IL-4 Rat monoclonal antibody

IL-4 is produced by T cells, NK T cells, γδ cells, and mast cells. Target cells include B cells, T cells, and macrophages. IL-4 induces the polarization of naïve helper T cells into the TH2 phenotype. IL-4 also promotes B cell proliferation, antibody class switching and the production other TH2 cytokines including IL-5 and IL-9. IL-4 induced TH2 polarization is important in developing humoral immunity against extracellular pathogens and is involved in the development of allergy and asthma. IL-4 binds to two distinct receptors, the Type I receptor and Type II receptor. Type I receptor is a heterodimer consisting of IL-4Rα chain and the common gamma chain, γc. Type II receptor, which is shared with IL-13, is a heterodimer of IL-4Rα and IL-13Rα1. Signaling initiated via Type I receptor results in the activation of Jak1/Stat6, Jak3 and the PI3K/Akt pathways. The Type II receptor activates the Jak1/Stat6 and the Tyk2/Stat3 pathways.