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Palmucci JR, Sells BE, Giamberardino CD, Toffaletti DL, Dai B, Asfaw YG, Dubois LG, Li Z, Theriot B, Schell WA, Hope W, Tenor JL, Perfect JR. A ketogenic diet enhances fluconazole efficacy in murine models of systemic fungal infection. mBio 2024; 15:e0064924. [PMID: 38619236 PMCID: PMC11077957 DOI: 10.1128/mbio.00649-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Accepted: 03/21/2024] [Indexed: 04/16/2024] Open
Abstract
Invasive fungal infections are a significant public health concern, with mortality rates ranging from 20% to 85% despite current treatments. Therefore, we examined whether a ketogenic diet could serve as a successful treatment intervention in murine models of Cryptococcus neoformans and Candida albicans infection in combination with fluconazole-a low-cost, readily available antifungal therapy. The ketogenic diet is a high-fat, low-carbohydrate diet that promotes fatty acid oxidation as an alternative to glycolysis through the production of ketone bodies. In this series of experiments, mice fed a ketogenic diet prior to infection with C. neoformans and treated with fluconazole had a significant decrease in fungal burden in both the brain (mean 2.66 ± 0.289 log10 reduction) and lung (mean 1.72 ± 0.399 log10 reduction) compared to fluconazole treatment on a conventional diet. During C. albicans infection, kidney fungal burden of mice in the keto-fluconazole combination group was significantly decreased compared to fluconazole alone (2.37 ± 0.770 log10-reduction). Along with higher concentrations of fluconazole in the plasma and brain tissue, fluconazole efficacy was maximized at a significantly lower concentration on a keto diet compared to a conventional diet, indicating a dramatic effect on fluconazole pharmacodynamics. Our findings indicate that a ketogenic diet potentiates the effect of fluconazole at multiple body sites during both C. neoformans and C. albicans infection and could have practical and promising treatment implications.IMPORTANCEInvasive fungal infections cause over 2.5 million deaths per year around the world. Treatments for fungal infections are limited, and there is a significant need to develop strategies to enhance antifungal efficacy, combat antifungal resistance, and mitigate treatment side effects. We determined that a high-fat, low-carbohydrate ketogenic diet significantly potentiated the therapeutic effect of fluconazole, which resulted in a substantial decrease in tissue fungal burden of both C. neoformans and C. albicans in experimental animal models. We believe this work is the first of its kind to demonstrate that diet can dramatically influence the treatment of fungal infections. These results highlight a novel strategy of antifungal drug enhancement and emphasize the need for future investigation into dietary effects on antifungal drug activity.
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Affiliation(s)
- Julia R Palmucci
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - Blake E Sells
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Charles D Giamberardino
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - Dena L Toffaletti
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - Baodi Dai
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - Yohannes G Asfaw
- Department of Laboratory Animal Resources, Duke University Medical Center, Durham, North Carolina, USA
| | - Laura G Dubois
- Duke Proteomics and Metabolomics Core Facility, Duke University, Durham, North Carolina, USA
| | - Zhong Li
- Duke Proteomics and Metabolomics Core Facility, Duke University, Durham, North Carolina, USA
| | - Barbara Theriot
- Department of Pediatrics, Duke University School of Medicine, Durham, North Carolina, USA
| | - Wiley A Schell
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - William Hope
- Antimicrobial Pharmacodynamics and Therapeutics, University of Liverpool, Liverpool Health Partners, Liverpool, United Kingdom
| | - Jennifer L Tenor
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - John R Perfect
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
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2
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Messina JA, Giamberardino CD, Tenor JL, Toffaletti DL, Schell WA, Asfaw YG, Palmucci JR, Lionakis MS, Perfect JR. Susceptibility to Cryptococcus neoformans Infection with Bruton's Tyrosine Kinase Inhibition. Infect Immun 2023; 91:e0004223. [PMID: 37404186 PMCID: PMC10429641 DOI: 10.1128/iai.00042-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 05/01/2023] [Indexed: 07/06/2023] Open
Abstract
Patients receiving the Bruton's tyrosine kinase (BTK) inhibitor ibrutinib have an increased likelihood of fungal infections. The objectives of this study were to determine if Cryptococcus neoformans infection severity was isolate dependent with BTK inhibition and whether blocking BTK impacted infection severity in a mouse model. We compared four clinical isolates from patients on ibrutinib to virulent (H99) and avirulent (A1-35-8) reference strains. BTK knockout (KO) and wild-type (WT) C57 mice and WT CD1 mice were infected by intranasal (i.n.), oropharyngeal aspiration (OPA), and intravenous (i.v.) routes. Infection severity was assessed by survival and fungal burden (CFU per gram of tissue). Ibrutinib (25 mg/kg) or vehicle was administered daily through intraperitoneal injections. In the BTK KO model, no isolate-dependent effect on fungal burden was observed, and infection severity was not significantly different from that of the WT with i.n., OPA, and i.v. routes. Ibrutinib treatment did not impact infection severity. However, when the four clinical isolates were compared to H99, two of these isolates were less virulent, with significantly longer survival and reduced rates of brain infection. In conclusion, C. neoformans infection severity in the BTK KO model does not appear to be isolate dependent. BTK KO and ibrutinib treatment did not result in significantly different infection severities. However, based on repeated clinical observations of increased susceptibility to fungal infections with BTK inhibitor therapy, further work is needed to optimize a mouse model with BTK inhibition to better understand the role that this pathway plays in susceptibility to C. neoformans infection.
