Fig. 1

Expression of integrin αvβ6 and PD-L1 in cholangiocarcinoma (CCA) cell lines. A Immunofluorescence analysis showing the expression of integrin αvβ6 (green) and PD-L1 (red) in three CCA cell lines: KKU-055, KKU-100, and KKU-213A. The scale bar represents 50 μm. B Immunoblot analysis detecting PD-L1 (~ 55 kDa) and glyceraldehyde 3-phosphate dehydrogenase (GAPDH, 37 kDa) as a loading control (upper panel). Densitometry quantification of PD-L1 relative to GAPDH was performed using ImageJ software (lower panel). C Flow cytometry histograms displaying the surface expression of integrin αvβ6 and (E) PD-L1, with isotype controls shown in light gray. Quantification of (D) integrin αvβ6- and (F) PD-L1-positive cells is presented as percentages. Data are shown as mean ± standard error of the mean (SEM) from three independent experiments (N = 3). Statistical analysis was performed using one-way ANOVA with Tukey’s post hoc test (*p < 0.05, ***p < 0.001, ****p < 0.0001)