Structure and Regulation of the Genes Encoding Interleukin-2 and its Receptor

Abstract

The immune system requires a mechanism which ensures the selective clonal expansion of antigen-stimulated lyphocytes. Interleukin-2 (IL-2), a lymphokine that is produced by activated helper T cells play a key role in the proliferation of T cell subsets by virtue of the interaction with a specific cell surface receptor (1, 2). As the expression of both IL-2 and IL-2 receptor requires the activation of T cells by antigen, the IL-2:receptor system appears to guarantee the clonal expansion of the antigen specific T cells. IL-2 also seems to be involved in the mitogenic response of thymocytes (3), in augmenting natural killer cell activity (4), in the generation of cytotoxic T cells (5) and in the induction of other lymphokines such as γ-interferon (6). More recently, there has been evidence for the involvement of IL-2 (per se in the stimulation of B-cell growth (7) and induction of its own receptor (8). Such IL-2 specific signals may be delivere via interaction of the ligand to a single receptor.