PDCD1LG2 Gene - Programmed Cell Death 1 Ligand 2 | Immune Checkpoint

PDCD1LG2 encodes programmed cell death 1 ligand 2 (PD-L2), a member of the B7 family of immune regulatory ligands. PD-L2 binds to the PD-1 receptor on activated T cells, delivering a co-inhibitory signal that suppresses T-cell proliferation, cytokine production, and cytotoxicity. It is expressed on antigen-presenting cells (dendritic cells, macrophages) and some non-hematopoietic cells. PD-L2 plays a critical role in peripheral tolerance, autoimmunity, and tumor immune evasion. The gene is located on chromosome 9p24.1, a region frequently altered in Hodgkin lymphoma and other cancers.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• PD-1 signaling (Reactome: R-HSA-389948)

• Immune checkpoint pathway (KEGG: hsa05340)

• Costimulation by the CD28 family (Reactome: R-HSA-388841)

PD-L2 (UniProt Q9BQ51) is a 273-amino acid type I transmembrane protein with an extracellular Ig-like V-type domain and a short cytoplasmic tail. It is expressed on antigen-presenting cells and induced by cytokines such as IL-4 and IFN-γ. PD-L2 binds PD-1 with higher affinity than PD-L1, delivering inhibitory signals that reduce T-cell activation. The protein is a target for cancer immunotherapy; blocking antibodies are in clinical development. Soluble forms of PD-L2 are detected in serum and may serve as biomarkers.