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de Sousa MCF, Imhof D, Hänggeli KPA, Choi R, Hulverson MA, Arnold SLM, Van Voorhis WC, Fan E, Roberto SS, Ortega-Mora LM, Hemphill A. Efficacy of the bumped kinase inhibitor BKI-1708 against the cyst-forming apicomplexan parasites Toxoplasma gondii and Neospora caninum in vitro and in experimentally infected mice. Int J Parasitol Drugs Drug Resist 2024; 25:100553. [PMID: 38917582 PMCID: PMC11254172 DOI: 10.1016/j.ijpddr.2024.100553] [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: 05/05/2024] [Revised: 06/18/2024] [Accepted: 06/19/2024] [Indexed: 06/27/2024]
Abstract
Toxoplasma gondii and Neospora caninum are major worldwide morbidity-causing pathogens. Bumped kinase inhibitors (BKIs) are a compound class that has been optimized to target the apicomplexan calcium-dependent protein kinase 1 (CDPK1) - and several members of this class have proven to be safe and highly active in vitro and in vivo. BKI-1708 is based on a 5-aminopyrazole-4-carboxamide scaffold, and exhibited in vitro IC50 values of 120 nM for T. gondii and 480 nM for N. caninum β-galactosidase expressing strains, and did not affect human foreskin fibroblast (HFF) viability at concentrations up to 25 μM. Electron microscopy established that exposure of tachyzoite-infected fibroblasts to 2.5 μM BKI-1708 in vitro induced the formation of multinucleated schizont-like complexes (MNCs), characterized by continued nuclear division and harboring newly formed intracellular zoites that lack the outer plasma membrane. These zoites were unable to finalize cytokinesis to form infective tachyzoites. BKI-1708 did not affect zebrafish (Danio rerio) embryo development during the first 96 h following egg hatching at concentrations up to 2 μM. Treatments of mice with BKI-1708 at 20 mg/kg/day during five consecutive days resulted in drug plasma levels ranging from 0.14 to 4.95 μM. In vivo efficacy of BKI-1708 was evaluated by oral application of 20 mg/kg/day from day 9-13 of pregnancy in mice experimentally infected with N. caninum (NcSpain-7) tachyzoites or T. gondii (TgShSp1) oocysts. This resulted in significantly decreased cerebral parasite loads and reduced vertical transmission in both models without drug-induced pregnancy interference.
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Affiliation(s)
- Maria Cristina Ferreira de Sousa
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Switzerland; Graduate School for Cellular and Biomedical Sciences (GCB), University of Bern, Switzerland.
| | - Dennis Imhof
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Switzerland; Graduate School for Cellular and Biomedical Sciences (GCB), University of Bern, Switzerland
| | - Kai Pascal Alexander Hänggeli
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Switzerland; Graduate School for Cellular and Biomedical Sciences (GCB), University of Bern, Switzerland
| | - Ryan Choi
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Matthew A Hulverson
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Samuel L M Arnold
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA, USA; Department of Pharmaceutics, University of Washington, Seattle, WA, USA
| | - Wesley C Van Voorhis
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Erkang Fan
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Sánchez-Sánchez Roberto
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, Madrid, Spain
| | - Luis M Ortega-Mora
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, Madrid, Spain
| | - Andrew Hemphill
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Switzerland.
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Müller J, Hemphill A. In vitro screening technologies for the discovery and development of novel drugs against Toxoplasma gondii. Expert Opin Drug Discov 2024; 19:97-109. [PMID: 37921660 DOI: 10.1080/17460441.2023.2276349] [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: 08/31/2023] [Accepted: 10/24/2023] [Indexed: 11/04/2023]
Abstract
INTRODUCTION Toxoplasmosis constitutes a challenge for public health, animal production and welfare. Since more than 60 years, only a limited panel of drugs has been in use for clinical applications. AREAS COVERED Herein, the authors describe the methodology and the results of library screening approaches to identify inhibitors of Toxoplasma gondii and related strains. The authors then provide the reader with their expert perspectives for the future. EXPERT OPINION Various library screening projects, in particular those using reporter strains, have led to the identification of numerous compounds with good efficacy and specificity in vitro. However, only few compounds are effective in suitable animal models such as rodents. Whereas no novel compound has cleared the hurdle to applications in humans, the few compounds with known indication and application profiles in human patients are of interest for further investigations. Taken together, drug repurposing as well as high-throughput screening of novel compound libraries may shorten the way to novel drugs against toxoplasmosis.
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Affiliation(s)
- Joachim Müller
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Andrew Hemphill
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
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Schlange C, Müller J, Imhof D, Hänggeli KPA, Boubaker G, Ortega-Mora LM, Wong HN, Haynes RK, Van Voorhis WC, Hemphill A. Single and combination treatment of Toxoplasma gondii infections with a bumped kinase inhibitor and artemisone in vitro and with artemiside in experimentally infected mice. Exp Parasitol 2023; 255:108655. [PMID: 37981259 PMCID: PMC11585351 DOI: 10.1016/j.exppara.2023.108655] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 11/01/2023] [Accepted: 11/13/2023] [Indexed: 11/21/2023]
Abstract
In previous studies, the artemisinin derivatives artemisone, its pro-drug artemiside and the bumped-kinase inhibitor BKI-1748 were effective against T. gondii via different modes of action. This suggests that they may act synergistically resulting in improved efficacies in vitro and in vivo. To test this hypothesis, the compounds were applied alone and in combination to T. gondii infected human fibroblast host cells in order to determine their inhibition constants and effects on cellular ultrastructure. In addition, the efficacy of either single- or combined treatments were assessed in an acute TgShSp1-oocyst infection model based on CD1 outbred mice. Whereas the IC50 of the compounds in combination (42 nM) was close to the IC50 of BKI-1748 alone (46 nM) and half of the IC50 of artemisone alone (92 nM), the IC90 of the combination was half of the values found with the single compounds (138 nM vs. ca. 270 nM). Another indication for synergistic effects in vitro were distinct alterations of the cellular ultrastructure of tachyzoites observed in combination, but not with the single compounds. These promising results could not be reproduced in vivo. There was no decrease in number of T. gondii positive brains by either treatment. However, the levels of infection in these brains, i. e. the number of tachyzoites, was significantly decreased upon BKI-1748 treatment alone, and the combination with artemiside did not produce any further decrease. The treatment with artemiside alone had no significant effects. A vertical transmission model could not be established since artemiside strongly interfered with pregnancy and caused abortion. These results show that is difficult to extrapolate from promising in vitro results to the situation in vivo.
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Affiliation(s)
- Carling Schlange
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Länggass-Strasse 122, CH-3012, Bern, Switzerland
| | - Joachim Müller
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Länggass-Strasse 122, CH-3012, Bern, Switzerland
| | - Dennis Imhof
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Länggass-Strasse 122, CH-3012, Bern, Switzerland
| | - Kai Pascal Alexander Hänggeli
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Länggass-Strasse 122, CH-3012, Bern, Switzerland
| | - Ghalia Boubaker
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Länggass-Strasse 122, CH-3012, Bern, Switzerland
| | - Luis-Miguel Ortega-Mora
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria S/n, 28040, Madrid, Spain
| | - Ho Ning Wong
- Rural Health Research Institute, Charles Sturt University, Orange, New South Wales, 2800, Australia
| | - Richard K Haynes
- Rural Health Research Institute, Charles Sturt University, Orange, New South Wales, 2800, Australia; Centre of Excellence for Pharmaceutical Sciences, Faculty of Health Sciences, North-West University, Potchefstroom, 2520, South Africa
| | - Wesley C Van Voorhis
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
| | - Andrew Hemphill
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Länggass-Strasse 122, CH-3012, Bern, Switzerland.
