Figure 6.

Supernatants collected from P. stomatis challenge have chemotactic activity for both neutrophils and monocytes. (A) Human neutrophils and in (B) monocytes were placed in the upper chamber of the transwell insert and 600 µL of buffer, CXCL1 (10 nM, a neutrophil chemoattractant), CCL3 (100 ng/mL, a monocyte chemoattractant), neutrophil-derived cell/bacteria-free conditioned supernatant collected after 24 h from unstimulated (UT), stimulated with P. gingivalis (Pg), P. stomatis (Ps), or F. alocis (Fa); were placed in the lower chamber. For neutrophil (A) or monocytes (B) chemotaxis the corresponding inserts were incubated at 37 °C, 5% CO₂ incubator for 30 min or 120 min, respectively. Chemotaxis was assessed by light microscopic examination (magnification x100) of the underside of the membrane. The average number of cells from a total of 10 high-power fields was determined and data expressed as mean ± SEM of number of migrating cells/insert. (A), n = 7 independent experiments; (B), n = 4 independent experiments. * p < 0.05, ** p < 0.01.