Functional expression of TLR5 in murine salivary gland epithelial cells.
Toll-like receptors (TLR) recognize microbe-associated molecular patterns and induce the innate immune response. Among them, TLR5 recognizes the Gram-negative bacterial component flagellin. The aim of this study was to examine the expression of TLR5 in mouse salivary gland (SG). The SG was excised from 8- to 10-week-old female C57BL/6 mice. Salivary gland epithelial cells (SGECs) were purified and subjected to reverse transcription polymerase chain reaction (RT-PCR). Western blotting was performed to detect TLR5 expression at the protein level in several organs. The localization of TLR5 in SG was examined using immunohistochemical staining. The responsiveness of SGECs to flagellin was further examined by evaluating the induction of CXCL1 by real-time PCR and immunoprecipitation followed by Western blotting. TLR5 expression in SG was confirmed at the gene and protein levels. Immunohistochemical staining detected TLR5 in both acinic and ductal cells of the sublingual gland, but not in serous acinic cells of the submandibular gland. Although TLR5 was detected throughout the cytoplasm in ductal cells, positive staining was observed on the basal side of the mucous acinic cells. The purified SGECs responded to flagellin and induced the production of CXCL1. These findings suggest that TLR5 is functionally expressed in the SG and responds to its cognate ligand flagellin. (J Oral Sci 58, 317-323, 2016).
Department of Pediatric Dentistry, Nihon University School of Dentistry.
Satoko
S
Iwasa
Hirotaka
H
Ota
Kensuke
K
Nishio
Mariko
M
Ohtsu
Masafumi
M
Kusunoki
Takahiro
T
Gojoubori
Tetsuo
T
Shirakawa
Masatake
M
Asano
D000818:Animals; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D005260:Female; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D012469:Salivary Glands / Q000166:cytology / Q000378:metabolism*; D051198:Toll-Like Receptor 5 / Q000378:metabolism*
D051198:Toll-Like Receptor 5