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Fernández-Álvarez M, Horcajo P, Jiménez-Meléndez A, Diezma-Díaz C, Ferre I, Pastor-Fernández I, Miguel Ortega-Mora L, Álvarez-García G. Transcriptional changes associated with apoptosis and Type I IFN underlie the early interaction between Besnoitia besnoiti tachyzoites and monocyte-derived macrophages. Int J Parasitol 2023:S0020-7519(23)00094-2. [PMID: 37207972 DOI: 10.1016/j.ijpara.2023.05.002] [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: 11/07/2022] [Revised: 04/03/2023] [Accepted: 05/03/2023] [Indexed: 05/21/2023]
Abstract
Besnoitia besnoiti-infected bulls may develop severe systemic clinical signs and orchitis that may ultimately cause sterility during the acute infection. Macrophages might play a relevant role in pathogenesis of the disease and the immune response raised against B. besnoiti infection. This study aimed to dissect the early interaction between B. besnoiti tachyzoites and primary bovine monocyte-derived macrophages in vitro. First, the B. besnoiti tachyzoite lytic cycle was characterized. Next, dual transcriptomic profiling of B. besnoiti tachyzoites and macrophages was conducted at early infection (4 h and 8 h p.i. by high-throughput RNA sequencing. Macrophages inoculated with heat-killed tachyzoites (MO-hkBb) and non-infected macrophages (MO) were used as controls. Besnoitia besnoiti was able to invade and proliferate in macrophages. Upon infection, macrophage activation was demonstrated by morphological and transcriptomic changes. Infected macrophages were smaller, round and lacked filopodial structures, which might be associated with a migratory phenotype demonstrated in other apicomplexan parasites. The number of differentially expressed genes (DEGs) increased substantially during infection. In B. besnoiti-infected macrophages (MO-Bb), apoptosis and mitogen-activated protein kinase (MAPK) pathways were regulated at 4 h p.i., and apoptosis was confirmed by TUNEL assay. The Herpes simplex virus 1 infection pathway was the only significantly enriched pathway in MO-Bb at 8 h p.i. Relevant DEGs of the Herpes simplex virus 1 infection (IFNα) and the apoptosis pathways (CHOP-2) were also significantly regulated in the testicular parenchyma of naturally infected bulls. Furthermore, the parasite transcriptomic analysis revealed DEGs mainly related to host cell invasion and metabolism. These results provide a deep overview of the earliest macrophage modulation by B. besnoiti that may favour parasite survival and proliferation in a specialized phagocytic immune cell. Putative parasite effectors were also identified.
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Affiliation(s)
- María Fernández-Álvarez
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Spain
| | - Pilar Horcajo
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Spain
| | - Alejandro Jiménez-Meléndez
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Spain
| | - Carlos Diezma-Díaz
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Spain
| | - Ignacio Ferre
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Spain
| | - Iván Pastor-Fernández
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Spain
| | - Luis Miguel Ortega-Mora
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Spain
| | - Gema Álvarez-García
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Spain.
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Chiurillo MA, Jensen BC, Docampo R. Drug Target Validation of the Protein Kinase AEK1, Essential for Proliferation, Host Cell Invasion, and Intracellular Replication of the Human Pathogen Trypanosoma cruzi. Microbiol Spectr 2021; 9:e0073821. [PMID: 34585973 PMCID: PMC8557885 DOI: 10.1128/spectrum.00738-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 08/31/2021] [Indexed: 12/02/2022] Open
Abstract
Protein phosphorylation is involved in several key biological roles in the complex life cycle of Trypanosoma cruzi, the etiological agent of Chagas disease, and protein kinases are potential drug targets. Here, we report that the AGC essential kinase 1 (TcAEK1) exhibits a cytosolic localization and a higher level of expression in the replicative stages of the parasite. A CRISPR/Cas9 editing technique was used to generate ATP analog-sensitive TcAEK1 gatekeeper residue mutants that were selectively and acutely inhibited by bumped kinase inhibitors (BKIs). Analysis of a single allele deletion cell line (TcAEK1-SKO), and gatekeeper mutants upon treatment with inhibitor, showed that epimastigote forms exhibited a severe defect in cytokinesis. Moreover, we also demonstrated that TcAEK1 is essential for epimastigote proliferation, trypomastigote host cell invasion, and amastigote replication. We suggest that TcAEK1 is a pleiotropic player involved in cytokinesis regulation in T. cruzi and thus validate TcAEK1 as a drug target for further exploration. The gene editing strategy we applied to construct the ATP analog-sensitive enzyme could be appropriate for the study of other proteins of the T. cruzi kinome. IMPORTANCE Chagas disease affects 6 to 7 million people in the Americas, and its treatment has been limited to drugs with relatively high toxicity and low efficacy in the chronic phase of the infection. New validated targets are needed to combat this disease. In this work, we report the chemical and genetic validation of the protein kinase AEK1, which is essential for cytokinesis and infectivity, using a novel gene editing strategy.
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Affiliation(s)
- Miguel A. Chiurillo
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
- Department of Biological Sciences, University of Cincinnati, Cincinnati, Ohio, USA
| | - Bryan C. Jensen
- Seattle Children’s Research Institute, Seattle, Washington, USA
| | - Roberto Docampo
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
- Department of Cellular Biology, University of Georgia, Athens, Georgia, USA
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6
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Anghel N, Imhof D, Winzer P, Balmer V, Ramseier J, Haenggeli K, Choi R, Hulverson MA, Whitman GR, Arnold SL, Ojo KK, Van Voorhis WC, Doggett JS, Ortega-Mora LM, Hemphill A. Endochin-like quinolones (ELQs) and bumped kinase inhibitors (BKIs): Synergistic and additive effects of combined treatments against Neospora caninum infection in vitro and in vivo. Int J Parasitol Drugs Drug Resist 2021; 17:92-106. [PMID: 34482255 PMCID: PMC8416643 DOI: 10.1016/j.ijpddr.2021.08.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/19/2021] [Accepted: 08/26/2021] [Indexed: 12/30/2022]
Abstract
The apicomplexan parasite Neospora caninum is an important causative agent of congenital neosporosis, resulting in abortion, birth of weak offspring and neuromuscular disorders in cattle, sheep, and many other species. Among several compound classes that are currently being developed, two have been reported to limit the effects of congenital neosporosis: (i) bumped kinase inhibitors (BKIs) target calcium dependent protein kinase 1 (CDPK1), an enzyme that is encoded by an apicoplast-derived gene and found only in apicomplexans and plants. CDPK1 is essential for host cell invasion and egress; (ii) endochin-like quinolones (ELQs) are inhibitors of the cytochrome bc1 complex of the mitochondrial electron transport chain and thus inhibit oxidative phosphorylation. We here report on the in vitro and in vivo activities of BKI-1748, and of ELQ-316 and its respective prodrugs ELQ-334 and ELQ-422, applied either as single-compounds or ELQ-BKI-combinations. In vitro, BKI-1748 and ELQ-316, as well as BKI-1748 and ELQ-334, acted synergistically, while this was not observed for the BKI-1748/ELQ-422 combination treatment. In a N. caninum-infected pregnant BALB/c mouse model, the synergistic effects observed in vitro were not entirely reproduced, but 100% postnatal survival and 100% inhibition of vertical transmission was noted in the group treated with the BKI-1748/ELQ-334 combination. In addition, the combined drug applications resulted in lower neonatal mortality compared to treatments with single drugs.
