1
|
Mei J, Yang Q, Jiang L, Wang T, Li Y, Yu X, Wu Z. Immune protection of grass carp by oral vaccination with recombinant Bacillus methylotrophicus expressing the heterologous tolC gene. FISH & SHELLFISH IMMUNOLOGY 2024; 151:109701. [PMID: 38878911 DOI: 10.1016/j.fsi.2024.109701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 06/06/2024] [Accepted: 06/13/2024] [Indexed: 06/19/2024]
Abstract
In the field of aquaculture, the enhancement of animal health and disease prevention is progressively being tackled using alternatives to antibiotics, including vaccines and probiotics. This study was designed to evaluate the potential of a recombinant Bacillus methylotrophicus, engineered to express the outer membrane channel protein TolC of Aeromonas hydrophila AH3 and the green fluorescent protein GFP, as an oral vaccine. Initially, the genes encoding tolC and GFP were cloned into a prokaryotic expression system, and anti-TolC mouse antiserum was generated. Subsequently, the tolC gene was subcloned into a modified pMDGFP plasmid, which was transformed into B. methylotrophicus WM-1 for protein expression. The recombinant B. methylotrophicus BmT was then administered to grass carp via co-feeding, and its efficacy as an oral vaccine was assessed. Our findings demonstrated successful expression of the 55 kDa TolC and 28 kDa GFP proteins, and the preparation of polyclonal antibodies with high specificity. The BmT exhibited stable expression of the GFP-TolC fusion protein and excellent genetic stability. Following oral immunization, significant elevations were observed in serum-specific IgM levels and the activities of acid phosphatase (ACP), alkaline phosphatase (AKP), superoxide dismutase (SOD), and lysozyme (LZM) in grass carp. Concurrently, significant upregulation of immune-related genes, including IFN-I, IL-10, IL-1β, TNF-α, and IgT, was noted in the intestines, head kidney, and spleen of the grass carp. Colonization tests further revealed that the BmT persisted in the gut of immunized fish even after a fasting period of 7 days. Notably, oral administration of BmT enhanced the survival rate of grass carp following A. hydrophila infection. These results suggest that the oral BmT vaccine developed in this study holds promise for future applications in aquaculture.
Collapse
Affiliation(s)
- Jing Mei
- College of Fisheries, Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Aquatic Biodiversity Protection Research Center, Southwest University, Chongqing, 400715, China
| | - Qinglin Yang
- College of Fisheries, Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Aquatic Biodiversity Protection Research Center, Southwest University, Chongqing, 400715, China
| | - Liyan Jiang
- College of Fisheries, Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Aquatic Biodiversity Protection Research Center, Southwest University, Chongqing, 400715, China
| | - Tao Wang
- College of Fisheries, Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Aquatic Biodiversity Protection Research Center, Southwest University, Chongqing, 400715, China
| | - Yanhong Li
- College of Fisheries, Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Aquatic Biodiversity Protection Research Center, Southwest University, Chongqing, 400715, China
| | - Xiaobo Yu
- College of Fisheries, Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Aquatic Biodiversity Protection Research Center, Southwest University, Chongqing, 400715, China
| | - Zhengli Wu
- College of Fisheries, Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Aquatic Biodiversity Protection Research Center, Southwest University, Chongqing, 400715, China.
| |
Collapse
|
2
|
Ochai SO, Crafford JE, Hassim A, Byaruhanga C, Huang YH, Hartmann A, Dekker EH, van Schalkwyk OL, Kamath PL, Turner WC, van Heerden H. Immunological Evidence of Variation in Exposure and Immune Response to Bacillus anthracis in Herbivores of Kruger and Etosha National Parks. Front Immunol 2022; 13:814031. [PMID: 35237267 PMCID: PMC8882864 DOI: 10.3389/fimmu.2022.814031] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 01/17/2022] [Indexed: 11/13/2022] Open
Abstract
Exposure and immunity to generalist pathogens differ among host species and vary across spatial scales. Anthrax, caused by a multi-host bacterial pathogen, Bacillus anthracis, is enzootic in Kruger National Park (KNP), South Africa and Etosha National Park (ENP), Namibia. These parks share many of the same potential host species, yet the main anthrax host in one (greater kudu (Tragelaphus strepsiceros) in KNP and plains zebra (Equus quagga) in ENP) is only a minor host in the other. We investigated species and spatial patterns in anthrax mortalities, B. anthracis exposure, and the ability to neutralize the anthrax lethal toxin to determine if observed host mortality differences between locations could be attributed to population-level variation in pathogen exposure and/or immune response. Using serum collected from zebra and kudu in high and low incidence areas of each park (18- 20 samples/species/area), we estimated pathogen exposure from anti-protective antigen (PA) antibody response using enzyme-linked immunosorbent assay (ELISA) and lethal toxin neutralization with a toxin neutralization assay (TNA). Serological evidence of pathogen exposure followed mortality patterns within each system (kudus: 95% positive in KNP versus 40% in ENP; zebras: 83% positive in ENP versus 63% in KNP). Animals in the high-incidence area of KNP had higher anti-PA responses than those in the low-incidence area, but there were no significant differences in exposure by area within ENP. Toxin neutralizing ability was higher for host populations with lower exposure prevalence, i.e., higher in ENP kudus and KNP zebras than their conspecifics in the other park. These results indicate that host species differ in their exposure to and adaptive immunity against B. anthracis in the two parks. These patterns may be due to environmental differences such as vegetation, rainfall patterns, landscape or forage availability between these systems and their interplay with host behavior (foraging or other risky behaviors), resulting in differences in exposure frequency and dose, and hence immune response.
Collapse
Affiliation(s)
- Sunday O. Ochai
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
| | - Jan E. Crafford
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
| | - Ayesha Hassim
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
| | - Charles Byaruhanga
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
| | - Yen-Hua Huang
- Wisconsin Cooperative Wildlife Research Unit, Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI, United States
| | - Axel Hartmann
- Etosha Ecological Institute, Ministry of Environment, Forestry and Tourism, Okaukuejo, Namibia
| | - Edgar H. Dekker
- Office of the State Veterinarian, Department of Agriculture, Forestry and Fisheries, Government of South Africa, Skukuza, South Africa
| | - O. Louis van Schalkwyk
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
- Office of the State Veterinarian, Department of Agriculture, Forestry and Fisheries, Government of South Africa, Skukuza, South Africa
- Department of Migration, Max Planck Institute of Animal Behavior, Radolfzell, Germany
| | - Pauline L. Kamath
- School of Food and Agriculture, University of Maine, Orono, ME, United States
| | - Wendy C. Turner
- U.S. Geological Survey, Wisconsin Cooperative Wildlife Research Unit, Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI, United States
| | - Henriette van Heerden
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
| |
Collapse
|
3
|
Kumar M, Kumari N, Thakur N, Bhatia SK, Saratale GD, Ghodake G, Mistry BM, Alavilli H, Kishor DS, Du X, Chung SM. A Comprehensive Overview on the Production of Vaccines in Plant-Based Expression Systems and the Scope of Plant Biotechnology to Combat against SARS-CoV-2 Virus Pandemics. PLANTS (BASEL, SWITZERLAND) 2021; 10:1213. [PMID: 34203729 PMCID: PMC8232254 DOI: 10.3390/plants10061213] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/28/2021] [Accepted: 06/12/2021] [Indexed: 12/23/2022]
Abstract
Many pathogenic viral pandemics have caused threats to global health; the COVID-19 pandemic is the latest. Its transmission is growing exponentially all around the globe, putting constraints on the health system worldwide. A novel coronavirus, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), causes this pandemic. Many candidate vaccines are available at this time for COVID-19, and there is a massive international race underway to procure as many vaccines as possible for each country. However, due to heavy global demand, there are strains in global vaccine production. The use of a plant biotechnology-based expression system for vaccine production also represents one part of this international effort, which is to develop plant-based heterologous expression systems, virus-like particles (VLPs)-vaccines, antiviral drugs, and a rapid supply of antigen-antibodies for detecting kits and plant origin bioactive compounds that boost the immunity and provide tolerance to fight against the virus infection. This review will look at the plant biotechnology platform that can provide the best fight against this global pandemic.
