[Cytotoxicity of allogenetic natural killer cells against CD34+ acute myelogenous leukemia cells].
OBJECTIVE
To study the cytotoxic effect of allogenetic natural killer (NK) cells in vitro on human CD34+ acute myelogenous leukemia cells.


METHODS
CD34 expression on acute myelogenous leukemia KG1a cells was detected by flow cytometry. KG1a cells were co-cultured at different effector-to-target (E:T) ratios with NK cells isolated from 5 healthy individuals using magnetic cell sorting. Lactate dehydrogenase (LDH) release assay was employed to examine the cytolysis of KG1a cells in the co-culture, and the inhibition rate of the KG1a cell colony formation in methylcellulose was determined with K562 cells sensitive to NK cells as the control.


RESULTS
A expression rate as much as (98.0-/+1.1)% was detected for CD34 antigen on KG1a cells, and the isolated NK cells (CD3(-)CD16+CD56+ cells) had a purity of (93.2-/+3.7)% after magnetic cell sorting. Allogenetic NK cells exhibited obvious cytotoxicity and colony inhibition in vitro against KG1a cells at different E:T ratios, and the effects were significantly enhanced as the E:T ratios increased (P<0.05). At the same E:T ratio, the cytotoxicity and colony inhibition rate of allogenetic NK cells against KG1a cells was lower than those against K562 cells (P<0.05).


CONCLUSIONS
Allogenetic NK cells exhibit obvious cytotoxicity and colony formation against CD34+ acute myelogenous leukemia cells.
Niu
Xin-qing
XQ
Department of Hematology, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China. xingqingniu@163.com
Guo
Kun-yuan
KY
Zhou
Jian
J
Hu
Liang-shan
LS
Tu
San-fang
SF
She
Miao-rong
MR
D018952:Antigens, CD34 / Q000276:immunology; D018920:Coculture Techniques; D003602:Cytotoxicity, Immunologic; D005434:Flow Cytometry; D006801:Humans; D020014:K562 Cells; D007694:Killer Cells, Natural / Q000276:immunology*; D015470:Leukemia, Myeloid, Acute / Q000276:immunology*
D018952:Antigens, CD34