Hiasa Jun, Nishimura Maki, Itamoto Kazuhito, Xuan Xuenan, Inokuma Hisashi, Nishikawa Yoshifumi
National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido, Japan.
Clin Vaccine Immunol. 2012 Mar;19(3):411-7. doi: 10.1128/CVI.05669-11. Epub 2012 Jan 18.
Neospora caninum is an intracellular protozoan parasite that causes bovine and canine neosporosis, characterized by fetal abortion and neonatal mortality and by neuromuscular paralysis, respectively. Although many diagnostic methods to detect parasite-specific antibodies or parasite DNA have been reported, to date no effective serodiagnostic techniques for estimating pathological status have been described. Our study aimed to elucidate the relationship between the parasite-specific antibody response, parasite activation, and neurological symptoms caused by N. caninum infection by using a recombinant antigen-based enzyme-linked immunosorbent assay. Among experimentally infected mice, anti-N. caninum profilin (NcPF) antibody was only detected in neurologically symptomatic animals. Parasite numbers within the brains of the symptomatic mice were significantly higher than those in asymptomatic animals. In addition, anti-NcPF and anti-NcGRA7 antibodies were mainly detected at the acute stage in experimentally infected dogs, while anti-NcSAG1 antibody was produced during both acute and chronic stages. Furthermore, among anti-NcSAG1 antibody-positive clinical dogs, the positive rates of anti-NcGRA7 and anti-NcPF antibodies in the neurologically symptomatic dogs were significantly higher than those in the non-neurologically symptomatic animals. Our results suggested that the levels of anti-NcGRA7 and anti-NcPF antibodies reflect parasite activation and neurological symptoms in dogs. In conclusion, antibodies against NcGRA7 and NcPF may have potential as suitable indicators for estimating the pathological status of neosporosis.
犬新孢子虫是一种细胞内原生动物寄生虫，可引起牛和犬的新孢子虫病，分别以胎儿流产和新生儿死亡以及神经肌肉麻痹为特征。尽管已经报道了许多检测寄生虫特异性抗体或寄生虫DNA的诊断方法，但迄今为止，尚未描述用于评估病理状态的有效血清学诊断技术。我们的研究旨在通过使用基于重组抗原的酶联免疫吸附测定法，阐明犬新孢子虫感染引起的寄生虫特异性抗体反应、寄生虫激活与神经症状之间的关系。在实验感染的小鼠中，仅在出现神经症状的动物中检测到抗犬新孢子虫肌动蛋白结合蛋白（NcPF）抗体。有症状小鼠大脑中的寄生虫数量明显高于无症状动物。此外，在实验感染的犬中，抗NcPF和抗NcGRA7抗体主要在急性期检测到，而抗NcSAG1抗体在急性期和慢性期均产生。此外，在抗NcSAG1抗体阳性的临床犬中，出现神经症状的犬中抗NcGRA7和抗NcPF抗体的阳性率明显高于无神经症状的动物。我们的结果表明，抗NcGRA7和抗NcPF抗体的水平反映了犬的寄生虫激活和神经症状。总之，抗NcGRA7和NcPF抗体可能有潜力作为评估新孢子虫病病理状态的合适指标。
