1
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Tolman LE, Mantis NJ. Inflammatory Profiles Induced by Intranasal Immunization with Ricin Toxin-immune Complexes. Immunohorizons 2024; 8:457-463. [PMID: 38922287 DOI: 10.4049/immunohorizons.2400007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 05/29/2024] [Indexed: 06/27/2024] Open
Abstract
The underlying contribution of immune complexes in modulating adaptive immunity in mucosal tissues remains poorly understood. In this report, we examined, in mice, the proinflammatory response elicited by intranasal delivery of the biothreat agent ricin toxin (RT) in association with two toxin-neutralizing mAbs, SylH3 and PB10. We previously demonstrated that ricin-immune complexes (RICs) induce the rapid onset of high-titer toxin-neutralizing Abs that persist for months. We now demonstrate that such responses are dependent on CD4+ T cell help, because treatment of mice with an anti-CD4 mAb abrogated the onset of RT-specific Abs following intranasal RICs exposure. To define the inflammatory environment associated with RIC exposure, we collected bronchoalveolar lavage fluid (BALF) and sera from mice 6, 12, and 18 h after they had received RT or RICs by the intranasal route. A 32-plex cytometric bead array revealed an inflammatory profile elicited by RT that was dominated by IL-6 (>1500-fold increase in BALF) and secondarily by KC (CXCL1), G-CSF, GM-CSF, and MCP-1. RICs induced inflammatory profiles in both BALF and serum response that were similar to RT, albeit at markedly reduced levels. These results demonstrate that RICs retain the capacity to induce local and systemic inflammatory cytokines/chemokines that, in turn, may influence Ag sampling and presentation in the lung mucosa and draining lymph nodes. A better understanding of the fate of immune complexes following intranasal delivery has implications for the development of mucosal vaccines for biothreats and emerging infectious diseases.
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Affiliation(s)
- Lindsey E Tolman
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, NY
| | - Nicholas J Mantis
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, NY
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY
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2
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Sapoznikov A, Evgy Y, Ben-Shmuel A, Schwartz A, Alcalay R, Aftalion M, Ben David A, Erez N, Falach R. Short- and long-term outcomes of pulmonary exposure to a sublethal dose of ricin in mice. Sci Rep 2024; 14:11637. [PMID: 38773158 PMCID: PMC11109263 DOI: 10.1038/s41598-024-62222-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 05/15/2024] [Indexed: 05/23/2024] Open
Abstract
Ricin, an extremely potent toxin produced from the seeds of castor plant, Ricinus communis, is ribosome-inactivating protein that blocks cell-protein synthesis. It is considered a biological threat due to worldwide availability of castor beans, massive quantities as a by-product of castor oil production, high stability and ease of production. The consequence of exposure to lethal dose of ricin was extensively described in various animal models. However, it is assumed that in case of aerosolized ricin bioterror attack, the majority of individuals would be exposed to sublethal doses rather than to lethal ones. Therefore, the purpose of current study was to assess short- and long-term effects on physiological parameters and function following sublethal pulmonary exposure. We show that in the short-term, sublethal exposure of mice to ricin resulted in acute lung injury, including interstitial pneumonia, cytokine storm, neutrophil influx, edema and cellular death. This damage was manifested in reduced lung performance and physiological function. Interestingly, although in the long-term, mice recovered from acute lung damage and restored pulmonary and physiological functionality, the reparative process was associated with lasting fibrotic lesions. Therefore, restriction of short-term acute phase of the disease and management of long-term pulmonary fibrosis by medical countermeasures is expected to facilitate the quality of life of exposed survivors.
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Affiliation(s)
- Anita Sapoznikov
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, 74100, Ness-Ziona, Israel
| | - Yentl Evgy
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, 74100, Ness-Ziona, Israel
| | - Amir Ben-Shmuel
- Department of Infectious Diseases, Israel Institute for Biological Research, 74100, Ness-Ziona, Israel
| | - Arieh Schwartz
- Department of Biotechnology, Israel Institute for Biological Research, 74100, Ness-Ziona, Israel
| | - Ron Alcalay
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, 74100, Ness-Ziona, Israel
| | - Moshe Aftalion
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, 74100, Ness-Ziona, Israel
| | - Alon Ben David
- Department of Biotechnology, Israel Institute for Biological Research, 74100, Ness-Ziona, Israel
| | - Noam Erez
- Department of Infectious Diseases, Israel Institute for Biological Research, 74100, Ness-Ziona, Israel.
| | - Reut Falach
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, 74100, Ness-Ziona, Israel.
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3
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Xu Y, Dong M, Sun C, Wang Y, Zhao N, Yu K, Lu N, Xu N, Liu W, Wu C. Caspase-3/Gasdermin E-mediated pyroptosis contributes to Ricin toxin-induced inflammation. Toxicol Lett 2024; 396:19-27. [PMID: 38642674 DOI: 10.1016/j.toxlet.2024.04.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 03/09/2024] [Accepted: 04/17/2024] [Indexed: 04/22/2024]
Abstract
Ricin toxin (RT) is highly cytotoxic and can release a considerable amount of pro-inflammatory factors due to depurination, causing excessive inflammation that may aggravate the harm to the body. Pyroptosis, a type of gasdermin-mediated cell death, is a contributor to the exacerbation of inflammation. Accumulating evidence indicate that pyroptosis plays a significant role in the pathogen infection and tissue injury, suggesting a potential correlation between pyroptosis and RT-induced inflammation. Here, we aim to demonstrate this correlation and explore its molecular mechanisms. Results showed that RT triggers mouse alveolar macrophage MH-S cells pyroptosis by activating caspase-3 and cleaving Gasgermin E (GSDME). In contrast, inhibition of caspase-3 with Z-DEVD-FMK (inhibitor of caspase-3) or knockdown of GSDME attenuates this process, suggesting the essential role of caspase-3/GSDME-mediated pyroptosis in contributing to RT-induced inflammation. Collectively, our study enhances our understanding of a novel mechanism of ricin cytotoxicity, which may emerge as a potential target in immunotherapy to control the RT-induced inflammation.
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Affiliation(s)
- Yuxin Xu
- School of Chemistry and Life Science, Changchun University of Technology, Changchun 130012, China
| | - Mingxin Dong
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Science, Changchun 130122, China
| | - Chengbiao Sun
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Science, Changchun 130122, China
| | - Yan Wang
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Science, Changchun 130122, China; Department of Epidemiology and Biostatistics, School of Public Health, Jilin University, Changchun 130021, China
| | - Na Zhao
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Science, Changchun 130122, China
| | - Kaikai Yu
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Science, Changchun 130122, China
| | - Nan Lu
- School of Life Science and Technology, Changchun University of Science and Technology, Changchun 130022, China
| | - Na Xu
- Jilin Medical University, Jilin 132013, China.
| | - Wensen Liu
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Science, Changchun 130122, China.
| | - Congmei Wu
- School of Chemistry and Life Science, Changchun University of Technology, Changchun 130012, China.
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4
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Vance DJ, Rudolph MJ, Davis SA, Mantis NJ. Structural Basis of Antibody-Mediated Inhibition of Ricin Toxin Attachment to Host Cells. Biochemistry 2023; 62:3181-3187. [PMID: 37903428 DOI: 10.1021/acs.biochem.3c00480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2023]
Abstract
Monoclonal antibodies, JB4 and SylH3, neutralize ricin toxin (RT) by inhibiting the galactose-specific lectin activity of the B subunit of the toxin (RTB), which is required for cell attachment and entry. It is not immediately apparent how the antibodies accomplish this feat, considering that RTB consists of two globular domains (D1, D2) each divided into three homologous subdomains (α, β, γ) with the two functional galactosyl-specific carbohydrate recognition domains (CRDs) situated on opposite poles (subdomains 1α and 2γ). Here, we report the X-ray crystal structures of JB4 and SylH3 Fab fragments bound to RTB in the context of RT. The structures revealed that neither Fab obstructed nor induced detectable conformational alterations in subdomains 1α or 2γ. Rather, JB4 and SylH3 Fabs recognize nearly identical epitopes within an ancillary carbohydrate recognition pocket located in subdomain 1β. Despite limited amino acid sequence similarity between SylH3 and JB4 Fabs, each paratope inserts a Phe side chain from the heavy (H) chain complementarity determining region (CDR3) into the 1β CRD pocket, resulting in local aromatic stacking interactions that potentially mimic a ligand interaction. Reconciling the fact that stoichiometric amounts of SylH3 and JB4 are sufficient to disarm RTB's lectin activity without evidence of allostery, we propose that subdomain 1β functions as a "coreceptor" required to stabilize glycan interactions principally mediated by subdomains 1α and 2γ. Further investigation into subdomain 1β will yield fundamental insights into the large family of R-type lectins and open novel avenues for countermeasures aimed at preventing toxin uptake into vulnerable tissues and cells.
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Affiliation(s)
- David J Vance
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, New York 12208, United States
| | - Michael J Rudolph
- New York Structural Biology Center, New York, New York 10027, United States
| | - Simon A Davis
- New York Structural Biology Center, New York, New York 10027, United States
| | - Nicholas J Mantis
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, New York 12208, United States
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5
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Su D, Jiao Z, Li S, Yue L, Li C, Deng M, Hu L, Dai L, Gao B, Wang J, Zhang H, Xiao H, Chen F, Yang H, Zhou D. Spatiotemporal single-cell transcriptomic profiling reveals inflammatory cell states in a mouse model of diffuse alveolar damage. EXPLORATION (BEIJING, CHINA) 2023; 3:20220171. [PMID: 37933384 PMCID: PMC10624389 DOI: 10.1002/exp.20220171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 02/10/2023] [Indexed: 11/08/2023]
Abstract
Diffuse alveolar damage (DAD) triggers neutrophilic inflammation in damaged tissues of the lung, but little is known about the distinct roles of tissue structural cells in modulating the recruitment of neutrophils to damaged areas. Here, by combining single-cell and spatial transcriptomics, and using quantitative assays, we systematically analyze inflammatory cell states in a mouse model of DAD-induced neutrophilic inflammation after aerosolized intratracheal inoculation with ricin toxin. We show that homeostatic resident fibroblasts switch to a hyper-inflammatory state, and the subsequent occurrence of a CXCL1-CXCR2 chemokine axis between activated fibroblasts (AFib) as the signal sender and neutrophils as the signal receiver triggers further neutrophil recruitment. We also identify an anatomically localized inflamed niche (characterized by a close-knit spatial intercellular contact between recruited neutrophils and AFib) in peribronchial regions that facilitate the pulmonary inflammation outbreak. Our findings identify an intricate interplay between hyper-inflammatory fibroblasts and neutrophils and provide an overarching profile of dynamically changing inflammatory microenvironments during DAD progression.
