scholarly journals Comparative analysis of proteins in the culture supernatants of human intestinal epithelial cells infected with the wild-type and rtxE mutant of Vibrio vulnificus

2011 ◽  
Author(s):  
Tae Kim
Keyword(s):  
Comparative Analysis ◽  
Epithelial Cells ◽  
Vibrio Vulnificus ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Wild Type ◽  
Human Intestinal Epithelial Cells ◽  
Culture Supernatants

scholarly journals Vibrio vulnificus rtxE Is Important for Virulence, and Its Expression Is Induced by Exposure to Host Cells

2008 ◽  
Vol 76 (4) ◽  
pp. 1509-1517 ◽  
Author(s):  
Byung Cheol Lee ◽  
Jeong Hyun Lee ◽  
Myung Won Kim ◽  
Byoung Sik Kim ◽  
Man Hwan Oh ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Vibrio Vulnificus ◽  
Lethal Dose ◽  
Host Cells ◽  
Transcriptional Unit ◽  
Intestinal Epithelial ◽  
Wild Type ◽  
Reading Frame ◽  
Human Intestinal Epithelial Cells

ABSTRACT Numerous secreted virulence factors have been proposed to account for the fulminating and destructive nature of Vibrio vulnificus infections. A mutant of V. vulnificus that exhibited less cytotoxicity to INT-407 human intestinal epithelial cells was screened from a library of mutants constructed by random transposon mutagenesis. A transposon-tagging method was used to identify and clone an open reading frame encoding an RTX toxin secretion ATP binding protein, RtxE, from V. vulnificus. The deduced amino acid sequence of RtxE from V. vulnificus was 91% identical to that reported from Vibrio cholerae. Functions of the rtxE gene in virulence were assessed by constructing an isogenic mutant whose rtxE gene was inactivated by allelic exchanges and by evaluating the differences between its virulence phenotype and that of the wild type in vitro and in mice. The disruption of rtxE blocked secretion of RtxA to the cell exterior and resulted in a significant reduction in cytotoxic activity against epithelial cells in vitro. Also, the intraperitoneal 50% lethal dose of the rtxE mutant was 104 to 105 times higher than that of the parental wild type, indicating that RtxE is essential for the virulence of V. vulnificus. Furthermore, the present study demonstrated that the rtxBDE genes are transcribed as one transcriptional unit under the control of a single promoter, P rtxBDE . The activity of V. vulnificus P rtxBDE is induced by exposure to INT-407 cells, and the induction requires direct contact of the bacteria with the host cells.

Sign in / Sign up

Export Citation Format

Share Document