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Vanhoffelen E, Vermoesen L, Michiels L, Lagrou K, Reséndiz-Sharpe A, Vande Velde G. Sensitive bioluminescence imaging of cryptococcosis in Galleria mellonella improves antifungal screening under in vivo conditions. Virulence 2024; 15:2327883. [PMID: 38465639 PMCID: PMC10939141 DOI: 10.1080/21505594.2024.2327883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 02/28/2024] [Indexed: 03/12/2024] Open
Abstract
Cryptococcus neoformans is an environmental yeast that primarily affects immunocompromised individuals, causing respiratory infections and life-threatening meningoencephalitis. Treatment is complicated by limited antifungal options, with concerns such as adverse effects, dose-limiting toxicity, blood-brain barrier permeability, and resistance development, emphasizing the critical need to optimize and expand current treatment options against invasive cryptococcosis. Galleria mellonella larvae have been introduced as an ethical intermediate for in vivo testing, bridging the gap between in vitro antifungal screening and mouse studies. However, current infection readouts in G. mellonella are indirect, insensitive, or invasive, which hampers the full potential of the model. To address the absence of a reliable non-invasive method for tracking infection, we longitudinally quantified the cryptococcal burden in G. mellonella using bioluminescence imaging (BLI). After infection with firefly luciferase-expressing C. neoformans, the resulting bioluminescence signal was quantitatively validated using colony-forming unit analysis. Longitudinal comparison of BLI to health and survival analysis revealed increased sensitivity of BLI in discriminating cryptococcal burden during early infection. Furthermore, BLI improved the detection of treatment efficacy using first-line antifungals, thereby benchmarking this model for antifungal testing. In conclusion, we introduced BLI as a real-time, quantitative readout of cryptococcal burden in G. mellonella over time, enabling more sensitive and reliable antifungal screening.
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Affiliation(s)
- Eliane Vanhoffelen
- Department of Imaging and Pathology, Biomedical MRI unit/MoSAIC, KULeuven, Leuven, Belgium
| | - Lori Vermoesen
- Department of Imaging and Pathology, Biomedical MRI unit/MoSAIC, KULeuven, Leuven, Belgium
| | - Lauren Michiels
- Department of Imaging and Pathology, Biomedical MRI unit/MoSAIC, KULeuven, Leuven, Belgium
| | - Katrien Lagrou
- Department of Microbiology, Immunology and Transplantation, Laboratory of Clinical Microbiology, KULeuven, Leuven, Belgium
- Department of Laboratory Medicine, National Reference Center for Mycosis, University Hospitals Leuven, Leuven, Belgium
| | | | - Greetje Vande Velde
- Department of Imaging and Pathology, Biomedical MRI unit/MoSAIC, KULeuven, Leuven, Belgium
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2
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Mucorales and Mucormycosis: Recent Insights and Future Prospects. J Fungi (Basel) 2023; 9:jof9030335. [PMID: 36983503 PMCID: PMC10058716 DOI: 10.3390/jof9030335] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/28/2023] [Accepted: 03/04/2023] [Indexed: 03/11/2023] Open
Abstract
The classification of Mucorales encompasses a collection of basal fungi that have traditionally demonstrated an aversion to modern genetic manipulation techniques. This aversion led to a scarcity of knowledge regarding their biology compared to other fungal groups. However, the emergence of mucormycosis, a fungal disease caused by Mucorales, has attracted the attention of the clinical field, mainly because available therapies are ineffective for decreasing the fatal outcome associated with the disease. This revitalized curiosity about Mucorales and mucormycosis, also encouraged by the recent COVID-19 pandemic, has spurred a significant and productive effort to uncover their mysteries in recent years. Here, we elaborate on the most remarkable breakthroughs related to the recently discovered genetic advances in Mucorales and mucormycosis. The utilization of a few genetic study models has enabled the identification of virulence factors in Mucorales that were previously described in other pathogens. More notably, recent investigations have identified novel genes and mechanisms controlling the pathogenic potential of Mucorales and their interactions with the host, providing fresh avenues to devise new strategies against mucormycosis. Finally, new study models are allowing virulence studies that were previously hampered in Mucorales, predicting a prolific future for the field.
