Tenter A M, Zimmerman G L, Johnson A M
Department of Microbiology and Infectious Diseases, Flinders University School of Medicine, Flinders Medical Centre, Bedford Park, South Australia.
J Parasitol. 1991 Oct;77(5):727-36.
Crude antigen preparations from bradyzoites of Sarcocystis species exhibit a high degree of cross-reactivity with antisera against heterologous Sarcocystis species, preventing the development of a species-specific immunological test for sarcocystiosis. In this study, we fractionated bradyzoite-derived protein extracts from Sarcocystis tenella, Sarcocystis arieticanis, Sarcocystis gigantea, and Sarcocystis muris by chromatofocusing and obtained distinct protein elution profiles for each species. We then examined the isolated protein fractions for antigenicity with homologous and heterologous reference sera in an enzyme-linked immunosorbent assay. Whereas some antigenic fractions of bradyzoite proteins had equally high reactivity with the homologous and heterologous sera, the reactivity of other fractions was 3-38 times higher with homologous serum than with heterologous sera. Mice immunized with less cross-reactive protein fractions of S. gigantea and S. muris bradyzoites produced a specific immune serum. Thus, it is possible to isolate species-specific antigens from crude mixtures of bradyzoite-derived Sarcocystis antigens for development of species-specific immunological tests for sarcocystiosis.
来自肉孢子虫缓殖子的粗抗原制剂与针对异源肉孢子虫物种的抗血清表现出高度的交叉反应性，这阻碍了针对肉孢子虫病的种特异性免疫检测方法的开发。在本研究中，我们通过层析聚焦法对来自柔嫩肉孢子虫、绵羊肉孢子虫、巨型肉孢子虫和鼠肉孢子虫的缓殖子衍生蛋白提取物进行了分级分离，并获得了每个物种独特的蛋白洗脱图谱。然后，我们在酶联免疫吸附试验中用同源和异源参考血清检测了分离出的蛋白组分的抗原性。虽然缓殖子蛋白的一些抗原组分与同源和异源血清具有同样高的反应性，但其他组分与同源血清的反应性比与异源血清高3至38倍。用巨型肉孢子虫和鼠肉孢子虫缓殖子的交叉反应性较低的蛋白组分免疫的小鼠产生了特异性免疫血清。因此，有可能从缓殖子衍生的肉孢子虫抗原的粗混合物中分离出种特异性抗原，用于开发针对肉孢子虫病的种特异性免疫检测方法。
