Laboratory of Parasitology, College of Veterinary Medicine, South China Agricultural University, 483 Wushan Street, Tianhe District, Guangzhou, Guangdong Province, 510642, People's Republic of China.
Parasitol Res. 2010 Apr;106(5):1079-84. doi: 10.1007/s00436-010-1742-0. Epub 2010 Feb 23.
Microneme protein 8 (MIC8) is considered a new essential invasion factor in Toxoplasma gondii. In the present study, a deoxyribonucleic acid vaccine expressing MIC8 of T. gondii was constructed and the immune response it induced in Kunming mice was evaluated. The gene sequence encoding MIC8 was inserted into the eukaryotic expression vector pVAX I, and the pVAX-MIC8 expression plasmid was constructed, and the plasmid diluted with PBS to 100 mg/100 microl was injected into the Kunming mice muscularly. Levels of IgG antibody, gamma-interferon (IFN-gamma), interleukin-2 (IL-2), interleukin-4, and interleukin-10 were detected. The mice were challenged with tachyzoites of the virulent T. gondii RH strain at the 14th day after the last immunization to observe the survival time. The high level of IFN-gamma, IL-2, and IgG antibody indicated that mice vaccinated with recombinant pVAX-MIC8 plasmid could elicit strong cellular and humoral immune responses and showed a significantly increased survival time (10.3 +/- 0.9 days) compared with control mice which died within 5 days of challenge infection. These data demonstrate that the T. gondii MIC8 is a potential vaccine candidate against toxoplasmosis.
微线蛋白 8（MIC8）被认为是刚地弓形虫新的必需入侵因子。在本研究中，构建了表达刚地弓形虫 MIC8 的脱氧核糖核酸疫苗，并评估了其在昆明小鼠中诱导的免疫应答。将编码 MIC8 的基因序列插入真核表达载体 pVAX I 中，构建 pVAX-MIC8 表达质粒，用 PBS 将质粒稀释至 100 mg/100 μl，肌肉注射昆明小鼠。检测 IgG 抗体、γ-干扰素（IFN-γ）、白细胞介素-2（IL-2）、白细胞介素-4 和白细胞介素-10 的水平。末次免疫后第 14 天，用强毒 RH 株速殖子攻击小鼠，观察存活时间。高水平的 IFN-γ、IL-2 和 IgG 抗体表明，用重组 pVAX-MIC8 质粒免疫的小鼠可诱导强烈的细胞和体液免疫应答，并显示出与对照组相比明显延长的存活时间（10.3 ± 0.9 天），对照组小鼠在感染后 5 天内死亡。这些数据表明，刚地弓形虫 MIC8 是一种潜在的弓形虫病疫苗候选物。
