Abstract: XIAO Meng, WANG Jing, LIU Quan-zhong, QI Man-li. Department of Dermatology and Venereology, Tianjin Medical University General Hospital, Tianjin 300052, China Corresponding author: QI Man-li, Email: qiml7512@163.com 【Abstract】 Objective To detect antibodies against chlamydial plasmid-encoded protein 3 （Pgp3）, outer membrane complex protein B C-terminal peptide （OmcBc）, CT841 protein and heat shock protein 60 （HSP60） in the sera of patients with urogenital Chlamydia trachomatis infection. Methods Recombinant plasmids encoding the aforementioned four proteins and an empty plasmid were transformed into Escherichia coli separately followed by 2-hour isopropyl-1-thio-β-galactopyranoside （IPTG） induction and cell lysis. The expressed proteins were purified with glutathione magnetic beads and then used to coat 96-well enzyme-linked immunosorbent assay （ELISA） plates precoated by glutathione. Serum samples were collected from 20 patients with and 20 clients without urogenital C. trachomatis infection attending the sexually transmitted disease （STD） clinic of Tianjin Medical University General Hospital. ELISA with the expressed protein-coated plates was adopted to detect antibodies against these proteins in the serum samples. Results Of the 20 serum samples from C. trachomatis-infected patients, 14 （70%） had anti-Pgp3 antibody, 9 （45%） anti-OmcBc antibody, 8 （40%） anti-CT841 antibody, and 5 （25%） anti-HSP60 antibody. Meanwhile, no antibody was detected in any of the serum samples from uninfected clients except for one with anti-HSP60 antibody. Conclusions Of the four studied C. trachomatis proteins, Pgp3 appears to have the strongest antigenicity with the highest antibody-detection rate, while HSP60 exhibits the weakest antigenicity with the lowest antibody-detection rate. 【Key words】 Chlamydia trachomatis; Chaperonin 60; Pgp3; OmcB; CT841

Key words: Pgp3, OmcB, CT841, Hsp-60