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Figure S1. L. pneumophila induced a macrophage death with features distinct from classical apoptosis. A/J macrophages were incubated for 1 or 5 h with the L. pneumophila strain indicated or 1 µM of the apoptosis inducer staurosporine (Sigma-Aldrich). Caspase 3 activation was analyzed by immunofluorescence microscopy using a rabbit antibody specific for the activated form of caspase 3 (1:1,000 dilution; Invitrogen) and DAPI as described previously (A; reference 20) as well as the fraction of positive cells enumerated (B). In parallel, the percentage of cells with phase dark condensed nuclei was quantified (C). Results are shown from one experiment that is representative of more than two others. Error bars represent SD.