Immune enhancing effects of interleukin 2 genetic adjuvant on DNA vaccine against Chlamydia trachomatis serovar E / 中华皮肤科杂志

ABSTRACT

ObjectiveTo study the effect of a recombinant plasmid encoding mouse interleukin 2 (mlL-2) on the immunogenicity of DNA vaccine against Chlamydia trachomatis(Ct) serovar E.Methods BALB/c mice were divided into 4 groups to be intramuscularly inoculated with blank plasmid(negative control group),DNA vaccine against Ct serovar E(DNA vaccine group),DNA vaccine against Ct serovar E and a recombinant plasmid containing mIL-2(combination group),and inactivated Ct serovar E elementary bodies (positive control group),respectively.The immunological effects were evaluated by posterior foot pad thickness,proliferation level of spleen lymphocytes,serum level of IL-4 and interferon (IFN)-γ in mice,and the capability to clear Ct genital tract infection.ResultsThe proliferation index of spleen lymphocytes in the combination group and positive control group was similar(3.64 ± 0.41 vs.3.77 ± 0.34),but was significantly different from that in the blank control group and DNA vaccine group (1.37 ± 0.21 and 2.52 ± 0.30).The serum level of IL-4 was(38.49 ± 12.24) pg/ml in the positive control group,significantly higher than in the negative control group,DNA vaccine group and combination group ((25.37 ± 18.93),(24.75 ± 8.49),(21.74 ± 6.43) pg/ml,respectively).With respect to the serum level of IFN-γ,the combination group and positive control group were similar ((1923.3 ± 518.1) pg/ml vs.(2712.5 ± 887.2) pg/ml),but were significantly different from the negative control group and vaccine group((310.8 ± 160.7) pg/ml and(601.3 ± 357.9) pg/ml).Six days after Ct challenge,the exfoliated cells from genital tract were positive for Ct culture in the negative control group,but negative in the other 3 groups.ConclusionIL-2 genetic adjuvant can enhance the immune response,especially Th1 type response,induced by the DNA vaccine against Ct serovar E.