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Ibnidris A, Liaskos N, Eldem E, Gunn A, Streffer J, Gold M, Rea M, Teipel S, Gardiol A, Boccardi M. Facilitating the use of the target product profile in academic research: a systematic review. J Transl Med 2024; 22:693. [PMID: 39075460 PMCID: PMC11288132 DOI: 10.1186/s12967-024-05476-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2024] [Accepted: 07/03/2024] [Indexed: 07/31/2024] Open
Abstract
BACKGROUND The Target Product Profile (TPP) is a tool used in industry to guide development strategies by addressing user needs and fostering effective communication among stakeholders. However, they are not frequently used in academic research, where they may be equally useful. This systematic review aims to extract the features of accessible TPPs, to identify commonalities and facilitate their integration in academic research methodology. METHODS We searched peer-reviewed papers published in English developing TPPs for different products and health conditions in four biomedical databases. Interrater agreement, computed on random abstract and paper sets (Cohen's Kappa; percentage agreement with zero tolerance) was > 0.91. We interviewed experts from industry contexts to gain insight on the process of TPP development, and extracted general and specific features on TPP use and structure. RESULTS 138 papers were eligible for data extraction. Of them, 92% (n = 128) developed a new TPP, with 41.3% (n = 57) focusing on therapeutics. The addressed disease categories were diverse; the largest (47.1%, n = 65) was infectious diseases. Only one TPP was identified for several fields, including global priorities like dementia. Our analyses found that 56.5% of papers (n = 78) was authored by academics, and 57.8% of TPPs (n = 80) featured one threshold level of product performance. The number of TPP features varied widely across and within product types (n = 3-44). Common features included purpose/context of use, shelf life for drug stability and validation aspects. Most papers did not describe the methods used to develop the TPP. We identified aspects to be taken into account to build and report TPPs, as a starting point for more focused initiatives guiding use by academics. DISCUSSION TPPs are used in academic research mostly for infectious diseases and have heterogeneous features. Our extraction of key features and common structures helps to understand the tool and widen its use in academia. This is of particular relevance for areas of notable unmet needs, like dementia. Collaboration between stakeholders is key for innovation. Tools to streamline communication such as TPPs would support the development of products and services in academia as well as industry.
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Affiliation(s)
- Aliaa Ibnidris
- German Center for Neurodegenerative Diseases (DZNE), Rostock-Greifswald site, Gehlsheimer Str. 20, 18147, Rostock, Germany
- Neuroscience Institute, Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa
| | - Nektarios Liaskos
- German Center for Neurodegenerative Diseases (DZNE), Rostock-Greifswald site, Gehlsheimer Str. 20, 18147, Rostock, Germany
- European Infrastructure for Translational Medicine (EATRIS), Amsterdam, The Netherlands
| | - Ece Eldem
- German Center for Neurodegenerative Diseases (DZNE), Rostock-Greifswald site, Gehlsheimer Str. 20, 18147, Rostock, Germany
| | | | - Johannes Streffer
- Reference Center for Biological Markers of Dementia (BIODEM), Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Michael Gold
- AriLex Life Sciences LLC, 780 Elysian Way, Deerfield, IL, 60015, USA
| | | | - Stefan Teipel
- German Center for Neurodegenerative Diseases (DZNE), Rostock-Greifswald site, Gehlsheimer Str. 20, 18147, Rostock, Germany
- Department of Psychosomatic Medicine and Psychotherapy, University of Medicine Rostock, Rostock, Germany
| | - Alejandra Gardiol
- European Infrastructure for Translational Medicine (EATRIS), Amsterdam, The Netherlands
- Queen Mary University of London, London, UK
| | - Marina Boccardi
- German Center for Neurodegenerative Diseases (DZNE), Rostock-Greifswald site, Gehlsheimer Str. 20, 18147, Rostock, Germany.
- Department of Psychosomatic Medicine and Psychotherapy, University of Medicine Rostock, Rostock, Germany.
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2
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Hasan MM, Mattice EB, Teixeira JE, Jumani RS, Stebbins EE, Klopfer CE, Franco SE, Love MS, McNamara CW, Huston CD. Cryptosporidium life cycle small molecule probing implicates translational repression and an Apetala 2 transcription factor in macrogamont differentiation. PLoS Pathog 2024; 20:e1011906. [PMID: 38669269 PMCID: PMC11078545 DOI: 10.1371/journal.ppat.1011906] [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: 12/15/2023] [Revised: 05/08/2024] [Accepted: 04/08/2024] [Indexed: 04/28/2024] Open
Abstract
The apicomplexan parasite Cryptosporidium is a leading cause of childhood diarrhea in developing countries. Current treatment options are inadequate and multiple preclinical compounds are being actively pursued as potential drugs for cryptosporidiosis. Unlike most apicomplexans, Cryptosporidium spp. sequentially replicate asexually and then sexually within a single host to complete their lifecycles. Anti-cryptosporidial compounds are generally identified or tested through in vitro phenotypic assays that only assess the asexual stages. Therefore, compounds that specifically target the sexual stages remain unexplored. In this study, we leveraged the ReFRAME drug repurposing library against a newly devised multi-readout imaging assay to identify small-molecule compounds that modulate macrogamont differentiation and maturation. RNA-seq studies confirmed selective modulation of macrogamont differentiation for 10 identified compounds (9 inhibitors and 1 accelerator). The collective transcriptomic profiles of these compounds indicates that translational repression accompanies Cryptosporidium sexual differentiation, which we validated experimentally. Additionally, cross comparison of the RNA-seq data with promoter sequence analysis for stage-specific genes converged on a key role for an Apetala 2 (AP2) transcription factor (cgd2_3490) in differentiation into macrogamonts. Finally, drug annotation for the ReFRAME hits indicates that an elevated supply of energy equivalence in the host cell is critical for macrogamont formation.
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Affiliation(s)
- Muhammad M. Hasan
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, Vermont, United States of America
- Cell, Molecular, and Biomedical Sciences Graduate Program, University of Vermont, Burlington, Vermont, United States of America
| | - Ethan B. Mattice
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, Vermont, United States of America
- Cell, Molecular, and Biomedical Sciences Graduate Program, University of Vermont, Burlington, Vermont, United States of America
| | - José E. Teixeira
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, Vermont, United States of America
| | - Rajiv S. Jumani
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, Vermont, United States of America
- Cell, Molecular, and Biomedical Sciences Graduate Program, University of Vermont, Burlington, Vermont, United States of America
| | - Erin E. Stebbins
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, Vermont, United States of America
| | - Connor E. Klopfer
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, Vermont, United States of America
| | - Sebastian E. Franco
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, Vermont, United States of America
| | - Melissa S. Love
- Calibr at Scripps Research, San Diego, California, United States of America
| | - Case W. McNamara
- Calibr at Scripps Research, San Diego, California, United States of America
| | - Christopher D. Huston
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, Vermont, United States of America
- Cell, Molecular, and Biomedical Sciences Graduate Program, University of Vermont, Burlington, Vermont, United States of America
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Fenwick M, Reers AR, Liu Y, Zigweid R, Sankaran B, Shin J, Hulverson MA, Hammerson B, Fernández Álvaro E, Myler PJ, Kaushansky A, Van Voorhis WC, Fan E, Staker BL. Identification of and Structural Insights into Hit Compounds Targeting N-Myristoyltransferase for Cryptosporidium Drug Development. ACS Infect Dis 2023; 9:1821-1833. [PMID: 37722671 PMCID: PMC10580320 DOI: 10.1021/acsinfecdis.3c00151] [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] [Indexed: 09/20/2023]
Abstract
Each year, approximately 50,000 children under 5 die as a result of diarrhea caused by Cryptosporidium parvum, a protozoan parasite. There are currently no effective drugs or vaccines available to cure or prevent Cryptosporidium infection, and there are limited tools for identifying and validating targets for drug or vaccine development. We previously reported a high throughput screening (HTS) of a large compound library against Plasmodium N-myristoyltransferase (NMT), a validated drug target in multiple protozoan parasite species. To identify molecules that could be effective against Cryptosporidium, we counter-screened hits from the Plasmodium NMT HTS against Cryptosporidium NMT. We identified two potential hit compounds and validated them against CpNMT to determine if NMT might be an attractive drug target also for Cryptosporidium. We tested the compounds against Cryptosporidium using both cell-based and NMT enzymatic assays. We then determined the crystal structure of CpNMT bound to Myristoyl-Coenzyme A (MyrCoA) and structures of ternary complexes with MyrCoA and the hit compounds to identify the ligand binding modes. The binding site architectures display different conformational states in the presence of the two inhibitors and provide a basis for rational design of selective inhibitors.
