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Brown GD, Ballou ER, Bates S, Bignell EM, Borman AM, Brand AC, Brown AJP, Coelho C, Cook PC, Farrer RA, Govender NP, Gow NAR, Hope W, Hoving JC, Dangarembizi R, Harrison TS, Johnson EM, Mukaremera L, Ramsdale M, Thornton CR, Usher J, Warris A, Wilson D. The pathobiology of human fungal infections. Nat Rev Microbiol 2024:10.1038/s41579-024-01062-w. [PMID: 38918447 DOI: 10.1038/s41579-024-01062-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/14/2024] [Indexed: 06/27/2024]
Abstract
Human fungal infections are a historically neglected area of disease research, yet they cause more than 1.5 million deaths every year. Our understanding of the pathophysiology of these infections has increased considerably over the past decade, through major insights into both the host and pathogen factors that contribute to the phenotype and severity of these diseases. Recent studies are revealing multiple mechanisms by which fungi modify and manipulate the host, escape immune surveillance and generate complex comorbidities. Although the emergence of fungal strains that are less susceptible to antifungal drugs or that rapidly evolve drug resistance is posing new threats, greater understanding of immune mechanisms and host susceptibility factors is beginning to offer novel immunotherapeutic options for the future. In this Review, we provide a broad and comprehensive overview of the pathobiology of human fungal infections, focusing specifically on pathogens that can cause invasive life-threatening infections, highlighting recent discoveries from the pathogen, host and clinical perspectives. We conclude by discussing key future challenges including antifungal drug resistance, the emergence of new pathogens and new developments in modern medicine that are promoting susceptibility to infection.
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Affiliation(s)
- Gordon D Brown
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, UK.
| | - Elizabeth R Ballou
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Steven Bates
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Elaine M Bignell
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Andrew M Borman
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Alexandra C Brand
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Alistair J P Brown
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Carolina Coelho
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Peter C Cook
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Rhys A Farrer
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Nelesh P Govender
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Neil A R Gow
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - William Hope
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - J Claire Hoving
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Rachael Dangarembizi
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Thomas S Harrison
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Elizabeth M Johnson
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Liliane Mukaremera
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Mark Ramsdale
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, UK
| | | | - Jane Usher
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Adilia Warris
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Duncan Wilson
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, UK
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Alonso-Monge R, Cortés-Prieto I, Román E, Pla J. Morphogenetic transitions in the adaptation of Candida albicans to the mammalian gut. Microbes Infect 2024; 26:105253. [PMID: 37977323 DOI: 10.1016/j.micinf.2023.105253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 11/06/2023] [Accepted: 11/12/2023] [Indexed: 11/19/2023]
Abstract
Candida albicans is a pathobiont in humans that forms part of the mycobiota in healthy individuals and can cause different pathologies upon alterations of the host defenses. The mammalian gut is clinically relevant as this niche is the most common pool for bloodstream-derived infections. The ability of C. albicans to switch from yeast to hypha has been related to the commensal-to-pathogen transition and is, therefore, considered relevant in virulence. Recently, filaments have been implicated in the humoral response in the gut. C. albicans exhibits other morphologies that play different roles in pathogenicity and commensalism. This review focuses on the role of these morphological transitions in C. albicans proliferation and its establishment as a commensal in the mammalian gut, paying special attention to the transcription factors involved in their regulation.
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Affiliation(s)
- Rebeca Alonso-Monge
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza de Ramón y Cajal s/n, 28040 Madrid, Spain.
| | - Isabel Cortés-Prieto
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza de Ramón y Cajal s/n, 28040 Madrid, Spain.
| | - Elvira Román
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza de Ramón y Cajal s/n, 28040 Madrid, Spain.
| | - Jesús Pla
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza de Ramón y Cajal s/n, 28040 Madrid, Spain.
