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Archana CA, Sekar YS, Suresh KP, Subramaniam S, Sagar N, Rani S, Anandakumar J, Pandey RK, Barman NN, Patil SS. Investigating the Influence of ANTXR2 Gene Mutations on Protective Antigen Binding for Heightened Anthrax Resistance. Genes (Basel) 2024; 15:426. [PMID: 38674361 DOI: 10.3390/genes15040426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 03/14/2024] [Accepted: 03/18/2024] [Indexed: 04/28/2024] Open
Abstract
Bacillus anthracis is the bacterium responsible for causing the zoonotic disease called anthrax. The disease presents itself in different forms like gastrointestinal, inhalation, and cutaneous. Bacterial spores are tremendously adaptable, can persist for extended periods and occasionally endanger human health. The Anthrax Toxin Receptor-2 (ANTXR2) gene acts as membrane receptor and facilitates the entry of the anthrax toxin into host cells. Additionally, mutations in the ANTXR2 gene have been linked to various autoimmune diseases, including Hyaline Fibromatosis Syndrome (HFS), Ankylosing Spondylitis (AS), Juvenile Hyaline Fibromatosis (JHF), and Infantile Systemic Hyalinosis (ISH). This study delves into the genetic landscape of ANTXR2, aiming to comprehend its associations with diverse disorders, elucidate the impacts of its mutations, and pinpoint minimal non-pathogenic mutations capable of reducing the binding affinity of the ANTXR2 gene with the protective antigen. Recognizing the pivotal role of single-nucleotide polymorphisms (SNPs) in shaping genetic diversity, we conducted computational analyses to discern highly deleterious and tolerated non-synonymous SNPs (nsSNPs) in the ANTXR2 gene. The Mutpred2 server determined that the Arg465Trp alteration in the ANTXR2 gene leads to altered DNA binding (p = 0.22) with a probability of a deleterious mutation of 0.808; notably, among the identified deleterious SNPs, rs368288611 (Arg465Trp) stands out due to its significant impact on altering the DNA-binding ability of ANTXR2. We propose these SNPs as potential candidates for hypertension linked to the ANTXR2 gene, which is implicated in blood pressure regulation. Noteworthy among the tolerated substitutions is rs200536829 (Ala33Ser), recognized as less pathogenic; this highlights its potential as a valuable biomarker, potentially reducing side effects on the host while also reducing binding with the protective antigen protein. Investigating these SNPs holds the potential to correlate with several autoimmune disorders and mitigate the impact of anthrax disease in humans.
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Affiliation(s)
| | - Yamini Sri Sekar
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Bengaluru 560064, India
| | | | | | - Ningegowda Sagar
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Bengaluru 560064, India
| | - Swati Rani
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Bengaluru 560064, India
| | - Jayashree Anandakumar
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Bengaluru 560064, India
| | - Rajan Kumar Pandey
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, 17177 Solna, Sweden
| | - Nagendra Nath Barman
- College of Veterinary Science, Assam Agricultural University (AAU), Guwahati 781022, India
| | - Sharanagouda S Patil
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Bengaluru 560064, India
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Georgopoulos AP, James LM. Anthrax Vaccines in the 21st Century. Vaccines (Basel) 2024; 12:159. [PMID: 38400142 PMCID: PMC10892718 DOI: 10.3390/vaccines12020159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/24/2024] [Accepted: 01/30/2024] [Indexed: 02/25/2024] Open
Abstract
Vaccination against Bacillus anthracis is the best preventive measure against the development of deadly anthrax disease in the event of exposure to anthrax either as a bioweapon or in its naturally occurring form. Anthrax vaccines, however, have historically been plagued with controversy, particularly related to their safety. Fortunately, recent improvements in anthrax vaccines have been shown to confer protection with reduced short-term safety concerns, although questions about long-term safety remain. Here, we (a) review recent and ongoing advances in anthrax vaccine development, (b) emphasize the need for thorough characterization of current (and future) vaccines, (c) bring to focus the importance of host immunogenetics as the ultimate determinant of successful antibody production and protection, and (d) discuss the need for the systematic, active, and targeted monitoring of vaccine recipients for possible Chronic Multisymptom Illness (CMI).
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Affiliation(s)
- Apostolos P. Georgopoulos
- The Gulf War Illness Working Group, Brain Sciences Center, Department of Veterans Affairs Health Care System, Minneapolis, MN 55417, USA;
- Department of Neuroscience, University of Minnesota Medical School, Minneapolis, MN 55455, USA
- Department of Psychiatry, University of Minnesota Medical School, Minneapolis, MN 55455, USA
- Department of Neurology, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Lisa M. James
- The Gulf War Illness Working Group, Brain Sciences Center, Department of Veterans Affairs Health Care System, Minneapolis, MN 55417, USA;
- Department of Neuroscience, University of Minnesota Medical School, Minneapolis, MN 55455, USA
- Department of Psychiatry, University of Minnesota Medical School, Minneapolis, MN 55455, USA
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Buyuk F, Dyson H, Laws TR, Celebi O, Doganay M, Sahin M, Baillie L. Human Exposure to Naturally Occurring Bacillus anthracis in the Kars Region of Eastern Türkiye. Microorganisms 2024; 12:167. [PMID: 38257993 PMCID: PMC10818668 DOI: 10.3390/microorganisms12010167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 12/14/2023] [Accepted: 12/20/2023] [Indexed: 01/24/2024] Open
Abstract
Environmental contamination with Bacillus anthracis spores poses uncertain threats to human health. We undertook a study to determine whether inhabitants of the anthrax-endemic region of Kars in eastern Türkiye could develop immune responses to anthrax toxins without recognised clinical infection. We measured anti-PA and anti-LF IgG antibody concentrations by ELISA in serum from 279 volunteers, 105 of whom had previously diagnosed anthrax infection (100 cutaneous, 5 gastrointestinal). Of the 174 without history of infection, 72 had prior contact with anthrax-contaminated material. Individuals were classified according to demographic parameters, daily working environment, and residence type. All villages in this study had recorded previous animal or human anthrax cases. Stepwise regression analyses showed that prior clinical infection correlated strongly with concentrations at the upper end of the ranges observed for both antibodies. For anti-PA, being a butcher and duration of continuous exposure risk correlated with high concentrations, while being a veterinarian or shepherd, time since infection, and town residence correlated with low concentrations. For anti-LF, village residence correlated with high concentrations, while infection limited to fingers or thumbs correlated with low concentrations. Linear discriminant analysis identified antibody concentration profiles associated with known prior infection. Profiles least typical of prior infection were observed in urban dwellers with known previous infection and in veterinarians without history of infection. Four individuals without history of infection (two butchers, two rural dwellers) had profiles suggesting unrecognised prior infection. Healthy humans therefore appear able to tolerate low-level exposure to environmental B. anthracis spores without ill effect, but it remains to be determined whether this exposure is protective. These findings have implications for authorities tasked with reducing the risk posed to human health by spore-contaminated materials and environments.
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Affiliation(s)
- Fatih Buyuk
- Department of Microbiology, Faculty of Veterinary Medicine, Kafkas University, Kars 36300, Türkiye; (F.B.); (M.S.)
| | - Hugh Dyson
- CBR Division, Defence Science and Technology Laboratory, Porton Down, Salisbury SP4 0JQ, UK; (H.D.); (T.R.L.)
| | - Thomas R. Laws
- CBR Division, Defence Science and Technology Laboratory, Porton Down, Salisbury SP4 0JQ, UK; (H.D.); (T.R.L.)
| | - Ozgur Celebi
- Department of Medical Microbiology, Faculty of Medicine, Kafkas University, Kars 36100, Türkiye;
| | - Mehmet Doganay
- Department of Infectious Diseases, Faculty of Medicine, Lokman Hekim University, Ankara 06530, Türkiye;
| | - Mitat Sahin
- Department of Microbiology, Faculty of Veterinary Medicine, Kafkas University, Kars 36300, Türkiye; (F.B.); (M.S.)
- Faculty of Veterinary Medicine, Kyrgyz-Turkısh Manas Unıversıty, Chingiz Aitmatov Campus, Djal, Bishkek 720038, Kyrgyzstan
| | - Les Baillie
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, UK
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Kaufmann SHE. Vaccine development against tuberculosis before and after Covid-19. Front Immunol 2023; 14:1273938. [PMID: 38035095 PMCID: PMC10684952 DOI: 10.3389/fimmu.2023.1273938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 10/16/2023] [Indexed: 12/02/2023] Open
Abstract
Coronavirus disease (Covid-19) has not only shaped awareness of the impact of infectious diseases on global health. It has also provided instructive lessons for better prevention strategies against new and current infectious diseases of major importance. Tuberculosis (TB) is a major current health threat caused by Mycobacterium tuberculosis (Mtb) which has claimed more lives than any other pathogen over the last few centuries. Hence, better intervention measures, notably novel vaccines, are urgently needed to accomplish the goal of the World Health Organization to end TB by 2030. This article describes how the research and development of TB vaccines can benefit from recent developments in the Covid-19 vaccine pipeline from research to clinical development and outlines how the field of TB research can pursue its own approaches. It begins with a brief discussion of major vaccine platforms in general terms followed by a short description of the most widely applied Covid-19 vaccines. Next, different vaccination regimes and particular hurdles for TB vaccine research and development are described. This specifically considers the complex immune mechanisms underlying protection and pathology in TB which involve innate as well as acquired immune mechanisms and strongly depend on fine tuning the response. A brief description of the TB vaccine candidates that have entered clinical trials follows. Finally, it discusses how experiences from Covid-19 vaccine research, development, and rollout can and have been applied to the TB vaccine pipeline, emphasizing similarities and dissimilarities.
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Affiliation(s)
- Stefan H. E. Kaufmann
- Max Planck Institute for Infection Biology, Berlin, Germany
- Systems Immunology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Hagler Institute for Advanced Study, Texas A&M University, College Station, TX, United States
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Ouyang W, Xie T, Fang H, Frucht DM. Development of a New Cell-Based AP-1 Gene Reporter Potency Assay for Anti-Anthrax Toxin Therapeutics. Toxins (Basel) 2023; 15:528. [PMID: 37755954 PMCID: PMC10538138 DOI: 10.3390/toxins15090528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 08/18/2023] [Accepted: 08/24/2023] [Indexed: 09/28/2023] Open
Abstract
Anthrax toxin is a critical virulence factor of Bacillus anthracis. The toxin comprises protective antigen (PA) and two enzymatic moieties, edema factor (EF) and lethal factor (LF), forming bipartite lethal toxin (LT) and edema toxin (ET). PA binds cellular surface receptors and is required for intracellular translocation of the enzymatic moieties. For this reason, anti-PA antibodies have been developed as therapeutics for prophylaxis and treatment of human anthrax infection. Assays described publicly for the control of anti-PA antibody potency quantify inhibition of LT-mediated cell death or the ET-induced increase in c-AMP levels. These assays do not fully reflect and/or capture the pathological functions of anthrax toxin in humans. Herein, we report the development of a cell-based gene reporter potency assay for anti-PA antibodies based on the rapid LT-induced degradation of c-Jun protein, a pathogenic effect that occurs in human cells. This new assay was developed by transducing Hepa1c1c7 cells with an AP-1 reporter lentiviral construct and has been qualified for specificity, accuracy, repeatability, intermediate precision, and linearity. This assay not only serves as a bioassay for LT activity, but has applications for characterization and quality control of anti-PA therapeutic antibodies or other products that target the AP-1 signaling pathway.
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Affiliation(s)
- Weiming Ouyang
- Division of Biotechnology Review and Research II, Office of Biotechnology Products, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA; (T.X.); (H.F.)
| | | | | | - David M. Frucht
- Division of Biotechnology Review and Research II, Office of Biotechnology Products, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA; (T.X.); (H.F.)
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Tsai JM, Kuo HW, Cheng W. Retrospective Screening of Anthrax-like Disease Induced by Bacillus tropicus str. JMT from Chinese Soft-Shell Turtles in Taiwan. Pathogens 2023; 12:pathogens12050693. [PMID: 37242363 DOI: 10.3390/pathogens12050693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 04/19/2023] [Accepted: 05/08/2023] [Indexed: 05/28/2023] Open
Abstract
Bacillus cereus is ubiquitous in the environment and a well-known causative agent of foodborne disease. Surprisingly, more and more emerging strains of atypical B. cereus have been identified and related to severe disease in humans and mammals such as chimpanzees, apes, and bovine. Recently, the atypical B. cereus isolates, which mainly derive from North America and Africa, have drawn great attention due to the potential risk of zoonosis. The cluster of B. cereus carries several anthrax-like virulent genes that are implicated in lethal disease. However, in non-mammals, the distribution of atypical B. cereus is still unknown. In this study, we conducted a retrospective screening of the 32 isolates of Bacillus spp. from diseased Chinese soft-shelled turtles from 2016 to 2020. To recognize the causative agent, we used various methods, such as sequencing analysis using PCR-amplification of the 16S rRNA gene, multiplex PCR for discriminating, and colony morphology by following previous studies. Furthermore, the digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values were calculated, respectively, below the 70 and 96% cutoff to define species boundaries. According to the summarized results, the pathogen is taxonomically classified as Bacillus tropicus str. JMT (previous atypical Bacillus cereus). Subsequently, analyses such as targeting the unique genes using PCR and visual observation of the bacteria under various staining techniques were implemented in our study. Our findings show that all (32/32, 100%) isolates in this retrospective screening share similar phenotypical properties and carry the protective antigen (PA), edema factor (EF), hyaluronic acid (HA), and exopolysaccharide (Bps) genes on their plasmids. In this study, the results indicate that the geographic distribution and host range of B. tropicus were previously underestimated.
