DNA VACCINATION WITH THE MAJOR OUTER-MEMBRANE PROTEIN GENE INDUCES ACQUIRED-IMMUNITY TO CHLAMYDIA-TRACHOMATIS (MOUSE PNEUMONITIS) INFECTION

The efficacy of DNA vaccination for prevention of Chlamydia trachomati s infection was studied using the murine model of pneumonia induced by the mouse pneumonitis (MoPn) isolate of C. trachomatis. Intramuscular DNA immunization with two chlamydial genes, one that encodes the majo r outer-membrane protein (MOMP) and one that encodes a cytoplasmic enz yme (cytosine triphosphate [CTP] synthetase) were tested. The MOMP DNA vaccine but not the CTP synthetase DNA vaccine generated significant delayed-type hypersensitivity and serum antibodies to MoPn elementary bodies and reduced the peak growth of MoPn by >100-fold following lung challenge infection. MOMP DNA immunization suggests a new approach to vaccine development for prevention of human chlamydial infection.