1
|
Czajka TF, Vance DJ, Song R, Mantis NJ. A Biparatopic Intrabody Renders Vero Cells Impervious to Ricin Intoxication. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.02.601761. [PMID: 39005371 PMCID: PMC11244990 DOI: 10.1101/2024.07.02.601761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Expression of camelid-derived, single-domain antibodies (VHHs) within the cytoplasm of mammalian cells as "intrabodies" has opened-up novel avenues for medical countermeasures against fast-acting biothreat agents. In this report, we describe a heterodimeric intrabody that renders Vero cells virtually impervious to ricin toxin (RT), a potent Category B ribosome-inactivating protein (RIP). The intrabody consists of two structurally defined VHHs that target distinct epitopes on RT's enzymatic subunit (RTA): V9E1 targets RTA's P-stalk recruitment site, and V2A11 targets RTA's active site. Resistance to RT conferred by the biparatopic VHH construct far exceeded that of either of the VHHs alone and effectively inhibited all measurable RT-induced cytotoxicty in vitro. We propose that targeted delivery of bispecific intrabodies to lung tissues may represent a novel means to shield the airways from the effects of inhalational RT exposure.
Collapse
Affiliation(s)
- Timothy F. Czajka
- Department of Biomedical Sciences, University at Albany, Albany, NY 12201 United States
| | - David J. Vance
- Department of Biomedical Sciences, University at Albany, Albany, NY 12201 United States
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY, 12208
| | - Renji Song
- Division of Research, Wadsworth Center, New York State Department of Health, Albany, NY, 12208
| | - Nicholas J. Mantis
- Department of Biomedical Sciences, University at Albany, Albany, NY 12201 United States
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY, 12208
| |
Collapse
|
2
|
Tolman LE, Mantis NJ. Inflammatory Profiles Induced by Intranasal Immunization with Ricin Toxin-immune Complexes. Immunohorizons 2024; 8:457-463. [PMID: 38922287 PMCID: PMC11220739 DOI: 10.4049/immunohorizons.2400007] [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] [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.
Collapse
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
| |
Collapse
|
3
|
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.
Collapse
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.
| |
Collapse
|
4
|
Rudolph MJ, Chen Y, Vorauer C, Vance DJ, Piazza CL, Willsey GG, McCarthy K, Muriuki B, Cavacini LA, Guttman M, Mantis NJ. Structure of a human monoclonal antibody in complex with Outer surface protein C (OspC) of the Lyme disease spirochete, Borreliella burgdorferi. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.29.591597. [PMID: 38746285 PMCID: PMC11092446 DOI: 10.1101/2024.04.29.591597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Lyme disease is a tick-borne, multisystem infection caused by the spirochete, Borreliella burgdorferi . Although antibodies have been implicated in the resolution of Lyme disease, the specific B cell epitopes targeted during human infections remain largely unknown. In this study, we characterized and defined the structural epitope of a patient-derived bactericidal monoclonal IgG ("B11") against Outer surface protein C (OspC), a homodimeric lipoprotein necessary for B. burgdorferi tick-mediated transmission and early-stage colonization of vertebrate hosts. High-resolution epitope mapping was accomplished through hydrogen deuterium exchange-mass spectrometry (HDX-MS) and X-ray crystallography. Structural analysis of B11 Fab-OspC A complexes revealed the B11 Fabs associated in a 1:1 stoichiometry with the lateral faces of OspC A homodimers such that the antibodies are essentially positioned perpendicular to the spirochete's outer surface. B11's primary contacts reside within the membrane proximal regions of α-helices 1 and 6 and adjacent loops 5 and 6 in one OspC A monomer. In addition, B11 spans the OspC A dimer interface, engaging opposing α-helix 1', α-helix 2', and loop 2-3' in the second OspC A monomer. The B11-OspC A structure is reminiscent of the recently solved mouse transmission blocking monoclonal IgG B5 in complex with OspC A , indicating a mode of engagement with OspC that is conserved across species. In conclusion, we provide the first detailed insight into the interaction between a functional human antibody and an immunodominant Lyme disease antigen long considered an important vaccine target.
