Notch receptor-ligand binding strongly supported the tethering of MCs to stromal cells.

<p>(A and B) An adhesion assay with an anti-IL-7Rα mAb (control) or anti-Kit mAb (5 µg/ml each) in the presence of NaN₃ (50 mM) or the same volume of PBS (0.083% vol/vol) in a 96-well plate. (A) Data represent the percentages of non-adherent MCs (mean ± SEM of triplicate cultures) (*p<0.05 significantly different from OP9-Ctrl with each treatment, the Student’s <i>t-</i>test). (B) Representative photomicrographs of adherent MCs on each OP9 stromal cell after the removal of floating cells were shown (original magnification x200). Scale bars; 50 µm. Insets; higher magnification of a spreading adherent MC. (C) An adhesion assay with human IgG1 (control) or DLL4-Fc (25 µg/ml each) in the presence of anti-Kit mAb (5 µg/ml) and NaN₃ (50 mM) in a 96-well plate. (D and E) An adhesion assay (60 min) in a 48-well plate (D) at 37°C or on ice, and (E) on non-fixed or 4% PFA-fixed stromal cells. (C to E) Data represent the percentages of non-adherent MCs (mean ± SEM of triplicate cultures) (*p<0.05 significantly different from OP9-Ctrl with each treatment, the Student’s <i>t-</i>test). In (A), (D) and (E), data displayed significant differences between treatments on the same OP9 cells in most cases (the Student’s <i>t-</i>test).