The role of precursor frequency in the differentiation of memory T cells: memory by numbers

Abstract

Immunological memory is considered the hallmark of adaptive, or acquired, immunity. That ability of our immune system to recognize and respond to those pathogens we have encountered before not only typifies acquired immunity but has provided the basis for the most notable of medical interventions: vaccination. Yet, as much as we now know about this process, we are still on the cusp of fully understanding how memory T cells develop, how they are maintained and the importance of memory T-cell heterogeneity. In this review we will primarily focus on our understanding of CD8 T-cell memory generated during acute infections and how precursor frequency influences their development and functional attributes.