Collapse
|
5
|
Gal Y, Sapoznikov A, Lazar S, Shoseyov D, Aftalion M, Gutman H, Evgy Y, Gez R, Nevo R, Falach R. Long-Term Pulmonary Damage in Surviving Antitoxin-Treated Mice following a Lethal Ricin Intoxication. Toxins (Basel) 2024; 16:103. [PMID: 38393180 PMCID: PMC10892648 DOI: 10.3390/toxins16020103] [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: 12/13/2023] [Revised: 01/30/2024] [Accepted: 02/08/2024] [Indexed: 02/25/2024] Open
Abstract
Ricin, a highly potent plant-derived toxin, is considered a potential bioterrorism weapon due to its pronounced toxicity, high availability, and ease of preparation. Acute damage following pulmonary ricinosis is characterized by local cytokine storm, massive neutrophil infiltration, and edema formation, resulting in respiratory insufficiency and death. A designated equine polyclonal antibody-based (antitoxin) treatment was developed in our laboratory and proved efficacious in alleviating lung injury and increasing survival rates. Although short-term pathogenesis was thoroughly characterized in antitoxin-treated mice, the long-term damage in surviving mice was never determined. In this study, long-term consequences of ricin intoxication were evaluated 30 days post-exposure in mice that survived antitoxin treatment. Significant pulmonary sequelae were demonstrated in surviving antitoxin-treated mice, as reflected by prominent histopathological changes, moderate fibrosis, increased lung hyperpermeability, and decreased lung compliance. The presented data highlight, for the first time to our knowledge, the possibility of long-term damage development in mice that survived lethal-dose pulmonary exposure to ricin due to antitoxin treatment.
Collapse
Affiliation(s)
- Yoav Gal
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 74100, Israel; (A.S.); (M.A.); (Y.E.)
| | - Anita Sapoznikov
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 74100, Israel; (A.S.); (M.A.); (Y.E.)
| | - Shlomi Lazar
- Department of Pharmacology, Israel Institute for Biological Research, Ness-Ziona 74100, Israel; (S.L.); (H.G.); (R.G.)
| | - David Shoseyov
- Pediatric Pulmonology Unit, Hadassah Medical Center, Jerusalem P.O. Box 12000, Israel;
| | - Moshe Aftalion
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 74100, Israel; (A.S.); (M.A.); (Y.E.)
| | - Hila Gutman
- Department of Pharmacology, Israel Institute for Biological Research, Ness-Ziona 74100, Israel; (S.L.); (H.G.); (R.G.)
| | - Yentl Evgy
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 74100, Israel; (A.S.); (M.A.); (Y.E.)
| | - Rellie Gez
- Department of Pharmacology, Israel Institute for Biological Research, Ness-Ziona 74100, Israel; (S.L.); (H.G.); (R.G.)
| | - Reinat Nevo
- Department of Biomolecular Sciences, Weizmann Institute of Science, Herzel 234, Rehovot P.O. Box 26, Israel;
| | - Reut Falach
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 74100, Israel; (A.S.); (M.A.); (Y.E.)
| |
Collapse
|
6
|
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.
Collapse
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
| |
Collapse
|
7
|
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: 3] [Impact Index Per Article: 1.5] [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.
Collapse
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.
