Human corneal epithelial cells respond to ocular-pathogenic, but not to nonpathogenic-flagellin.
In this study, we investigated the expression of TLR5 in human corneal epithelial cells (CEC), and the functional outcome of TLR5 triggering by flagellins of pathogenic- and nonpathogenic bacteria. Flagellins derived from Pseudomonas aeruginosa, Salmonella typhimurium, Serratia marcescense or Bacillus subtilis were used. The TLR5 protein and TLR5 specific mRNA expression was evident on human CEC. In human corneal epithelium tissues, TLR5 protein was detected at the basal and wing cells of the tissues. Ocular pathogenic bacteria, namely P. aeruginosa and S. marcescense, derived flagellin induced the significantly increased level of gene activation and IL-6 and IL-8 production. In contrast, ocular nonpathogenic S. typhimurium- and B. subtilis-derived flagellin induced neither the gene activation nor the increased production of IL-6 and IL-8 in human CEC. Human CEC would respond only to flagellin derived of ocular pathogenic bacteria, but not to those derived of ocular nonpathogenic bacteria, to generate pro-inflammatory cytokines.
Hozono
Yukako
Y
Department of Ophthalmology, Kyoto Prefectural University of Medicine, Hirokoji-agaru, Kawaramachi-dori, Kamigyo-ku, Japan.
Ueta
Mayumi
M
Hamuro
Junji
J
Kojima
Kentaro
K
Kawasaki
Satoshi
S
Yamazaki
Kenta
K
Kinoshita
Shigeru
S
D001426:Bacterial Proteins / Q000008:administration & dosage*; D002460:Cell Line; D016207:Cytokines / Q000276:immunology*; D004847:Epithelial Cells / Q000187:drug effects / Q000276:immunology*; D019573:Epithelium, Corneal / Q000187:drug effects / Q000276:immunology*; D005408:Flagellin / Q000008:administration & dosage*; D006801:Humans; D051198:Toll-Like Receptor 5 / Q000276:immunology*
D001426:Bacterial Proteins; D016207:Cytokines; C495346:TLR5 protein, human; D051198:Toll-Like Receptor 5; D005408:Flagellin