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Affiliation(s)
- Nicoleta Anghel
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Switzerland,Graduate School for Cellular and Biomedical Sciences (GCB), University of Bern, Switzerland,Corresponding author. Institute of Parasitology, Vetsuisse Faculty, University of Bern, Switzerland.
| | - Dennis Imhof
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Switzerland,Graduate School for Cellular and Biomedical Sciences (GCB), University of Bern, Switzerland
| | - Pablo Winzer
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Switzerland,Graduate School for Cellular and Biomedical Sciences (GCB), University of Bern, Switzerland
| | - Vreni Balmer
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Switzerland
| | - Jessica Ramseier
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Switzerland
| | - Kai Haenggeli
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Switzerland,Graduate School for Cellular and Biomedical Sciences (GCB), University of Bern, Switzerland
| | - Ryan Choi
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
| | - Matthew A. Hulverson
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
| | - Grant R. Whitman
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
| | - Samuel L.M. Arnold
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA,Department of Pharmaceutics, University of Washington, Seattle, WA, USA
| | - Kayode K. Ojo
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
| | - Wesley C. Van Voorhis
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA,Departments of Global Health and Microbiology, University of Washington, Seattle, WA, USA
| | - J. Stone Doggett
- VA Portland Health Care System, Research and Development Service, Portland, OR, USA
| | - Luis M. Ortega-Mora
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, Madrid, Spain
| | - Andrew Hemphill
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Switzerland,Corresponding author.
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Imhof D, Anghel N, Winzer P, Balmer V, Ramseier J, Hänggeli K, Choi R, Hulverson MA, Whitman GR, Arnold SLM, Ojo KK, Van Voorhis WC, Doggett JS, Ortega-Mora LM, Hemphill A. In vitro activity, safety and in vivo efficacy of the novel bumped kinase inhibitor BKI-1748 in non-pregnant and pregnant mice experimentally infected with Neospora caninum tachyzoites and Toxoplasma gondii oocysts. Int J Parasitol Drugs Drug Resist 2021; 16:90-101. [PMID: 34030110 PMCID: PMC8144743 DOI: 10.1016/j.ijpddr.2021.05.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 05/10/2021] [Accepted: 05/11/2021] [Indexed: 12/12/2022]
Abstract
Bumped kinase inhibitors (BKIs) target the apicomplexan calcium-dependent protein kinase 1 (CDPK1). BKI-1748, a 5-aminopyrazole-4-carboxamide compound when added to fibroblast cells concomitantly to the time of infection, inhibited proliferation of apicomplexan parasites at EC50s of 165 nM (Neospora caninum) and 43 nM (Toxoplasma gondii). Immunofluorescence and electron microscopy showed that addition of 2.5 μM BKI-1748 to infected HFF monolayers transformed parasites into multinucleated schizont-like complexes (MNCs) containing newly formed zoites, which were unable to separate and form infective tachyzoites or undergo egress. In zebrafish (Danio rerio) embryo development assays, no embryonic impairment was detected within 96 h at BKI-1748 concentrations up to 10 μM. In pregnant mice, BKI-1748 applied at days 9-13 of pregnancy at a dose of 20 mg/kg/day was safe and no pregnancy interference was observed. The efficacy of BKI-1748 was assessed in standardized pregnant mouse models infected with N. caninum (NcSpain-7) tachyzoites or T. gondii (TgShSp1) oocysts. In both models, treatments resulted in increased pup survival and profound inhibition of vertical transmission. However, in dams and non-pregnant mice, BKI-1748 treatments resulted in significantly decreased cerebral parasite loads only in T. gondii infected mice. In the T. gondii-model, ocular infection was detected in 10 out of 12 adult mice of the control group, but only in 3 out of 12 mice in the BKI-1748-treated group. Thus, TgShSp1 oocyst infection is a suitable model to study both cerebral and ocular infection by T. gondii. BKI-1748 represents an interesting candidate for follow-up studies on neosporosis and toxoplasmosis in larger animal models.
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Affiliation(s)
- Dennis Imhof
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Switzerland; Graduate School for Cellular and Biomedical Sciences (GCB), University of Bern, Switzerland.
| | - Nicoleta Anghel
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Switzerland; Graduate School for Cellular and Biomedical Sciences (GCB), University of Bern, Switzerland
| | - Pablo Winzer
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Switzerland; Graduate School for Cellular and Biomedical Sciences (GCB), University of Bern, Switzerland
| | - Vreni Balmer
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Switzerland
| | - Jessica Ramseier
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Switzerland
| | - Kai Hänggeli
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Switzerland; Graduate School for Cellular and Biomedical Sciences (GCB), University of Bern, Switzerland
| | - Ryan Choi
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
| | - Matthew A Hulverson
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
| | - Grant R Whitman
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
| | - Samuel L M Arnold
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA; Department of Pharmaceutics, University of Washington, Seattle, WA, USA
| | - Kayode K Ojo
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
| | - Wesley C Van Voorhis
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA; Departments of Global Health and Microbiology, University of Washington, Seattle, WA, USA
| | - J Stone Doggett
- VA Portland Health Care System, Research and Development Service, Portland, OR, USA
| | - Luis M Ortega-Mora
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, Madrid, Spain
| | - Andrew Hemphill
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Switzerland.
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ApiCOWplexa 2019 - 5th International Meeting on Apicomplexan Parasites in Farm Animals. Int J Parasitol 2021; 50:345-347. [PMID: 32503686 DOI: 10.1016/j.ijpara.2020.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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9
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Van Voorhis WC, Hulverson MA, Choi R, Huang W, Arnold SLM, Schaefer DA, Betzer DP, Vidadala RSR, Lee S, Whitman GR, Barrett LK, Maly DJ, Riggs MW, Fan E, Kennedy TJ, Tzipori S, Doggett JS, Winzer P, Anghel N, Imhof D, Müller J, Hemphill A, Ferre I, Sanchez-Sanchez R, Ortega-Mora LM, Ojo KK. One health therapeutics: Target-Based drug development for cryptosporidiosis and other apicomplexa diseases. Vet Parasitol 2021; 289:109336. [PMID: 33418437 PMCID: PMC8582285 DOI: 10.1016/j.vetpar.2020.109336] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 12/12/2020] [Accepted: 12/14/2020] [Indexed: 12/14/2022]
Abstract
This is a review of the development of bumped-kinase inhibitors (BKIs) for the therapy of One Health parasitic apicomplexan diseases. Many apicomplexan infections are shared between humans and livestock, such as cryptosporidiosis and toxoplasmosis, as well as livestock only diseases such as neosporosis. We have demonstrated proof-of-concept for BKI therapy in livestock models of cryptosporidiosis (newborn calves infected with Cryptosporidium parvum), toxoplasmosis (pregnant sheep infected with Toxoplasma gondii), and neosporosis (pregnant sheep infected with Neospora caninum). We discuss the potential uses of BKIs for the treatment of diseases caused by apicomplexan parasites in animals and humans, and the improvements that need to be made to further develop BKIs.
