Comparison of mRNA and lentiviral based transfection of natural killer cells with chimeric antigen receptors recognizing lymphoid antigens

Abstract

Natural killer (NK) cells can be engineered to kill resistant B-lymphoid cell lines and primary B-cell chronic lymphocytic leukemia (B-CLL) cells after transfection with chimeric antigen receptors (CARs) recognizing CD19 or CD20. Here we compared mRNA electroporation with lentiviral vector (LV) transduction for both CARs. Transfection efficiency and cytotoxicity of previously NK-92 resistant CLL cells were significantly higher after mRNA electroporation than after LV transduction. Further cell sorting of LV-transduced NK-92 cells resulted in a highly enriched population of transduced cells with significant target cell lysis. Compared to NK-92 cells, peripheral blood and cord blood cells consistently showed < 10% transfection efficiency with mRNA, while LV transduction varied between 8 and 16% for peripheral blood and 12 and 73% for cord blood. These results suggest that LV should be used to achieve sufficient transgene expression if blood NK cells are considered for CAR transduction. Transfection with mRNA results in clinically relevant levels of transfection only in NK-92 cells.

Keywords::

• CAR
• lymphoid malignancies
• lentiviral vector
• NK cells
• NK-92

Acknowledgements

We thank Dr. Richard Childs for cloning the αCD19-CAR cDNA into the pCL20c vector and for advice on lentiviral transduction, and Allen Parmelee and Steve Kwok for their help with cell sorting. This work was supported by a grant from the National Heart, Lung and Blood Institute (RO1HL093981).

Potential conflict of interest:

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