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Affiliation(s)
- Julia A. Messina
- Duke University School of Medicine, Department of Medicine, Division of Infectious Diseases, Durham, North Carolina, USA
| | - Charles D. Giamberardino
- Duke University School of Medicine, Department of Medicine, Division of Infectious Diseases, Durham, North Carolina, USA
| | - Jennifer L. Tenor
- Duke University School of Medicine, Department of Medicine, Division of Infectious Diseases, Durham, North Carolina, USA
| | - Dena L. Toffaletti
- Duke University School of Medicine, Department of Medicine, Division of Infectious Diseases, Durham, North Carolina, USA
| | - Wiley A. Schell
- Duke University School of Medicine, Department of Medicine, Division of Infectious Diseases, Durham, North Carolina, USA
| | - Yohannes G. Asfaw
- Duke University School of Medicine, Department of Medicine, Division of Infectious Diseases, Durham, North Carolina, USA
| | - Julia R. Palmucci
- Duke University School of Medicine, Department of Medicine, Division of Infectious Diseases, Durham, North Carolina, USA
| | - Michail S. Lionakis
- National Institutes of Health, Fungal Pathogenesis Section, Laboratory of Clinical Immunology and Microbiology, National Institutes of Allergy and Infectious Diseases, Bethesda, Maryland, USA
| | - John R. Perfect
- Duke University School of Medicine, Department of Medicine, Division of Infectious Diseases, Durham, North Carolina, USA
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3
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Shwab EK, Juvvadi PR, Shaheen SK, Allen J, Waitt G, Soderblom EJ, Asfaw YG, Moseley MA, Steinbach WJ. Protein Kinase A Regulates Autophagy-Associated Proteins Impacting Growth and Virulence of Aspergillus fumigatus. J Fungi (Basel) 2022; 8:jof8040354. [PMID: 35448585 PMCID: PMC9029100 DOI: 10.3390/jof8040354] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/14/2022] [Accepted: 03/28/2022] [Indexed: 01/07/2023] Open
Abstract
Cellular recycling via autophagy-associated proteins is a key catabolic pathway critical to invasive fungal pathogen growth and virulence in the nutrient-limited host environment. Protein kinase A (PKA) is vital for the growth and virulence of numerous fungal pathogens. However, the underlying basis for its regulation of pathogenesis remains poorly understood in any species. Our Aspergillus fumigatus PKA-dependent whole proteome and phosphoproteome studies employing advanced mass spectroscopic approaches identified numerous previously undefined PKA-regulated proteins in catabolic pathways. Here, we demonstrate reciprocal inhibition of autophagy and PKA activity, and identify 16 autophagy-associated proteins as likely novel PKA-regulated effectors. We characterize the novel PKA-phosphoregulated sorting nexin Atg20, and demonstrate its importance for growth, cell wall stress response, and virulence of A. fumigatus in a murine infection model. Additionally, we identify physical and functional interaction of Atg20 with previously characterized sorting nexin Atg24. Furthermore, we demonstrate the importance of additional uncharacterized PKA-regulated putative autophagy-associated proteins to hyphal growth. Our data presented here indicate that PKA regulates the autophagy pathway much more extensively than previously known, including targeting of novel effector proteins with fungal-specific functions important for invasive disease.
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Affiliation(s)
- E. Keats Shwab
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham, NC 27710, USA; (E.K.S.); (P.R.J.); (S.K.S.); (J.A.IV)
| | - Praveen R. Juvvadi
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham, NC 27710, USA; (E.K.S.); (P.R.J.); (S.K.S.); (J.A.IV)
| | - Shareef K. Shaheen
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham, NC 27710, USA; (E.K.S.); (P.R.J.); (S.K.S.); (J.A.IV)
| | - John Allen
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham, NC 27710, USA; (E.K.S.); (P.R.J.); (S.K.S.); (J.A.IV)
| | - Greg Waitt
- Duke Proteomics Core Facility, Institute for Genome Sciences and Policy, Duke University, Durham, NC 27701, USA; (G.W.); (E.J.S.); (M.A.M.)
