Interaction of PD-L1 on tumor cells with PD-1 on tumor-specific T cells as a mechanism of immune evasion: implications for tumor immunotherapy

C Blank, TF Gajewski, A Mackensen - Cancer Immunology …, 2005 - Springer
Cancer Immunology, Immunotherapy, 2005Springer
Programmed death receptor ligand 1 (PD-L1, also called B7-H1) is a recently described B7
family member. In contrast to B7-1 and B7-2, PD-L1 does not interact with either CD28 or
CTLA-4. To date, one specific receptor has been identified that can be ligated by PD-L1.
This receptor, programmed death receptor 1 (PD-1), has been shown to negatively regulate
T-cell receptor (TCR) signaling. Upon ligating its receptor, PD-L1 has been reported to
decrease TCR-mediated proliferation and cytokine production. PD-1 gene–deficient mice …
Abstract
Programmed death receptor ligand 1 (PD-L1, also called B7-H1) is a recently described B7 family member. In contrast to B7-1 and B7-2, PD-L1 does not interact with either CD28 or CTLA-4. To date, one specific receptor has been identified that can be ligated by PD-L1. This receptor, programmed death receptor 1 (PD-1), has been shown to negatively regulate T-cell receptor (TCR) signaling. Upon ligating its receptor, PD-L1 has been reported to decrease TCR-mediated proliferation and cytokine production. PD-1 gene–deficient mice developed autoimmune diseases, which early led to the hypothesis of PD-L1 regulating peripheral tolerance. In contrast to normal tissues, which show minimal surface expression of PD-L1 protein, PD-L1 expression was found to be abundant on many murine and human cancers and could be further up-regulated upon IFN-γ stimulation. Thus, PD-L1 might play an important role in tumor immune evasion. This review discusses the currently available data concerning negative T-cell regulation via PD-1, the blockade of PD-L1/PD-1 interactions, and the implications for adoptive T-cell therapies.
Springer