Fig. 2

CD4⁺ T cell help supports formation of CD8⁺ T_CM and T_EM cells. a–f Mice (n = 4 per group) received Help or No Help vaccine on days 0, 3, and 6 and were analyzed on day 50 or 120. a, c, e Representative flow cytometric plots indicating within the H-2D^b/E7_49-57 tetramer⁺ CD8⁺ population frequencies of cells with an effector memory T (T_EM) phenotype (CD44⁺CD62L⁻) or central memory T (T_CM) phenotype (CD44⁺CD62L⁺), as determined in draining lymph node (dLN) (a), spleen (c), and blood (e). b, d, f Quantification of frequencies of E7-specific CD44⁺CD62^- T_EM and CD44⁺CD62⁺ T_CM phenotype CD8⁺ T cells determined in dLN (b), spleen (d), and blood (f). g, h Cell surface expression of IL2RB (CD122) as determined by flow cytometry on E7-specific CD8⁺ T_CM and T_EM cell subsets in spleen at day 50. g Primary data. Filled grey: No Help; open black line: Help. Dotted line: unstained control. h Quantification of mean fluorescence intensity (MFI) for n = 3. i Experimental set up. CD45.1⁺ OT-I T cells were adoptively transferred into CD45.2⁺ recipient mice (n = 5 per group) that 1 day later received OVA-encoding Help or No Help vaccine. From day 20 onwards, indicated groups were treated with isotype control antibody or neutralizing αIL-15 antibody every 5 days until day 50. j, k Frequencies of CD45.1⁺ T_CM cells (j) and T_EM cells (k) were determined at day 100 in dLN and spleen. Data in this figure are from one experiment representative of two experiments. Error bars indicate SD, *p < 0.05, **p < 0.01, ***p < 0.001 (unpaired two-tailed Student’s t test). Source data are provided as a Source Data file.