FIGURE 3.

Cytotoxicity of B‐cell activating factor receptor (BAFF‐R) chimeric antigen receptor (CAR) T cells against three chronic lymphocytic leukemia (CLL) cell lines in vitro. BAFF‐R (A) or CD19 (B) expression in MEC‐1 WT, HG‐3, or CII cell lines were characterized by BAFF‐R‐AF647 or CD19 APC antibodies staining and assessed using flow cytometry. (C and D) BAFF‐R CAR T cells were incubated with MEC‐1 WT, HG‐3, or CII cells at an E:T ratio of 2:1. CD107a‐positive cell analysis, which was utilized to indicate antigen‐specific cytotoxicity, was focused on CD8⁺ (C) or CD4⁺ CAR T cells (D); non‐CAR T cells were used as negative controls. (E) Additionally, cytotoxicity of BAFF‐R CAR T cells was observed with the co‐incubated with either MEC‐1 WT, HG‐3, or CII cell lines at an E:T ratio of 4:1. Interferon‐gamma (IFN‐γ) was measured from the harvested supernatant after 72 h. Non‐CAR T cells were used as controls. The results were showed as mean ± SEM from four replicates and representative from three independent experiments (^∗∗∗ p < 0.001).