Monoclonal Antibodies Targeting the PD-1/PD-L1 Checkpoint

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MONOCLONAL ANTIBODIES TARGETING THE
PD-1/PD-L1 CHECKPOINT

PD-1 expression is common on peripheral T cells within inflamed tissues and tumors, where it helps keep the immune response under control when it binds to its ligand, PD-L1, which is found on some nonmalignant cells.

For many human cancers, the cancer immunity cycle is intact up to the point of tumor cell killing by T cells, which can be powerfully restrained by PD-L1. Many human cancers acquire the ability to express large amounts of PD-L1 on their surfaces, which helps them evade immune attack from activated PD-1–bearing T cells. If the PD-L1–PD-1 interaction is blocked, the cell-killing functions of anticancer T cells can be rapidly restored.

Monoclonal antibodies that target either PD-1 or PD-L1 can boost the immune response against cancer. Select the animation below to learn more about therapeutic blockade of
PD-L1 by atezolizumab.