1
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Agnihotri P, Mishra AK, Agarwal P, Vignali KM, Workman CJ, Vignali DAA, Mariuzza RA. Epitope Mapping of Therapeutic Antibodies Targeting Human LAG3. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2022; 209:1586-1594. [PMID: 36104110 PMCID: PMC9696730 DOI: 10.4049/jimmunol.2200309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 08/11/2022] [Indexed: 12/12/2022]
Abstract
Lymphocyte activation gene 3 protein (LAG3; CD223) is an inhibitory receptor that is highly upregulated on exhausted T cells in tumors and chronic viral infection. Consequently, LAG3 is now a major immunotherapeutic target for the treatment of cancer, and many mAbs against human (h) LAG3 (hLAG3) have been generated to block its inhibitory activity. However, little or no information is available on the epitopes they recognize. We selected a panel of seven therapeutic mAbs from the patent literature for detailed characterization. These mAbs were expressed as Fab or single-chain variable fragments and shown to bind hLAG3 with nanomolar affinities, as measured by biolayer interferometry. Using competitive binding assays, we found that the seven mAbs recognize four distinct epitopes on hLAG3. To localize the epitopes, we carried out epitope mapping using chimeras between hLAG3 and mouse LAG3. All seven mAbs are directed against the first Ig-like domain (D1) of hLAG3, despite their different origins. Three mAbs almost exclusively target a unique 30-residue loop of D1 that forms at least part of the putative binding site for MHC class II, whereas four mainly recognize D1 determinants outside this loop. However, because all the mAbs block binding of hLAG3 to MHC class II, each of the epitopes they recognize must at least partially overlap the MHC class II binding site.
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Affiliation(s)
- Pragati Agnihotri
- W.M. Keck Laboratory for Structural Biology, University of Maryland Institute for Bioscience and Biotechnology Research, Rockville, MD
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD
| | - Arjun K Mishra
- W.M. Keck Laboratory for Structural Biology, University of Maryland Institute for Bioscience and Biotechnology Research, Rockville, MD
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD
| | - Priyanka Agarwal
- Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA
- Tumor Microenvironment Center, UPMC Hillman Cancer Center, Pittsburgh, PA; and
| | - Kate M Vignali
- Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA
- Tumor Microenvironment Center, UPMC Hillman Cancer Center, Pittsburgh, PA; and
| | - Creg J Workman
- Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA
- Tumor Microenvironment Center, UPMC Hillman Cancer Center, Pittsburgh, PA; and
| | - Dario A A Vignali
- Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA
- Tumor Microenvironment Center, UPMC Hillman Cancer Center, Pittsburgh, PA; and
- Cancer Immunology and Immunotherapy Program, UPMC Hillman Cancer Center, Pittsburgh, PA
| | - Roy A Mariuzza
- W.M. Keck Laboratory for Structural Biology, University of Maryland Institute for Bioscience and Biotechnology Research, Rockville, MD;
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD
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2
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Rosenfeld R, Alcalay R, Zvi A, Ben-David A, Noy-Porat T, Chitlaru T, Epstein E, Israeli O, Lazar S, Caspi N, Barnea A, Dor E, Chomsky I, Pitel S, Makdasi E, Zichel R, Mazor O. Centaur antibodies: Engineered chimeric equine-human recombinant antibodies. Front Immunol 2022; 13:942317. [PMID: 36059507 PMCID: PMC9437483 DOI: 10.3389/fimmu.2022.942317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 07/28/2022] [Indexed: 11/27/2022] Open
Abstract
Hyper-immune antisera from large mammals, in particular horses, are routinely used for life-saving anti-intoxication intervention. While highly efficient, the use of these immunotherapeutics is complicated by possible recipient reactogenicity and limited availability. Accordingly, there is an urgent need for alternative improved next-generation immunotherapies to respond to this issue of high public health priority. Here, we document the development of previously unavailable tools for equine antibody engineering. A novel primer set, EquPD v2020, based on equine V-gene data, was designed for efficient and accurate amplification of rearranged horse antibody V-segments. The primer set served for generation of immune phage display libraries, representing highly diverse V-gene repertoires of horses immunized against botulinum A or B neurotoxins. Highly specific scFv clones were selected and expressed as full-length antibodies, carrying equine V-genes and human Gamma1/Lambda constant genes, to be referred as “Centaur antibodies”. Preliminary assessment in a murine model of botulism established their therapeutic potential. The experimental approach detailed in the current report, represents a valuable tool for isolation and engineering of therapeutic equine antibodies.
