IL-2 receptors in adult T-cell leukemia: a target for immunotherapy.

The induction of a T-cell immune response to a foreign antigen requires the activation of T-lymphocytes that is initiated by the interaction of the T-cell antigen receptor with antigen presented in the context of products of the major histocompatibility locus and the macrophage-derived interleukin-1. Following this interaction, T cells express the gene encoding the lymphokine interleukin-2 (IL-2) [1,2]. To exert its biological effect, IL-2 must interact with specific high-affinity membrane receptors. Resting T cells do not express IL-2 receptors, but receptors are rapidly expressed on T cells after activation with an antigen or mitogen [3–5]. Thus, the growth factor IL-2 and its receptor are absent in resting T cells, but after activation the genes for both proteins become expressed.