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3
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Román E, Prieto D, Hidalgo-Vico S, Alonso-Monge R, Pla J. The defective gut colonization of Candida albicans hog1 MAPK mutants is restored by overexpressing the transcriptional regulator of the white opaque transition WOR1. Virulence 2023; 14:2174294. [PMID: 36760104 PMCID: PMC9928469 DOI: 10.1080/21505594.2023.2174294] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
Abstract
The transcriptional master regulator of the white opaque transition of Candida albicans WOR1 is important for the adaptation to the commensal lifestyle in the mammalian gut, a major source of invasive candidiasis. We have generated cells that overproduce Wor1 in mutants defective in the Hog1 MAP kinase, defective in several stress responses and unable to colonize the mice gut. WOR1 overexpression allows hog1 to be established as a commensal in the murine gut in a commensalism model and even compete with wild-type C. albicans cells for establishment. This increased fitness correlates with an enhanced ability to adhere to biotic surfaces as well as increased proteinase and phospholipase production and a decrease in filamentation in vitro. We also show that hog1 WOR1OE are avirulent in a systemic candidiasis model in mice.
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Affiliation(s)
- Elvira Román
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain,CONTACT Elvira Román
| | - Daniel Prieto
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Susana Hidalgo-Vico
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Rebeca Alonso-Monge
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Jesús Pla
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain,Jesús Pla Parasitología Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
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4
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Wang F, Wang Z, Tang J. The interactions of Candida albicans with gut bacteria: a new strategy to prevent and treat invasive intestinal candidiasis. Gut Pathog 2023; 15:30. [PMID: 37370138 DOI: 10.1186/s13099-023-00559-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 06/15/2023] [Indexed: 06/29/2023] Open
Abstract
BACKGROUND The gut microbiota plays an important role in human health, as it can affect host immunity and susceptibility to infectious diseases. Invasive intestinal candidiasis is strongly associated with gut microbiota homeostasis. However, the nature of the interaction between Candida albicans and gut bacteria remains unclear. OBJECTIVE This review aimed to determine the nature of interaction and the effects of gut bacteria on C. albicans so as to comprehend an approach to reducing intestinal invasive infection by C. albicans. METHODS This review examined 11 common gut bacteria's interactions with C. albicans, including Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Enterococcus faecalis, Staphylococcus aureus, Salmonella spp., Helicobacter pylori, Lactobacillus spp., Bacteroides spp., Clostridium difficile, and Streptococcus spp. RESULTS Most of the studied bacteria demonstrated both synergistic and antagonistic effects with C. albicans, and just a few bacteria such as P. aeruginosa, Salmonella spp., and Lactobacillus spp. demonstrated only antagonism against C. albicans. CONCLUSIONS Based on the nature of interactions reported so far by the literature between gut bacteria and C. albicans, it is expected to provide new ideas for the prevention and treatment of invasive intestinal candidiasis.
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Affiliation(s)
- Fei Wang
- Department of Trauma-Emergency & Critical Care Medicine, Shanghai Fifth People's Hospital, Fudan University, 128 Ruili Road, Shanghai, 200240, China
| | - Zetian Wang
- Department of Trauma-Emergency & Critical Care Medicine, Shanghai Fifth People's Hospital, Fudan University, 128 Ruili Road, Shanghai, 200240, China.
| | - Jianguo Tang
- Department of Trauma-Emergency & Critical Care Medicine, Shanghai Fifth People's Hospital, Fudan University, 128 Ruili Road, Shanghai, 200240, China.
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5
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Gervais NC, La Bella AA, Wensing LF, Sharma J, Acquaviva V, Best M, Cadena López RO, Fogal M, Uthayakumar D, Chavez A, Santiago-Tirado F, Flores-Mireles AL, Shapiro RS. Development and applications of a CRISPR activation system for facile genetic overexpression in Candida albicans. G3 (BETHESDA, MD.) 2023; 13:jkac301. [PMID: 36450451 PMCID: PMC9911074 DOI: 10.1093/g3journal/jkac301] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 11/02/2021] [Accepted: 11/04/2022] [Indexed: 12/02/2022]
Abstract
For the fungal pathogen Candida albicans, genetic overexpression readily occurs via a diversity of genomic alterations, such as aneuploidy and gain-of-function mutations, with important consequences for host adaptation, virulence, and evolution of antifungal drug resistance. Given the important role of overexpression on C. albicans biology, it is critical to develop and harness tools that enable the analysis of genes expressed at high levels in the fungal cell. Here, we describe the development, optimization, and application of a novel, single-plasmid-based CRISPR activation (CRISPRa) platform for targeted genetic overexpression in C. albicans, which employs a guide RNA to target an activator complex to the promoter region of a gene of interest, thus driving transcriptional expression of that gene. Using this system, we demonstrate the ability of CRISPRa to drive high levels of gene expression in C. albicans, and we assess optimal guide RNA targeting for robust and constitutive overexpression. We further demonstrate the specificity of the system via RNA sequencing. We highlight the application of CRISPR activation to overexpress genes involved in pathogenesis and drug susceptibility, and contribute toward the identification of novel phenotypes. Consequently, this tool will facilitate a broad range of applications for the study of C. albicans genetic overexpression.
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Affiliation(s)
- Nicholas C Gervais
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1H 5N4, Canada
| | - Alyssa A La Bella
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Lauren F Wensing
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1H 5N4, Canada
| | - Jehoshua Sharma
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1H 5N4, Canada
| | - Victoria Acquaviva
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1H 5N4, Canada
| | - Madison Best
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1H 5N4, Canada
| | | | - Meea Fogal
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1H 5N4, Canada
| | - Deeva Uthayakumar
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1H 5N4, Canada
- Present address: Department of Immunology, University of Toronto, Toronto, ON, Canada
| | - Alejandro Chavez
- Department of Pathology and Cell Biology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | | | - Ana L Flores-Mireles
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Rebecca S Shapiro
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1H 5N4, Canada
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6
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Hidalgo-Vico S, Casas J, García C, Lillo MP, Alonso-Monge R, Román E, Pla J. Overexpression of the White Opaque Switching Master Regulator Wor1 Alters Lipid Metabolism and Mitochondrial Function in Candida albicans. J Fungi (Basel) 2022; 8:1028. [PMID: 36294593 PMCID: PMC9604646 DOI: 10.3390/jof8101028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 09/15/2022] [Accepted: 09/26/2022] [Indexed: 02/26/2024] Open
Abstract
Candida albicans is a commensal yeast that inhabits the gastrointestinal tract of humans; increased colonization of this yeast in this niche has implicated the master regulator of the white-opaque transition, Wor1, by mechanisms not completely understood. We have addressed the role that this transcription factor has on commensalism by the characterization of strains overexpressing this gene. We show that WOR1 overexpression causes an alteration of the total lipid content of the fungal cell and significantly alters the composition of structural and reserve molecular species lipids as determined by lipidomic analysis. These cells are hypersensitive to membrane-disturbing agents such as SDS, have increased tolerance to azoles, an augmented number of peroxisomes, and increased phospholipase activity. WOR1 overexpression also decreases mitochondrial activity and results in altered susceptibility to certain oxidants. All together, these changes reflect drastic alterations in the cellular physiology that facilitate adaptation to the gastrointestinal tract environment.
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Affiliation(s)
- Susana Hidalgo-Vico
- Departamento de Microbiología y Parasitología-IRYCIS, Facultad de Farmacia, Universidad Complutense de Madrid, Avda. Ramón y Cajal s/n, 28040 Madrid, Spain
| | - Josefina Casas
- Research Unit on BioActive Molecules (RUBAM), Department of Biological Chemistry, Instituto de Química Avanzada de Cataluña, Jordi Girona 18–26, 08034 Barcelona, Spain
| | - Carolina García
- Departamento de Química Física Biológica, Instituto Química Física “Rocasolano”, Consejo Superior de Investigaciones Científicas, Serrano 119, 28006 Madrid, Spain
| | - M. Pilar Lillo
- Departamento de Química Física Biológica, Instituto Química Física “Rocasolano”, Consejo Superior de Investigaciones Científicas, Serrano 119, 28006 Madrid, Spain
| | - Rebeca Alonso-Monge
- Departamento de Microbiología y Parasitología-IRYCIS, Facultad de Farmacia, Universidad Complutense de Madrid, Avda. Ramón y Cajal s/n, 28040 Madrid, Spain
| | - Elvira Román
- Departamento de Microbiología y Parasitología-IRYCIS, Facultad de Farmacia, Universidad Complutense de Madrid, Avda. Ramón y Cajal s/n, 28040 Madrid, Spain
| | - Jesús Pla
- Departamento de Microbiología y Parasitología-IRYCIS, Facultad de Farmacia, Universidad Complutense de Madrid, Avda. Ramón y Cajal s/n, 28040 Madrid, Spain
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7
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Prieto D, Pla J. Comparative Analysis of the Fitness of Candida albicans Strains During Colonization of the Mice Gastrointestinal Tract. Methods Mol Biol 2022; 2542:233-244. [PMID: 36008669 DOI: 10.1007/978-1-0716-2549-1_17] [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: 06/15/2023]