| |
Collapse
|
8
|
Zong F, Li S, Wang Y, Xiao N, Deng M, Zhang Z, Su D, Gao B, Zhou D, Hu L, Yang H. Csf2ra deletion attenuates acute lung injuries induced by intratracheal inoculation of aerosolized ricin in mice. Front Immunol 2022; 13:900755. [PMID: 36203597 PMCID: PMC9531258 DOI: 10.3389/fimmu.2022.900755] [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: 03/21/2022] [Accepted: 09/06/2022] [Indexed: 11/13/2022] Open
Abstract
Specific therapeutics are not available for acute lung injury (ALI) induced by ricin toxin (RT). Inhibiting the host immune response in the course of pulmonary ricinosis is hypothesized to be of benefit and can be achieved by impairing granulocyte-macrophage colony-stimulating factor (GM-CSF) signaling, thereby reducing the pro-inflammatory response to exogenous foreign body invasion. However, it is unknown whether mice with impaired GM-CSF signaling can survive after RT inhalation. To test this, colony stimulating factor 2 receptor alpha (Csf2ra) knockout (KO) mice that lack GM-CSF signaling and wild-type (WT) mice models of intratracheal exposure to a lethal dose (2× LD50) of RT were established. Survival was greater in Csf2ra KO mice 21 days after RT inhalation compared with WT mice. Highly co-expressed genes that probably attenuated the pro-inflammatory response in the lung of Csf2ra KO mice were identified. Bioinformatics analysis revealed that transcriptome changes involved mostly inflammation-related genes after RT exposure in both Csf2ra KO mice and WT mice. However, the activity levels of pro-inflammatory pathways, such as the TNF signaling pathway and NF-κB signaling pathway, in Csf2ra KO mice were significantly decreased and the degree of neutrophil chemotaxis and recruitment inhibited after RT-exposure relative to WT mice. RT-qPCR and flow cytometry validated results of RNA-Seq analysis. This work provides potential avenues for host-directed therapeutic applications that can mitigate the severity of ALI-induced by RT.
Collapse
Affiliation(s)
- Fuliang Zong
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Sha Li
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Yifeng Wang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Nan Xiao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Mengyun Deng
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Zhipeng Zhang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Duo Su
- Department of Gynecology and Obstetrics, Bethune International Peace Hospital, Shijiazhuang, China
| | - Bo Gao
- Institute of Military Cognition and Brain Sciences, Beijing, China
| | - Dongsheng Zhou
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Lingfei Hu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Huiying Yang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| |
Collapse
|
9
|
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.
Collapse
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
| |
Collapse
|
10
|
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.
Collapse
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.
| |
Collapse
|
11
|
Blair RV, Vaccari M, Doyle-Meyers LA, Roy CJ, Russell-Lodrigue K, Fahlberg M, Monjure CJ, Beddingfield B, Plante KS, Plante JA, Weaver SC, Qin X, Midkiff CC, Lehmicke G, Golden N, Threeton B, Penney T, Allers C, Barnes MB, Pattison M, Datta PK, Maness NJ, Birnbaum A, Fischer T, Bohm RP, Rappaport J. Acute Respiratory Distress in Aged, SARS-CoV-2-Infected African Green Monkeys but Not Rhesus Macaques. THE AMERICAN JOURNAL OF PATHOLOGY 2021. [PMID: 33171111 DOI: 10.1101/2020.06.18.157933] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces a wide range of disease severity, ranging from asymptomatic infection to a life-threating illness, particularly in the elderly population and individuals with comorbid conditions. Among individuals with serious coronavirus 2019 (COVID-19) disease, acute respiratory distress syndrome (ARDS) is a common and often fatal presentation. Animal models of SARS-CoV-2 infection that manifest severe disease are needed to investigate the pathogenesis of COVID-19-induced ARDS and evaluate therapeutic strategies. We report two cases of ARDS in two aged African green monkeys (AGMs) infected with SARS-CoV-2 that had pathological lesions and disease similar to severe COVID-19 in humans. We also report a comparatively mild COVID-19 phenotype characterized by minor clinical, radiographic, and histopathologic changes in the two surviving, aged AGMs and four rhesus macaques (RMs) infected with SARS-CoV-2. Notable increases in circulating cytokines were observed in three of four infected, aged AGMs but not in infected RMs. All the AGMs had increased levels of plasma IL-6 compared with baseline, a predictive marker and presumptive therapeutic target in humans infected with SARS-CoV-2. Together, our results indicate that both RMs and AGMs are capable of modeling SARS-CoV-2 infection and suggest that aged AGMs may be useful for modeling severe disease manifestations, including ARDS.