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Affiliation(s)
- Ronit Rosenfeld
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona, Israel
- *Correspondence: Ronit Rosenfeld, ; Ohad Mazor,
| | - Ron Alcalay
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Anat Zvi
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Alon Ben-David
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Tal Noy-Porat
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Theodor Chitlaru
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Eyal Epstein
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Ofir Israeli
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Shirley Lazar
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Noa Caspi
- Veterinary Center for Preclinical Research, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Ada Barnea
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Eyal Dor
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Inbar Chomsky
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Shani Pitel
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Efi Makdasi
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Ran Zichel
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Ohad Mazor
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona, Israel
- *Correspondence: Ronit Rosenfeld, ; Ohad Mazor,
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3
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Ricin toxin and its neutralizing antibodies: A review. Toxicon 2022; 214:47-53. [PMID: 35595086 DOI: 10.1016/j.toxicon.2022.05.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 05/10/2022] [Accepted: 05/13/2022] [Indexed: 11/22/2022]
Abstract
Ricin toxin (RT) belongs to the ribosome-inactivating protein (RIP) family of toxins and is considered to be a moderate threat by the US Center of Disease Control and Prevention (CDC). RT poses a great potential threat to the public, but there has been a lack of effective treatment options so far. Over the past few decades, researches on the prevention and treatment of RT poisoning have been investigated, among which neutralizing antibodies targeting RT specifically have always been a research hotspot. In this review, we have summarized the mechanism of action of RT, the research results and the design strategies of RT neutralizing antibodies, and discussed the key issues in the development of RT neutralizing antibody researches.
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4
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Rosenfeld R, Noy-Porat T, Mechaly A, Makdasi E, Levy Y, Alcalay R, Falach R, Aftalion M, Epstein E, Gur D, Chitlaru T, Vitner EB, Melamed S, Politi B, Zauberman A, Lazar S, Beth-Din A, Evgy Y, Yitzhaki S, Shapira SC, Israely T, Mazor O. Post-exposure protection of SARS-CoV-2 lethal infected K18-hACE2 transgenic mice by neutralizing human monoclonal antibody. Nat Commun 2021; 12:944. [PMID: 33574228 PMCID: PMC7878817 DOI: 10.1038/s41467-021-21239-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Accepted: 01/19/2021] [Indexed: 12/11/2022] Open
Abstract
The coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), exhibits high levels of mortality and morbidity and has dramatic consequences on human life, sociality and global economy. Neutralizing antibodies constitute a highly promising approach for treating and preventing infection by this novel pathogen. In the present study, we characterize and further evaluate the recently identified human monoclonal MD65 antibody for its ability to provide protection against a lethal SARS-CoV-2 infection of K18-hACE2 transgenic mice. Eighty percent of the untreated mice succumbed 6-9 days post-infection, while administration of the MD65 antibody as late as 3 days after exposure rescued all infected animals. In addition, the efficiency of the treatment is supported by prevention of morbidity and ablation of the load of infective virions in the lungs of treated animals. The data demonstrate the therapeutic value of human monoclonal antibodies as a life-saving treatment for severe COVID-19 infection.
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MESH Headings
- Animals
- Antibodies, Monoclonal/administration & dosage
- Antibodies, Monoclonal/genetics
- Antibodies, Monoclonal/immunology
- Antibodies, Neutralizing/administration & dosage
- Antibodies, Neutralizing/genetics
- Antibodies, Neutralizing/immunology
- Antibodies, Viral/administration & dosage
- Antibodies, Viral/genetics
- Antibodies, Viral/immunology
- COVID-19/immunology
- Chlorocebus aethiops
- Female
- Immunoglobulin G/administration & dosage
- Immunoglobulin G/genetics
- Immunoglobulin G/immunology
- Lung/pathology
- Lung/virology
- Male
- Mice, Inbred C57BL
- Mice, Transgenic
- SARS-CoV-2/classification
- SARS-CoV-2/physiology
- Seroconversion
- Vero Cells
- Viral Load
- COVID-19 Drug Treatment
- Mice
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Affiliation(s)
- Ronit Rosenfeld
- Israel Institute for Biological Research, Ness-Ziona, Israel.
| | - Tal Noy-Porat
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Adva Mechaly
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Efi Makdasi
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Yinon Levy
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Ron Alcalay
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Reut Falach
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Moshe Aftalion
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Eyal Epstein
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | - David Gur
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | | | - Einat B Vitner
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Sharon Melamed
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Boaz Politi
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | | | - Shirley Lazar
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Adi Beth-Din
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Yentl Evgy
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Shmuel Yitzhaki
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | | | - Tomer Israely
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Ohad Mazor
- Israel Institute for Biological Research, Ness-Ziona, Israel.