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3
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Resendiz-Sharpe A, Vanhoffelen E, Velde GV. Bioluminescence Imaging, a Powerful Tool to Assess Fungal Burden in Live Mouse Models of Infection. Methods Mol Biol 2023; 2667:197-210. [PMID: 37145286 DOI: 10.1007/978-1-0716-3199-7_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Aspergillus fumigatus and Cryptococcus neoformans species infections are two of the most common life-threatening fungal infections in the immunocompromised population. Acute invasive pulmonary aspergillosis (IPA) and meningeal cryptococcosis are the most severe forms affecting patients with elevated associated mortality rates despite current treatments. As many unanswered questions remain concerning these fungal infections, additional research is greatly needed not only in clinical scenarios but also under controlled preclinical experimental settings to increase our understanding concerning their virulence, host-pathogen interactions, infection development, and treatments. Preclinical animal models are powerful tools to gain more insight into some of these needs. However, assessment of disease severity and fungal burden in mouse models of infection are often limited to less sensitive, single-time, invasive, and variability-prone techniques such as colony-forming unit counting. These issues can be overcome by in vivo bioluminescence imaging (BLI). BLI is a noninvasive tool that provides longitudinal dynamic visual and quantitative information on the fungal burden from the onset of infection and potential dissemination to different organs throughout the development of disease in individual animals. Hereby, we describe an entire experimental pipeline from mouse infection to BLI acquisition and quantification, readily available to researchers to provide a noninvasive, longitudinal readout of fungal burden and dissemination throughout the course of infection development, which can be applied for preclinical studies into pathophysiology and treatment of IPA and cryptococcosis in vivo.
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Affiliation(s)
| | - Eliane Vanhoffelen
- KU Leuven, Department of Imaging and Pathology, Biomedical MRI / MoSAIC, Leuven, Belgium
| | - Greetje Vande Velde
- KU Leuven, Department of Imaging and Pathology, Biomedical MRI / MoSAIC, Leuven, Belgium.
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4
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Genetic Manipulation in Mucorales and New Developments to Study Mucormycosis. Int J Mol Sci 2022; 23:ijms23073454. [PMID: 35408814 PMCID: PMC8998210 DOI: 10.3390/ijms23073454] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 03/16/2022] [Accepted: 03/18/2022] [Indexed: 12/04/2022] Open
Abstract
The study of the Mucoralean fungi physiology is a neglected field that the lack of effective genetic tools has hampered in the past. However, the emerging fungal infection caused by these fungi, known as mucormycosis, has prompted many researchers to study the pathogenic potential of Mucorales. The main reasons for this current attraction to study mucormycosis are its high lethality, the lack of effective antifungal drugs, and its recent increased incidence. The most contemporary example of the emergence character of mucormycosis is the epidemics declared in several Asian countries as a direct consequence of the COVID-19 pandemic. Fortunately, this pressure to understand mucormycosis and develop new treatment strategies has encouraged the blossoming of new genetic techniques and methodologies. This review describes the history of genetic manipulation in Mucorales, highlighting the development of methods and how they allowed the main genetic studies in these fungi. Moreover, we have emphasized the recent development of new genetic models to study mucormycosis, a landmark in the field that will configure future research related to this disease.
