resilience to oxidative stress is essential for the manifestation of B. anthracis pathogenicity. Here, we announce transcriptome data sets detailing global gene expression in B. anthracis wild-type and htrA-disrupted strains following H2O2-induced oxidative stress.
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6
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Zasada AA. Detection and Identification of Bacillus anthracis: From Conventional to Molecular Microbiology Methods. Microorganisms 2020; 8:E125. [PMID: 31963339 PMCID: PMC7023132 DOI: 10.3390/microorganisms8010125] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 01/13/2020] [Accepted: 01/15/2020] [Indexed: 02/06/2023] Open
Abstract
Rapid and reliable identification of Bacillus anthracis is of great importance, especially in the event of suspected deliberate release of anthrax spores. However, the identification of B. anthracis is challenging due to its high similarity to closely related species. Since Amerithrax in 2001, a lot of effort has been made to develop rapid methods for detection and identification of this microorganism with special focus on easy-to-perform rapid tests for first-line responders. This article presents an overview of the evolution of B. anthracis identification methods from the time of the first description of the microorganism until the present day.
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Affiliation(s)
- Aleksandra A Zasada
- Department of Sera and Vaccines Evaluation, National Institute of Public Health-National Institute of Hygiene, Chocimska 24, 00-791 Warsaw, Poland
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7
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Israeli M, Elia U, Rotem S, Cohen H, Tidhar A, Bercovich-Kinori A, Cohen O, Chitlaru T. Distinct Contribution of the HtrA Protease and PDZ Domains to Its Function in Stress Resilience and Virulence of Bacillus anthracis. Front Microbiol 2019; 10:255. [PMID: 30833938 PMCID: PMC6387919 DOI: 10.3389/fmicb.2019.00255] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 01/30/2019] [Indexed: 12/19/2022] Open
Abstract
Anthrax is a lethal disease caused by the Gram-positive spore-producing bacterium Bacillus anthracis. We previously demonstrated that disruption of htrA gene, encoding the chaperone/protease HtrABA (High Temperature Requirement A of B. anthracis) results in significant virulence attenuation, despite unaffected ability of ΔhtrA strains (in which the htrA gene was deleted) to synthesize the key anthrax virulence factors: the exotoxins and capsule. B. anthracis ΔhtrA strains exhibited increased sensitivity to stress regimens as well as silencing of the secreted starvation-associated Neutral Protease A (NprA) and down-modulation of the bacterial S-layer. The virulence attenuation associated with disruption of the htrA gene was suggested to reflect the susceptibility of ΔhtrA mutated strains to stress insults encountered in the host indicating that HtrABA represents an important B. anthracis pathogenesis determinant. As all HtrA serine proteases, HtrABA exhibits a protease catalytic domain and a PDZ domain. In the present study we interrogated the relative impact of the proteolytic activity (mediated by the protease domain) and the PDZ domain (presumably necessary for the chaperone activity and/or interaction with substrates) on manifestation of phenotypic characteristics mediated by HtrABA. By inspecting the phenotype exhibited by ΔhtrA strains trans-complemented with either a wild-type, truncated (ΔPDZ), or non-proteolytic form (mutated in the catalytic serine residue) of HtrABA, as well as strains exhibiting modified chromosomal alleles, it is shown that (i) the proteolytic activity of HtrABA is essential for its N-terminal autolysis and subsequent release into the extracellular milieu, while the PDZ domain was dispensable for this process, (ii) the PDZ domain appeared to be dispensable for most of the functions related to stress resilience as well as involvement of HtrABA in assembly of the bacterial S-layer, (iii) conversely, the proteolytic activity but not the PDZ domain, appeared to be dispensable for the role of HtrABA in mediating up-regulation of the extracellular protease NprA under starvation stress, and finally (iv) in a murine model of anthrax, the HtrABA PDZ domain, was dispensable for manifestation of B. anthracis virulence. The unexpected dispensability of the PDZ domain may represent a unique characteristic of HtrABA amongst bacterial serine proteases of the HtrA family.
