1
|
Costa MV, Landgraf TN, Corrêa PC, Souza IEL, Fernandes FF, Panunto-Castelo A. Quantitation of pulmonary fungal burden in Paracoccidioides brasiliensis-infected mice by real-time PCR. Rev Inst Med Trop Sao Paulo 2018; 61:e2. [PMID: 30570075 PMCID: PMC6300791 DOI: 10.1590/s1678-9946201961002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 11/12/2018] [Indexed: 11/21/2022] Open
Abstract
Although colony-forming unit (CFU) counting is widely used to quantify fungal
load in tissue from animal experimentally infected with Paracoccidioides
brasiliensis, several technical disadvantages have been described.
Here we developed highly accurate quantitative PCR (qPCR) assays to determine
the relative P brasiliensis load in lungs from infected mice.
SYBR Green- and TaqMan-based assays using primers and probe for the 43-kDa
glycoprotein (gp43) gene detected as little as 270 gene copies (about 2 fg of
DNA) per reaction. Although qPCR assays cannot distinguish between living and
dead yeasts, we found a highly positive linear correlation between CFU and
qPCR.
Collapse
Affiliation(s)
- Marcelo Vieira Costa
- Universidade de São Paulo, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Departamento de Biologia, Ribeirão Preto, São Paulo, Brazil
| | - Taise Natali Landgraf
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Programa de Pós-Graduação em Imunologia Básica e Aplicada, Ribeirão Preto, São Paulo, Brazil
| | - Priscila C Corrêa
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Programa de Pós-Graduação em Imunologia Básica e Aplicada, Ribeirão Preto, São Paulo, Brazil
| | - Igor Emiliano Lemos Souza
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Programa de Pós-Graduação em Imunologia Básica e Aplicada, Ribeirão Preto, São Paulo, Brazil
| | - Fabrício Freitas Fernandes
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Biologia Celular e Molecular, Ribeirão Preto, São Paulo, Brazil
| | - Ademilson Panunto-Castelo
- Universidade de São Paulo, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Departamento de Biologia, Ribeirão Preto, São Paulo, Brazil
| |
Collapse
|
2
|
McBride JA, Gauthier GM, Klein BS. Turning on virulence: Mechanisms that underpin the morphologic transition and pathogenicity of Blastomyces. Virulence 2018. [PMID: 29532714 PMCID: PMC6779398 DOI: 10.1080/21505594.2018.1449506] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
This review article focuses on the mechanisms underlying temperature adaptation and virulence of the etiologic agents of blastomycosis, Blastomyces dermatitidis, Blastomyces gilchristii, and Blastomyces percursus. In response to temperature, Blastomyces undergoes a reversible morphologic switch between hyphae and yeast known as the phase transition. The conversion to yeast for Blastomyces and related thermally dimorphic fungi is essential for virulence. In the yeast phase, Blastomyces upregulates the essential virulence factor, BAD1, which promotes attachment to host cells, impairs activation of immune cells, and blunts cytokine release. Blastomyces yeast also secrete dipeptidyl-peptidase IVA (DPPIVA), a serine protease that blunts the action of cytokines released from host immune cells. In vivo transcriptional profiling of Blastomyces yeast has uncovered genes such as PRA1 and ZRT1 involved in zinc scavenging that contribute to virulence during murine pulmonary infection. The discovery and characterization of genes important for virulence has led to advances at the bedside regarding novel diagnostics, vaccine development, and new targets for drug discovery.
