The contribution of MHC class I presentation and CD8⁺ T cells in suppressing tumor growth by intratumoral administration of AdNK4 and DCs.

(A) Role of MHC class I and class II presentation of DCs coadministered with AdNK4. B16-F10 cells (3 × 10⁵) were implanted subcutaneously in the right flank of wild-type C57Bl/6 mice (day 0). On day 8, established B16-F10 tumors were treated with AdNK4 (10⁹ pfu), and 3 days later (day 11), tumors were inoculated with 2 × 10⁵ DCs prepared from MHC class I–deficient (○), MHC class II–deficient (▪), or wild-type (▵) C57Bl/6 mice. (B) Role of CD4⁺ and CD8⁺ T cells in mice treated with AdNK4 and DCs. By subcutaneous injections of B16-F10 cells (3 × 10⁵), tumors were established in the flank of MHC class I–deficient (ie, CD8⁺ T cell–deficient, ○), MHC class II–deficient (ie, CD4⁺ T cell–deficient, ▪), or wild-type (▵) C57Bl/6. Eight-day established B16-F10 tumors were treated with direct injection of AdNK4 followed by the injection of DCs prepared from wild-type C57Bl/6 mice 3 days later. For both panels, the size of each tumor was assessed 3 times per week and is reported as the average tumor area (mm²) ± the standard error of n = 5 mice per group. Each experiment included tumor-bearing wild-type mice without any treatment as a control (■).