Collapse
Affiliation(s)
- Robert V Blair
- Tulane National Primate Research Center, Covington, Louisiana; Department of Pathology and Laboratory Animal Medicine, Tulane University School of Medicine, New Orleans, Louisiana.
| | - Monica Vaccari
- Tulane National Primate Research Center, Covington, Louisiana; Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, Louisiana
| | - Lara A Doyle-Meyers
- Tulane National Primate Research Center, Covington, Louisiana; Department of Medicine, Tulane University School of Medicine, New Orleans, Louisiana
| | - Chad J Roy
- Tulane National Primate Research Center, Covington, Louisiana; Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, Louisiana
| | - Kasi Russell-Lodrigue
- Tulane National Primate Research Center, Covington, Louisiana; Department of Medicine, Tulane University School of Medicine, New Orleans, Louisiana
| | | | - Chris J Monjure
- Tulane National Primate Research Center, Covington, Louisiana
| | - Brandon Beddingfield
- Tulane National Primate Research Center, Covington, Louisiana; Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, Louisiana
| | - Kenneth S Plante
- World Reference Center for Emerging Viruses and Arboviruses, Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas
| | - Jessica A Plante
- World Reference Center for Emerging Viruses and Arboviruses, Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas
| | - Scott C Weaver
- World Reference Center for Emerging Viruses and Arboviruses, Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas
| | - Xuebin Qin
- Tulane National Primate Research Center, Covington, Louisiana; Department of Pathology and Laboratory Animal Medicine, Tulane University School of Medicine, New Orleans, Louisiana
| | | | | | - Nadia Golden
- Tulane National Primate Research Center, Covington, Louisiana
| | | | - Toni Penney
- Tulane National Primate Research Center, Covington, Louisiana
| | - Carolina Allers
- Tulane National Primate Research Center, Covington, Louisiana
| | - Mary B Barnes
- Tulane National Primate Research Center, Covington, Louisiana
| | | | - Prasun K Datta
- Tulane National Primate Research Center, Covington, Louisiana; Department of Pathology and Laboratory Animal Medicine, Tulane University School of Medicine, New Orleans, Louisiana
| | - Nicholas J Maness
- Tulane National Primate Research Center, Covington, Louisiana; Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, Louisiana
| | - Angela Birnbaum
- Tulane National Primate Research Center, Covington, Louisiana
| | - Tracy Fischer
- Tulane National Primate Research Center, Covington, Louisiana; Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, Louisiana
| | - Rudolf P Bohm
- Tulane National Primate Research Center, Covington, Louisiana; Department of Medicine, Tulane University School of Medicine, New Orleans, Louisiana
| | - Jay Rappaport
- Tulane National Primate Research Center, Covington, Louisiana; Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, Louisiana
| |
Collapse
|
12
|
Montgomery VA, Lindsey CY, Smith LA, Webb RP. Development of an o-pthalaldehyde (OPA) assay to measure protein content in Ricin Vaccine E. coli (RVEc™). Vaccine 2020; 39:564-570. [PMID: 33339670 DOI: 10.1016/j.vaccine.2020.12.008] [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: 06/23/2020] [Revised: 11/23/2020] [Accepted: 12/01/2020] [Indexed: 11/20/2022]
Abstract
A recombinant ricin vaccine from E. coli (RVEc™), was developed at the US Army Medical Research Institute of Infectious Diseases (USAMRIID) and assessed in an FDA sponsored Phase 1a clinical trial. At the maximum dosage, two of the study participants developed physiological responses that were elevated to the level of severe adverse reactions. To stay within safe dosing guidelines, the FDA recommended that an assay be developed to accurately quantify the recombinant protein content in the vaccine. The RVEc™ vaccine Final Drug Product (FDP) contains the adjuvant Alhydrogel®, which by its colloidal nature interferes with most conventional protein assay methods. We decided to develop an assay measuring RVEc™ FDP using o-pthalaldehyde (OPA) reagent. The OPA reagent reacts to the primary amines and lysine side chains of proteins in the presence of a thiol under alkaline conditions with a quantifiable fluorescent signature, but does not react with Alhydrogel®. Protein content in the RVEc™ FDP can be determined by comparing the fluorescence of the test sample to the fluorescence of a standard curve of defined concentration. Each phase of the assay was tested to optimize and simplify the assay procedure. The accuracy, specificity, reproducibility, and stability of the assay were evaluated. Results indicated that the optimized and modified OPA assay was simple and able to quantify antigen concentration from a standard curve in the 25 µg/mL-600 µg/mL range. The assay accuracy and coefficient of variation (CV) was 95% and less than 8%, respectively, when determining the ricin protein content in the 200 µg/mL vialed RVEc™ FDP. The assay was simple to perform and used conventional laboratory equipment. This assay could be adapted to measure the protein content in the FDP of other vaccines, but with the proviso that each step of the assay would need to be optimized for each antigen.