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Affiliation(s)
- Ma'ayan Israeli
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Uri Elia
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Shahar Rotem
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Hila Cohen
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Avital Tidhar
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Adi Bercovich-Kinori
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Ofer Cohen
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Theodor Chitlaru
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona, Israel
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8
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Backert S, Bernegger S, Skórko-Glonek J, Wessler S. Extracellular HtrA serine proteases: An emerging new strategy in bacterial pathogenesis. Cell Microbiol 2018; 20:e12845. [PMID: 29582532 DOI: 10.1111/cmi.12845] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 03/20/2018] [Indexed: 12/18/2022]
Abstract
The HtrA family of chaperones and serine proteases is important for regulating stress responses and controlling protein quality in the periplasm of bacteria. HtrA is also associated with infectious diseases since inactivation of htrA genes results in significantly reduced virulence properties by various bacterial pathogens. These virulence features of HtrA can be attributed to reduced fitness of the bacteria, higher susceptibility to environmental stress and/or diminished secretion of virulence factors. In some Gram-negative and Gram-positive pathogens, HtrA itself can be exposed to the extracellular environment promoting bacterial colonisation and invasion of host tissues. Most of our knowledge on the function of exported HtrAs stems from research on Helicobacter pylori, Campylobacter jejuni, Borrelia burgdorferi, Bacillus anthracis, and Chlamydia species. Here, we discuss recent progress showing that extracellular HtrAs are able to cleave cell-to-cell junction factors including E-cadherin, occludin, and claudin-8, as well as extracellular matrix proteins such as fibronectin, aggrecan, and proteoglycans, disrupting the epithelial barrier and producing substantial host cell damage. We propose that the export of HtrAs is a newly discovered strategy, also applied by additional bacterial pathogens. Consequently, exported HtrA proteases represent highly attractive targets for antibacterial treatment by inhibiting their proteolytic activity or application in vaccine development.
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Affiliation(s)
- Steffen Backert
- Department of Biology, Division of Microbiology, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany
| | - Sabine Bernegger
- Department of Biosciences, Division of Microbiology, Paris Lodron University of Salzburg, Salzburg, Austria
| | - Joanna Skórko-Glonek
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Gdansk, Poland
| | - Silja Wessler
- Department of Biosciences, Division of Microbiology, Paris Lodron University of Salzburg, Salzburg, Austria
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9
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Chitlaru T, Israeli M, Rotem S, Elia U, Bar-Haim E, Ehrlich S, Cohen O, Shafferman A. A novel live attenuated anthrax spore vaccine based on an acapsular Bacillus anthracis Sterne strain with mutations in the htrA, lef and cya genes. Vaccine 2017; 35:6030-6040. [DOI: 10.1016/j.vaccine.2017.03.033] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 01/24/2017] [Accepted: 03/08/2017] [Indexed: 02/06/2023]
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10
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Kim SK, Park YM, Jung KH, Chai YG. Deletion of a putative NlpC/P60 endopeptidase BAS1812 affects germination, long-term survival and endospore formation in Bacillus anthracis. MICROBIOLOGY-SGM 2016; 163:144-152. [PMID: 28008818 DOI: 10.1099/mic.0.000416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Bacillus anthracis, an aetiologic agent of the zoonotic disease anthrax, encodes a putative NlpC/P60 endopeptidase BAS1812. It harbours a signal peptide, three bacterial SH3 domains and an NlpC/P60 family domain. Previous studies showed that BAS1812 is immunogenic in infected hosts and is a potential biomarker for anthrax treatment. To date, however, little information is known about its function and involvement in anthrax pathogenesis. Here we describe the phenotypic effect of BAS1812 deletion in B. anthracis Sterne strain. Transcriptional analysis showed that BAS1812 expression in a host-like environment was enhanced at the end of log phase, started to diminish after entry to stationary phase and increased again late in stationary phase. The constructed BAS1812 mutant showed impaired long-term survival in the stationary growth phase, less resilience to detergent, lesser endospore formation and delayed germination. The mutant also showed diminished ability to degrade peptidoglycan, but its ability to produce anthrax exotoxins was not affected. We hypothesize that BAS1812 is a cell wall hydrolase involved in biological activities related to maintaining cell wall integrity, sporulation and spore germination.
