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Matzaraki V, Beno A, Jaeger M, Gresnigt MS, Keur N, Boahen C, Cunha C, Gonçalves SM, Leite L, Lacerda JF, Campos A, van de Veerdonk FL, Joosten L, Netea MG, Carvalho A, Kumar V. Genetic determinants of fungi-induced ROS production are associated with the risk of invasive pulmonary aspergillosis. Redox Biol 2022; 55:102391. [PMID: 35834984 PMCID: PMC9283926 DOI: 10.1016/j.redox.2022.102391] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 06/29/2022] [Indexed: 11/18/2022] Open
Abstract
Reactive oxygen species (ROS) are an essential component of the host defense against fungal infections. However, little is known about how common genetic variation affects ROS-mediated antifungal host defense. In the present study, we investigated the genetic factors that regulate ROS production capacity in response to the two human fungal pathogens: Candida albicans and Aspergillus fumigatus. We investigated fungal-stimulated ROS production by immune cells isolated from a population-based cohort of approximately 200 healthy individuals (200FG cohort), and mapped ROS-quantitative trait loci (QTLs). We identified several genetic loci that regulate ROS levels (P < 9.99 × 10-6), with some of these loci being pathogen-specific, and others shared between the two fungi. These ROS-QTLs were investigated for their influence on the risk of invasive pulmonary aspergillosis (IPA) in a disease relevant context. We stratified hematopoietic stem-cell transplant (HSCT) recipients based on the donor's SNP genotype and tested their impact on the risk of IPA. We identified rs4685368 as a ROS-QTL locus that was significantly associated with an increased risk of IPA after controlling for patient age and sex, hematological malignancy, type of transplantation, conditioning regimen, acute graft-versus-host-disease grades III-IV, and antifungal prophylaxis. Collectively, this data provides evidence that common genetic variation can influence ROS production capacity, and, importantly, the risk of developing IPA among HSCT recipients. This evidence warrants further research for patient stratification based on the genetic profiling that would allow the identifications of patients at high-risk for an invasive fungal infection, and who would benefit the most from a preventive strategy.
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Affiliation(s)
- Vasiliki Matzaraki
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, 6525 HP, the Netherlands.
| | - Alexandra Beno
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, 6525 HP, the Netherlands
| | - Martin Jaeger
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, 6525 HP, the Netherlands
| | - Mark S Gresnigt
- Junior Research Group Adaptive Pathogenicity Strategies, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knoell-Institute, Jena, Germany
| | - Nick Keur
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, 6525 HP, the Netherlands
| | - Collins Boahen
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, 6525 HP, the Netherlands
| | - Cristina Cunha
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Guimarães/Braga, Portugal
| | - Samuel M Gonçalves
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Guimarães/Braga, Portugal
| | - Luis Leite
- Serviço de Transplantação de Medula Óssea (STMO), Instituto Português de Oncologia do Porto, Porto, Portugal
| | - João F Lacerda
- Serviço de Hematologia e Transplantação de Medula, Hospital de Santa Maria, Lisboa, Portugal; Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
| | - António Campos
- Serviço de Transplantação de Medula Óssea (STMO), Instituto Português de Oncologia do Porto, Porto, Portugal
| | - Frank L van de Veerdonk
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, 6525 HP, the Netherlands
| | - Leo Joosten
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, 6525 HP, the Netherlands
| | - Mihai G Netea
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, 6525 HP, the Netherlands; Department for Genomics & Immunoregulation, Life and Medical Sciences Institute (LIMES), University of Bonn, Bonn, Germany
| | - Agostinho Carvalho
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Guimarães/Braga, Portugal
| | - Vinod Kumar
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, 6525 HP, the Netherlands; University of Groningen, University Medical Center Groningen, Department of Genetics, Groningen, 9700RB, the Netherlands; Nitte (Deemed to be University), Nitte University Centre for Science Education and Research (NUCSER), Medical Sciences Complex, Deralakatte, Mangalore, 575018, India
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Macherla C, Sanchez DA, Ahmadi MS, Vellozzi EM, Friedman AJ, Nosanchuk JD, Martinez LR. Nitric oxide releasing nanoparticles for treatment of Candida albicans burn infections. Front Microbiol 2012; 3:193. [PMID: 22701111 PMCID: PMC3370663 DOI: 10.3389/fmicb.2012.00193] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [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: 02/08/2012] [Accepted: 05/11/2012] [Indexed: 11/15/2022] Open
Abstract
Candida albicans is a leading fungal cause of burn infections in hospital settings, and sepsis is one of the principle causes of death after a severe burn. The prevalence of invasive candidiasis in burn cases varies widely, but it accounts for 3–23% of severe infection with a mortality rate ranging from 14 to 70%. Therefore, it is imperative that we develop innovative therapeutics to which this fungus is unlikely to evolve resistance, thus curtailing the associated morbidity and mortality and ultimately improving our capacity to treat these infections. An inexpensive and stable nitric oxide (NO)-releasing nanoparticle (NO-np) platform has been recently developed. NO is known to have direct antifungal activity, modulate host immune responses and significantly regulate wound healing. In this study, we hypothesized that NO-np would be an effective therapy in the treatment of C. albicans burn infections. Using a murine burn model, NO-np demonstrated antifungal activity against C. albicans in vivo, most likely by arresting its growth and morphogenesis as demonstrated in vitro. NO-np demonstrated effective antimicrobial activity against yeast and filamentous forms of the fungus. Moreover, we showed that NO-np significantly accelerated the rate of wound healing in cutaneous burn infections when compared to controls. The histological evaluation of the affected tissue revealed that NO-np treatment modified leukocyte infiltration, minimized the fungal burden, and reduced collagen degradation, thus providing potential mechanisms for the therapeutics’ biological activity. Together, these data suggest that NO-np have the potential to serve as a novel topical antifungal which can be used for the treatment of cutaneous burn infections and wounds.
