Interleukin-9 (IL-9) is a cytokine that plays a crucial role in the regulation of hematopoiesis and immune responses. It is produced by various cell types, including T-helper cells, mast cells, and regulatory T cells. IL-9 has been shown to enhance the growth of human mast cells and megakaryoblastic leukemic cells, as well as murine helper T-cell clones .
IL-9 is a glycoprotein with a molecular weight ranging from 32 to 39 kDa. The human recombinant IL-9 produced in Sf9 Baculovirus cells is a single, glycosylated polypeptide chain containing 132 amino acids (19-144 aa) and having a molecular mass of approximately 14.9 kDa . The recombinant protein is fused to a 6 amino acid His tag at the C-terminus and purified using proprietary chromatographic techniques .
IL-9 acts as a regulator of hematopoiesis by stimulating cell proliferation and preventing apoptosis. It has been shown to enhance the growth of human mast cells and megakaryoblastic leukemic cells . The biological activity of IL-9 is determined by its ability to stimulate cell proliferation in a cell proliferation assay using MO7e human megakaryocytic leukemic cells. The effective dose (ED50) for this effect is less than or equal to 0.3 ng/ml .
The IL-9 protein solution is formulated in phosphate-buffered saline (pH 7.4) with 10% glycerol. For short-term storage (2-4 weeks), it is recommended to store the solution at 4°C. For long-term storage, the solution should be frozen at -20°C, and a carrier protein (0.1% HSA or BSA) should be added to prevent degradation. It is important to avoid multiple freeze-thaw cycles to maintain the protein’s stability .
IL-9 is primarily used in laboratory research to study its role in hematopoiesis and immune responses. It is not intended for use as a drug, agricultural or pesticidal product, food additive, or household chemical . Researchers utilize IL-9 to investigate its effects on various cell types and its potential therapeutic applications in diseases such as asthma, allergies, and certain types of cancer.