Impaired homeostatic proliferation of c-myc^+/– CD8 T cells after adoptive transfer into sublethally irradiated recipients. Total splenocytes from wt (Thy1.1⁺) and c-myc⁺/– (Thy1.2⁺) littermates were CFSE labeled and adoptively cotransferred into sublethally irradiated wt (A-B) or c-myc⁺/– (D) recipients (Thy1.1⁺Thy1.2⁺). Spleen and LN cells were removed after 4, 7, and 17 days, pooled, and stained for CD4, CD8, Thy1.1, and Thy1.2. Histograms show representative CFSE profiles from donor CD8 (A,D) and CD4 (B) T-cell populations gated on the appropriate Thy1 marker. Upper numbers in histograms indicate the percentage of cells in the undivided peak; lower bold numbers indicate population doublings. Numbers were calculated according to Wells and colleagues.⁴³  Bar graph represents the ratio of the percentage of wt versus c-myc^+/– CD8 T cells. The results shown are representative of 2 experiments, and 1 to 3 mice per group were analyzed at each time point. (C) CD44^low and CD44^high CD8 T cells were sorted from wt (Thy1.2⁺) and c-myc⁺/– (Thy1.1⁺Thy1.2⁺) mice, CFSE labeled, and adoptively cotransferred into sublethally irradiated B6.PL (Thy1.1⁺) recipients. Splenocytes from wt and c-myc⁺/– littermates infected with LCMV 50 days before were CFSE labeled and adoptively transferred into sublethally irradiated wt recipients. Histograms show representative CFSE profiles from donor CD44^low, CD44^high, and tetramer⁺ CD8 T-cell populations gated on the appropriate Thy1 marker 6 or 7 days after transfer. Bar graph represents the ratio of the cell expansion of wt versus c-myc⁺/– cells.