IL-4 Protein, Human (His)

IL-4 Protein is a cytokine of the interleukin-4 family, a glycoprotein with an α-helical structure, and an endogenous agonist of the IL-4 receptor (IL-4R), binding to the IL-4Rα and γc chains. IL-4 Protein was originally called B cell growth factor BSF1 and was described in the supernatant of activated EL-4 thymoma cells to costimulate with subservient concentrations of anti-IgM. IL-4 Protein exerts biological activity through the JAK1/JAK3-STAT6 signaling pathway, and can promote the proliferation of human intestinal mast cells (ED₅₀=100 pg/mL) in coordination with stem cell factor (SCF), enhance the release of histamine, leukotriene C₄, and IL-5 mediated by IgE receptors, inhibit the secretion of IL-8 mRNA and protein by human monocytes stimulated by LPS/TNF-α/IL-1β, and selectively enhance the secretion of IL-6 and inhibit IL-8 by human umbilical vein endothelial cells. Its mechanism of action involves regulating the expression of cell membrane receptors and the activation of downstream transcription factors. It is mainly used in the study of immune regulation mechanisms and targeted therapy of allergic diseases (such as asthma) and tumors (such as malignant pleural mesothelioma), especially the application of IL-4R-targeted cytotoxin fusion proteins (such as IL-4-PE, cpIL-4-PE) in tumor ablation. IL-4 Protein plays an important role in regulating inflammation and immune response. IL-4 Protein induces naive helper T cells to differentiate into Th2 cells. While IL-4 Protein binds to the IL-4 receptor, the IL-4 receptor also binds to another cytokine, IL-13, which may explain the overlapping functions of IL-4 and IL-13^{[1][2][3][4][5]}.