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Affiliation(s)
- Michael
K. Fenwick
- Seattle
Structural Genomics Center for Infectious Disease (SSGCID), Seattle, Washington 98109, United States
| | - Alexandra R. Reers
- Seattle
Structural Genomics Center for Infectious Disease (SSGCID), Seattle, Washington 98109, United States
- Center
for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington 98109, United States
| | - Yi Liu
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
| | - Rachael Zigweid
- Seattle
Structural Genomics Center for Infectious Disease (SSGCID), Seattle, Washington 98109, United States
- Center
for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington 98109, United States
| | - Banumathi Sankaran
- Berkeley
Center for Structural Biology, Advanced Light Source, Berkeley National
Laboratory, Berkeley, California 94720, United States
| | - Janis Shin
- Seattle
Structural Genomics Center for Infectious Disease (SSGCID), Seattle, Washington 98109, United States
- Center
for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington 98109, United States
| | - Matthew A. Hulverson
- Center
for Emerging and Re-emerging Infectious Diseases, Division of Allergy
and Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington 98109, United States
| | - Bradley Hammerson
- Seattle
Structural Genomics Center for Infectious Disease (SSGCID), Seattle, Washington 98109, United States
- Center
for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington 98109, United States
| | | | - Peter J. Myler
- Seattle
Structural Genomics Center for Infectious Disease (SSGCID), Seattle, Washington 98109, United States
- Center
for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington 98109, United States
- Department
of Global Health, University of Washington, Seattle, Washington 98195, United States
- Department
of Pediatrics, University of Washington, Seattle, Washington 98195, United States
| | - Alexis Kaushansky
- Center
for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington 98109, United States
- Center
for Emerging and Re-emerging Infectious Diseases, Division of Allergy
and Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington 98109, United States
- Department
of Global Health, University of Washington, Seattle, Washington 98195, United States
| | - Wesley C. Van Voorhis
- Seattle
Structural Genomics Center for Infectious Disease (SSGCID), Seattle, Washington 98109, United States
- Center
for Emerging and Re-emerging Infectious Diseases, Division of Allergy
and Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington 98109, United States
| | - Erkang Fan
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
| | - Bart L. Staker
- Seattle
Structural Genomics Center for Infectious Disease (SSGCID), Seattle, Washington 98109, United States
- Center
for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington 98109, United States
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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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Structural Analyses of a Dominant Cryptosporidium parvum Epitope Presented by H-2K b Offer New Options To Combat Cryptosporidiosis. mBio 2023; 14:e0266622. [PMID: 36602309 PMCID: PMC9973275 DOI: 10.1128/mbio.02666-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Cryptosporidium parvum has gained much attention as a major cause of diarrhea in the world, particularly in those with compromised immune systems. The data currently available on how the immune system recognizes C. parvum are growing rapidly, but we lack data on the interactions among host major histocompatibility complex (MHC) diversity and parasitic T-cell epitopes. To identify antigenic epitopes in a murine model, we performed systematic profiling of H-2Kb-restricted peptides by screening the dominant Cryptosporidium antigens. The results revealed that the glycoprotein-derived epitope Gp40/15-SVF9 induced an immunodominant response in C. parvum-recovered C57BL/6 mice, and injection of the cytotoxic-T-lymphocyte (CTL) peptide with the adjuvant activated peptide-specific CD8+ T cells. Notably, the SVF9 epitope was highly conserved across Cryptosporidium hominis, C. parvum, and many other Cryptosporidium species. SVF9 also formed stable peptide-MHC class I (MHC I) complexes with HLA-A*0201, suggesting cross-reactivity between H-2Kb and human MHC I specificities. Crystal structure analyses revealed that the interactions of peptide-MHC surface residues of H-2Kb and HLA-A*0201 are highly conserved. The hydrogen bonds of H-2Kb-SVF9 are similar to those of a dominant epitope presented by HLA-A*0201, which can be recognized by a public human T-cell receptor (TCR). Notably, we found double conformations in position 4 (P4), 5 (P5) of the SVF9 peptide, which showed high flexibility, and multiple peptide conformations generated more molecular surfaces that can potentially be recognized by TCRs. Our findings demonstrate that an immunodominant C. parvum epitope and its homologs from different Cryptosporidium species and subtypes can benefit vaccine development to combat cryptosporidiosis. IMPORTANCE Adaptive immune responses and T lymphocytes have been implicated as important mechanisms of parasite-induced protection. However, the role of CD8+ T lymphocytes in the resolution of C. parvum infection is largely unresolved. Our results revealed that the glycoprotein-derived epitope Gp40/15-SVF9 induced an immunodominant CD8+ T-cell response in C57BL/6 mice. Crystal structure analyses revealed that the interactions of the H-2Kb-SVF9 peptide are similar to those of a dominant epitope presented by HLA-A*0201, which can be recognized by human TCRs. In addition, we found double conformations of the SVF9 peptide, which showed high flexibility and multiple peptide conformations that can potentially be recognized by TCRs.
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Advances in therapeutic and vaccine targets for Cryptosporidium: Challenges and possible mitigation strategies. Acta Trop 2022; 226:106273. [PMID: 34906550 DOI: 10.1016/j.actatropica.2021.106273] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/07/2021] [Accepted: 12/08/2021] [Indexed: 12/14/2022]
Abstract
Cryptosporidium is known to be the second most common diarrheal pathogen in children, causing potentially fatal diarrhea and associated with long-term growth stunting and cognitive deficits. The only Food and Drug Administration-approved treatment for cryptosporidiosis is nitazoxanide, but this drug has not shown potentially effective results in susceptible hosts. Therefore, a safe and effective drug for cryptosporidiosis is urgently needed. Cryptosporidium genome sequencing analysis may help develop an effective drug, but both in vitro and in vivo approaches to drug evaluation are not fully standardized. On the other hand, the development of partial immunity after exposure suggests the possibility of a successful and effective vaccine, but protective surrogates are not precise. In this review, we present our current perspectives on novel cryptosporidiosis therapies, vaccine targets and efficacies, as well as potential mitigation plans, recommendations and perceived challenges.
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Abstract
PURPOSE OF REVIEW Substantial progress has been made recently on the development of new therapeutics for cryptosporidiosis, an infection by the protozoan parasite Cryptosporidium that is associated with diarrhea, malnutrition, growth stunting, cognitive deficits, and oral vaccine failure in children living in low-resource settings. RECENT FINDINGS Various drug discovery approaches have generated promising lead candidates. The repurposed antimycobacterial drug clofazimine was tested in Malawian HIV patients with cryptosporidiosis but was ineffective. Target-based screens identified inhibitors of lysyl-tRNA synthetase, phenylalanyl-tRNA synthetase, methionyl-tRNA synthetase, and calcium-dependent protein kinase 1. Phenotypic screens led to discovery of a phosphatidylinositol 4-kinase inhibitor, the piperazine MMV665917, and the benzoxaborole AN7973. The relationship between pharmacokinetic properties and in-vivo efficacy is gradually emerging. A pathway to clinical trials, regulatory approval, and introduction has been proposed but additional work is needed to strengthen the route. SUMMARY Several lead compounds with potent activity in animal models and a favorable safety profile have been identified. A sustained effort will be required to advance at least one to clinical proof-of-concept studies. The demonstrated risk of resistance indicates multiple candidates should be advanced as potential components of a combination therapy.
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Affiliation(s)
- Melissa S. Love
- Calibr, a division of The Scripps Research Institute, La Jolla, California, USA
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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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Huston CD. The Clofazimine for Treatment of Cryptosporidiosis in HIV-Infected Adults (CRYPTOFAZ) and Lessons Learned for Anticryptosporidial Drug Development. Clin Infect Dis 2021; 73:192-194. [PMID: 32277815 PMCID: PMC8427724 DOI: 10.1093/cid/ciaa425] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Indexed: 11/12/2022] Open
Affiliation(s)
- Christopher D Huston
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, Vermont, USA
- Department of Microbiology and Molecular Genetics, University of Vermont Larner College of Medicine, Burlington, Vermont, USA
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Diawara EH, François A, Stachulski AV, Razakandrainibe R, Costa D, Favennec L, Rossignol JF, Gargala G. Systemic efficacy on Cryptosporidium parvum infection of aminoxanide (RM-5061), a new amino-acid ester thiazolide prodrug of tizoxanide. Parasitology 2021; 148:975-984. [PMID: 33775260 PMCID: PMC11010128 DOI: 10.1017/s0031182021000524] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 02/13/2021] [Accepted: 03/21/2021] [Indexed: 11/05/2022]
Abstract
Cryptosporidiosis is a gastrointestinal illness with profuse diarrhoea. Although there are no other Food and Drug Administration (FDA)-approved alternatives for the treatment of cryptosporidiosis, nitazoxanide (NTZ) can be qualified as partially effective. In immunosuppressed conditions, severe and/or disseminated cryptosporidiosis may occur and patients should be treated parenterally. To achieve the goal of developing parenteral treatment for cryptosporidiosis, the current study was undertaken to investigate the in vitro and in vivo anticryptosporidial activity of aminoxanide. This new l-tert-leucyl thiazolide is a soluble prodrug of tizoxanide (TIZ), the main metabolite of NTZ. Confirming the good efficacy of aminoxanide in Cryptosporidium parvum-infected HCT-8 cells with a 50% inhibitory concentration of 1.55 μm (±0.21), in immunosuppressed C. parvum-infected Mongolian gerbils (Meriones unguiculatus), a 5-day treatment with a daily intramuscular dose of 100 mg kg−1 aminoxanide resulted in a 72.5% oocyst excretion inhibition, statistically equivalent to 75.5% in gerbils treated with a 4-fold lower oral dose of NTZ. Cryptosporidium parvum-induced intestinal pathology and inflammation were improved. Aminoxanide provides an injectable form of TIZ that NTZ was unable to do and is a promising drug for which optimization of the formulation should be further explored. These results represent a first promising step towards the goal of developing a parenteral treatment for cryptosporidiosis.
