B6-hIL4RA Mouse

Interleukin-4 (IL-4) and its receptor, IL-4R, are pivotal regulators of immune responses and inflammation. The IL4 gene encodes the IL-4 cytokine, a multifunctional protein predominantly secreted by Th2 cells, mast cells, and eosinophils, while the IL4R gene encodes the IL-4 receptor, which is expressed on a variety of immune cells, including B cells, T cells, macrophages, and endothelial cells. IL-4 binds to IL-4R, which exists in two distinct forms: Type I (comprising IL-4Rα and the common γ-chain) and Type II (comprising IL-4Rα and IL-13Rα1) ^[1]. This interaction activates the JAK-STAT signaling pathway, driving Th2 cell differentiation, B cell class switching to IgE, and anti-inflammatory responses. The IL-4/IL-4R signaling axis is critically implicated in allergic diseases such as asthma, atopic dermatitis, and allergic rhinitis, as well as in parasitic infections and certain cancers ^[2-5]. Dysregulation of this pathway underlies various pathological conditions, positioning IL-4R as a promising therapeutic target. For instance, dupilumab, a monoclonal antibody targeting IL-4Rα, has been approved for the treatment of atopic dermatitis, asthma, and chronic rhinosinusitis with nasal polyps, underscoring the therapeutic potential of modulating this pathway ^[6-7].

B6-hIL4RA mice are humanized models generated using gene editing technology by replacing the extracellular domain of the mouse Il4ra with the corresponding human IL4R extracellular domain, while retaining the murine signal peptide. Homozygous B6-hIL4RA mice are viable and fertile. This model is an invaluable tool for studying allergic diseases (e.g., asthma and atopic dermatitis), Th2 immune responses, parasitic infections, tumor immunology, and chronic inflammation. Furthermore, it is a robust preclinical platform for evaluating the efficacy and mechanisms of therapeutic agents targeting the IL-4Rα.