Pertussis Toxin Exploits Specific Host Cell Signaling Pathways for Promoting Invasion and Translocation of Escherichia coli K1 RS218 in Human Brain-derived Microvascular Endothelial Cells.
Pertussis toxin (PTx), an AB5 toxin and major virulence factor of the whooping cough-causing pathogen Bordetella pertussis, has been shown to affect the blood-brain barrier. Dysfunction of the blood-brain barrier may facilitate penetration of bacterial pathogens into the brain, such as Escherichia coli K1 (RS218). In this study, we investigated the influence of PTx on blood-brain barrier permissiveness to E. coli infection using human brain-derived endothelial HBMEC and TY10 cells as in vitro models. Our results indicate that PTx acts at several key points of host cell intracellular signaling pathways, which are also affected by E. coli K1 RS218 infection. Application of PTx increased the expression of the pathogen binding receptor gp96. Further, we found an activation of STAT3 and of the small GTPase Rac1, which have been described as being essential for bacterial invasion involving host cell actin cytoskeleton rearrangements at the bacterial entry site. In addition, we showed that PTx induces a remarkable relocation of VE-cadherin and β-catenin from intercellular junctions. The observed changes in host cell signaling molecules were accompanied by differences in intracellular calcium levels, which might act as a second messenger system for PTx. In summary, PTx not only facilitates invasion of E. coli K1 RS218 by activating essential signaling cascades; it also affects intercellular barriers to increase paracellular translocation.
From the Institute of Infectiology, Center for Molecular Biology of Inflammation, Westfälische Wilhelms-Universität Münster, D-48149 Münster, Germany.
Sascha
S
Karassek
From the Institute of Infectiology, Center for Molecular Biology of Inflammation, Westfälische Wilhelms-Universität Münster, D-48149 Münster, Germany.
Laura
L
Starost
From the Institute of Infectiology, Center for Molecular Biology of Inflammation, Westfälische Wilhelms-Universität Münster, D-48149 Münster, Germany.
Johanna
J
Solbach
From the Institute of Infectiology, Center for Molecular Biology of Inflammation, Westfälische Wilhelms-Universität Münster, D-48149 Münster, Germany.
Lilo
L
Greune
the Department of Neurology and Clinical Neuroscience, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan, and.
Yasuteru
Y
Sano
the Department of Neurology and Clinical Neuroscience, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan, and.
Takashi
T
Kanda
the Pediatric Infectious Diseases Division, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287.
KwangSik
K
Kim
From the Institute of Infectiology, Center for Molecular Biology of Inflammation, Westfälische Wilhelms-Universität Münster, D-48149 Münster, Germany, infekt@uni-muenster.de.
M Alexander
MA
Schmidt
D015703:Antigens, CD / Q000378:metabolism; D018988:Bacterial Translocation / Q000187:drug effects*; D001921:Brain / Q000166:cytology*; D015820:Cadherins / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D042783:Endothelial Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism / Q000382:microbiology; D004926:Escherichia coli / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics; D055806:Microvessels / Q000166:cytology*; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D037342:Pertussis Toxin / Q000494:pharmacology*; D021381:Protein Transport / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D050796:STAT3 Transcription Factor / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*; D015854:Up-Regulation / Q000187:drug effects; D051176:beta Catenin / Q000378:metabolism; D020830:rac1 GTP-Binding Protein / Q000378:metabolism; D000099152:Cadherin 5
D015703:Antigens, CD; D015820:Cadherins; D008562:Membrane Glycoproteins; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D037342:Pertussis Toxin; D012333:RNA, Messenger; D050796:STAT3 Transcription Factor; D051176:beta Catenin; D020830:rac1 GTP-Binding Protein; D000099152:Cadherin 5; C053387:endoplasmin
Bordetella pertussis; Escherichia coli (E. coli); VE-cadherin; beta-catenin (B-catenin); endothelial dysfunction; pertussis toxin; translocation