Gene expression differences between low IL2/7- and high IL-2-expanded CD8+ T effectors at day 8 of LCMV Armtrong infection

Here, we reported a novel subset of CD8+ T effectors with transcriptional similarity to central memory CD8+ T cells (Tcm). Such CD8+ T effectors were characterized with abundant surface expression of both Cxcr3 and CD62L and possessed strong stemness. These CD8+ T effectors mainly developed into Tcm in adoptive transfer and exclusively possessed the capacity to generate Tcm in antigen re-stimulation, indicating they functioned to be Tcm precursors. These Cxcr3+CD62L+ Tcm precursors were determined by high expression of T cell transcription factor 1 (TCF-1), which guaranteed CD62L expression by binding to distal enhancers of Sell (gene symbol for CD62L). Cxcr3+CD62L+ Tcm precursors could be massively obtained by expansion of anti-CD3/28 activated CD8+ T cells with low IL-2 plus IL-7, and these in vitro-expanded Cxcr3+CD62L+ Tcm precursors exhibited strong effective in tumor elimination and were better than conventional high IL-2 expanded-CD8+ T effectors for clearance of tumors. Comparative gene expression profiling analysis of RNA-seq data for low IL2/7 or high IL-2 expanded CD8+ T effecotors.