1
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Borges BM, Ramos RBC, Preite NW, Kaminski VDL, Alves de Castro P, Camacho M, Maximo MF, Fill TP, Calich VLG, Traynor AM, Sarikaya-Bayram Ö, Doyle S, Bayram Ö, de Campos CBL, Zelanis A, Goldman GH, Loures FV. Transcriptional profiling of a fungal granuloma reveals a low metabolic activity of Paracoccidioides brasiliensis yeasts and an actively regulated host immune response. Front Cell Infect Microbiol 2023; 13:1268959. [PMID: 37868350 PMCID: PMC10585178 DOI: 10.3389/fcimb.2023.1268959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 09/11/2023] [Indexed: 10/24/2023] Open
Abstract
Granulomas are important immunological structures in the host defense against the fungus Paracoccidioides brasiliensis, the main etiologic agent of Paracoccidioidomycosis (PCM), a granulomatous systemic mycosis endemic in Latin America. We have performed transcriptional and proteomic studies of yeasts present in the pulmonary granulomas of PCM aiming to identify relevant genes and proteins that act under stressing conditions. C57BL/6 mice were infected with 1x106 yeasts and after 8- and 12-weeks of infection, granulomatous lesions were obtained for extraction of fungal and murine RNAs and fungal proteins. Dual transcriptional profiling was done comparing lung cells and P. brasiliensis yeasts from granulomas with uninfected lung cells and the original yeast suspension used in the infection, respectively. Mouse transcripts indicated a lung malfunction, with low expression of genes related to muscle contraction and organization. In addition, an increased expression of transcripts related to the activity of neutrophils, eosinophils, macrophages, lymphocytes as well as an elevated expression of IL-1β, TNF-α, IFN-γ, IL-17 transcripts were observed. The increased expression of transcripts for CTLA-4, PD-1 and arginase-1, provided evidence of immune regulatory mechanisms within the granulomatous lesions. Also, our results indicate iron as a key element for the granuloma to function, where a high number of transcripts related to fungal siderophores for iron uptake was observed, a mechanism of fungal virulence not previously described in granulomas. Furthermore, transcriptomics and proteomics analyzes indicated a low fungal activity within the granuloma, as demonstrated by the decreased expression of genes and proteins related to energy metabolism and cell cycle.
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Affiliation(s)
- Bruno Montanari Borges
- Institute of Science and Technology (ICT), Federal University of São Paulo (UNIFESP), São José dos Campos, SP, Brazil
| | - Rafael Berton Correia Ramos
- Institute of Science and Technology (ICT), Federal University of São Paulo (UNIFESP), São José dos Campos, SP, Brazil
| | - Nycolas Willian Preite
- Institute of Science and Technology (ICT), Federal University of São Paulo (UNIFESP), São José dos Campos, SP, Brazil
| | - Valéria de Lima Kaminski
- Institute of Science and Technology (ICT), Federal University of São Paulo (UNIFESP), São José dos Campos, SP, Brazil
| | - Patrícia Alves de Castro
- Faculty of Pharmaceutical Science of Ribeirão Preto (FCFRP), University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Maurício Camacho
- Institute of Science and Technology (ICT), Federal University of São Paulo (UNIFESP), São José dos Campos, SP, Brazil
| | | | - Taicia Pacheco Fill
- Institute of Chemistry, Universidade Estadual de Campinas, Campinas, SP, Brazil
| | - Vera Lúcia Garcia Calich
- Department of Immunology, Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo, Brazil
| | - Aimee M. Traynor
- Department of Biology, Maynooth University, Maynooth, County Kildare, Ireland
| | | | - Sean Doyle
- Department of Biology, Maynooth University, Maynooth, County Kildare, Ireland
| | - Özgür Bayram
- Department of Biology, Maynooth University, Maynooth, County Kildare, Ireland
| | | | - André Zelanis
- Institute of Science and Technology (ICT), Federal University of São Paulo (UNIFESP), São José dos Campos, SP, Brazil
| | - Gustavo H. Goldman
- Faculty of Pharmaceutical Science of Ribeirão Preto (FCFRP), University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Flávio Vieira Loures
- Institute of Science and Technology (ICT), Federal University of São Paulo (UNIFESP), São José dos Campos, SP, Brazil
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2
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Brechting PJ, Shah C, Rakotondraibe L, Shen Q, Rappleye CA. Histoplasma capsulatum requires peroxisomes for multiple virulence functions including siderophore biosynthesis. mBio 2023; 14:e0328422. [PMID: 37432032 PMCID: PMC10470777 DOI: 10.1128/mbio.03284-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 05/30/2023] [Indexed: 07/12/2023] Open
Abstract
Peroxisomes are versatile eukaryotic organelles essential for many functions in fungi, including fatty acid metabolism, reactive oxygen species detoxification, and secondary metabolite biosynthesis. A suite of Pex proteins (peroxins) maintains peroxisomes, while peroxisomal matrix enzymes execute peroxisome functions. Insertional mutagenesis identified peroxin genes as essential components supporting the intraphagosomal growth of the fungal pathogen Histoplasma capsulatum. Disruption of the peroxins Pex5, Pex10, or Pex33 in H. capsulatum prevented peroxisome import of proteins targeted to the organelle via the PTS1 pathway. This loss of peroxisome protein import limited H. capsulatum intracellular growth in macrophages and attenuated virulence in an acute histoplasmosis infection model. Interruption of the alternate PTS2 import pathway also attenuated H. capsulatum virulence, although only at later time points of infection. The Sid1 and Sid3 siderophore biosynthesis proteins contain a PTS1 peroxisome import signal and localize to the H. capsulatum peroxisome. Loss of either the PTS1 or PTS2 peroxisome import pathway impaired siderophore production and iron acquisition in H. capsulatum, demonstrating compartmentalization of at least some biosynthetic steps for hydroxamate siderophore biosynthesis. However, the loss of PTS1-based peroxisome import caused earlier virulence attenuation than either the loss of PTS2-based protein import or the loss of siderophore biosynthesis, indicating additional PTS1-dependent peroxisomal functions are important for H. capsulatum virulence. Furthermore, disruption of the Pex11 peroxin also attenuated H. capsulatum virulence independently of peroxisomal protein import and siderophore biosynthesis. These findings demonstrate peroxisomes contribute to H. capsulatum pathogenesis by facilitating siderophore biosynthesis and another unidentified role(s) for the organelle during fungal virulence. IMPORTANCE The fungal pathogen Histoplasma capsulatum infects host phagocytes and establishes a replication-permissive niche within the cells. To do so, H. capsulatum overcomes and subverts antifungal defense mechanisms which include the limitation of essential micronutrients. H. capsulatum replication within host cells requires multiple distinct functions of the fungal peroxisome organelle. These peroxisomal functions contribute to H. capsulatum pathogenesis at different times during infection and include peroxisome-dependent biosynthesis of iron-scavenging siderophores to enable fungal proliferation, particularly after activation of cell-mediated immunity. The multiple essential roles of fungal peroxisomes reveal this organelle as a potential but untapped target for the development of therapeutics.
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Affiliation(s)
| | - Chandan Shah
- Department of Microbiology, Ohio State University, Columbus, Ohio, USA
| | - Liva Rakotondraibe
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, Ohio State University, Columbus, Ohio, USA
| | - Qian Shen
- Department of Biology, Rhodes College, Memphis, Tennessee, USA
| | - Chad A. Rappleye
- Department of Microbiology, Ohio State University, Columbus, Ohio, USA
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3
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Shen Q, Gonzalez-Mireles A, Ray SC, Rappleye CA. Histoplasma capsulatum Relies on Tryptophan Biosynthesis To Proliferate within the Macrophage Phagosome. Infect Immun 2023; 91:e0005923. [PMID: 37184383 PMCID: PMC10269170 DOI: 10.1128/iai.00059-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 05/01/2023] [Indexed: 05/16/2023] Open
Abstract
Histoplasma capsulatum yeasts reside and proliferate within the macrophage phagosome during infection. This nutrient-depleted phagosomal environment imposes challenges to Histoplasma yeasts for nutrition acquisition. Histoplasma yeasts require all 20 amino acids, which can be formed by de novo biosynthesis and/or acquired directly from the phagosomal environment. We investigated how Histoplasma obtains aromatic amino acids (i.e., phenylalanine, tyrosine, and tryptophan) within the phagosome during infection of macrophages. Depletion of key enzymes of the phenylalanine or tyrosine biosynthetic pathway neither impaired Histoplasma's ability to proliferate within macrophages nor resulted in attenuated virulence in vivo. However, loss of tryptophan biosynthesis resulted in reduced growth within macrophages and severely attenuated virulence in vivo. Together, these results indicate that phenylalanine and tyrosine, but not tryptophan, are available to Histoplasma within the macrophage phagosome. The herbicide glyphosate, which targets 5-enolpyruvylshikimate-3-phosphate synthase of the aromatic amino acid biosynthetic pathway, inhibited Histoplasma yeast growth, and this growth inhibition was partially reversed by aromatic amino acid supplementation or overexpression of ARO1. These results suggest that the aromatic amino acid biosynthetic pathway is a candidate drug target to develop novel antifungal therapeutics.
