Shaia C I, Voyich J, Gillis S J, Singh B N, Burgess D E
Montana State University, Bozeman 59717-0360, USA.
Infect Immun. 1998 Mar;66(3):1100-5. doi: 10.1128/IAI.66.3.1100-1105.1998.
Bovine trichomoniasis is a sexually transmitted disease caused by Tritrichomonas foetus and characterized by early embryo loss. The mechanism of this loss is not known, although the parasite is known to cause inflammation and to have the ability to kill host cells by a contact-dependent cytotoxic mechanism. Antibody specific for a 190,000-Da surface complex (Tf190) was previously shown to inhibit this adhesion. In this study we used immunoaffinity chromatography to purify Tf190 from T. foetus in order to analyze its composition and examine its expression. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of purified Tf190 followed by silver staining revealed three components of Tf190. Western blotting and antibody-binding experiments showed that the 140- and 60-kDa bands were immunogenic. By using a battery of monoclonal antibodies (MAbs) periodate-sensitive epitopes were identified on Tf190, suggesting that these epitopes contained carbohydrate structures. Analyses of affinity-purified Tf190 by high-performance liquid chromatography and gas-liquid chromatography demonstrated the presence of the monosaccharides and lipids known to be prominent constituents of the lipophosphoglycan (LPG) of T. foetus. Flow cytometry experiments on several isolates of T. foetus with Tf190-specific antibodies revealed that Tf190 was present on subpopulations of all isolates but that not all epitopes were present on every isolate. This pattern of reactivities on the different parasite isolates was confirmed by Western blots of whole-parasite extracts probed with MAbs and antiserum. These results suggest that although variation in the expression of epitopes of Tf190 occurs in different strains of T. foetus, the Tf190 adhesion complex is widespread in different populations of the parasite. The data further suggest that immunogenic structures, important in the adhesion of T. foetus to mammalian cells, are located in the LPG-like component of Tf190.
牛毛滴虫病是一种由胎儿三毛滴虫引起的性传播疾病，其特征为早期胚胎损失。虽然已知该寄生虫会引发炎症并具有通过接触依赖性细胞毒性机制杀死宿主细胞的能力，但这种胚胎损失的机制尚不清楚。先前已证明，针对一种190,000道尔顿表面复合物（Tf190）的抗体可抑制这种黏附。在本研究中，我们使用免疫亲和色谱法从胎儿三毛滴虫中纯化Tf190，以分析其组成并检测其表达情况。通过十二烷基硫酸钠 - 聚丙烯酰胺凝胶电泳对纯化的Tf190进行分析，随后进行银染，结果显示Tf190有三个组分。蛋白质印迹法和抗体结合实验表明，140 kDa和60 kDa的条带具有免疫原性。通过使用一系列单克隆抗体（MAb），在Tf190上鉴定出了对高碘酸盐敏感的表位，这表明这些表位含有碳水化合物结构。通过高效液相色谱法和气 - 液色谱法对亲和纯化的Tf190进行分析，结果表明存在已知为胎儿三毛滴虫脂磷壁酸（LPG）主要成分的单糖和脂质。用Tf190特异性抗体对几种胎儿三毛滴虫分离株进行的流式细胞术实验表明，Tf190存在于所有分离株的亚群中，但并非所有表位都存在于每个分离株上。用MAb和抗血清对全寄生虫提取物进行蛋白质印迹分析，证实了不同寄生虫分离株上这种反应模式。这些结果表明，虽然Tf190表位的表达在不同的胎儿三毛滴虫菌株中存在差异，但Tf190黏附复合物在该寄生虫的不同群体中广泛存在。数据进一步表明，在胎儿三毛滴虫与哺乳动物细胞黏附中起重要作用的免疫原性结构位于Tf190的LPG样组分中。
