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Gokool S, Townson S, Freeman A, Siemienski-Kleyn J, Zubrzycki J, Tagboto S, Hübner MP, Scandale I. Onchocerciasis Drug Discovery: In Vitro Evaluation of FDA-Approved Drugs against Onchocerca gutturosa in Gambia. Pharmaceutics 2024; 16:210. [PMID: 38399264 PMCID: PMC10891533 DOI: 10.3390/pharmaceutics16020210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 01/18/2024] [Accepted: 01/25/2024] [Indexed: 02/25/2024] Open
Abstract
Onchocerciasis treatment and control relies mainly on the use of ivermectin which has high activity against the microfilarial stage of Onchocerca volvulus but limited activity against the long-lived, tissue dwelling adult nematodes. As this neglected tropical disease has now been targeted for elimination, there is an urgent need for new drugs to combat these parasites, ideally with macrofilaricidal activity. In this study, we have examined the anti-Onchocerca activity of a range of existing FDA-approved drugs with a view to repurposing, which can lead to rapid and relatively inexpensive development. From the Pharmakon-1600 library, 106 drugs were selected and tested against O. gutturosa adult male parasites using a concentration of 1.25 × 10-5 M in an in vitro 5-day standard assay to assess motility and viability (using MTT/formazan colorimetry). The findings revealed that 44 drugs produced marginal/moderate activity (50-99% motility and/or MTT reductions) including cefuroxime sodium, methenamine, primaquine phosphate and rivastigmine tartrate, while 23 drugs produced good activity (100% motility reductions and significant MTT reductions), including atovaquone, isradipine, losartan, rifaximin, cefaclor and pyrantel pamoate. Although this study represents only a first step, some of the identified hits indicate there are potential anti-Onchocerca drug candidates worthy of further investigation.
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Affiliation(s)
- Suzanne Gokool
- Tropical Parasitic Diseases Unit, Northwick Park Institute for Medical Research, Watford Road, Harrow, London HA1 3UJ, UK; (S.G.); (S.T.)
| | - Simon Townson
- Tropical Parasitic Diseases Unit, Northwick Park Institute for Medical Research, Watford Road, Harrow, London HA1 3UJ, UK; (S.G.); (S.T.)
| | - Andrew Freeman
- Tropical Parasitic Diseases Unit, Northwick Park Institute for Medical Research, Watford Road, Harrow, London HA1 3UJ, UK; (S.G.); (S.T.)
| | - Jadzia Siemienski-Kleyn
- Tropical Parasitic Diseases Unit, Northwick Park Institute for Medical Research, Watford Road, Harrow, London HA1 3UJ, UK; (S.G.); (S.T.)
| | - Jakub Zubrzycki
- Tropical Parasitic Diseases Unit, Northwick Park Institute for Medical Research, Watford Road, Harrow, London HA1 3UJ, UK; (S.G.); (S.T.)
| | - Senyo Tagboto
- Tropical Parasitic Diseases Unit, Northwick Park Institute for Medical Research, Watford Road, Harrow, London HA1 3UJ, UK; (S.G.); (S.T.)
| | - Marc P. Hübner
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany;
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, 53127 Bonn, Germany
| | - Ivan Scandale
- Drugs for Neglected Diseases Initiative, 1202 Geneva, Switzerland;
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2
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Williams PDE, Kashyap SS, Robertson AP, Martin RJ. Diethylcarbamazine elicits Ca 2+ signals through TRP-2 channels that are potentiated by emodepside in Brugia malayi muscles. Antimicrob Agents Chemother 2023; 67:e0041923. [PMID: 37728916 PMCID: PMC10583680 DOI: 10.1128/aac.00419-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Accepted: 07/03/2023] [Indexed: 09/22/2023] Open
Abstract
Filarial nematode infections are a major health concern in several countries. Lymphatic filariasis is caused by Wuchereria bancrofti and Brugia spp. affecting over 120 million people. Heavy infections can lead to elephantiasis, which has serious effects on individuals' lives. Although current anthelmintics are effective at killing microfilariae in the bloodstream, they have little to no effect against adult parasites found in the lymphatic system. The anthelmintic diethylcarbamazine is one of the central pillars of lymphatic filariasis control. Recent studies have reported that diethylcarbamazine can open transient receptor potential (TRP) channels in the muscles of adult female Brugia malayi, leading to contraction and paralysis. Diethylcarbamazine has synergistic effects in combination with emodepside on Brugia, inhibiting motility: emodepside is an anthelmintic that has effects on filarial nematodes and is under trial for the treatment of river blindness. Here, we have studied the effects of diethylcarbamazine on single Brugia muscle cells by measuring the change in Ca2+ fluorescence in the muscle using Ca2+-imaging techniques. Diethylcarbamazine interacts with the transient receptor potential channel, C classification (TRPC) ortholog receptor TRP-2 to promote Ca2+ entry into the Brugia muscle cells, which can activate Slopoke (SLO-1) Ca2+-activated K+ channels, the putative target of emodepside. A combination of diethylcarbamazine and emodepside leads to a bigger Ca2+ signal than when either compound is applied alone. Our study shows that diethylcarbamazine targets TRP channels to promote Ca2+ entry that is increased by emodepside activation of SLO-1 K+ channels.
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Affiliation(s)
| | | | - Alan P. Robertson
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, USA
| | - Richard J. Martin
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, USA
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3
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Williams PDE, Kashyap SS, Robertson AP, Martin RJ. Diethylcarbamazine elicits Ca 2+ signals through TRP-2 channels that are potentiated by emodepside in Brugia malayi muscles. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.10.536248. [PMID: 37090573 PMCID: PMC10120635 DOI: 10.1101/2023.04.10.536248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Filarial nematode infections are a major health concern in several countries. Lymphatic filariasis is caused by Wucheria bancrofti and Brugia spp. affecting over 120 million people. Heavy infections can lead to elephantiasis having serious effects on individuals’ lives. Although current anthelmintics are effective at killing the microfilariae in the bloodstream, they have little to no effect against adult parasites found in the lymphatic system. The anthelmintic diethylcarbamazine is one of the central pillars of lymphatic filariasis control. Recent studies have reported that diethylcarbamazine can open Transient Receptor Potential (TRP) channels on the muscles of adult female Brugia malayi leading to contraction and paralysis. Diethylcarbamazine has synergistic effects in combination with emodepside on Brugia inhibiting motility: emodepside is an anthelmintic that has effects on filarial nematodes and is under trials for treatment of river blindness. Here we have studied the effects of diethylcarbamazine on single Brugia muscle cells by measuring the change in Ca 2+ fluorescence in the muscle using Ca 2+ -imaging techniques. Diethylcarbamazine interacts with the TRPC orthologue receptor TRP-2 to promote Ca 2+ entry into the Brugia muscle cells which can activate SLO-1 Ca 2+ activated K + channels, the putative target of emodepside. A combination of diethylcarbamazine and emodepside leads to a bigger Ca 2+ signal than when either compound is applied alone. Our study shows that diethylcarbamazine targets TRP channels to promote Ca 2+ entry that is increased by emodepside activation of SLO-1 channels.
