UMMS Affiliation

Massachusetts Supranational TB Reference Laboratory; Department of Medicine, Division of Infectious Diseases and Immunology

Publication Date

2018-11-15

Document Type

Article

Disciplines

Amino Acids, Peptides, and Proteins | Bacteria | Bacterial Infections and Mycoses | Bacteriology | Immunology and Infectious Disease | Molecular Biology | Pathogenic Microbiology

Abstract

Dectin-2 is a C-type lectin involved in the recognition of several pathogens such as Aspergillus fumigatus, Candida albicans, Schistosoma mansonii, and Mycobacterium tuberculosis that triggers Th17 immune responses. Identifying pathogen ligands and understanding the molecular basis of their recognition is one of the current challenges. Purified M. tuberculosis mannose-capped lipoarabinomannan (ManLAM) was shown to induce signaling via Dectin-2, an activity that requires the (alpha1 --> 2)-linked mannosides forming the caps. Here, using isogenic M. tuberculosis mutant strains, we demonstrate that ManLAM is a bona fide and actually the sole ligand mediating bacilli recognition by Dectin-2, although M. tuberculosis produces a variety of cell envelope mannoconjugates, such as phosphatidyl-myo-inositol hexamannosides, lipomannan or manno(lipo)proteins, that bear (alpha1 --> 2)-linked mannosides. In addition, we found that Dectin-2 can recognize lipoglycans from other bacterial species, such as Saccharotrix aerocolonigenes or the human opportunistic pathogen Tsukamurella paurometabola, suggesting that lipoglycans are prototypical Dectin-2 ligands. Finally, from a structure/function relationship perspective, we show, using lipoglycan variants and synthetic mannodendrimers, that dimannoside caps and multivalent interaction are required for ligand binding to and signaling via Dectin-2. Better understanding of the molecular basis of ligand recognition by Dectin-2 will pave the way for the rational design of potent adjuvants targeting this receptor.

Rights and Permissions

© The Author(s) 2018. Open Access: This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

DOI of Published Version

10.1038/s41598-018-35393-5

Source

Sci Rep. 2018 Nov 15;8(1):16840. doi: 10.1038/s41598-018-35393-5. Link to article on publisher's site

Journal/Book/Conference Title

Scientific reports

Comments

Full author list omitted for brevity. For the full list of authors, see article.

Related Resources

Link to Article in PubMed

PubMed ID

30443026

Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

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