• CD4/helper T cells;
  • memory;
  • T-cell receptor;
  • T cells;
  • vaccines


The initiation of a T-cell response begins with the interaction of an individual T-cell clone with its cognate antigen presented by MHC. Although the strength of the T-cell receptor (TCR) –antigen–MHC (TCR-pMHC) interaction plays an important and obvious role in the recruitment of T cells into the immune response, evidence in recent years has suggested that the strength of this initial interaction can influence various other aspects of the fate of an individual T-cell clone and its daughter cells. In this review, we will describe differences in the way CD4+ and CD8+ T cells incorporate antigen-driven differentiation and survival signals during the response to acute infection. Furthermore, we will discuss increasing evidence that the quality and/or quantity of the initial TCR-pMHC interaction can drive the differentiation and long-term survival of T helper type 1 memory populations.