Signaling control of memory T cell generation and function

Memory T cells exhibit low activation thresholds and mediate rapid effector responses when recalled by antigen; contrasting the higher activation threshold, slower responses and predominant IL-2 production by naive T cells. While the sequence of intracellular events coupling the T cell-receptor (TCR) to naive T cell activation is well characterized, biochemical control of memory T cell differentiation and function remains undefined. In this review, we will discuss recent developments in T cell-receptor signal transduction as they pertain to memory T cells, and will discuss how signal dampening may drive memory generation, and more efficient spatial organization of signaling molecules may promote rapid recall responses. (C) 2004 Elsevier Ltd. All rights reserved.