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Affiliation(s)
- Qian Shen
- Rhodes College, Department of Biology, Memphis, Tennessee, USA
| | | | - Stephanie C. Ray
- Ohio State University, Department of Microbiology, Columbus, Ohio, USA
| | - Chad A. Rappleye
- Ohio State University, Department of Microbiology, Columbus, Ohio, USA
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4
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Rubitschung K, Sherwood A, Crisologo AP, Bhavan K, Haley RW, Wukich DK, Castellino L, Hwang H, La Fontaine J, Chhabra A, Lavery L, Öz OK. Pathophysiology and Molecular Imaging of Diabetic Foot Infections. Int J Mol Sci 2021; 22:11552. [PMID: 34768982 PMCID: PMC8584017 DOI: 10.3390/ijms222111552] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Revised: 10/16/2021] [Accepted: 10/20/2021] [Indexed: 12/27/2022] Open
Abstract
Diabetic foot infection is the leading cause of non-traumatic lower limb amputations worldwide. In addition, diabetes mellitus and sequela of the disease are increasing in prevalence. In 2017, 9.4% of Americans were diagnosed with diabetes mellitus (DM). The growing pervasiveness and financial implications of diabetic foot infection (DFI) indicate an acute need for improved clinical assessment and treatment. Complex pathophysiology and suboptimal specificity of current non-invasive imaging modalities have made diagnosis and treatment response challenging. Current anatomical and molecular clinical imaging strategies have mainly targeted the host's immune responses rather than the unique metabolism of the invading microorganism. Advances in imaging have the potential to reduce the impact of these problems and improve the assessment of DFI, particularly in distinguishing infection of soft tissue alone from osteomyelitis (OM). This review presents a summary of the known pathophysiology of DFI, the molecular basis of current and emerging diagnostic imaging techniques, and the mechanistic links of these imaging techniques to the pathophysiology of diabetic foot infections.
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Affiliation(s)
- Katie Rubitschung
- Department of Radiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8542, USA; (K.R.); (A.S.); (A.C.)
| | - Amber Sherwood
- Department of Radiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8542, USA; (K.R.); (A.S.); (A.C.)
| | - Andrew P. Crisologo
- Department of Plastic Surgery, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH 45267-0558, USA;
| | - Kavita Bhavan
- Department of Internal Medicine, Division of Infectious Diseases and Geographic Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8542, USA; (K.B.); (L.C.)
| | - Robert W. Haley
- Department of Internal Medicine, Epidemiology Division, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8542, USA;
| | - Dane K. Wukich
- Department of Orthopedic Surgery, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8542, USA;
| | - Laila Castellino
- Department of Internal Medicine, Division of Infectious Diseases and Geographic Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8542, USA; (K.B.); (L.C.)
| | - Helena Hwang
- Department of Pathology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8542, USA;
| | - Javier La Fontaine
- Department of Plastic Surgery, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8542, USA; (J.L.F.); (L.L.)
| | - Avneesh Chhabra
- Department of Radiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8542, USA; (K.R.); (A.S.); (A.C.)
| | - Lawrence Lavery
- Department of Plastic Surgery, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8542, USA; (J.L.F.); (L.L.)
| | - Orhan K. Öz
- Department of Radiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8542, USA; (K.R.); (A.S.); (A.C.)
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5
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Rubitschung K, Sherwood A, Crisologo AP, Bhavan K, Haley RW, Wukich DK, Castellino L, Hwang H, La Fontaine J, Chhabra A, Lavery L, Öz OK. Pathophysiology and Molecular Imaging of Diabetic Foot Infections. Int J Mol Sci 2021; 22:ijms222111552. [PMID: 34768982 DOI: 10.3390/ijms222111552.pmid:34768982;pmcid:pmc8584017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Revised: 10/16/2021] [Accepted: 10/20/2021] [Indexed: 05/27/2023] Open
Abstract
Diabetic foot infection is the leading cause of non-traumatic lower limb amputations worldwide. In addition, diabetes mellitus and sequela of the disease are increasing in prevalence. In 2017, 9.4% of Americans were diagnosed with diabetes mellitus (DM). The growing pervasiveness and financial implications of diabetic foot infection (DFI) indicate an acute need for improved clinical assessment and treatment. Complex pathophysiology and suboptimal specificity of current non-invasive imaging modalities have made diagnosis and treatment response challenging. Current anatomical and molecular clinical imaging strategies have mainly targeted the host's immune responses rather than the unique metabolism of the invading microorganism. Advances in imaging have the potential to reduce the impact of these problems and improve the assessment of DFI, particularly in distinguishing infection of soft tissue alone from osteomyelitis (OM). This review presents a summary of the known pathophysiology of DFI, the molecular basis of current and emerging diagnostic imaging techniques, and the mechanistic links of these imaging techniques to the pathophysiology of diabetic foot infections.
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Affiliation(s)
- Katie Rubitschung
- Department of Radiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8542, USA
| | - Amber Sherwood
- Department of Radiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8542, USA
| | - Andrew P Crisologo
- Department of Plastic Surgery, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH 45267-0558, USA
| | - Kavita Bhavan
- Department of Internal Medicine, Division of Infectious Diseases and Geographic Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8542, USA
| | - Robert W Haley
- Department of Internal Medicine, Epidemiology Division, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8542, USA
| | - Dane K Wukich
- Department of Orthopedic Surgery, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8542, USA
| | - Laila Castellino
- Department of Internal Medicine, Division of Infectious Diseases and Geographic Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8542, USA
| | - Helena Hwang
- Department of Pathology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8542, USA
| | - Javier La Fontaine
- Department of Plastic Surgery, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8542, USA
| | - Avneesh Chhabra
- Department of Radiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8542, USA
| | - Lawrence Lavery
- Department of Plastic Surgery, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8542, USA
| | - Orhan K Öz
- Department of Radiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8542, USA
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Rossi DC, Figueroa JAL, Buesing WR, Candor K, Blancett LT, Evans HM, Lenchitz R, Crowther BL, Elsegeiny W, Williamson PR, Rupp J, Deepe GS. A metabolic inhibitor arms macrophages to kill intracellular fungal pathogens by manipulating zinc homeostasis. J Clin Invest 2021; 131:e147268. [PMID: 34237029 DOI: 10.1172/jci147268] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 07/06/2021] [Indexed: 01/01/2023] Open
Abstract
Macrophages deploy numerous strategies to combat invasion by microbes. One tactic is to restrict acquisition of diverse nutrients, including trace metals, a process termed nutritional immunity. Intracellular pathogens adapt to a resource-poor environment by marshaling mechanisms to harvest nutrients. Carbon acquisition is crucial for pathogen survival; compounds that reduce availability are a potential strategy to control intracellular replication. Treatment of macrophages with the glucose analog 2-deoxy-D-glucose (2-DG) armed phagocytes to eliminate the intracellular fungal pathogen Histoplasma capsulatum in vitro and in vivo. Killing did not rely on altering access to carbon-containing molecules or changes in ATP, ER stress, or autophagy. Unexpectedly, 2-DG undermined import of exogenous zinc into macrophages, decreasing the quantity of cytosolic and phagosomal zinc. The fungus perished as a result of zinc starvation. This change in metal ingress was not ascribed to a defect in a single importer; rather, there was a collective impairment in transporter activity. This effect promoted the antifungal machinery of macrophages and expanded the complexity of 2-DG activities far beyond manipulating glycolysis. Mechanistic metabolic studies employing 2-DG will have to consider its effect on zinc transport. Our preclinical data support consideration of this agent as a possible adjunctive therapy for histoplasmosis.
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Affiliation(s)
- Diego Cp Rossi
- Division of Infectious Diseases, College of Medicine and
| | - Julio A Landero Figueroa
- University of Cincinnati/Agilent Technologies Metallomics Center of the Americas, Department of Chemistry, University of Cincinnati, Cincinnati, Ohio, USA
| | | | - Kathleen Candor
- Division of Infectious Diseases, College of Medicine and.,University of Cincinnati/Agilent Technologies Metallomics Center of the Americas, Department of Chemistry, University of Cincinnati, Cincinnati, Ohio, USA.,Immunology Graduate Program and
| | | | | | - Rena Lenchitz
- Division of Infectious Diseases, College of Medicine and
| | - Bradford L Crowther
- Division of Infectious Diseases, College of Medicine and.,Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Waleed Elsegeiny
- Laboratory of Clinical Immunology and Microbiology (LCIM), National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, Maryland, USA
| | - Peter R Williamson
- Laboratory of Clinical Immunology and Microbiology (LCIM), National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, Maryland, USA
| | - Jan Rupp
- Department of Infectious Diseases and Microbiology, German Center for Infection Research, Hamburg-Lübeck-Borstel-Riems, Lübeck, Germany
| | - George S Deepe
- Division of Infectious Diseases, College of Medicine and
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7
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Almeida MA, Baeza LC, Almeida-Paes R, Bailão AM, Borges CL, Guimarães AJ, Soares CMA, Zancopé-Oliveira RM. Comparative Proteomic Analysis of Histoplasma capsulatum Yeast and Mycelium Reveals Differential Metabolic Shifts and Cell Wall Remodeling Processes in the Different Morphotypes. Front Microbiol 2021; 12:640931. [PMID: 34177824 PMCID: PMC8226243 DOI: 10.3389/fmicb.2021.640931] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Accepted: 05/10/2021] [Indexed: 11/13/2022] Open
Abstract
Histoplasma capsulatum is a thermally dimorphic fungus distributed worldwide, but with the highest incidence in the Americas within specific geographic areas, such as the Mississippi River Valley and regions in Latin America. This fungus is the etiologic agent of histoplasmosis, an important life-threatening systemic mycosis. Dimorphism is an important feature for fungal survival in different environments and is related to the virulence of H. capsulatum, and essential to the establishment of infection. Proteomic profiles have made important contributions to the knowledge of metabolism and pathogenicity in several biological models. However, H. capsulatum proteome studies have been underexplored. In the present study, we report the first proteomic comparison between the mycelium and the yeast cells of H. capsulatum. Liquid chromatography coupled to mass spectrometry was used to evaluate the proteomic profile of the two phases of H. capsulatum growth, mycelium, and yeast. In summary, 214 and 225 proteins were only detected/or preferentially abundant in mycelium or yeast cells, respectively. In mycelium, enzymes related to the glycolytic pathway and to the alcoholic fermentation occurred in greater abundance, suggesting a higher use of anaerobic pathways for energy production. In yeast cells, proteins related to the tricarboxylic acid cycle and response to temperature stress were in high abundance. Proteins related to oxidative stress response or involved with cell wall metabolism were identified with differential abundance in both conditions. Proteomic data validation was performed by enzymatic activity determination, Western blot assays, or immunofluorescence microscopy. These experiments corroborated, directly or indirectly, the abundance of isocitrate lyase, 2-methylcitrate synthase, catalase B, and mannosyl-oligosaccharide-1,2-alpha-mannosidase in the mycelium and heat shock protein (HSP) 30, HSP60, glucosamine-fructose-6-phosphate aminotransferase, glucosamine-6-phosphate deaminase, and N-acetylglucosamine-phosphate mutase in yeast cells. The proteomic profile-associated functional classification analyses of proteins provided new and interesting information regarding the differences in metabolism between the two distinct growth forms of H. capsulatum.