Collapse
Affiliation(s)
- Manu Kumar
- Department of Life Science, College of Life Science and Biotechnology, Dongguk University, Seoul 10326, Korea; (M.K.); (D.S.K.); (X.D.)
| | - Nisha Kumari
- Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul 03080, Korea;
| | - Nishant Thakur
- Department of Hospital Pathology, Yeouido St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, 10, 63-ro, Yeongdeungpo-gu, Seoul 07345, Korea;
| | - Shashi Kant Bhatia
- Department of Biological Engineering, College of Engineering, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 05029, Korea;
| | - Ganesh Dattatraya Saratale
- Department of Food Science and Biotechnology, Dongguk University, Seoul 10326, Korea; (G.D.S.); (B.M.M.)
| | - Gajanan Ghodake
- Department of Biological and Environmental Science, Dongguk University, Seoul 10326, Korea;
| | - Bhupendra M. Mistry
- Department of Food Science and Biotechnology, Dongguk University, Seoul 10326, Korea; (G.D.S.); (B.M.M.)
| | - Hemasundar Alavilli
- Department of Biochemistry and Molecular Biology, College of Medicine, Korea University, Seoul 02841, Korea;
| | - D. S. Kishor
- Department of Life Science, College of Life Science and Biotechnology, Dongguk University, Seoul 10326, Korea; (M.K.); (D.S.K.); (X.D.)
| | - Xueshi Du
- Department of Life Science, College of Life Science and Biotechnology, Dongguk University, Seoul 10326, Korea; (M.K.); (D.S.K.); (X.D.)
| | - Sang-Min Chung
- Department of Life Science, College of Life Science and Biotechnology, Dongguk University, Seoul 10326, Korea; (M.K.); (D.S.K.); (X.D.)
| |
Collapse
|
4
|
Benn JS, Chaki SP, Xu Y, Ficht TA, Rice-Ficht AC, Cook WE. Protective antibody response following oral vaccination with microencapsulated Bacillus Anthracis Sterne strain 34F2 spores. NPJ Vaccines 2020; 5:59. [PMID: 32685200 PMCID: PMC7351773 DOI: 10.1038/s41541-020-0208-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 06/05/2020] [Indexed: 11/30/2022] Open
Abstract
An oral vaccine against anthrax (Bacillus anthracis) is urgently needed to prevent annual anthrax outbreaks that are causing catastrophic losses in free-ranging livestock and wildlife worldwide. The Sterne vaccine, the current injectable livestock vaccine, is a suspension of live attenuated B. anthracis Sterne strain 34F2 spores (Sterne spores) in saponin. It is not effective when administered orally and individual subcutaneous injections are not a practical method of vaccination for wildlife. In this study, we report the development of a microencapsulated oral vaccine against anthrax. Evaluating Sterne spore stability at varying pH's in vitro revealed that spore exposure to pH 2 results in spore death, confirming that protection from the gastric environment is of main concern when producing an oral vaccine. Therefore, Sterne spores were encapsulated in alginate and coated with a protein shell containing poly-L-lysine (PLL) and vitelline protein B (VpB), a non-immunogenic, proteolysis resistant protein isolated from Fasciola hepatica. Capsule exposure to pH 2 demonstrated enhanced acid gel character suggesting that alginate microcapsules provided the necessary protection for spores to survive the gastric environment. Post vaccination IgG levels in BALBc/J mouse serum samples indicated that encapsulated spores induced anti-anthrax specific responses in both the subcutaneous and the oral vaccination groups. Furthermore, the antibody responses from both vaccination routes were protective against anthrax lethal toxin in vitro, suggesting that further optimization of this vaccine formulation may result in a reliable oral vaccine that will conveniently and effectively prevent anthrax in wildlife populations.
Collapse
Affiliation(s)
- Jamie S. Benn
- Texas A&M University, Department of Veterinary Pathobiology, College Station, TX 77843 USA
| | - Sankar P. Chaki
- Texas A&M University, Department of Veterinary Pathobiology, College Station, TX 77843 USA
| | - Yi Xu
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX 77030 USA
| | - Thomas A. Ficht
- Texas A&M University, Department of Veterinary Pathobiology, College Station, TX 77843 USA
| | - Allison C. Rice-Ficht
- Texas A&M University, Department of Veterinary Pathobiology, College Station, TX 77843 USA
- Texas A&M Health Science Center, Department of Molecular and Cellular Medicine, College Station, TX 77843 USA
| | - Walter E. Cook
- Texas A&M University, Department of Veterinary Pathobiology, College Station, TX 77843 USA
| |
Collapse
|
5
|
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: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [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.
Collapse
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
| |
Collapse
|
6
|
Carlson CJ, Getz WM, Kausrud KL, Cizauskas CA, Blackburn JK, Bustos Carrillo FA, Colwell R, Easterday WR, Ganz HH, Kamath PL, Økstad OA, Turner WC, Kolstø AB, Stenseth NC. Spores and soil from six sides: interdisciplinarity and the environmental biology of anthrax (Bacillus anthracis). Biol Rev Camb Philos Soc 2018; 93:1813-1831. [PMID: 29732670 DOI: 10.1111/brv.12420] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Revised: 03/27/2018] [Accepted: 04/03/2018] [Indexed: 12/11/2022]
Abstract
Environmentally transmitted diseases are comparatively poorly understood and managed, and their ecology is particularly understudied. Here we identify challenges of studying environmental transmission and persistence with a six-sided interdisciplinary review of the biology of anthrax (Bacillus anthracis). Anthrax is a zoonotic disease capable of maintaining infectious spore banks in soil for decades (or even potentially centuries), and the mechanisms of its environmental persistence have been the topic of significant research and controversy. Where anthrax is endemic, it plays an important ecological role, shaping the dynamics of entire herbivore communities. The complex eco-epidemiology of anthrax, and the mysterious biology of Bacillus anthracis during its environmental stage, have necessitated an interdisciplinary approach to pathogen research. Here, we illustrate different disciplinary perspectives through key advances made by researchers working in Etosha National Park, a long-term ecological research site in Namibia that has exemplified the complexities of the enzootic process of anthrax over decades of surveillance. In Etosha, the role of scavengers and alternative routes (waterborne transmission and flies) has proved unimportant relative to the long-term persistence of anthrax spores in soil and their infection of herbivore hosts. Carcass deposition facilitates green-ups of vegetation to attract herbivores, potentially facilitated by the role of anthrax spores in the rhizosphere. The underlying seasonal pattern of vegetation, and herbivores' immune and behavioural responses to anthrax risk, interact to produce regular 'anthrax seasons' that appear to be a stable feature of the Etosha ecosystem. Through the lens of microbiologists, geneticists, immunologists, ecologists, epidemiologists, and clinicians, we discuss how anthrax dynamics are shaped at the smallest scale by population genetics and interactions within the bacterial communities up to the broadest scales of ecosystem structure. We illustrate the benefits and challenges of this interdisciplinary approach to disease ecology, and suggest ways anthrax might offer insights into the biology of other important pathogens. Bacillus anthracis, and the more recently emerged Bacillus cereus biovar anthracis, share key features with other environmentally transmitted pathogens, including several zoonoses and panzootics of special interest for global health and conservation efforts. Understanding the dynamics of anthrax, and developing interdisciplinary research programs that explore environmental persistence, is a critical step forward for understanding these emerging threats.