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Affiliation(s)
- Wesley C Van Voorhis
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA, 98109, USA.
| | - Matthew A Hulverson
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA, 98109, USA
| | - Ryan Choi
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA, 98109, USA
| | - Wenlin Huang
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
| | - Samuel L M Arnold
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA, 98109, USA
| | - Deborah A Schaefer
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ, 85721, USA
| | - Dana P Betzer
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ, 85721, USA
| | - Rama S R Vidadala
- Department of Chemistry, University of Washington, Seattle, WA, 98195, USA
| | - Sangun Lee
- Department of Infectious Disease and Global Health, Cummings School of Veterinary Medicine at Tufts University, North Grafton, MA, 01536, USA
| | - Grant R Whitman
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA, 98109, USA
| | - Lynn K Barrett
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA, 98109, USA
| | - Dustin J Maly
- Department of Chemistry, University of Washington, Seattle, WA, 98195, USA
| | - Michael W Riggs
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ, 85721, USA
| | - Erkang Fan
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
| | | | - Saul Tzipori
- Department of Infectious Disease and Global Health, Cummings School of Veterinary Medicine at Tufts University, North Grafton, MA, 01536, USA
| | - J Stone Doggett
- Oregon Health & Science University, Portland, OR, 97239, USA
| | - Pablo Winzer
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, 3012, Bern, Switzerland
| | - Nicoleta Anghel
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, 3012, Bern, Switzerland
| | - Dennis Imhof
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, 3012, Bern, Switzerland
| | - Joachim Müller
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, 3012, Bern, Switzerland
| | - Andrew Hemphill
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, 3012, Bern, Switzerland
| | - Ignacio Ferre
- Saluvet, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Roberto Sanchez-Sanchez
- Saluvet, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Luis Miguel Ortega-Mora
- Saluvet, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Kayode K Ojo
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA, 98109, USA
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10
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Anghel N, Winzer PA, Imhof D, Müller J, Langa X, Rieder J, Barrett LK, Vidadala RSR, Huang W, Choi R, Hulverson MA, Whitman GR, Arnold SL, Van Voorhis WC, Ojo KK, Maly DJ, Fan E, Hemphill A. Comparative assessment of the effects of bumped kinase inhibitors on early zebrafish embryo development and pregnancy in mice. Int J Antimicrob Agents 2020; 56:106099. [PMID: 32707170 DOI: 10.1016/j.ijantimicag.2020.106099] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 07/07/2020] [Accepted: 07/13/2020] [Indexed: 01/30/2023]
Abstract
Bumped kinase inhibitors (BKIs) are effective against a variety of apicomplexan parasites. Fifteen BKIs with promising in vitro efficacy against Neospora caninum tachyzoites, low cytotoxicity in mammalian cells, and no toxic effects in non-pregnant BALB/c mice were assessed in pregnant mice. Drugs were emulsified in corn oil and were applied by gavage for 5 days. Five BKIs did not affect pregnancy, five BKIs exhibited ~15-35% neonatal mortality and five compounds caused strong effects (infertility, abortion, stillbirth and pup mortality). Additionally, the impact of these compounds on zebrafish (Danio rerio) embryo development was assessed by exposing freshly fertilised eggs to 0.2-50 μM of BKIs and microscopic monitoring of embryo development in a blinded manner for 4 days. We propose an algorithm that includes quantification of malformations and embryo deaths, and established a scoring system that allows the calculation of an impact score (Si) indicating at which concentrations BKIs visibly affect zebrafish embryo development. Comparison of the two models showed that for nine compounds no clear correlation between Si and pregnancy outcome was observed. However, the three BKIs affecting zebrafish embryos only at high concentrations (≥40 μM) did not impair mouse pregnancy at all, and the three compounds that inhibited zebrafish embryo development already at 0.2 μM showed detrimental effects in the pregnancy model. Thus, the zebrafish embryo development test has limited predictive value to foresee pregnancy outcome in BKI-treated mice. We conclude that maternal health-related factors such as cardiovascular, pharmacokinetic and/or bioavailability properties also contribute to BKI-pregnancy effects.
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Affiliation(s)
- Nicoleta Anghel
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Länggass-Strasse 122, CH-3012 Bern, Switzerland
| | - Pablo A Winzer
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Länggass-Strasse 122, CH-3012 Bern, Switzerland
| | - Dennis Imhof
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Länggass-Strasse 122, CH-3012 Bern, Switzerland
| | - Joachim Müller
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Länggass-Strasse 122, CH-3012 Bern, Switzerland
| | - Xavier Langa
- Department of Developmental Biology and Regeneration, Institute of Anatomy, University of Bern, Baltzerstrasse 2, CH-3000 Bern, Switzerland
| | - Jessica Rieder
- Centre for Fish and Wildlife Health (FIWI), Vetsuisse Faculty, University of Bern, Länggass-Strasse 122, 3012 Bern, Switzerland
| | - Lynn K Barrett
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA 98109, USA
| | | | - Wenlin Huang
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Ryan Choi
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA 98109, USA
| | - Mathew A Hulverson
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA 98109, USA
| | - Grant R Whitman
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA 98109, USA
| | - Samuel L Arnold
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA 98109, USA
| | - Wesley C Van Voorhis
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA 98109, USA
| | - Kayode K Ojo
- Center for Emerging and Re-emerging Infectious Diseases (CERID), Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA 98109, USA
| | - Dustin J Maly
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Erkang Fan
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Andrew Hemphill
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Länggass-Strasse 122, CH-3012 Bern, Switzerland.
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11
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Neospora caninum: Structure and Fate of Multinucleated Complexes Induced by the Bumped Kinase Inhibitor BKI-1294. Pathogens 2020; 9:pathogens9050382. [PMID: 32429314 PMCID: PMC7281336 DOI: 10.3390/pathogens9050382] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 05/11/2020] [Accepted: 05/12/2020] [Indexed: 11/17/2022] Open
Abstract
Background: Bumped kinase inhibitors (BKIs) are potential drugs for neosporosis treatment in farm animals. BKI-1294 exposure results in the formation of multinucleated complexes (MNCs), which remain viable in vitro under constant drug pressure. We investigated the formation of BKI-1294 induced MNCs, the re-emergence of viable tachyzoites following drug removal, and the localization of CDPK1, the molecular target of BKIs. Methods: N. caninum tachyzoites and MNCs were studied by TEM and immunofluorescence using antibodies directed against CDPK1, and against NcSAG1 and IMC1 as markers for tachyzoites and newly formed zoites, respectively. Results: After six days of drug exposure, MNCs lacked SAG1 surface expression but remained intracellular, and formed numerous zoites incapable of disjoining from each other. Following drug removal, proliferation continued, and zoites lacking NcSAG1 emerged from the periphery of these complexes, forming infective tachyzoites after 10 days. In intracellular tachyzoites, CDPK1 was evenly distributed but shifted towards the apical part once parasites were extracellular. This shift was not affected by BKI-1294. Conclusions: CDPK1 has a dynamic distribution depending on whether parasites are located within a host cell or outside. During MNC-to-tachyzoite reconversion newly formed tachyzoites are generated directly from MNCs through zoites of unknown surface antigen composition. Further in vivo studies are needed to determine if MNCs could lead to a persistent reservoir of infection after BKI treatment.