Abstract
Candida albicans populations present in the mammalian gastrointestinal tract are a major source of candidemia and subsequent severe invasive candidiasis in those individuals with acquired or congenital immune defects. Understanding the mechanisms used by this fungus to colonize this niche is, therefore, of primary importance to develop new therapeutic options that could lead to control its proliferation in the host. The recent popularization of models of commensalism in mice combined with the already powerful tools in C. albicans genetics allows to analyze the role of specific genes during colonization. Fitness can be analyzed for a specific C. albicans strain (test strain) by comparing its growth in vivo with an otherwise isogenic control strain via the analysis of the luminal content of the mouse gastrointestinal tract using flow cytometry, qPCR, or viable fungal cell counting. While all these procedures have limitations, they can be used to estimate the degree of adaptation of the test strain to the mammalian tract by determining its relative abundance with an internal control strain. By using specific genetically engineered C. albicans and mouse strains, antibiotic regimes, or even germ-free mice, this methodology allows to determine the role of the host immunological status, the bacterial microbiota, or individual fungal features (e.g., dimorphism) in the process of colonization of C. albicans of the mammalian gut.
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Affiliation(s)
- Daniel Prieto
- Departamento de Microbiología y Parasitología-IRYCIS, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Jesús Pla
- Departamento de Microbiología y Parasitología-IRYCIS, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain.
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8
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Identification of Clinical Isolates of Candida albicans with Increased Fitness in Colonization of the Murine Gut. J Fungi (Basel) 2021; 7:jof7090695. [PMID: 34575733 PMCID: PMC8468482 DOI: 10.3390/jof7090695] [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: 07/28/2021] [Revised: 08/23/2021] [Accepted: 08/24/2021] [Indexed: 12/22/2022] Open
Abstract
The commensal and opportunistic pathogen Candida albicans is an important cause of fungal diseases in humans, with the gastrointestinal tract being an important reservoir for its infections. The study of the mechanisms promoting the C. albicans commensal state has attracted considerable attention over the last few years, and several studies have focused on the identification of the intestinal human mycobiota and the characterization of Candida genes involved in its establishment as a commensal. In this work, we have barcoded 114 clinical C. albicans isolates to identify strains with an enhanced fitness in a murine gastrointestinal commensalism model. The 114 barcoded clinical isolates were pooled in four groups of 28 to 30 strains that were inoculated by gavage in mice previously treated with antibacterial therapy. Eight strains that either exhibited higher colonization load and/or remained in the gut after antibiotic removal were selected. The phenotypic analysis of these strains compared to an RFP-tagged SC5314 wild type strain did not reveal any specific trait associated with its increased colonization; all strains were able to filament and six of the eight strains displayed invasive growth on Spider medium. Analysis of one of these strains, CaORAL3, revealed that although mice required previous bacterial microbiota reduction with antibiotics to be able to be colonized, removal of this procedure could take place the same day (or even before) Candida inoculation. This strain was able to colonize the intestine of mice already colonized with Candida without antibiotic treatment in co-housing experiments. CaORAL3 was also able to be established as a commensal in mice previously colonized by another (CaHG43) or the same (CaORAL3) C. albicans strain. Therefore, we have identified C. albicans isolates that display higher colonization load than the standard strain SC5314 which will surely facilitate the analysis of the factors that regulate fungal colonization.
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9
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Vico SH, Prieto D, Monge RA, Román E, Pla J. The Glyoxylate Cycle Is Involved in White-Opaque Switching in Candida albicans. J Fungi (Basel) 2021; 7:jof7070502. [PMID: 34202465 PMCID: PMC8304919 DOI: 10.3390/jof7070502] [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: 06/08/2021] [Revised: 06/21/2021] [Accepted: 06/22/2021] [Indexed: 11/16/2022] Open
Abstract
Candida albicans is a commensal yeast that inhabits the gastrointestinal tract of humans. The master regulator of the white-opaque transition WOR1 has been implicated in the adaptation to this commensal status. A proteomic analysis of cells overexpressing this transcription factor (WOR1OE) suggested an altered metabolism of carbon sources and a phenotypic analysis confirmed this alteration. The WOR1OE cells are deficient in using trehalose and xylose and are unable to use 2C sources, which is consistent with a reduction in the amount of Icl1, the isocitrate lyase enzyme. The icl1Δ/Δ mutants overexpressing WOR1 are deficient in the production of phloxine B positive cells, a main characteristic of opaque cells, a phenotype also observed in mating type hemizygous mtla1Δ icl1Δ/Δ cells, suggesting the involvement of Icl1 in the adaptation to the commensal state. In fact, icl1Δ/Δ cells have reduced fitness in mouse gastrointestinal tract as compared with essentially isogenic heterozygous ICL1/icl1Δ, but overproduction of WOR1 in an icl1Δ/Δ mutant does not restore fitness. These results implicate the glyoxylate shunt in the adaptation to commensalism of C. albicans by mechanisms that are partially independent of WOR1.
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10
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Mishra AA, Koh AY. The microbial and host factors that govern Candida gastrointestinal colonization and dissemination. Curr Opin Microbiol 2021; 63:29-35. [PMID: 34111679 DOI: 10.1016/j.mib.2021.05.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/21/2021] [Accepted: 05/25/2021] [Indexed: 12/18/2022]
Abstract
Candida species are among the most prevalent and abundant members of the gut mycobiota, with Candida albicans (CA) being the most prominent member. CA colonizes numerous mucosal surfaces, most notably the gastrointestinal (GI) and genitourinary tracts. In a healthy host, CA is a pathobiont that exists as a commensal but can become pathogenic if the host's immune system becomes suppressed. The microbial and/or host factors that dictate CA's ability to colonize mucosal surfaces and its ability to disseminate remain of great interest. Here, we review the recent advances and insights regarding Candida colonization and dissemination of the mammalian GI tract.
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Affiliation(s)
- Animesh Anand Mishra
- Department of Pediatrics, University of Texas, Southwestern Medical Center, Dallas, TX 75390, USA
| | - Andrew Y Koh
- Department of Pediatrics, University of Texas, Southwestern Medical Center, Dallas, TX 75390, USA; Department of Pediatrics, Division of Hematology/Oncology, University of Texas, Southwestern Medical Center, Dallas, TX, USA; Department of Microbiology, University of Texas, Southwestern Medical Center, Dallas, TX, USA; Harold C. Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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11
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Rai LS, Wijlick LV, Bougnoux ME, Bachellier-Bassi S, d'Enfert C. Regulators of commensal and pathogenic life-styles of an opportunistic fungus-Candida albicans. Yeast 2021; 38:243-250. [PMID: 33533498 DOI: 10.1002/yea.3550] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/28/2021] [Accepted: 01/29/2021] [Indexed: 12/12/2022] Open
Abstract
The yeast Candida albicans is primarily a commensal of humans that colonizes the mucosal surfaces of the gastrointestinal and genital tracts. Yet, C. albicans can under certain circumstances undergo a shift from commensalism to pathogenicity. This transition is governed by fungal factors such as morphological transitions, environmental cues for instance relationships with gut microbiota and the host immune system. C. albicans utilizes distinct sets of regulatory programs to colonize or infect its host and to evade the host defense systems. Moreover, an orchestrated iron acquisition mechanism operates to adapt to specific niches with variable iron availability. Studies on regulatory networks and morphogenesis of these two distinct modes of C. albicans growth, suggest that both yeast and hyphal forms exist in both growth patterns and the regulatory circuits are inter-connected. Here, we summarize current knowledge about C. albicans commensal-to-pathogen shift, its regulatory elements and their contribution to human disease.