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Affiliation(s)
- Marcos Abreu Almeida
- Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Lilian Cristiane Baeza
- Centro de Ciências Médicas e Farmacêuticas, Universidade Estadual do Oeste do Paraná, Cascavel, Brazil
| | - Rodrigo Almeida-Paes
- Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | | | - Clayton Luiz Borges
- Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil
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Prabahar A, Shanmugam L, Jose MA, Radhakrishnan KM, Raja K. A Summary on Up-To-Date Research on Fungal Siderophores on Disease, Treatment and Pathogenicity Based on Text Mining, Bioinformatics and Experts’ Opinion. Fungal Biol 2021. [DOI: 10.1007/978-3-030-53077-8_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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9
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Almeida MA, Almeida-Paes R, Guimarães AJ, Valente RH, Soares CMDA, Zancopé-Oliveira RM. Immunoproteomics Reveals Pathogen's Antigens Involved in Homo sapiens- Histoplasma capsulatum Interaction and Specific Linear B-Cell Epitopes in Histoplasmosis. Front Cell Infect Microbiol 2020; 10:591121. [PMID: 33251160 PMCID: PMC7673445 DOI: 10.3389/fcimb.2020.591121] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 10/07/2020] [Indexed: 12/15/2022] Open
Abstract
Histoplasmosis is one of the most frequent systemic mycosis in HIV patients. In these patients, histoplasmosis has high rates of morbidity/mortality if diagnosis and treatment are delayed. Despite its relevance, there is a paucity of information concerning the interaction between Histoplasma capsulatum and the human host, especially regarding the B-cell response, which has a direct impact on the diagnosis. Culture-based “gold-standard” methods have limitations, making immunodiagnostic tests an attractive option for clinical decisions. Despite the continuous development of those tests, improving serological parameters is necessary to make these methods efficient tools for definitive diagnosis of histoplasmosis. This includes the determination of more specific and immunogenic antigens to improve specificity and sensitivity of assays. In this study, we performed a co-immunoprecipitation assay between a protein extract from the yeast form of H. capsulatum and pooled sera from patients with proven histoplasmosis, followed by shotgun mass spectrometry identification of antigenic targets. Sera from patients with other pulmonary infections or from healthy individuals living in endemic areas of histoplasmosis were also assayed to determine potentially cross-reactive proteins. The primary structures of H. capsulatum immunoprecipitated proteins were evaluated using the DNAStar Protean 7.0 software. In parallel, the online epitope prediction server, BCPREDS, was used to complement the B-epitope prediction analysis. Our approach detected 132 reactive proteins to antibodies present in histoplasmosis patients’ sera. Among these antigens, 127 were recognized also by antibodies in heterologous patients’ and/or normal healthy donors’ sera. Therefore, the only three antigens specifically recognized by antibodies of histoplasmosis patients were mapped as potential antigenic targets: the M antigen, previously demonstrated in the diagnosis of histoplasmosis, and the catalase P and YPS-3 proteins, characterized as virulence factors of H. capsulatum, with antigenic properties still unclear. The other two proteins were fragments of the YPS-3 and M antigen. Overlapping results obtained from the two aforementioned bioinformatic tools, 16 regions from these three proteins are proposed as putative B-cell epitopes exclusive to H. capsulatum. These data reveal a new role for these proteins on H. capsulatum interactions with the immune system and indicate their possible use in new methods for the diagnosis of histoplasmosis.
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Affiliation(s)
- Marcos Abreu Almeida
- Laboratório de Micologia, Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Rodrigo Almeida-Paes
- Laboratório de Micologia, Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Allan Jefferson Guimarães
- Departamento de Microbiologia e Parasitologia, Instituto Biomédico, Universidade Federal Fluminense, Niterói, Brazil
| | - Richard Hemmi Valente
- Laboratório de Toxinologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | | | - Rosely Maria Zancopé-Oliveira
- Laboratório de Micologia, Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
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Shen Q, Rappleye CA. Living Within the Macrophage: Dimorphic Fungal Pathogen Intracellular Metabolism. Front Cell Infect Microbiol 2020; 10:592259. [PMID: 33178634 PMCID: PMC7596272 DOI: 10.3389/fcimb.2020.592259] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 09/15/2020] [Indexed: 12/19/2022] Open
Abstract
Histoplasma and Paracoccidioides are related thermally dimorphic fungal pathogens that cause deadly mycoses (i.e., histoplasmosis and paracoccidioidomycosis, respectively) primarily in North, Central, and South America. Mammalian infection results from inhalation of conidia and their subsequent conversion into pathogenic yeasts. Macrophages in the lung are the first line of defense, but are generally unable to clear these fungi. Instead, Histoplasma and Paracoccidioides yeasts survive and proliferate within the phagosomal compartment of host macrophages. Growth within macrophages requires strategies for acquisition of sufficient nutrients (e.g., carbon, nitrogen, and essential trace elements and co-factors) from the nutrient-depleted phagosomal environment. We review the transcriptomic and recent functional genetic studies that are defining how these intracellular fungal pathogens tune their metabolism to the resources available in the macrophage phagosome. In addition, recent studies have shown that the nutritional state of the macrophage phagosome is not static, but changes upon activation of adaptive immune responses. Understanding the metabolic requirements of these dimorphic pathogens as they thrive within host cells can provide novel targets for therapeutic intervention.
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Affiliation(s)
- Qian Shen
- Department of Biology, Rhodes College, Memphis, TN, United States
| | - Chad A Rappleye
- Department of Microbiology, Ohio State University, Columbus, OH, United States
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Abstract
Histoplasma capsulatum is a member of a group of fungal pathogens called thermally dimorphic fungi, all of which respond to mammalian body temperature by converting from an environmental mold form into a parasitic host form that causes disease. Histoplasma is a primary fungal pathogen, meaning it is able to cause disease in healthy individuals. We are beginning to understand how host temperature is utilized as a key signal to facilitate growth in the parasitic yeast form and promote production of virulence factors. In recent years, multiple regulators of morphology and virulence have been identified in Histoplasma. Mutations in these regulators render the pathogen unable to convert to the parasitic yeast form. Additionally, several virulence factors have been characterized for their importance in in vivo survival and pathogenesis. These virulence factors and regulators can serve as molecular handles for the development of effective drugs and therapeutics to counter Histoplasma infection.
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Affiliation(s)
- Sinem Beyhan
- Department of Infectious Diseases, J. Craig Venter Institute , La Jolla , CA , USA
| | - Anita Sil
- Department of Microbiology and Immunology, University of California , San Francisco , CA , USA
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12
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Silva MG, de Curcio JS, Silva-Bailão MG, Lima RM, Tomazett MV, de Souza AF, Cruz-Leite VRM, Sbaraini N, Bailão AM, Rodrigues F, Pereira M, Gonçales RA, de Almeida Soares CM. Molecular characterization of siderophore biosynthesis in Paracoccidioides brasiliensis. IMA Fungus 2020; 11:11. [PMID: 32742914 PMCID: PMC7359926 DOI: 10.1186/s43008-020-00035-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 06/11/2020] [Indexed: 12/22/2022] Open
Abstract
Iron is an essential nutrient for all organisms. For pathogenic fungi, iron is essential for the success of infection. Thus, these organisms have developed high affinity iron uptake mechanisms to deal with metal deprivation imposed by the host. Siderophore production is one of the mechanisms that fungal pathogens employ for iron acquisition. Paracoccidioides spp. present orthologous genes encoding the enzymes necessary for the biosynthesis of hydroxamates, and plasma membrane proteins related to the transport of these molecules. All these genes are induced in iron deprivation. In addition, it has been observed that Paracoccidioides spp. are able to use siderophores to scavenge iron. Here we observed that addition of the xenosiderophore ferrioxamine B FOB) to P. brasiliensis culture medium results in repression (at RNA and protein levels) of the SidA, the first enzyme of the siderophore biosynthesis pathway. Furthermore, SidA activity was reduced in the presence of FOB, suggesting that P. brasiliensis blocks siderophores biosynthesis and can explore siderophores in the environment to scavenge iron. In order to support the importance of siderophores on Paracoccidioides sp. life and infection cycle, silenced mutants for the sidA gene were obtained by antisense RNA technology. The obtained AsSidA strains displayed decreased siderophore biosynthesis in iron deprivation conditions and reduced virulence to an invertebrate model.