Collapse
Affiliation(s)
- Colin J Carlson
- National Socio-Environmental Synthesis Center (SESYNC), University of Maryland, Annapolis, MD 21401, U.S.A.,Department of Biology, Georgetown University, Washington, DC 20057, U.S.A
| | - Wayne M Getz
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720, U.S.A.,School of Mathematical Sciences, University of KwaZulu-Natal, PB X 54001, Durban 4000, South Africa
| | - Kyrre L Kausrud
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, PO Box 1066 Blindern, N-0316, Oslo, Norway
| | - Carrie A Cizauskas
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720, U.S.A
| | - Jason K Blackburn
- Spatial Epidemiology & Ecology Research Lab, Department of Geography, University of Florida, Gainesville, FL 32611, U.S.A.,Emerging Pathogens Institute, University of Florida, Gainesville, FL, U.S.A
| | - Fausto A Bustos Carrillo
- Department of Epidemiology & Department of Biostatistics, School of Public Health, University of California, Berkeley, CA 94720-7360, U.S.A
| | - Rita Colwell
- CosmosID Inc., Rockville, MD 20850, U.S.A.,Center for Bioinformatics and Computational Biology, University of Maryland Institute for Advanced Computer Studies, University of Maryland, College Park, MD 20742, U.S.A.,Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, U.S.A
| | - W Ryan Easterday
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, PO Box 1066 Blindern, N-0316, Oslo, Norway
| | - Holly H Ganz
- UC Davis Genome Center, University of California, Davis, CA 95616, U.S.A
| | - Pauline L Kamath
- School of Food and Agriculture, University of Maine, Orono, ME 04469, U.S.A
| | - Ole A Økstad
- Centre for Integrative Microbial Evolution and Section for Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, PO Box 1068 Blindern, N-0316, Oslo, Norway
| | - Wendy C Turner
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, U.S.A
| | - Anne-Brit Kolstø
- Centre for Integrative Microbial Evolution and Section for Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, PO Box 1068 Blindern, N-0316, Oslo, Norway
| | - Nils C Stenseth
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, PO Box 1066 Blindern, N-0316, Oslo, Norway
| |
Collapse
|
7
|
Chitlaru T, Israeli M, Rotem S, Elia U, Bar-Haim E, Ehrlich S, Cohen O, Shafferman A. A novel live attenuated anthrax spore vaccine based on an acapsular Bacillus anthracis Sterne strain with mutations in the htrA, lef and cya genes. Vaccine 2017; 35:6030-6040. [DOI: 10.1016/j.vaccine.2017.03.033] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 01/24/2017] [Accepted: 03/08/2017] [Indexed: 02/06/2023]
|
8
|
The Exosporium Layer of Bacterial Spores: a Connection to the Environment and the Infected Host. Microbiol Mol Biol Rev 2016; 79:437-57. [PMID: 26512126 DOI: 10.1128/mmbr.00050-15] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Much of what we know regarding bacterial spore structure and function has been learned from studies of the genetically well-characterized bacterium Bacillus subtilis. Molecular aspects of spore structure, assembly, and function are well defined. However, certain bacteria produce spores with an outer spore layer, the exosporium, which is not present on B. subtilis spores. Our understanding of the composition and biological functions of the exosporium layer is much more limited than that of other aspects of the spore. Because the bacterial spore surface is important for the spore's interactions with the environment, as well as being the site of interaction of the spore with the host's innate immune system in the case of spore-forming bacterial pathogens, the exosporium is worthy of continued investigation. Recent exosporium studies have focused largely on members of the Bacillus cereus family, principally Bacillus anthracis and Bacillus cereus. Our understanding of the composition of the exosporium, the pathway of its assembly, and its role in spore biology is now coming into sharper focus. This review expands on a 2007 review of spore surface layers which provided an excellent conceptual framework of exosporium structure and function (A. O. Henriques and C. P. Moran, Jr., Annu Rev Microbiol 61:555-588, 2007, http://dx.doi.org/10.1146/annurev.micro.61.080706.093224). That review began a process of considering outer spore layers as an integrated, multilayered structure rather than simply regarding the outer spore components as independent parts.
Collapse
|
9
|
Next-Generation Bacillus anthracis Live Attenuated Spore Vaccine Based on the htrA(-) (High Temperature Requirement A) Sterne Strain. Sci Rep 2016; 6:18908. [PMID: 26732659 PMCID: PMC4702213 DOI: 10.1038/srep18908] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 11/30/2015] [Indexed: 12/17/2022] Open
Abstract
Anthrax is a lethal disease caused by the gram-positive spore-producing bacterium Bacillus anthracis. Live attenuated vaccines, such as the nonencapsulated Sterne strain, do not meet the safety standards mandated for human use in the Western world and are approved for veterinary purposes only. Here we demonstrate that disrupting the htrA gene, encoding the chaperone/protease HtrA (High Temperature Requirement A), in the virulent Bacillus anthracis Vollum strain results in significant virulence attenuation in guinea pigs, rabbits and mice, underlying the universality of the attenuated phenotype associated with htrA knockout. Accordingly, htrA disruption was implemented for the development of a Sterne-derived safe live vaccine compatible with human use. The novel B. anthracis SterneΔhtrA strain secretes functional anthrax toxins but is 10–104-fold less virulent than the Sterne vaccine strain depending on animal model (mice, guinea pigs, or rabbits). In spite of this attenuation, double or even single immunization with SterneΔhtrA spores elicits immune responses which target toxaemia and bacteremia resulting in protection from subcutaneous or respiratory lethal challenge with a virulent strain in guinea pigs and rabbits. The efficacy of the immune-protective response in guinea pigs was maintained for at least 50 weeks after a single immunization.
Collapse
|
10
|
Chen H, Zhang T, Jia J, Vastermark A, Tian R, Ni Z, Chen Z, Chen K, Yang S. Expression and display of a novel thermostable esterase from Clostridium thermocellum on the surface of Bacillus subtilis using the CotB anchor protein. ACTA ACUST UNITED AC 2015; 42:1439-48. [DOI: 10.1007/s10295-015-1676-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 08/14/2015] [Indexed: 11/28/2022]
Abstract
Abstract
Esterases expressed in microbial hosts are commercially valuable, but their applications are limited due to high costs of production and harsh industrial processes involved. In this study, the esterase-DSM (from Clostridium thermocellum) was expressed and successfully displayed on the spore surface, and the spore-associated esterase was confirmed by western blot analysis and activity measurements. The optimal temperature and pH of spore surface-displayed DSM was 60 and 8.5 °C, respectively. It also demonstrates a broad temperature and pH optimum in the range of 50–70, 7–9.5 °C. The spore surface-displayed esterase-DSM retained 78, 68 % of its original activity after 5 h incubation at 60 and 70 °C, respectively, which was twofold greater activity than that of the purified DSM. The recombinant spores has high activity and stability in DMSO, which was 49 % higher than the retained activity of the purified DSM in DMSO (20 % v/v), and retained 65.2 % of activity after 7 h of incubation in DMSO (20 % v/v). However, the recombinant spores could retain 77 % activity after 3 rounds of recycling. These results suggest that enzyme displayed on the surface of the Bacillus subtilis spore could serve as an effective approach for enzyme immobilization.