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Affiliation(s)
- Duo Su
- State Key Laboratory of Pathogen and BiosecurityBeijing Institute of Microbiology and EpidemiologyBeijingChina
- Reproductive Genetics CenterBethune International Peace HospitalShijiazhuangChina
| | - Zhouguang Jiao
- State Key Laboratory of Pathogen and BiosecurityBeijing Institute of Microbiology and EpidemiologyBeijingChina
- State Key Laboratory of Biochemical Engineering, Institute of Process EngineeringChinese Academy of SciencesBeijingChina
| | - Sha Li
- State Key Laboratory of Pathogen and BiosecurityBeijing Institute of Microbiology and EpidemiologyBeijingChina
- School of Basic Medical SciencesAnhui Medical UniversityHefeiChina
| | - Liya Yue
- Laboratory of Genome Sciences & Information, Beijing Institute of GenomicsChinese Academy of Sciences and China National Center for BioinformationBeijingChina
| | - Cuidan Li
- Laboratory of Genome Sciences & Information, Beijing Institute of GenomicsChinese Academy of Sciences and China National Center for BioinformationBeijingChina
| | - Mengyun Deng
- State Key Laboratory of Pathogen and BiosecurityBeijing Institute of Microbiology and EpidemiologyBeijingChina
| | - Lingfei Hu
- State Key Laboratory of Pathogen and BiosecurityBeijing Institute of Microbiology and EpidemiologyBeijingChina
| | - Lupeng Dai
- State Key Laboratory of Pathogen and BiosecurityBeijing Institute of Microbiology and EpidemiologyBeijingChina
- School of Basic Medical SciencesAnhui Medical UniversityHefeiChina
| | - Bo Gao
- State Key Laboratory of Pathogen and BiosecurityBeijing Institute of Microbiology and EpidemiologyBeijingChina
- School of Basic Medical SciencesAnhui Medical UniversityHefeiChina
| | - Jinglin Wang
- State Key Laboratory of Pathogen and BiosecurityBeijing Institute of Microbiology and EpidemiologyBeijingChina
| | - Hanchen Zhang
- Beijing National Laboratory for Molecular Science, State Key Laboratory of Polymer Physical and ChemistryInstitute of Chemistry, Chinese Academy of ScienceBeijingChina
| | - Haihua Xiao
- Beijing National Laboratory for Molecular Science, State Key Laboratory of Polymer Physical and ChemistryInstitute of Chemistry, Chinese Academy of ScienceBeijingChina
| | - Fei Chen
- Laboratory of Genome Sciences & Information, Beijing Institute of GenomicsChinese Academy of Sciences and China National Center for BioinformationBeijingChina
| | - Huiying Yang
- State Key Laboratory of Pathogen and BiosecurityBeijing Institute of Microbiology and EpidemiologyBeijingChina
| | - Dongsheng Zhou
- State Key Laboratory of Pathogen and BiosecurityBeijing Institute of Microbiology and EpidemiologyBeijingChina
- School of Basic Medical SciencesAnhui Medical UniversityHefeiChina
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6
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Stoll A, Shenton DP, Green AC, Holley JL. Comparative Aspects of Ricin Toxicity by Inhalation. Toxins (Basel) 2023; 15:toxins15040281. [PMID: 37104219 PMCID: PMC10145923 DOI: 10.3390/toxins15040281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 03/30/2023] [Accepted: 04/04/2023] [Indexed: 04/28/2023] Open
Abstract
The pathogenesis of ricin toxicity following inhalation has been investigated in many animal models, including the non-human primate (predominantly the rhesus macaque), pig, rabbit and rodent. The toxicity and associated pathology described in animal models are broadly similar, but variation appears to exist. This paper reviews the published literature and some of our own unpublished data and describes some of the possible reasons for this variation. Methodological variation is evident, including method of exposure, breathing parameters during exposure, aerosol characteristics, sampling protocols, ricin cultivar, purity and challenge dose and study duration. The model species and strain used represent other significant sources of variation, including differences in macro- and microscopic anatomy, cell biology and function, and immunology. Chronic pathology of ricin toxicity by inhalation, associated with sublethal challenge or lethal challenge and treatment with medical countermeasures, has received less attention in the literature. Fibrosis may follow acute lung injury in survivors. There are advantages and disadvantages to the different models of pulmonary fibrosis. To understand their potential clinical significance, these factors need to be considered when choosing a model for chronic ricin toxicity by inhalation, including species and strain susceptibility to fibrosis, time it takes for fibrosis to develop, the nature of the fibrosis (e.g., self-limiting, progressive, persistent or resolving) and ensuring that the analysis truly represents fibrosis. Understanding the variables and comparative aspects of acute and chronic ricin toxicity by inhalation is important to enable meaningful comparison of results from different studies, and for the investigation of medical countermeasures.
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Affiliation(s)
- Alexander Stoll
- Defence Science and Technology Laboratory, Salisbury SP4 0JQ, UK
| | - Daniel P Shenton
- Defence Science and Technology Laboratory, Salisbury SP4 0JQ, UK
| | | | - Jane L Holley
- Defence Science and Technology Laboratory, Salisbury SP4 0JQ, UK
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7
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Roy CJ, Ehrbar D, Van Slyke G, Doering J, Didier PJ, Doyle-Meyers L, Donini O, Vitetta ES, Mantis NJ. Serum antibody profiling identifies vaccine-induced correlates of protection against aerosolized ricin toxin in rhesus macaques. NPJ Vaccines 2022; 7:164. [PMID: 36526642 PMCID: PMC9755799 DOI: 10.1038/s41541-022-00582-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 11/24/2022] [Indexed: 12/23/2022] Open
Abstract
Inhalation of the biothreat agent, ricin toxin (RT), provokes a localized inflammatory response associated with pulmonary congestion, edema, neutrophil infiltration, and severe acute respiratory distress. The extreme toxicity of RT is the result of the toxin's B chain (RTB) promoting rapid uptake into alveolar macrophages and lung epithelial cells, coupled with the A chain's (RTA) potent ribosome-inactivating properties. We previously reported that intramuscular vaccination of rhesus macaques with a lyophilized, alum-adsorbed recombinant RTA subunit vaccine (RiVax®) was sufficient to confer protection against a lethal dose of aerosolized RT. That study implicated RT-specific serum IgG, toxin-neutralizing activity (TNA), and epitope-specific responses as being associated with immunity. However, it was not possible to define actual correlates of protection (COP) because all vaccinated animals survived the RT challenge. We addressed the issue of COP in the current study, by vaccinating groups of rhesus macaques with RiVax® following the previously determined protective regimen (100 µg on study days 0, 30 and 60) or one of two anticipated suboptimal regimens (100 µg on study days 30 and 60; 35 µg on study days 0, 30, and 60). Two unvaccinated animals served as controls. The animals were challenged with ~5 × LD50s of aerosolized RT on study day 110. We report that all vaccinated animals seroconverted prior to RT challenge, with the majority also having measurable TNA, although neither antibody levels nor TNA reached statistical significance with regard to a correlation with protection. By contrast, survival correlated with pre-challenge, epitope-specific serum IgG levels, derived from a competitive sandwich ELISA using a panel of toxin-neutralizing monoclonal antibodies directed against distinct epitopes on RiVax®. The identification of a species-neutral, competitive ELISA that correlates with vaccine-induced protection against RT in nonhuman represents an important advance in the development of medical countermeasures (MCM) against a persistent biothreat.
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Affiliation(s)
- Chad J Roy
- Tulane National Primate Research Center, Covington, LA, 70433, USA.
| | - Dylan Ehrbar
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY, 12208, USA
| | - Greta Van Slyke
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY, 12208, USA
| | - Jennifer Doering
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY, 12208, USA
| | - Peter J Didier
- Tulane National Primate Research Center, Covington, LA, 70433, USA
| | | | | | - Ellen S Vitetta
- Departments of Immunology and Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
| | - Nicholas J Mantis
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY, 12208, USA.
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8
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Parenteral Exposure of Mice to Ricin Toxin Induces Fatal Hypoglycemia by Cytokine-Mediated Suppression of Hepatic Glucose-6-Phosphatase Expression. Toxins (Basel) 2022; 14:toxins14120820. [PMID: 36548717 PMCID: PMC9786807 DOI: 10.3390/toxins14120820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/08/2022] [Accepted: 11/14/2022] [Indexed: 11/25/2022] Open
Abstract
Ricin toxin is an agent of biodefense concern and we have been developing countermeasures for ricin threats. In doing so, we sought biomarkers of ricin toxicosis and found that in mice parenteral injection of ricin toxin causes profound hypoglycemia, in the absence of other clinical laboratory abnormalities. We now seek to identify the mechanisms underlying this hypoglycemia. Within the first hours following injection, while still normoglycemic, lymphopenia and pro-inflammatory cytokine secretion were observed, particularly tumor necrosis factor (TNF)-α. The cytokine response evolved over the next day into a complex storm of both pro- and anti-inflammatory cytokines. Evaluation of pancreatic function and histology demonstrated marked islet hypertrophy involving predominantly β-cells, but only mildly elevated levels of insulin secretion, and diminished hepatic insulin signaling. Drops in blood glucose were observed even after destruction of β-cells with streptozotocin. In the liver, we observed a rapid and persistent decrease in the expression of glucose-6-phosphatase (G6Pase) RNA and protein levels, accompanied by a drop in glucose-6-phosphate and increase in glycogen. TNF-α has previously been reported to suppress G6Pase expression. In humans, a genetic deficiency of G6Pase results in glycogen storage disease, type-I (GSD-1), a hallmark of which is potentially fatal hypoglycemia.
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Kempa J, O’Shea-Stone G, Moss CE, Peters T, Marcotte TK, Tripet B, Eilers B, Bothner B, Copié V, Pincus SH. Distinct Metabolic States Are Observed in Hypoglycemia Induced in Mice by Ricin Toxin or by Fasting. Toxins (Basel) 2022; 14:toxins14120815. [PMID: 36548712 PMCID: PMC9782143 DOI: 10.3390/toxins14120815] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/08/2022] [Accepted: 11/15/2022] [Indexed: 11/23/2022] Open
Abstract
Hypoglycemia may be induced by a variety of physiologic and pathologic stimuli and can result in life-threatening consequences if untreated. However, hypoglycemia may also play a role in the purported health benefits of intermittent fasting and caloric restriction. Previously, we demonstrated that systemic administration of ricin toxin induced fatal hypoglycemia in mice. Here, we examine the metabolic landscape of the hypoglycemic state induced in the liver of mice by two different stimuli: systemic ricin administration and fasting. Each stimulus produced the same decrease in blood glucose and weight loss. The polar metabolome was studied using 1H NMR, quantifying 59 specific metabolites, and untargeted LC-MS on approximately 5000 features. Results were analyzed by multivariate analyses, using both principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA), to identify global metabolic patterns, and by univariate analyses (ANOVA) to assess individual metabolites. The results demonstrated that while there were some similarities in the responses to the two stimuli including decreased glucose, ADP, and glutathione, they elicited distinct metabolic states. The metabolite showing the greatest difference was O-phosphocholine, elevated in ricin-treated animals and known to be affected by the pro-inflammatory cytokine TNF-α. Another difference was the alternative fuel source utilized, with fasting-induced hypoglycemia primarily ketotic, while the response to ricin-induced hypoglycemia involves protein and amino acid catabolism.
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Affiliation(s)
- Jacob Kempa
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Galen O’Shea-Stone
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Corinne E. Moss
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Tami Peters
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Tamera K. Marcotte
- Animal Resources Center, Montana State University, Bozeman, MT 59717, USA
| | - Brian Tripet
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Brian Eilers
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Brian Bothner
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Valérie Copié
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
- Correspondence: (V.C.); (S.H.P.)
| | - Seth H. Pincus
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
- Correspondence: (V.C.); (S.H.P.)
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10
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Shao M, Yang S, Zheng A, Wu Z, Chen M, Yao R, Shi Y, Chen G. Pathophysiological Changes in Rhesus Monkeys with Paraquat-Induced Pulmonary Fibrosis. Lung 2022; 200:549-560. [PMID: 36163517 PMCID: PMC9512975 DOI: 10.1007/s00408-022-00572-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 09/13/2022] [Indexed: 11/29/2022]
Abstract
Purpose Pulmonary fibrosis is a life-threatening lung disorder. A comprehensive understanding of the pathophysiological changes in the development of pulmonary fibrosis will lead to new insights into its treatment. Methods We used a paraquat (PQ)-induced rhesus monkey model of pulmonary fibrosis to comprehensively investigate the process of pulmonary fibrosis development. Rhesus monkeys were orally administered PQ at concentrations of 25 mg/kg, 40 mg/kg, and 80 mg/kg. The dose was given once. Behavior and clinical data, such as PQ concentration, arterial oxygen saturation, biochemical evaluation, lung histopathology, and medical imaging, were continuously observed. Results Paraquat-exposed monkeys developed pulmonary fibrosis following an expected time course, especially at 25 mg/kg. CT images showed ground-glass lesions in the lung after 4 weeks, and pulmonary fibrosis persisted until the end of follow-up. Using pathological examination, the lung sustained collagen deposition and slight inflammatory cell infiltration. All rhesus monkeys had obvious inflammatory infiltration within 1 week according to the immunohistochemical results and the number of leukocytes in the blood. The CT results showed that pulmonary fibrosis had not formed, indicating that drugs with powerful anti-inflammatory ability are potential candidates for early pulmonary fibrosis treatment. Conclusion Our study describes the dynamic process of paraquat-induced pulmonary fibrosis in rhesus monkeys and provided a pathophysiological basis for the treatment of pulmonary fibrosis. Supplementary Information The online version contains supplementary material available at 10.1007/s00408-022-00572-9.
