title: Specific adherence of Borrelia burgdorferi extracellular vesicles to human endothelial cells in culture.
abstract: Borrelia burgdorferi produces extracellular vesicles which contain some of the outer surface proteins of the bacterium (e.g., OspA and OspB). Borrelial vesicles, isolated by differential centrifugation and filtration, were tested for the ability to bind to cultured human umbilical vein endothelial (HUVE) cells in culture. The recently described lipoprotein OspD was expressed on vesicles. Vesicles exhibited differential expression of OspB and OspD in a relationship with passage number and medium serum supplement type, respectively. Qualitative immunoblotting analyses demonstrated dose-dependent, passage number-dependent adsorption of vesicles by HUVE cells. This adsorption was demonstrated to be dependent upon a borrelial component of the vesicle and not due to the presence of minor contamination with intact spirochetes. Quantitative experiments examining inhibition of B. burgdorferi-HUVE association as a function of prior vesicle-HUVE association demonstrated dependence upon (i) a borrelial component(s) in the vesicle, (ii) low passage number, and (iii) vesicle protein concentration. However, vesicle pretreatment of the HUVE cell monolayer was not requisite for this inhibition. Vesicles from highly passaged borrelias were noninhibitory for B. burgdorferi-HUVE cell association, regardless of the serum used to supplement the medium. The use of vesicles as a tool for studying B. burgdorferi pathogenesis and/or physiology is proposed.
authors.affiliation: Department of Periodontics, University of Texas Health Science Center, San Antonio 78284.
authors.forename: R J
authors.initials: RJ
authors.lastname: Shoberg
authors.forename: D D
authors.initials: DD
authors.lastname: Thomas
mesh_terms: D000327:Adsorption; D000818:Animals; D000942:Antigens, Bacterial; D000954:Antigens, Surface / Q000032:analysis; D001422:Bacterial Adhesion; D001425:Bacterial Outer Membrane Proteins / Q000032:analysis; D001428:Bacterial Vaccines; D015748:Borrelia burgdorferi Group / Q000472:pathogenicity*; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000382:microbiology*; D006801:Humans; D007075:Immunoglobulin M / Q000502:physiology; D008074:Lipoproteins; D051379:Mice; D011817:Rabbits
chemical_list: D000942:Antigens, Bacterial; D000954:Antigens, Surface; D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines; D007075:Immunoglobulin M; D008074:Lipoproteins; C072045:OspA protein; C077524:outer surface protein D, Borrelia burgdorferi; C077030:OspB protein, Borrelia burgdorferi