| | - Erik J. Soderblom
- Duke Proteomics Core Facility, Institute for Genome Sciences and Policy, Duke University, Durham, NC 27701, USA; (G.W.); (E.J.S.); (M.A.M.)
| | - Yohannes G. Asfaw
- Department of Laboratory Animal Resources, Duke University Medical Center, Durham, NC 27710, USA;
| | - M. Arthur Moseley
- Duke Proteomics Core Facility, Institute for Genome Sciences and Policy, Duke University, Durham, NC 27701, USA; (G.W.); (E.J.S.); (M.A.M.)
| | - William J. Steinbach
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham, NC 27710, USA; (E.K.S.); (P.R.J.); (S.K.S.); (J.A.IV)
- Department of Molecular Genetics & Microbiology, Duke University Medical Center, Durham, NC 27710, USA
- Correspondence:
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4
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Steele JW, Bayliss S, Bayliss J, Lin YL, Wlodarczyk BJ, Cabrera RM, Asfaw YG, Cummings TJ, Finnell RH, George TM. Heritable spina bifida in sheep: A potential model for fetal repair of myelomeningocele. J Pediatr Surg 2020; 55:475-481. [PMID: 31301886 PMCID: PMC6935438 DOI: 10.1016/j.jpedsurg.2019.06.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 05/28/2019] [Accepted: 06/23/2019] [Indexed: 10/26/2022]
Abstract
BACKGROUND/PURPOSE In 2004, a heritable occurrence of spina bifida was reported in sheep on a farm in the United States. We maintained and characterized the spina bifida phenotype in this flock to assess its potential as an alternative surgical model. METHODS A breeding strategy was developed in which the sheep were crossed to maintain or increase the occurrence of spina bifida. Measurements and observations were recorded regarding lesion size, birthweight, ambulatory capacity, or urological function, and necropsies were performed on spina bifida afflicted lambs in conjunction with magnetic resonance imaging to determine the character of the spina bifida defects and assess the presence of Chiari-like malformations or hydrocephalus. RESULTS The defects were observed to be more prevalent in ram lambs, and the rate of spina bifida per litter could be increased through backcrossing or by selection of a productive ewe breed. The lambs displayed a range of ambulatory and urological deficits which could be used to evaluate new fetal repair methodologies. Finally, affected lambs were shown to demonstrate severe Chiari malformations and hydrocephalus. CONCLUSIONS We have determined that use of these sheep as a natural source for spina bifida fetuses is feasible and could supplement the deficits of current sheep models for myelomeningocele repair. LEVEL OF EVIDENCE Level IV.
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Affiliation(s)
- John W. Steele
- Center for Precision Environmental Health, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030,Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712
| | | | | | - Ying Linda Lin
- Center for Precision Environmental Health, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030.
| | - Bogdan J. Wlodarczyk
- Center for Precision Environmental Health, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030
| | - Robert M. Cabrera
- Center for Precision Environmental Health, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030
| | - Yohannes G. Asfaw
- Division of Laboratory Animal Resources, Duke University Medical Center, Durham, NC 27710
| | - Thomas J. Cummings
- Department of Pathology, Duke University Medical Center, Durham, NC 27710
| | - Richard H. Finnell
- Center for Precision Environmental Health, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030
| | - Timothy M. George
- Department of Neurosurgery/Pediatric Neurosurgery, Dell Medical School, Dell Children’s Medical Center, Austin, TX 78712
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5
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Foster MH, Ord JR, Zhao EJ, Birukova A, Fee L, Korte FM, Asfaw YG, Roggli VL, Ghio AJ, Tighe RM, Clark AG. Silica Exposure Differentially Modulates Autoimmunity in Lupus Strains and Autoantibody Transgenic Mice. Front Immunol 2019; 10:2336. [PMID: 31632407 PMCID: PMC6781616 DOI: 10.3389/fimmu.2019.02336] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Accepted: 09/16/2019] [Indexed: 11/13/2022] Open
Abstract
Inhalational exposure to crystalline silica is linked to several debilitating systemic autoimmune diseases characterized by a prominent humoral immune component, but the mechanisms by which silica induces autoantibodies is poorly understood. To better understand how silica lung exposure breaks B cell tolerance and unleashes autoreactive B cells, we exposed both wildtype mice of healthy C57BL/6 and lupus-prone BXSB, MRL, and NZB strains and mice carrying an autoantibody transgene on each of these backgrounds to instilled silica or vehicle and monitored lung injury, autoimmunity, and B cell fate. Silica exposure induced lung damage and pulmonary lymphoid aggregates in all strains, including in genetically diverse backgrounds and in autoantibody transgenic models. In wildtype mice strain differences were observed in specificity of autoantibodies and site of enhanced autoantibody production, consistent with genetic modulation of the autoimmune response to silica. The unique autoantibody transgene reporter system permitted the in vivo fate of autoreactive B cells and tolerance mechanisms to be tracked directly, and demonstrated the presence of transgenic B cells and antibody in pulmonary lymphoid aggregates and bronchoalveolar lavage fluid, respectively, as well as in spleen and serum. Nonetheless, B cell enumeration and transgenic antibody quantitation indicated that B cell deletion and anergy were intact in the different genetic backgrounds. Thus, silica exposure sufficient to induce substantial lung immunopathology did not overtly disrupt central B cell tolerance, even when superimposed on autoimmune genetic susceptibility. This suggests that silica exposure subverts tolerance at alternative checkpoints, such as regulatory cells or follicle entry, or requires additional interactions or co-exposures to induce loss of tolerance. This possibility is supported by results of differentiation assays that demonstrated transgenic autoantibodies in supernatants of Toll-like receptor (TLR)7/TLR9-stimulated splenocytes harvested from silica-exposed, but not vehicle-exposed, C57BL/6 mice. This suggests that lung injury induced by silica exposure has systemic effects that subtly alter autoreactive B cell regulation, possibly modulating B cell anergy, and that can be unmasked by superimposed exposure to TLR ligands or other immunostimulants.
