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Williams PDE, Brewer MT, Aroian RV, Robertson AP, Martin RJ. The nematode (Ascaris suum) intestine is a location of synergistic anthelmintic effects of Cry5B and levamisole. PLoS Pathog 2024; 20:e1011835. [PMID: 38758969 PMCID: PMC11139322 DOI: 10.1371/journal.ppat.1011835] [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: 11/17/2023] [Revised: 05/30/2024] [Accepted: 04/26/2024] [Indexed: 05/19/2024] Open
Abstract
A novel group of biocidal compounds are the Crystal 3D (Cry) and Cytolytic (Cyt) proteins produced by Bacillus thuringiensis (Bt). Some Bt Cry proteins have a selective nematocidal activity, with Cry5B being the most studied. Cry5B kills nematode parasites by binding selectively to membrane glycosphingolipids, then forming pores in the cell membranes of the intestine leading to damage. Cry5B selectively targets multiple species of nematodes from different clades and has no effect against mammalian hosts. Levamisole is a cholinergic anthelmintic that acts by selectively opening L-subtype nicotinic acetylcholine receptor ion-channels (L-AChRs) that have been found on muscles of nematodes. A synergistic nematocidal interaction between levamisole and Cry5B at the whole-worm level has been described previously, but the location, mechanism and time-course of this synergism is not known. In this study we follow the timeline of the effects of levamisole and Cry5B on the Ca2+ levels in enterocyte cells in the intestine of Ascaris suum using fluorescence imaging. The peak Ca2+ responses to levamisole were observed after approximately 10 minutes while the peak responses to activated Cry5B were observed after approximately 80 minutes. When levamisole and Cry5B were applied simultaneously, we observed that the responses to Cry5B were bigger and occurred sooner than when it was applied by itself. It is proposed that the synergism is due to the cytoplasmic Ca2+ overload that is induced by the combination of levamisole opening Ca2+ permeable L-subtype nAChRs and the Ca2+ permeable Cry5B toxin pores produced in the enterocyte plasma membranes. The effect of levamisole potentiates and speeds the actions of Cry5B that gives rise to bigger Ca2+ overloads that accelerates cell-death of the enterocytes.
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Affiliation(s)
- Paul D. E. Williams
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America
| | - Matthew T. Brewer
- Department of Veterinary Pathology, Iowa State University, Ames, Iowa, United States of America
| | - Raffi V. Aroian
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Alan P. Robertson
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America
| | - Richard J. Martin
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America
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2
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Williams PDE, Brewer MT, Aroian R, Robertson AP, Martin RJ. The nematode ( Ascaris suum) intestine is a location of synergistic anthelmintic effects of Cry5B and levamisole. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.20.567786. [PMID: 38045368 PMCID: PMC10690214 DOI: 10.1101/2023.11.20.567786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
A novel group of biocidal compounds are the Crystal 3D (Cry) and Cytolytic (Cyt) proteins produced by Bacillus thuringiensis (Bt). Some Bt Cry proteins have a selective nematocidal activity, with Cry5B being the most studied. Cry5B kills nematode parasites by binding selectively to membrane glycosphingolipids, then forming pores in the cell membranes of the intestine leading to damage. Cry5B selectively targets multiple species of nematodes from different clades and has no effect against mammalian hosts. Levamisole is a cholinomimetic anthelmintic that acts by selectively opening L-subtype nicotinic acetylcholine receptor ion-channels (L-AChRs) that have been found on muscles of nematodes. A synergistic nematocidal interaction between levamisole and Cry5B has been described previously, but the location, mechanism and time-course of this synergism is not known. In this study we follow the timeline of the effects of levamisole and Cry5B on the Ca2+ levels in enterocyte cells from the intestine of Ascaris suum using fluorescence imaging. The peak Ca2+ responses to levamisole were observed after approximately 10 minutes while the peak responses to activated Cry5B were observed after approximately 80 minutes. When levamisole and Cry5B were applied simultaneously, we observed that the responses to Cry5B were bigger and occurred sooner than when it was applied by itself. It is proposed that there is an irreversible cytoplasmic Ca2+ overload that leads to necrotic cell-death in the enterocyte that is induced by levamisole opening Ca2+ permeable L-subtype nAChRs and the development of Ca2+ permeable Cry5B toxin pores in enterocyte plasma membranes. The effects of levamisole potentiate and speed the actions of Cry5B.
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Affiliation(s)
- Paul D. E. Williams
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America
| | - Matthew T. Brewer
- Department of Veterinary Pathology, Iowa State University, Ames, Iowa, United States of America
| | - Raffi Aroian
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Alan P. Robertson
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America
| | - Richard J. Martin
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America
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3
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Chen F, Pang C, Zheng Z, Zhou W, Guo Z, Xiao D, Du H, Bravo A, Soberón M, Sun M, Peng D. Aminopeptidase MNP-1 triggers intestine protease production by activating daf-16 nuclear location to degrade pore-forming toxins in Caenorhabditis elegans. PLoS Pathog 2023; 19:e1011507. [PMID: 37440595 PMCID: PMC10368266 DOI: 10.1371/journal.ppat.1011507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Accepted: 06/23/2023] [Indexed: 07/15/2023] Open
Abstract
Pore-forming toxins (PFTs) are effective tools for pathogens infection. By disrupting epithelial barriers and killing immune cells, PFTs promotes the colonization and reproduction of pathogenic microorganisms in their host. In turn, the host triggers defense responses, such as endocytosis, exocytosis, or autophagy. Bacillus thuringiensis (Bt) bacteria produce PFT, known as crystal proteins (Cry) which damage the intestinal cells of insects or nematodes, eventually killing them. In insects, aminopeptidase N (APN) has been shown to act as an important receptor for Cry toxins. Here, using the nematode Caenorhabditis elegans as model, an extensive screening of APN gene family was performed to analyze the potential role of these proteins in the mode of action of Cry5Ba against the nematode. We found that one APN, MNP-1, participate in the toxin defense response, since the mnp-1(ok2434) mutant showed a Cry5Ba hypersensitive phenotype. Gene expression analysis in mnp-1(ok2434) mutant revealed the involvement of two protease genes, F19C6.4 and R03G8.6, that participate in Cry5Ba degradation. Finally, analysis of the transduction pathway involved in F19C6.4 and R03G8.6 expression revealed that upon Cry5Ba exposure, the worms up regulated both protease genes through the activation of the FOXO transcription factor DAF-16, which was translocated into the nucleus. The nuclear location of DAF-16 was found to be dependent on mnp-1 under Cry5Ba treatment. Our work provides evidence of new host responses against PFTs produced by an enteric pathogenic bacterium, resulting in activation of host intestinal proteases that degrade the PFT in the intestine.
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Affiliation(s)
- Feng Chen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China
| | - Cuiyun Pang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China
| | - Ziqiang Zheng
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China
| | - Wei Zhou
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China
| | - Zhiqing Guo
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China
| | - Danyang Xiao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China
| | - Hongwen Du
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China
| | - Alejandra Bravo
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
| | - Mario Soberón
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
| | - Ming Sun
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China
| | - Donghai Peng
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China
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4
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Li H, Gazzola D, Hu Y, Aroian RV. An efficient method for viable cryopreservation and recovery of hookworms and other gastrointestinal nematodes in the laboratory. Int J Parasitol 2023; 53:451-458. [PMID: 37201563 PMCID: PMC10330584 DOI: 10.1016/j.ijpara.2023.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 04/11/2023] [Accepted: 05/03/2023] [Indexed: 05/20/2023]
Abstract
Hookworms (genera Ancylostoma and Necator) are amongst the most prevalent and important parasites of humans globally. These intestinal parasites ingest blood, resulting in anemia, growth stunting, malnutrition, and adverse pregnancy outcomes. They are also critical parasites of dogs and other animals. In addition, hookworms and hookworm products are being explored for their use in treatment of autoimmune and inflammatory diseases. There is thus a significant and growing interest in these mammalian host-obligate parasites. Laboratory research is hampered by the lack of good means of cryopreservation and recovery of parasites. Here, we describe a robust method for long-term (≥3 year) cryopreservation and recovery of both Ancylostoma and Necator hookworms that is also applicable to two other intestinal parasites that passage through the infective L3 stage, Strongyloides ratti and Heligmosomoides polygyrus bakeri. The key is a revised recovery method, in which cryopreserved L1s are thawed and raised to the infective L3 stage using activated charcoal mixed with uninfected feces from a permissive host. This technique will greatly facilitate research on and availability of gastrointestinal parasitic nematodes with great importance to global health, companion animal health, and autoimmune/inflammatory disease therapies.
