Fig. 2

Alteration in effector function and receptor expression of NK cells by the ADSC secretome. NK-92 cells stimulated with IL-2 were cultured for 48 h with 25 (blue) or 150 μg/ml ADSC secretome (red), or without (gray). Unstimulated NK cells were also cultured for negative control (white). A The production of effector cytokines (IFN-γ and IL-10) and cytolytic granules (granzyme B and perforin) in the supernatant was measured by ELISA. B Cytotoxicity of NK-92 cells against K562 target cells at the indicated NK:K562 (E:T, effector:target) ratios of 1:1, 2.5:1, 5:1, or 10:1 (upper). Stimulated NK cells were treated with 150 μg/ml ADSC secretome for 48 h, followed by co-culture with K562 target cells at a 10:1 ratio for 4 h (bottom). C Degranulation marker from activated NK-92 cells was assessed using flow cytometry (CD56⁺ CD107a⁺) as shown dot blot (at a 5:1 ratio, upper), frequency of CD107a⁺ NK cells (at the indicated ratios, bottom), and the expression level of CD107a on NK cells (at the indicated ratios, right side). D to F Flow cytometry analysis of activating receptors, such as NKG2D, NKp30, and NKp46 (D; histogram, MFI, and frequencies), inhibitory receptors, such as CD96, TIGIT, CD94, and Tim-3 (E; histogram, MFI, and frequencies), and IL-2 receptors, such as CD25, CD122, and CD132 (F; MFI only). Error bars represent mean ± SEM of five to seven independent experiments. Statistical tests were determined by Student’s paired two-tailed t-test; not significant (ns), *P < 0.05, **P < 0.01, ***P < 0.001