Galactosaminogalactan, a New Immunosuppressive Polysaccharide of Aspergillus fumigatus

PLoS Pathogens

Luigina Romani¹  Silvia Moretti¹  Silvia Bozza¹  Sandra J. van Vliet²  Yvette van Kooyk²  Markus Aebi³  Flavio Schwarz³  Bernadette Coddeville⁴  Catherine Simenel⁵  Muriel Delepierre⁵  Thierry Fontaine⁶  Jean-Paul Latgé⁶  Aurélie Delangle⁶  Carole Elbim⁷  Coline Trichot⁷ 

[1] Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Perugia, Italy;Department of Molecular Cell Biology and Immunology, VU University Medical Center, Amsterdam, The Netherlands;Institute of Microbiology, ETH Hönggerberg, Zürich, Switzerland;Laboratoire de Glycobiologie Structurale et Fonctionnelle, UMR 8576 CNRS, Université des sciences et Technologies de Lille Flandres-Artois, Villeneuve d'Ascq, France;Unité de Résonance Magnétique Nucléaire des Biomolécules, CNRS URA 2185, Institut Pasteur, Paris, France;Unité des Aspergillus, Institut Pasteur, Paris, France;Université Pierre et Marie Curie – Paris 6, UMR-S 945 Immunité et Infection, Faculté de Médecine Pitié Salpétrière, Paris, France

关键词: Aspergillus fumigatus;    Polysaccharides;    Enzyme-linked immunoassays;    Galactose;    Apoptosis;    Cell walls;    Hydrolysis;    Neutrophils;   

DOI  :  10.1371/journal.ppat.1002372

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

A new polysaccharide secreted by the human opportunistic fungal pathogen Aspergillus fumigatus has been characterized. Carbohydrate analysis using specific chemical degradations, mass spectrometry, 1H and 13C nuclear magnetic resonance showed that this polysaccharide is a linear heterogeneous galactosaminogalactan composed of α1-4 linked galactose and α1-4 linked N-acetylgalactosamine residues where both monosacharides are randomly distributed and where the percentage of galactose per chain varied from 15 to 60%. This polysaccharide is antigenic and is recognized by a majority of the human population irrespectively of the occurrence of an Aspergillus infection. GalNAc oligosaccharides are an essential epitope of the galactosaminogalactan that explains the universal antibody reaction due to cross reactivity with other antigenic molecules containing GalNAc stretches such as the N-glycans of Campylobacter jejuni. The galactosaminogalactan has no protective effect during Aspergillus infections. Most importantly, the polysaccharide promotes fungal development in immunocompetent mice due to its immunosuppressive activity associated with disminished neutrophil infiltrates.

【 授权许可】

CC BY