PD-1/PD-L1 Blockade: A New Promising Therapy for the Treatment of Pancreatic Cancer?

Abstract

Programmed cell death protein 1 (PD-1), a member of the CD28 family, is an immune-checkpoint receptor expressed on a variety of immune cells, such as T-cells, monocytes, B-cells, den-dritic cells, and tumor-infiltrating lymphocytes (TILs).1 PD-1 ma-jor role is to limit the activity of T-cells in peripheral tissues at the time of an inflammatory response to constrain autoimmunity and tissue damage.1,2 Engagement of PD-1 by one of its two known ligands (PD-L1 and PD-L2) inhibits kinases involved in immune cell activation.2 Interestingly, PD-1 has an opposite function in Treglymphocytes.