Collapse
Affiliation(s)
- Huayou Chen
- grid.440785.a 000000010743511X Institute of Life Sciences Jiangsu University 212013 Zhenjiang Jiangsu Province China
- grid.9227.e 0000000119573309 National Key Laboratory of Biochemical Engineering, Institute of Process Engineering Chinese Academy of Sciences 10090 Beijing China
- grid.266100.3 0000000121074242 Division of Biological Sciences University of California at San Diego 92093-0116 La Jolla CA USA
| | - Tianxi Zhang
- grid.440785.a 000000010743511X Institute of Life Sciences Jiangsu University 212013 Zhenjiang Jiangsu Province China
| | - Jinru Jia
- grid.440785.a 000000010743511X Institute of Life Sciences Jiangsu University 212013 Zhenjiang Jiangsu Province China
| | - Ake Vastermark
- grid.266100.3 0000000121074242 Division of Biological Sciences University of California at San Diego 92093-0116 La Jolla CA USA
| | - Rui Tian
- grid.440785.a 000000010743511X Institute of Life Sciences Jiangsu University 212013 Zhenjiang Jiangsu Province China
| | - Zhong Ni
- grid.440785.a 000000010743511X Institute of Life Sciences Jiangsu University 212013 Zhenjiang Jiangsu Province China
| | - Zhi Chen
- grid.440785.a 000000010743511X Institute of Life Sciences Jiangsu University 212013 Zhenjiang Jiangsu Province China
| | - Keping Chen
- grid.440785.a 000000010743511X Institute of Life Sciences Jiangsu University 212013 Zhenjiang Jiangsu Province China
| | - Shengli Yang
- grid.440785.a 000000010743511X Institute of Life Sciences Jiangsu University 212013 Zhenjiang Jiangsu Province China
| |
Collapse
|
11
|
Gorantala J, Grover S, Rahi A, Chaudhary P, Rajwanshi R, Sarin NB, Bhatnagar R. Generation of protective immune response against anthrax by oral immunization with protective antigen plant-based vaccine. J Biotechnol 2014; 176:1-10. [PMID: 24548460 DOI: 10.1016/j.jbiotec.2014.01.033] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 12/30/2013] [Accepted: 01/29/2014] [Indexed: 01/04/2023]
Abstract
In concern with frequent recurrence of anthrax in endemic areas and inadvertent use of its spores as biological weapon, the development of an effective anthrax vaccine suitable for both human and veterinary needs is highly desirable. A simple oral delivery through expression in plant system could offer promising alternative to the current methods that rely on injectable vaccines extracted from bacterial sources. In the present study, we have expressed protective antigen (PA) gene in Indian mustard by Agrobacterium-mediated transformation and in tobacco by plastid transformation. Putative transgenic lines were verified for the presence of transgene and its expression by molecular analysis. PA expressed in transgenic lines was biologically active as evidenced by macrophage lysis assay. Intraperitoneal (i.p.) and oral immunization with plant PA in murine model indicated high serum PA specific IgG and IgA antibody titers. PA specific mucosal immune response was noted in orally immunized groups. Further, antibodies indicated lethal toxin neutralizing potential in-vitro and conferred protection against in-vivo toxin challenge. Oral immunization experiments demonstrated generation of immunoprotective response in mice. Thus, our study examines the feasibility of oral PA vaccine expressed in an edible plant system against anthrax.
Collapse
Affiliation(s)
- Jyotsna Gorantala
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Sonam Grover
- Molecular Technology Laboratory, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Amit Rahi
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Prerna Chaudhary
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Ravi Rajwanshi
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Neera Bhalla Sarin
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Rakesh Bhatnagar
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India.
| |
Collapse
|
12
|
Cizauskas CA, Bellan SE, Turner WC, Vance RE, Getz WM. Frequent and seasonally variable sublethal anthrax infections are accompanied by short-lived immunity in an endemic system. J Anim Ecol 2014; 83:1078-90. [PMID: 24499424 DOI: 10.1111/1365-2656.12207] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 01/25/2014] [Indexed: 01/07/2023]
Abstract
Few studies have examined host-pathogen interactions in wildlife from an immunological perspective, particularly in the context of seasonal and longitudinal dynamics. In addition, though most ecological immunology studies employ serological antibody assays, endpoint titre determination is usually based on subjective criteria and needs to be made more objective. Despite the fact that anthrax is an ancient and emerging zoonotic infectious disease found world-wide, its natural ecology is not well understood. In particular, little is known about the adaptive immune responses of wild herbivore hosts against Bacillus anthracis. Working in the natural anthrax system of Etosha National Park, Namibia, we collected 154 serum samples from plains zebra (Equus quagga), 21 from springbok (Antidorcas marsupialis) and 45 from African elephants (Loxodonta africana) over 2-3 years, resampling individuals when possible for seasonal and longitudinal comparisons. We used enzyme-linked immunosorbent assays to measure anti-anthrax antibody titres and developed three increasingly conservative models to determine endpoint titres with more rigourous, objective mensuration. Between 52 and 87% of zebra, 0-15% of springbok and 3-52% of elephants had measurable anti-anthrax antibody titres, depending on the model used. While the ability of elephants and springbok to mount anti-anthrax adaptive immune responses is still equivocal, our results indicate that zebra in ENP often survive sublethal anthrax infections, encounter most B. anthracis in the wet season and can partially booster their immunity to B. anthracis. Thus, rather than being solely a lethal disease, anthrax often occurs as a sublethal infection in some susceptible hosts. Though we found that adaptive immunity to anthrax wanes rapidly, subsequent and frequent sublethal B. anthracis infections cause maturation of anti-anthrax immunity. By triggering host immune responses, these common sublethal infections may act as immunomodulators and affect population dynamics through indirect immunological and co-infection effects. In addition, with our three endpoint titre models, we introduce more mensuration rigour into serological antibody assays, even under the often-restrictive conditions that come with adapting laboratory immunology methods to wild systems. With these methods, we identified significantly more zebras responding immunologically to anthrax than have previous studies using less comprehensive titre analyses.
Collapse
Affiliation(s)
- Carrie A Cizauskas
- Department of Environmental Science, Policy & Management, University of California, Berkeley, Berkeley, CA, USA.,Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | - Steven E Bellan
- Department of Environmental Science, Policy & Management, University of California, Berkeley, Berkeley, CA, USA.,Center for Computational Biology and Informatics, University of Texas at Austin, Austin, TX, USA
| | - Wendy C Turner
- Department of Environmental Science, Policy & Management, University of California, Berkeley, Berkeley, CA, USA.,Department of Biosciences, Centre for Ecological and Evolutionary Synthesis, University of Oslo, Oslo, Norway
| | - Russell E Vance
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Wayne M Getz
- Department of Environmental Science, Policy & Management, University of California, Berkeley, Berkeley, CA, USA.,School of Mathematical Sciences, University of KwaZulu-Natal, Durban, South Africa
| |
Collapse
|
13
|
Tournier JN, Ulrich RG, Quesnel-Hellmann A, Mohamadzadeh M, Stiles BG. Anthrax, toxins and vaccines: a 125-year journey targetingBacillus anthracis. Expert Rev Anti Infect Ther 2014; 7:219-36. [DOI: 10.1586/14787210.7.2.219] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
14
|
Bouzianas DG. Potential biological targets ofBacillus anthracisin anti-infective approaches against the threat of bioterrorism. Expert Rev Anti Infect Ther 2014; 5:665-84. [PMID: 17678429 DOI: 10.1586/14787210.5.4.665] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The terrorist attacks of 2001 involving anthrax underscore the imperative that safe and effective medical countermeasures should be readily available. Vaccination appears to be the most effective form of mass protection against a biological attack, but the current vaccines have drawbacks that justify the enormous amount of effort currently being put into developing more effective vaccines and other treatment modalities. After providing a comprehensive overview of the organism Bacillus anthracis as a biological weapon and its pathogenicity, this review briefly summarizes the current knowledge vital to the management of anthrax disease. This knowledge has been acquired since 2001 as a result of the progress on anthrax research and focuses on the possible development of improved human anti-infective strategies targeting B. anthracis spore components, as well as strategies based on host-pathogen interactions.