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Affiliation(s)
- Laxmi Shanker Rai
- Unité Biologie et Pathogénicité Fongiques, Institut Pasteur, USC2019 INRA, Paris, France
| | - Lasse Van Wijlick
- Unité Biologie et Pathogénicité Fongiques, Institut Pasteur, USC2019 INRA, Paris, France
| | - Marie-Elisabeth Bougnoux
- Unité Biologie et Pathogénicité Fongiques, Institut Pasteur, USC2019 INRA, Paris, France.,Unité de Parasitologie-Mycologie, Service de Microbiologie Clinique, Hôpital Necker-Enfants-Malades, Assistance Publique des Hôpitaux de Paris (APHP), Paris, France
| | | | - Christophe d'Enfert
- Unité Biologie et Pathogénicité Fongiques, Institut Pasteur, USC2019 INRA, Paris, France
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12
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Dai B, Xu Y, Gao N, Chen J. Wor1-regulated ferroxidases contribute to pigment formation in opaque cells of Candida albicans. FEBS Open Bio 2021; 11:598-621. [PMID: 33350590 PMCID: PMC7931227 DOI: 10.1002/2211-5463.13070] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 12/14/2020] [Accepted: 12/19/2020] [Indexed: 12/25/2022] Open
Abstract
Candida albicans is a harmless commensal resident in the human gut and a prevalent opportunistic pathogen. A key part of its commensalism and pathogenesis is its ability to switch between different morphological forms, including white‐to‐opaque switching. The Wor1 protein was previously identified as a master regulator of white‐to‐opaque switching in mating type locus (MTL) homozygous cells. The mechanisms by which the dark color of the opaque colonies is controlled and the pimpled surface of opaque cells is formed remain unknown. Candida albicans produces melanin pigment in vitro and during infection. However, the molecular mechanism underlying the regulation of melanin production is unclear. In this study, we demonstrated that ferroxidases (Fets) function as pigment multicopper oxidases and regulate the production of dark‐pigmented melanin in opaque cells. The FET genes presented distinct regulation patterns in response to different extracellular stimuli. In YPD (1% yeast extract, 2% peptone and 2% dextrose)‐rich medium, four of the five FET genes were up‐regulated by Wor1, especially at the human body temperature of 37 °C. In minimal medium with low ammonium concentrations, all five FET genes were up‐regulated by Wor1. However, at high ammonium concentrations, some FET genes were down‐regulated by Wor1. Wor1‐up‐regulated Fets contributed to dark pigment formation in opaque colonies, but not to the elongated shape of these opaque cells. Increased melanin externalization was associated with the pimpled surface of the opaque cells. Melanized C. albicans cells were more resistant to fungal clearance. Deletion of the five FET genes completely blocked melanin production in opaque cells and resulted in the generation of white elongated ‘opaque’ cells. In addition, the up‐regulated Fets are important for defense against oxidant attacks. The functional diversity of Fets may reflect the multiple strategies of C. albicans to rapidly adapt to diverse host niches.
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Affiliation(s)
- Baodi Dai
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Yinxing Xu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Ning Gao
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Jiangye Chen
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
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Kumamoto CA, Gresnigt MS, Hube B. The gut, the bad and the harmless: Candida albicans as a commensal and opportunistic pathogen in the intestine. Curr Opin Microbiol 2020; 56:7-15. [PMID: 32604030 PMCID: PMC7744392 DOI: 10.1016/j.mib.2020.05.006] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 05/04/2020] [Accepted: 05/11/2020] [Indexed: 12/26/2022]
Abstract
Candida albicans is a regular member of the intestinal microbiota in the majority of the human population. This underscores C. albicans' adaptation to life in the intestine without inducing competitive interactions with other microbes, or immune responses detrimental to its survival. However, specific conditions such as a dysbalanced microbiome, a suppression of the immune system, and an impaired intestinal barrier can predispose for invasive, mostly nosocomial, C. albicans infections. Colonization of the intestine and translocation through the intestinal barrier are fundamental aspects of the processes preceding life-threatening systemic candidiasis. Insights into C. albicans' commensal lifestyle and translocation can thus help us to understand how patients develop candidiasis, and may provide leads for therapeutic strategies aimed at preventing infection. In this review, we discuss the commensal lifestyle of C. albicans in the intestine, the role of morphology for commensalism, the influence of diet, and the interactions with bacteria of the microbiota.
