In Vitro Expansion Of NK Cells By Combination Of CD137Monoclonal Antibody And IL-15and Their Cytotoxicity Against Lung Cancer Cells

Objective: To explore an in vitro expansion method of NK cells by CD137monoclonal antibody combination with IL-15.Methods: CD3-CD56+NK cells were isolated from peripheral blood mononuclearcells (PBMC) using negative MACS, and divided into five groups: a control group, IL-2,IL-2+IL-15, IL-2+CD137mAb, IL-2+IL-15+CD137mAb groups. The expansion,phenotype and cytotocity of lung cancer A549cells and IFN-γ serection of NK cells wereevaluated by MTT, FACS, LDH, and ELLSA, respectively.Results: The purity of NK cells increased to (93.28+3.21)%after MACS sorting. Ingroup IL-2+IL-15+CD137mAb, the NK cells were expanded obviously higher than werethose IL-2+CD137mAb, IL-2+IL-15, IL-2, control groups (86.20+5.00vs60.01+5.00,49.06+4.39,17.04+1.49,3.95+0.23fold P<0.01). The cytotoxicity of expanded NK cells ingroup IL-2+IL-15+CD137mAb was significantly higher than that in the other groups[(93.14±3.27)%vs(83.15±4.03)%,(71.25±3.24)%,(62.27±3.01)%,(49.38±2.35)%。P<0.01]. In group IL-2+IL-15+CD137mAb, the IFN-γ level in cell supernatant wassignificantly higher than in IL-2+CD137mAb, IL-2+IL-15, IL-2, control groups[(296.25±9.79) pg/ml vs (260.47±11.55) pg/ml,(201.13±6.36) pg/ml,(138.36±6.09) pg/ml,(38.42±3.56) pg/ml, P<0.01]。Conclusions: CD137monoclonal antibody combination with IL-15can efficientlyexpand NK cells with an effective cytotoxicity on lung cancer A549cells.