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4
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Pfarr KM, Krome AK, Al-Obaidi I, Batchelor H, Vaillant M, Hoerauf A, Opoku NO, Kuesel AC. The pipeline for drugs for control and elimination of neglected tropical diseases: 1. Anti-infective drugs for regulatory registration. Parasit Vectors 2023; 16:82. [PMID: 36859332 PMCID: PMC9979492 DOI: 10.1186/s13071-022-05581-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 11/05/2022] [Indexed: 03/03/2023] Open
Abstract
The World Health Organization 'Ending the neglect to attain the Sustainable Development Goals: A road map for neglected tropical diseases 2021-2030' outlines the targets for control and elimination of neglected tropical diseases (NTDs). New drugs are needed to achieve some of them. We are providing an overview of the pipeline for new anti-infective drugs for regulatory registration and steps to effective use for NTD control and elimination. Considering drugs approved for an NTD by at least one stringent regulatory authority: fexinidazole, included in WHO guidelines for Trypanosoma brucei gambiense African trypanosomiasis, is in development for Chagas disease. Moxidectin, registered in 2018 for treatment of individuals ≥ 12 years old with onchocerciasis, is undergoing studies to extend the indication to 4-11-year-old children and obtain additional data to inform WHO and endemic countries' decisions on moxidectin inclusion in guidelines and policies. Moxidectin is also being evaluated for other NTDs. Considering drugs in at least Phase 2 clinical development, a submission is being prepared for registration of acoziborole as an oral treatment for first and second stage T.b. gambiense African trypanosomiasis. Bedaquiline, registered for tuberculosis, is being evaluated for multibacillary leprosy. Phase 2 studies of emodepside and flubentylosin in O. volvulus-infected individuals are ongoing; studies for Trichuris trichuria and hookworm are planned. A trial of fosravuconazole in Madurella mycetomatis-infected patients is ongoing. JNJ-64281802 is undergoing Phase 2 trials for reducing dengue viral load. Studies are ongoing or planned to evaluate oxantel pamoate for onchocerciasis and soil-transmitted helminths, including Trichuris, and oxfendazole for onchocerciasis, Fasciola hepatica, Taenia solium cysticercosis, Echinococcus granulosus and soil-transmitted helminths, including Trichuris. Additional steps from first registration to effective use for NTD control and elimination include country registrations, possibly additional studies to inform WHO guidelines and country policies, and implementation research to address barriers to effective use of new drugs. Relative to the number of people suffering from NTDs, the pipeline is small. Close collaboration and exchange of experience among all stakeholders developing drugs for NTDs may increase the probability that the current pipeline will translate into new drugs effectively implemented in affected countries.
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Affiliation(s)
- Kenneth M. Pfarr
- grid.15090.3d0000 0000 8786 803XInstitute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany ,grid.452463.2German Center for Infection Research, Partner Site Bonn-Cologne, Bonn, Germany
| | - Anna K. Krome
- grid.10388.320000 0001 2240 3300Department of Pharmaceutical Technology and Biopharmaceutics, University of Bonn, Bonn, Germany
| | - Issraa Al-Obaidi
- grid.11984.350000000121138138Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Hannah Batchelor
- grid.11984.350000000121138138Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Michel Vaillant
- grid.451012.30000 0004 0621 531XCompetence Center for Methodology and Statistics, Luxembourg Institute of Health, Strassen, Grand Duchy of Luxembourg
| | - Achim Hoerauf
- grid.15090.3d0000 0000 8786 803XInstitute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany ,grid.452463.2German Center for Infection Research, Partner Site Bonn-Cologne, Bonn, Germany
| | - Nicholas O. Opoku
- grid.449729.50000 0004 7707 5975Department of Epidemiology and Biostatistics School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana
| | - Annette C. Kuesel
- UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (WHO/TDR), World Health Organization, Geneva, Switzerland
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5
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Hawryluk N, Robinson D, Shen Y, Kyne G, Bedore M, Menon S, Canan S, von Geldern T, Townson S, Gokool S, Ehrens A, Koschel M, Lhermitte-Vallarino N, Martin C, Hoerauf A, Hernandez G, Dalvie D, Specht S, Hübner MP, Scandale I. Discovery of Substituted Di(pyridin-2-yl)-1,2,4-thiadiazol-5-amines as Novel Macrofilaricidal Compounds for the Treatment of Human Filarial Infections. J Med Chem 2022; 65:11388-11403. [PMID: 35972896 PMCID: PMC9421654 DOI: 10.1021/acs.jmedchem.2c00960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Filarial diseases, including lymphatic filariasis and onchocerciasis, are considered among the most devastating of all tropical diseases, affecting about 145 million people worldwide. Efforts to control and eliminate onchocerciasis are impeded by a lack of effective treatments that target the adult filarial stage. Herein, we describe the discovery of a series of substituted di(pyridin-2-yl)-1,2,4-thiadiazol-5-amines as novel macrofilaricides for the treatment of human filarial infections.
