Recombinant Human IL-13 Variant

This lyophilized preparation is stable at 2-4C, but should be kept desiccated at -20C for long term storage. Upon reconstitution, the preparation is stable for up to one week at 2-4C. For maximal stability, apportion the reconstituted preparation into working aliquots and store at -20C to -80C. Avoid repeated freeze/thaw cycles.

The human IL-13 cDNA encodes a 132 amino acid protein containing a proposed 20 amino acid signal peptide. Human IL-13 shares approximately 30% amino acid sequence homology to human IL-4 and the two cytokines exhibit overlapping biological activities. Human IL-13 is produced by activated Th0, Th1-like, Th2-like, and CD8 T cells. Similarly to IL-4, IL-13 has multiple effects on the differentiation and functions of monocytes/macrophages. IL-13 can suppress the cytotoxic functions of monocytes/macrophages. It can also suppress the production of proinflammatory cytokines and upregulate the production of IL-1ra by monocytes/macrophages.

Centrifuge vial prior to opening. Add sterile distilled water or aqueous buffer to a concentration of 0.1-1.0 mg/mL. Further dilutions should be made in appropriate buffered solutions. Stock solutions should be apportioned into working aliquots and stored at <-20C. Further dilutions should be made in appropriate buffered solutions.

Fully biologically active when compared to standard. The ED50 as determined by the dose-dependent proliferation of TF-1 cells was < 1.0 ng/ml.