Exocytotic secretion of toxins from macrophages infected with Escherichia coli O157

Cell Structure and Function
O ShimadaS Atsumi

Abstract

This study examined whether macrophages are involved in the development of pathogenicity in Shiga-like toxin (SLT)-producing enterohemorrhagic Escherichia coil (EHEC) O157:H7. Macrophages were infected with the bacteria, after which the macrophage culture medium showed a clear increase in toxicity in rats in vivo as well as in rat aortic endothelial cells in vitro. The increased toxicity resulted mainly from a rapid increase in the concentrations of SLT type I (SLT-I) and type II (SLT-II) and partly from an increase in concentrations of the proinflammatory cytokines, tumor necrosis factor alpha (TNFalpha) and interleukin-1 (IL-1), in the culture medium. Most of the EHEC O157 added to the macrophage culture were quickly incorporated to form phagosomes, which then fused with lysosomes to become phagolysosomes. During this intracellular digestion process, the EHEC O157 remained alive for about 15 min, and continued synthesizing and secreting the toxins SLT-1 and SLT-II. The bacteria were then killed and digested in the phagolysosomes with significant amounts of the toxins retained. Subsequently, the contents of the phagolysosomes were exocytotically secreted from the macrophage cell membrane into the surrounding culture medium. Su...Continue Reading

References

May 1, 1990·Pediatric Nephrology : Journal of the International Pediatric Nephrology Association·B S KaplanT G Obrig
Aug 1, 1990·Microbial Pathogenesis·T J BarrettN A Strockbine
Jan 1, 1989·Clinical Microbiology Reviews·M A Karmali
Jul 1, 1987·Proceedings of the National Academy of Sciences of the United States of America·S B CalderwoodJ J Mekalanos
Oct 1, 1987·The Journal of Cell Biology·J A Cooper
Nov 1, 1987·The Journal of Experimental Zoology·C E Arboleda, G L Gerton
Jun 1, 1986·Food and Chemical Toxicology : an International Journal Published for the British Industrial Biological Research Association·R J RiddellM Balls
Mar 24, 1983·The New England Journal of Medicine·L W RileyM L Cohen
Aug 10, 1995·The New England Journal of Medicine·T G BoyceP M Griffin
Jun 1, 1994·The Pediatric Infectious Disease Journal·L K PickeringF B Stapleton
Jan 1, 1996·The Journal of Cell Biology·S ZimmerliJ D Ernst
Apr 1, 1996·The Journal of Pediatrics·R L SieglerJ B Cook
Aug 1, 1997·The Journal of Biological Chemistry·L JohannesB Goud
Jun 20, 1998·The Journal of Histochemistry and Cytochemistry : Official Journal of the Histochemistry Society·O ShimadaS Suzuki

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Citations

Mar 2, 2013·PloS One·Leticia V BentancorMarina S Palermo
Nov 13, 2012·IEEE Journal of Biomedical and Health Informatics·Lin MaKuanguan Wang
Dec 14, 2007·IEEE Transactions on Bio-medical Engineering·Zhiwei Zhu, Qiang Ji
Mar 28, 2006·IEEE Transactions on Neural Systems and Rehabilitation Engineering : a Publication of the IEEE Engineering in Medicine and Biology Society·Matthew A Schiefer, Warren M Grill
Aug 9, 2003·IEEE Transactions on Medical Imaging·Adam Hoover, Michael Goldbaum
Dec 23, 2014·IEEE Transactions on Image Processing : a Publication of the IEEE Signal Processing Society·Jixu Chen, Qiang Ji

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