Apoptosis of CD19+ chimeric antigen receptor T cells after treatment with chemotherapeutic agents.

ABSTRACT

The use of chemotherapeutic agents prior to treatment with infusion of cluster of differentiation (CD)19-chimeric antigen receptor (CAR)­T cells is important for the efficacy of clinical therapies against hematological malignancies. However, the effect of chemotherapeutic agents on CD19­CAR­T cells and the associated underlying mechanisms remain unknown. The first aim of the present study was to determine the effect of chemotherapeutic agents on CAR­T cells using the in vitro Cell Counting kit 8 assay. The second aim was to evaluate the abilities of fludarabine (FDR) and mafosfamide (MFA; a metabolite of cyclophosphamide) to induce apoptosis of CD19­CAR­T cells via the use of Annexin V/propidium iodide double staining. In addition, a JC­1 fluorescent probe was used to detect alterations in cell membrane potential, and flow cytometry analysis was used to measure concentrations of caspase­3/7 to identify apoptotic pathways of CD19­CAR­T cells. The data of the present study suggested that FDR and MFA inhibit the activities of CD19­CAR­T cells. Alterations to the mitochondrial membrane potential and an increase in the concentration of caspase­3/7 indicated early apoptosis of FDR­ and MFA­treated CD19­CAR­T cells. The present study laid a theoretical foundation for the development of programs for clinical treatment.