IL 33 Human

IL-33 is an 18 kDa protein composed of 169 amino acid residues . It exists in both an un-cleaved (full-length) and a cleaved form, although the proteins responsible for IL-33 maturation are still under investigation . The recombinant form of human IL-33 is optimized for use in cell culture, differentiation studies, and functional assays .

When IL-33 binds to its receptor, ST2L (also known as IL1RL1), it activates mast cells and innate lymphoid cells, leading to the production of IL-5 and IL-13 . These cytokines are essential for allergic inflammation and type-2 innate immunity . IL-33 also acts as an alarm signal, alerting the immune system to cellular damage .

IL-33 is involved in regulating type 2-associated innate immune responses . It enhances the activation of Tʜ2 cells, mast cells, and eosinophils, sustaining the humoral response and contributing to adverse Tʜ2 reactions such as dermatitis, asthma, and allergies . Additionally, IL-33 is expressed in blood epithelium and smooth muscle, playing a role in bone protection .

Recombinant human IL-33 is used in various applications, including:

• Tʜ2 cell activation and maintenance
• Investigation of intracellular signaling of IL-1 family and apoptotic/necrotic pathways
• In vitro inhibition of osteoclast differentiation

Recombinant human IL-33 is typically lyophilized and should be reconstituted in sterile water to a concentration of not less than 200 μg/mL . It is stable for 12 months when stored at -20°C in its lyophilized state and for one month under sterile conditions after reconstitution . It is important to avoid repeated freeze/thaw cycles to maintain its stability .