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5
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Resendiz-Sharpe A, da Silva RP, Geib E, Vanderbeke L, Seldeslachts L, Hupko C, Brock M, Lagrou K, Vande Velde G. Longitudinal multimodal imaging-compatible mouse model of triazole-sensitive and -resistant invasive pulmonary aspergillosis. Dis Model Mech 2022; 15:274857. [PMID: 35352801 PMCID: PMC8990085 DOI: 10.1242/dmm.049165] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Accepted: 01/09/2022] [Indexed: 12/18/2022] Open
Abstract
Invasive pulmonary aspergillosis (IPA) caused by the mold Aspergillus fumigatus is one of the most important life-threatening infections in immunocompromised patients. The alarming increase of isolates resistant to the first-line recommended antifungal therapy urges more insights into triazole-resistant A. fumigatus infections. In this study, we systematically optimized a longitudinal multimodal imaging-compatible neutropenic mouse model of IPA. Reproducible rates of pulmonary infection were achieved through immunosuppression (sustained neutropenia) with 150 mg/kg cyclophosphamide at day −4, −1 and 2, and an orotracheal inoculation route in both sexes. Furthermore, increased sensitivity of in vivo bioluminescence imaging for fungal burden detection, as early as the day after infection, was achieved by optimizing luciferin dosing and through engineering isogenic red-shifted bioluminescent A. fumigatus strains, one wild type and two triazole-resistant mutants. We successfully tested appropriate and inappropriate antifungal treatment scenarios in vivo with our optimized multimodal imaging strategy, according to the in vitro susceptibility of our luminescent fungal strains. Therefore, we provide novel essential mouse models with sensitive imaging tools for investigating IPA development and therapy in triazole-susceptible and triazole-resistant scenarios. Summary: A novel reproducible longitudinal multimodal imaging-compatible neutropenic mouse model of invasive pulmonary aspergillosis provides increased early fungal detection through novel red-shifted luciferase-expressing triazole-susceptible and -resistant Aspergillus fumigatus strains, and boosted bioluminescence.
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Affiliation(s)
- Agustin Resendiz-Sharpe
- Laboratory of Clinical Microbiology, Department of Microbiology, Immunology and Transplantation, Katholieke Universiteit (KU) Leuven, 3000 Leuven, Belgium
| | - Roberta Peres da Silva
- Fungal Biology Group, School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Elena Geib
- Fungal Biology Group, School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Lore Vanderbeke
- Laboratory of Clinical Microbiology, Department of Microbiology, Immunology and Transplantation, Katholieke Universiteit (KU) Leuven, 3000 Leuven, Belgium
| | - Laura Seldeslachts
- Department of Imaging and Pathology, Biomedical MRI unit/MoSAIC, KU Leuven, 3000 Leuven, Belgium
| | - Charlien Hupko
- Laboratory of Clinical Microbiology, Department of Microbiology, Immunology and Transplantation, Katholieke Universiteit (KU) Leuven, 3000 Leuven, Belgium
| | - Matthias Brock
- Fungal Biology Group, School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Katrien Lagrou
- Laboratory of Clinical Microbiology, Department of Microbiology, Immunology and Transplantation, Katholieke Universiteit (KU) Leuven, 3000 Leuven, Belgium.,Department of Laboratory Medicine and National Reference Centre for Mycosis, Excellence Centre for Medical Mycology (ECMM), University Hospitals Leuven, 3000 Leuven, Belgium
| | - Greetje Vande Velde
- Department of Imaging and Pathology, Biomedical MRI unit/MoSAIC, KU Leuven, 3000 Leuven, Belgium
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Garre V. Recent Advances and Future Directions in the Understanding of Mucormycosis. Front Cell Infect Microbiol 2022; 12:850581. [PMID: 35281441 PMCID: PMC8907824 DOI: 10.3389/fcimb.2022.850581] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 02/04/2022] [Indexed: 11/13/2022] Open
Abstract
Mucormycosis is an emerging infection caused by fungi of the order Mucorales that has recently gained public relevance due to the high incidence among COVID-19 patients in some countries. The reduced knowledge about Mucorales pathogenesis is due, in large part, to the historically low interest for these fungi fostered by their reluctance to be genetically manipulated. The recent introduction of more tractable genetic models together with an increasing number of available whole genome sequences and genomic analyses have improved our understanding of Mucorales biology and mucormycosis in the last ten years. This review summarizes the most significant advances in diagnosis, understanding of the innate and acquired resistance to antifungals, identification of new virulence factors and molecular mechanisms involved in the infection. The increased awareness about the disease and the recent successful genetic manipulation of previous intractable fungal models using CRISPR-Cas9 technology are expected to fuel the characterization of Mucorales pathogenesis, facilitating the development of effective treatments to fight this deadly infection.