Collapse
Affiliation(s)
- Joseph A McBride
- Division of Infectious Disease, Department of Medicine, University of Wisconsin School of Medicine and Public Health , 600 Highland Avenue, Madison , WI , USA.,Division of Infectious Disease, Department of Pediatrics, University of Wisconsin School of Medicine and Public Health , 1675 Highland Avenue, Madison , WI , USA
| | - Gregory M Gauthier
- Division of Infectious Disease, Department of Medicine, University of Wisconsin School of Medicine and Public Health , 600 Highland Avenue, Madison , WI , USA
| | - Bruce S Klein
- Division of Infectious Disease, Department of Medicine, University of Wisconsin School of Medicine and Public Health , 600 Highland Avenue, Madison , WI , USA.,Division of Infectious Disease, Department of Pediatrics, University of Wisconsin School of Medicine and Public Health , 1675 Highland Avenue, Madison , WI , USA.,Department of Medical Microbiology and Immunology, University of Wisconsin School of Medicine and Public Health , 1550 Linden Drive, Madison , WI , USA
| |
Collapse
|
3
|
Wang H, Lee TJ, Fites SJ, Merkhofer R, Zarnowski R, Brandhorst T, Galles K, Klein B, Wüthrich M. Ligation of Dectin-2 with a novel microbial ligand promotes adjuvant activity for vaccination. PLoS Pathog 2017; 13:e1006568. [PMID: 28793349 PMCID: PMC5565193 DOI: 10.1371/journal.ppat.1006568] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 08/21/2017] [Accepted: 08/04/2017] [Indexed: 11/18/2022] Open
Abstract
The development of vaccines against fungi and other intracellular microbes is impeded in part by a lack of suitable adjuvants. While most current vaccines against infectious diseases preferentially induce production of antibodies, cellular immunity is essential for the resolution of fungal infections. Microbes such as fungi and Mycobacterium tuberculosis require Th17 and Th1 cells for resistance, and engage the C-type lectin receptors including Dectin-2. Herein, we discovered a novel Dectin-2 ligand, the glycoprotein Blastomyces Eng2 (Bl-Eng2). Bl-Eng2 triggers robust signaling in Dectin-2 reporter cells and induces IL-6 in human PBMC and BMDC from wild type but not Dectin-2-/- and Card9-/- mice. The addition of Bl-Eng2 to a pan-fungal subunit vaccine primed large numbers of Ag-specific Th17 and Th1 cells, augmented activation and killing of fungi by myeloid effector cells, and protected mice from lethal fungal challenge, revealing Bl-Eng2’s potency as a vaccine adjuvant. Thus, ligation of Dectin-2 by Bl-Eng-2 could be harnessed as a novel adjuvant strategy to protect against infectious diseases requiring cellular immunity. Despite several million new systemic fungal infections annually worldwide, there are no commercial vaccines available. The lack of appropriate adjuvants is one major impediment to developing safe and effective vaccines against infections with fungal pathogens. Current vaccines against infectious diseases preferentially induce protective antibodies, driven by adjuvants such as alum. While clonally-derived and adoptively transferred monoclonal antibodies may confer protection against fungi, the contribution of antibody to host defense is likely to be limited. Animal studies and clinical observations implicate cellular immunity as an essential component of the resolution of fungal infections. We found a promising adjuvant that augments cell mediated immune responses and vaccine-induced protection against fungal infection. We anticipate that our discovery will be a useful adjuvant for vaccination with non-replicating and safe subunit vaccines against many microbial pathogens that require protective cell mediated immune responses.
Collapse
Affiliation(s)
- Huafeng Wang
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, United States of America
| | - Taek-Jin Lee
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, United States of America
| | - Scott J. Fites
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, United States of America
| | - Richard Merkhofer
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, United States of America
| | - Robert Zarnowski
- Department of Medicine (Infectious Disease Division), University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, United States of America
| | - Tristan Brandhorst
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, United States of America
| | - Kevin Galles
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, United States of America
| | - Bruce Klein
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, United States of America
- Department of Internal Medicine, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, United States of America
- Department of Medical Microbiology and Immunology, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, United States of America
| | - Marcel Wüthrich
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, United States of America
- * E-mail:
| |
Collapse
|
5
|
Fludioxonil Induces Drk1, a Fungal Group III Hybrid Histidine Kinase, To Dephosphorylate Its Downstream Target, Ypd1. Antimicrob Agents Chemother 2017; 61:AAC.01414-16. [PMID: 27872062 DOI: 10.1128/aac.01414-16] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 11/05/2016] [Indexed: 12/16/2022] Open
Abstract
Novel antifungal drugs and targets are urgently needed. Group III hybrid histidine kinases (HHKs) represent an appealing new therapeutic drug target because they are widely expressed in fungi but absent from humans. We investigated the mode of action of the widely utilized, effective fungicide fludioxonil. The drug acts in an HHK-dependent manner by constitutive activation of the HOG (high-osmolarity glycerol) pathway, but its mechanism of action is poorly understood. Here, we report a new mode of drug action that entails conversion of the HHK from a kinase into a phosphatase. We expressed Drk1 (dimorphism-regulating kinase), which is an intracellular group III HHK from the fungal pathogen Blastomyces dermatitidis, in Saccharomyces cerevisiae Drk1 engendered drug sensitivity in B. dermatitidis and conferred sensitivity upon S. cerevisiae In response to fludioxonil, Drk1 behaved as a phosphatase rather than as a kinase, leading to dephosphorylation of its downstream target, Ypd1, constitutive activation of the HOG pathway, and yeast cell death. Aspartic acid residue 1140 in the Drk1 receiver domain was required for in vivo phosphatase activity on Ypd1, and Hog1 was required for drug effect, indicating fidelity in HHK-dependent drug action. In in vitro assays with purified protein, intact Drk1 demonstrated intrinsic kinase activity, and the Drk1 receiver domain exhibited intrinsic phosphatase activity. However, fludioxonil failed to induce intact Drk1 to dephosphorylate Ypd1. We conclude that fludioxonil treatment in vivo likely acts on an upstream target that triggers HHK to become a phosphatase, which dephosphorylates its downstream target, Ypd1.
Collapse
|
6
|
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.
Collapse
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:
| |
Collapse
|