title: In vivo dose response and in vitro mechanistic analysis of enhanced immunoglobulin A production by Lactobacillus plantarum AYA.
abstract: Secretory immunoglobulin A (IgA) mediates the mucosal immune system, which provides the first line of defense against inhaled and ingested pathogenic bacteria and viruses. Lactobacillus plantarum AYA increases the IgA level of Peyer's patch (PP) cells, but the recommended amount of consumption and the mechanism of action remains unclear. Better understanding of these is essential to development of L. plantarum AYA for use in functional foods. Therefore, we investigated the dose-response effect (in vivo) and mechanism (in vitro) of IgA enhancement induced by L. plantarum AYA. In the small intestine of the mice fed a diet containing 0.03% or 0.3% of L. plantarum AYA powder for 4 weeks, the IgA levels were significantly increased. Thus, it is suggested that the recommended amount of consumption of L. plantarum AYA is about 0.72 mg per day. In addition, the bacterial cell wall fraction significantly enhanced the IgA production level of murine PP cells in the in vitro assay. The ability of whole cells and the cell wall fraction to enhance IgA levels was significantly inhibited by an anti-Toll-like receptor-2 (TLR-2) antibody, which suggests that the cell wall fraction of L. plantarum AYA increases the IgA level via TLR-2. These findings indicate that L. plantarum AYA is a potential functional food source that maintains mucosal immunity.
authors.affiliation: Research Center for Basic Science, Research, and Development, Quality Assurance Division, Nisshin Seifun Group Inc., 5-3-1 Tsurugaoka, Fujimino, Saitama 356-8511, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Kikuchi
authors.affiliation: Graduate School of Biosphere Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-hiroshima, Hiroshima 739-8528, Japan.
authors.forename: Hikaru
authors.initials: H
authors.lastname: Yoshida
authors.affiliation: Graduate School of Biosphere Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-hiroshima, Hiroshima 739-8528, Japan.
authors.forename: Tasuku
authors.initials: T
authors.lastname: Ogita
authors.affiliation: Yeast Function Development Unit, Oriental Yeast Co., Ltd., 3-6-10 Azusawa, Itabashi, Tokyo 174-8505, Japan.
authors.forename: Kimiko
authors.initials: K
authors.lastname: Okita
authors.affiliation: Research Center for Basic Science, Research, and Development, Quality Assurance Division, Nisshin Seifun Group Inc., 5-3-1 Tsurugaoka, Fujimino, Saitama 356-8511, Japan.
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Fukudome
authors.affiliation: Graduate School of Biosphere Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-hiroshima, Hiroshima 739-8528, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Graduate School of Biosphere Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-hiroshima, Hiroshima 739-8528, Japan.
authors.forename: Soichi
authors.initials: S
authors.lastname: Tanabe
keywords: Lactobacillus plantarum AYA; Peyer’s patch; Toll-like receptor 2; cell wall; immunoglobulin A; probiotics