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Affiliation(s)
- Se Kye Kim
- Department of Molecular and Life Science, Hanyang University, 55 Hanyangdaehak-ro, Sangnok-gu, Ansan, Gyeonggi-do 15588, Republic of Korea
| | - Yun Min Park
- Department of Molecular and Life Science, Hanyang University, 55 Hanyangdaehak-ro, Sangnok-gu, Ansan, Gyeonggi-do 15588, Republic of Korea
| | - Kyoung Hwa Jung
- Department of Molecular and Life Science, Hanyang University, 55 Hanyangdaehak-ro, Sangnok-gu, Ansan, Gyeonggi-do 15588, Republic of Korea
| | - Young Gyu Chai
- Department of Bionanotechnology, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea.,Department of Molecular and Life Science, Hanyang University, 55 Hanyangdaehak-ro, Sangnok-gu, Ansan, Gyeonggi-do 15588, Republic of Korea
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11
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Animal Models for the Pathogenesis, Treatment, and Prevention of Infection by Bacillus anthracis. Microbiol Spectr 2016; 3:TBS-0001-2012. [PMID: 26104551 DOI: 10.1128/microbiolspec.tbs-0001-2012] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
This article reviews the characteristics of the major animal models utilized for studies on Bacillus anthracis and highlights their contributions to understanding the pathogenesis and host responses to anthrax and its treatment and prevention. Advantages and drawbacks associated with each model, to include the major models (murine, guinea pig, rabbit, nonhuman primate, and rat), and other less frequently utilized models, are discussed. Although the three principal forms of anthrax are addressed, the main focus of this review is on models for inhalational anthrax. The selection of an animal model for study is often not straightforward and is dependent on the specific aims of the research or test. No single animal species provides complete equivalence to humans; however, each species, when used appropriately, can contribute to a more complete understanding of anthrax and its etiologic agent.
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12
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Next-Generation Bacillus anthracis Live Attenuated Spore Vaccine Based on the htrA(-) (High Temperature Requirement A) Sterne Strain. Sci Rep 2016; 6:18908. [PMID: 26732659 PMCID: PMC4702213 DOI: 10.1038/srep18908] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 11/30/2015] [Indexed: 12/17/2022] Open
Abstract
Anthrax is a lethal disease caused by the gram-positive spore-producing bacterium Bacillus anthracis. Live attenuated vaccines, such as the nonencapsulated Sterne strain, do not meet the safety standards mandated for human use in the Western world and are approved for veterinary purposes only. Here we demonstrate that disrupting the htrA gene, encoding the chaperone/protease HtrA (High Temperature Requirement A), in the virulent Bacillus anthracis Vollum strain results in significant virulence attenuation in guinea pigs, rabbits and mice, underlying the universality of the attenuated phenotype associated with htrA knockout. Accordingly, htrA disruption was implemented for the development of a Sterne-derived safe live vaccine compatible with human use. The novel B. anthracis SterneΔhtrA strain secretes functional anthrax toxins but is 10–104-fold less virulent than the Sterne vaccine strain depending on animal model (mice, guinea pigs, or rabbits). In spite of this attenuation, double or even single immunization with SterneΔhtrA spores elicits immune responses which target toxaemia and bacteremia resulting in protection from subcutaneous or respiratory lethal challenge with a virulent strain in guinea pigs and rabbits. The efficacy of the immune-protective response in guinea pigs was maintained for at least 50 weeks after a single immunization.
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13
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Efficacy of ETI-204 monoclonal antibody as an adjunct therapy in a New Zealand white rabbit partial survival model for inhalational anthrax. Antimicrob Agents Chemother 2015; 59:2206-14. [PMID: 25645849 DOI: 10.1128/aac.04593-14] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Inhalational anthrax is characterized by extensive bacteremia and toxemia as well as nonspecific to mild flu-like symptoms, until the onset of hypotension, shock, and mortality. Without treatment, the mortality rate approaches 100%. Antibiotic treatment is not always effective, and alternative treatments are needed, such as monotherapy for antibiotic-resistant inhalational anthrax or as an adjunct therapy in combination with antibiotics. The Bacillus anthracis antitoxin monoclonal antibody (MAb) ETI-204 is a high-affinity chimeric deimmunized antibody which targets the anthrax toxin protective antigen (PA). In this study, a partial protection New Zealand White (NZW) rabbit model was used to evaluate the protective efficacy of the adjunct therapy with the MAb. Following detection of PA in the blood, NZW rabbits were administered either an antibiotic (doxycycline) alone or the antibiotic in conjunction with ETI-204. Survival was evaluated to compare the efficacy of the combination adjunct therapy with that of an antibiotic alone in treating inhalational anthrax. Overall, the results from this study indicate that a subtherapeutic regimen consisting of an antibiotic in combination with an anti-PA MAb results in increased survival compared to the antibiotic alone and would provide an effective therapeutic strategy against symptomatic anthrax in nonvaccinated individuals.
