Recombinant Human IL13 protein

Interleukin-13 (IL-13) is a pleiotropic Th2 cytokine central to type 2 immune responses, primarily produced by activated CD4+ T cells, mast cells, basophils, and innate lymphoid cells. It plays critical roles in allergic inflammation, tissue remodeling, and host defense against helminth infections by regulating immune cell communication and effector functions. IL-13 signals through a heterodimeric receptor complex comprising IL-13Rα1 and IL-4Rα, activating JAK-STAT pathways (mainly STAT6) to drive gene expression linked to mucus production, smooth muscle hyperreactivity, and fibrosis. Dysregulated IL-13 signaling is implicated in asthma, atopic dermatitis, eosinophilic esophagitis, and fibrotic diseases.

Recombinant IL-13 proteins are engineered using bacterial (e.g., *E. coli*), mammalian, or insect expression systems to preserve native structure and bioactivity. These proteins typically lack post-translational modifications when prokaryotically expressed but retain receptor-binding capacity. They serve as essential tools for *in vitro* studies (e.g., cell differentiation assays), *in vivo* disease modeling, and therapeutic target validation. Notably, IL-13 inhibitors like lebrikizumab and tralokinumab (monoclonal antibodies targeting IL-13 or its receptor) have emerged as biologics for asthma and atopic dermatitis, underscoring the therapeutic relevance of recombinant IL-13 in drug discovery. Researchers also utilize tagged versions (e.g., His, Fc fusions) for purification, detection, or prolonged half-life in experimental settings. Quality assessments include endotoxin testing, receptor-binding ELISAs, and functional assays measuring STAT6 phosphorylation or epithelial cell responses.