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5
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Chaves EJF, Gomes da Cruz LE, Padilha IQM, Silveira CH, Araujo DAM, Rocha GB. Discovery of RTA ricin subunit inhibitors: a computational study using PM7 quantum chemical method and steered molecular dynamics. J Biomol Struct Dyn 2021; 40:5427-5445. [PMID: 33526002 DOI: 10.1080/07391102.2021.1878058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Ricin is a potent toxin derived from the castor bean plant and comprises two subunits, RTA and RTB. Because of its cytotoxicity, ricin has alarmed world authorities for its potential use as a chemical weapon. Ricin also affects castor bean agribusiness, given the risk of animal and human poisoning. Over the years, many groups attempted to propose small-molecules that bind to the RTA active site, the catalytic chain. Despite such efforts, there is still no effective countermeasure against ricin poisoning. The computational study carried out in the present work renews the discussion about small-molecules that may inhibit this toxin. Here, a structure-based virtual screening protocol capable of discerning active RTA inhibitors from inactive ones was performed to screen over 2 million compounds from the ZINC database to find novel scaffolds that strongly bind into the active site of the RTA. Besides, a novel score method based on ligand undocking force profiles and semi-empirical quantum chemical calculations provided insights into the rescore of docking poses. Summing up, the filtering steps pointed out seven main compounds, with the SCF00-451 as a promising candidate to inhibit the killing activity of such potent phytotoxin.
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Affiliation(s)
| | | | | | | | | | - Gerd Bruno Rocha
- Department of Chemistry, Federal University of Paraíba, João Pessoa, PB, Brazil
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6
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Orsini Delgado ML, Avril A, Prigent J, Dano J, Rouaix A, Worbs S, Dorner BG, Rougeaux C, Becher F, Fenaille F, Livet S, Volland H, Tournier JN, Simon S. Ricin Antibodies' Neutralizing Capacity against Different Ricin Isoforms and Cultivars. Toxins (Basel) 2021; 13:100. [PMID: 33573016 PMCID: PMC7911099 DOI: 10.3390/toxins13020100] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Revised: 01/21/2021] [Accepted: 01/25/2021] [Indexed: 12/11/2022] Open
Abstract
Ricin, a highly toxic protein from Ricinus communis, is considered a potential biowarfare agent. Despite the many data available, no specific treatment has yet been approved. Due to their ability to provide immediate protection, antibodies (Abs) are an approach of choice. However, their high specificity might compromise their capacity to protect against the different ricin isoforms (D and E) found in the different cultivars. In previous work, we have shown the neutralizing potential of different Abs (43RCA-G1 (anti ricin A-chain) and RB34 and RB37 (anti ricin B-chain)) against ricin D. In this study, we evaluated their protective capacity against both ricin isoforms. We show that: (i) RB34 and RB37 recognize exclusively ricin D, whereas 43RCA-G1 recognizes both isoforms, (ii) their neutralizing capacity in vitro varies depending on the cultivar, and (iii) there is a synergistic effect when combining RB34 and 43RCA-G1. This effect is also demonstrated in vivo in a mouse model of intranasal intoxication with ricin D/E (1:1), where approximately 60% and 40% of mice treated 0 and 6 h after intoxication, respectively, are protected. Our results highlight the importance of evaluating the effectiveness of the Abs against different ricin isoforms to identify the treatment with the broadest spectrum neutralizing effect.