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Affiliation(s)
- Hanchen Li
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - David Gazzola
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Yan Hu
- Department of Biology, Worcester State University, Worcester, MA, USA
| | - Raffi V Aroian
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA.
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5
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Li H, Gazzola D, Hu Y, Aroian RV. An efficient method for viable cryopreservation of hookworms and other gastrointestinal nematodes in the laboratory. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.01.526637. [PMID: 36778351 PMCID: PMC9915591 DOI: 10.1101/2023.02.01.526637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Hookworms (genera Ancylostoma and Necator ) are amongst of the most prevalent and important parasites of humans globally. These intestinal parasites ingest blood, resulting in anemia, growth stunting, malnutrition, and adverse pregnancy outcomes. They are also critical parasites of dogs and other animals. In addition, hookworms and hookworm products are being explored for their use in treatment of autoimmune and inflammatory diseases. There is thus a significant and growing interest in these mammalian host-obligate parasites. Laboratory research is hampered by the lack of good means of cryopreservation. Here, we describe a robust method for long-term (≥3 year) cryoprotection and recovery of both Ancylostoma and Necator hookworms that is also applicable to two other intestinal parasites that passages through the infective third larval stage, Strongyloides ratti and H eligmosomoides polygyrus bakeri . The key is the use cryo-preserved first-staged larvae raised to the infective third larval stage using activated charcoal mixed with uninfected feces from a permissive host. This technique will greatly facilitate research on and availability of gastrointestinal parasitic nematodes with great importance to global health, companion animal health, and autoimmune/inflammatory disease therapies.
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Shalash AO, Becker L, Yang J, Giacomin P, Pearson M, Hussein WM, Loukas A, Toth I, Skwarczynski M. Development of a Peptide Vaccine against Hookworm Infection: Immunogenicity, Efficacy, and Immune Correlates of Protection. J Allergy Clin Immunol 2022; 150:157-169.e10. [DOI: 10.1016/j.jaci.2022.02.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/14/2022] [Accepted: 02/21/2022] [Indexed: 10/18/2022]
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Shalash AO, Hussein WM, Skwarczynski M, Toth I. Hookworm infection: Toward development of safe and effective peptide vaccines. J Allergy Clin Immunol 2021; 148:1394-1419.e6. [PMID: 34872650 DOI: 10.1016/j.jaci.2021.10.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 10/07/2021] [Accepted: 10/18/2021] [Indexed: 11/28/2022]
Abstract
Hookworms are hematophagous nematode parasites that have infected a billion people worldwide. Anthelmintic drugs have limited efficacy and do not prevent reinfection. Therefore, prophylactic vaccines are in high demand. Whole parasite vaccines are allergic and unsafe; thus, research into subunit vaccines has been warranted. A comprehensive overview of protein or peptide subunit vaccines' safety, protective efficacy, and associated immune responses is provided herein. The differences between the immune responses against hookworm infection by patients from epidemic versus nonepidemic areas are discussed in detail. Moreover, the different immunologic mechanisms of protection are discussed, including those that rely on allergic and nonallergic humoral and antibody-dependent cellular responses. The allergic and autoimmune potential of hookworm antigens is also explored, as are the immunoregulatory responses induced by the hookworm secretome. The potential of oral mucosal immunizations has been overlooked. Oral immunity against hookworms is a long-lived and safer immune response that is associated with elimination of infection and protective against reinfections. However, the harsh conditions of the gastrointestinal environment necessitates special oral delivery systems to unlock vaccines' protective potential. The potential for development of safer and more effective peptide- and protein-based anthelmintic vaccines is explored herein.
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Affiliation(s)
- Ahmed O Shalash
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Waleed M Hussein
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Mariusz Skwarczynski
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia.
| | - Istvan Toth
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia; School of Pharmacy, The University of Queensland, Woolloongabba, Queensland, Australia.
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8
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Bacillus thuringiensis: From biopesticides to anticancer agents. Biochimie 2021; 192:83-90. [PMID: 34653542 DOI: 10.1016/j.biochi.2021.10.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 09/17/2021] [Accepted: 10/06/2021] [Indexed: 01/22/2023]
Abstract
Bacillus thuringiensis (Bt) is a ubiquitous bacterium that produces several proteins that are toxic to different invertebrates such as insects, nematodes, mites, and also some protozoans. Among these, Cry and Cyt proteins are most explored as biopesticides for their action against agricultural pests and vectors of human diseases. In 2000, a group of researchers from Japan isolated parasporal inclusion proteins from B. thuringiensis, and reported their cytotoxic action against human leukemia. Later, other proteins with similar antitumor properties were also isolated from this bacterium and these cytotoxic proteins with specific activity against human cancer cells were named parasporins. At present, nineteen different parasporins are registered and classified in six families. These parasporins have been described to have specific in vitro antitumor activity against several cancer cell lines. The antitumor activity makes parasporins possible candidates as anticancer agents. Various research groups around the world are involved in isolating and characterizing in vitro antitumor activity of these proteins and many articles reporting such activities in detail have been published. However, there are virtually no data regarding the antitumor activity of parasporins in vivo. This review summarizes the properties of these potentially useful antitumor agents of natural origin, focusing on their in vivo activity thus also highlighting the importance of testing these proteins in animal models for a possible application in clinical oncology.
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9
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Soto ER, Rus F, Li H, Garceau C, Chicca J, Elfawal M, Gazzola D, Nielsen MK, Urban JF, Aroian RV, Ostroff GR. Yeast Particle Encapsulation of Scaffolded Terpene Compounds for Controlled Terpene Release. Foods 2021; 10:1207. [PMID: 34071798 PMCID: PMC8228553 DOI: 10.3390/foods10061207] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/16/2021] [Accepted: 05/20/2021] [Indexed: 12/27/2022] Open
Abstract
Terpenes are naturally occurring compounds produced by plants that are of great commercial interest in the food, agricultural, cosmetic, and pharmaceutical industries due to their broad spectra of antibacterial, antifungal, anthelmintic, membrane permeation enhancement, and antioxidant biological activities. Applications of terpenes are often limited by their volatility and the need for surfactants or alcohols to produce stable, soluble (non-precipitated) products. Yeast particles (YPs) are hollow, porous microspheres that have been used for the encapsulation of terpenes (YP terpenes) by passive diffusion of terpenes through the porous YP cell walls. We here report the development of a second generation YP encapsulated terpene technology that incorporates the stimuli-responsive control of terpene release using biodegradable pro-terpene compounds (YP pro-terpenes). YP terpenes and YP pro-terpenes were both produced, in which high levels of carvacrol, eugenol, thymol and geraniol were encapsulated. The YP pro-terpenes show higher encapsulation stability than YP terpenes due to pro-terpenes being non-volatile solids at room temperature and stable in suspensions at neutral pH. YP pro-terpenes and YP terpenes were evaluated for biological activity in antibacterial, antifungal and anthelmintic assays. The YP pro-terpenes retained the full biological activity of the parent terpene compound.
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Affiliation(s)
- Ernesto R. Soto
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA; (E.R.S.); (F.R.); (H.L.); (C.G.); (J.C.); (M.E.); (D.G.); (R.V.A.)
| | - Florentina Rus
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA; (E.R.S.); (F.R.); (H.L.); (C.G.); (J.C.); (M.E.); (D.G.); (R.V.A.)
| | - Hanchen Li
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA; (E.R.S.); (F.R.); (H.L.); (C.G.); (J.C.); (M.E.); (D.G.); (R.V.A.)
| | - Carli Garceau
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA; (E.R.S.); (F.R.); (H.L.); (C.G.); (J.C.); (M.E.); (D.G.); (R.V.A.)
| | - Jeffrey Chicca
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA; (E.R.S.); (F.R.); (H.L.); (C.G.); (J.C.); (M.E.); (D.G.); (R.V.A.)
| | - Mostafa Elfawal
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA; (E.R.S.); (F.R.); (H.L.); (C.G.); (J.C.); (M.E.); (D.G.); (R.V.A.)
| | - David Gazzola
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA; (E.R.S.); (F.R.); (H.L.); (C.G.); (J.C.); (M.E.); (D.G.); (R.V.A.)
| | - Martin K. Nielsen
- M.H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY 40546, USA;
| | - Joseph F. Urban
- Beltsville Human Nutrition Research Center, Diet, Genomics and Immunology Laboratory, United States Department of Agriculture, Agricultural Research Service, Beltsville, MD 20705, USA;
- Beltsville Agricultural Research Center, Animal and Parasitic Diseases Laboratory, United States Department of Agriculture, Agricultural Research Service, Beltsville, MD 20705, USA
| | - Raffi V. Aroian
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA; (E.R.S.); (F.R.); (H.L.); (C.G.); (J.C.); (M.E.); (D.G.); (R.V.A.)
| | - Gary R. Ostroff
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA; (E.R.S.); (F.R.); (H.L.); (C.G.); (J.C.); (M.E.); (D.G.); (R.V.A.)
