FIG 7.

P. gingivalis-induced expression of PD-L1 depends on the kinase activity of RIP2 and MAPKs. (A) SCC-25 cells were incubated with the RIP2 inhibitor gefitinib and stimulated with P. gingivalis TM for 4 and 24 h as shown, followed by the analysis of PD-L1 expression by Western blotting. (B) SCC-25 cells were incubated with the indicated MAPK and NOD inhibitors as shown and stimulated with the P. gingivalis TM fraction. PD-L1 protein expression was scored by immunoblotting and the results from three Western blots were quantified by Image J. Maximal PD-L1 protein expression from stimulated cells was arbitrarily set as 100%; the error bars show standard deviations. Triplicates of the Western blots were used for protein quantification using the Image J software; the error bars show standard deviations. (C) PHGKs were stimulated with the P. gingivalis TM fraction in the presence of the indicated inhibitors for 24 h. The analysis of PD-L1 expression was revealed by Western blotting; the results from three Western blots were quantified by Image J. Maximal PD-L1 protein expression from stimulated cells was arbitrarily set as 100%; the error bars show standard deviations.