title: Cytotoxic necrotizing factor-1 contributes to Escherichia coli K1 invasion of the central nervous system.
abstract: Escherichia coli K1 invasion of brain microvascular endothelial cells (BMECs) is a prerequisite for penetration into the central nervous system and requires actin cytoskeletal rearrangements. Here, we demonstrate that E. coli K1 invasion of BMECs requires RhoA activation. In addition, we show that cytotoxic necrotizing factor-1 (CNF1) contributes to E. coli K1 invasion of brain endothelial cells in vitro and traversal of the blood-brain barrier in the experimental hematogenous meningitis animal model. These in vitro and in vivo effects of CNF1 were dependent upon RhoA activation as shown by (a) decreased invasion and RhoA activation with the Delta cnf1 mutant of E. coli K1 and (b) restoration of invasion frequency of the Delta cnf1 mutant to the level of the parent E. coli K1 strain in BMECs with constitutively active RhoA. In addition, CNF1-enhanced E. coli invasion of brain endothelial cells and stress fiber formation were independent of focal adhesion kinase and phosphatidylinositol 3-kinase activation. This is the first demonstration that CNF1 contributes to E. coli K1 invasion of BMECs.
authors.affiliation: Division of Pediatric Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.
authors.forename: Naveed Ahmed
authors.initials: NA
authors.lastname: Khan
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Kee Jun
authors.initials: KJ
authors.lastname: Kim
authors.forename: Jin Woong
authors.initials: JW
authors.lastname: Chung
authors.forename: Carol Ann
authors.initials: CA
authors.lastname: Wass
authors.forename: Kwang Sik
authors.initials: KS
authors.lastname: Kim
mesh_terms: D000577:Amides / Q000494:pharmacology; D000818:Animals; D001427:Bacterial Toxins / Q000235:genetics; D001483:Base Sequence; D001812:Blood-Brain Barrier; D001921:Brain / Q000382:microbiology*; D002478:Cells, Cultured; D002560:Cerebrovascular Circulation / Q000502:physiology; D003603:Cytotoxins / Q000235:genetics / Q000502:physiology*; D017931:DNA Primers; D004195:Disease Models, Animal; D004730:Endothelium, Vascular / Q000382:microbiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004926:Escherichia coli / Q000302:isolation & purification / Q000472:pathogenicity* / Q000502:physiology; D029968:Escherichia coli Proteins; D017353:Gene Deletion; D006801:Humans; D007231:Infant, Newborn; D016920:Meningitis, Bacterial / Q000382:microbiology; D016297:Mutagenesis, Site-Directed; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D011994:Recombinant Proteins / Q000378:metabolism; D014162:Transfection; D020742:rhoA GTP-Binding Protein / Q000378:metabolism
chemical_list: D000577:Amides; D001427:Bacterial Toxins; D003603:Cytotoxins; D017931:DNA Primers; D004791:Enzyme Inhibitors; D029968:Escherichia coli Proteins; D011725:Pyridines; D011994:Recombinant Proteins; C060296:cytotoxic necrotizing factor type 1; C108830:Y 27632; D020742:rhoA GTP-Binding Protein