Programmed death-1/programmed death-L1 signaling pathway and its blockade in hepatitis C virus immunotherapy

Figure 2 Proliferation of exhausted T cells and blockage strategies to reverse exhaustion. Severely exhausted T cells (red cells) proliferate poorly in comparison to partially exhausted and normal T cells (yellow and green cells). Antibody blockade of the pathway with PD-1 and its ligand reverses exhaustion and restores the functional capacities of exhausted T cells. PD-1: Programmed death-1.