The Biology of PD-L2:

Programmed death ligand 2 (PD-L2) is a cell surface protein that competes with PD-L1 for binding to PD-1.¹

• PD-L2 interaction with PD-1 negatively regulates T cell proliferation, cytokine production and cytotoxic activity.²
• PD-L2 has a higher affinity for PD-1 but is expressed at lower levels.^1,3
• PD-L2 is expressed on tumor cells, antigen-presenting cells or APCs (e.g., macrophages and dendritic cells), and a variety of other immune and nonimmune cells.¹
• PD-L2 expression can be measured by immunohistochemistry (IHC) using an anti-PD-L2 primary antibody.^1,4

Tumor expression of PD-L2 may contribute to tumor evasion of immune destruction by inactivating T cells.^1,2,5,6

References
1. Rozali EN et al. Clin Dev Immunol. 2016:656340.
2. Ma W et al. J Hematol Oncol. 2016; 9:47.
3. Youngak P et al. Biochem Biophys Res Commun. 2003; 307: 672-677.
4. Shi M et al. Am J Surg Pathol. 2014; 38(12): 1715-1723.
5. McDermott DF, Atkins MB. Cancer Med. 2013; 2(5):662-673.
6. Mellman I et al. Nature. 2011; 480:480-489.