title: Enhanced Adhesion and OspC Protein Synthesis of the Lyme Disease Spirochete Borrelia Burgdorferi Cultivated in a Host-Derived Tissue Co-Culture System.
abstract: BACKGROUND
  The adhesion process of Borrelia burgdorferi to susceptible host cell has not yet been completely understood regarding the function of OspA, OspB and OspC proteins and a conflict exists in the infection process.
  
  
  OBJECTIVE
  The adhesion rates of pathogenic (low BSK medium passaged or susceptible rat joint tissue co-cultivated) or non-pathogenic Borrelia burgdorferi (high BSK medium passaged) isolate (FNJ) to human umbilical vein endothelial cells (HUVEC) cultured on coverslips and the synthesis of OspA and OspC proteins were investigated to analyze the infection process of this bacterium.
  
  
  METHODS
  In-vitro study.
  
  
  METHODS
  Spirochetes were cultured in BSK medium or in a LEW/N rat tibiotarsal joint tissue feeder layer supported co-culture system using ESG co-culture medium and labelled with 3H-adenine for 48 hours. SDS-PAGE, Western Blotting, Immunogold A labeling as well as radiolabeling experiments were used to compare pathogenic or non pathogenic spirochetes during the adhesion process.
  
  
  RESULTS
  Tissue co-cultured B. burgdorferi adhered about ten times faster than BSK-grown spirochetes. Trypsin inhibited attachment to HUVEC and co-culture of trypsinized spirochetes with tissues reversed the inhibition. Also, the synthesis of OspC protein by spirochetes was increased in abundance after tissue co-cultures, as determined by SDS-PAGE and by electron microscopy analysis of protein A-immunogold staining by anti-OspC antibodies. OspA protein was synthesized in similar quantities in all Borrelia cultures analyzed by the same techniques.
  
  
  CONCLUSIONS
  Low BSK passaged or tissue co-cultured pathogenic Lyme disease spirochetes adhere to HUVEC faster than non-pathogenic high BSK passaged forms of this bacterium. Spirochetes synthesized OspC protein during host tissue-associated growth. However, we did not observe a reduction of OspA synthesis during host tissue co-cultivation in vitro.
authors.affiliation: Department of Basic and Industrial Microbiology, Trakya University Faculty of Science, Edirne, Turkey.
authors.forename: Ece
authors.initials: E
authors.lastname: Sen
authors.affiliation: Department of Internal Medicine Rheumatology, University of Medicine and Dentistry of New Jersey, New Brunswick, USA.
authors.forename: Leonard H
authors.initials: LH
authors.lastname: Sigal
keywords: Adhesion; Borrelia burgdorferi; HUVEC; OspA; OspC; cell culture; pathogenicity