Fig. 2.

Co-stimulation with PD-L1 epitopes boosts the immunogenicity of a DC-based vaccine. PBMC (numerous colors) was stimulated with an autologous DC-based vaccine (blue) in the presence of IL-2. Subsequently, DC-reactive T cells (green) expand, and this is augmented when PD-L1-specific T cells are activated by co-stimulation with PD-L1-derived epitopes (yellow) assessed in cultures co-stimulated with an HIV control epitope (red)