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10
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Urban JF, Nielsen MK, Gazzola D, Xie Y, Beshah E, Hu Y, Li H, Rus F, Flanagan K, Draper A, Vakalapudi S, Li RW, Ostroff GR, Aroian RV. An inactivated bacterium (paraprobiotic) expressing Bacillus thuringiensis Cry5B as a therapeutic for Ascaris and Parascaris spp. infections in large animals. One Health 2021; 12:100241. [PMID: 33889707 PMCID: PMC8048022 DOI: 10.1016/j.onehlt.2021.100241] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 03/22/2021] [Accepted: 03/22/2021] [Indexed: 02/07/2023] Open
Abstract
Ascaris and Parascaris are important parasites in the family Ascarididae, large, ubiquitous intestinal-dwelling nematodes infecting all classes of vertebrates. Parasitic nematode drug resistance in veterinary medicine and drug recalcitrance in human medicine are increasing worldwide, with few if any new therapeutic classes on the horizon. Some of these parasites are zoonotic, e.g., Ascaris is passed from humans to pigs and vice versa. The development of new therapies against this family of parasites would have major implications for both human and livestock health. Here we tested the therapeutic ability of a paraprobiotic or dead probiotic that expresses the Bacillus thuringiensis Cry5B protein with known anthelmintic properties, against zoonotic Ascaris suum and Parascaris spp. This paraprobiotic, known as IBaCC, intoxicated A. suum larvae in vitro and was highly effective in vivo against intestinal A. suum infections in a new mouse model for this parasite. Fermentation was scaled up to 350 l to treat pigs and horses. Single dose Cry5B IBaCC nearly completely cleared A. suum infections in pigs. Furthermore, single dose Cry5B IBaCC drove fecal egg counts in Parascaris-infected foals to zero, showing at least parity with, and potential superiority to, current efficacy of anthelmintics used against this parasite. Cry5B IBaCC therefore represents a new, paraprobiotic One Health approach towards targeting Ascarididae that is safe, effective, massively scalable, stable, and useful in human and veterinary medicine in both the developed and developing regions of the world. IBaCC is Bacillus thuringiensis Cry5B protein crystals trapped inside dead bacteria. IBaCC intoxicates Ascaris suum intestinal parasitic nematodes in vitro. IBaCC is highly effective against A. suum parasites in vivo in mice and pigs. IBaCC is highly effective against related Parascaris parasites in foals. IBaCC represents a new paradigm for treating ascarid parasites of humans and animals.
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Affiliation(s)
- Joseph F Urban
- U. S. Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal and Parasitic Diseases Laboratory, Beltsville, MD, United States of America.,U. S. Department of Agriculture, Agricultural Research Service, Beltsville Human Nutrition Research Center, Diet, Genomics and Immunology Laboratory, Beltsville, MD, United States of America
| | - Martin K Nielsen
- M.H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, United States of America
| | - David Gazzola
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - Yue Xie
- U. S. Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal and Parasitic Diseases Laboratory, Beltsville, MD, United States of America.,U. S. Department of Agriculture, Agricultural Research Service, Beltsville Human Nutrition Research Center, Diet, Genomics and Immunology Laboratory, Beltsville, MD, United States of America.,Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Sichuan, China
| | - Ethiopia Beshah
- U. S. Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal and Parasitic Diseases Laboratory, Beltsville, MD, United States of America.,U. S. Department of Agriculture, Agricultural Research Service, Beltsville Human Nutrition Research Center, Diet, Genomics and Immunology Laboratory, Beltsville, MD, United States of America
| | - Yan Hu
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - Hanchen Li
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - Florentina Rus
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - Kelly Flanagan
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - Austin Draper
- Synthetic Biomanufacturing Facility, Utah State University, Logan, UT, United States of America
| | - Sridhar Vakalapudi
- Synthetic Biomanufacturing Facility, Utah State University, Logan, UT, United States of America
| | - Robert W Li
- U. S. Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal and Parasitic Diseases Laboratory, Beltsville, MD, United States of America
| | - Gary R Ostroff
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - Raffi V Aroian
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, United States of America
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11
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Recombinant Paraprobiotics as a New Paradigm for Treating Gastrointestinal Nematode Parasites of Humans. Antimicrob Agents Chemother 2021; 65:AAC.01469-20. [PMID: 33318013 PMCID: PMC8092541 DOI: 10.1128/aac.01469-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 12/08/2020] [Indexed: 12/11/2022] Open
Abstract
Gastrointestinal nematodes (GINs) of humans, e.g., hookworms, negatively impact childhood growth, cognition, nutrition, educational attainment, income, productivity, and pregnancy. Hundreds of millions of people are targeted with mass drug administration (MDA) of donated benzimidazole anthelmintics. Gastrointestinal nematodes (GINs) of humans, e.g., hookworms, negatively impact childhood growth, cognition, nutrition, educational attainment, income, productivity, and pregnancy. Hundreds of millions of people are targeted with mass drug administration (MDA) of donated benzimidazole anthelmintics. However, benzimidazole efficacy against GINs is suboptimal, and reduced/low efficacy has been seen. Developing an anthelmintic for human MDA is daunting: it must be safe, effective, inexpensive, stable without a cold chain, and massively scalable. Bacillus thuringiensis crystal protein 5B (Cry5B) has anthelmintic properties that could fill this void. Here, we developed an active pharmaceutical ingredient (API) containing B. thuringiensis Cry5B compatible with MDA. We expressed Cry5B in asporogenous B. thuringiensis during vegetative phase, forming cytosolic crystals. These bacteria with cytosolic crystals (BaCC) were rendered inviable (inactivated BaCC [IBaCC]) with food-grade essential oils. IBaCC potency was validated in vitro against nematodes. IBaCC was also potent in vivo against human hookworm infections in hamsters. IBaCC production was successfully scaled to 350 liters at a contract manufacturing facility. A simple fit-for-purpose formulation to protect against stomach digestion and powdered IBaCC were successfully made and used against GINs in hamsters and mice. A pilot histopathology study and blood chemistry workup showed that five daily consecutive doses of 200 mg/kg body weight Cry5B IBaCC (the curative single dose is 40 mg/kg) was nontoxic to hamsters and completely safe. IBaCC is a safe, inexpensive, highly effective, easy-to-manufacture, and scalable anthelmintic that is practical for MDA and represents a new paradigm for treating human GINs.
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Sanders J, Xie Y, Gazzola D, Li H, Abraham A, Flanagan K, Rus F, Miller M, Hu Y, Guynn S, Draper A, Vakalapudi S, Petersson KH, Zarlenga D, Li RW, Urban JF, Ostroff GR, Zajac A, Aroian RV. A new paraprobiotic-based treatment for control of Haemonchus contortus in sheep. Int J Parasitol Drugs Drug Resist 2020; 14:230-236. [PMID: 33242790 PMCID: PMC7695930 DOI: 10.1016/j.ijpddr.2020.11.004] [Citation(s) in RCA: 9] [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: 09/08/2020] [Revised: 11/16/2020] [Accepted: 11/16/2020] [Indexed: 12/21/2022]
Abstract
Haemonchus contortus is a critical parasite of goats and sheep. Infection by this blood-feeding gastrointestinal nematode (GIN) parasite has significant health consequences, especially in lambs and kids. The parasite has developed resistance to virtually all known classes of small molecule anthelmintics used to treat it, giving rise in some areas to multidrug resistant parasites that are very difficult to control. Thus, new anthelmintics are urgently needed. Bacillus thuringiensis (Bt) crystal protein 5B (Cry5B), a naturally occurring protein made by a bacterium widely and safely used around the world as a bioinsecticide, represents a new non-small molecule modality for treating GINs. Cry5B has demonstrated anthelmintic activities against parasites of monogastric animals, including some related to those that infect humans, but has not yet been studied in a ruminant. Here we show that H. contortus adults are susceptible to Cry5B protein in vitro. Cry5B produced in its natural form as a spore-crystal lysate against H. contortus infections in goats had no significant efficacy. However, a new Active Pharmaceutical Ingredient (API) paraprobiotic form of Cry5B called IBaCC (Inactivated Bacterium with Cytosolic Crystals), in which Cry5B crystals are encapsulated in dead Bt cell wall ghosts, showed excellent efficacy in vitro against larval stages of H. contortus and relative protein stability in bovine rumen fluid. When given to sheep experimentally infected with H. contortus as three 60 mg/kg doses, Cry5B IBaCC resulted in significant reductions in fecal egg counts (90%) and parasite burdens (72%), with a very high impact on female parasites (96% reduction). These data indicate that Cry5B IBaCC is a potent new treatment tool for small ruminants in the battle against H. contortus.