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Affiliation(s)
- El Hadji Diawara
- Laboratoire de Parasitologie-Mycologie, Rouen University Hospital and EA7510, University of Rouen, Rouen, France
| | - Arnaud François
- Laboratoire d'Anatomo-Pathologie, Rouen University Hospital, Rouen, France
| | - Andrew V. Stachulski
- Robert Robinson Laboratories, Department of Chemistry, University of Liverpool, LiverpoolL69 7ZD, UK
| | - Romy Razakandrainibe
- Laboratoire de Parasitologie-Mycologie, Rouen University Hospital and EA7510, University of Rouen, Rouen, France
| | - Damien Costa
- Laboratoire de Parasitologie-Mycologie, Rouen University Hospital and EA7510, University of Rouen, Rouen, France
| | - Loïc Favennec
- Laboratoire de Parasitologie-Mycologie, Rouen University Hospital and EA7510, University of Rouen, Rouen, France
| | | | - Gilles Gargala
- Laboratoire de Parasitologie-Mycologie, Rouen University Hospital and EA7510, University of Rouen, Rouen, France
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11
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Vinayak S, Jumani RS, Miller P, Hasan MM, McLeod BI, Tandel J, Stebbins EE, Teixeira JE, Borrel J, Gonse A, Zhang M, Yu X, Wernimont A, Walpole C, Eckley S, Love MS, McNamara CW, Sharma M, Sharma A, Scherer CA, Kato N, Schreiber SL, Melillo B, Striepen B, Huston CD, Comer E. Bicyclic azetidines kill the diarrheal pathogen Cryptosporidium in mice by inhibiting parasite phenylalanyl-tRNA synthetase. Sci Transl Med 2021; 12:12/563/eaba8412. [PMID: 32998973 DOI: 10.1126/scitranslmed.aba8412] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Accepted: 09/11/2020] [Indexed: 12/21/2022]
Abstract
Cryptosporidium is a protozoan parasite and a leading cause of diarrheal disease and mortality in young children. Currently, there are no fully effective treatments available to cure infection with this diarrheal pathogen. In this study, we report a broad drug repositioning effort that led to the identification of bicyclic azetidines as a new anticryptosporidial series. Members of this series blocked growth in in vitro culture of three Cryptosporidium parvum isolates with EC50 's in 1% serum of <0.4 to 96 nM, had comparable potencies against Cryptosporidium hominis and C. parvum, and was effective in three of four highly susceptible immunosuppressed mice with once-daily dosing administered for 4 days beginning 2 weeks after infection. Comprehensive genetic, biochemical, and chemical studies demonstrated inhibition of C. parvum phenylalanyl-tRNA synthetase (CpPheRS) as the mode of action of this new lead series. Introduction of mutations directly into the C. parvum pheRS gene by CRISPR-Cas9 genome editing resulted in parasites showing high degrees of compound resistance. In vitro, bicyclic azetidines potently inhibited the aminoacylation activity of recombinant ChPheRS. Medicinal chemistry optimization led to the identification of an optimal pharmacokinetic/pharmacodynamic profile for this series. Collectively, these data demonstrate that bicyclic azetidines are a promising series for anticryptosporidial drug development and establish a broad framework to enable target-based drug discovery for this infectious disease.
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Affiliation(s)
- Sumiti Vinayak
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL 61802, USA
| | - Rajiv S Jumani
- Cellular, Molecular and Biomedical Sciences Graduate Program, University of Vermont, Burlington, VT 05405, USA
| | - Peter Miller
- Department of Medicine, Larner College of Medicine, University of Vermont, Burlington, VT 05405, USA
| | - Muhammad M Hasan
- Cellular, Molecular and Biomedical Sciences Graduate Program, University of Vermont, Burlington, VT 05405, USA
| | - Briana I McLeod
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jayesh Tandel
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Erin E Stebbins
- Department of Medicine, Larner College of Medicine, University of Vermont, Burlington, VT 05405, USA
| | - Jose E Teixeira
- Department of Medicine, Larner College of Medicine, University of Vermont, Burlington, VT 05405, USA
| | - Julien Borrel
- Chemical Biology and Therapeutics Science Program, Broad Institute, Cambridge, MA 02142, USA
| | - Arthur Gonse
- Chemical Biology and Therapeutics Science Program, Broad Institute, Cambridge, MA 02142, USA
| | - Mingliang Zhang
- International Discovery Service Unit, WuXi AppTec (Tianjin) Co. Ltd., Tianjin 300457, P.R. China
| | - Xianshui Yu
- International Discovery Service Unit, WuXi AppTec (Tianjin) Co. Ltd., Tianjin 300457, P.R. China
| | - Amy Wernimont
- Structural Genomics Consortium, MaRS Building, South Tower, 101 College Street, Suite 700, Toronto, Ontario M5G 1L7, Canada
| | - Chris Walpole
- Structural Genomics Consortium, MaRS Building, South Tower, 101 College Street, Suite 700, Toronto, Ontario M5G 1L7, Canada
| | | | - Melissa S Love
- Calibr, a division of The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Case W McNamara
- Calibr, a division of The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Manmohan Sharma
- Structural Parasitology, Molecular Medicine Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Road, New Delhi 110070, India
| | - Amit Sharma
- Structural Parasitology, Molecular Medicine Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Road, New Delhi 110070, India
| | - Christina A Scherer
- Chemical Biology and Therapeutics Science Program, Broad Institute, Cambridge, MA 02142, USA
| | - Nobutaka Kato
- Chemical Biology and Therapeutics Science Program, Broad Institute, Cambridge, MA 02142, USA
| | - Stuart L Schreiber
- Chemical Biology and Therapeutics Science Program, Broad Institute, Cambridge, MA 02142, USA.,Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Bruno Melillo
- Chemical Biology and Therapeutics Science Program, Broad Institute, Cambridge, MA 02142, USA.,Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA.,Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Boris Striepen
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Christopher D Huston
- Department of Medicine, Larner College of Medicine, University of Vermont, Burlington, VT 05405, USA.
| | - Eamon Comer
- Chemical Biology and Therapeutics Science Program, Broad Institute, Cambridge, MA 02142, USA.
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12
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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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13
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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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14
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Lambrinidis G, Tsantili-Kakoulidou A. Multi-objective optimization methods in novel drug design. Expert Opin Drug Discov 2020; 16:647-658. [PMID: 33353441 DOI: 10.1080/17460441.2021.1867095] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Introduction: In multi-objective drug design, optimization gains importance, being upgraded to a discipline that attracts its own research. Current strategies are broadly classified into single - objective optimization (SOO) and multi-objective optimization (MOO).Areas covered: Starting with SOO and the ways used to incorporate multiple criteria into it, the present review focuses on MOO techniques, their comparison, advantages, and restrictions. Pareto analysis and the concept of dominance stand in the core of MOO. The Pareto front, Pareto ranking, and limitations of Pareto-based methods, due to high dimensions and data uncertainty, are outlined. Desirability functions and the weighted sum approaches are described as stand-alone techniques to transform the MOO problem to SOO or in combination with pareto analysis and evolutionary algorithms. Representative applications in different drug research areas are also discussed.Expert opinion: Despite their limitations, the use of combined MOO techniques, as well as being complementary to SOO or in conjunction with artificial intelligence, contributes dramatically to efficient drug design, assisting decisions and increasing success probabilities. For multi-target drug design, optimization is supported by network approaches, while applicability of MOO to other fields like drug technology or biological complexity opens new perspectives in the interrelated fields of medicinal chemistry and molecular biology.
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Affiliation(s)
- George Lambrinidis
- Division of Pharmaceutical Chemistry, Department of Pharmacy, National and Kapodistrian University of Athens, Panepistimiopolis, Zografou, Athens, Greece
| | - Anna Tsantili-Kakoulidou
- Division of Pharmaceutical Chemistry, Department of Pharmacy, National and Kapodistrian University of Athens, Panepistimiopolis, Zografou, Athens, Greece
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15
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Johansen ØH, Abdissa A, Zangenberg M, Mekonnen Z, Eshetu B, Bjørang O, Alemu Y, Sharew B, Langeland N, Robertson LJ, Hanevik K. Performance and operational feasibility of two diagnostic tests for cryptosporidiosis in children (CRYPTO-POC): a clinical, prospective, diagnostic accuracy study. THE LANCET. INFECTIOUS DISEASES 2020; 21:722-730. [PMID: 33278916 PMCID: PMC8064915 DOI: 10.1016/s1473-3099(20)30556-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 04/27/2020] [Accepted: 06/19/2020] [Indexed: 12/11/2022]
Abstract
Background Cryptosporidiosis is a common cause of diarrhoea in young children (aged younger than 24 months) in low-resource settings but is currently challenging to diagnose. Light-emitting diode fluorescence microscopy with auramine-phenol staining (LED-AP), recommended for tuberculosis testing, can also detect Cryptosporidium species. A lateral-flow test not requiring refrigerator storage (by contrast with most immunochromatographic lateral-flow assays) has also recently been developed for Cryptosporidium spp detection. We aimed to evaluate the diagnostic accuracy and operational feasibility of LED-AP and the lateral-flow test strip for cryptosporidiosis in children. Methods We did a prospective diagnostic accuracy study in two health-care facilities in Ethiopia, in a consecutive series of children younger than 5 years of age with diarrhoea (three or more loose stools within the previous 24 h) or dysentery (at least one loose stool with stains of blood within the previous 24 h). Stool samples were tested for Cryptosporidium spp by LED-AP and the lateral-flow test strip; accuracy of each test was estimated by independent and blind comparison with a composite reference standard comprising quantitative immunofluorescent antibody test (qIFAT), ELISA, and quantitative PCR (qPCR). Quantitative cutoff values for diarrhoea-associated infection were established in an embedded case-control substudy, with cases of cryptosporidiosis coming from the 15 districts in and around Jimma and the eight districts surrounding Serbo, and community controls without diarrhoea in the previous 48 h recruited by weekly frequency matching by geographical district of the household, age group, and enrolment week. Findings Stool samples from 912 children with diarrhoea or dysentery and 706 controls from the case-control substudy were tested between Dec 22, 2016, and July 6, 2018. Estimated reference-standard cutoff values for cryptosporidiosis positivity were 2·3 × 105 DNA copies per g of wet stool for qPCR, and 725 oocysts per g for qIFAT. LED-AP had a sensitivity for cryptosporidiosis of 88% (95% CI 79–94; 66 of 75 samples) and a specificity of 99% (98–99; 717 of 726 samples); the lateral-flow test strip had a sensitivity of 89% (79–94; 63 of 71 samples) and a specificity of 99% (97–99; 626 of 635 samples). Interpretation LED-AP has high sensitivity and specificity for cryptosporidiosis and should be considered as a dual-use technology that can be easily integrated with existing laboratory infrastructures in low-resource settings. The lateral-flow test strip has similar sensitivity and specificity and provides an alternative that does not require microscopy, although purchase cost of the test strip is unknown as it is not yet available on the market. Funding Norwegian Research Council GLOBVAC fund, The Bill & Melinda Gates Foundation, Norwegian Society for Medical Microbiology, University of Bergen, and Vestfold Hospital Trust.
