title: Infection of human endothelial cells with Bartonella bacilliformis is dependent on Rho and results in activation of Rho.
abstract: Bartonella bacilliformis was continuously internalized into human endothelial cells beginning shortly after addition of the bacteria and continuing for at least 24 h after infection in vitro, with a major increase in uptake occurring between 16 and 24 h. Preincubation of endothelial cells with C3 exoenzyme, which inactivated intracellular Rho-GTPase, blocked internalization of the bacteria. Addition of C3 exoenzyme at any time after addition of the bacteria blocked further internalization of bacteria, including the major uptake of bacteria internalized at 16 to 24 h. Rho, a key signaling protein in pathways involving actin organization, was directly shown to be activated in endothelial cells undergoing infection with B. bacilliformis, with maximal activation and translocation to the plasma membrane at 12 to 16 h. At late times of infection, most of the bacteria were found in a perinuclear location. Staining of the Golgi complex with specific markers, anti-human Golgin-97, anti-KDEL receptor, and BODIPY-TR ceramide, showed colocalization of bacteria in the Golgi complex region. Disruption of the Golgi complex with brefeldin A scattered the bacteria from this perinuclear location and resulted in inhibition of internalization of the bacteria in endothelial cells.
authors.affiliation: Department of Medical Biochemistry and Genetics, Texas A&M University System, Health Science Center, College of Medicine, College Station, Texas 77843-1114, USA.
authors.forename: A
authors.initials: A
authors.lastname: Verma
authors.forename: G E
authors.initials: GE
authors.lastname: Davis
authors.forename: G M
authors.initials: GM
authors.lastname: Ihler
mesh_terms: D036002:ADP Ribose Transferases / Q000378:metabolism; D001473:Bartonella / Q000472:pathogenicity*; D001905:Botulinum Toxins; D002462:Cell Membrane / Q000201:enzymology; D002478:Cells, Cultured; D003600:Cytosol / Q000201:enzymology; D004730:Endothelium, Vascular / Q000166:cytology / Q000382:microbiology*; D004789:Enzyme Activation; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D018613:Microscopy, Confocal; D014471:Umbilical Veins; D014774:Virulence; D020741:rho GTP-Binding Proteins / Q000378:metabolism*
chemical_list: D036002:ADP Ribose Transferases; C063007:exoenzyme C3, Clostridium botulinum; D001905:Botulinum Toxins; D020741:rho GTP-Binding Proteins