Interleukin-2 (IL-2) has been described as a factor that promotes the growth and proliferation of human T-cells thus occupying a pivotal role in the generation of the immune response. This proliferation of T lymphocytes is triggered by the interaction of IL-2 with its specific cell surface receptor following T lymphocyte activation. The receptor for IL-2 is composed of at least three distinct polypeptide subunits , the IL-2R alpha, IL-2R beta, and the IL-2R gamma chains giving rise to a 55-65 kD membrane bound protein. Evidence has accumulated that suggests a critical role of IL-2R beta in IL-2 signal transduction. IL-2R coupled tyrosine kinases are believed to play a crucial role in that signal transduction. In addition to the de-novo expression of IL-2R by activated peripheral blood T-cells, a released and fully soluble form of IL-2R (sIL-2R) has been detected. It was shown that sIL-2R is present in vivo, at low levels in the sera of healthy persons and at markedly elevated levels in various pathological conditions like neoplastic disorders.
KristÝn SigurgeirsdˇttirSigr˙n H PÚtursdˇttirGumundur Sig■ˇrssonIngibj÷rg Loftsdˇttir
Sigr˙n H PÚtursdˇttir