Objective: To observe the splenocytes immune response elicited by different concentrations of recombinant Toxoplasma gondii profiling (rTgPRF) through the nasal route, and determine the optimal dose.
Methods: Fifty female BALB/c mice were randomly divided into 5 groups. The immunized groups were intranasally administered with 10, 20, 30 μg or 40 μg of rTgPRF that was separately dissolved in 20 μl of phosphate-buffered saline (PBS) on days 0, 14, and 21 respectively, while the control mice were given PBS solution instead. Two weeks after the last immunization, all mice were killed. Under asceptic conditions, the spleens from the immunized mice were dissected, and then the splenocyte proliferative responses in vitro were tested by CCK-8 kit. The levels of IFN-γ, IL-2, IL-4 and IL-10 of splenocyte culture supernatant were detected by ELISA.
Results: Compared to the control group, the splenocytes from the 30 μg and 40 μg groups exhibited a significantly higher proliferative response to rTgPRF (P < 0.05), and SI from the 30 μg rTgPRF group was higher than that from the 40 μg group (P < 0.05). The levels of IFN-γ in all the immunized groups (P < 0.05) and IL-2 in the 20, 30 μg and 40 μg groups were significantly stronger than those in the control (P < 0.05), and the 30 μg group presented the highest concentrations of IFN-γ (P < 0.01) and IL-2 (P < 0.01). There were no statistical differences among the groups in the levels of IL-4 and IL-10.
Conclusions: The intranasal immunization with rTgPRF can induce the splenocyteproliferation and Th1-type mediated immunity. The best immunized dose is confirmed as 30 μg.
[摘要]目的 观察不同浓度重组刚地弓形虫抑制蛋白 (rTgPRF) 滴鼻免疫小鼠诱导的脾淋巴细胞免疫应答, 探讨其最 佳免疫剂量。 方法 50只雌性BALB/c小鼠随机分为5组, 免疫组分别用10、20、30 μg和40 μg rTgPRF溶于20 μl磷酸盐 缓冲液 (PBS) 后滴鼻免疫, 对照组用20 μl PBS。分别于第0、14和21 天滴鼻免疫小鼠, 末次免疫后2周, 颈椎脱臼处死小 鼠。无菌取脾, 采用CCK-8法测定脾淋巴细胞刺激指数 (SI), 酶联免疫吸附试验 (ELISA) 测定脾淋巴细胞上清液中IFN-γ、IL-2、IL-4和IL-10浓度。 结果 经rTgPRF刺激, 30 μg和40 μg免疫组小鼠脾淋巴细胞SI均高于对照组 (P均< 0.05), 且30 μg组显著高于40 μg组 (P < 0.05)。与对照组比较, 所有免疫组小鼠脾淋巴细胞培养上清中IFN-γ含量升高 (P 均< 0.05), 20、30 μg和40 μg组小鼠脾淋巴细胞培养上清中IL-2含量增加 (P 均< 0.05), 其中30 μg组小鼠脾淋巴细胞培养上 清中IFN-γ (P 均< 0.01) 和IL-2含量最高 (P 均< 0.01); 所有免疫组小鼠脾淋巴细胞培养上清中IL-4和IL-10含量与对照组 比较差异均无统计学意义 (P均> 0.05)。 结论 rTgPRF滴鼻免疫小鼠可诱导脾淋巴细胞增殖和Th1型细胞免疫应答, 以 30 μg剂量免疫效果最佳。.
Keywords: Immune response; Intranasal immunization; Profilin; Splenocyte; Toxoplasma gondii.