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Muñoz JF, Gauthier GM, Desjardins CA, Gallo JE, Holder J, Sullivan TD, Marty AJ, Carmen JC, Chen Z, Ding L, Gujja S, Magrini V, Misas E, Mitreva M, Priest M, Saif S, Whiston EA, Young S, Zeng Q, Goldman WE, Mardis ER, Taylor JW, McEwen JG, Clay OK, Klein BS, Cuomo CA. The Dynamic Genome and Transcriptome of the Human Fungal Pathogen Blastomyces and Close Relative Emmonsia. PLoS Genet 2015; 11:e1005493. [PMID: 26439490 PMCID: PMC4595289 DOI: 10.1371/journal.pgen.1005493] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 08/11/2015] [Indexed: 12/05/2022] Open
Abstract
Three closely related thermally dimorphic pathogens are causal agents of major fungal diseases affecting humans in the Americas: blastomycosis, histoplasmosis and paracoccidioidomycosis. Here we report the genome sequence and analysis of four strains of the etiological agent of blastomycosis, Blastomyces, and two species of the related genus Emmonsia, typically pathogens of small mammals. Compared to related species, Blastomyces genomes are highly expanded, with long, often sharply demarcated tracts of low GC-content sequence. These GC-poor isochore-like regions are enriched for gypsy elements, are variable in total size between isolates, and are least expanded in the avirulent B. dermatitidis strain ER-3 as compared with the virulent B. gilchristii strain SLH14081. The lack of similar regions in related species suggests these isochore-like regions originated recently in the ancestor of the Blastomyces lineage. While gene content is highly conserved between Blastomyces and related fungi, we identified changes in copy number of genes potentially involved in host interaction, including proteases and characterized antigens. In addition, we studied gene expression changes of B. dermatitidis during the interaction of the infectious yeast form with macrophages and in a mouse model. Both experiments highlight a strong antioxidant defense response in Blastomyces, and upregulation of dioxygenases in vivo suggests that dioxide produced by antioxidants may be further utilized for amino acid metabolism. We identify a number of functional categories upregulated exclusively in vivo, such as secreted proteins, zinc acquisition proteins, and cysteine and tryptophan metabolism, which may include critical virulence factors missed before in in vitro studies. Across the dimorphic fungi, loss of certain zinc acquisition genes and differences in amino acid metabolism suggest unique adaptations of Blastomyces to its host environment. These results reveal the dynamics of genome evolution and of factors contributing to virulence in Blastomyces. Dimorphic fungal pathogens including Blastomyces are the cause of major fungal diseases in North and South America. The genus Emmonsia includes species infecting small mammals as well as a newly emerging pathogenic species recently reported in HIV-positive patients in South Africa. Here, we synthesize both genome sequencing of four isolates of Blastomyces and two species of Emmonsia as well as deep sequencing of Blastomyces RNA to draw major new insights into the evolution of this group and the pathogen response to infection. We investigate the trajectory of genome evolution of this group, characterizing the phylogenetic relationships of these species, a remarkable genome expansion that formed large isochore-like regions of low GC content in Blastomyces, and variation of gene content, related to host interaction, among the dimorphic fungal pathogens. Using RNA-Seq, we profile the response of Blastomyces to macrophage and mouse pulmonary infection, identifying key pathways and novel virulence factors. The identification of key fungal genes involved in adaptation to the host suggests targets for further study and therapeutic intervention in Blastomyces and related dimorphic fungal pathogens.
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Affiliation(s)
- José F. Muñoz
- Cellular and Molecular Biology Unit, Corporación para Investigaciones Biológicas, Medellín, Colombia
- Institute of Biology, Universidad de Antioquia, Medellín, Colombia
| | - Gregory M. Gauthier
- Department of Medicine, University of Wisconsin, Madison, Madison, Wisconsin, United States of America
| | | | - Juan E. Gallo
- Cellular and Molecular Biology Unit, Corporación para Investigaciones Biológicas, Medellín, Colombia
- Doctoral Program in Biomedical Sciences, Universidad del Rosario, Bogotá, Colombia
| | - Jason Holder
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Thomas D. Sullivan
- Department of Pediatrics, University of Wisconsin, Madison, Madison, Wisconsin, United States of America
| | - Amber J. Marty
- Department of Medicine, University of Wisconsin, Madison, Madison, Wisconsin, United States of America
| | - John C. Carmen
- Department of Pediatrics, University of Wisconsin, Madison, Madison, Wisconsin, United States of America
| | - Zehua Chen
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Li Ding
- The Genome Institute, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Sharvari Gujja
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Vincent Magrini
- The Genome Institute, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Elizabeth Misas
- Cellular and Molecular Biology Unit, Corporación para Investigaciones Biológicas, Medellín, Colombia
- Institute of Biology, Universidad de Antioquia, Medellín, Colombia
| | - Makedonka Mitreva
- The Genome Institute, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Margaret Priest
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Sakina Saif
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Emily A. Whiston
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, United States of America
| | - Sarah Young
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Qiandong Zeng
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - William E. Goldman
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Elaine R. Mardis
- The Genome Institute, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - John W. Taylor
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, United States of America
| | - Juan G. McEwen
- Cellular and Molecular Biology Unit, Corporación para Investigaciones Biológicas, Medellín, Colombia
- School of Medicine, Universidad de Antioquia, Medellín, Colombia
| | - Oliver K. Clay
- Cellular and Molecular Biology Unit, Corporación para Investigaciones Biológicas, Medellín, Colombia
- School of Medicine and Health Sciences, Universidad del Rosario, Bogotá, Colombia