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12
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Jiménez-Meléndez A, Ramakrishnan C, Hehl AB, Russo G, Álvarez-García G. RNA-Seq Analyses Reveal That Endothelial Activation and Fibrosis Are Induced Early and Progressively by Besnoitia besnoiti Host Cell Invasion and Proliferation. Front Cell Infect Microbiol 2020; 10:218. [PMID: 32500038 PMCID: PMC7242738 DOI: 10.3389/fcimb.2020.00218] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 04/20/2020] [Indexed: 12/12/2022] Open
Abstract
The pathogenesis of bovine besnoitiosis and the molecular bases that govern disease progression remain to be elucidated. Thus, we have employed an in vitro model of infection based on primary bovine aortic endothelial cells (BAEC), target cells during the acute infection. Host-parasite interactions were investigated by RNA-Seq at two post-infection (pi) time points: 12 hpi, when tachyzoites have already invaded host cells, and 32 hpi, when tachyzoites have replicated for at least two generations. Additionally, the gene expression profile of B. besnoiti tachyzoites was studied at both pi time points. Up to 446 differentially expressed B. taurus genes (DEGs) were found in BAEC between both pi time points: 249 DEGs were up-regulated and 197 DEGs were down-regulated at 32 hpi. Upregulation of different genes encoding cytokines, chemokines, leukocyte adhesion molecules predominantly at 12 hpi implies an activation of endothelial cells, whilst upregulation of genes involved in angiogenesis and extracellular matrix organization was detected at both time points. NF-κB and TNF-α signaling pathways appeared to be mainly modulated upon infection, coordinating the expression of several effector proteins with proinflammatory and pro-fibrotic phenotypes. These mediators are thought to be responsible for macrophage recruitment setting the basis for chronic inflammation and fibrosis characteristic of chronic besnoitiosis. Angiogenesis regulation also predominated, and this multistep process was evidenced by the upregulation of markers involved in both early (e.g., growth factors and matrix metalloproteinases) and late steps (e.g., integrins and vasohibin). Besnoitia besnoiti ortholog genes present in other Toxoplasmatinae members and involved in the lytic cycle have shown to be differentially expressed among the two time points studied, with a higher expression at 32 hpi (e.g., ROP40, ROP5B, MIC1, MIC10). This study gives molecular clues on B. besnoiti- BAECs interaction and shows the progression of type II endothelial cell activation upon parasite invasion and proliferation.
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Affiliation(s)
- Alejandro Jiménez-Meléndez
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Madrid, Spain
| | | | - Adrian B Hehl
- Institute of Parasitology, University of Zurich, Zurich, Switzerland
| | | | - Gema Álvarez-García
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Madrid, Spain
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13
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Eberhard N, Balmer V, Müller J, Müller N, Winter R, Pou S, Nilsen A, Riscoe M, Francisco S, Leitao A, Doggett JS, Hemphill A. Activities of Endochin-Like Quinolones Against in vitro Cultured Besnoitia besnoiti Tachyzoites. Front Vet Sci 2020; 7:96. [PMID: 32161765 PMCID: PMC7054222 DOI: 10.3389/fvets.2020.00096] [Citation(s) in RCA: 5] [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: 11/26/2019] [Accepted: 02/10/2020] [Indexed: 12/14/2022] Open
Abstract
Endochin-like quinolones (ELQs) potently inhibit the proliferation of Plasmodium, Toxoplasma, Neospora, and Babesia by targeting the cytochrome b Qo and Qi sites and interfering with oxidative phosphorylation and pyrimidine biosynthesis. The activities of 14 different ELQs were assessed against B. besnoiti tachyzoites grown in human foreskin fibroblasts (HFF) by quantitative real time PCR. The values for 50% proliferation inhibition (IC50) of five ELQs were determined in a 3-days growth assay after an initial screen of 12 ELQs at 0.01, 0.1, and 1 μM. The IC50s of ELQ-121, -136, and -316 were 0.49, 2.36, and 7.97 nM, respectively. The IC50s of ELQs tested against B. besnoiti were higher than IC50s previously observed for P. falciparum and T. gondii. However, the B. besnoiti cytochrome b sequence and the predicted Qo and Qi ELQ binding sites in the Toxoplasma, Neospora, and Besnoitia cytochrome b are virtually identical, suggesting that the differences in ELQ susceptibility are not due to variations in the substrate binding sites. TEM of ELQ-treated parasites primarily demonstrated alterations within the parasite mitochondrion, profound thickening of the nuclear membrane, as well as increased vacuolization within the tachyzoite cytoplasm. Long-term treatment assays of intracellular B. besnoiti with ELQs for up to 20 days followed by the release of drug pressure caused a substantial delay in parasite growth and proliferation while ELQs were present, but parasite proliferation resumed days after ELQs were removed. Interestingly, structural alterations persisted after ELQ removal and parasite proliferation was slowed. These findings provide a basis for further in vivo studies of ELQs as therapeutic options against B. besnoiti infection.