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Affiliation(s)
- Maria Lucia Orsini Delgado
- Paris-Saclay University, CEA, INRAE, Medicines and Healthcare Technologies Department (DMTS), SPI, 91191 Gif-sur-Yvette, France; (J.P.); (J.D.); (A.R.); (F.B.); (F.F.); (S.L.); (H.V.)
| | - Arnaud Avril
- Microbiology and Infectious Diseases Department, Anti-Infectious Biotherapies and Immunity Unit, Army Biomedical Research Institute, 91220 Brétigny-sur-Orge, France; (A.A.); (C.R.); (J.-N.T.)
| | - Julie Prigent
- Paris-Saclay University, CEA, INRAE, Medicines and Healthcare Technologies Department (DMTS), SPI, 91191 Gif-sur-Yvette, France; (J.P.); (J.D.); (A.R.); (F.B.); (F.F.); (S.L.); (H.V.)
| | - Julie Dano
- Paris-Saclay University, CEA, INRAE, Medicines and Healthcare Technologies Department (DMTS), SPI, 91191 Gif-sur-Yvette, France; (J.P.); (J.D.); (A.R.); (F.B.); (F.F.); (S.L.); (H.V.)
| | - Audrey Rouaix
- Paris-Saclay University, CEA, INRAE, Medicines and Healthcare Technologies Department (DMTS), SPI, 91191 Gif-sur-Yvette, France; (J.P.); (J.D.); (A.R.); (F.B.); (F.F.); (S.L.); (H.V.)
| | - Sylvia Worbs
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute (RKI), 13353 Berlin, Germany; (S.W.); (B.G.D.)
| | - Brigitte G. Dorner
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute (RKI), 13353 Berlin, Germany; (S.W.); (B.G.D.)
| | - Clémence Rougeaux
- Microbiology and Infectious Diseases Department, Anti-Infectious Biotherapies and Immunity Unit, Army Biomedical Research Institute, 91220 Brétigny-sur-Orge, France; (A.A.); (C.R.); (J.-N.T.)
| | - François Becher
- Paris-Saclay University, CEA, INRAE, Medicines and Healthcare Technologies Department (DMTS), SPI, 91191 Gif-sur-Yvette, France; (J.P.); (J.D.); (A.R.); (F.B.); (F.F.); (S.L.); (H.V.)
| | - François Fenaille
- Paris-Saclay University, CEA, INRAE, Medicines and Healthcare Technologies Department (DMTS), SPI, 91191 Gif-sur-Yvette, France; (J.P.); (J.D.); (A.R.); (F.B.); (F.F.); (S.L.); (H.V.)
| | - Sandrine Livet
- Paris-Saclay University, CEA, INRAE, Medicines and Healthcare Technologies Department (DMTS), SPI, 91191 Gif-sur-Yvette, France; (J.P.); (J.D.); (A.R.); (F.B.); (F.F.); (S.L.); (H.V.)
| | - Hervé Volland
- Paris-Saclay University, CEA, INRAE, Medicines and Healthcare Technologies Department (DMTS), SPI, 91191 Gif-sur-Yvette, France; (J.P.); (J.D.); (A.R.); (F.B.); (F.F.); (S.L.); (H.V.)
| | - Jean-Nicolas Tournier
- Microbiology and Infectious Diseases Department, Anti-Infectious Biotherapies and Immunity Unit, Army Biomedical Research Institute, 91220 Brétigny-sur-Orge, France; (A.A.); (C.R.); (J.-N.T.)
| | - Stéphanie Simon
- Paris-Saclay University, CEA, INRAE, Medicines and Healthcare Technologies Department (DMTS), SPI, 91191 Gif-sur-Yvette, France; (J.P.); (J.D.); (A.R.); (F.B.); (F.F.); (S.L.); (H.V.)
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7
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Feldberg L, Elhanany E, Laskar O, Schuster O. Rapid, Sensitive and Reliable Ricin Identification in Serum Samples Using LC-MS/MS. Toxins (Basel) 2021; 13:79. [PMID: 33499033 PMCID: PMC7911523 DOI: 10.3390/toxins13020079] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 01/11/2021] [Accepted: 01/16/2021] [Indexed: 12/18/2022] Open
Abstract
Ricin, a protein derived from the seeds of the castor bean plant (Ricinus communis), is a highly lethal toxin that inhibits protein synthesis, resulting in cell death. The widespread availability of ricin, its ease of extraction and its extreme toxicity make it an ideal agent for bioterrorism and self-poisoning. Thus, a rapid, sensitive and reliable method for ricin identification in clinical samples is required for applying appropriate and timely medical intervention. However, this goal is challenging due to the low predicted toxin concentrations in bio-fluids, accompanied by significantly high matrix interferences. Here we report the applicability of a sensitive, selective, rapid, simple and antibody-independent assay for the identification of ricin in body fluids using mass spectrometry (MS). The assay involves lectin affinity capturing of ricin by easy-to-use commercial lactose-agarose (LA) beads, following by tryptic digestion and selected marker identification using targeted LC-MS/MS (Multiple Reaction Monitoring) analysis. This enables ricin identification down to 5 ng/mL in serum samples in 2.5 h. To validate the assay, twenty-four diverse naive- or ricin-spiked serum samples were evaluated, and both precision and accuracy were determined. A real-life test of the assay was successfully executed in a challenging clinical scenario, where the toxin was identified in an abdominal fluid sample taken 72 h post self-injection of castor beans extraction in an eventual suicide case. This demonstrates both the high sensitivity of this assay and the extended identification time window, compared to similar events that were previously documented. This method developed for ricin identification in clinical samples has the potential to be applied to the identification of other lectin toxins.