| | - Bruce S. Klein
- Department of Medicine, University of Wisconsin, Madison, Madison, Wisconsin, United States of America
- Department of Pediatrics, University of Wisconsin, Madison, Madison, Wisconsin, United States of America
- Department of Medical Microbiology & Immunology, University of Wisconsin, Madison, Madison, Wisconsin, United States of America
| | - Christina A. Cuomo
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
- * E-mail:
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Costa DL, Dias-Melicio LA, Acorci MJ, Bordon AP, Tavian EG, Peraçoli MTS, Soares AMVDC. Effect of interleukin-10 on the Paracoccidioides brasiliensis killing by gamma-interferon activated human neutrophils. Microbiol Immunol 2007; 51:73-80. [PMID: 17237601 DOI: 10.1111/j.1348-0421.2007.tb03892.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Paracoccidioidomycosis, a deep mycosis endemic in Latin America, is a chronic granulomatous disease caused by the fungus Paracoccidioides brasiliensis. Phagocytic cells play a critical role against this fungus, and several studies have shown the effects of activator and suppressive cytokines on macrophage and monocyte functions. However, studies on polymorphonuclear neutrophils (PMNs), that are the first cells recruited to the infection sites, are scarcer. Thus, the objective of this paper was to assess whether interleukin-10 (IL-10), a potent anti-inflammatory cytokine, is able to block the activity of IFN-gamma-activated human PMNs upon P. brasiliensis intracellular killing, in vitro. The results showed that IFN-gamma-activated PMNs have an effective fungicidal activity against the fungus. This activity was associated with the release of high levels of H(2)O(2), the metabolite involved in phagocytic cells antifungal activities. However, the concomitant incubation of these cells with IFN-gamma and IL-10 significantly blocked IFN-gamma activation. As a consequence, PMNs killing activity and H(2)O(2) release were inhibited. Together, our results show the importance of PMNs exposure to activator or suppressor cytokines in the early stages of paracoccidioidomycosis infection.
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Affiliation(s)
- Diego Luís Costa
- Department of Microbiology and Immunology, Biosciences Institute, São Paulo State University-UNESP, Brazil
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Hamilton AJ, Holdom MD. Antioxidant systems in the pathogenic fungi of man and their role in virulence. Med Mycol 1999; 37:375-89. [PMID: 10647118 DOI: 10.1046/j.1365-280x.1999.00208.x] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In the last two decades, a variety of fungal antioxidants have attracted considerable interest, largely arising from their hypothetical role as virulence determinants. Melanin is a potent free radical scavenger and in Cryptococcus neoformans, there is now good evidence that the production of melanin is a significant virulence determinant. There is also recent evidence linking melanin biosynthesis to the virulence of Aspergillus fumigatus conidia. Superoxide dismutases are important housekeeping antioxidants and have an additional hypothetical role in virulence; however, although these enzymes have been biochemically characterized from Aspergillus and Cryptococcus, there is as yet no firm evidence that these enzymes are involved in pathogenicity. Catalase production may play some role in the virulence of Candida albicans but this enzyme has not been shown, as yet, to influence the virulence of A. fumigatus. There are some data supporting an antioxidant function for the acyclic hexitol mannitol in C. neoformans, but further investigations are required in this area. Research into the putative antioxidant activities of a range of other fungal enzymes, such as acid phosphatases, remains limited at this time.
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Affiliation(s)
- A J Hamilton
- Dermatology Department, St Johns Institute of Dermatology, Guys Hospital, Kings College, London, UK.
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Klein BS, Chaturvedi S, Hogan LH, Jones JM, Newman SL. Altered expression of surface protein WI-1 in genetically related strains of Blastomyces dermatitidis that differ in virulence regulates recognition of yeasts by human macrophages. Infect Immun 1994; 62:3536-42. [PMID: 8039924 PMCID: PMC302988 DOI: 10.1128/iai.62.8.3536-3542.1994] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The molecular basis for pathogenicity and virulence of the dimorphic fungus Blastomyces dermatitidis remains unknown. WI-1 is a major cell wall protein of B. dermatitidis yeasts and is a recognition target of both humoral and cell-mediated immunity. As an initial study to determine if WI-1 might be linked to virulence of B. dermatitidis, we quantified WI-1 expression on three genetically related strains that differ in their virulence for mice: wild-type virulent ATCC strain 26199, mutant ATCC strain 60915 (which is 10,000-fold reduced in virulence), and mutant ATCC strain 60916 (which is avirulent). Two principal alterations in WI-1 expression were observed in the mutants. First, the mutants express more WI-1 on their surface, as quantified by flow cytometry with monoclonal antibody to WI-1 and by radioimmunoassay, but the WI-1 on their cell wall is less extractable than that on the wild-type strain. Second, the mutants shed less WI-1 during culture and demonstrate impaired processing of shed WI-1. Surface alterations in WI-1 were accompanied by significant differences in the binding of the virulent and mutant strains to human monocyte-derived macrophages. Attachment of yeasts to macrophages paralleled and was proportional to the expression of WI-1. Compared with wild-type yeasts, both mutants bound to macrophages more rapidly and in two- to threefold-greater magnitude. Furthermore, about 75% of yeast binding to macrophages was inhibited by a Fab anti-WI-1 monoclonal antibody. These results suggest that altered WI-1 expression on attenuated and avirulent mutant B. dermatitidis yeasts greatly facilitates macrophage recognition and binding of yeasts and, in turn, may contribute to more rapid ingestion and killing in the host.
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Affiliation(s)
- B S Klein
- Department of Pediatrics, University of Wisconsin Medical School, University of Wisconsin Hospital and Clinics, Madison 53792
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