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7
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Lax C, Navarro-Mendoza MI, Pérez-Arques C, Navarro E, Nicolás FE, Garre V. Stable and reproducible homologous recombination enables CRISPR-based engineering in the fungus Rhizopus microsporus. CELL REPORTS METHODS 2021; 1:100124. [PMID: 35475217 PMCID: PMC9017206 DOI: 10.1016/j.crmeth.2021.100124] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 09/20/2021] [Accepted: 11/09/2021] [Indexed: 04/22/2023]
Abstract
Mucormycosis is a lethal and emerging disease that has lacked a genetic model fulfilling both high virulence and the possibility of performing stable and reproducible gene manipulation by homologous recombination (HR). Here, we developed a new methodology to successfully perform HR in Rhizopus microsporus. We isolated an uracil auxotrophic recipient strain and optimized the critical steps in the genetic transformation of this fungus. This was followed by an adaptation of a plasmid-free CRISPR-Cas9 system coupled with microhomology repair templates. We reproducibly generated stable mutants in the genes leuA and crgA, encoding a 3-isopropylmalate dehydratase and an ubiquitin ligase, respectively. Our new genetic model showed that mutations in the gene pyrF, a key virulence gene in several bacterial and fungal pathogens, correlated with an avirulent phenotype in an immunocompetent murine host. This was reverted by gene complementation, showing the broad possibilities of our methodology.
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Affiliation(s)
- Carlos Lax
- Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, 30100 Murcia, Spain
| | | | - Carlos Pérez-Arques
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Eusebio Navarro
- Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, 30100 Murcia, Spain
| | - Francisco Esteban Nicolás
- Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, 30100 Murcia, Spain
| | - Victoriano Garre
- Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, 30100 Murcia, Spain
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8
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Naz T, Yang J, Nosheen S, Sun C, Nazir Y, Mohamed H, Fazili ABA, Ullah S, Li S, Yang W, Garre V, Song Y. Genetic Modification of Mucor circinelloides for Canthaxanthin Production by Heterologous Expression of β-carotene Ketolase Gene. Front Nutr 2021; 8:756218. [PMID: 34722614 PMCID: PMC8548569 DOI: 10.3389/fnut.2021.756218] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 09/06/2021] [Indexed: 12/21/2022] Open
Abstract
Canthaxanthin is a reddish-orange xanthophyll with strong antioxidant activity and higher bioavailability than carotenes, primarily used in food, cosmetics, aquaculture, and pharmaceutical industries. The spiking market for natural canthaxanthin promoted researchers toward genetic engineering of heterologous hosts for canthaxanthin production. Mucor circinelloides is a dimorphic fungus that produces β-carotene as the major carotenoid and is considered as a model organism for carotenogenic studies. In this study, canthaxanthin-producing M. circinelloides strain was developed by integrating the codon-optimized β-carotene ketolase gene (bkt) of the Haematococcus pluvialis into the genome of the fungus under the control of strong promoter zrt1. First, a basic plasmid was constructed to disrupt crgA gene, a negative regulator of carotene biosynthesis resulted in substantial β-carotene production, which served as the building block for canthaxanthin by further enzymatic reaction of the ketolase enzyme. The genetically engineered strain produced a significant amount (576 ± 28 μg/g) of canthaxanthin, which is the highest amount reported in Mucor to date. Moreover, the cell dry weight of the recombinant strain was also determined, producing up to more than 9.0 g/L, after 96 h. The mRNA expression level of bkt in the overexpressing strain was analyzed by RT-qPCR, which increased by 5.3-, 4.1-, and 3-folds at 24, 48, and 72 h, respectively, compared with the control strain. The canthaxanthin-producing M. circinelloides strain obtained in this study provided a basis for further improving the biotechnological production of canthaxanthin and suggested a useful approach for the construction of more valuable carotenoids, such as astaxanthin.