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Affiliation(s)
- Liron Feldberg
- Department of Analytical Chemistry, Israel Institute for Biological Research, Ness Ziona 74100, Israel
| | - Eytan Elhanany
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona 74100, Israel;
| | - Orly Laskar
- Department of Infectious Diseases, Israel Institute for Biological Research, Ness Ziona 74100, Israel;
| | - Ofir Schuster
- Department of Infectious Diseases, Israel Institute for Biological Research, Ness Ziona 74100, Israel;
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8
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A panel of human neutralizing mAbs targeting SARS-CoV-2 spike at multiple epitopes. Nat Commun 2020; 11:4303. [PMID: 32855401 PMCID: PMC7452893 DOI: 10.1038/s41467-020-18159-4] [Citation(s) in RCA: 110] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 08/05/2020] [Indexed: 12/14/2022] Open
Abstract
The novel highly transmissible human coronavirus SARS-CoV-2 is the causative agent of the COVID-19 pandemic. Thus far, there is no approved therapeutic drug specifically targeting this emerging virus. Here we report the isolation and characterization of a panel of human neutralizing monoclonal antibodies targeting the SARS-CoV-2 receptor binding domain (RBD). These antibodies were selected from a phage display library constructed using peripheral circulatory lymphocytes collected from patients at the acute phase of the disease. These neutralizing antibodies are shown to recognize distinct epitopes on the viral spike RBD. A subset of the antibodies exert their inhibitory activity by abrogating binding of the RBD to the human ACE2 receptor. The human monoclonal antibodies described here represent a promising basis for the design of efficient combined post-exposure therapy for SARS-CoV-2 infection. Here, Noy-Porat, Makdasi et al. report the isolation of a panel of neutralizing mAbs selected against SARS-CoV-2 receptor-binding domain (RBD) from a phage display library constructed based on patient samples collected in the acute phase of the disease, which show efficient neutralizing activities against authentic virus in vitro.
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9
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Falach R, Sapoznikov A, Gal Y, Elhanany E, Evgy Y, Shifman O, Aftalion M, Ehrlich S, Lazar S, Sabo T, Kronman C, Mazor O. The low density receptor-related protein 1 plays a significant role in ricin-mediated intoxication of lung cells. Sci Rep 2020; 10:9007. [PMID: 32488096 PMCID: PMC7265403 DOI: 10.1038/s41598-020-65982-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 05/11/2020] [Indexed: 01/15/2023] Open
Abstract
Ricin, a highly lethal plant-derived toxin, is a potential biological threat agent due to its high availability, ease of production and the lack of approved medical countermeasures for post-exposure treatment. To date, no specific ricin receptors were identified. Here we show for the first time, that the low density lipoprotein receptor-related protein-1 (LRP1) is a major target molecule for binding of ricin. Pretreating HEK293 acetylcholinesterase-producer cells with either anti-LRP1 antibodies or with Receptor-Associated Protein (a natural LRP1 antagonist), or using siRNA to knock-down LRP1 expression resulted in a marked reduction in their sensitivity towards ricin. Binding assays further demonstrated that ricin bound exclusively to the cluster II binding domain of LRP1, via the ricin B subunit. Ricin binding to the cluster II binding domain of LRP1 was significantly reduced by an anti-ricin monoclonal antibody, which confers high-level protection to ricin pulmonary-exposed mice. Finally, we tested the contribution of LRP1 receptor to ricin intoxication of lung cells derived from mice. Treating these cells with anti-LRP1 antibody prior to ricin exposure, prevented their intoxication. Taken together, our findings clearly demonstrate that the LRP1 receptor plays an important role in ricin-induced pulmonary intoxications.
