title: The hypothetical protein CT813 is localized in the Chlamydia trachomatis inclusion membrane and is immunogenic in women urogenitally infected with C. trachomatis.
abstract: Using antibodies raised with chlamydial fusion proteins, we have localized a protein encoded by hypothetical open reading frame CT813 in the inclusion membrane of Chlamydia trachomatis. The detection of the C. trachomatis inclusion membrane by an anti-CT813 antibody was blocked by the CT813 protein but not unrelated fusion proteins. The CT813 protein was detected as early as 12 h after chlamydial infection and was present in the inclusion membrane during the entire growth cycle. All tested serovars from C. trachomatis but not other chlamydial species expressed the CT813 protein. Exogenously expressed CT813 protein in HeLa cells displayed a cytoskeleton-like structure similar to but not overlapping with host cell intermediate filaments, suggesting that the CT813 protein is able to either polymerize or associate with host cell cytoskeletal structures. Finally, women with C. trachomatis urogenital infection developed high titers of antibodies to the CT813 protein, demonstrating that the CT813 protein is not only expressed but also immunogenic during chlamydial infection in humans. In all, the CT813 protein is an inclusion membrane protein unique to C. trachomatis species and has the potential to interact with host cells and induce host immune responses during natural infection. Thus, the CT813 protein may represent an important candidate for understanding C. trachomatis pathogenesis and developing intervention and prevention strategies for controlling C. trachomatis infection.
authors.affiliation: Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, Texas 78229, USA.
authors.forename: Chaoqun
authors.initials: C
authors.lastname: Chen
authors.forename: Ding
authors.initials: D
authors.lastname: Chen
authors.forename: Jyotika
authors.initials: J
authors.lastname: Sharma
authors.forename: Wen
authors.initials: W
authors.lastname: Cheng
authors.forename: Youmin
authors.initials: Y
authors.lastname: Zhong
authors.forename: Kaiyang
authors.initials: K
authors.lastname: Liu
authors.forename: Jani
authors.initials: J
authors.lastname: Jensen
authors.forename: Rochelle
authors.initials: R
authors.lastname: Shain
authors.forename: Bernard
authors.initials: B
authors.lastname: Arulanandam
authors.forename: Guangming
authors.initials: G
authors.lastname: Zhong
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000276:immunology / Q000378:metabolism; D001426:Bacterial Proteins / Q000276:immunology* / Q000378:metabolism* / Q000648:ultrastructure; D002690:Chlamydia Infections / Q000276:immunology / Q000382:microbiology; D002692:Chlamydia trachomatis / Q000378:metabolism / Q000472:pathogenicity* / Q000648:ultrastructure; D005260:Female; D052776:Female Urogenital Diseases / Q000276:immunology* / Q000382:microbiology; D006367:HeLa Cells; D006801:Humans; D002479:Inclusion Bodies / Q000378:metabolism* / Q000648:ultrastructure; D007425:Intracellular Membranes / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins