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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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2
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Giamberardino C, Perfect JR. The Rabbit Model of Cryptococcal Meningitis. Methods Mol Biol 2024; 2775:13-27. [PMID: 38758308 DOI: 10.1007/978-1-0716-3722-7_2] [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] [Indexed: 05/18/2024]
Abstract
Cryptococcal meningitis (CM) is a fungal disease caused by the invasion of Cryptococcus yeast cells into the central nervous system. The organism is thought to enter the body through the lungs and then escape due to dysregulation of the immune response. Multiple animal species have been used to model the infection and characterize CM including mice, rats, dogs, guinea pigs, and rabbits. The rabbit model has over 40 years of data and has been used to study host-pathogen interactions and the efficacy of antifungal therapeutics. The model begins with immune suppression to eliminate the lymphocytic cell population followed by direct infection of the central nervous system via an injection of a suspension of yeast cells into the cisterna magna. The organism remains in the CNS during the course of infection, and cerebrospinal fluid can be repeatedly sampled to quantify the burden of organism, measure drug levels in the CSF, profile the immune response in the CSF, and/or characterize the yeast cells. The rabbit model of infection is a robust experimental model for better understanding CM and Cryptococcus cellular behavior.
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Affiliation(s)
- Charles Giamberardino
- Duke University School of Medicine, Department of Medicine, Division of Infectious Diseases, Durham, NC, USA.
| | - John R Perfect
- Duke University School of Medicine, Department of Medicine, Division of Infectious Diseases, Durham, NC, USA
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3
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Hoffman HJ, McClelland EE. Measuring Urease and Phospholipase Secretion in Cryptococcus neoformans. Methods Mol Biol 2024; 2775:269-275. [PMID: 38758324 DOI: 10.1007/978-1-0716-3722-7_18] [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] [Indexed: 05/18/2024]
Abstract
Urease and phospholipase are enzymes that are important virulence factors for Cryptococcus neoformans. These are two of the most studied enzymes involved in how C. neoformans breaches the blood-brain barrier. Additionally, phospholipase secretion also supports dissemination from the lungs. This chapter describes the methods used to measure the secretion of these enzymes, which may be used to characterize strain invasiveness and virulence.
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Affiliation(s)
- Hunter J Hoffman
- Department of Biomedical Sciences, Marian University College of Osteopathic Medicine, Indianapolis, IN, USA
| | - Erin E McClelland
- Department of Biomedical Sciences, Marian University College of Osteopathic Medicine, Indianapolis, IN, USA.
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4
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Sauters TJC, Roth C, Murray D, Sun S, Floyd Averette A, Onyishi CU, May RC, Heitman J, Magwene PM. Amoeba predation of Cryptococcus: A quantitative and population genomic evaluation of the accidental pathogen hypothesis. PLoS Pathog 2023; 19:e1011763. [PMID: 37956179 PMCID: PMC10681322 DOI: 10.1371/journal.ppat.1011763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 11/27/2023] [Accepted: 10/18/2023] [Indexed: 11/15/2023] Open
Abstract
The "Amoeboid Predator-Fungal Animal Virulence Hypothesis" posits that interactions with environmental phagocytes shape the evolution of virulence traits in fungal pathogens. In this hypothesis, selection to avoid predation by amoeba inadvertently selects for traits that contribute to fungal escape from phagocytic immune cells. Here, we investigate this hypothesis in the human fungal pathogens Cryptococcus neoformans and Cryptococcus deneoformans. Applying quantitative trait locus (QTL) mapping and comparative genomics, we discovered a cross-species QTL region that is responsible for variation in resistance to amoeba predation. In C. neoformans, this same QTL was found to have pleiotropic effects on melanization, an established virulence factor. Through fine mapping and population genomic comparisons, we identified the gene encoding the transcription factor Bzp4 that underlies this pleiotropic QTL and we show that decreased expression of this gene reduces melanization and increases susceptibility to amoeba predation. Despite the joint effects of BZP4 on amoeba resistance and melanin production, we find no relationship between BZP4 genotype and escape from macrophages or virulence in murine models of disease. Our findings provide new perspectives on how microbial ecology shapes the genetic architecture of fungal virulence, and suggests the need for more nuanced models for the evolution of pathogenesis that account for the complexities of both microbe-microbe and microbe-host interactions.
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Affiliation(s)
- Thomas J. C. Sauters
- Department of Biology, Duke University, Durham, North Carolina, United States of America
- University Program in Genetics and Genomics, Duke University, Durham, North Carolina, United States of America
| | - Cullen Roth
- Department of Biology, Duke University, Durham, North Carolina, United States of America
- University Program in Genetics and Genomics, Duke University, Durham, North Carolina, United States of America
| | - Debra Murray
- Department of Biology, Duke University, Durham, North Carolina, United States of America
| | - Sheng Sun
- Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, United States of America
| | - Anna Floyd Averette
- Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, United States of America
| | - Chinaemerem U. Onyishi
- School of Biosciences, College of Life and Environmental Sciences, The University of Birmingham, Birmingham, United Kingdom
| | - Robin C. May
- School of Biosciences, College of Life and Environmental Sciences, The University of Birmingham, Birmingham, United Kingdom
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, United States of America
| | - Paul M. Magwene
- Department of Biology, Duke University, Durham, North Carolina, United States of America
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5
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Kietrungruang K, Sookkree S, Sangboonruang S, Semakul N, Poomanee W, Kitidee K, Tragoolpua Y, Tragoolpua K. Ethanolic Extract Propolis-Loaded Niosomes Diminish Phospholipase B1, Biofilm Formation, and Intracellular Replication of Cryptococcus neoformans in Macrophages. Molecules 2023; 28:6224. [PMID: 37687052 PMCID: PMC10488685 DOI: 10.3390/molecules28176224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 08/21/2023] [Accepted: 08/22/2023] [Indexed: 09/10/2023] Open
Abstract
Secretory phospholipase B1 (PLB1) and biofilms act as microbial virulence factors and play an important role in pulmonary cryptococcosis. This study aims to formulate the ethanolic extract of propolis-loaded niosomes (Nio-EEP) and evaluate the biological activities occurring during PLB1 production and biofilm formation of Cryptococcus neoformans. Some physicochemical characterizations of niosomes include a mean diameter of 270 nm in a spherical shape, a zeta-potential of -10.54 ± 1.37 mV, and 88.13 ± 0.01% entrapment efficiency. Nio-EEP can release EEP in a sustained manner and retains consistent physicochemical properties for a month. Nio-EEP has the capability to permeate the cellular membranes of C. neoformans, causing a significant decrease in the mRNA expression level of PLB1. Interestingly, biofilm formation, biofilm thickness, and the expression level of biofilm-related genes (UGD1 and UXS1) were also significantly reduced. Pre-treating with Nio-EEP prior to yeast infection reduced the intracellular replication of C. neoformans in alveolar macrophages by 47%. In conclusion, Nio-EEP mediates as an anti-virulence agent to inhibit PLB1 and biofilm production for preventing fungal colonization on lung epithelial cells and also decreases the intracellular replication of phagocytosed cryptococci. This nano-based EEP delivery might be a potential therapeutic strategy in the prophylaxis and treatment of pulmonary cryptococcosis in the future.
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Affiliation(s)
- Kritapat Kietrungruang
- Division of Clinical Microbiology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai 50200, Thailand; (K.K.); (S.S.); (S.S.)
| | - Sanonthinee Sookkree
- Division of Clinical Microbiology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai 50200, Thailand; (K.K.); (S.S.); (S.S.)
| | - Sirikwan Sangboonruang
- Division of Clinical Microbiology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai 50200, Thailand; (K.K.); (S.S.); (S.S.)
| | - Natthawat Semakul
- Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand;
| | - Worrapan Poomanee
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, Chiang Mai University, Chiang Mai 50200, Thailand;
| | - Kuntida Kitidee
- Center for Research Innovation and Biomedical Informatics, Faculty of Medical Technology, Mahidol University, Salaya, Nakhon Pathom 73170, Thailand;
| | - Yingmanee Tragoolpua
- Natural Extracts and Innovative Products for Alternative Healthcare Research Group, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand;
- Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Khajornsak Tragoolpua
- Division of Clinical Microbiology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai 50200, Thailand; (K.K.); (S.S.); (S.S.)
- Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand;
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6
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Phospholipase B Is Critical for Cryptococcus neoformans Survival in the Central Nervous System. mBio 2023; 14:e0264022. [PMID: 36786559 PMCID: PMC10127605 DOI: 10.1128/mbio.02640-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
Cryptococcus neoformans (Cn) is an opportunistic, encapsulated, yeast-like fungus that causes severe meningoencephalitis, especially in countries with high HIV prevalence. In addition to its well-known polysaccharide capsule, Cn has other virulence factors such as phospholipases, a heterogeneous group of enzymes that hydrolyze ester linkages in glycerophospholipids. Phospholipase B (PLB1) has been demonstrated to play a key role in Cn pathogenicity. In this study, we used a PLB1 mutant (plb1) and its reconstituted strain (Rec1) to assess the importance of this enzyme on Cn brain infection in vivo and in vitro. Mice infected with the plb1 strain survive significantly longer, have lower peripheral and central nervous system (CNS) fungal loads, and have fewer and smaller cryptococcomas or biofilm-like brain lesions compared to H99- and Rec1-infected animals. PLB1 causes extensive brain tissue damage and changes microglia morphology during cryptococcal disease, observations which can have important implications in patients with altered mental status or dementia as these manifestations are related to poorer survival outcomes. plb1 cryptococci are significantly more phagocytosed and killed by NR-9460 microglia-like cells. plb1 cells have altered capsular polysaccharide biophysical properties which impair their ability to stimulate glial cell responses or morphological changes. Here, we provide significant evidence demonstrating that Cn PLB1 is an important virulence factor for fungal colonization of and survival in the CNS as well as in the progression of cryptococcal meningoencephalitis. These findings may potentially help fill in a gap of knowledge in our understanding of cerebral cryptococcosis and provide novel research avenues in Cn pathogenesis. IMPORTANCE Cryptococcal meningoencephalitis (CME) is a serious disease caused by infection by the neurotropic fungal pathogen Cryptococcus neoformans. Due to the increasing number of cases in HIV-infected individuals, as well as the limited therapies available, investigation into potential targets for new therapeutics has become critical. Phospholipase B is an enzyme synthesized by Cn that confers virulence to the fungus through capsular enlargement, immunomodulation, and intracellular replication. In this study, we examined the properties of PLB1 by comparing infection of a Cn PLB1 mutant strain with both the wild-type and a PLB1-reconstituted strain. We show that PLB1 augments the survival and proliferation of the fungus in the CNS and strengthens virulence by modulating the immune response and enhancing specific biophysical properties of the fungus. PLB1 expression causes brain tissue damage and impacts glial cell functions, which may be responsible for the dementia observed in patients which may persist even after resolving from CME. The implications of PLB1 inhibition reveal its involvement in Cn infection and suggest that it may be a possible molecular target in the development of antifungal therapies. The results of this study support additional investigation into the mechanism of PLB1 to further understand the intricacies of cerebral Cn infection.
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7
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Cheng X, Zhu H, Bai S, Zou Y, Xia Z, Yang R. Pathogenicity of phospholipase B1 of Trichosporon asahii in immunosuppressed mice. Mycoses 2023; 66:467-476. [PMID: 36680377 DOI: 10.1111/myc.13568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 12/28/2022] [Accepted: 01/16/2023] [Indexed: 01/22/2023]
Abstract
BACKGROUND Trichosporon asahii is an opportunistic pathogenic yeast-like fungus. Phospholipase B1 (PLB1) is an important virulence factor of pathogenic fungi such as Candida albicans and Cryptococcus neoformans, and there are few studies on the role of PLB1 in the pathogenicity of T. asahii. OBJECTIVES To investigate the role of PLB1 in the pathogenicity of T. asahii. METHODS A strain with low secretion of PLB1 (4848) was screened, a PLB1 overexpression strain (PLB1OX ) was constructed, and the differences in histopathology, fungal load of organ, survival time of mice, the levels of IL-6, IL-10, TNF-α, and GM-GSF in the serum and organs caused by the two strains were compared. RESULTS Histopathology showed that spores and hyphae were observed in both groups, and PLB1OX led to more fungal invasion. The fungal loads in the kidney, lung, spleen and liver in the PLB1OX group were significantly higher than those in the 4848 group, and the survival time of mice was significantly lower than that in the 4848 group. The levels of TNF-α in the serum, liver, spleen, lung and kidney of the PLB1OX group were lower than those of the 4848 group, while the level of IL-10 in the serum was higher than that of the 4848 group. CONCLUSIONS These results suggest that PLB1 can enhance the invasive function of T. asahii and affect the secretion of TNF-α and IL-10 which may affect the host antifungal immune response, providing evidence that PLB1 plays a role in the pathogenic infection of T. asahii.
