Gene-expression profile of Id2+ versus Id2KO KLRG1lo cells during infection

CD8+ T cells play a crucial role in the clearance of intracellular pathogens through the generation of cytotoxic effector cells that eliminate infected cells and long-lived memory cells that provide enhanced protection against reinfection. We have previously shown that the inhibitor of E protein transcription factors, Id2, is necessary for accumulation of effector and memory CD8+ T cells during infection. Here we show that CD8+ T cells lacking Id2 did not generate a robust terminally-differentiated KLRG1hi effector population, but displayed a cell-surface phenotype and cytokine profile consistent with memory precursors, raising the question as to whether loss of Id2 impairs the differentiation and/or survival of effector-memory cells. We found that deletion of Bim rescued Id2-deficient CD8+ cell survival during infection. However, the dramatic reduction in KLRG1hi cells caused by loss of Id2 remained in the absence of Bim, such that Id2/Bim double-deficient cells form an exclusively KLRG1loCD127hi memory precursor population. Thus we describe a role for Id2 in both the survival and differentation of normal CD8+ effector and memory populations.

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Knell J, Best JA, Lind NA, Yang E, D'Cruz LM, Goldrath AW