IL-2 Receptor - Discovery and Characterization

Discovery and Characterization

The IL-2 receptor (IL-2R) was the first interleukin receptor to be described and characterized by Kendall Smith and his team at Dartmouth Medical School. It was found to have a high affinity binding site and is expressed by antigen-activated T lymphocytes (T cells). Radiolabeled IL-2 concentrations found to saturate these sites (e.g. 1-100 pM) were identical to those determined to promote T cell proliferation. Subsequently, the three distinct receptor chains, termed alpha (α), beta (β) and gamma (γ) were identified. The high affinity of IL-2 binding is created by a rapid association rate (k = 107/M/s) contributed by the alpha chain, and a relatively slow dissociation rate (k' = 10−4/s) contributed by the beta and gamma chains.