Figure 3

P. gingivalis is involved in the degradation of CXCL8 protein. Dermal fibroblasts (50,000 cells/well) were stimulated with 50 ng/ml TNF-α for 6 h, where after the cells were treated with either the indicated concentrations of viable P. gingivalis (A) or heat-killed P. gingivalis (MOI:1000) (B) for 24 h. CXCL8 levels were significantly suppressed by viable, but not heat-killed, P. gingivalis. (C) Gingival fibroblasts were stimulated with 50 ng/ml TNF-α for 6 h followed by treatment with viable or heat-killed P. gingivalis (MOI:100) for 24 h. Statistically significant differences compared to the negative control (#) or positive control TNF-α (*) were determined using Student’s t-test (###/***- p < 0.001).