Detection of CD25/IL-2 R alpha in Human PBMCs by Flow Cytometry. Human peripheral blood mononuclear cells (PBMCs) treated with 20 ng/mL Recombinant Human IL‑2 (Catalog # 202-IL) and 10 ng/mL Recombinant Human TGF‑ beta 1 (Catalog # 240-B) for 2 days were stained with Mouse Anti-Human CD4 APC‑conjugated Monoclonal Antibody (Catalog # FAB3791A) and either (A) Mouse Anti-Human CD25/IL-2 R alpha Alexa Fluor® 488‑conjugated Monoclonal Antibody (Catalog # FAB1020G) or (B) Mouse IgG2A Alexa Fluor 488 Isotype Control (Catalog # IC003G). View our protocol for Staining Membrane-associated Proteins.
Preparation and Storage
The product is shipped with polar packs. Upon receipt, store it immediately at the temperature recommended below.
Stability & Storage
Protect from light. Do not freeze.
12 months from date of receipt, 2 to 8 °C as supplied.
Background: CD25/IL-2 R alpha
Human CD25, also known as IL-2 receptor alpha (IL-2 R alpha ) and asTac antigen, was initially identified as a 55 kDa membrane glycoprotein that is capable of binding IL‑2. The IL-2 R alpha cDNA encodes a 272 amino acid residue precursor Type I membrane protein with a 21 residue signal peptide, a 219 residue extracellular region, a 19 residue transmembrane region and a 13 residue cytoplasmic domain. IL-2 R alpha lacks structural features characteristic of members of the cytokine receptor superfamily. By itself, IL-2 R alpha binds IL-2 with low affinity. However, when IL-2 R alpha is associated with the IL-2 receptor beta and gamma chains, a high affinity heterotrimeric receptor complex that transduces IL-2 signals is formed. Soluble forms of many cytokine receptors have been reported, and a soluble form of IL-2 R alpha (IL-2 sR alpha ) appears in serum, concomitant with its increased expression on cells. The function of the soluble IL-2 R alpha is unclear. Increased levels of IL-2 sR alpha in biological fluids reportedly correlate with increased T and B cell activation and immune system activation. Increased serum concentration of IL-2 sR alpha has been observed in patients with a variety of inflammatory conditions and in the course of some leukemias and lymphomas.