CD273 (B7-DC) Monoclonal Antibody (122), eBioscience™, Invitrogen™

Description

• Description: The 122 monoclonal antibody reacts with mouse B7-DC, also known as PD-L2
• B7-DC, a recently identified member of the B7 family, has a predicted molecular weight of approximately 25 kDa and belongs to the Ig superfamily
• The mouse B7-DC has a short cytoplasmic tail (4aa)
• B7-DC is primarily expressed by subpopulations of dendritic cells and monocytes/macrophages in the mouse
• Although B7-DC has structural and sequence similarities to the B7 family, it does not bind CD28/CTLA-4, rather it is a ligand for PD-1
• The interactions between PD-1 and B7-DC/PD-L2 have been reported to be involved in costimulation or suppression of T cell proliferation depending on state of cellular activation
• 122 has been demonstrated to block binding of TY25 (Cat
• No.14-5986), another mAb specific for mouse B7-DC
• Applications Reported: 122 has been reported for use in flow cytometric analysis
• Applications Tested: The 122 antibody has been tested by flow cytometric analysis of mouse dendritic cells or mouse B7-DC transfected cells
• This can be used at less than or equal to 0.5 μg per test
• A test is defined as the amount (μg) of antibody that will stain a cell sample in a final volume of 100 μL
• Cell number should be determined empirically but can range from 10^5 to 10^8 cells/test
• It is recommended that the antibody be carefully titrated for optimal performance in the assay of interest
• 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.