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Affiliation(s)
- Marielle Garcia Silva
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, ICB II, Campus II, Universidade Federal de Goiás, Goiânia, GO Brazil
- Programa de Pós-graduação em Patologia Molecular, Faculdade de Medicina, Universidade de Brasília, Brasília, DF 70910-900 Brazil
| | - Juliana Santana de Curcio
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, ICB II, Campus II, Universidade Federal de Goiás, Goiânia, GO Brazil
| | - Mirelle Garcia Silva-Bailão
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, ICB II, Campus II, Universidade Federal de Goiás, Goiânia, GO Brazil
| | - Raisa Melo Lima
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, ICB II, Campus II, Universidade Federal de Goiás, Goiânia, GO Brazil
| | - Mariana Vieira Tomazett
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, ICB II, Campus II, Universidade Federal de Goiás, Goiânia, GO Brazil
| | - Aparecido Ferreira de Souza
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, ICB II, Campus II, Universidade Federal de Goiás, Goiânia, GO Brazil
| | | | - Nicolau Sbaraini
- Centro de Biotecnologia, Programa de Pós-graduação em Biologia Celular e Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS Brazil
| | - Alexandre Melo Bailão
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, ICB II, Campus II, Universidade Federal de Goiás, Goiânia, GO Brazil
| | - Fernando Rodrigues
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B’s - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Maristela Pereira
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, ICB II, Campus II, Universidade Federal de Goiás, Goiânia, GO Brazil
| | - Relber Aguiar Gonçales
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B’s - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Célia Maria de Almeida Soares
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, ICB II, Campus II, Universidade Federal de Goiás, Goiânia, GO Brazil
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13
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Chakraborty T, Tóth R, Nosanchuk JD, Gácser A. Multicopper Oxidases in Saccharomyces cerevisiae and Human Pathogenic Fungi. J Fungi (Basel) 2020; 6:E56. [PMID: 32349384 DOI: 10.3390/jof6020056] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 04/20/2020] [Accepted: 04/25/2020] [Indexed: 12/11/2022] Open
Abstract
Multicopper oxidases (MCOs) are produced by microscopic and macroscopic fungal species and are involved in various physiological processes such as morphogenesis, lignin degradation, and defense mechanisms to stress inducing environmental conditions as well as fungal virulence. This review will summarize our current understanding regarding the functions of MCOs present in Saccharomyces cerevisiae and in different human fungal pathogens. Of the two main MCO groups, the first group of MCOs is involved in iron homoeostasis and the second includes laccases. This review will also discuss their role in the pathogenesis of human fungal pathogens.
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Shen Q, Ray SC, Evans HM, Deepe GS, Rappleye CA. Metabolism of Gluconeogenic Substrates by an Intracellular Fungal Pathogen Circumvents Nutritional Limitations within Macrophages. mBio 2020; 11:e02712-19. [PMID: 32265333 PMCID: PMC7157778 DOI: 10.1128/mbio.02712-19] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 03/17/2020] [Indexed: 12/25/2022] Open
Abstract
Microbial pathogens exploit host nutrients to proliferate and cause disease. Intracellular pathogens, particularly those exclusively living in the phagosome such as Histoplasma capsulatum, must adapt and acquire nutrients within the nutrient-limited phagosomal environment. In this study, we investigated which host nutrients could be utilized by Histoplasma as carbon sources to proliferate within macrophages. Histoplasma yeasts can grow on hexoses and amino acids but not fatty acids as the carbon source in vitro Transcriptional analysis and metabolism profiling showed that Histoplasma yeasts downregulate glycolysis and fatty acid utilization but upregulate gluconeogenesis within macrophages. Depletion of glycolysis or fatty acid utilization pathways does not prevent Histoplasma growth within macrophages or impair virulence in vivo However, loss of function in Pck1, the enzyme catalyzing the first committed step of gluconeogenesis, impairs Histoplasma growth within macrophages and severely attenuates virulence in vivo, indicating that Histoplasma yeasts rely on catabolism of gluconeogenic substrates (e.g., amino acids) to proliferate within macrophages.IMPORTANCEHistoplasma is a primary human fungal pathogen that survives and proliferates within host immune cells, particularly within the macrophage phagosome compartment. The phagosome compartment is a nutrient-limited environment, requiring Histoplasma yeasts to be able to assimilate available carbon sources within the phagosome to meet their nutritional needs. In this study, we showed that Histoplasma yeasts do not utilize fatty acids or hexoses for growth within macrophages. Instead, Histoplasma yeasts consume gluconeogenic substrates to proliferate in macrophages. These findings reveal the phagosome composition from a nutrient standpoint and highlight essential metabolic pathways that are required for a phagosomal pathogen to proliferate in this intracellular environment.
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Affiliation(s)
- Qian Shen
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
| | - Stephanie C Ray
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
| | - Heather M Evans
- Division of Infectious Diseases, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - George S Deepe
- Division of Infectious Diseases, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Chad A Rappleye
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
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Abstract
Fungi from the order Onygenales include human pathogens. Although secondary metabolites are critical for pathogenic interactions, relatively little is known about Onygenales compounds. Here, we use chemical and genetic methods on Aioliomyces pyridodomos, the first representative of a candidate new family within Onygenales. We isolated 14 new bioactive metabolites, nine of which are first disclosed here. Thirty-two specialized metabolite biosynthetic gene clusters (BGCs) were identified. BGCs were correlated to some of the new compounds by heterologous expression of biosynthetic genes. Some of the compounds were found after one year of fermentation. By comparing BGCs from A. pyridodomos with those from 68 previously sequenced Onygenales fungi, we delineate a large biosynthetic potential. Most of these biosynthetic pathways are specific to Onygenales fungi and have not been found elsewhere. Family level specificity and conservation of biosynthetic gene content are evident within Onygenales. Identification of these compounds may be important to understanding pathogenic interactions.
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Affiliation(s)
- Zhenjian Lin
- Department of Medicinal Chemistry , University of Utah , Salt Lake City , Utah 84112 , United States
| | - Thomas B Kakule
- Department of Medicinal Chemistry , University of Utah , Salt Lake City , Utah 84112 , United States
| | - Christopher A Reilly
- Department of Pharmacology & Toxicology and Center for Human Toxicology , University of Utah , Salt Lake City , Utah 84112 , United States
| | - Sinem Beyhan
- Department of Infectious Diseases , J. Craig Venter Institute , La Jolla , California 92037 , United States
- Department of Medicine , University of California, San Diego , La Jolla , California 92093 , United States
| | - Eric W Schmidt
- Department of Medicinal Chemistry , University of Utah , Salt Lake City , Utah 84112 , United States
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Brechting PJ, Rappleye CA. Histoplasma Responses to Nutritional Immunity Imposed by Macrophage Activation. J Fungi (Basel) 2019; 5. [PMID: 31195617 DOI: 10.3390/jof5020045] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 05/31/2019] [Accepted: 05/31/2019] [Indexed: 01/25/2023] Open
Abstract
The fungal pathogen Histoplasma capsulatum resides within the phagosome of host phagocytic cells. Within this intracellular compartment, Histoplasma yeast replication requires the acquisition of several essential nutrients, including metal ions. Recent work has shown that while iron, zinc, and copper are sufficiently abundant in resting macrophages, cytokine activation of these host cells causes restriction of these metals from intracellular yeasts as a form of nutritional immunity. Faced with limited iron availability in the phagosome following macrophage activation by IFN-γ, Histoplasma yeasts secrete iron-scavenging siderophores and employ multiple strategies for reduction of ferric iron to the more physiologically useful ferrous form. IFN-γ activation of macrophages also limits availability of copper in the phagosome, forcing Histoplasma reliance on the high affinity Ctr3 copper importer for copper acquisition. GM-CSF activation stimulates macrophage production of zinc-chelating metallothioneins and zinc transporters to sequester zinc from Histoplasma yeasts. In response, Histoplasma yeasts express the Zrt2 zinc importer. These findings highlight the dynamics of phagosomal metal ion concentrations in host-pathogen interactions and explain one mechanism by which macrophages become a less permissive environment for Histoplasma replication with the onset of adaptive immunity.
