INTERLEUKIN-4 RECEPTOR - SIGNALING MECHANISMS

Achsah Keegan and colleagues consider the signaling mechanisms utilize d by the interleukin 4 (IL-4) receptor and review evidence suggesting that these mechanisms cart account for the known responses of hematopo ietic and non-hematopoietic cells to IL-4. Most of these data have bee n obtained from analyses of the ability of IL-4 to regulate the growth of IL-3-dependent myeloid cell lines. These results have implicated a pathway of activation homologous to that utilized by insulin and insu lin-like growth factor 1 (IGF-1). However, it is possible that the reg ulation of growth responses through the IL-4 receptor (and other recep tors), and the differentiative events elicited in lymphocytes, may not be mediated by the same post-receptor events.