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Affiliation(s)
- Mingyang Shao
- Institute of Clinical Pathology, Key Laboratory of Transplant Engineering and Immunology, West China Hospital, Sichuan University, 37 Guoxue Alley, Wuhou, Chengdu, 610041, China
| | - Sha Yang
- The Emergency Department, West China Hospital, Sichuan University, 37 Guoxue Alley, Wuhou, Chengdu, 610041, China
| | - Aiyi Zheng
- The Emergency Department, West China Hospital, Sichuan University, 37 Guoxue Alley, Wuhou, Chengdu, 610041, China
| | - Zhenru Wu
- Institute of Clinical Pathology, Key Laboratory of Transplant Engineering and Immunology, West China Hospital, Sichuan University, 37 Guoxue Alley, Wuhou, Chengdu, 610041, China
| | - Menglin Chen
- Institute of Clinical Pathology, Key Laboratory of Transplant Engineering and Immunology, West China Hospital, Sichuan University, 37 Guoxue Alley, Wuhou, Chengdu, 610041, China
| | - Rong Yao
- The Emergency Department, West China Hospital, Sichuan University, 37 Guoxue Alley, Wuhou, Chengdu, 610041, China.
| | - Yujun Shi
- Institute of Clinical Pathology, Key Laboratory of Transplant Engineering and Immunology, West China Hospital, Sichuan University, 37 Guoxue Alley, Wuhou, Chengdu, 610041, China
| | - Gen Chen
- Development and Application of Human Major Disease Monkey Model Key Laboratory of Sichuan, Sichuan Yibin Horizontal and Vertical Biotechnology Co., Ltd., Yibin, 644601, China
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11
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Sapoznikov A, Gal Y, Alcalay R, Evgy Y, Sabo T, Kronman C, Falach R. Characterization of Lung Injury following Abrin Pulmonary Intoxication in Mice: Comparison to Ricin Poisoning. Toxins (Basel) 2022; 14:toxins14090614. [PMID: 36136552 PMCID: PMC9504197 DOI: 10.3390/toxins14090614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 08/29/2022] [Accepted: 08/31/2022] [Indexed: 11/25/2022] Open
Abstract
Abrin is a highly toxic protein obtained from the seeds of the rosary pea plant Abrus precatorius, and it is closely related to ricin in terms of its structure and chemical properties. Both toxins inhibit ribosomal function, halt protein synthesis and lead to cellular death. The major clinical manifestations following pulmonary exposure to these toxins consist of severe lung inflammation and consequent respiratory insufficiency. Despite the high similarity between abrin and ricin in terms of disease progression, the ability to protect mice against these toxins by postexposure antibody-mediated treatment differs significantly, with a markedly higher level of protection achieved against abrin intoxication. In this study, we conducted an in-depth comparison between the kinetics of in vivo abrin and ricin intoxication in a murine model. The data demonstrated differential binding of abrin and ricin to the parenchymal cells of the lungs. Accordingly, toxin-mediated injury to the nonhematopoietic compartment was shown to be markedly lower in the case of abrin intoxication. Thus, profiling of alveolar epithelial cells demonstrated that although toxin-induced damage was restricted to alveolar epithelial type II cells following abrin intoxication, as previously reported for ricin, it was less pronounced. Furthermore, unlike following ricin intoxication, no direct damage was detected in the lung endothelial cell population following abrin exposure. Reduced impairment of intercellular junction molecules following abrin intoxication was detected as well. In contrast, similar damage to the endothelial surface glycocalyx layer was observed for the two toxins. We assume that the reduced damage to the lung stroma, which maintains a higher level of tissue integrity following pulmonary exposure to abrin compared to ricin, contributes to the high efficiency of the anti-abrin antibody treatment at late time points after exposure.
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Affiliation(s)
- Anita Sapoznikov
- Correspondence: (A.S.); (R.F.); Tel.: +972-89381847 (A.S.); +972-89381522 (R.F.)
| | | | | | | | | | | | - Reut Falach
- Correspondence: (A.S.); (R.F.); Tel.: +972-89381847 (A.S.); +972-89381522 (R.F.)
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12
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Deng M, Su D, Xiao N, Zhang Z, Wang Y, Zong F, Li S, Wang J, Zhou D, Zhao Y, Yang H. Gdf15 deletion exacerbates acute lung injuries induced by intratracheal inoculation of aerosolized ricin in mice. Toxicology 2022; 469:153135. [DOI: 10.1016/j.tox.2022.153135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 02/16/2022] [Accepted: 02/17/2022] [Indexed: 10/19/2022]
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13
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Falach R, Goldvaser M, Halpern P, Rosner A, Sapoznikov A, Gal Y, Goren O, Sabo T, Kronman C, Katalan S. Pathophysiological profile of awake and anesthetized pigs following systemic exposure to the highly lethal ricin toxin. Clin Toxicol (Phila) 2022; 60:76-82. [PMID: 34080504 DOI: 10.1080/15563650.2021.1933513] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 04/27/2021] [Accepted: 05/18/2021] [Indexed: 10/21/2022]
Abstract
Ricin, a plant-derived toxin originating from the seeds of Ricinus communis (castor bean plant), is one of the most lethal toxins known. To date, no in-depth study of systemic exposure to ricin in a standardized large animal model has been reported. This study details for the first time the pathophysiological hemodynamic profile following systemic/intramuscular exposure to the ricin toxin in a porcine model by comprehensive cardiorespiratory monitoring of awake and anesthetized pigs. Unlike respiratory exposure to ricin, which is characterized by the development of acute respiratory distress syndrome, following intramuscular exposure to ricin respiratory parameters were grossly unaffected, however the hemodynamics of both awake and anesthetize pigs were unsustainably compromised. We show that in the early phase until approximately 24 h post-exposure, cardiac output is not impaired although one of its components, stroke volume, is relatively low. This is due to compensatory increase in heart rate, which eventually becomes insufficient. Later, distributive shock develops, characterized by severe vasodilatation (decreased systemic vascular resistance), low central venous oxygen saturation and elevation of venous-to-arterial carbon dioxide difference indicating increase in tissue oxygen demand not met by cardiac supply. These findings serve as a basis for further studies to evaluate the ability of supportive treatments such as vasoactive and inotropic drugs, to postpone the hemodynamic deterioration and thus expand the therapeutic window for the anti-ricin treatment. Such studies are of crucial importance for judicious treatment of victims of acts of bioterrorism or of intentional self-poisoning.
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Affiliation(s)
- Reut Falach
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Michael Goldvaser
- Division of Medicinal Chemistry, Israel Institute for Biological Research, Ness Ziona, Israel
| | | | - Amir Rosner
- Veterinary Center for Preclinical Research, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Anita Sapoznikov
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Yoav Gal
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Orr Goren
- Anesthesia, Pain and Intensive Care Division, Tel-Aviv Medical Center, Tel-Aviv University, Tel Aviv, Israel
| | - Tamar Sabo
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Chanoch Kronman
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Shahaf Katalan
- Division of Medicinal Chemistry, Israel Institute for Biological Research, Ness Ziona, Israel
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14
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Novak H, Doering J, Ehrbar D, Donini O, Mantis NJ. Durable Immunity to Ricin Toxin Elicited by a Thermostable, Lyophilized Subunit Vaccine. mSphere 2021; 6:e0075021. [PMID: 34730377 PMCID: PMC8565519 DOI: 10.1128/msphere.00750-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 10/15/2021] [Indexed: 11/26/2022] Open
Abstract
The development of vaccines against biothreat toxins like ricin (RT) is considered an integral component of the U.S. national security efforts. RiVax is a thermostable, lyophilized RT subunit vaccine adsorbed to aluminum salt adjuvant intended for use by military personnel and first responders. Phase 1 studies indicated that RiVax is safe and immunogenic, while a three-dose intramuscular vaccination regimen in nonhuman primates elicited protection against lethal dose RT challenge by aerosol. Here, we investigated, in a mouse model, the durability of RiVax-induced antibody responses and corresponding immunity to lethal dose RT challenge. Groups of mice were subcutaneously administered 3 or 1 μg of RiVax on days 0 and 21 and challenged with 10× 50% lethal dose (LD50) RT by injection at six different intervals over the course of 12 months. Serum antibody titers and epitope-specific competition assays were determined prior to each challenge. We report that the two-dose, 3-μg regimen conferred near-complete protection against RT challenge on day 35 and complete protection thereafter (challenge days 65, 95, 125, 245, and 365). The two-dose, 3-μg regimen was superior to the 1-μg regimen as revealed by slight differences in survival and morbidity scores (e.g., hypoglycemia, weight loss) on challenge days 35 and 365. In separate experiments, a single 3-μg RiVax vaccination proved only marginally effective at eliciting protective immunity to RT, underscoring the necessity of a prime-boost regimen to achieve full and long-lasting protection against RT. IMPORTANCE Ricin toxin (RT) is a notorious biothreat, as exposure to even trace amounts via injection or inhalation can induce organ failure and death within a matter of hours. In this study, we advance the preclinical testing of a candidate RT vaccine known as RiVax. RiVax is a recombinant nontoxic derivative of RT's enzymatic subunit that has been evaluated for safety in phase I clinical trials and efficacy in a variety of animal models. We demonstrate that two doses of RiVax are sufficient to protect mice from lethal dose RT challenge for up to 1 year. We describe kinetics and other immune parameters of the antibody response to RiVax and discuss how these immune factors may translate to humans.
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Affiliation(s)
- Hayley Novak
- Department of Biomedical Sciences, University at Albany, Albany, New York, USA
| | - Jennifer Doering
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Dylan Ehrbar
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | | | - Nicholas J. Mantis
- Department of Biomedical Sciences, University at Albany, Albany, New York, USA
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, New York, USA
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15
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Rudolph MJ, Poon AY, Kavaliauskiene S, Myrann AG, Reynolds-Peterson C, Davis SA, Sandvig K, Vance DJ, Mantis NJ. Structural Analysis of Toxin-Neutralizing, Single-Domain Antibodies that Bridge Ricin's A-B Subunit Interface. J Mol Biol 2021; 433:167086. [PMID: 34089718 DOI: 10.1016/j.jmb.2021.167086] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 05/18/2021] [Accepted: 05/27/2021] [Indexed: 01/20/2023]
Abstract
Ricin toxin kills mammalian cells with notorious efficiency. The toxin's B subunit (RTB) is a Gal/GalNAc-specific lectin that attaches to cell surfaces and promotes retrograde transport of ricin's A subunit (RTA) to the trans Golgi network (TGN) and endoplasmic reticulum (ER). RTA is liberated from RTB in the ER and translocated into the cell cytoplasm, where it functions as a ribosome-inactivating protein. While antibodies against ricin's individual subunits have been reported, we now describe seven alpaca-derived, single-domain antibodies (VHHs) that span the RTA-RTB interface, including four Tier 1 VHHs with IC50 values <1 nM. Crystal structures of each VHH bound to native ricin holotoxin revealed three different binding modes, based on contact with RTA's F-G loop (mode 1), RTB's subdomain 2γ (mode 2) or both (mode 3). VHHs in modes 2 and 3 were highly effective at blocking ricin attachment to HeLa cells and immobilized asialofetuin, due to framework residues (FR3) that occupied the 2γ Gal/GalNAc-binding pocket and mimic ligand. The four Tier 1 VHHs also interfered with intracellular functions of RTB, as they neutralized ricin in a post-attachment cytotoxicity assay (e.g., the toxin was bound to cell surfaces before antibody addition) and reduced the efficiency of toxin transport to the TGN. We conclude that the RTA-RTB interface is a target of potent toxin-neutralizing antibodies that interfere with both extracellular and intracellular events in ricin's cytotoxic pathway.
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Affiliation(s)
| | - Amanda Y Poon
- Department of Biomedical Sciences, University at Albany, Albany, NY, USA; Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY, USA
| | - Simona Kavaliauskiene
- Department of Molecular Cell Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Montebello, Oslo, Norway
| | - Anne Grethe Myrann
- Department of Molecular Cell Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Montebello, Oslo, Norway
| | - Claire Reynolds-Peterson
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY, USA
| | - Simon A Davis
- New York Structural Biology Center, New York, NY, USA
| | - Kirsten Sandvig
- Department of Molecular Cell Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Montebello, Oslo, Norway; Department of Biosciences, University of Oslo, Oslo, Norway
| | - David J Vance
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY, USA
| | - Nicholas J Mantis
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY, USA.
