Title: Mountain cedar pollen induces IgE-independent mast cell degranulation, IL-4 production, and intracellular reactive oxygen species generation.

Authors: Endo, Shuichiro; Hochman, Daniel J; Midoro-Horiuti, Terumi; Goldblum, Randall M; Brooks, Edward G

Published In Cell Immunol, (2011)

Abstract: Cedar pollens cause severe allergic disease throughout the world. We have previously characterized allergenic pollen glycoproteins from mountain cedar (Juniperus ashei) that bind to allergen-specific immunoglobulin E (IgE). In the present report, we investigated an alternative pathway of mast cell activation by mountain cedar pollen extract through IgE-independent mechanisms. We show that mountain cedar pollen directly induces mast cell serotonin and IL-4 release and enhances release induced by IgE cross-linking. Concomitant with mediator release, high levels of intracellular reactive oxygen species (ROS) were generated, and both ROS and serotonin release were inhibited by anti-oxidants. These findings suggest that alternative mechanisms exist whereby pollen exposure enhances allergic inflammatory mediator release through mechanisms that involve ROS. These mechanisms have the potential for enhancing the allergenic potency of pollens.

PubMed ID: 21944563

MeSH Terms: Animals; Antioxidants/pharmacology; Biogenic Amines/biosynthesis; Cell Degranulation/drug effects; Cell Degranulation/immunology; Cell Line; Humans; Immunoglobulin E/metabolism; Interleukin-4/biosynthesis*; Interleukin-4/genetics; Juniperus/immunology*; Mast Cells/drug effects; Mast Cells/immunology*; Mast Cells/physiology; Pollen/adverse effects*; Pollen/immunology; RNA, Messenger/genetics; RNA, Messenger/metabolism; Rats; Reactive Oxygen Species/metabolism; Rhinitis, Allergic, Seasonal/etiology; Rhinitis, Allergic, Seasonal/immunology; Serotonin/biosynthesis; Up-Regulation