Vaccination of mice with DNA plasmids coding for the Chlamydia trachomatismajor outer membrane protein elicits an immune response but fails to protect against a genital challenge

A DNA plasmid encoding the gene of the major outer membrane protein (MOMP) of the Chlamydia trachomatis mouse pneumonitis (MoPn) serovar and three pla smids containing the variable domains (VD) of the MOMP were constructed. Fe male mice were inoculated with the plasmids and 60 days later were challeng ed in the genital tract with C. trachomatis, Six weeks after challenge fema le mice were caged with male mice and the course of the mating followed. Mi ce immunized with the MOMP plasmids mounted weak humoral and cell mediated immune responses. However, following the genital challenge no significant d ifferences in vaginal shedding were observed between the groups immunized w ith the MOMP and control plasmids, In addition, the fertility rates were si milar in the experimental and negative control groups. In conclusion, vacci nation with DNA plasmids encoding the MOMP elicited a modest immune respons e but did not protect against infection or disease. (C) 1999 Elsevier Scien ce Ltd. All-rights reserved.