Fig. 4

Nb-TriTE enhances the specific lysis of FAP-expressing target cells by T cells in vitro. A Schematic diagram of enhanced tumor-specific cytotoxic T cells induced by Nb-TriTE due to PD-1 blockade. B–E Dose-dependent lysis of HepG2 versus HepG2-FAP cells, U87 cells and primary CAF cells by unstimulated T cells varies proportionally with Nb-TriTE concentration (E:T ratio 10:1; incubation time, 16 h). F Nb-TriTE-induced cytotoxicity assays of target HepG2, HepG2-FAP, U87 and CAF cells were carried out at E:T ratios of 1:1, 5:1, and 10:1 for 16 h. G Cytotoxicity assays of target HepG2-FAP, U87 and CAF cells in the presence of Nb-BiTE and Nb-TriTE or Nb-BiTE (no T cells) and Nb-TriTE (no T cells) were carried out at E:T ratios of 10:1 for 16 h. H Cytotoxic lysis of HepG2-FAP in the presence of Nb-TriTE and T cells at a concentration of 2 μg/mL at an E:T ratio of 10:1 after 16 h, which is significantly interfered in the presence of hCD3ε, hPD-1 and hFAP blockade, respectively