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Affiliation(s)
- John Sanders
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Yue Xie
- United State Department of Agriculture, Agricultural Research Service, Beltsville Human Nutrition Research Center, Diet, Genomics, Immunology Laboratory, Beltsville, MD, 20705, USA
| | - David Gazzola
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, 01605, USA
| | - Hanchen Li
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, 01605, USA
| | - Ambily Abraham
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, 01605, USA
| | - Kelly Flanagan
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, 01605, USA
| | - Florentina Rus
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, 01605, USA
| | - Melanie Miller
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Yan Hu
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, 01605, USA; Biology Department, Worcester State University, Worcester, MA, 01602, USA
| | - Sierra Guynn
- Department of Large Animal Clinical Sciences, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Austin Draper
- Synthetic Biomanufacturing Facility, Utah State University, Logan, UT, 84341, USA
| | - Sridhar Vakalapudi
- Synthetic Biomanufacturing Facility, Utah State University, Logan, UT, 84341, USA
| | - Katherine H Petersson
- Department of Fisheries, Animal, and Veterinary Sciences, University of Rhode Island, Kingston, RI, 02881, USA
| | - Dante Zarlenga
- United State Department of Agriculture, Agricultural Research Service, Animal Parasitic Diseases Laboratory, Beltsville, MD, 20705, USA
| | - Robert W Li
- United State Department of Agriculture, Agricultural Research Service, Animal Parasitic Diseases Laboratory, Beltsville, MD, 20705, USA
| | - Joseph F Urban
- United State Department of Agriculture, Agricultural Research Service, Beltsville Human Nutrition Research Center, Diet, Genomics, Immunology Laboratory, Beltsville, MD, 20705, USA; United State Department of Agriculture, Agricultural Research Service, Animal Parasitic Diseases Laboratory, Beltsville, MD, 20705, USA
| | - Gary R Ostroff
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, 01605, USA
| | - Anne Zajac
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Raffi V Aroian
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, 01605, USA.
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13
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Mirza Z, Soto ER, Hu Y, Nguyen TT, Koch D, Aroian RV, Ostroff GR. Anthelmintic Activity of Yeast Particle-Encapsulated Terpenes. Molecules 2020; 25:E2958. [PMID: 32605043 PMCID: PMC7411854 DOI: 10.3390/molecules25132958] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 06/22/2020] [Accepted: 06/24/2020] [Indexed: 12/31/2022] Open
Abstract
Soil-transmitted nematodes (STN) infect 1-2 billion of the poorest people worldwide. Only benzimidazoles are currently used in mass drug administration, with many instances of reduced activity. Terpenes are a class of compounds with anthelmintic activity. Thymol, a natural monoterpene phenol, was used to help eradicate hookworms in the U.S. South circa 1910. However, the use of terpenes as anthelmintics was discontinued because of adverse side effects associated with high doses and premature stomach absorption. Furthermore, the dose-response activity of specific terpenes against STNs has been understudied. Here we used hollow, porous yeast particles (YPs) to efficiently encapsulate (>95%) high levels of terpenes (52% w/w) and evaluated their anthelmintic activity on hookworms (Ancylostoma ceylanicum), a rodent parasite (Nippostrongylus brasiliensis), and whipworm (Trichuris muris). We identified YP-terpenes that were effective against all three parasites. Further, YP-terpenes overcame albendazole-resistant Caenorhabditis elegans. These results demonstrate that terpenes are broad-acting anthelmintics. Terpenes are predicted to be extremely difficult for parasites to resist, and YP encapsulation provides water-suspendable terpene materials without surfactants and sustained terpene release that could lead to the development of formulations for oral delivery that overcome fast absorption in the stomach, thus reducing dosage and toxic side effects.
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Affiliation(s)
- Zeynep Mirza
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA; (Z.M.); (E.R.S.); (Y.H.); (T.-T.N.); (D.K.); (R.V.A.)
| | - Ernesto R. Soto
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA; (Z.M.); (E.R.S.); (Y.H.); (T.-T.N.); (D.K.); (R.V.A.)
| | - Yan Hu
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA; (Z.M.); (E.R.S.); (Y.H.); (T.-T.N.); (D.K.); (R.V.A.)
- Department of Biology, Worcester State University, Worcester, MA 01602, USA
| | - Thanh-Thanh Nguyen
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA; (Z.M.); (E.R.S.); (Y.H.); (T.-T.N.); (D.K.); (R.V.A.)
| | - David Koch
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA; (Z.M.); (E.R.S.); (Y.H.); (T.-T.N.); (D.K.); (R.V.A.)
| | - Raffi V. Aroian
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA; (Z.M.); (E.R.S.); (Y.H.); (T.-T.N.); (D.K.); (R.V.A.)
| | - Gary R. Ostroff
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA; (Z.M.); (E.R.S.); (Y.H.); (T.-T.N.); (D.K.); (R.V.A.)
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Charuchaibovorn S, Sanprasert V, Sutthanont N, Hu Y, Abraham A, Ostroff GR, Aroian RV, Jaleta TG, Lok JB, Nuchprayoon S. Bacillus thuringiensis Cry5B is Active against Strongyloides stercoralis in vitro. Am J Trop Med Hyg 2020; 101:1177-1182. [PMID: 31516117 DOI: 10.4269/ajtmh.19-0083] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Strongyloidiasis, caused by Strongyloides stercoralis infection, is an important neglected tropical disease that causes significant public health problems in the tropics and subtropics. The disease can persist in hosts for decades and may be life-threatening because of hyperinfection and dissemination. Ivermectin (mostly) and albendazole are the most common anthelmintics used for treatment. Albendazole is suboptimal for this parasite, and although ivermectin is quite effective in immunocompromised patients, a multiple-course regimen is required. Furthermore, reliance on a single drug class for treating intestinal nematodes is a recipe for future failure. Therefore, it is important to discover new anthelmintics to treat or prevent human strongyloidiasis. One promising candidate is the Bacillus thuringiensis crystal protein Cry5B. Cry5B is highly potent against parasitic nematodes, for example, hookworms and Ascaris suum. Here, we investigated the potential of Cry5B against S. stercoralis. Multiple stages of S. stercoralis, including the first larval stage (L1s), infective stage (iL3s), free-living adult stage, and parasitic female stage, were all susceptible to Cry5B as indicated by impairment of motility and decreased viability in vitro. In summary, Cry5B demonstrated strong potential as an effective anthelmintic for treatment and transmission control of human strongyloidiasis, justifying further experiments to investigate in vivo therapeutic efficacy.
