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Roosen L, Maes D, Musetta L, Himmelreich U. Preclinical Models for Cryptococcosis of the CNS and Their Characterization Using In Vivo Imaging Techniques. J Fungi (Basel) 2024; 10:146. [PMID: 38392818 PMCID: PMC10890286 DOI: 10.3390/jof10020146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/24/2024] [Accepted: 01/30/2024] [Indexed: 02/24/2024] Open
Abstract
Infections caused by Cryptococcus neoformans and Cryptococcus gattii remain a challenge to our healthcare systems as they are still difficult to treat. In order to improve treatment success, in particular for infections that have disseminated to the central nervous system, a better understanding of the disease is needed, addressing questions like how it evolves from a pulmonary to a brain disease and how novel treatment approaches can be developed and validated. This requires not only clinical research and research on the microorganisms in a laboratory environment but also preclinical models in order to study cryptococci in the host. We provide an overview of available preclinical models, with particular emphasis on models of cryptococcosis in rodents. In order to further improve the characterization of rodent models, in particular the dynamic aspects of disease manifestation, development, and ultimate treatment, preclinical in vivo imaging methods are increasingly used, mainly in research for oncological, neurological, and cardiac diseases. In vivo imaging applications for fungal infections are rather sparse. A second aspect of this review is how research on models of cryptococcosis can benefit from in vivo imaging methods that not only provide information on morphology and tissue structure but also on function, metabolism, and cellular properties in a non-invasive way.
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Affiliation(s)
- Lara Roosen
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, 3000 Leuven, Belgium
| | - Dries Maes
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, 3000 Leuven, Belgium
| | - Luigi Musetta
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, 3000 Leuven, Belgium
| | - Uwe Himmelreich
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, 3000 Leuven, Belgium
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Abulikemu N, Gao X, Wang W, He Q, Wang G, Jiang T, Wang X, Cheng Y, Chen M, Li Y, Liu L, Zhao J, Li J, Jiang C, Wang Y, Han H, Wang J. Mechanism of extracellular space changes in cryptococcal brain granuloma revealed by MRI tracer. Front Neurosci 2022; 16:1034091. [PMID: 36605557 PMCID: PMC9808069 DOI: 10.3389/fnins.2022.1034091] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 11/24/2022] [Indexed: 12/24/2022] Open
Abstract
Purpose This study aimed to investigate the changes in extracellular space (ECS) in cryptococcal brain granuloma and its pathological mechanism. Materials and methods The animal model of cryptococcal brain granuloma was established by injecting 1 × 106 CFU/ml of Cryptococcus neoformans type A suspension into the caudate nucleus of Sprague-Dawley rats with stereotactic technology. The infection in the brain was observed by conventional MRI scanning on days 14, 21, and 28 of modeling. The tracer-based MRI with a gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) as a magnetic tracer was performed on the rats with cryptococcal granuloma and the rats in the control group. The parameters of ECS in each area of cryptococcal brain granuloma were measured. The parameters of ECS in the two groups were compared by independent sample t-test, and the changes in ECS and its mechanism were analyzed. Results Up to 28 days of modeling, the success rate of establishing the brain cryptococcal granuloma model with 1 × 106 CFU/ml Cryptococcus neoformans suspension was 60%. In the internal area of cryptococcal granuloma, the effective diffusion coefficient D* was significantly higher than that of the control group (t = 2.76, P < 0.05), and the same trend showed in the volume ratio α (t = 3.71, P < 0.05), the clearance rate constant k (t = 3.137, P < 0.05), and the tracer half-life T1/2 (t = 3.837, P < 0.05). The tortuosity λ decreased compared with the control group (t = -2.70, P < 0.05). At the edge of the cryptococcal granuloma, the D* and α decreased, while the λ increased compared with the control group (D*:t = -6.05, P < 0.05; α: t = -4.988, P < 0.05; λ: t = 6.222, P < 0.05). Conclusion The internal area of the lesion demonstrated a quicker, broader, and more extended distribution of the tracer, while the edge of the lesion exhibited a slower and narrower distribution. MRI tracer method can monitor morphological and functional changes of ECS in pathological conditions and provide a theoretical basis for the treatment via ECS.