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Affiliation(s)
- Tahira Naz
- Colin Ratledge Center for Microbial Lipids, School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, China
| | - Junhuan Yang
- Colin Ratledge Center for Microbial Lipids, School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, China
| | - Shaista Nosheen
- Colin Ratledge Center for Microbial Lipids, School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, China
| | - Caili Sun
- Colin Ratledge Center for Microbial Lipids, School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, China
| | - Yusuf Nazir
- Colin Ratledge Center for Microbial Lipids, School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, China.,Department of Food Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Malaysia
| | - Hassan Mohamed
- Colin Ratledge Center for Microbial Lipids, School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, China.,Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, Assiut, Egypt
| | - Abu Bakr Ahmad Fazili
- Colin Ratledge Center for Microbial Lipids, School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, China
| | - Samee Ullah
- Colin Ratledge Center for Microbial Lipids, School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, China.,University Institute of Diet and Nutritional Sciences, Faculty of Allied Health Sciences, The University of Lahore, Lahore, Pakistan
| | - Shaoqi Li
- Colin Ratledge Center for Microbial Lipids, School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, China
| | - Wu Yang
- Colin Ratledge Center for Microbial Lipids, School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, China
| | - Victoriano Garre
- Departamento de Genética y Microbiología (Unidad asociada al Instituto de Química Física Rocasolano-Consejo Superior de Investigaciones Científicas (IQFR-CSIC)), Facultad de Biología, Universidad de Murcia, Murcia, Spain
| | - Yuanda Song
- Colin Ratledge Center for Microbial Lipids, School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, China
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Cánovas-Márquez JT, Navarro-Mendoza MI, Pérez-Arques C, Lax C, Tahiri G, Pérez-Ruiz JA, Lorenzo-Gutiérrez D, Calo S, López-García S, Navarro E, Nicolás FE, Garre V, Murcia L. Role of the Non-Canonical RNAi Pathway in the Antifungal Resistance and Virulence of Mucorales. Genes (Basel) 2021; 12:genes12040586. [PMID: 33920552 PMCID: PMC8072676 DOI: 10.3390/genes12040586] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/12/2021] [Accepted: 04/14/2021] [Indexed: 12/19/2022] Open
Abstract
Mucorales are the causal agents for the lethal disease known as mucormycosis. Mortality rates of mucormycosis can reach up to 90%, due to the mucoralean antifungal drug resistance and the lack of effective therapies. A concerning urgency among the medical and scientific community claims to find targets for the development of new treatments. Here, we reviewed different studies describing the role and machinery of a novel non-canonical RNAi pathway (NCRIP) only conserved in Mucorales. Its non-canonical features are the independence of Dicer and Argonaute proteins. Conversely, NCRIP relies on RNA-dependent RNA Polymerases (RdRP) and an atypical ribonuclease III (RNase III). NCRIP regulates the expression of mRNAs by degrading them in a specific manner. Its mechanism binds dsRNA but only cuts ssRNA. NCRIP exhibits a diversity of functional roles. It represses the epimutational pathway and the lack of NCRIP increases the generation of drug resistant strains. NCRIP also regulates the control of retrotransposons expression, playing an essential role in genome stability. Finally, NCRIP regulates the response during phagocytosis, affecting the multifactorial process of virulence. These critical NCRIP roles in virulence and antifungal drug resistance, along with its exclusive presence in Mucorales, mark this pathway as a promising target to fight against mucormycosis.
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Affiliation(s)
- José Tomás Cánovas-Márquez
- Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, 30100 Murcia, Spain; (J.T.C.-M.); (C.L.); (G.T.); (J.A.P.-R.); (D.L.-G.); (S.L.-G.); (E.N.); (F.E.N.); (V.G.)
| | - María Isabel Navarro-Mendoza
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA; (M.I.N.-M.); (C.P.-A.)
| | - Carlos Pérez-Arques
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA; (M.I.N.-M.); (C.P.-A.)
| | - Carlos Lax
- Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, 30100 Murcia, Spain; (J.T.C.-M.); (C.L.); (G.T.); (J.A.P.-R.); (D.L.-G.); (S.L.-G.); (E.N.); (F.E.N.); (V.G.)
| | - Ghizlane Tahiri
- Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, 30100 Murcia, Spain; (J.T.C.-M.); (C.L.); (G.T.); (J.A.P.-R.); (D.L.-G.); (S.L.-G.); (E.N.); (F.E.N.); (V.G.)
| | - José Antonio Pérez-Ruiz
- Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, 30100 Murcia, Spain; (J.T.C.-M.); (C.L.); (G.T.); (J.A.P.-R.); (D.L.-G.); (S.L.-G.); (E.N.); (F.E.N.); (V.G.)