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Shen Q, Beucler MJ, Ray SC, Rappleye CA. Macrophage activation by IFN-γ triggers restriction of phagosomal copper from intracellular pathogens. PLoS Pathog 2018; 14:e1007444. [PMID: 30452484 PMCID: PMC6277122 DOI: 10.1371/journal.ppat.1007444] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 12/03/2018] [Accepted: 10/30/2018] [Indexed: 11/19/2022] Open
Abstract
Copper toxicity and copper limitation can both be effective host defense mechanisms against pathogens. Tolerance of high copper by fungi makes toxicity as a defense mechanism largely ineffective against fungal pathogens. A forward genetic screen for Histoplasma capsulatum mutant yeasts unable to replicate within macrophages showed the Ctr3 copper transporter is required for intramacrophage proliferation. Ctr3 mediates copper uptake and is required for growth in low copper. Transcription of the CTR3 gene is induced by differentiation of H. capsulatum into pathogenic yeasts and by low available copper, but not decreased iron. Low expression of a CTR3 transcriptional reporter by intracellular yeasts implies that phagosomes of non-activated macrophages have moderate copper levels. This is further supported by the replication of Ctr3-deficient yeasts within the phagosome of non-activated macrophages. However, IFN-γ activation of phagocytes causes restriction of phagosomal copper as shown by upregulation of the CTR3 transcriptional reporter and by the failure of Ctr3-deficient yeasts, but not Ctr3 expressing yeasts, to proliferate within these macrophages. Accordingly, in a respiratory model of histoplasmosis, Ctr3-deficient yeasts are fully virulent during phases of the innate immune response but are attenuated after the onset of adaptive immunity. Thus, while technical limitations prevent direct measurement of phagosomal copper concentrations and copper-independent factors can influence gene expression, both the CTR3 promoter induction and the attenuation of Ctr3-deficient yeasts indicate activation of macrophages switches the phagosome from a copper-replete to a copper-depleted environment, forcing H. capsulatum reliance on Ctr3 for copper acquisition. Control of primary pathogens that infect phagocytes often requires adaptive immunity, but the mechanisms that convert host cells from permissive to antimicrobial states are only partially understood. The intracellular fungal pathogen Histoplasma capsulatum resides and proliferates within the macrophage phagosome. During innate immunity, macrophages which normally control fungi prove ineffective against H. capsulatum yeasts. At this stage, the phagosome of unactivated macrophages has ample copper that facilitates intracellular growth of Histoplasma but does not cause copper toxicity. However, the onset of adaptive immunity and the subsequent activation of macrophages decreases phagosomal copper and macrophages become less permissive to Histoplasma proliferation. IFN-γ acts as a key cytokine for switching the macrophage strategy by changing phagosomes from a copper-sufficient to a copper-depleted state in order to control intracellular pathogens. In such activated macrophages, H. capsulatum yeasts upregulate expression of the Ctr3 copper transporter to enable continued acquisition of essential copper.
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Affiliation(s)
- Qian Shen
- Department of Microbiology, Ohio State University, Columbus, OH, United States of America
| | - Matthew J. Beucler
- Department of Microbiology, Ohio State University, Columbus, OH, United States of America
| | - Stephanie C. Ray
- Department of Microbiology, Ohio State University, Columbus, OH, United States of America
| | - Chad A. Rappleye
- Department of Microbiology, Ohio State University, Columbus, OH, United States of America
- * E-mail:
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Wang Q, Du M, Wang S, Liu L, Xiao L, Wang L, Li T, Zhuang H, Yang E. MADS-Box Transcription Factor MadsA Regulates Dimorphic Transition, Conidiation, and Germination of Talaromyces marneffei. Front Microbiol 2018; 9:1781. [PMID: 30131782 PMCID: PMC6090077 DOI: 10.3389/fmicb.2018.01781] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2018] [Accepted: 07/16/2018] [Indexed: 01/05/2023] Open
Abstract
The opportunistic human pathogen Talaromyces marneffei exhibits a temperature-dependent dimorphic transition, which is closely related with its pathogenicity. This species grows as multinucleate mycelia that produce infectious conidia at 25°C, while undergoes a dimorphic transition to generate uninucleate yeast form cells at 37°C. The mechanisms of phenotype switching are not fully understood. The transcription factor madsA gene is a member of the MADS-box gene family. Previously, it was found that overexpression of madsA gene resulted in mycelial growth instead of yeast form at 37°C. In the current study, the madsA deletion mutant (ΔmadsA) and complemented strain (CMA) were constructed by genetic manipulation. We compared the phenotypes, growth, conidiation, conidial germination and susceptibility to stresses (including osmotic and oxidative) of the ΔmadsA with the wild-type (WT) and CMA strains. The results showed that the ΔmadsA displayed a faster process of the yeast-to-mycelium transition than the WT and CMA. In addition, the deletion of madsA led to a delay in conidia production and conidial germination. The tolerance of ΔmadsA conidia to hydrogen peroxide was better than that of the WT and CMA strains. Then, RNA-seq was performed to identify differences in gene expression between the ΔmadsA mutant and WT strain during the yeast phase, mycelium phase, yeast-to-mycelium transition and mycelium-to-yeast transition, respectively. Gene ontology functional enrichment analyses indicated that some important processes such as transmembrane transport, oxidation-reduction process, protein catabolic process and response to oxidative stress were affected by the madsA deletion. Together, our results suggest that madsA functions as a global regulator involved in the conidiation and germination, especially in the dimorphic transition of T. marneffei. Its roles in the survival, pathogenicity and transmission of T. marneffei require further investigation.
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Affiliation(s)
- Qiangyi Wang
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Minghao Du
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China.,Institute of Systems Biomedicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Shuai Wang
- Department of Laboratorial Science and Technology, School of Public Health, Peking University, Beijing, China
| | - Linxia Liu
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,Institute of Microbiology, University of Chinese Academy of Sciences, Beijing, China
| | - Liming Xiao
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China.,Institute of Systems Biomedicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Linqi Wang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Tong Li
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Hui Zhuang
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Ence Yang
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China.,Institute of Systems Biomedicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
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Baltazar LM, Zamith-Miranda D, Burnet MC, Choi H, Nimrichter L, Nakayasu ES, Nosanchuk JD. Concentration-dependent protein loading of extracellular vesicles released by Histoplasma capsulatum after antibody treatment and its modulatory action upon macrophages. Sci Rep 2018; 8:8065. [PMID: 29795301 PMCID: PMC5966397 DOI: 10.1038/s41598-018-25665-5] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 04/23/2018] [Indexed: 12/03/2022] Open
Abstract
Diverse pathogenic fungi secrete extracellular vesicles (EV) that contain macromolecules, including virulence factors that can modulate the host immune response. We recently demonstrated that the binding of monoclonal antibodies (mAb) modulates how Histoplasma capsulatum load and releases its extracellular vesicles (EV). In the present paper, we addressed a concentration-dependent impact on the fungus' EV loading and release with different mAb, as well as the pathophysiological role of these EV during the host-pathogen interaction. We found that the mAbs differentially regulate EV content in concentration-dependent and independent manners. Enzymatic assays demonstrated that laccase activity in EV from H. capsulatum opsonized with 6B7 was reduced, but urease activity was not altered. The uptake of H. capsulatum by macrophages pre-treated with EV, presented an antibody concentration-dependent phenotype. The intracellular killing of yeast cells was potently inhibited in macrophages pre-treated with EV from 7B6 (non-protective) mAb-opsonized H. capsulatum and this inhibition was associated with a decrease in the reactive-oxygen species generated by these macrophages. In summary, our findings show that opsonization quantitatively and qualitatively modifies H. capsulatum EV load and secretion leading to distinct effects on the host's immune effector mechanisms, supporting the hypothesis that EV sorting and secretion are dynamic mechanisms for a fine-tuned response by fungal cells.
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Affiliation(s)
- Ludmila Matos Baltazar
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
- Division of Infectious Diseases, Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA
- Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Daniel Zamith-Miranda
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
- Division of Infectious Diseases, Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Meagan C Burnet
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Hyungwon Choi
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore
| | - Leonardo Nimrichter
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brazil
| | - Ernesto S Nakayasu
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Joshua D Nosanchuk
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA.
- Division of Infectious Diseases, Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA.
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Abstract
Metals are essential for life, and they play a central role in the struggle between infecting microbes and their hosts. In fact, an important aspect of microbial pathogenesis is the 'nutritional immunity', in which metals are actively restricted (or, in an extended definition of the term, locally enriched) by the host to hinder microbial growth and virulence. Consequently, fungi have evolved often complex regulatory networks, uptake and detoxification systems for essential metals such as iron, zinc, copper, nickel and manganese. These systems often differ fundamentally from their bacterial counterparts, but even within the fungal pathogens we can find common and unique solutions to maintain metal homeostasis. Thus, we here compare the common and species-specific mechanisms used for different metals among different fungal species-focusing on important human pathogens such as Candida albicans, Aspergillus fumigatus or Cryptococcus neoformans, but also looking at model fungi such as Saccharomyces cerevisiae or A. nidulans as well-studied examples for the underlying principles. These direct comparisons of our current knowledge reveal that we have a good understanding how model fungal pathogens take up iron or zinc, but that much is still to learn about other metals and specific adaptations of individual species-not the least to exploit this knowledge for new antifungal strategies.
