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Waldron-Young E, Wijitrmektong W, Choi R, Whitman GR, Hulverson MA, Charania R, Keelaghan A, Li L, Srinual S, Nikhar S, McNamara CW, Love MS, Huerta L, Bakowski MA, Hu M, Van Voorhis WC, Mead JR, Cuny GD. Pyridopyrimidinones as a new chemotype of calcium dependent protein kinase 1 (CDPK1) inhibitors for Cryptosporidium. Mol Biochem Parasitol 2024; 260:111637. [PMID: 38901801 DOI: 10.1016/j.molbiopara.2024.111637] [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: 03/31/2024] [Revised: 06/08/2024] [Accepted: 06/12/2024] [Indexed: 06/22/2024]
Abstract
The protozoan protein kinase calcium-dependent protein kinase 1 (CDPK1) has emerged as a potential therapeutic target for the treatment of cryptosporidiosis. A focused screen of known kinase inhibitors identified a pyridopyrimidinone as a new chemotype of Cryptosporidium parvum (Cp) CDPK1 inhibitors. Structural comparison of CpCDPK1 to two representative human kinases, RIPK2 and Src, revealed differences in the positioning of the αC-helix that was used in the design of a potent pyridopyrimidinone-based CpCDPK1 inhibitor 7 (a.k.a. UH15-16, IC50 = 10 nM), which blocked the growth of three C. parvum strains (EC50 = 12-40 nM) as well as C. hominis (EC50 = 85 nM) in HCT-8 host cells. Pharmacokinetic and tissue distribution analyses indicated that 7 had low systemic exposure after oral administration, but high gastrointestinal concentration, as well as good Caco-2 cell permeability. Finally, 7 demonstrated partial efficacy in an IL-12 knock-out mouse model of acute cryptosporidiosis.
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Affiliation(s)
- Elise Waldron-Young
- Department of Pharmaceutical and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, United States
| | - Wissarut Wijitrmektong
- Department of Pharmaceutical and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, United States
| | - Ryan Choi
- Department of Allergy and Infectious Diseases, University of Washington, Seattle, WA 98109, United States
| | - Grant R Whitman
- Department of Allergy and Infectious Diseases, University of Washington, Seattle, WA 98109, United States
| | - Matthew A Hulverson
- Department of Allergy and Infectious Diseases, University of Washington, Seattle, WA 98109, United States
| | - Raheela Charania
- Department of Pediatrics, Emory University and Children's Healthcare Organization of Atlanta, Atlanta, GA 30322, United States; Atlanta VA Medical Center, Decatur, GA 30033, United States
| | - Aidan Keelaghan
- Department of Pediatrics, Emory University and Children's Healthcare Organization of Atlanta, Atlanta, GA 30322, United States; Atlanta VA Medical Center, Decatur, GA 30033, United States
| | - Li Li
- Department of Pharmaceutical and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, United States
| | - Songpol Srinual
- Department of Pharmaceutical and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, United States
| | - Sameer Nikhar
- Department of Pharmaceutical and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, United States
| | - Case W McNamara
- Calibr-Skaggs Institute for Innovative Medicines, A division of The Scripps Research Institute, La Jolla, CA 92037, United States
| | - Melissa S Love
- Calibr-Skaggs Institute for Innovative Medicines, A division of The Scripps Research Institute, La Jolla, CA 92037, United States
| | - Lauren Huerta
- Calibr-Skaggs Institute for Innovative Medicines, A division of The Scripps Research Institute, La Jolla, CA 92037, United States
| | - Malina A Bakowski
- Calibr-Skaggs Institute for Innovative Medicines, A division of The Scripps Research Institute, La Jolla, CA 92037, United States
| | - Ming Hu
- Department of Pharmaceutical and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, United States
| | - Wesley C Van Voorhis
- Department of Allergy and Infectious Diseases, University of Washington, Seattle, WA 98109, United States
| | - Jan R Mead
- Department of Pediatrics, Emory University and Children's Healthcare Organization of Atlanta, Atlanta, GA 30322, United States; Atlanta VA Medical Center, Decatur, GA 30033, United States
| | - Gregory D Cuny
- Department of Pharmaceutical and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, United States.
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Stensvold CR, Larsen TG, Grüttner J, Nielsen L, Engberg J, Lebbad M. Rodent-adapted Cryptosporidium infection in humans: Seven new cases and review of the literature. One Health 2024; 18:100682. [PMID: 39010954 PMCID: PMC11247268 DOI: 10.1016/j.onehlt.2024.100682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 01/19/2024] [Indexed: 07/17/2024] Open
Abstract
Cases of cryptosporidiosis in humans have been reported with strong indication of transmission from rodents. Here, we report seven new human cases of cryptosporidiosis involving rodent-adapted species (Cryptosporidium ditrichi [n = 1], Cryptosporidium mortiferum [n = 4; previously known as Cryptosporidium chipmunk genotype I], Cryptosporidium tyzzeri [n = 1], and Cryptosporidium viatorum [n = 1]) and review cases of human infection caused by these four species published to date. The seven new cases were detected in Denmark within a period of twelve months from 2022 to 2023. Only the C. tyzzeri and C. viatorum cases were associated with travel outside Denmark. The total number of human cases of cryptosporidiosis due to C. ditrichi and C. tyzzeri documented to date globally are still limited (4 and 7, respectively), whereas cases involving C. viatorum and C. mortiferum have been detected to a larger extent (43 and 63 cases, respectively). The four new cases of C. mortiferum were all of the XIVaA20G2T1 subtype, which is the only subtype identified so far in Scandinavia, and which is a subtype not yet found outside of Scandinavia. The new C. viatorum case was identified as the XVaA3g subtype. The C. tyzzeri case was subtyped as IXbA6. No subtype data were produced for C. ditrichi due to lack of a subtype assay. Review of existing data suggests the presence of C. ditrichi and C. mortiferum primarily in northern countries and C. tyzzeri and C. viatorum primarily in warmer climates. While our data may further support the role of Cryptosporidium as a cause of zoonotic disease, case descriptions should be obtained where possible to determine if Cryptosporidium species primarily adapted to rodents are the likely cause of symptoms or just an incidental finding.
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Affiliation(s)
- Christen Rune Stensvold
- Laboratory of Parasitology, Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen S, Denmark
| | - Tine Graakjær Larsen
- Department of Infectious Disease Epidemiology and Prevention, Statens Serum Institut, Copenhagen, Denmark
- European Programme for Public Health Microbiology Training (EUPHEM), European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden
| | - Jana Grüttner
- Laboratory of Parasitology, Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen S, Denmark
- European Programme for Public Health Microbiology Training (EUPHEM), European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden
| | - Lene Nielsen
- Department of Clinical Microbiology, Copenhagen University Hospital, Herlev and Gentofte, Denmark
| | - Jørgen Engberg
- Department of Clinical Microbiology, Zealand University Hospital, Roskilde, Denmark
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3
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Lenière AC, Vlandas A, Follet J. Treating cryptosporidiosis: A review on drug discovery strategies. Int J Parasitol Drugs Drug Resist 2024; 25:100542. [PMID: 38669849 PMCID: PMC11066572 DOI: 10.1016/j.ijpddr.2024.100542] [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: 11/28/2023] [Revised: 04/15/2024] [Accepted: 04/18/2024] [Indexed: 04/28/2024]
Abstract
Despite several decades of research on therapeutics, cryptosporidiosis remains a major concern for human and animal health. Even though this field of research to assess antiparasitic drug activity is highly active and competitive, only one molecule is authorized to be used in humans. However, this molecule was not efficacious in immunocompromised people and the lack of animal therapeutics remains a cause of concern. Indeed, the therapeutic arsenal needs to be developed for both humans and animals. Our work aims to clarify research strategies that historically were diffuse and poorly directed. This paper reviews in vitro and in vivo methodologies to assess the activity of future therapeutic compounds by screening drug libraries or through drug repurposing. It focuses on High Throughput Screening methodologies (HTS) and discusses the lack of knowledge of target mechanisms. In addition, an overview of several specific metabolic pathways and enzymatic activities used as targets against Cryptosporidium is provided. These metabolic processes include glycolytic pathways, fatty acid production, kinase activities, tRNA elaboration, nucleotide synthesis, gene expression and mRNA maturation. As a conclusion, we highlight emerging future strategies for screening natural compounds and assessing drug resistance issues.
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Affiliation(s)
- Anne-Charlotte Lenière
- University of Lille, CNRS, Centrale Lille, Junia, Université Polytechnique Hauts de France, UMR 8520, IEMN Institut d'Electronique de Microélectronique et de Nanotechnologie, F, 59000, Lille, France
| | - Alexis Vlandas
- University of Lille, CNRS, Centrale Lille, Junia, Université Polytechnique Hauts de France, UMR 8520, IEMN Institut d'Electronique de Microélectronique et de Nanotechnologie, F, 59000, Lille, France
| | - Jérôme Follet
- University of Lille, CNRS, Centrale Lille, Junia, Université Polytechnique Hauts de France, UMR 8520, IEMN Institut d'Electronique de Microélectronique et de Nanotechnologie, F, 59000, Lille, France.
