Figure 2.

The effect of IL-7/15 on memory CD8 T cell epigenetic programs. (A) IL-7/15-mediated signaling and epigenetic propagation during homeostatic proliferation. IL-7 and IL-15 are expressed by hematopoietic and non-hematopoietic cells resulting in survival and proliferation of memory CD8 T cells. During memory CD8 T cell homeostatic proliferation, effector-associated programs, including IFNg, are maintained over several rounds of cell division while other programs such as CCR7 remain plastic during cell division. (B) Hypothetical model for selective modification of epigenetic programs during memory T cell self-renewal. Following IL-7 and IL-15 binding to their perspective receptors, activated JAK1 and JAK3 signaling proteins phosphorylate different members of STAT family. Activated STATs may induce or inhibit expression of key epigenetic enzymes, including DNA methyl transferases (DNMTs) and dioxygeneases, that result in de novo DNA methylation, maintenance, or demethylation of regulatory regions at target genes.