Intercellular adhesion molecule-1-dependent stable interactions between T cells and dendritic cells determine CD8+ T cell memory

The importance of prolonged binding to antigen-presenting cells for T cell fate decisions

How critical is it for T cells to stably arrest on antigen-presenting cells? In this issue of Immunity, Scholer et al. (2008) demonstrate profound effector and memory defects for CD8(+) T cells encountering "nonsticky" antigen-presenting cells lacking intercellular adhesion molecule-1.

Dendritic cells: driving the differentiation programme of T cells in viral infections

Protective immunity against viral pathogens depends on the generation and maintenance of a small population of memory CD8(+) T cells. Successful memory cell generation begins with early interactions between naïve T cell and dendritic cells (DCs) within the inflammatory milieu of the secondary lymphoid tissues. Recent insights into the role of different populations of DCs, and kinetics of antigen presentation, during viral infections have helped to understand how DCs can shape the immune response. Here, we review the recent progress that has been made towards defining how specific DC subsets drive effector CD8(+) T-cell expansion and differentiation into memory cells. Further, we endeavour to examine how the molecular signals imparted by DCs coordinate to generate protective CD8(+) T-cell immunity.