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16
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Reynolds-Peterson C, Ehrbar DJ, McHale SM, LaRocca TJ, Mantis NJ. Sensitization of Airway Epithelial Cells to Toxin-Induced Death by TNF Superfamily Cytokines. Methods Mol Biol 2021; 2248:19-42. [PMID: 33185865 DOI: 10.1007/978-1-0716-1130-2_2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The TNF superfamily of proinflammatory and proapoptotic cytokines influence tissue-wide responses to molecular insults such as small molecules, toxins, and viral infections that perturb cellular homeostasis at the level of DNA replication, transcription, and translation. In the context of acute lung injury, for example, TNF superfamily members like TNF-α and TRAIL can severely exacerbate disease pathophysiology. This chapter describes a systematic approach to optimization of mammalian cell viability assays and transcriptional profiling through nCounter® Technology to permit a detailed examination of how TNF-α and TRAIL modulate programmed cell death pathways in concert with ricin toxin, a ribosome-inactivating protein (RIP) and a potent inducer of acute respiratory distress. We compare two widely used luciferase- and colorimetric-based cell viability assays and provide optimization protocols for adherent and non-adherent cell lines. We provide a computational workflow to facilitate downstream analysis of datasets generated from nCounter® gene expression panels. While combined treatment with ricin toxin and TRAIL serves as the exemplar, the methodologies are applicable to any TNF superfamily member in combination with any biological agent of interest.
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Affiliation(s)
- Claire Reynolds-Peterson
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY, USA
| | - Dylan J Ehrbar
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY, USA
| | - Susanne M McHale
- Advanced Genomic Technologies Cluster, Wadsworth Center, New York State Department of Health, Albany, NY, USA
| | - Timothy J LaRocca
- Department of Basic and Clinical Sciences, Albany College of Pharmacy and Health Sciences, Albany, NY, USA
| | - Nicholas J Mantis
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY, USA.
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17
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Doering J, Czajka T, Yates JL, Donini O, Mantis NJ. Potency determination of ricin toxin using a monoclonal antibody-based competition assay. J Immunol Methods 2020; 486:112844. [PMID: 32891616 DOI: 10.1016/j.jim.2020.112844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 08/04/2020] [Accepted: 08/17/2020] [Indexed: 10/23/2022]
Abstract
Mouse challenge studies with death as an endpoint remain the gold standard in assessing the potency of ricin toxin, a Category B biothreat agent derived from the castor bean (Ricinus communis). However, animal studies are expensive, time consuming and ethically concerning. In an effort to reduce reliance on animals in vaccine development, we developed a monoclonal antibody (MAb)-based ricin competition ELISA (RiCoE) that indicates conformation integrity of ricin toxin. In forced degradation (heat-denaturation) experiments with native ricin holotoxin, we demonstrate a correlation between the decline in MAb reactivity in RiCoE and a corresponding loss of toxin potency in Vero cells (IC50) and mice (LD50). The RiCoE assay was applied to differentially sourced commercial lots of ricin toxin derived from R. communis blends and compared to toxin potency in mice. There was near perfect congruence between RiCoE values with two different MAbs (PB10, SyH7) and ricin potency in the mouse model using morbidity as an endpoint. In conclusion, we propose that RiCoE can serve as a rapid and sensitive substitute to mouse lethal dose challenge studies as a means to determine ricin toxin potency and will be valuable at various stages of vaccine development.
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Affiliation(s)
- Jennifer Doering
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, NY 12208, United States of America
| | - Timothy Czajka
- Department of Biomedical Sciences, University at Albany, Albany, NY 12201, United States of America
| | - Jennifer L Yates
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, NY 12208, United States of America
| | - Oreola Donini
- Soligenix, Inc., Princeton, NJ 08540, United States of America
| | - Nicholas J Mantis
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, NY 12208, United States of America; Department of Biomedical Sciences, University at Albany, Albany, NY 12201, United States of America.
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18
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Slyke GV, Ehrbar DJ, Doering J, Yates JL, Vitetta ES, Donini O, Mantis NJ. Endpoint and epitope-specific antibody responses as correlates of vaccine-mediated protection of mice against ricin toxin. Vaccine 2020; 38:6721-6729. [PMID: 32891474 DOI: 10.1016/j.vaccine.2020.08.047] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 08/11/2020] [Accepted: 08/18/2020] [Indexed: 12/17/2022]
Abstract
The successful licensure of vaccines for biodefense is contingent upon the availability of well-established correlates of protection (CoP) in at least two animal species that can be applied to humans, without the need to assess efficacy in the clinic. In this report we describe a multivariate model that combines pre-challenge serum antibody endpoint titers (EPT) and values derived from an epitope profiling immune-competition capture (EPICC) assay as a predictor in mice of vaccine-mediated immunity against ricin toxin (RT), a Category B biothreat. EPICC is a modified competition ELISA in which serum samples from vaccinated mice were assessed for their ability to inhibit the capture of soluble, biotinylated (b)-RT by a panel of immobilized monoclonal antibodies (mAbs) directed against four immunodominant toxin-neutralizing regions on the enzymatic A chain (RTA) of RT. In a test cohort of mice (n = 40) vaccinated with suboptimal doses of the RTA subunit vaccine, RiVax®, we identified two mAbs, PB10 and SyH7, which had EPICC inhibition values in pre-challenge serum samples that correlated with survival following a challenge with 5 × LD50 of RT administered by intraperitoneal (IP) injection. Analysis of a larger cohort of mice (n = 645) revealed that a multivariate model combining endpoint titers and EPICC values for PB10 and SyH7 as predictive variables had significantly higher statistical power than any one of the independent variables alone. Establishing the correlates of vaccine-mediated protection in mice represents an important steppingstone in the development of RiVax® as a medical countermeasure under the United States Food and Drug Administration's "Animal Rule."
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Affiliation(s)
- Greta Van Slyke
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, NY 12208, United States
| | - Dylan J Ehrbar
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, NY 12208, United States
| | - Jennifer Doering
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, NY 12208, United States
| | - Jennifer L Yates
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, NY 12208, United States
| | - Ellen S Vitetta
- Department of Immunology and Microbiology, University of Texas Southwestern Medical School, Dallas, TX, United States
| | | | - Nicholas J Mantis
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, NY 12208, United States.
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19
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Rong Y, Pauly M, Guthals A, Pham H, Ehrbar D, Zeitlin L, Mantis NJ. A Humanized Monoclonal Antibody Cocktail to Prevent Pulmonary Ricin Intoxication. Toxins (Basel) 2020. [PMID: 32235318 DOI: 10.3390/toxins1204215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023] Open
Abstract
PB10 IgG1, a monoclonal antibody (MAb) directed against an immunodominant epitope on the enzymatic subunit (RTA) of ricin toxin (RT), has been shown to passively protect mice and non-human primates from an aerosolized lethal-dose RT challenge. However, it was recently demonstrated that the therapeutic efficacy of PB10 IgG1 is significantly improved when co-administered with a second MAb, SylH3, targeting RT's binding subunit (RTB). Here we report that the PB10/SylH3 cocktail is also superior to PB10 alone when used as a pre-exposure prophylactic (PrEP) in a mouse model of intranasal RT challenge. The benefit of the PB10/SylH3 cocktail prompted us to engineer a humanized IgG1 version of SylH3 (huSylH3). The huPB10/huSylH3 cocktail proved highly efficacious in the mouse model, thereby opening the door to future testing in non-human primates.
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MESH Headings
- Administration, Inhalation
- Animals
- Antibodies, Monoclonal, Humanized/administration & dosage
- Antibodies, Monoclonal, Humanized/pharmacology
- Antibodies, Neutralizing/administration & dosage
- Antibodies, Neutralizing/pharmacology
- Antidotes/administration & dosage
- Antidotes/pharmacology
- Chlorocebus aethiops
- Disease Models, Animal
- Drug Therapy, Combination
- Female
- Lung Diseases/chemically induced
- Lung Diseases/prevention & control
- Mice, Inbred BALB C
- Pre-Exposure Prophylaxis
- Ricin/antagonists & inhibitors
- Ricin/immunology
- Vero Cells
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Affiliation(s)
- Yinghui Rong
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY 12208, USA
| | - Michael Pauly
- Mapp Biopharmaceutical, Inc. 6160 Lusk Blvd, San Diego, CA 92121, USA
| | - Adrian Guthals
- Mapp Biopharmaceutical, Inc. 6160 Lusk Blvd, San Diego, CA 92121, USA
| | - Henry Pham
- Mapp Biopharmaceutical, Inc. 6160 Lusk Blvd, San Diego, CA 92121, USA
| | - Dylan Ehrbar
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY 12208, USA
| | - Larry Zeitlin
- Mapp Biopharmaceutical, Inc. 6160 Lusk Blvd, San Diego, CA 92121, USA
| | - Nicholas J Mantis
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY 12208, USA
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20
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A Humanized Monoclonal Antibody Cocktail to Prevent Pulmonary Ricin Intoxication. Toxins (Basel) 2020; 12:toxins12040215. [PMID: 32235318 PMCID: PMC7232472 DOI: 10.3390/toxins12040215] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 03/24/2020] [Accepted: 03/26/2020] [Indexed: 12/11/2022] Open
Abstract
PB10 IgG1, a monoclonal antibody (MAb) directed against an immunodominant epitope on the enzymatic subunit (RTA) of ricin toxin (RT), has been shown to passively protect mice and non-human primates from an aerosolized lethal-dose RT challenge. However, it was recently demonstrated that the therapeutic efficacy of PB10 IgG1 is significantly improved when co-administered with a second MAb, SylH3, targeting RT’s binding subunit (RTB). Here we report that the PB10/SylH3 cocktail is also superior to PB10 alone when used as a pre-exposure prophylactic (PrEP) in a mouse model of intranasal RT challenge. The benefit of the PB10/SylH3 cocktail prompted us to engineer a humanized IgG1 version of SylH3 (huSylH3). The huPB10/huSylH3 cocktail proved highly efficacious in the mouse model, thereby opening the door to future testing in non-human primates.
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21
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Roy CJ, Van Slyke G, Ehrbar D, Bornholdt ZA, Brennan MB, Campbell L, Chen M, Kim D, Mlakar N, Whaley KJ, Froude JW, Torres-Velez FJ, Vitetta E, Didier PJ, Doyle-Meyers L, Zeitlin L, Mantis NJ. Passive immunization with an extended half-life monoclonal antibody protects Rhesus macaques against aerosolized ricin toxin. NPJ Vaccines 2020; 5:13. [PMID: 32128254 PMCID: PMC7018975 DOI: 10.1038/s41541-020-0162-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 01/13/2020] [Indexed: 02/07/2023] Open
Abstract
Inhalation of ricin toxin (RT), a Category B biothreat agent, provokes an acute respiratory distress syndrome marked by pro-inflammatory cytokine and chemokine production, neutrophilic exudate, and pulmonary edema. The severity of RT exposure is attributed to the tropism of the toxin's B subunit (RTB) for alveolar macrophages and airway epithelial cells, coupled with the extraordinarily potent ribosome-inactivating properties of the toxin's enzymatic subunit (RTA). While there are currently no vaccines or treatments approved to prevent RT intoxication, we recently described a humanized anti-RTA IgG1 MAb, huPB10, that was able to rescue non-human primates (NHPs) from lethal dose RT aerosol challenge if administered by intravenous (IV) infusion within hours of toxin exposure. We have now engineered an extended serum half-life variant of that MAb, huPB10-LS, and evaluated it as a pre-exposure prophylactic. Five Rhesus macaques that received a single intravenous infusion (25 mg/kg) of huPB10-LS survived a lethal dose aerosol RT challenge 28 days later, whereas three control animals succumbed to RT intoxication within 48 h. The huPB10-LS treated animals remained clinically normal in the hours and days following toxin insult, suggesting that pre-existing antibody levels were sufficient to neutralize RT locally. Moreover, pro-inflammatory markers in sera and BAL fluids collected 24 h following RT challenge were significantly dampened in huPB10-LS treated animals, as compared to controls. Finally, we found that all five surviving animals, within days after RT exposure, had anti-RT serum IgG titers against epitopes other than huPB10-LS, indicative of active immunization by residual RT and/or RT-immune complexes.
