Differential responses of cells from human skin keratinocyte and bovine mammary epithelium to attack by pore-forming Staphylococcus aureus alpha-toxin.
Human skin keratinocytes HaCat attacked by Staphylococcus aureus alpha-toxin showed a transient drop of cellular ATP levels whereas in toxin-perforated bovine mammary epithelial cells (BMEC), the ATP levels dropped more slowly. Morphologically, during the ATP level depletion, HaCat cell developed a spacious intracellular vacuole together with the transient influx of trypan blue. WST-1 signal, which tested the function of mitochondrial enzyme in viable cells, also decreased concomitantly. On the other hand, BMEC excluded trypan blue and vacuolation was not observed throughout the experiment. We conclude that mammary epithelial cells resist the toxin better than keratinocytes. This is the first report showing that alpha-toxin enhances transient membrane permeability to large molecules, temporary vacuole formation and the transient defect of mitochondrial enzyme in viable cells without cell lysis.
Suriyaphol
Gunnaporn
G
Biochemistry Unit, Department of Physiology, Faculty of Veterinary Science, Chulalongkorn University, Pathumwan, Bangkok 10330, Thailand. Gunnaporn.V@chula.ac.th
Sarikaputi
Meena
M
Suriyaphol
Prapat
P