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Vibrio vulnificus RtxA1 Toxin Expression Upon Contact With Host Cells Is RpoS-Dependent

The expression of virulence genes in bacteria is known to be regulated by various environmental and host factors. Vibrio vulnificus, an estuarine bacterium, experiences a dramatic environmental change during its infection process. We reported that V. vulnificus RtxA1 toxin caused acute cell death on...

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Autores principales: Guo, Rui Hong, Lim, Ju Young, Tra My, Duong Nu, Jo, Se Jin, Park, Jung Up, Rhee, Joon Haeng, Kim, Young Ran
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5862816/
https://www.ncbi.nlm.nih.gov/pubmed/29600196
http://dx.doi.org/10.3389/fcimb.2018.00070
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author Guo, Rui Hong
Lim, Ju Young
Tra My, Duong Nu
Jo, Se Jin
Park, Jung Up
Rhee, Joon Haeng
Kim, Young Ran
author_facet Guo, Rui Hong
Lim, Ju Young
Tra My, Duong Nu
Jo, Se Jin
Park, Jung Up
Rhee, Joon Haeng
Kim, Young Ran
author_sort Guo, Rui Hong
collection PubMed
description The expression of virulence genes in bacteria is known to be regulated by various environmental and host factors. Vibrio vulnificus, an estuarine bacterium, experiences a dramatic environmental change during its infection process. We reported that V. vulnificus RtxA1 toxin caused acute cell death only when close contact to host cells was allowed. A sigma factor RpoS is a very important regulator for the maximal survival of pathogens under stress conditions. Here, we studied the role of RpoS in V. vulnificus cytotoxicity and mouse lethality. The growth of rpoS mutant strain was comparable to that of wild-type in heart infusion (HI) media and DMEM with HeLa cell lysate. An rpoS mutation resulted in decreased cytotoxicity, which was restored by in trans complementation. Interestingly, host contact increased the expression and secretion of V. vulnificus RtxA1 toxin, which was decreased and delayed by the rpoS mutation. Transcription of the cytotoxic gene rtxA1 and its transporter rtxB1 was significantly increased after host factor contact, whereas the activity was decreased by the rpoS mutation. In contrast, the rpoS mutation showed no effect on the transcriptional activity of a cytolytic heamolysin gene (vvhA). Additionally, the LD(50) of the rpoS mutant was 15-fold higher than that of the wild-type in specific pathogen-free CD-1 female mice. Taken together, these results show that RpoS regulates the expression of V. vulnificus RtxA1 toxin and its transporter upon host contact.
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spelling pubmed-58628162018-03-29 Vibrio vulnificus RtxA1 Toxin Expression Upon Contact With Host Cells Is RpoS-Dependent Guo, Rui Hong Lim, Ju Young Tra My, Duong Nu Jo, Se Jin Park, Jung Up Rhee, Joon Haeng Kim, Young Ran Front Cell Infect Microbiol Microbiology The expression of virulence genes in bacteria is known to be regulated by various environmental and host factors. Vibrio vulnificus, an estuarine bacterium, experiences a dramatic environmental change during its infection process. We reported that V. vulnificus RtxA1 toxin caused acute cell death only when close contact to host cells was allowed. A sigma factor RpoS is a very important regulator for the maximal survival of pathogens under stress conditions. Here, we studied the role of RpoS in V. vulnificus cytotoxicity and mouse lethality. The growth of rpoS mutant strain was comparable to that of wild-type in heart infusion (HI) media and DMEM with HeLa cell lysate. An rpoS mutation resulted in decreased cytotoxicity, which was restored by in trans complementation. Interestingly, host contact increased the expression and secretion of V. vulnificus RtxA1 toxin, which was decreased and delayed by the rpoS mutation. Transcription of the cytotoxic gene rtxA1 and its transporter rtxB1 was significantly increased after host factor contact, whereas the activity was decreased by the rpoS mutation. In contrast, the rpoS mutation showed no effect on the transcriptional activity of a cytolytic heamolysin gene (vvhA). Additionally, the LD(50) of the rpoS mutant was 15-fold higher than that of the wild-type in specific pathogen-free CD-1 female mice. Taken together, these results show that RpoS regulates the expression of V. vulnificus RtxA1 toxin and its transporter upon host contact. Frontiers Media S.A. 2018-03-15 /pmc/articles/PMC5862816/ /pubmed/29600196 http://dx.doi.org/10.3389/fcimb.2018.00070 Text en Copyright © 2018 Guo, Lim, Tra My, Jo, Park, Rhee and Kim. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Microbiology
Guo, Rui Hong
Lim, Ju Young
Tra My, Duong Nu
Jo, Se Jin
Park, Jung Up
Rhee, Joon Haeng
Kim, Young Ran
Vibrio vulnificus RtxA1 Toxin Expression Upon Contact With Host Cells Is RpoS-Dependent
title Vibrio vulnificus RtxA1 Toxin Expression Upon Contact With Host Cells Is RpoS-Dependent
title_full Vibrio vulnificus RtxA1 Toxin Expression Upon Contact With Host Cells Is RpoS-Dependent
title_fullStr Vibrio vulnificus RtxA1 Toxin Expression Upon Contact With Host Cells Is RpoS-Dependent
title_full_unstemmed Vibrio vulnificus RtxA1 Toxin Expression Upon Contact With Host Cells Is RpoS-Dependent
title_short Vibrio vulnificus RtxA1 Toxin Expression Upon Contact With Host Cells Is RpoS-Dependent
title_sort vibrio vulnificus rtxa1 toxin expression upon contact with host cells is rpos-dependent
topic Microbiology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5862816/
https://www.ncbi.nlm.nih.gov/pubmed/29600196
http://dx.doi.org/10.3389/fcimb.2018.00070
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