K562和K562/AO2细胞HLA I类分子与MICA/B的表达及其对NK细胞杀伤活性的影响  

Expression of HLA Class I Molecules and MHC Class I Chain-related Molecules A/B in K562 and K562/AO2 Cell Lines and Their Effects on Cytotoxicity of NK Cells

作　　者：梅家转[1] 牛新清[1] 郭坤元[1] 周健[1] 魏红梅[1] 

机构地区：[1]南方医科大学珠江医院血液科,广州510282

出　　处：《中国实验血液学杂志》2007年第2期288-291,共4页Journal of Experimental Hematology

摘　　要：本研究探讨K562亲本细胞株及多药耐药细胞株K562/AO2细胞表面HLAI类分子和MHCI类链相关分子(MICA/B)的表达及其对NK细胞杀伤活性的影响。用流式细胞仪检测K562和K562/AO2细胞株HLAI类分子和MICA/B的表达情况;LDH释放法测定3例健康人NK细胞在不同效靶比时对K562和K562/AO2细胞的杀伤活性;效靶比10∶1时,用抗HLAI类分子单克隆抗体(W6/32)和抗MICA/B单克隆抗体(BAMO-1)分别封闭MHCⅠ类分子和MICA/B,观察NK细胞杀伤K562及K562/AO2细胞活性的变化。结果表明:K562和K562/AO2细胞均不表达HLAI类分子,K562细胞的MICA/B表达较K562/AO2明显增高(P<0.01)。效靶比5∶1、10∶1、20∶1、30∶1时NK细胞杀伤K562和K562/AO2细胞的活性分别为(29.32±0.12)%、(45.33±0.78)%、(58.37±0.87)%、(72.37±0.96)和(12.47±0.91)%、(24.36±1.11)%、(33.29±1.03)%、(53.87±1.27)%,各效靶比时NK细胞对K562细胞的杀伤活性较K562/AO2细胞明显增强(P=0.000);效靶比10∶1时W6/32不抑制NK细胞杀伤K562和K562/AO2细胞的活性,BAMO-1能明显抑制NK细胞杀伤K562和K562/AO2细胞的活性。结论:MICA/B在K562和K562/AO2细胞表达的差异与NK细胞的杀伤活性有关;NK细胞对K562/AO2细胞杀伤活性降低与HLAI类分子无关;MICA/B在多药耐药肿瘤细胞的低表达导致耐药肿瘤细胞对NK细胞杀伤敏感性下降。The study was aimed to investigate the expression of HLA class Ⅰ molecules and MHC class Ⅰ chain-related molecules A/B （ MICA/MICB ） in K562 and adriamycin （ADM） -resistant K562 cell lines （ K562/AO2 ） and their effect on cytotoxicity of NK cells. Expression of HLA class I molecules and MICA/MICB on the surface of K562 and K562/AO2 cell lines were analyzed by flow cytometry. Cytotoxicity of NK cells （isolated from 3 healthy persons） against K562 and K562/AO2 cells were detected by LDH releasing assay at different effect-to-target cell ratios （E： T）, In blocking experiments, anti-MHC class Ⅰ monoclonal antibody （McAb） （ W6/32, a pan anti-HLA class Ⅰ antibody） and anti-MHC class Ⅰ chain-related molecules McAb （ BAMO-1, specificly against MICA and MICB ） were added to the target cells at E： T of 10： 1. The results showed that the expression of MHC class Ⅰ chain-related molecules on K562 was higher than that on K562/AO2 （P =0.000）, and HLA class I molecules were not detectable on both cells. Cytotoxici- ties of NK cells against K562 and K562/AO2 cells were （29.32 ± 0.12） %, （45.33 ± 0.78 ） %, （ 58.37 ± 0.87 ） %, （72.37 ±0.96）% and （12.47 ± 0.91）%, （24.36 ± 1.11）%, （33.29 ±1.03）%, （53.87 ± 1.27）% at E＇T ratios of 5： 1,10： 1, 20： 1 and 30： 1 respectively （P = 0.000 ）, the cytotoxicity of NK cells on K562 cells was signficanfly higher than that on K562/A02 cells at different E： T ratios. Blocking experiments confirmed that at E： T of 10： 1 killing of NK cells against K562 and K562/AO2 cells was efficiently inhibited by BAMO-1, whereas W6/32 had no effect on K562 and K562/AO2 cells. It is concluded that the expression of MHC class Ⅰ chain-related molecules on K562 and K562/AO2 cells is correlated with NK cell-mediated lysis. NK cells display higher cytotoxicity against parental K562 cells than multi-drug resistant K562/AO2 cells. Down-regulation of MICA/B in multi-drug resistant tumor cell lines leads to re

关 键 词：自然杀伤细胞 MHC Ⅰ类链相关分子A/B K562细胞 

分 类 号：R733.7[医药卫生—肿瘤] R730.54[医药卫生—临床医学]