超抗原对NK细胞亚群凋亡诱导配体表达与功能的调节  

Expression and function of apoptosis-inducing ligands in NK cells activated by SEA or SEB

作　　者：张赟[1] 程光[2] 韩卫宁[1] 曹云新[1] 李琦[1] 金伯泉[1] 

机构地区：[1]第四军医大学免疫学教研室 [2]第四军医大学西京医院神经外科,西安710032

出　　处：《免疫学杂志》2006年第3期239-242,共4页Immunological Journal

基　　金：国家自然科学基金重点课题资助项目(30030130)

摘　　要：目的研究凋亡诱导配体分子在超抗原活化NK细胞CD56bright亚群和CD56dim亚群上的表达规律和功能。方法以超抗原金黄色葡萄球菌肠毒素A/B(SEA/B)活化PBMC为模型,应用双重免疫荧光染色和流式细胞术分析,观察不同活化模型中凋亡诱导配体分子在NK细胞CD56bright和CD56dim亚群表达的变化;采用51Cr释放实验及抗体阻断实验,观察NK细胞亚群的功能与凋亡诱导配体分子表达的关系;利用激光共聚焦显微镜,观察凋亡诱导配体分子在NK细胞杀伤相的分布。结果当超抗原浓度为0.1μg/mL时,TRAIL和TNF在NK细胞上的表达率及NK细胞杀伤活性于培养第2天时达到高峰,FasL在NK细胞上表达未见明显变化。TRAIL和TNF分子聚集于NK细胞与靶细胞的接触部位,FasL分布未见明显变化。结论超抗原SEA和SEB促进TRAIL和TNF在CD56dim亚群表达,TRAIL和TNF可能参与NK细胞免疫突触的形成。Objective To study the expression and function of apoptusis-inducing ligands （AILs） in CD56^bright and CD56^dim NK subsets activated by superantigens. Methods Double fluorescent staining and flow cytometry analysis were employed to detect the expression of AILs on CD56^bright and CD56^dim NK subsets among human peripheral blood mononuclear cells （PBMC） stimulated by Staphylococcus enterotoxin A/B （SEA/B） or SEB. The cytotoxicities of NK cells in different activation models were detected and compared by using ^51Cr release assay. Laser scanning confocal microscopy was used to observe the redistribution of AILs on NK cells activated by superantigens at killing stage. Results Both TRAIL and TNF were mainly expressed on CD56^dim NK subset and greatly increased by SEA or SEB （0.1 μg/mL） with the peak appeared after 2 days of stimulations, whereas SEA and SEB had no effect on the expression of membrane-bound FasL. Furthermore, the TRAIL and TNF were concentrated at the interface of NK cells and target cells at killing stage. The cytotoxicity of NK cells against K562 cells was,remarkably decreased when the blocking antibodies were added at killing stage. Conclusion Both the expressions of TRAIL and TNF on CD56^dim NK subset and the NK cytotxicity are enhanced by SEA or SEB. TRAIL and TNF may be involved in the formation of NK synapse.

关 键 词：凋亡诱导配体 NK细胞 亚群 超抗原 

分 类 号：R392[医药卫生—免疫学]