Résumé
Objective To investigate the expression of complement regulatory proteins on placentas of pregnant C57BL/6 mice infected with Toxoplasma gondii in order to explore the molecular immunological mechanism for abnormal pregnancy induced by T. gondii infection. Methods Twenty-four pregnant C57BL/6 mice were randomly divided into two groups equally. The infection group was intraperitoneally injected with 200 of living T, gondii RH strain tachyzoites on the 8th day of gestation, and the normal group of mice was injected with physiological saline. All mice were killed on day 14 after gestation and placentas were collected. The expression levels of Crry, GPI-DAF and CD59a mRNA were analyzed by real-time quantitative PCR, and the positive rates of Crry and GPI-DAF were measured with flow cytometry. Results The died fetus rates of infected group and control were 80. 95% and 4. 41% , respectively. The infected group was significantly higher than of that the control group (P＜0.01). The expression levels of Crry, GPT-DAF and CD59a mRNA in the infected and control group were 0.786 ±0. 199, 0.594 ±0.096, 0.880 ±0. 179 and 0.550 ±0.077, 0.221 ±0.074, 0.591 ± 0.075 , respectively, and the difference of three kind of complement regulation proteins between two groups was all significant (P＜0.01). The positive percentages of Crry and GPI-DAF cells of infected and control group were (10. 03 ± 2. 11) % , (2.95 ±1.04)% and (3. 15 ± 1. 32) % , (0. 66 ±0. 26) % , respectively, and the difference of the two kind complement regulation proteins between two groups was also significant ( P ＜ 0. 01). Conclusion The expression level of mouse placental complement regulatory proteins was increased after infection with T. gondii, and then immunological microenvironment at the fetomaternal interface was destroyed. It may be one of important immunological mechanism for abnormal pregnancy induced by T. gondii infection.
Résumé
Objective To study protective immunity effects of co-immunization with P30 DNA vaccine and protein vaccine. Methods Forty-eight 5-6 weeks old BALB/c female mice were divided into four groups (A,B,C,D), 12 mice of each group. In group A (control group) each mouse was immunized with 100 ?g pcDNA3.1 plasmid DNA by intramuscular (i.m.) for three times at week 0,2 and 4; in group B (P30 protein group) each mouse was immunized (i.m.) with 50 ?g rP30+50 ?g CFA for three times at week 0, 2 and 4; in group C (pcDNA3.1-P30 group) each mouse was immunized with 100 ?g pcDNA3.1-P30 plasmid DNA (i.m.) for three times at week 0, 2 and 4; in group D (P30 DNA+rP30 co-immunization group) each mouse was immunized with 100 ?g pcDNA3.1-P30 plasmid DNA (i.m.) for two times at week 0, 2 and immunized by subcutaneous with 50 ?g rP30+50 ?g CFA at week 4. Each mouse was infected with 100 tachyzoites of Toxoplasma gondii RH strain four weeks later after last immunization. The anti-P30 antibodies were detected with ELISA before the challenge. Results The P30 DNA vaccine was successfully constructed. High titers of anti-P30 antibodies were induced in each mouse immunized with DNA vaccine. The protective trial proved that there was no significant difference between control group and experimental group though the survival time of mouse from experimental group had been prolonged. Conclusion The P30 DNA vaccine could induced high titers of anti- P30 antibodies in immunized mice, and it may be a potential DNA vaccine candidate.