Detection Of Anti-chlamydial Immunodominant Protein’s Antibody In The Serum Of Urogenital Chlamydia Trachomatis Infected Person

In recent years, Chlamydia trachomatis (C.t) urogenital infection becomes the most common sexually transmitted disease. In the worldwide, nearly10million people are diagnosed as C.t annually. The majority of genital C.t infections are initially asymptomatic and unnoticed, which lasts for a long time and finally may result in severe complications including female infertility, ectopic pregnancy, male prostatitis and epididymitis. About70%to90%of C.t infected women and50%to70%of C.t infected men are asymptomatic. They become the important C.t reservoir host and source of infection which contributes to the widespread C.t popularity.In order to control C.t infection, it’s very important to detect early C.t infections and provide efficient treatment for them. However, our available C.t test kits are not suitable for early screening. The main target proteins used for C.t detection kits are Chlamydial MOMP (major outer membrane protein, MOMP) or heat shock protein60(chlamydial heat shock protein60, Hsp-60). Recent studies show that antigenicity of these two proteins are not strong enough.In our study, we express three C.t immunodominant proteins while Hsp-60as a control. Then we collect clinical C.t infected and uninfected person’s sera. ELISA is adopted to detect antibodies to these four C.t proteins in the sera.Objective:To express three C.t immunodominant proteins while C.t Hsp-60as a control and verify the antigenic of these four proteins. To explore C.t antigen proteins suitable for early screening of C.t infection.Methods:The recombinant plasmids of pGEX-6P-1-pgp3, pGEX-6P-1-omcBc, pGEX-6P-1-ct841and pGEX-6P-1-ct110(hsp60) were transferred into E.coli respectively. The protein expression was induced by IPTG. The protein lysate were purified with glutathione magnetic beads and then used to coat glutathione precoated96-well ELISA plates.20sera of C.t infected person and20sera of C.t uninfected person in our STD clinic were collected. Elisa was adopted to detect the antibodies of the four proteins in sera.Results:In the20C.t infected person’s sera, the antibodies anti Pgp3, OmcBc, CT841and Hsp-60were detected in14cases (70%),9cases (45%),8cases (40%) and5cases (25%) respectively. In the20C.t uninfected person’s sera, only Hsp-60antibody was detected in one serum.Conclusions:In the four studied C.t proteins, Pgp3showed the highest antigenicity, while Hsp-60showed the lowest antigenicity.