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Affiliation(s)
- Mary H Foster
- Department of Medicine, Duke University Health System, Durham, NC, United States.,Durham VA Medical Center, Durham, NC, United States
| | - Jeffrey R Ord
- Department of Medicine, Duke University Health System, Durham, NC, United States
| | - Emma J Zhao
- Department of Medicine, Duke University Health System, Durham, NC, United States
| | - Anastasiya Birukova
- Department of Medicine, Duke University Health System, Durham, NC, United States
| | - Lanette Fee
- Department of Medicine, Duke University Health System, Durham, NC, United States.,Durham VA Medical Center, Durham, NC, United States
| | - Francesca M Korte
- Department of Medicine, Duke University Health System, Durham, NC, United States
| | - Yohannes G Asfaw
- Division of Laboratory Animal Resources, Duke University Medical Center, Durham, NC, United States
| | - Victor L Roggli
- Department of Pathology, Duke University Health System, Durham, NC, United States
| | - Andrew J Ghio
- National Health and Environmental Effects Research Laboratory, US Environmental Protection Agency, Chapel Hill, NC, United States
| | - Robert M Tighe
- Department of Medicine, Duke University Health System, Durham, NC, United States.,Durham VA Medical Center, Durham, NC, United States
| | - Amy G Clark
- Department of Medicine, Duke University Health System, Durham, NC, United States.,Durham VA Medical Center, Durham, NC, United States
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6
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Shwab EK, Juvvadi PR, Waitt G, Soderblom EJ, Barrington BC, Asfaw YG, Moseley MA, Steinbach WJ. Calcineurin-dependent dephosphorylation of the transcription factor CrzA at specific sites controls conidiation, stress tolerance, and virulence of Aspergillus fumigatus. Mol Microbiol 2019; 112:62-80. [PMID: 30927289 DOI: 10.1111/mmi.14254] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/24/2019] [Indexed: 12/15/2022]
Abstract
Calcium signaling through calcineurin and its major transcription factor (TF), CrzA, is integral to hyphal growth, stress response and virulence of the pathogenic fungus Aspergillus fumigatus, the leading etiology of invasive aspergillosis. Dephosphorylation of CrzA by calcineurin activates the TF, but the specific phosphorylation sites and their roles in the activation/inactivation mechanism are unknown. Mass spectroscopic analysis identified 20 phosphorylation sites, the majority of which were specific to filamentous fungi and distributed throughout the CrzA protein, with particular concentration in a serine-rich region N-terminal to the conserved DNA-binding domain (DBD). Site-directed mutagenesis of phosphorylated residues revealed that CrzA activity during calcium stimulation can only be suppressed by a high degree of phosphorylation in multiple regions of the protein. Our findings further suggest that this regulation is not solely accomplished through control of CrzA nuclear import. Additionally, we demonstrate the importance of the CrzA phosphorylation state in regulating growth, conidiation, calcium and cell wall stress tolerance, and virulence. Finally, we identify two previously undescribed nuclear localization sequences in the DBD. These findings provide novel insight into the phosphoregulation of CrzA which may be exploited to selectively target A. fumigatus.