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Ahmad MF, Yadav B, Kumar P, Puri A, Mazumder M, Ali A, Gourinath S, Muthuswami R, Komath SS. The GPI anchor signal sequence dictates the folding and functionality of the Als5 adhesin from Candida albicans. PLoS One 2012; 7:e35305. [PMID: 22509405 DOI: 10.1371/journal.pone.0035305] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Accepted: 03/13/2012] [Indexed: 01/09/2023] Open
Abstract
Background Proteins destined to be Glycosylphosphatidylinositol (GPI) anchored are translocated into the ER lumen completely before the C-terminal GPI anchor attachment signal sequence (SS) is removed by the GPI-transamidase and replaced by a pre-formed GPI anchor precursor. Does the SS have a role in dictating the conformation and function of the protein as well? Methodology/Principal Findings We generated two variants of the Als5 protein without and with the SS in order to address the above question. Using a combination of biochemical and biophysical techniques, we show that in the case of Als5, an adhesin of C. albicans, the C-terminal deletion of 20 amino acids (SS) results in a significant alteration in conformation and function of the mature protein. Conclusions/Significance We propose that the locking of the conformation of the precursor protein in an alternate conformation from that of the mature protein is one probable strategy employed by the cell to control the behaviour and function of proteins intended to be GPI anchored during their transit through the ER.
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Fisher JF. Candida urinary tract infections--epidemiology, pathogenesis, diagnosis, and treatment: executive summary. Clin Infect Dis 2012; 52 Suppl 6:S429-32. [PMID: 21498835 DOI: 10.1093/cid/cir108] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The frequency of infection of the urinary tract due to Candida species is increasing in parallel with the rapid advances of medical progress, and these infections are now among the most common problems facing physicians. Despite this fact, much remains to be learned regarding the pathogenesis, diagnosis, and management of bloodborne (antegrade) kidney infections and ascending (retrograde) invasion of the urinary collecting system. The following is a summary of the in-depth analysis of available information from the literature provided in this journal supplement.
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Affiliation(s)
- John F Fisher
- Infectious Disease Section, Medical College of Georgia, Augusta, Georgia, USA.
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Karkowska-Kuleta J, Kedracka-Krok S, Rapala-Kozik M, Kamysz W, Bielinska S, Karafova A, Kozik A. Molecular determinants of the interaction between human high molecular weight kininogen and Candida albicans cell wall: Identification of kininogen-binding proteins on fungal cell wall and mapping the cell wall-binding regions on kininogen molecule. Peptides 2011; 32:2488-96. [PMID: 22074954 DOI: 10.1016/j.peptides.2011.10.021] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 10/23/2011] [Accepted: 10/24/2011] [Indexed: 11/28/2022]
Abstract
An excessive production of vasoactive and proinflammatory bradykinin-related peptides, the kinins, is often involved in the human host defense against microbial infections. Recent studies have shown that a major fungal pathogen to humans, Candida albicans, can bind the proteinaceous kinin precursor, the high molecular weight kininogen (HK) and trigger the kinin-forming cascade on the cell surface. In this work, we preliminarily characterized a molecular mechanism underlying the HK adhesion to the fungal surface by (i) identification of major kininogen-binding constituents on the candidial cell wall and (ii) mapping the cell wall-binding regions on HK molecule. A major fraction of total fungal kininogen-binding capacity was assigned to β-1,3-glucanase-extractable cell wall proteins (CWP). By adsorption of CWP on HK-coupled agarose gel and mass spectrometric analysis of the eluted material, major putative HK receptors were identified, including Als3 adhesin and three glycolytic enzymes, i.e., enolase 1, phosphoglycerate mutase 1 and triosephosphate isomerase 1. Using monoclonal antibodies directed against selected parts of HK molecule and synthetic peptides with sequences matching selected HK fragments, we assigned the major fungal cell wall-binding ability to a short stretch of amino acids in the C-terminal part of domain 3 and a large continuous region involving the C-terminal part of domain 5 and N-terminal part of domain 6 (residues 479-564). The latter characteristics of HK binding to C. albicans surface differ from those reported for bacteria and host cells.