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Affiliation(s)
- Natalie Hawryluk
- Bristol Myers Squibb, San Diego, California 92121, United States
| | - Dale Robinson
- Bristol Myers Squibb, San Diego, California 92121, United States
| | - Yixing Shen
- Bristol Myers Squibb, San Diego, California 92121, United States
| | - Graham Kyne
- Zoetis, Kalamazoo, Michigan 49001, United States
| | | | - Sanjay Menon
- Zoetis, Kalamazoo, Michigan 49001, United States
| | - Stacie Canan
- Bristol Myers Squibb, San Diego, California 92121, United States
| | | | - Simon Townson
- Northwick Park Institute for Medical Research, London HA1 3UJ, UK
| | - Suzanne Gokool
- Northwick Park Institute for Medical Research, London HA1 3UJ, UK
| | - Alexandra Ehrens
- Institute for Medical Microbiology, Immunology & Parasitology, University Hospital Bonn, 53127 Bonn, Germany.,German Center for Infection Research (DZIF), partner site Bonn-Cologne, 53127 Bonn, Germany
| | - Marianne Koschel
- Institute for Medical Microbiology, Immunology & Parasitology, University Hospital Bonn, 53127 Bonn, Germany
| | - Nathaly Lhermitte-Vallarino
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Muséum national d'Histoire Naturelle, Paris 75005, France
| | - Coralie Martin
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Muséum national d'Histoire Naturelle, Paris 75005, France
| | - Achim Hoerauf
- Institute for Medical Microbiology, Immunology & Parasitology, University Hospital Bonn, 53127 Bonn, Germany.,German Center for Infection Research (DZIF), partner site Bonn-Cologne, 53127 Bonn, Germany
| | | | - Deepak Dalvie
- Bristol Myers Squibb, San Diego, California 92121, United States
| | - Sabine Specht
- Institute for Medical Microbiology, Immunology & Parasitology, University Hospital Bonn, 53127 Bonn, Germany.,Drugs for Neglected Diseases Initiative, Geneva 1204, Switzerland
| | - Marc Peter Hübner
- Institute for Medical Microbiology, Immunology & Parasitology, University Hospital Bonn, 53127 Bonn, Germany.,German Center for Infection Research (DZIF), partner site Bonn-Cologne, 53127 Bonn, Germany
| | - Ivan Scandale
- Drugs for Neglected Diseases Initiative, Geneva 1204, Switzerland
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6
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Hawryluk N, Zhiru L, Carlow C, Gokool S, Townson S, Kreiss T, Chojnowski A, Prorok M, Siekierka J, Ehrens A, Koschel M, Lhermitte-Vallarino N, Martin C, Hoerauf A, Hernandez G, Canan S, Khetani V, Zeldis J, Specht S, Hübner MP, Scandale I. Filarial nematode phenotypic screening cascade to identify compounds with anti-parasitic activity for drug discovery optimization. Int J Parasitol Drugs Drug Resist 2022; 19:89-97. [PMID: 35834918 PMCID: PMC9278491 DOI: 10.1016/j.ijpddr.2022.06.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 06/13/2022] [Accepted: 06/13/2022] [Indexed: 11/18/2022]
Abstract
Filarial diseases, including lymphatic filariasis and onchocerciasis, are considered among the most devastating of all tropical diseases, affecting over 86 million people worldwide. To control and more rapidly eliminate onchocerciasis requires treatments that target the adult stage of the parasite. Drug discovery efforts are challenged by the lack of preclinical animal models using the human-pathogenic filariae, requiring the use of surrogate parasites for Onchocerca volvulus for both ex vivo and in vivo evaluation. Herein, we describe a platform utilizing phenotypic ex vivo assays consisting of the free-living nematode Caenorhabditis elegans, microfilariae and adult filariae of the bovine filariae Onchocerca lienalis and Onchocerca gutturosa, respectively, as well as microfilariae and adult filariae of the feline filariae Brugia pahangi, the rodent filariae Litomosoides sigmodontis and the human-pathogenic filariae Brugia malayi to assess activity across various surrogate parasites. Utilization of those surrogate nematodes for phenotypic ex vivo assays in order to assess activity across various parasites led to the successful establishment of a screening cascade and identification of multiple compounds with potential macrofilaricidal activity and desirable physicochemical, MW = 200-400 and low lipophilicity, logP <4, and pharmacokinetic properties, rat and human liver S9 stability of ≥70% remaining at 60 min, and AUC exposures above 3 μM h. This platform demonstrated the successful establishment of a screening cascade which resulted in the discovery of potential novel macrofilaricidal compounds for futher drug discovery lead optimization efforts. This screening cascade identified two distinct chemical series wherein one compound produced a significant 68% reduction of adult Litomosoides sigmodontis in the mouse model. Successful demonstration of efficacy prompted lead optimization medicinal chemistry efforts for this novel series.
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Affiliation(s)
| | - Li Zhiru
- New England Biolabs, Ipswich, MA, USA
| | | | - Suzanne Gokool
- Northwick Park Institute for Medical Research, London, UK
| | - Simon Townson
- Northwick Park Institute for Medical Research, London, UK
| | - Tamara Kreiss
- Sokol Institute of Pharmaceutical Life Sciences, Montclair State University, Montclair, NJ, USA
| | - Agnieszka Chojnowski
- Sokol Institute of Pharmaceutical Life Sciences, Montclair State University, Montclair, NJ, USA
| | - Monika Prorok
- Sokol Institute of Pharmaceutical Life Sciences, Montclair State University, Montclair, NJ, USA
| | - John Siekierka
- Sokol Institute of Pharmaceutical Life Sciences, Montclair State University, Montclair, NJ, USA
| | - Alexandra Ehrens
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Germany; German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany
| | - Marianne Koschel
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Germany
| | | | - Coralie Martin
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Muséum national d'Histoire naturelle, Paris, France
| | - Achim Hoerauf
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Germany; German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany
| | | | | | | | | | - Sabine Specht
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Germany; Drugs for Neglected Diseases Initiative, Geneva, Switzerland
| | - Marc P Hübner
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Germany; German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany
| | - Ivan Scandale
- Drugs for Neglected Diseases Initiative, Geneva, Switzerland
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7
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Bazzocchi C, Genchi M, Lucchetti C, Cafiso A, Ciuca L, McCall J, Kramer LH, Vismarra A. Transporter gene expression and Wolbachia quantification in adults of Dirofilaria immitis treated in vitro with ivermectin or moxidectin alone or in combination with doxycycline for 12 hours. Mol Biochem Parasitol 2022; 249:111475. [PMID: 35346758 DOI: 10.1016/j.molbiopara.2022.111475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 03/18/2022] [Accepted: 03/21/2022] [Indexed: 11/19/2022]
Abstract
Due to their marked larvicidal activity, macrocyclic lactones (MLs) are used for the prevention of heartworm disease ( Dirofilaria immitis) in dogs. They have also been shown to eliminate adult parasites after long-term administration, with a so-called "slow-kill" effect. In addition, recent studies have established that a combination of doxycycline, which eliminates the endosymbiont Wolbachia, and MLs has superior adulticide effects when compared to MLs alone. It has been hypothesized that the apparent synergism between doxycycline/MLs may be due to interaction with drug efflux transport proteins. The aim of the present study was to evaluate gene expression of several transport proteins in D. immitis adults treated in vitro either with doxycycline alone, ivermectin alone, moxidectin alone, or a combination of ivermectin or moxidectin with doxycycline for 12h. Quantitative PCR analysis showed a sex-dependent response to treatments. In female worms, Dim-pgp-10, Dim-haf-1 and Dim-haf-5 were upregulated compared to controls with doxycycline alone and when combined with ivermectin. Moxidectin did not induce any changes in gene expression. In males, moxidectin administered alone induced a slight increase in Dim-pgp-10, Dim-pgp-11and Di-avr-14, while ivermectin in combination with doxycycline produced significant upregulation of the ML receptor Di-avr-14. These results suggest possible synergism between the two drug classes and different susceptibility of males vs. females to adulticide effects.
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Affiliation(s)
- Chiara Bazzocchi
- Dipartimento di Medicina Veterinaria e Scienze Animali, Università degli Studi di Milano, via dell'Università 6, 26900 Lodi, Italy
| | - Marco Genchi
- Dipartimento di Scienze Medico-Veterinarie, Università di Parma, via del Taglio, 10, 43126 Parma, Italy
| | - Chiara Lucchetti
- Dipartimento di Scienze Medico-Veterinarie, Università di Parma, via del Taglio, 10, 43126 Parma, Italy
| | - Alessandra Cafiso
- Dipartimento di Medicina Veterinaria e Scienze Animali, Università degli Studi di Milano, via dell'Università 6, 26900 Lodi, Italy
| | - Lavinia Ciuca
- Dipartimento di Medicina Veterinaria e Produzioni Animali, Università di Napoli Federico II, Via Federico Delpino 1, 80137 Napoli, Italy
| | - John McCall
- TRS Labs Inc, 215 Paradise Blvd, Athens, GA 30607, USA
| | - Laura Helen Kramer
- Dipartimento di Scienze Medico-Veterinarie, Università di Parma, via del Taglio, 10, 43126 Parma, Italy
| | - Alice Vismarra
- Dipartimento di Scienze Medico-Veterinarie, Università di Parma, via del Taglio, 10, 43126 Parma, Italy.