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Affiliation(s)
- Jia-Ming Tsai
- Department of Aquaculture, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
- Fish Doctor Veterinary Clinic, Pingtung 94042, Taiwan
| | - Hsin-Wei Kuo
- General Research Service Center, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
| | - Winton Cheng
- Department of Aquaculture, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
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Zhang RR, Wang ZJ, Zhu YL, Tang W, Zhou C, Zhao SQ, Wu M, Ming T, Deng YQ, Chen Q, Jin NY, Ye Q, Li X, Qin CF. Rational development of multicomponent mRNA vaccine candidates against mpox. Emerg Microbes Infect 2023; 12:2192815. [PMID: 36947428 PMCID: PMC10071941 DOI: 10.1080/22221751.2023.2192815] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
The re-emerging mpox (formerly monkeypox) virus (MPXV), a member of Orthopoxvirus genus together with variola virus (VARV) and vaccinia virus (VACV), has led to public health emergency of international concern since July, 2022. Inspired by the unprecedent success of coronavirus disease 2019 (COVID-19) mRNA vaccines, the development of a safe and effective mRNA vaccine against MPXV is of high priority. Based on our established lipid nanoparticle (LNP)-encapsulated mRNA vaccine platform, we rationally constructed and prepared a panel of multicomponent MPXV vaccine candidates encoding different combinations of viral antigens including M1R, E8L, A29L, A35R and B6R. In vitro and in vivo characterization demonstrated that two immunizations of all mRNA vaccine candidates elicit a robust antibody response as well as antigen specific Th1-biased cellular response in mice. Importantly, the penta- and tetra-component vaccine candidates AR-MPXV5 and AR-MPXV4a showed superior capability of inducing neutralizing antibodies as well as of protecting from VACV challenge in mice. Our study provides critical insights to understand the protection mechanism of MPXV infection and direct evidence supporting further clinical development of these multicomponent mRNA vaccine candidates.
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Affiliation(s)
- Rong-Rong Zhang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Zheng-Jian Wang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Yi-Long Zhu
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, China
- Academicians Workstation of Jilin Province, Changchun University of Chinese Medicine, Changchun, 130117, China
| | - Wei Tang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Chao Zhou
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Suo-Qun Zhao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Mei Wu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Tao Ming
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Yong-Qiang Deng
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Qi Chen
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Ning-Yi Jin
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, China
| | - Qing Ye
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Xiao Li
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, China
| | - Cheng-Feng Qin
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
- Research Unit of Discovery and Tracing of Natural Focus Diseases, Chinese Academy of Medical Sciences, Beijing 100071, China
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Zhai LN, Zhao Y, Song XL, Qin TT, Zhang ZJ, Wang JZ, Sui CY, Zhang LL, Lv M, Hu LF, Zhou DS, Fang TY, Yang WH, Wang YC. Inhalable vaccine of bacterial culture supernatant extract mediates protection against fatal pulmonary anthrax. Emerg Microbes Infect 2023; 12:2191741. [PMID: 36920800 PMCID: PMC10071900 DOI: 10.1080/22221751.2023.2191741] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
AbstractPulmonary anthrax is the most fatal clinical form of anthrax and currently available injectable vaccines do not provide adequate protection against it. Hence, next-generation vaccines that effectively induce immunity against pulmonary anthrax are urgently needed. In the present study, we prepared an attenuated and low protease activity Bacillus anthracis strain A16R-5.1 by deleting five of its extracellular protease activity-associated genes and its lef gene through the CRISPR-Cas9 genome editing system. This mutant strain was then used to formulate a lethal toxin (LeTx)-free culture supernatant extract (CSE) anthrax vaccine,of which half was protective antigen (PA). We generated liquid, powder, and powder reconstituted formulations that could be delivered by aerosolized intratracheal inoculation. All of them induced strong humoral, cellular, and mucosal immune responses. The vaccines also produced LeTx neutralizing antibodies and conferred full protection against the lethal aerosol challenges of B. anthracis Pasteur II spores in mice. Compared to the recombinant PA vaccine, the CSE anthrax vaccine with equal PA content provided superior immunoprotection against pulmonary anthrax. The preceding results suggest that the CSE anthrax vaccine developed herein is suitable and scalable for use in inhalational immunization against pulmonary anthrax.
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Affiliation(s)
- Li-Na Zhai
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China.,State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Yue Zhao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China.,Basic medical college, Guizhou Medical University, Guizhou 550004, China
| | - Xiao-Lin Song
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Tong-Tong Qin
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Zhi-Jun Zhang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Jia-Zhen Wang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Cheng-Yu Sui
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Li-Li Zhang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Meng Lv
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Ling-Fei Hu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Dong-Sheng Zhou
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Tong-Yu Fang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Wen-Hui Yang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Yan-Chun Wang
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Biotechnology, Beijing 100071, China
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Sharma S, Bahl V, Srivastava G, Shamim R, Bhatnagar R, Gaur D. Recombinant full-length Bacillus Anthracis protective antigen and its 63 kDa form elicits protective response in formulation with addavax. Front Immunol 2023; 13:1075662. [PMID: 36713362 PMCID: PMC9877290 DOI: 10.3389/fimmu.2022.1075662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 12/16/2022] [Indexed: 01/14/2023] Open
Abstract
Introduction Bacillus anthracis is the causative agent for the lethal disease anthrax, primarily affecting animals and humans in close contact with an infected host. The pathogenicity of B. anthracis is attributed to the secreted exotoxins and their outer capsule. The host cell-binding exotoxin component "protective antigen" (PA) is reported to be a potent vaccine candidate. The aim of our study is to produce several PA constructs and analyze their vaccine potential. Methods We have designed the various subunit, PA-based recombinant proteins, i.e., full-length Protective antigen (PA-FL), C-terminal 63 kDa fragment (PA63), Protective antigen domain 1-domain 4 chimeras (PA-D1-4) and protective antigen domain 4 (PA-D4) and analyzed their vaccine potential with different human-compatible adjuvants in the mouse model. We have optimized the process and successfully expressed our recombinant antigens as soluble proteins, except full-length PA. All the recombinant antigen formulations with three different adjuvants i.e., Addavax, Alhydrogel, and Montanide ISA 720, were immunized in different mouse groups. The vaccine efficacy of the formulations was analyzed by mouse serum antigen-specific antibody titer, toxin neutralization assay, and survival analysis of mouse groups challenged with a lethal dose of B. anthracis virulent spores. Results We have demonstrated that the PA-FL addavax and PA63 addavax formulations were most effective in protecting spore-challenged mice and serum from the mice immunized with PAFL addavax, PA-FL alhydrogel, PA63 addavax, and PA63 alhydrogel formulations were equivalently efficient in neutralizing the anthrax lethal toxin. The higher levels of serum Th1, Th2, and Th17 cytokines in PA-FL addavax immunized mice correspond to the enhanced protection provided by the formulation in challenged mice. Discussion We have demonstrated that the PA-FL addavax and PA63 addavax formulations exhibit equivalent efficiency as vaccine formulation both in a mouse model of anthrax and mammalian cell lines. However, PA63 is a smaller antigen than PA-FL and more importantly, PA63 is expressed as a soluble protein in E. coli, which imparts a translational advantage to PA63-based formulation. Thus, the outcome of our study has significant implications for the development of protective antigen-based vaccine formulations for human use against the lethal disease anthrax.
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Affiliation(s)
- Shikhar Sharma
- Laboratory of Malaria & Vaccine Research, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India,Department of Oncology Science, University of Oklahoma Health Science Center, Oklahoma City, OK, United States,*Correspondence: Shikhar Sharma, ;
| | - Vanndita Bahl
- Laboratory of Malaria & Vaccine Research, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Gaurav Srivastava
- Food Technology Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India
| | - Risha Shamim
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Rakesh Bhatnagar
- Molecular Biology and Genetic Engineering Laboratory, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Deepak Gaur
- Laboratory of Malaria & Vaccine Research, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
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Wang J, Chen Y, He X, Du X, Gao Y, Shan X, Hu Z, Hu Q. PaR1 secreted by the type IX secretion system is a protective antigen of Riemerella anatipestifer. Front Microbiol 2023; 13:1082712. [PMID: 36713192 PMCID: PMC9874225 DOI: 10.3389/fmicb.2022.1082712] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 12/28/2022] [Indexed: 01/12/2023] Open
Abstract
Riemerella anatipestifer mainly infects domestic ducks, geese, turkeys, and other birds, and causes considerable economic losses to the global duck industry. Previous studies have shown that concentrated cell-free culture filtrates of R. anatipestifer induce highly significant protection against homologous challenge. In this study, 12 immunogenic proteins were identified in the culture supernatant of R. anatipestifer strain Yb2 with immunoproteomic analysis. Of these, three immunogenic proteins, AS87_RS06600 (designated "PaR1" in this study), AS87_RS09020, and AS87_RS09965, which appeared in more than three spots on the western-blotted membrane, were expressed in Escherichia coli and purified. Animal experiments showed that the recombinant PaR1 (rPaR1) protein protected 41.67% of immunized ducklings against challenge with virulent Yb2, whereas rAS87_RS09020 or rAS87_RS09965 did not, and that ducklings immunized once with rPaR1 were 20, 40, and 0% protected from challenge with R. anatipestifer strains WJ4 (serotype 1), Yb2 (serotype 2), and HXb2 (serotype 10), respectively. In addition, rPaR1 immunized rabbit serum showed bactericidal activity against strain Yb2 at a titer of 1:8. These results indicate that rPaR1 of strain Yb2 protects against homologous challenge. Amino acid homology analysis show that PaR1 is a non-serotype-specific protein among different R. anatipestifer serotypes. Furthermore, PaR1 is mainly secreted outside the cell through the T9SS. Overall, our results demonstrate that R. anatipestifer PaR1 is a non-serotype-specific protective protein secreted by the T9SS.
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11
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Abstract
BACKGROUND The deliberate use of Bacillus anthracis spores is believed by the US government to be a high bioweapons threat. The first line of defense following potential exposure to B. anthracis spores would be postexposure prophylaxis with antimicrobials that have activity against B. anthracis. Additional therapies to address the effects of toxins may be needed in systemically ill individuals. Over the last 2 decades, the United States government (USG) collaborated with the private sector to develop, test, and stockpile 3 antitoxins: anthrax immunoglobulin intravenous (AIGIV), raxibacumab, and obiltoxaximab. All 3 products target protective antigen, a protein factor common to the 2 exotoxins released by B. anthracis, and hamper or block the toxins' effects and prevent or reduce pathogenesis. These antitoxins were approved for licensure by the United States Food and Drug Administration based on animal efficacy studies compared to placebo. METHODS We describe USG-sponsored pre- and postlicensure studies that compared efficacy of 3 antitoxins in a New Zealand White rabbit model of inhalation anthrax; survival following a lethal aerosolized dose of B. anthracis spores was the key measure of effectiveness. To model therapeutic intervention, intravenous treatments were started following onset of antigenemia. RESULTS In pre- and postlicensure studies, all 3 antitoxins were superior to placebo; in the postlicensure study, raxibacumab and obiltoxaximab were superior to AIGIV, but neither was superior to the other. CONCLUSIONS These data illustrate the relative therapeutic benefit of the 3 antitoxins and provide a rationale to prioritize their deployment.
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Affiliation(s)
- Raymond M Slay
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Rachel Cook
- Oak Ridge Institute for Science and Education, CDC Fellowship Program, Division of High-Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Katherine Hendricks
- Division of High-Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - David Boucher
- Office of the Assistant Secretary for Preparedness and Response, Biomedical Advanced Research and Development Authority, Washington, District of Columbia, USA
| | - Michael Merchlinsky
- Office of the Assistant Secretary for Preparedness and Response, Biomedical Advanced Research and Development Authority, Washington, District of Columbia, USA
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12
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Michelman-Ribeiro A, Rubinson KA, Silin V, Kasianowicz JJ. Solution Structures of Bacillus anthracis Protective Antigen Proteins Using Small Angle Neutron Scattering and Protective Antigen 63 Ion Channel Formation Kinetics. Toxins (Basel) 2021; 13:888. [PMID: 34941724 DOI: 10.3390/toxins13120888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/03/2021] [Accepted: 12/06/2021] [Indexed: 11/17/2022] Open
Abstract
We are studying the structures of bacterial toxins that form ion channels and enable macromolecule transport across membranes. For example, the crystal structure of the Staphylococcus aureus α-hemolysin (α-HL) channel in its functional state was confirmed using neutron reflectometry (NR) with the protein reconstituted in membranes tethered to a solid support. This method, which provides sub-nanometer structural information, could also test putative structures of the Bacillus anthracis protective antigen 63 (PA63) channel, locate where B. anthracis lethal factor and edema factor toxins (LF and EF, respectively) bind to it, and determine how certain small molecules can inhibit the interaction of LF and EF with the channel. We report here the solution structures of channel-forming PA63 and its precursor PA83 (which does not form channels) obtained with small angle neutron scattering. At near neutral pH, PA83 is a monomer and PA63 a heptamer. The latter is compared to two cryo-electron microscopy structures. We also show that although the α-HL and PA63 channels have similar structural features, unlike α-HL, PA63 channel formation in lipid bilayer membranes ceases within minutes of protein addition, which currently precludes the use of NR for elucidating the interactions between PA63, LF, EF, and potential therapeutic agents.
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13
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Sun W, Zhang H, Fan W, He L, Chen T, Zhou X, Qi Y, Sun L, Hu R, Luo T, Liu W, Li J. Evaluation of Cellular Immunity with ASFV Infection by Swine Leukocyte Antigen (SLA)-Peptide Tetramers. Viruses 2021; 13:v13112264. [PMID: 34835070 PMCID: PMC8617699 DOI: 10.3390/v13112264] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/05/2021] [Accepted: 11/10/2021] [Indexed: 12/27/2022] Open
Abstract
African swine fever virus (ASFV) causes acute hemorrhagic fever in domestic pigs and wild boars, resulting in incalculable economic losses to the pig industry. As the mechanism of viral infection is not clear, protective antigens have not been discovered or identified. In this study, we determined that the p30, pp62, p72, and CD2v proteins were all involved in the T cell immune response of live pigs infected with ASFV, among which p72 and pp62 proteins were the strongest. Panoramic scanning was performed on T cell epitopes of the p72 protein, and three high-frequency positive epitopes were selected to construct a swine leukocyte antigen (SLA)-tetramer, and ASFV-specific T cells were detected. Subsequently, the specific T cell and humoral immune responses of ASFV-infected pigs and surviving pigs were compared. The results demonstrate that the specific T cellular immunity responses gradually increased during the infection and were higher than that in the surviving pigs in the late stages of infection. The same trend was observed in specific humoral immune responses, which were highest in surviving pigs. In general, our study provides key information for the exploration of ASFV-specific immune responses and the development of an ASFV vaccine.
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Affiliation(s)
- Wenqiang Sun
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources & Laboratory of Animal Infectious Diseases, College of Animal Sciences and Veterinary Medicine, Guangxi University, Nanning 530004, China;
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (H.Z.); (W.F.); (L.H.); (L.S.)
