Studies On The Immunological Effects Of DNA Vaccine For Chlamydia Trachomatis E Serotype

The hightest morbidity of sexually transmitted diseases(SID) isnon-gonococcal urethritis caused by Chlamydia trachomatis (C.t). C.tinfection may result in severe complications such as prostatitis,infertility, ectopic pregnancy and chronic pelvic inflammatory diseaseetc. Study on C.t infection has been one of the popular topics of theworld. It's urgent to improve the prevention and control measures for C.tprevalence. Research on C.t vaccine is the key point of preventionmeasures. Among all the C.t vaccines studied, DNA vaccine is predominant.Nevertheless, it's a pity that no successful C.t vaccine is born by now.Objective: to evaluate the immune response and protective effect ofthe DNA vaccine for C.t E serotype in mice.Methods: C.t E serotype was cultured in McCoy cells. Mice weredivided into three groups. They were blank plasmid negative control group,DNA vaccine group, and inactivated C.t positive control group.Intramuscular inoculation was adopted. In the 0\2th\4th week, the micewere injected in musculus quadriceps fexoris of two legs. Negativecontrol group was given blank plasmid. Positive control group was giveninactivated C.t complete Freund's adjuvant and incomplete Freund'sadjuvant. In the 6th week their serum and secreta of gential tract wascollected for detecting of antibodies, lymphokines, counteract abilityof serum specific antibodies. At the same time part of them were observedof DTH response, and later they were killed for proliferation assay ofspleen lymphocytes. The rest ones were given luteohormone to enhance thesensitivity of C.t infection. In the 7th week mice were inoculated withC.t serotype E through vagina. In 8th week immunofluorescence and C.tisolation were adopted to know the infection of them. Next week theirserum, secreta of gential, uterus, and spleen cells were detected for antibodies, lymphokines, proliferation assay of spleen lymphocytes andcervix pathology.Results: 1. Culture C.t serotype E successfully and get a C.t EBconcentration of 2.1750×10~7IFU/mL, the concentration of protein is3081.74μg/ml. 2 The results of antibodies, lymphokines, counteractability of serum specific antibodies, proliferation assay of spleenlymphocytes show inoculating DNA vaccine could induce C.t specific cellmediated immunity (CMI) and humoral immunity to some extend. 3. It couldprotect mice from C.t vagina challenge.Conclusion: 1. Inoculating DNA vaccine could induce C.t specificcell mediated immunity (CMI) and humoral immunity to some extend. 2.Antibodies against major outer membrane protein encoded by ompl gene wereprotective. 3. The DNA vaccine of C.t E serotype exhibited someimmunoprotection effect in mice.