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Affiliation(s)
- Xiaoxian Cheng
- Chinese PLA Medical School, Peking, China.,Department of Dermatology, The Seventh Medical Center of PLA General Hospital, Peking, China
| | - He Zhu
- Chinese PLA Medical School, Peking, China.,Department of Dermatology, The Seventh Medical Center of PLA General Hospital, Peking, China
| | - Shuang Bai
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China.,Department of Dermatology, Affiliated Hospital of Inner Mongolia Medical University, Inner Mongolia, China
| | - Yuekun Zou
- Chinese PLA Medical School, Peking, China.,Department of Geriatrics, The Sixth Medical Center of PLA General Hospital, Peking, China
| | - Zhikuan Xia
- Department of Dermatology, The Seventh Medical Center of PLA General Hospital, Peking, China.,The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Rongya Yang
- Chinese PLA Medical School, Peking, China.,Department of Dermatology, The Seventh Medical Center of PLA General Hospital, Peking, China
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8
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Singh V, Rai R, Mathew BJ, Chourasia R, Singh AK, Kumar A, Chaurasiya SK. Phospholipase C: underrated players in microbial infections. Front Cell Infect Microbiol 2023; 13:1089374. [PMID: 37139494 PMCID: PMC10149971 DOI: 10.3389/fcimb.2023.1089374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 03/21/2023] [Indexed: 05/05/2023] Open
Abstract
During bacterial infections, one or more virulence factors are required to support the survival, growth, and colonization of the pathogen within the host, leading to the symptomatic characteristic of the disease. The outcome of bacterial infections is determined by several factors from both host as well as pathogen origin. Proteins and enzymes involved in cellular signaling are important players in determining the outcome of host-pathogen interactions. phospholipase C (PLCs) participate in cellular signaling and regulation by virtue of their ability to hydrolyze membrane phospholipids into di-acyl-glycerol (DAG) and inositol triphosphate (IP3), which further causes the activation of other signaling pathways involved in various processes, including immune response. A total of 13 PLC isoforms are known so far, differing in their structure, regulation, and tissue-specific distribution. Different PLC isoforms have been implicated in various diseases, including cancer and infectious diseases; however, their roles in infectious diseases are not clearly understood. Many studies have suggested the prominent roles of both host and pathogen-derived PLCs during infections. PLCs have also been shown to contribute towards disease pathogenesis and the onset of disease symptoms. In this review, we have discussed the contribution of PLCs as a determinant of the outcome of host-pathogen interaction and pathogenesis during bacterial infections of human importance.
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Affiliation(s)
- Vinayak Singh
- Molecular Signalling Lab, Department of Biological Science and Engineering, Maulana Azad National Institute of Technology, Bhopal, Madhya Pradesh, India
| | - Rupal Rai
- Molecular Signalling Lab, Department of Biological Science and Engineering, Maulana Azad National Institute of Technology, Bhopal, Madhya Pradesh, India
| | - Bijina J. Mathew
- Molecular Signalling Lab, Department of Biological Science and Engineering, Maulana Azad National Institute of Technology, Bhopal, Madhya Pradesh, India
| | - Rashmi Chourasia
- Department of Chemistry, IES University, Bhopal, Madhya Pradesh, India
| | - Anirudh K. Singh
- School of Sciences, SAM Global University, Raisen, Madhya Pradesh, India
| | - Awanish Kumar
- Department of Biotechnology, National Institute of Technology, Raipur, Chhattisgarh, India
| | - Shivendra K. Chaurasiya
- Molecular Signalling Lab, Department of Biological Science and Engineering, Maulana Azad National Institute of Technology, Bhopal, Madhya Pradesh, India
- *Correspondence: Shivendra K. Chaurasiya,
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de Castro RJA, Rêgo MTAM, Brandão FS, Pérez ALA, De Marco JL, Poças-Fonseca MJ, Nichols C, Alspaugh JA, Felipe MSS, Alanio A, Bocca AL, Fernandes L. Engineered Fluorescent Strains of Cryptococcus neoformans: a Versatile Toolbox for Studies of Host-Pathogen Interactions and Fungal Biology, Including the Viable but Nonculturable State. Microbiol Spectr 2022; 10:e0150422. [PMID: 36005449 PMCID: PMC9603711 DOI: 10.1128/spectrum.01504-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 08/05/2022] [Indexed: 12/31/2022] Open
Abstract
Cryptococcus neoformans is an opportunistic fungal pathogen known for its remarkable ability to infect and subvert phagocytes. This ability provides survival and persistence within the host and relies on phenotypic plasticity. The viable but nonculturable (VBNC) phenotype was recently described in C. neoformans, whose study is promising in understanding the pathophysiology of cryptococcosis. The use of fluorescent strains is improving host interaction research, but it is still underexploited. Here, we fused histone H3 or the poly(A) binding protein (Pab) to enhanced green fluorescent protein (eGFP) or mCherry, obtaining a set of C. neoformans transformants with different colors, patterns of fluorescence, and selective markers (hygromycin B resistance [Hygr] or neomycin resistance [Neor]). We validated their similarity to the parental strain in the stress response, the expression of virulence-related phenotypes, mating, virulence in Galleria mellonella, and survival within murine macrophages. PAB-GFP, the brightest transformant, was successfully applied for the analysis of phagocytosis by flow cytometry and fluorescence microscopy. Moreover, we demonstrated that an engineered fluorescent strain of C. neoformans was able to generate VBNC cells. GFP-tagged Pab1, a key regulator of the stress response, evidenced nuclear retention of Pab1 and the assembly of cytoplasmic stress granules, unveiling posttranscriptional mechanisms associated with dormant C. neoformans cells. Our results support that the PAB-GFP strain is a useful tool for research on C. neoformans. IMPORTANCE Cryptococcus neoformans is a human-pathogenic yeast that can undergo a dormant state and is responsible for over 180,000 deaths annually worldwide. We engineered a set of fluorescent transformants to aid in research on C. neoformans. A mutant with GFP-tagged Pab1 improved fluorescence-based techniques used in host interaction studies. Moreover, this mutant induced a viable but nonculturable phenotype and uncovered posttranscriptional mechanisms associated with dormant C. neoformans. The experimental use of fluorescent mutants may shed light on C. neoformans-host interactions and fungal biology, including dormant phenotypes.
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Affiliation(s)
- Raffael Júnio Araújo de Castro
- Laboratory of Applied Immunology, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasília, Federal District, Brazil
- CNRS, Unité de Mycologie Moléculaire, Centre National de Référence Mycoses et Antifongiques, Institut Pasteur, Paris, France
| | - Marco Túlio Aidar Mariano Rêgo
- Laboratory of Applied Immunology, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasília, Federal District, Brazil
| | - Fabiana S. Brandão
- Faculty of Health Science, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasília, Federal District, Brazil
| | - Ana Laura Alfonso Pérez
- Department of Cell Biology, Institute of Biological Sciences, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasilia, Federal District, Brazil
| | - Janice Lisboa De Marco
- Department of Cell Biology, Institute of Biological Sciences, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasilia, Federal District, Brazil
| | - Marcio José Poças-Fonseca
- Department of Genetics and Morphology, Institute of Biological Sciences, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasília, Federal District, Brazil
| | - Connie Nichols
- Duke University School of Medicine, Department of Medicine, Durham, North Carolina, USA
| | - J. Andrew Alspaugh
- Duke University School of Medicine, Department of Medicine, Durham, North Carolina, USA
| | - Maria Sueli S. Felipe
- Catholic University of Brasilia, Campus Asa Norte, Asa Norte, Brasília, Federal District, Brazil
| | - Alexandre Alanio
- CNRS, Unité de Mycologie Moléculaire, Centre National de Référence Mycoses et Antifongiques, Institut Pasteur, Paris, France
- Laboratoire de Mycologie et Parasitologie, AP-HP, Hôpital Saint Louis, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Anamélia Lorenzetti Bocca
- Laboratory of Applied Immunology, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasília, Federal District, Brazil
| | - Larissa Fernandes
- Laboratory of Applied Immunology, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasília, Federal District, Brazil
- Faculty of Ceilândia, Campus UnB Ceilândia, University of Brasília, Ceilândia Sul, Brasília, Federal District, Brazil
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10
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Cryptococcus neoformans Infection in the Central Nervous System: The Battle between Host and Pathogen. J Fungi (Basel) 2022; 8:jof8101069. [PMID: 36294634 PMCID: PMC9605252 DOI: 10.3390/jof8101069] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 09/28/2022] [Accepted: 10/07/2022] [Indexed: 11/17/2022] Open
Abstract
Cryptococcus neoformans (C. neoformans) is a pathogenic fungus with a global distribution. Humans become infected by inhaling the fungus from the environment, and the fungus initially colonizes the lungs. If the immune system fails to contain C. neoformans in the lungs, the fungus can disseminate to the blood and invade the central nervous system, resulting in fatal meningoencephalitis particularly in immunocompromised individuals including HIV/AIDS patients. Following brain invasion, C. neoformans will encounter host defenses involving resident as well as recruited immune cells in the brain. To overcome host defenses, C. neoformans possesses multiple virulence factors capable of modulating immune responses. The outcome of the interactions between the host and C. neoformans will determine the disease progression. In this review, we describe the current understanding of how C. neoformans migrates to the brain across the blood–brain barrier, and how the host immune system responds to the invading organism in the brain. We will also discuss the virulence factors that C. neoformans uses to modulate host immune responses.
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11
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Abstract
Cryptococcosis is a disease caused by the pathogenic fungi Cryptococcus neoformans and Cryptococcus gattii, both environmental fungi that cause severe pneumonia and may even lead to cryptococcal meningoencephalitis. Although C. neoformans affects more fragile individuals, such as immunocompromised hosts through opportunistic infections, C. gattii causes a serious indiscriminate primary infection in immunocompetent individuals. Typically seen in tropical and subtropical environments, C. gattii has increased its endemic area over recent years, largely due to climatic factors that favor contagion in warmer climates. It is important to point out that not only C. gattii, but the Cryptococcus species complex produces a polysaccharidic capsule with immunomodulatory properties, enabling the pathogenic species of Cryptococccus to subvert the host immune response during the establishment of cryptococcosis, facilitating its dissemination in the infected organism. C. gattii causes a more severe and difficult-to-treat infection, with few antifungals eliciting an effective response during chronic treatment. Much of the immunopathology of this cryptococcosis is still poorly understood, with most studies focusing on cryptococcosis caused by the species C. neoformans. C. gattii became more important in the epidemiological scenario with the outbreaks in the Pacific Northwest of the United States, which resulted in phylogenetic studies of the virulent variant responsible for the severe infection in the region. Since then, the study of cryptococcosis caused by C. gattii has helped researchers understand the immunopathological aspects of different variants of this pathogen.
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12
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Gibson JF, Bojarczuk A, Evans RJ, Kamuyango AA, Hotham R, Lagendijk AK, Hogan BM, Ingham PW, Renshaw SA, Johnston SA. Blood vessel occlusion by Cryptococcus neoformans is a mechanism for haemorrhagic dissemination of infection. PLoS Pathog 2022; 18:e1010389. [PMID: 35446924 PMCID: PMC9022829 DOI: 10.1371/journal.ppat.1010389] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 02/21/2022] [Indexed: 11/18/2022] Open
Abstract
Meningitis caused by infectious pathogens is associated with vessel damage and infarct formation, however the physiological cause is often unknown. Cryptococcus neoformans is a human fungal pathogen and causative agent of cryptococcal meningitis, where vascular events are observed in up to 30% of patients, predominantly in severe infection. Therefore, we aimed to investigate how infection may lead to vessel damage and associated pathogen dissemination using a zebrafish model that permitted noninvasive in vivo imaging. We find that cryptococcal cells become trapped within the vasculature (dependent on their size) and proliferate there resulting in vasodilation. Localised cryptococcal growth, originating from a small number of cryptococcal cells in the vasculature was associated with sites of dissemination and simultaneously with loss of blood vessel integrity. Using a cell-cell junction tension reporter we identified dissemination from intact blood vessels and where vessel rupture occurred. Finally, we manipulated blood vessel tension via cell junctions and found increased tension resulted in increased dissemination. Our data suggest that global vascular vasodilation occurs following infection, resulting in increased vessel tension which subsequently increases dissemination events, representing a positive feedback loop. Thus, we identify a mechanism for blood vessel damage during cryptococcal infection that may represent a cause of vascular damage and cortical infarction during cryptococcal meningitis. Meningitis is a life threatening form of infection in the brain that is difficult to treat. How infection spreads from the blood to cause meningitis is not well understood. Here we have shown how infection with the fungus Cryptococcus neoformans can be spread from the blood by blocking and bursting blood vessels. Using zebrafish larvae, we were able to follow the same infections over a period of days to understand how this infection behaves in blood vessels. We found that fungal cells become stuck within blood vessels depending on their size. These cells grow within blood vessels, resulting in the blood vessels becoming wider. We measured increased tension in blood vessels suggesting that, with the bloackage and widening of vessels, there was increased local blood pressure. We found that vessel blockage was associated with their rupture and spreading of fungus into the surround tissue. Finally, by increasing the tension in vessels we could increase the number of blood bursting events supporting our conclusion that blood vessel blockage leads to the spread of the infection outside of blood vessels.
