T_(TN) cells proliferate, differentiate, and self-renew on antigen encounter. (A) Diagram summarizing the TCR transfer model: purified T-cell subsets were bCD3/CD28-stimulated and LV-transduced in the presence of IL-7 and IL-15, to express a TCR recognizing the HLA-A2–restricted WT1_126-134 peptide. Transduced cells were stimulated with irradiated T2 cells pulsed with WT1_126-134 peptide and tested for: (B) proliferation expressed as CFSE dilution, evaluated 5 days after stimulation; (C) expansion, expressed as absolute counts (left panel) and fold increase at day 16 (right panel); (D) memory subset compositions (based on CD45RA and CD62L expression) before and after transduction, and after antigen-specific stimulation. Stacked histograms represent mean values ± SEM of memory subset composition from 3 independent donors. (E) Representative FACS plots of the cytokine secretion profile of T_(TN) cells gated on CD45RA⁺CD62L⁺ and CD45RA^+/−CD62L⁻ CD8⁺ lymphocytes, and (F) mean histograms from 3 independent donors. UT indicates untransduced cells; and LV⁺, TCR-transduced cells.