Establishment and application of TLR2 receptor-based cell screening model

TLR2 activity plays an important role in the pathogenesis of autoimmune diseases, tumor carcinogenesis and cardio-cerebrovascular diseases.  To establish a TLR2 receptor-based cell screening model, NF-κB promoter-driven luciferase reporter plasmids were transfected into human embryonic kidney cells (HEK293) stably expressing human TLR2 and co-receptors CD14, TLR1 and TLR6.  Single clones were then isolated and characterized.  Using this screening system, a human TLR2-binding peptide C8 was obtained from the Ph.D.™-7 Phage Display Peptide Library through biopanning and rapid analysis of selective interactive ligands (BRASIL).  The binding characteristic of C8 with human TLR2 was evaluated by ELISA, flow cytometry and immunofluorescence.  The NF-κB luciferase activity assay showed that C8 could activate the TLR2/TLR1 signaling pathway and induce the production of cytokines TNF-α and IL-6.  In conclusion, the TLR2 receptor-based cell screening system is successfully established and a new TLR2-binding peptide is identified by using this system.