食管癌患者外周血自然杀伤T 细胞及其表面受体NKG2A与NKG2D检测的临床意义

 【摘要】　目的　研究外周血中自然杀伤（NK）T细胞及其CD+8 NKT细胞亚群在食管癌患者与健康人中的表达水平及NKT细胞活性改变，探讨NKT细胞受体与临床病理分期的相关性及其临床意义。方法　采用流式细胞术分析53例食管癌患者及39名健康对照者外周血中NKT细胞及CD+8 NKT亚群，检测NKT细胞受体NKG2A和NKG2D的表达并结合临床病理因素作比较分析。结果　与健康对照组相比，食管癌患者外周血NKT细胞表达增加（4.32±0.73）%，（5.97±1.29）%]（t＝3.562，P＜0.01），NKT细胞表面NKG2D的表达水平降低（17.56±5.92）%，（15.12±1.56）%]（t＝3.892，P＜0.05），而NKG2A的表达水平升高（4.02±1.41）%，（5.99±4.59）%]（t＝4.015，P＜0.05），且其变化与食管癌的病情进展有关。结论　NKT细胞及其CD+8 NKT亚群在食管癌患者中表达增加，提示患者机体抗肿瘤效应的免疫反馈增强；NKT细胞表面活化性受体NKG2D表达减少与其表面抑制性受体NKG2A表达增加可能是致使NKT细胞活性降低及食管癌患者免疫逃逸的机制之一，且这种NKT细胞表面受体的变化和食管癌病情的发展有一定的相关性。

Clinical significance of detecting the NKT cell content and its surface receptors NKG2A and NKG2D in the peripheral blood of patients with esophageal carcinoma

Objective NKT cells are very important as a kind of non-specific immune cells. Much attention in antitumor significance has been received in the study of its effect on malignant diseases. The aim of this study was to detect the expression of NKT cells and its CD+8 NKT subsets in peripheral blood of esophageal patients and normal person, and to analyze the changes in the expression of NKG2D and NKG2A receptorsand its clinical pathological factors. Methods By flow cytometric analysis, 53 patients with esophageal carcinoma and 39 normal controls were analysed for peripheral blood of NKT cells and CD+8 NKT subsets, and the expression of NKT cells NKG2A and expression of NKG2D receptor. The clinical pathological factors were collected for the comparative analysis. Results Compared with the normal control group, the expression of NKT cells in peripheral blood of esophageal patients increased (4.32±0.73) %, (5.97±1.29) %] (t =3.562, P <0.01), and the expression level of its surface receptor NKG2D reduced (17.56±5.92) %, (15.12±1.56) %] (t =3.892, P <0.05), but the express levels of NKG2A (4.02±1.41) %, (5.99±4.59) %] in creased (r = 4.015, P <0.05), those expression change with the development of the esophageal cancer. Conclusion The increased expression of NKT cells and CD+8 NKT subsets in the peripheral blood of patients with esophageal carcinoma refletcs that the immune feedback of patients' antineoplastic effect is strengthened. The decresed expression of the active receptor NKG2D and the increased expression of the inhibitory receptor NKG2A on NKT cells might be one of mechanisms leading to the reduction of NKT cell activity and immune escape of patients with esophageal carcinoma. The changes of surface receptors of NKT cells may be associated with the development of the esophageal cancer.