Comparison of Ex Vivo Expanded and Highly Purified NK Cell-Mediated Cytotoxicity Detected by 3 Different Staining Methods of Flow Cytometry / 中国实验血液学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To compare the cytotoxicity of ex vivo expanded NK cells detected by flow cytometry with 3 different staining methods.</p><p><b>METHODS</b>NK cells were collected from peripheral blood on the 17day after culture. The cultured cells were divided into 3 groups group A , B, and C. The cells in group A were stained with CFSE/Annectin-V/7-AAD; the cells in group B were stained with Annectin-V/PI, and the cells in group C cells were stained with CFSE/PI. The ET ratios in 3 groups were 101, 201 and 401, respectively, the K562 cells were incubated with NK cells for 4 hrs.</p><p><b>RESULTS</b>The purity of NK cells(CD3CD56) reached to (16.34±10.51)% on day 0 and to (83.63±10.63)% on the day 17 after incubation(P<0.05); the cytotoxicity of group A was significantly higher than thay of group B at different ET ratio (P<0.05). The cytotoxicities in A, B, C groups at ET ratio=101 were (36.56±3.69)%, (10.85±2.09)% and (22.35±2.71)% respectively; the cytotoxicities in A, B, C groups at ET ratio=91 were (47.83±5.52)%, (39.07±5.55)% and (29.61±4.81)%; the cytotoxicities in A, B, C groups at ET ratio=401 were (67.7±4.77)%, (51.51±4.43)% and (44.12±5.62)% respectively. Meanwhile, the cytotoxicity in group A was significantly higher than that in group C at different ET ratio (P<0.05), the percentage of cytotoxicity was (36.56±3.69)% vs (10.85±2.09)%, (47.83±5.52)% vs (29.61±4.81)%, (67.7±4.77)% vs (44.12±5.62)%, respectively.</p><p><b>CONCLUSION</b>CFSE/Annectin-V/7-AAD is able to clearly show human NK cell cytotoxicity against human tumors. Moreover, this staining technique also allows to distinguish different stages of cytotoxic killing as early and late apoptotic phase.</p>