CXCR2/IL-8 RB

Chemokine receptors are seven-transmembrane domain G-protein coupled receptors that mediate the biological activities of chemokines. Most of these receptors exhibit promiscuous binding properties whereby several different chemokines signal through the same receptor. They are named according to the chemokine subfamily they bind. There are currently six CXC-specific receptors designated CXCR1 to CXCR6, eleven CC-specific receptors designated CCR1 to CCR11, and one C receptor, XCR1. CX3CR1 is the receptor for fractalkine. 

Neutralization of Human Cell Surface CXCR2 mediated Bioactivity -The exact concentration of antibody required to neutralize the mouse cell surface CXCR2 mediated bioactivity is dependent on the concentration as well as on the number of CXCR2 receptors present on the cell surface (a function of cell type and culture conditions). To provide a guideline, R&D Systems has determined the neutralization dose for this antibody under a specific set of conditions. The Neutralization Dose50 (ND50) for this antibody is defined as that concentration of antibody required to yield one-half maximal inhibition of the cell surface CXCR2 mediated rmMIP-2 response on responsive cells at a specific rmMIP-2 concentration. 

The ND50 for this lot of anti-mouse CXCR2 antibody was determined to be approximately 15 - 50 µg/mL in the presence of 2 ng/mL rmMIP-2 in a chemotaxis assay using BaF/3 cells transfected with mCXCR2. The specific conditions are described in the figure legends.

   Figure 1-Mouse MIP-2 chemoattracts BaF/3 cells that have been transfected with mCXCR2. The number of cells that have migrated through to the lower chamber are quantitated using Resazurin  fluorescence staining. The ED50 for this effect is typically 0.1 - 0.5 ng/mL. 

Figure 2-To measure the ability of the antibody to block rmMIP-2 induced chemotaxis of mCXCR2 transfected BaF/3 cells, rmMIP-2 at 2 ng/mL was added to the lower compartment of a 96-well chemotaxis chamber (NeuroProbe, Cabin John, MD). The chemotaxis chamber was then assembled using a PVP-free polycarbonate filter (5 micron pore size). Serial dilutions of the antibody (at the concentrations indicated) and 0.2 x 106 cells/well were added to the top wells of the chamber. After incubation for 3 hours at 37° C in a 5% CO2 humidified incubator, the chamber was disassembled and the cells that migrated through to the lower chamber were transferred to a working plate and quantitated using Resazurin Fluorescence. As shown in Figure 2, the ND50 for this lot of antibody is approximately 15 - 50 µg/mL.