Recombinant Human IL-1RL1 (ST2)-Fc Chimera (carrier-free)
Description
IL-1RL1/ST2 was initially identified in stimulated Balc3T3 cells and is encoded by the IL-1RL1 gene that produces different isoforms by alternative splicing. In humans, four isoforms have been described: a membrane attached ST2L isoform and a soluble protein (sST2/ IL1RL-a) that lacks the transmembrane and cytoplasmic domains, which acts as a natural antagonist of IL-33. The other splice variants are ST2V and ST2LV. ST2V lacks the third immunoglobulin motif and C-terminal portion of ST2 and is mainly present in the gut whereas ST2LV does not have the transmembrane domain. The membrane isoform of ST2L (IL-1RL1) associates with IL-1 receptor accessory proteins (IL-1RAcP) to form the IL-33R. The interaction of IL-33 to its receptor activates NF-kB and MAP kinases and induces Th2 cytokines from in vitro polarized Th2 cells. In vivo, IL-33 promotes the expression of IL-4, IL-5, and IL-13. IL-33 acts as an inflammatory cytokine in Th2-type immune responses during asthma and atopic dermatitis. It is host-protective against helminth infections and reduces atherosclerosis by promoting Th2-type immune responses. Human aortic, coronary artery, and heart microvascular endothelial cells express mRNA for ST2L and sST2 isoforms, acting as a source for sST2 proteins. In fact, sST2 is considered as a prognostic biomarker in myocardial infarction and heart failure. In addition, sST2 has been associated with other human diseases including asthma with acute exacerbation, eosinophilic pneumonia, sepsis and trauma, and exacerbated idiopathic pulmonary fibrosis.