Figure 3.

Evaluation of anti-tumor capacity in vivo by passive immunization with the rabbit IgG against JT–mPD1 in a syngeneic tumor mouse model. (A) Inhibition ELISA showing the binding of mPD–L1 to coated mPD1, before or after preincubation with control rabbit IgG or with different concentrations of rabbit-specific IgG against JT–mPD1 n = 4 for each data point. (B) BALB/c mice either remained untreated (naïve) or were injected as depicted. (C) In vivo anti-tumor effect shown by bars expressing the weight of the tumors explanted upon sacrifice from all the mice in each group. The levels of tumor growth reduction in the mice immunized with the rabbit IgG Abs or the examined mAb against mPD1, compared to the naïve mice, are indicated in percentages above the respective bars. Corresponding macroscopic images of representative explanted tumors are shown below each bar n = 8 for each data point. The results are representative of at least two repeated experiments. Significant differences are indicated by asterisks (**P < 0.01, ***P < 0.001).