Zimic Mirko, Pajuelo Mónica, Gilman Robert H, Gutiérrez Andrés H, Rueda Luis D, Flores Myra, Chile Nancy, Verástegui Manuela, Gonzalez Armando, García Héctor H, Sheen Patricia
Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Av. Honorio Delgado 430 Urb. Ingeniería SMP-Lima 31, Lima, Peru.
Vet Immunol Immunopathol. 2012 Jan 15;145(1-2):171-8. doi: 10.1016/j.vetimm.2011.11.002. Epub 2011 Nov 11.
Cathepsin L-like proteases are secreted by several parasites including Taenia solium. The mechanism used by T. solium oncospheres to degrade and penetrate the intestine and infect the host is incompletely understood. It is assumed that intestinal degradation is driven by the proteolytic activity of enzymes secreted by the oncosphere. Blocking the proteolytic activity by an antibody response would prevent the oncosphere penetration and further infection. Serine and cysteine proteases including chymotrypsin, trypsin, elastase, and cathepsin L, are secreted by T. solium and Taenia saginata oncospheres when cultured in vitro, being potential vaccine candidates. However, the purification of a sufficient quantity of proteases secreted by oncospheres to conduct a vaccine trial is costly and lengthy. A 53/25 kDa cathepsin L-like fraction partially purified from T. solium cyst fluid was described previously as an important antigen for immunodiagnostics. In this study we found that this antigen is present in the T. solium oncosphere and is also secreted by the cysticercus. This protein fraction was tested for its ability to protect pigs against an oral challenge with T. solium oncospheres in a vaccine trial. IgG antibodies against the 53/25 kDa cathepsin L-like protein fraction were elicited in the vaccinated animals but did not confer protection.
组织蛋白酶L样蛋白酶由包括猪带绦虫在内的几种寄生虫分泌。猪带绦虫六钩蚴降解并穿透肠道以及感染宿主所采用的机制尚未完全明了。据推测，肠道降解是由六钩蚴分泌的酶的蛋白水解活性驱动的。通过抗体反应阻断蛋白水解活性将阻止六钩蚴的穿透和进一步感染。当在体外培养时，猪带绦虫和牛带绦虫六钩蚴会分泌包括胰凝乳蛋白酶、胰蛋白酶、弹性蛋白酶和组织蛋白酶L在内的丝氨酸和半胱氨酸蛋白酶，它们是潜在的疫苗候选物。然而，纯化足够量的六钩蚴分泌的蛋白酶以进行疫苗试验既昂贵又耗时。先前从猪带绦虫囊液中部分纯化的一种53/25 kDa组织蛋白酶L样组分被描述为免疫诊断的重要抗原。在本研究中，我们发现这种抗原存在于猪带绦虫六钩蚴中，并且也由囊尾蚴分泌。在一项疫苗试验中，对该蛋白组分保护猪抵抗猪带绦虫六钩蚴口服攻击的能力进行了测试。在接种疫苗的动物中引发了针对53/25 kDa组织蛋白酶L样蛋白组分的IgG抗体，但并未提供保护作用。
