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Chlamydia trachomatis Transformants Show a Significant Reduction in Rates of Invasion upon Removal of Key Tarp Domains

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Date Issued:
2016
Abstract/Description:
Chlamydia trachomatis is an obligate, intracellular bacterium which is known to cause multiple human infections including nongonococcal urethritis (serovars D-K), lymphogranuloma venereum (serovars L1, L2, L3) and trachoma (serovars A-C). The infectious form of the bacterium, called the elementary body (EB), harbors a type III secreted effector known as Tarp (translocated actin recruiting phosphoprotein) which is a candidate virulence factor and is hypothesized to play a role in C. trachomatis' ability to invade and grow within epithelial cells in a human host. C. trachomatis L2 Tarp harbors five unique protein domains which include the Phosphorylation Domain, the Proline Rich Domain, the Actin Binding Domain, and two F-Actin Binding Domains. Tarp has been biochemically characterized in vitro, but it has yet to be characterized in vivo due to a lack of genetic tools in C. trachomatis. Through the recent generation of a chlamydial transformation system, we have created transformants which express epitope tagged wild type or mutant Tarp effectors. In this thesis, C. trachomatis transformants expressing Tarp lacking one of the five biochemically defined protein domains were used to examine both bacterial invasion and bacterial development within mammalian host cells. Our results demonstrate that those EBs which harbor mutant Tarp missing either its Phosphorylation Domain or its Actin Binding Domain were less capable of host cell invasion. However, these transformants, once internalized, were capable of normal development when compared to wild type C. trachomatis or C. trachomatis harboring an epitope tagged wild type Tarp effector. These results suggest that transformant expressed Tarp lacking the Phosphorylation Domain or Actin Binding Domain may be acting as a dominant-negative effector protein. Ultimately, these results support the hypothesis that Tarp is a virulence factor for Chlamydia trachomatis. Furthermore, this data indicates that through the manipulation of the Tarp effector, C. trachomatis pathogenesis may be attenuated.
Title: Chlamydia trachomatis Transformants Show a Significant Reduction in Rates of Invasion upon Removal of Key Tarp Domains.
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Name(s): Parrett, Christopher, Author
Jewett, Travis, Committee Chair
Roy, Herve, Committee Member
Moore, Sean, Committee Member
University of Central Florida, Degree Grantor
Type of Resource: text
Date Issued: 2016
Publisher: University of Central Florida
Language(s): English
Abstract/Description: Chlamydia trachomatis is an obligate, intracellular bacterium which is known to cause multiple human infections including nongonococcal urethritis (serovars D-K), lymphogranuloma venereum (serovars L1, L2, L3) and trachoma (serovars A-C). The infectious form of the bacterium, called the elementary body (EB), harbors a type III secreted effector known as Tarp (translocated actin recruiting phosphoprotein) which is a candidate virulence factor and is hypothesized to play a role in C. trachomatis' ability to invade and grow within epithelial cells in a human host. C. trachomatis L2 Tarp harbors five unique protein domains which include the Phosphorylation Domain, the Proline Rich Domain, the Actin Binding Domain, and two F-Actin Binding Domains. Tarp has been biochemically characterized in vitro, but it has yet to be characterized in vivo due to a lack of genetic tools in C. trachomatis. Through the recent generation of a chlamydial transformation system, we have created transformants which express epitope tagged wild type or mutant Tarp effectors. In this thesis, C. trachomatis transformants expressing Tarp lacking one of the five biochemically defined protein domains were used to examine both bacterial invasion and bacterial development within mammalian host cells. Our results demonstrate that those EBs which harbor mutant Tarp missing either its Phosphorylation Domain or its Actin Binding Domain were less capable of host cell invasion. However, these transformants, once internalized, were capable of normal development when compared to wild type C. trachomatis or C. trachomatis harboring an epitope tagged wild type Tarp effector. These results suggest that transformant expressed Tarp lacking the Phosphorylation Domain or Actin Binding Domain may be acting as a dominant-negative effector protein. Ultimately, these results support the hypothesis that Tarp is a virulence factor for Chlamydia trachomatis. Furthermore, this data indicates that through the manipulation of the Tarp effector, C. trachomatis pathogenesis may be attenuated.
Identifier: CFE0006159 (IID), ucf:51142 (fedora)
Note(s): 2016-05-01
M.S.
Medicine, Molecular Biology and Micro
Masters
This record was generated from author submitted information.
Subject(s): Chlamydia trachomatis -- sexually transmitted disease -- Tarp -- translocated actin recruiting phosphoprotein -- deletion mutant -- transformant -- dominant-negative effect -- tyrosine phosphorylation -- pyrene actin polymerization assay -- invasion assay -- SDS-PAGE -- western blot -- immunoprecipitation -- c-myc tag -- growth curve -- subcellular fractionation and protein extraction -- phosphorylation domain -- proline rich domain -- actin binding domain -- F-actin binding domains 1 and 2 -- shuttle vector PctSV.1 -- L2 serovar
Persistent Link to This Record: http://purl.flvc.org/ucf/fd/CFE0006159
Restrictions on Access: campus 2021-05-15
Host Institution: UCF

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