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4
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Zhang CX, Conrad TM, Hermann D, Gordon MA, Houpt E, Iroh Tam P, Jere KC, Nedi W, Operario DJ, Phulusa J, Quinnan GV, Sawyer LA, Barrett LK, Thole H, Toto N, Van Voorhis WC, Arnold SLM. Clofazimine pharmacokinetics in HIV-infected adults with diarrhea: Implications of diarrheal disease on absorption of orally administered therapeutics. CPT Pharmacometrics Syst Pharmacol 2024; 13:410-423. [PMID: 38164114 PMCID: PMC10941540 DOI: 10.1002/psp4.13092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 11/05/2023] [Accepted: 11/20/2023] [Indexed: 01/03/2024] Open
Abstract
Oral drug absorption kinetics are usually established in populations with a properly functioning gastrointestinal tract. However, many diseases and therapeutics can alter gastrointestinal physiology and cause diarrhea. The extent of diarrhea-associated impact on drug pharmacokinetics has not been quantitatively described. To address this knowledge gap, we used a population pharmacokinetic modeling approach with data collected in a phase IIa study of matched human immunodeficiency virus (HIV)-infected adults with/without cryptosporidiosis and diarrhea to examine diarrhea-associated impact on oral clofazimine pharmacokinetics. A population pharmacokinetic model was developed with 428 plasma samples from 23 HIV-infected adults with/without Cryptosporidium infection using nonlinear mixed-effects modeling. Covariates describing cryptosporidiosis-associated diarrhea severity (e.g., number of diarrhea episodes, diarrhea grade) or HIV infection (e.g., viral load, CD4+ T cell count) were evaluated. A two-compartment model with lag time and first-order absorption and elimination best fit the data. Maximum diarrhea grade over the study duration was found to be associated with a more than sixfold reduction in clofazimine bioavailability. Apparent clofazimine clearance, intercompartmental clearance, central volume of distribution, and peripheral volume of distribution were 3.71 L/h, 18.2 L/h (interindividual variability [IIV] 45.0%), 473 L (IIV 3.46%), and 3434 L, respectively. The absorption rate constant was 0.625 h-1 (IIV 149%) and absorption lag time was 1.83 h. In conclusion, the maximum diarrhea grade observed for the duration of oral clofazimine administration was associated with a significant reduction in clofazimine bioavailability. Our results highlight the importance of studying disease impacts on oral therapeutic pharmacokinetics to inform dose optimization and maximize the chance of treatment success.
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Affiliation(s)
- Cindy X. Zhang
- Department of PharmaceuticsUniversity of WashingtonSeattleWashingtonUSA
| | - Thomas M. Conrad
- EmmesRockvilleMarylandUSA
- Present address:
AstraZenecaRockvilleMDUSA
| | | | - Melita A. Gordon
- Paediatrics and Child Health Research GroupMalawi‐Liverpool Wellcome Trust Clinical Research ProgrammeBlantyreMalawi
- Institute of Infection and Global HealthUniversity of LiverpoolLiverpoolUK
| | - Eric Houpt
- Division of Infectious Diseases and International HealthUniversity of VirginiaCharlottesvilleVirginiaUSA
| | - Pui‐Ying Iroh Tam
- Paediatrics and Child Health Research GroupMalawi‐Liverpool Wellcome Trust Clinical Research ProgrammeBlantyreMalawi
- Liverpool School of Tropical MedicineLiverpoolUK
| | - Khuzwayo C. Jere
- Paediatrics and Child Health Research GroupMalawi‐Liverpool Wellcome Trust Clinical Research ProgrammeBlantyreMalawi
- Institute of Infection and Global HealthUniversity of LiverpoolLiverpoolUK
| | - Wilfred Nedi
- Paediatrics and Child Health Research GroupMalawi‐Liverpool Wellcome Trust Clinical Research ProgrammeBlantyreMalawi
| | - Darwin J. Operario
- Division of Infectious Diseases and International HealthUniversity of VirginiaCharlottesvilleVirginiaUSA
- Present address:
World Health OrganizationSuvaCentralFiji
| | - Jacob Phulusa
- Paediatrics and Child Health Research GroupMalawi‐Liverpool Wellcome Trust Clinical Research ProgrammeBlantyreMalawi
| | | | | | - Lynn K. Barrett
- Center for Emerging and Re‐emerging Infectious DiseasesUniversity of WashingtonSeattleWashingtonUSA
| | - Herbert Thole
- Paediatrics and Child Health Research GroupMalawi‐Liverpool Wellcome Trust Clinical Research ProgrammeBlantyreMalawi
| | - Neema Toto
- Liverpool School of Tropical MedicineLiverpoolUK
| | - Wesley C. Van Voorhis
- Center for Emerging and Re‐emerging Infectious DiseasesUniversity of WashingtonSeattleWashingtonUSA
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5
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Ali AM, P. Solans B, Hesseling AC, Winckler J, Schaaf HS, Draper HR, van der Laan L, Hughes J, Fourie B, Nielsen J, Wiesner L, Garcia-Prats AJ, Savic RM. Pharmacokinetics and cardiac safety of clofazimine in children with rifampicin-resistant tuberculosis. Antimicrob Agents Chemother 2024; 68:e0079423. [PMID: 38112526 PMCID: PMC10777824 DOI: 10.1128/aac.00794-23] [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: 06/16/2023] [Accepted: 10/18/2023] [Indexed: 12/21/2023] Open
Abstract
Clofazimine is recommended for the treatment of rifampicin-resistant tuberculosis (RR-TB), but there is currently no verified dosing guideline for its use in children. There is only limited safety and no pharmacokinetic (PK) data available for children. We aimed to characterize clofazimine PK and its relationship with QT-interval prolongation in children. An observational cohort study of South African children <18 years old routinely treated for RR-TB with a clofazimine-containing regimen was analyzed. Clofazimine 100 mg gelatin capsules were given orally once daily (≥20 kg body weight), every second day (10 to <20 kg), or thrice weekly (<10 kg). PK sampling and electrocardiograms were completed pre-dose and at 1, 4, and 10 hours post-dose, and the population PK and Fridericia-corrected QT (QTcF) interval prolongation were characterized. Fifty-four children contributed both PK and QTcF data, with a median age (2.5th-97.5th centiles) of 3.3 (0.5-15.6) years; five children were living with HIV. Weekly area under the time-concentration curve at steady state was 79.1 (15.0-271) mg.h/L compared to an adult target of 60.9 (56.0-66.6) mg.h/L. Children living with HIV had four times higher clearance compared to those without. No child had a QTcF ≥500 ms. A linear concentration-QTcF relationship was found, with a drug effect of 0.05 (0.027, 0.075) ms/µg/L. In some of the first PK data in children, we found clofazimine exposure using an off-label dosing strategy was higher in children versus adults. Clofazimine concentrations were associated with an increase in QTcF, but severe prolongation was not observed. More data are required to inform dosing strategies in children.
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Affiliation(s)
- Ali Mohamed Ali
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, California, USA
- Department of Interventions and Clinical Trials, Bagamoyo Research and Training Center, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Belén P. Solans
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, California, USA
| | - Anneke C. Hesseling
- Department of Paediatrics and Child Health, Desmond Tutu TB Centre, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Jana Winckler
- Department of Paediatrics and Child Health, Desmond Tutu TB Centre, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - H. Simon Schaaf
- Department of Paediatrics and Child Health, Desmond Tutu TB Centre, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Heather R. Draper
- Department of Paediatrics and Child Health, Desmond Tutu TB Centre, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Louvina van der Laan
- Department of Paediatrics and Child Health, Desmond Tutu TB Centre, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Jennifer Hughes
- Department of Paediatrics and Child Health, Desmond Tutu TB Centre, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Barend Fourie
- Department of Paediatrics and Child Health, Desmond Tutu TB Centre, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - James Nielsen
- Department of Pediatrics, New York University School of Medicine, New York, New York, USA
| | - Lubbe Wiesner
- Department of Medicine, Division of Clinical Pharmacology, University of Cape Town, Cape Town, South Africa
| | - Anthony J. Garcia-Prats
- Department of Paediatrics and Child Health, Desmond Tutu TB Centre, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
- Department of Pediatrics, University of Wisconsin-Madison, School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Radojka M. Savic
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, California, USA
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Ali M, Xu C, Nawaz S, Ahmed AE, Hina Q, Li K. Anti-Cryptosporidial Drug-Discovery Challenges and Existing Therapeutic Avenues: A "One-Health" Concern. Life (Basel) 2024; 14:80. [PMID: 38255695 PMCID: PMC10820218 DOI: 10.3390/life14010080] [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: 11/22/2023] [Revised: 12/20/2023] [Accepted: 12/28/2023] [Indexed: 01/24/2024] Open
Abstract
Cryptosporidiosis is the leading cause of life-threatening diarrheal infection, especially in infants. Oocysts contaminate the environment, and also, being a zoonotic disease, cryptosporidiosis is a threat to One Health. Nitazoxanide is the only FDA-approved drug, effective only in immunocompetent adults, and is not safe for infants. The absence of mitochondria and apicoplast, the presence of an electron-dense band (ED band), hindrances in its genetic and phenotypic manipulations, and its unique position inside the host cell are some challenges to the anti-cryptosporidial drug-discovery process. However, many compounds, including herbal products, have shown efficacy against Cryptosporidium during in vitro and in vivo trials. Still, the "drug of choice" against this protozoan parasite, especially in immunocompromised individuals and infants, has not yet been explored. The One-Health approach addresses this issue, focusing on the intersection of animal, human, and environmental health. The objective of this review is to provide knowledge about novel anti-cryptosporidial drug targets, available treatment options with associated limitations, and possible future shifts toward natural products to treat cryptosporidiosis. The current review is organized to address the treatment and prevention of cryptosporidiosis. An anti-cryptosporidial drug that is effective in immunocompromised individuals and infants is a necessity of our time.