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Affiliation(s)
- Franziska Gerwien
- Department Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology– Hans Knoell Institute, 07745 Jena, Germany
| | - Volha Skrahina
- Department Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology– Hans Knoell Institute, 07745 Jena, Germany
| | - Lydia Kasper
- Department Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology– Hans Knoell Institute, 07745 Jena, Germany
| | - Bernhard Hube
- Department Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology– Hans Knoell Institute, 07745 Jena, Germany
| | - Sascha Brunke
- Department Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology– Hans Knoell Institute, 07745 Jena, Germany
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21
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Shen Q, Rappleye CA. Differentiation of the fungus Histoplasma capsulatum into a pathogen of phagocytes. Curr Opin Microbiol 2017; 40:1-7. [PMID: 29096192 DOI: 10.1016/j.mib.2017.10.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 10/09/2017] [Indexed: 01/06/2023]
Abstract
Mammalian body temperature triggers differentiation of the fungal pathogen Histoplasma capsulatum into yeast cells. The Drk1 regulatory kinase and an interdependent network of Ryp transcription factors establish the yeast state. Beyond morphology, the differentiation-dependent expression program equips yeasts for invasion and survival within phagosomes. Yeast cells produce α-glucan and the Eng1 endoglucanase which hide yeasts from immune detection. Secretion of yeast phase-specific Sod3 and CatB detoxify phagocyte-derived reactive oxygen molecules. Histoplasma cells adapt to iron and zinc limitation in activated macrophages by production of siderophores and the Zrt2 transporter, respectively. Yeasts also respond to inflammation-associated hypoxia. Histoplasma pathogenicity thus relies on factors controlled by yeast differentiation as well as environment-dependent responses.
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Affiliation(s)
- Qian Shen
- Ohio State University, Columbus, OH 43210, USA
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Hernández-Chávez MJ, Pérez-García LA, Niño-Vega GA, Mora-Montes HM. Fungal Strategies to Evade the Host Immune Recognition. J Fungi (Basel) 2017; 3:jof3040051. [PMID: 29371567 PMCID: PMC5753153 DOI: 10.3390/jof3040051] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 09/18/2017] [Accepted: 09/19/2017] [Indexed: 12/23/2022] Open
Abstract
The recognition of fungal cells by the host immune system is key during the establishment of a protective anti-fungal response. Even though the immune system has evolved a vast number of processes to control these organisms, they have developed strategies to fight back, avoiding the proper recognition by immune components and thus interfering with the host protective mechanisms. Therefore, the strategies to evade the immune system are as important as the virulence factors and attributes that damage the host tissues and cells. Here, we performed a thorough revision of the main fungal tactics to escape from the host immunosurveillance processes. These include the composition and organization of the cell wall, the fungal capsule, the formation of titan cells, biofilms, and asteroid bodies; the ability to undergo dimorphism; and the escape from nutritional immunity, extracellular traps, phagocytosis, and the action of humoral immune effectors.
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Affiliation(s)
- Marco J Hernández-Chávez
- Departamento de Biología, División de Ciencias Naturales y Exactas, Campus Guanajuato, Universidad de Guanajuato, Noria Alta s/n, col. Noria Alta, C.P., Guanajuato Gto. 36050, México.
| | - Luis A Pérez-García
- Unidad Académica Multidisciplinaria Zona Huasteca, Universidad Autónoma de San Luis Potosí, Romualdo del Campo 501, Fracc. Rafael Curiel, C.P., Cd. Valle SLP. 79060, México.
| | - Gustavo A Niño-Vega
- Departamento de Biología, División de Ciencias Naturales y Exactas, Campus Guanajuato, Universidad de Guanajuato, Noria Alta s/n, col. Noria Alta, C.P., Guanajuato Gto. 36050, México.
| | - Héctor M Mora-Montes
- Departamento de Biología, División de Ciencias Naturales y Exactas, Campus Guanajuato, Universidad de Guanajuato, Noria Alta s/n, col. Noria Alta, C.P., Guanajuato Gto. 36050, México.
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Abstract
Histoplasma capsulatum, an environmental fungus, is the most common endemic pulmonary mycosis in the USA. Disease is most frequently observed in immunocompromised patients living in endemic areas. We present the mechanisms of fungal recognition, innate immune response and adaptive immune response that lead to protection or exacerbation of disease. Current understanding of these mechanisms is the result of a continuing dialogue between clinical observations and murine studies. Mice are a powerful model to study the immune response to H. capsulatum alone or in the presence of immunomodulatory drugs. Vigilance for histoplasmosis should be exercised with novel immunosuppressive agents that target the important immune pathways identified here.
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Affiliation(s)
- Michael C Horwath
- Division of Infectious Diseases, University of Cincinnati College of Medicine, 3230 Eden Ave, Cincinnati, OH 45267, USA.,Division of Immunobiology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, 2600 Clifton Ave, Cincinnati, OH 45220, USA
| | - Roger A Fecher
- Division of Infectious Diseases, University of Cincinnati College of Medicine, 3230 Eden Ave, Cincinnati, OH 45267, USA.,Division of Immunobiology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, 2600 Clifton Ave, Cincinnati, OH 45220, USA
| | - George S Deepe
- Division of Infectious Diseases, University of Cincinnati College of Medicine, 3230 Eden Ave, Cincinnati, OH 45267, USA.,Medical Service, Veterans Affairs Hospital, Cincinnati, OH 45220, USA
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24
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Garfoot AL, Rappleye CA. Histoplasma capsulatum surmounts obstacles to intracellular pathogenesis. FEBS J 2015; 283:619-33. [PMID: 26235362 DOI: 10.1111/febs.13389] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 07/25/2015] [Accepted: 07/27/2015] [Indexed: 11/28/2022]
Abstract
The fungal pathogen Histoplasma capsulatum causes respiratory and disseminated disease, even in immunocompetent hosts. In contrast to opportunistic pathogens, which are readily controlled by phagocytic cells, H. capsulatum yeasts are able to infect macrophages, survive antimicrobial defenses, and proliferate as an intracellular pathogen. In this review, we discuss some of the molecular mechanisms that enable H. capsulatum yeasts to overcome obstacles to intracellular pathogenesis. H. capsulatum yeasts gain refuge from extracellular obstacles such as antimicrobial lung surfactant proteins by engaging the β-integrin family of phagocytic receptors to promote entry into macrophages. In addition, H. capsulatum yeasts conceal immunostimulatory β-glucans to avoid triggering signaling receptors such as the β-glucan receptor Dectin-1. H. capsulatum yeasts counteract phagocyte-produced reactive oxygen species by expression of oxidative stress defense enzymes including an extracellular superoxide dismutase and an extracellular catalase. Within the phagosome, H. capsulatum yeasts block phagosome acidification, acquire essential metals such as iron and zinc, and utilize de novo biosynthesis pathways to overcome nutritional limitations. These mechanisms explain how H. capsulatum yeasts avoid and negate macrophage defense strategies and establish a hospitable intracellular niche, making H. capsulatum a successful intracellular pathogen of macrophages.
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Affiliation(s)
- Andrew L Garfoot
- Department of Microbiology, Department of Microbial Infection and Immunity, Ohio State University, Columbus, OH, USA
| | - Chad A Rappleye
- Department of Microbiology, Department of Microbial Infection and Immunity, Ohio State University, Columbus, OH, USA
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Boyce KJ, Andrianopoulos A. Fungal dimorphism: the switch from hyphae to yeast is a specialized morphogenetic adaptation allowing colonization of a host. FEMS Microbiol Rev 2015; 39:797-811. [DOI: 10.1093/femsre/fuv035] [Citation(s) in RCA: 131] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/02/2015] [Indexed: 01/19/2023] Open
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26
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Giuliano Garisto Donzelli B, Gibson DM, Krasnoff SB. Intracellular siderophore but not extracellular siderophore is required for full virulence in Metarhizium robertsii. Fungal Genet Biol 2015; 82:56-68. [PMID: 26135511 DOI: 10.1016/j.fgb.2015.06.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 06/26/2015] [Accepted: 06/27/2015] [Indexed: 10/23/2022]
Abstract
Efficient iron acquisition mechanisms are fundamental for microbial survival in the environment and for pathogen virulence within their hosts. M. robertsii produces two known iron-binding natural products: metachelins, which are used to scavenge extracellular iron, and ferricrocin, which is strictly intracellular. To study the contribution of siderophore-mediated iron uptake and storage to M. robertsii fitness, we generated null mutants for each siderophore synthase gene (mrsidD and mrsidC, respectively), as well as for the iron uptake transcriptional repressor mrsreA. All of these mutants showed impaired germination speed, differential sensitivity to hydrogen peroxide, and differential ability to overcome iron chelation on growth-limiting iron concentrations. RT-qPCR data supported regulation of mrsreA, mrsidC, and mrsidD by supplied iron in vitro and during growth within the insect host, Spodoptera exigua. We also observed strong upregulation of the insect iron-binding proteins, transferrins, during infection. Insect bioassays revealed that ferricrocin is required for full virulence against S. exigua; neither the loss of metachelin production nor the deletion of the transcription factor mrsreA significantly affected M. robertsii virulence.