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Affiliation(s)
- Nuerbiyemu Abulikemu
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China,Beijing Key Laboratory of Magnetic Resonance Imaging Devices and Technology, Peking University Third Hospital, Beijing, China,Institute of Medical Technology, Peking University Health Science Center, Beijing, China
| | - Xin Gao
- Shanghai Universal Medical Imaging Diagnostic Center, Shanghai University, Shanghai, China
| | - Wei Wang
- Department of Rehabilitation Radiology, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, China
| | - Qingyuan He
- Beijing Key Laboratory of Magnetic Resonance Imaging Devices and Technology, Peking University Third Hospital, Beijing, China,Institute of Medical Technology, Peking University Health Science Center, Beijing, China,Department of Radiology, Peking University Third Hospital, Beijing, China
| | - Gang Wang
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China,Imaging Center, Xi’an Gem Flower Changqing Hospital, Xi’an, China
| | - Tao Jiang
- The Animal Experimental Center, Xinjiang Medical University, Ürümqi, China
| | - Xiaodong Wang
- Department of Dermatology, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China
| | - Yumeng Cheng
- Beijing Key Laboratory of Magnetic Resonance Imaging Devices and Technology, Peking University Third Hospital, Beijing, China,Institute of Medical Technology, Peking University Health Science Center, Beijing, China
| | - Min Chen
- Department of Dermatology, Shanghai Key Laboratory of Molecular Medical Mycology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Yanran Li
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China
| | - Lulu Liu
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China
| | - Jingjing Zhao
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China
| | - Jin Li
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China
| | - Chunhui Jiang
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China
| | - Yunling Wang
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China
| | - Hongbin Han
- Beijing Key Laboratory of Magnetic Resonance Imaging Devices and Technology, Peking University Third Hospital, Beijing, China,Institute of Medical Technology, Peking University Health Science Center, Beijing, China,Department of Radiology, Peking University Third Hospital, Beijing, China,Hongbin Han,
| | - Jian Wang
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China,Shanghai Universal Medical Imaging Diagnostic Center, Shanghai University, Shanghai, China,*Correspondence: Jian Wang,
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Vanherp L, Govaerts K, Riva M, Poelmans J, Coosemans A, Lagrou K, Gsell W, Vande Velde G, Himmelreich U. CryptoCEST: A promising tool for spatially resolved identification of fungal brain lesions and their differentiation from brain tumors with MRI. NEUROIMAGE-CLINICAL 2021; 31:102737. [PMID: 34225021 PMCID: PMC8261661 DOI: 10.1016/j.nicl.2021.102737] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 05/25/2021] [Accepted: 06/19/2021] [Indexed: 02/01/2023]
Abstract
The fungal disaccharide trehalose generates a concentration-dependent CEST MRI contrast. CEST MRI can detect endogenous trehalose in Cryptococcus neoformans and C. gattii cells. This enables spatially resolved identification of fungal lesions in the mouse brain. The CryptoCEST contrast can differentiate cryptococcal brain lesions from gliomas. CryptoCEST holds potential for non-invasive differential diagnosis of cryptococcomas.
Infectious brain lesions caused by the pathogenic fungi Cryptococcus neoformans and C. gattii, also referred to as cryptococcomas, could be diagnosed incorrectly as cystic brain tumors if only based on conventional magnetic resonance (MR) images. Previous MR spectroscopy (MRS) studies showed high local concentrations of the fungal disaccharide trehalose in cryptococcomas. The aim of this study was to detect and localize fungal brain lesions caused by Cryptococcus species based on Chemical Exchange Saturation Transfer (CEST) MR imaging of endogenous trehalose, and hereby to distinguish cryptococcomas from gliomas. In phantoms, trehalose and cryptococcal cells generated a concentration-dependent CEST contrast in the 0.2 – 2 ppm chemical shift range, similar to glucose, but approximately twice as strong. In vivo single voxel MRS of a murine cryptococcoma model confirmed the presence of trehalose in cryptococcomas, but mainly for lesions that were large enough compared to the size of the MRS voxel. With CEST MRI, combining the more specific CEST signal at 0.7 ppm with the higher signal-to-noise ratio signal at 4 ppm in the CryptoCEST contrast enabled localization and distinction of cryptococcomas from the normal brain and from gliomas, even for lesions smaller than 1 mm3. Thanks to the high endogenous concentration of the fungal biomarker trehalose in cryptococcal cells, the CryptoCEST contrast allowed identification of cryptococcomas with high spatial resolution and differentiation from gliomas in mice. Furthermore, the CryptoCEST contrast was tested to follow up antifungal treatment of cryptococcomas. Translation of this non-invasive method to the clinic holds potential for improving the differential diagnosis and follow-up of cryptococcal infections in the brain.