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Affiliation(s)
- Munwar Ali
- Institute of Traditional Chinese Veterinary Medicine, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; (M.A.); (C.X.)
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Chang Xu
- Institute of Traditional Chinese Veterinary Medicine, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; (M.A.); (C.X.)
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Shah Nawaz
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China;
| | - Ahmed Ezzat Ahmed
- Biology Department, College of Science, King Khalid University, Abha 61413, Saudi Arabia;
| | - Qazal Hina
- Department of Animal Nutrition, University of Veterinary and Animal Sciences, Lahore 54000, Pakistan;
| | - Kun Li
- Institute of Traditional Chinese Veterinary Medicine, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; (M.A.); (C.X.)
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
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Nyirenda JT, Henrion MYR, Nyasulu V, Msakwiza M, Nedi W, Thole H, Phulusa J, Toto N, Jere KC, Winter A, Sawyer LA, Conrad T, Hebert D, Chen C, Van Voorhis WC, Houpt ER, Iroh Tam PY, Operario DJ. Examination of ELISA against PCR for assessing treatment efficacy against Cryptosporidium in a clinical trial context. PLoS One 2023; 18:e0289929. [PMID: 37682856 PMCID: PMC10490871 DOI: 10.1371/journal.pone.0289929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 07/25/2023] [Indexed: 09/10/2023] Open
Abstract
BACKGROUND Cryptosporidium is a gastrointestinal pathogen that presents a serious opportunistic infection in immunocompromised individuals including those living with human immunodeficiency syndrome. The CRYPTOFAZ trial, previously published, was conducted in Malawi to evaluate the efficacy of clofazimine in response to an unmet need for drugs to treat cryptosporidiosis in HIV populations. A combination of rapid diagnostic tests, ELISA, qPCR, and conventional sequencing were employed to detect Cryptosporidium in 586 individuals during pre-screening and monitor oocyst shedding and identify enteric co-pathogens in 22 enrolled/randomized participants during the in-patient period and follow-up visits. METHODOLOGY Oocyst shedding as measured by qPCR was used to determine primary trial outcomes, however pathogen was detected even at trial days 41-55 in individuals randomized to either clofazimine or placebo arms of the study. Therefore, in this work we re-examine the trial outcomes and conclusions in light of data from the other diagnostics, particularly ELISA. ELISA data was normalized between experiments prior to comparison to qPCR. The amount of all identified enteric pathogens was examined to determine if co-pathogens other than Cryptosporidium were major causative agents to a participant's diarrhea. CONCLUSION ELISA had higher sample-to-sample variability and proved to be equally or less sensitive than qPCR in detecting Cryptosporidium positive samples. Compared to qPCR, ELISA had equal or greater specificity in detecting Cryptosporidium negative samples. Sequencing identified several Cryptosporidium species including viatorum which has never been identified in Malawi and Southern Africa. In addition to Cryptosporidium, enterotoxigenic E. coli was also identified as a pathogen in diarrheagenic amounts in 4 out of 22 participants.
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Affiliation(s)
- James T. Nyirenda
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Marc Y. R. Henrion
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Vita Nyasulu
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Mike Msakwiza
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Wilfred Nedi
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Herbert Thole
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Jacob Phulusa
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Neema Toto
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Khuzwayo C. Jere
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Centre for Global Vaccine Research, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Alex Winter
- Emmes Corporation, Rockville, Maryland, United States of America
| | - Leigh A. Sawyer
- Emmes Corporation, Rockville, Maryland, United States of America
| | - Thomas Conrad
- Emmes Corporation, Rockville, Maryland, United States of America
| | - Donnie Hebert
- Emmes Corporation, Rockville, Maryland, United States of America
| | - Crystal Chen
- Emmes Corporation, Rockville, Maryland, United States of America
| | | | - Eric R. Houpt
- University of Virginia, Charlottesville, Virginia, United States of America
| | - Pui-Ying Iroh Tam
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Darwin J. Operario
- University of Virginia, Charlottesville, Virginia, United States of America
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8
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Hanna JC, Corpas-Lopez V, Seizova S, Colon BL, Bacchetti R, Hall GMJ, Sands EM, Robinson L, Baragaña B, Wyllie S, Pawlowic MC. Mode of action studies confirm on-target engagement of lysyl-tRNA synthetase inhibitor and lead to new selection marker for Cryptosporidium. Front Cell Infect Microbiol 2023; 13:1236814. [PMID: 37600947 PMCID: PMC10436570 DOI: 10.3389/fcimb.2023.1236814] [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: 06/08/2023] [Accepted: 07/10/2023] [Indexed: 08/22/2023] Open
Abstract
Introduction Cryptosporidiosis is a leading cause of diarrheal-associated morbidity and mortality, predominantly affecting children under 5 years old in low-and-middle-income countries. There is no effective treatment and no vaccine. New therapeutics are emerging from drug discovery efforts. It is critical that mode of action studies are performed alongside drug discovery to ensure the best clinical outcomes. Unfortunately, technology to identify and validate drug targets for Cryptosporidium is severely lacking. Methods We used C. parvum lysyl-tRNA synthetase (CpKRS) and DDD01510706 as a target-compound pair to develop both chemical and genetic tools for mode of action studies for Cryptosporidium. We adapted thermal proteome profiling (TPP) for Cryptosporidium, an unbiased approach for target identification. Results Using TPP we identified the molecular target of DDD01510706 and confirm that it is CpKRS. Genetic tools confirm that CpKRS is expressed throughout the life cycle and that this target is essential for parasite survival. Parasites genetically modified to over-express CpKRS or parasites with a mutation at the compound-binding site are resistant to treatment with DDD01510706. We leveraged these mutations to generate a second drug selection marker for genetic modification of Cryptosporidium, KRSR. This second selection marker is interchangeable with the original selection marker, NeoR, and expands the range of reverse genetic approaches available to study parasite biology. Due to the sexual nature of the Cryptosporidium life cycle, parental strains containing different drug selection markers can be crossed in vivo. Discussion Selection with both drug markers produces highly efficient genetic crosses (>99% hybrid progeny), paving the way for forward genetics approaches in Cryptosporidium.
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Affiliation(s)
- Jack C. Hanna
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Victor Corpas-Lopez
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Simona Seizova
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Beatrice L. Colon
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Ross Bacchetti
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Grant M. J. Hall
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Emma M. Sands
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Lee Robinson
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Beatriz Baragaña
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
- Drug Discovery Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Susan Wyllie
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Mattie C. Pawlowic
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
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9
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Biglari-Moghadam N, Najafzadehvarzi H, Gorgani-Firouzjaee T, Ghasemi-Kasman M. Efficacy of clofazimine against acute and chronic Toxoplasma gondii infection in mice. Microb Pathog 2023:106206. [PMID: 37331670 DOI: 10.1016/j.micpath.2023.106206] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Revised: 05/25/2023] [Accepted: 06/15/2023] [Indexed: 06/20/2023]
Abstract
Toxoplasmosis is a zoonotic protozoal disease affecting approximately one-third of the world's population. The lack of current treatment options necessitates the development of drugs with good tolerance and effectiveness on the active and cystic stages of the parasite. The present study was established to investigate, for the first time, the potential potency of clofazimine (CFZ) against acute and chronic experimental toxoplasmosis. For this purpose, the type II T. gondii (Me49 strain) was used for induction acute (20 cysts in each mouse) and chronic (10 cysts in each mouse) experimental toxoplasmosis. The mice were treated with 20 mg/kg of CFZ intraperitoneally and orally. The histopathological changes, brain cyst count, total Antioxidant Capacity (TAC), malondialdehyde (MDA) assay, and the level of INF-γ were also evaluated. In the acute toxoplasmosis, both IP and oral administration of CFZ induced a significant reduction in brain parasite burden by 90.2 and 89%, respectively, and increased the survival rate to 100% compared with 60% in untreated controls. In the chronic infection, cyst burden decreased at 85.71 and 76.18% in CFZ-treated subgroups in comparison to infected untreated controls. In addition, 87.5% and 100% of CFZ-treated subgroups survived versus untreated control 62.5%. Moreover, CFZ significantly increased INF-γ levels in acute and chronic toxoplasmosis. Tissue inflammatory lesions were considerably reduced in the CFZ-treated chronic subgroups. CFZ treatment significantly reduced MDA levels and elevated TAC in both acute and chronic infections. In conclusion, CFZ showed a promising finding regarding the ability to reduce cyst burden in acute and chronic infection. Further studies are needed to investigate the therapeutic role of CFZ on toxoplasmosis using the long-term treatment and more advanced approaches. In addition, clofazimine may need to be accompanied by another drug to augment its effect and prevent the regrowth of parasites.
