Efficient amplification of NK cells and their anti-tumor cytotoxic activity in vitro / 中国免疫学杂志

ABSTRACT

Objective:To efficiently amplify NK cells and determine their cytotoxic activity against a variety of tumor cell lines in vitro,thereby providing evidence for potential clinical application.Methods: PBMCs were isolated from adult peripheral blood and co-cultured with K562 cells that were genetically modified to express 4-1BBL,IL-15 and IL-21 on the surface for 15 days to effectively amplify NK cells.The total cell number and Purity of CD3-CD56+ cells were measured.Granzyme B and perforin expression of the amplified NK cells were detected by flow cytometry and real-time PCR.The anti-tumor effect on different cancer cells was evaluated.Results: This method obtained a more than 1.1×1010 CD3-CD56+ NK cells with 95% purity over a 15 day amplification procedure.The expanded NK cells could efficiently release granzyme B and Perforin.The cytotoxicity against different tumor cells was followed the order from strong to weakgastric,pancreatic,cervical,ovarian and renal cancer cells,with the highest activity against gastric cancer cell line A549 (90% at E∶T=10∶1) (P<0.05).A time-dependent killing effect of activated NK cells on cervical,liver and pancreatic cancer cells was observed.Conclusion: This amplification procedure can consistently generate large amounts of pure NK cells with effective cytotoxic function against a variety of tumor cells.