Collapse
Affiliation(s)
- Dimitrios G Bouzianas
- Department of Medical Laboratories, Faculty of Health and Care Professions, University-level Technological Educational Institute of Thessaloniki, Greece.
| |
Collapse
|
15
|
The role of nuclear technologies in the diagnosis and control of livestock diseases--a review. Trop Anim Health Prod 2013; 44:1341-66. [PMID: 22286376 PMCID: PMC3433664 DOI: 10.1007/s11250-012-0077-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/08/2012] [Indexed: 01/15/2023]
Abstract
Nuclear and nuclear-related technologies have played an important role in animal health, particularly in relation to disease diagnosis and characterization of pathogenic organisms. This review focuses primarily on how and where nuclear technologies, both non-isotopic and isotopic methods, have made their impact in the past and where it might be expected they could have an impact in the future. The review outlines the extensive use of radiation attenuation in attempts to create vaccines for a multiplicity of pathogenic organisms and how the technology is being re-examined in the light of recent advances in irradiation techniques and cryopreservation/lyophilization that might obviate some of the problems of maintenance of viable, attenuate vaccines and their transport and use in the field. This approach could be used for a number of parasitic diseases where vaccination has been problematic and where investigations into the development of molecular vaccines have still failed to deliver satisfactory candidates for generating protective immune responses. Irradiation of antigens or serum samples also has its uses in diagnosis, especially when the samples need to be transported across international boundaries, or when handling the pathogens in question when carrying out a test presents serious health hazards to laboratory personnel. The present-day extensive use of enzyme immunoassays and molecular methods (e.g., polymerase chain reaction) for diagnosis and characterization of animal pathogens has its origins in the use of isotope-labeled antigens and antibodies. These isotopic techniques that included the use of 75Se, 32P, 125I, and 35S isotopes enabled a level of sensitivity and specificity that was hitherto unrealized, and it is prescient to remind ourselves of just how successful these technologies were, in spite of their infrequent use nowadays. Finally, the review looks at the potential for stable isotope analysis for a variety of applications--in the tracking of animal migrations, where the migrant are potential carriers of transboundary animal diseases, and where it would be useful to determine the origins of the carrier, e.g., Highly Pathogenic Avian Influenza and its dissemination by wild water fowl. Other applications could be in monitoring sequestered microbial culture (e.g., rinderpest virus) where in the case of accidental or deliberate release of infective culture it would be possible to identify the laboratory from which the isolate originated.
Collapse
|
16
|
Chitlaru T, Altboum Z, Reuveny S, Shafferman A. Progress and novel strategies in vaccine development and treatment of anthrax. Immunol Rev 2011; 239:221-36. [PMID: 21198675 DOI: 10.1111/j.1600-065x.2010.00969.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The lethal anthrax disease is caused by spores of the gram-positive Bacillus anthracis, a member of the cereus group of bacilli. Although the disease is very rare in the Western world, development of anthrax countermeasures gains increasing attention due to the potential use of B. anthracis spores as a bio-terror weapon. Protective antigen (PA), the non-toxic subunit of the bacterial secreted exotoxin, fulfills the role of recognizing a specific receptor and mediating the entry of the toxin into the host target cells. PA elicits a protective immune response and represents the basis for all current anthrax vaccines. Anti-PA neutralizing antibodies are useful correlates for protection and for vaccine efficacy evaluation. Post exposure anti-toxemic and anti-bacteremic prophylactic treatment of anthrax requires prolonged antibiotic administration. Shorter efficient postexposure treatments may require active or passive immunization, in addition to antibiotics. Although anthrax is acknowledged as a toxinogenic disease, additional factors, other than the bacterial toxin, may be involved in the virulence of B. anthracis and may be needed for the long-lasting protection conferred by PA immunization. The search for such novel factors is the focus of several high throughput genomic and proteomic studies that are already leading to identification of novel targets for therapeutics, for vaccine candidates, as well as biomarkers for detection and diagnosis.
Collapse
Affiliation(s)
- Theodor Chitlaru
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
| | | | | | | |
Collapse
|
17
|
Wang YC, Jiang N, Zhan DW, Tao HX, Yuan SL, Wang P, Wang LC, Zhang ZS, Liu CJ. Surface display of the 20-kDa N-terminal fragment of anthrax protective antigen based on attenuated recombinant Bacillus anthracis. World J Microbiol Biotechnol 2011. [DOI: 10.1007/s11274-011-0729-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
18
|
Wycoff KL, Belle A, Deppe D, Schaefer L, Maclean JM, Haase S, Trilling AK, Liu S, Leppla SH, Geren IN, Pawlik J, Peterson JW. Recombinant anthrax toxin receptor-Fc fusion proteins produced in plants protect rabbits against inhalational anthrax. Antimicrob Agents Chemother 2011; 55:132-9. [PMID: 20956592 PMCID: PMC3019684 DOI: 10.1128/aac.00592-10] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Revised: 06/03/2010] [Accepted: 10/07/2010] [Indexed: 11/20/2022] Open
Abstract
Inhalational anthrax, a zoonotic disease caused by the inhalation of Bacillus anthracis spores, has a ∼50% fatality rate even when treated with antibiotics. Pathogenesis is dependent on the activity of two toxic noncovalent complexes: edema toxin (EdTx) and lethal toxin (LeTx). Protective antigen (PA), an essential component of both complexes, binds with high affinity to the major receptor mediating the lethality of anthrax toxin in vivo, capillary morphogenesis protein 2 (CMG2). Certain antibodies against PA have been shown to protect against anthrax in vivo. As an alternative to anti-PA antibodies, we produced a fusion of the extracellular domain of human CMG2 and human IgG Fc, using both transient and stable tobacco plant expression systems. Optimized expression led to the CMG2-Fc fusion protein being produced at high levels: 730 mg/kg fresh leaf weight in Nicotiana benthamiana and 65 mg/kg in N. tabacum. CMG2-Fc, purified from tobacco plants, fully protected rabbits against a lethal challenge with B. anthracis spores at a dose of 2 mg/kg body weight administered at the time of challenge. Treatment with CMG2-Fc did not interfere with the development of the animals' own immunity to anthrax, as treated animals that survived an initial challenge also survived a rechallenge 30 days later. The glycosylation of the Fc (or lack thereof) had no significant effect on the protective potency of CMG2-Fc in rabbits or on its serum half-life, which was about 5 days. Significantly, CMG2-Fc effectively neutralized, in vitro, LeTx-containing mutant forms of PA that were not neutralized by anti-PA monoclonal antibodies.
Collapse
|
19
|
Klinman DM, Yamamoto M, Tross D, Tomaru K. Anthrax prevention and treatment: utility of therapy combining antibiotic plus vaccine. Expert Opin Biol Ther 2010; 9:1477-86. [PMID: 19769541 DOI: 10.1517/14712590903307347] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The intentional release of anthrax spores in 2001 confirmed this pathogen's ability to cause widespread panic, morbidity and mortality. While individuals exposed to anthrax can be successfully treated with antibiotics, pre-exposure vaccination can reduce susceptibility to infection-induced illness. Concern over the safety and immunogenicity of the licensed US vaccine (Anthrax Vaccine Adsorbed (AVA)) has fueled research into alternatives. Second-generation anthrax vaccines based on purified recombinant protective antigen (rPA) have entered clinical trials. These rPA vaccines induce neutralizing antibodies that prevent illness, but the magnitude and duration of the resultant protective response is modest. Efforts are underway to bolster the immunogenicity of rPA by combining it with adjuvants and other immunostimulatory agents. Third generation vaccines are under development that utilize a wide variety of immunization platforms, antigens, adjuvants, delivery methods and routes of delivery to optimize the induction of a protective immunity. For the foreseeable future, vaccination will rely on first and second generation vaccines co-administered with immune adjuvants. Optimal post-exposure treatment of immunologically naive individuals should include a combination of vaccine plus antibiotic therapy.
