EFFECT OF INTERLEUKINS 2, 7, 15 ON THE PROLIFERATION OF NATURAL KILLERS IN VITRO

Introduction. The actual task of modern adoptive cancer immunotherapy is the selection of the optimal composition of cytokines for ex vivo stimulation of immunocompetent cells for subsequent administration to oncological patients. The purpose of the study was to compare the effect of interleukin (IL) 2, 7, 15 and their combinations on the proliferation of natural killer cells in breast cancer (BC) patients in vitro. Materials and methods. The research was conducted on natural killer cells isolated by magnetic separation from mononuclear cells of peripheral blood of ten patients with locally advanced BC (stage II). After separation, the cells were cultured at a concentration of 2.5 × 105 cells / ml for 10 days in RPMI 1640 medium supplemented with cytokines at a concentration of 40 ng / ml each in five experimental variants: IL‑2; IL‑7; IL‑15; IL‑7 / IL‑15; IL‑2 / IL‑7 / IL‑15. On the 10th day of cultivation, the phenotype of cells and the cell cycle were studied by flow cytometry. For immunophenotyping of cells, we used monoclonal antibodies to antigens: CD3, CD16 / 56, CD45, CD4, CD19, and CD8. For cell cycle study cells were stained with propidium iodide. Results . On the final 10th day of cultivation the number of living cells expressed as percentage of the seeding numbers were significantly different from control (45.9 %) in samples IL‑2 (86.8 %) and IL‑7 / IL‑15 (85.6 %), IL‑15 (76.4 %), IL‑2 / IL‑7 / IL‑15 (75.8 %). The proportion of natural killers (CD16+CD56+) significantly differed from the control (18.2 %) in samples IL‑2 (45.6 %), IL‑15 (39.9 %), IL‑7 / IL‑15 (36.2 %), IL‑2 / IL‑7 / IL‑15 (35.9 %). The propor‑ tion of natural killer T cells (CD3+ / CD16+CD56+) significantly differed from the control (0.4 %) in samples incu‑ bated with IL‑2 (2.06 %), IL‑15 (2.2 %), IL‑7 (0.9 %), IL‑7 / IL‑15 (1.26 %), IL‑2 / IL‑7 / IL‑15 (2.46 %). All experimental tests also showed a significant increase in the proportion of cells in the S‑phase and increase in the proliferation index (G2 / M + S). Conclusion. The maximum stimulation of the proliferation of natural killer cells isolated from the blood of patients with BC in vitro was obtained by stimulation with IL‑15 alone and in combinations with γc‑cytokines.