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Affiliation(s)
- Josie F. Gibson
- Department of Infection, Immunity and Cardiovascular disease, Bateson Centre and Florey Institute, University of Sheffield, United Kingdom
- Institute of Molecular and Cell Biology, Agency of Science, Technology and Research (A-Star), Singapore
| | - Aleksandra Bojarczuk
- Department of Infection, Immunity and Cardiovascular disease, Bateson Centre and Florey Institute, University of Sheffield, United Kingdom
- Faculty of Physical Education, Gdansk University of Physical Education and Sport, Gdansk, Poland
| | - Robert J. Evans
- Department of Infection, Immunity and Cardiovascular disease, Bateson Centre and Florey Institute, University of Sheffield, United Kingdom
| | - Alfred Alinafe Kamuyango
- Department of Infection, Immunity and Cardiovascular disease, Bateson Centre and Florey Institute, University of Sheffield, United Kingdom
| | - Richard Hotham
- Department of Infection, Immunity and Cardiovascular disease, Bateson Centre and Florey Institute, University of Sheffield, United Kingdom
| | - Anne K. Lagendijk
- Division of Genomics of Development and Disease, Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia
| | - Benjamin M. Hogan
- Division of Genomics of Development and Disease, Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia
| | - Philip W. Ingham
- Institute of Molecular and Cell Biology, Agency of Science, Technology and Research (A-Star), Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Stephen A. Renshaw
- Department of Infection, Immunity and Cardiovascular disease, Bateson Centre and Florey Institute, University of Sheffield, United Kingdom
| | - Simon A. Johnston
- Department of Infection, Immunity and Cardiovascular disease, Bateson Centre and Florey Institute, University of Sheffield, United Kingdom
- * E-mail:
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13
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Rathore SS, Sathiyamoorthy J, Lalitha C, Ramakrishnan J. A holistic review on Cryptococcus neoformans. Microb Pathog 2022; 166:105521. [DOI: 10.1016/j.micpath.2022.105521] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 04/06/2022] [Accepted: 04/06/2022] [Indexed: 12/21/2022]
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14
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Wang Y, Pawar S, Dutta O, Wang K, Rivera A, Xue C. Macrophage Mediated Immunomodulation During Cryptococcus Pulmonary Infection. Front Cell Infect Microbiol 2022; 12:859049. [PMID: 35402316 PMCID: PMC8987709 DOI: 10.3389/fcimb.2022.859049] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 02/28/2022] [Indexed: 12/21/2022] Open
Abstract
Macrophages are key cellular components of innate immunity, acting as the first line of defense against pathogens to modulate homeostatic and inflammatory responses. They help clear pathogens and shape the T-cell response through the production of cytokines and chemokines. The facultative intracellular fungal pathogen Cryptococcus neoformans has developed a unique ability to interact with and manipulate host macrophages. These interactions dictate how Cryptococcus infection can remain latent or how dissemination within the host is achieved. In addition, differences in the activities of macrophages have been correlated with differential susceptibilities of hosts to Cryptococcus infection, highlighting the importance of macrophages in determining disease outcomes. There is now abundant information on the interaction between Cryptococcus and macrophages. In this review we discuss recent advances regarding macrophage origin, polarization, activation, and effector functions during Cryptococcus infection. The importance of these strategies in pathogenesis and the potential of immunotherapy for cryptococcosis treatment is also discussed.
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Affiliation(s)
- Yan Wang
- Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, NJ, United States
- Department of Microbiology and Immunology , Guangdong Medical University, Dongguan, China
| | - Siddhi Pawar
- Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, NJ, United States
| | - Orchi Dutta
- Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, NJ, United States
| | - Keyi Wang
- Center for Immunity and Inflammation, New Jersey Medical School, Rutgers University, Newark, NJ, United States
| | - Amariliz Rivera
- Center for Immunity and Inflammation, New Jersey Medical School, Rutgers University, Newark, NJ, United States
| | - Chaoyang Xue
- Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, NJ, United States
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15
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Abstract
The pathogenic potential (PP) concept posits that all microorganisms have some pathogenic potential that can be calculated by an equation that includes the fraction symptomatic, inoculum, and mortality fraction. The PP concept dispenses with characterizing microbes as pathogens, nonpathogens, commensals, pathobionts, etc., by providing an alternative approach to the problem of virulence that considers the contributions of both the host and the microbe. Here, the PP concept is extended to incorporate the role of time in virulence by introducing a new parameter, fulminancy, which is a measure of the rapidity of the pathogenic process. Fulminancy allows PP calculations in situations where all hosts are affected equally, but the process occurs later for attenuated strains. Differences in the PP of wild-type and mutant microbes lacking virulence factors can be used to estimate the contribution of virulence factors to the pathogenic process, thus providing a new quantitative approach to these important pathogenicity parameters.
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16
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Abstract
Invasive fungal diseases are rare in individuals with intact immunity. This, together with the fact that there are only a few species that account for most mycotic diseases, implies a remarkable natural resistance to pathogenic fungi. Mammalian immunity to fungi rests on two pillars, powerful immune mechanisms and elevated temperatures that create a thermal restriction zone for most fungal species. Conditions associated with increased susceptibility generally reflect major disturbances of immune function involving both the cellular and humoral innate and adaptive arms, which implies considerable redundancy in host defense mechanisms against fungi. In general, tissue fungal invasion is controlled through either neutrophil or granulomatous inflammation, depending on the fungal species. Neutrophils are critical against Candida spp. and Aspergillus spp. while macrophages are essential for controlling mycoses due to Cryptococcus spp., Histoplasma spp., and other fungi. The increasing number of immunocompromised patients together with climate change could significantly increase the prevalence of fungal diseases. Expected final online publication date for the Annual Review of Immunology, Volume 40 is April 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins School of Public Health, Baltimore, Maryland, USA
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17
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The Environmental Effects on Virulence Factors and the Antifungal Susceptibility of Cryptococcus neoformans. Int J Mol Sci 2021; 22:ijms22126302. [PMID: 34208294 PMCID: PMC8230809 DOI: 10.3390/ijms22126302] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 06/09/2021] [Accepted: 06/10/2021] [Indexed: 01/10/2023] Open
Abstract
Cryptococcus neoformans is a facultative intracellular pathogen responsible for fungal meningoencephalitis primarily in immunocompromised individuals. It has become evident the pathogenicity of C. neoformans is dependent on the fungal cell’s environment. The differential expression of virulence factors, based on the cell’s environmental conditions, is one mechanism allowing for the environmental control of the pathogenic ability of C. neoformans. Here, we discuss how these virulence factors (including melanin, the polysaccharide capsule, and Antiphagocytic protein 1) have been shown to be differentially expressed dependent on the cell’s environment. The genetics and signaling pathways leading to the environmental-dependent regulation of virulence factors will also be examined. Susceptibility to antifungal therapeutics is also regulated by the environment, and thus affects the pathogenic abilities of C. neoformans and disease outcomes. This review will also examine the role of the C. neoformans’s environment on antifungal susceptibilities, and the genetics and signaling pathways responsible for these susceptibility alterations. By examining the complex interplay between the environment and the pathogenicity of C. neoformans, we have a better understanding of the intricacies of the pathogen–environment interaction and how to exploit this interaction to develop the most effective treatment protocols.
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18
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Fu MS, Liporagi-Lopes LC, Dos Santos SR, Tenor JL, Perfect JR, Cuomo CA, Casadevall A. Amoeba Predation of Cryptococcus neoformans Results in Pleiotropic Changes to Traits Associated with Virulence. mBio 2021; 12:e00567-21. [PMID: 33906924 PMCID: PMC8092252 DOI: 10.1128/mbio.00567-21] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 03/30/2021] [Indexed: 11/20/2022] Open
Abstract
Amoeboid predators, such as amoebae, are proposed to select for survival traits in soil microbes such as Cryptococcus neoformans; these traits can also function in animal virulence by defeating phagocytic immune cells, such as macrophages. Consistent with this notion, incubation of various fungal species with amoebae enhanced their virulence, but the mechanisms involved are unknown. In this study, we exposed three strains of C. neoformans (1 clinical and 2 environmental) to predation by Acanthamoeba castellanii for prolonged times and then analyzed surviving colonies phenotypically and genetically. Surviving colonies comprised cells that expressed either pseudohyphal or yeast phenotypes, which demonstrated variable expression of traits associated with virulence, such as capsule size, urease production, and melanization. Phenotypic changes were associated with aneuploidy and DNA sequence mutations in some amoeba-passaged isolates, but not in others. Mutations in the gene encoding the oligopeptide transporter (CNAG_03013; OPT1) were observed among amoeba-passaged isolates from each of the three strains. Isolates derived from environmental strains gained the capacity for enhanced macrophage toxicity after amoeba selection and carried mutations on the CNAG_00570 gene encoding Pkr1 (AMP-dependent protein kinase regulator) but manifested reduced virulence in mice because they elicited more effective fungal-clearing immune responses. Our results indicate that C. neoformans survival under constant amoeba predation involves the generation of strains expressing pleiotropic phenotypic and genetic changes. Given the myriad potential predators in soils, the diversity observed among amoeba-selected strains suggests a bet-hedging strategy whereby variant diversity increases the likelihood that some will survive predation.IMPORTANCECryptococcus neoformans is a ubiquitous environmental fungus that is also a leading cause of fatal fungal infection in humans, especially among immunocompromised patients. A major question in the field is how an environmental yeast such as C. neoformans becomes a human pathogen when it has no need for an animal host in its life cycle. Previous studies showed that C. neoformans increases its pathogenicity after interacting with its environmental predator amoebae. Amoebae, like macrophages, are phagocytic cells that are considered an environmental training ground for pathogens to resist macrophages, but the mechanism by which C. neoformans changes its virulence through interactions with protozoa is unknown. Our study indicates that fungal survival in the face of amoeba predation is associated with the emergence of pleiotropic phenotypic and genomic changes that increase the chance of fungal survival, with this diversity suggesting a bet-hedging strategy to ensure that some forms survive.
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Affiliation(s)
- Man Shun Fu
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Livia C Liporagi-Lopes
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Samuel R Dos Santos
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Jennifer L Tenor
- Division of Infectious Diseases, Department of Medicine and Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, USA
| | - John R Perfect
- Division of Infectious Diseases, Department of Medicine and Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, USA
| | - Christina A Cuomo
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, Massachusetts, USA
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
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19
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Associations between Cryptococcus Genotypes, Phenotypes, and Clinical Parameters of Human Disease: A Review. J Fungi (Basel) 2021; 7:jof7040260. [PMID: 33808500 PMCID: PMC8067209 DOI: 10.3390/jof7040260] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 03/25/2021] [Accepted: 03/25/2021] [Indexed: 12/11/2022] Open
Abstract
The genus Cryptococcus contains two primary species complexes that are significant opportunistic human fungal pathogens: C. neoformans and C. gattii. In humans, cryptococcosis can manifest in many ways, but most often results in either pulmonary or central nervous system disease. Patients with cryptococcosis can display a variety of symptoms on a spectrum of severity because of the interaction between yeast and host. The bulk of our knowledge regarding Cryptococcus and the mechanisms of disease stem from in vitro experiments and in vivo animal models that make a fair attempt, but do not recapitulate the conditions inside the human host. To better understand the dynamics of initiation and progression in cryptococcal disease, it is important to study the genetic and phenotypic differences in the context of human infection to identify the human and fungal risk factors that contribute to pathogenesis and poor clinical outcomes. In this review, we summarize the current understanding of the different clinical presentations and health outcomes that are associated with pathogenicity and virulence of cryptococcal strains with respect to specific genotypes and phenotypes.
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20
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F. Q. Smith D, Casadevall A. Fungal immunity and pathogenesis in mammals versus the invertebrate model organism Galleria mellonella. Pathog Dis 2021; 79:ftab013. [PMID: 33544836 PMCID: PMC7981337 DOI: 10.1093/femspd/ftab013] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 02/03/2021] [Indexed: 02/07/2023] Open
Abstract
In recent decades, Galleria mellonella (Lepidoptera: Pyralidae) have emerged as a model system to explore experimental aspects of fungal pathogenesis. The benefits of the G. mellonella model include being faster, cheaper, higher throughput and easier compared with vertebrate models. Additionally, as invertebrates, their use is subject to fewer ethical and regulatory issues. However, for G. mellonella models to provide meaningful insight into fungal pathogenesis, the G. mellonella-fungal interactions must be comparable to mammalian-fungal interactions. Indeed, as discussed in the review, studies suggest that G. mellonella and mammalian immune systems share many similarities, and fungal virulence factors show conserved functions in both hosts. While the moth model has opened novel research areas, many comparisons are superficial and leave large gaps of knowledge that need to be addressed concerning specific mechanisms underlying G. mellonella-fungal interactions. Closing these gaps in understanding will strengthen G. mellonella as a model for fungal virulence in the upcoming years. In this review, we provide comprehensive comparisons between fungal pathogenesis in mammals and G. mellonella from immunological and virulence perspectives. When information on an antifungal immune component is unknown in G. mellonella, we include findings from other well-studied Lepidoptera. We hope that by outlining this information available in related species, we highlight areas of needed research and provide a framework for understanding G. mellonella immunity and fungal interactions.