- Institute of Infectious Diseases, Shenzhen Bay Laboratory, Shenzhen 518000, China
| | - He Zhang
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (H.Z.); (W.F.); (L.H.); (L.S.)
- Institute of Infectious Diseases, Shenzhen Bay Laboratory, Shenzhen 518000, China
| | - Wenhui Fan
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (H.Z.); (W.F.); (L.H.); (L.S.)
| | - Lihong He
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (H.Z.); (W.F.); (L.H.); (L.S.)
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Teng Chen
- Institute of Military Veterinary Medicine, Academy of Military Medical Science, Changchun 130122, China; (T.C.); (X.Z.); (Y.Q.)
| | - Xintao Zhou
- Institute of Military Veterinary Medicine, Academy of Military Medical Science, Changchun 130122, China; (T.C.); (X.Z.); (Y.Q.)
| | - Yu Qi
- Institute of Military Veterinary Medicine, Academy of Military Medical Science, Changchun 130122, China; (T.C.); (X.Z.); (Y.Q.)
| | - Lei Sun
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (H.Z.); (W.F.); (L.H.); (L.S.)
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Rongliang Hu
- Institute of Military Veterinary Medicine, Academy of Military Medical Science, Changchun 130122, China; (T.C.); (X.Z.); (Y.Q.)
- Correspondence: (R.H.); (T.L.); (W.L.); (J.L.)
| | - Tingrong Luo
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources & Laboratory of Animal Infectious Diseases, College of Animal Sciences and Veterinary Medicine, Guangxi University, Nanning 530004, China;
- Correspondence: (R.H.); (T.L.); (W.L.); (J.L.)
| | - Wenjun Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources & Laboratory of Animal Infectious Diseases, College of Animal Sciences and Veterinary Medicine, Guangxi University, Nanning 530004, China;
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (H.Z.); (W.F.); (L.H.); (L.S.)
- Institute of Infectious Diseases, Shenzhen Bay Laboratory, Shenzhen 518000, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence: (R.H.); (T.L.); (W.L.); (J.L.)
| | - Jing Li
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (H.Z.); (W.F.); (L.H.); (L.S.)
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence: (R.H.); (T.L.); (W.L.); (J.L.)
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14
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Romanenko YO, Riabko AK, Marin MA, Kartseva AS, Silkina MV, Shemyakin IG, Firstova VV. Mechanism of Action of Monoclonal Antibodies That Block the Activity of the Lethal Toxin of Bacillus Anthracis. Acta Naturae 2021; 13:98-104. [PMID: 35127153 PMCID: PMC8807536 DOI: 10.32607/actanaturae.11387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 03/22/2021] [Indexed: 11/20/2022] Open
Abstract
Neutralization of the lethal toxin of Bacillus anthracis is an important topic of both fundamental medicine and practical health care, regarding the fight against highly dangerous infections. We have generated a neutralizing monoclonal antibody 1E10 against the lethal toxin of Bacillus anthracis and described the stages of receptor interaction between the protective antigen (PA) and the surface of eukaryotic cells, the formation of PA oligomers, assembly of the lethal toxin (LT), and its translocation by endocytosis into the eukaryotic cell, followed by the formation of a true pore and the release of LT into the cell cytosol. The antibody was shown to act selectively at the stage of interaction between Bacillus anthracis and the eukaryotic cell, and the mechanism of toxin-neutralizing activity of the 1E10 antibody was revealed. The interaction between the 1E10 monoclonal antibody and PA was found to lead to inhibition of the enzymatic activity of the lethal factor (LF), most likely due to a disruption of true pore formation by PA, which blocks the release of LF into the cytosol.
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Affiliation(s)
- Ya. O. Romanenko
- Federal Budget Institution of Science State Research Center for Applied Microbiology and Biotechnology of Rospotrebnadzor, Obolensk, Moscow Region, 142279 Russia
| | - A. K. Riabko
- Federal Budget Institution of Science State Research Center for Applied Microbiology and Biotechnology of Rospotrebnadzor, Obolensk, Moscow Region, 142279 Russia
| | - M. A. Marin
- Federal Budget Institution of Science State Research Center for Applied Microbiology and Biotechnology of Rospotrebnadzor, Obolensk, Moscow Region, 142279 Russia
| | - A. S. Kartseva
- Federal Budget Institution of Science State Research Center for Applied Microbiology and Biotechnology of Rospotrebnadzor, Obolensk, Moscow Region, 142279 Russia
| | - M. V. Silkina
- Federal Budget Institution of Science State Research Center for Applied Microbiology and Biotechnology of Rospotrebnadzor, Obolensk, Moscow Region, 142279 Russia
| | - I. G. Shemyakin
- Federal Budget Institution of Science State Research Center for Applied Microbiology and Biotechnology of Rospotrebnadzor, Obolensk, Moscow Region, 142279 Russia
| | - V. V. Firstova
- Federal Budget Institution of Science State Research Center for Applied Microbiology and Biotechnology of Rospotrebnadzor, Obolensk, Moscow Region, 142279 Russia
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15
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Vietri NJ, Tobery SA, Chabot DJ, Ingavale S, Somerville BC, Miller JA, Schellhase CW, Twenhafel NA, Fetterer DP, Cote CK, Klimko CP, Boyer AE, Woolfitt AR, Barr JR, Wright ME, Friedlander AM. Clindamycin Protects Nonhuman Primates Against Inhalational Anthrax But Does Not Enhance Reduction of Circulating Toxin Levels When Combined With Ciprofloxacin. J Infect Dis 2021; 223:319-325. [PMID: 32697310 DOI: 10.1093/infdis/jiaa365] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 06/19/2020] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Inhalational anthrax is rare and clinical experience limited. Expert guidelines recommend treatment with combination antibiotics including protein synthesis-inhibitors to decrease toxin production and increase survival, although evidence is lacking. METHODS Rhesus macaques exposed to an aerosol of Bacillus anthracis spores were treated with ciprofloxacin, clindamycin, or ciprofloxacin + clindamycin after becoming bacteremic. Circulating anthrax lethal factor and protective antigen were quantitated pretreatment and 1.5 and 12 hours after beginning antibiotics. RESULTS In the clindamycin group, 8 of 11 (73%) survived demonstrating its efficacy for the first time in inhalational anthrax, compared to 9 of 9 (100%) with ciprofloxacin, and 8 of 11 (73%) with ciprofloxacin + clindamycin. These differences were not statistically significant. There were no significant differences between groups in lethal factor or protective antigen levels from pretreatment to 12 hours after starting antibiotics. Animals that died after clindamycin had a greater incidence of meningitis compared to those given ciprofloxacin or ciprofloxacin + clindamycin, but numbers of animals were very low and no definitive conclusion could be reached. CONCLUSION Treatment of inhalational anthrax with clindamycin was as effective as ciprofloxacin in the nonhuman primate. Addition of clindamycin to ciprofloxacin did not enhance reduction of circulating toxin levels.
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Affiliation(s)
- Nicholas J Vietri
- Division of Bacteriology, United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, USA
| | - Steven A Tobery
- Division of Bacteriology, United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, USA
| | - Donald J Chabot
- Division of Bacteriology, United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, USA
| | - Susham Ingavale
- Division of Bacteriology, United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, USA
| | - Brandon C Somerville
- Division of Bacteriology, United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, USA
| | - Jeremy A Miller
- Division of Bacteriology, United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, USA
| | - Chris W Schellhase
- Division of Pathology, United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, USA
| | - Nancy A Twenhafel
- Division of Pathology, United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, USA
| | - David P Fetterer
- Division of Biostatistics, United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, USA
| | - Christopher K Cote
- Division of Bacteriology, United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, USA
| | - Christopher P Klimko
- Division of Bacteriology, United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, USA
| | - Anne E Boyer
- National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Adrian R Woolfitt
- National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - John R Barr
- National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Mary E Wright
- Division of Clinical Research, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, USA
| | - Arthur M Friedlander
- Headquarters, United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, USA.,Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
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16
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Hoelzgen F, Zalk R, Alcalay R, Cohen-Schwartz S, Garau G, Shahar A, Mazor O, Frank GA. Neutralization of the anthrax toxin by antibody-mediated stapling of its membrane-penetrating loop. Acta Crystallogr D Struct Biol 2021; 77:1197-1205. [PMID: 34473089 DOI: 10.1107/s2059798321007816] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 07/30/2021] [Indexed: 12/15/2022]
Abstract
Anthrax infection is associated with severe illness and high mortality. Protective antigen (PA) is the central component of the anthrax toxin, which is one of two major virulence factors of Bacillus anthracis, the causative agent of anthrax disease. Upon endocytosis, PA opens a pore in the membranes of endosomes, through which the cytotoxic enzymes of the toxin are extruded. The PA pore is formed by a cooperative conformational change in which the membrane-penetrating loops of PA associate, forming a hydrophobic rim that pierces the membrane. Due to its crucial role in anthrax progression, PA is an important target for monoclonal antibody-based therapy. cAb29 is a highly effective neutralizing antibody against PA. Here, the cryo-EM structure of PA in complex with the Fab portion of cAb29 was determined. It was found that cAb29 neutralizes the toxin by clamping the membrane-penetrating loop of PA to the static surface-exposed loop of the D3 domain of the same subunit, thereby preventing pore formation. These results provide the structural basis for the antibody-based neutralization of PA and bring into focus the membrane-penetrating loop of PA as a target for the development of better anti-anthrax vaccines.
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Affiliation(s)
- F Hoelzgen
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel
| | - R Zalk
- Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel
| | - R Alcalay
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - S Cohen-Schwartz
- The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel
| | - G Garau
- Biostructures Lab, IIT@NEST - Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56124 Pisa, Italy
| | - A Shahar
- Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel
| | - O Mazor
- Department of Infectious Diseases, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - G A Frank
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel
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17
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Dyke JS, Huertas-Diaz MC, Michel F, Holladay NE, Hogan RJ, He B, Lafontaine ER. The Peptidoglycan-associated lipoprotein Pal contributes to the virulence of Burkholderia mallei and provides protection against lethal aerosol challenge. Virulence 2021; 11:1024-1040. [PMID: 32799724 PMCID: PMC7567441 DOI: 10.1080/21505594.2020.1804275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Burkholderia mallei is a highly pathogenic bacterium that causes the fatal zoonosis glanders. The organism specifies multiple membrane proteins, which represent prime targets for the development of countermeasures given their location at the host-pathogen interface. We investigated one of these proteins, Pal, and discovered that it is involved in the ability of B. mallei to resist complement-mediated killing and replicate inside host cells in vitro, is expressed in vivo and induces antibodies during the course of infection, and contributes to virulence in a mouse model of aerosol infection. A mutant in the pal gene of the B. mallei wild-type strain ATCC 23344 was found to be especially attenuated, as BALB/c mice challenged with the equivalent of 5,350 LD50 completely cleared infection. Based on these findings, we tested the hypothesis that a vaccine containing the Pal protein elicits protective immunity against aerosol challenge. To achieve this, the pal gene was cloned in the vaccine vector Parainfluenza Virus 5 (PIV5) and mice immunized with the virus were infected with a lethal dose of B. mallei. These experiments revealed that a single dose of PIV5 expressing Pal provided 80% survival over a period of 40 days post-challenge. In contrast, only 10% of mice vaccinated with a PIV5 control virus construct survived infection. Taken together, our data establish that the Peptidoglycan-associated lipoprotein Pal is a critical virulence determinant of B. mallei and effective target for developing a glanders vaccine.
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Affiliation(s)
- Jeremy S Dyke
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine , Athens, GA, USA
| | | | - Frank Michel
- Department of Veterinary Biosciences and Diagnostic Imaging, University of Georgia College of Veterinary Medicine , Athens, GA, USA
| | - Nathan E Holladay
- Department of Veterinary Biosciences and Diagnostic Imaging, University of Georgia College of Veterinary Medicine , Athens, GA, USA
| | - Robert J Hogan
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine , Athens, GA, USA.,Department of Veterinary Biosciences and Diagnostic Imaging, University of Georgia College of Veterinary Medicine , Athens, GA, USA
| | - Biao He
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine , Athens, GA, USA
| | - Eric R Lafontaine
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine , Athens, GA, USA
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18
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Abdous M, Hasannia S, Salmanian AH, Arab SS. Efficacy assessment of a triple anthrax chimeric antigen as a vaccine candidate in guinea pigs: challenge test with Bacillus anthracis 17 JB strain spores. Immunopharmacol Immunotoxicol 2021; 43:495-502. [PMID: 34259590 DOI: 10.1080/08923973.2021.1945087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
CONTEXT Bacillus anthracis secretes a tripartite toxin comprising protective antigen (PA), edema factor (EF), and lethal factor (LF). The human anthrax vaccine is mainly composed of the anthrax protective antigen (PA). Considerable efforts are being directed towards improving the efficacy of vaccines because the use of commercial anthrax vaccines (human/veterinary) is associated with several limitations. OBJECTIVE In this study, a triple chimeric antigen referred to as ELP (gene accession no: MT590758) comprising highly immunogenic domains of PA, LF, and EF was designed, constructed, and assessed for the immunization capacity against anthrax in a guinea pig model. MATERIALS AND METHODS Immunization was carried out considering antigen titration and immunization protocol. The immunoprotective efficacy of the ELP was evaluated in guinea pigs and compared with the potency of veterinary anthrax vaccine using a challenge test with B. anthracis 17JB strain spores. RESULTS The results demonstrated that the ELP antigen induced strong humoral responses. The T-cell response of the ELP was found to be similar to PA, and showed that the ELP could protect 100%, 100%, 100%, 80% and 60% of the animals from 50, 70, 90, 100 and 120 times the minimum lethal dose (MLD, equal 5 × 105 spore/ml), respectively, which killed control animals within 48 h. DISCUSSION AND CONCLUSIONS It is concluded that the ELP antigen has the necessary requirement for proper immunization against anthrax and it can be used to develop an effective recombinant vaccine candidate against anthrax.