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Affiliation(s)
- Sarit Charuchaibovorn
- Siriraj Center of Excellence for Stem Cell Research (SiSCR), Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.,Lymphatic Filariasis and Tropical Medicine Research Unit, Chulalongkorn Medical Research Center, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Vivornpun Sanprasert
- Department of Parasitology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.,Lymphatic Filariasis and Tropical Medicine Research Unit, Chulalongkorn Medical Research Center, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Nataya Sutthanont
- Lymphatic Filariasis and Tropical Medicine Research Unit, Chulalongkorn Medical Research Center, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Yan Hu
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts.,Biology Department, Worcester State University, Worcester, Massachusetts
| | - Ambily Abraham
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Gary R Ostroff
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Raffi V Aroian
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Tegegn G Jaleta
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - James B Lok
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Surang Nuchprayoon
- Lymphatic Filariasis and Tropical Medicine Research Unit, Chulalongkorn Medical Research Center, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.,Department of Parasitology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
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Drug Screening for Discovery of Broad-spectrum Agents for Soil-transmitted Nematodes. Sci Rep 2019; 9:12347. [PMID: 31451730 PMCID: PMC6710243 DOI: 10.1038/s41598-019-48720-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Accepted: 08/05/2019] [Indexed: 12/17/2022] Open
Abstract
Soil-transmitted nematodes (STNs), namely hookworms, whipworms, and ascarids, are extremely common parasites, infecting 1-2 billion of the poorest people worldwide. Two benzimidazoles, albendazole and mebendazole, are currently used in STN mass drug administration, with many instances of low/reduced activity reported. New drugs against STNs are urgently needed. We tested various models for STN drug screening with the aim of identifying the most effective tactics for the discovery of potent, safe and broad-spectrum agents. We screened a 1280-compound library of approved drugs to completion against late larval/adult stages and egg/larval stages of both the human hookworm parasite Ancylostoma ceylanicum and the free-living nematode Caenorhabditis elegans, which is often used as a surrogate for STNs in screens. The quality of positives was further evaluated based on cheminformatics/data mining analyses and activity against evolutionarily distant Trichuris muris whipworm adults. From these data, two pairs of positives, sulconazole/econazole and pararosaniline/cetylpyridinium, predicted to target nematode CYP-450 and HSP-90 respectively, were prioritized for in vivo evaluation against A. ceylanicum infections in hamsters. One of these positives, pararosaniline, showed a significant impact on hookworm fecundity in vivo. Taken together, our results suggest that anthelmintic screening with A. ceylanicum larval stages is superior to C. elegans based on both reduced false negative rate and superior overall quality of actives. Our results also highlight two potentially important targets for the discovery of broad-spectrum human STN drugs.
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16
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Identification of small molecule enzyme inhibitors as broad-spectrum anthelmintics. Sci Rep 2019; 9:9085. [PMID: 31235822 PMCID: PMC6591293 DOI: 10.1038/s41598-019-45548-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 06/06/2019] [Indexed: 11/18/2022] Open
Abstract
Targeting chokepoint enzymes in metabolic pathways has led to new drugs for cancers, autoimmune disorders and infectious diseases. This is also a cornerstone approach for discovery and development of anthelmintics against nematode and flatworm parasites. Here, we performed omics-driven knowledge-based identification of chokepoint enzymes as anthelmintic targets. We prioritized 10 of 186 phylogenetically conserved chokepoint enzymes and undertook a target class repurposing approach to test and identify new small molecules with broad spectrum anthelmintic activity. First, we identified and tested 94 commercially available compounds using an in vitro phenotypic assay, and discovered 11 hits that inhibited nematode motility. Based on these findings, we performed chemogenomic screening and tested 32 additional compounds, identifying 6 more active hits. Overall, 6 intestinal (single-species), 5 potential pan-intestinal (whipworm and hookworm) and 6 pan-Phylum Nematoda (intestinal and filarial species) small molecule inhibitors were identified, including multiple azoles, Tadalafil and Torin-1. The active hit compounds targeted three different target classes in humans, which are involved in various pathways, including carbohydrate, amino acid and nucleotide metabolism. Last, using representative inhibitors from each target class, we demonstrated in vivo efficacy characterized by negative effects on parasite fecundity in hamsters infected with hookworms.
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17
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Cognitive and Microbiome Impacts of Experimental Ancylostoma ceylanicum Hookworm Infections in Hamsters. Sci Rep 2019; 9:7868. [PMID: 31133690 PMCID: PMC6536493 DOI: 10.1038/s41598-019-44301-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 05/13/2019] [Indexed: 12/13/2022] Open
Abstract
Hookworms are one of the most prevalent and important parasites, infecting ~500 million people worldwide. Hookworm disease is among the leading causes of iron-deficiency anemia in the developing world and is associated with significant growth stunting and malnutrition. In humans, hookworms appear to impair memory and other forms of cognition, although definitive data are hard to come by. Here we study the impact of a human hookworm parasite, Ancylostoma ceylanicum, on cognition in hamsters in a controlled laboratory setting. We developed tests that measure long-term memory in hamsters. We find that hookworm-infected hamsters were fully capable of detecting a novel object. However, hookworm-infected hamsters were impaired in detecting a displaced object. Defects could be discerned at even at low levels of infection, whereas at higher levels of infection, hamsters were statistically unable to distinguish between displaced and non-displaced objects. These spatial memory deficiencies could not be attributed to defects in infected hamster mobility or to lack of interest. We also found that hookworm infection resulted in reproducible reductions in diversity and changes in specific taxanomic groups in the hamster gut microbiome. These data demonstrate that human hookworm infection in a laboratory mammal results in a specific, rapid, acute, and measurable deficit in spatial memory, and we speculate that gut alterations could play some role in these cognitive deficits. Our findings highlight the importance of hookworm elimination and suggest that finer tuned spatial memory studies be carried out in humans.
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Noon JB, Schwarz EM, Ostroff GR, Aroian RV. A highly expressed intestinal cysteine protease of Ancylostoma ceylanicum protects vaccinated hamsters from hookworm infection. PLoS Negl Trop Dis 2019; 13:e0007345. [PMID: 31009474 PMCID: PMC6497320 DOI: 10.1371/journal.pntd.0007345] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 05/02/2019] [Accepted: 03/28/2019] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Human hookworms (Necator americanus, Ancylostoma duodenale, and Ancylostoma ceylanicum) are intestinal blood-feeding parasites that infect ~500 million people worldwide and are among the leading causes of iron-deficiency anemia in the developing world. Drugs are useful against hookworm infections, but hookworms rapidly reinfect people, and the parasites can develop drug resistance. Therefore, having a hookworm vaccine would be of tremendous benefit. METHODOLOGY/PRINCIPAL FINDINGS We investigated the vaccine efficacy in outbred Syrian hamsters of three A. ceylanicum hookworm antigen candidates from two classes of proteins previously identified as promising vaccine candidates. These include two intestinally-enriched, putatively secreted cathepsin B cysteine proteases (AceyCP1, AceyCPL) and one small Kunitz-type protease inhibitor (AceySKPI3). Recombinant proteins were produced in Pichia pastoris, and adsorbed to Alhydrogel. Recombinant AceyCPL (rAceyCPL)/Alhydrogel and rAceySKPI3/Alhydrogel induced high serum immunoglobulin G (IgG) titers in 8/8 vaccinates, but were not protective. rAceyCP1/Alhydrogel induced intermediate serum IgG titers in ~60% of vaccinates in two different trials. rAceyCP1 serum IgG responders had highly significantly decreased hookworm burdens, fecal egg counts and clinical pathology compared to Alhydrogel controls and nonresponders. Protection was highly correlated with rAceyCP1 serum IgG titer. Antisera from rAceyCP1 serum IgG responders, but not nonresponders or rAceyCPL/Alhydrogel vaccinates, significantly reduced adult A. ceylanicum motility in vitro. Furthermore, rAceyCP1 serum IgG responders had canonical Th2-specific recall responses (IL4, IL5, IL13) in splenocytes stimulated ex vivo. CONCLUSIONS/SIGNIFICANCE These findings indicate that rAceyCP1 is a promising vaccine candidate and validates a genomic/transcriptomic approach to human hookworm vaccine discovery.