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Affiliation(s)
| | - Hossein Najafzadehvarzi
- Department of Pharmacology and Toxicology, Faculty of Medical Sciences, Babol University of Medical Sciences, Babol, Iran.
| | - Tahmineh Gorgani-Firouzjaee
- Infectious Diseases and Tropical Medicine Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran.
| | - Maryam Ghasemi-Kasman
- Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran; Neuroscience Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran
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10
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Lee S, Love MS, Modukuri R, Chatterjee AK, Huerta L, Lawson AP, McNamara CW, Mead JR, Hedstrom L, Cuny GD. Structure-activity relationship of BMS906024 derivatives for Cryptosporidium parvum growth inhibition. Bioorg Med Chem Lett 2023; 90:129328. [PMID: 37196868 PMCID: PMC10290938 DOI: 10.1016/j.bmcl.2023.129328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 04/28/2023] [Accepted: 05/10/2023] [Indexed: 05/19/2023]
Abstract
BMS906024, a γ-secretase inhibitor that blocks Notch signaling, was previously shown to inhibit Cryptosporidium parvum growth in vitro. A structure-activity relationship (SAR) analysis of BMS906024 reported herein demonstrates the importance of the stereochemistry of the C-3 benzodiazepine and the succinyl β-substituent. However, concomitant removal of the succinyl α-substituent and switching the primary amide with secondary amides was tolerated. For example, 32 (SH287) inhibited C. parvum growth in HCT-8 host cells with an EC50 = 6.4 nM and an EC90 = 16 nM; however, blocking C. parvum growth with BMS906024 derivatives was correlative with inhibition of Notch signaling, highlighting that additional SAR analysis will be needed to separate these two activities.
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Affiliation(s)
- Seungheon Lee
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston, Health Building 2, Houston, TX 77204, USA
| | - Melissa S Love
- Calibr, a Division of The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Ramkumar Modukuri
- Calibr, a Division of The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Arnab K Chatterjee
- Calibr, a Division of The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Lauren Huerta
- Calibr, a Division of The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Ann P Lawson
- Department of Biology, Brandeis University, 415 South St., Waltham, MA 02454, USA
| | - Case W McNamara
- Calibr, a Division of The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Jan R Mead
- Atlanta VA Medical Center and Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Lizbeth Hedstrom
- Department of Biology, Brandeis University, 415 South St., Waltham, MA 02454, USA; Department of Chemistry, Brandeis University, 415 South St., Waltham, MA 02454, USA
| | - Gregory D Cuny
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston, Health Building 2, Houston, TX 77204, USA.
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11
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Oboh E, Teixeira JE, Schubert TJ, Maribona AS, Denman BN, Patel R, Huston CD, Meyers MJ. Structure-Activity relationships of replacements for the triazolopyridazine of Anti-Cryptosporidium lead SLU-2633. Bioorg Med Chem 2023; 86:117295. [PMID: 37148788 PMCID: PMC10201403 DOI: 10.1016/j.bmc.2023.117295] [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: 03/29/2023] [Revised: 04/18/2023] [Accepted: 04/21/2023] [Indexed: 05/08/2023]
Abstract
Cryptosporidiosis is a diarrheal disease particularly harmful to children and immunocompromised people. Infection is caused by the parasite Cryptosporidium and leads to dehydration, malnutrition, and death in severe cases. Nitazoxanide is the only FDA approved drug but is only modestly effective in children and ineffective in immunocompromised patients. To address this unmet medical need, we previously identified triazolopyridazine SLU-2633 as potent against Cryptosporidium parvum, with an EC50 of 0.17 µM. In the present study, we develop structure-activity relationships (SAR) for the replacement of the triazolopyridazine head group by exploring different heteroaryl groups with the aim of maintaining potency while reducing affinity for the hERG channel. 64 new analogs of SLU-2633 were synthesized and assayed for potency versus C. parvum. The most potent compound, 7,8-dihydro-[1,2,4]triazolo[4,3-b]pyridazine 17a, was found to have a Cp EC50 of 1.2 µM, 7-fold less potent than SLU-2633 but has an improved lipophilic efficiency (LipE) score. 17a was found to decrease inhibition in an hERG patch-clamp assay by about two-fold relative to SLU-2633 at 10 µM despite having similar inhibition in a [3H]-dofetilide competitive binding assay. While most other heterocycles were significantly less potent than the lead, some analogs such as azabenzothiazole 31b, have promising potency in the low micromolar range, similar to the drug nitazoxanide, and represent potential new leads for optimization. Overall, this work highlights the important role of the terminal heterocyclic head group and represents a significant extension of the understanding of the SAR for this class of anti-Cryptosporidium compounds.
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Affiliation(s)
- Edmund Oboh
- Department of Chemistry, School of Science and Engineering, Saint Louis University, Saint Louis, MO 63103, United States
| | - José E Teixeira
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, VT 05401, United States
| | - Tanner J Schubert
- Department of Chemistry, School of Science and Engineering, Saint Louis University, Saint Louis, MO 63103, United States
| | - Adriana S Maribona
- Department of Chemistry, School of Science and Engineering, Saint Louis University, Saint Louis, MO 63103, United States
| | - Brylon N Denman
- Department of Chemistry, School of Science and Engineering, Saint Louis University, Saint Louis, MO 63103, United States
| | - Radhika Patel
- Department of Chemistry, School of Science and Engineering, Saint Louis University, Saint Louis, MO 63103, United States
| | - Christopher D Huston
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, VT 05401, United States.
| | - Marvin J Meyers
- Department of Chemistry, School of Science and Engineering, Saint Louis University, Saint Louis, MO 63103, United States; Institute for Drug and Biotherapeutic Innovation, Saint Louis University, St. Louis, MO 63103, United States.
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12
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Caravedo MA, White AC. Treatment of cryptosporidiosis: nitazoxanide yes, but we can do better. Expert Rev Anti Infect Ther 2023; 21:167-173. [PMID: 36533398 DOI: 10.1080/14787210.2023.2160704] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
INTRODUCTION Cryptosporidiosis was initially recognized as an important cause of diarrhea in AIDS patients. It has been underdiagnosed in other populations. Recent studies have highlighted the importance of Cryptosporidium as a cause of diarrhea and malnutrition in young children in resource-poor countries and an emerging pathogen in organ-transplant recipients. AREAS COVERED Nitazoxanide is FDA approved for treatment of cryptosporidiosis in immunocompetent people. However, it is less effective in HIV and transplant patients and malnourished children. In transplant recipients, there is emerging data on antiparasitic combinations for cryptosporidiosis, including combinations of nitazoxanide, azithromycin, and in one case rifaximin. High-throughput phenotypic screens have identified some potential treatments. Among them, clofazimine was no better than placebo in a trial in AIDS patients. There have also been efforts to develop drug versus specific parasite targets. However, in part due to safety issues, none of these compounds have advanced into clinical trials. EXPERT OPINION Development of new and more efficacious therapies for cryptosporidium is imperative. Current approve therapy is far from optimal and lacks efficacy in high-risk populations, such as, patients living with HIV. Additionally, there is limited data on patients with other types of immunosuppression (Transplanted, autoimmune conditions, etc).
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Affiliation(s)
- Maria A Caravedo
- Infectious Disease Division Department of Internal Medicine University of Texas Medical Branch, Galveston, Texas, USA
| | - A Clinton White
- Infectious Disease Division Department of Internal Medicine University of Texas Medical Branch, Galveston, Texas, USA
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13
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Khan SM, Witola WH. Past, current, and potential treatments for cryptosporidiosis in humans and farm animals: A comprehensive review. Front Cell Infect Microbiol 2023; 13:1115522. [PMID: 36761902 PMCID: PMC9902888 DOI: 10.3389/fcimb.2023.1115522] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Accepted: 01/09/2023] [Indexed: 01/25/2023] Open
Abstract
The intracellular protozoan parasite of the genus Cryptosporidium is among the leading causes of waterborne diarrheal disease outbreaks throughout the world. The parasite is transmitted by ingestion of infective oocysts that are highly stable in the environment and resistant to almost all conventional disinfection methods and water treatments. Control of the parasite infection is exceedingly difficult due to the excretion of large numbers of oocysts in the feces of infected individuals that contaminate the environment and serve as a source of infection for susceptible hosts including humans and animals. Drug development against the parasite is challenging owing to its limited genetic tractability, absence of conventional drug targets, unique intracellular location within the host, and the paucity of robust cell culture platforms for continuous parasite propagation. Despite the high prevalence of the parasite, the only US Food and Drug Administration (FDA)-approved treatment of Cryptosporidium infections is nitazoxanide, which has shown moderate efficacy in immunocompetent patients. More importantly, no effective therapeutic drugs are available for treating severe, potentially life-threatening cryptosporidiosis in immunodeficient patients, young children, and neonatal livestock. Thus, safe, inexpensive, and efficacious drugs are urgently required to reduce the ever-increasing global cryptosporidiosis burden especially in low-resource countries. Several compounds have been tested for both in vitro and in vivo efficacy against the disease. However, to date, only a few experimental compounds have been subjected to clinical trials in natural hosts, and among those none have proven efficacious. This review provides an overview of the past and present anti-Cryptosporidium pharmacotherapy in humans and agricultural animals. Herein, we also highlight the progress made in the field over the last few years and discuss the different strategies employed for discovery and development of effective prospective treatments for cryptosporidiosis.