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Affiliation(s)
- Bruno Giuliano Garisto Donzelli
- School of Integrative Plant Science - Plant Pathology and Plant-Microbe Biology Section, Cornell University, Ithaca, NY 14853, United States.
| | - Donna M Gibson
- USDA ARS, Robert W. Holley Center for Agriculture and Health, 538 Tower Road, Ithaca, NY 14853, United States
| | - Stuart B Krasnoff
- USDA ARS, Robert W. Holley Center for Agriculture and Health, 538 Tower Road, Ithaca, NY 14853, United States
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27
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Polvi EJ, Li X, O’Meara TR, Leach MD, Cowen LE. Opportunistic yeast pathogens: reservoirs, virulence mechanisms, and therapeutic strategies. Cell Mol Life Sci 2015; 72:2261-87. [PMID: 25700837 PMCID: PMC11113693 DOI: 10.1007/s00018-015-1860-z] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Revised: 02/06/2015] [Accepted: 02/11/2015] [Indexed: 12/21/2022]
Abstract
Life-threatening invasive fungal infections are becoming increasingly common, at least in part due to the prevalence of medical interventions resulting in immunosuppression. Opportunistic fungal pathogens of humans exploit hosts that are immunocompromised, whether by immunosuppression or genetic predisposition, with infections originating from either commensal or environmental sources. Fungal pathogens are armed with an arsenal of traits that promote pathogenesis, including the ability to survive host physiological conditions and to switch between different morphological states. Despite the profound impact of fungal pathogens on human health worldwide, diagnostic strategies remain crude and treatment options are limited, with resistance to antifungal drugs on the rise. This review will focus on the global burden of fungal infections, the reservoirs of these pathogens, the traits of opportunistic yeast that lead to pathogenesis, host genetic susceptibilities, and the challenges that must be overcome to combat antifungal drug resistance and improve clinical outcome.
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Affiliation(s)
- Elizabeth J. Polvi
- Department of Molecular Genetics, University of Toronto, 1 King’s College Circle, Medical Sciences Building, Room 4368, Toronto, ON M5S 1A8 Canada
| | - Xinliu Li
- Department of Molecular Genetics, University of Toronto, 1 King’s College Circle, Medical Sciences Building, Room 4368, Toronto, ON M5S 1A8 Canada
| | - Teresa R. O’Meara
- Department of Molecular Genetics, University of Toronto, 1 King’s College Circle, Medical Sciences Building, Room 4368, Toronto, ON M5S 1A8 Canada
| | - Michelle D. Leach
- Department of Molecular Genetics, University of Toronto, 1 King’s College Circle, Medical Sciences Building, Room 4368, Toronto, ON M5S 1A8 Canada
- Aberdeen Fungal Group, Institute of Medical Sciences, School of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, UK
| | - Leah E. Cowen
- Department of Molecular Genetics, University of Toronto, 1 King’s College Circle, Medical Sciences Building, Room 4368, Toronto, ON M5S 1A8 Canada
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28
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Abstract
Fungi are adept at changing their cell shape and developmental program in response to signals in their surroundings. Here we focus on a group of evolutionarily related fungal pathogens of humans known as the thermally dimorphic fungi. These organisms grow in a hyphal form in the environment but shift their morphology drastically within a mammalian host. Temperature is one of the main host signals that initiates their conversion to the "host" form and is sufficient in the laboratory to trigger establishment of this host-adapted developmental program. Here we discuss the major human pathogens in this group, which are Blastomyces dermatiditis, Coccidioides immitis/posadasii, Histoplasma capsulatum, Paracoccidioides brasiliensis/lutzii, Sporothrix schenckii, and Talaromyces marneffei (formerly known as Penicillium marneffei). The majority of these organisms are primary pathogens, with the ability to cause disease in healthy humans who encounter them in endemic areas.
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Affiliation(s)
- Anita Sil
- Department of Microbiology and Immunology, University of California, San Francisco, California 94143
| | - Alex Andrianopoulos
- Department of Genetics, The University of Melbourne, Victoria 3010, Australia
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Holbrook ED, Kemski MM, Richer SM, Wheat LJ, Rappleye CA. Glycosylation and immunoreactivity of the Histoplasma capsulatum Cfp4 yeast-phase exoantigen. Infect Immun 2014; 82:4414-25. [PMID: 25114108 PMCID: PMC4187849 DOI: 10.1128/iai.01893-14] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Accepted: 08/02/2014] [Indexed: 11/20/2022] Open
Abstract
The yeast phase of Histoplasma capsulatum is the virulent form of this thermally dimorphic fungal pathogen. Among the secreted proteome of Histoplasma, culture filtrate protein 4 (Cfp4) is a heavily glycosylated factor produced abundantly and specifically by Histoplasma yeast cells, suggesting its role in pathogenesis. We have generated three monoclonal antibodies as tools for characterization and detection of Cfp4 and determined the epitope each recognizes. Through site-directed mutagenesis of Cfp4, we identified three asparagines that function as the principal sites of N-linked glycan modification. To test the function of Cfp4 in Histoplasma pathogenesis, we generated Cfp4-deficient strains by insertional mutagenesis and by RNA interference. Cfp4-deficient strains are not attenuated in virulence in human macrophages or during lung infection in a murine model of histoplasmosis. Coinfection of differentially marked Cfp4-producing and Cfp4-deficient strains demonstrates that production of Cfp4 does not confer a fitness advantage to Histoplasma yeasts during murine lung infection. Despite no apparent role in acute virulence in mice, secretion of the Cfp4 glycoprotein by yeast cells is consistent across clinical and laboratory isolates of the North American type 1 and type 2 phylogenetic groups as well as a strain from Panama. In addition, human immune sera recognize the Histoplasma Cfp4 protein, confirming Cfp4 production during infection of human hosts. These results suggest the potential utility of Cfp4 as a diagnostic exoantigen for histoplasmosis.
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Affiliation(s)
- Eric D Holbrook
- Department of Microbiology, Department of Microbial Infection and Immunity, Ohio State University, Columbus, Ohio, USA
| | - Megan M Kemski
- Department of Microbiology, Department of Microbial Infection and Immunity, Ohio State University, Columbus, Ohio, USA
| | | | | | - Chad A Rappleye
- Department of Microbiology, Department of Microbial Infection and Immunity, Ohio State University, Columbus, Ohio, USA
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Silva-Bailão MG, Bailão EFLC, Lechner BE, Gauthier GM, Lindner H, Bailão AM, Haas H, de Almeida Soares CM. Hydroxamate production as a high affinity iron acquisition mechanism in Paracoccidioides spp. PLoS One 2014; 9:e105805. [PMID: 25157575 PMCID: PMC4144954 DOI: 10.1371/journal.pone.0105805] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 07/25/2014] [Indexed: 12/21/2022] Open
Abstract
Iron is a micronutrient required by almost all living organisms, including fungi. Although this metal is abundant, its bioavailability is low either in aerobic environments or within mammalian hosts. As a consequence, pathogenic microorganisms evolved high affinity iron acquisition mechanisms which include the production and uptake of siderophores. Here we investigated the utilization of these molecules by species of the Paracoccidioides genus, the causative agents of a systemic mycosis. It was demonstrated that iron starvation induces the expression of Paracoccidioides ortholog genes for siderophore biosynthesis and transport. Reversed-phase HPLC analysis revealed that the fungus produces and secretes coprogen B, which generates dimerumic acid as a breakdown product. Ferricrocin and ferrichrome C were detected in Paracoccidioides as the intracellular produced siderophores. Moreover, the fungus is also able to grow in presence of siderophores as the only iron sources, demonstrating that beyond producing, Paracoccidioides is also able to utilize siderophores for growth, including the xenosiderophore ferrioxamine. Exposure to exogenous ferrioxamine and dimerumic acid increased fungus survival during co-cultivation with macrophages indicating that these molecules play a role during host-pathogen interaction. Furthermore, cross-feeding experiments revealed that Paracoccidioides siderophores promotes growth of Aspergillus nidulans strain unable to produce these iron chelators. Together, these data denote that synthesis and utilization of siderophores is a mechanism used by Paracoccidioides to surpass iron limitation. As iron paucity is found within the host, siderophore production may be related to fungus pathogenicity.
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Affiliation(s)
- Mirelle Garcia Silva-Bailão
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Goiás, Brazil
- Programa de Pós-Graduação em Patologia Molecular, Universidade de Brasília, Brasília, Brazil
| | - Elisa Flávia Luiz Cardoso Bailão
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Goiás, Brazil
- Unidade Universitária de Iporá, Universidade Estadual de Goiás, Iporá, Goiás, Brazil
| | | | - Gregory M. Gauthier
- Department of Medicine, Section of Infectious Diseases, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Herbert Lindner
- Division of Clinical Biochemistry/Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Alexandre Melo Bailão
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Goiás, Brazil
| | - Hubertus Haas
- Division of Molecular Biology/Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Célia Maria de Almeida Soares
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Goiás, Brazil
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Potrykus J, Ballou ER, Childers DS, Brown AJ. Conflicting interests in the pathogen-host tug of war: fungal micronutrient scavenging versus mammalian nutritional immunity. PLoS Pathog 2014; 10:e1003910. [PMID: 24626223 DOI: 10.1371/journal.ppat.1003910] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Edwards JA, Chen C, Kemski MM, Hu J, Mitchell TK, Rappleye CA. Histoplasma yeast and mycelial transcriptomes reveal pathogenic-phase and lineage-specific gene expression profiles. BMC Genomics 2013; 14:695. [PMID: 24112604 PMCID: PMC3852720 DOI: 10.1186/1471-2164-14-695] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 10/07/2013] [Indexed: 11/13/2022] Open
Abstract
Background The dimorphic fungus Histoplasma capsulatum causes respiratory and systemic disease in mammalian hosts by expression of factors that enable survival within phagocytic cells of the immune system. Histoplasma’s dimorphism is distinguished by growth either as avirulent mycelia or as pathogenic yeast. Geographically distinct strains of Histoplasma differ in their relative virulence in mammalian hosts and in production of and requirement for specific virulence factors. The close similarity in the genome sequences of these diverse strains suggests that phenotypic variations result from differences in gene expression rather than gene content. To provide insight into how the transcriptional program translates into morphological variation and the pathogenic lifestyle, we compared the transcriptional profile of the pathogenic yeast phase and the non-pathogenic mycelial phase of two clinical isolates of Histoplasma. Results To overcome inaccuracies in ab initio genome annotation of the Histoplasma genome, we used RNA-seq methodology to generate gene structure models based on experimental evidence. Quantitative analyses of the sequencing reads revealed 6% to 9% of genes are differentially regulated between the two phases. RNA-seq-based mRNA quantitation was strongly correlated with gene expression levels determined by quantitative RT-PCR. Comparison of the yeast-phase transcriptomes between strains showed 7.6% of all genes have lineage-specific expression differences including genes contributing, or potentially related, to pathogenesis. GFP-transcriptional fusions and their introduction into both strain backgrounds revealed that the difference in transcriptional activity of individual genes reflects both variations in the cis- and trans-acting factors between Histoplasma strains. Conclusions Comparison of the yeast and mycelial transcriptomes highlights genes encoding virulence factors as well as those involved in protein glycosylation, alternative metabolism, lipid remodeling, and cell wall glycanases that may contribute to Histoplasma pathogenesis. These studies lay an essential foundation for understanding how gene expression variations contribute to the strain- and phase-specific virulence differences of Histoplasma.
