IL-33 Recombinant Protein

Interleukin-33 (IL-33) is a recently identified member of the IL-1 family of cytokines whose other members include IL-1, IL-1Ra and IL-18 (1,2) . Its receptor has been shown to be ST2, an IL-1 receptor family member that also acts as a negative regulator of TLR-IL-1R signaling (1,3) and IL-1R accessory protein (IL-1RAcP) (4) . Receptor binding of IL-33 activates NF-B and MAP kinases and induces the expression of TH2-associated cytokines such as IL-4, IL-5 and IL-6. Prolonged IL-33 treatment of mice led to the development of eosinophilia, splenomegaly, and severe pathological changes in mucosal organs such as lungs, esophagus and small intestine (2) . Recent experiments have shown that IL-33 can also co-localize with heterochromatin and possesses transcriptional repressor activities, indicating that IL-33 may function as both a proinflammatory cytokine and an intracellular nuclear factor with transcriptional regulatory properties (5) . This recombinant protein represents the cleaved and presumably activated form of IL-33, but has not been tested in any biological assays.

Store in working aliquots at -70˚ C. Avoid freeze/thaw cycles. When working with proteins care should be taken to keep recombinant protein at a cool and stable temperature.

Schmitz J, Owyang A, Oldham E, et al. IL-33, and interleukin-1-like cytokine that signals via the IL-1 receptor-related protein ST2 and induces T helper type 2-associated cytokines. Immunity 2005; 23:479-90.

Brint EK, Xu D, Liu H, et al. ST2 is an inhibitor of interleukin 1 receptor and Toll-like receptor 4 signaling and maintains endotoxin tolerance. Nat. Immunol. 2004; 5:373-9.