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Affiliation(s)
- Daniel F. Q. Smith
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Arturo Casadevall
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
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21
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Araújo GRDS, Alcantara CDL, Rodrigues N, de Souza W, Pontes B, Frases S. Ultrastructural Study of Cryptococcus neoformans Surface During Budding Events. Front Microbiol 2021; 12:609244. [PMID: 33732220 PMCID: PMC7957021 DOI: 10.3389/fmicb.2021.609244] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 02/10/2021] [Indexed: 11/25/2022] Open
Abstract
Cryptococcus neoformans is a fungal pathogen that causes life-threatening infections in immunocompromised individuals. It is surrounded by three concentric structures that separate the cell from the extracellular space: the plasma membrane, the cell wall and the polysaccharide (PS) capsule. Although several studies have revealed the chemical composition of these structures, little is known about their ultrastructural organization and remodeling during C. neoformans budding events. Here, by combining the latest and most accurate light and electron microscopy techniques, we describe the morphological remodeling that occurs among the capsule, cell wall and plasma membrane during budding in C. neoformans. Our results show that the cell wall deforms to generate a specialized region at one of the cell’s poles. This region subsequently begins to break into layers that are slightly separated from each other and with thick tips. We also observe a reorganization of the capsular PS around the specialized regions. While daughter cells present their PS fibers aligned in the direction of budding, mother cells show a similar pattern but in the opposite direction. Also, daughter cells form multilamellar membrane structures covering the continuous opening between both cells. Together, our findings provide compelling ultrastructural evidence for C. neoformans surface remodeling during budding, which may have important implications for future studies exploring these remodeled specialized regions as drug-targets against cryptococcosis.
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Affiliation(s)
- Glauber R de S Araújo
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Laboratório de Biofísica de Fungos, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Carolina de L Alcantara
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Noêmia Rodrigues
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Wanderley de Souza
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Centro Nacional de Biologia Estrutural e Bioimagem (CENABIO), Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Bruno Pontes
- Centro Nacional de Biologia Estrutural e Bioimagem (CENABIO), Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Laboratório de Pinças Óticas (LPO-COPEA), Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Susana Frases
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Laboratório de Biofísica de Fungos, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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22
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da Silva-Junior EB, Firmino-Cruz L, Guimarães-de-Oliveira JC, De-Medeiros JVR, de Oliveira Nascimento D, Freire-de-Lima M, de Brito-Gitirana L, Morrot A, Previato JO, Mendonça-Previato L, Decote-Ricardo D, de Matos Guedes HL, Freire-de-Lima CG. The role of Toll-like receptor 9 in a murine model of Cryptococcus gattii infection. Sci Rep 2021; 11:1407. [PMID: 33446850 PMCID: PMC7809259 DOI: 10.1038/s41598-021-80959-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 12/31/2020] [Indexed: 02/07/2023] Open
Abstract
Toll-like receptor 9 (TLR9) is crucial to the host immune response against fungi, such as Candida albicans, Aspergillus fumigatus and Cryptococcus neoformans, but its importance in Cryptococcus gattii infection is unknown. Our study aimed to understand the role of TLR9 during the course of experimental C. gattii infection in vivo, considering that the cryptococcal DNA interaction with the receptor could contribute to host immunity even in an extremely susceptible model. We inoculated C57BL/6 (WT) and TLR9 knock-out (TLR9−/−) mice intratracheally with 104C. gattii yeast cells. TLR9−/− mice had a higher mortality rate compared to WT mice and more yeast cells that had abnormal size, known as titan cells, in the lungs. TLR9−/− mice also had a greater number of CFUs in the spleen and brain than WT mice, in addition to having lower levels of IFN-γ and IL-17 in the lung. With these markers of aggressive cryptococcosis, we can state that TLR9−/− mice are more susceptible to C. gattii, probably due to a mechanism associated with the decrease of a Th1 and Th17-type immune response that promotes the formation of titan cells in the lungs. Therefore, our results indicate the participation of TLR9 in murine resistance to C. gattii infection.
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Affiliation(s)
- Elias Barbosa da Silva-Junior
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-900, Brazil
| | - Luan Firmino-Cruz
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-900, Brazil.,Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, 21045-900, Brazil
| | | | - Juliana Valente Rodrigues De-Medeiros
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-900, Brazil.,Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, 21045-900, Brazil
| | | | - Matheus Freire-de-Lima
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-900, Brazil
| | - Lycia de Brito-Gitirana
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-900, Brazil
| | - Alexandre Morrot
- Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, 21045-900, Brazil.,Faculdade de Medicina, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-900, Brazil
| | - Jose Osvaldo Previato
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-900, Brazil
| | - Lucia Mendonça-Previato
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-900, Brazil
| | - Debora Decote-Ricardo
- Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, 23890-000, Brazil.
| | - Herbert Leonel de Matos Guedes
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-900, Brazil. .,Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, 21045-900, Brazil.
| | - Celio Geraldo Freire-de-Lima
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-900, Brazil.
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23
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García-Carnero LC, Martínez-Álvarez JA, Salazar-García LM, Lozoya-Pérez NE, González-Hernández SE, Tamez-Castrellón AK. Recognition of Fungal Components by the Host Immune System. Curr Protein Pept Sci 2021; 21:245-264. [PMID: 31889486 DOI: 10.2174/1389203721666191231105546] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 08/08/2019] [Accepted: 10/15/2019] [Indexed: 11/22/2022]
Abstract
By being the first point of contact of the fungus with the host, the cell wall plays an important role in the pathogenesis, having many molecules that participate as antigens that are recognized by immune cells, and also that help the fungus to establish infection. The main molecules reported to trigger an immune response are chitin, glucans, oligosaccharides, proteins, melanin, phospholipids, and others, being present in the principal pathogenic fungi with clinical importance worldwide, such as Histoplasma capsulatum, Paracoccidioides brasiliensis, Aspergillus fumigatus, Candida albicans, Cryptococcus neoformans, Blastomyces dermatitidis, and Sporothrix schenckii. Knowledge and understanding of how the immune system recognizes and responds to fungal antigens are relevant for the future research and development of new diagnostic tools and treatments for the control of mycosis caused by these fungi.
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Affiliation(s)
- Laura C García-Carnero
- Department of Biology, Exact and Natural Sciences Division, Universidad de Guanajuato, Guanajuato, Mexico
| | - José A Martínez-Álvarez
- Department of Biology, Exact and Natural Sciences Division, Universidad de Guanajuato, Guanajuato, Mexico
| | - Luis M Salazar-García
- Department of Biology, Exact and Natural Sciences Division, Universidad de Guanajuato, Guanajuato, Mexico
| | - Nancy E Lozoya-Pérez
- Department of Biology, Exact and Natural Sciences Division, Universidad de Guanajuato, Guanajuato, Mexico
| | | | - Alma K Tamez-Castrellón
- Department of Biology, Exact and Natural Sciences Division, Universidad de Guanajuato, Guanajuato, Mexico
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24
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Yu QK, Han LT, Wu YJ, Liu TB. The Role of Oxidoreductase-Like Protein Olp1 in Sexual Reproduction and Virulence of Cryptococcus neoformans. Microorganisms 2020; 8:microorganisms8111730. [PMID: 33158259 PMCID: PMC7694259 DOI: 10.3390/microorganisms8111730] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 10/31/2020] [Accepted: 11/03/2020] [Indexed: 11/16/2022] Open
Abstract
Cryptococcus neoformans is a basidiomycete human fungal pathogen causing lethal meningoencephalitis, mainly in immunocompromised patients. Oxidoreductases are a class of enzymes that catalyze redox, playing a crucial role in biochemical reactions. In this study, we identified one Cryptococcus oxidoreductase-like protein-encoding gene OLP1 and investigated its role in the sexual reproduction and virulence of C. neoformans. Gene expression patterns analysis showed that the OLP1 gene was expressed in each developmental stage of Cryptococcus, and the Olp1 protein was located in the cytoplasm of Cryptococcus cells. Although it produced normal major virulence factors such as melanin and capsule, the olp1Δ mutants showed growth defects on the yeast extract peptone dextrose (YPD) medium supplemented with lithium chloride (LiCl) and 5-fluorocytosine (5-FC). The fungal mating analysis showed that Olp1 is also essential for fungal sexual reproduction, as olp1Δ mutants show significant defects in hyphae growth and basidiospores production during bisexual reproduction. The fungal nuclei imaging showed that during the bilateral mating of olp1Δ mutants, the nuclei failed to undergo meiosis after fusion in the basidia, indicating that Olp1 is crucial for regulating meiosis during mating. Moreover, Olp1 was also found to be required for fungal virulence in C. neoformans, as the olp1Δ mutants showed significant virulence attenuation in a murine inhalation model. In conclusion, our results showed that the oxidoreductase-like protein Olp1 is required for both fungal sexual reproduction and virulence in C. neoformans.
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Affiliation(s)
- Qi-Kun Yu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; (Q.-K.Y.); (L.-T.H.); (Y.-J.W.)
- Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing 400715, China
| | - Lian-Tao Han
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; (Q.-K.Y.); (L.-T.H.); (Y.-J.W.)
- Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing 400715, China
| | - Yu-Juan Wu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; (Q.-K.Y.); (L.-T.H.); (Y.-J.W.)
- Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing 400715, China
| | - Tong-Bao Liu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; (Q.-K.Y.); (L.-T.H.); (Y.-J.W.)
- Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing 400715, China
- Correspondence: ; Tel.: +86-23-6825-1088
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Gaylord EA, Choy HL, Doering TL. Dangerous Liaisons: Interactions of Cryptococcus neoformans with Host Phagocytes. Pathogens 2020; 9:E891. [PMID: 33121050 PMCID: PMC7692806 DOI: 10.3390/pathogens9110891] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 10/22/2020] [Accepted: 10/25/2020] [Indexed: 02/07/2023] Open
Abstract
Cryptococcus neoformans is an opportunistic fungal pathogen and a leading cause of death in immunocompromised individuals. The interactions of this yeast with host phagocytes are critical to disease outcome, and C. neoformans is equipped with an array of factors to modulate these processes. Cryptococcal infection begins with the deposition of infectious particles into the lungs, where the fungal cells deploy various antiphagocytic factors to resist internalization by host cells. If the cryptococci are still engulfed, they can survive and proliferate within host cells by modulating the phagolysosome environment in which they reside. Lastly, cryptococcal cells may escape from phagocytes by host cell lysis, nonlytic exocytosis, or lateral cell-to-cell transfer. The interactions between C. neoformans and host phagocytes also influence the dissemination of this pathogen to the brain, where it may cross the blood-brain barrier and cause an often-fatal meningoencephalitis. In this review, we highlight key cryptococcal factors involved in various stages of cryptococcal-host interaction and pathogenesis.
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Affiliation(s)
| | | | - Tamara L. Doering
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO 63110, USA; (E.A.G.); (H.L.C.)
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Khodadadi F, González JB, Martin PL, Giroux E, Bilodeau GJ, Peter KA, Doyle VP, Aćimović SG. Identification and characterization of Colletotrichum species causing apple bitter rot in New York and description of C. noveboracense sp. nov. Sci Rep 2020; 10:11043. [PMID: 32632221 PMCID: PMC7338416 DOI: 10.1038/s41598-020-66761-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Accepted: 05/27/2020] [Indexed: 11/21/2022] Open
Abstract
Apple bitter rot caused by Colletotrichum species is a growing problem worldwide. Colletotrichum spp. are economically important but taxonomically un-resolved. Identification of Colletotrichum spp. is critical due to potential species-level differences in pathogenicity-related characteristics. A 400-isolate collection from New York apple orchards were morphologically assorted to two groups, C. acutatum species complex (CASC) and C. gloeosporioides species complex (CGSC). A sub-sample of 44 representative isolates, spanning the geographical distribution and apple varieties, were assigned to species based on multi-locus phylogenetic analyses of nrITS, GAPDH and TUB2 for CASC, and ITS, GAPDH, CAL, ACT, TUB2, APN2, ApMat and GS genes for CGSC. The dominant species was C. fioriniae, followed by C. chrysophilum and a novel species, C. noveboracense, described in this study. This study represents the first report of C. chrysophilum and C. noveboracense as pathogens of apple. We assessed the enzyme activity and fungicide sensitivity for isolates identified in New York. All isolates showed amylolytic, cellulolytic and lipolytic, but not proteolytic activity. C. chrysophilum showed the highest cellulase and the lowest lipase activity, while C. noveboracense had the highest amylase activity. Fungicide assays showed that C. fioriniae was sensitive to benzovindiflupyr and thiabendazole, while C. chrysophilum and C. noveboracense were sensitive to fludioxonil, pyraclostrobin and difenoconazole. All species were pathogenic on apple fruit with varying lesion sizes. Our findings of differing pathogenicity-related characteristics among the three species demonstrate the importance of accurate species identification for any downstream investigations of Colletotrichum spp. in major apple growing regions.