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8
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Hübner MP, Townson S, Gokool S, Tagboto S, Maclean MJ, Verocai GG, Wolstenholme AJ, Frohberger SJ, Hoerauf A, Specht S, Scandale I, Harder A, Glenschek-Sieberth M, Hahnel SR, Kulke D. Evaluation of the in vitro susceptibility of various filarial nematodes to emodepside. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2021; 17:27-35. [PMID: 34339934 PMCID: PMC8347670 DOI: 10.1016/j.ijpddr.2021.07.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 07/19/2021] [Accepted: 07/24/2021] [Indexed: 11/25/2022]
Abstract
Filariae are vector-borne nematodes responsible for an enormous burden of disease. Human lymphatic filariasis, caused by Wuchereria bancrofti, Brugia malayi, and Brugia timori, and onchocerciasis (caused by Onchocerca volvulus) are neglected parasitic diseases of major public health significance in tropical regions. To date, therapeutic efforts to eliminate human filariasis have been hampered by the lack of a drug with sufficient macrofilaricidal and/or long-term sterilizing effects that is suitable for use in mass drug administration (MDA) programs, particularly in areas co-endemic with Loa loa, the causative agent of loiasis. Emodepside, a semi-synthetic cyclooctadepsipeptide, has been shown to have broad-spectrum efficacy against gastrointestinal nematodes in a variety of mammalian hosts, and has been approved as an active ingredient in dewormers for cats and dogs. This paper evaluates, compares (where appropriate) and summarizes the in vitro effects of emodepside against a range of filarial nematodes at various developmental stages. Emodepside inhibited the motility of all tested stages of filariae frequently used as surrogate species for preclinical investigations (Acanthocheilonema viteae, Brugia pahangi, Litomosoides sigmodontis, Onchocerca gutturosa, and Onchocerca lienalis), human-pathogenic filariae (B. malayi) and filariae of veterinary importance (Dirofilaria immitis) in a concentration-dependent manner. While motility of all filariae was inhibited, both stage- and species-specific differences were observed. However, whether these differences were detected because of stage- and/or species-specific factors or as a consequence of variations in protocol parameters among the participating laboratories (such as purification of the parasites, read-out units, composition of media, incubation conditions, duration of incubation etc.) remains unclear. This study, however, clearly shows that emodepside demonstrates broad-spectrum in vitro activity against filarial nematode species across different genera and can therefore be validated as a promising candidate for the treatment of human filariases, including onchocerciasis and lymphatic filariasis.
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Affiliation(s)
- Marc P Hübner
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Venusberg-Campus 1, 53127, Bonn, Germany; German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany.
| | - Simon Townson
- Griffin Institute (formerly Northwick Park Institute for Medical Research), London, HA1 3UJ, United Kingdom.
| | - Suzanne Gokool
- Griffin Institute (formerly Northwick Park Institute for Medical Research), London, HA1 3UJ, United Kingdom.
| | - Senyo Tagboto
- Griffin Institute (formerly Northwick Park Institute for Medical Research), London, HA1 3UJ, United Kingdom.
| | - Mary J Maclean
- National Institutes of Health, National Eye Institute, Clinical and Translational Immunology Section, Laboratory of Immunology, 10 Center Drive, Building 10, Room 10N113, Bethesda, MD, 20892, USA.
| | - Guilherme G Verocai
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, 501 D.W. Brooks Drive, (current Address: INRAE Centre Val de Loire, 37380 Nouzilly, France), Athens, GA, 30602, USA; Department of Veterinary Pathobiology, College of Veterinary & Biomedical Sciences, Texas A&M University, 4467 TAMU College Station, TX, 77843, USA.
| | - Adrian J Wolstenholme
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, 501 D.W. Brooks Drive, (current Address: INRAE Centre Val de Loire, 37380 Nouzilly, France), Athens, GA, 30602, USA.
| | - Stefan J Frohberger
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Venusberg-Campus 1, 53127, Bonn, Germany.
| | - Achim Hoerauf
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Venusberg-Campus 1, 53127, Bonn, Germany; German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany.
| | - Sabine Specht
- Drugs for Neglected Diseases Initiative, Geneva, Switzerland.
| | - Ivan Scandale
- Drugs for Neglected Diseases Initiative, Geneva, Switzerland.
| | - Achim Harder
- Independent Scholar, Europaring 54, 51109, Cologne, Germany.
| | | | - Steffen R Hahnel
- Elanco Animal Health, Alfred-Nobel-Str. 50, 40789, Monheim, Germany.
| | - Daniel Kulke
- Elanco Animal Health, Alfred-Nobel-Str. 50, 40789, Monheim, Germany; Iowa State University, Department of Biomedical Sciences, 2008 Vet Med, Ames, IA, 50011, United States.
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Krücken J, Holden-Dye L, Keiser J, Prichard RK, Townson S, Makepeace BL, Hübner MP, Hahnel SR, Scandale I, Harder A, Kulke D. Development of emodepside as a possible adulticidal treatment for human onchocerciasis-The fruit of a successful industrial-academic collaboration. PLoS Pathog 2021; 17:e1009682. [PMID: 34293063 PMCID: PMC8297762 DOI: 10.1371/journal.ppat.1009682] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Current mass drug administration (MDA) programs for the treatment of human river blindness (onchocerciasis) caused by the filarial worm Onchocerca volvulus rely on ivermectin, an anthelmintic originally developed for animal health. These treatments are primarily directed against migrating microfilariae and also suppress fecundity for several months, but fail to eliminate adult O. volvulus. Therefore, elimination programs need time frames of decades, well exceeding the life span of adult worms. The situation is worsened by decreased ivermectin efficacy after long-term therapy. To improve treatment options against onchocerciasis, a drug development candidate should ideally kill or irreversibly sterilize adult worms. Emodepside is a broad-spectrum anthelmintic used for the treatment of parasitic nematodes in cats and dogs (Profender and Procox). Our current knowledge of the pharmacology of emodepside is the result of more than 2 decades of intensive collaborative research between academia and the pharmaceutical industry. Emodepside has a novel mode of action with a broad spectrum of activity, including against extraintestinal nematode stages such as migrating larvae or macrofilariae. Therefore, emodepside is considered to be among the most promising candidates for evaluation as an adulticide treatment against onchocerciasis. Consequently, in 2014, Bayer and the Drugs for Neglected Diseases initiative (DNDi) started a collaboration to develop emodepside for the treatment of patients suffering from the disease. Macrofilaricidal activity has been demonstrated in various models, including Onchocerca ochengi in cattle, the parasite most closely related to O. volvulus. Emodepside has now successfully passed Phase I clinical trials, and a Phase II study is planned. This Bayer–DNDi partnership is an outstanding example of “One World Health,” in which experience gained in veterinary science and drug development is translated to human health and leads to improved tools to combat neglected tropical diseases (NTDs) and shorten development pathways and timelines in an otherwise neglected area. Onchocerca volvulus is the causative agent of human river blindness, and current elimination programs rely on the use of ivermectin to kill microfilariae. Since no adulticidal drug is available and adult worms have a life span of up to 15 years, elimination programs need to be sustained over several decades. Emodepside is an anthelmintic that is licensed as a dewormer for cats and dogs. Due to its ability to eliminate nematodes located in various extraintestinal host tissues, including migrating larvae and adult filarial worms, it is considered to be an excellent candidate for the treatment of onchocerciasis. Intense collaboration between academia and the pharmaceutical industry has led to a deep understanding of the novel mode of action of the drug and of its parasite target spectrum. Phase I clinical trials with emodepside have demonstrated its safety and adulticide activity against the closely related cattle parasite Onchocerca ochengi. Currently, Phase II clinical trials are planned to confirm that emodepside, developed initially to improve animal health, has also the potential to improve human health by tackling a very important neglected tropical disease (NTD).
