title: Human antibody responses to a Chlamydia-secreted protease factor.
abstract: We have previously identified a chlamydia-secreted protein (designated chlamydial proteasome/protease-like activity factor, or CPAF) in the cytosol of chlamydia-infected cells. Although CPAF is known to degrade host transcription factors required for major histocompatibility complex antigen expression in cultured cells, it is not clear whether CPAF is produced and maintains similar functions in humans infected with chlamydial organisms. We now report that CPAF does not preexist in chlamydial organisms and that CPAF synthesis requires live organism replication in cultured cells. Mice inoculated with live, but not mice inoculated with dead, chlamydial organisms produced a strong antibody response to CPAF, correlating CPAF-specific antibody production with CPAF synthesis in animals. Sera from women diagnosed with Chlamydia trachomatis cervicitis displayed higher levels of antibodies to CPAF than to either chlamydial major outer membrane protein or heat shock protein 60, suggesting that CPAF is both produced and immunogenic during human chlamydial infection.
authors.affiliation: Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA.
authors.forename: Jyotika
authors.initials: J
authors.lastname: Sharma
authors.forename: Anthony M
authors.initials: AM
authors.lastname: Bosnic
authors.forename: Jeanna M
authors.initials: JM
authors.lastname: Piper
authors.forename: Guangming
authors.initials: G
authors.lastname: Zhong
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000276:immunology*; D018834:Chaperonin 60 / Q000096:biosynthesis / Q000276:immunology; D002690:Chlamydia Infections / Q000378:metabolism; D002692:Chlamydia trachomatis / Q000276:immunology*; D005260:Female; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018272:Porins / Q000096:biosynthesis / Q000276:immunology; D046988:Proteasome Endopeptidase Complex / Q000096:biosynthesis / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D018834:Chaperonin 60; D018272:Porins; C071677:omp1 protein, Chlamydia trachomatis; D046988:Proteasome Endopeptidase Complex