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Affiliation(s)
- Masoud Abdous
- Institute of Medical Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | - Sadegh Hasannia
- Faculty of Biological Sciences, Department of Biochemistry, Tarbiat Modares University, Tehran, Iran
| | - Ali Hatef Salmanian
- Institute of Medical Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | - Seyed-Shahryar Arab
- Faculty of Biological Sciences, Department of Biochemistry, Tarbiat Modares University, Tehran, Iran
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19
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Byvalov AA, Konyshev IV, Uversky VN, Dentovskaya SV, Anisimov AP. Yersinia Outer Membrane Vesicles as Potential Vaccine Candidates in Protecting against Plague. Biomolecules 2020; 10:E1694. [PMID: 33353123 PMCID: PMC7766529 DOI: 10.3390/biom10121694] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 12/03/2020] [Accepted: 12/16/2020] [Indexed: 11/18/2022] Open
Abstract
Despite the relatively low incidence of plague, its etiological agent, Yersinia pestis, is an exceptional epidemic danger due to the high infectivity and mortality of this infectious disease. Reports on the isolation of drug-resistant Y. pestis strains indicate the advisability of using asymmetric responses, such as phage therapy and vaccine prophylaxis in the fight against this problem. The current relatively effective live plague vaccine is not approved for use in most countries because of its ability to cause heavy local and system reactions and even a generalized infectious process in people with a repressed immune status or metabolic disorders, as well as lethal infection in some species of nonhuman primates. Therefore, developing alternative vaccines is of high priority and importance. However, until now, work on the development of plague vaccines has mainly focused on screening for the potential immunogens. Several investigators have identified the protective potency of bacterial outer membrane vesicles (OMVs) as a promising basis for bacterial vaccine candidates. This review is aimed at presenting these candidates of plague vaccine and the results of their analysis in animal models.
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Affiliation(s)
- Andrey A. Byvalov
- Komi Research Center, Laboratory of Microbial Physiology, Institute of Physiology, Ural Branch, Russian Academy of Sciences, 167982 Syktyvkar, Russia;
- Department of Biotechnology, Vyatka State University, 610000 Kirov, Russia
| | - Ilya V. Konyshev
- Komi Research Center, Laboratory of Microbial Physiology, Institute of Physiology, Ural Branch, Russian Academy of Sciences, 167982 Syktyvkar, Russia;
- Department of Biotechnology, Vyatka State University, 610000 Kirov, Russia
| | - Vladimir N. Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer’s Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia
| | - Svetlana V. Dentovskaya
- Laboratory for Plague Microbiology, Especially Dangerous Infections Department, State Research Center for Applied Microbiology and Biotechnology, 142279 Obolensk, Russia;
| | - Andrey P. Anisimov
- Laboratory for Plague Microbiology, Especially Dangerous Infections Department, State Research Center for Applied Microbiology and Biotechnology, 142279 Obolensk, Russia;
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Lawrence WS, Peel JE, Sivasubramani SK, Baze WB, Whorton EB, Beasley DWC, Comer JE, Hughes DE, Ling LL, Peterson JW. Teixobactin Provides Protection against Inhalation Anthrax in the Rabbit Model. Pathogens 2020; 9:pathogens9090773. [PMID: 32971758 PMCID: PMC7558628 DOI: 10.3390/pathogens9090773] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 09/17/2020] [Accepted: 09/18/2020] [Indexed: 01/20/2023] Open
Abstract
The use of antibiotics is a vital means of treating infections caused by the bacteria Bacillus (B.) anthracis. Importantly, with the potential future use of multidrug-resistant strains of B. anthracis as bioweapons, new antibiotics are needed as alternative therapeutics. In this blinded study, we assessed the protective efficacy of teixobactin, a recently discovered antibiotic, against inhalation anthrax infection in the adult rabbit model. New Zealand White rabbits were infected with a lethal dose of B. anthracis Ames spores via the inhalation route, and blood samples were collected at various times to assess antigenemia, bacteremia, tissue bacterial load, and antibody production. Treatments were administered upon detection of B. anthracis protective antigen in the animals’ sera. For comparison, a fully protective dose of levofloxacin was used as a positive control. Rabbits treated with teixobactin showed 100% survival following infection, and the bacteremia was completely resolved by 24–48 h post-treatment. In addition, the bacterial/spore loads in tissues of the animals treated with teixobactin were either zero or dramatically less relative to that of the negative control animals. Moreover, microscopic evaluation of the tissues revealed decreased pathology following treatment with teixobactin. Overall, these results show that teixobactin was protective against inhalation anthrax infection in the rabbit model, and they indicate the potential of teixobactin as a therapeutic for the disease.
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Affiliation(s)
- William S. Lawrence
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA; (J.E.P.); (D.W.C.B.); (J.E.C.); (J.W.P.)
- Institute for Human Infections & Immunity, University of Texas Medical Branch, Galveston, TX 77555, USA;
- Correspondence: ; Tel.: +1-409-266-6919
| | - Jennifer E. Peel
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA; (J.E.P.); (D.W.C.B.); (J.E.C.); (J.W.P.)
| | - Satheesh K. Sivasubramani
- Directorate of Environmental Health Effects Laboratory, Naval Medical Research Unit, Dayton, OH 45433, USA;
| | - Wallace B. Baze
- Department of Comparative Medicine, University of Texas MD Anderson Cancer Center, Bastrop, TX 78602, USA;
| | - Elbert B. Whorton
- Institute for Human Infections & Immunity, University of Texas Medical Branch, Galveston, TX 77555, USA;
| | - David W. C. Beasley
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA; (J.E.P.); (D.W.C.B.); (J.E.C.); (J.W.P.)
- Institutional Office of Regulated Nonclinical Studies, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Jason E. Comer
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA; (J.E.P.); (D.W.C.B.); (J.E.C.); (J.W.P.)
- Institutional Office of Regulated Nonclinical Studies, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Dallas E. Hughes
- NovoBiotic Pharmaceuticals, LLC, Cambridge, MA 02138, USA; (D.E.H.); (L.L.L.)
| | - Losee L. Ling
- NovoBiotic Pharmaceuticals, LLC, Cambridge, MA 02138, USA; (D.E.H.); (L.L.L.)
| | - Johnny W. Peterson
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA; (J.E.P.); (D.W.C.B.); (J.E.C.); (J.W.P.)
- Institute for Human Infections & Immunity, University of Texas Medical Branch, Galveston, TX 77555, USA;
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Ryabchevskaya EM, Evtushenko EA, Granovskiy DL, Ivanov PA, Atabekov JG, Kondakova OA, Nikitin NA, Karpova OV. Two approaches for the stabilization of Bacillus anthracis recombinant protective antigen. Hum Vaccin Immunother 2020; 17:560-565. [PMID: 32614657 DOI: 10.1080/21645515.2020.1772632] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Anthrax is a zoonotic disease caused by the gram-positive spore-forming bacteria Bacillus anthracis. There is a need for safe, highly effective, long-term storage vaccine formulations for mass vaccination. However, the development of new subunit vaccines based on recombinant protective antigen (rPA) faces the problem of vaccine antigen instability. Here, the potential of simultaneous application of two different approaches to stabilize rPA was demonstrated. Firstly, we employed spherical particles (SPs) obtained from the tobacco mosaic virus (TMV). Previously, we had reported that SPs can serve as an adjuvant and platform for antigen presentation. In the current work, SPs were shown to increase the stability of the full-size rPA without loss of its antigenic properties. The second direction was site-specific mutagenesis of asparagine residues to avoid deamidation that causes partial protein degradation. The modified recombinant protein comprising the PA immunogenic domains 3 and 4 (rPA3 + 4) was stable during storage at 4 and 25°C. rPA3 + 4 interacts with antibodies to rPA83 both individually and as a part of a complex with SPs. The results obtained can underpin the development of a recombinant vaccine with a full-size modified rPA (with similar amino acid substitutions that stabilize the protein) and SPs.
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Affiliation(s)
- Ekaterina M Ryabchevskaya
- Department of Virology, Faculty of Biology, Lomonosov Moscow State University , Moscow, Russian Federation
| | - Ekaterina A Evtushenko
- Department of Virology, Faculty of Biology, Lomonosov Moscow State University , Moscow, Russian Federation
| | - Dmitry L Granovskiy
- Department of Virology, Faculty of Biology, Lomonosov Moscow State University , Moscow, Russian Federation
| | - Peter A Ivanov
- Department of Virology, Faculty of Biology, Lomonosov Moscow State University , Moscow, Russian Federation
| | - Joseph G Atabekov
- Department of Virology, Faculty of Biology, Lomonosov Moscow State University , Moscow, Russian Federation
| | - Olga A Kondakova
- Department of Virology, Faculty of Biology, Lomonosov Moscow State University , Moscow, Russian Federation
| | - Nikolai A Nikitin
- Department of Virology, Faculty of Biology, Lomonosov Moscow State University , Moscow, Russian Federation
| | - Olga V Karpova
- Department of Virology, Faculty of Biology, Lomonosov Moscow State University , Moscow, Russian Federation
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Kumar M, Puranik N, Varshney A, Tripathi N, Pal V, Goel AK. BA3338, a surface layer homology domain possessing protein augments immune response and protection efficacy of protective antigen against Bacillus anthracis in mouse model. J Appl Microbiol 2020; 129:443-452. [PMID: 32118336 DOI: 10.1111/jam.14624] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 02/20/2020] [Accepted: 02/26/2020] [Indexed: 02/07/2023]
Abstract
AIM Category A classified Bacillus anthracis is highly fatal pathogen that causes anthrax and creates challenges for global security and public health. In this study, development of a safe and ideal next-generation subunit anthrax vaccine has been evaluated in mouse model. METHOD AND RESULTS Protective antigen (PA) and BA3338, a surface layer homology (SLH) domain possessing protein were cloned, expressed in heterologous system and purified by IMAC. Recombinant PA and BA3338 with alum were administered in mouse alone or in combination. The humoral and cell-mediated immune response was measured by ELISA and vaccinated animals were challenged with B. anthracis spores via intraperitoneal route. The circulating IgG antibody titre of anti-PA and anti-BA3338 was found significantly high in the first and second booster sera. A significant enhanced level of IL-4, IFN-γ and IL-12 was observed in antigens stimulated supernatant of splenocytes of PA + BA3338 vaccinated animals. A combination of PA and BA3338 provided 80% protection against 20 LD50 lethal dose of B. anthracis spores. CONCLUSION Both antigens induced admirable humoral and cellular immune response as well as protective efficacy against B. anthracis spores. SIGNIFICANCE AND IMPACT OF THE STUDY This study has been evaluated for the first time using BA3338 as a vaccine candidate alone or in combination with well-known anthrax vaccine candidate PA. The findings of this study demonstrated that BA3338 could be a co-vaccine candidate for development of dual subunit vaccine against anthrax.
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Affiliation(s)
- M Kumar
- Bioprocess Technology Division, Defence Research and Development Establishment, Gwalior, India
| | - N Puranik
- Bioprocess Technology Division, Defence Research and Development Establishment, Gwalior, India
| | - A Varshney
- Bioprocess Technology Division, Defence Research and Development Establishment, Gwalior, India
| | - N Tripathi
- Bioprocess Technology Division, Defence Research and Development Establishment, Gwalior, India
| | - V Pal
- Bioprocess Technology Division, Defence Research and Development Establishment, Gwalior, India
| | - A K Goel
- Bioprocess Technology Division, Defence Research and Development Establishment, Gwalior, India
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Makdasi E, Laskar O, Glinert I, Alcalay R, Mechaly A, Levy H. Rapid and Sensitive Multiplex Assay for the Detection of B. anthracis Spores from Environmental Samples. Pathogens 2020; 9:E164. [PMID: 32120986 DOI: 10.3390/pathogens9030164] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 02/24/2020] [Accepted: 02/27/2020] [Indexed: 11/24/2022] Open
Abstract
Prompt and accurate detection of Bacillus anthracis spores is crucial in the event of intentional spore dissemination in order to reduce the number of expected casualties. Specific identification of these spores from environmental samples is both challenging and time-consuming. This is due to the high homology with other Bacillus species as well as the complex composition of environmental samples, which further impedes assay sensitivity. Previously, we showed that a short incubation of B.anthracis spores in a defined growth medium results in rapid germination, bacterial growth, and secretion of toxins, including protective antigen. In this work, we tested whether coupling the incubation process to a newly developed immune-assay will enable the detection of secreted toxins as markers for the presence of spores in environmental samples. The new immune assay is a flow cytometry-based multiplex that simultaneously detects a protective antigen, lethal factor, and edema factor. Our combined assay detects 1 × 103–1 × 104/mL spores after a 2 h incubation followed by the ~80 min immune-multiplex detection. Extending the incubation step to 5 h increased assay sensitivity to 1 × 102/mL spore. The protocol was validated in various environmental samples using attenuated or fully virulent B. anthracis spores. There was no substantial influence of contaminants derived from real environmental samples on the performance of the assay compared to clean samples, which allow the unequivocal detection of 3 × 103/mL and 3 × 102/mL spores following 2 and 5 hour’s incubation, respectively. Overall, we propose this method as a rapid, sensitive, and specific procedure for the identification of B. anthracis spores in environmental samples.
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Liu K, Yin Y, Zhang J, Zai X, Li R, Ma H, Xu J, Shan J, Chen W. Polysaccharide PCP-I isolated from Poria cocos enhances the immunogenicity and protection of an anthrax protective antigen-based vaccine. Hum Vaccin Immunother 2019; 16:1699-1707. [PMID: 31809637 DOI: 10.1080/21645515.2019.1675457] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
Polysaccharides isolated from natural plants may represent a novel source of vaccine adjuvants. In this research, we focused on a natural plant polysaccharide, PCP-I, which is derived from Poria cocos, a Chinese traditional herbal medicine. We chose the anthrax protective antigen (PA) as a model to evaluate the adjuvant ability of PCP-I in enhancing the immunogenicity and protection of a PA-based anthrax vaccine. According to our results, PCP-I could significantly enhance anthrax specific anti-PA antibodies, toxin-neutralizing antibodies, anti-PA antibody affinity, as well as IgG1 and IgG2a levels. Besides, PCP-I increased the frequency of PA-specific memory B cells, increased the proliferation of PA-specific splenocytes, significantly stimulated the secretion of IL-4, and enhanced the activation of Dendritic cells (DCs) in vitro. The combination of PCP-I and CpG significantly enhanced the level of anti-PA antibodies and neutralizing antibodies, particularly PA-specific IgG2a, and shifted the Th2-bias to a Th1/Th2 balanced response. In addition, PCP-I with or without CpG could significantly improve the survival rate of immunized mice following challenge with the anthrax lethal toxin. These findings suggest that PCP-I may be a promising vaccine adjuvant that warrants further study.
