Human IL-8/CXCL8 ELISA Kit

Detection Principle:

This kit uses double antibody sandwich enzyme-linked immunosorbent assay technology. The specific anti human il-8antibody was pre coated on a high affinity enzyme plate. The standard, sample to be tested and biotinylated detection antibody are added into the wells of the enzyme plate. After incubation, the il-8present in the sample combines with the solid-phase antibody and detection antibody to form an immune complex. After washing to remove unbound material, horseradish peroxidase labeled streptavidin (streptavidin HRP) was added. After washing, the chromogenic substrate was added to avoid light for color development. Stop the reaction by adding stop solution, and determine the absorbance value at 450 nmwavelength (reference correction wavelength 540nmor 570nm).

Test Type: double antibody sandwich method

Form: pre coated 96orifice plate

Test Sample Type: cell supernatant, Serum, plasma

Sample Loading: 100ul

Kit Components:

Pre coated 96well plates, standards, il-8detection antibody, dilution buffer, chromogenic solution (a, b)One copy of washing solution, termination solution, sa-hrp, plate sealing membrane and instructions.

Sensitivity: 7.8pg/ml

Detection Range: 31.2 - 2000 pg/ml

Recovery Range: 96-118%

Saving Method: 2-8℃

Standard Curve

 

Background:

Interleukin-8 (IL-8, also known as GCP-1, NAP-1 and CXCL8) is a member of α "Chemokines of the type I or CXC family, 8-9 kda, that bind heparin." Found so far, a total of 15 kinds of CXC family proteins, size between 8 to 12 kda. Most of them are located on human chromosome 4 and have typical trisomy. Fold layer/a α Helical structure, most showing a Glu-Leu-Arg tripeptide motif at the N-terminus. Human IL-8 is first synthesized as a 99-amino acid precursor containing a 20-amino acid signal sequence, and a 79-amino acid mature region. It can circulate in vivo as a monomer, a homodimer, and a heterodimer with CXCL4/PF4. The IL-8 monomer is thought to be the most biologically active, whereas the heterodimer may enhance PF4 activity. At the amino acid level, mature human IL-8 shares 65% and 70% identity with pig and dog, respectively. In rodents, IL - 8 of the corresponding genes have been found. By alternative splicing and differential protein hydrolysis to produce a wide variety of IL - 8 subtype. Alternative splicing occurs at the C-terminus, where there is an 11-amino acid substitution (aa#92-99). Protease hydrolysis may be a cell-specific event that produces a truncation at the N-terminus of IL-8. Fibroblasts and endothelial cells, for instance, cutting the 21st and 22nd amino acid, the formation of IL - 8, and 21-25 amino acid monomer cells and lymphocytes in cutting, IL - 8. The short form of IL - 8 in general have a higher biological activity, especially for CXCR 1 IL - 8 increased the activity of receptors. About 15% of IL-8 is citrullinated at Arg27, which increases the half-life of IL-8 and promotes leukocytosis. Many types of cells can secrete IL - 8, including monocytes, neutrophils, fibroblasts and horny cells, mast cells, visceral smooth muscle cells, dendritic cells, type II alveolar cells and endothelial cells.

There are two IL-8 receptors, both belonging to G protein-coupled receptor proteins: CXCR1/IL-8RA and CXCR2/IL-8RB, which share 77% amino acid sequence identity. CXCR1 has a molecular weight of 45-50 kda and is almost exclusively reserved by IL-8. CXCR2 has a molecular mass of 35-40 kda and is shared by all CXC chemokines. CXCR1 and CXCR2 form constitutive homodimers, respectively, which appear to be their functional configuration. When expressed by the same cell, the heterodimer is also formed; But when it is combined with IL - 8 after will be collapse. CXCR2 has response to the low concentration of IL - 8, and mainly related to the chemotaxis and MMP - 9 release. On the contrary, CXCR1 has response to the high concentration of IL - 8, and associated with respiratory burst and the activation of phospholipase D2. So in neutrophils CXCR2 thought may guide neutrophils migrated to inflammation of the parts, and then trigger a CXCR1 mediated antibacterial activity.

IL-8 is best known for its proinflammatory role in immune cells. In essence, IL - 8 is exposed by inflammatory stimulation factor secretion of a variety of cell types. For monocytes/macrophages, microbial exposure caused IL-8 release; Subsequently, CXCR2 mediated the chemotaxis of neutrophils migration to antigen attack site, and the antibacterial activities associated with the activation and start. IL - 8 can enhance the effect of bone marrow M - CSF, causing granulocyte mature and release. IL - 8 function of the two complement each other. It has been reported that IL-8 exerts an angiogenic function on tumor-associated endothelial cells. At this point, tumor-derived IL-8 can activate CXCR1 and CXCR2 in vascular endothelial cells in a paracrine manner. Both CXCR1 and CXCR2 are associated with PI3-K/Akt and RasGTP signaling pathways and are involved in cell survival and proliferation. In addition, IL - 8 is adjusting VEGFR2 and EGFR is mediated cell growth and migration of winding glycine receptor kinase.