Animal-Free IL-33 Protein, Mouse (His)

The IL-33 Protein, a cytokine, binds to and signals through the IL1RL1/ST2 receptor, activating NF-kappa-B and MAPK signaling pathways in target cells. It is implicated in the maturation of Th2 cells, inducing the secretion of T-helper type 2-associated cytokines. Furthermore, IL-33 is involved in the activation of mast cells, basophils, eosinophils, and natural killer cells, acting as an enhancer of the polarization of alternatively activated macrophages. It serves as a chemoattractant for Th2 cells and may function as an 'alarmin,' amplifying immune responses during tissue injury. Notably, it induces rapid UCP2-dependent mitochondrial rewiring, attenuating the generation of reactive oxygen species and preserving the integrity of the Krebs cycle required for the persistent production of itaconate, leading to GATA3-dependent differentiation of inflammation-resolving alternatively activated macrophages. In quiescent endothelia, the uncleaved form of IL-33 is constitutively and abundantly expressed, acting as a chromatin-associated nuclear factor with transcriptional repressor properties, potentially sequestering nuclear NF-kappaB/RELA and lowering the expression of its targets. This form is rapidly lost upon angiogenic or pro-inflammatory activation.