Bispecific nanobodies targeting Bet v 1 and ICAM-1 decrease respiratory epithelial penetration of Bet v 1

Le résumé fourni par la source

Background: The major birch pollen allergen Bet v 1 primarily affects the nose and eyes of allergic patients. After crossing the epithelial barrier, it causes IgE-mediated effector cell release, triggering inflammatory responses. We sought to develop bispecific nanobodies that bind Bet v 1 on mucosal surfaces to prevent allergen penetration and subsequent activation of effector cells. Intercellular adhesion molecule 1 (ICAM-1), highly upregulated on epithelial cells of allergic individuals, was chosen as an anchor. Methods: Genetically fused nanobodies targeting Bet v 1 and ICAM-1 were generated and characterized for specificity, affinity, Bet v 1 immobilization on the surface of the human bronchial epithelial cell line, 16HBE14o-, and their potential to inhibit Bet v 1 penetration through a cell monolayer. Results: Bispecific nanobodies recognized ICAM-1, Bet v 1 and related tree pollen allergens (Aln g 1, Cor a 1). While we observed a clear co-localization of nanobodies and Bet v 1 on the 16HBE14o-cell surface after 30 min, Bet v 1 was slightly internalized after 4h at 32 °C. Dissociation rate constants between bispecific nanobodies and antigens were 3-6 times faster at 32 °C compared to 25 °C. Bispecific nanobodies reduced Bet v 1 penetration and hence decreased basophil activation. Conclusion: We generated bivalent nanobodies specific for ICAM-1 and Bet v 1. These nanobodies diminished trans-epithelial transport of Bet v 1 by ICAM-1-mediated immobilization at the cell surface. Reduced Bet v 1 penetration resulted in decreased basophil activation, demonstrating the potential of local administration of nanobodies for the prevention of pollen allergy.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.