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Affiliation(s)
- Justyna Karkowska-Kuleta
- Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Krakow, Poland
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Fisher JF, Kavanagh K, Sobel JD, Kauffman CA, Newman CA. Candida Urinary Tract Infection: Pathogenesis. Clin Infect Dis 2011; 52 Suppl 6:S437-51. [DOI: 10.1093/cid/cir110] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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Parkin JD, San Antonio JD, Pedchenko V, Hudson B, Jensen ST, Savige J. Mapping structural landmarks, ligand binding sites, and missense mutations to the collagen IV heterotrimers predicts major functional domains, novel interactions, and variation in phenotypes in inherited diseases affecting basement membranes. Hum Mutat 2011; 32:127-43. [PMID: 21280145 DOI: 10.1002/humu.21401] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Collagen IV is the major protein found in basement membranes. It comprises three heterotrimers (α1α1α2, α3α4α5, and α5α5α6) that form distinct networks, and are responsible for membrane strength and integrity.We constructed linear maps of the collagen IV heterotrimers ("interactomes") that indicated major structural landmarks, known and predicted ligand-binding sites, and missense mutations, in order to identify functional and disease-associated domains, potential interactions between ligands, and genotype–phenotype relationships. The maps documented more than 30 known ligand-binding sites as well as motifs for integrins, heparin, von Willebrand factor (VWF), decorin, and bone morphogenetic protein (BMP). They predicted functional domains for angiogenesis and haemostasis, and disease domains for autoimmunity, tumor growth and inhibition, infection, and glycation. Cooperative ligand interactions were indicated by binding site proximity, for example, between integrins, matrix metalloproteinases, and heparin. The maps indicated that mutations affecting major ligand-binding sites, for example, for Von Hippel Lindau (VHL) protein in the α1 chain or integrins in the α5 chain, resulted in distinctive phenotypes (Hereditary Angiopathy, Nephropathy, Aneurysms, and muscle Cramps [HANAC] syndrome, and early-onset Alport syndrome, respectively). These maps further our understanding of basement membrane biology and disease, and suggest novel membrane interactions, functions, and therapeutic targets.
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Affiliation(s)
- J Des Parkin
- Department of Medicine (Northern Health), The University of Melbourne, Northern Health, Epping VIC 3076, Australia
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ten Cate J, Klis F, Pereira-Cenci T, Crielaard W, de Groot P. Molecular and Cellular Mechanisms That Lead to Candida Biofilm Formation. J Dent Res 2009; 88:105-15. [DOI: 10.1177/0022034508329273] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Fungal infections in the oral cavity are mainly caused by C. albicans, but other Candida species are also frequently identified. They are increasing in prevalence, especially in denture-wearers and aging people, and may lead to invasive infections, which have a high mortality rate. Attachment to mucosal tissues and to abiotic surfaces and the formation of biofilms are crucial steps for Candida survival and proliferation in the oral cavity. Candida species possess a wide arsenal of glycoproteins located at the exterior side of the cell wall, many of which play a determining role in these steps. In addition, C. albicans secretes signaling molecules that inhibit the yeast-to-hypha transition and biofilm formation. In vivo, Candida species are members of mixed biofilms, and subject to various antagonistic and synergistic interactions, which are beginning to be explored. We believe that these new insights will allow for more efficacious treatments of fungal oral infections. For example, the use of signaling molecules that inhibit biofilm formation should be considered. In addition, cell-wall biosynthetic enzymes, wall cross-linking enzymes, and wall proteins, which include adhesins, proteins involved in biofilm formation, fungal-bacterial interactions, and competition for surface colonization sites, offer a wide range of potential targets for therapeutic intervention.