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Affiliation(s)
- Chad J. Roy
- Tulane National Primate Research Center, Covington, LA 70433 USA
| | - Greta Van Slyke
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, NY 12208 USA
| | - Dylan Ehrbar
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, NY 12208 USA
| | | | | | | | - Michelle Chen
- Mapp Biopharmaceutical, Inc, San Diego, CA 92121 USA
| | - Do Kim
- Mapp Biopharmaceutical, Inc, San Diego, CA 92121 USA
| | - Neil Mlakar
- Mapp Biopharmaceutical, Inc, San Diego, CA 92121 USA
| | | | - Jeffrey W. Froude
- Clinical Pharmacology Branch, Walter Reed Institute of Research, 503 Robert Grant Ave, Silver Spring, MD 20910 USA
- Present Address: Vaccines and Therapeutics Division, Defense Threat Reduction Agency, 8725 John J. Kingman Rd., Fort Belvoir, VA 22060 USA
| | - Fernando J Torres-Velez
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, NY 12208 USA
| | - Ellen Vitetta
- Departments of Immunology and Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
| | - Peter J. Didier
- Tulane National Primate Research Center, Covington, LA 70433 USA
| | | | - Larry Zeitlin
- Mapp Biopharmaceutical, Inc, San Diego, CA 92121 USA
| | - Nicholas J. Mantis
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, NY 12208 USA
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22
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Rong Y, Torres-Velez FJ, Ehrbar D, Doering J, Song R, Mantis NJ. An intranasally administered monoclonal antibody cocktail abrogates ricin toxin-induced pulmonary tissue damage and inflammation. Hum Vaccin Immunother 2019; 16:793-807. [PMID: 31589555 DOI: 10.1080/21645515.2019.1664243] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Ricin toxin, a plant-derived, mannosylated glycoprotein, elicits an incapacitating and potentially lethal inflammatory response in the airways following inhalation. Uptake of ricin by alveolar macrophages (AM) and other pulmonary cell types occurs via two parallel pathways: one mediated by ricin's B subunit (RTB), a galactose-specific lectin, and one mediated by the mannose receptor (MR;CD206). Ricin's A subunit (RTA) is a ribosome-inactivating protein that triggers apoptosis in mammalian cells. It was recently reported that a single monoclonal antibody (MAb), PB10, directed against an immunodominant epitope on RTA and administered intravenously, was able to rescue Rhesus macaques from lethal aerosol dose of ricin. In this study, we now demonstrate in mice that the effectiveness PB10 is significantly improved when combined with a second MAb, SylH3, against RTB. Mice treated with PB10 alone survived lethal-dose intranasal ricin challenge, but experienced significant weight loss, moderate pulmonary inflammation (e.g., elevated IL-1 and IL-6 levels, PMN influx), and apoptosis of lung macrophages. In contrast, mice treated with the PB10/SylH3 cocktail were essentially impervious to pulmonary ricin toxin exposure, as evidenced by no weight loss, no change in local IL-1 and IL-6 levels, retention of lung macrophages, and a significant dampening of PMN recruitment into the bronchoalveolar lavage (BAL) fluids. The PB10/SylH3 cocktail only marginally reduced ricin binding to target cells in the BAL, suggesting that the antibody mixture neutralizes ricin by interfering with one or more steps in the RTB- and MR-dependent uptake pathways.
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Affiliation(s)
- Yinghui Rong
- New York State Department of Health, Division of Infectious Disease, Wadsworth Center, Albany, NY, USA
| | - Fernando J Torres-Velez
- New York State Department of Health, Division of Infectious Disease, Wadsworth Center, Albany, NY, USA
| | - Dylan Ehrbar
- New York State Department of Health, Division of Infectious Disease, Wadsworth Center, Albany, NY, USA
| | - Jennifer Doering
- New York State Department of Health, Division of Infectious Disease, Wadsworth Center, Albany, NY, USA
| | - Renjie Song
- New York State Department of Health, Division of Infectious Disease, Wadsworth Center, Albany, NY, USA
| | - Nicholas J Mantis
- New York State Department of Health, Division of Infectious Disease, Wadsworth Center, Albany, NY, USA
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TNF Family Cytokines Induce Distinct Cell Death Modalities in the A549 Human Lung Epithelial Cell Line when Administered in Combination with Ricin Toxin. Toxins (Basel) 2019; 11:toxins11080450. [PMID: 31374990 PMCID: PMC6723388 DOI: 10.3390/toxins11080450] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 07/19/2019] [Accepted: 07/28/2019] [Indexed: 01/10/2023] Open
Abstract
Ricin is a member of the ribosome-inactivating protein (RIP) family of toxins and is classified as a biothreat agent by the Centers for Disease Control and Prevention (CDC). Inhalation, the most potent route of toxicity, triggers an acute respiratory distress-like syndrome that coincides with near complete destruction of the lung epithelium. We previously demonstrated that the TNF-related apoptosis-inducing ligand (TRAIL; CD253) sensitizes human lung epithelial cells to ricin-induced death. Here, we report that ricin/TRAIL-mediated cell death occurs via apoptosis and involves caspases -3, -7, -8, and -9, but not caspase-6. In addition, we show that two other TNF family members, TNF-α and Fas ligand (FasL), also sensitize human lung epithelial cells to ricin-induced death. While ricin/TNF-α- and ricin/FasL-mediated killing of A549 cells was inhibited by the pan-caspase inhibitor, zVAD-fmk, evidence suggests that these pathways were not caspase-dependent apoptosis. We also ruled out necroptosis and pyroptosis. Rather, the combination of ricin plus TNF-α or FasL induced cathepsin-dependent cell death, as evidenced by the use of several pharmacologic inhibitors. We postulate that the effects of zVAD-fmk were due to the molecule’s known off-target effects on cathepsin activity. This work demonstrates that ricin-induced lung epithelial cell killing occurs by distinct cell death pathways dependent on the presence of different sensitizing cytokines, TRAIL, TNF-α, or FasL.
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Sapoznikov A, Rosner A, Falach R, Gal Y, Aftalion M, Evgy Y, Israeli O, Sabo T, Kronman C. Intramuscular Ricin Poisoning of Mice Leads to Widespread Damage in the Heart, Spleen, and Bone Marrow. Toxins (Basel) 2019; 11:E344. [PMID: 31208156 PMCID: PMC6628730 DOI: 10.3390/toxins11060344] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 06/11/2019] [Accepted: 06/13/2019] [Indexed: 12/21/2022] Open
Abstract
Ricin, a lethal toxin derived from castor oil beans, is a potential bio-threat due to its high availability and simplicity of preparation. Ricin is prepared according to simple recipes available on the internet, and was recently considered in terrorist, suicide, or homicide attempts involving the parenteral route of exposure. In-depth study of the morbidity developing from parenteral ricin poisoning is mandatory for tailoring appropriate therapeutic measures to mitigate ricin toxicity in such instances. The present study applies various biochemical, hematological, histopathological, molecular, and functional approaches to broadly investigate the systemic effects of parenteral intoxication by a lethal dose of ricin in a murine model. Along with prompt coagulopathy, multi-organ hemorrhages, and thrombocytopenia, ricin induced profound morpho-pathological and functional damage in the spleen, bone marrow, and cardiovascular system. In the heart, diffuse hemorrhages, myocyte necrosis, collagen deposition, and induction in fibrinogen were observed. Severe functional impairment was manifested by marked thickening of the left ventricular wall, decreased ventricular volume, and a significant reduction in stroke volume and cardiac output. Unexpectedly, the differential severity of the ricin-induced damage did not correlate with the respective ricin-dependent catalytic activity measured in the various organs. These findings emphasize the complexity of ricin toxicity and stress the importance of developing novel therapeutic strategies that will combine not only anti-ricin specific therapy, but also will target ricin-induced indirect disturbances.
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Affiliation(s)
- Anita Sapoznikov
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 76100, Israel.
| | - Amir Rosner
- Veterinary Center for Preclinical Research, Israel Institute for Biological Research, Ness-Ziona 76100, Israel.
| | - Reut Falach
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 76100, Israel.
| | - Yoav Gal
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 76100, Israel.
| | - Moshe Aftalion
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 76100, Israel.
| | - Yentl Evgy
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 76100, Israel.
| | - Ofir Israeli
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 76100, Israel.
| | - Tamar Sabo
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 76100, Israel.
| | - Chanoch Kronman
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 76100, Israel.
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25
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Ricin: An Ancient Story for a Timeless Plant Toxin. Toxins (Basel) 2019; 11:toxins11060324. [PMID: 31174319 PMCID: PMC6628454 DOI: 10.3390/toxins11060324] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 06/03/2019] [Accepted: 06/05/2019] [Indexed: 12/20/2022] Open
Abstract
The castor plant (Ricinus communis L.) has been known since time immemorial in traditional medicine in the pharmacopeia of Mediterranean and eastern ancient cultures. Moreover, it is still used in folk medicine worldwide. Castor bean has been mainly recommended as anti-inflammatory, anthelmintic, anti-bacterial, laxative, abortifacient, for wounds, ulcers, and many other indications. Many cases of human intoxication occurred accidentally or voluntarily with the ingestion of castor seeds or derivatives. Ricinus toxicity depends on several molecules, among them the most important is ricin, a protein belonging to the family of ribosome-inactivating proteins. Ricin is the most studied of this category of proteins and it is also known to the general public, having been used for several biocrimes. This manuscript intends to give the reader an overview of ricin, focusing on the historical path to the current knowledge on this protein. The main steps of ricin research are here reported, with particular regard to its enzymatic activity, structure, and cytotoxicity. Moreover, we discuss ricin toxicity for animals and humans, as well as the relation between bioterrorism and ricin and its impact on environmental toxicity. Ricin has also been used to develop immunotoxins for the elimination of unwanted cells, mainly cancer cells; some of these immunoconjugates gave promising results in clinical trials but also showed critical limitation.
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Integrative transcriptomics, proteomics, and metabolomics data analysis exploring the injury mechanism of ricin on human lung epithelial cells. Toxicol In Vitro 2019; 60:160-172. [PMID: 31103672 DOI: 10.1016/j.tiv.2019.05.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 05/05/2019] [Accepted: 05/15/2019] [Indexed: 11/24/2022]
Abstract
Ricin (RT) is a plant toxin belonging to the family of type II ribosome-inactivating protein with high bioterrorism potential. Aerosol RT exposure is the most lethal route, but its mechanism of injury needs further investigation. In the present study, we performed a comprehensive transcriptomics, proteomics and metabolomics analysis on the potential mechanism of injury caused by RT on human lung epithelial cells. In total, 5872 genes, 187 proteins, and 143 metabolites were shown to be significantly changed in human lung epithelial cells after RT treatment. Molecular function, pathway, and network analyses, the genes and proteins regulated in RT-treated cells were mainly attributed to fatty acid metabolism, arginine and proline metabolism and ubiquitin-mediated proteolysis pathway. Furthermore, a comprehensive analysis of transcripts, proteins, and metabolites was performed. The results revealed the correlated genes, proteins, and metabolic pathways regulated in metabolic pathways, amino acid metabolism, transcription and energy metabolism. These genes, proteins, and metabolites involved in these dis-regulated pathways may provide a more targeted and credible direction to study the mechanism of RT injury on human lung epithelial cells. This study provides large-scale omics data that can be used to develop a new strategy for the prevention, rapid diagnosis, and treatment of RT poisoning, especially of RT aerosol.