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Affiliation(s)
- Liesbeth Vanherp
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Kristof Govaerts
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Matteo Riva
- Laboratory of Tumor Immunology and Immunotherapy, Department of Oncology, Leuven Cancer Institute, KU Leuven, Leuven, Belgium; Department of Neurosurgery, Mont-Godinne Hospital, UCL Namur, Yvoir, Belgium
| | - Jennifer Poelmans
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - An Coosemans
- Laboratory of Tumor Immunology and Immunotherapy, Department of Oncology, Leuven Cancer Institute, KU Leuven, Leuven, Belgium
| | - Katrien Lagrou
- Laboratory of Clinical Bacteriology and Mycology, Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium; National Reference Centre for Mycosis, Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium
| | - Willy Gsell
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Greetje Vande Velde
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Uwe Himmelreich
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium.
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Vanherp L, Poelmans J, Weerasekera A, Hillen A, Croitor-Sava AR, Sorrell TC, Lagrou K, Vande Velde G, Himmelreich U. Trehalose as quantitative biomarker for in vivo diagnosis and treatment follow-up in cryptococcomas. Transl Res 2021; 230:111-122. [PMID: 33166695 DOI: 10.1016/j.trsl.2020.11.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 10/29/2020] [Accepted: 11/03/2020] [Indexed: 12/26/2022]
Abstract
Brain lesions caused by Cryptococcus neoformans or C. gattii (cryptococcomas) are typically difficult to diagnose correctly and treat effectively, but rapid differential diagnosis and treatment initiation are crucial for good outcomes. In previous studies, cultured cryptococcal isolates and ex vivo lesion material contained high concentrations of the virulence factor and fungal metabolite trehalose. Here, we studied the in vivo metabolic profile of cryptococcomas in the brain using magnetic resonance spectroscopy (MRS) and assessed the relationship between trehalose concentration, fungal burden, and treatment response in order to validate its suitability as marker for early and noninvasive diagnosis and its potential to monitor treatment in vivo. We investigated the metabolites present in early and late stage cryptococcomas using in vivo 1H MRS in a murine model and evaluated changes in trehalose concentrations induced by disease progression and antifungal treatment. Animal data were compared to 1H and 13C MR spectra of Cryptococcus cultures and in vivo data from 2 patients with cryptococcomas in the brain. In vivo MRS allowed the noninvasive detection of high concentrations of trehalose in cryptococcomas and showed a comparable metabolic profile of cryptococcomas in the murine model and human cases. Trehalose concentrations correlated strongly with the fungal burden. Treatment studies in cultures and animal models showed that trehalose concentrations decrease following exposure to effective antifungal therapy. Although further cases need to be studied for clinical validation, this translational study indicates that the noninvasive MRS-based detection of trehalose is a promising marker for diagnosis and therapeutic follow-up of cryptococcomas.
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Affiliation(s)
- Liesbeth Vanherp
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Jennifer Poelmans
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Akila Weerasekera
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium; A.A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School (MGH/HMS), Boston, Massachusetts, USA
| | - Amy Hillen
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Anca R Croitor-Sava
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium; STADIUS, Department of Electrical Engineering (ESAT), KU Leuven, Leuven, Belgium
| | - Tania C Sorrell
- Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, and Westmead Institute for Medical Research, Centre for Infectious Diseases and Microbiology, Sydney, Australia
| | - Katrien Lagrou
- Laboratory of Clinical Bacteriology and Mycology, Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium; National Reference Centre for Mycosis, Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium
| | - Greetje Vande Velde
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Uwe Himmelreich
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium.
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Ulett KB, Cockburn JWJ, Jeffree R, Woods ML. Cerebral cryptococcoma mimicking glioblastoma. BMJ Case Rep 2017; 2017:bcr-2016-218824. [PMID: 28188169 DOI: 10.1136/bcr-2016-218824] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Cryptococcus neoformans and C. gattii cause invasive fungal disease, with meningitis being the most common manifestation of central nervous system (CNS) disease. Encapsulated cryptococcomas occur rarely, predominantly in immunocompetent hosts, usually related to C. gattii Our patient was an immunocompetent man who presented with headache and a large cystic CNS lesion thought to be glioblastoma. Biopsy of a concomitant lung lesion confirmed cryptococcoma and empiric antifungal therapy was started for presumed CNS cryptococcoma. Antifungal therapy failed to shrink the CNS lesion, and surgical excision confirmed C. gattii CNS cryptococcoma. Following surgery he had complete resolution of symptoms. This case highlights that cryptococcoma cannot be distinguished from tumour on clinical or imaging findings. A combined medical and surgical approach is optimal for the management of large or surgically accessible cryptococcomas, as antifungal therapy alone is unlikely to penetrate large lesions sufficiently to lead to a cure.
