FIGURE 6.

NK cells contribute to relaying the effects of ISG15 to E7-specific CD8⁺ T cells. (A) Scheme showing ISG15 interaction with LFA-1 (αLβ2 integrin and CD11a/CD18) receptor in NK cells and its biological impact as described for human cells in vitro (33). (B–E) Mice (n = 4 per group) were vaccinated on days 0, 3, and 6 with plasmid encoding E7SH combined with ISG15 WT. On days −1, 0, 3, and 6, mice were injected i.v. with control serum or anti-asialo GM1 antiserum. (B) Frequency of CD8⁺ cells among live cells in blood at the indicated days postvaccination. (C) Frequency of NK1.1⁺ cells within CD3-negative cells in blood at the indicated days postvaccination to validate NK cell depletion. (D) E7-specific cells within CD8⁺ cells in blood at the indicated days postvaccination. (E) Percentage of SLECs (KLRG1⁺CD127⁻) (left) and MPECs (CD127⁺KLRG1⁻) (right) within E7-specific CD8⁺ T cells in blood at days 10 and 13. Results are representative of two experiments. Statistical evaluation was performed using one-way ANOVA evaluation and Tukey posttest and is indicated for day 10. **p < 0.01, ****p < 0.0001.