Immunological Study on the Host Cell Penetration Factor of Toxoplasma gondii
Immunological Study on the Host Cell Penetration Factor of Toxoplasma gondii
复制标题
弓形虫宿主细胞穿透因子的免疫学研究
作者：
R. Norrby
应用生物化学和免疫学技术对弓形虫的宿主细胞穿透因子（PEF）进行了研究。硫酸铵沉淀的PEF的Sephadex凝胶过滤产生两种具有不同分子量的组分，但都具有渗透增强活性。纯化方法去除了至少99.9%的外源蛋白。为了证明渗透的显著增强，0.001 μg蛋白质就足够了。在生物化学上，它们似乎是具有相同电泳迁移率的酸性蛋白质。两种组分在pH7.6和37 ℃下均表现出最大的渗透增强作用。PEF抗血清降低了弓形虫的穿透能力。PEF的两个组分的渗透增强作用被针对其中任何一个的抗血清抑制。此外，当抗血清与两种组分反应时，获得免疫学上相同的免疫沉淀物。因此，结果表明PEF的两种组分在免疫原性上是相同的，并且分子量的差异可能是由聚集引起的。免疫荧光结果表明，PEF与弓形虫前端的胞质结构有关。讨论了这些结构与成对细胞器或曲管的可能关系。免疫荧光寄生虫的数量低宿主细胞渗透后不久，并增加在细胞内的生命的寄生虫动力学后，以前观察到的PEF的合成以及弓形虫的溶酶体活性。
The host cell penetration factor (PEF) of Toxoplasma gondii was studied by biochemical and immunological techniques. Sephadex gel filtration of an ammonium sulfate-precipitated PEF yielded two components with different molecular weight, but both having penetration-enhancing activity. The methods for purification removed at least 99.9% of extraneous protein. For demonstration of a significant enhancement of penetration, 0.001 μg of protein was sufficient. Biochemically, they appeared to be acid proteins with the same electrophoretic mobility. Both components showed maximal enhancement of penetration at pH 7.6 and 37 C. PEF antisera reduced the penetrative capacity of Toxoplasma parasites. The penetration-enhancing effect of the two components of PEF was inhibited by antiserum against any of them. Moreover, immunologically identical immunoprecipitates were obtained when antiserum reacted with the two components. The results thus indicated that the two components of PEF were immunogenically identical and that the difference in molecular weights might result from aggregation. Immunofluorescence indicated that PEF was related to cytoplasmic structures located in the anterior end of Toxoplasma. A possible relation between these structures and the paired organelle or the convoluted tubes was discussed. The number of parasites with immunofluorescence was low shortly after host cell penetration and increased during the intracellular life of the parasites after kinetics, previously observed for synthesis of PEF as well as for lysosomal activity of Toxoplasma.