Fig. 3.

Short- and long-term influence of MPA on surface expression of NK cell receptors. a Influence of long- and short-term MPA incubation on surface phenotype. Plots show MFI of central NK cell surface molecules involved in cytotoxicity (NKp30, NKp44, NKp46, NKG2D, NKG2A, DNAM-1), adhesion/migration (CXCR3, CCR5), CD11a/LFA-1, CD62L/L-selectin), and activation (CD25/IL2-Rα). All investigated surface molecules become highly up-regulated upon IL-2 stimulation (white square) compared with unstimulated NK cells at day 0. This was significantly inhibited by long-term MPA incubation (red triangle), while short-term (24 h) MPA treatment (orange triangle) had no effect on previously up-regulated surface receptors (n = 10, plots gated on viable CD56⁺CD3⁻ NK cells, p < 0.05 and p < 0.01 indicated as * and **, Wilcoxon matched-pairs signed rank test). b Overlay plots show representative results regarding NKG2D, CD11a and CD25 expression following 9 days of IL-2 stimulation (black) ± long- (red) and short-term (orange) MPA incubation compared with unstimulated NK cells at day 0 (gray area), (MFI vs. events, plots gated on viable CD56⁺CD3⁻ NK cells)