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Affiliation(s)
- Naja Eberhard
- Vetsuisse Faculty, Institute of Parasitology, University of Bern, Bern, Switzerland
| | - Vreni Balmer
- Vetsuisse Faculty, Institute of Parasitology, University of Bern, Bern, Switzerland
| | - Joachim Müller
- Vetsuisse Faculty, Institute of Parasitology, University of Bern, Bern, Switzerland
| | - Norbert Müller
- Vetsuisse Faculty, Institute of Parasitology, University of Bern, Bern, Switzerland
| | - Rolf Winter
- VA Portland Health Care System Research and Development Service, Portland, OR, United States
| | - Soviti Pou
- VA Portland Health Care System Research and Development Service, Portland, OR, United States
| | - Aaron Nilsen
- VA Portland Health Care System Research and Development Service, Portland, OR, United States
| | - Mike Riscoe
- VA Portland Health Care System Research and Development Service, Portland, OR, United States
| | - Samuel Francisco
- Faculdade de Medicina Veterinária, CIISA—Centro de Investigação Interdisciplinar em Sanidade Animal, Universidade de Lisboa, Lisbon, Portugal
| | - Alexandre Leitao
- Faculdade de Medicina Veterinária, CIISA—Centro de Investigação Interdisciplinar em Sanidade Animal, Universidade de Lisboa, Lisbon, Portugal
| | - J. Stone Doggett
- VA Portland Health Care System Research and Development Service, Portland, OR, United States
| | - Andrew Hemphill
- Vetsuisse Faculty, Institute of Parasitology, University of Bern, Bern, Switzerland
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14
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Diezma-Díaz C, Ferre I, Re M, Jiménez-Meléndez A, Tabanera E, Pizarro-Díaz M, González-Huecas M, Alcaide-Pardo M, Blanco-Murcia FJ, Ortega-Mora LM, Álvarez-García G. A model for chronic bovine besnoitiosis: Parasite stage and inoculation route are key factors. Transbound Emerg Dis 2019; 67:234-249. [PMID: 31483955 DOI: 10.1111/tbed.13345] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 08/21/2019] [Accepted: 08/21/2019] [Indexed: 12/17/2022]
Abstract
In this work, an experimental model for chronic besnoitiosis in bovine was developed and characterized. Using a previously established calf model, two new variables (parasite stage and inoculation route) were combined and used. Twelve Holstein Friesian 3-month-old male calves were randomly divided into four groups of three animals each. Bradyzoites were obtained from a chronically infected bull and used for inoculation via three different inoculation routes. Three groups were inoculated with 106 bradyzoites by intravenous (G1), subcutaneous (G2) and intradermal (G3) routes, and a non-infected control group (G4) was inoculated with PBS. The trial lasted for 90 days and included daily clinical monitoring as well as weekly skin biopsies and blood sampling. Sera were obtained to analyse both cellular and humoral responses. Once the calves were euthanized, tissues from the skin, eyes, respiratory and reproductive tracts, among others, were collected to study presence of the parasite. Clinically, the infection was classified as mild to moderate for the acute stage since all infected calves showed lymphadenopathy from four days post-infection (pi) and fever from one week pi until 24 days pi. However, the most relevant results were achieved during the chronic stage that was classified as moderate to severe. In fact, pathognomonic conjunctival cysts were observed in all infected calves from 40 days pi onwards and were more abundant in G3. Moreover, one calf from this group developed skin lesions (49 days pi). The microscopic tissue cysts and Besnoitia DNA were detected primarily in skin, reproductive tract and respiratory tissue samples, and parasite load was higher in G3. In conclusion, the parasite stage (bradyzoite) and the inoculation route are key factors that influence the outcome of an infection. In particular, the intradermal route led to more severe clinical signs of the chronic phase in the inoculated calves.
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Affiliation(s)
- Carlos Diezma-Díaz
- Animal Health Department, Faculty of Veterinary Sciences, SALUVET, Complutense University of Madrid, Ciudad Universitaria s/n, Madrid, Spain
| | - Ignacio Ferre
- Animal Health Department, Faculty of Veterinary Sciences, SALUVET, Complutense University of Madrid, Ciudad Universitaria s/n, Madrid, Spain
| | - Michela Re
- Animal Health Department, Faculty of Veterinary Sciences, SALUVET, Complutense University of Madrid, Ciudad Universitaria s/n, Madrid, Spain.,Animal Medicine and Surgery Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, Madrid, Spain
| | - Alejandro Jiménez-Meléndez
- Animal Health Department, Faculty of Veterinary Sciences, SALUVET, Complutense University of Madrid, Ciudad Universitaria s/n, Madrid, Spain
| | - Enrique Tabanera
- Animal Medicine and Surgery Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, Madrid, Spain
| | - Manuel Pizarro-Díaz
- Animal Medicine and Surgery Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, Madrid, Spain
| | - Marta González-Huecas
- Animal Medicine and Surgery Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, Madrid, Spain
| | - María Alcaide-Pardo
- Animal Health Department, Faculty of Veterinary Sciences, SALUVET, Complutense University of Madrid, Ciudad Universitaria s/n, Madrid, Spain
| | - Francisco Javier Blanco-Murcia
- Animal Health Department, Faculty of Veterinary Sciences, SALUVET, Complutense University of Madrid, Ciudad Universitaria s/n, Madrid, Spain.,Animal Medicine and Surgery Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, Madrid, Spain
| | - Luis Miguel Ortega-Mora
- Animal Health Department, Faculty of Veterinary Sciences, SALUVET, Complutense University of Madrid, Ciudad Universitaria s/n, Madrid, Spain
| | - Gema Álvarez-García
- Animal Health Department, Faculty of Veterinary Sciences, SALUVET, Complutense University of Madrid, Ciudad Universitaria s/n, Madrid, Spain
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15
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Bumped kinase inhibitor 1369 is effective against Cystoisospora suis in vivo and in vitro. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2019; 10:9-19. [PMID: 30959327 PMCID: PMC6453670 DOI: 10.1016/j.ijpddr.2019.03.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Revised: 03/25/2019] [Accepted: 03/28/2019] [Indexed: 12/22/2022]
Abstract
Cystoisosporosis is a leading diarrheal disease in suckling piglets. With the confirmation of resistance against the only available drug toltrazuril, there is a substantial need for novel therapeutics to combat the infection and its negative effects on animal health. In closely related apicomplexan species, bumped kinase inhibitors (BKIs) targeting calcium-dependent protein kinase 1 (CDPK1) were shown to be effective in inhibiting host-cell invasion and parasite growth. Therefore, the gene coding for Cystoisospora suis CDPK1 (CsCDPK1) was identified and cloned to investigate activity and thermal stabilization of the recombinant CsCDPK1 enzyme by BKI 1369. In this comprehensive study, the efficacy, safety and pharmacokinetics of BKI 1369 in piglets experimentally infected with Cystoisospora suis (toltrazuril-sensitive, Wien-I and toltrazuril-resistant, Holland-I strains) were determined in vivo and in vitro using an established animal infection model and cell culture, respectively. BKI 1369 inhibited merozoite proliferation in intestinal porcine epithelial cells-1 (IPEC-1) by at least 50% at a concentration of 40 nM, and proliferation was almost completely inhibited (>95%) at 200 nM. Nonetheless, exposure of infected cultures to 200 nM BKI 1369 for five days did not induce structural alterations in surviving merozoites as confirmed by transmission electron microscopy. Five-day treatment with BKI 1369 (10 mg/kg BW twice a day) effectively suppressed oocyst excretion and diarrhea and improved body weight gains in treated piglets without obvious side effects for both toltrazuril-sensitive, Wien-I and resistant, Holland-I C. suis strains. The plasma concentration of BKI 1369 in piglets increased to 11.7 μM during treatment, suggesting constant drug accumulation and exposure of parasites to the drug. Therefore, oral applications of BKI 1369 could potentially be a therapeutic alternative against porcine cystoisosporosis. For use in pigs, future studies on BKI 1369 should be directed towards ease of drug handling and minimizing treatment frequencies. Oral application of BKI 1369 effectively reduced oocyst excretion and diarrhea in Cystoisospora suis infected piglets. 200 nM of BKI 1369 almost completely suppressed parasite proliferation in vitro. IC50 and IC95 concentrations of BKI 1369 did not induce morphological alterations in in vitro cultured merozoites. Cystoisosporasuis CDPK1, the putative target of BKI 1369, has glycine as gatekeeper residue.
