Fig. 4.

The therapeutic effect of Ab-retargeting is mediated by NK cell-dependent triggering of CD8 T cells. a According to the procedure illustrated in Fig. 2a, subcutaneous MC38-pSia tumors were established in Ad5-vaccinated mice and treated with i.v. injections of DE1scFv-pSia or saline. In addition, the influence of NK cells, CD8 T cells, and macrophages on treatment success was studied by depletion of the indicated immune cell subsets starting 2 days before first adapter treatment using depleting antibodies α-NK1.1 and α-CD8 for depletions of NK cells and CD8 T cells, respectively, or clodronate liposomes for depletion of macrophages. Tumor development (left) and survival (right) were monitored. Group size n = 5 for all groups, except for the macrophage depleted group (DE1scFv-pSia + clodronate; n = 4); the same control and DE1scFv-pSia group without depletion agent is shown in each plot. b On day 17 after tumor inoculation, splenocytes of control and adapter-treated groups with or without NK cell depletion were prepared and examined for Adpgk-R304M-reactive tumor-specific CD8 T cells (n = 5 per group) by incubation with the corresponding peptide ASMTNMELM as described in Fig. 3f. Log-rank (Mantel–Cox) test was used to calculate survival statistics in a. Two-tailed unpaired t test was used to calculate statistics in b. *p ≤ 0.05; **p ≤ 0.01. Error bars refer to standard deviation (SD). Source data are provided as a source data file