Characteristics of the Phagocytic Cup Induced by Uropathogenic E. coli
Huaibin Wang 1, Feng-Xia Liang 1 and Xiang-Peng Kong 1*
1 Departments of Biochemistry (HW,X-PK) and Dermatology (F-XL), New York University School of Medicine, New York, New York
* To whom correspondence should be addressed. E-mail: kong{at}saturn.med.nyu.edu.
Submitted on January 18, 2008
Accepted on 7 March 2008
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Abstract |
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Uropathogenic E. coli invade the urothelial umbrella cells by utilizing the zipper mechanism. However, the details of the early events of this invasion, such as the formation of the phagocytic cup, are not yet well understood. We show here, using thin section electron microscopy (EM) and immunogold labeling, that the plasma membrane curves around the bacterial surface in the phagocytic cup. There exists a uniform gap between the bacterium and the urothelial membrane, and actin filaments are present in the phagocytic cup. We suggest that the action-reaction between the mechanical forces generated by pilus retraction of the bacterium and the actin polymerization in the urothelial cell play a role in maintaining the phagocytic cup. This manuscript contains online supplemental material at http://www.jhc.org. Please visit this article online to view these materials.
Key Words:
urinary tract infection, uropathogenic bacteria, urinary bladder, urothelium, bacteria invasion, phagocytosis, actin filaments, immunogold labeling, electron microscopy