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Affiliation(s)
- Jason B. Noon
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Erich M. Schwarz
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - Gary R. Ostroff
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Raffi V. Aroian
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
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Hu Y, Miller M, Zhang B, Nguyen TT, Nielsen MK, Aroian RV. In vivo and in vitro studies of Cry5B and nicotinic acetylcholine receptor agonist anthelmintics reveal a powerful and unique combination therapy against intestinal nematode parasites. PLoS Negl Trop Dis 2018; 12:e0006506. [PMID: 29775454 PMCID: PMC5979042 DOI: 10.1371/journal.pntd.0006506] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 05/31/2018] [Accepted: 05/08/2018] [Indexed: 01/21/2023] Open
Abstract
Background The soil-transmitted nematodes (STNs) or helminths (hookworms, whipworms, large roundworms) infect the intestines of ~1.5 billion of the poorest peoples and are leading causes of morbidity worldwide. Only one class of anthelmintic or anti-nematode drugs, the benzimidazoles, is currently used in mass drug administrations, which is a dangerous situation. New anti-nematode drugs are urgently needed. Bacillus thuringiensis crystal protein Cry5B is a powerful, promising new candidate. Drug combinations, when properly made, are ideal for treating infectious diseases. Although there are some clinical trials using drug combinations against STNs, little quantitative and systemic work has been performed to define the characteristics of these combinations in vivo. Methodology/Principal findings Working with the hookworm Ancylostoma ceylanicum-hamster infection system, we establish a laboratory paradigm for studying anti-nematode combinations in vivo using Cry5B and the nicotinic acetylcholine receptor (nAChR) agonists tribendimidine and pyrantel pamoate. We demonstrate that Cry5B strongly synergizes in vivo with both tribendimidine and pyrantel at specific dose ratios against hookworm infections. For example, whereas 1 mg/kg Cry5B and 1 mg/kg tribendimidine individually resulted in only a 0%-6% reduction in hookworm burdens, the combination of the two resulted in a 41% reduction (P = 0.020). Furthermore, when mixed at synergistic ratios, these combinations eradicate hookworm infections at doses where the individual doses do not. Using cyathostomin nematode parasites of horses, we find based on inhibitory concentration 50% values that a strongylid parasite population doubly resistant to nAChR agonists and benzimidazoles is more susceptible or “hypersusceptible” to Cry5B than a cyathostomin population not resistant to nAChR agonists, consistent with previous Caenhorhabditis elegans results. Conclusions/Significance Our study provides a powerful means by which anthelmintic combination therapies can be examined in vivo in the laboratory. In addition, we demonstrate that Cry5B and nAChR agonists have excellent combinatorial properties—Cry5B combined with nAChR agonists gives rise to potent cures that are predicted to be recalcitrant to the development of parasite resistance. These drug combinations highlight bright spots in new anthelmintic development for human and veterinary animal intestinal nematode infections. Intestinal nematodes are roundworm parasites of humans and animals, causing significant morbidity in both. In humans, these parasites are leading causes of morbidity in children, e.g., causing growth stunting, cognitive impairment, and malnutrition. Few drugs are used to treat these parasites in humans and animals and there is increasing evidence that the drugs are losing efficacy and/or have low efficacy. Infectious diseases are best treated with drug combinations and not single drugs. However, there has been little work to characterize in detail how various anti-nematode drugs combine. Here we establish a new laboratory model to study anti-nematode drug combinations using the human hookworm Ancylostoma ceylanicum infection in hamsters. We show that two classes of anti-nematode drugs, Cry5B and the nicotinic acetylcholine receptor agonists tribendimidine and pyrantel, combine (synergize) in a way that is more powerful at specific drug ratios than predicted from their individual impacts. Furthermore, when combined at these ratios, these combinations completely eliminated parasites at doses where normally neither drug has that effect. Horse parasites resistant to pyrantel also appear to be hypersensitive (more sensitive than wild-type parasites) to Cry5B. These characteristics predict that combinations of Cry5B with tribendimidine or pyrantel will be extremely effective therapeutically and relatively recalcitrant to the development of parasite resistance.
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Affiliation(s)
- Yan Hu
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - Melanie Miller
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA, United States of America
| | - Bo Zhang
- Department of Quantitative Health Sciences, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - Thanh-Thanh Nguyen
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - Martin K. Nielsen
- Department of Veterinary Science, University of Kentucky, Lexington, KY, United States of America
| | - Raffi V. Aroian
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, United States of America
- * E-mail:
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Bacillus thuringiensis Cry5B protein as a new pan-hookworm cure. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2018; 8:287-294. [PMID: 29772478 PMCID: PMC6039361 DOI: 10.1016/j.ijpddr.2018.05.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 04/27/2018] [Accepted: 05/03/2018] [Indexed: 11/20/2022]
Abstract
Hookworms are intestinal nematode parasites that infect nearly half a billion people and are globally one of the most important contributors to iron-deficiency anemia. These parasites have significant impacts in developing children, pregnant women and working adults. Of all the soil-transmitted helminths or nematodes (STNs), hookworms are by far the most important, with disease burdens conservatively estimated at four million DALYs (Disability-Adjusted Life Years) and with productivity losses of up to US$139 billion annually. To date, mainly one drug, albendazole is used for hookworm therapy in mass drug administration, which has on average ∼80% cure rate that is lower (<40%) in some places. Given the massive numbers of people needing treatment, the threat of parasite resistance, and the inadequacy of current treatments, new and better cures against hookworms are urgently needed. Cry5B, a pore-forming protein produced by the soil bacterium Bacillus thuringiensis (Bt) has demonstrated good efficacy against Ancylostoma ceylanicum hookworm infections in hamsters. Here we broaden studies of Cry5B to include tests against infections of Ancylostoma caninum hookworms in dogs and against infections of the dominant human hookworm, Necator americanus, in hamsters. We show that Cry5B is highly effective against all hookworm parasites tested in all models. Neutralization of stomach acid improves Cry5B efficacy, which will aid in practical application of Cry5B significantly. Importantly, we also demonstrate that the anti-nematode therapeutic efficacy of Cry5B is independent of the host immune system and is not itself negated by repeated dosing. This study indicates that Bt Cry5B is a pan-hookworm anthelmintic with excellent properties for use in humans and other animals.
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Loukas A, Hotez PJ, Diemert D, Yazdanbakhsh M, McCarthy JS, Correa-Oliveira R, Croese J, Bethony JM. Hookworm infection. Nat Rev Dis Primers 2016; 2:16088. [PMID: 27929101 DOI: 10.1038/nrdp.2016.88] [Citation(s) in RCA: 161] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Hookworms are soil-transmitted nematode parasites that can reside for many years in the small intestine of their human hosts; Necator americanus is the predominant infecting species. Adult worms feed on the blood of a host and can cause iron deficiency anaemia, especially in high-risk populations (children and women of childbearing age). Almost 500 million people in developing tropical countries are infected, and simulation models estimate that hookworm infection is responsible for >4 million disability-adjusted life years lost annually. Humans mount an immune response to hookworms, but it is mostly unsuccessful at removing adult worms from the bowel. Accordingly, the host switches to an immune-tolerant state that enables hookworms to reside in the gut for many years. Although anthelmintic drugs are available and widely used, their efficacy varies and the drugs do not prevent reinfection. Thus, other control strategies aimed at improving water quality, sanitation and hygiene are needed. In addition, efforts are underway to develop a human hookworm vaccine through public-private partnerships. However, hookworms could also be a resource; as hookworms have the capability to regulate the host's inflammation, researchers are experimentally infecting patients to treat some inflammatory diseases as an approach to discover new anti-inflammatory molecules. This area of endeavour might well yield new biotherapeutics for autoimmune and allergic diseases.
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Affiliation(s)
- Alex Loukas
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, Building E4, James Cook University, McGregor Rd, Smithfield, Cairns, Queensland 4878, Australia
| | - Peter J Hotez
- Departments of Pediatrics and Molecular Virology and Microbiology, National School of Tropical Medicine, Baylor College Of Medicine, Houston, Texas, USA.,Sabin Vaccine Institute, Houston, Texas, USA.,Texas Children's Hospital Center for Vaccine Development, Houston, Texas, USA
| | - David Diemert
- Department of Microbiology, Tropical Medicine and Immunology, George Washington University, Washington DC, USA.,Sabin Vaccine Institute, Washington DC, USA
| | - Maria Yazdanbakhsh
- Department of Parasitology, Leiden University Medical Centre, Leiden, The Netherlands
| | - James S McCarthy
- Queensland Institute of Medical Research (QIMR) Berghofer Medical Research Institute, Brisbane, Queensland, Australia.,University of Queensland, Brisbane, Queensland, Australia
| | | | - John Croese
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, Building E4, James Cook University, McGregor Rd, Smithfield, Cairns, Queensland 4878, Australia.,Department of Gastroenterology, Prince Charles Hospital, Brisbane, Queensland, Australia
| | - Jeffrey M Bethony
- Department of Microbiology, Tropical Medicine and Immunology, George Washington University, Washington DC, USA
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Larvicidal activity of Bacillus circulans against the gastrointestinal nematode Haemonchus contortus in sheep. J Helminthol 2016; 90:68-73. [PMID: 26693886 DOI: 10.1017/s0022149x14000844] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Efficient control of gastrointestinal parasites is necessary in sheep breeding. However, the available chemically based anthelmintics are becoming less effective due to the development of parasite resistance. An alternative to this problem is biological control. In the present study, we tested the larvicidal effect of Bacillus circulans by administering a spore suspension (2 × 109 colony forming units/ml) orally to lambs naturally infected with Haemonchus contortus. The number of faecal larvae was quantified daily and a significant reduction (~87%, P< 0.05) of larval development was observed after administration of B. circulans. Using a transformed B. circulans with green fluorescent protein, we were able to detect B. circulans in the faeces at 4 h post-administration and 72 h after cessation of its administration. These results suggest the use of B. circulans as a promising biological alternative for parasite control.
