Human IL-2 R beta Antibody

Functional IL-2 receptors can exist in two affinity states on cell surfaces, the high affinity complex consisting of heterotrimers of the alpha, beta, and gamma chains and the intermediate affinity complex comprising heterodimers of the beta and gamma chains. Individual beta chains and alpha chains exhibit low affinity IL-2 binding, and the gamma chain alone does not bind IL-2. In addition to their involvement in IL-2 mediated signal transduction, both the beta chain and gamma chain have been shown to be required for IL-15 mediated signaling. IL-2 R beta is a member of the cytokine receptor superfamily. Human IL-2 R beta cDNA encodes a 551 amino acid (aa) precursor Type I membrane protein with a 26 aa signal peptide, a 214 aa extracellular region, a 25 aa transmembrane region and a 286 aa cytoplasmic domain. A soluble IL-2 R beta has been identified in the culture supernatants of a human lymphoid cell line, YT, that displays IL-2 R beta. Soluble IL-2 R beta binds IL-2 with low affinity and is not an effective IL-2 antagonist on cells displaying the high or intermediate affinity IL-2 signaling receptors. Nevertheless, soluble IL-2 R beta binds IL-15 with sufficient affinity to neutralize IL-15 biological activities.