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Affiliation(s)
- Reut Falach
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, 19 Reuven Lerer St., Ness-Ziona, 76100, Israel.
| | - Anita Sapoznikov
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, 19 Reuven Lerer St., Ness-Ziona, 76100, Israel
| | - Yoav Gal
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, 19 Reuven Lerer St., Ness-Ziona, 76100, Israel
| | - Eytan Elhanany
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, 19 Reuven Lerer St., Ness-Ziona, 76100, Israel
| | - Yentl Evgy
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, 19 Reuven Lerer St., Ness-Ziona, 76100, Israel
| | - Ohad Shifman
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, 19 Reuven Lerer St., Ness-Ziona, 76100, Israel
| | - Moshe Aftalion
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, 19 Reuven Lerer St., Ness-Ziona, 76100, Israel
| | - Sharon Ehrlich
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, 19 Reuven Lerer St., Ness-Ziona, 76100, Israel
| | - Shlomi Lazar
- Department of Pharmacology, Israel Institute for Biological Research, 19 Reuven Lerer St., Ness-Ziona, 76100, Israel
| | - Tamar Sabo
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, 19 Reuven Lerer St., Ness-Ziona, 76100, Israel
| | - Chanoch Kronman
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, 19 Reuven Lerer St., Ness-Ziona, 76100, Israel
| | - Ohad Mazor
- Department of Infectious Diseases, Israel Institute for Biological Research, 19 Reuven Lerer St., Ness-Ziona, 76100, Israel
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10
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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.
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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.)
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11
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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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Franke H, Scholl R, Aigner A. Ricin and Ricinus communis in pharmacology and toxicology-from ancient use and "Papyrus Ebers" to modern perspectives and "poisonous plant of the year 2018". Naunyn Schmiedebergs Arch Pharmacol 2019; 392:1181-1208. [PMID: 31359089 DOI: 10.1007/s00210-019-01691-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 07/04/2019] [Indexed: 12/19/2022]
Abstract
While probably originating from Africa, the plant Ricinus communis is found nowadays around the world, grown for industrial use as a source of castor oil production, wildly sprouting in many regions, or used as ornamental plant. As regards its pharmacological utility, a variety of medical purposes of selected parts of the plant, e.g., as a laxative, an anti-infective, or an anti-inflammatory drug, have been described already in the sixteenth century BC in the famous Papyrus Ebers (treasured in the Library of the University of Leipzig). Quite in contrast, on the toxicological side, the native plant has become the "poisonous plant 2018" in Germany. As of today, a number of isolated components of the plant/seeds have been characterized, including, e.g., castor oil, ricin, Ricinus communis agglutinin, ricinin, nudiflorin, and several allergenic compounds. This review mainly focuses on the most toxic protein, ricin D, classified as a type 2 ribosome-inactivating protein (RIP2). Ricin is one of the most potent and lethal substances known. It has been considered as an important bioweapon (categorized as a Category B agent (second-highest priority)) and an attractive agent for bioterroristic activities. On the other hand, ricin presents great potential, e.g., as an anti-cancer agent or in cell-based research, and is even explored in the context of nanoparticle formulations in tumor therapy. This review provides a comprehensive overview of the pharmacology and toxicology-related body of knowledge on ricin. Toxicokinetic/toxicodynamic aspects of ricin poisoning and possibilities for analytical detection and therapeutic use are summarized as well.
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Affiliation(s)
- Heike Franke
- Rudolf-Boehm-Institute of Pharmacology and Toxicology, Medical Faculty, University of Leipzig, Haertelstrasse 16-18, 04107, Leipzig, Germany.