Collapse
Affiliation(s)
- Dennis M Klinman
- National Cancer Institute (NCI), NCI, NIH, Frederick, MD 21702, USA.
| | | | | | | |
Collapse
|
20
|
Abstract
Bacillus anthracis is a Gram-positive, spore-forming bacterium representing the etiological cause of anthrax, a rare lethal disease of animals and humans. Development of anthrax countermeasures has gained increasing attention owing to the potential use of B. anthracis spores as a bioterror weapon. The various forms of infection by B. anthracis are characterized both by toxemia and septicemia, both of which are the result of spore entry into the host followed by their germination into rapidly multiplying, toxin-producing bacilli. Following the publication of the bacterial genome, proteomic studies were carried out to determine the protein composition of the spore and identify exposed vegetative (membrane-located or secreted) proteins. These studies included comparison of strains differing in their virulence, cultured under different conditions and, in some cases, were complemented by serological inspection, which addressed expression during infection of proteomically identified proteins and their immunogenicity. The proteomic approach emerged as a valuable strategy for the generation of a pool of potential B. anthracis protein targets for further evaluation in detection, diagnostics, therapy and prophylaxis, and contributed to the elucidation of some aspects of the pathogenesis of the disease.
Collapse
Affiliation(s)
- Theodor Chitlaru
- Department of Biochemistry & Molecular Genetics, Israel Institute for Biological Research, PO Box 19, Ness-Ziona 74100, Israel
| | - Avigdor Shafferman
- Department of Biochemistry & Molecular Genetics, Israel Institute for Biological Research, PO Box 19, Ness-Ziona 74100, Israel
| |
Collapse
|
21
|
Cybulski RJ, Sanz P, O'Brien AD. Anthrax vaccination strategies. Mol Aspects Med 2009; 30:490-502. [PMID: 19729034 DOI: 10.1016/j.mam.2009.08.006] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2009] [Accepted: 08/24/2009] [Indexed: 01/10/2023]
Abstract
The biological attack conducted through the US postal system in 2001 broadened the threat posed by anthrax from one pertinent mainly to soldiers on the battlefield to one understood to exist throughout our society. The expansion of the threatened population placed greater emphasis on the reexamination of how we vaccinate against Bacillus anthracis. The currently-licensed Anthrax Vaccine, Adsorbed (AVA) and Anthrax Vaccine, Precipitated (AVP) are capable of generating a protective immune response but are hampered by shortcomings that make their widespread use undesirable or infeasible. Efforts to gain US Food and Drug Administration (FDA) approval for licensure of a second generation recombinant protective antigen (rPA)-based anthrax vaccine are ongoing. However, this vaccine's reliance on the generation of a humoral immune response against a single virulence factor has led a number of scientists to conclude that the vaccine is likely not the final solution to optimal anthrax vaccine design. Other vaccine approaches, which seek a more comprehensive immune response targeted at multiple components of the B. anthracis organism, are under active investigation. This review seeks to summarize work that has been done to build on the current PA-based vaccine methodology and to evaluate the search for future anthrax prophylaxis strategies.
Collapse
Affiliation(s)
- Robert J Cybulski
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814-4799, United States
| | | | | |
Collapse
|
22
|
Abstract
The prevention of infectious diseases of animals by vaccination has been routinely practiced for decades and has proved to be one of the most cost-effective methods of disease control. However, since the pioneering work of Pasteur in the 1880s, the composition of veterinary vaccines has changed very little from a conceptual perspective and this has, in turn, limited their application in areas such as the control of chronic infectious diseases. New technologies in the areas of vaccine formulation and delivery as well as our increased knowledge of disease pathogenesis and the host responses associated with protection from disease offer promising alternatives for vaccine formulation as well as targets for the prevention of bacterial disease. These new vaccines have the potential to lessen our reliance on antibiotics for disease control, but will only reach their full potential when used in combination with other intervention strategies.
Collapse
|
23
|
Efficacy of a vaccine based on protective antigen and killed spores against experimental inhalational anthrax. Infect Immun 2008; 77:1197-207. [PMID: 19114543 DOI: 10.1128/iai.01217-08] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Protective antigen (PA)-based anthrax vaccines acting on toxins are less effective than live attenuated vaccines, suggesting that additional antigens may contribute to protective immunity. Several reports indicate that capsule or spore-associated antigens may enhance the protection afforded by PA. Addition of formaldehyde-inactivated spores (FIS) to PA (PA-FIS) elicits total protection against cutaneous anthrax. Nevertheless, vaccines that are effective against cutaneous anthrax may not be so against inhalational anthrax. The aim of this work was to optimize immunization with PA-FIS and to assess vaccine efficacy against inhalational anthrax. We assessed the immune response to recombinant anthrax PA from Bacillus anthracis (rPA)-FIS administered by various immunization protocols and the protection provided to mice and guinea pigs infected through the respiratory route with spores of a virulent strain of B. anthracis. Combined subcutaneous plus intranasal immunization of mice yielded a mucosal immunoglobulin G response to rPA that was more than 20 times higher than that in lung mucosal secretions after subcutaneous vaccination. The titers of toxin-neutralizing antibody and antispore antibody were also significantly higher: nine and eight times higher, respectively. The optimized immunization elicited total protection of mice intranasally infected with the virulent B. anthracis strain 17JB. Guinea pigs were fully protected, both against an intranasal challenge with 100 50% lethal doses (LD(50)) and against an aerosol with 75 LD(50) of spores of the highly virulent strain 9602. Conversely, immunization with PA alone did not elicit protection. These results demonstrate that the association of PA and spores is very much more effective than PA alone against experimental inhalational anthrax.
Collapse
|
24
|
Fasanella A, Tonello F, Garofolo G, Muraro L, Carattoli A, Adone R, Montecucco C. Protective activity and immunogenicity of two recombinant anthrax vaccines for veterinary use. Vaccine 2008; 26:5684-8. [DOI: 10.1016/j.vaccine.2008.08.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2008] [Revised: 08/12/2008] [Accepted: 08/14/2008] [Indexed: 11/26/2022]
|
25
|
A DNA vaccine candidate for B. anthracis immunization, pcDNA3.1+PA plasmid, induce Th1/Th2 mixed responses and protection in mice. World J Microbiol Biotechnol 2008. [DOI: 10.1007/s11274-008-9725-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
26
|
Gat O, Zaide G, Inbar I, Grosfeld H, Chitlaru T, Levy H, Shafferman A. Characterization of Bacillus anthracis iron-regulated surface determinant (Isd) proteins containing NEAT domains. Mol Microbiol 2008; 70:983-99. [PMID: 18826411 DOI: 10.1111/j.1365-2958.2008.06460.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Three iron-regulated surface determinant (Isd) proteins, containing NEAr Transporter (NEAT) domains (GBAA4789-7), constitute part of an eight-member Bacillus anthracis operon. GBAA4789 (IsdC), previously characterized by others as a haem-binding protein, and two novel Isd proteins characterized in this study, GBAA4788 (IsdJ) and GBAA4787 (IsdK) proteins, can be translated from two alternative overlapping transcriptional units. The three NEAT-containing Isd proteins are shown to be expressed in vivo during B. anthracis infection. Expression in vitro is regulated by iron ions independent of the virulence plasmids pXO1 and pXO2, yet their presence affects the range of response to iron ion concentration. The expression of IsdC, J and K is strongly repressed under high CO(2) tension, conditions that are optimal for B. anthracis toxin and capsule expression, suggesting that these Isd proteins are elements of a B. anthracis'air-regulon'. Deletion mutants of isdC, isdK or the entire isdCJK locus are as virulent and pathogenic to guinea pigs as the fully virulent wild-type Vollum strain. The isdC-deleted mutant is defective in sequestration of haemin, consistent with previous biochemical observations, while the DeltaisdK mutant is defective in haemoglobin uptake. Studies with recombinant IsdK demonstrate specific binding to haemoglobin.
