Fig. 4

Effects of heat-killed P. intermedia on SCC7 cell proliferation and cytokine release at different MOIs. a–c Viability of SCC7 cells treated with/without heat-killed P. intermedia. a Cell viability at 24 h. b Cell viability at 48 h. c Cell viability at 72 h. d, e Cell invasion ability at 24 h detected by using transwell assays. f–k Secretory levels of TNF-α, IL-6, IL-10, IL-1β, IL-17A, and PD-L1 by SCC7 cells treated with/without heat-killed P. intermedia. Data are the means of values from three independent experiments, shown as the mean ± SEM, and were analyzed using one-way ANOVA. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001. ns, not significant.