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Affiliation(s)
- Carol A Kumamoto
- Department of Molecular Biology and Microbiology, Tufts University, Boston, MA 02111, USA
| | - Mark S Gresnigt
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knoell-Institute, Beutenbergstraße 11a, 07745 Jena, Germany; Junior Research Group Adaptive Pathogenicity Strategies, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Beutenbergstraße 11a 07745, Jena, Germany
| | - Bernhard Hube
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knoell-Institute, Beutenbergstraße 11a, 07745 Jena, Germany; Institute of Microbiology, Faculty of Biological Sciences, Friedrich Schiller University, 07743 Jena, Germany.
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Deletion of the SKO1 Gene in a hog1 Mutant Reverts Virulence in Candida albicans. J Fungi (Basel) 2019; 5:jof5040107. [PMID: 31731583 PMCID: PMC6958353 DOI: 10.3390/jof5040107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 11/07/2019] [Accepted: 11/13/2019] [Indexed: 11/18/2022] Open
Abstract
Candida albicans displays the ability to adapt to a wide variety of environmental conditions, triggering signaling pathways and transcriptional regulation. Sko1 is a transcription factor that was previously involved in early hypoxic response, cell wall remodeling, and stress response. In the present work, the role of sko1 mutant in in vivo and ex vivo studies was explored. The sko1 mutant behaved as its parental wild type strain regarding the ability to colonize murine intestinal tract, ex vivo adhesion to murine gut epithelium, or systemic virulence. These observations suggest that Sko1 is expendable during commensalism or pathogenesis. Nevertheless, the study of the hog1 sko1 double mutant showed unexpected phenotypes. Previous researches reported that the deletion of the HOG1 gene led to avirulent C. albicans mutant cell, which was, therefore, unable to establish as a commensal in a gastrointestinal murine model. Here, we show that the deletion of sko1 in a hog1 background reverted the virulence of the hog1 mutant in a systemic infection model in Galleria mellonella larvae and slightly improved the ability to colonize the murine gut in a commensalism animal model compared to the hog1 mutant. These results indicate that Sko1 acts as a repressor of virulence related genes, concluding that Sko1 plays a relevant role during commensalism and systemic infection.
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16
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Znaidi S, van Wijlick L, Hernández‐Cervantes A, Sertour N, Desseyn J, Vincent F, Atanassova R, Gouyer V, Munro CA, Bachellier‐Bassi S, Dalle F, Jouault T, Bougnoux M, d'Enfert C. Systematic gene overexpression in Candida albicans identifies a regulator of early adaptation to the mammalian gut. Cell Microbiol 2018; 20:e12890. [PMID: 29998470 PMCID: PMC6220992 DOI: 10.1111/cmi.12890] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 06/28/2018] [Accepted: 06/28/2018] [Indexed: 12/12/2022]
Abstract
Candida albicans is part of the human gastrointestinal (GI) microbiota. To better understand how C. albicans efficiently establishes GI colonisation, we competitively challenged growth of 572 signature-tagged strains (~10% genome coverage), each conditionally overexpressing a single gene, in the murine gut. We identified CRZ2, a transcription factor whose overexpression and deletion respectively increased and decreased early GI colonisation. Using clues from genome-wide expression and gene-set enrichment analyses, we found that the optimal activity of Crz2p occurs under hypoxia at 37°C, as evidenced by both phenotypic and transcriptomic analyses following CRZ2 genetic perturbation. Consistent with early colonisation of the GI tract, we show that CRZ2 overexpression confers resistance to acidic pH and bile salts, suggesting an adaptation to the upper sections of the gut. Genome-wide location analyses revealed that Crz2p directly modulates the expression of many mannosyltransferase- and cell-wall protein-encoding genes, suggesting a link with cell-wall function. We show that CRZ2 overexpression alters cell-wall phosphomannan abundance and increases sensitivity to tunicamycin, suggesting a role in protein glycosylation. Our study reflects the powerful use of gene overexpression as a complementary approach to gene deletion to identify relevant biological pathways involved in C. albicans interaction with the host environment.