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Affiliation(s)
- Kimberly B Ulett
- Royal Brisbane and Women's Hospital, Herston, Queensland, Australia
| | | | - Rosalind Jeffree
- Royal Brisbane and Women's Hospital, Herston, Queensland, Australia
| | - Marion L Woods
- Royal Brisbane and Women's Hospital, Herston, Queensland, Australia.,University of Queensland, Brisbane, Queensland, Australia
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Abstract
Understanding of the taxonomy and phylogeny of Cryptococcus gattii has been advanced by modern molecular techniques. C. gattii probably diverged from Cryptococcus neoformans between 16 million and 160 million years ago, depending on the dating methods applied, and maintains diversity by recombining in nature. South America is the likely source of the virulent C. gattii VGII molecular types that have emerged in North America. C. gattii shares major virulence determinants with C. neoformans, although genomic and transcriptomic studies revealed that despite similar genomes, the VGIIa and VGIIb subtypes employ very different transcriptional circuits and manifest differences in virulence phenotypes. Preliminary evidence suggests that C. gattii VGII causes severe lung disease and death without dissemination, whereas C. neoformans disseminates readily to the central nervous system (CNS) and causes death from meningoencephalitis. Overall, currently available data indicate that the C. gattii VGI, VGII, and VGIII molecular types more commonly affect nonimmunocompromised hosts, in contrast to VGIV. New, rapid, cheap diagnostic tests and imaging modalities are assisting early diagnosis and enabling better outcomes of cerebral cryptococcosis. Complications of CNS infection include increased intracranial pressure, severe neurological sequelae, and development of immune reconstitution syndrome, although the mortality rate is low. C. gattii VGII isolates may exhibit higher fluconazole MICs than other genotypes. Optimal therapeutic regimens are yet to be determined; in most cases, initial therapy with amphotericin B and 5-flucytosine is recommended.
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Guimarães AJ, Frases S, Cordero RJB, Nimrichter L, Casadevall A, Nosanchuk JD. Cryptococcus neoformans responds to mannitol by increasing capsule size in vitro and in vivo. Cell Microbiol 2010; 12:740-53. [PMID: 20070311 DOI: 10.1111/j.1462-5822.2010.01430.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The polysaccharide capsule of the fungus Cryptococcus neoformans is its main virulence factor. In this study, we determined the effects of mannitol and glucose on the capsule and exopolysaccharide production. Growth in mannitol significantly increased capsular volume compared with cultivation in glucose. However, cells grown in glucose concentrations higher than 62.5 mM produced more exopolysaccharide than cells grown in mannitol. The fibre lengths and glycosyl composition of capsular polysaccharide from yeast grown in mannitol was structurally different from that of yeast grown in glucose. Furthermore, mannitol treatment of mice infected intratracheally with C. neoformans resulted in fungal cells with significantly larger capsules and the mice had reduced fungal dissemination to the brain. Our results demonstrate the capacity of carbohydrate source and concentration to modify the expression of a major virulence factor of C. neoformans. These findings may impact the clinical management of cryptococcosis.
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Sorrell TC, Himmelreich U. The role of nuclear magnetic resonance in medical mycology. CURRENT FUNGAL INFECTION REPORTS 2008. [DOI: 10.1007/s12281-008-0022-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Hauck EF, McGinnis M, Nauta HJ. Cerebral phaeohyphomycosis mimics high-grade astrocytoma. J Clin Neurosci 2008; 15:1061-6. [DOI: 10.1016/j.jocn.2007.08.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2007] [Revised: 08/01/2007] [Accepted: 08/09/2007] [Indexed: 10/21/2022]
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Sorrell TC, Wright LC, Malik R, Himmelreich U. Application of proton nuclear magnetic resonance spectroscopy to the study of Cryptococcus and cryptococcosis. FEMS Yeast Res 2006; 6:558-66. [PMID: 16696651 DOI: 10.1111/j.1567-1364.2006.00079.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Proton nuclear magnetic resonance spectroscopy is a nondestructive technique that identifies chemicals in solution and in living cells. It has been used in cryptococcal research to identify the primary structure of capsular glucuronoxylomannans, link cellular apoptosis susceptibility (CAS) genes to positioning of residues on the mannose backbone of glucuronoxylomannan, and verify that the cryptococcal virulence determinant, phospholipase B, is elaborated in vivo. Promising clinical applications include speciation (Cryptococcus neoformans and Cryptococcus gattii), with preliminary evidence that varieties neoformans and grubii can also be distinguished, non-invasive diagnosis of cerebral cryptococcomas, and, in cases of meningitis, monitoring therapeutic response by analysis of cerebrospinal fluid.
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Affiliation(s)
- Tania C Sorrell
- Centre for Infectious Diseases and Microbiology and Westmead Millennium Institute, University of Sydney at Westmead, NSW, Australia.
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