Non-Viral Cell Engineering of Peripheral Blood NK Cells Using a GMP-Compliant, Scalable Electroporation Platform

Natural killer (NK) cells are an integral part of the innate immune system as they recognize an abundance of surface receptors on target cells without the need for antigen specificity and recruit and activate other immune cells by secreting a myriad of cytokines. The hallmark of NK cells is their cytotoxic function which enables them to recognize and attack tumor or infected cells by releasing granules that induce apoptosis of target cells. Electroporation (EP) is a nonviral method for cellular engineering that has been used with virtually all cell types and has been specifically shown to be an effective cell engineering method for peripheral blood NK cells. Advantages of electroporation include highly efficient transfection with a variety of molecules (e.g., DNA, RNA, and ribonucleoprotein (RNP) complexes), regulatory acceptance, and cGMP compatibility. In this study, we optimized conditions for electroporating primary NK cells with the GMP-compliant MaxCyte ExPERT GTx electroporation platform, with specific focus on maximizing cell viability, cell recovery, transfection efficiency, cell expansion and functionality.

Key takeaways

• Previous studies showed that expansion of NK cells before electroporation was necessary for effective transfection
• Electroporation with mRNA had over 90% gene expression and viability
• Electroporation with minicircle DNA (mcDNA) had over 60% expression and viability
• Minimal impact on cell viability, cell expansion, surface marker expression and killing capacity was observed after electroporation