The fungal ligand chitin directly binds TLR2 and triggers inflammation dependent on oligomer size

Abstract Chitin is the second most abundant polysaccharide in nature and linked to fungal infection and asthma. However, bona fide immune receptors directly binding chitin and signaling immune activation and inflammation have not been clearly identified because polymeric crude chitin with unknown pu...

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Bibliographic Details
Main Authors: Fuchs, Katharina (Author) , Frauhammer, Felix (Author)
Format: Article (Journal)
Language:English
Published: 18 October 2018
In: EMBO reports
Year: 2018, Volume: 19, Issue: 12, Pages: e46065
ISSN:1469-3178
DOI:10.15252/embr.201846065
Online Access:Verlag, Volltext: https://doi.org/10.15252/embr.201846065
Verlag: https://www.embopress.org/doi/10.15252/embr.201846065
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Author Notes:Katharina Fuchs, Yamel Cardona Gloria, Olaf-Oliver Wolz, Franziska Herster, Lokesh Sharma, Carly A Dillen, Christoph Täumer, Sabine Dickhöfer, Zsofia Bittner, Truong-Minh Dang, Anurag Singh, Daniel Haischer, Maria A Schlöffel, Kirsten J Koymans, Tharmila Sanmuganantham, Milena Krach, Thierry Roger, Didier Le Roy, Nadine A Schilling, Felix Frauhammer, Lloyd S Miller, Thorsten Nürnberger, Salomé LeibundGut-Landmann, Andrea A Gust, Boris Macek, Martin Frank, Cécile Gouttefangeas, Charles S Dela Cruz, Dominik Hartl and Alexander NR Weber
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Summary:Abstract Chitin is the second most abundant polysaccharide in nature and linked to fungal infection and asthma. However, bona fide immune receptors directly binding chitin and signaling immune activation and inflammation have not been clearly identified because polymeric crude chitin with unknown purity and molecular composition has been used. By using defined chitin (N-acetyl-glucosamine) oligomers, we here identify six-subunit-long chitin chains as the smallest immunologically active motif and the innate immune receptor Toll-like receptor (TLR2) as a primary fungal chitin sensor on human and murine immune cells. Chitin oligomers directly bind TLR2 with nanomolar affinity, and this fungal TLR2 ligand shows overlapping and distinct signaling outcomes compared to known mycobacterial TLR2 ligands. Unexpectedly, chitin oligomers composed of five or less subunits are inactive, hinting to a size-dependent system of immuno-modulation that appears conserved in plants and humans. Since blocking of the chitin-TLR2 interaction effectively prevents chitin-mediated inflammation in vitro and in vivo, our study highlights the chitin-TLR2 interaction as a potential target for developing novel therapies in chitin-related pathologies and fungal disease.
Item Description:Gesehen am 10.12.2019
Physical Description:Online Resource
ISSN:1469-3178
DOI:10.15252/embr.201846065