Fig. 3

T-cell mediated lysis of the BiTE® antibody construct AMG 330 is significantly enhanced by additional administration of PVR and PVRL2 or TIGIT blocking antibodies. TF-1 (a, n = 3), Molm-13 (b, n = 6), Kasumi-1 (c, n = 6) cells were incubated with HD-PBMCs and AMG 330 in the presence or absence of blocking antibodies against PVR or PVRL2. Blocking the receptor TIGIT on immune cells showed similar results for the cell line TF-1 (d, n = 5) and MV4-11 (e, n = 3). Results are depicted as the mean ± SD fold change (FC) of dead target cells, relative to the control without blocking antibodies. Lysis is mediated via CD3⁺ cells, as comparing HD-PBMCs and purified CD3⁺ cells from the same donor showed comparable results using the cell line TF-1 (f, n = 2). Results are depicted as the mean ± SD of dead target cells of two independent experiments. Measurements were performed in technical triplicates, and for statistical analysis Mann–Whitney U-tests were performed (#p ≤ 0.05; *p ≤ 0.001)