Abstract
INTRODUCTION: Cytotoxic (CD8+) and natural killer (NK) cells play critical roles in anti-tumor immunity. Dysfunction in these cells is considered as one of the extrinsic mechanisms for tumor relapse. AIM: We aimed in this study to assess cytotoxic activities of CD8 + T and NK cells in the peripheral blood from lung cancer patients before and after induction of chemotherapy. SUBJECTS AND METHODS: Healthy (n = 5) volunteers and lung cancer patients (n = 15:5 before, 5 during, and 5 after induction of chemotherapy) were recruited. Flow cytometry was used to analyze the numbers of CD8 + T cells, NK and CD56(+)T cells and their intracellular expression of granzyme B (GzB) in fresh peripheral blood mononuclear cells (PBMCs) and after 72 h of their culture in vitro and stimulation with 5 µg/ml Concanavalin A (Con A) and 50ng/ml IL-2). In addition, the plasma levels of inflammatory cytokines were measured using luminex. RESULTS: After culture, significant increases in the number of GzB expressing cells gated on CD3+, CD4+, CD8 + and NKCD8 + T cells in the PBMCs from lung cancer patients before induction of chemotherapy as compared to control individuals as well as patients during and after induction of chemotherapy. Serum levels of IL-1 and CXCL8 in patients before induction of chemotherapy showed 37- and 40-fold increases, respectively, as compared to control individuals. Both GzB expression and cytokines levels in patients during and after chemotherapy were similar. CONCLUSION: Polyclonal stimulation of PBMCs can restore the cytolytic activities of cytotoxic CD8 and NK cells from lung cancer patients even after chemotherapy.