Rat FCGR2 (Low affinity immunoglobulin gamma Fc region receptor II) ELISA Kit

Receptors for the Fc region of IgG (Fc γ R) are members of the Ig superfamily that function in the activation or inhibition of immune responses. Three classes of human Fc γ Rs: RI (CD64), RII (CD32), and RIII (CD16), which generate multiple isoforms, are recognized. The activating-type receptor either has or associates non-covalently with an accessory subunit (FcRγ or ζ chain) that has an immunoreceptor tyrosine-based activation motif (ITAM) in its cytoplasmic domain. In contrast, the inhibitory receptor (Fc γ RIIB) has a built-in immunoreceptor tyrosine-based inhibitory motif (ITIM) in its own cytoplasmic domain. Fc γ RI is a high-affinity receptor that binds monomeric IgG, both Fc γ RII and RIII are low-affinity receptors that bind aggregated or immune complexed IgG (IC) . Three genes for human Fc γ RII (A, B, and C) and one for mouse (Fc γ RIIB), encoding type I transmembrane proteins with ITAM motifs (Fc γ RII A and C) or ITIM motifs (Fc γ RIIB) in their cytoplasmic domains, have been identified. The extracellular domain of human Fc γ RIIA shares approximately 90% amino acid sequence homology with human Fc γ RIIB and Fc γ RIIC. Fc γ RIIA is expressed on many immune cell types (macrophage, neutrophil, eosinophils, platelets, dendritic cells and Langerhan cells) where inhibitory ITIM-bearing receptors may also be coexpressed and co-engaged by specific ligands. Signaling through Fc γ RIIA results in the initiation of inflammatory responses (cytolysis, phagocytosis, degranulation and cytokine production) that can be modulated by signals from the inhibitory receptors. The strength of the signal is dependent on the ratio of expression of the activating and inhibitory receptors. Besides IC, Fc γ RII A also binds C-reactive protein (CRP) . Two allelic variants (R167 and H167) of Fc γ RIIA that differ in their ability to ligate human IgG2 or CRP exist. The H167 allele has been found to have a protective effect against lupus nephritis.

This ELISA kit uses the Sandwich-ELISA principle. The micro ELISA plate provided in this kit has been pre-coated with an antibody specific to Rat FCGR2. Standards or samples are added to the micro ELISA plate wells and combined with the specific antibody. Then a biotinylated detection antibody specific for Rat FCGR2 and Avidin-Horseradish Peroxidase (HRP) conjugate are added successively to each micro plate well and incubated. Free components are washed away. The substrate solution is added to each well. Only those wells that contain Rat FCGR2, biotinylated detection antibody and Avidin-HRP conjugate will appear blue in color. The enzyme-substrate reaction is terminated by the addition of stop solution and the color turns yellow. The optical density (OD) is measured spectrophotometrically at a wavelength of 450 nm ± 10 nm. The OD value is proportional to the concentration of Rat FCGR2. You can calculate the concentration of Rat FCGR2 in the samples by comparing the OD of the samples to the standard curve.