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14
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The Marine Compound Tartrolon E Targets the Asexual and Early Sexual Stages of Cryptosporidium parvum. Microorganisms 2022; 10:microorganisms10112260. [PMID: 36422330 PMCID: PMC9693555 DOI: 10.3390/microorganisms10112260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/08/2022] [Accepted: 11/10/2022] [Indexed: 11/16/2022] Open
Abstract
New therapeutic agents for cryptosporidiosis are a critical medical need. The marine organic compound, tartrolon E (trtE), is highly effective against multiple apicomplexan parasites, including Cryptosporidium. Understanding the mechanism of action of trtE is required to advance in the drug development pipeline. Here, we validate using Nluc C. parvum parasites for the study of trtE and pinpoint the life stage targeted by trtE. Results show that trtE kills Nluc and wild type C. parvum with equal efficiency, confirming the use of the Nluc C. parvum to study this compound. Results revealed that trtE kills the parasite within an hour of treatment and while the compound has no effect on viability of sporozoites, trtE does inhibit establishment of infection. Targeting treatment at particular life cycle stages demonstrated that trtE is effective against asexual of the parasite but has reduced efficacy against mature sexual stages. Gene expression analysis shows that trtE inhibits the early sexual stage of the parasite. Results from these studies will aid the development of trtE as a therapeutic for cryptosporidiosis.
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15
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Ryan U, Hill K, Deere D. Review of generic screening level assumptions for quantitative microbial risk assessment (QMRA) for estimating public health risks from Australian drinking water sources contaminated with Cryptosporidium by recreational activities. WATER RESEARCH 2022; 220:118659. [PMID: 35635918 DOI: 10.1016/j.watres.2022.118659] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 04/26/2022] [Accepted: 05/21/2022] [Indexed: 06/15/2023]
Abstract
As urban communities continue to grow, demand for recreational access (including swimming) in drinking water sources have increased, yet relatively little is understood about the public health implications this poses for drinking water consumers. Preventative risk-based approaches to catchment management, informed by quantitative microbial risk assessment (QMRA), requires accurate input data to effectively model risks. A sound understanding of the knowledge gaps is also important to comprehend levels of uncertainty and help prioritise research needs. Cryptosporidium is one of the most important causes of waterborne outbreaks of gastroenteritis globally due to its resistance to chlorine. This review was undertaken by Water Research Australia to provide the most up-to-date information on current Cryptosporidium epidemiological data and underlying assumptions for exposure assessment, dose response and risk assessment for generic components of QMRA for Cryptosporidium and highlights priorities for common research. Key interim recommendations and guidelines for numerical values for relatively simple screening level QMRA modelling are provided to help support prospective studies of risks to drinking water consumers from Cryptosporidium due to body-contact recreation in source water. The review does not cover site-specific considerations, such as the levels of activity in the source water, the influence of dilution and inactivation in reservoirs, or water treatment. Although the focus is Australia, the recommendations and numerical values developed in this review, and the highlighted research priorities, are broadly applicable across all drinking source water sources that allow recreational activities.
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Affiliation(s)
- U Ryan
- Harry Butler Institute, Murdoch University, 90 South Street, Perth, Australia.
| | - Kelly Hill
- Water Research Australia, 250 Victoria Square, Adelaide, South Australia, Australia
| | - Dan Deere
- Water Futures, Sydney, Australia and Water Research Australia, Australia
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16
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Willmer AR, Nie J, De la Rosa MVG, Wen W, Dunne S, Rosania GR. Molecular design of a pathogen activated, self-assembling mechanopharmaceutical device. J Control Release 2022; 347:620-631. [PMID: 35623493 PMCID: PMC9901583 DOI: 10.1016/j.jconrel.2022.05.029] [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: 03/25/2022] [Accepted: 05/18/2022] [Indexed: 02/08/2023]
Abstract
Weakly basic small molecule drugs like clofazimine can be used as building blocks for endowing cells with unnatural structural and functional elements. Here, we describe how clofazimine represents a first-in-class mechanopharmaceutical device, serving to construct inert, inactive and stimulus responsive drug depots within the endophagolysosomal compartment of cells of living organisms. Upon oral administration, clofazimine molecules self-assemble into stable, membrane-bound, crystal-like drug inclusions (CLDI) that accumulate within macrophages to form a "smart" biocompatible, pathogen activatable mechanopharmaceutical device. Upon perturbation of the mechanism maintaining pH and ion homeostasis of these CLDIs, the inert encapsulated drug precipitates are destabilized, releasing bioactive drug molecules into the cell and its surrounding. The resulting increase in clofazimine solubility activates this broad-spectrum antimicrobial, antiparasitic, antiviral or cytotoxic agent within the infected macrophage. We present a general, molecular design strategy for using clofazimine and other small molecule building blocks for the cytoplasmic construction of mechanopharmaceutical devices, aimed at rapid deployment during infectious disease outbreaks, for the purpose of pandemic prevention.
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Affiliation(s)
- Andrew R. Willmer
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI 48109, USA,Corresponding author: Andrew R. Willmer, PharmD, University of Michigan College of Pharmacy, Ann Arbor, MI 48109, Phone: 734-536-3383,
| | - Jiayi Nie
- Department of Biostatistics, University of Southern California, Los Angeles, CA 90089, USA
| | - Mery Vet George De la Rosa
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI 48109, USA
| | - Winnie Wen
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI 48109, USA
| | - Steven Dunne
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Gus R. Rosania
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI 48109, USA
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17
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Dhal AK, Panda C, Yun SIL, Mahapatra RK. An update on Cryptosporidium biology and therapeutic avenues. J Parasit Dis 2022; 46:923-939. [PMID: 35755159 PMCID: PMC9215156 DOI: 10.1007/s12639-022-01510-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 06/07/2022] [Indexed: 12/02/2022] Open
Abstract
Cryptosporidium species has been identified as an important pediatric diarrheal pathogen in resource-limited countries, particularly in very young children (0–24 months). However, the only available drug (nitazoxanide) has limited efficacy and can only be prescribed in a medical setting to children older than one year. Many drug development projects have started to investigate new therapeutic avenues. Cryptosporidium’s unique biology is challenging for the traditional drug discovery pipeline and requires novel drug screening approaches. Notably, in recent years, new methods of oocyst generation, in vitro processing, and continuous three-dimensional cultivation capacities have been developed. This has enabled more physiologically pertinent research assays for inhibitor discovery. In a short time, many great strides have been made in the development of anti-Cryptosporidium drugs. These are expected to eventually turn into clinical candidates for cryptosporidiosis treatment in the future. This review describes the latest development in Cryptosporidium biology, genomics, transcriptomics of the parasite, assay development, and new drug discovery.
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Affiliation(s)
- Ajit Kumar Dhal
- School of Biotechnology, KIIT Deemed to Be University, Bhubaneswar, Odisha 751024 India
| | - Chinmaya Panda
- School of Biotechnology, KIIT Deemed to Be University, Bhubaneswar, Odisha 751024 India
| | - Soon-IL Yun
- Department of Food Science and Technology, Jeonbuk National University, Jeonju, 54896 Republic of Korea
- Department of Agricultural Convergence Technology, Jeonbuk National University, Jeonju, 54896 Republic of Korea
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18
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RNA-Based Therapy for Cryptosporidium parvum Infection: Proof-of-Concept Studies. Infect Immun 2022; 90:e0019622. [PMID: 35647663 DOI: 10.1128/iai.00196-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cryptosporidium is a leading cause of moderate-to-severe diarrhea in children, which is one of the major causes of death in children under 5 years old. Nitazoxanide is the only FDA-approved treatment for cryptosporidiosis. However, it has limited efficacy in immunosuppressed patients and malnourished children. Therefore, it is urgent to develop novel therapies against this parasite. RNA interference-mediated therapies are emerging as novel approaches for the treatment of infectious diseases. We have developed a novel method to silence essential genes in Cryptosporidium using single-stranded RNA (ssRNA)/Argonaute (Ago) complexes. In this work we conducted proof-of-concept studies to test the anticryptosporidial activity of these complexes by silencing Cryptosporidium parvum nucleoside diphosphate kinase (NDK) using in vitro and in vivo models. We demonstrated that a 3-day treatment with anti-sense NDK ssRNA/Ago decreased parasite burden by ~98% on infected cells. In vivo studies showed that ssRNA/Ago complexes encapsulated in lipid nanoparticles can be delivered onto intestinal epithelial cells of mice treated orally. In addition a cryptosporidiosis-mouse model showed that treatment with NDK ssRNA/Ago complexes reduced oocyst shedding in 4/5 SCID/beige mice during the acute phase of the infection. Our findings highlight the potential use of antisense RNA-based therapy as an alternative approach to cryptosporidiosis treatment.