Collapse
Affiliation(s)
- Vicki A Montgomery
- Division of Bacteriology, U.S. Army Medical Research Institute of Infectious Diseases, 1425 Porter St, Ft Detrick, MD 21702, United States.
| | - Changhong Y Lindsey
- Division of Advanced Regulated Studies, U.S. Army Medical Research Institute of Infectious Diseases, 1412 Porter St, Ft Detrick, MD 21702, United States
| | - Leonard A Smith
- Medical Countermeasures Technology, U.S. Army Medical Research and Material Command, 1425 Porter St, Ft Detrick, MD 21702, United States
| | - Robert P Webb
- Division of Bacteriology, U.S. Army Medical Research Institute of Infectious Diseases, 1425 Porter St, Ft Detrick, MD 21702, United States
| |
Collapse
|
13
|
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.
Collapse
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.
| |
Collapse
|
14
|
Falach R, Sapoznikov A, Evgy Y, Aftalion M, Makovitzki A, Agami A, Mimran A, Lerer E, Ben David A, Zichel R, Katalan S, Rosner A, Sabo T, Kronman C, Gal Y. Post-Exposure Anti-Ricin Treatment Protects Swine Against Lethal Systemic and Pulmonary Exposures. Toxins (Basel) 2020; 12:toxins12060354. [PMID: 32481526 PMCID: PMC7354453 DOI: 10.3390/toxins12060354] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 05/21/2020] [Accepted: 05/25/2020] [Indexed: 12/04/2022] Open
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, there is no approved post-exposure therapy for ricin exposures. This work demonstrates for the first time the therapeutic efficacy of equine-derived anti-ricin F(ab’)2 antibodies against lethal pulmonary and systemic ricin exposures in swine. While administration of the antitoxin at 18 h post-exposure protected more than 80% of both intratracheally and intramuscularly ricin-intoxicated swine, treatment at 24 h post-exposure protected 58% of the intramuscular-exposed swine, as opposed to 26% of the intratracheally exposed animals. Quantitation of the anti-ricin neutralizing units in the anti-toxin preparations confirmed that the disparate protection conferred to swine subjected to the two routes of exposure stems from variance between the two models. Furthermore, dose response experiments showed that approximately 3 times lesser amounts of antibody are needed for high-level protection of the intramuscularly compared to the intratracheally intoxicated swine. This study, which demonstrates the high-level post-exposure efficacy of anti-ricin antitoxin at clinically relevant time-points in a large animal model, can serve as the basis for the formulation of post-exposure countermeasures against ricin poisoning in humans.
Collapse
Affiliation(s)
- Reut Falach
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 76100, Israel; (R.F.); (A.S.); (Y.E.); (M.A.); (T.S.)
| | - Anita Sapoznikov
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 76100, Israel; (R.F.); (A.S.); (Y.E.); (M.A.); (T.S.)
| | - Yentl Evgy
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 76100, Israel; (R.F.); (A.S.); (Y.E.); (M.A.); (T.S.)
| | - Moshe Aftalion
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 76100, Israel; (R.F.); (A.S.); (Y.E.); (M.A.); (T.S.)
