| Autor: |
Bayles, Kenneth W., Wesson, Carla A., Liou, Linda E., Fox, Lawrence K., Bohach, Gregory A., Trumble, W. R. |
| Zdroj: |
Infection and Immunity; January 1998, Vol. 66 Issue: 1 p336-342, 7p |
| Abstrakt: |
ABSTRACTWe examined the invasion of an established bovine mammary epithelial cell line (MAC-T) by a Staphylococcus aureusmastitis isolate to study the potential role of intracellular survival in the persistence of staphylococcal infections. S. aureuscells displayed dose-dependent invasion of MAC-T cells and intracellular survival. An electron microscopic examination of infected cells indicated that the bacteria induced internalization via a mechanism involving membrane pseudopod formation and then escaped into the cytoplasm following lysis of the endosomal membrane. Two hours after the internalization of S. aureus, MAC-T cells exhibited detachment from the matrix, rounding, a mottled cell membrane, and vacuolization of the cytoplasm, all of which are indicative of cells undergoing programmed cell death (apoptosis). By 18 h, the majority of the MAC-T cell population exhibited an apoptotic morphology. Other evidence for apoptosis was the generation of MAC-T cell DNA fragments differing in size by increments of approximately 180 bp and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling of the fragmented nuclear DNA of the infected host cells. These results demonstrate that after internalizationS. aureusescapes the endosome and induces apoptosis in nonprofessional phagocytes. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
|
