Skip to main content
. 2018 Jun 22;41(6):274–283. doi: 10.1097/CJI.0000000000000229

FIGURE 6.

FIGURE 6

IL-21-induced CD8+ TSCM cells mediate superior antitumor responses in a melanoma xenograft model. A, Flow cytometry analysis of IFN-γ expression in sorted human naive CD8+ T cells after the 2-week stimulation with coated anti-CD3, soluble anti-CD28 in the presence of IL-2 (10 ng/mL), or IL-21 (20 ng/mL). Data are gated on total CD8+ TSCM cells. B, IFN-γ release by IL-21-induced CD8+ T cells compared with IL-2-induced CD8+ T cells (control) in response to NY-ESO-1-expressing A375 melanoma cell lines. The IFN-γ production was measured by ELISPOT assay. Data were representative of 2 independently performed experiments. The paired t test was used. **P<0.01. C, The educated CD8+ T cells were mixed with melanoma cell line A375 in a 12-hour cytotoxicity assay at E/T ratios from 10 to 2.5. The cell lysis rate was measured with the LDH release assay. Three replicates were used for each dilution of effector cells. Data are presented as means±SEM (error bars) (n=3; 1-way analysis of variance followed by Tukey’s post hoc test was used for statistical analysis of the data; ***P<0.001). D, Mice bearing human A375 tumor xenografts received adoptive therapy of IL-2-stimulated or IL-21-stimulated CD8+ T cells as indicated. Tumor growth was measured by caliper twice per week. Data are 1 representative of 3 independent experiments (4–6 mice in each experiment). **P<0.01 after 20 days. Mann-Whitney U test was used. E, Flow cytometry analysis for human CD45+ and mouse CD45+ cells 7 days after the adoptive transfer of indicated T cell. Percentages of human T cells are shown. Data are from 3 to 5 mice per group. The paired t test was used. P<0.05 indicates statistically significant difference. **P<0.01. F, Flow cytometry analysis of human T cells in tumor xenografts at study endpoint. Percentages of human T cells are shown. Data are from 3 to 5 mice per group. The paired t test was used. P<0.05 indicates statistically significant difference. **P<0.01. ELISPOT indicates enzyme-linked immunospot; IFN-γ, interferon-γ; IL-21, interleukin-21; TSCM, T memory stem cell.