| | - Reinhold Scholl
- Department of History, University of Leipzig, Leipzig, Germany
| | - Achim Aigner
- Rudolf-Boehm-Institute of Pharmacology and Toxicology, Clinical Pharmacology, Medical Faculty, University of Leipzig, Leipzig, Germany
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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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14
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Schlake T, Thran M, Fiedler K, Heidenreich R, Petsch B, Fotin-Mleczek M. mRNA: A Novel Avenue to Antibody Therapy? Mol Ther 2019; 27:773-784. [PMID: 30885573 PMCID: PMC6453519 DOI: 10.1016/j.ymthe.2019.03.002] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 03/01/2019] [Accepted: 03/01/2019] [Indexed: 12/12/2022] Open
Abstract
First attempts to use exogenous mRNA for protein expression in vivo were made more than 25 years ago. However, widespread appreciation of in vitro transcribed mRNA as a powerful technology for supplying therapeutic proteins to the body has evolved only during the past few years. Various approaches to turning mRNA into a potent therapeutic have been developed. All of them share utilization of specifically designed, rather than endogenous, sequences and thorough purification protocols. Apart from this, there are two fundamental philosophies, one promoting the use of chemically modified nucleotides, the other advocating restriction to unmodified building blocks. Meanwhile, both strategies have received broad support by successful mRNA-based protein treatments in animal models. For such in vivo use, specifically optimized mRNA had to be combined with potent formulations to enable efficient in vivo delivery. The present review analyzes the applicability of mRNA technology to antibody therapy in all main fields: antitoxins, infectious diseases, and oncology.
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15
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Mechaly A, Alcalay R, Noy-Porat T, Epstein E, Gal Y, Mazor O. Novel Phage Display-Derived Anti-Abrin Antibodies Confer Post-Exposure Protection against Abrin Intoxication. Toxins (Basel) 2018; 10:toxins10020080. [PMID: 29438273 PMCID: PMC5848181 DOI: 10.3390/toxins10020080] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 02/06/2018] [Accepted: 02/08/2018] [Indexed: 11/20/2022] Open
Abstract
Abrin toxin is a type 2 ribosome inactivating glycoprotein isolated from the seeds of Abrus precatorius (jequirity pea). Owing to its high toxicity, relative ease of purification and accessibility, it is considered a biological threat agent. To date, there is no effective post-exposure treatment for abrin poisoning and passive immunization remains the most effective therapy. However, the effectiveness of anti-abrin monoclonal antibodies for post-exposure therapy following abrin intoxication has not been demonstrated. The aim of this study was to isolate high affinity anti-abrin antibodies that possess potent toxin-neutralization capabilities. An immune scFv phage-display library was constructed from an abrin-immunized rabbit and a panel of antibodies (six directed against the A subunit of abrin and four against the B subunit) was isolated and expressed as scFv-Fc antibodies. By pair-wise analysis, we found that these antibodies target five distinct epitopes on the surface of abrin and that antibodies against all these sites can bind the toxin simultaneously. Several of these antibodies (namely, RB9, RB10, RB28 and RB30) conferred high protection against pulmonary intoxication of mice, when administered six hours post exposure to a lethal dose of abrin. The data presented in this study demonstrate for the first time the efficacy of monoclonal antibodies in treatment of mice after pulmonary intoxication with abrin and promote the use of these antibodies, one or several, for post-exposure treatment of abrin intoxication.
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Affiliation(s)
- Adva Mechaly
- Department of Infectious Diseases, Israel Institute for Biological Research, Ness-Ziona 76100, Israel;
| | - Ron Alcalay
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 76100, Israel; (R.A.); (T.N.-P.); (Y.G.)
| | - Tal Noy-Porat
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 76100, Israel; (R.A.); (T.N.-P.); (Y.G.)
| | - Eyal Epstein
- Department of Biotechnology, 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; (R.A.); (T.N.-P.); (Y.G.)
| | - Ohad Mazor
- Department of Infectious Diseases, Israel Institute for Biological Research, Ness-Ziona 76100, Israel;
- Correspondence: ; Tel.: +972-8-938-5862; Fax: +972-8-938-1544
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16
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An imaging flow cytometry method to assess ricin trafficking in A549 human lung epithelial cells. Methods 2018; 134-135:41-49. [DOI: 10.1016/j.ymeth.2017.10.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 10/12/2017] [Accepted: 10/30/2017] [Indexed: 11/18/2022] Open
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17
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Whitfield SJC, Griffiths GD, Jenner DC, Gwyther RJ, Stahl FM, Cork LJ, Holley JL, Green AC, Clark GC. Production, Characterisation and Testing of an Ovine Antitoxin against Ricin; Efficacy, Potency and Mechanisms of Action. Toxins (Basel) 2017; 9:E329. [PMID: 29057798 PMCID: PMC5666376 DOI: 10.3390/toxins9100329] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 10/10/2017] [Accepted: 10/13/2017] [Indexed: 12/18/2022] Open
Abstract
Ricin is a type II ribosome-inactivating toxin that catalytically inactivates ribosomes ultimately leading to cell death. The toxicity of ricin along with the prevalence of castor beans (its natural source) has led to its increased notoriety and incidences of nefarious use. Despite these concerns, there are no licensed therapies available for treating ricin intoxication. Here, we describe the development of a F(ab')₂ polyclonal ovine antitoxin against ricin and demonstrate the efficacy of a single, post-exposure, administration in an in vivo murine model of intoxication against aerosolised ricin. We found that a single dose of antitoxin afforded a wide window of opportunity for effective treatment with 100% protection observed in mice challenged with aerosolised ricin when given 24 h after exposure to the toxin and 75% protection when given at 30 h. Treated mice had reduced weight loss and clinical signs of intoxication compared to the untreated control group. Finally, using imaging flow cytometry, it was found that both cellular uptake and intracellular trafficking of ricin toxin to the Golgi apparatus was reduced in the presence of the antitoxin suggesting both actions can contribute to the therapeutic mechanism of a polyclonal antitoxin. Collectively, the research highlights the significant potential of the ovine F(ab')₂ antitoxin as a treatment for ricin intoxication.