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Affiliation(s)
- Kun Liu
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology , Beijing, China
| | - Ying Yin
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology , Beijing, China
| | - Jun Zhang
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology , Beijing, China
| | - Xiaodong Zai
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology , Beijing, China
| | - Ruihua Li
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology , Beijing, China
| | - Hao Ma
- Institute of Pharmacology and Toxicology , Academy of Military Medical Sciences, Beijing, China
| | - Junjie Xu
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology , Beijing, China
| | - Junjie Shan
- Institute of Pharmacology and Toxicology , Academy of Military Medical Sciences, Beijing, China
| | - Wei Chen
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology , Beijing, China
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Żakowska D, Graniak G, Rutyna P, Naylor K, Głowacka P, Niemcewicz M. Protective antigen domain 4 of Bacillus anthracis as a candidate for use as vaccine for anthrax. Ann Agric Environ Med 2019; 26:392-395. [PMID: 31559791 DOI: 10.26444/aaem/99669] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Existing research for using the protective antigen (PA) of Bacillus anthracis as a vaccine component shows that protection against anthrax may be obtained using fragments of this protein. The aim of the research is to check whether the selected protein fragment of the protective antigen (domain 4) encoded by an appropriate nucleotide sequence of gene pag of B. anthracis, was expressed in the bacterial system of E. coli. In order to examine the selected sequence of the pag gene, a PCR reaction and a highly effective TOPO cloning strategy were used, followed by purification of the recombinant proteins and their detection by a western-blot method. In the planning of the PA4 antigen expression a higher level of effectiveness in production of small protein - domain 4 - was anticipated. As a result, the 139 amino acids protein fragment of B. anthracis PA (domain 4) was isolated. The research may have found the basis for in vivo research aimed at finding potential anthrax vaccine components.
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Affiliation(s)
- Dorota Żakowska
- Biological Threats Identification and Countermeasure Center of the General Karol Kaczkowski Military Institute of Hygiene and Epidemiology, Puławy, Poland
| | - Grzegorz Graniak
- Biological Threats Identification and Countermeasure Center of the General Karol Kaczkowski Military Institute of Hygiene and Epidemiology, Puławy, Poland
| | - Paweł Rutyna
- Biological Threats Identification and Countermeasure Center of the General Karol Kaczkowski Military Institute of Hygiene and Epidemiology, Puławy, Poland
| | - Katarzyna Naylor
- Department of Didactics and Medical Simulation, Medical University, Lublin, Poland
| | - Patrycja Głowacka
- Biological Threats Identification and Countermeasure Center of the General Karol Kaczkowski Military Institute of Hygiene and Epidemiology, Puławy, Poland
| | - Marcin Niemcewicz
- Biological Threats Identification and Countermeasure Center of the General Karol Kaczkowski Military Institute of Hygiene and Epidemiology, Puławy, Poland
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Kondakova OA, Nikitin NA, Evtushenko EA, Ryabchevskaya EM, Atabekov JG, Karpova OV. Vaccines against anthrax based on recombinant protective antigen: problems and solutions. Expert Rev Vaccines 2019; 18:813-828. [PMID: 31298973 DOI: 10.1080/14760584.2019.1643242] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Introduction: Anthrax is a dangerous bio-terror agent because Bacillus anthracis spores are highly resilient and can be easily aerosolized and disseminated. There is a threat of deliberate use of anthrax spores aerosol that could lead to serious fatal diseases outbreaks. Existing control measures against inhalation form of the disease are limited. All of this has provided an impetus to the development of new generation vaccines. Areas сovered: This review is devoted to challenges and achievements in the design of vaccines based on the anthrax recombinant protective antigen (rPA). Scientific databases have been searched, focusing on causes of PA instability and solutions to this problem, including new approaches of rPA expression, novel rPA-based vaccines formulations as well as the simultaneous usage of PA with other anthrax antigens. Expert opinion: PA is a central anthrax toxin component, playing a key role in the defense against encapsulated and unencapsulated strains. Subunit rPA-based vaccines have a good safety and protective profile. However, there are problems of PA instability that are greatly enhanced when using aluminum adjuvants. New adjuvant compositions, dry formulations and resistant to proteolysis and deamidation mutant PA forms can help to handle this issue. Devising a modern anthrax vaccine requires huge efforts.
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Affiliation(s)
- Olga A Kondakova
- a Department of Virology, Faculty of Biology, Lomonosov Moscow State University , Moscow , Russian Federation
| | - Nikolai A Nikitin
- a Department of Virology, Faculty of Biology, Lomonosov Moscow State University , Moscow , Russian Federation
| | - Ekaterina A Evtushenko
- a Department of Virology, Faculty of Biology, Lomonosov Moscow State University , Moscow , Russian Federation
| | - Ekaterina M Ryabchevskaya
- a Department of Virology, Faculty of Biology, Lomonosov Moscow State University , Moscow , Russian Federation
| | - Joseph G Atabekov
- a Department of Virology, Faculty of Biology, Lomonosov Moscow State University , Moscow , Russian Federation
| | - Olga V Karpova
- a Department of Virology, Faculty of Biology, Lomonosov Moscow State University , Moscow , Russian Federation
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Abstract
Inhalational anthrax caused by Bacillus anthracis, a spore-forming Gram-positive bacterium, is a highly lethal infection. Antibodies targeting the protective antigen (PA) binding component of the toxins have recently been authorized as an adjunct to antibiotics, although no conclusive evidence demonstrates that anthrax antitoxin therapy has any significant benefit. We discuss here the rational basis of anti-PA development regarding the pathogenesis of the disease. Inhalational anthrax caused by Bacillus anthracis, a spore-forming Gram-positive bacterium, is a highly lethal infection. Antibodies targeting the protective antigen (PA) binding component of the toxins have recently been authorized as an adjunct to antibiotics, although no conclusive evidence demonstrates that anthrax antitoxin therapy has any significant benefit. We discuss here the rational basis of anti-PA development regarding the pathogenesis of the disease. We argue that inductive reasoning may induce therapeutic bias. We identified anthrax animal model analysis as another bias. Further studies are needed to assess the benefit of anti-PA antibodies in the treatment of inhalational anthrax, while a clearer consensus should be established around what evidence should be proven in an anthrax model.
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Fischer ES, Campbell WA, Liu S, Ghirlando R, Fattah RJ, Bugge TH, Leppla SH. Bismaleimide cross-linked anthrax toxin forms functional octamers with high specificity in tumor targeting. Protein Sci 2019; 28:1059-1070. [PMID: 30942916 DOI: 10.1002/pro.3613] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 04/01/2019] [Indexed: 12/12/2022]
Abstract
In recent years, anthrax toxin has been reengineered to act as a highly specific antiangiogenic cancer therapeutic, shown to kill tumors in animal models. This has been achieved by modifying protective antigen (PA) so that its activation and toxicity require the presence of two proteases, matrix metalloproteinase (MMP) and urokinase plasminogen activator (uPA), which are upregulated in tumor microenvironments. These therapeutics consist of intercomplementing PA variants, which are individually nontoxic, but form functional toxins upon complementary oligomerization. Here, we have created a dual-protease requiring PA targeting system which utilizes bismaleimide cross-linked PA (CLPA) rather than the intercomplementing PA variants. Three different CLPA agents were tested and, as expected, found to exclusively form octamers. Two of the CLPA agents have in vitro toxicities equal to those of previous intercomplementing agents, while the third CLPA agent had compromised in vitro cleavage and was significantly less cytotoxic. We hypothesize this difference was due to steric hindrance caused by cross-linking two PA monomers in close proximity to the PA cleavage site. Overall, this work advances the development and use of the PA and LF tumor-targeting system as a practical cancer therapeutic, as it provides a way to reduce the drug components of the anthrax toxin drug delivery system from three to two, which may lower the cost and simplify testing in clinical trials. HIGHLIGHT: Previously, anthrax toxin has been reengineered to act as a highly specific antiangiogenic cancer therapeutic. Here, we present a version, which utilizes bismaleimide cross-linked protective antigen (PA) rather than intercomplementing PA variants. This advances the development of anthrax toxin as a practical cancer therapeutic as it reduces the components of the drug delivery system to two, which may lower the cost and simplify testing in clinical trials.
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Affiliation(s)
- Elyse S Fischer
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland
| | - Warren A Campbell
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland
| | - Shihui Liu
- Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, Bethesda, Maryland
| | - Rodolfo Ghirlando
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, 20892
| | - Rasem J Fattah
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland
| | - Thomas H Bugge
- Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, Bethesda, Maryland
| | - Stephen H Leppla
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland
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Gogoi H, Mani R, Bhatnagar R. A niosome formulation modulates the Th1/Th2 bias immune response in mice and also provides protection against anthrax spore challenge. Int J Nanomedicine 2018; 13:7427-7440. [PMID: 30532531 PMCID: PMC6241689 DOI: 10.2147/ijn.s153150] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Introduction In this study, we have investigated the immunogenicity and protective efficacy of a niosomal formulation encapsulating protective antigen (PA) and PA domain 4 (D4) of Bacillus anthracis. Methods Nonionic surfactant–based vesicles (NISV) + PA and NISV + D4 were prepared from span-60 and cholesterol by reverse-phase evaporation method and were evaluated for in vitro characteristics and immunological studies. Results Particle characterization using transmission electron microscopy and atomic force microscopy analysis showed that the niosomal formulation was spherical in shape. The entrapment efficiency values were calculated to be 58.5% and 44.75% for PA and D4, respectively. Confocal microscopy and flow cytometry studies showed an enhanced uptake of antigen in THP1 macrophages by niosome as compared to antigen only. An in vitro release assay showed a burst release of antigen from niosome within 24 hours followed by a gradual release for 144 hours. Immunological studies showed that both PA- and D4-encapsulated niosome elicited a robust IgG titer. Antibody isotyping and cytokine profile showed that NISV + PA and NISV + D4 enhanced both Th1 and Th2 responses in mice, suggesting a mixed Th1/Th2 response. Both NISV + PA and NISV + D4 elicited high levels of anti-inflammatory cytokine interleukin-10 with low levels of pro-inflammatory cytokine tumor necrosis factor-α, suggesting the anti-inflammatory property of niosome. Both the niosomal formulations were also able to confer protection against BA infection as compared to only PA and D4. Conclusion PA and D4 encapsulated NISV formulation could modulate both the Th1 and Th2 adaptive immune system and was found to be a better prophylactic against anthrax.
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Affiliation(s)
- Himanshu Gogoi
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India,
| | - Rajesh Mani
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India,
| | - Rakesh Bhatnagar
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India,
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Dupke S, Barduhn A, Franz T, Leendertz FH, Couacy-Hymann E, Grunow R, Klee SR. Analysis of a newly discovered antigen of Bacillus cereus biovar anthracis for its suitability in specific serological antibody testing. J Appl Microbiol 2018; 126:311-323. [PMID: 30253024 DOI: 10.1111/jam.14114] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 08/31/2018] [Accepted: 09/12/2018] [Indexed: 12/21/2022]
Abstract
AIMS The aim of this work was to identify a protein which can be used for specific detection of antibodies against Bacillus cereus biovar anthracis (Bcbva), an anthrax-causing pathogen that so far has been described in African rainforest areas. METHODS AND RESULTS Culture supernatants of Bcbva and classic Bacillus anthracis (Ba) were analysed by gel electrophoresis, and a 35-kDa protein secreted only by Bcbva and not Ba was detected. The protein was identified as pXO2-60 by mass spectrometry. Sequence analysis showed that Ba is unable to secrete this protein due to a premature stop codon in the sequence for the signal peptide. Immunization of five outbred mice with sterile bacterial culture supernatants of Bcbva revealed an immune response in ELISA against pXO2-60 (three mice positive, one borderline) and the protective antigen (PA; four mice). When supernatants of classic Ba were injected into mice or human sera from anthrax patients were analysed, only antibodies against PA were detected. CONCLUSIONS In combination with PA, the pXO2-60 protein can be used for the detection of antibodies specific against Bcbva and discriminating from Ba. SIGNIFICANCE AND IMPACT OF THE STUDY After further validation, serological assays based on pXO2-60 can be used to perform seroprevalence studies to determine the epidemiology of B. cereus bv anthracis in affected countries and assess its impact on the human population.
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Affiliation(s)
- S Dupke
- Robert Koch-Institute, Centre for Biological Threats and Special Pathogens (ZBS2), Berlin, Germany
| | - A Barduhn
- Robert Koch-Institute, Centre for Biological Threats and Special Pathogens (ZBS2), Berlin, Germany
| | - T Franz
- Robert Koch-Institute, Centre for Biological Threats and Special Pathogens (ZBS2), Berlin, Germany
| | - F H Leendertz
- Robert Koch-Institute, Epidemiology of Highly Pathogenic Microorganisms (P3), Berlin, Germany
| | - E Couacy-Hymann
- Laboratoire National d'Appui au Développement Agricole (LANADA), Laboratoire Central Vétérinaire de Bingerville (LCVB), Bingerville, Côte d'Ivoire
| | - R Grunow
- Robert Koch-Institute, Centre for Biological Threats and Special Pathogens (ZBS2), Berlin, Germany
| | - S R Klee
- Robert Koch-Institute, Centre for Biological Threats and Special Pathogens (ZBS2), Berlin, Germany
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Suzuki K, Shinzawa N, Ishigaki K, Nakamura K, Abe H, Fukui-Miyazaki A, Ikuta K, Horiguchi Y. Protective effects of in vivo-expressed autotransporters against Bordetella pertussis infection. Microbiol Immunol 2018; 61:371-379. [PMID: 28752940 DOI: 10.1111/1348-0421.12504] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 06/28/2017] [Accepted: 07/24/2017] [Indexed: 12/12/2022]
Abstract
Bordetella pertussis causes whooping cough, a severe and prolonged respiratory disease that results inhas high morbidity and mortality rates, particularly in developing countries. The number incidence of whooping cough cases is increasing in many countries despite high vaccine coverage. Causes for the re-emergence of the disease include the limited duration of protection conferred by the acellular pertussis vaccines (aP)s and pathogenic adaptations that involve antigenic divergence from vaccine strains. Therefore, current vaccines therefore need to be improved. In the present study, we focused on five autotransporters: namely SphB1, BatB, SphB2, Phg, and Vag8, which were previously found to be expressed by B. bronchiseptica during the course of infection in rats and examined their protective efficiencies as vaccine antigens. The passenger domains of these proteins were produced in recombinant forms and used as antigens. An intranasal murine challenge assay showed that immunization with a mixture of SphB1 and Vag8 (SV) significantly reduced bacterial load in the lower respiratory tract and a combination of aP and SV acts synergistically in effects of conferring protection against B. pertussis infection, implying that these antigens have potential as components to for improvinge th the currently available acellular pertussis vaccine.
