PD-L1 co-stimulation, ligand-induced TCR down-modulation and anti-tumor immunotherapy

Oncoimmunology. 2012 Jan 1;1(1):86-88. doi: 10.4161/onci.1.1.17824.


PD-1 engagement on the surface of effector T cells strongly suppresses their cytotoxic function, which constitutes a major obstacle for T cell-mediated anti-tumor activities. Surprisingly, PD-1 is strongly upregulated in T cells, engaging its ligand PD-L1 during antigen presentation. However, our recent published data may provide an explanation for this apparent contradiction.