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Affiliation(s)
- J.M. ten Cate
- Department of Cariology Endodontology Pedodontology, Academic Centre for Dentistry Amsterdam -ACTA-, University of Amsterdam and Free University Amsterdam, Louwesweg 1, 1066 EA Amsterdam, the Netherlands
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands; and
- Department of Prosthodontics and Periodontology, Faculty of Dentistry of Piracicaba, UNICAMP, Brazil
| | - F.M. Klis
- Department of Cariology Endodontology Pedodontology, Academic Centre for Dentistry Amsterdam -ACTA-, University of Amsterdam and Free University Amsterdam, Louwesweg 1, 1066 EA Amsterdam, the Netherlands
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands; and
- Department of Prosthodontics and Periodontology, Faculty of Dentistry of Piracicaba, UNICAMP, Brazil
| | - T. Pereira-Cenci
- Department of Cariology Endodontology Pedodontology, Academic Centre for Dentistry Amsterdam -ACTA-, University of Amsterdam and Free University Amsterdam, Louwesweg 1, 1066 EA Amsterdam, the Netherlands
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands; and
- Department of Prosthodontics and Periodontology, Faculty of Dentistry of Piracicaba, UNICAMP, Brazil
| | - W. Crielaard
- Department of Cariology Endodontology Pedodontology, Academic Centre for Dentistry Amsterdam -ACTA-, University of Amsterdam and Free University Amsterdam, Louwesweg 1, 1066 EA Amsterdam, the Netherlands
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands; and
- Department of Prosthodontics and Periodontology, Faculty of Dentistry of Piracicaba, UNICAMP, Brazil
| | - P.W.J. de Groot
- Department of Cariology Endodontology Pedodontology, Academic Centre for Dentistry Amsterdam -ACTA-, University of Amsterdam and Free University Amsterdam, Louwesweg 1, 1066 EA Amsterdam, the Netherlands
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands; and
- Department of Prosthodontics and Periodontology, Faculty of Dentistry of Piracicaba, UNICAMP, Brazil
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Abstract
The Candida albicans cell wall maintains the structural integrity of the organism in addition to providing a physical contact interface with the environment. The major components of the cell wall are fibrillar polysaccharides and proteins. The proteins of the cell wall are the focus of this review. Three classes of proteins are present in the candidal cell wall. One group of proteins attach to the cell wall via a glycophosphatidylinositol remnant or by an alkali-labile linkage. A second group of proteins with N-terminal signal sequences but no covalent attachment sequences are secreted by the classical secretory pathway. These proteins may end up in the cell wall or in the extracellular space. The third group of proteins lack a secretory signal, and the pathway(s) by which they become associated with the surface is unknown. Potential constituents of the first two classes have been predicted from analysis of genome sequences. Experimental analyses have identified members of all three classes. Some members of each class selected for consideration of confirmed or proposed function, phenotypic analysis of a mutant, and regulation by growth conditions and transcription factors are discussed in more detail.
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Rapala-kozik M, Karkowska J, Jacher A, Golda A, Barbasz A, Guevara-lora I, Kozik A. Kininogen adsorption to the cell surface of Candida spp. Int Immunopharmacol 2008; 8:237-41. [DOI: 10.1016/j.intimp.2007.07.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2007] [Accepted: 07/10/2007] [Indexed: 11/22/2022]
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Abstract
OBJECTIVE: To determine whether several topical compounds and other chemical entities are able to diminish the surface hydrophobicity of yeast cells. METHOD: Hydrophobicity of yeast cells was determined by binding styrene microspheres to the surface of untreated yeast or yeast pre-incubated with various substances with potential for cell surface modification. The degree of microsphere adherence to yeast cells was measured by flow cytometry. RESULTS: A significant reduction in cell surface hydrophobicity was observed when yeast was incubated in protein-containing media. Other compounds that effectively reduced microsphere binding were various formulations of K-Y and heparin. Divalent cations (Ca+ + , Mg+ + , Zn+ + , Cu + + ) were also potent inhibitors of microsphere adherence. It was possible to remove substances contributing to microsphere binding by chemical extraction of the yeast. Yeast having reduced microsphere binding activity also showed diminished binding of concanavalin A. CONCLUSIONS: Several commercially available compounds were able to block binding of styrene microspheres to yeast. Some of the binding activity appeared to be attributable to mannose-containing surface components. These findings have implications for formulating therapeutic products that might block yeast binding to tissues.