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Affiliation(s)
- Jessica A Edwards
- The Department of Microbiology, Ohio State University, 484 W, 12th Ave,, Columbus, OH 43210, USA.
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Gilmore SA, Naseem S, Konopka JB, Sil A. N-acetylglucosamine (GlcNAc) triggers a rapid, temperature-responsive morphogenetic program in thermally dimorphic fungi. PLoS Genet 2013; 9:e1003799. [PMID: 24068964 PMCID: PMC3778022 DOI: 10.1371/journal.pgen.1003799] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 07/30/2013] [Indexed: 01/24/2023] Open
Abstract
The monosaccharide N-acetylglucosamine (GlcNAc) is a major component of microbial cell walls and is ubiquitous in the environment. GlcNAc stimulates developmental pathways in the fungal pathogen Candida albicans, which is a commensal organism that colonizes the mammalian gut and causes disease in the setting of host immunodeficiency. Here we investigate GlcNAc signaling in thermally dimorphic human fungal pathogens, a group of fungi that are highly evolutionarily diverged from C. albicans and cause disease even in healthy individuals. These soil organisms grow as polarized, multicellular hyphal filaments that transition into a unicellular, pathogenic yeast form when inhaled by a human host. Temperature is the primary environmental cue that promotes reversible cellular differentiation into either yeast or filaments; however, a shift to a lower temperature in vitro induces filamentous growth in an inefficient and asynchronous manner. We found GlcNAc to be a potent and specific inducer of the yeast-to-filament transition in two thermally dimorphic fungi, Histoplasma capsulatum and Blastomyces dermatitidis. In addition to increasing the rate of filamentous growth, micromolar concentrations of GlcNAc induced a robust morphological transition of H. capsulatum after temperature shift that was independent of GlcNAc catabolism, indicating that fungal cells sense GlcNAc to promote filamentation. Whole-genome expression profiling to identify candidate genes involved in establishing the filamentous growth program uncovered two genes encoding GlcNAc transporters, NGT1 and NGT2, that were necessary for H. capsulatum cells to robustly filament in response to GlcNAc. Unexpectedly, NGT1 and NGT2 were important for efficient H. capsulatum yeast-to-filament conversion in standard glucose medium, suggesting that Ngt1 and Ngt2 monitor endogenous levels of GlcNAc to control multicellular filamentous growth in response to temperature. Overall, our work indicates that GlcNAc functions as a highly conserved cue of morphogenesis in fungi, which further enhances the significance of this ubiquitous sugar in cellular signaling in eukaryotes.
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Affiliation(s)
- Sarah A. Gilmore
- Department of Microbiology and Immunology and the Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, California, United States of America
| | - Shamoon Naseem
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, United States of America
| | - James B. Konopka
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, United States of America
| | - Anita Sil
- Department of Microbiology and Immunology and the Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, California, United States of America
- * E-mail:
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Hu G, Caza M, Cadieux B, Chan V, Liu V, Kronstad J. Cryptococcus neoformans requires the ESCRT protein Vps23 for iron acquisition from heme, for capsule formation, and for virulence. Infect Immun 2013; 81:292-302. [PMID: 23132495 DOI: 10.1128/IAI.01037-12] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Iron availability is a key regulator of virulence factor elaboration in Cryptococcus neoformans, the causative agent of fungal meningoencephalitis in HIV/AIDS patients. In addition, iron is an essential nutrient for pathogen proliferation in mammalian hosts but little is known about the mechanisms of iron sensing and uptake in fungal pathogens that attack humans. In this study, we mutagenized C. neoformans by Agrobacterium-mediated T-DNA insertion and screened for mutants with reduced growth on heme as the sole iron source. Among 34 mutants, we identified a subset with insertions in the gene for the ESCRT-I (endosomal sorting complex required for transport) protein Vps23 that resulted in a growth defect on heme, presumably due to a defect in uptake via endocytosis or misregulation of iron acquisition from heme. Remarkably, vps23 mutants were also defective in the elaboration of the cell-associated capsular polysaccharide that is a major virulence factor, while overexpression of Vps23 resulted in cells with a slightly enlarged capsule. These phenotypes were mirrored by a virulence defect in the vps23 mutant in a mouse model of cryptococcosis and by hypervirulence of the overexpression strain. Overall, these results reveal an important role for trafficking via ESCRT functions in both heme uptake and capsule formation, and they further reinforce the connection between iron and virulence factor deployment in C. neoformans.
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Hwang LH, Seth E, Gilmore SA, Sil A. SRE1 regulates iron-dependent and -independent pathways in the fungal pathogen Histoplasma capsulatum. Eukaryot Cell 2012; 11:16-25. [PMID: 22117028 DOI: 10.1128/EC.05274-11] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Regulation of iron acquisition genes is critical for microbial survival under both iron-limiting conditions (to acquire essential iron) and iron-replete conditions (to limit iron toxicity). In fungi, iron acquisition genes are repressed under iron-replete conditions by a conserved GATA transcriptional regulator. Here we investigate the role of this transcription factor, Sre1, in the cellular responses of the fungal pathogen Histoplasma capsulatum to iron. We showed that cells in which SRE1 levels were diminished by RNA interference were unable to repress siderophore biosynthesis and utilization genes in the presence of abundant iron and thus produced siderophores even under iron-replete conditions. Mutation of a GATA-containing consensus site found in the promoters of these genes also resulted in inappropriate gene expression under iron-replete conditions. Microarray analysis comparing control and SRE1-depleted strains under conditions of iron limitation or abundance revealed both iron-responsive genes and Sre1-dependent genes, which comprised distinct but overlapping sets. Iron-responsive genes included those encoding putative oxidoreductases, metabolic and mitochondrial enzymes, superoxide dismutase, and nitrosative-stress-response genes; Sre1-dependent genes were of diverse functions. Genes regulated by iron levels and Sre1 included all of the siderophore biosynthesis genes, a gene involved in reductive iron acquisition, an iron-responsive transcription factor, and two catalases. Based on transcriptional profiling and phenotypic analyses, we conclude that Sre1 plays a critical role in the regulation of both traditional iron-responsive genes and iron-independent pathways such as regulation of cell morphology. These data highlight the evolving realization that the effect of Sre1 orthologs on fungal biology extends beyond the iron regulon.
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Edwards JA, Rappleye CA. Histoplasma mechanisms of pathogenesis--one portfolio doesn't fit all. FEMS Microbiol Lett 2011; 324:1-9. [PMID: 22092757 PMCID: PMC3228276 DOI: 10.1111/j.1574-6968.2011.02363.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Revised: 07/12/2011] [Accepted: 07/13/2011] [Indexed: 01/15/2023] Open
Abstract
Histoplasma capsulatum is the leading cause of endemic mycosis in the world. Analyses of clinical isolates from different endemic regions show important diversity within the species. Recent molecular studies of two isolates, the Chemotype I NAm2 strain G217B and the Chemotype II Panamanian strain G186A, reveal significant genetic, structural, and molecular differences between these representative Histoplasma strains. Some of these variations have functional consequences, representing distinct molecular mechanisms that facilitate Histoplasma pathogenesis. The realization of Histoplasma strain diversity highlights the importance of characterizing Histoplasma virulence factors in the context of specific clinical strain isolates.
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Affiliation(s)
- Jessica A. Edwards
- Departments of Microbiology and Internal Medicine, The Center for Microbial Interface Biology, Ohio State University, 484 W. 12Avenue, Columbus, OH 43210, USA
| | - Chad A. Rappleye
- Departments of Microbiology and Internal Medicine, The Center for Microbial Interface Biology, Ohio State University, 484 W. 12Avenue, Columbus, OH 43210, USA
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Abstract
Histoplasma capsulatum is the most prevalent cause of fungal respiratory disease. The disease extent and outcomes are the result of the complex interaction between the pathogen and a host's immune system. The focus of our paper consists in presenting the current knowledge regarding the multiple facets of the dynamic host-pathogen relationship in the context of the virulence arsenal displayed by the fungus and the innate and adaptive immune responses of the host.
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