title: Dietary nucleotides increase the mucosal IgA response and the secretion of transforming growth factor beta from intestinal epithelial cells in mice.
abstract: We have investigated the influence of dietary nucleotides on the intestinal immune system in ovalbumin (OVA)-specific T-cell receptor (TCR) transgenic mice (OVA-TCR Tg mice). When mice were supplied with water supplemented with 2% OVA ad libitum, the faecal OVA-specific immunoglobulin A (IgA) level significantly increased in those fed a nucleotide-supplemented diet (NT(+) diet) compared with those fed a nucleotide-free control diet (NT(-) diet). In the NT(+) diet-fed mice, secretion of transforming growth factor beta (TGF-beta), which is an isotype-specific switch factor for IgA, from intestinal epithelial cells (IECs) was significantly increased. Furthermore, an increased proportion of intestinal intraepithelial lymphocytes (IELs) bearing gammadelta TCR (TCRgammadelta(+) IELs) and increased secretion from IECs of interleukin 7 (IL-7), which is essential for the development of TCRgammadelta(+) IELs, were also observed in OVA-TCR-Tg mice fed the NT(+) diet, as we previously demonstrated using BALB/c mice (Nagafuchi et al., Biosci. Biotechnol. Biochem. 64: 1459-65 (2000)). Considering that TCRgammadelta(+) T cells and TGF-beta are important for an induction of the mucosal IgA response, our results suggest that dietary nucleotides augment the mucosal OVA-specific IgA response by increasing the secretion of TGF-beta from IECs and the proportion of TCRgammadelta(+) IELs.
authors.affiliation: Nutrition Science Institute, Meiji Dairies Co., Ltd., 540, Naruda, Odawara, Kanagawa, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Nagafuchi
authors.forename: Mamoru
authors.initials: M
authors.lastname: Totsuka
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hachimura
authors.forename: Masao
authors.initials: M
authors.lastname: Goto
authors.forename: Takeshi
authors.initials: T
authors.lastname: Takahashi
authors.forename: Takaji
authors.initials: T
authors.lastname: Yajima
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Kuwata
authors.forename: Shuichi
authors.initials: S
authors.lastname: Kaminogawa