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111 results on '"Wimmerova, Michaela"'

5. FleA Expression in Aspergillus fumigatus Is Recognized by Fucosylated Structures on Mucins and Macrophages to Prevent Lung Infection.

Author

Kerr, Sheena C, Fischer, Gregory J, Sinha, Meenal, McCabe, Orla, Palmer, Jonathan M, Choera, Tsokyi, Lim, Fang Yun, Wimmerova, Michaela, Carrington, Stephen D, Yuan, Shaopeng, Lowell, Clifford A, Oscarson, Stefan, Keller, Nancy P, and Fahy, John V

Subjects
Macrophages, Animals, Mice, Inbred C57BL, Humans, Mice, Spores, Fungal, Aspergillus fumigatus, Disease Models, Animal, Fucose, Fungal Proteins, Mucins, Lectins, Fluorescent Antibody Technique, Blotting, Western, Flow Cytometry, Immunity, Mucosal, Adult, Middle Aged, Female, Male, Pulmonary Aspergillosis, Inbred C57BL, Spores, Fungal, Disease Models, Animal, Blotting, Western, Immunity, Mucosal, Virology, Microbiology, Immunology, Medical Microbiology
Abstract

The immune mechanisms that recognize inhaled Aspergillus fumigatus conidia to promote their elimination from the lungs are incompletely understood. FleA is a lectin expressed by Aspergillus fumigatus that has twelve binding sites for fucosylated structures that are abundant in the glycan coats of multiple plant and animal proteins. The role of FleA is unknown: it could bind fucose in decomposed plant matter to allow Aspergillus fumigatus to thrive in soil, or it may be a virulence factor that binds fucose in lung glycoproteins to cause Aspergillus fumigatus pneumonia. Our studies show that FleA protein and Aspergillus fumigatus conidia bind avidly to purified lung mucin glycoproteins in a fucose-dependent manner. In addition, FleA binds strongly to macrophage cell surface proteins, and macrophages bind and phagocytose fleA-deficient (∆fleA) conidia much less efficiently than wild type (WT) conidia. Furthermore, a potent fucopyranoside glycomimetic inhibitor of FleA inhibits binding and phagocytosis of WT conidia by macrophages, confirming the specific role of fucose binding in macrophage recognition of WT conidia. Finally, mice infected with ΔfleA conidia had more severe pneumonia and invasive aspergillosis than mice infected with WT conidia. These findings demonstrate that FleA is not a virulence factor for Aspergillus fumigatus. Instead, host recognition of FleA is a critical step in mechanisms of mucin binding, mucociliary clearance, and macrophage killing that prevent Aspergillus fumigatus pneumonia.

Published
2016

6. Microbe-focused glycan array screening platform

Author

Geissner, Andreas, Reinhardt, Anika, Rademacher, Christoph, Johannssen, Timo, Monteiro, João, Lepenies, Bernd, Thépaut, Michel, Fieschi, Franck, Mrázková, Jana, Wimmerova, Michaela, Schuhmacher, Frank, Götze, Sebastian, Grünstein, Dan, Guo, Xiaoqiang, Kandasamy, Jeyakumar, Leonori, Daniele, Martin, Christopher E., Parameswarappa, Sharavathi G., Pasari, Sandip, Schlegel, Mark K., Tanaka, Hidenori, Xiao, Guozhi, Yang, You, Pereira, Claney L., Anish, Chakkumkal, and Seeberger, Peter H.

Published
2019

7. X-Ray Crystallography

Author

Degtjarik, Oksana, Demo, Gabriel, Wimmerova, Michaela, Kuta Smatanova, Ivana, Hejátko, Jan, editor, and Hakoshima, Toshio, editor

Published
2018
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12. Conformational dynamics are a key factor in signaling mediated by the receiver domain of a sensor histidine kinase from Arabidopsis thaliana

Author

Otrusinová, Olga, Demo, Gabriel, Padrta, Petr, Jaseňáková, Zuzana, Pekárová, Blanka, Gelová, Zuzana, Szmitkowska, Agnieszka, Kadeřávek, Pavel, Jansen, Séverine, Zachrdla, Milan, Klumpler, Tomáš, Marek, Jaromír, Hritz, Jozef, Janda, Lubomír, Iwaï, Hideo, Wimmerová, Michaela, Hejátko, Jan, and Žídek, Lukáš

Published
2017
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31. Architecture and Evolution of Blade Assembly in beta-propeller Lectins

Author

Bonnardel, Francois, Kumar, Atul, Wimmerova, Michaela, Lahmann, Martina, Perez, Serge, Varrot, Annabelle, Lisacek, Frederique, Imberty, Anne, Bonnardel, Francois, Kumar, Atul, Wimmerova, Michaela, Lahmann, Martina, Perez, Serge, Varrot, Annabelle, Lisacek, Frederique, and Imberty, Anne

Abstract

Lectins with a beta-propeller fold bind glycans on the cell surface through multivalent binding sites and appropriate directionality. These proteins are formed by repeats of short domains, raising questions about evolutionary duplication. However, these repeats are difficult to detect in translated genomes and seldom correctly annotated in sequence databases. To address these issues, we defined the blade signature of the five types of beta-propellers using 3D-structural data. With these templates, we predicted 3,887 beta-propeller lectins in 1,889 species and organized this information in a searchable online database. The data reveal a widespread distribution of beta-propeller lectins across species. Prediction also emphasizes multiple architectures and led to the discovery of a beta-propeller assembly scenario. This was confirmed by producing and characterizing a predicted protein coded in the genome of Kordia zhangzhouensis. The crystal structure uncovers an intermediate in the evolution of beta-propeller assembly and demonstrates the power of our tools., QC 20211206