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Affiliation(s)
- Sadri Znaidi
- Institut Pasteur, INRAUnité Biologie et Pathogénicité FongiquesParisFrance
- Institut Pasteur de Tunis, University of Tunis El ManarLaboratoire de Microbiologie Moléculaire, Vaccinologie et Développement BiotechnologiqueTunisTunisia
| | - Lasse van Wijlick
- Institut Pasteur, INRAUnité Biologie et Pathogénicité FongiquesParisFrance
| | | | - Natacha Sertour
- Institut Pasteur, INRAUnité Biologie et Pathogénicité FongiquesParisFrance
| | - Jean‐Luc Desseyn
- Lille Inflammation Research International Center, UMR 995 InsermUniversité Lille 2, Faculté de MédecineLilleFrance
| | | | | | - Valérie Gouyer
- Lille Inflammation Research International Center, UMR 995 InsermUniversité Lille 2, Faculté de MédecineLilleFrance
| | - Carol A. Munro
- Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Institute of Medical SciencesUniversity of AberdeenAberdeenUK
| | | | - Frédéric Dalle
- UMR 1347Université de BourgogneDijonFrance
- Centre Hospitalier UniversitaireService de Parasitologie MycologieDijonFrance
| | - Thierry Jouault
- Lille Inflammation Research International Center, UMR 995 InsermUniversité Lille 2, Faculté de MédecineLilleFrance
| | - Marie‐Elisabeth Bougnoux
- Institut Pasteur, INRAUnité Biologie et Pathogénicité FongiquesParisFrance
- Laboratoire de Parasitologie‐Mycologie, Service de Microbiologie, Hôpital Necker‐Enfants MaladesUniversité Paris Descartes, Faculté de MédecineParisFrance
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Mishra AA, Koh AY. Adaptation of Candida albicans during gastrointestinal tract colonization. CURRENT CLINICAL MICROBIOLOGY REPORTS 2018; 5:165-172. [PMID: 30560045 DOI: 10.1007/s40588-018-0096-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Purpose of Review Colonization of the gastrointestinal (GI) tract with Candida albicans (CA), the most common human fungal pathogen, is the first step towards the development of invasive infection. Yet the fungal virulence factors and host factors that modulate CA GI colonization are still poorly understood. In this review, we will review emerging evidence of the importance of select CA genetic determinants and CA's interaction with the host that contribute to its successful adaptation as a pathobiont in the human GI tract. Recent Findings Recent data reveal the importance of 1) CA genetic determinants; 2) host factors; and 3) environmental factors in modulating CA GI colonization in humans. Summary As evidence continues to grow supporting the notion that the GI tract and its resident microbiota are an integral part of the host immune system, it will be critical for studies to interrogate the interaction of CA with the host (including both the host innate and adaptive immune system as well as the endogenous gut microbiota) in order to dissect the mechanisms of CA pathogenesis and thus lay the foundation for novel therapeutic approaches to prevent and/or treat invasive fungal infections.
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Affiliation(s)
- Animesh A Mishra
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Andrew Y Koh
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.,Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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Román E, Huertas B, Prieto D, Díez-Orejas R, Pla J. TUP1-mediated filamentation in Candida albicans leads to inability to colonize the mouse gut. Future Microbiol 2018; 13:857-867. [PMID: 29877100 DOI: 10.2217/fmb-2018-0012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
AIM To investigate the role of Candida albicans TUP1-mediated filamentation in the colonization of the mice gut. MATERIALS & METHODS We used molecular genetics to generate a strain where filamentation is regulated by altering the expression of the TUP1 gene with tetracyclines. RESULTS The colonization rates reached with the TUP1REP-RFPREP strain were lower compared with wild-type strain and completely absent after induction of filamentation. No differences in the susceptibility to bile salts nor in the adhesion to the mouse intestine epithelium were observed. CONCLUSION Blockage of C. albicans in a filamentous form impedes gut cell colonization in the mouse.
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Affiliation(s)
- Elvira Román
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza de Ramón y Cajal s/n, E-28040 Madrid, Spain
| | - Blanca Huertas
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza de Ramón y Cajal s/n, E-28040 Madrid, Spain
| | - Daniel Prieto
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza de Ramón y Cajal s/n, E-28040 Madrid, Spain
| | - Rosalía Díez-Orejas
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza de Ramón y Cajal s/n, E-28040 Madrid, Spain
| | - Jesús Pla
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza de Ramón y Cajal s/n, E-28040 Madrid, Spain
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