Hemphill A, Fuchs N, Sonda S, Gottstein B, Hentrich B
Institute of Parasitology, University of Berne, Switzerland.
Parasitology. 1997 Oct;115 ( Pt 4):371-80. doi: 10.1017/s0031182097001455.
Neospora caninum, the causative agent of neosporosis, is a recently identified apicomplexan parasite which is structurally and biologically closely related to, but antigenically distinct from, Toxoplasma gondii. Molecules associated with the surfaces of N. caninum tachyzoites are likely to participate in the host cell entry process, could be involved in the interaction of the parasite with the immune system, and they could influence the pathogenesis of neosporosis. Isolated N. caninum tachyzoites were extracted with the non-ionic detergent Triton X-114 and were further analysed using a polyclonal anti-N. caninum antiserum. Immunoblots revealed several reactive bands, 1 of which represented a glycoprotein of approximately 36 kDa (Nc-p36). This molecule was present in 2 isolates of Neospora (NC-1 and Liverpool), but was absent in Toxoplasma (RH-strain) tachyzoites. Immunofluorescence and pre-embedding immunogold transmission electron microscopy employing affinity-purified anti-Nc-p36 antibodies showed that the Nc-p36 is a cell surface-associated protein. Immunogold on-section labelling of LR-White-embedded parasites, fixed prior and at defined time-points after host cell entry, demonstrated the presence of this molecule on the surface as well as within the dense granules of N. caninum tachyzoites.
犬新孢子虫是新孢子虫病的病原体，是一种最近才被鉴定出来的顶复门寄生虫，在结构和生物学特性上与刚地弓形虫密切相关，但抗原性不同。与犬新孢子虫速殖子表面相关的分子可能参与宿主细胞的侵入过程，可能参与寄生虫与免疫系统的相互作用，并且可能影响新孢子虫病的发病机制。用非离子去污剂Triton X-114提取分离出的犬新孢子虫速殖子，并用多克隆抗犬新孢子虫抗血清进行进一步分析。免疫印迹显示出几条反应带，其中一条代表约36 kDa的糖蛋白（Nc-p36）。该分子存在于新孢子虫的2个分离株（NC-1和利物浦株）中，但在刚地弓形虫（RH株）速殖子中不存在。采用亲和纯化的抗Nc-p36抗体进行免疫荧光和包埋前免疫金透射电子显微镜观察表明，Nc-p36是一种细胞表面相关蛋白。对宿主细胞侵入前及侵入后特定时间点固定的LR-White包埋寄生虫进行切片免疫金标记，结果显示该分子存在于犬新孢子虫速殖子的表面以及致密颗粒内。
