In the quest to enhance the efficacy of chimeric antigen receptor T (CAR-T) cell therapy against hepatocellular carcinoma (HCC), a recent study has identified a pivotal role for CD39 expression in modulating the function of CAR-T cells. The research, conducted by a team of scientists, investigated the impact of CD39 modulation on CAR-T cells, hypothesizing that optimal levels of CD39 could boost the therapeutic potential of these cells against HCC. The study utilized a combination of in vitro and in vivo experiments, including the use of a subcutaneous HCC mouse model, to demonstrate that CAR-T cells with moderate CD39 expression levels displayed superior antitumor activity compared to those with high or low CD39 levels. Furthermore, the study explored the use of mdivi-1, a small molecule inhibitor, to modulate CD39 expression, revealing a synergistic effect when combined with CD39 knockdown that significantly enhanced the antitumor response.

The study commenced with the isolation and culture of primary human T lymphocytes, which were subsequently transduced with a lentiviral vector encoding the CD39 CAR construct. The researchers then systematically evaluated the cytotoxicity, proliferation, and cytokine secretion of these modified CAR-T cells under various conditions. Notably, the study found that reducing CD39 expression through shRNA knockdown impaired the cytotoxicity and proliferation of CAR-T cells, but it also reduced apoptosis, suggesting a complex role of CD39 in CAR-T cell function. Conversely, the treatment of CAR-T cells with mdivi-1 increased the frequency of CD39 intermediate-expressing cells and enhanced cytokine secretion, proliferation, and cytotoxicity, albeit at the cost of increasing exhaustion and apoptosis.

The researchers further explored the synergistic potential of combining mdivi-1 with CD39 knockdown in CAR-T cells, demonstrating that this approach could significantly boost the antitumor activity of CAR-T cells in an HCC organoid model. The combination strategy led to an increased infiltration of CD39int CAR-T cells and heightened IFN-γ secretion, indicating a more effective antitumor response. This was further validated in an HCC xenograft mouse model, where the combination of shCD39-CAR-T cells with mdivi-1 resulted in slower tumor growth and greater tumor infiltration by CD39int CAR-T cells compared to other treatment groups.

The findings from this study offer valuable insights into the role of CD39 in CAR-T cell therapy for HCC. By demonstrating that moderate CD39 expression is associated with optimal CAR-T cell function, the research provides a rationale for developing strategies to fine-tune CD39 levels in CAR-T cells to improve their efficacy against HCC. The study also highlights the potential of using small molecule modulators like mdivi-1 to enhance CAR-T cell function, offering a promising avenue for improving cellular immunotherapy for HCC. Despite the study's promising results, the authors acknowledge the need for further research to fully understand the mechanisms at play and to translate these findings into clinical applications.
DOI: 10.1007/s11684-024-1071-9