Figure 3. SENP7 is indispensable for CD8⁺ T cell proliferation in vivo and in vitro.

(A) Heatmap of downregulated genes associated with T cell proliferation in tumor-infiltrating WT and SENP7-deficient CD8⁺ T cells. CD8⁺ T cells were isolated from tumor-bearing WT and KO mice on day 7 after injection of tumors with MC38 murine colon cancer cells. (B and C) Flow cytometric analysis of the frequency of Ki-67⁺ tumor-infiltrating CD8⁺ T cells (B) and CD4⁺ T cells (C) from WT and KO mice injected s.c. with MC38 murine colon cancer cells (day 14, n = 5). (D) Tumor growth in WT and KO mice injected with MC38 colon cancer cells (n = 6) followed by i.p. injection with 50 μg anti–PD-1 antibody or control antibody (Ctrl) on days 7, 10, and 13. (E) Flow cytometric analysis of the frequency of Ki-67⁺ WT and KO CD8⁺ T cells stimulated with anti-CD3 and anti-CD28 antibodies for 2 days (n = 7). (F) Flow cytometric analysis of the division of WT and KO CD8⁺ T cells. Naive WT and KO CD8⁺ T cells labeled with CFSE were stimulated for 72 hours with antibodies against CD3 and CD28. (G) Flow cytometric analysis of apoptotic WT and KO CD8⁺ T cells stimulated with anti-CD3 and anti-CD28 antibodies for 1 day (n = 5). Data are representative of 3 or more independent experiments and are presented as the mean ± SEM. *P < 0.05 and **P < 0.01, by 2-way ANOVA with Geisser-Greenhouse correction (D) and 2-tailed Student’s t test (B, C, and E–G).