| | - Damaris Lorenzo-Gutiérrez
- Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, 30100 Murcia, Spain; (J.T.C.-M.); (C.L.); (G.T.); (J.A.P.-R.); (D.L.-G.); (S.L.-G.); (E.N.); (F.E.N.); (V.G.)
| | - Silvia Calo
- School of Natural and Exact Sciences, Pontificia Universidad Católica Madre y Maestra, Santiago de los Caballeros 51033, Dominican Republic;
| | - Sergio López-García
- Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, 30100 Murcia, Spain; (J.T.C.-M.); (C.L.); (G.T.); (J.A.P.-R.); (D.L.-G.); (S.L.-G.); (E.N.); (F.E.N.); (V.G.)
| | - Eusebio Navarro
- Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, 30100 Murcia, Spain; (J.T.C.-M.); (C.L.); (G.T.); (J.A.P.-R.); (D.L.-G.); (S.L.-G.); (E.N.); (F.E.N.); (V.G.)
| | - Francisco Esteban Nicolás
- Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, 30100 Murcia, Spain; (J.T.C.-M.); (C.L.); (G.T.); (J.A.P.-R.); (D.L.-G.); (S.L.-G.); (E.N.); (F.E.N.); (V.G.)
| | - Victoriano Garre
- Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, 30100 Murcia, Spain; (J.T.C.-M.); (C.L.); (G.T.); (J.A.P.-R.); (D.L.-G.); (S.L.-G.); (E.N.); (F.E.N.); (V.G.)
| | - Laura Murcia
- Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, 30100 Murcia, Spain; (J.T.C.-M.); (C.L.); (G.T.); (J.A.P.-R.); (D.L.-G.); (S.L.-G.); (E.N.); (F.E.N.); (V.G.)
- Correspondence:
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10
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Pérez-Arques C, Navarro-Mendoza MI, Murcia L, Navarro E, Garre V, Nicolás FE. The RNAi Mechanism Regulates a New Exonuclease Gene Involved in the Virulence of Mucorales. Int J Mol Sci 2021; 22:ijms22052282. [PMID: 33668930 PMCID: PMC7956310 DOI: 10.3390/ijms22052282] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 02/16/2021] [Accepted: 02/22/2021] [Indexed: 12/17/2022] Open
Abstract
Mucormycosis is a lethal disease caused by Mucorales, which are emerging as human causes that explain the high mortality for this disease. Consequently, the research community is searching for virulence determinants that could be repurposed as targets to develop new treatments against mucormycosis. Our work explores an RNA interference (RNAi)-based approach to find targets involved in the virulence of Mucorales. A transcriptomewide analysis compared sRNAs and their target mRNAs in two Mucor lusitanicus different pathotypes, virulent and avirulent, generating a list of 75 loci selected by their differential sRNA accumulation in these strains. As a proof of concept and validity, an experimental approach characterized two loci showing opposite behavior, confirming that RNAi activity causes their differential expression in the two pathotypes. We generated deletion mutants for two loci and a knockin-strain overexpressing for one of these loci. Their functional analysis in murine virulence assays identified the gene wex1, a putative DEDDy exonuclease with RNase domains, as an essential factor for virulence. The identification of wex1 showed the potential of our approach to discover virulence factors not only in Mucorales but also in any other fungal model with an active RNAi machinery. More importantly, it adds a new layer to the biological processes controlled by RNAi in M. lusitanicus, confirming that the Dicer-dependent RNAi pathway can silence gene expression to promote virulence.