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Affiliation(s)
- Jürgen Krücken
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Lindy Holden-Dye
- School of Biological Sciences, Institute for Life Sciences, University of Southampton, Southampton, United Kingdom
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Roger K. Prichard
- Institute of Parasitology, McGill University, Sainte Anne-de-Bellevue, Quebec, Canada
| | - Simon Townson
- The Griffin Institute, Northwick Park and St. Mark’s Hospital, Harrow, United Kingdom
| | - Benjamin L. Makepeace
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Marc P. Hübner
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
- German Center for Infection Research (DZIF), partner site Bonn-Cologne, Bonn, Germany
| | - Steffen R. Hahnel
- Elanco Animal Health, Research & Exploratory Development, Monheim, Germany
| | - Ivan Scandale
- Drugs for Neglected Disease initiative, Geneva, Switzerland
| | | | - Daniel Kulke
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America
- * E-mail:
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Oxfendazole mediates macrofilaricidal efficacy against the filarial nematode Litomosoides sigmodontis in vivo and inhibits Onchocerca spec. motility in vitro. PLoS Negl Trop Dis 2020; 14:e0008427. [PMID: 32628671 PMCID: PMC7365463 DOI: 10.1371/journal.pntd.0008427] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 07/16/2020] [Accepted: 05/27/2020] [Indexed: 12/13/2022] Open
Abstract
A major impediment to eliminate lymphatic filariasis and onchocerciasis is the lack of effective short-course macrofilaricidal drugs or regimens that are proven to be safe for both infections. In this study we tested oxfendazole, an anthelmintic shown to be well tolerated in phase 1 clinical trials. In vitro, oxfendazole exhibited modest to marginal motility inhibition of adult worms of Onchocerca gutturosa, pre-adult worms of Onchocerca volvulus and Onchocerca lienalis microfilariae. In vivo, five days of oral treatments provided sterile cure with up to 100% macrofilaricidal efficacy in the murine Litomosoides sigmodontis model of filariasis. In addition, 10 days of oral treatments with oxfendazole inhibited filarial embryogenesis in patent L. sigmodontis-infected jirds and subsequently led to a protracted but complete clearance of microfilaremia. The macrofilaricidal effect observed in vivo was selective, as treatment with oxfendazole of microfilariae-injected naïve mice was ineffective. Based on pharmacokinetic analysis, the driver of efficacy is the maintenance of a minimal efficacious concentration of approximately 100 ng/ml (based on subcutaneous treatment at 25 mg/kg in mice). From animal models, the human efficacious dose is predicted to range from 1.5 to 4.1 mg/kg. Such a dose has already been proven to be safe in phase 1 clinical trials. Oxfendazole therefore has potential to be efficacious for treatment of human filariasis without causing adverse reactions due to drug-induced microfilariae killing. Onchocerciasis and lymphatic filariasis represent two debilitating filarial diseases that belong to the neglected tropical diseases. The current efforts to eliminate those diseases is hampered by the lack of short-course macrofilaricidal drugs, i.e. drugs that kill the adult worms, or regimens that are proven to be safe for both diseases. In the present study we demonstrate that the anthelmintic drug oxfendazole, currently used in veterinary medicine against intestinal helminths, has excellent efficacy in the Litomosoides sigmodontis rodent model of filariasis. Oxfendazole caused complete clearance of adult filariae after a short oral regimen in vivo. Oxfendazole was not directly active against the circulating filarial progeny, the microfilariae, suggesting that drug-induced serious adverse events due to the clearance of microfilariae are unlikely. Human dose was predicted based on the efficacy in the rodent model, the calculation estimated a low efficacious dose, which has already been shown to be safe in phase 1 clinical trials. Thus, oxfendazole represents a promising drug candidate for the treatment of human filarial diseases such as onchocerciasis and lymphatic filariasis.
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Abstract
Neglected parasitic helminth diseases such as onchocerciasis and lymphatic filariasis affect an estimated 145 million people worldwide, creating a serious health burden in endemic areas such as sub-Saharan Africa and India. Although these diseases are not usually lethal, these filarial nematodes, transmitted by blood-feeding insect vectors, cause severe debilitation and cause chronic disability to infected individuals. The adult worms can reproduce from 5 to up to 14 years, releasing millions of microfilariae, juvenile worms, over an infected individual's lifetime. The current treatments for controlling human filarial infections is focused on killing microfilariae, the earliest larval stage. Currently, there is an unmet medical need for treatments consisting of a macrofilaricidal regimen, one that targets the adult stage of the parasite, to increase the rate of elimination, allow for safe use in coendemic regions of Onchocerca volvulus and Loa loa, and to provide a rapid method to resolve reinfections. Herein, recent approaches for targeting human filarial diseases are discussed, including direct acting agents to target parasitic nematodes and antibacterial approaches to target the endosymbiotic bacteria, Wolbachia.
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Affiliation(s)
- Natalie A. Hawryluk
- Bristol-Myers Squibb, Global Health, 10300 Campus Point Drive, San Diego, California 92121, United States
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The ABL kinase inhibitor imatinib causes phenotypic changes and lethality in adult Schistosoma japonicum. Parasitol Res 2019; 118:881-890. [PMID: 30729300 DOI: 10.1007/s00436-019-06224-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 01/17/2019] [Indexed: 12/11/2022]
Abstract
Schistosomiasis caused by different species of schistosome parasites is one of the most debilitating helminthic diseases of humans worldwide. For decades, chemotherapy is the main method of controlling schistosomiasis. However, the fear of drug resistance has motivated the search for alternatives. It has been demonstrated that the ABL kinase inhibitor imatinib affected the development and survival of Schistosoma mansoni in vitro; however, there is still lack of information on whether imatinib also affects other schistosome species such as Schistosoma japonicum. In the present study, the anti-schistosomal potency of imatinib on adult S. japonicum was investigated in vitro, and the results showed that imatinib had a significant impact on various physiological processes of S. japonicum adult worms. Besides its negative effects on worm motility, pairing stability, and gonad development, imatinib caused pathological changes in the gastrodermis as well as the death of the parasite. Our findings suggest that imatinib is an intriguing candidate for further development as an option to fight S. japonicum.