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Affiliation(s)
- Sarah J C Whitfield
- Chemical, Biological and Radiological Division, Dstl, Porton Down, Salisbury SP4 0JQ, UK.
| | - Gareth D Griffiths
- Chemical, Biological and Radiological Division, Dstl, Porton Down, Salisbury SP4 0JQ, UK.
| | - Dominic C Jenner
- Chemical, Biological and Radiological Division, Dstl, Porton Down, Salisbury SP4 0JQ, UK.
| | - Robert J Gwyther
- Chemical, Biological and Radiological Division, Dstl, Porton Down, Salisbury SP4 0JQ, UK.
| | - Fiona M Stahl
- Chemical, Biological and Radiological Division, Dstl, Porton Down, Salisbury SP4 0JQ, UK.
| | - Lucy J Cork
- Chemical, Biological and Radiological Division, Dstl, Porton Down, Salisbury SP4 0JQ, UK.
| | - Jane L Holley
- Chemical, Biological and Radiological Division, Dstl, Porton Down, Salisbury SP4 0JQ, UK
| | - A Christopher Green
- Chemical, Biological and Radiological Division, Dstl, Porton Down, Salisbury SP4 0JQ, UK.
| | - Graeme C Clark
- Chemical, Biological and Radiological Division, Dstl, Porton Down, Salisbury SP4 0JQ, UK.
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18
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Gal Y, Mazor O, Falach R, Sapoznikov A, Kronman C, Sabo T. Treatments for Pulmonary Ricin Intoxication: Current Aspects and Future Prospects. Toxins (Basel) 2017; 9:E311. [PMID: 28972558 PMCID: PMC5666358 DOI: 10.3390/toxins9100311] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 09/26/2017] [Accepted: 09/29/2017] [Indexed: 12/13/2022] Open
Abstract
Ricin, a plant-derived toxin originating from the seeds of Ricinus communis (castor beans), is one of the most lethal toxins known, particularly if inhaled. Ricin is considered a potential biological threat agent due to its high availability and ease of production. The clinical manifestation of pulmonary ricin intoxication in animal models is closely related to acute respiratory distress syndrome (ARDS), which involves pulmonary proinflammatory cytokine upregulation, massive neutrophil infiltration and severe edema. Currently, the only post-exposure measure that is effective against pulmonary ricinosis at clinically relevant time-points following intoxication in pre-clinical studies is passive immunization with anti-ricin neutralizing antibodies. The efficacy of this antitoxin treatment depends on antibody affinity and the time of treatment initiation within a limited therapeutic time window. Small-molecule compounds that interfere directly with the toxin or inhibit its intracellular trafficking may also be beneficial against ricinosis. Another approach relies on the co-administration of antitoxin antibodies with immunomodulatory drugs, thereby neutralizing the toxin while attenuating lung injury. Immunomodulators and other pharmacological-based treatment options should be tailored according to the particular pathogenesis pathways of pulmonary ricinosis. This review focuses on the current treatment options for pulmonary ricin intoxication using anti-ricin antibodies, disease-modifying countermeasures, anti-ricin small molecules and their various combinations.
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Affiliation(s)
- Yoav Gal
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 76100, Israel.
| | - Ohad Mazor
- Department of Infectious Diseases, 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.
| | - Anita Sapoznikov
- 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.
| | - Tamar Sabo
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 76100, Israel.
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