A T cell derived growth factor.

Interleukin-9 was first identified as a T cell derived growth factor. High affinity receptors for IL-9 are located on a variety of hematopoietic cells including T cells and macrophages.

Interleukin-9 was first identified as a T cell derived growth factor. High affinity receptors for IL-9 are located on a variety of hematopoietic cells including T cells and macrophages. There is high sequence homology between mouse and human IL-9. Overall sequence homology between human and mouse IL-9 cDNAs is 56% and 67% identity at the amino acid and nucleotide levels, respectively. MO7e cells are responsive to both mouse and human IL-9, while only mouse IL-9 can stimulate mouse P40-responsive cell lines. Mouse IL-9 enhances erythroid burst formation by normal mouse bone marrow cells. In addition, mouse IL-9 induces day 15 fetal thymocyte proliferation in the presence of IL-2 and enhances the mast cell growth elicited by IL-3 or IL-4. Mouse IL-9 also supports the growth of certain helper T cell clones. Human IL-9 supports erythroid colony formation and synergizes with IL-4 in the production of IgE and IgG.

Lyophilized from a 0.2 μm filtered solution in phosphate buffered saline containing 0.5 mg bovine serum albumin

The biological activity is measured in a cell proliferation assay using the mouse cell line TS1.