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Huang J, Guan Z, Wan L, Zou T, Sun M. Crystal structure of Cry6Aa: A novel nematicidal ClyA-type α-pore-forming toxin from Bacillus thuringiensis. Biochem Biophys Res Commun 2016; 478:307-313. [DOI: 10.1016/j.bbrc.2016.07.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Accepted: 07/01/2016] [Indexed: 01/30/2023]
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Entomotoxic and nematotoxic lectins and protease inhibitors from fungal fruiting bodies. Appl Microbiol Biotechnol 2015; 100:91-111. [DOI: 10.1007/s00253-015-7075-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 10/04/2015] [Accepted: 10/11/2015] [Indexed: 01/26/2023]
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Wang Q, Rosa BA, Jasmer DP, Mitreva M. Pan-Nematoda Transcriptomic Elucidation of Essential Intestinal Functions and Therapeutic Targets With Broad Potential. EBioMedicine 2015; 2:1079-89. [PMID: 26501106 PMCID: PMC4587998 DOI: 10.1016/j.ebiom.2015.07.030] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 07/22/2015] [Accepted: 07/22/2015] [Indexed: 01/22/2023] Open
Abstract
The nematode intestine is continuous with the outside environment, making it easily accessible to anthelmintics for parasite control, but the development of new therapeutics is impeded by limited knowledge of nematode intestinal cell biology. We established the most comprehensive nematode intestinal functional database to date by generating transcriptional data from the dissected intestines of three parasitic nematodes spanning the phylum, and integrating the results with the whole proteomes of 10 nematodes (including 9 pathogens of humans or animals) and 3 host species and 2 outgroup species. We resolved 10,772 predicted nematode intestinal protein families (IntFams), and studied their presence and absence within the different lineages (births and deaths) among nematodes. Conserved intestinal cell functions representing ancestral functions of evolutionary importance were delineated, and molecular features useful for selective therapeutic targeting were identified. Molecular patterns conserved among IntFam proteins demonstrated large potential as therapeutic targets to inhibit intestinal cell functions with broad applications towards treatment and control of parasitic nematodes.
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Affiliation(s)
- Qi Wang
- McDonnell Genome Institute, Washington University School of Medicine, St. Louis, MO, USA
| | - Bruce A. Rosa
- McDonnell Genome Institute, Washington University School of Medicine, St. Louis, MO, USA
| | - Douglas P. Jasmer
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, USA
| | - Makedonka Mitreva
- McDonnell Genome Institute, Washington University School of Medicine, St. Louis, MO, USA
- Division of Infectious Disease, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, USA
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Wu CC, Hu Y, Miller M, Aroian RV, Sailor MJ. Protection and Delivery of Anthelmintic Protein Cry5B to Nematodes Using Mesoporous Silicon Particles. ACS NANO 2015; 9:6158-67. [PMID: 25950754 PMCID: PMC5704939 DOI: 10.1021/acsnano.5b01426] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The ability of nano- and microparticles of partially oxidized mesoporous silicon (pSi) to sequester, protect, and deliver the anthelmintic pore-forming protein Cry5B to nematodes is assessed in vitro and in vivo. Thermally oxidized pSi particles are stable under gastric conditions and show relatively low toxicity to nematodes. Fluorescence images of rhodamine-labeled pSi particles within the nematodes Caenorhabditis elegans and Ancylostoma ceylanicum show that ingestion is dependent on particle size: particles of a 0.4 ± 0.2 μm size are noticeably ingested by both species within 2 h of introduction in vitro, whereas 5 ± 2 μm particles are excluded from C. elegans but enter the pharynx region of A. ceylanicum after 24 h. The anthelmintic protein Cry5B, a pore-forming crystal (Cry) protein derived from Bacillus thuringiensis, is incorporated into the pSi particles by aqueous infiltration. Feeding of Cry5B-loaded pSi particles to C. elegans leads to significant intoxication of the nematode. Protein-loaded particles of size 0.4 μm display the highest level of in vitro toxicity toward C. elegans on a drug-mass basis. The porous nanostructure protects Cry5B from hydrolytic and enzymatic (pepsin) degradation in simulated gastric fluid (pH 1.2) for time periods up to 2 h. In vivo experiments with hookworm-infected hamsters show no significant reduction in worm burden with the Cry5B-loaded particles, which is attributed to slow release of the protein from the particles and/or short residence time of the particles in the duodenum of the animal.
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Affiliation(s)
- Chia-Chen Wu
- Materials Science and Engineering, University of California, San Diego, La Jolla, California 92093, United States
| | - Yan Hu
- Section of Cell and Development Biology, University of California, San Diego, La Jolla, California 92093, United States
| | - Melanie Miller
- Section of Cell and Development Biology, University of California, San Diego, La Jolla, California 92093, United States
| | - Raffi V. Aroian
- Section of Cell and Development Biology, University of California, San Diego, La Jolla, California 92093, United States
| | - Michael J. Sailor
- Materials Science and Engineering, University of California, San Diego, La Jolla, California 92093, United States
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
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Schwarz EM, Hu Y, Antoshechkin I, Miller MM, Sternberg PW, Aroian RV. The genome and transcriptome of the zoonotic hookworm Ancylostoma ceylanicum identify infection-specific gene families. Nat Genet 2015; 47:416-22. [PMID: 25730766 PMCID: PMC4617383 DOI: 10.1038/ng.3237] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Accepted: 02/05/2015] [Indexed: 12/19/2022]
Abstract
Hookworms infect over 400 million people, stunting and impoverishing them. Sequencing hookworm genomes and finding which genes they express during infection should help in devising new drugs or vaccines against hookworms. Unlike other hookworms, Ancylostoma ceylanicum infects both humans and other mammals, providing a laboratory model for hookworm disease. We determined an A. ceylanicum genome sequence of 313 Mb, with transcriptomic data throughout infection showing expression of 30,738 genes. Approximately 900 genes were upregulated during early infection in vivo, including ASPRs, a cryptic subfamily of activation-associated secreted proteins (ASPs). Genes downregulated during early infection included ion channels and G protein-coupled receptors; this downregulation was observed in both parasitic and free-living nematodes. Later, at the onset of heavy blood feeding, C-lectin genes were upregulated along with genes for secreted clade V proteins (SCVPs), encoding a previously undescribed protein family. These findings provide new drug and vaccine targets and should help elucidate hookworm pathogenesis.
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Affiliation(s)
- Erich M Schwarz
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, USA
| | - Yan Hu
- 1] Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA. [2] Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, California, USA
| | - Igor Antoshechkin
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA
| | - Melanie M Miller
- Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, California, USA
| | - Paul W Sternberg
- 1] Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA. [2] Howard Hughes Medical Institute, California Institute of Technology, Pasadena, California, USA
| | - Raffi V Aroian
- 1] Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA. [2] Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, California, USA
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Abstract
PURPOSE OF REVIEW To highlight the gastrointestinal helminths in the context of renewed global commitment to control or eliminate neglected tropical diseases in the coming decade. RECENT FINDINGS Two key documents, namely the 2012 London Declaration for Neglected Tropical Diseases and the 2013 World Health Assembly resolution, emphasize the importance of mass drug administration (MDA) for controlling several key neglected tropical diseases. These documents, together with the Global Burden of Disease Study 2010, establish the major gastrointestinal helminth infections, including the soil-transmitted helminthiases - ascariasis, trichuriasis, hookworm, and strongyloidiasis - in addition to the intestinal and liver fluke infections, as some of the most important gastrointestinal infections of humankind. Current MDA approaches using single-dose albendazole or mebendazole are effective for ascariasis, less so for other soil-transmitted helminth infections. Expanded use of albendazole in combination with ivermectin would ensure improved drug efficacies against trichuriasis and strongyloidiasis. There is no effective elimination strategy for targeting hookworm and liver and intestinal fluke infections through current MDA approaches. SUMMARY The global community must expand current MDA efforts, while simultaneously developing additional drugs, diagnostics, and vaccines alongside better utilizing transmission dynamics and modeling, if it is to successfully meet the goals and targets established by policymakers.
