Figure 8. Adoptive transfer therapy with miR-23a–inhibited CTLs in mouse models of established tumors.

Seven days after s.c. inoculation of 0.2 × 10⁶ B16/F10 melanoma or LLC-OVA cells, C57BL/6 tumor-bearing mice were sublethally irradiated and left untreated (PBS), or treated with intratumoral injections of 0.2 × 10⁶ sorted iRFP⁺GFP⁺ mock or miR-23a decoy–expressing pMel-1 or OT-I CTLs. Tumors were excised 10 days after T cell transfer, and mock and miR-23a decoy–expressing Thy1.1⁺ pMel-1 CTLs within the tumor masses were analyzed by flow cytometry. (A) B16/F10 and (D) LLC-OVA tumor progression after the initiation of CTL therapy. Data represent mean ± SEM, from n = 6 mice per group in 1 representative of 3 independent experiments in A, and from n = 10 mice per group in D. *P < 0.05, **P < 0.01, and ***P < 0.001 indicate mock vs. miR-23a decoy; ^#P < 0.05, ^##P < 0.01, and ^###P < 0.001 indicate mock vs. PBS by 2-way ANOVA and Bonferroni post-test. (B and C) B16/F10 and (E and F) LLC-OVA tumor sizes and weight 10 days after CTL therapy. (G) Absolute numbers of Thy1.1⁺ pMel-1 CTLs present in tumors. (H–K) Expression of the CTL master regulators and effector molecules (H) T-bet, (I) EOMES, (J) IFN-γ, and (K) granzyme B in Thy1.1⁺ pMel-1 CTLs isolated from B16/F10 tumors. Data represent mean ± SEM.