Objective To determine the diversity of Porphytomonas gingivalis lipopolysaccharide (LPS)induced IL-1β,TNF-αand IL-6 levels in THP-1 cells and the associated Toll-like receptors(TLR).Methods P.gingivalis strain ATCC33277 LPS (Pg-LPS)was prepared using phenol-water method and then identified by both infrared spectrometry and limulus test.The levels of IL-1β,TNF-α and IL-6 secreted by THP-1 cells under inducement of Pg-LPS were quantitatively detected using commercial ELISA kits.The bloc-king test using TLR2 or TLR4 monoelonal antibody(McAb)plus the ELISA were used to determine the types of Pg-LPS binding TLR on the surface of target cells.In this study.a commercial LPS from E.coli strain O111:B4(E-LPS)was used as the contr01.Results When 1彬ml ofPg.u,s induced THP.1 ceHs for0.5,6 and 6 h.or l∥rnl ofE-LPs induced for 6,24 and 24 h,respectively,tIIe levels ofTNF.a,IL-1B and IL广6 were in.creased obviously(P<0.01).However,the maximal concentration of tlle t11ree cytokines induced by Pg.LP$ were similar to that induced by E-LPS(P>0.05).tLR2 or TLR4 McAb could block the effects of Pg-LPS in-ducing THP-1 cells to secrete IL-1β and IL-6(P<0.05),where as only TLR2 McAb displayed the inhibition of TNF-α secretion(P<0.05).On the contrast,only TLR4 McAb showed the effects blocking the three cytokines secretion in the THP-1 cells under inducement of E-LPS(P<0.05).Conclusion Pg-LPS shows a slight high-er activity inducing THP-1 cells to secrete IL-1β,TNF-α and IL-6 than E-LPS.TLR2,but not TLR4,is the major receptor of Pg-LPS on the target cells to mediate the secretion of the three cytokines.