Ayón-Núñez Dolores A, Fragoso Gladis, Espitia Clara, García-Varela Martín, Soberón Xavier, Rosas Gabriela, Laclette Juan P, Bobes Raúl J
Dept. of Immunology, Institute for Biomedical Research, Universidad Nacional Autónoma de México, Mexico City, Mexico.
Dept. of Zoology, Institute of Biology, Universidad Nacional Autónoma de México, Mexico City, Mexico.
Acta Trop. 2018 Jun;182:69-79. doi: 10.1016/j.actatropica.2018.02.020. Epub 2018 Feb 18.
The larval stage of Taenia solium (cysticerci) is the causal agent of human and swine cysticercosis. When ingested by the host, T. solium eggs are activated and hatch in the intestine, releasing oncospheres that migrate to various tissues and evolve into cysticerci. Plasminogen (Plg) receptor proteins have been reported to play a role in migration processes for several pathogens. This work is aimed to identify Plg-binding proteins in T. solium cysticerci and determine whether T. solium recombinant enolase (rTsEnoA) is capable of specifically binding and activating human Plg. To identify Plg-binding proteins, a 2D-SDS-PAGE ligand blotting was performed, and recognized spots were identified by MS/MS. Seven proteins from T. solium cysticerci were found capable of binding Plg: fascicilin-1, fasciclin-2, enolase, MAPK, annexin, actin, and cytosolic malate dehydrogenase. To determine whether rTsEnoA binds human Plg, a ligand blotting was performed and the results were confirmed by ELISA both in the presence and absence of εACA, a competitive Plg inhibitor. Finally, rTsEnoA-bound Plg was activated to plasmin in the presence of tPA. To better understand the evolution of enolase isoforms in T. solium, a phylogenetic inference analysis including 75 enolase amino acid sequences was conducted. The origin of flatworm enolase isoforms, except for Eno4, is independent of their vertebrate counterparts. Therefore, herein we propose to designate tapeworm protein isoforms as A, B, C, and 4. In conclusion, recombinant enolase showed a strong plasminogen binding and activating activity in vitro. T. solium enolase could play a role in parasite invasion along with other plasminogen-binding proteins.
猪带绦虫的幼虫阶段（囊尾蚴）是人和猪囊尾蚴病的病原体。当被宿主摄入后，猪带绦虫卵被激活并在肠道内孵化，释放出六钩蚴，六钩蚴迁移到各种组织并演变成囊尾蚴。据报道，纤溶酶原（Plg）受体蛋白在几种病原体的迁移过程中发挥作用。这项工作旨在鉴定猪带绦虫囊尾蚴中的Plg结合蛋白，并确定猪带绦虫重组烯醇化酶（rTsEnoA）是否能够特异性结合并激活人Plg。为了鉴定Plg结合蛋白，进行了二维SDS-PAGE配体印迹分析，并通过串联质谱法鉴定了识别的斑点。发现来自猪带绦虫囊尾蚴的7种蛋白质能够结合Plg：成束蛋白-1、成束蛋白-2、烯醇化酶、丝裂原活化蛋白激酶、膜联蛋白、肌动蛋白和胞质苹果酸脱氢酶。为了确定rTsEnoA是否结合人Plg，进行了配体印迹分析，并在存在和不存在竞争性Plg抑制剂ε-氨基己酸（εACA）的情况下通过酶联免疫吸附测定（ELISA）对结果进行了确认。最后，在组织型纤溶酶原激活剂（tPA）存在的情况下，rTsEnoA结合的Plg被激活为纤溶酶。为了更好地了解猪带绦虫烯醇化酶同工型的进化，进行了包括75个烯醇化酶氨基酸序列的系统发育推断分析。除Eno4外，扁形动物烯醇化酶同工型的起源与其脊椎动物对应物无关。因此，在此我们建议将绦虫蛋白同工型命名为A、B、C和4。总之，重组烯醇化酶在体外表现出强大的纤溶酶原结合和激活活性。猪带绦虫烯醇化酶可能与其他纤溶酶原结合蛋白一起在寄生虫入侵中发挥作用。