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Affiliation(s)
- Øystein H Johansen
- Department of Clinical Science, University of Bergen, Bergen, Norway; Department of Microbiology, Vestfold Hospital Trust, Tønsberg, Norway.
| | - Alemseged Abdissa
- School of Medical Laboratory Sciences, Jimma University, Jimma, Ethiopia
| | - Mike Zangenberg
- Department of Immunology and Microbiology, Centre for Medical Parasitology, University of Copenhagen, Copenhagen, Denmark; Department of Clinical Microbiology, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Zeleke Mekonnen
- School of Medical Laboratory Sciences, Jimma University, Jimma, Ethiopia
| | - Beza Eshetu
- Department of Paediatrics and Child Health, Jimma Institute of Health, Jimma University, Jimma, Ethiopia
| | - Ola Bjørang
- Department of Microbiology, Vestfold Hospital Trust, Tønsberg, Norway
| | - Yonas Alemu
- School of Medical Laboratory Sciences, Jimma University, Jimma, Ethiopia
| | - Bizuwarek Sharew
- School of Medical Laboratory Sciences, Jimma University, Jimma, Ethiopia
| | - Nina Langeland
- Department of Clinical Science, University of Bergen, Bergen, Norway; Norwegian National Advisory Unit on Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, Bergen, Norway
| | - Lucy J Robertson
- Parasitology, Department of Paraclinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - Kurt Hanevik
- Department of Clinical Science, University of Bergen, Bergen, Norway; Norwegian National Advisory Unit on Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, Bergen, Norway
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16
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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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17
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Swale C, Bougdour A, Gnahoui-David A, Tottey J, Georgeault S, Laurent F, Palencia A, Hakimi MA. Metal-captured inhibition of pre-mRNA processing activity by CPSF3 controls Cryptosporidium infection. Sci Transl Med 2020; 11:11/517/eaax7161. [PMID: 31694928 DOI: 10.1126/scitranslmed.aax7161] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 10/18/2019] [Indexed: 12/11/2022]
Abstract
Cryptosporidium is an intestinal pathogen that causes severe but self-limiting diarrhea in healthy humans, yet it can turn into a life-threatening, unrelenting infection in immunocompromised patients and young children. Severe diarrhea is recognized as the leading cause of mortality for children below 5 years of age in developing countries. The only approved treatment against cryptosporidiosis, nitazoxanide, has limited efficacy in the most vulnerable patient populations, including malnourished children, and is ineffective in immunocompromised individuals. Here, we investigate inhibition of the parasitic cleavage and polyadenylation specificity factor 3 (CPSF3) as a strategy to control Cryptosporidium infection. We show that the oxaborole AN3661 selectively blocked Cryptosporidium growth in human HCT-8 cells, and oral treatment with AN3661 reduced intestinal parasite burden in both immunocompromised and neonatal mouse models of infection with greater efficacy than nitazoxanide. Furthermore, we present crystal structures of recombinantly produced Cryptosporidium CPSF3, revealing a mechanism of action whereby the mRNA processing activity of this enzyme is efficiently blocked by the binding of the oxaborole group at the metal-dependent catalytic center. Our data provide insights that may help accelerate the development of next-generation anti-Cryptosporidium therapeutics.
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Affiliation(s)
- Christopher Swale
- Institute for Advanced Biosciences (IAB), Host-Pathogen Interactions and Immunity to Infection, INSERM U1209, CNRS UMR 5309, University Grenoble Alpes, 38000 Grenoble, France
| | - Alexandre Bougdour
- Institute for Advanced Biosciences (IAB), Host-Pathogen Interactions and Immunity to Infection, INSERM U1209, CNRS UMR 5309, University Grenoble Alpes, 38000 Grenoble, France
| | - Audrey Gnahoui-David
- INRA, Université François Rabelais de Tours, Centre Val de Loire, UMR1282 ISP, Laboratoire Apicomplexes et Immunité Mucosale, 37380 Nouzilly, France
| | - Julie Tottey
- INRA, Université François Rabelais de Tours, Centre Val de Loire, UMR1282 ISP, Laboratoire Apicomplexes et Immunité Mucosale, 37380 Nouzilly, France
| | - Sonia Georgeault
- Plateforme des Microscopies, Université et CHRU de Tours, 37000 Tours, France
| | - Fabrice Laurent
- INRA, Université François Rabelais de Tours, Centre Val de Loire, UMR1282 ISP, Laboratoire Apicomplexes et Immunité Mucosale, 37380 Nouzilly, France.
| | - Andrés Palencia
- Institute for Advanced Biosciences (IAB), Host-Pathogen Interactions and Immunity to Infection, INSERM U1209, CNRS UMR 5309, University Grenoble Alpes, 38000 Grenoble, France. .,Institute for Advanced Biosciences (IAB), Structural Biology of Novel Drug Targets in Human Diseases, INSERM U1209, CNRS UMR 5309, University Grenoble Alpes, 38000 Grenoble, France
| | - Mohamed-Ali Hakimi
- Institute for Advanced Biosciences (IAB), Host-Pathogen Interactions and Immunity to Infection, INSERM U1209, CNRS UMR 5309, University Grenoble Alpes, 38000 Grenoble, France.
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18
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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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19
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Arnold SLM, Choi R, Hulverson MA, Whitman GR, Mccloskey MC, Dorr CS, Vidadala RSR, Khatod M, Morada M, Barrett LK, Maly DJ, Yarlett N, Van Voorhis WC. P-Glycoprotein-Mediated Efflux Reduces the In Vivo Efficacy of a Therapeutic Targeting the Gastrointestinal Parasite Cryptosporidium. J Infect Dis 2020; 220:1188-1198. [PMID: 31180118 PMCID: PMC6736360 DOI: 10.1093/infdis/jiz269] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 05/17/2019] [Indexed: 12/04/2022] Open
Abstract
Recent studies have illustrated the burden Cryptosporidium infection places on the lives of malnourished children and immunocompromised individuals. Treatment options remain limited, and efforts to develop a new therapeutic are currently underway. However, there are unresolved questions about the ideal pharmacokinetic characteristics of new anti-Cryptosporidium therapeutics. Specifically, should drug developers optimize therapeutics and formulations to increase drug exposure in the gastrointestinal lumen, enterocytes, or systemic circulation? Furthermore, how should researchers interpret data suggesting their therapeutic is a drug efflux transporter substrate? In vivo drug transporter–mediated alterations in efficacy are well recognized in multiple disease areas, but the impact of intestinal transporters on therapeutic efficacy against enteric diseases has not been established. Using multiple in vitro models and a mouse model of Cryptosporidium infection, we characterized the effect of P-glycoprotein efflux on bumped kinase inhibitor pharmacokinetics and efficacy. Our results demonstrated P-glycoprotein decreases bumped kinase inhibitor enterocyte exposure, resulting in reduced in vivo efficacy against Cryptosporidium. Furthermore, a hollow fiber model of Cryptosporidium infection replicated the in vivo impact of P-glycoprotein on anti-Cryptosporidium efficacy. In conclusion, when optimizing drug candidates targeting the gastrointestinal epithelium or gastrointestinal epithelial infections, drug developers should consider the adverse impact of active efflux transporters on efficacy.
