Figure 4 |. Strategies that might be used to preserve or to confer stemness to T cells.

a | The process of arresting T cell development is shown. Differentiation of primed naive T (T_N) cells can be suppressed using cytokines, such as interleukin-21 (IL-21), or by using small molecules targeting key metabolic and developmental pathways. b | Two step reprogramming of terminally differentiated effector T (T_EFF) cells through an induced pluripotent stem (iPS) cell intermediate is shown. T_EFF cells are reprogrammed to generate iPS cells by ectopic co-expression of the Yamanaka factors, and OCT4, sex determining region Y (SRY) BOX 2 (SOX2) and Kruppel-like factor 4 (KLF4) with or without MYC or by forced expression of the microRNA (miRNA) cluster 302–367. iPS cells can be subsequently redifferentiated into T_N cells through the induction of NOTCH signalling. c | Direct reprogramming of T_EFF into T_N or memory stem (T_SCM) cells by enforced expression of T_N or T_SCM-associated transcription factors or miRNAs is shown. GSK3β, glycogen synthase 3β; T_CM, central memory; T_EM, effector memory.