Soh WT, Aglas L, Mueller GA, Gilles S, Weiss R, Scheiblhofer S, Huber S, Scheidt T, Thompson PM, Briza P, London RE, Traidl‐Hoffmann C, Cabrele C, Brandstetter H, Ferreira F. Multiple roles of Bet v 1 ligands in allergen stabilization and modulation of endosomal protease activity.
Allergy 2019;
74:2382-2393. [PMID:
31230350 PMCID:
PMC6910946 DOI:
10.1111/all.13948]
[Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 04/30/2019] [Indexed: 12/21/2022]
Abstract
Background
Over 100 million people worldwide suffer from birch pollen allergy. Bet v 1 has been identified as the major birch pollen allergen. However, the molecular mechanisms of birch allergic sensitization, including the roles of Bet v 1 and other components of the birch pollen extract, remain incompletely understood. Here, we examined how known birch pollen–derived molecules influence the endolysosomal processing of Bet v 1, thereby shaping its allergenicity.
Methods
We analyzed the biochemical and immunological interaction of ligands with Bet v 1. We then investigated the proteolytic processing of Bet v 1 by endosomal extracts in the presence and absence of ligands, followed by a detailed kinetic analysis of Bet v 1 processing by individual endolysosomal proteases as well as the T‐cell epitope presentation in BMDCs.
Results
We identified E1 phytoprostanes as novel Bet v 1 ligands. Pollen‐derived ligands enhanced the proteolytic resistance of Bet v 1, affecting degradation kinetics and preferential cleavage sites of the endolysosomal proteases cathepsin S and legumain. E1 phytoprostanes exhibited a dual role by stabilizing Bet v 1 and inhibiting cathepsin protease activity.
Conclusion
Bet v 1 can serve as a transporter of pollen‐derived, bioactive compounds. When carried to the endolysosome, such compounds can modulate the proteolytic activity, including its processing by cysteine cathepsins. We unveil a paradigm shift from an allergen‐centered view to a more systemic view that includes the host endolysosomal enzymes.
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