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19
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Bone Relat RM, Winder PL, Bowden GD, Guzmán EA, Peterson TA, Pomponi SA, Roberts JC, Wright AE, O’Connor RM. High-Throughput Screening of a Marine Compound Library Identifies Anti-Cryptosporidium Activity of Leiodolide A. Mar Drugs 2022; 20:md20040240. [PMID: 35447913 PMCID: PMC9026894 DOI: 10.3390/md20040240] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/24/2022] [Accepted: 03/24/2022] [Indexed: 02/04/2023] Open
Abstract
Cryptosporidium sp. are apicomplexan parasites that cause significant morbidity and possible mortality in humans and valuable livestock. There are no drugs on the market that are effective in the population most severely affected by this parasite. This study is the first high-throughput screen for potent anti-Cryptosporidium natural products sourced from a unique marine compound library. The Harbor Branch Oceanographic Institute at Florida Atlantic University has a collection of diverse marine organisms some of which have been subjected to medium pressure liquid chromatography to create an enriched fraction library. Numerous active compounds have been discovered from this library, but it has not been tested against Cryptosporidium parvum. A high-throughput in vitro growth inhibition assay was used to test 3764 fractions in the library, leading to the identification of 23 fractions that potently inhibited the growth of Cryptosporidium parvum. Bioassay guided fractionation of active fractions from a deep-sea sponge, Leiodermatium sp., resulted in the purification of leiodolide A, the major active compound in the organism. Leiodolide A displayed specific anti-Cryptosporidium activity at a half maximal effective concentration of 103.5 nM with selectivity indexes (SI) of 45.1, 11.9, 19.6 and 14.3 for human ileocecal colorectal adenocarcinoma cells (HCT-8), human hepatocellular carcinoma cells (Hep G2), human neuroblastoma cells (SH-SY5Y) and green monkey kidney cells (Vero), respectively. The unique structure of leiodolide A provides a valuable drug scaffold on which to develop new anti-Cryptosporidium compounds and supports the importance of screening natural product libraries for new chemical scaffolds.
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Affiliation(s)
- Rachel M. Bone Relat
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, 100 Dairy Rd, Pullman, WA 99164, USA; (R.M.B.R.); (G.D.B.)
| | - Priscilla L. Winder
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US Highway 1 North, Fort Pierce, FL 34946, USA; (P.L.W.); (E.A.G.); (T.A.P.); (S.A.P.); (J.C.R.)
| | - Gregory D. Bowden
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, 100 Dairy Rd, Pullman, WA 99164, USA; (R.M.B.R.); (G.D.B.)
| | - Esther A. Guzmán
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US Highway 1 North, Fort Pierce, FL 34946, USA; (P.L.W.); (E.A.G.); (T.A.P.); (S.A.P.); (J.C.R.)
| | - Tara A. Peterson
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US Highway 1 North, Fort Pierce, FL 34946, USA; (P.L.W.); (E.A.G.); (T.A.P.); (S.A.P.); (J.C.R.)
| | - Shirley A. Pomponi
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US Highway 1 North, Fort Pierce, FL 34946, USA; (P.L.W.); (E.A.G.); (T.A.P.); (S.A.P.); (J.C.R.)
| | - Jill C. Roberts
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US Highway 1 North, Fort Pierce, FL 34946, USA; (P.L.W.); (E.A.G.); (T.A.P.); (S.A.P.); (J.C.R.)
| | - Amy E. Wright
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US Highway 1 North, Fort Pierce, FL 34946, USA; (P.L.W.); (E.A.G.); (T.A.P.); (S.A.P.); (J.C.R.)
- Correspondence: (A.E.W.); (R.M.O.)
| | - Roberta M. O’Connor
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, 100 Dairy Rd, Pullman, WA 99164, USA; (R.M.B.R.); (G.D.B.)
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, 1971 Commonwealth Ave, St Paul, MN 55108, USA
- Correspondence: (A.E.W.); (R.M.O.)
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20
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Pharmacokinetics and pharmacodynamics of clofazimine for treatment of cryptosporidiosis. Antimicrob Agents Chemother 2021; 66:e0156021. [PMID: 34748385 PMCID: PMC8765308 DOI: 10.1128/aac.01560-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Infection with Cryptosporidium spp. can cause severe diarrhea, leading to long-term adverse impacts and even death in malnourished children and immunocompromised patients. The only FDA-approved drug for treating cryptosporidiosis, nitazoxanide, has limited efficacy in the populations impacted the most by the diarrheal disease, and safe, effective treatment options are urgently needed. Initially identified by a large-scale phenotypic screening campaign, the antimycobacterial therapeutic clofazimine demonstrated great promise in both in vitro and in vivo preclinical models of Cryptosporidium infection. Unfortunately, a phase 2a clinical trial in HIV-infected adults with cryptosporidiosis did not identify any clofazimine treatment effect on Cryptosporidium infection burden or clinical outcomes. To explore whether clofazimine’s lack of efficacy in the phase 2a trial may have been due to subtherapeutic clofazimine concentrations, a pharmacokinetic/pharmacodynamic modeling approach was undertaken to determine the relationship between clofazimine in vivo concentrations and treatment effects in multiple preclinical infection models. Exposure-response relationships were characterized using Emax and logistic models, which allowed predictions of efficacious clofazimine concentrations for the control and reduction of disease burden. After establishing exposure-response relationships for clofazimine treatment of Cryptosporidium infection in our preclinical model studies, it was unmistakable that the clofazimine levels observed in the phase 2a study participants were well below concentrations associated with anti-Cryptosporidium efficacy. Thus, despite a dosing regimen above the highest doses recommended for mycobacterial therapy, it is very likely the lack of treatment effect in the phase 2a trial was at least partially due to clofazimine concentrations below those required for efficacy against cryptosporidiosis. It is unlikely that clofazimine will provide a remedy for the large number of cryptosporidiosis patients currently without a viable treatment option unless alternative, safe clofazimine formulations with improved oral absorption are developed. (This study has been registered in ClinicalTrials.gov under identifier NCT03341767.)
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21
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Iroh Tam PY, Chisala M, Nyangulu W, Thole H, Nyirenda J. Respiratory cryptosporidiosis in Malawian children with diarrheal disease. PLoS Negl Trop Dis 2021; 15:e0009643. [PMID: 34329296 PMCID: PMC8357119 DOI: 10.1371/journal.pntd.0009643] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 08/11/2021] [Accepted: 07/11/2021] [Indexed: 11/29/2022] Open
Abstract
Background Respiratory cryptosporidiosis has been documented in children with diarrhea. We sought to describe the dynamics of respiratory involvement in children hospitalized with gastrointestinal (GI) diarrheal disease. Methods We conducted a prospective, observational longitudinal study of Malawian children 2–24 months hospitalized with diarrhea. Nasopharyngeal (NP) swabs, induced sputum and stool specimens were collected. Participants that were positive by Cryptosporidium PCR in any of the three compartments were followed up with fortnightly visits up to 8 weeks post-enrollment. Results Of the 162 children recruited, participants had mild-moderate malnutrition (mean HAZ -1.6 (SD 2.1)), 37 (21%) were PCR-positive for Cryptosporidium at enrollment (37 stool, 11 sputum, and 4 NP) and 27 completed the majority of follow-up visits (73%). Cryptosporidium was detected in all compartments over the 4 post-enrollment visits, most commonly in stool (100% at enrollment with mean cycle thresholds (Ct) of 28.8±4.3 to 44% at 8 weeks with Ct 29.9±4.1), followed by sputum (31% at enrollment with mean Ct 31.1±4.4 to 20% at 8 weeks with Ct 35.7±2.6), then NP (11% with mean Ct 33.5±1.0 to 8% with Ct 36.6±0.7). Participants with Cryptosporidium detection in both the respiratory and GI tract over the study period reported respiratory and GI symptoms in 81% and 62% of study visits, respectively, compared to 68% and 27%, respectively, for those with only GI detection, and had longer GI shedding (17.5±6.6 v. 15.9±2.9 days). Conclusion Cryptosporidium was detected in both respiratory and GI tracts throughout the 8 weeks post-enrollment. The development of therapeutics for Cryptosporidium in children should target the respiratory as well as GI tract. We conducted a prospective, observational longitudinal study of Malawian children 2–24 months hospitalized with diarrhea. NP swabs, induced sputum and stool specimens were collected. Participants that were positive by Cryptosporidium PCR in any of the three compartments were followed up with fortnightly visits up to 8 weeks post-enrollment. Cryptosporidium was detected by PCR in 21%, 7% and 3% in stool, sputum and nasopharynx of children hospitalized with diarrhea. Of those positive at enrollment, detection was noted in 44%, 20%, and 8%, respectively, by 8 weeks post-enrollment.
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Affiliation(s)
- Pui-Ying Iroh Tam
- Paediatrics and Child Health Research Group, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Department of Paediatrics, University of Malawi College of Medicine, Blantyre, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- * E-mail:
| | - Mphatso Chisala
- Paediatrics and Child Health Research Group, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Wongani Nyangulu
- Paediatrics and Child Health Research Group, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Herbert Thole
- Paediatrics and Child Health Research Group, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - James Nyirenda
- Paediatrics and Child Health Research Group, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
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22
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Schneider A, Wendt S, Lübbert C, Trawinski H. Current pharmacotherapy of cryptosporidiosis: an update of the state-of-the-art. Expert Opin Pharmacother 2021; 22:2337-2342. [PMID: 34281461 DOI: 10.1080/14656566.2021.1957097] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Introduction: Cryptosporidiosis has emerged as a major cause of diarrheal disease worldwide. It has especially serious health consequences for young, malnourished children living in endemic areas and for individuals with highly impaired T-cell function, such as HIV-positive individuals with low CD4 counts or immunosuppressed solid-organ transplant recipients.Areas covered: A selective literature search using PubMed was performed to review the available therapeutics to treat cryptosporidiosis, as well as related advances in drug development.Expert opinion: The only FDA-approved antiparasitic treatment in immunocompetent patients is nitazoxanide; however, it has failed to demonstrate convincing effectiveness among HIV-positive patients, immunosuppressed individuals and malnourished children. Thus, restoring HIV-positive patients' cellular immune response through effective antiretroviral therapy (ART), or reducing or changing immunosuppressive drugs, is important. Several new targets have been identified for chemotherapy, and the development of drugs for these targets has progressed, including parasite kinases, nucleic acid synthesis and processing, proteases and lipid metabolism. Candidate drugs that have been shown to be effective and safe in a neonatal calf model will most likely constitute the next advance for clinical trials in humans. However, developing an effective and inexpensive vaccination, as well as complementing structural preventive measures, would most decisively reduce the global cryptosporidiosis burden.
