Purchase this article with an account.
Y. Hozono, M. Ueta, J. Hamuro, S. Kinoshita; Human Corneal Epithelial Cells Respond to Ocular Pathogenic, but Not to Non–Pathogenic Bacterial Flagellin . Invest. Ophthalmol. Vis. Sci. 2006;47(13):1290.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
We previously reported that human corneal epithelium cells (HCEC) failed to respond functionally to peptidoglycan and lipopolysaccharide, while they respond to viral double stranded RNA to produce pro–inflammatory cytokines through TLR3. In this study, we investigated the expression of TLR5 in HCEC, and the functional outcome of TLR 5 triggering by flagellins of pathogenic–, and non–pathogenic bacteria.
Expression levels of TLR5 protein in HCEC were analyzed by flowcytometry and that of mRNA by RT–PCR. Flagellins were derived from Pseudomonas aeruginosa, Salmonella typhimurium, Serratia marcescense or Bacillus subtilis. The gene activation and the amount of IL–6 and IL–8 produced were traced by real time semi–quantitative PCR and ELISA, respectively.
The TLR5 protein expression was evident on HCEC at the level comparable to that on human peripheral mononuclear cells. 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 it was found that non–pathogenic S. typhymurium– and B. subtilis derived flagellin induced neither the gene activation nor the increased production of IL–6 and IL–8 in HCEC.
TLR5 is expressed in HCEC and HCEC respond to TLR5 ligands to produce pro–inflammatory cytokines. The present findings provide the intriguing suggestion that HCEC might distinguish flagellin of pathogenic bacteria from that of nonpathogenic bacteria through TLR5, thereby regulating the infection driven pathogenesis on ocular surface.
This PDF is available to Subscribers Only