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11
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The Added Value of Longitudinal Imaging for Preclinical In Vivo Efficacy Testing of Therapeutic Compounds against Cerebral Cryptococcosis. Antimicrob Agents Chemother 2020; 64:AAC.00070-20. [PMID: 32284382 DOI: 10.1128/aac.00070-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 04/04/2020] [Indexed: 02/07/2023] Open
Abstract
Brain infections with Cryptococcus neoformans are associated with significant morbidity and mortality. Cryptococcosis typically presents as meningoencephalitis or fungal mass lesions called cryptococcomas. Despite frequent in vitro discoveries of promising novel antifungals, the clinical need for drugs that can more efficiently treat these brain infections remains. A crucial step in drug development is the evaluation of in vivo drug efficacy in animal models. This mainly relies on survival studies or postmortem analyses in large groups of animals, but these techniques only provide information on specific organs of interest at predefined time points. In this proof-of-concept study, we validated the use of noninvasive preclinical imaging to obtain longitudinal information on the therapeutic efficacy of amphotericin B or fluconazole monotherapy in meningoencephalitis and cryptococcoma mouse models. Bioluminescence imaging enabled the rapid in vitro and in vivo evaluation of drug efficacy, while complementary high-resolution anatomical information obtained by magnetic resonance imaging of the brain allowed a precise assessment of the extent of infection and lesion growth rates. We demonstrated a good correlation between both imaging readouts and the fungal burden in various organs. Moreover, we identified potential pitfalls associated with the interpretation of therapeutic efficacy based solely on postmortem studies, demonstrating the added value of this noninvasive dual imaging approach compared to standard mortality curves or fungal load endpoints. This novel preclinical imaging platform provides insights in the dynamic aspects of the therapeutic response and facilitates a more efficient and accurate translation of promising antifungal compounds from bench to bedside.
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CRISPR-Cas9-Based Mutagenesis of the Mucormycosis-Causing Fungus Lichtheimia corymbifera. Int J Mol Sci 2020; 21:ijms21103727. [PMID: 32466287 PMCID: PMC7279233 DOI: 10.3390/ijms21103727] [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: 03/12/2020] [Revised: 05/20/2020] [Accepted: 05/25/2020] [Indexed: 12/18/2022] Open
Abstract
Lichtheimia corymbifera is considered as one of the most frequent agents of mucormycosis. The lack of efficient genetic manipulation tools hampers the characterization of the pathomechanisms and virulence factors of this opportunistic pathogenic fungus. Although such techniques have been described for certain species, the performance of targeted mutagenesis and the construction of stable transformants have remained a great challenge in Mucorales fungi. In the present study, a plasmid-free CRISPR-Cas9 system was applied to carry out a targeted gene disruption in L. corymbifera. The described method is based on the non-homologous end-joining repair of the double-strand break caused by the Cas9 enzyme. Using this method, short, one-to-five nucleotide long-targeted deletions could be induced in the orotidine 5′-phosphate decarboxylase gene (pyrG) and, as a result, uracil auxotrophic strains were constructed. These strains are applicable as recipient strains in future gene manipulation studies. As we know, this is the first genetic modification of this clinically relevant fungus.
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Lax C, Pérez-Arques C, Navarro-Mendoza MI, Cánovas-Márquez JT, Tahiri G, Pérez-Ruiz JA, Osorio-Concepción M, Murcia-Flores L, Navarro E, Garre V, Nicolás FE. Genes, Pathways, and Mechanisms Involved in the Virulence of Mucorales. Genes (Basel) 2020; 11:E317. [PMID: 32188171 PMCID: PMC7140881 DOI: 10.3390/genes11030317] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 03/06/2020] [Accepted: 03/09/2020] [Indexed: 12/19/2022] Open
Abstract
The order Mucorales is a group of ancient fungi with limited tools for gene manipulation. The main consequence of this manipulation unwillingness is the limited knowledge about its biology compared to other fungal groups. However, the emerging of mucormycosis, a fungal infection caused by Mucorales, is attracting the medical spotlight in recent years because the treatments available are not efficient in reducing the high mortality associated with this disease. The result of this renewed interest in Mucorales and mucormycosis is an extraordinarily productive effort to unveil their secrets during the last decade. In this review, we describe the most compelling advances related to the genetic study of virulence factors, pathways, and molecular mechanisms developed in these years. The use of a few genetic study models has allowed the characterization of virulence factors in Mucorales that were previously described in other pathogens, such as the uptake iron systems, the mechanisms of dimorphism, and azole resistances. More importantly, recent studies are identifying new genes and mechanisms controlling the pathogenic potential of Mucorales and their interactions with the host, offering new alternatives to develop specific strategies against mucormycosis.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Francisco Esteban Nicolás
- Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, 30100 Murcia, Spain; (C.L.); (C.P.-A.); (M.I.N.-M.); (J.T.C.-M.); (G.T.); (J.A.P.-R.); (M.O.-C.); (L.M.-F.); (V.G.)