Published
2019
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37. Unusual entropy-driven affinity of Chromobacterium violaceum lectin CV-IIL toward fucose and mannose

Author

Pokorna, Martina, Cioci, Gianluca, Perret, Stephanie, Rebuffet, Etienne, Kostlanova, Nikola, Adam, Jan, Gilboa-Garber, Nechama, Mitchell, Edward P., Imberty, Anne, and Wimmerova, Michaela

Subjects
Affinity labeling -- Usage, Monosaccharides -- Research, Sugars -- Research, Entropy (Physics) -- Research, Biological sciences, Chemistry
Abstract

The cloning of CV-IIL and its expression as a recombinant protein is described and a complete structure-function characterization is made to analyze the specificity and affinity of CV-IIL for fucose and mannose. Crystal structures of CV-IIL complexes with monosaccharids have yielded the molecular basis of the specificity and each monomer contains two close calcium cations that mediate the binding of the monosaccharides, which occurs in different orientations for fucose and mannose.

Published
2006

42. A Soluble Fucose-Specific Lectin from Aspergillus fumigatus Conidia - Structure, Specificity and Possible Role in Fungal Pathogenicity

Author

Houser, Josef, Komarek, Jan, Kostlanova, Nikola, Cioci, Gianluca, Varrot, Annabelle, Kerr, Sheena C., Lahmann, Martina, Balloy, Viviane, Fahy, John V., Chignard, Michel, Imberty, Anne, Wimmerova, Michaela, Houser, Josef, Komarek, Jan, Kostlanova, Nikola, Cioci, Gianluca, Varrot, Annabelle, Kerr, Sheena C., Lahmann, Martina, Balloy, Viviane, Fahy, John V., Chignard, Michel, Imberty, Anne, and Wimmerova, Michaela

Abstract

Aspergillus fumigatus is an important allergen and opportunistic pathogen. Similarly to many other pathogens, it is able to produce lectins that may be involved in the host-pathogen interaction. We focused on the lectin AFL, which was prepared in recombinant form and characterized. Its binding properties were studied using hemagglutination and glycan array analysis. We determined the specificity of the lectin towards l-fucose and fucosylated oligosaccharides, including alpha 1-6 linked core-fucose, which is an important marker for cancerogenesis. Other biologically relevant saccharides such as sialic acid, d-mannose or d-galactose were not bound. Blood group epitopes of the ABH and Lewis systems were recognized, Le(Y) being the preferred ligand among others. To provide a correlation between the observed functional characteristics and structural basis, AFL was crystallized in a complex with methyl-alpha,L-selenofucoside and its structure was solved using the SAD method. Six binding sites, each with different compositions, were identified per monomer and significant differences from the homologous AAL lectin were found. Structure-derived peptides were utilized to prepare anti-AFL polyclonal antibodies, which suggested the presence of AFL on the Aspergillus' conidia, confirming its expression in vivo. Stimulation of human bronchial cells by AFL led to IL-8 production in a dose-dependent manner. AFL thus probably contributes to the inflammatory response observed upon the exposure of a patient to A. fumigatus. The combination of affinity to human epithelial epitopes, production by conidia and pro-inflammatory activity is remarkable and shows that AFL might be an important virulence factor involved in an early stage of A. fumigatus infection., QC 20211206

Published
2013
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44. A Soluble Fucose-Specific Lectin from Aspergillus fumigatus Conidia - Structure, Specificity and Possible Role in Fungal Pathogenicity

Author

Houser, Josef, primary, Komarek, Jan, additional, Kostlanova, Nikola, additional, Cioci, Gianluca, additional, Varrot, Annabelle, additional, Kerr, Sheena C., additional, Lahmann, Martina, additional, Balloy, Viviane, additional, Fahy, John V., additional, Chignard, Michel, additional, Imberty, Anne, additional, and Wimmerova, Michaela, additional

Published
2013
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50. Structural insights into Aspergillus fumigatus lectin specificity: AFL binding sites are functionally non-equivalent.

Author

Houser, Josef, Komarek, Jan, Cioci, Gianluca, Varrot, Annabelle, Imberty, Anne, and Wimmerova, Michaela

Subjects
ASPERGILLUS fumigatus, LECTINS, BINDING sites, MONOSACCHARIDES, SURFACE plasmon resonance, EPITOPES
Abstract

The Aspergillus fumigatus lectin AFL was recently described as a new member of the AAL lectin family. As a lectin from an opportunistic pathogen, it might play an important role in the interaction of the pathogen with the human host. A detailed study of structures of AFL complexed with several monosaccharides and oligosaccharides, including blood-group epitopes, was combined with affinity data from SPR and discussed in the context of previous findings. Its six binding sites are non-equivalent, and owing to minor differences in amino-acid composition they exhibit a marked difference in specific ligand recognition. AFL displays a high affinity in the micromolar range towards oligosaccharides which were detected in plants and also those bound on the human epithelia. All of these results indicate AFL to be a complex member of the lectin family and a challenging target for future medical research and, owing to its binding properties, a potentially useful tool in specific biotechnological applications. [ABSTRACT FROM AUTHOR]

Published
2015
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