Ex vivo expansion of human peripheral blood natural killer cells and cytotoxic T lymphocytes from lung cancer patients

Lung cancer is the most common type of cancer with the highest cancer-associated mortality rates worldwide, as well as in Vietnam. Numerous studies have demonstrated that higher numbers and higher rate of activity of infiltrating natural killer (NK) cells and cytotoxic T lymphocytes (CTLs) in the tumor are closely correlated with positive prognosis, tumor size decrease and longer survival of lung cancer patients. In the present study, the effectiveness of BINKIT(®) kit in the ex vivo expansion of NK cells and CTLs in the peripheral blood of 7 patients aged between 30 and 84 years with metastatic lung cancer was evaluated. After 21 days of culture, the average number of CTLs (CD3(+)CD8(+)) increased by 742.3-fold in the CTL culture, accounting for 72.2% of the cultured cell population, and the mean cell viability was 95.7%. In the NK cell culture, the average number of NK cells (CD3(−)CD56(+)) increased by 637.5-fold, accounting for 84.3% of the cultured cell population, with an average viability of 94.7%. The percentage of active NK cells (CD3(−)CD56(+) bright) was 82.1%, which increased by 408.9-fold. Notably, a close correlation was identified between the numbers of cytokine-induced killer (CD3(+)CD56(+)) and NK (CD3(−)CD56(+)) cells in the NK cell culture (P<0.05). In the two culture conditions (namely NK cell and CTL cultures), no clear correlation was identified between the rate of initial immune cells in the peripheral blood and the corresponding number following ex vivo expansion (P>0.05). These results revealed that the method of expansion and activation of NK cells and CTLs from peripheral blood was successfully applied using BINKIT, and reached the requirements for clinical applications in cancer treatment in Vietnam.