Control of Homeostasis of CD8 ⁺ Memory T Cells by Opposing Cytokines

Abstract

Memory T cells maintain their numbers for long periods after antigen exposure. Here we show that CD8+ T cells of memory phenotype divide slowly in animals. This division requires interleukin-15 and is markedly increased by inhibition of interleukin-2 (IL-2). Therefore, the numbers of CD8+ memory T cells in animals are controlled by a balance between IL-15 and IL-2.