Transition of T Cells from Effector to Memory Phase

CD8 T cells play a pivotal role in our defense against viruses and intracellular bacteria. A productive CD8 T cell response requires the generation of a large number of effector cells in order to clear the infection. Most of these cells will die following the clearance of a pathogen, while a small fraction of them will survive and mature into long-lived memory cells that provide enhanced protection against future encounters with the same pathogen. What determines the eventual fate of these effector CD8 T cells has been a long-standing question. In this article, we summarize recent advances in understanding how pathogen-specific CD8 T cells transition from the effector to memory phase by focusing on the identification of effector and memory precursors, the models that help to explain this differentiation process, and the cytokine signaling and genetic pathways that influence these cell fate decisions.