Figure 2

Cytotoxicity of TCRγ4δ1-engineered αβT cells to tumor cells in vitro. (A) Flow cytometry profiles of the binding of TCRγ4δ1-Fc fusion protein to the tumor cell lines HepG2, BGC-803, K562 and Raji. After incubation with TCRγ4δ1-Fc, tested cells were stained with FITC-conjugated goat anti-human IgG and assessed by flow cytometry. (B) Confocal images of the binding of the TCRγ4δ1-Fc fusion protein to the tumor cell lines HepG2, BGC-803, K562 and Raji. After incubation with TCRγ4δ1-Fc, tested cells were stained with FITC-conjugated goat anti-human IgG and detected by laser scanning confocal microscopy. (C) Cytolytic activity of TCRγ4δ1-engineered αβT cells against tumor cells. TCRγ4δ1-engineered αβT cells were incubated with HepG2, BGC-803, K562 and Raji target cells at an effector-to-target ratio of 10:1 for 6 h. Cytotoxicity was analyzed by the LDH cytotoxicity detection kit. The data are representative of 3 independent experiments and expressed as the mean ± SD. *, P < 0.05; **, P < 0.01 (ns, no significance). (D) Expression of FasL and granzyme B in TCRγ4δ1-engineered αβT cells was determined by flow cytometry. Mock- and TCRγ4δ1-engineered αβT cells were cultured with HepG2 at an effector-to-target ratio of 10:1 for 6 h, and the cellular surface molecule FasL and intracellular granzyme B were analyzed by flow cytometry. A representative FCM analysis of cytotoxic molecules is shown. (LDH, lactate dehydrogenase.)