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Affiliation(s)
- Lisa Colling
- Infectious Disease Research Laboratory, Des Moines University, Des Moines, IA 50312-4198, USA
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González A, Gómez BL, Diez S, Hernández O, Restrepo A, Hamilton AJ, Cano LE. Purification and partial characterization of a Paracoccidioides brasiliensis protein with capacity to bind to extracellular matrix proteins. Infect Immun 2005; 73:2486-95. [PMID: 15784595 PMCID: PMC1087412 DOI: 10.1128/iai.73.4.2486-2495.2005] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microorganisms adhere to extracellular matrix proteins by means of their own surface molecules. Paracoccidioides brasiliensis conidia have been shown to be capable of interacting with extracellular matrix proteins. We aimed at determining the presence of fungal proteins that could interact with extracellular matrix protein and, if found, attempt their purification and characterization. Various extracts were prepared from P. brasiliensis mycelial and yeast cultures (total homogenates, beta-mercaptoethanol, and sodium dodecyl sulfate [SDS] extracts) and analyzed by ligand affinity assays with fibronectin, fibrinogen and laminin. Two polypeptides were detected in both fungal forms. SDS extracts that interacted with all the extracellular matrix protein were tested; their molecular masses were 19 and 32 kDa. Analysis of the N-terminal amino acid sequence of the purified 32-kDa mycelial protein showed substantial homology with P. brasiliensis, Histoplasma capsulatum, and Neurospora crassa hypothetical proteins. Additionally, a monoclonal antibody (MAb) produced against this protein recognized the 32-kDa protein in the SDS extracts of both fungal forms for immunoblot. Immunofluorescence analysis revealed that this MAb reacted not only with mycelia and yeast cells, but also with conidia, indicating that this protein was shared by the three fungal propagules. By immunoelectron microscopy, this protein was detected in the cell walls and in the cytoplasm. Both the 32-kDa purified protein and MAb inhibited the adherence of conidia to the three extracellular matrix proteins in a dose-dependent manner. These findings demonstrate the presence of two polypeptides capable of interacting with extracellular matrix proteins on the surface of P. brasiliensis propagules, indicating that there may be common receptors for laminin, fibronectin, and fibrinogen. These proteins would be crucial for initial conidial adherence and perhaps also in dissemination of paracoccidioidomycosis.
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Affiliation(s)
- Angel González
- Medical and Experimental Mycology Group, Corporación para Investigaciones Biológicas (CIB), Carrera 72 A, No. 78B 141, A. A. 73 78 Medellín, Colombia.
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Abstract
The adhesion of microorganism to host cells or extracellular matrix (ECM) proteins is the first step in the establishment of an infectious process. Interaction between Paracoccidioides brasiliensis yeast cells and ECM proteins has been previously noted. In vivo, in the chronic phase of experimental paracoccidioidomycosis (PCM), laminin and fibronectin have been detected on the surface of yeast cells located inside granulomatous lesions. The aim of the present study was to examine the ability of P. brasiliensis yeast cells to interact with extracellular matrix proteins (laminin, fibrinogen and fibronectin) and to establish which molecules were involved in this interaction. Immunofluorescence microscopy and flow cytometry demonstrated that all three ECM proteins tested were able to bind to the surface of P. brasiliensis yeast cells. Treatment with trypsin, chymotrypsin, chitinase, proteinase K or different sugars resulted in no change in laminin binding. In addition, ligand affinity assays were performed using different yeast extracts (total homogenates, beta-mercaptoethanol, SDS extracts). These assays demonstrated the presence of 19 and 32-kDa proteins in the cell wall with the ability to bind to laminin, fibrinogen and fibronectin. This interaction could be important in mediating attachment of the fungus to host tissues and may consequently play a role in the pathogenesis of PCM.
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Affiliation(s)
- Angel Gonzalez
- Medical and Experimental Mycology Group, Corporación para Investigaciones Biológicas Medellin, Colombia.
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Abstract
Sepsis can occur during disseminated candidiasis, but its pathogenesis differs from that caused by typical prokaryotic pathogens. Complex interactions between defects in host defense and "relative" virulence factors expressed by Candida lead to dissemination of the saprophyte to parenchymal organs, and subsequently to onset of multiorgan failure. This review focuses first on the pathophysiology of Candida sepsis, detailing current understanding of host-pathogen interactions. We then consider the choice of antifungal and supportive treatments.
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Affiliation(s)
- Brad Spellberg
- Division of Infectious Diseases, Harbor-UCLA Medical Center, St. Johns Cardiovascular Research Center, Research and Education Institute, 1124 West Carson Street, Torrance, CA 90502, USA. ;
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Current awareness on yeast. Yeast 2001; 18:1449-56. [PMID: 11746606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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