Figure 1.

Characterization of Chemokines Involved in NK-Cell-Mediated MSC Recruitment

(A and B) MSC invasion through filters coated with Matrigel was determined after 24 hr of incubation. (A) The lower compartment of the invasion chamber was filled with serum-free medium, as a negative control, or with NK cells. MSCs were either untreated (control) or pre-treated with pertussis toxin at 100 ng/ml for 2 hr at 37°C/5% CO₂ (n = 6 independent experiments with four NK cell and two MSC donors, ^∗p < 0.05; Wilcoxon test). (B) The lower compartment was filled with serum-free medium, NK cells, or with supernatants (sup) from MSCs or NK cells cultured alone or collected after an invasion assay. n = 6–9 independent experiments with six NK cell and three MSC donors, ^∗p < 0.05; ^∗∗∗p < 0.001; Kruskal-Wallis test followed by the Dunn's multiple comparisons test to compare each sample against the negative control.

(C) The supernatants were analyzed with protein arrays detecting 38 different factors. Examples of the developed membranes with indication of factors of interest.

(D) Concentrations of RANTES, GRO-β, GRO-γ, NAP-2, and IL-8 in supernatants of NK cells, MSCs, or NK cells co-cultured with MSCs in invasion assays were determined by ELISA. Graphs are min-max whisker plots. n = 10 independent experiments with ten NK cell and three MSC donors; ^∗p < 0.05; ^∗∗∗p < 0.001; Friedman test followed by Dunn's multiple comparisons test to compare each sample against the negative control.

(E) Intracellular staining of NAP-2 (bottom) was performed on isolated NK cells (CD56+/CD3−, top). Plots are representative of data from four NK cell donors.