IL-15 signaling promotes adoptive effector T-cell survival and memory formation in irradiation-induced lymphopenia

Background Lymphopenia promotes naive T-cell homeostatic proliferation and adoptive effector T-cell survival and memory formation. IL-7 plays a critical role in homeostatic proliferation, survival and memory formation of naive T-cells in lymphopenia, and its underlying molecular mechanism has also been well studied. However, the mechanism for adoptively transferred effector T-cell survival and memory formation is not fully understood. Here, we transferred in vitro-activated transgenic OT-I CD8+ effector T-cells into irradiation (600 rads)-induced lymphopenic C57BL/6, IL-7 knockout (KO) and IL-15 KO mice, and investigated the survival and memory formation of transferred T-cells in lymphopenia.