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14
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Righetti PG, Candiano G, Citterio A, Boschetti E. Combinatorial Peptide Ligand Libraries as a “Trojan Horse” in Deep Discovery Proteomics. Anal Chem 2014; 87:293-305. [DOI: 10.1021/ac502171b] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Pier Giorgio Righetti
- Politecnico di Milano, Department of Chemistry, Materials and Chemical Engineering “Giulio
Natta”, Via Mancinelli
7, Milano 20131, Italy
| | - Giovanni Candiano
- Laboratory on Pathophysiology of Uremia
and Department of Nephrology, Istituto Giannina Gaslini, Genova, Italy
| | - Attilio Citterio
- Politecnico di Milano, Department of Chemistry, Materials and Chemical Engineering “Giulio
Natta”, Via Mancinelli
7, Milano 20131, Italy
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Coleman JL, Crowley JT, Toledo AM, Benach JL. The HtrA protease of Borrelia burgdorferi degrades outer membrane protein BmpD and chemotaxis phosphatase CheX. Mol Microbiol 2013; 88:619-33. [PMID: 23565798 PMCID: PMC3641820 DOI: 10.1111/mmi.12213] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/20/2013] [Indexed: 12/25/2022]
Abstract
Borrelia burgdorferi, the spirochaetal agent of Lyme disease, codes for a single HtrA protein, HtrABb (BB0104) that is homologous to DegP of Escherichia coli (41% amino acid identity). HtrABb shows physical and biochemical similarities to DegP in that it has the trimer as its fundamental unit and can degrade casein via its catalytic serine. Recombinant HtrABb exhibits proteolytic activity in vitro, while a mutant (HtrABbS198A) does not. However, HtrABb and DegP have some important differences as well. Native HtrABb occurs in both membrane-bound and soluble forms. Despite its homology to DegP, HtrABb could not complement an E. coli DegP deletion mutant. Late stage Lyme disease patients, as well as infected mice and rabbits developed a robust antibody response to HtrABb, indicating that it is a B-cell antigen. In co-immunoprecipitation studies, a number of potential binding partners for HtrABb were identified, as well as two specific proteolytic substrates, basic membrane protein D (BmpD/BB0385) and chemotaxis signal transduction phosphatase CheX (BB0671). HtrABb may function in regulating outer membrane lipoproteins and in modulating the chemotactic response of B. burgdorferi.
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Affiliation(s)
- James L Coleman
- New York State Department of Health, Stony Brook University, Stony Brook, NY 11794-5120, USA.
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Kim S, Shahid S, Kim S, Park J, Lee H, Jung K, Chai Y. Comparative analysis of virulence factors secreted by Bacillus anthracis Sterne at host body temperature. Lett Appl Microbiol 2012; 54:306-12. [DOI: 10.1111/j.1472-765x.2012.03209.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Chitlaru T, Zaide G, Ehrlich S, Inbar I, Cohen O, Shafferman A. HtrA is a major virulence determinant of Bacillus anthracis. Mol Microbiol 2011; 81:1542-59. [PMID: 21801240 DOI: 10.1111/j.1365-2958.2011.07790.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We demonstrate that disruption of the htrA (high temperature requirement A) gene in either the virulent Bacillus anthracis Vollum (pXO1(+) , pXO2(+) ), or in the ΔVollum (pXO1(-), pXO2(-), nontoxinogenic and noncapsular) strains, affect significantly the ability of the resulting mutants to withstand heat, oxidative, ethanol and osmotic stress. The ΔhtrA mutants manifest altered secretion of several proteins, as well as complete silencing of the abundant extracellular starvation-associated neutral protease A (NprA). VollumΔhtrA bacteria exhibit delayed proliferation in a macrophage infection assay, and despite their ability to synthesize the major B. anthracis toxins LT (lethal toxin) and ET (oedema toxin) as well as the capsule, show a decrease of over six orders of magnitude in virulence (lethal dose 50% = 3 × 10(8) spores, in the guinea pig model of anthrax), as compared with the parental wild-type strain. This unprecedented extent of loss of virulence in B. anthracis, as a consequence of deletion of a single gene, as well as all other phenotypic defects associated with htrA mutation, are restored in their corresponding trans-complemented strains. It is suggested that the loss of virulence is due to increased susceptibility of the ΔhtrA bacteria to stress insults encountered in the host. On a practical note, it is demonstrated that the attenuated Vollum ΔhtrA is highly efficacious in protecting guinea pigs against a lethal anthrax challenge.