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Affiliation(s)
- Fatemeh Khodadadi
- Cornell University, Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Hudson Valley Research Laboratory, Highland, NY, USA
| | - Jonathan B González
- Cornell University, Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Ithaca, NY, USA
| | - Phillip L Martin
- Pennsylvania State University, Department of Plant Pathology and Environmental Microbiology, Fruit Research and Extension Center, Biglerville, PA, USA
| | - Emily Giroux
- Pathogen Identification Research Laboratory, Canadian Food Inspection Agency, Ottawa, Ontario, Canada
| | - Guillaume J Bilodeau
- Pathogen Identification Research Laboratory, Canadian Food Inspection Agency, Ottawa, Ontario, Canada
| | - Kari A Peter
- Pennsylvania State University, Department of Plant Pathology and Environmental Microbiology, Fruit Research and Extension Center, Biglerville, PA, USA
| | - Vinson P Doyle
- Louisiana State University AgCenter, Department of Plant Pathology and Crop Physiology, Baton Rouge, Louisiana, USA
| | - Srđan G Aćimović
- Cornell University, Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Hudson Valley Research Laboratory, Highland, NY, USA.
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Liu M, Zhang Z, Ding C, Wang T, Kelly B, Wang P. Transcriptomic Analysis of Extracellular RNA Governed by the Endocytic Adaptor Protein Cin1 of Cryptococcus deneoformans. Front Cell Infect Microbiol 2020; 10:256. [PMID: 32656093 PMCID: PMC7324655 DOI: 10.3389/fcimb.2020.00256] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 05/01/2020] [Indexed: 12/31/2022] Open
Abstract
Membrane vesicles are considered virulence cargoes as they carry capsular and melanin components whose secretory transport is critical for the virulence of the human fungal pathogen Cryptococcus species. However, other components of the vesicles and their function in the growth and virulence of the fungus remain unclear. We have previously found that the cryptococcal intersectin protein Cin1 governs a unique Cin1-Wsp1-Cdc42 endocytic pathway required for intracellular transport and virulence. Using RNA sequencing, we compared the profiles of extracellular RNA (exRNA), including microRNA (miRNA), small interference RNA (siRNA), long noncoding RNA (lncRNA), and messenger RNA (mRNA) between the wild-type (WT), and derived Δcin1 mutant strains of Cryptococcus deneoformans. Seven hundred twelve miRNAs and 88 siRNAs were identified from WT, whereas 799 miRNAs and 66 siRNAs were found in Δcin1. Also, 572 lncRNAs and 7,721 mRNAs were identified from WT and 584 lncRNAs and 7,703 mRNAs from Δcin1. Differential expression analysis revealed that the disruption of CIN1 results in many important cellular changes, including those in exRNA expression, transport, and function. First, for miRNA target genes, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that cellular processes, components, and macromolecular functions are the most affected pathways. A higher number of genes were involved in the intracellular transport of endocytosis. Second, the results of GO term and KEGG analysis of differentially expressed lncRNA target genes and mRNA genes were consistent with those of miRNA targets. In particular, protein export is the topmost affected pathway among lncRNA target genes and one of the affected pathways among mRNA genes. The result of quantitative real-time reverse transcription PCR (qRT-PCR) from 12 mRNAs tested is largely agreeable with that of RNA-Seq. Taken together, our studies provide a comprehensive reference that Cryptococcus secretes abundant RNAs and that Cin1 plays a critical role in regulating their secretion. Given the growing clinical importance of exRNAs, our studies illuminate the significance of exploring this cutting-edge technology in studies of cryptococcal pathogenesis for the discovery of novel therapeutic strategies.
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Affiliation(s)
- Muxing Liu
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Zhengguang Zhang
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Chen Ding
- College of Life and Health Sciences, Northeastern University, Liaoning, China
| | - Tuo Wang
- Department of Chemistry, Louisiana State University, Baton Rouge, LA, United States
| | - Ben Kelly
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, United States
| | - Ping Wang
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, United States.,Department of Pediatrics, Louisiana State University Health Sciences Center, New Orleans, LA, United States
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Core N-Glycan Structures Are Critical for the Pathogenicity of Cryptococcus neoformans by Modulating Host Cell Death. mBio 2020; 11:mBio.00711-20. [PMID: 32398313 PMCID: PMC7218283 DOI: 10.1128/mbio.00711-20] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
We previously reported that the outer mannose chains of N-glycans are dispensable for the virulence of C. neoformans, which is in stark contrast to findings for the other human-pathogenic yeast, Candida albicans. Here, we present evidence that an intact core N-glycan structure is required for C. neoformans pathogenicity by systematically analyzing alg3Δ, alg9Δ, and alg12Δ strains that have defects in lipid-linked N-glycan assembly and in in vivo virulence. The alg null mutants producing truncated core N-glycans were defective in inducing host cell death after phagocytosis, which is triggered as a mechanism of pulmonary escape and dissemination of C. neoformans, thus becoming inactive in causing fatal infection. The results clearly demonstrated the critical features of the N-glycan structure in mediating the interaction with host cells during fungal infection. The delineation of the roles of protein glycosylation in fungal pathogenesis not only provides insight into the glycan-based fungal infection mechanism but also will aid in the development of novel antifungal agents. Cryptococcus neoformans is a human-pathogenic fungal pathogen that causes life-threatening meningoencephalitis in immunocompromised individuals. To investigate the roles of N-glycan core structure in cryptococcal pathogenicity, we constructed mutant strains of C. neoformans with defects in the assembly of lipid-linked N-glycans in the luminal side of the endoplasmic reticulum (ER). Deletion of ALG3 (alg3Δ), which encodes dolichyl-phosphate-mannose (Dol-P-Man)-dependent α-1,3-mannosyltransferase, resulted in the production of truncated neutral N-glycans carrying five mannose residues as a major species. Despite moderate or nondetectable defects in virulence-associated phenotypes in vitro, the alg3Δ mutant was avirulent in a mouse model of systemic cryptococcosis. Notably, the mutant did not show defects in early stages of host cell interaction during infection, including attachment to lung epithelial cells, opsonic/nonopsonic phagocytosis, and manipulation of phagosome acidification. However, the ability to drive macrophage cell death was greatly decreased in this mutant, without loss of cell wall remodeling capacity. Furthermore, deletion of ALG9 and ALG12, encoding Dol-P-Man-dependent α-1,2-mannosyltransferases and α-1,6-mannosyltransferases, generating truncated core N-glycans with six and seven mannose residues, respectively, also displayed remarkably reduced macrophage cell death and in vivo virulence. However, secretion levels of interleukin-1β (IL-1β) were not reduced in the bone marrow-derived dendritic cells obtained from Asc- and Gsdmd-deficient mice infected with the alg3Δ mutant strain, excluding the possibility that pyroptosis is a main host cell death pathway dependent on intact core N-glycans. Our results demonstrated N-glycan structures as a critical feature in modulating death of host cells, which is exploited by as a strategy for host cell escape for dissemination of C. neoformans.
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Fungal kinases and transcription factors regulating brain infection in Cryptococcus neoformans. Nat Commun 2020; 11:1521. [PMID: 32251295 PMCID: PMC7090016 DOI: 10.1038/s41467-020-15329-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 03/03/2020] [Indexed: 12/19/2022] Open
Abstract
Cryptococcus neoformans causes fatal fungal meningoencephalitis. Here, we study the roles played by fungal kinases and transcription factors (TFs) in blood-brain barrier (BBB) crossing and brain infection in mice. We use a brain infectivity assay to screen signature-tagged mutagenesis (STM)-based libraries of mutants defective in kinases and TFs, generated in the C. neoformans H99 strain. We also monitor in vivo transcription profiles of kinases and TFs during host infection using NanoString technology. These analyses identify signalling components involved in BBB adhesion and crossing, or survival in the brain parenchyma. The TFs Pdr802, Hob1, and Sre1 are required for infection under all the conditions tested here. Hob1 controls the expression of several factors involved in brain infection, including inositol transporters, a metalloprotease, PDR802, and SRE1. However, Hob1 is dispensable for most cellular functions in Cryptococcus deuterogattii R265, a strain that does not target the brain during infection. Our results indicate that Hob1 is a master regulator of brain infectivity in C. neoformans. Cryptococcus neoformans causes fatal fungal meningoencephalitis. Here, the authors identify fungal kinases and transcription factors involved in blood-brain barrier crossing and brain infection in mice.
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Evans RJ, Johnston SA. PPAR-gamma Fun(gi) With Prostaglandin. NUCLEAR RECEPTOR SIGNALING 2020; 17:1550762919899641. [PMID: 35582457 PMCID: PMC9109145 DOI: 10.1177/1550762919899641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 12/11/2019] [Indexed: 11/16/2022]
Abstract
In our recent publication, we show for the first time that the fungal pathogen Cryptococcus neoformans is able to manipulate host cells by producing eicosanoids that mimic those found in the host. Using complementary in vivo zebrafish and in vitro macrophage cell culture models of Cryptococcus infection, we found that these eicosanoids manipulate host innate immune cells by activating the host receptor PPAR-gamma which is an important regulator of macrophage inflammatory phenotypes. We initially identified PGE2 as the eicosanoid species responsible for this effect; however, we later found that a derivative of PGE2—15-keto-PGE2—was ultimately responsible and that this eicosanoid acted as a partial agonist to PPAR-gamma. In this commentary, we will discuss some of the concepts and conclusions in our original publication and expand on their implications and future directions.
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Aaron PA, Gelli A. Harnessing the Activity of the Fungal Metalloprotease, Mpr1, To Promote Crossing of Nanocarriers through the Blood-Brain Barrier. ACS Infect Dis 2020; 6:138-149. [PMID: 31820926 DOI: 10.1021/acsinfecdis.9b00348] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Cryptococcus neoformans (Cn) is the leading cause of fungal meningitis primarily in immunosuppressed patients. Cn invades the central nervous system by overcoming the highly restricted blood-brain barrier (BBB). We previously determined that a secreted fungal metalloprotease, Mpr1, that also confers crossing ability to yeast upon CnMPR1 expression in Saccharomyces cerevisiae is central to this process. This led us to question whether Mpr1 could be engineered to function as part of a nanocarrier delivery vehicle. Here, a eukaryotic expression system produced proteolytically active Mpr1 recombinant protein that was successfully conjugated to functionalized quantum dot (QD) nanoparticles and readily internalized by brain microvascular endothelial cells. An in vitro BBB model showed QD-Mpr1 crossed the BBB significantly better than mock QD, and QD-Mpr1 did not damage BBB integrity. Internalization of QD-Mpr1 occurred by membrane invaginations and endocytic pits typical of receptor-mediated endocytosis involving clathrin-coated entry points. This study substantiates the notion that fungal mechanisms of BBB entry may be harnessed for new drug delivery platform technologies.
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Affiliation(s)
- Phylicia A. Aaron
- Department of Pharmacology, School of Medicine, University of California, 3503 Genome and Biomedical Sciences Facility, 451 Health Sciences Drive, Davis, California 95616, United States
| | - Angie Gelli
- Department of Pharmacology, School of Medicine, University of California, 3503 Genome and Biomedical Sciences Facility, 451 Health Sciences Drive, Davis, California 95616, United States
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Seoane PI, May RC. Vomocytosis: What we know so far. Cell Microbiol 2019; 22:e13145. [PMID: 31730731 DOI: 10.1111/cmi.13145] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 10/23/2019] [Accepted: 10/26/2019] [Indexed: 01/10/2023]
Abstract
Vomocytosis, or nonlytic exocytosis, has been reported for Cryptococcus neoformans since 2006. Since then, the repertoire of vomocytosing pathogens and host cells has increased and so have the molecular components linked to vomocytosis occurrence. Nonetheless, the mechanism underlying this phenomenon, whether it is triggered by the host or the pathogen, and how it affects disease progression are still unresolved. This review contains a summary of the main findings regarding vomocytosis and the outstanding questions puzzling scientists to this day.
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Affiliation(s)
- Paula I Seoane
- Laboratory of Host and Pathogen Interactions, Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK
| | - Robin C May
- Laboratory of Host and Pathogen Interactions, Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK
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Denham ST, Wambaugh MA, Brown JCS. How Environmental Fungi Cause a Range of Clinical Outcomes in Susceptible Hosts. J Mol Biol 2019; 431:2982-3009. [PMID: 31078554 PMCID: PMC6646061 DOI: 10.1016/j.jmb.2019.05.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 04/18/2019] [Accepted: 05/01/2019] [Indexed: 12/11/2022]
Abstract
Environmental fungi are globally ubiquitous and human exposure is near universal. However, relatively few fungal species are capable of infecting humans, and among fungi, few exposure events lead to severe systemic infections. Systemic infections have mortality rates of up to 90%, cost the US healthcare system $7.2 billion annually, and are typically associated with immunocompromised patients. Despite this reputation, exposure to environmental fungi results in a range of outcomes, from asymptomatic latent infections to severe systemic infection. Here we discuss different exposure outcomes for five major fungal pathogens: Aspergillus, Blastomyces, Coccidioides, Cryptococcus, and Histoplasma species. These fungi include a mold, a budding yeast, and thermal dimorphic fungi. All of these species must adapt to dramatically changing environments over the course of disease. These dynamic environments include the human lung, which is the first exposure site for these organisms. Fungi must defend themselves against host immune cells while germinating and growing, which risks further exposing microbe-associated molecular patterns to the host. We discuss immune evasion strategies during early infection, from disruption of host immune cells to major changes in fungal cell morphology.
