Human CCL18 (Chemokine CC Motif Ligand 18), also known as PARC (Pulmonary and Activation-Regulated Chemokine), alternative macrophage activation-associated CC chemokine 1 (AMAC-1), macrophage inflammatory protein-4 (MIP-4), and dendritic cell-derived chemokine 1 (DCCK1), belongs to the Cys-Cys (CC) motif-containing chemokine family. It is an 89aa precursor protein with a 20aa putative signal peptide that is cleaved to generate a 69aa residue mature protein. CCL18 is highly expressed in lung, lymph nodes and placenta. It was initially identified as a chemotactic factor for naive CD4+ T cells and immature dendritic cells, suggesting that it plays an important role in immune responses. It displays strong chemotactic activity for naive CD4+ and CD8+ T cells and nonactivated lymphocytes. It attracts naive T lymphocytes toward dendritic cells and activated macrophages in lymph nodes. CCL18 is mainly induced by Th2 type cytokines, such as IL-4 and IL-13, and inhibited by IFN-g. CCL18 can also facilitate the generation of tolerogenic dendritic cells and adaptive regulatory T cells. Besides its chemotactic effects, CCL18 enhances the proliferation of monocytes and increases cytokine production. Additionally, CCL18 is involved in stimulation of collagen production by fibroblasts. Thus, it may directly contribute to the development of pulmonary fibrosis by stimulating collagen production. CCL18 is an orphan chemokine without any known receptor. Its rodent homolog has not been identified so far. High levels of CCL18 have been detected in various body fluids, such as serum and synovial fluid. CCL18 is dysregulated in a number of pathological conditions. Increased CCL18 in bronchoalveolar lavages and sera has been found to be linked to allergic asthma. CCL18 is able to mediate skin homing of human memory T cells. It was present in skin biopsies of atopic dermatitis patients but not in normal skin. It has been reported that CCL18 serum levels correlate with the disease severity of atopic dermatitis. Elevated CCL18 levels were detected in synovial fluid from rheumatoid arthritis patients, suggesting that it may be involved in the autoimmune and inflammatory process. Additionally, elevated serum CCL18 reflects lung fibrosis activity in systemic sclerosis and could be an early marker of lung function worsening. In patients with chronic obstructive pulmonary diseases, serum CCL18 levels are also elevated and may be useful to track clinical outcomes. Furthermore, recent investigations indicate that CCL18 is a potential valuable diagnostic and prognostic biomarker in coronary artery disease. The CCL18, Human, ELISA, BioAssay™ Kit is a 4.5h solid-phase ELISA designed to measure human CCL18 in cell culture supernates, serum, and plasma. It contains E. coli-expressed recombinant human CCL18 and has been shown to accurately quantitate the recombinant factor. Results obtained using natural human CCL18 showed linear curves that were parallel to the standard curves obtained using the Quantikine kit standards. These results indicate that this kit can be used to determine relative mass values for naturally occurring human CCL18.
Sample Type:Cell culture supernates, serum, and plasma
Intended Use:For the quantitative determination of human CCL18 concentrations in cell culture supernates, serum, and plasma.
Sensitivity:~0.358ng/ml
Range:0.130-0.909ng/ml
Specificity:Human
Test Principle:This assay employs the quantitative sandwich enzyme immunoassay technique. A monoclonal antibody specific for CCL18 has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any CCL18 present is bound by the immobilized antibody. After washing away any unbound substances, an enzyme-linked monoclonal antibody specific for CCL18 is added to the wells. Following a wash to remove any unbound antibody-enzyme reagent, a substrate solution is added to the wells and color develops in proportion to the amount of CCL18 bound in the initial step. The color development is stopped and the intensity of the color is measured.
Kit Components:CCL18 Microplate: 96 well polystyrene microplate (12 strips x 8 wells) coated with a mouse monoclonal antibody against CCL18.
CCL18 Conjugate: 1x21ml of monoclonal antibody against CCL18 conjugated to horseradish peroxidase with preservativesCCL18 Standard: 100ng of recombinant human CCL18 in a buffered protein base with preservatives; lyophilizedAssay Diluent RD1W: 1x11ml of a buffer with preservatives
Calibrator Diluent RD5-55: 2x21ml of a buffered protein base with preservatives
Wash Buffer Concentrate: 1x21ml of a 25-fold concentrated solution of buffered surfactant with preservativesColor Reagent A: 1x12ml of stabilized hydrogen peroxideColor Reagent B: 1x12ml of stabilized chromogen (tetramethylbenzidine)Stop Solution: 1x6ml of 2 N sulfuric acid
Plate Sealers: 4 adhesive strips
Storage and Stability:See Kit Protocol for detailed storage instructions.