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Affiliation(s)
- Samuel L M Arnold
- Division of Allergy and Infectious Disease, Department of Medicine, University of Washington, Seattle.,Center for Emerging and Reemerging Infectious Disease, University of Washington, Seattle
| | - Ryan Choi
- Division of Allergy and Infectious Disease, Department of Medicine, University of Washington, Seattle.,Center for Emerging and Reemerging Infectious Disease, University of Washington, Seattle
| | - Matthew A Hulverson
- Division of Allergy and Infectious Disease, Department of Medicine, University of Washington, Seattle.,Center for Emerging and Reemerging Infectious Disease, University of Washington, Seattle
| | - Grant R Whitman
- Division of Allergy and Infectious Disease, Department of Medicine, University of Washington, Seattle.,Center for Emerging and Reemerging Infectious Disease, University of Washington, Seattle
| | - Molly C Mccloskey
- Division of Allergy and Infectious Disease, Department of Medicine, University of Washington, Seattle.,Center for Emerging and Reemerging Infectious Disease, University of Washington, Seattle
| | - Carlie S Dorr
- Division of Allergy and Infectious Disease, Department of Medicine, University of Washington, Seattle.,Center for Emerging and Reemerging Infectious Disease, University of Washington, Seattle
| | | | | | | | - Lynn K Barrett
- Division of Allergy and Infectious Disease, Department of Medicine, University of Washington, Seattle.,Center for Emerging and Reemerging Infectious Disease, University of Washington, Seattle
| | - Dustin J Maly
- Department of Chemistry, University of Washington, Seattle.,Department of Biochemistry, University of Washington, Seattle
| | | | - Wesley C Van Voorhis
- Division of Allergy and Infectious Disease, Department of Medicine, University of Washington, Seattle.,Center for Emerging and Reemerging Infectious Disease, University of Washington, Seattle
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20
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Jumani RS, Spector JM, Izadnegahdar R, Kelly P, Diagana TT, Manjunatha UH. Innovations in Addressing Pediatric Diarrhea in Low Resource Settings. ACS Infect Dis 2020; 6:14-24. [PMID: 31612701 DOI: 10.1021/acsinfecdis.9b00315] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Diarrhea has long been recognized as an important cause of mortality during childhood. In parallel with ensuring access to proven care practices is the imperative to apply modern advances in medicine, science, and technology to accelerate progress against diarrheal disease, particularly in developing countries where the burden of avoidable harm is the greatest. In order to highlight achievements and identify outstanding areas of need, we reviewed the landscape of recent innovations that have significance for the study and clinical management of pediatric diarrhea in low resource settings.
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Affiliation(s)
- Rajiv S. Jumani
- Novartis Institute for Tropical Diseases, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Jonathan M. Spector
- Novartis Institute for Tropical Diseases, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Rasa Izadnegahdar
- Bill and Melinda Gates Foundation, 440 5th Ave N, Seattle, Washington 98109, United States
| | - Paul Kelly
- Blizard Institute, Barts and The London School of Medicine, Queen Mary University of London, Turner Street, London E1 2AD, United Kingdom
- Tropical Gastroenterology and Nutrition group, University of Zambia School of Medicine, Nationalist Road, Lusaka, Zambia
| | - Thierry T. Diagana
- Novartis Institute for Tropical Diseases, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Ujjini H. Manjunatha
- Novartis Institute for Tropical Diseases, 5300 Chiron Way, Emeryville, California 94608, United States
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21
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Systematic gene silencing identified Cryptosporidium nucleoside diphosphate kinase and other molecules as targets for suppression of parasite proliferation in human intestinal cells. Sci Rep 2019; 9:12153. [PMID: 31434931 PMCID: PMC6704102 DOI: 10.1038/s41598-019-48544-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 08/05/2019] [Indexed: 01/06/2023] Open
Abstract
Cryptosporidiosis is a major cause of diarrheal disease. The only drug approved for cryptosporidiosis has limited efficacy in high-risk populations. Therefore novel drugs are urgently needed. We have identified several enzymes as potential targets for drug development and we have optimized a rapid method to silence genes in Cryptosporidium. In this study, we knocked down expression of the four selected genes: Actin (Act), Apicomplexan DNA-binding protein (Ap2), Rhomboid protein 1 (Rom 1), and nucleoside diphosphate kinase (NDK). After gene silencing, we evaluated the role of each target on parasite development using in vitro models of excystation, invasion, proliferation, and egress. We showed that silencing of Act, Ap2, NDK, and Rom1 reduced invasion, proliferation, and egress of Cryptosporidium. However, silencing of NDK markedly inhibited Cryptosporidium proliferation (~70%). We used an infection model to evaluate the anticryptosporidial activity of ellagic acid (EA), an NDK inhibitor. We showed that EA (EC50 = 15–30 µM) reduced parasite burden without showing human cell toxicity. Here, we demonstrated the usefulness of a rapid silencing method to identify novel targets for drug development. Because EA is a dietary supplement already approved for human use, this compound should be studied as a potential treatment for cryptosporidiosis.
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22
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Lunde CS, Stebbins EE, Jumani RS, Hasan MM, Miller P, Barlow J, Freund YR, Berry P, Stefanakis R, Gut J, Rosenthal PJ, Love MS, McNamara CW, Easom E, Plattner JJ, Jacobs RT, Huston CD. Identification of a potent benzoxaborole drug candidate for treating cryptosporidiosis. Nat Commun 2019; 10:2816. [PMID: 31249291 PMCID: PMC6597546 DOI: 10.1038/s41467-019-10687-y] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 05/23/2019] [Indexed: 11/09/2022] Open
Abstract
Cryptosporidiosis is a leading cause of life-threatening diarrhea in young children and causes chronic diarrhea in AIDS patients, but the only approved treatment is ineffective in malnourished children and immunocompromised people. We here use a drug repositioning strategy and identify a promising anticryptosporidial drug candidate. Screening a library of benzoxaboroles comprised of analogs to four antiprotozoal chemical scaffolds under pre-clinical development for neglected tropical diseases for Cryptosporidium growth inhibitors identifies the 6-carboxamide benzoxaborole AN7973. AN7973 blocks intracellular parasite development, appears to be parasiticidal, and potently inhibits the two Cryptosporidium species most relevant to human health, C. parvum and C. hominis. It is efficacious in murine models of both acute and established infection, and in a neonatal dairy calf model of cryptosporidiosis. AN7973 also possesses favorable safety, stability, and PK parameters, and therefore, is an exciting drug candidate for treating cryptosporidiosis.
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Affiliation(s)
| | - Erin E Stebbins
- Department of Medicine, University of Vermont Robert R. Larner College of Medicine, Burlington, VT, 05405, USA
| | - Rajiv S Jumani
- Department of Medicine, University of Vermont Robert R. Larner College of Medicine, Burlington, VT, 05405, USA
- Department of Microbiology and Molecular Genetics, University of Vermont College of Agriculture and Life Sciences, Burlington, VT, 05405, USA
| | - Md Mahmudul Hasan
- Department of Medicine, University of Vermont Robert R. Larner College of Medicine, Burlington, VT, 05405, USA
- Department of Microbiology and Molecular Genetics, University of Vermont College of Agriculture and Life Sciences, Burlington, VT, 05405, USA
| | - Peter Miller
- Department of Medicine, University of Vermont Robert R. Larner College of Medicine, Burlington, VT, 05405, USA
| | - John Barlow
- Department of Animal and Veterinary Sciences, University of Vermont College of Agriculture and Life Sciences, Burlington, VT, 05405, USA
| | | | - Pamela Berry
- Anacor Pharmaceuticals, Palo Alto, CA, 4230, USA
| | | | - Jiri Gut
- Department of Medicine, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Philip J Rosenthal
- Department of Medicine, University of California San Francisco, San Francisco, CA, 94143, USA
| | | | | | - Eric Easom
- Anacor Pharmaceuticals, Palo Alto, CA, 4230, USA
| | | | | | - Christopher D Huston
- Department of Medicine, University of Vermont Robert R. Larner College of Medicine, Burlington, VT, 05405, USA.
- Department of Microbiology and Molecular Genetics, University of Vermont College of Agriculture and Life Sciences, Burlington, VT, 05405, USA.
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23
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A Genetically Tractable, Natural Mouse Model of Cryptosporidiosis Offers Insights into Host Protective Immunity. Cell Host Microbe 2019; 26:135-146.e5. [PMID: 31231045 PMCID: PMC6617386 DOI: 10.1016/j.chom.2019.05.006] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 04/30/2019] [Accepted: 05/15/2019] [Indexed: 12/31/2022]
Abstract
Cryptosporidium is a leading cause of diarrheal disease and an important contributor to early childhood mortality, malnutrition, and growth faltering. Older children in high endemicity regions appear resistant to infection, while previously unexposed adults remain susceptible. Experimental studies in humans and animals support the development of disease resistance, but we do not understand the mechanisms that underlie protective immunity to Cryptosporidium. Here, we derive an in vivo model of Cryptosporidium infection in immunocompetent C57BL/6 mice by isolating parasites from naturally infected wild mice. Similar to human cryptosporidiosis, this infection causes intestinal pathology, and interferon-γ controls early infection while T cells are critical for clearance. Importantly, mice that controlled a live infection were resistant to secondary challenge and vaccination with attenuated parasites provided protection equal to live infection. Both parasite and host are genetically tractable and this in vivo model will facilitate mechanistic investigation and rational vaccine design. We isolated and sequenced Cryptosporidium tyzzeri, a natural mouse pathogen C. tyzzeri can be genetically manipulated using CRISPR-driven homologous repair C. tyzzeri models human cryptosporidiosis with T cell- and IFN-γ-dependent resolution Mice develop protective immunity following both live infection and vaccination
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24
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Jumani RS, Hasan MM, Stebbins EE, Donnelly L, Miller P, Klopfer C, Bessoff K, Teixeira JE, Love MS, McNamara CW, Huston CD. A suite of phenotypic assays to ensure pipeline diversity when prioritizing drug-like Cryptosporidium growth inhibitors. Nat Commun 2019; 10:1862. [PMID: 31015448 PMCID: PMC6478823 DOI: 10.1038/s41467-019-09880-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 04/01/2019] [Indexed: 01/07/2023] Open
Abstract
Cryptosporidiosis is a leading cause of life-threatening diarrhea in children, and the only currently approved drug is ineffective in malnourished children and immunocompromised people. Large-scale phenotypic screens are ongoing to identify anticryptosporidial compounds, but optimal approaches to prioritize inhibitors and establish a mechanistically diverse drug development pipeline are unknown. Here, we present a panel of medium-throughput mode of action assays that enable testing of compounds in several stages of the Cryptosporidium life cycle. Phenotypic profiles are given for thirty-nine anticryptosporidials. Using a clustering algorithm, the compounds sort by phenotypic profile into distinct groups of inhibitors that are either chemical analogs (i.e. same molecular mechanism of action (MMOA)) or known to have similar MMOA. Furthermore, compounds belonging to multiple phenotypic clusters are efficacious in a chronic mouse model of cryptosporidiosis. This suite of phenotypic assays should ensure a drug development pipeline with diverse MMOA without the need to identify underlying mechanisms.
