This study was purposed to explore the changes in biological functions of human peripheral blood derived NK Cells after ex vivo expansion with different combinations of interleukin IL2 and/or IL12, IL15. According to different combination of cytokines, cultured NK cells were divided into 4 groups: group IL2, group IL2 + IL12, group IL2 + IL15 and group IL2 + IL15 + IL12. The group in which NK cells were cultured without cytokines was used as control. The cytotoxicity of cultured NK cells to target K562 cells was determined by using cell counting kit-8; the level of IFN-gamma in supernatants of NK cell culture was detected by ELISA; the perforin and granzyme B mRNA expressions were assayed by competitive quantitative RT-PCR. The results showed that the cytotoxicity of expanded NK cells in groups cultured with cytokines at different E:T ratio was significantly higher than that in group without cytokines (p < 0.01), although the cytotoxicity of NK cells in IL2 + IL15 + IL12 group seem to be slightly higher than that in IL2 + IL15 group, but there was no statistic difference (p > 0.05). The IFN-gamma levels in the supernatants of NK cell culture in the presence of cytokines significantly increased, and the IFN-gamma levels in IL2 + IL15 + IL12 group and IL2 + IL12 group were significantly higher than that in others (p < 0.01). The expressions of perforin and granzyme B mRNA of expanded NK cells in groups cultured with cytokines was significantly higher than that in control group (p < 0.01), and was consistent with cytotoxicity of NK cells. It is concluded that there are differences in the functions of NK cells cultured with different cytokines. IL2 and IL15 have synergistic effect on strengthening cytotoxicity of NK cells and promoting cell expansion. However, the main function of IL12 promotes NK cells to secrete IFN-gamma, which plays a role in immunoregulation.
Humans ; Interferon-gamma ; secretion ; Interleukin-12 ; administration & dosage ; pharmacology ; Interleukin-15 ; administration & dosage ; pharmacology ; Interleukin-2 ; administration & dosage ; pharmacology ; K562 Cells ; Killer Cells, Natural ; drug effects ; immunology

Although nickel hypersensitivity is known as a delayed-type hypersensitivity mediated by nickel-specific T cells, it is greatly influenced by other immune cells. Here we show that splenic natural killer cells (NK cells) directly or indirectly respond to nickel by secretion of IFN-gamma. Using enzyme-linked immunosorbent spot (ELISPOT) assays, we found that nickel-reactive cells readily secreted IFN-gamma when splenocytes were cultured in the presence of varying concentrations of nickel sulfate (NiSO4) for 24 h. However, nickel-reactive IL-2- or IL- 4-secreting cells were infrequent during the 24-h culture with NiSO4. Immune responses to nickel were innate, not adaptive, in nature since the frequency of nickel-reactive IFN-gamma-secreting cells did not increase upon previous exposure to NiSO4 and recombination activating gene (RAG)-1-deficient mice contained nickel-reactive IFN-gamma-secreting cells. The involvement of NK cells in the innate response to NiSO4 was confirmed since we could observe a significant reduction of the frequency of nickel-reactive cells in NK cell-depleted mice. Furthermore, the number of IFN-gamma secreting cells was significantly reduced in the ELISPOT assays when NKG2D was blocked by anti-NKG2D antibody. These results suggest that there is an early and rapid innate immune response to nickel, which is mediated by NK cells and the NKG2D receptor. The significance of the innate response to nickel is that it may contribute to development of the late T cell-mediated delayed type hypersensitivity against nickel.
Animals ; Homeodomain Proteins/genetics/metabolism ; Humans ; Immunity, Innate/immunology ; Interferon-gamma/*secretion ; *Irritants/immunology/pharmacology ; *Killer Cells, Natural/drug effects/immunology/secretion ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; NK Cell Lectin-Like Receptor Subfamily K/genetics/metabolism ; *Nickel/immunology/pharmacology ; Spleen/*cytology/immunology