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Effective Treatment of Staphylococcal Enterotoxin B Aerosol Intoxication in Rhesus Macaques by Using Two Parenterally Administered High-Affinity Monoclonal Antibodies. Antimicrob Agents Chemother 2019; 63:AAC.02049-18. [PMID: 30782986 PMCID: PMC6496046 DOI: 10.1128/aac.02049-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 02/13/2019] [Indexed: 11/23/2022] Open
Abstract
Staphylococcal enterotoxin B (SEB) is a protein exotoxin found on the cell surface of Staphylococcus aureus that is the source for multiple pathologies in humans. When purified and concentrated in aerosol form, SEB can cause an acute and often fatal intoxication and thus is considered a biological threat agent. Staphylococcal enterotoxin B (SEB) is a protein exotoxin found on the cell surface of Staphylococcus aureus that is the source for multiple pathologies in humans. When purified and concentrated in aerosol form, SEB can cause an acute and often fatal intoxication and thus is considered a biological threat agent. There are currently no vaccines or treatments approved for human use. Studies with rodent models of SEB intoxication show that antibody therapy may be a promising treatment strategy; however, many have used antibodies only prophylactically or well before any clinical signs of intoxication are apparent. We assessed and compared the protective efficacies of two monoclonal antibodies, Ig121 and c19F1, when administered after aerosol exposure in a uniformly lethal nonhuman primate model of SEB intoxication. Rhesus macaques were challenged using small-particle aerosols of SEB and then were infused intravenously with a single dose of either Ig121 or c19F1 (10 mg/kg of body weight) at either 0.5, 2, or 4 h postexposure. Onset of clinical signs and hematological and cytokine response in untreated controls confirmed the acute onset and potency of the toxin used in the challenge. All animals administered either Ig121 or c19F1 survived SEB challenge, whereas the untreated controls succumbed to SEB intoxication 30 to 48 h postexposure. These results represent the successful therapeutic in vivo protection by two investigational drugs against SEB in a severe nonhuman primate disease model and punctuate the therapeutic value of monoclonal antibodies when faced with treatment options for SEB-induced toxicity in a postexposure setting.
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Roy CJ, Ehrbar DJ, Bohorova N, Bohorov O, Kim D, Pauly M, Whaley K, Rong Y, Torres-Velez FJ, Vitetta ES, Didier PJ, Doyle-Meyers L, Zeitlin L, Mantis NJ. Rescue of rhesus macaques from the lethality of aerosolized ricin toxin. JCI Insight 2019; 4:124771. [PMID: 30626745 DOI: 10.1172/jci.insight.124771] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 11/27/2018] [Indexed: 12/12/2022] Open
Abstract
Ricin toxin (RT) ranks at the top of the list of bioweapons of concern to civilian and military personnel alike, due to its high potential for morbidity and mortality after inhalation. In nonhuman primates, aerosolized ricin triggers severe acute respiratory distress characterized by perivascular and alveolar edema, neutrophilic infiltration, and severe necrotizing bronchiolitis and alveolitis. There are currently no approved countermeasures for ricin intoxication. Here, we report the therapeutic potential of a humanized mAb against an immunodominant epitope on ricin's enzymatic A chain (RTA). Rhesus macaques that received i.v. huPB10 4 hours after a lethal dose of ricin aerosol exposure survived toxin challenge, whereas control animals succumbed to ricin intoxication within 30 hours. Antibody intervention at 12 hours resulted in the survival of 1 of 5 monkeys. Changes in proinflammatory cytokine, chemokine, and growth factor profiles in bronchial alveolar lavage fluids before and after toxin challenge successfully clustered animals by treatment group and survival, indicating a relationship between local tissue damage and experimental outcome. This study represents the first demonstration, to our knowledge, in nonhuman primates that the lethal effects of inhalational ricin exposure can be negated by a drug candidate, and it opens up a path forward for product development.
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Affiliation(s)
- Chad J Roy
- Tulane National Primate Research Center (TNPRC), Covington, Louisiana, USA
| | - Dylan J Ehrbar
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | | | | | - Do Kim
- Mapp Biopharmaceutical Inc., San Diego, California, USA
| | - Michael Pauly
- Mapp Biopharmaceutical Inc., San Diego, California, USA
| | - Kevin Whaley
- Mapp Biopharmaceutical Inc., San Diego, California, USA
| | - Yinghui Rong
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Fernando J Torres-Velez
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Ellen S Vitetta
- Departments of Immunology and Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Peter J Didier
- Tulane National Primate Research Center (TNPRC), Covington, Louisiana, USA
| | - Lara Doyle-Meyers
- Tulane National Primate Research Center (TNPRC), Covington, Louisiana, USA
| | - Larry Zeitlin
- Mapp Biopharmaceutical Inc., San Diego, California, USA
| | - Nicholas J Mantis
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, New York, USA
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Abstract
In this report, we used hydrogen exchange-mass spectrometry (HX-MS) to identify the epitopes recognized by 21 single-domain camelid antibodies (VHHs) directed against the ribosome-inactivating subunit (RTA) of ricin toxin, a biothreat agent of concern to military and public health authorities. The VHHs, which derive from 11 different B-cell lineages, were binned together based on competition ELISAs with IB2, a monoclonal antibody that defines a toxin-neutralizing hotspot ("cluster 3") located in close proximity to RTA's active site. HX-MS analysis revealed that the 21 VHHs recognized four distinct epitope subclusters (3.1-3.4). Sixteen of the 21 VHHs grouped within subcluster 3.1 and engage RTA α-helices C and G. Three VHHs grouped within subcluster 3.2, encompassing a-helices C and G, plus α-helix B. The single VHH in subcluster 3.3 engaged RTA α-helices B and G, while the epitope of the sole VHH defining subcluster 3.4 encompassed α-helices C and E, and β-strand h. Modeling these epitopes on the surface of RTA predicts that the 20 VHHs within subclusters 3.1-3.3 physically occlude RTA's active site cleft, while the single antibody in subcluster 3.4 associates on the active site's upper rim.
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30
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Abstract
Ricin toxin is a biothreat agent that is particularly damaging to lung tissue following inhalation. A hallmark of ricin exposure is widespread inflammation and concomitant destruction of the airway epithelium. In this study, we investigated the possible interaction between ricin and known proinflammatory cytokines associated with lung tissue. Using an established human airway epithelial cell line, we demonstrate that epithelial cell killing by ricin is significantly enhanced in the presence of the proinflammatory cytokine known as TRAIL (CD253). Moreover, epithelial cells that are simultaneously exposed to ricin and TRAIL produced large amounts of secondary proinflammatory signals, including IL-6, which in the context of the lung would be expected to exacerbate toxin-induced tissue damage. Our results suggest that therapies designed to neutralize proinflammatory cytokines such as TRAIL and IL-6 may limit the bystander damage associated with ricin exposure. Inhalation of ricin toxin is associated with the onset of acute respiratory distress syndrome (ARDS), characterized by hemorrhage, inflammatory exudates, and tissue edema, as well as the nearly complete destruction of the lung epithelium. Here we report that the Calu-3 human airway epithelial cell line is relatively impervious to the effects of ricin, with little evidence of cell death even upon exposure to microgram amounts of toxin. However, the addition of exogenous soluble tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL; CD253) dramatically sensitized Calu-3 cells to ricin-induced apoptosis. Calu-3 cell killing in response to ricin and TRAIL exposure was partially inhibited by caspase-8 and caspase-3/7 inhibitors, consistent with involvement of extrinsic apoptotic pathways in cell death. We employed nCounter Technology to define the transcriptional response of Calu-3 cells to ricin, TRAIL, and the combination of ricin plus TRAIL. An array of genes associated with inflammation and cell death were significantly upregulated upon treatment with ricin toxin and were further amplified upon addition of TRAIL. Of particular note was interleukin-6 (IL-6), whose expression in Calu-3 cells increased 300-fold upon ricin treatment and more than 750-fold upon ricin and TRAIL treatment. IL-6 secretion by Calu-3 cells was confirmed by cytometric bead array analysis. On the basis of these finding, we speculate that the severe airway epithelial cell damage observed in animal models following ricin exposure is a result of a positive-feedback loop driven by proinflammatory cytokines such as TRAIL and IL-6. IMPORTANCE Ricin toxin is a biothreat agent that is particularly damaging to lung tissue following inhalation. A hallmark of ricin exposure is widespread inflammation and concomitant destruction of the airway epithelium. In this study, we investigated the possible interaction between ricin and known proinflammatory cytokines associated with lung tissue. Using an established human airway epithelial cell line, we demonstrate that epithelial cell killing by ricin is significantly enhanced in the presence of the proinflammatory cytokine known as TRAIL (CD253). Moreover, epithelial cells that are simultaneously exposed to ricin and TRAIL produced large amounts of secondary proinflammatory signals, including IL-6, which in the context of the lung would be expected to exacerbate toxin-induced tissue damage. Our results suggest that therapies designed to neutralize proinflammatory cytokines such as TRAIL and IL-6 may limit the bystander damage associated with ricin exposure.
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31
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Westfall J, Yates JL, Van Slyke G, Ehrbar D, Measey T, Straube R, Donini O, Mantis NJ. Thermal stability and epitope integrity of a lyophilized ricin toxin subunit vaccine. Vaccine 2018; 36:5967-5976. [PMID: 30172637 PMCID: PMC6320669 DOI: 10.1016/j.vaccine.2018.08.059] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 08/18/2018] [Accepted: 08/23/2018] [Indexed: 12/18/2022]
Abstract
Biodefense vaccine are destined to be stockpiled for periods of time and deployed in the event of a public health emergency. In this report, we compared the potency of liquid and lyophilized (thermostabilized) formulations of a candidate ricin toxin subunit vaccine, RiVax, adsorbed to aluminum salts adjuvant, over a 12-month period. The liquid and lyophilized formulations were stored at stressed (40 °C) and unstressed (4 °C) conditions and evaluated at 3, 6 and 12-month time points for potency in a mouse model of lethal dose ricin challenge. At the same time points, the vaccine formulations were interrogated in vitro by competition ELISA for conformational integrity using a panel of three monoclonal antibodies (mAbs), PB10, WECB2, and SyH7, directed against known immunodominant toxin-neutralizing epitopes on RiVax. We found that the liquid vaccine under stress conditions declined precipitously within the first three months, as evidenced by a reduction in in vivo potency and concomitant loss of mAb recognition in vitro. In contrast, the lyophilized RiVax vaccine retained in vivo potency and conformational integrity for up to one year at 4 °C and 40 °C. We discuss the utility of monitoring the integrity of one or more toxin-neutralizing epitopes on RiVax as a possible supplement to animal studies to assess vaccine potency.
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Affiliation(s)
- Jennifer Westfall
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, NY 12208, United States
| | - Jennifer L Yates
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, NY 12208, United States
| | - Greta Van Slyke
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, NY 12208, United States
| | - Dylan Ehrbar
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, NY 12208, United States
| | | | | | | | - Nicholas J Mantis
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, NY 12208, United States.
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Van Slyke G, Angalakurthi SK, Toth RT, Vance DJ, Rong Y, Ehrbar D, Shi Y, Middaugh CR, Volkin DB, Weis DD, Mantis NJ. Fine-Specificity Epitope Analysis Identifies Contact Points on Ricin Toxin Recognized by Protective Monoclonal Antibodies. Immunohorizons 2018; 2:262-273. [PMID: 30766971 DOI: 10.4049/immunohorizons.1800042] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Ricin is a fast-acting protein toxin classified by the Centers for Disease Control and Prevention as a biothreat agent. In this report, we describe five new mouse mAbs directed against an immunodominant region, so-called epitope cluster II, on the surface of ricin's ribosome-inactivating enzymatic subunit A (RTA). The five mAbs were tested alongside four previously described cluster II-specific mAbs for their capacity to passively protect mice against 10× LD50 ricin challenge by injection. Only three of the mAbs (LE4, PH12, and TB12) afforded protection over the 7-d study period. Neither binding affinity nor in vitro toxin-neutralizing activity could fully account for LE4, PH12, and TB12's potent in vivo activity relative to the other six mAbs. However, epitope mapping studies by hydrogen exchange-mass spectrometry revealed that LE4, PH12, and TB12 shared common contact points on RTA corresponding to RTA α-helices D and E and β-strands d and e located on the back side of RTA relative to the active site. The other six mAbs recognized overlapping epitopes on RTA, but none shared the same hydrogen exchange-mass spectrometry profile as LE4, PH12, and TB12. A high-density competition ELISA with a panel of ricin-specific, single-domain camelid Abs indicated that even though LE4, PH12, and TB12 make contact with similar secondary motifs, they likely approach RTA from different angles. These results underscore how subtle differences in epitope specificity can significantly impact Ab functionality in vivo. ImmunoHorizons, 2018, 2: 262-273.
