Materials and Methods:
The study utilized the WST-1 assay to measure the cytotoxic effects of CBD.
CD19-CAR T cells, created through retroviral transduction, were treated with CBD at a non-toxic dose.
The researchers employed flow cytometry to analyze changes in immune characteristics, including transgene expression, T cell subsets, and memory phenotypes.
Standard methods were used to examine cell proliferation, apoptosis, and cell cycle distribution.
The study also evaluated the cytotoxic function and antitumor activity of CD19-CAR T cells exposed to CBD.

Results:
CBD’s half-maximum inhibitory concentration (IC50) on NALM6, Raji, and T cells ranged between 16 and 22 μM.
The maximum non-toxic dose of CBD, which maintained cell viability at approximately 100%, was determined to be 8 μM.
CBD treatment did not alter the surface expression or immune characteristics, such as T cell subsets and memory phenotypes, of CD19-CAR T cells.
Notably, CBD was found to suppress the proliferation of CD19-CAR T cells by inducing apoptosis, marked by an increased proportion of cells in the Sub-G1 phase, indicating cell cycle arrest.
However, the antitumor activity and cytokine secretion of the CD19-CAR T cells were not affected by CBD exposure.

Conclusions:
This study reveals that while a non-toxic dose of CBD can affect the proliferation of CD19-CAR T cells, it does not alter their immune characteristics or cytotoxic functions. These findings offer valuable insights into the potential impact of CBD on CD19-CAR T cell therapy, a crucial area in the advancement of cancer treatment options. This research opens the door to further investigations into the compatibility and efficacy of combining CBD with CAR T cell therapies in cancer treatment.