Interleukin-9 (IL-9), also known as P40 and MEA (mast cell growth-enhancing activity), is a 30-40 kDa glycosylated member of a cytokine family that includes Interleukins-2, -4, -7, -15, and -21. These proteins utilize heteromeric receptors containing the Common gamma chain ( gamma c) in addition to ligand-specific subunits. IL-9 interacts selectively with IL-9 R which then associates with gamma c to form the functional receptor complex. IL‑9 contributes to allergic inflammation, autoimmunity-induced inflammation, parasite clearance from the GI tract, and Treg-mediated immune suppression (1, 2). It enhances the expansion and recruitment of mast cells and eosinophils as well as the production of IgE and Th2 cytokines (3‑6). It is required for anaphylactic responses to ingested allergens but not to systemic allergens (7). IL-9 plays multiple roles in the development and function of subsets within the CD4+ T cell lineage (8). It is expressed by activated Th9, Th17, Treg, and Th2 cells (3, 9‑12). IL-9 acts as an autocrine growth and activation factor for Th17, Treg, and mast cells (3, 11, 13). It also can inhibit immune responses by enhancing the suppressive properties of Treg and by recruiting immune-suppressive mast cells to sites of inflammation (11, 12). Mature rat IL-9 shares 58% and 74% amino acid sequence identity with human and mouse IL-9, respectively.
Recombinant protein corresponding to Gln19-Ala144 from rat interleukin-9, expressed in NS0 cells.
Molecular Mass:The mature recombinant rat IL-9, generated by proteolytic removal of the signal peptide region, is a monomer protein. Based on N-terminal amino acid sequencing, the recombinant rat IL-9 starts at Gln 19. It has a calculated molecular mass of 14.1 kD. As a result of glycosylation, the recombinant monomer is heterogeneous and it migrates as an approximately 30-35 kD protein in SDS-PAGE under reducing conditions.
Biological Activity:Measured in a cell proliferation assay using TS1 mouse helper T cells, the ED50 for this effect is 3-15ng/ml
Storage and Stability:Lyophilized and reconstituted products are stable for 6 months after receipt at -20°C. Reconstitute with sterile PBS containing 0.1% HSA or BSA. 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.