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Shukla R, Gupta J, Shukla P, Dwivedi P, Tripathi P, Bhattacharya SM, Mishra PR. Chitosan coated alginate micro particles for the oral delivery of antifilarial drugs and combinations for intervention in Brugia malayi induced lymphatic filariasis. RSC Adv 2015. [DOI: 10.1039/c5ra06982c] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Mechanism of targeting of MPs and absorption through Peyer’s patches, to lymphatics where an adult worm resides.
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Affiliation(s)
- Rahul Shukla
- Pharmaceutics Division
- CSIR-Central Drug Research Institute
- Lucknow 226031
- India
| | - J. Gupta
- Parasitology Division
- CSIR-Central Drug Research Institute
- Lucknow 226031
- India
| | - P. Shukla
- Pharmaceutics Division
- CSIR-Central Drug Research Institute
- Lucknow 226031
- India
| | - P. Dwivedi
- Pharmaceutics Division
- CSIR-Central Drug Research Institute
- Lucknow 226031
- India
| | - P. Tripathi
- Pharmaceutics Division
- CSIR-Central Drug Research Institute
- Lucknow 226031
- India
| | | | - Prabhat R. Mishra
- Pharmaceutics Division
- CSIR-Central Drug Research Institute
- Lucknow 226031
- India
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14
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Johnston KL, Ford L, Umareddy I, Townson S, Specht S, Pfarr K, Hoerauf A, Altmeyer R, Taylor MJ. Repurposing of approved drugs from the human pharmacopoeia to target Wolbachia endosymbionts of onchocerciasis and lymphatic filariasis. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2014; 4:278-86. [PMID: 25516838 PMCID: PMC4266796 DOI: 10.1016/j.ijpddr.2014.09.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
There is an urgent need to discover a macrofilaricide for filariasis. The A·WOL approach is to target the Wolbachia bacteria of filarial nematodes. The human pharmacopoeia was screened against Wolbachia for potential repurposing. 69 orally available hits from different drug categories were identified in vitro. In vivo, the tetracyclines, fluoroquinolones and rifamycins were the most active.
Lymphatic filariasis and onchocerciasis are debilitating diseases caused by parasitic filarial nematodes infecting around 150 million people throughout the tropics with more than 1.5 billion at risk. As with other neglected tropical diseases, classical drug-discovery and development is lacking and a 50 year programme of macrofilaricidal discovery failed to deliver a drug which can be used as a public health tool. Recently, antibiotic targeting of filarial Wolbachia, an essential bacterial symbiont, has provided a novel drug treatment for filariasis with macrofilaricidal activity, although the current gold-standard, doxycycline, is unsuitable for use in mass drug administration (MDA). The anti-Wolbachia (A·WOL) Consortium aims to identify novel anti-Wolbachia drugs, compounds or combinations that are suitable for use in MDA. Development of a Wolbachia cell-based assay has enabled the screening of the approved human drug-pharmacopoeia (∼2600 drugs) for a potential repurposing. This screening strategy has revealed that approved drugs from various classes show significant bacterial load reduction equal to or superior to the gold-standard doxycycline, with 69 orally available hits from different drug categories being identified. Based on our defined hit criteria, 15 compounds were then selectively screened in a Litomosoides sigmodontis mouse model, 4 of which were active. These came from the tetracycline, fluoroquinolone and rifamycin classes. This strategy of repurposing approved drugs is a promising development in the goal of finding a novel treatment against filariasis and could also be a strategy applicable for other neglected tropical diseases.
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Affiliation(s)
- Kelly L Johnston
- Filariasis Research Group, Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Louise Ford
- Filariasis Research Group, Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Indira Umareddy
- CombinatoRx-Singapore Ptd Ltd, 11 Biopolis Way, 138667 Singapore, Singapore
| | - Simon Townson
- Tropical Parasitic Diseases Unit, Northwick Park Institute for Medical Research, Watford Road, Harrow, Middlesex HA1 3UJ, UK
| | - Sabine Specht
- Institute of Medical Microbiology, Immunology & Parasitology, University Hospital of Bonn, Sigmund Freud Strasse 25, 53105 Bonn, Germany
| | - Kenneth Pfarr
- Institute of Medical Microbiology, Immunology & Parasitology, University Hospital of Bonn, Sigmund Freud Strasse 25, 53105 Bonn, Germany
| | - Achim Hoerauf
- Institute of Medical Microbiology, Immunology & Parasitology, University Hospital of Bonn, Sigmund Freud Strasse 25, 53105 Bonn, Germany
| | - Ralf Altmeyer
- CombinatoRx-Singapore Ptd Ltd, 11 Biopolis Way, 138667 Singapore, Singapore ; Institut Pasteur Shanghai, Chinese Academy of Sciences, 320 Yueyang Road, 200031 Shanghai, People's Republic of China
| | - Mark J Taylor
- Filariasis Research Group, Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
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Rebollo MP, Bockarie MJ. Toward the elimination of lymphatic filariasis by 2020: treatment update and impact assessment for the endgame. Expert Rev Anti Infect Ther 2014; 11:723-31. [PMID: 23879610 DOI: 10.1586/14787210.2013.811841] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Lymphatic filariasis (LF) is an important public health problem endemic in 73 countries, where it is a major cause of acute and chronic morbidity and a significant impediment to socioeconomic development. It is targeted for elimination by 2020, through preventive chemotherapy using albendazole in combination with either ivermectin or diethylcarbamazine citrate. Preventive chemotherapy enables the regular and coordinated administration of safe, single-dose medications delivered through mass drug administration (MDA). Many countries are now scaling down MDA activities after achieving 100% geographic coverage and instituting monitoring and evaluation procedures to establish the impact of several consecutive rounds of MDA and determine if transmission has been interrupted. At the same time, countries yet to initiate MDA for elimination of LF will adopt improved mapping and coverage assessment protocols to accelerate the efforts for achieving global elimination by 2020. This review provides an update on treatment for LF and describes the current global status of the elimination efforts, transmission control processes and strategies for measuring impact and continuing surveillance after MDA has ceased.
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Affiliation(s)
- Maria P Rebollo
- Center for Neglected Tropical Diseases, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
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16
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Johnston KL, Ford L, Taylor MJ. Overcoming the challenges of drug discovery for neglected tropical diseases: the A·WOL experience. ACTA ACUST UNITED AC 2013; 19:335-43. [PMID: 24241712 DOI: 10.1177/1087057113511270] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Neglected tropical diseases (NTDs) are a group of 17 diseases that typically affect poor people in tropical countries. Each has been neglected for decades in terms of funding, research, and policy, but the recent grouping of them into one unit, which can be targeted using integrated control measures, together with increased advocacy has helped to place them on the global health agenda. The World Health Organization has set ambitious goals to control or eliminate 10 NTDs by 2020 and launched a roadmap in January 2012 to guide this global plan. The result of the launch meeting, which brought together representatives from the pharmaceutical industry, donors, and politicians, was the London Declaration: a series of commitments to provide more drugs, research, and funds to achieve the 2020 goals. Drug discovery and development for these diseases are extremely challenging, and this article highlights these challenges in the context of the London Declaration, before focusing on an example of a drug discovery and development program for the NTDs onchocerciasis and lymphatic filariasis (the anti-Wolbachia consortium, A·WOL).
