Fig. 6.

Anti-PD-L1 significantly enhanced the anti-tumor effect of ALDH dual peptide-DC vaccine in the D5 therapy model. a: PD-L1 expression of unsorted D5, ALDH^high D5 CSCs and ALDH^low D5 non-CSCs as determined by flow cytometry. b: The expression of PD-L1 on unsorted D5 cells, ALDH^high CSCs and ALDH^low non-CSCs. Data graph was generated using the flow plot data in three independent experiments. c: Tumor growth in the day 1 D5 therapy model in mice (n = 5 for each group) treated with PBS, dual peptide-DC with or without anti-PD-1 or anti-PD-L1 iso. Data are representative of three experiments. d: Cytotoxicity of splenic T cells isolated from D5-bearing mice treated in C (E/T = 10:1 ratio) against D5 ALDH^high CSCs vs. ALDH^low non-CSCs. This experiment was repeated twice. e: IFNγ-producing splenic T cells from animals in C were assayed by Elispot in responses to D5 ALDH^high CSCs versus ALDH^low non-CSCs. Data are presented as a histogram graph. This experiment was repeated twice