Objective To investigate the pathogenicity of matrix metalloproteinase 8, 9（MMP-8, MMP-9） regulations of polymorphonuclear leukocytes（PMNs） by challenge of Porphyromonas gingivalis（P.gingivalis） with different fimA genotypes. Methods The studies mainly adopt the isopycnic sedimentation separation to separate the PMNs from human peripheral blood. P.gingivalis ATCC 33277（typeⅠ），WCSP 115（typeⅡ），WCSP 1.5（typeⅢ），W83（typeⅣ）， WCSP 559（typeⅣ） were assessed for their inductions of MMP-8, MMP-9 expression in PMNs. MMP-8, MMP-9 protein levels in culture supernatant were determined by ELISA at different time intervals（5 min, 30 min, 1 h, 2 h） following continuous co-culture of bacteria with PMNs. Results MMP-8 and MMP-9 protein levels produced by PMNs co-culture with the ⅠfimA—ⅣfimA P.gingivalis were significantly stronger than unsimulated group. The velocity and quantity of MMP-8 produced by PMNs co-culture with the ⅡfimA P.gingivalis and ⅣfimA P.gingivalis were more than ⅢfimA, ⅣfimA P.gingivalis. The MMP-9 protein levels produced by PMNs co-culture with the ⅠfimA, ⅡfimA, ⅣfimA P.gingivalis was significantly stronger than ⅢfimA and ⅣfimA P.gingivalis. Conclusion Ⅱ fimA and ⅣfimA P.gingivalis have stronger pathogenicity relatively, which indicate that fimA genotype is associated with pathogenesis of P.gingivalis.
