IL-4 is a pleiotropic cytokine that regulates diverse T and B cell responses including cell proliferation, survival and gene expression. Produced by mast cells, T cells and bone marrow stromal cells, IL-4 regulates the differentiation of naive CD4+ T cells into helper Th2 cells, characterized by their cytokine-secretion profile that includes secretion of IL-4, IL-5, IL-6, IL-10, and IL-13, which favor a humoral immune response. Another dominant function of IL-4 is the regulation of immunoglobulin class switching to the IgG1 and IgE isotypes. Excessive IL-4 production by Th2 cells has been associated with elevated IgE production and allergy. Recombinant human IL-4 is a 14.9 kDa globular protein containing 129 amino acid residues.
Greater than 98% by SDS-PAGE gel and HPLC analyses.
Endotoxin Level :
Endotoxin level is less than 0.1 ng per μg (1EU/μg).
Biological Activity :
The ED50 as determined by the dose-dependent stimulation of human TF-1 cells is ≤ 0.2 ng/ml, corresponding to a specific activity of ≥ 5 x 106 units/mg.