Recombinant Human IL-9 (I-379-50ug)

Interleukin-9 (IL-9), also known as P40, is an immunoregulatory cytokine produced by IL-2 activated Th2 lymphocytes (1). This cytokine stimulates cell proliferation and prevents apoptosis. IL-9 functions through the IL-9 receptor (IL-9R), which activates different signal transducer and activator (STAT) proteins and thus connects this cytokine to various biological processes (2). It enhances the proliferation of T lymphocytes, mast cells, erthroid precursor cells and megakaryoblastic leukemia cell lines. Th2 cells have historically been thought to be the source of IL-9. However, recent data suggest the existence of a Th2-related cell type that is characterized by the secretion of IL-9 and IL-10 (3). These so-called Th9 cells can differentiate from Th2 cells in the presence of TGF-β, or they can differentiate from a naïve CD4 cell with a combination of IL-4 and TGF-β. IL-9 plays a role in the complex pathogenesis of bronchial hyperresponsiveness as a risk factor for asthma (4). Over-expression of IL-9 has been implicated in the pathogenesis of anaplastic lymphoma and Hodgkin's disease (5).