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16
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Diezma-Díaz C, Ferre I, Re M, Jiménez-Meléndez A, Tabanera E, González-Huecas M, Pizarro-Díaz M, Yanguas-Pérez D, Brum PL, Blanco-Murcia J, Ortega-Mora LM, Álvarez-García G. The route of Besnoitia besnoiti tachyzoites inoculation does not influence the clinical outcome of the infection in calves. Vet Parasitol 2019; 267:21-25. [PMID: 30878080 DOI: 10.1016/j.vetpar.2019.02.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 01/30/2019] [Accepted: 02/02/2019] [Indexed: 12/12/2022]
Abstract
In a previous attempt, an experimental model of bovine besnoitiosis was established in calves that were intravenously inoculated with different doses of Besnoitia besnoiti tachyzoites. Despite the fact that all infected calves developed the acute stage of disease, only microscopic findings characteristic of chronic besnoitiosis were reported. In the present study, calves were inoculated by subcutaneous and intradermal routes with B. besnoiti tachyzoites with the aim of developing clinical signs and macroscopic lesions characteristic of chronic besnoitiosis. Nine 3-month-old male calves were randomly distributed into three groups of three animals each. Next, 106 tachyzoites were inoculated by either the subcutaneous (G1) or intradermal route (G2). The negative control group (G3) was inoculated with PBS. Daily clinical monitoring and regular blood collection were performed. At 70 days post-infection (pi), animals were euthanized, and tissues were collected to investigate lesions and parasites. Infected animals developed mild-moderate acute besnoitiosis characterized by lymphadenopathy from four days to 47 days pi, and sporadic fever peaks were only observed in one calf from G2. However, other clinical signs and macroscopic lesions characteristic of chronic besnoitiosis were not detected. Only nine tissue samples were B. besnoiti-DNA-positive, eight of which belonged to reproductive and respiratory tracts tissues from G1. Finally, the kinetics of the immune responses were similar in both infected groups. However, delayed and lower cellular and humoral immune responses were observed in G1 followed by G2 and were compared with intravenously inoculated calves. The differences observed among the three inoculation routes could be due to different effector mechanisms of the host early innate immune response against B. besnoiti. Accordingly, the inoculation route of B. besnoiti tachyzoites does not significantly influence the clinical outcome of the infection in calves. Thus, a further refinement of this experimental model of bovine besnoitiosis is needed to reproduce macroscopic lesions characteristic of chronic stage disease.
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Affiliation(s)
- C Diezma-Díaz
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - I Ferre
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - M Re
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain; Animal Medicine and Surgery Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - A Jiménez-Meléndez
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - E Tabanera
- Animal Medicine and Surgery Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - M González-Huecas
- Animal Medicine and Surgery Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - M Pizarro-Díaz
- Animal Medicine and Surgery Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - D Yanguas-Pérez
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - P L Brum
- Laboratory of Microbiology and Parasitology, UNIPAMPA, Federal University of Pampa, Dom Pedrito, Brazil
| | - J Blanco-Murcia
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain; Animal Medicine and Surgery Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - L M Ortega-Mora
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - G Álvarez-García
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain.
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Cervantes-Valencia ME, Hermosilla C, Alcalá-Canto Y, Tapia G, Taubert A, Silva LMR. Antiparasitic Efficacy of Curcumin Against Besnoitia besnoiti Tachyzoites in vitro. Front Vet Sci 2019; 5:333. [PMID: 30687723 PMCID: PMC6336690 DOI: 10.3389/fvets.2018.00333] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 12/14/2018] [Indexed: 01/29/2023] Open
Abstract
Besnoitia besnoiti is the causative agent of bovine besnoitiosis. B. besnoiti infections lead to reduced fertility and productivity in cattle causing high economic losses, not only in Europe, but also in Asia and Africa. Mild to severe clinical signs, such as anasarca, oedema, orchitis, hyperkeratosis, and characteristic skin and mucosal cysts, are due to B. besnoiti tachyzoite and bradyzoite replication in intermediate host tissues. So far, there are no commercially available effective drugs against this parasite. Curcumin, a polyphenolic compound from Curcuma longa rhizome is well-known for its antioxidant, anti-inflammatory, immunomodulatory and also anti-protozoan effects. Hence, the objective of this study was to evaluate the effects of curcumin on viability, motility, invasive capacity, and proliferation of B. besnoiti tachyzoites replicating in primary bovine umbilical vein endothelial cells (BUVEC) in vitro. Functional inhibition assays revealed that curcumin treatments reduce tachyzoite viability and induce lethal effects in up to 57% of tachyzoites (IC50 in 5.93 μM). Referring to general motility, significant dose-dependent effects of curcumin treatments were observed. Interestingly, curcumin treatments only dampened helical gliding and twirling activities whilst longitudinal gliding motility was not significantly affected. In addition, curcumin pretreatments of tachyzoites resulted in a dose-dependent reduction of host cell invasion as detected by infections rates at 1 day p. i. These findings demonstrate feeding cattle with Curcuma longa rhizomes may represent a new strategy for besnoitiosis treatment.
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Affiliation(s)
- María Eugenia Cervantes-Valencia
- Graduate Program of Animal Health and Production, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Carlos Hermosilla
- Institute of Parasitology, Justus Liebig University Giessen, Giessen, Germany
| | - Yazmín Alcalá-Canto
- Department of Parasitology, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Graciela Tapia
- Department of Genetics and Biostatistics, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Anja Taubert
- Institute of Parasitology, Justus Liebig University Giessen, Giessen, Germany
| | - Liliana M. R. Silva
- Institute of Parasitology, Justus Liebig University Giessen, Giessen, Germany
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Jiménez-Meléndez A, Rico-San Román L, Hemphill A, Balmer V, Ortega-Mora LM, Álvarez-García G. Repurposing of commercially available anti-coccidials identifies diclazuril and decoquinate as potential therapeutic candidates against Besnoitia besnoiti infection. Vet Parasitol 2018; 261:77-85. [PMID: 30253854 DOI: 10.1016/j.vetpar.2018.08.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 08/20/2018] [Accepted: 08/30/2018] [Indexed: 01/07/2023]
Abstract
Repurposing of currently marketed compounds with proven efficacy against apicomplexan parasites was used as an approach to define novel candidate therapeutics for bovine besnoitiosis. Besnoitia besnoiti tachyzoites grown in MARC-145 cells were exposed to different concentrations of toltrazuril, diclazuril, imidocarb, decoquinate, sulfadiazine and trimethoprim alone or in combination with sulfadiazine. Drugs were added either just prior to infection of MARC-145 cells (0 h post infection, hpi) or at 6 hpi. A primary evaluation of drug effects was done by direct immunofluorescence staining and counting. Potential effects on the host cells were assessed using a XTT kit for cell proliferation. Compounds displaying promising efficacy were selected for IC50 and IC99 determination by qPCR. In addition, the impact of drugs on the tachyzoite ultrastructure was assessed by TEM and long-term treatment assays were performed. Cytotoxicity assays confirmed that none of the compounds affected the host cells. Decoquinate and diclazuril displayed invasion inhibition rates of 90 and 83% at 0 h pi and 73 and 72% at 6 h pi, respectively. The remaining drugs showed lower efficacy and were not further studied. Decoquinate and diclazuril exhibited IC99 values of 100 nM and 29.9 μM, respectively. TEM showed that decoquinate primarily affected the parasite mitochondrium, whilst diclazuril interfered in cytokinesis of daughter zoites. The present study demonstrates the efficacy of diclazuril and decoquinate against B. besnoiti in vitro and further assessments of safety and efficacy of both drugs should be performed in the target species.