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Affiliation(s)
- Koichiro Suzuki
- Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan.,Research Foundation for Microbial Diseases of Osaka University (BIKEN), 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Naoaki Shinzawa
- Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Keisuke Ishigaki
- Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Keiji Nakamura
- Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Hiroyuki Abe
- Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Aya Fukui-Miyazaki
- Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Kazuyoshi Ikuta
- Research Foundation for Microbial Diseases of Osaka University (BIKEN), 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Yasuhiko Horiguchi
- Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan
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Seldina YI, Petro CD, Servetas SL, Vergis JM, Ventura CL, Merrell DS, O'Brien AD. Certhrax Is an Antivirulence Factor for the Anthrax-Like Organism Bacillus cereus Strain G9241. Infect Immun 2018; 86:e00207-18. [PMID: 29610258 DOI: 10.1128/IAI.00207-18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 03/28/2018] [Indexed: 11/20/2022] Open
Abstract
Bacillus cereus G9241 caused a life-threatening anthrax-like lung infection in a previously healthy human. This strain harbors two large virulence plasmids, pBCXO1 and pBC210, that are absent from typical B. cereus isolates. The pBCXO1 plasmid is nearly identical to pXO1 from Bacillus anthracis and carries genes (pagA1, lef, and cya) for anthrax toxin components (protective antigen [called PA1 in G9241], lethal factor [LF], and edema factor [EF], respectively). The plasmid also has an intact hyaluronic acid capsule locus. The pBC210 plasmid has a tetrasaccharide capsule locus, a gene for a PA1 homolog called PA2 (pagA2), and a gene (cer) for Certhrax, an ADP-ribosyltransferase toxin that inactivates vinculin. LF, EF, and Certhrax require PA for entry into cells. In this study, we asked what role PA1, PA2, LF, and Certhrax play in the pathogenicity of G9241. To answer this, we generated isogenic deletion mutations in the targeted toxin gene components and then assessed the strains for virulence in highly G9241-susceptible (A/J) and moderately G9241-sensitive (C57BL/6) mice. We found that full virulence of G9241 required PA1 and LF, while PA2 contributed minimally to pathogenesis of G9241 but could not functionally replace PA1 as a toxin-binding subunit in vivo Surprisingly, we discovered that Certhrax attenuated the virulence of G9241; i.e., a Δcer Δlef mutant strain was more virulent than a Δlef mutant strain following subcutaneous inoculation of A/J mice. Moreover, the enzymatic activity of Certhrax contributed to this phenotype. We concluded that Certhrax acts as an antivirulence factor in the anthrax-like organism B. cereus G9241.
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Khandia R, Pattnaik B, Rajukumar K, Pateriya A, Bhatia S, Murugkar H, Prakash A, Pradhan HK, Dhama K, Munjal A, Joshi SK. Anti-proliferative role of recombinant lethal toxin of Bacillus anthracis on primary mammary ductal carcinoma cells revealing its therapeutic potential. Oncotarget 2018; 8:35835-35847. [PMID: 28415766 PMCID: PMC5482621 DOI: 10.18632/oncotarget.16214] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Accepted: 03/07/2017] [Indexed: 12/11/2022] Open
Abstract
Bacillus anthracis secretes three secretary proteins; lethal factor (LF), protective antigen (PA) and edema factor (EF). The LF has ability to check proliferation of mammary tumors, chiefly depending on mitogen activated protein kinase (MAPK) signaling pathway. Evaluation of therapeutic potential of recombinant LF (rLF), recombinant PA (rPA) and lethal toxin (rLF + rPA = LeTx) on the primary mammary ductal carcinoma cells revealed significant (p < 0.01) reduction in proliferation of tumor cells with mean inhibition indices of 28.0 ± 1.37% and 19.6 ± 1.47% respectively. However, treatment with rPA alone had no significant anti-proliferative effect as evident by low mean inhibition index of 3.4 ± 3.87%. The higher inhibition index observed for rLF alone as compared to LeTx is contrary to the existing knowledge on LF, which explains the requirement of PA dependent endocytosis for its enzymatic activity. Therefore, the plausible existence of PA independent mode of action of LF including direct receptor mediated endocytosis or modulation of signal transduction cascade via unknown means is hypothesized. In silico protein docking analysis of other cellular receptors for any plausibility to play the role of receptor for LF revealed c-Met receptor showing strongest affinity for LF (H bond = 19; Free energy = −773.96), followed by nerve growth factor receptor (NGFR) and human epidermal growth factor receptor (HER)-1. The study summarizes the use of rLF or LeTx as therapeutic molecule against primary mammary ductal carcinoma cells and also the c-Met as potential alternative receptor for LF to mediate and modulate PA independent signal transduction.
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Affiliation(s)
- Rekha Khandia
- ICAR-National Institute of High Security Animal Diseases, Bhopal, Madhya Pradesh, India.,Department of Biochemistry and Genetics, Barkatullah University, Bhopal, Madhya Pradesh, India
| | - Bramhadev Pattnaik
- Project Directorate on Foot and Mouth Disease, Mukteswar, Uttarakhand, India
| | | | - Atul Pateriya
- ICAR-National Institute of High Security Animal Diseases, Bhopal, Madhya Pradesh, India
| | - Sandeep Bhatia
- ICAR-National Institute of High Security Animal Diseases, Bhopal, Madhya Pradesh, India
| | - Harshad Murugkar
- ICAR-National Institute of High Security Animal Diseases, Bhopal, Madhya Pradesh, India
| | - Anil Prakash
- Department of Microbiology, Barkatullah University, Bhopal, Madhya Pradesh, India
| | - Hare Krishna Pradhan
- Ex-Avian Influenza National Consultant, Indian Office of WHO Consultant, Bhartiya Kala Kendra, New Delhi, India
| | - Kuldeep Dhama
- Division of Pathology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly Uttar Pradesh, India
| | - Ashok Munjal
- Department of Biochemistry and Genetics, Barkatullah University, Bhopal, Madhya Pradesh, India
| | - Sunil K Joshi
- Cellular Immunology Laboratory, Frank Reidy Research Center of Bioelectrics, College of Health Sciences, Old Dominion University Norfolk, VA USA
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Malik A, Gupta M, Mani R, Gogoi H, Bhatnagar R. Trimethyl Chitosan Nanoparticles Encapsulated Protective Antigen Protects the Mice Against Anthrax. Front Immunol 2018; 9:562. [PMID: 29616046 PMCID: PMC5870345 DOI: 10.3389/fimmu.2018.00562] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 03/06/2018] [Indexed: 01/08/2023] Open
Abstract
Anthrax is an era old deadly disease against which there are only two currently available licensed vaccines named anthrax vaccine adsorbed and precipitated (AVP). Though they can provide a protective immunity, their multiple side-effects owing to their ill-defined composition and presence of toxic proteins (LF and EF) of Bacillus anthracis, the causative organism of anthrax, in the vaccine formulation makes their widespread use objectionable. Hence, an anthrax vaccine that contains well-defined and controlled components would be highly desirable. In this context, we have evaluated the potential of various vaccine formulations comprising of protective antigen (PA) encapsulated trimethyl-chitosan nanoparticles (TMC-PA) in conjunction with either CpG-C ODN 2395 (CpG) or Poly I:C. Each formulation was administered via three different routes, viz., subcutaneous (SC), intramuscular (IM), and intraperitoneal in female BALB/c mice. Irrespective of the route of immunization, CpG or Poly I:C adjuvanted TMC-PA nanoparticles induced a significantly higher humoral response (total serum IgG and its isotypes viz., IgG1, IgG2a, and IgG2b), compared to their CpG or Poly I:C PA counterparts. This clearly demonstrates the synergistic behavior of CpG and Poly I:C with TMC nanoparticles. The adjuvant potential of TMC nanoparticles could be observed in all the three routes as the TMC-PA nanoparticles by themselves induced IgG titers (1-1.5 × 105) significantly higher than both CpG PA and Poly I:C PA groups (2-8 × 104). The effect of formulations on T-helper (Th) cell development was assessed by quantifying the Th1-dependant (TNF-α, IFN-γ, and IL-2), Th2-dependant (IL-4, IL-6, and IL-10), and Th17-type (IL-17A) cytokines. Adjuvanation with CpG and Poly I:C, the TMC-PA nanoparticles triggered a Th1 skewed immune response, as suggested by an increase in the levels of total IgG2a along with IFN-γ cytokine production. Interestingly, the TMC-PA group showed a Th2-biased immune response. Upon challenge with the B. anthracis Ames strain, CpG and Poly I:C adjuvanted TMC-PA nanoparticles immunized via the SC and IM routes showed the highest protective efficacy of ~83%. Altogether, the results suggest that CpG or Poly I:C adjuvanted, PA-loaded TMC nanoparticles could be used as an effective, non-toxic, second generation subunit-vaccine candidate against anthrax.
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Affiliation(s)
- Anshu Malik
- Molecular Biology and Genetic Engineering Laboratory, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Manish Gupta
- Molecular Biology and Genetic Engineering Laboratory, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Rajesh Mani
- Molecular Biology and Genetic Engineering Laboratory, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Himanshu Gogoi
- Molecular Biology and Genetic Engineering Laboratory, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Rakesh Bhatnagar
- Molecular Biology and Genetic Engineering Laboratory, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
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Henning LN, Carpenter S, Stark GV, Serbina NV. Development of Protective Immunity in New Zealand White Rabbits Challenged with Bacillus anthracis Spores and Treated with Antibiotics and Obiltoxaximab, a Monoclonal Antibody against Protective Antigen. Antimicrob Agents Chemother 2018; 62:e01590-17. [PMID: 29133571 PMCID: PMC5786786 DOI: 10.1128/aac.01590-17] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 11/03/2017] [Indexed: 02/08/2023] Open
Abstract
The recommended management of inhalational anthrax, a high-priority bioterrorist threat, includes antibiotics and antitoxins. Obiltoxaximab, a chimeric monoclonal antibody against anthrax protective antigen (PA), is licensed under the U.S. Food and Drug Administration's (FDA's) Animal Rule for the treatment of inhalational anthrax. Because of spore latency, disease reemergence after treatment cessation is a concern, and there is a need to understand the development of endogenous protective immune responses following antitoxin-containing anthrax treatment regimens. Here, acquired protective immunity was examined in New Zealand White (NZW) rabbits challenged with a targeted lethal dose of Bacillus anthracis spores and treated with antibiotics, obiltoxaximab, or a combination of both. Survivors of the primary challenge were rechallenged 9 months later and monitored for survival. Survival rates after primary and rechallenge for controls and animals treated with obiltoxaximab, levofloxacin, or a combination of both were 0, 65, 100, and 95%, and 0, 100, 95, and 89%, respectively. All surviving immune animals had circulating antibodies to PA and serum toxin-neutralizing titers prior to rechallenge. Following rechallenge, systemic bacteremia and toxemia were not detected in most animals, and the levels of circulating anti-PA IgG titers increased starting at 5 days postrechallenge. We conclude that treatment with obiltoxaximab, alone or combined with antibiotics, significantly improves the survival of rabbits that received a lethal inhalation B. anthracis spore challenge dose and does not interfere with the development of immunity. Survivors of primary challenge are protected against reexposure, have rare incidents of systemic bacteremia and toxemia, and have evidence of an anamnestic response.
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Ong E, Wong MU, He Y. Identification of New Features from Known Bacterial Protective Vaccine Antigens Enhances Rational Vaccine Design. Front Immunol 2017; 8:1382. [PMID: 29123525 PMCID: PMC5662880 DOI: 10.3389/fimmu.2017.01382] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 10/06/2017] [Indexed: 11/13/2022] Open
Abstract
With many protective vaccine antigens reported in the literature and verified experimentally, how to use the knowledge mined from these antigens to support rational vaccine design and study underlying design mechanism remains unclear. In order to address the problem, a systematic bioinformatics analysis was performed on 291 Gram-positive and Gram-negative bacterial protective antigens with experimental evidence manually curated in the Protegen database. The bioinformatics analyses evaluated included subcellular localization, adhesin probability, peptide signaling, transmembrane α-helix and β-barrel, conserved domain, Clusters of Orthologous Groups, and Gene Ontology functional annotations. Here we showed the critical role of adhesins, along with subcellular localization, peptide signaling, in predicting secreted extracellular or surface-exposed protective antigens, with mechanistic explanations supported by functional analysis. We also found a significant negative correlation of transmembrane α-helix to antigen protectiveness in Gram-positive and Gram-negative pathogens, while a positive correlation of transmembrane β-barrel was observed in Gram-negative pathogens. The commonly less-focused cytoplasmic and cytoplasmic membrane proteins could be potentially predicted with the help of other selection criteria such as adhesin probability and functional analysis. The significant findings in this study can support rational vaccine design and enhance our understanding of vaccine design mechanisms.
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Affiliation(s)
- Edison Ong
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, United States
| | - Mei U Wong
- Unit for Laboratory Animal Medicine, Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, United States
| | - Yongqun He
- Unit for Laboratory Animal Medicine, Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, United States.,Center of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, United States
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37
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Machen AJ, Akkaladevi N, Trecazzi C, O'Neil PT, Mukherjee S, Qi Y, Dillard R, Im W, Gogol EP, White TA, Fisher MT. Asymmetric Cryo-EM Structure of Anthrax Toxin Protective Antigen Pore with Lethal Factor N-Terminal Domain. Toxins (Basel) 2017; 9:E298. [PMID: 28937604 DOI: 10.3390/toxins9100298] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 09/18/2017] [Accepted: 09/19/2017] [Indexed: 11/17/2022] Open
Abstract
The anthrax lethal toxin consists of protective antigen (PA) and lethal factor (LF). Understanding both the PA pore formation and LF translocation through the PA pore is crucial to mitigating and perhaps preventing anthrax disease. To better understand the interactions of the LF-PA engagement complex, the structure of the LFN-bound PA pore solubilized by a lipid nanodisc was examined using cryo-EM. CryoSPARC was used to rapidly sort particle populations of a heterogeneous sample preparation without imposing symmetry, resulting in a refined 17 Å PA pore structure with 3 LFN bound. At pH 7.5, the contributions from the three unstructured LFN lysine-rich tail regions do not occlude the Phe clamp opening. The open Phe clamp suggests that, in this translocation-compromised pH environment, the lysine-rich tails remain flexible and do not interact with the pore lumen region.