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Affiliation(s)
- E Keats Shwab
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Duke University Medical Center, Durham, NC, USA
| | - Praveen R Juvvadi
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Duke University Medical Center, Durham, NC, USA
| | - Greg Waitt
- Duke Proteomics and Metabolomics Core Facility, Center for Genomic and Computational Biology, Duke University, Durham, NC, USA
| | - Erik J Soderblom
- Duke Proteomics and Metabolomics Core Facility, Center for Genomic and Computational Biology, Duke University, Durham, NC, USA
| | - Blake C Barrington
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Duke University Medical Center, Durham, NC, USA
| | - Yohannes G Asfaw
- Department of Laboratory Animal Resources, Duke University Medical Center, Durham, NC, USA
| | - M Arthur Moseley
- Duke Proteomics and Metabolomics Core Facility, Center for Genomic and Computational Biology, Duke University, Durham, NC, USA
| | - William J Steinbach
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Duke University Medical Center, Durham, NC, USA.,Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA
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7
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Asfaw YG, Reynolds R, Alderman S, Norton JN. Managing Research Animal Specimens and Laboratory Safety. ILAR J 2018; 59:144-149. [PMID: 30590683 DOI: 10.1093/ilar/ily017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 09/18/2018] [Indexed: 11/13/2022] Open
Abstract
The procedures necessary to perform testing in a veterinary diagnostic laboratory have inherent associated risks to personnel in regard to exposure to infectious agents. In research institutions animals can be experimentally infected, acquire naturally occurring infections and can also be exposed to other hazards such as toxic chemicals or radiologic entities. A critical component of the use of animals in a research environment is the collaboration between the responsible researcher and the veterinary diagnostic laboratory with the institutional health and safety professionals to ensure that the proper engineering controls, personal protective equipment, laboratory procedures and training are in place for personnel working with the animals or their specimens. Unlike the typical researcher, the veterinary diagnostic laboratory generally has to be equipped to safely process and work with a wide range of potential hazards where the communication of pertinent information from the researcher to the diagnostic laboratory regarding the identity of the potential hazard is paramount. Diagnostic laboratory design, safety equipment, personal protective equipment, laboratory procedures, occupational health program and personnel training must be sufficient to address hazards based on a risk assessment performed in conjunction with safety professionals. This article will summarize safety considerations with the various areas of concern in the operation of a diagnostic laboratory for research animal specimens.
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Affiliation(s)
- Yohannes G Asfaw
- Duke University Medical Center, Division of Laboratory Animal Resources, Durham, North Carolina
| | - Randall Reynolds
- Division of Laboratory Animal Resources, Duke University, Durham, North Carolina
| | - Scott Alderman
- Duke Human Vaccine Institute, and Duke Infectious Disease Response Training, Duke University, Durham, North Carolina
| | - John N Norton
- Division of Laboratory Animal Resources, Duke University, Durham, North Carolina
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8
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Brooks ED, Landau DJ, Everitt JI, Brown TT, Grady KM, Waskowicz L, Bass CR, D'Angelo J, Asfaw YG, Williams K, Kishnani PS, Koeberl DD. Long-term complications of glycogen storage disease type Ia in the canine model treated with gene replacement therapy. J Inherit Metab Dis 2018; 41:965-976. [PMID: 30043186 PMCID: PMC6328337 DOI: 10.1007/s10545-018-0223-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 06/09/2018] [Accepted: 06/19/2018] [Indexed: 12/28/2022]
Abstract
BACKGROUND Glycogen storage disease type Ia (GSD Ia) in dogs closely resembles human GSD Ia. Untreated patients with GSD Ia develop complications associated with glucose-6-phosphatase (G6Pase) deficiency. Survival of human patients on intensive nutritional management has improved; however, long-term complications persist including renal failure, nephrolithiasis, hepatocellular adenomas (HCA), and a high risk for hepatocellular carcinoma (HCC). Affected dogs fail to thrive with dietary therapy alone. Treatment with gene replacement therapy using adeno-associated viral vectors (AAV) expressing G6Pase has greatly prolonged life and prevented hypoglycemia in affected dogs. However, long-term complications have not been described to date. METHODS Five GSD Ia-affected dogs treated with AAV-G6Pase were evaluated. Dogs were euthanized due to reaching humane endpoints related to liver and/or kidney involvement, at 4 to 8 years of life. Necropsies were performed and tissues were analyzed. RESULTS Four dogs had liver tumors consistent with HCA and HCC. Three dogs developed renal failure, but all dogs exhibited progressive kidney disease histologically. Urolithiasis was detected in two dogs; uroliths were composed of calcium oxalate and calcium phosphate. One affected and one carrier dog had polycystic ovarian disease. Bone mineral density was not significantly affected. CONCLUSIONS Here, we show that the canine GSD Ia model demonstrates similar long-term complications as GSD Ia patients in spite of gene replacement therapy. Further development of gene therapy is needed to develop a more effective treatment to prevent long-term complications of GSD Ia.
