CD122 Antibody [5H4] (FITC)

The IL-2 receptor is a complex of three distinct polypeptide chains: (i) the alpha chain which binds IL-2 with low affinity; (ii) the beta chain that binds IL-2 with high affinity; and (iii) the common gamma chain (gammac) that does not bind IL-2. The high affinity receptor complex is an alpha/beta/gamma heterotrimer with a Kd of 1.3 x 10-11 M. In mouse spleen, CD122 is expresed on ~30% of CD8+ cells and all NK cells but <1% of B cells and CD4+ T lymphocytes. In the thymus, its expression is confined to CD4-CD8+ single positive and CD4-CD8- double negative cells. Cytoplasmic regions of the IL-2R beta chain are involved in IL-2-mediated cellular signaling and, via the interaction of IL-2 and its receptor complex, may be involved in the generation and differentiation of T lymphocytes. The monoclonal antibody 5H4 does not block IL-2 binding.