This is an unconjugated, non-therapeutic recombinant analog of daclizumab, a humanized IgG1 monoclonal antibody directed against IL2RA (CD25), the alpha chain of the high-affinity interleukin-2 receptor. It is manufactured for research use only and is not the clinical drug, not for human or veterinary use. The molecule reproduces the antigen-binding specificity of the originator, making it a convenient tool for laboratory studies of CD25 biology, IL-2 signaling, and regulatory T-cell dynamics. Typical applications include use as a well-characterized binding reference, a positive or isotype-matched control in assay development, a capture or detection reagent, and a benchmark in comparability and biosimilarity workflows. It is supplied at research grade with low endotoxin (<1 EU/mg, with an ultra-low <0.5 EU/mg option) and is available in bulk milligram-to-gram quantities to support in-vitro assays, ADCC/ADC development pipelines, and preclinical model work. As an anti-CD25 analog it is useful for probing IL-2 pathway modulation and immune-tolerance mechanisms in controlled experimental settings.
IL2RA (CD25, Tac antigen) encodes the alpha subunit of the interleukin-2 receptor. Alone it binds IL-2 with low affinity, but when it assembles with the beta (IL2RB/CD122) and common gamma (IL2RG/CD132) chains it forms the high-affinity trimeric receptor that drives downstream JAK/STAT5, PI3K, and MAPK signaling. CD25 is expressed at high, constitutive levels on CD4+CD25+FoxP3+ regulatory T cells, where IL-2 signaling is essential for their development, survival, and suppressive function, and it is transiently upregulated on conventional T and B lymphocytes upon activation. Because of this expression pattern, CD25 is a central node in T-cell activation, clonal expansion, and peripheral immune tolerance, and it serves as an activation marker and a therapeutic target for dampening pathogenic lymphocyte responses.