Collapse
Affiliation(s)
- Orit Gat
- Department of Biochemistry and Molecular Genetics, Israel Institute for biological Research, Ness Ziona, Israel.
| | | | | | | | | | | | | |
Collapse
|
27
|
Passalacqua KD, Bergman NH. Bacillus anthracis: interactions with the host and establishment of inhalational anthrax. Future Microbiol 2007; 1:397-415. [PMID: 17661631 DOI: 10.2217/17460913.1.4.397] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Due to its potential as a bioweapon, Bacillus anthracis has received a great deal of attention in recent years, and a significant effort has been devoted to understanding how this organism causes anthrax. There has been a particular focus on the inhalational form of the disease, and studies over the past several years have painted an increasingly complex picture of how B. anthracis enters the mammalian host, survives the host's defense mechanisms, disseminates throughout the body and causes death. This article reviews recent advances in these areas, with a focus on how the bacterium interacts with its host in establishing infection and causing anthrax.
Collapse
Affiliation(s)
- Karla D Passalacqua
- University of Michigan Medical School, Department of Microbiology & Immunology, Ann Arbor, MI 48109, USA.
| | | |
Collapse
|
28
|
Abstract
Vaccination is an important tool for handling healthcare programs both in developed and developing countries. The current global scenario calls for a more-efficacious, acceptable, cost-effective and reliable method of immunization for many fatal diseases. It is hoped that the adoption of oral vaccines will help to provide an effective vaccination strategy, especially in developing countries. Mucosal immunity generated by oral vaccines can serve as a strong first line of defense against most of the pathogens infecting through the mucosal lining. Advances in elucidating the mechanism of action of oral vaccines will facilitate the design of more effective, new generation vaccines. There are promising developments in the use of different agents to effectively deliver the vaccine candidate. It is hoped that ongoing research may be able to set another cardinal point, after polio vaccine, in eradicating infectious diseases.
Collapse
Affiliation(s)
- Mohd Azhar Aziz
- Department of Radiation Oncology, Case Western Reserve University, Cleveland, OH, USA
| | | | | | | |
Collapse
|
29
|
Bienek DR, Chang CK, Cohen ME. Detection of anti-protective antigen salivary IgG antibodies in recipients of the US licensed anthrax vaccine. Vaccine 2007; 25:5978-84. [PMID: 17597265 DOI: 10.1016/j.vaccine.2007.05.043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2007] [Revised: 04/27/2007] [Accepted: 05/21/2007] [Indexed: 11/25/2022]
Abstract
The immune response of anthrax vaccine recipients is not routinely monitored. For field use, a noninvasive test would be beneficial to evaluate the antibody response of anthrax-vaccinated individuals working within a high-risk area of possible exposure. The aim of this cross-sectional study was to determine whether whole saliva can be used as a surrogate matrix for the detection of 83 kDa protective antigen (PA)-specific immunoglobulin G (IgG). An enzyme-linked immunosorbent assay was used for the detection of PA-specific IgG in matched samples (serum and saliva) that were collected from vaccinated and unvaccinated participants. Specimens from 180 individuals revealed a positive correlation (r=0.73; P<0.0001) between the level of PA-specific antibody detected in the saliva and serum. The number of vaccinations influenced both the saliva and serum antibody response. On average, the concentration of serological PA-specific antibodies in the vaccinated group was nearly 1600-fold greater than that in saliva. The magnitude of the salivary anti-PA antibody response was not significantly affected by the consumption of food, beverage, or tobacco products or other factors, which could potentially affect oral fluid properties. These results suggest that an oral fluid-based immunoassay may be a feasible alternative to monitoring the serological antibody response of individuals that have been vaccinated against anthrax.
Collapse
Affiliation(s)
- Diane R Bienek
- Naval Institute for Dental and Biomedical Research, Great Lakes, IL 60088-5259, United States.
| | | | | |
Collapse
|
30
|
Chitlaru T, Gat O, Grosfeld H, Inbar I, Gozlan Y, Shafferman A. Identification of in vivo-expressed immunogenic proteins by serological proteome analysis of the Bacillus anthracis secretome. Infect Immun 2007; 75:2841-52. [PMID: 17353282 PMCID: PMC1932864 DOI: 10.1128/iai.02029-06] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2006] [Revised: 02/15/2007] [Accepted: 03/04/2007] [Indexed: 01/24/2023] Open
Abstract
In a previous comparative proteomic study of Bacillus anthracis examining the influence of the virulence plasmids and of various growth conditions on the composition of the bacterial secretome, we identified 64 abundantly expressed proteins (T. Chitlaru, O. Gat, Y. Gozlan, N. Ariel, and A. Shafferman, J. Bacteriol. 188:3551-3571, 2006). Using a battery of sera from B. anthracis-infected animals, in the present study we demonstrated that 49 of these proteins are immunogenic. Thirty-eight B. anthracis immunogens are documented in this study for the first time. The relative immunogenicities of the 49 secreted proteins appear to span a >10,000-fold range. The proteins eliciting the highest humoral response in the course of infection include, in addition to the well-established immunogens protective antigen (PA), Sap, and EA1, GroEL (BA0267), AhpC (BA0345), MntA (BA3189), HtrA (BA3660), 2,3-cyclic nucleotide diesterase (BA4346), collagen adhesin (BAS5205), an alanine amidase (BA0898), and an endopeptidase (BA1952), as well as three proteins having unknown functions (BA0796, BA0799, and BA0307). Of these 14 highly potent secreted immunogens, 11 are known to be associated with virulence and pathogenicity in B. anthracis or in other bacterial pathogens. Combining the results reported here with the results of a similar study of the membranal proteome of B. anthracis (T. Chitlaru, N. Ariel, A. Zvi, M. Lion, B. Velan, A. Shafferman, and E. Elhanany, Proteomics 4:677-691, 2004) and the results obtained in a functional genomic search for immunogens (O. Gat, H. Grosfeld, N. Ariel, I. Inbar, G. Zaide, Y. Broder, A. Zvi, T. Chitlaru, Z. Altboum, D. Stein, S. Cohen, and A. Shafferman, Infect. Immun. 74:3987-4001, 2006), we generated a list of 84 in vivo-expressed immunogens for future evaluation for vaccine development, diagnostics, and/or therapeutic intervention. In a preliminary study, the efficacies of eight immunogens following DNA immunization of guinea pigs were compared to the efficacy of a PA DNA vaccine. All eight immunogens induced specific high antibody titers comparable to the titers elicited by PA; however, unlike PA, none of them provided protection against a lethal challenge (50 50% lethal doses) of virulent B. anthracis strain Vollum spores.
Collapse
Affiliation(s)
- Theodor Chitlaru
- Israel Institute for Biological Research, P.O. Box 19, Ness-Ziona 74100, Israel
| | | | | | | | | | | |
Collapse
|
31
|
Shakya KP, Hugh-Jones ME, Elzer PH. Evaluation of immune response to orally administered Sterne strain 34F2 anthrax vaccine. Vaccine 2007; 25:5374-7. [PMID: 17555849 DOI: 10.1016/j.vaccine.2007.05.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2007] [Revised: 04/17/2007] [Accepted: 05/02/2007] [Indexed: 11/26/2022]
Abstract
Present animal vaccines against Bacillus anthracis infection are capable of inducing protective immunity. However, due to the route of administration, the vaccine has limited or no use in wildlife especially in rural areas of the world. Hence, an oral vaccine is needed for controlling this disease. For proof of concept we used the commercially available Sterne strain 34F2 vaccine mixed with oral scarifying agents. Although the immunological response as measured by ELISA in this group was not equal to the parenterally inoculated animals, the results indicate that the oral administration of this vaccine with oropharyngeal mucosa scarifying agents mixed with feed can induce immune responses in goats.
