Live-/Dead staining
THP-1-CWT cells were seeded with 300 µl/well of a 1∙10cells/ml cell suspension in THP-1 culture medium on a microscopy IBIDI-slide and stimulated with 160 nM Phorbol 12-myristate 13-acetate (PMA). Infection was done like already described with an MOI of 10. At the respective timepoint, the cells were washed with HBSS and then fixed with 150 µl ice-cold Fix Mix for 30 min at RT. Cells were permeabilised with 300 µl 0.1 % TritonX-100 in PBS for 5 min (RT) and then stained with 150 µl staining solution for 15 min at RT in the dark. The staining solution was prepared with 1.5 µl of each dye component A and B per ml PBS (LIVE/DEAD BacLight. Bacterial Viability Kits, Invitrogen). The cells were finally washed three times with HBSS and covered with three drops of Dako fluorescence mounting medium (Agilent Technologies). The slides were stored at 4 °C in the dark until imaging. Microscopy was performed with a LSM800 microscope (Zeiss) using a 63 x objective with immersion oil. The propidium iodide (PI) channel received an excitation wavelength of 305 nm, an emission wavelength of 617 nm and a detection wavelength of 576-700 nm. For detection of Syto9, an excitation wavelength of 483 nm, an emission wavelength of 500 nm and a detection wavelength of 495-560 nm were used.