Figure 1
From: Back from the dead: TIL apoptosis in cancer immune evasion
Tumour antigen-specific TILs undergo apoptosis during tumour progression (top): Zhu and colleagues found that TIL apoptosis was a result of FasL expression on MDSCs that was driven by TIL-produced IFNγ. Horton and colleagues found that TIL apoptosis was associated with antigen-induced T-cell dysfunction, and possibly due to the accumulation of DNA damage in dysfunctional TILs. Inhibiting TIL apoptosis enhances tumour control (bottom): Zhu and colleagues found that administration of an Fas-Fc protein and depletion of MDSCs enhanced the efficacy of checkpoint blockade. Horton and colleagues found that an agonist 4-1BB antibody synergised with checkpoint blockade to decrease TIL apoptosis and enhance tumour control. Mechanisms of human TIL apoptosis should be investigated in order to develop therapeutic strategies to enhance TIL survival.
