肺癌患者外周血CD+8 自然杀伤T细胞表面受体NKG2D和NKG2A表达的临床意义

 【摘要】　目的　检测肺癌患者外周血CD+8 自然杀伤（NK）T细胞表面受体NKG2D和NKG2A的表达，探讨二者表达失衡与肺癌免疫逃逸的关系。方法　选择95例原发未治疗的肺癌患者，采用流式细胞术检测CD+8 NKT细胞表面受体NKG2D和NKG2A的表达，以50名健康人为对照。结果　肺癌组CD+8 NKT细胞NKG2D+表达率（77.07±5.77）%]明显低于对照组（84.13±4.49）%]，差异有统计学意义（t＝8.14，P＜0.05）；在TNM分期中，Ⅰ～ⅢA、ⅢB、Ⅳ期患者CD+8 NKT细胞NKG2D+表达率依次为（81.07±5.02）%、（76.95±4.70）%、（72.80±5.16）%，差异有统计学意义（F＝18.74，P＜0.05）。肺癌组CD+8 NKT细胞NKG2A+表达率（33.58±8.82）%]明显高于对照组（25.31±8.38）%]，差异有统计学意义（t＝-5.46，P＜0.05）；在TNM分期中，Ⅰ～ⅢA、ⅢB、Ⅳ期患者CD+8 NKT细胞NKG2A+的表达率依次为（25.10±6.93）%、（33.24±3.76）%、（43.64±6.10）%，差异有统计学意义（F＝75.73，P＜0.05）。结论　肺癌患者CD+8 NKT细胞表面NKG2A和NKG2D表达失衡可能抑制该细胞的杀伤功能，而这可能是肿瘤免疫逃逸的机制之一。

Expression and clinical significance of CD+8 natural killer T cell receptors NKG2D and NKG2A in peripheral blood of patients with lung cancer

Objective The aim of this study is to investigate CD+8 natural killer T cell receptors NKG2D and NKG2A expression in peripheral blood of patients with lung cancer and discuss the relation between imbalance expression of NKG2A and NKG2D and tumor immune escape. Methods Flow cytometry was used to determine the percentage of NKG2D and NKG2A-expressing of CD+8 NKT cells in peripheral blood of 95 untreated lung cancer patients and 50 healthy controls. Results NKG2D was lower expressed on CD+8 NKT in lung cancer, the level of NKG2D in patients (77.07±5.77) % was significantly lower than that in the controls (84.13±4.49) % (t =8.14, P <0.05). In the TNM stage, the level of NKG2D in patients of Ⅰ-ⅢA, ⅢB, Ⅳ stage were (81.07±5.02) %, (76.95 ±4.70)%, (72.80±5.16) %, respectively, the level of NKG2D was significantly decreased in order (F =18.74, P <0.05). NKG2A was expressed higher on CD+8 NKT in lung cancer, the level of NKG2A in patients (33.58±8.82) % was significantly higher than that in the controls (25.31 ±8.38) % (t =-5.46, P<0.05). In the TNM stage, the level of NKG2A in patients of Ⅰ - Ⅲ A, ⅢB, Ⅳ stage were (25.10±6.93) %, (33.24±3.76) %, (43.64±6.10) %, respectively, the level of NKG2A was significantly increased in order (F =75.73,P <0.05). Conclusion Imbalance expression of NKG2A and NKG2D may restrain the function of CD+8 NKT cell of lung cancer patients in peripheral blood and that may be one of important factors in tumor immunological escape.