Abstract
Purpose: :
To investigate the Toll-like receptor (TLR) signal transduction pathway in Telomerase-immortalized Human Stromal Fibroblasts (THSFs) and Telomerase-immortalized Human Corneal Epithelial cells (THCEs) challenged with Acanthamoeba and animal models of Acanthamoeba keratitis.
Methods: :
THSFs and THCEs were challenged with Acanthamoeba. The expression of TLRs were detected in the cell lines with Real time-PCR, Western blot and Immunofluorescence staining analysis. The levels of interleukin (IL)-6, IL-8, interferon (IFN)-β, and downstream molecules of TLR signal pathway such as myeloid differentiation protein (MyD)88, nuclear factor kappa B (NF-ΚB), extracellular signal-regulated protein kinase (ERK), c-Jun N-terminal kinase (JNK), p38 mitogen activated protein kinase (P38) in THSFs were also analyzed with Real-time PCR. Antibody blocking experiment was carried out to analyze the main receptor involved and the interaction between the receptors and cytokines in THSFs. The rat models of Acanthamoeba keratitis were established and the expressions of TLR2 and 4 in the corneal stroma were detected by Real-time PCR, Western blot, and Immunofluorescence staining analysis.
Results: :
The expression of TLR2 and 4 increased in THSFs, THCEs, and corneal stroma of animal models challenged with Acanthamoeba. And the expression level of TLR4 was much higher than that of TLR2. The expressions of IL-6, 8 and IFN-β, gene transcription of downstream molecules of the TLR signal pathway such as MyD88, NF-ΚB, and ERK also increased significantly in THSFs challenged with Acanthamoeba. Anti-TLR4 antibody could significantly inhibit the production of inflammatory cytokines in THSFs induced by Acanthamoeba.
Keywords: Acanthamoeba • inflammation • signal transduction