Fig. 4

Macrophage engulfment by invading cells following exposure to resistant MP. a Fluorescence images show macrophages co-cultured with cells for 24 h +/− MPs. (i) Res cells labelled with Cell Trace Far Red dye internalise macrophages (Ø) labelled with the CellTracker Green dye in the presence and absence of all MPs. (ii) Sen cells (red) engulf macrophages following co-culture with Res-MPs only and (iii) D3 cells (non-malignant) (red) are engulfed by macrophages (green). Images are slice views of confocal z-series and show cell internalization. Data represents a typical experiment. Scale bar as indicated (b) Flow cytometric quantitation of cell engulfment by macrophages. Co-culture of APC conjugated anti-CD11b antibody labelled macrophages with CFSE labelled sensitive (Sen) or resistant (Res) or D3 cells +/− (i) Res-MPs, (ii) Sen-MPs, or (iii) D3-MPs. Data represents mean ± SEM (n = 3). Student’s unpaired two tailed T-test used *P < 0.05 and **P < 0.01. Phagocytosis of cells by macrophages. c Confocal image of the phagocytosis of MDR acquired Sen cell (following Res-MP exposure) by macrophages. Scale bar as indicated. Representative image shown. d Flow cytometric quantitation of phagocytosis. APC conjugated anti-CD11b antibody labelled macrophages were co-cultured with CFSE labelled Sen cells or Res cells and D3 cells +/− MPs. Macrophage engulfed cells are positive for both CFSE and CD11b. Data represents mean ± SEM values of three independent experiments