Expression and clinical significance of CD+8 natural killer T cell receptors NKG2D and NKG2A in peripheral blood of patients with lung cancer / 肿瘤研究与临床

ABSTRACT

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.