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Tao P, Mahalingam M, Zhu J, Moayeri M, Kirtley ML, Fitts EC, Andersson JA, Lawrence WS, Leppla SH, Chopra AK, Rao VB. A Bivalent Anthrax-Plague Vaccine That Can Protect against Two Tier-1 Bioterror Pathogens, Bacillus anthracis and Yersinia pestis. Front Immunol 2017; 8:687. [PMID: 28694806 PMCID: PMC5483451 DOI: 10.3389/fimmu.2017.00687] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 05/26/2017] [Indexed: 01/14/2023] Open
Abstract
Bioterrorism remains as one of the biggest challenges to global security and public health. Since the deadly anthrax attacks of 2001 in the United States, Bacillus anthracis and Yersinia pestis, the causative agents of anthrax and plague, respectively, gained notoriety and were listed by the CDC as Tier-1 biothreat agents. Currently, there is no Food and Drug Administration-approved vaccine against either of these threats for mass vaccination to protect general public, let alone a bivalent vaccine. Here, we report the development of a single recombinant vaccine, a triple antigen consisting of all three target antigens, F1 and V from Y. pestis and PA from B. anthracis, in a structurally stable context. Properly folded and soluble, the triple antigen retained the functional and immunogenicity properties of all three antigens. Remarkably, two doses of this immunogen adjuvanted with Alhydrogel® elicited robust antibody responses in mice, rats, and rabbits and conferred complete protection against inhalational anthrax and pneumonic plague. No significant antigenic interference was observed. Furthermore, we report, for the first time, complete protection of animals against simultaneous challenge with Y. pestis and the lethal toxin of B. anthracis, demonstrating that a single biodefense vaccine can protect against a bioterror attack with weaponized B. anthracis and/or Y. pestis. This bivalent anthrax–plague vaccine is, therefore, a strong candidate for stockpiling, after demonstration of its safety and immunogenicity in human clinical trials, as part of national preparedness against two of the deadliest bioterror threats.
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Affiliation(s)
- Pan Tao
- Department of Biology, The Catholic University of America, Washington, DC, United States
| | - Marthandan Mahalingam
- Department of Biology, The Catholic University of America, Washington, DC, United States
| | - Jingen Zhu
- Department of Biology, The Catholic University of America, Washington, DC, United States
| | - Mahtab Moayeri
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Michelle L Kirtley
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
| | - Eric C Fitts
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
| | - Jourdan A Andersson
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
| | - William S Lawrence
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States.,Galveston National Laboratory, University of Texas Medical Branch, Galveston, TX, United States
| | - Stephen H Leppla
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Ashok K Chopra
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States.,Galveston National Laboratory, University of Texas Medical Branch, Galveston, TX, United States.,Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, United States.,Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, TX, United States.,Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, TX, United States
| | - Venigalla B Rao
- Department of Biology, The Catholic University of America, Washington, DC, United States
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Ghosal K, Colby JM, Das D, Joy ST, Arora PS, Krantz BA. Dynamic Phenylalanine Clamp Interactions Define Single-Channel Polypeptide Translocation through the Anthrax Toxin Protective Antigen Channel. J Mol Biol 2017; 429:900-910. [PMID: 28192089 DOI: 10.1016/j.jmb.2017.02.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 02/03/2017] [Accepted: 02/08/2017] [Indexed: 10/20/2022]
Abstract
Anthrax toxin is an intracellularly acting toxin where sufficient detail is known about the structure of its channel, allowing for molecular investigations of translocation. The toxin is composed of three proteins, protective antigen (PA), lethal factor (LF), and edema factor (EF). The toxin's translocon, PA, translocates the large enzymes, LF and EF, across the endosomal membrane into the host cell's cytosol. Polypeptide clamps located throughout the PA channel catalyze the translocation of LF and EF. Here, we show that the central peptide clamp, the ϕ clamp, is a dynamic site that governs the overall peptide translocation pathway. Single-channel translocations of a 10-residue, guest-host peptide revealed that there were four states when peptide interacted with the channel. Two of the states had intermediate conductances of 10% and 50% of full conductance. With aromatic guest-host peptides, the 50% conducting intermediate oscillated with the fully blocked state. A Trp guest-host peptide was studied by manipulating its stereochemistry and prenucleating helix formation with a covalent linkage in the place of a hydrogen bond or hydrogen-bond surrogate (HBS). The Trp peptide synthesized with ʟ-amino acids translocated more efficiently than peptides synthesized with D- or alternating D,ʟ-amino acids. HBS stapled Trp peptide exhibited signs of steric hindrance and difficulty translocating. However, when mutant ϕ clamp (F427A) channels were tested, the HBS peptide translocated normally. Overall, peptide translocation is defined by dynamic interactions between the peptide and ϕ clamp. These dynamics require conformational flexibility, such that the peptide productively forms both extended-chain and helical states during translocation.
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Affiliation(s)
- Koyel Ghosal
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, 650 W, Baltimore Street, Baltimore, MD 21201, USA
| | - Jennifer M Colby
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Debasis Das
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, 650 W, Baltimore Street, Baltimore, MD 21201, USA
| | - Stephen T Joy
- Department of Chemistry, New York University, New York, NY 10003, USA
| | - Paramjit S Arora
- Department of Chemistry, New York University, New York, NY 10003, USA
| | - Bryan A Krantz
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, 650 W, Baltimore Street, Baltimore, MD 21201, USA.
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40
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Mamillapalli S, Miyagi M, Bann JG. Stability of domain 4 of the anthrax toxin protective antigen and the effect of the VWA domain of CMG2 on stability. Protein Sci 2016; 26:355-364. [PMID: 27874231 DOI: 10.1002/pro.3087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 11/14/2016] [Accepted: 11/15/2016] [Indexed: 01/04/2023]
Abstract
The major immunogenic component of the current anthrax vaccine, anthrax vaccine adsorbed (AVA) is protective antigen (PA). We have shown recently that the thermodynamic stability of PA can be significantly improved by binding to the Von-Willebrand factor A (VWA) domain of capillary morphogenesis protein 2 (CMG2), and improvements in thermodynamic stability may improve storage and long-term stability of PA for use as a vaccine. In order to understand the origin of this increase in stability, we have isolated the receptor binding domain of PA, domain 4 (D4), and have studied the effect of the addition of CMG2 on thermodynamic stability. We are able to determine a binding affinity between D4 and CMG2 (∼300 nM), which is significantly weaker than that between full-length PA and CMG2 (170-300 pM). Unlike full-length PA, we observe very little change in stability of D4 on binding to CMG2, using either fluorescence or 19 F-NMR experiments. Because in previous experiments we could observe a stabilization of both domain 4 and domain 2, the mechanism of stabilization of PA by CMG2 is likely to involve a mutual stabilization of these two domains.
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Affiliation(s)
| | - Masaru Miyagi
- Case Center for Proteomics and Bioinformatics, Department of Pharmacology and Department of Opthamology and Visual Sciences, Case Western Reserve University, Cleveland, Ohio, 44106
| | - James G Bann
- Department of Chemistry, Wichita State University, Wichita, Kansas, 67260
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Yamini G, Kalu N, Nestorovich EM. Impact of Dendrimer Terminal Group Chemistry on Blockage of the Anthrax Toxin Channel: A Single Molecule Study. Toxins (Basel) 2016; 8:E337. [PMID: 27854272 DOI: 10.3390/toxins8110337] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 11/07/2016] [Accepted: 11/07/2016] [Indexed: 12/19/2022] Open
Abstract
Nearly all the cationic molecules tested so far have been shown to reversibly block K⁺ current through the cation-selective PA63 channels of anthrax toxin in a wide nM-mM range of effective concentrations. A significant increase in channel-blocking activity of the cationic compounds was achieved when multiple copies of positively charged ligands were covalently linked to multivalent scaffolds, such as cyclodextrins and dendrimers. Even though multivalent binding can be strong when the individual bonds are relatively weak, for drug discovery purposes we often strive to design multivalent compounds with high individual functional group affinity toward the respective binding site on a multivalent target. Keeping this requirement in mind, here we perform a single-channel/single-molecule study to investigate kinetic parameters of anthrax toxin PA63 channel blockage by second-generation (G2) poly(amido amine) (PAMAM) dendrimers functionalized with different surface ligands, including G2-NH₂, G2-OH, G2-succinamate, and G2-COONa. We found that the previously reported difference in IC50 values of the G2-OH/PA63 and G2-NH₂/PA63 binding was determined by both on- and off-rates of the reversible dendrimer/channel binding reaction. In 1 M KCl, we observed a decrease of about three folds in k o n and a decrease of only about ten times in t r e s with G2-OH compared to G2-NH₂. At the same time for both blockers, k o n and t r e s increased dramatically with transmembrane voltage increase. PAMAM dendrimers functionalized with negatively charged succinamate, but not carboxyl surface groups, still had some residual activity in inhibiting the anthrax toxin channels. At 100 mV, the on-rate of the G2-succinamate binding was comparable with that of G2-OH but showed weaker voltage dependence when compared to G2-OH and G2-NH₂. The residence time of G2-succinamate in the channel exhibited opposite voltage dependence compared to G2-OH and G2-NH₂, increasing with the cis-negative voltage increase. We also describe kinetics of the PA63 ion current modulation by two different types of the "imperfect" PAMAM dendrimers, the mixed-surface G2 75% OH 25% NH₂ dendrimer and G3-NH₂ dendron. At low voltages, both "imperfect" dendrimers show similar rate constants but significantly weaker voltage sensitivity when compared with the intact G2-NH₂ PAMAM dendrimer.
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Chen KH, Liu S, Leysath CE, Miller-Randolph S, Zhang Y, Fattah R, Bugge TH, Leppla SH. Anthrax Toxin Protective Antigen Variants That Selectively Utilize either the CMG2 or TEM8 Receptors for Cellular Uptake and Tumor Targeting. J Biol Chem 2016; 291:22021-22029. [PMID: 27555325 DOI: 10.1074/jbc.m116.753301] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Indexed: 11/06/2022] Open
Abstract
The protective antigen (PA) moiety of anthrax toxin binds to cellular receptors and mediates the translocation of the two enzymatic moieties of the toxin to the cytosol. Two PA receptors are known, with capillary morphogenesis protein 2 (CMG2) being the more important for pathogenesis and tumor endothelial marker 8 (TEM8) playing a minor role. The C-terminal PA domain 4 (PAD4) has extensive interactions with the receptors and is required for binding. Our previous study identified PAD4 variants having enhanced TEM8 binding specificity. To obtain PA variants that selectively bind to CMG2, here we performed phage display selections using magnetic beads having bound CMG2. We found that PA residue isoleucine 656 plays a critical role in PA binding to TEM8 but has a much lesser effect on PA binding to CMG2. We further characterized the role of residue 656 in distinguishing PA binding to CMG2 versus TEM8 by substituting it with the other 19 amino acids. Of the resulting variants, PA I656Q and PA I656V had significantly reduced activity on TEM8-expressing CHO cells but maintained their activity on CMG2-expressing CHO cells. The preference of these PA mutants for CMG2 over TEM8 was further demonstrated using mouse embryonic fibroblast cells and mice deficient in the CMG2 and/or the TEM8 receptors. The structural basis of the alterations in the receptor binding activities of these mutants is also discussed.
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Affiliation(s)
- Kuang-Hua Chen
- From the Laboratory of Parasitic Diseases, NIAID, National Institutes of Health, Bethesda, Maryland 20892-3202 and
| | - Shihui Liu
- From the Laboratory of Parasitic Diseases, NIAID, National Institutes of Health, Bethesda, Maryland 20892-3202 and the Proteases and Tissue Remodeling Section, Oral and Pharyngeal Cancer Branch, NIDCR, National Institutes of Health, Bethesda, Maryland 20892
| | - Clinton E Leysath
- From the Laboratory of Parasitic Diseases, NIAID, National Institutes of Health, Bethesda, Maryland 20892-3202 and
| | - Sharmina Miller-Randolph
- From the Laboratory of Parasitic Diseases, NIAID, National Institutes of Health, Bethesda, Maryland 20892-3202 and
| | - Yi Zhang
- From the Laboratory of Parasitic Diseases, NIAID, National Institutes of Health, Bethesda, Maryland 20892-3202 and
| | - Rasem Fattah
- From the Laboratory of Parasitic Diseases, NIAID, National Institutes of Health, Bethesda, Maryland 20892-3202 and
| | - Thomas H Bugge
- the Proteases and Tissue Remodeling Section, Oral and Pharyngeal Cancer Branch, NIDCR, National Institutes of Health, Bethesda, Maryland 20892
| | - Stephen H Leppla
- From the Laboratory of Parasitic Diseases, NIAID, National Institutes of Health, Bethesda, Maryland 20892-3202 and
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Coppock MB, Warner CR, Dorsey B, Orlicki JA, Sarkes DA, Lai BT, Pitram SM, Rohde RD, Malette J, Wilson JA, Kearney P, Fang KC, Law SM, Candelario SL, Farrow B, Finch AS, Agnew HD, Heath JR, Stratis-Cullum DN. Protein catalyzed capture agents with tailored performance for in vitro and in vivo applications. Biopolymers 2016; 108. [PMID: 27539157 PMCID: PMC6585716 DOI: 10.1002/bip.22934] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 07/25/2016] [Accepted: 08/17/2016] [Indexed: 12/12/2022]
Abstract
We report on peptide‐based ligands matured through the protein catalyzed capture (PCC) agent method to tailor molecular binders for in vitro sensing/diagnostics and in vivo pharmacokinetics parameters. A vascular endothelial growth factor (VEGF) binding peptide and a peptide against the protective antigen (PA) protein of Bacillus anthracis discovered through phage and bacterial display panning technologies, respectively, were modified with click handles and subjected to iterative in situ click chemistry screens using synthetic peptide libraries. Each azide‐alkyne cycloaddition iteration, promoted by the respective target proteins, yielded improvements in metrics for the application of interest. The anti‐VEGF PCC was explored as a stable in vivo imaging probe. It exhibited excellent stability against proteases and a mean elimination in vivo half‐life (T1/2) of 36 min. Intraperitoneal injection of the reagent results in slow clearance from the peritoneal cavity and kidney retention at extended times, while intravenous injection translates to rapid renal clearance. The ligand competed with the commercial antibody for binding to VEGF in vivo. The anti‐PA ligand was developed for detection assays that perform in demanding physical environments. The matured anti‐PA PCC exhibited no solution aggregation, no fragmentation when heated to 100°C, and > 81% binding activity for PA after heating at 90°C for 1 h. We discuss the potential of the PCC agent screening process for the discovery and enrichment of next generation antibody alternatives.
