R&D Systems Recombinant Mouse PD-L2/B7-DC Fc Chimera Protein, CF (100 UG) Item ID: RDS1022PL100

Programmed Death Ligand 2 (PD-L2), also known as B7-DC and butyrophilin-like protein, is a member of the B7 family of proteins that provide signals for regulating T-cell activation and tolerance (1). Mature mouse PD-L2 consists of a 199 amino acid (aa) extracellular domain (ECD) with one V-like and one C-like Ig domain, a 23 aa transmembrane segment, and a 5 aa cytoplasmic domain (2, 3). Within the ECD, mouse and human PD-L2 share 72% aa sequence identity. PD-L2 is expressed on dendritic cells, subsets of activated CD4⁺ and CD8⁺ T cells, and memory B cells that differentiate into plasma cells (3-5). At inflammatory sites such as rheumatoid arthritis, allergen exposure, and virus infection, PD-L2 is up-regulated on synoviocytes, infiltrating macrophages, dendritic cells, and airway epithelial cells (6-10).
PD-L2, along with B7-H1/PD-L1, binds to T cell PD-1 where it promotes IFN-gamma production and CD40 Ligand up-regulation while inhibiting IL-4 production (2, 3, 11, 12). In addition, PD-L2 binds to RGM-B on macrophages and alveolar epithelial cells, supporting respiratory immune tolerance (13). In asthma, PD-L2 suppresses IL-5 and
IL-13 production, promotes IL-12 production by dendritic cells, and supports allergen-induced airway hyper-responsiveness and mucus production (8, 10).