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Affiliation(s)
- Rajiv S Jumani
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, VT, 05405, USA.,Cellular, Molecular and Biomedical Sciences Graduate Program, University of Vermont, Burlington, VT, 05405, USA.,Novartis Institute for Tropical Diseases, Novartis Institutes for BioMedical Research, Emeryville, CA, 94608, USA
| | - Muhammad M Hasan
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, VT, 05405, USA.,Cellular, Molecular and Biomedical Sciences Graduate Program, University of Vermont, Burlington, VT, 05405, USA
| | - Erin E Stebbins
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, VT, 05405, USA
| | - Liam Donnelly
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, VT, 05405, USA
| | - Peter Miller
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, VT, 05405, USA
| | - Connor Klopfer
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, VT, 05405, USA
| | - Kovi Bessoff
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, VT, 05405, USA.,Department of Surgery, Stanford University School of Medicine, Palo Alto, CA, 94305-5101, USA
| | - Jose E Teixeira
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, VT, 05405, USA
| | - Melissa S Love
- Calibr at The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Case W McNamara
- Calibr at The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Christopher D Huston
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, VT, 05405, USA. .,Cellular, Molecular and Biomedical Sciences Graduate Program, University of Vermont, Burlington, VT, 05405, USA. .,Department of Microbiology and Molecular Genetics, University of Vermont Larner College of Medicine, Burlington, VT, 05405, USA.
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25
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Chavez MA, White AC. Novel treatment strategies and drugs in development for cryptosporidiosis. Expert Rev Anti Infect Ther 2018; 16:655-661. [PMID: 30003818 DOI: 10.1080/14787210.2018.1500457] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
INTRODUCTION Cryptosporidium is a protozoan pathogen that can cause diarrheal disease in healthy and immunosuppressed individuals, worldwide. Recent studies have highlighted the impact of cryptosporidiosis on children in resource-limited countries. Nitazoxanide is the only Food and Drug Administration approved treatment, but it is not consistently effective therapy for cryptosporidiosis in the most vulnerable populations. Areas covered: This review focused on recent published studies evaluating novel drugs and new compounds for the treatment of cryptosporidiosis. Expert commentary: Combinations of approved drugs have demonstrated some activity. Broad screens have demonstrated activity against Cryptosporidium for a number of available drugs, including statins and clofazimine, and the latter has advanced into clinical trials. Cryptosporidium calcium-dependent protein kinase 1 (CDPK1) has been identified as an attractive target for treatment, and bumped kinase inhibitors have been developed which inhibit CDPK1 and are active against Cryptosporidium growth both in vitro and in vivo. Inhibition of Plasmodium lipid kinase PI(4)K8 of Cryptosporidium by KDU731 greatly reduced oocyst shedding and improved diarrhea in calves with limited effects on the human PI(4)K. Another novel potent inhibitor MMV665917 was efficacious in mouse models with cidal activity against Cryptosporidium. Additional compounds have proved active in vitro. So far, only clofazimine has entered human trials.
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Affiliation(s)
- Miguel A Chavez
- a Department of Internal Medicine , University of Texas Medical Branch , Galveston , Texas , USA
| | - A Clinton White
- b Infectious Diseases Division, Department of Internal Medicine , University of Texas Medical Branch , Galveston , Texas , USA
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26
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De Rycker M, Baragaña B, Duce SL, Gilbert IH. Challenges and recent progress in drug discovery for tropical diseases. Nature 2018; 559:498-506. [PMID: 30046073 PMCID: PMC6129172 DOI: 10.1038/s41586-018-0327-4] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 05/02/2018] [Indexed: 02/07/2023]
Abstract
Infectious tropical diseases have a huge effect in terms of mortality and morbidity, and impose a heavy economic burden on affected countries. These diseases predominantly affect the world's poorest people. Currently available drugs are inadequate for the majority of these diseases, and there is an urgent need for new treatments. This Review discusses some of the challenges involved in developing new drugs to treat these diseases and highlights recent progress. While there have been notable successes, there is still a long way to go.
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Affiliation(s)
- Manu De Rycker
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee, UK
| | - Beatriz Baragaña
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee, UK
| | - Suzanne L Duce
- Medicines Monitoring Unit (MEMO), Division of Molecular and Clinical Medicine, School of Medicine, University of Dundee, Dundee, UK
| | - Ian H Gilbert
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee, UK.
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27
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Jumani RS, Bessoff K, Love MS, Miller P, Stebbins EE, Teixeira JE, Campbell MA, Meyers MJ, Zambriski JA, Nunez V, Woods AK, McNamara CW, Huston CD. A Novel Piperazine-Based Drug Lead for Cryptosporidiosis from the Medicines for Malaria Venture Open-Access Malaria Box. Antimicrob Agents Chemother 2018; 62:e01505-17. [PMID: 29339392 PMCID: PMC5913971 DOI: 10.1128/aac.01505-17] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 01/05/2018] [Indexed: 12/21/2022] Open
Abstract
Cryptosporidiosis causes life-threatening diarrhea in children under the age of 5 years and prolonged diarrhea in immunodeficient people, especially AIDS patients. The standard of care, nitazoxanide, is modestly effective in children and ineffective in immunocompromised individuals. In addition to the need for new drugs, better knowledge of drug properties that drive in vivo efficacy is needed to facilitate drug development. We report the identification of a piperazine-based lead compound for Cryptosporidium drug development, MMV665917, and a new pharmacodynamic method used for its characterization. The identification of MMV665917 from the Medicines for Malaria Venture Malaria Box was followed by dose-response studies, in vitro toxicity studies, and structure-activity relationship studies using commercial analogues. The potency of this compound against Cryptosporidium parvum Iowa and field isolates was comparable to that against Cryptosporidium hominis Furthermore, unlike nitazoxanide, clofazimine, and paromomycin, MMV665917 appeared to be curative in a NOD SCID gamma mouse model of chronic cryptosporidiosis. MMV665917 was also efficacious in a gamma interferon knockout mouse model of acute cryptosporidiosis. To determine if efficacy in this mouse model of chronic infection might relate to whether compounds are parasiticidal or parasitistatic for C. parvum, we developed a novel in vitro parasite persistence assay. This assay suggested that MMV665917 was parasiticidal, unlike nitazoxanide, clofazimine, and paromomycin. The assay also enabled determination of the concentration of the compound required to maximize the rate of parasite elimination. This time-kill assay can be used to prioritize early-stage Cryptosporidium drug leads and may aid in planning in vivo efficacy experiments. Collectively, these results identify MMV665917 as a promising lead and establish a new method for characterizing potential anticryptosporidial agents.
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Affiliation(s)
- R S Jumani
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, Vermont, USA
- Cellular, Molecular and Biomedical Sciences Graduate Program, University of Vermont, Burlington, Vermont, USA
| | - K Bessoff
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, Vermont, USA
| | - M S Love
- California Institute for Biomedical Research, La Jolla, California, USA
| | - P Miller
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, Vermont, USA
| | - E E Stebbins
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, Vermont, USA
| | - J E Teixeira
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, Vermont, USA
| | - M A Campbell
- Saint Louis University School of Medicine, St. Louis, Missouri, USA
| | - M J Meyers
- Saint Louis University School of Medicine, St. Louis, Missouri, USA
| | - J A Zambriski
- Paul G. Allen School for Global Animal Health, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - V Nunez
- California Institute for Biomedical Research, La Jolla, California, USA
| | - A K Woods
- California Institute for Biomedical Research, La Jolla, California, USA
| | - C W McNamara
- California Institute for Biomedical Research, La Jolla, California, USA
| | - C D Huston
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, Vermont, USA
- Cellular, Molecular and Biomedical Sciences Graduate Program, University of Vermont, Burlington, Vermont, USA
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28
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Stebbins E, Jumani RS, Klopfer C, Barlow J, Miller P, Campbell MA, Meyers MJ, Griggs DW, Huston CD. Clinical and microbiologic efficacy of the piperazine-based drug lead MMV665917 in the dairy calf cryptosporidiosis model. PLoS Negl Trop Dis 2018; 12:e0006183. [PMID: 29309415 PMCID: PMC5774826 DOI: 10.1371/journal.pntd.0006183] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 01/19/2018] [Accepted: 12/20/2017] [Indexed: 02/08/2023] Open
Abstract
Cryptosporidiosis causes life-threatening diarrhea in infants, but the best available treatment is only modestly efficacious. Rodents infected with relevant Cryptosporidium species do not develop diarrhea, which complicates drug development. Cryptosporidium parvum infection of dairy calves, however, causes an illness like that seen in infants. Here, the clinical and microbiologic anti-Cryptosporidium efficacy of the piperazine-based compound MMV665917 was demonstrated in neonatal calves. Oral administration of MMV665917 (22 mg/kg once daily) was begun two days after the onset of severe diarrhea and continued for seven days. Treatment resulted in prompt resolution of diarrhea, and reduced total fecal oocyst shedding by ~94%. MMV665917 was useful for treatment, rather than just prophylaxis, since it was safe and effective when administered well after the onset of diarrhea. Furthermore, even though all animals received intensive supportive care, there was a strong trend towards improved secondary health outcomes, including general health, appetite, and dehydration measures amongst treated animals. These data establish MMV665917 as an outstanding lead compound for Cryptosporidium drug development.
