人巨细胞病毒对自然杀伤细胞表面自然杀伤细胞2族成员受体表达的影响

Influence of human cytomegalovirus on the expression of natural-killer group 2-members receptors on the natural killer cells

目的 观察人CMV对NK细胞表面自然杀伤细胞2族（NKG2）成员,包括NKG2A、NKG2C和NKG2D表达的影响.方法 免疫磁珠法提取健康人PBMC中的NK细胞,与感染人CMV的人胚肺成纤维细胞（HELF）共培养24 h;同时设未感染CMV的HELF与NK细胞共培养组和NK细胞组.流式细胞技术检测各组NK细胞NKG2A、NKG2C和NKG2D的表达.组间比较采用Wilcoxon检验.结果 感染CMV的HELF＋ NK细胞共培养组NKG2C和NKG2D表达水平为34.26％±7.99％和24.94％±5.24％,高于HELF＋NK细胞共培养组的26.31％±6.41％（Z=-3.285,P=0.001）和20.02％±6.80％（Z=-3.285,P=0.001）,也高于NK细胞组的25.78％±6.62％（Z=-3.211,P=0.001）和20.12％±6.75％（Z=-3.285,P=0.001）;而HELF＋NK细胞共培养组与NK细胞组比较差异无统计学意义（均P＞0.05）.NKG2A在各组间表达差异亦无统计学意义（均P＞0.05）.感染CMV的HELF＋NK细胞共培养组NKG2A＋ NKG2C-为2.99％±2.62％,NKG2A＋NKG2D-为6.13％±2.44％,NKG2C＋ NKG2A-为26.62％±7.63％,NKG2D＋ NKG2A为20.44％±5.68％,而HELF＋ NK细胞组分别为4.44％±4.25％（Z=-2.240,P=0.025）、6.99％±2.33％（Z=-2.053,P=0.040）、19.52％±6.80％（Z=-2.800,P=0.005）和15.78％±7.48％（Z=-2.875,P=0.004）.NKG2A＋ NKG2C＋和NKG2A＋ NKG2D＋在各组间比较差异均无统计学意义（均P＞0.05）.结论 人CMV感染可改变NK细胞受体的表达量,使NKG2C、NKG2D转导的活化性信号增强,NKG2A转导的抑制性信号减弱.

Objective To examine the effect of human cytomegalovirus （CMV） on the expressions of natural killer group 2 members （NKG2）,including natural-killer group 2-member A （NKG2A）,natural-killer group 2-member C （NKG2C） and natural-killer group 2 member D （NKG2D） receptors on the natural killer （NK） cells.Methods NK cells were isolated from the peripheral blood mononuclear cells of 20 healthy individuals using EasySep magnetic beads.NK cells and CMV-infected human embryonic lung fibroblast （HELF） were co-cultured for 24 h and regarded as experimental group.While CMV-uninfected NK cells co-cultured with HELF and only NK cells were taken as control groups.Flow cytometry was used to detect the expressions of the NK cell receptors in experimental and control groups.The comparison between groups was done by Wilcoxon rank sum test.Results The percentages of NK cells expressing NKG2C and NKG2D in group of CMV-infected NK cells co-cultured with HELF were 34.26%±7.99% and 24.94% ± 5.24%,respectively,which were significantly higher than those in CMVuninfected NK cells co cultured with HELF （26.31% ±6.41%; Z=-3.285,P=0.001 and 20.02%±6.80% ; Z=-3.285,P=0.001,respectively） and NK cells alone （25.78%± 6.62% ; Z=-3.211,P=0.001 and 20.12 % ± 6.75 % ; Z=-3.285,P =0.001,respectively）,while no significant changes were found in the expressions of the two receptors between groups of CMV-uninfected NK cells co-cultured with HELF and NK cells alone （both P〉0.05）.Moreover,no significant changes were found in the expression of NKG2A among groups （all P〉0.05）.The levels of NKG2A＋ NKG2C,NKG2A＋NKG2D,NKG2C＋ NKG2A-and NKG2D＋ NKG2A-cells in CMV infected NK cells co-cultured with HELFgroup were 2.99% ±2.62%,6.13%±2.44%,26.62% ±7.63% and 20.44%±5.68%,respectively,while those in group of CMV-uninfected NK cells co-cultured with HELF were 4.44% ± 4.25% （Z=-2.240,P=0.025）,6.99%±2.33% （Z=-2.053,P=0.040）,19.52%±6.80% （Z=-2.800,P=0.005） and 15.78%±7.48% （Z=-2.875,P=0.004）,respectively.However,no significant changes were found in the expressions of NKG2A＋ NKG2C＋ and NKG2A＋ NKG2D＋ among groups （all P〉0.05）.Conclusions CMV infection may change the NK receptor expressions,then stimulatory NKG2C and NKG2D signal transductions are enhanced and the inhibitory NKG2A signal conduction is weakened during CMV infection.