The Quantikine Human IL-8 Immunoassay is a 3.5 hour solid phase ELISA designed to measure human IL-8 in cell culture supernates, serum, and plasma. It is based on antibodies raised against the 72 aa variant of human IL-8 derived from E. coli. It is calibrated with the same recombinant factor. This immunoassay accurately quantitates recombinant human IL-8. Measurement of natural huma...n IL-8 or the 77 aa variant of human IL-8 gave results parallel to the standard curves obtained using the E. coli-expressed Quantikine kit standards. These results indicate that this kit can be used to determine relative mass values for natural human IL-8.
Store the unopened product at 2 - 8 °C. Do not use past expiration date.
This product is produced by and ships from R&D Systems, Inc., a Bio-Techne brand.
Alternate Names for Human IL-8/CXCL8 Quantikine ELISA Kit
C-X-C motif chemokine 8
Neutrophil-activating protein 1
T cell chemotactic factor
T-cell chemotactic factor
Interleukin-8 (IL-8), also known as IL-8, GCP-1, and NAP-1,
is a heparin-binding 8-9 kDa member of the alpha, or CXC family of chemokines.
There are at least 15 human CXC family members that all adopt a three
beta -sheet/one alpha -helix structure. Most CXC chemokines show an N-terminal
Glu-Leu-Arg (ELR) tripeptide motif. IL-8 circulates as a monomer, homodimer,
and heterodimer with CXCL4/PF4. The monomer is considered the most bio-active,
while the heterodimer can potentiate PF4 activity. IL-8 oligomerization is
modulated by its interactions with matrix and cell surface glycosaminoglycans
(GAGs). Mature human IL-8 shares 65-69% amino acid (aa) identity with canine,
feline, and porcine IL-8. There is no IL-8 gene counterpart in rodent.
Multiple isoforms of IL-8 are generated through both
alternative splicing and differential proteolytic cleavage. In humans,
alternative splicing generates an iso-form with an eleven aa substitution at
the C-terminus. Proteolytic processing results in N-terminal truncation of IL-8
and is likely a cell-specific event. For example, fibroblasts and endothelial
cells generate the 1-77 form by cleaving IL-8 following Glu21, while monocytes
and lymphocytes generate the 6-77 form by cleaving following Leu25. These
truncated forms generally show increased bioactivity, particularly through the
CXCR1 receptor. IL-8 can also undergo citrullination on Arg27 of the precursor,
a modification that increases its half-life and ability to induce leukocytosis.
A wide variety of cells secrete IL-8 including monocytes and neutrophils, fibroblasts
and keratinocytes, mast cells, visceral smooth muscle cells, dendritic cells,
type II great alveolar cells, and endothelial cells.
IL-8 bioactivity is mediated through two G-protein-coupled
receptors, termed CXCR1/IL-8 RA and CXCR2/IL-8 RB. CXCR1 is 45-50 kDa in size
and is used almost exclusively by IL-8. CXCR2 is 35-40 kDa in size and is used
by nearly all CXC chemokines. Both CXCR1 and CXCR2 constitutively associate
into functional homodimers. They can also heterodimerize, but these complexes
dissociate following IL-8 binding. CXCR2 responds to low concentrations of IL-8
and is principally associated with chemotaxis and MMP-9 release. CXCR1, in
contrast, responds to high concentrations of IL-8 and is associated with
respiratory burst and phospholipase D2 activation. Thus, CXCR2 ligation induces
leukocyte adhesion to activated vascular endothelium and migration to sites of
inflammation, while CXCR1 ligation primes neutrophil antimicrobial activity.
IL-8 can also form a complex with Serpin A1/alpha-1 Antitrypsin, and this
prevents IL-8 interaction with CXCR1.
In addition to its pro-inflammatory effects, IL-8 is
involved in angiogenesis and the pathogenesis of atherosclerosis and cancer. It
induces VEGF expression in vascular endothelial cells and functions as an
autocrine factor for EC growth and angiogenesis. It is upregulated in
atherosclerotic lesions and is elevated in the serum and cerebrospinal fluid
following myocardial infarction. In cancer, IL-8 promotes
epithelial-mesenchymal transition as well as tumor cell invasiveness and
PRODUCT AVAILABILITY: Update Regarding the Evolving COVID-19 Situation
Bio-Techne appreciates the critical role that you and our products and services play in research efforts to further scientific innovation and discovery. We are continually assessing our manufacturing and supplier capabilities during the COVID-19 situation and are implementing precautionary measures to ensure uninterrupted supply of products and services. Currently, and as we abide by local shelter in place orders across the world, we are fully operational and do not anticipate any material supply disruptions across our Bio-Techne brands and product lines. As the situation evolves, our goal is to utilize preventive measures to reduce the threat that COVID-19 poses to our ability to meet the needs of our customers globally.