Anti-Oncostatin M (OSM, Oncostatin-M)

Oncostatin M (OSM) is a cytokine originally isolated from medium conditioned by PMA-treated U-937 human histiocytic leukemia cells based on its ability to inhibit growth of A375 melanoma cells. The human OSM cDNA encodes a 252aa pre-pro-OSM polypeptide with a 25 residue hydrophobic signal peptide and a hydrophilic C-terminal domain that are proteolytically processed to generate the 196 residue mature form of OSM. Although both mature and pro-OSM are equally active in radio-receptor assays, the mature OSM is 5-60 -fold more active in growth inhibition assays. Thus, proteolytic processing of the pro-OSM peptide may be important in regulating the activities of OSM. OSM is a pleiotropic cytokine that initiates its biological activities by binding to specific cell surface receptors. The biological activity of human OSM is mediated either b y the LIF/OSM receptor complex composed of gp130 and LIF Ra or by a human OSM specific receptor composed of gp130 and OSM Ra. The gp130, a signal transducing component (B subunit) of the IL-6, LIF and CNTF receptor complexes, was identified as a low-affinity OSM receptor that does not transduce OSM signals. The low affinity LIF receptor has been identified to be a component of a high-affinity OSM receptor that will transduce OSM signals. Besides its growth inhibitory activities on human A375 melanoma and mouse M1 myeloid leukemic cells, as well as on other solid tumor cells, OSM also has growth stimulatory activities on normal fibroblasts, AIDS-Kaposi's sarcoma cells, and a human erythroleukemia cell line, TF-1. Other OSM-mediated activities reported to date include: stimulation of plasminogen activator activity in cultured bovine aortic endothelial cells, regulation of IL-6 expression in human endothelial cells, and stimulation of LDL uptake and up-regulation of cell surface LDL receptors in HepG2 cells. Applications: Suitable for use in Direct ELISA, Flow Cytometry and Neutralization. Other applications have not been tested. Recommended Dilution: Flow Cytometry: 2.5ug labels 10e6 human monocyte-derived dendritic cells fixed with paraformaldehyde and permeabilized with saponin., Neutralization: 0.3-1.5ug/ml in the presence of 2ng/ml recombinant human Oncostatin M. , Optimal dilutions to be determined by the researcher. Storage and Stability: Lyophilized and reconstituted products are stable for 12 months after receipt at -20°C. Reconstitute with sterile PBS. Aliquot to avoid repeated freezing and thawing. Store at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.