Virginio Veridiana G, Monteiro Karina M, Drumond Fernanda, de Carvalho Marcos O, Vargas Daiani M, Zaha Arnaldo, Ferreira Henrique B
Laboratório de Biologia Molecular de Cestódeos e Laboratório de Genômica Estrutural e Funcional, Centro de Biotecnologia, UFRGS, Porto Alegre, RS, Brazil.
Mol Biochem Parasitol. 2012 May;183(1):15-22. doi: 10.1016/j.molbiopara.2012.01.001. Epub 2012 Jan 13.
Cystic hydatid disease (CHD) is caused by infection with Echinococcus granulosus metacestodes and affects humans and livestock. Proteins secreted or excreted by protoscoleces, pre-adult worms found in the metacestode, are thought to play fundamental roles in the host-parasite relationship. In this work, we performed an LC-MS/MS proteomic analysis of the excretory-secretory products obtained from the first 48 h of an in vitro culture of the protoscoleces. We identified 32 proteins, including 18 that were never detected previously in metacestode proteomic studies. Among the novel identified excretory-secretory products are antigenic proteins, such as EG19 and P-29 and a calpain protease. We also identified other important protoscolex excretory-secretory products, such as thioredoxin peroxidase and 14-3-3 proteins, which are potentially involved in evasion mechanisms adopted by parasites to establish infection. Several intracellular proteins were found in the excretory-secretory products, revealing a set of identified proteins not previously thought to be exposed at the host-parasite interface. Additionally, immunological analyses established the antigenic profiles of the newly identified excretory-secretory products and revealed, for the first time, the in vitro secretion of the B antigen by protoscoleces. Considering that the excretory-secretory products obtained in vitro might reflect the products released and exposed to the host in vivo, our results provide valuable information on parasite survival strategies in adverse host environments and on the molecular mechanisms underpinning CHD immunopathology.
囊型包虫病（CHD）由细粒棘球绦虫中绦期幼虫感染引起，可感染人类和家畜。原头节（中绦期发现的未成熟虫体）分泌或排泄的蛋白质被认为在宿主与寄生虫的关系中起重要作用。在这项研究中，我们对原头节体外培养48小时获得的排泄-分泌产物进行了液相色谱-串联质谱（LC-MS/MS）蛋白质组学分析。我们鉴定出32种蛋白质，其中18种在之前的中绦期蛋白质组学研究中从未被检测到。新鉴定出的排泄-分泌产物中包括抗原蛋白，如EG19和P-29以及一种钙蛋白酶。我们还鉴定出其他重要的原头节排泄-分泌产物，如硫氧还蛋白过氧化物酶和14-3-3蛋白，它们可能参与寄生虫建立感染所采用的逃避机制。在排泄-分泌产物中发现了几种细胞内蛋白质，揭示了一组以前认为不会在宿主-寄生虫界面暴露的已鉴定蛋白质。此外，免疫学分析确定了新鉴定的排泄-分泌产物的抗原谱，并首次揭示了原头节在体外分泌B抗原。鉴于体外获得的排泄-分泌产物可能反映体内释放并暴露于宿主的产物，我们的结果为寄生虫在不利宿主环境中的生存策略以及CHD免疫病理学的分子机制提供了有价值的信息。