| | - Arik Makovitzki
- Department of Biotechnology, Israel Institute for Biological Research, Ness-Ziona 76100, Israel; (A.M.); (A.A.); (A.M.); (E.L.); (A.B.D.); (R.Z.)
| | - Avi Agami
- Department of Biotechnology, Israel Institute for Biological Research, Ness-Ziona 76100, Israel; (A.M.); (A.A.); (A.M.); (E.L.); (A.B.D.); (R.Z.)
| | - Avishai Mimran
- Department of Biotechnology, Israel Institute for Biological Research, Ness-Ziona 76100, Israel; (A.M.); (A.A.); (A.M.); (E.L.); (A.B.D.); (R.Z.)
| | - Elad Lerer
- Department of Biotechnology, Israel Institute for Biological Research, Ness-Ziona 76100, Israel; (A.M.); (A.A.); (A.M.); (E.L.); (A.B.D.); (R.Z.)
| | - Alon Ben David
- Department of Biotechnology, Israel Institute for Biological Research, Ness-Ziona 76100, Israel; (A.M.); (A.A.); (A.M.); (E.L.); (A.B.D.); (R.Z.)
| | - Ran Zichel
- Department of Biotechnology, Israel Institute for Biological Research, Ness-Ziona 76100, Israel; (A.M.); (A.A.); (A.M.); (E.L.); (A.B.D.); (R.Z.)
| | - Shahaf Katalan
- Department of Pharmacology, 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;
| | - Tamar Sabo
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 76100, Israel; (R.F.); (A.S.); (Y.E.); (M.A.); (T.S.)
| | - Chanoch Kronman
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 76100, Israel; (R.F.); (A.S.); (Y.E.); (M.A.); (T.S.)
- Correspondence: (C.K.); (Y.G.); Tel.: +972–8–9381522 (C.K.); +972–8–9381479 (Y.G.)
| | - Yoav Gal
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 76100, Israel; (R.F.); (A.S.); (Y.E.); (M.A.); (T.S.)
- Correspondence: (C.K.); (Y.G.); Tel.: +972–8–9381522 (C.K.); +972–8–9381479 (Y.G.)
| |
Collapse
|
15
|
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.
Collapse
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
Collapse
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
| |
Collapse
|
16
|
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.
Collapse
|
17
|
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.
Collapse
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
| |
Collapse
|
18
|
Mooney B, Torres‐Velez FJ, Doering J, Ehrbar DJ, Mantis NJ. Sensitivity of Kupffer cells and liver sinusoidal endothelial cells to ricin toxin and ricin toxin-Ab complexes. J Leukoc Biol 2019; 106:1161-1176. [PMID: 31313388 PMCID: PMC7008010 DOI: 10.1002/jlb.4a0419-123r] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 06/03/2019] [Accepted: 07/02/2019] [Indexed: 12/11/2022] Open
Abstract
Ricin toxin is a plant-derived, ribosome-inactivating protein that is rapidly cleared from circulation by Kupffer cells (KCs) and liver sinusoidal endothelial cells (LSECs)-with fatal consequences. Rather than being inactivated, ricin evades normal degradative pathways and kills both KCs and LSECs with remarkable efficiency. Uptake of ricin by these 2 specialized cell types in the liver occurs by 2 parallel routes: a "lactose-sensitive" pathway mediated by ricin's galactose/N-acetylgalactosamine-specific lectin subunit (RTB), and a "mannose-sensitive" pathway mediated by the mannose receptor (MR; CD206) or other C-type lectins capable of recognizing the mannose-side chains displayed on ricin's A (RTA) and B subunits. In this report, we investigated the capacity of a collection of ricin-specific mouse MAb and camelid single-domain (VH H) antibodies to protect KCs and LSECs from ricin-induced killing. In the case of KCs, individual MAbs against RTA or RTB afforded near complete protection against ricin in ex vivo and in vivo challenge studies. In contrast, individual MAbs or VH Hs afforded little (<40%) or even no protection to LSECs against ricin-induced death. Complete protection of LSECs was only achieved with MAb or VH H cocktails, with the most effective mixtures targeting RTA and RTB simultaneously. Although the exact mechanisms of protection of LSECs remain unknown, evidence indicates that the Ab cocktails exert their effects on the mannose-sensitive uptake pathway without the need for Fcγ receptor involvement. In addition to advancing our understanding of how toxins and small immune complexes are processed by KCs and LSECs, our study has important implications for the development of Ab-based therapies designed to prevent or treat ricin exposure should the toxin be weaponized.