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Affiliation(s)
- Steven T Denham
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Morgan A Wambaugh
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Jessica C S Brown
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, UT 84132, USA.
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de Oliveira HC, Trevijano-Contador N, Garcia-Rodas R. Cryptococcal Pathogenicity and Morphogenesis. CURRENT FUNGAL INFECTION REPORTS 2019. [DOI: 10.1007/s12281-019-00340-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Sharapova I. Prospects of using entomopathogenic fungus in development of a biopesticide product with nematicidal activity. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2019. [DOI: 10.1016/j.bcab.2019.101098] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Evans RJ, Pline K, Loynes CA, Needs S, Aldrovandi M, Tiefenbach J, Bielska E, Rubino RE, Nicol CJ, May RC, Krause HM, O’Donnell VB, Renshaw SA, Johnston SA. 15-keto-prostaglandin E2 activates host peroxisome proliferator-activated receptor gamma (PPAR-γ) to promote Cryptococcus neoformans growth during infection. PLoS Pathog 2019; 15:e1007597. [PMID: 30921435 PMCID: PMC6438442 DOI: 10.1371/journal.ppat.1007597] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 01/25/2019] [Indexed: 12/19/2022] Open
Abstract
Cryptococcus neoformans is one of the leading causes of invasive fungal infection in humans worldwide. C. neoformans uses macrophages as a proliferative niche to increase infective burden and avoid immune surveillance. However, the specific mechanisms by which C. neoformans manipulates host immunity to promote its growth during infection remain ill-defined. Here we demonstrate that eicosanoid lipid mediators manipulated and/or produced by C. neoformans play a key role in regulating pathogenesis. C. neoformans is known to secrete several eicosanoids that are highly similar to those found in vertebrate hosts. Using eicosanoid deficient cryptococcal mutants Δplb1 and Δlac1, we demonstrate that prostaglandin E2 is required by C. neoformans for proliferation within macrophages and in vivo during infection. Genetic and pharmacological disruption of host PGE2 synthesis is not required for promotion of cryptococcal growth by eicosanoid production. We find that PGE2 must be dehydrogenated into 15-keto-PGE2 to promote fungal growth, a finding that implicated the host nuclear receptor PPAR-γ. C. neoformans infection of macrophages activates host PPAR-γ and its inhibition is sufficient to abrogate the effect of 15-keto-PGE2 in promoting fungal growth during infection. Thus, we describe the first mechanism of reliance on pathogen-derived eicosanoids in fungal pathogenesis and the specific role of 15-keto-PGE2 and host PPAR-γ in cryptococcosis. Cryptococcus neoformans is an opportunistic fungal pathogen that is responsible for significant numbers of deaths in the immunocompromised population worldwide. Here we address whether eicosanoids produced by C. neoformans manipulate host innate immune cells during infection. Cryptococcus neoformans produces several eicosanoids that are notable for their similarity to vertebrate eicosanoids, it is therefore possible that fungal-derived eicosanoids may provoke physiological effects in the host. Using a combination of in vitro and in vivo infection models we identify a specific eicosanoid species—prostaglandin E2 –that is required by C. neoformans for growth during infection. We subsequently show that prostaglandin E2 must be converted to 15-keto-prostaglandin E2 within the host before it has these effects. Furthermore, we find that prostaglandin E2/15-keto-prostaglandin E2 mediated virulence is via activation of host PPAR-γ –an intracellular eicosanoid receptor known to interact with 15-keto-PGE2.
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Affiliation(s)
- Robert J. Evans
- Bateson Centre, Firth Court, University of Sheffield, Sheffield, South Yorkshire, United Kingdom
- Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, South Yorkshire, United Kingdom
| | - Katherine Pline
- Bateson Centre, Firth Court, University of Sheffield, Sheffield, South Yorkshire, United Kingdom
- Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, South Yorkshire, United Kingdom
| | - Catherine A. Loynes
- Bateson Centre, Firth Court, University of Sheffield, Sheffield, South Yorkshire, United Kingdom
- Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, South Yorkshire, United Kingdom
| | - Sarah Needs
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, West Midlands, United Kingdom
| | - Maceler Aldrovandi
- Systems Immunity Research Institute, and Division of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, South Glamorgan, United Kingdom
| | - Jens Tiefenbach
- Banting and Best Department of Medical Research, The Terrence Donnelly Centre for Cellular and Biomolecular Research (CCBR), University of Toronto, Toronto, Ontario, Canada
- InDanio Bioscience Inc., Toronto, Ontario, Canada
| | - Ewa Bielska
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, West Midlands, United Kingdom
| | - Rachel E. Rubino
- Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, Canada
| | - Christopher J. Nicol
- Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, Canada
| | - Robin C. May
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, West Midlands, United Kingdom
| | - Henry M. Krause
- Banting and Best Department of Medical Research, The Terrence Donnelly Centre for Cellular and Biomolecular Research (CCBR), University of Toronto, Toronto, Ontario, Canada
- InDanio Bioscience Inc., Toronto, Ontario, Canada
| | - Valerie B. O’Donnell
- Systems Immunity Research Institute, and Division of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, South Glamorgan, United Kingdom
| | - Stephen A. Renshaw
- Bateson Centre, Firth Court, University of Sheffield, Sheffield, South Yorkshire, United Kingdom
- Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, South Yorkshire, United Kingdom
| | - Simon A. Johnston
- Bateson Centre, Firth Court, University of Sheffield, Sheffield, South Yorkshire, United Kingdom
- Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, South Yorkshire, United Kingdom
- * E-mail:
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Westman J, Hube B, Fairn GD. Integrity under stress: Host membrane remodelling and damage by fungal pathogens. Cell Microbiol 2019; 21:e13016. [DOI: 10.1111/cmi.13016] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 01/30/2019] [Accepted: 02/05/2019] [Indexed: 12/28/2022]
Affiliation(s)
- Johannes Westman
- Program in Cell Biology The Hospital for Sick Children Toronto Ontario Canada
| | - Bernhard Hube
- Department Microbial Pathogenicity Mechanisms Hans Knoell Institute Jena Germany
- Institute of Microbiology Microbial Pathogenicity Friedrich Schiller University Jena Germany
| | - Gregory D. Fairn
- Keenan Research Centre for Biomedical Sciences St. Michael's Hospital Toronto Ontario Canada
- Department of Surgery University of Toronto Toronto Ontario Canada
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38
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Shourian M, Qureshi ST. Resistance and Tolerance to Cryptococcal Infection: An Intricate Balance That Controls the Development of Disease. Front Immunol 2019; 10:66. [PMID: 30761136 PMCID: PMC6361814 DOI: 10.3389/fimmu.2019.00066] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 01/11/2019] [Indexed: 12/25/2022] Open
Abstract
Cryptococcus neoformans is a ubiquitous environmental yeast and a leading cause of invasive fungal infection in humans. The most recent estimate of global disease burden includes over 200,000 cases of cryptococcal meningitis each year. Cryptococcus neoformans expresses several virulence factors that may have originally evolved to protect against environmental threats, and human infection may be an unintended consequence of these acquired defenses. Traditionally, C. neoformans has been viewed as a purely opportunistic pathogen that targets severely immune compromised hosts; however, during the past decade the spectrum of susceptible individuals has grown considerably. In addition, the closely related strain Cryptococcus gattii has recently emerged in North America and preferentially targets individuals with intact immunity. In parallel to the changing epidemiology of cryptococcosis, an increasing role for host immunity in the pathogenesis of severe disease has been elucidated. Initially, the HIV/AIDS epidemic revealed the capacity of C. neoformans to cause host damage in the absence of adaptive immunity. Subsequently, the development and clinical implementation of highly active antiretroviral treatment (HAART) led to recognition of an immune reconstitution inflammatory syndrome (IRIS) in a subset of HIV+ individuals, demonstrating the pathological role of host immunity in disease. A post-infectious inflammatory syndrome (PIIRS) characterized by abnormal T cell-macrophage activation has also been documented in HIV-negative individuals following antifungal therapy. These novel clinical conditions illustrate the highly complex host-pathogen relationship that underlies severe cryptococcal disease and the intricate balance between tolerance and resistance that is necessary for effective resolution. In this article, we will review current knowledge of the interactions between cryptococci and mammalian hosts that result in a tolerant phenotype. Future investigations in this area have potential for translation into improved therapies for affected individuals.
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Affiliation(s)
- Mitra Shourian
- Translational Research in Respiratory Diseases Program, Meakins-Christie Laboratories, Research Institute of the McGill University Health Centre, Montreal, QC, Canada.,Division of Experimental Medicine, Department of Medicine, McGill University Health Centre, Montreal, QC, Canada
| | - Salman T Qureshi
- Translational Research in Respiratory Diseases Program, Meakins-Christie Laboratories, Research Institute of the McGill University Health Centre, Montreal, QC, Canada.,Division of Experimental Medicine, Department of Medicine, McGill University Health Centre, Montreal, QC, Canada
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Rosowski EE, Knox BP, Archambault LS, Huttenlocher A, Keller NP, Wheeler RT, Davis JM. The Zebrafish as a Model Host for Invasive Fungal Infections. J Fungi (Basel) 2018; 4:jof4040136. [PMID: 30551557 PMCID: PMC6308935 DOI: 10.3390/jof4040136] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 12/10/2018] [Accepted: 12/11/2018] [Indexed: 12/14/2022] Open
Abstract
The zebrafish has become a widely accepted model host for studies of infectious disease, including fungal infections. The species is genetically tractable, and the larvae are transparent and amenable to prolonged in vivo imaging and small molecule screening. The aim of this review is to provide a thorough introduction into the published studies of fungal infection in the zebrafish and the specific ways in which this model has benefited the field. In doing so, we hope to provide potential new zebrafish researchers with a snapshot of the current toolbox and prior results, while illustrating how the model has been used well and where the unfulfilled potential of this model can be found.
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Affiliation(s)
- Emily E Rosowski
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53716, USA.
| | - Benjamin P Knox
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53716, USA.
| | - Linda S Archambault
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME 04469, USA.
| | - Anna Huttenlocher
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53716, USA.
- Department of Pediatrics, University of Wisconsin-Madison, Madison, WI 53792, USA.
| | - Nancy P Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53716, USA.
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA.
| | - Robert T Wheeler
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME 04469, USA.
- Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, ME 04469, USA.
| | - J Muse Davis
- Stead Family Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA.
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40
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Sang H, Hulvey JP, Green R, Xu H, Im J, Chang T, Jung G. A Xenobiotic Detoxification Pathway through Transcriptional Regulation in Filamentous Fungi. mBio 2018; 9:e00457-18. [PMID: 30018104 PMCID: PMC6050962 DOI: 10.1128/mbio.00457-18] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 06/22/2018] [Indexed: 12/12/2022] Open
Abstract
Fungi are known to utilize transcriptional regulation of genes that encode efflux transporters to detoxify xenobiotics; however, to date it is unknown how fungi transcriptionally regulate and coordinate different phases of detoxification system (phase I, modification; phase II, conjugation; and phase III, secretion). Here we present evidence of an evolutionary convergence between the fungal and mammalian lineages, whereby xenobiotic detoxification genes (phase I coding for cytochrome P450 monooxygenases [CYP450s] and phase III coding for ATP-binding cassette [ABC] efflux transporters) are transcriptionally regulated by structurally unrelated proteins. Following next-generation RNA sequencing (RNA-seq) analyses of a filamentous fungus, Sclerotinia homoeocarpa, the causal agent of dollar spot on turfgrasses, a multidrug resistant (MDR) field strain was found to overexpress phase I and III genes, coding for CYP450s and ABC transporters for xenobiotic detoxification. Furthermore, there was confirmation of a gain-of-function mutation of the fungus-specific transcription factor S. homoeocarpa XDR1 (ShXDR1), which is responsible for constitutive and induced overexpression of the phase I and III genes, resulting in resistance to multiple classes of fungicidal chemicals. This fungal pathogen detoxifies xenobiotics through coordinated transcriptional control of CYP450s, biotransforming xenobiotics with different substrate specificities and ABC transporters, excreting a broad spectrum of xenobiotics or biotransformed metabolites. A Botrytis cinerea strain harboring the mutated ShXDR1 showed increased expression of phase I (BcCYP65) and III (BcatrD) genes, resulting in resistance to fungicides. This indicates the regulatory system is conserved in filamentous fungi. This molecular genetic mechanism for xenobiotic detoxification in fungi holds potential for facilitating discovery of new antifungal drugs and further studies of convergent and divergent evolution of xenobiotic detoxification in eukaryote lineages.IMPORTANCE Emerging multidrug resistance (MDR) in pathogenic filamentous fungi is a significant threat to human health and agricultural production. Understanding mechanisms of MDR is essential to combating fungal pathogens; however, there is still limited information on MDR mechanisms conferred by xenobiotic detoxification. Here, we report for the first time that overexpression of phase I drug-metabolizing monooxygenases (cytochrome P450s) and phase III ATP-binding cassette efflux transporters is regulated by a gain-of-function mutation in the fungus-specific transcription factor in the MDR strains of the filamentous plant-pathogenic fungus Sclerotinia homoeocarpa This study establishes a novel molecular mechanism of MDR through the xenobiotic detoxification pathway in filamentous fungi, which may facilitate the discovery of new antifungal drugs to control pathogenic fungi.
