Recombinant Rhesus Macaque Interleukin-4 protein (IL4) (Active)

IL-4 is a pleiotropic cytokine central to Th2 polarization, B-cell class switching, and alternative macrophage activation, making a well-characterized rhesus macaque ortholog essential for translational immunology in nonhuman primate models. This tag-free recombinant protein, encompassing the full-length mature sequence (residues 25–153) produced in *E. coli*, demonstrates potent bioactivity with an ED₅₀ below 1.0 ng/mL in a TF-1 cell proliferation assay, corresponding to a specific activity exceeding 1.0 × 10⁶ IU/mg — providing a reliable basis for dose-dependent functional studies including T-cell and B-cell activation, Th2 differentiation, and JAK/STAT signaling pathway analysis. Endotoxin levels below 1.0 EU/μg minimize LPS-driven artifacts that can confound immune cell readouts, which supports use in sensitive primary cell cultures and *in vivo* primate studies of inflammation or infection. Purity exceeding 96% by SDS-PAGE further qualifies this protein as a reference standard in cytokine detection assays and as a positive control for antibody validation by ELISA or Western blot.