Collapse
Affiliation(s)
- Bridget Mooney
- Division of Infectious DiseasesWadsworth CenterNew York State Department of HealthAlbanyNew YorkUSA
| | - Fernando J. Torres‐Velez
- Division of Infectious DiseasesWadsworth CenterNew York State Department of HealthAlbanyNew YorkUSA
| | - Jennifer Doering
- Division of Infectious DiseasesWadsworth CenterNew York State Department of HealthAlbanyNew YorkUSA
| | - Dylan J. Ehrbar
- Division of Infectious DiseasesWadsworth CenterNew York State Department of HealthAlbanyNew YorkUSA
| | - Nicholas J. Mantis
- Division of Infectious DiseasesWadsworth CenterNew York State Department of HealthAlbanyNew YorkUSA
| |
Collapse
|
19
|
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.
Collapse
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
| |
Collapse
|
20
|
Guo Z, Wang Z, Meng S, Zhao Z, Zhang C, Fu Y, Li J, Nie X, Zhang C, Liu L, Lu B, Qian J. Effects of ricin on primary pulmonary alveolar macrophages. J Int Med Res 2019; 47:3763-3777. [PMID: 31156015 PMCID: PMC6726780 DOI: 10.1177/0300060519842959] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Objective We systematically investigated the cytotoxic effects of ricin in primary pulmonary alveolar macrophages (PAMs). Methods Primary PAMs were isolated from BALB/c mice. The cytotoxic effects of ricin were investigated in vitro by optical and transmission electron microscopy, detection of the inflammatory cytokine response, proteomic analysis, and subsequent biological functional analysis. Results Ricin induced shrinkage, apoptosis, vacuolization, and multi-organelle lesions in primary PAMs as demonstrated by optical and transmission electron microscopy. Ricin also induced a pronounced pro-inflammatory cytokine response in primary PAMs, including induction of tumor necrosis factor-α, interferon-γ, interleukin (IL)-1, IL-2, IL-6, IL-12, C-C motif chemokine ligand 2, and C-X-C motif chemokine ligand 2, while the anti-inflammatory cytokines IL-4 and IL-10 were less affected. Proteomic analysis and subsequent biological functional analysis identified eight proteins that were up/downregulated by ricin treatment and which might thus contribute to ricin toxicity. These proteins were involved in various functions, including redox, molecular chaperone, glycolysis, protein translation, and protein degradation functions. Conclusion The results of the present study further our understanding of the pathogenic mechanism of inhalational ricin poisoning.
Collapse
Affiliation(s)
- Zhendong Guo
- 1 Academy of Military Medical Sciences, Beijing, China
| | - Zhongyi Wang
- 1 Academy of Military Medical Sciences, Beijing, China
| | - Shanyu Meng
- 2 Agricultural and Biological Engineering Department, University of Florida, Gainesville, FL, USA
| | | | - Chunmao Zhang
- 1 Academy of Military Medical Sciences, Beijing, China
| | - Yingying Fu
- 1 Academy of Military Medical Sciences, Beijing, China
| | - Jiaming Li
- 1 Academy of Military Medical Sciences, Beijing, China
| | - Xin Nie
- 3 No. 65316 Unit of PLA, Dalian, China
| | - Cheng Zhang
- 1 Academy of Military Medical Sciences, Beijing, China
| | - Linna Liu
- 1 Academy of Military Medical Sciences, Beijing, China
| | - Bing Lu
- 1 Academy of Military Medical Sciences, Beijing, China
| | - Jun Qian
- 1 Academy of Military Medical Sciences, Beijing, China
| |
Collapse
|