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Affiliation(s)
- Hyunkyu Sang
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, Massachusetts, USA
| | - Jonathan P Hulvey
- Department of Biology, Eastern Connecticut State University, Willimantic, Connecticut, USA
| | - Robert Green
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, Massachusetts, USA
| | - Hao Xu
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Jeongdae Im
- Department of Civil Engineering, Kansas State University, Manhattan, Kansas, USA
| | - Taehyun Chang
- School of Ecology and Environmental System, Kyungpook National University, Sangju, South Korea
| | - Geunhwa Jung
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, Massachusetts, USA
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41
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De Leon-Rodriguez CM, Rossi DCP, Fu MS, Dragotakes Q, Coelho C, Guerrero Ros I, Caballero B, Nolan SJ, Casadevall A. The Outcome of the Cryptococcus neoformans-Macrophage Interaction Depends on Phagolysosomal Membrane Integrity. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2018; 201:583-603. [PMID: 29858266 PMCID: PMC6245949 DOI: 10.4049/jimmunol.1700958] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 05/08/2018] [Indexed: 01/15/2023]
Abstract
Cryptococcus neoformans is a fungal pathogen with worldwide distribution. C. neoformans resides within mature phagolysosomes where it often evades killing and replicates. C. neoformans induces phagolysosomal membrane permeabilization (PMP), but the mechanism for this phenomenon and its consequences for macrophage viability are unknown. In this study, we used flow cytometry methodology in combination with cell viability markers and LysoTracker to measure PMP in J774.16 and murine bone marrow-derived macrophages infected with C. neoformans Our results showed that cells manifesting PMP were positive for apoptotic markers, indicating an association between PMP and apoptosis. We investigated the role of phospholipase B1 in C. neoformans induction of PMP. Macrophages infected with a C. neoformans Δplb1 mutant had reduced PMP compared with those infected with wild-type and phospholipase B1-complemented strains, suggesting a mechanism of action for this virulence factor. Capsular enlargement inside macrophages was identified as an additional likely mechanism for phagolysosomal membrane damage. Macrophages undergoing apoptosis did not maintain an acidic phagolysosomal pH. Induction of PMP with ciprofloxacin enhanced macrophages to trigger lytic exocytosis whereas nonlytic exocytosis was common in those without PMP. Our results suggest that modulation of PMP is a critical event in determining the outcome of C. neoformans-macrophage interaction.
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Affiliation(s)
| | - Diego C P Rossi
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205
| | - Man Shun Fu
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205
| | - Quigly Dragotakes
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205
| | - Carolina Coelho
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205
| | - Ignacio Guerrero Ros
- Department of Pathology, Albert Einstein College of Medicine, New York, NY 10461; and
| | - Benjamin Caballero
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, New York, NY 10461
| | - Sabrina J Nolan
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205
| | - Arturo Casadevall
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, New York, NY 10461;
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205
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42
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Obando D, Koda Y, Pantarat N, Lev S, Zuo X, Bijosono Oei J, Widmer F, Djordjevic JT, Sorrell TC, Jolliffe KA. Synthesis and Evaluation of a Series of Bis(pentylpyridinium) Compounds as Antifungal Agents. ChemMedChem 2018; 13:1421-1436. [PMID: 29781143 DOI: 10.1002/cmdc.201800331] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Indexed: 01/05/2023]
Abstract
A series of bis(4-pentylpyridinium) compounds with a variety of spacers between the pyridinium headgroups was synthesised, and the antifungal activity of these compounds was investigated. Lengthening the alkyl spacer between the pentylpyridinium headgroups from 12 to 16 methylene units resulted in increased antifungal activity against C. neoformans and C. albicans, but also resulted in increased hemolytic activity and cytotoxicity against mammalian cells. However, inclusion of an ortho-substituted benzene ring in the centre of the alkyl spacer resulted in decreased cytotoxicity and hemolytic activity, while maintaining antifungal potency. Replacement of the alkyl and aromatic-containing spacers by more hydrophilic ethylene glycol groups resulted in a loss of antifungal activity. Some of the compounds inhibited fungal PLB1 activity, but the low correlation of this inhibition with antifungal potency indicates PLB1 inhibition is unlikely to be the predominant mode of antifungal action of this class of compounds, with preliminary studies suggesting they may act via disruption of fungal mitochondrial function.
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Affiliation(s)
- Daniel Obando
- School of Chemistry, The University of Sydney, 2006, NSW, Australia
| | - Yasuko Koda
- School of Chemistry, The University of Sydney, 2006, NSW, Australia.,The University of Sydney, Marie Bashir Institute for Infectious Diseases and Biosecurity, Centre for Infectious Diseases and Microbiology, Westmead Institute for Medical Research, Westmead, 2145, NSW, Australia
| | - Namfon Pantarat
- The University of Sydney, Marie Bashir Institute for Infectious Diseases and Biosecurity, Centre for Infectious Diseases and Microbiology, Westmead Institute for Medical Research, Westmead, 2145, NSW, Australia
| | - Sophie Lev
- The University of Sydney, Marie Bashir Institute for Infectious Diseases and Biosecurity, Centre for Infectious Diseases and Microbiology, Westmead Institute for Medical Research, Westmead, 2145, NSW, Australia
| | - Xiaoming Zuo
- The University of Sydney, Marie Bashir Institute for Infectious Diseases and Biosecurity, Centre for Infectious Diseases and Microbiology, Westmead Institute for Medical Research, Westmead, 2145, NSW, Australia
| | - Johanes Bijosono Oei
- The University of Sydney, Marie Bashir Institute for Infectious Diseases and Biosecurity, Centre for Infectious Diseases and Microbiology, Westmead Institute for Medical Research, Westmead, 2145, NSW, Australia
| | - Fred Widmer
- The University of Sydney, Marie Bashir Institute for Infectious Diseases and Biosecurity, Centre for Infectious Diseases and Microbiology, Westmead Institute for Medical Research, Westmead, 2145, NSW, Australia
| | - Julianne T Djordjevic
- The University of Sydney, Marie Bashir Institute for Infectious Diseases and Biosecurity, Centre for Infectious Diseases and Microbiology, Westmead Institute for Medical Research, Westmead, 2145, NSW, Australia
| | - Tania C Sorrell
- The University of Sydney, Marie Bashir Institute for Infectious Diseases and Biosecurity, Centre for Infectious Diseases and Microbiology, Westmead Institute for Medical Research, Westmead, 2145, NSW, Australia
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43
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Casadevall A, Coelho C, Alanio A. Mechanisms of Cryptococcus neoformans-Mediated Host Damage. Front Immunol 2018; 9:855. [PMID: 29760698 PMCID: PMC5936990 DOI: 10.3389/fimmu.2018.00855] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 04/06/2018] [Indexed: 01/22/2023] Open
Abstract
Cryptococcus neoformans is not usually considered a cytotoxic fungal pathogen but there is considerable evidence that this microbe can damage host cells and tissues. In this essay, we review the evidence that C. neoformans damages host cells and note that the mechanisms involved are diverse. We consider C. neoformans-mediated host damage at the molecular, cellular, tissue, and organism level. Direct mechanisms of cytotoxicity include lytic exocytosis, organelle dysfunction, phagolysosomal membrane damage, and cytoskeletal alterations. Cytotoxicity contributes to pathogenesis by interfering with immune effector cell function and disrupting endothelial barriers thus allowing dissemination. When C. neoformans-mediated and immune-mediated host damage is sufficient to affect homeostasis, cryptococcosis occurs at the organism level.
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Affiliation(s)
- Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins School of Public Health, Baltimore, MD, United States
| | - Carolina Coelho
- Department of Molecular Microbiology and Immunology, Johns Hopkins School of Public Health, Baltimore, MD, United States
| | - Alexandre Alanio
- Department of Molecular Microbiology and Immunology, Johns Hopkins School of Public Health, Baltimore, MD, United States
- Institut Pasteur, Molecular Mycology Unit, CNRS UMR2000, Paris, France
- Laboratoire de Parasitologie-Mycologie, Hôpital Saint-Louis, Groupe Hospitalier Lariboisière, Saint-Louis, Fernand Widal, Assistance Publique-Hôpitaux de Paris (AP-HP), Université Paris Diderot, Sorbonne Paris Cité, Paris, France
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44
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Esher SK, Zaragoza O, Alspaugh JA. Cryptococcal pathogenic mechanisms: a dangerous trip from the environment to the brain. Mem Inst Oswaldo Cruz 2018; 113:e180057. [PMID: 29668825 PMCID: PMC5909089 DOI: 10.1590/0074-02760180057] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 03/08/2018] [Indexed: 12/16/2022] Open
Abstract
Cryptococcus neoformans is an opportunistic pathogenic yeast that causes serious infections, most commonly of the central nervous system (CNS). C. neoformans is mainly found in the environment and acquired by inhalation. It could be metaphorically imagined that cryptococcal disease is a "journey" for the microorganism that starts in the environment, where this yeast loads its suitcase with virulence traits. C. neoformans first encounters the infected mammalian host in the lungs, a site in which it must choose the right elements from its "virulence suitcase" to survive the pulmonary immune response. However, the lung is often only the first stop in this journey, and in some individuals the fungal trip continues to the brain. To enter the brain, C. neoformans must "open" the main barrier that protects this organ, the blood brain barrier (BBB). Once in the brain, C. neoformans expresses a distinct set of protective attributes that confers a strong neurotropism and the ability to cause brain colonisation. In summary, C. neoformans is a unique fungal pathogen as shown in its ability to survive in the face of multiple stress factors and to express virulence factors that contribute to the development of disease.
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Affiliation(s)
- Shannon K Esher
- Duke University School of Medicine, Department of Molecular Genetics and Microbiology, Department of Medicine, Durham, USA
| | - Oscar Zaragoza
- Instituto de Salud Carlos III, National Centre for Microbiology, Mycology Reference Laboratory, Madrid, Spain
| | - James Andrew Alspaugh
- Duke University School of Medicine, Department of Molecular Genetics and Microbiology, Department of Medicine, Durham, USA
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45
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Watkins RA, Andrews A, Wynn C, Barisch C, King JS, Johnston SA. Cryptococcus neoformans Escape From Dictyostelium Amoeba by Both WASH-Mediated Constitutive Exocytosis and Vomocytosis. Front Cell Infect Microbiol 2018; 8:108. [PMID: 29686972 PMCID: PMC5900056 DOI: 10.3389/fcimb.2018.00108] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 03/19/2018] [Indexed: 01/01/2023] Open
Abstract
Cryptococcus neoformans is an environmental yeast that can cause opportunistic infections in humans. As infecting animals does not form part of its normal life-cycle, it has been proposed that the virulence traits that allow cryptococci to resist immune cells were selected through interactions with environmental phagocytes such as amoebae. Here, we investigate the interactions between C. neoformans and the social amoeba Dictyostelium discoideum. We show that like macrophages, D. discoideum is unable to kill C. neoformans upon phagocytosis. Despite this, we find that the yeast pass through the amoebae with an apparently normal phagocytic transit and are released alive by constitutive exocytosis after ~80 min. This is the canonical pathway in amoebae, used to dispose of indigestible material after nutrient extraction. Surprisingly however, we show that upon either genetic or pharmacological blockage of constitutive exocytosis, C. neoformans still escape from D. discoideum by a secondary mechanism. We demonstrate that constitutive exocytosis-independent egress is stochastic and actin-independent. This strongly resembles the non-lytic release of cryptococci by vomocytosis from macrophages, which do not perform constitutive exocytosis and normally retain phagocytosed material. Our data indicate that vomocytosis is functionally redundant for escape from amoebae, which thus may not be the primary driver for its evolutionary selection. Nonetheless, we show that vomocytosis of C. neoformans is mechanistically conserved in hosts ranging from amoebae to man, providing new avenues to understand this poorly-understood but important virulence mechanism.