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Affiliation(s)
- Elizabeth D Brooks
- Division of Medical Genetics, Duke University Medical Center (DUMC), Box 103856, Durham, NC, 27710, USA
- Division of Laboratory Animal Resources, Duke University Medical Center, Durham, NC, USA
| | - Dustin J Landau
- Division of Medical Genetics, Duke University Medical Center (DUMC), Box 103856, Durham, NC, 27710, USA
| | - Jeffrey I Everitt
- Department of Pathology, Duke University Medical Center, Durham, NC, USA
| | - Talmage T Brown
- College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Kylie M Grady
- Division of Medical Genetics, Duke University Medical Center (DUMC), Box 103856, Durham, NC, 27710, USA
| | - Lauren Waskowicz
- Division of Medical Genetics, Duke University Medical Center (DUMC), Box 103856, Durham, NC, 27710, USA
| | - Cameron R Bass
- Department of Biomedical Engineering, Duke University Medical Center, Durham, NC, USA
| | - John D'Angelo
- Department of Biomedical Engineering, Duke University Medical Center, Durham, NC, USA
| | - Yohannes G Asfaw
- Division of Laboratory Animal Resources, Duke University Medical Center, Durham, NC, USA
| | - Kyha Williams
- Division of Laboratory Animal Resources, Duke University Medical Center, Durham, NC, USA
| | - Priya S Kishnani
- Division of Medical Genetics, Duke University Medical Center (DUMC), Box 103856, Durham, NC, 27710, USA
| | - Dwight D Koeberl
- Division of Medical Genetics, Duke University Medical Center (DUMC), Box 103856, Durham, NC, 27710, USA.
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9
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Clark A, Zhao EJ, Birukova A, Buckley ES, Ord JR, Asfaw YG, Tighe RM, Foster MH. Inhaled silica induces autoimmunity in a strain-dependent manner. The Journal of Immunology 2017. [DOI: 10.4049/jimmunol.198.supp.58.13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Abstract
Background
Respiratory exposure to crystalline silica in man is associated with autoimmunity that includes a prominent humoral component. We hypothesize that autoimmune B cell recruitment and regulation are altered in silica-exposed lungs in genetically susceptible individuals.
Methods
Wildtype and autoAb transgenic (Tg+) mice of B6 and lupus-prone NZB, MRL, and BXSB backgrounds were exposed to silica dust or vehicle by oropharyngeal aspiration. After 1–3 months, lung pathology and lymphocytic infiltrates were scored. Lupus and vasculitis autoAb levels were measured in bronchoalveolar lavage fluid (BALF), serum, and supernatants from cultured lung and spleen cells.
Results
All silica-exposed strains showed extensive lung pathology and focal B and T cell infiltrates consistent with ectopic lymphoid structures (ELS). In wildtype mice, % lung area containing ELS after silica exposure varied by strain (BXSB>MRL>B6>NZB, p=0.03). Significant increases in autoAb production with silica exposure were observed in BALF, lung cell supernatants, and serum, and varied by genetic background. Among Tg+ mice, Tg+ Ig levels in BALF were higher in silica- vs vehicle-exposed mice in B6 and BXSB strains (p<0.05).
Conclusions
Respiratory exposure to silica leads to pulmonary B and T cell accumulation with ELS formation and enhanced autoAb production. This occurs in a strain-dependent manner, highlighting the impact of genetic influences on silica-induced autoimmunity. Evidence of local autoAb secretion implicates dysregulated control of autoreactive B cells at the environment/lung interface, possibly through the intermediary of silica-induced ELS.
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Affiliation(s)
- Amy Clark
- 1Duke Univ. Med. Ctr
- 2Durham VA Medical Center
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Brooks ED, Landau DJ, Brown TT, Asfaw YG, Koeberl DD. 701. Long-Term Complications of Glycogen Storage Disease Type IA in the Dog Model Treated With Gene Replacement Therapy. Mol Ther 2015. [DOI: 10.1016/s1525-0016(16)34310-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Lamoth F, Juvvadi PR, Gehrke C, Asfaw YG, Steinbach WJ. Transcriptional activation of heat shock protein 90 mediated via a proximal promoter region as trigger of caspofungin resistance in Aspergillus fumigatus. J Infect Dis 2013; 209:473-81. [PMID: 24096332 DOI: 10.1093/infdis/jit530] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Invasive aspergillosis is a deadly infection for which new antifungal therapies are needed. Heat shock protein 90 (Hsp90) is an essential chaperone in Aspergillus fumigatus representing an attractive antifungal target. Using a thiamine-repressible promoter (pthiA), we showed that genetic repression of Hsp90 significantly reduced virulence in a murine model of invasive aspergillosis. Moreover, substituting the A. fumigatus hsp90 promoter with 2 artificial promoters (potef, pthiA) and the Candida albicans hsp90 promoter resulted in hypersensitivity to caspofungin and abolition of the paradoxical effect (resistance at high caspofungin concentrations). By inducing truncations in the hsp90 promoter, we identified a 100-base pair proximal sequence that triggers a significant increase of hsp90 expression (≥1.5-fold) and is essential for the paradoxical effect. Preventing this increase of hsp90 expression was sufficient to abolish the paradoxical effect and therefore optimize the antifungal activity of caspofungin.