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Affiliation(s)
- Greta Van Slyke
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY 12208
| | - Siva Krishna Angalakurthi
- Macromolecule and Vaccine Stabilization Center, Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS 66045
| | - Ronald T Toth
- Macromolecule and Vaccine Stabilization Center, Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS 66045
| | - David J Vance
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY 12208
| | - Yinghui Rong
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY 12208
| | - Dylan Ehrbar
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY 12208
| | - Yuqi Shi
- Department of Chemistry, University of Kansas, Lawrence, KS 66045
| | - C Russell Middaugh
- Macromolecule and Vaccine Stabilization Center, Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS 66045
| | - David B Volkin
- Macromolecule and Vaccine Stabilization Center, Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS 66045
| | - David D Weis
- Department of Chemistry, University of Kansas, Lawrence, KS 66045
| | - Nicholas J Mantis
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY 12208
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33
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Rudolph MJ, Vance DJ, Kelow S, Angalakurthi SK, Nguyen S, Davis SA, Rong Y, Middaugh CR, Weis DD, Dunbrack R, Karanicolas J, Mantis NJ. Contribution of an unusual CDR2 element of a single domain antibody in ricin toxin binding affinity and neutralizing activity. Protein Eng Des Sel 2018; 31:277-287. [PMID: 30265352 PMCID: PMC6277176 DOI: 10.1093/protein/gzy022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 08/03/2018] [Indexed: 11/13/2022] Open
Abstract
Ricin toxin's enzymatic subunit (RTA) has been subjected to intensive B cell epitope mapping studies using a combination of competition ELISAs, hydrogen exchange-mass spectrometry and X-ray crystallography. Those studies identified four spatially distinct clusters (I-IV) of toxin-neutralizing epitopes on the surface of RTA. Here we describe A9, a new single domain camelid antibody (VHH) that was proposed to recognize a novel epitope on RTA that straddles clusters I and III. The X-ray crystal structure of A9 bound to RTA (2.6 Å resolution) revealed extensive antibody contact with RTA's β-strand h (732 Å2 buried surface area; BSA), along with limited engagement with α-helix D (90 Å2) and α-helix C (138 Å2). Collectively, these contacts explain the overlap between epitope clusters I and III, as identified by competition ELISA. However, considerable binding affinity, and, consequently, toxin-neutralizing activity of A9 is mediated by an unusual CDR2 containing five consecutive Gly residues that interact with α-helix B (82 Å2), a known neutralizing hotspot on RTA. Removal of a single Gly residue from the penta-glycine stretch in CDR2 reduced A9's binding affinity by 10-fold and eliminated toxin-neutralizing activity. Computational modeling indicates that removal of a Gly from CDR2 does not perturb contact with RTA per se, but results in the loss of an intramolecular hydrogen bond network involved in stabilizing CDR2 in the unbound state. These results reveal a novel configuration of a CDR2 element involved in neutralizing ricin toxin.
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Affiliation(s)
| | - David J Vance
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY, USA
| | - Simon Kelow
- Department of Biochemistry and Molecular Biophysics Graduate Group, University of Pennsylvania, Philadelphia, PA, USA
| | - Siva Krishna Angalakurthi
- Department of Pharmaceutical Chemistry and Macromolecule and Vaccine Stabilization Center, University of Kansas, Lawrence, KS, USA
| | - Sophie Nguyen
- New York Structural Biology Center, New York, NY, USA
| | - Simon A Davis
- New York Structural Biology Center, New York, NY, USA
| | - Yinghui Rong
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY, USA
| | - C Russell Middaugh
- Department of Pharmaceutical Chemistry and Macromolecule and Vaccine Stabilization Center, University of Kansas, Lawrence, KS, USA
| | - David D Weis
- Department of Chemistry and Ralph Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, KS, USA
| | - Roland Dunbrack
- Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - John Karanicolas
- Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Nicholas J Mantis
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY, USA
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High-Definition Mapping of Four Spatially Distinct Neutralizing Epitope Clusters on RiVax, a Candidate Ricin Toxin Subunit Vaccine. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2017; 24:CVI.00237-17. [PMID: 29046307 DOI: 10.1128/cvi.00237-17] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 10/12/2017] [Indexed: 12/20/2022]
Abstract
RiVax is a promising recombinant ricin toxin A subunit (RTA) vaccine antigen that has been shown to be safe and immunogenic in humans and effective at protecting rhesus macaques against lethal-dose aerosolized toxin exposure. We previously used a panel of RTA-specific monoclonal antibodies (MAbs) to demonstrate, by competition enzyme-linked immunosorbent assay (ELISA), that RiVax elicits similar serum antibody profiles in humans and macaques. However, the MAb binding sites on RiVax have yet to be defined. In this study, we employed hydrogen exchange-mass spectrometry (HX-MS) to localize the epitopes on RiVax recognized by nine toxin-neutralizing MAbs and one nonneutralizing MAb. Based on strong protection from hydrogen exchange, the nine MAbs grouped into four spatially distinct epitope clusters (namely, clusters I to IV). Cluster I MAbs protected RiVax's α-helix B (residues 94 to 107), a protruding immunodominant secondary structure element known to be a target of potent toxin-neutralizing antibodies. Cluster II consisted of two subclusters located on the "back side" (relative to the active site pocket) of RiVax. One subcluster involved α-helix A (residues 14 to 24) and α-helices F-G (residues 184 to 207); the other encompassed β-strand d (residues 62 to 69) and parts of α-helices D-E (154 to 164) and the intervening loop. Cluster III involved α-helices C and G on the front side of RiVax, while cluster IV formed a sash from the front to back of RiVax, spanning strands b, c, and d (residues 35 to 59). Having a high-resolution B cell epitope map of RiVax will enable the development and optimization of competitive serum profiling assays to examine vaccine-induced antibody responses across species.
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Vance DJ, Tremblay JM, Rong Y, Angalakurthi SK, Volkin DB, Middaugh CR, Weis DD, Shoemaker CB, Mantis NJ. High-Resolution Epitope Positioning of a Large Collection of Neutralizing and Nonneutralizing Single-Domain Antibodies on the Enzymatic and Binding Subunits of Ricin Toxin. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2017; 24:e00236-17. [PMID: 29021300 PMCID: PMC5717184 DOI: 10.1128/cvi.00236-17] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 10/02/2017] [Indexed: 01/05/2023]
Abstract
We previously produced a heavy-chain-only antibody (Ab) VH domain (VHH)-displayed phage library from two alpacas that had been immunized with ricin toxoid and nontoxic mixtures of the enzymatic ricin toxin A subunit (RTA) and binding ricin toxin B subunit (RTB) (D. J. Vance, J. M. Tremblay, N. J. Mantis, and C. B. Shoemaker, J Biol Chem 288:36538-36547, 2013, https://doi.org/10.1074/jbc.M113.519207). Initial and subsequent screens of that library by direct enzyme-linked immunosorbent assay (ELISA) yielded more than two dozen unique RTA- and RTB-specific VHHs, including 10 whose structures were subsequently solved in complex with RTA. To generate a more complete antigenic map of ricin toxin and to define the epitopes associated with toxin-neutralizing activity, we subjected the VHH-displayed phage library to additional "pannings" on both receptor-bound ricin and antibody-captured ricin. We now report the full-length DNA sequences, binding affinities, and neutralizing activities of 68 unique VHHs: 31 against RTA, 33 against RTB, and 4 against ricin holotoxin. Epitope positioning was achieved through cross-competition ELISAs performed with a panel of monoclonal antibodies (MAbs) and verified, in some instances, with hydrogen-deuterium exchange mass spectrometry. The 68 VHHs grouped into more than 20 different competition bins. The RTA-specific VHHs with strong toxin-neutralizing activities were confined to bins that overlapped two previously identified neutralizing hot spots, termed clusters I and II. The four RTB-specific VHHs with potent toxin-neutralizing activity grouped within three adjacent bins situated at the RTA-RTB interface near cluster II. These results provide important insights into epitope interrelationships on the surface of ricin and delineate regions of vulnerability that can be exploited for the purpose of vaccine and therapeutic development.
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Affiliation(s)
- David J Vance
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Jacqueline M Tremblay
- Department of Infectious Disease and Global Health, Tufts Cummings School of Veterinary Medicine, North Grafton, Massachusetts, USA
| | - Yinghui Rong
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Siva Krishna Angalakurthi
- Department of Pharmaceutical Chemistry, Macromolecule and Vaccine Stabilization Center, University of Kansas, Lawrence, Kansas, USA
| | - David B Volkin
- Department of Pharmaceutical Chemistry, Macromolecule and Vaccine Stabilization Center, University of Kansas, Lawrence, Kansas, USA
| | - C Russell Middaugh
- Department of Pharmaceutical Chemistry, Macromolecule and Vaccine Stabilization Center, University of Kansas, Lawrence, Kansas, USA
| | - David D Weis
- Department of Chemistry, University of Kansas, Lawrence, Kansas, USA
| | - Charles B Shoemaker
- Department of Infectious Disease and Global Health, Tufts Cummings School of Veterinary Medicine, North Grafton, Massachusetts, USA
| | - Nicholas J Mantis
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, New York, USA
- Department of Biomedical Sciences, University at Albany, SUNY, Albany, New York, USA
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Rong Y, Van Slyke G, Vance DJ, Westfall J, Ehrbar D, Mantis NJ. Spatial location of neutralizing and non-neutralizing B cell epitopes on domain 1 of ricin toxin's binding subunit. PLoS One 2017; 12:e0180999. [PMID: 28700745 PMCID: PMC5507285 DOI: 10.1371/journal.pone.0180999] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 06/23/2017] [Indexed: 12/14/2022] Open
Abstract
Ricin toxin’s binding subunit (RTB) is a galactose-/N-acetylgalactosamine (Gal/GalNac)-specific lectin that mediates uptake and intracellular trafficking of ricin within mammalian cells. Structurally, RTB consists of two globular domains, each divided into three homologous sub-domains (α, β, γ). In this report, we describe five new murine IgG monoclonal antibodies (mAbs) against RTB: MH3, 8A1, 8B3, LF1, and LC5. The mAbs have similar binding affinities (KD) for ricin holotoxin, but displayed a wide range of in vitro toxin-neutralizing activities. Competition ELISAs indicate that the two most potent toxin-neutralizing mAbs (MH3, 8A1), as well as one of the moderate toxin-neutralizing mAbs (LF1), recognize distinct epitopes near the low affinity Gal recognition domain in RTB subdomain 1α. Evaluated in a mouse model of systemic ricin challenge, all five mAbs afforded some benefit against intoxication, but only MH3 was protective. However, neither MH3 nor 24B11, another well-characterized mAb against RTB subdomain 1α, could passively protect mice against a mucosal (intranasal) ricin challenge. This is in contrast to SylH3, a previously characterized mAb directed against an epitope near RTB’s high affinity Gal/GalNac recognition element in sub-domain 2γ, which protected animals against systemic and mucosal ricin exposure. SylH3 was significantly more effective than MH3 and 24B11 at blocking ricin attachment to host cell receptors, suggesting that mucosal immunity to ricin is best imparted by antibodies that target RTB’s high affinity Gal/GalNac recognition element in subdomain 2γ, not the low affinity Gal recognition domain in subdomain 1α.
