CD273 (B7-DC) Monoclonal Antibody (2011CT241.19.54), Invitrogen™

Description

• Programmed death-ligand 2 (PD-L2), or B7-DC, is a member of the B7 ligand family within the immunoglobulin superfamily that, along with programmed death-ligand 1 (PD-L1), acts as a ligand for programmed cell death protein 1 (PD-1)
• Though expressed primarily in dendritic cells, PD-L2 expression can be induced on a wide variety of immune and non-immune cells depending on the microenvironment
• PD-L2 expression is particularly upregulated in the presence of Th2 cytokine, IL-4, as well as Th1 cytokines, TNF-alpha and IFN-gamma to a lesser degree
• While generally expressed at lower levels compared to PD-L1, PD-L2 demonstrates a 2 to 6 times higher relative affinity to PD-1 than PD-L1
• PD-1 and its ligands are referred to as inhibitory immune checkpoint molecules in that they provide useful negative feedback during physiological homeostasis
• Ligation of PD-L2 or PD-L1 inhibits activation, proliferation, and cytokine secretion (e.g
• IFN-gamma, IL-10) in T cells, μgtimately dampening immune response
• Conversely, studies have shown that PD-L2 can also stimulate T cell proliferation and cytokine production, even in PD-1-deficient T cells, suggesting additional receptors
• Recent studies have concluded that PD-L2 also binds to a second receptor, repulsive guidance molecule b (RGMb), which was originally identified as a receptor for bone morphogenetic proteins (BMPs)
• RGMb is expressed in the central nervous system, as well as in macrophages, however, its role in immunity is only beginning to emerge
• Interaction between PD-L2 and RGMb regulates the development of respiratory tolerance in the lung through BMP and/or neogenin signaling pathways
• The naturally occurring human PD-L2 monomer consists of a 201-amino-acid extracellular domain, a 21-amino-acid transmembrane domain, and a 32-amino-acid cytoplasmic domain.