Fig. 4. Effect of inhibiting kinesin or dynein on SCVs. HeLa cells were treated with aurintricarboxilic acid (ATA) 3 hours prior to infection, or transfected with vectors expressing p50/dynamitin (p50) or GFP-KLC2-TPR (TPR) 16 hours prior to infection with either wild-type (WT) S. typhimurium or a sifA mutant strain (green in merged images). Cells were fixed 8 hours p.i. and labelled with an anti-LAMP-1 antibody (red in merged images). (A) Representative confocal micrographs showing LAMP-1 distribution in cells infected with GFP-WT bacteria. Left panel of p50-expressing cells is at lower magnification to show redistribution of LAMP-1 to cell periphery (indicated by arrowheads); boxed area is at higher magnification. Right panel of p50-expressing cells shows a second example of SCVs at higher magnification. Scale bar: 2 µm. (B) Representative confocal micrographs showing LAMP-1 distribution (red in merged images) in cells infected with GFP-sifA mutant (green in merged images). (C) Association of bacteria with LAMP-1 in untreated cells or cells expressing p50 or TPR, or which had been incubated with ATA. Association was evaluated by confocal microscopy. Results show the mean ± s.d. of at least three independent experiments in which more than 100 bacteria were analysed for each experiment.