Killing efficiency affected by mutually modulated PD-1 and PD-L1 expression via NKT-hepatoma cell interactions

Area of Science:

• Immunology
• Oncology
• Molecular Biology

Background:

• Programmed death-1 (PD-1) and its ligand (PD-L1) are key regulators of immune responses.
• Hepatoma cells and natural killer T (NKT) cells interact within the tumor microenvironment.
• Understanding these interactions is crucial for developing effective cancer immunotherapies.

Purpose of the Study:

• To investigate the mutual expression of PD-1/PD-L1 between NKT cells and hepatoma cells.
• To evaluate the impact of PD-1 blockade on antitumor efficiency.
• To compare PD-1 knockout with monoclonal antibody blockade for enhancing NKT cell-mediated cytotoxicity.

Main Methods:

• CRISPR/Cas9 gene editing technology was employed.
• Flow cytometry and ELISA were used to analyze protein expression.
• Cell Counting Kit-8 (CCK-8) assay and mouse models assessed antitumor activity.

Main Results:

• NKT cells and hepatoma cells reciprocally modulated PD-1 and PD-L1 expression.
• NKT cell-mediated PD-L1 expression on hepatoma cells correlated positively with tumor cell killing.
• Hepatoma cells exhibited varied responses to NKT-induced PD-L1 stimulation based on genetic background.

Conclusions:

• Hepatoma cells with low PD-L1 expression are less responsive to PD-1 blocking interventions.
• PD-1 knockout demonstrated a more time-efficient enhancement of antitumor effects compared to monoclonal antibody blockade.
• Targeting the PD-1/PD-L1 pathway offers potential for improving NKT cell-based hepatoma treatment.