Antigen-inexperienced memory CD8+ T cells: where they come from and why we need them

In this Opinion article, the authors discuss our growing appreciation of antigen-inexperienced memory T cell subsets. They focus on the development and functions of the recently described 'virtual memory' and 'innate memory' CD8+T cell populations, and propose a unified nomenclature for these subsets. Memory-phenotype CD8+ T cells exist in substantial numbers within hosts that have not been exposed to either foreign antigen or overt lymphopenia....