Anti-human CD25 mAb (detection), biotin

CD25 is expressed by activated T cells, B cells, and monocytes. Tregs, responsible for regulating immune tolerance, express the highest amounts of CD25. CD25 is the IL-2 receptor α chain, which functions as one subunit of the high-affinity variant of the IL-2 receptor. When cleaved off by proteases, the soluble receptor (sIL-2Rα) is released extracellularly. Soluble CD25 has a low affinity for IL-2 and can function either as a decoy receptor reducing the activity of IL-2 or by enabling trans presentation to cells expressing the dimeric, intermediate-affinity IL-2R. Increased levels of soluble CD25 indicate ongoing immune responses, and therefore CD25 has been investigated as a biomarker for disease. For example, elevated sCD25 levels have been associated with autoimmune disorders, severe COVID-19, and some types of cancer.