Abnormal expression and clinical significance of surface receptors on natural killer cells in the peripheral blood of patients with non-small cell lung cancer

Background Natural killer (NK) cells typically function as frontline lymphocytes against cancer although little is known about their engagement in non–small cell lung cancer (NSCLC). This study compared the performance and activity of NK cells and their subsets in the peripheral blood of NSCLC sufferers and healthy participants. Methods In total, 67 healthy controls (40 men; 59.7%) and 56 patients with NSCLC (35 men; 62.5%) were included (mean age, 66.6 years). Flow cytometry identified NK cells and their subpopulations in external blood, and the total number, proportion, activity, surface activating and inhibitory receptor expression levels were determined. Results NK cell surface receptors CD107a, IFN-γ, and TNF-α activity were markedly reduced in lung cancer patients compared to healthy controls. The number and ratio of NK cells within the lymphocyte population were decreased in patients. The concentration of the inhibitory receptors TIGIT, TIM-3, CD96, PD-1, and Siglec-7 were increased in patients, whereas the expression level of the activating receptor NKP30 was decreased. Moreover, the expression levels of IFN-γ, TIGIT, CD96, PD-1, and TIM-3 were correlated with the clinical phase of NSCLC.Conclusions NSCLC patients have decreased number and function of external blood NK cells, and the proportion of most of the inhibitory receptors assessed on NK cells in this study increased as the disease progressed. These findings suggest that surface receptors from NK cells are likely to be involved in the evolution of NSCLC.