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Hu Y, Ellis BL, Yiu YY, Miller MM, Urban JF, Shi LZ, Aroian RV. An extensive comparison of the effect of anthelmintic classes on diverse nematodes. PLoS One 2013; 8:e70702. [PMID: 23869246 PMCID: PMC3712009 DOI: 10.1371/journal.pone.0070702] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 06/20/2013] [Indexed: 11/19/2022] Open
Abstract
Soil-transmitted helminths are parasitic nematodes that inhabit the human intestine. These parasites, which include two hookworm species, Ancylostomaduodenale and Necator americanus, the whipworm Trichuristrichiura, and the large roundworm Ascarislumbricoides, infect upwards of two billion people and are a major cause of disease burden in children and pregnant women. The challenge with treating these diseases is that poverty, safety, and inefficient public health policy have marginalized drug development and distribution to control infection in humans. Anthelmintics (anti-worm drugs) have historically been developed and tested for treatment of non-human parasitic nematodes that infect livestock and companion animals. Here we systematically compare the in vitro efficacy of all major anthelmintic classes currently used in human therapy (benzimidazoles, nicotinic acetylcholine receptor agonists, macrocyclic lactones, nitazoxanide) against species closely related to human parasitic nematodes-Ancylostoma ceylanicum, Trichurismuris, and Ascarissuum--- as well as a rodent parasitic nematode used in veterinary drug discovery, Heligmosomoidesbakeri, and the free-living nematode Caenorhabditis elegans. Extensive in vitro data is complemented with single-dose in vivo data in three rodent models of parasitic diseases. We find that the effects of the drugs in vitro and in vivo can vary greatly among these nematode species, e.g., the efficacy of albendazole is strong on A. ceylanicum but weak on H. bakeri. Nonetheless, certain commonalities of the in vitro effects of the drugs can be seen, e.g., nitazoxanide consistently shows an all-or-nothing response. Our in vitro data suggest that further optimization of the clinical efficacy of some of these anthelmintics could be achieved by altering the treatment routine and/or dosing. Most importantly, our in vitro and in vivo data indicate that the hookworm A. ceylanicum is a particularly sensitive and useful model for anthelmintic studies and should be incorporated early on in drug screens for broad-spectrum human soil-transmitted helminth therapies.
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Affiliation(s)
- Yan Hu
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Brian L. Ellis
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Ying Y. Yiu
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Melanie M. Miller
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Joseph F. Urban
- United States Department of Agriculture, Agriculture Research Service, Beltsville Human Nutrition Research Center, Diet, Genomics and Immunology Laboratory, Beltsville, Maryland, United States of America
| | - Linda Z. Shi
- Institute of Engineering in Medicine, University of California, San Diego, La Jolla, California, United States of America
| | - Raffi V. Aroian
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
- * E-mail:
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Bacillus subtilis strain engineered for treatment of soil-transmitted helminth diseases. Appl Environ Microbiol 2013; 79:5527-32. [PMID: 23835175 DOI: 10.1128/aem.01854-13] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Soil-transmitted helminths (hookworms, whipworms, and large roundworms) are agents of intestinal roundworm diseases of poverty that infect upwards of 2 billion people worldwide. A great challenge in treating these diseases is the development of anthelmintic therapeutics that are inexpensive, can be produced in great quantity, and are capable of delivery under varied and adverse environmental conditions. A potential solution to this challenge is the use of live bacteria that are acceptable for human consumption, e.g., Bacillus subtilis, and that can be engineered with therapeutic properties. In this study, we expressed the Bacillus thuringiensis anthelmintic protein Cry5B in a bacterial strain that has been used as a model for live bacterial therapy, Bacillus subtilis PY79. PY79 transformed with a Cry5B expression plasmid (PY79-Cry5B) is able to express Cry5B from the endogenous B. thuringiensis cry5B promoter. During sporulation of PY79-Cry5B, Cry5B is packaged as a crystal. Furthermore, Cry5B produced in PY79 is bioactive, with a 50% lethal concentration (LC50) of 4.3 μg/ml against the roundworm Caenorhabditis elegans. PY79-Cry5B was a significantly effective therapeutic in experimental Ancylostoma ceylanicum hookworm infections of hamsters. A single 10-mg/kg (0.071 μmol/kg of body weight) dose of Cry5B administered as a Cry5B-PY79 spore crystal lysate achieved a 93% reduction in hookworm burdens, which is superior on a molar level to reductions seen with clinically used anthelmintics. Given that a bacterial strain such as this one can be produced cheaply in massive quantities, our results demonstrate that the engineering and delivery of live bacterial strains have great potential to treat a significant contributor to poverty worldwide, namely, hookworm disease and other soil-transmitted helminthiasis.
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Urban JF, Hu Y, Miller MM, Scheib U, Yiu YY, Aroian RV. Bacillus thuringiensis-derived Cry5B has potent anthelmintic activity against Ascaris suum. PLoS Negl Trop Dis 2013; 7:e2263. [PMID: 23818995 PMCID: PMC3688533 DOI: 10.1371/journal.pntd.0002263] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 04/27/2013] [Indexed: 11/18/2022] Open
Abstract
Ascaris suum and Ascaris lumbricoides are two closely related geo-helminth parasites that ubiquitously infect pigs and humans, respectively. Ascaris suum infection in pigs is considered a good model for A. lumbricoides infection in humans because of a similar biology and tissue migration to the intestines. Ascaris lumbricoides infections in children are associated with malnutrition, growth and cognitive stunting, immune defects, and, in extreme cases, life-threatening blockage of the digestive tract and aberrant migration into the bile duct and peritoneum. Similar effects can be seen with A. suum infections in pigs related to poor feed efficiency and performance. New strategies to control Ascaris infections are needed largely due to reduced treatment efficacies of current anthelmintics in the field, the threat of resistance development, and the general lack of new drug development for intestinal soil-transmitted helminths for humans and animals. Here we demonstrate for the first time that A. suum expresses the receptors for Bacillus thuringiensis crystal protein and novel anthelmintic Cry5B, which has been previously shown to intoxicate hookworms and which belongs to a class of proteins considered non-toxic to vertebrates. Cry5B is able to intoxicate A. suum larvae and adults and triggers the activation of the p38 mitogen-activated protein kinase pathway similar to that observed with other nematodes. Most importantly, two moderate doses of 20 mg/kg body weight (143 nM/kg) of Cry5B resulted in a near complete cure of intestinal A. suum infections in pigs. Taken together, these results demonstrate the excellent potential of Cry5B to treat Ascaris infections in pigs and in humans and for Cry5B to work effectively in the human gastrointestinal tract. Ascaris suum is an intestinal parasitic nematode of pigs that is very closely related to Ascaris lumbricoides, a major intestinal parasitic nematode of humans that infects more than one billion people worldwide. Because of reduced efficacy and the threat of resistance to the current small set of approved drugs to treat Ascaris infections, new treatments are needed. Here we test against A. suum infections the effectiveness of Cry5B, a nematode-killing protein made by the natural soil bacterium Bacillus thuringiensis and representing a promising new class of anthelmintics. We demonstrate for the first time that A. suum possesses the receptors to bind Cry5B and that Cry5B can kill A. suum larvae and adults in culture. Most importantly, we demonstrate that oral administration of Cry5B to pigs infected with A. suum larvae results in a near complete elimination of the infection. Given the similarities between A. suum and A. lumbricoides and the similarity between the pig and human gastrointestinal tracts, our data indicate that Cry5B has excellent potential to treat Ascaris infections in veterinary animals and in humans.
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Affiliation(s)
- Joseph F. Urban
- USDA, Agricultural Research Service, Beltsville Human Nutrition Research Center, Diet, Genomics, and Immunology Laboratory, Beltsville, Maryland, United States of America
| | - Yan Hu
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Melanie M. Miller
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Ulrike Scheib
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Ying Y. Yiu
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Raffi V. Aroian
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
- * E-mail:
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