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Affiliation(s)
- Alejandro Jiménez-Meléndez
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Laura Rico-San Román
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Andrew Hemphill
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Länggass-Strasse 122, CH-3012, Bern, Switzerland
| | - Vreni Balmer
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Länggass-Strasse 122, CH-3012, Bern, Switzerland
| | - Luis Miguel Ortega-Mora
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Gema Álvarez-García
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain.
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Development and characterization of monoclonal antibodies againstBesnoitia besnoititachyzoites. Parasitology 2018; 146:187-196. [DOI: 10.1017/s0031182018001336] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
AbstractThis is the first report on the development and characterization of eight monoclonal antibodies (MABs) generated against whole- and membrane-enriched tachyzoite extracts of the apicomplexan parasiteBesnoitia besnoiti. Confocal laser scanning immunofluorescence microscopy was used to localize respective epitopes inB. besnoititachyzoites along the lytic cycle. A pattern compatible with dense granule staining was observed with MABs 2.A.12, 2.F.3 and 2.G.4, which could be confirmed by immunogold electron microscopy for MABs 2.A.12 and 2.F.3. In particular, MABs 2.F.3 and 2.G.4 were secreted during early invasion, proliferation and egress phases. MABs 3.10.8 and 5.5.11 labelled the tachyzoite surface, whilst MABs 1.17.8, 8.9.2 and 2.G.A recognized the apical tip, which is reminiscent for microneme localization. Besides, the epitopes recognized by the latter two (MABs 8.9.2 and 2.G.A) exhibited a redistribution from the anterior part across the parasite surface towards the posterior end during invasion. Most MABs developed were genus-specific. Indeed, the MABs cross-reacted neither withT. gondiinor withN. caninumtachyzoites. In summary, we have generated MABs that will be useful to study the key processes in the lytic cycle of the parasite and with additional promising diagnostic value. However, the molecular identity of the antigens recognized remains to be elucidated.
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Diezma-Díaz C, Jiménez-Meléndez A, Re MT, Ferre I, Ferreras MDC, Gutiérrez-Expósito D, Rojo-Montejo S, Román-Trufero A, Benavides-Silván J, García-Lunar P, Calleja-Bueno L, Blanco-Murcia J, Osoro K, Ortega-Mora LM, Álvarez-García G. Effect of parasite dose and host age on the infection with Besnoitia besnoiti
tachyzoites in cattle. Transbound Emerg Dis 2018; 65:1979-1990. [DOI: 10.1111/tbed.12980] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 07/09/2018] [Accepted: 07/13/2018] [Indexed: 12/25/2022]
Affiliation(s)
- Carlos Diezma-Díaz
- SALUVET; Animal Health Department; Faculty of Veterinary Sciences; Complutense University of Madrid; Madrid Spain
| | - Alejandro Jiménez-Meléndez
- SALUVET; Animal Health Department; Faculty of Veterinary Sciences; Complutense University of Madrid; Madrid Spain
| | - Michela Tatiana Re
- SALUVET; Animal Health Department; Faculty of Veterinary Sciences; Complutense University of Madrid; Madrid Spain
- Animal Medicine and Surgery Department; Faculty of Veterinary Sciences; Complutense University of Madrid; Madrid Spain
| | - Ignacio Ferre
- SALUVET; Animal Health Department; Faculty of Veterinary Sciences; Complutense University of Madrid; Madrid Spain
| | | | - Daniel Gutiérrez-Expósito
- SALUVET; Animal Health Department; Faculty of Veterinary Sciences; Complutense University of Madrid; Madrid Spain
- Livestock Health and Production Institute (ULE-CSIC); León Spain
| | - Silvia Rojo-Montejo
- SALUVET; Animal Health Department; Faculty of Veterinary Sciences; Complutense University of Madrid; Madrid Spain
- Regional Service for Research and Agri-Food Development (SERIDA); Animal Production Systems; Villaviciosa Spain
| | - Alicia Román-Trufero
- Regional Service for Research and Agri-Food Development (SERIDA); Animal Production Systems; Villaviciosa Spain
| | | | - Paula García-Lunar
- SALUVET; Animal Health Department; Faculty of Veterinary Sciences; Complutense University of Madrid; Madrid Spain
| | - Lydia Calleja-Bueno
- Animal Medicine and Surgery Department; Faculty of Veterinary Sciences; Complutense University of Madrid; Madrid Spain
| | - Javier Blanco-Murcia
- SALUVET; Animal Health Department; Faculty of Veterinary Sciences; Complutense University of Madrid; Madrid Spain
- Animal Medicine and Surgery Department; Faculty of Veterinary Sciences; Complutense University of Madrid; Madrid Spain
| | - Koldo Osoro
- Regional Service for Research and Agri-Food Development (SERIDA); Animal Production Systems; Villaviciosa Spain
| | - Luis-Miguel Ortega-Mora
- SALUVET; Animal Health Department; Faculty of Veterinary Sciences; Complutense University of Madrid; Madrid Spain
| | - Gema Álvarez-García
- SALUVET; Animal Health Department; Faculty of Veterinary Sciences; Complutense University of Madrid; Madrid Spain
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In vitro treatment of Besnoitia besnoiti with the naphto-quinone buparvaquone results in marked inhibition of tachyzoite proliferation, mitochondrial alterations and rapid adaptation of tachyzoites to increased drug concentrations. Parasitology 2018; 146:112-120. [PMID: 29921336 DOI: 10.1017/s0031182018000975] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
We here assessed the in vitro efficacy of the naptho-quinone buparvaquone (BPQ) against Besnoitia besnoiti tachyzoites in vitro. BPQ is currently licensed for the treatment of theileriosis in cattle in many countries, but not in the EU. In 4-day treatment assays, BPQ massively impaired tachyzoite proliferation with an IC50 of 10 ± 3 nm, and virtually complete inhibition was obtained in the presence of nm BPQ. Exposure to 1 µm BPQ leads to ultrastructural changes affecting initially the mitochondrial matrix and the cristae. After 96 h, most parasites were largely distorted, filled with cytoplasmic amylopectin granules and vacuoles containing components of unknown composition. Host cell mitochondria did not appear to be notably affected by the drug. However, upon prolonged exposure (14-16 days) to increased BPQ concentrations, B. besnoiti tachyzoites exhibited the capacity to adapt, and they resumed proliferation at dosages of up to 10 µm BPQ, albeit at a lower rate. These BPQ-adapted parasites maintained this lower susceptibility to BPQ treatment after freeze-thawing, and inspection by the transmission electron microscopy revealed that they underwent proliferation in the absence of structurally intact mitochondria.
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Hemphill A, Leitão A, Ortega-Mora LM, Cooke BM. ApiCOWplexa 2017 - 4th International Meeting on Apicomplexan Parasites in Farm Animals. Int J Parasitol 2017; 47:697-699. [PMID: 28942797 DOI: 10.1016/j.ijpara.2017.09.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Andrew Hemphill
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Länggass-Strasse 122, CH-3012 Bern, Switzerland.
| | - Alexandre Leitão
- CIISA, Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal.
| | - Luis-Miguel Ortega-Mora
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain.
| | - Brian M Cooke
- Biomedicine Discovery Institute and Department of Microbiology, Monash University, Victoria 3800, Australia.
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