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Affiliation(s)
- Anne Schneider
- Division of Infectious Diseases and Tropical Medicine, Department of Medicine II, Leipzig University Hospital, Leipzig, Germany.,Interdisciplinary Center for Infectious Diseases (ZINF), Leipzig University Hospital, Leipzig, Germany
| | - Sebastian Wendt
- Division of Infectious Diseases and Tropical Medicine, Department of Medicine II, Leipzig University Hospital, Leipzig, Germany.,Interdisciplinary Center for Infectious Diseases (ZINF), Leipzig University Hospital, Leipzig, Germany.,Institute of Medical Microbiology and Virology, Leipzig University Hospital, Leipzig, Germany
| | - Christoph Lübbert
- Division of Infectious Diseases and Tropical Medicine, Department of Medicine II, Leipzig University Hospital, Leipzig, Germany.,Interdisciplinary Center for Infectious Diseases (ZINF), Leipzig University Hospital, Leipzig, Germany
| | - Henning Trawinski
- Division of Infectious Diseases and Tropical Medicine, Department of Medicine II, Leipzig University Hospital, Leipzig, Germany.,Interdisciplinary Center for Infectious Diseases (ZINF), Leipzig University Hospital, Leipzig, Germany
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23
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Hulverson MA, Choi R, McCloskey MC, Whitman GR, Ojo KK, Michaels SA, Somepalli M, Love MS, McNamara CW, Rabago LM, Barrett LK, Verlinde CLMJ, Arnold SL, Striepen B, Jimenez-Alfaro D, Ballell L, Fernández E, Greenwood MN, las Heras LD, Calderón F, Van Voorhis WC. Repurposing Infectious Disease Hits as Anti- Cryptosporidium Leads. ACS Infect Dis 2021; 7:1275-1282. [PMID: 33740373 DOI: 10.1021/acsinfecdis.1c00076] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
New drugs are critically needed to treat Cryptosporidium infections, particularly for malnourished children under 2 years old in the developing world and persons with immunodeficiencies. Bioactive compounds from the Tres-Cantos GSK library that have activity against other pathogens were screened for possible repurposing against Cryptosporidium parvum growth. Nineteen compounds grouped into nine structural clusters were identified using an iterative process to remove excessively toxic compounds and screen related compounds from the Tres-Cantos GSK library. Representatives of four different clusters were advanced to a mouse model of C. parvum infection, but only one compound, an imidazole-pyrimidine, led to significant clearance of infection. This imidazole-pyrimidine compound had a number of favorable safety and pharmacokinetic properties and was maximally active in the mouse model down to 30 mg/kg given daily. Though the mechanism of action against C. parvum was not definitively established, this imidazole-pyrimidine compound inhibits the known C. parvum drug target, calcium-dependent protein kinase 1, with a 50% inhibitory concentration of 2 nM. This compound, and related imidazole-pyrimidine molecules, should be further examined as potential leads for Cryptosporidium therapeutics.
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Affiliation(s)
- Matthew A. Hulverson
- Department of Medicine Division of Allergy Infectious Disease Center for Emerging Reemerging Infectious Diseases, University of Washington, Seattle, Washington 98109, United States
| | - Ryan Choi
- Department of Medicine Division of Allergy Infectious Disease Center for Emerging Reemerging Infectious Diseases, University of Washington, Seattle, Washington 98109, United States
| | - Molly C. McCloskey
- Department of Medicine Division of Allergy Infectious Disease Center for Emerging Reemerging Infectious Diseases, University of Washington, Seattle, Washington 98109, United States
| | - Grant R. Whitman
- Department of Medicine Division of Allergy Infectious Disease Center for Emerging Reemerging Infectious Diseases, University of Washington, Seattle, Washington 98109, United States
| | - Kayode K. Ojo
- Department of Medicine Division of Allergy Infectious Disease Center for Emerging Reemerging Infectious Diseases, University of Washington, Seattle, Washington 98109, United States
| | - Samantha A. Michaels
- Department of Medicine Division of Allergy Infectious Disease Center for Emerging Reemerging Infectious Diseases, University of Washington, Seattle, Washington 98109, United States
| | - Mastanbabu Somepalli
- Department of Pathobiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Melissa S. Love
- Calibr, a division of The Scripps Research Institute, La Jolla, California 92037, United States
| | - Case W. McNamara
- Calibr, a division of The Scripps Research Institute, La Jolla, California 92037, United States
| | - Lesley M. Rabago
- Department of Medicine Division of Allergy Infectious Disease Center for Emerging Reemerging Infectious Diseases, University of Washington, Seattle, Washington 98109, United States
| | - Lynn K. Barrett
- Department of Medicine Division of Allergy Infectious Disease Center for Emerging Reemerging Infectious Diseases, University of Washington, Seattle, Washington 98109, United States
| | | | - Samuel L.M. Arnold
- Department of Medicine Division of Allergy Infectious Disease Center for Emerging Reemerging Infectious Diseases, University of Washington, Seattle, Washington 98109, United States
| | - Boris Striepen
- Department of Pathobiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Dolores Jimenez-Alfaro
- Medicines Development Campus, Global Health Pharma Unit, GlaxoSmithKline, Tres Cantos, 28760, Madrid Spain
| | - Lluis Ballell
- Medicines Development Campus, Global Health Pharma Unit, GlaxoSmithKline, Tres Cantos, 28760, Madrid Spain
| | - Elena Fernández
- Medicines Development Campus, Global Health Pharma Unit, GlaxoSmithKline, Tres Cantos, 28760, Madrid Spain
| | - M. Nicole Greenwood
- Academic Liaison, GlaxoSmithKline, Upper Providence, Pennsylvania 19426, United States
| | | | - Felix Calderón
- Medicines Development Campus, Global Health Pharma Unit, GlaxoSmithKline, Tres Cantos, 28760, Madrid Spain
| | - Wesley C. Van Voorhis
- Department of Medicine Division of Allergy Infectious Disease Center for Emerging Reemerging Infectious Diseases, University of Washington, Seattle, Washington 98109, United States
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24
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Opportunities and Challenges in Developing a Cryptosporidium Controlled Human Infection Model for Testing Antiparasitic Agents. ACS Infect Dis 2021; 7:959-968. [PMID: 33822577 PMCID: PMC8154424 DOI: 10.1021/acsinfecdis.1c00057] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Cryptosporidiosis is a leading cause of moderate-to-severe diarrhea in low- and middle-income countries, responsible for high mortality in children younger than two years of age, and it is also strongly associated with childhood malnutrition and growth stunting. There is no vaccine for cryptosporidiosis and existing therapeutic options are suboptimal to prevent morbidity and mortality in young children. Recently, novel therapeutic agents have been discovered through high-throughput phenotypic and target-based screening strategies, repurposing malaria hits, etc., and these agents have a promising preclinical in vitro and in vivo anti-Cryptosporidium efficacy. One key step in bringing safe and effective new therapies to young vulnerable children is the establishment of some prospect of direct benefit before initiating pediatric clinical studies. A Cryptosporidium controlled human infection model (CHIM) in healthy adult volunteers can be a robust clinical proof of concept model for evaluating novel therapeutics. CHIM could potentially accelerate the development path to pediatric studies by establishing the safety of a proposed pediatric dosing regimen and documenting preliminary efficacy in adults. We present, here, perspectives regarding the opportunities and perceived challenges with the Cryptosporidium human challenge model.
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25
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Zhu G, Yin J, Cuny GD. Current status and challenges in drug discovery against the globally important zoonotic cryptosporidiosis. ANIMAL DISEASES 2021. [DOI: 10.1186/s44149-021-00002-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
AbstractThe zoonotic cryptosporidiosis is globally distributed, one of the major diarrheal diseases in humans and animals. Cryptosporidium oocysts are also one of the major environmental concerns, making it a pathogen that fits well into the One Health concept. Despite its importance, fully effective drugs are not yet available. Anti-cryptosporidial drug discovery has historically faced many unusual challenges attributed to unique parasite biology and technical burdens. While significant progresses have been made recently, anti-cryptosporidial drug discovery still faces a major obstacle: identification of systemic drugs that can be absorbed by patients experiencing watery diarrhea and effectively pass through electron-dense (ED) band at the parasite-host cell interface to act on the epicellular parasite. There may be a need to develop an in vitro assay to effectively screen hits/leads for their capability to cross ED band. In the meantime, non-systemic drugs with strong mucoadhesive properties for extended gastrointestinal exposure may represent another direction in developing anti-cryptosporidial therapeutics. For developing both systemic and non-systemic drugs, a non-ruminant animal model exhibiting diarrheal symptoms suitable for routine evaluation of drug absorption and anti-cryptosporidial efficacy may be very helpful.