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Affiliation(s)
- Kelly L Johnston
- 1Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK
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17
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Ali M, Afzal M, Kaushik U, Bhattacharya SM, Ahmad FJ, Dinda AK. Perceptive solutions to anti-filarial chemotherapy of lymphatic filariasis from the plethora of nanomedical sciences. J Drug Target 2013; 22:1-13. [DOI: 10.3109/1061186x.2013.832766] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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18
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Kushwaha S, Singh PK, Rana AK, Misra-Bhattacharya S. Immunization of Mastomys coucha with Brugia malayi recombinant trehalose-6-phosphate phosphatase results in significant protection against homologous challenge infection. PLoS One 2013; 8:e72585. [PMID: 24015262 PMCID: PMC3755969 DOI: 10.1371/journal.pone.0072585] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 07/18/2013] [Indexed: 11/19/2022] Open
Abstract
Development of a vaccine to prevent or reduce parasite development in lymphatic filariasis would be a complementary approach to existing chemotherapeutic tools. Trehalose-6-phosphate phosphatase of Brugia malayi (Bm-TPP) represents an attractive vaccine target due to its absence in mammals, prevalence in the major life stages of the parasite and immunoreactivity with human bancroftian antibodies, especially from endemic normal subjects. We have recently reported on the cloning, expression, purification and biochemical characterization of this vital enzyme of B. malayi. In the present study, immunoprophylactic evaluation of Bm-TPP was carried out against B. malayi larval challenge in a susceptible host Mastomys coucha and the protective ability of the recombinant protein was evaluated by observing the adverse effects on microfilarial density and adult worm establishment. Immunization caused 78.4% decrease in microfilaremia and 71.04% reduction in the adult worm establishment along with sterilization of 70.06% of the recovered live females. The recombinant protein elicited a mixed Th1/Th2 type of protective immune response as evidenced by the generation of both pro- and anti-inflammatory cytokines IL-2, IFN-γ, TNF-α, IL-4 and an increased production of antibody isotypes IgG1, IgG2a, IgG2b and IgA. Thus immunization with Bm-TPP conferred considerable protection against B. malayi establishment by engendering a long-lasting effective immune response and therefore emerges as a potential vaccine candidate against lymphatic filariasis (LF).
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Affiliation(s)
- Susheela Kushwaha
- Division of Parasitology, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India
| | - Prashant Kumar Singh
- Division of Parasitology, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India
| | - Ajay Kumar Rana
- Division of Parasitology, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India
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19
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Geary TG, Mackenzie CD. Progress and challenges in the discovery of macrofilaricidal drugs. Expert Rev Anti Infect Ther 2013; 9:681-95. [PMID: 21819332 DOI: 10.1586/eri.11.76] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Control of human filarial infections currently depends on chemotherapeutic strategies predominantly directed at microfilariae. Doxycycline therapy in an extended daily dose regimen sterilizes and kills adult stages, but the utility of this drug for routine field use remains an issue of concern. No macrofilaricidal drugs with efficacy after one or two doses are available for use, delaying the achievement of the elimination or eradication of onchocerciasis and lymphatic filariasis. Moxidectin, a macrocyclic lactone, is currently in clinical trials for onchocerciasis. A few other drugs that have already been approved for use in veterinary practice or in human medicine for other indications are available for investigation. Early drug discovery pipelines are poorly populated and the process of macrofilaricide discovery and development remains highly challenging. In particular, the lack of convenient, validated animal models in an antifilarial drug discovery pathway is an unresolved issue.
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Affiliation(s)
- Timothy G Geary
- Institute of Parasitology, McGill University, 21111 Lakeshore Road, Ste-Anne-de-Bellevue QC, H9X 3V9, Canada.
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Caffrey CR, Steverding D. Recent initiatives and strategies to developing new drugs for tropical parasitic diseases. Expert Opin Drug Discov 2013; 3:173-86. [PMID: 23480221 DOI: 10.1517/17460441.3.2.173] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Despite the toll of tropical parasitic diseases on human life in the developing world, present therapies still rely on drugs developed decades ago. In many cases, the clinical usefulness of these compounds is limited due to poor efficacy, toxicity and the constant attrition of drug resistance. The absence of a profit incentive regarding diseases afflicting the very poor has resulted in a lack of investment by the pharmaceutical industry in new chemotherapies. OBJECTIVE Given this background, this review addresses what alternative economic and scientific strategies have been implemented to procure novel drugs. METHODS The latest chemical, genetic and screening technologies to discover and develop drugs for tropical parasitic diseases are reviewed. In many cases these strategies are being implemented within the framework of public-private partnerships established to sustain dynamic drug development portfolios. Examples of public-private partnerships and their portfolios are discussed. Further, the contribution of dedicated academic screening centres to target discovery and preclinical prosecution of new small molecules is also highlighted. In every case, the latest scientific literature is cited, but also relevant press releases and website information to indicate the present vitality in the field. CONCLUSION The tools, institutions and consortia are now in place and evolving to deliver new pharmaceuticals. Short-term results have already been realised in the clinic, mainly through the provision of new formulations of existing drugs. Long-term and consistent investment will be required, however, to identify, develop and clinically validate new chemical entities.
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Affiliation(s)
- Conor R Caffrey
- University of California San Francisco, Sandler Center for Basic Research in Parasitic Diseases, California Institute for Quantitative Biosciences, Byers Hall 501E, 1700 4th Street, San Francisco, CA 94158, USA
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Integrated dataset of screening hits against multiple neglected disease pathogens. PLoS Negl Trop Dis 2011; 5:e1412. [PMID: 22247786 PMCID: PMC3243694 DOI: 10.1371/journal.pntd.0001412] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Accepted: 10/21/2011] [Indexed: 12/19/2022] Open
Abstract
New chemical entities are desperately needed that overcome the limitations of existing drugs for neglected diseases. Screening a diverse library of 10,000 drug-like compounds against 7 neglected disease pathogens resulted in an integrated dataset of 744 hits. We discuss the prioritization of these hits for each pathogen and the strong correlation observed between compounds active against more than two pathogens and mammalian cell toxicity. Our work suggests that the efficiency of early drug discovery for neglected diseases can be enhanced through a collaborative, multi-pathogen approach.
