title: Tannic acid, a higher galloylated pentagalloylglucose, suppresses antigen-specific IgE production by inhibiting ɛ germline transcription induced by STAT6 activation.
abstract: Interleukin (IL)-4 is a critical stimulator that induces ɛ germline transcripts (ɛGT) for switch recombination to initiate immunoglobulin (Ig) E and is important in allergic disease pathogenesis. We found pentagalloylglucose (PGG) inhibited IL-4-induced ɛGT expression. PGG exerted its inhibitory function by suppressing IL-4-induced activation of IL-4Rα, JAK3 and STAT6. Furthermore, tannic acid, a higher galloylated PGG, attenuated ovalbumin-induced IgE production in vivo by inhibiting IL-4-induced ɛGT expression and the IL-4 signaling pathway. In conclusion, our results suggest that tannic acid may attenuate allergic diseases by suppressing IgE production by inhibiting IL-4-induced signaling.
authors.affiliation: Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan.
authors.forename: Yoon Hee
authors.initials: YH
authors.lastname: Kim
authors.forename: Miki
authors.initials: M
authors.lastname: Yoshimoto
authors.forename: Kazuko
authors.initials: K
authors.lastname: Nakayama
authors.forename: Sousuke
authors.initials: S
authors.lastname: Tanino
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Fujimura
authors.forename: Koji
authors.initials: K
authors.lastname: Yamada
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Tachibana
keywords: IFN-γ, interferon-gamma; IL, interleukin; IgE; IgE, immunoglobulin E; JAK, Janus kinase; OVA, ovalbumin; PGG, 1,2,3,4,6-penta-O-galloyl-β-d-glucose; Pentagalloylglucose; STAT, signal transducer and activator of transcription; Signal transducers and activators of transcription6; TGF-β, transforming growth factor-beta; Tannic acid; ɛ Germline transcript; ɛGT, ɛ germline transcript