Figure 5.

Cytotoxicity of CAR T cells when target cells were pre-treated with the SINE compound eltanexor. Nalm-6 (A) Reh (B) Daudi (C) and Raji (D) cells were cultivated with eltanexor at different concentrations (0.05 µM: Blue, 0.1 µM: Orange, 0.5 µM: Red) or with DMSO as control (brown) for 24 h. After washing with medium, CAR T cells were added. Cytotoxicity of CAR T cells on Nalm-6 cells was assessed via flow cytometry following co-cultivation for 24 h. Reh, Daudi and Raji cells were co-cultured for 4 h with CAR T cells prior to evaluation of cytotoxicity of CAR T cells via chromium release. Increased cytotoxicity of CAR T cells was observed for Nalm-6, Reh and Daudi cells when low concentrations of eltanexor pre-treatment were used (0.05 µM on both Nalm-6 and Reh, 0.1 µM on Daudi) as compared to the DMSO control (brown). Higher concentrations of eltanexor (0.1 µM on Reh, 0.5 µM on Daudi) abrogated the lytic effects of CAR T cells. Improvement of lytic capacity after pretreatment with eltanexor was not observed for Raji cells. Experiments were performed in triplicate. Results are presented as mean ± standard deviation (SD). *P<0.05, **P<0.005, ***P<0.0005, ****P<0.00005 indicate statistical significance. E: Effector cells, i.e., CAR T cells; T: Target cells. i.e., Nalm-6, Reh, Daudi and Raji cells.