BaEV-pseudotyped lentiviral vectors enable stable CAR expression and cytotoxic function in NK cells

Area of Science:

• Immunology
• Gene Therapy
• Cell Biology

Background:

• Lentiviral vectors (LVs) are utilized for gene delivery in cell therapies.
• Chimeric antigen receptor (CAR) engineering of natural killer (NK) cells enhances their anti-cancer activity.
• The choice of LV envelope glycoprotein impacts CAR expression stability and vector genome persistence.

Purpose of the Study:

• To compare the efficacy of vesicular stomatitis virus glycoprotein (VSV-G) and baboon envelope glycoprotein (BaEV) pseudotyped LVs for CAR transduction in NK cells.
• To evaluate the kinetics of CAR expression, cytotoxic function, and vector DNA persistence over time.
• To assess the applicability of BaEV-LVs in primary expanded NK (eNK) cells.

Main Methods:

• Generation of CAR-NK92 cells using VSV-G- or BaEV-pseudotyped LVs.
• Kinetic analysis of CAR surface expression.
• Assessment of cytotoxic function.
• Genomic DNA analysis to determine vector DNA persistence and integration stability.
• Transduction of primary eNK cells with BaEV-LVs.

Main Results:

• VSV-G-pseudotyped LVs resulted in transient CAR expression in NK92 cells with rapid decline.
• VSV-G-transduced cells showed significant degradation of transfer DNA and reduced integration stability.
• BaEV-pseudotyped LVs supported sustained CAR expression and durable cytotoxicity in NK92 cells.
• BaEV-LVs demonstrated persistent genomic DNA integration and maintained cytotoxic function in primary eNK cells.

Conclusions:

• BaEV-pseudotyped LVs are a more suitable platform than VSV-G-pseudotyped LVs for CAR-NK cell engineering.
• BaEV-LVs ensure stable CAR expression, persistent vector genomes, and durable anti-tumor activity.
• This study highlights BaEV-LVs for robust CAR-NK cell-based immunotherapies.