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Affiliation(s)
- Yinghui Rong
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, New York, United States of America
| | - Greta Van Slyke
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, New York, United States of America
| | - David J. Vance
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, New York, United States of America
| | - Jennifer Westfall
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, New York, United States of America
| | - Dylan Ehrbar
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, New York, United States of America
| | - Nicholas J. Mantis
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, New York, United States of America
- Department of Biomedical Sciences, University at Albany School of Public Health, Albany, New York, United States of America
- * E-mail:
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Katalan S, Falach R, Rosner A, Goldvaser M, Brosh-Nissimov T, Dvir A, Mizrachi A, Goren O, Cohen B, Gal Y, Sapoznikov A, Ehrlich S, Sabo T, Kronman C. A novel swine model of ricin-induced acute respiratory distress syndrome. Dis Model Mech 2017; 10:173-183. [PMID: 28067630 PMCID: PMC5312011 DOI: 10.1242/dmm.027847] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 12/13/2016] [Indexed: 12/22/2022] Open
Abstract
Pulmonary exposure to the plant toxin ricin leads to respiratory insufficiency and death. To date, in-depth study of acute respiratory distress syndrome (ARDS) following pulmonary exposure to toxins is hampered by the lack of an appropriate animal model. To this end, we established the pig as a large animal model for the comprehensive study of the multifarious clinical manifestations of pulmonary ricinosis. Here, we report for the first time, the monitoring of barometric whole body plethysmography for pulmonary function tests in non-anesthetized ricin-treated pigs. Up to 30 h post-exposure, as a result of progressing hypoxemia and to prevent carbon dioxide retention, animals exhibited a compensatory response of elevation in minute volume, attributed mainly to a large elevation in respiratory rate with minimal response in tidal volume. This response was followed by decompensation, manifested by a decrease in minute volume and severe hypoxemia, refractory to oxygen treatment. Radiological evaluation revealed evidence of early diffuse bilateral pulmonary infiltrates while hemodynamic parameters remained unchanged, excluding cardiac failure as an explanation for respiratory insufficiency. Ricin-intoxicated pigs suffered from increased lung permeability accompanied by cytokine storming. Histological studies revealed lung tissue insults that accumulated over time and led to diffuse alveolar damage. Charting the decline in PaO2/FiO2 ratio in a mechanically ventilated pig confirmed that ricin-induced respiratory damage complies with the accepted diagnostic criteria for ARDS. The establishment of this animal model of pulmonary ricinosis should help in the pursuit of efficient medical countermeasures specifically tailored to deal with the respiratory deficiencies stemming from ricin-induced ARDS.
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Affiliation(s)
- Shahaf Katalan
- Department of Pharmacology, Israel Institute for Biological Research, 7410001 Ness-Ziona, Israel
| | - Reut Falach
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, 7410001 Ness-Ziona, Israel
| | - Amir Rosner
- Veterinary Center for Preclinical Research, Israel Institute for Biological Research, 7410001 Ness-Ziona, Israel
| | - Michael Goldvaser
- Department of Organic Chemistry, Israel Institute for Biological Research, 7410001 Ness-Ziona, Israel
| | - Tal Brosh-Nissimov
- Infectious Disease Unit, Sheba Medical Center, 5262160 Tel-Hashomer, Israel
| | - Ayana Dvir
- General Intensive Care Unit, Asaf Harofeh Medical Center, 70300 Zerifin, Israel
| | - Avi Mizrachi
- General Intensive Care Unit, Kaplan Medical Center, 7661041 Rehovot, Israel
| | - Orr Goren
- Anesthesia, Pain and Intensive Care Division, Tel-Aviv Medical Center, Tel-Aviv University, 6093000 Tel-Aviv, Israel
| | - Barak Cohen
- Anesthesia, Pain and Intensive Care Division, Tel-Aviv Medical Center, Tel-Aviv University, 6093000 Tel-Aviv, Israel
| | - Yoav Gal
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, 7410001 Ness-Ziona, Israel
| | - Anita Sapoznikov
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, 7410001 Ness-Ziona, Israel
| | - Sharon Ehrlich
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, 7410001 Ness-Ziona, Israel
| | - Tamar Sabo
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, 7410001 Ness-Ziona, Israel
| | - Chanoch Kronman
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, 7410001 Ness-Ziona, Israel
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Vance DJ, Mantis NJ. Progress and challenges associated with the development of ricin toxin subunit vaccines. Expert Rev Vaccines 2016; 15:1213-22. [PMID: 26998662 PMCID: PMC5193006 DOI: 10.1586/14760584.2016.1168701] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The past several years have seen major advances in the development of a safe and efficacious ricin toxin vaccine, including the completion of two Phase I clinical trials with two different recombinant A subunit (RTA)-based vaccines: RiVax™ and RVEc™ adsorbed to aluminum salt adjuvant, as well as a non-human primate study demonstrating that parenteral immunization with RiVax elicits a serum antibody response that was sufficient to protect against a lethal dose aerosolized ricin exposure. One of the major obstacles moving forward is assessing vaccine efficacy in humans, when neither ricin-specific serum IgG endpoint titers nor toxin-neutralizing antibody levels are accepted as definitive predictors of protective immunity. In this review we summarize ongoing efforts to leverage recent advances in our understanding of RTA-antibody interactions at the structural level to develop novel assays to predict vaccine efficacy in humans.
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Affiliation(s)
- David J. Vance
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Nicholas J. Mantis
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, New York, USA
- Department of Biomedical Sciences, University at Albany, Albany, New York, USA
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40
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Respaud R, Marchand D, Pelat T, Tchou-Wong KM, Roy CJ, Parent C, Cabrera M, Guillemain J, Mac Loughlin R, Levacher E, Fontayne A, Douziech-Eyrolles L, Junqua-Moullet A, Guilleminault L, Thullier P, Guillot-Combe E, Vecellio L, Heuzé-Vourc'h N. Development of a drug delivery system for efficient alveolar delivery of a neutralizing monoclonal antibody to treat pulmonary intoxication to ricin. J Control Release 2016; 234:21-32. [PMID: 27173943 DOI: 10.1016/j.jconrel.2016.05.018] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 05/06/2016] [Accepted: 05/07/2016] [Indexed: 12/13/2022]
Abstract
The high toxicity of ricin and its ease of production have made it a major bioterrorism threat worldwide. There is however no efficient and approved treatment for poisoning by ricin inhalation, although there have been major improvements in diagnosis and therapeutic strategies. We describe the development of an anti-ricin neutralizing monoclonal antibody (IgG 43RCA-G1) and a device for its rapid and effective delivery into the lungs for an application in humans. The antibody is a full-length IgG and binds to the ricin A-chain subunit with a high affinity (KD=53pM). Local administration of the antibody into the respiratory tract of mice 6h after pulmonary ricin intoxication allowed the rescue of 100% of intoxicated animals. Specific operational constraints and aerosolization stresses, resulting in protein aggregation and loss of activity, were overcome by formulating the drug as a dry-powder that is solubilized extemporaneously in a stabilizing solution to be nebulized. Inhalation studies in mice showed that this formulation of IgG 43RCA-G1 did not induce pulmonary inflammation. A mesh nebulizer was customized to improve IgG 43RCA-G1 deposition into the alveolar region of human lungs, where ricin aerosol particles mostly accumulate. The drug delivery system also comprises a semi-automatic reconstitution system to facilitate its use and a specific holding chamber to maximize aerosol delivery deep into the lung. In vivo studies in monkeys showed that drug delivery with the device resulted in a high concentration of IgG 43RCA-G1 in the airways for at least 6h after local deposition, which is consistent with the therapeutic window and limited passage into the bloodstream.
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Affiliation(s)
- Renaud Respaud
- Université François-Rabelais de Tours, UMR 1100, CHRU de Tours, Service de Pharmacie, F-37032 Tours, France; INSERM, Centre d'Etude des Pathologies Respiratoires, UMR 1100, F-37032 Tours, France
| | - Denis Marchand
- Université François Rabelais, UMR 1100, F-37032 Tours, France; INSERM, Centre d'Etude des Pathologies Respiratoires, UMR 1100, F-37032 Tours, France; Aerodrug, F-37032 Tours, France
| | - Thibaut Pelat
- Institut de Recherche Biomédicale des Armées (IRBA-CRSSA); Département de Microbiologie; Unité de biotechnologie des anticorps et des toxines; Brétigny sur Orge, France; BIOTEM, Parc d'activité Bièvre Dauphine, Apprieu, France
| | - Kam-Meng Tchou-Wong
- NYU School of Medicine, Department of Environmental Medicine, 57 Old Forge Road, Tuxedo, New York 10987, USA
| | - Chad J Roy
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, Louisiana, USA; Division of Microbiology, Tulane National Primate Research Center, Covington, Louisiana, USA
| | - Christelle Parent
- Université François Rabelais, UMR 1100, F-37032 Tours, France; INSERM, Centre d'Etude des Pathologies Respiratoires, UMR 1100, F-37032 Tours, France
| | - Maria Cabrera
- Université François Rabelais, UMR 1100, F-37032 Tours, France; INSERM, Centre d'Etude des Pathologies Respiratoires, UMR 1100, F-37032 Tours, France
| | - Joël Guillemain
- SESAME, Expertise en toxicologie, Chambray-les-tours, France
| | | | | | | | | | | | - Laurent Guilleminault
- Université François Rabelais, UMR 1100, F-37032 Tours, France; INSERM, Centre d'Etude des Pathologies Respiratoires, UMR 1100, F-37032 Tours, France
| | - Philippe Thullier
- Institut de Recherche Biomédicale des Armées (IRBA-CRSSA); Département de Microbiologie; Unité de biotechnologie des anticorps et des toxines; Brétigny sur Orge, France
| | - Emmanuelle Guillot-Combe
- DGA, Direction de la Stratégie (DS), Mission pour la recherche et l'Innovation scientifique (MRIS), France
| | - Laurent Vecellio
- Université François Rabelais, UMR 1100, F-37032 Tours, France; INSERM, Centre d'Etude des Pathologies Respiratoires, UMR 1100, F-37032 Tours, France; Aerodrug, F-37032 Tours, France
| | - Nathalie Heuzé-Vourc'h
- Université François Rabelais, UMR 1100, F-37032 Tours, France; INSERM, Centre d'Etude des Pathologies Respiratoires, UMR 1100, F-37032 Tours, France.
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Brey RN, Mantis NJ, Pincus SH, Vitetta ES, Smith LA, Roy CJ. Recent advances in the development of vaccines against ricin. Hum Vaccin Immunother 2016; 12:1196-201. [PMID: 26810367 DOI: 10.1080/21645515.2015.1124202] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Several promising subunit vaccines against ricin toxin (RT) have been developed during the last decade and are now being tested for safety and immunogenicity in humans and for efficacy in nonhuman primates. The incentive to develop a preventive vaccine as a countermeasure against RT use as a bioweapon is based on the high toxicity of RT after aerosol exposure, its environmental stability, abundance, and ease of purification. RT is the second most lethal biological toxin and is considered a "universal toxin" because it can kill all eukaryotic cells through binding to ubiquitous cell surface galactosyl residues. RT has two subunits conjoined by a single disulfide linkage: RTB, which binds galactosyl residues and RTA which enzymatically inactivates ribosomes intracellularly by cleavage ribosomal RNA. Attenuation of toxicity by elimination of the active site or introduction of other structural mutations of RTA has generated two similar clinical subunit vaccine candidates which induce antibodies in both humans and nonhuman primates. In rhesus macaques, inhaled RT causes rapid lung necrosis and fibrosis followed by death. After parenteral vaccination with RTA vaccine, macaques can be protected against aerosol RT exposure, suggesting that circulating antibodies can protect lung mucosa. Vaccination induces RT-neutralizing antibodies, the most likely correlate of protection. Macaques responded to conformational determinants in an RTA vaccine formulation, indicating preservation of RTA structure during initial manufacture. Comparative mapping studies have also demonstrated that macaques and humans recognize the same epitopes, significant in the study of macaques as a model during development of vaccines which cannot be tested for efficacy in humans.
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Affiliation(s)
| | - Nicholas J Mantis
- b Division of Infectious Disease , Wadsworth Center, New York State Department of Health, Albany, NY, USA Department of Biomedical Sciences, University of Albany School of Public Health , Albany , NY , USA
| | - Seth H Pincus
- c Departments of Pediatrics and Microbiology , Louisiana State University School of Medicine, Children's Hospital , New Orleans , LA , USA
| | - Ellen S Vitetta
- d Departments of Immunology and Microbiology , The University of Texas Southwestern Medical Center , Dallas , TX , USA
| | - Leonard A Smith
- e Medical Countermeasures Technology, US Army Medical Research Institute of Infectious Diseases , Fort Detrick , MD , USA
| | - Chad J Roy
- f Division of Microbiology, Tulane National Primate Research Center , Covington , LA , USA.,g Department of Microbiology and Immunology , Tulane School of Medicine , New Orleans , LA , USA
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