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Affiliation(s)
- Theodor Chitlaru
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 74100, Israel
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Chitlaru T, Altboum Z, Reuveny S, Shafferman A. Progress and novel strategies in vaccine development and treatment of anthrax. Immunol Rev 2011; 239:221-36. [PMID: 21198675 DOI: 10.1111/j.1600-065x.2010.00969.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The lethal anthrax disease is caused by spores of the gram-positive Bacillus anthracis, a member of the cereus group of bacilli. Although the disease is very rare in the Western world, development of anthrax countermeasures gains increasing attention due to the potential use of B. anthracis spores as a bio-terror weapon. Protective antigen (PA), the non-toxic subunit of the bacterial secreted exotoxin, fulfills the role of recognizing a specific receptor and mediating the entry of the toxin into the host target cells. PA elicits a protective immune response and represents the basis for all current anthrax vaccines. Anti-PA neutralizing antibodies are useful correlates for protection and for vaccine efficacy evaluation. Post exposure anti-toxemic and anti-bacteremic prophylactic treatment of anthrax requires prolonged antibiotic administration. Shorter efficient postexposure treatments may require active or passive immunization, in addition to antibiotics. Although anthrax is acknowledged as a toxinogenic disease, additional factors, other than the bacterial toxin, may be involved in the virulence of B. anthracis and may be needed for the long-lasting protection conferred by PA immunization. The search for such novel factors is the focus of several high throughput genomic and proteomic studies that are already leading to identification of novel targets for therapeutics, for vaccine candidates, as well as biomarkers for detection and diagnosis.
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Affiliation(s)
- Theodor Chitlaru
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
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Yee SB, Hatkin JM, Dyer DN, Orr SA, Pitt MLM. Aerosolized Bacillus anthracis infection in New Zealand white rabbits: natural history and intravenous levofloxacin treatment. Comp Med 2010; 60:461-468. [PMID: 21262133 PMCID: PMC3002106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Revised: 07/22/2010] [Accepted: 08/25/2010] [Indexed: 05/30/2023]
Abstract
The natural history for inhalational Bacillus anthracis (Ames strain) exposure in New Zealand white rabbits was investigated to better identify potential, early biomarkers of anthrax. Twelve SPF Bordetella-free rabbits were exposed to 150 LD(50) aerosolized B. anthracis spores, and clinical signs, body temperature, complete blood count, bacteremia, and presence of protective antigen in the blood (that is, antigenemia) were examined. The development of antigenemia and bacteremia coincided and preceded both pyrexia and inversion of the heterophil:lymphocyte ratio, an indicator of infection. Antigenemia was determined within 1 h by electrochemiluminescence immunoassay, compared with the 24-h traditional culture needed for bacteremia determination. Rabbits appeared clinically normal until shortly before succumbing to anthrax approximately 47 h after challenge or approximately 22 h after antigenemia, which suggests a relatively narrow therapeutic window of opportunity. To evaluate the therapeutic rabbit model, B. anthracis-exposed rabbits were treated (after determination of antigenemia and later confirmed to be bacteremic) intravenously with the fluoroquinolone antibiotic levofloxacin for 5 d at a total daily dose of 25 or 12.5 mg/kg, resulting in nearly 90% and 70% survival, respectively, to the study end (28 d after challenge). The peak level for 12.5 mg/kg was equivalent to that observed for a 500-mg daily levofloxacin dose in humans. These results suggest that intravenous levofloxacin is an effective therapeutic against inhalational anthrax. Taken together, our findings indicate that antigenemia is a viable and early biomarker for B. anthracis infection that can be used as a treatment trigger to allow for timely intervention against this highly pathogenic disease.
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Affiliation(s)
- Steven B Yee
- Center for Aerobiological Sciences, United States Army Medical Institute of Infectious Diseases, Fort Detrick, Maryland, USA.
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Abstract
Bacillus anthracis is a Gram-positive, spore-forming bacterium representing the etiological cause of anthrax, a rare lethal disease of animals and humans. Development of anthrax countermeasures has gained increasing attention owing to the potential use of B. anthracis spores as a bioterror weapon. The various forms of infection by B. anthracis are characterized both by toxemia and septicemia, both of which are the result of spore entry into the host followed by their germination into rapidly multiplying, toxin-producing bacilli. Following the publication of the bacterial genome, proteomic studies were carried out to determine the protein composition of the spore and identify exposed vegetative (membrane-located or secreted) proteins. These studies included comparison of strains differing in their virulence, cultured under different conditions and, in some cases, were complemented by serological inspection, which addressed expression during infection of proteomically identified proteins and their immunogenicity. The proteomic approach emerged as a valuable strategy for the generation of a pool of potential B. anthracis protein targets for further evaluation in detection, diagnostics, therapy and prophylaxis, and contributed to the elucidation of some aspects of the pathogenesis of the disease.
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Affiliation(s)
- Theodor Chitlaru
- Department of Biochemistry & Molecular Genetics, Israel Institute for Biological Research, PO Box 19, Ness-Ziona 74100, Israel
| | - Avigdor Shafferman
- Department of Biochemistry & Molecular Genetics, Israel Institute for Biological Research, PO Box 19, Ness-Ziona 74100, Israel
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