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26
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Ashigbie PG, Shepherd S, Steiner KL, Amadi B, Aziz N, Manjunatha UH, Spector JM, Diagana TT, Kelly P. Use-case scenarios for an anti-Cryptosporidium therapeutic. PLoS Negl Trop Dis 2021; 15:e0009057. [PMID: 33705395 PMCID: PMC7951839 DOI: 10.1371/journal.pntd.0009057] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Cryptosporidium is a widely distributed enteric parasite that has an increasingly appreciated pathogenic role, particularly in pediatric diarrhea. While cryptosporidiosis has likely affected humanity for millennia, its recent "emergence" is largely the result of discoveries made through major epidemiologic studies in the past decade. There is no vaccine, and the only approved medicine, nitazoxanide, has been shown to have efficacy limitations in several patient groups known to be at elevated risk of disease. In order to help frontline health workers, policymakers, and other stakeholders translate our current understanding of cryptosporidiosis into actionable guidance to address the disease, we sought to assess salient issues relating to clinical management of cryptosporidiosis drawing from a review of the literature and our own field-based practice. This exercise is meant to help inform health system strategies for improving access to current treatments, to highlight recent achievements and outstanding knowledge and clinical practice gaps, and to help guide research activities for new anti-Cryptosporidium therapies.
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Affiliation(s)
- Paul G. Ashigbie
- Novartis Institute for Tropical Diseases, Emeryville, California, United States of America
| | - Susan Shepherd
- Alliance for International Medical Action (ALIMA), Dakar, Senegal
| | - Kevin L. Steiner
- The Ohio State University, Columbus, Ohio, United States of America
| | - Beatrice Amadi
- Children’s Hospital, University Teaching Hospitals, Lusaka, Zambia
- Tropical Gastroenterology & Nutrition Group, University of Zambia School of Medicine, Lusaka, Zambia
| | - Natasha Aziz
- Novartis Institute for Tropical Diseases, Emeryville, California, United States of America
| | - Ujjini H. Manjunatha
- Novartis Institute for Tropical Diseases, Emeryville, California, United States of America
| | - Jonathan M. Spector
- Novartis Institute for Tropical Diseases, Emeryville, California, United States of America
| | - Thierry T. Diagana
- Novartis Institute for Tropical Diseases, Emeryville, California, United States of America
| | - Paul Kelly
- Tropical Gastroenterology & Nutrition Group, University of Zambia School of Medicine, Lusaka, Zambia
- Blizard Institute, Barts & The London School of Medicine, Queen Mary University of London, London, United Kingdom
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27
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Carlson TJ, Gonzales-Luna AJ, Garey KW. Recent developments in antimicrobial therapy for gastrointestinal infections. Curr Opin Gastroenterol 2021; 37:30-36. [PMID: 33229860 DOI: 10.1097/mog.0000000000000696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
PURPOSE OF REVIEW This focused, narrative review summarizes human clinical trial data for direct-acting antimicrobials in development for the treatment of gastrointestinal infections that were published in the past 18 months (1 January 2019 to 30 June 2020). RECENT FINDINGS Antimicrobial agents for Clostridioides difficile infection (n = 6), cryptosporidiosis (n = 1), cytomegalovirus infection (n = 3) and Helicobacter pylori infection (n = 1) have completed and/or are undergoing human clinical trials. SUMMARY Although this review highlights significant advances in four disease states, many common gastrointestinal pathogens have no antimicrobials in human clinical trials, emphasizing the need for continued prioritization in this field of study.
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Affiliation(s)
- Travis J Carlson
- Department of Clinical Sciences, High Point University Fred Wilson School of Pharmacy, High Point, North Carolina
| | - Anne J Gonzales-Luna
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas, USA
| | - Kevin W Garey
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas, USA
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28
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Love MS, McNamara CW. Phenotypic screening techniques for Cryptosporidium drug discovery. Expert Opin Drug Discov 2020; 16:59-74. [PMID: 32892652 DOI: 10.1080/17460441.2020.1812577] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Introduction: Two landmark epidemiological studies identified Cryptosporidium spp. as a significant cause of diarrheal disease in pediatric populations in resource-limited countries. Notably, nitazoxanide is the only approved drug for treatment of cryptosporidiosis but shows limited efficacy. As a result, many drug discovery efforts have commenced to find improved treatments. The unique biology of Cryptosporidium presents challenges for traditional drug discovery methods, which has inspired new assay platforms to study parasite biology and drug screening. Areas covered: The authors review historical advancements in phenotypic-based assays and techniques for Cryptosporidium drug discovery, as well as recent advances that will define future drug discovery. The reliance on phenotypic-based screens and repositioning of phenotypic hits from other pathogens has quickly created a robust pipeline of potential cryptosporidiosis therapeutics. The latest advances involve new in vitro culture methods for oocyst generation, continuous culturing capabilities, and more physiologically relevant assays for testing compounds. Expert opinion: Previous phenotypic screening techniques have laid the groundwork for recent cryptosporidiosis drug discovery efforts. The resulting improved methodologies characterize compound activity, identify, and validate drug targets, and prioritize new compounds for drug development. The most recent improvements in phenotypic assays are poised to help advance compounds into clinical development.
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Affiliation(s)
- Melissa S Love
- Calibr, a division of The Scripps Research Institute , La Jolla, CA, USA
| | - Case W McNamara
- Calibr, a division of The Scripps Research Institute , La Jolla, CA, USA
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29
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Toto N, Douglas E, Gmeiner M, Barrett LK, Lindblad R, Makhaza L, Nedi W, Phulusa J, Quinnan GV, Sawyer LA, Thole H, Van Voorhis WC, Iroh Tam PY. Conducting clinical trials in sub-Saharan Africa: challenges and lessons learned from the Malawi Cryptosporidium study. Trials 2020; 21:680. [PMID: 32711568 PMCID: PMC7382797 DOI: 10.1186/s13063-020-04620-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 07/16/2020] [Indexed: 01/17/2023] Open
Abstract
Background An effective drug to treat cryptosporidial diarrhea in HIV-infected individuals is a global health priority. Promising drugs need to be evaluated in endemic areas which may be challenged by both lack of resources and experience to conduct International Committee of Harmonisation-Good Clinical Practice (ICH-GCP)-compliant clinical trials. Methods We present the challenges and lessons learned in implementing a phase 2A, randomized, double-blind, placebo-controlled trial of clofazimine, in treatment of cryptosporidiosis among HIV-infected adults at a single site in Malawi. Results Primary challenges are grouped under study initiation, study population, study implementation, and cultural issues. The lessons learned primarily deal with regulatory system and operational barriers, and recommendations can be applied to other human experimental trials in low- and middle-income countries, specifically in sub-Saharan Africa. Conclusion This study demonstrated that initiating and implementing human experimental trials in sub-Saharan Africa can be challenging. However, solutions exist and successful execution requires careful planning, ongoing evaluation, responsiveness to new developments, and oversight of all trial operations.
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Affiliation(s)
- Neema Toto
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,Liverpool School of Tropical Medicine, Liverpool, UK
| | - Elaine Douglas
- Center for Emerging and Re-emerging Infectious Diseases (CERID), University of Washington, Seattle, WA, USA
| | - Markus Gmeiner
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,Liverpool School of Tropical Medicine, Liverpool, UK
| | - Lynn K Barrett
- Center for Emerging and Re-emerging Infectious Diseases (CERID), University of Washington, Seattle, WA, USA
| | | | - Lumbani Makhaza
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Wilfred Nedi
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Jacob Phulusa
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | | | | | - Herbert Thole
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Wesley C Van Voorhis
- Center for Emerging and Re-emerging Infectious Diseases (CERID), University of Washington, Seattle, WA, USA
| | - Pui-Ying Iroh Tam
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi. .,Liverpool School of Tropical Medicine, Liverpool, UK.
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30
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Wang B, Castellanos-Gonzalez A, White AC. Novel drug targets for treatment of cryptosporidiosis. Expert Opin Ther Targets 2020; 24:915-922. [PMID: 32552166 DOI: 10.1080/14728222.2020.1785432] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Introduction Cryptosporidium species are protozoan parasites that are important causes of diarrheal disease including waterborne outbreaks, childhood diarrhea in resource-poor countries, and diarrhea in compromised hosts worldwide. Recent studies highlight the importance of cryptosporidiosis in childhood diarrhea, malnutrition, and death in resource-poor countries. Despite this, only a single drug, nitazoxanide, has demonstrated efficacy in human cryptosporidiosis and its efficacy is limited in malnourished children and patients with HIV. Areas covered In this review, we highlight work on potential targets for chemotherapy and review progress on drug development. A number of new targets have been identified for chemotherapy and progress has been made at developing drugs for these targets. Targets include parasite kinases, nucleic acid synthesis and processing, proteases, and lipid metabolism. Other groups have performed high-throughput screening to identify potential drugs. Several compounds have advanced to large animal studies. Expert opinion Development of drugs for cryptosporidiosis has been plagued by a lack of success. Barriers have included poor correlations between in vitro activity and clinical success as well as frequent unanticipated adverse effects. Without a clear pathway forward, it is wise to maintain a diverse development pipeline. Drug developers should also realize that success will likely require a sustained, methodical effort.
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Affiliation(s)
- Beilin Wang
- Infectious Disease Division, Department of Internal Medicine, University of Texas Medical Branch , Galveston, TX, USA
| | | | - A Clinton White
- Infectious Disease Division, Department of Internal Medicine, University of Texas Medical Branch , Galveston, TX, USA
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