Immune responses induced by DNA vaccine combined with recombinant adenovirus containing MOMP gene of Chlamydia trachomatis serovar E / 中华微生物学和免疫学杂志

ABSTRACT

Objective To investigate the specific immune responses induced by DNA vaccine com-bined with recombinant adenovirus carrying major outer membrane protein ( MOMP) gene of Chlamydia trachom-atis (Ct) serovar E.Methods Recombinant eukaryotic expression plasmid pVAX 1-MOMP and recombinant adenovirus Ad-MOMP were constructed and purified .Four immunization strategies were designed including DNA immunization (DNA group), recombinant adenovirus immunization (Ad group), DNA prime-recombinant ade-novirus boost regimen ( DNA/Ad group ) and recombinant adenovirus prime-DNA boost regimen ( Ad/DNA group) .Two weeks after the final immunization , vaginal wash specimens , blood samples and spleens were col-lected from all mice for the evaluation of humoral and cellular immune responses .Results Th1 responses and mucosal responses were not found in DNA group .Ad group induced both Th 1 responses and local mucosal re-sponses , and its IgG and IgA levels were significantly higher than those in DNA group .DNA/Ad group and Ad/DNA group induced stronger Th 1 responses and humoral responses than DNA and Ad group .Serum antibodies and mucosal antibodies in DNA/Ad group were higher than those in Ad/DNA group, but Th1 responses in DNA/Ad group were impaired than those in Ad/DNA group.Conclusion The recombinant adenovirus could induce Th1 responses and genital mucosal responses .Combined immunization of DNA/Ad or Ad/DNA showed enhanced specific immune responses in comparison with the single immunization with DNA or Ad .The differ-ences between the two combination methods were that DNA /Ad group stimulated higher levels of specific anti-body responses , while Ad/DNA group produced stronger Th 1 responses .The study provided a reference for the enhancement and development of vaccines against Chlamydia trachomatis in further studies .