Fig. 2

Short CD3/CD28 costimulation increases CD4⁺ and CD8⁺ T_SCM frequencies compared with long costimulation. Naïve T cells from healthy donors (n = 6) were cultured for 10 days with short (48 h) (solid black line) or long (solid grey line) costimulation. a, b Frequency of CD4⁺ (a) and CD8⁺ (b) T_SCM cell subset (mean ± SEM). c, d Frequencies of total T_SCM (T_SCM + T_SCM-like) CD4⁺ (c) and CD8⁺ (d) (mean ± SEM). *p < 0.05; **p < 0.01; ***p < 0.001