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Affiliation(s)
- Frédéric Lamoth
- Division of Pediatric Infectious Diseases, Department of Pediatrics
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Juvvadi PR, Gehrke C, Fortwendel JR, Lamoth F, Soderblom EJ, Cook EC, Hast MA, Asfaw YG, Moseley MA, Creamer TP, Steinbach WJ. Phosphorylation of Calcineurin at a novel serine-proline rich region orchestrates hyphal growth and virulence in Aspergillus fumigatus. PLoS Pathog 2013; 9:e1003564. [PMID: 23990785 PMCID: PMC3749960 DOI: 10.1371/journal.ppat.1003564] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 07/02/2013] [Indexed: 12/26/2022] Open
Abstract
The fungus Aspergillus fumigatus is a leading infectious killer in immunocompromised patients. Calcineurin, a calmodulin (CaM)-dependent protein phosphatase comprised of calcineurin A (CnaA) and calcineurin B (CnaB) subunits, localizes at the hyphal tips and septa to direct A. fumigatus invasion and virulence. Here we identified a novel serine-proline rich region (SPRR) located between two conserved CnaA domains, the CnaB-binding helix and the CaM-binding domain, that is evolutionarily conserved and unique to filamentous fungi and also completely absent in human calcineurin. Phosphopeptide enrichment and tandem mass spectrometry revealed the phosphorylation of A. fumigatus CnaA in vivo at four clustered serine residues (S406, S408, S410 and S413) in the SPRR. Mutation of the SPRR serine residues to block phosphorylation led to significant hyphal growth and virulence defects, indicating the requirement of calcineurin phosphorylation at the SPRR for its activity and function. Complementation analyses of the A. fumigatus ΔcnaA strain with cnaA homologs from the pathogenic basidiomycete Cryptococcus neoformans, the pathogenic zygomycete Mucor circinelloides, the closely related filamentous fungi Neurospora crassa, and the plant pathogen Magnaporthe grisea, revealed filamentous fungal-specific phosphorylation of CnaA in the SPRR and SPRR homology-dependent restoration of hyphal growth. Surprisingly, circular dichroism studies revealed that, despite proximity to the CaM-binding domain of CnaA, phosphorylation of the SPRR does not alter protein folding following CaM binding. Furthermore, mutational analyses in the catalytic domain, CnaB-binding helix, and the CaM-binding domains revealed that while the conserved PxIxIT substrate binding motif in CnaA is indispensable for septal localization, CaM is required for its function at the hyphal septum but not for septal localization. We defined an evolutionarily conserved novel mode of calcineurin regulation by phosphorylation in filamentous fungi in a region absent in humans. These findings suggest the possibility of harnessing this unique SPRR for innovative antifungal drug design to combat invasive aspergillosis.
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Affiliation(s)
- Praveen R. Juvvadi
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Christopher Gehrke
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Jarrod R. Fortwendel
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Frédéric Lamoth
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Erik J. Soderblom
- Duke Proteomics Facility, Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina, United States of America
| | - Erik C. Cook
- Department of Molecular and Cellular Biochemistry and Center for Structural Biology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Michael A. Hast
- Department of Biochemistry, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Yohannes G. Asfaw
- Division of Laboratory Animal Resources, Duke University Medical Center, Durham, North Carolina, United States of America
| | - M. Arthur Moseley
- Duke Proteomics Facility, Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina, United States of America
| | - Trevor P. Creamer
- Department of Molecular and Cellular Biochemistry and Center for Structural Biology, University of Kentucky, Lexington, Kentucky, United States of America
| | - William J. Steinbach
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
- * E-mail:
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Asfaw YG, Sun FJ. Presumed mycobacteriosis in laboratory zebra finch (Taeniopygia guttata). J Am Assoc Lab Anim Sci 2010; 49:644-646. [PMID: 20858369 PMCID: PMC2949437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 10/22/2009] [Revised: 11/17/2009] [Accepted: 04/05/2010] [Indexed: 05/29/2023]
Abstract
Husbandry staff noticed a research-naïve, young-adult, female finch tossing its head back intermittently. A second finch exhibiting similar signs was reported a few days later. Postmortem necropsy and histopathology with hematoxylin and eosin and acid-fast staining on the first finch revealed the presence of acid-fast organisms in several organs. After presumptive diagnosis of mycobacteriosis, all remaining finches housed in the same room as the first underwent necropsy and histology. Three additional finches were positive for Mycobacterium-like acid-fast organisms. Incidental findings of megabacteriosis were noted histopathologically on 2 other finches.