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Affiliation(s)
- Erin Stebbins
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, Vermont
| | - Rajiv S. Jumani
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, Vermont
- Cell, Molecular and Biomedical Sciences graduate program, University of Vermont Larner College of Medicine, Burlington, Vermont
| | - Connor Klopfer
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, Vermont
| | - John Barlow
- Department of Animal and Veterinary Sciences, University of Vermont College of Agriculture and Life Sciences, Burlington, Vermont
| | - Peter Miller
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, Vermont
| | | | | | | | - Christopher D. Huston
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, Vermont
- Cell, Molecular and Biomedical Sciences graduate program, University of Vermont Larner College of Medicine, Burlington, Vermont
- Department of Microbiology and Molecular Genetics, University of Vermont Larner College of Medicine, Burlington, Vermont
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29
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Zhang Y, Feng J, McManus SA, Lu HD, Ristroph KD, Cho EJ, Dobrijevic EL, Chan HK, Prud’homme RK. Design and Solidification of Fast-Releasing Clofazimine Nanoparticles for Treatment of Cryptosporidiosis. Mol Pharm 2017; 14:3480-3488. [PMID: 28929769 PMCID: PMC5627342 DOI: 10.1021/acs.molpharmaceut.7b00521] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 08/03/2017] [Accepted: 08/09/2017] [Indexed: 11/28/2022]
Abstract
Clofazimine, a lipophilic (log P = 7.66) riminophenazine antibiotic approved by the US Food and Drug Administration (FDA) with a good safety record, was recently identified as a lead hit for cryptosporidiosis through a high-throughput phenotypic screen. Cryptosporidiosis requires fast-acting treatment as it leads to severe symptoms which, if untreated, result in morbidity for infants and small children. Consequently, a fast-releasing oral formulation of clofazimine in a water-dispersible form for pediatric administration is highly desirable. In this work, clofazimine nanoparticles were prepared with three surface stabilizers, hypromellose acetate succinate (HPMCAS), lecithin, and zein, using the flash nanoprecipitation (FNP) process. Drug encapsulation efficiencies of over 92% were achieved. Lyophilization and spray-drying were applied and optimized to produce redispersible nanoparticle powders. The release kinetics of these clofazimine nanoparticle powders in biorelevant media were measured and compared with those of crystalline clofazimine and the currently marketed formulation Lamprene. Remarkably improved dissolution rates and clofazimine supersaturation levels up to 90 times equilibrium solubility were observed with all clofazimine nanoparticles tested. Differential scanning calorimetry indicated a reduction of crystallinity of clofazimine in nanoparticles. These results strongly suggest that the new clofazimine nanoparticles prepared with affordable materials in this low-cost nanoparticle formulation process can be used as viable cryptosporidiosis therapeutics.
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Affiliation(s)
- Yingyue Zhang
- Department
of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08854, United States
| | - Jie Feng
- Department
of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08854, United States
| | - Simon A. McManus
- Department
of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08854, United States
| | - Hoang D. Lu
- Department
of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08854, United States
| | - Kurt D. Ristroph
- Department
of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08854, United States
| | - Eugene J. Cho
- Department
of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08854, United States
| | - Ellen L. Dobrijevic
- Department
of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08854, United States
| | - Hak-Kim Chan
- School
of Pharmacy, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Robert K. Prud’homme
- Department
of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08854, United States
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30
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Arnold SLM, Choi R, Hulverson MA, Schaefer DA, Vinayak S, Vidadala RSR, McCloskey MC, Whitman GR, Huang W, Barrett LK, Ojo KK, Fan E, Maly DJ, Riggs MW, Striepen B, Van Voorhis WC. Necessity of Bumped Kinase Inhibitor Gastrointestinal Exposure in Treating Cryptosporidium Infection. J Infect Dis 2017; 216:55-63. [PMID: 28541457 PMCID: PMC5853285 DOI: 10.1093/infdis/jix247] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 05/22/2017] [Indexed: 01/16/2023] Open
Abstract
There is a substantial need for novel therapeutics to combat the widespread impact caused by Crytosporidium infection. However, there is a lack of knowledge as to which drug pharmacokinetic (PK) characteristics are key to generate an in vivo response, specifically whether systemic drug exposure is crucial for in vivo efficacy. To identify which PK properties are correlated with in vivo efficacy, we generated physiologically based PK models to simulate systemic and gastrointestinal drug concentrations for a series of bumped kinase inhibitors (BKIs) that have nearly identical in vitro potency against Cryptosporidium but display divergent PK properties. When BKI concentrations were used to predict in vivo efficacy with a neonatal model of Cryptosporidium infection, these concentrations in the large intestine were the sole predictors of the observed in vivo efficacy. The significance of large intestinal BKI exposure for predicting in vivo efficacy was further supported with an adult mouse model of Cryptosporidium infection. This study suggests that drug exposure in the large intestine is essential for generating a superior in vivo response, and that physiologically based PK models can assist in the prioritization of leading preclinical drug candidates for in vivo testing.
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Affiliation(s)
- Samuel L M Arnold
- Department of Medicine, Division of Allergy and Infectious Disease, Center for Emerging and Reemerging Infectious Disease
| | - Ryan Choi
- Department of Medicine, Division of Allergy and Infectious Disease, Center for Emerging and Reemerging Infectious Disease
| | - Matthew A Hulverson
- Department of Medicine, Division of Allergy and Infectious Disease, Center for Emerging and Reemerging Infectious Disease
| | - Deborah A Schaefer
- School of Animal and Comparative Biomedical Sciences, College of Agriculture and Life Sciences, University of Arizona, Tucson
| | | | | | - Molly C McCloskey
- Department of Medicine, Division of Allergy and Infectious Disease, Center for Emerging and Reemerging Infectious Disease
| | - Grant R Whitman
- Department of Medicine, Division of Allergy and Infectious Disease, Center for Emerging and Reemerging Infectious Disease
| | | | - Lynn K Barrett
- Department of Medicine, Division of Allergy and Infectious Disease, Center for Emerging and Reemerging Infectious Disease
| | - Kayode K Ojo
- Department of Medicine, Division of Allergy and Infectious Disease, Center for Emerging and Reemerging Infectious Disease
| | - Erkang Fan
- Department of Biochemistry, Biomolecular Structure Center, University of Washington, Seattle
| | | | - Michael W Riggs
- School of Animal and Comparative Biomedical Sciences, College of Agriculture and Life Sciences, University of Arizona, Tucson
| | - Boris Striepen
- Center for Tropical and Emerging Global Diseases.,Department of Cellular Biology, University of Georgia, Athens
| | - Wesley C Van Voorhis
- Department of Medicine, Division of Allergy and Infectious Disease, Center for Emerging and Reemerging Infectious Disease
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31
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Breder CD, Du W, Tyndall A. What’s the Regulatory Value of a Target Product Profile? Trends Biotechnol 2017; 35:576-579. [DOI: 10.1016/j.tibtech.2017.02.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 02/17/2017] [Accepted: 02/28/2017] [Indexed: 11/28/2022]
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32
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Manjunatha UH, Vinayak S, Zambriski JA, Chao AT, Sy T, Noble CG, Bonamy GMC, Kondreddi RR, Zou B, Gedeck P, Brooks CF, Herbert GT, Sateriale A, Tandel J, Noh S, Lakshminarayana SB, Lim SH, Goodman LB, Bodenreider C, Feng G, Zhang L, Blasco F, Wagner J, Leong FJ, Striepen B, Diagana TT. A Cryptosporidium PI(4)K inhibitor is a drug candidate for cryptosporidiosis. Nature 2017; 546:376-380. [PMID: 28562588 PMCID: PMC5473467 DOI: 10.1038/nature22337] [Citation(s) in RCA: 120] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Accepted: 03/31/2017] [Indexed: 01/02/2023]
Abstract
Diarrhoeal disease is responsible for 8.6% of global child mortality. Recent epidemiological studies found the protozoan parasite Cryptosporidium to be a leading cause of paediatric diarrhoea, with particularly grave impact on infants and immunocompromised individuals. There is neither a vaccine nor an effective treatment. Here we establish a drug discovery process built on scalable phenotypic assays and mouse models that take advantage of transgenic parasites. Screening a library of compounds with anti-parasitic activity, we identify pyrazolopyridines as inhibitors of Cryptosporidium parvum and Cryptosporidium hominis. Oral treatment with the pyrazolopyridine KDU731 results in a potent reduction in intestinal infection of immunocompromised mice. Treatment also leads to rapid resolution of diarrhoea and dehydration in neonatal calves, a clinical model of cryptosporidiosis that closely resembles human infection. Our results suggest that the Cryptosporidium lipid kinase PI(4)K (phosphatidylinositol-4-OH kinase) is a target for pyrazolopyridines and that KDU731 warrants further preclinical evaluation as a drug candidate for the treatment of cryptosporidiosis. The establishment of a drug-discovery screening pipeline for cryptosporidiosis, and identification of pyrazolopyridines as selective ATP-competitive inhibitors of the Cryptosporidium lipid kinase PI(4)K. The apicomplexan parasite Cryptosporidium is a leading cause of paediatric diarrhoea, with high mortality in infants and individuals with weak immune systems. Here, the authors report the establishment of a drug discovery screening pipeline for cryptosporidiosis, and identify pyrazolopyridines as selective ATP-competitive inhibitors of the Cryptosporidium lipid kinase PI(4)K. The lead candidate, KDU731, inhibits growth of C. parvum and C. hominis in vitro, and demonstrated in vivo efficacy in immunocompromised mice and neonatal calves (a clinical model of human disease). Moreover, KDU731 meets a broad range of safety and pharmacology criteria, and has potential as a much-needed therapeutic for treatment of cryptosporidiosis.
