title: Toll-like receptor 9 is expressed on follicle-associated epithelia containing M cells in swine Peyer's patches.
abstract: The precise distribution and expression of Toll-like receptor (TLR) 9 in gut-associated lymphoid tissues (GALTs) has not been elucidated. In this study, we investigated the expression pattern of TLR9 in adult and neonatal swine GALTs by real-time quantitative PCR, western blot, confocal laser microscopy and flow cytometric analysis. The swine TLR9 gene was preferentially expressed in adult Peyer's patches (Pps) and mesenteric lymph nodes (MLNs), which contained approximately three times higher TLR9 than the spleen. Other tissues exhibited only weak expression of TLR9. In neonatal swine, elevated expression of TLR9 was detected only in MLNs. We firstly showed that highly expressive (TLR9(+)) cells were formed in Pps and MLNs. In addition, TLR9(+) cells were present not only in immune cells such as dendritic cells and B cells but also in follicle-associated epithelia (FAE) including membranous cells (M cells) in Pps. These results suggest that Pps and MLNs provide the host defense with the ability to respond to a variety of bioactive oligonucleotides (ODNs) from bacteria at a conductive site of initial immune responses.
authors.affiliation: Laboratory of Animal Products Chemistry, Graduate School of Agricultural Science, Tohoku University, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Shimosato
authors.forename: Masanori
authors.initials: M
authors.lastname: Tohno
authors.forename: Haruki
authors.initials: H
authors.lastname: Kitazawa
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Katoh
authors.forename: Kouichi
authors.initials: K
authors.lastname: Watanabe
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kawai
authors.forename: Hisashi
authors.initials: H
authors.lastname: Aso
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Tadao
authors.initials: T
authors.lastname: Saito
mesh_terms: D000818:Animals; D015153:Blotting, Western; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005434:Flow Cytometry; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000378:metabolism*; D010581:Peyer's Patches / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D011956:Receptors, Cell Surface / Q000378:metabolism*; D013552:Swine / Q000378:metabolism*; D051217:Toll-Like Receptor 9
chemical_list: D004268:DNA-Binding Proteins; D011956:Receptors, Cell Surface; D051217:Toll-Like Receptor 9