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Affiliation(s)
- Rhys A. Watkins
- Bateson Centre, University of Sheffield, Sheffield, United Kingdom
- Department of Infection Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, United Kingdom
| | - Alexandre Andrews
- Bateson Centre, University of Sheffield, Sheffield, United Kingdom
- Department of Infection Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, United Kingdom
| | - Charlotte Wynn
- Bateson Centre, University of Sheffield, Sheffield, United Kingdom
- Department of Infection Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, United Kingdom
| | - Caroline Barisch
- Department of Biochemistry, Faculty of Science, University of Geneva, Geneva, Switzerland
| | - Jason S. King
- Bateson Centre, University of Sheffield, Sheffield, United Kingdom
- Department of Biomedical Sciences, University of Sheffield, Sheffield, United Kingdom
| | - Simon A. Johnston
- Bateson Centre, University of Sheffield, Sheffield, United Kingdom
- Department of Infection Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, United Kingdom
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46
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Phospholipases play multiple cellular roles including growth, stress tolerance, sexual development, and virulence in fungi. Microbiol Res 2018; 209:55-69. [DOI: 10.1016/j.micres.2017.12.012] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 12/21/2017] [Accepted: 12/31/2017] [Indexed: 12/16/2022]
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47
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Desjardins CA, Giamberardino C, Sykes SM, Yu CH, Tenor JL, Chen Y, Yang T, Jones AM, Sun S, Haverkamp MR, Heitman J, Litvintseva AP, Perfect JR, Cuomo CA. Population genomics and the evolution of virulence in the fungal pathogen Cryptococcus neoformans. Genome Res 2018; 27:1207-1219. [PMID: 28611159 PMCID: PMC5495072 DOI: 10.1101/gr.218727.116] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 05/01/2017] [Indexed: 12/23/2022]
Abstract
Cryptococcus neoformans is an opportunistic fungal pathogen that causes approximately 625,000 deaths per year from nervous system infections. Here, we leveraged a unique, genetically diverse population of C. neoformans from sub-Saharan Africa, commonly isolated from mopane trees, to determine how selective pressures in the environment coincidentally adapted C. neoformans for human virulence. Genome sequencing and phylogenetic analysis of 387 isolates, representing the global VNI and African VNB lineages, highlighted a deep, nonrecombining split in VNB (herein, VNBI and VNBII). VNBII was enriched for clinical samples relative to VNBI, while phenotypic profiling of 183 isolates demonstrated that VNBI isolates were significantly more resistant to oxidative stress and more heavily melanized than VNBII isolates. Lack of melanization in both lineages was associated with loss-of-function mutations in the BZP4 transcription factor. A genome-wide association study across all VNB isolates revealed sequence differences between clinical and environmental isolates in virulence factors and stress response genes. Inositol transporters and catabolism genes, which process sugars present in plants and the human nervous system, were identified as targets of selection in all three lineages. Further phylogenetic and population genomic analyses revealed extensive loss of genetic diversity in VNBI, suggestive of a history of population bottlenecks, along with unique evolutionary trajectories for mating type loci. These data highlight the complex evolutionary interplay between adaptation to natural environments and opportunistic infections, and that selection on specific pathways may predispose isolates to human virulence.
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Affiliation(s)
| | - Charles Giamberardino
- Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Sean M Sykes
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
| | - Chen-Hsin Yu
- Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Jennifer L Tenor
- Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Yuan Chen
- Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Timothy Yang
- Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Alexander M Jones
- Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Sheng Sun
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Miriam R Haverkamp
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Anastasia P Litvintseva
- Mycotic Diseases Branch, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30329, USA
| | - John R Perfect
- Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Christina A Cuomo
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
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48
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Rizzo J, Colombo AC, Zamith-Miranda D, Silva VKA, Allegood JC, Casadevall A, Del Poeta M, Nosanchuk JD, Kronstad JW, Rodrigues ML. The putative flippase Apt1 is required for intracellular membrane architecture and biosynthesis of polysaccharide and lipids in Cryptococcus neoformans. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2018; 1865:532-541. [PMID: 29291962 PMCID: PMC6052768 DOI: 10.1016/j.bbamcr.2017.12.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 12/15/2017] [Accepted: 12/28/2017] [Indexed: 12/27/2022]
Abstract
Flippases are responsible for the asymmetric distribution of phospholipids in biological membranes. In the encapsulated fungal pathogen Cryptococcus neoformans, the putative flippase Apt1 is an important regulator of polysaccharide secretion and pathogenesis in mice by unknown mechanisms. In this study, we analyzed the role of C. neoformans Apt1 in intracellular membrane architecture and synthesis of polysaccharide and lipids. Analysis of wild type (WT), apt1Δ (mutant) and apt1Δ::APT1 (complemented) strains by transmission electron microscopy revealed that deletion of APT1 resulted in the formation of irregular vacuoles. Disorganization of vacuolar membranes in apt1Δ cells was accompanied by a significant increase in the amounts of intra-vacuolar and pigment-containing vesicles. Quantitative immunogold labeling of C. neoformans cells with a monoclonal antibody raised to a major capsular component suggested impaired polysaccharide synthesis. APT1 deletion also affected synthesis of phosphatidylserine, phosphatidylethanolamine, inositolphosphoryl ceramide, glucosylceramide and ergosterylglycoside. These results reveal novel functions of Apt1 and are in agreement with the notion that this putative flippase plays an important role in the physiology of C. neoformans.
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Affiliation(s)
- Juliana Rizzo
- Centro de Desenvolvimento Tecnológico em Saúde (CDTS), Fundação Oswaldo Cruz, Rio de Janeiro, Brazil; Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Ana C Colombo
- Departments of Biochemistry and Molecular Genetics and Microbiology, Stony Brook University, New York, USA; Programa de Pós-Graduação em Química Biológica do Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Daniel Zamith-Miranda
- Departments of Medicine and Microbiology and Immunology, Albert Einstein College of Medicine, New York, USA
| | - Vanessa K A Silva
- Centro de Desenvolvimento Tecnológico em Saúde (CDTS), Fundação Oswaldo Cruz, Rio de Janeiro, Brazil; Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Programa de Pós-Graduação em Biologia Parasitária do Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Jeremy C Allegood
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, USA
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA
| | - Maurizio Del Poeta
- Departments of Biochemistry and Molecular Genetics and Microbiology, Stony Brook University, New York, USA; Veterans Administration Medical Center, Northport, USA; Division of Infectious Diseases, Stony Brook University, New York, USA
| | - Joshua D Nosanchuk
- Departments of Medicine and Microbiology and Immunology, Albert Einstein College of Medicine, New York, USA
| | - James W Kronstad
- Michael Smith Laboratories, Department of Microbiology and Immunology, Faculty of Land and Food Systems, The University of British Columbia, Vancouver, Canada
| | - Marcio L Rodrigues
- Centro de Desenvolvimento Tecnológico em Saúde (CDTS), Fundação Oswaldo Cruz, Rio de Janeiro, Brazil; Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
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49
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Li C, Lev S, Desmarini D, Kaufman-Francis K, Saiardi A, Silva APG, Mackay JP, Thompson PE, Sorrell TC, Djordjevic JT. IP 3-4 kinase Arg1 regulates cell wall homeostasis and surface architecture to promote clearance of Cryptococcus neoformans infection in a mouse model. Virulence 2017; 8:1833-1848. [PMID: 28976803 DOI: 10.1080/21505594.2017.1385692] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
We previously identified a series of inositol polyphosphate kinases (IPKs), Arg1, Ipk1, Kcs1 and Asp1, in the opportunistic fungal pathogen Cryptococcus neoformans. Using gene deletion analysis, we characterized Arg1, Ipk1 and Kcs1 and showed that they act sequentially to convert IP3 to PP-IP5 (IP7), a key metabolite promoting stress tolerance, metabolic adaptation and fungal dissemination to the brain. We have now directly characterized the enzymatic activity of Arg1, demonstrating that it is a dual specificity (IP3/IP4) kinase producing IP5. We showed previously that IP5 is further phosphorylated by Ipk1 to produce IP6, which is a substrate for the synthesis of PP-IP5 by Kcs1. Phenotypic comparison of the arg1Δ and kcs1Δ deletion mutants (both PP-IP5-deficient) reveals that arg1Δ has the most deleterious phenotype: while PP-IP5 is essential for metabolic and stress adaptation in both mutant strains, PP-IP5 is dispensable for virulence-associated functions such as capsule production, cell wall organization, and normal N-linked mannosylation of the virulence factor, phospholipase B1, as these phenotypes were defective only in arg1Δ. The more deleterious arg1Δ phenotype correlated with a higher rate of arg1Δ phagocytosis by human peripheral blood monocytes and rapid arg1Δ clearance from lung in a mouse model. This observation is in contrast to kcs1Δ, which we previously reported establishes a chronic, confined lung infection. In summary, we show that Arg1 is the most crucial IPK for cryptococcal virulence, conveying PP-IP5-dependent and novel PP-IP5-independent functions.
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Affiliation(s)
- Cecilia Li
- a Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research , 176 Hawkesbury road, Westmead NSW 2145 , Australia.,b Sydney Medical School-Westmead, The University of Sydney , Westmead NSW 2145 , Australia.,c Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney , NSW Australia
| | - Sophie Lev
- a Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research , 176 Hawkesbury road, Westmead NSW 2145 , Australia.,b Sydney Medical School-Westmead, The University of Sydney , Westmead NSW 2145 , Australia.,c Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney , NSW Australia
| | - Desmarini Desmarini
- a Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research , 176 Hawkesbury road, Westmead NSW 2145 , Australia
| | - Keren Kaufman-Francis
- a Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research , 176 Hawkesbury road, Westmead NSW 2145 , Australia.,c Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney , NSW Australia
| | - Adolfo Saiardi
- d Medical Research Council Laboratory for Molecular Cell Biology, University College London , Gower street, London WC1E 6BT , UK
| | - Ana P G Silva
- e School of Life and Environmental Sciences, The University of Sydney , Camperdown , NSW 2006 , Australia
| | - Joel P Mackay
- e School of Life and Environmental Sciences, The University of Sydney , Camperdown , NSW 2006 , Australia
| | - Philip E Thompson
- f Medicinal Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences , Monash University , 381 Royal Parade, Parkville , VIC 3052 , Australia
| | - Tania C Sorrell
- a Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research , 176 Hawkesbury road, Westmead NSW 2145 , Australia.,b Sydney Medical School-Westmead, The University of Sydney , Westmead NSW 2145 , Australia.,c Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney , NSW Australia.,g Westmead Hospital , Westmead , NSW 2145 , Australia
| | - Julianne T Djordjevic
- a Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research , 176 Hawkesbury road, Westmead NSW 2145 , Australia.,b Sydney Medical School-Westmead, The University of Sydney , Westmead NSW 2145 , Australia.,c Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney , NSW Australia.,g Westmead Hospital , Westmead , NSW 2145 , Australia
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50
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Squizani ED, Oliveira NK, Reuwsaat JCV, Marques BM, Lopes W, Gerber AL, de Vasconcelos ATR, Lev S, Djordjevic JT, Schrank A, Vainstein MH, Staats CC, Kmetzsch L. Cryptococcal dissemination to the central nervous system requires the vacuolar calcium transporter Pmc1. Cell Microbiol 2017; 20. [PMID: 29113016 DOI: 10.1111/cmi.12803] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 10/27/2017] [Accepted: 10/30/2017] [Indexed: 12/26/2022]
Abstract
Cryptococcus neoformans is a basidiomycetous yeast and the cause of cryptococcosis in immunocompromised individuals. The most severe form of the disease is meningoencephalitis, which is one of the leading causes of death in HIV/AIDS patients. In order to access the central nervous system, C. neoformans relies on the activity of certain virulence factors such as urease, which allows transmigration through the blood-brain barrier. In this study, we demonstrate that the calcium transporter Pmc1 enables C. neoformans to penetrate the central nervous system, because the pmc1 null mutant failed to infect and to survive within the brain parenchyma in a murine systemic infection model. To investigate potential alterations in transmigration pathways in these mutants, global expression profiling of the pmc1 mutant strain was undertaken, and genes associated with urease, the Ca2+ -calcineurin pathway, and capsule assembly were identified as being differentially expressed. Also, a decrease in urease activity was observed in the calcium transporter null mutants. Finally, we demonstrate that the transcription factor Crz1 regulates urease activity and that the Ca2+ -calcineurin signalling pathway positively controls the transcription of calcium transporter genes and factors related to transmigration.
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Affiliation(s)
| | | | | | | | - William Lopes
- Centro de Biotecnologia, UFRGS, Porto Alegre, RS, Brazil
| | - Alexandra L Gerber
- Laboratório Nacional de Computação Científica (LNCC), Petrópolis, RJ, Brazil
| | | | - Sophie Lev
- Fungal Pathogenesis Laboratory, Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Westmead, NSW, Australia
| | - Julianne T Djordjevic
- Fungal Pathogenesis Laboratory, Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Westmead, NSW, Australia
| | | | | | | | - Lívia Kmetzsch
- Centro de Biotecnologia, UFRGS, Porto Alegre, RS, Brazil
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