- Inactive T cell
- Tumor cell
- PD-L1 on tumor-infiltrating immune cells can lead to inhibition of activated T cells
- Activation of the PD-1 receptor by binding of PD-L1 causes inhibition of T cell signaling
- PD-L1 binding to B7.1 on T cells and antigen-presenting cells can mediate down-regulation of immune responses
- Constitutive immune resistance PD-L1 expression on tumor cells can be up-regulated by oncogenic signaling
- Binding of the MHC antigen complex to the T cell receptor (TCR) triggers T cell signaling
- Tumor cells up-regulate PD-L1 to evade immune-mediated destruction