Collapse
Affiliation(s)
- Krishna P Shakya
- Louisiana State University, School of Veterinary Medicine, Department of Pathobiological Sciences, Skip Bertman Dr., Baton Rouge, LA 70803, United States
| | | | | |
Collapse
|
32
|
Day WA, Rasmussen SL, Carpenter BM, Peterson SN, Friedlander AM. Microarray analysis of transposon insertion mutations in Bacillus anthracis: global identification of genes required for sporulation and germination. J Bacteriol 2007; 189:3296-301. [PMID: 17277068 PMCID: PMC1855828 DOI: 10.1128/jb.01860-06] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A transposon site hybridization (TraSH) assay was developed for functional analysis of the Bacillus anthracis genome using a mini-Tn10 transposon which permitted analysis of 82% of this pathogen's genes. The system, used to identify genes required for generation of infectious anthrax spores, spore germination, and optimal growth on rich medium, was predictive of the contributions of two conserved hypothetical genes for the phenotypes examined.
Collapse
Affiliation(s)
- William A Day
- Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases, Frederick, MD 21702, USA.
| | | | | | | | | |
Collapse
|
33
|
Whipple EC, Ditto AH, Shanahan RS, Gatesman JJ, Little SF, Taylor RP, Lindorfer MA. Low doses of antigen coupled to anti-CR2 mAbs induce rapid and enduring IgG immune responses in mice and in cynomolgus monkeys. Mol Immunol 2007; 44:377-88. [PMID: 16631928 DOI: 10.1016/j.molimm.2006.02.032] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2005] [Revised: 02/23/2006] [Accepted: 02/24/2006] [Indexed: 11/29/2022]
Abstract
The complement system and B cell complement receptor 2 (CR2), specific for C component C3dg, play important roles in both the innate and adaptive immune response. We used hapten and protein conjugates of anti-CR2 mAbs as models for C3dg-opsonized antigens and immune complexes to examine the handling of and immune response to these reagents in mice and in non-human primates (NHP). Mice immunized and boosted i.v. with only 100 ng of Alexa 488 rat anti-mouse CR1/2 mAb 7G6 had strong IgG immune responses to the Alexa 488 hapten and to rat IgG, compared to very weak immune responses in mice treated with a comparable isotype control; larger doses of Alexa 488 mAb 7G6 did not increase the immune response. A vaccine constructed by cross-linking anthrax protective antigen to mAb 7G6 proved to be effective at low doses in generating sufficiently high titer serum IgG antibodies to neutralize anthrax lethal toxin in vitro and to protect mice from i.v. challenge with anthrax lethal toxin. When biotinylated HB135, a mouse mAb specific for human CR2, was injected i.v. into NHP, the probe manifested the same initial marginal zone B cell binding and subsequent localization to follicular dendritic cells as we have previously reported for comparable experiments in mice. Moreover, i.v. immunization of NHP with 1 microg/kg of Alexa 488 mAb HB135 promoted an IgG immune response to the Alexa 488 hapten and to mouse IgG. Taken together, these results demonstrate the efficacy of using anti-CR2 mAbs as antigen carriers for i.v. immunization with small amounts of antigens without adjuvant.
Collapse
Affiliation(s)
- Emily C Whipple
- Department of Biochemistry and Molecular Genetics, University of Virginia Health Sciences Center, Charlottesville, VA 22908, United States
| | | | | | | | | | | | | |
Collapse
|
34
|
Gat O, Grosfeld H, Ariel N, Inbar I, Zaide G, Broder Y, Zvi A, Chitlaru T, Altboum Z, Stein D, Cohen S, Shafferman A. Search for Bacillus anthracis potential vaccine candidates by a functional genomic-serologic screen. Infect Immun 2006; 74:3987-4001. [PMID: 16790772 PMCID: PMC1489694 DOI: 10.1128/iai.00174-06] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2006] [Revised: 03/17/2006] [Accepted: 03/30/2006] [Indexed: 12/28/2022] Open
Abstract
Bacillus anthracis proteins that possess antigenic properties and are able to evoke an immune response were identified by a reductive genomic-serologic screen of a set of in silico-preselected open reading frames (ORFs). The screen included in vitro expression of the selected ORFs by coupled transcription and translation of linear PCR-generated DNA fragments, followed by immunoprecipitation with antisera from B. anthracis-infected animals. Of the 197 selected ORFs, 161 were chromosomal and 36 were on plasmids pXO1 and pXO2, and 138 of the 197 ORFs had putative functional annotations (known ORFs) and 59 had no assigned functions (unknown ORFs). A total of 129 of the known ORFs (93%) could be expressed, whereas only 38 (64%) of the unknown ORFs were successfully expressed. All 167 expressed polypeptides were subjected to immunoprecipitation with the anti-B. anthracis antisera, which revealed 52 seroreactive immunogens, only 1 of which was encoded by an unknown ORF. The high percentage of seroreactive ORFs among the functionally annotated ORFs (37%; 51/129) attests to the predictive value of the bioinformatic strategy used for vaccine candidate selection. Furthermore, the experimental findings suggest that surface-anchored proteins and adhesins or transporters, such as cell wall hydrolases, proteins involved in iron acquisition, and amino acid and oligopeptide transporters, have great potential to be immunogenic. Most of the seroreactive ORFs that were tested as DNA vaccines indeed appeared to induce a humoral response in mice. We list more than 30 novel B. anthracis immunoreactive virulence-related proteins which could be useful in diagnosis, pathogenesis studies, and future anthrax vaccine development.
Collapse
Affiliation(s)
- Orit Gat
- Israel Institute for Biological Research, P.O. Box 19, Ness Ziona 74100, Israel.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Keim P, Mock M, Young J, Koehler TM. The International Bacillus anthracis, B. cereus, and B. thuringiensis Conference, "Bacillus-ACT05". J Bacteriol 2006; 188:3433-41. [PMID: 16672596 PMCID: PMC1482840 DOI: 10.1128/jb.188.10.3433-3441.2006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- Paul Keim
- Department of Microbiology and Molecular Genetics, University of Texas--Houston Medical School, 77030, USA
| | | | | | | |
Collapse
|
36
|
Gat O, Mendelson I, Chitlaru T, Ariel N, Altboum Z, Levy H, Weiss S, Grosfeld H, Cohen S, Shafferman A. The solute-binding component of a putative Mn(II) ABC transporter (MntA) is a novelBacillus anthracisvirulence determinant. Mol Microbiol 2005; 58:533-51. [PMID: 16194238 DOI: 10.1111/j.1365-2958.2005.04848.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Here we describe the characterization of a lipoprotein previously proposed as a potential Bacillus anthracis virulence determinant and vaccine candidate. This protein, designated MntA, is the solute-binding component of a manganese ion ATP-binding cassette transporter. Coupled proteomic-serological screen of a fully virulent wild-type B. anthracis Vollum strain, confirmed that MntA is expressed both in vitro and during infection. Expression of MntA is shown to be independent of the virulence plasmids pXO1 and pXO2. An mntA deletion, generated by allelic replacement, results in complete loss of MntA expression and its phenotypic analysis revealed: (i) impaired growth in rich media, alleviated by manganese supplementation; (ii) increased sensitivity to oxidative stress; and (iii) delayed release from cultured macrophages. The DeltamntA mutant expresses the anthrax-associated classical virulence factors, lethal toxin and capsule, in vitro as well as in vivo, and yet the mutation resulted in severe attenuation; a 10(4)-fold drop in LD(50) in a guinea pig model. MntA expressed in trans allowed to restore, almost completely, the virulence of the DeltamntA B. anthracis strain. We propose that MntA is a novel B. anthracis virulence determinant essential for the development of anthrax disease, and that B. anthracisDeltamntA strains have the potential to serve as platform for future live attenuated vaccines.
Collapse
Affiliation(s)
- Orit Gat
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, PO Box 19, Ness Ziona, 74100, Israel
| | | | | | | | | | | | | | | | | | | |
Collapse
|