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Affiliation(s)
| | - Sumiti Vinayak
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
| | - Jennifer A Zambriski
- Washington State University, College of Veterinary Medicine, Paul G. Allen School for Global Animal Health, Pullman, WA, USA
| | | | - Tracy Sy
- Washington State University, College of Veterinary Medicine, Paul G. Allen School for Global Animal Health, Pullman, WA, USA
| | | | | | | | - Bin Zou
- Novartis Institute for Tropical Diseases, Singapore 138670
| | - Peter Gedeck
- Novartis Institute for Tropical Diseases, Singapore 138670
| | - Carrie F Brooks
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
| | - Gillian T Herbert
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
| | - Adam Sateriale
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
| | - Jayesh Tandel
- Department of Cellular Biology, University of Georgia, Athens, GA, USA
| | - Susan Noh
- Washington State University, College of Veterinary Medicine, Paul G. Allen School for Global Animal Health, Pullman, WA, USA.,USDA-Agricultural Research Service, Animal Disease Research Unit and Washington State University, Department of Veterinary Microbiology and Pathology, Washington Animal Disease Diagnostic Laboratory, Pullman, WA, USA
| | | | - Siau H Lim
- Novartis Institute for Tropical Diseases, Singapore 138670
| | - Laura B Goodman
- Cornell University, College of Veterinary Medicine, Department of Population Medicine and Diagnostic Sciences, Ithaca, NY, USA
| | | | - Gu Feng
- Novartis Institute for Tropical Diseases, Singapore 138670
| | - Lijun Zhang
- China Novartis Institute for Biomedical Research, Shanghai 201203, China
| | | | - Juergen Wagner
- Novartis Institute for Tropical Diseases, Singapore 138670
| | - F Joel Leong
- Novartis Institute for Tropical Diseases, Singapore 138670
| | - Boris Striepen
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA.,Department of Cellular Biology, University of Georgia, Athens, GA, USA
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Love MS, Beasley FC, Jumani RS, Wright TM, Chatterjee AK, Huston CD, Schultz PG, McNamara CW. A high-throughput phenotypic screen identifies clofazimine as a potential treatment for cryptosporidiosis. PLoS Negl Trop Dis 2017; 11:e0005373. [PMID: 28158186 PMCID: PMC5310922 DOI: 10.1371/journal.pntd.0005373] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 02/15/2017] [Accepted: 01/30/2017] [Indexed: 11/19/2022] Open
Abstract
Cryptosporidiosis has emerged as a leading cause of non-viral diarrhea in children under five years of age in the developing world, yet the current standard of care to treat Cryptosporidium infections, nitazoxanide, demonstrates limited and immune-dependent efficacy. Given the lack of treatments with universal efficacy, drug discovery efforts against cryptosporidiosis are necessary to find therapeutics more efficacious than the standard of care. To date, cryptosporidiosis drug discovery efforts have been limited to a few targeted mechanisms in the parasite and whole cell phenotypic screens against small, focused collections of compounds. Using a previous screen as a basis, we initiated the largest known drug discovery effort to identify novel anticryptosporidial agents. A high-content imaging assay for inhibitors of Cryptosporidium parvum proliferation within a human intestinal epithelial cell line was miniaturized and automated to enable high-throughput phenotypic screening against a large, diverse library of small molecules. A screen of 78,942 compounds identified 12 anticryptosporidial hits with sub-micromolar activity, including clofazimine, an FDA-approved drug for the treatment of leprosy, which demonstrated potent and selective in vitro activity (EC50 = 15 nM) against C. parvum. Clofazimine also displayed activity against C. hominis-the other most clinically-relevant species of Cryptosporidium. Importantly, clofazimine is known to accumulate within epithelial cells of the small intestine, the primary site of Cryptosporidium infection. In a mouse model of acute cryptosporidiosis, a once daily dosage regimen for three consecutive days or a single high dose resulted in reduction of oocyst shedding below the limit detectable by flow cytometry. Recently, a target product profile (TPP) for an anticryptosporidial compound was proposed by Huston et al. and highlights the need for a short dosing regimen (< 7 days) and formulations for children < 2 years. Clofazimine has a long history of use and has demonstrated a good safety profile for a disease that requires chronic dosing for a period of time ranging 3-36 months. These results, taken with clofazimine's status as an FDA-approved drug with over four decades of use for the treatment of leprosy, support the continued investigation of clofazimine both as a new chemical tool for understanding cryptosporidium biology and a potential new treatment of cryptosporidiosis.
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Affiliation(s)
- Melissa S. Love
- California Institute for Biomedical Research, La Jolla, California, United States of America
| | - Federico C. Beasley
- California Institute for Biomedical Research, La Jolla, California, United States of America
| | - Rajiv S. Jumani
- Department of Medicine, University of Vermont College of Medicine, Burlington, Vermont, United States of America
| | - Timothy M. Wright
- California Institute for Biomedical Research, La Jolla, California, United States of America
| | - Arnab K. Chatterjee
- California Institute for Biomedical Research, La Jolla, California, United States of America
| | - Christopher D. Huston
- Department of Medicine, University of Vermont College of Medicine, Burlington, Vermont, United States of America
| | - Peter G. Schultz
- California Institute for Biomedical Research, La Jolla, California, United States of America
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Case W. McNamara
- California Institute for Biomedical Research, La Jolla, California, United States of America
- * E-mail:
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Manjunatha UH, Chao AT, Leong FJ, Diagana TT. Cryptosporidiosis Drug Discovery: Opportunities and Challenges. ACS Infect Dis 2016; 2:530-7. [PMID: 27626293 DOI: 10.1021/acsinfecdis.6b00094] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The apicomplexan parasite Cryptosporidium is the second most important diarrheal pathogen causing life-threatening diarrhea in children, which is also associated with long-term growth faltering and cognitive deficiency. Cryptosporidiosis is a parasitic disease of public health concern caused by Cryptosporidium parvum and Cryptosporidium hominis. Currently, nitazoxanide is the only approved treatment for cryptosporidium infections. Unfortunately, it has limited efficacy in the most vulnerable patients, thus there is an urgent need for a safe and efficacious cryptosporidiosis drug. In this work, we present our current perspectives on the target product profile for novel cryptosporidiosis therapies and the perceived challenges and possible mitigation plans at different stages in the cryptosporidiosis drug discovery process.
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Affiliation(s)
- Ujjini H. Manjunatha
- Novartis Institute for Tropical Diseases, 10 Biopolis Road, #05-01, Singapore 138670
| | - Alexander T. Chao
- Novartis Institute for Tropical Diseases, 10 Biopolis Road, #05-01, Singapore 138670
| | - F. Joel Leong
- Novartis Institute for Tropical Diseases, 10 Biopolis Road, #05-01, Singapore 138670
| | - Thierry T. Diagana
- Novartis Institute for Tropical Diseases, 10 Biopolis Road, #05-01, Singapore 138670
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Hain AUP, Miller AS, Levitskaya J, Bosch J. Virtual Screening and Experimental Validation Identify Novel Inhibitors of the Plasmodium falciparum Atg8-Atg3 Protein-Protein Interaction. ChemMedChem 2016; 11:900-10. [PMID: 26748931 PMCID: PMC8614111 DOI: 10.1002/cmdc.201500515] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Revised: 12/07/2015] [Indexed: 01/16/2023]
Abstract
New therapies are needed against malaria, a parasitic infection caused by Plasmodium falciparum, as drug resistance emerges against the current treatment, artemisinin. We previously characterized the Atg8-Atg3 protein-protein interaction (PPI), which is essential for autophagy and parasite survival. Herein we illustrate the use of virtual library screening to selectively block the PPI in the parasite without inhibiting the homologous interaction in humans by targeting the A-loop of PfAtg8. This A-loop is important for Atg3 binding in Plasmodium, but is absent from the human Atg8 homologues. In this proof-of-concept study, we demonstrate a shift in lipidation state of PfAtg8 and inhibition of P. falciparum growth in both blood- and liver-stage cultures upon drug treatment. Our results illustrate how in silico screening and structure-aided drug design against a PPI can be used to identify new hits for drug development. Additionally, as we targeted a region of Atg8 that is conserved within apicomplexans, we predict that our small molecule will have cross-reactivity against other disease-causing apicomplexans, such as Toxoplasma, Cryptosporidium, Theileria, Neospora, Eimeria, and Babesia.
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Affiliation(s)
- Adelaide U P Hain
- Department of Biochemistry and Molecular Biology, Johns Hopkins School of Public Health and, Johns Hopkins Malaria Research Institute, 615 N. Wolfe Street, Baltimore, MD, 21205, USA
| | - Alexia S Miller
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD, 21205, USA
| | - Jelena Levitskaya
- The W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD, 21205, USA
| | - Jürgen Bosch
- Department of Biochemistry and Molecular Biology, Johns Hopkins School of Public Health and, Johns Hopkins Malaria Research Institute, 615 N. Wolfe Street, Baltimore, MD, 21205, USA.
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