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In Vitro Activity of Geldanamycin Derivatives against Schistosoma japonicum and Brugia malayi. J Parasitol Res 2010; 2010:716498. [PMID: 21253549 PMCID: PMC3021863 DOI: 10.1155/2010/716498] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Revised: 10/22/2010] [Accepted: 11/23/2010] [Indexed: 12/24/2022] Open
Abstract
Geldanamycin (GA) is a benzoquinone-containing ansamycin that inhibits heat shock protein 90. GA derivatives are being evaluated as anti-neoplastic agents, but their utility against parasites whose heat shock proteins (Hsps) have homology with human Hsp90 is unknown. The activities of four synthetic GA derivatives were tested in vitro using adult Brugia malayi and Schistosoma japonicum. Two of the derivatives, 17-N-allyl-17-demethoxygeldanamycin (17-AAG) and 17-N-(2-dimethylaminoethylamino)-17-demethoxygeldanamycin (DMAG), are currently in human clinical trials as anticancer drugs. Using concentrations considered safe peak plasma concentrations for these two derivatives, all four derivatives were active against both parasites. The less toxic derivative 17-AAG was as effective as GA in killing S. japonicum, and both DMAG and 5′-bromogeldanoxazinone were more active than 17-AAG against B. malayi. This work supports continued evaluation of ansamycin derivatives as broad spectrum antiparasitic agents.
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Abstract
Lymphatic filariasis and onchocerciasis are parasitic helminth diseases that constitute a serious public health issue in tropical regions. The filarial nematodes that cause these diseases are transmitted by blood-feeding insects and produce chronic and long-term infection through suppression of host immunity. Disease pathogenesis is linked to host inflammation invoked by the death of the parasite, causing hydrocoele, lymphoedema, and elephantiasis in lymphatic filariasis, and skin disease and blindness in onchocerciasis. Most filarial species that infect people co-exist in mutualistic symbiosis with Wolbachia bacteria, which are essential for growth, development, and survival of their nematode hosts. These endosymbionts contribute to inflammatory disease pathogenesis and are a target for doxycycline therapy, which delivers macrofilaricidal activity, improves pathological outcomes, and is effective as monotherapy. Drugs to treat filariasis include diethylcarbamazine, ivermectin, and albendazole, which are used mostly in combination to reduce microfilariae in blood (lymphatic filariasis) and skin (onchocerciasis). Global programmes for control and elimination have been developed to provide sustained delivery of drugs to affected communities to interrupt transmission of disease and ultimately eliminate this burden on public health.
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Affiliation(s)
- Mark J Taylor
- Liverpool School of Tropical Medicine, Liverpool, UK.
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Nwaka S, Ramirez B, Brun R, Maes L, Douglas F, Ridley R. Advancing drug innovation for neglected diseases-criteria for lead progression. PLoS Negl Trop Dis 2009; 3:e440. [PMID: 19707561 PMCID: PMC2727960 DOI: 10.1371/journal.pntd.0000440] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The current drug R&D pipeline for most neglected diseases remains weak, and unlikely to support registration of novel drug classes that meet desired target product profiles in the short term. This calls for sustained investment as well as greater emphasis in the risky upstream drug discovery. Access to technologies, resources, and strong management as well as clear compound progression criteria are factors in the successful implementation of any collaborative drug discovery effort. We discuss how some of these factors have impacted drug discovery for tropical diseases within the past four decades, and highlight new opportunities and challenges through the virtual North–South drug discovery network as well as the rationale for greater participation of institutions in developing countries in product innovation. A set of criteria designed to facilitate compound progression from screening hits to drug candidate selection is presented to guide ongoing efforts.
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Affiliation(s)
- Solomon Nwaka
- Special Programme for Research and Training in Tropical Diseases (TDR), World Health Organization, Geneva, Switzerland
- * E-mail:
| | - Bernadette Ramirez
- Special Programme for Research and Training in Tropical Diseases (TDR), World Health Organization, Geneva, Switzerland
| | - Reto Brun
- Swiss Tropical Institute, Basel, Switzerland
| | | | - Frank Douglas
- Ewing Marion Kauffman Foundation, Kansas City, Missouri, United States of America
| | - Robert Ridley
- Special Programme for Research and Training in Tropical Diseases (TDR), World Health Organization, Geneva, Switzerland
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Ford L, Zhang J, Liu J, Hashmi S, Fuhrman JA, Oksov Y, Lustigman S. Functional analysis of the cathepsin-like cysteine protease genes in adult Brugia malayi using RNA interference. PLoS Negl Trop Dis 2009; 3:e377. [PMID: 19190745 PMCID: PMC2634747 DOI: 10.1371/journal.pntd.0000377] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2008] [Accepted: 01/13/2009] [Indexed: 12/05/2022] Open
Abstract
Background Cathepsin-like enzymes have been identified as potential targets for drug or vaccine development in many parasites, as their functions appear to be essential in a variety of important biological processes within the host, such as molting, cuticle remodeling, embryogenesis, feeding and immune evasion. Functional analysis of Caenorhabditis elegans cathepsin L (Ce-cpl-1) and cathepsin Z (Ce-cpz-1) has established that both genes are required for early embryogenesis, with Ce-cpl-1 having a role in regulating in part the processing of yolk proteins. Ce-cpz-1 also has an important role during molting. Methods and Findings RNA interference assays have allowed us to verify whether the functions of the orthologous filarial genes in Brugia malayi adult female worms are similar. Treatment of B. malayi adult female worms with Bm-cpl-1, Bm-cpl-5, which belong to group Ia of the filarial cpl gene family, or Bm-cpz-1 dsRNA resulted in decreased numbers of secreted microfilariae in vitro. In addition, analysis of the intrauterine progeny of the Bm-cpl-5 or Bm-cpl Pro dsRNA- and siRNA-treated worms revealed a clear disruption in the process of embryogenesis resulting in structural abnormalities in embryos and a varied differential development of embryonic stages. Conclusions Our studies suggest that these filarial cathepsin-like cysteine proteases are likely to be functional orthologs of the C. elegans genes. This functional conservation may thus allow for a more thorough investigation of their distinct functions and their development as potential drug targets. Filarial nematodes are an important group of human pathogens, causing lymphatic filariasis and onchocerciasis, and infecting around 150 million people throughout the tropics with more than 1.5 billion at risk of infection. Control of filariasis currently relies on mass drug administration (MDA) programs using drugs which principally target the microfilarial life-cycle stage. These control programs are facing major challenges, including the absence of a drug with macrofilaricidal or permanent sterilizing activity, and the possibility of the development of drug-resistance against the drugs available. Cysteine proteases are essential enzymes which play important roles in a wide range of cellular processes, and the cathepsin-like cysteine proteases have been identified as potential targets for drug or vaccine development in many parasites. Here we have studied the function of several of the cathepsin-like enzymes in the filarial nematode, B. malayi, and demonstrate that these cysteine proteases are involved in the development of embryos, show similar functions to their counterparts in C. elegans, and therefore, provide an important target for future drug development targeted to eliminate filariasis.
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Affiliation(s)
- Louise Ford
- Laboratory of Molecular Parasitology, Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York, United States of America.
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Mathew N, Karunan T, Srinivasan L, Muthuswamy K. Synthesis and screening of substituted 1,4-naphthoquinones (NPQs) as antifilarial agents. Drug Dev Res 2009. [DOI: 10.1002/ddr.20357] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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