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Affiliation(s)
- Yohannes G Asfaw
- Division of Laboratory Animal Resources, Duke University Medical Center, Durham, North Carolina, USA.
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Cramer RA, Perfect BZ, Pinchai N, Park S, Perlin DS, Asfaw YG, Heitman J, Perfect JR, Steinbach WJ. Calcineurin target CrzA regulates conidial germination, hyphal growth, and pathogenesis of Aspergillus fumigatus. Eukaryot Cell 2008; 7:1085-97. [PMID: 18456861 PMCID: PMC2446674 DOI: 10.1128/ec.00086-08] [Citation(s) in RCA: 135] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2008] [Accepted: 04/17/2008] [Indexed: 11/20/2022]
Abstract
The calcineurin pathway is a critical signal transduction pathway in fungi that mediates growth, morphology, stress responses, and pathogenicity. The importance of the calcineurin pathway in fungal physiology creates an opportunity for the development of new antifungal therapies that target this critical signaling pathway. In this study, we examined the role of the zinc finger transcription factor Crz1 homolog (CrzA) in the physiology and pathogenicity of the opportunistic human fungal pathogen Aspergillus fumigatus. Genetic replacement of the crzA locus in A. fumigatus resulted in a strain with significant defects in conidial germination, polarized hyphal growth, cell wall structure, and asexual development that are similar to but with differences from defects seen in the A. fumigatus DeltacnaA (calcineurin A) strain. Like the DeltacnaA strain, the DeltacrzA strain was incapable of causing disease in an experimental persistently neutropenic inhalational murine model of invasive pulmonary aspergillosis. Our results suggest that CrzA is an important downstream effector of calcineurin that controls morphology in A. fumigatus, but additional downstream effectors that mediate calcineurin signal transduction are likely present in this opportunistic fungal pathogen. In addition, the importance of CrzA to the production of disease is critical, and thus CrzA is an attractive fungus-specific antifungal target for the treatment of invasive aspergillosis.
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Affiliation(s)
- Robert A Cramer
- Duke University Medical Center, Box 3499, Pediatric Infectious Diseases, Durham, NC 27710, USA
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George TM, Asfaw YG, Cummings TJ. A Relevant Animal Model of Human Neural Tube Defects, Implications for Fetal Surgery. Neurosurgery 2007. [DOI: 10.1227/01.neu.0000279932.95869.a2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Steinbach WJ, Cramer RA, Perfect BZ, Asfaw YG, Sauer TC, Najvar LK, Kirkpatrick WR, Patterson TF, Benjamin DK, Heitman J, Perfect JR. Calcineurin controls growth, morphology, and pathogenicity in Aspergillus fumigatus. Eukaryot Cell 2006; 5:1091-103. [PMID: 16835453 PMCID: PMC1489296 DOI: 10.1128/ec.00139-06] [Citation(s) in RCA: 228] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Calcineurin is implicated in a myriad of human diseases as well as homeostasis and virulence in several major human pathogenic microorganisms. The fungus Aspergillus fumigatus is a leading cause of infectious death in the rapidly expanding immunocompromised patient population. Current antifungal treatments for invasive aspergillosis are often ineffective, and novel therapeutic approaches are urgently needed. We demonstrate that a mutant of A. fumigatus lacking the calcineurin A (cnaA) catalytic subunit exhibited defective hyphal morphology related to apical extension and polarized growth, which resulted in drastically decreased filamentation. The delta cnaA mutant lacked the extensive lattice of invading hyphae seen with the wild-type and complemented strains. Sporulation was also affected in the delta cnaA mutant, including morphological conidial defects with the absence of surface rodlets and the added presence of disjunctors creating long conidial chains. Infection with the delta cnaA mutant in several distinct animal models with different types of immunosuppression and inoculum delivery led to a profound attenuation of pathogenicity compared to infection with the wild-type and complemented strains. Lung tissue from animals infected with the delta cnaA mutant showed a complete absence of hyphae, in contrast to tissue from animals infected with the wild-type and complemented strains. Quantitative fungal burden and pulmonary infarct scoring confirmed these findings. Our results support the clinical observation that substantially decreasing fungal growth can prevent disease establishment and decrease mortality. Our findings reveal that calcineurin appears to play a globally conserved role in the virulence of several pathogenic fungi and yet plays specialized roles in each and can be an excellent target for therapeutic intervention.
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Affiliation(s)
- William J Steinbach
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Box 3499, Duke University Medical Center, Durham, North Carolina 27710, USA.
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