Aspergillus  


  HEADProf. Latgé Jean-Paul / platge@pasteur.fr
  MEMBERSDr AIMANIANDA BOPAIAH Kumar Vishu/ BEAU Rémi, Technician
Dr BEAUVAIS Anne/ Dr CLAVAUDCécile/ COMTE Catherine, Lab support/ Dr DESANGLE Aurélie/ Dr FONTAINE Thierry/ GASTEBOIS Amandine, Student/ HENRY Christine, Senior technician
Dr LAMARRE Claude/ Dr LAMBOU Karine/ Dr MOUYNA Isabelle/ PACORY Fabienne, Secretary/ SARFATI-BERT Jacqueline, INSERM / Dr WONG Joanne


  Annual Report

Aspergillus fumigatusis a ubiquitous thermophilic, saprophytic filamentous fungus that disseminates by producing spores that are present in all environments and are continuously inhaled by the humans. For that reason, this mould is responsible for invasive pulmonary diseases, most often fatal among immunocompromized patients. A.fumigatushas become today the major fungal air-borne pathogen in terms of morbidity and mortality in developed countries. The expertise of our unit in biochemistry and molecular biology of A.fumigatusis unique in the world and has allowed to progress significantly in the understanding of the pathology of these threatening infections.

A prominent fungal feature: The cell wall

In , like in other pathogenic fungi, the cell wall is essential for fungal growth as well as for resisting environmental stresses. The cell wall of A.fumigatusis exclusively composed of polysaccharides. The fibrillar core of the A.fumigatuscell wall is basically composed of branched glucan – chitin complex, embedded in an amorphous cement composed of linear chains of α(1-3) (1-4) glucan associated to galactomannan. These two polysaccharides are also major components of the extracellular matrix that hold hyphae together as a biofilm. This biofilm favours growth and increases resistance to antifungals. Organizing the three-dimensional network of polysaccharides responsible for the rigidity of the cell wall is a very complex and sequential enzymatic process. The enzymes involved in the biosynthesis of α and β1-3 glucans, chitin, galactan and N-and O- mannans have been analyzed using genomic and biochemical approaches. The enzymes that are responsible for the branching and cross-linking of the cell wall polysaccharides are also investigated, especially among proteins anchored to plasma membrane by a glycosylphosphatidylinositol moiety.

Host pathogen interactions

In collaboration with several other research laboratories, PAMPs and PRRs involved in the immune response of the immunocompetent and immunocompromized mammalian host against A.fumigatusare currently analysed. This approach will open the way to new cellular immunotherapies that are a promising alternative to the poorly efficient antifungal therapies currently available.

Keywords: Aspergillus, aspergillosis, cell wall, glycobiology, genetics

Aspergillus.jpg

Cryo-SEM (scanning electron microscopy) image of a Biofilm of Aspergillus fumigatus showing the extracellular matrix covering the hyphae at the surface of the biofilm.



  Publications

  • Costachel C, Coddeville B, Latgé JP, Fontaine T (2005) Glycosylphosphatidylinositol-anchored fungal polysaccharide in Aspergillus fumigatus. J. Biol. Chem. 280:39835-39842.

  • Mouyna I, Morelle W, Vai M, Mono, M, Léchenne B, Fontaine T, Beauvais A, Sarfati J, Prévost MC, Henry C, Latgé JP (2005) Deletion of GEL2 encoding for a ß(1-3) glucanosyltransferase affects morphogenesis and virulence in Aspergillus fumigatus. Mol. Microbiol. 56:1675-1688.

  • Beauvais A, Schmidt C, Guadagnisi S, Roux P, Perret E, Henry C, Paris S, Mallet A, Prevost MC, Latgé JP (2007). An extracellular matrix glues together the aerial grown hyphae of Aspergillus fumigatus. Cell Microbiol. 9:1588-600.

  • Lamarre C, Ibrahim-Granet O, Du C, Calderone R, Latgé JP (2007) Characterization of the SKN7 ortholog of Aspergillus fumigatus. Fungal Genet. Biol. 44:682-90

  • Latgé JP (2007) The cell wall: a carbohydrate armour for the fungal cell. Mol.Microbiol. 66:279-90



  Web Site

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Activity Reports 2007 - Institut Pasteur
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