Objective To investigate the expression of Toll like receptor 2（TLR2） and interleukin-1β（IL-1β） of cultured human periodontal ligament cells（HPDLCs） activated by Enterococcus faecalis（E.faecalis） lipoteichoic acid （LTA）. Methods HPDLCs that were obtained from the periodontal tissues of healthy humans were maintained in proper condition. Flow cytometry was used to detect the expression of TLR2 on normal HPDLCs and infectious HPDLCs which were incubated with 0.1, 1, 10 μg·mL-1 E.faecalis LTA for 24 h. IL-1β was detected by enzyme linked immunosorbent assay（ELISA） after incubating with LTA of the above concentration for 12, 24 and 48 h or pretreated with TLR2 neutralizing antibody for 1 h and then co-cultured with 1 μg·mL-1 LTA for 24 h. Results E.faecalis LTA promoted the expression of TLR2 in normal HPDLCs. The difference had statistical significance（P
