Lessons from Immunological, Biochemical, and Molecular Pathways of the Activation Mediated by IL-2 and IL-4

Abstract

Publisher Summary This chapter summarizes the data produced over the past few years, focusing on the IL-1/IL-2R system and illustrating the signaling molecules participating in cytokine signal transduction. Several studies have contributed to the delineation of a signaling pathway structured in three independent channels. As a general overview, these three channels serve as major landmarks—Lck-fos/jun (channel l), syk-myc (channel 2), and a pathway leading to actin organization/bcl-2 expression (channel 3). The detailed hierarchical organization of these three channels is presented throughout the chapter. Although the IL-2 receptor has a variety of intracellular signaling molecules, the evidence suggests that a similar heterogeneous group of signal transduction pathways can be used by other cytokine receptors. The chapter also discusses several molecules that are attractive candidates as transducing molecules involved in signaling processes, which mark the difference between signaling through IL-2R and IL-4R. TSlαβγ is the unique cellular model, which is able to proliferate in response to IL-2, IL-4, or IL-9, allows dissecting the pathways used by these lymphokines for signaling. The current challenge is to identify the downstream signal transduction molecules and target the genes that respond to the activation of different kinases.