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 CD19‑CAR‑T cells and the associated underlying mechanisms remain unknown. The first aim of the present study was to determine the effect of chemotherapeutic agents on CAR‑T 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 CD19‑CAR‑T cells via the use of Annexin V/propidium iodide double staining. In addition, a JC‑1 fluorescent probe was used to detect alterations in cell membrane potential, and flow cytometry analysis was used to measure concentrations of caspase‑3/7 to identify apoptotic pathways of CD19‑CAR‑T cells. The data of the present study suggested that FDR and MFA inhibit the activities of CD19‑CAR‑T cells. Alterations to the mitochondrial membrane potential and an increase in the concentration of caspase‑3/7 indicated early apoptosis of FDR‑ and MFA‑treated CD19‑CAR‑T cells. The present study laid a theoretical foundation for the development of programs for clinical treatment.