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Affiliation(s)
- Matthew B Coppock
- Sensors and Electron Devices Directorate, U.S. Army Research Laboratory, Adelphi, MD, 20783
| | - Candice R Warner
- Excet, Springfield, VA 22151 supporting USA Edgewood Chemical Biological Center, Aberdeen Proving Ground, MD, 21010
| | - Brandi Dorsey
- Federal Staffing Resources, Annapolis, MD supporting U.S. Army Research Laboratory, Adelphi, MD, 20783
| | - Joshua A Orlicki
- Weapons and Materials Research Directorate, U.S. Army Research Laboratory, Aberdeen Proving Ground, MD, 21005
| | - Deborah A Sarkes
- Sensors and Electron Devices Directorate, U.S. Army Research Laboratory, Adelphi, MD, 20783
| | - Bert T Lai
- Indi Molecular, 6162 Bristol Parkway, Culver City, CA, 90230
| | - Suresh M Pitram
- Indi Molecular, 6162 Bristol Parkway, Culver City, CA, 90230
| | | | - Jacquie Malette
- Indi Molecular, 6162 Bristol Parkway, Culver City, CA, 90230
| | - Jeré A Wilson
- Indi Molecular, 6162 Bristol Parkway, Culver City, CA, 90230
| | | | | | | | | | - Blake Farrow
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA, 91125
| | - Amethist S Finch
- Sensors and Electron Devices Directorate, U.S. Army Research Laboratory, Adelphi, MD, 20783
| | - Heather D Agnew
- Indi Molecular, 6162 Bristol Parkway, Culver City, CA, 90230
| | - James R Heath
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA, 91125
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Kobrinsky E, Soldatov NM. Electrophysiological evidences of interaction between calcium channels and PA of anthrax. Channels (Austin) 2016; 10:253-5. [PMID: 27045324 DOI: 10.1080/19336950.2016.1172886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Affiliation(s)
- Evgeny Kobrinsky
- a National Institute on Aging, National Institutes of Health , Baltimore , MD, USA
| | - Nikolai M Soldatov
- a National Institute on Aging, National Institutes of Health , Baltimore , MD, USA
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Silin V, Kasianowicz JJ, Michelman-Ribeiro A, Panchal RG, Bavari S, Robertson JWF. Biochip for the Detection of Bacillus anthracis Lethal Factor and Therapeutic Agents against Anthrax Toxins. Membranes (Basel) 2016; 6:E36. [PMID: 27348008 PMCID: PMC5041027 DOI: 10.3390/membranes6030036] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 06/13/2016] [Accepted: 06/14/2016] [Indexed: 01/18/2023]
Abstract
Tethered lipid bilayer membranes (tBLMs) have been used in many applications, including biosensing and membrane protein structure studies. This report describes a biosensor for anthrax toxins that was fabricated through the self-assembly of a tBLM with B. anthracis protective antigen ion channels that are both the recognition element and electrochemical transducer. We characterize the sensor and its properties with electrochemical impedance spectroscopy and surface plasmon resonance. The sensor shows a sensitivity similar to ELISA and can also be used to rapidly screen for molecules that bind to the toxins and potentially inhibit their lethal effects.
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Affiliation(s)
- Vitalii Silin
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899-8120, USA.
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899-8120, USA.
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20899, USA.
| | - John J Kasianowicz
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899-8120, USA.
| | - Ariel Michelman-Ribeiro
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899-8120, USA.
| | - Rekha G Panchal
- US Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, MD 21702-5011, USA.
| | - Sina Bavari
- US Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, MD 21702-5011, USA.
| | - Joseph W F Robertson
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899-8120, USA.
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Zai X, Zhang J, Liu J, Liu J, Li L, Yin Y, Fu L, Xu J, Chen W. Quantitative Determination of Lethal Toxin Proteins in Culture Supernatant of Human Live Anthrax Vaccine Bacillus anthracis A16R. Toxins (Basel) 2016; 8:E56. [PMID: 26927174 DOI: 10.3390/toxins8030056] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 02/04/2016] [Accepted: 02/05/2016] [Indexed: 12/26/2022] Open
Abstract
Bacillus anthracis (B. anthracis) is the etiological agent of anthrax affecting both humans and animals. Anthrax toxin (AT) plays a major role in pathogenesis. It includes lethal toxin (LT) and edema toxin (ET), which are formed by the combination of protective antigen (PA) and lethal factor (LF) or edema factor (EF), respectively. The currently used human anthrax vaccine in China utilizes live-attenuated B. anthracis spores (A16R; pXO1+, pXO2−) that produce anthrax toxin but cannot produce the capsule. Anthrax toxins, especially LT, have key effects on both the immunogenicity and toxicity of human anthrax vaccines. Thus, determining quantities and biological activities of LT proteins expressed by the A16R strain is meaningful. Here, we explored LT expression patterns of the A16R strain in culture conditions using another vaccine strain Sterne as a control. We developed a sandwich ELISA and cytotoxicity-based method for quantitative detection of PA and LF. Expression and degradation of LT proteins were observed in culture supernatants over time. Additionally, LT proteins expressed by the A16R and Sterne strains were found to be monomeric and showed cytotoxic activity, which may be the main reason for side effects of live anthrax vaccines. Our work facilitates the characterization of anthrax vaccines components and establishment of a quality control standard for vaccine production which may ultimately help to ensure the efficacy and safety of the human anthrax vaccine A16R.
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Li L, Guo Q, Liu J, Zhang J, Yin Y, Dong D, Fu L, Xu J, Chen W. Recombinant HSA-CMG2 Is a Promising Anthrax Toxin Inhibitor. Toxins (Basel) 2016; 8:toxins8010028. [PMID: 26805881 PMCID: PMC4728550 DOI: 10.3390/toxins8010028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 12/25/2015] [Accepted: 01/13/2016] [Indexed: 12/20/2022] Open
Abstract
Anthrax toxin is the major virulence factor produced by Bacillus anthracis. Protective antigen (PA) is the key component of the toxin and has been confirmed as the main target for the development of toxin inhibitors. The inhibition of the binding of PA to its receptor, capillary morphogenesis protein-2 (CMG2), can effectively block anthrax intoxication. The recombinant, soluble von Willebrand factor type A (vWA) domain of CMG2 (sCMG2) has demonstrated potency against anthrax toxin. However, the short half-life of sCMG2 in vivo is a disadvantage for its development as a new anthrax drug. In the present study, we report that HSA-CMG2, a protein combining human serum albumin (HSA) and sCMG2, produced in the Pichia pastoris expression system prolonged the half-life of sCMG2 while maintaining PA binding ability. The IC50 of HSA-CMG2 is similar to those of sCMG2 and CMG2-Fc in in vitro toxin neutralization assays, and HSA-CMG2 completely protects rats from lethal doses of anthrax toxin challenge; these same challenge doses exceed sCMG2 at a sub-equivalent dose ratio and overwhelm CMG2-Fc. Our results suggest that HSA-CMG2 is a promising inhibitor of anthrax toxin and may contribute to the development of novel anthrax drugs.
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Affiliation(s)
- Liangliang Li
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing 100071, China.
- Center for Disease Control and Prevention of Navy, Beijing 101113, China.
| | - Qiang Guo
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing 100071, China.
| | - Ju Liu
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing 100071, China.
| | - Jun Zhang
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing 100071, China.
| | - Ying Yin
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing 100071, China.
| | - Dayong Dong
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing 100071, China.
| | - Ling Fu
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing 100071, China.
| | - Junjie Xu
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing 100071, China.
| | - Wei Chen
- Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, Beijing 100071, China.
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Gong W, Qi Y, Xiong X, Jiao J, Duan C, Wen B. Rickettsia rickettsii outer membrane protein YbgF induces protective immunity in C3H/HeN mice. Hum Vaccin Immunother 2015; 11:642-9. [PMID: 25714655 DOI: 10.1080/21645515.2015.1011572] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Rickettsia rickettsii is the etiological agent of Rocky Mountain spotted fever (RMSF). YbgF and TolC are outer membrane-associated proteins of R. rickettsii that play important roles in its interaction with host cells. We investigated the immunogenicity of YbgF and TolC for protection against RMSF. We immunized C3H/HeN mice with recombinant R. rickettsii YbgF (rYbgF) or TolC (rTolC). Rickettsial burden and impairment in the lungs, spleens, and livers of rYbgF-immunized mice were significantly lower than in rTolC-immunized mice. The ratio of IgG2a to IgG1 in rYbgF-immunized mice continued to increase over the course of our experiments, while that in rTolC-immunized mice was reduced. The proliferation and cytokine secretion of CD4(+) and CD8(+) T cells isolated from R. rickettsii-infected mice were analyzed following antigen stimulation. The results indicated that proliferation and interferon (IFN)-γ secretion of CD4(+) or CD8(+) T cells in R. rickettsii-infected mice were significantly greater than in uninfected mice after stimulation with rYbgF. YbgF is a novel protective antigen of R. rickettsii. Protection conferred by YbgF is dependent upon IFN-γ-producing CD4(+) and CD8(+) T cells and IgG2a, which act in synergy to control R. rickettsii infection.
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Wang X, An C, Yang M, Li X, Ke Y, Lei S, Xu X, Yu J, Ren H, Du X, Wang Z, Qiu Y, Liu B, Chen Z. Immunization with individual proteins of the Lrp/AsnC family induces protection against Brucella melitensis 16M challenges in mice. Front Microbiol 2015; 6:1193. [PMID: 26579099 PMCID: PMC4625564 DOI: 10.3389/fmicb.2015.01193] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 10/13/2015] [Indexed: 11/13/2022] Open
Abstract
Brucellosis is one of the most common zoonoses worldwide. Subunit vaccines are promising for the prevention of human brucellosis. In our previous protective antigen screening studies, we identified a new protective antigen, BMEI0357, which belongs to the Lrp/asnC protein family, a conserved transcriptional regulator in bacteria that is absent in eukaryotes. In the present study, the Brucella genome annotation was screened and a total of six proteins were identified as members of the Lrp/AsnC family. Lrp/AsnC proteins have two domains that are conserved among the family members. However, sequence similarities between these proteins ranged from 9 to 50%, indicating high sequence heterogeneity. To test whether proteins of this family have similar characteristics, all six proteins were cloned and expressed in Escherichia coli. The recombinant proteins were purified and their protective efficacy was evaluated in BALB/c mice challenged with Brucella melitensis 16M. The results show that all six Lrp/AsnC proteins could induce a protective immune response against Brucella melitensis 16M. Antibodies against the Lrp/AsnC proteins were detected in the immunized mice. However, levels of antibodies against these proteins were relatively variable in human brucellosis sera. Taken together, our results show that these six proteins of the Lrp/AsnC family in Brucella could induce protective immune responses in mice.
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Affiliation(s)
- Xinhui Wang
- Key Laboratory of Zoonosis, Institute of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University Changchun, China ; Experimental Animal Center, Academy of Military Medical Sciences Beijing, China ; Department of Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Chang An
- Key Laboratory of Zoonosis, Institute of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University Changchun, China ; Experimental Animal Center, Academy of Military Medical Sciences Beijing, China
| | - Mingjuan Yang
- Department of Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Xinran Li
- Key Laboratory of Zoonosis, Institute of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University Changchun, China ; Department of Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Yuehua Ke
- Department of Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Shuangshuang Lei
- Department of Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Xiaoyang Xu
- Department of Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Jiuxuan Yu
- Department of Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Hang Ren
- Department of Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Xinying Du
- Department of Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Zhoujia Wang
- Department of Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Yefeng Qiu
- Experimental Animal Center, Academy of Military Medical Sciences Beijing, China
| | - Bo Liu
- Key Laboratory of Zoonosis, Institute of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University Changchun, China
| | - Zeliang Chen
- Department of Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
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Huang B, Xie T, Rotstein D, Fang H, Frucht DM. Passive Immunotherapy Protects against Enteric Invasion and Lethal Sepsis in a Murine Model of Gastrointestinal Anthrax. Toxins (Basel) 2015; 7:3960-76. [PMID: 26426050 DOI: 10.3390/toxins7103960] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 08/19/2015] [Indexed: 01/09/2023] Open
Abstract
The principal portal for anthrax infection in natural animal outbreaks is the digestive tract. Enteric exposure to anthrax, which is difficult to detect or prevent in a timely manner, could be exploited as an act of terror through contamination of human or animal food. Our group has developed a novel animal model of gastrointestinal (GI) anthrax for evaluation of disease pathogenesis and experimental therapeutics, utilizing vegetative Bacillus anthracis (Sterne strain) administered to A/J mice (a complement-deficient strain) by oral gavage. We hypothesized that a humanized recombinant monoclonal antibody (mAb) * that neutralizes the protective antigen (PA) component of B. anthracis lethal toxin (LT) and edema toxin (ET) could be an effective treatment. Although the efficacy of this anti-anthrax PA mAb has been shown in animal models of inhalational anthrax, its activity in GI infection had not yet been ascertained. We hereby demonstrate that passive immunotherapy with anti-anthrax PA mAb, administered at the same time as gastrointestinal exposure to B. anthracis, prevents lethal sepsis in nearly all cases (>90%), while a delay of up to forty-eight hours in treatment still greatly reduces mortality following exposure (65%). Moreover, passive immunotherapy protects against enteric invasion, associated mucosal injury and subsequent dissemination by gastrointestinal B. anthracis, indicating that it acts to prevent the initial stages of infection. * Expired raxibacumab being cycled off the Strategic National Stockpile; biological activity confirmed by in vitro assay.
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