• Login
    View Item 
    •   DSpace Home
    • Stony Brook University
    • Stony Brook Theses & Dissertations [SBU]
    • View Item
    •   DSpace Home
    • Stony Brook University
    • Stony Brook Theses & Dissertations [SBU]
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of DSpaceCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsDepartmentThis CollectionBy Issue DateAuthorsTitlesSubjectsDepartment

    My Account

    LoginRegister

    Statistics

    Most Popular ItemsStatistics by CountryMost Popular Authors

    The Inhibitory Effect of <italic>Francisella tularensis</italic> on Endothelial Cells

    Thumbnail
    View/Open
    Bublitz_grad.sunysb_0771E_10866.pdf (2.587Mb)
    Date
    1-May-12
    Author
    Bublitz, DeAnna
    Publisher
    The Graduate School, Stony Brook University: Stony Brook, NY.
    Metadata
    Show full item record
    Abstract
    The endothelium can be activated by various bacterial pathogens to secrete proinflammatory cytokines and recruit circulating leukocytes. However, there is a distinct lack of activation of these cells by Francisella tularensis, the causative agent of tularemia. Given the importance of endothelial cells in facilitating innate immunity, we investigated the ability of the attenuated live vaccine strain (LVS) and virulent Schu S4 strain of F. tularensis to inhibit the proinflammatory response of human umbilical vein endothelial cells (HUVEC). Living F. tularensis LVS and Schu S4 did not stimulate secretion of the chemokine CCL2 by HUVEC, whereas material released from heat-killed bacteria did. Furthermore, the living bacteria suppressed secretion in response to heat-killed F. tularensis. This phenomenon was dose- and contact-dependent, and it occurred relatively rapidly upon infection. The living bacteria did not inhibit the activation of HUVEC by E. coli LPS, highlighting the relative specificity of this suppression. The endothelial protein C receptor (EPCR) confers anti-inflammatory properties when bound by activated protein C. When the EPCR was blocked, F. tularensis lost the ability to suppress activation of HUVEC. To our knowledge, this is the first report that a bacterial pathogen inhibits the host immune response via the EPCR. As the suppressive effect of F. tularensis on endothelial cells requires contact with the cell and a functional EPCR, we investigated the fate of the EPCR. When HUVEC were exposed to live bacteria, there was less EPCR expressed on the cell surface but also less EPCR released into the medium. Furthermore, the EPCR was internalized by endothelial cells shortly after contact with the bacteria. The bacterial gene acrA, a part of a multi-drug efflux pump, was implicated as necessary to block activation of endothelial cells.
    Description
    154 pg.
    URI
    http://hdl.handle.net/1951/59590
    Collections
    • Stony Brook Theses & Dissertations [SBU] [1955]

    SUNY Digital Repository Support
    DSpace software copyright © 2002-2023  DuraSpace
    Contact Us | Send Feedback
    DSpace Express is a service operated by 
    Atmire NV
     

     


    SUNY Digital Repository Support
    DSpace software copyright © 2002-2023  DuraSpace
    Contact Us | Send Feedback
    DSpace Express is a service operated by 
    Atmire NV