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Vanherp L, Ristani A, Poelmans J, Hillen A, Lagrou K, Janbon G, Brock M, Himmelreich U, Vande Velde G. Sensitive bioluminescence imaging of fungal dissemination to the brain in mouse models of cryptococcosis. Dis Model Mech 2019; 12:dmm.039123. [PMID: 31101657 PMCID: PMC6602310 DOI: 10.1242/dmm.039123] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 05/08/2019] [Indexed: 12/18/2022] Open
Abstract
Cryptococcus neoformans is a leading cause of fungal brain infection, but the mechanism of dissemination and dynamics of cerebral infection following pulmonary disease are poorly understood. To address these questions, non-invasive techniques that can study the dynamic processes of disease development and progression in living animal models or patients are required. As such, bioluminescence imaging (BLI) has emerged as a powerful tool to evaluate the spatial and temporal distribution of infection in living animals. We aimed to study the time profile of the dissemination of cryptococcosis from the lung to the brain in murine models by engineering the first bioluminescent C. neoformans KN99α strain, expressing a sequence-optimized red-shifted luciferase. The high pathogen specificity and sensitivity of BLI was complemented by the three-dimensional anatomical information from micro-computed tomography (μCT) of the lung and magnetic resonance imaging (MRI) of the brain. These non-invasive imaging techniques provided longitudinal readouts on the spatial and temporal distribution of infection following intravenous, intranasal or endotracheal routes of inoculation. Furthermore, the imaging results correlated strongly with the fungal load in the respective organs. By obtaining dynamic and quantitative information about the extent and timing of brain infections for individual animals, we found that dissemination to the brain after primary infection of the lung is likely a late-stage event with a timeframe that is variable between animals. This novel tool in Cryptococcus research can aid the identification of host and pathogen factors involved in this process, and supports development of novel preventive or therapeutic approaches. Summary: A novel combination of bioluminescence and anatomical imaging non-invasively identified the timeframe and extent of Cryptococcus neoformans dissemination to the brain in animal models of systemic and pulmonary fungal infection.
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Affiliation(s)
- Liesbeth Vanherp
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, 3000 Leuven, Belgium.,Molecular Small Animal Imaging Center (MoSAIC), KU Leuven, 3000 Leuven, Belgium
| | - Alexandra Ristani
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, 3000 Leuven, Belgium.,Molecular Small Animal Imaging Center (MoSAIC), KU Leuven, 3000 Leuven, Belgium
| | - Jennifer Poelmans
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, 3000 Leuven, Belgium.,Molecular Small Animal Imaging Center (MoSAIC), KU Leuven, 3000 Leuven, Belgium
| | - Amy Hillen
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, 3000 Leuven, Belgium.,Molecular Small Animal Imaging Center (MoSAIC), KU Leuven, 3000 Leuven, Belgium
| | - Katrien Lagrou
- Laboratory of Clinical Bacteriology and Mycology, Department of Microbiology and Immunology, KU Leuven, 3000 Leuven, Belgium
| | - Guilhem Janbon
- RNA Biology of Fungal Pathogens, Department of Mycology, Pasteur Institute, Paris 75015, France
| | - Matthias Brock
- Fungal Biology Group, School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK
| | - Uwe Himmelreich
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, 3000 Leuven, Belgium.,Molecular Small Animal Imaging Center (MoSAIC), KU Leuven, 3000 Leuven, Belgium
| | - Greetje Vande Velde
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, 3000 Leuven, Belgium .,Molecular Small Animal Imaging Center (MoSAIC), KU Leuven, 3000 Leuven, Belgium
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Special Issue: Fungal Pathogenesis in Humans: The Growing Threat. Genes (Basel) 2019; 10:genes10020136. [PMID: 30759890 PMCID: PMC6409907 DOI: 10.3390/genes10020136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 02/04/2019] [Indexed: 11/17/2022] Open
Abstract
Approximately 150 fungal species are considered as primary pathogens of humans and animals[...].
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