Recruitment of Antigen-Specific CD8 + T Cells in Response to Infection Is Markedly Efficient

Preparation for Cell Wars When T cells encounter an infection, they proliferate to create a larger army to fight the invader. The overall magnitude of the T cell response depends on the severity of infection and is determined by the number of T cells of a particular antigen specificity that are initially recruited, as well as the magnitude of the proliferative response. The extent to which these two components contribute to the response is unknown. By using DNA barcoding to track the responses of individual T cells, van Heijst et al. (p. 1265 ) showed that the recruitment of T cells of a particular antigen specificity is similar and nearly complete, but that the extent of the proliferative response differed, and this determined the overall magnitude of the T cell response.