Protein kinase C activation and vacuolation in HeLa cells invaded by Mycoplasma penetrans

The AIDS-associated Mycoplasma penetrans is capable of inducing its own uptake by non-phagocytic cells, This study investigated the invasion of HeLa cells and its consequences by confocal laser scanning microscopy, Invasion was dependent on the duration of infection and temperature, diminished by inhibiting microfilament assembly with cytochalasin D and almost completely abolished by disorganising microtubules with vinblastine or taxol, After a short infection period (less than or equal to 20 min), pronounced activation of protein kinase C was detected in host cells, whereas prolonged infection resulted in intensive vacuolation of the host cells and a pronounced increment in intracellular organic peroxide levels. A marked decrease in the extent of vacuolation was observed when peroxide accumulation was partially prevented by cc-tocopherol. The possibility that M, penetrans entry into HeLa cells involves the activation of protein kinases and the recruitment of cytoskeleton components is discussed.