Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Cátedra de Salud Pública, Av. Chorroarín 280, C1427CWO, Buenos Aires, Argentina.
Servicio de Inmunología Parasitaria. Departamento de Parasitología, Instituto Nacional de Enfermedades Infecciosas Anlis "Dr. Carlos G. Malbrán", Av. Vélez Sarsfield 563, C1282AFF, Buenos Aires, Argentina.
Exp Parasitol. 2020 Nov;218:107997. doi: 10.1016/j.exppara.2020.107997. Epub 2020 Sep 15.
Toxocara cati is one of the causative agents of human toxocariasis. Serological methods are used for diagnosis in paratenic hosts like humans but the humoral immune response triggered by this parasite is unknown. We characterized the humoral immune response to T. cati excretory-secretory antigens (TES) in pigs as animal model during the acute and chronic stages of infection. ELISA and Western Blot techniques were used to determine antibody response. Pigs were experimentally inoculated with 100,000 infective Toxocara cati eggs. Blood was collected at 7, 14, 21 and 28 days post-inoculation (d.p.i.) to assess the acute stage of infection and 90, 120 and 180 d. p.i. for chronic stage analysis. ELISA showed values higher than the cut-off of specific IgM and IgG at 7 d. p.i. with significant differences at 0 and 7 d. p.i. for IgM and at 14, 21 and 28 d. p.i. for IgG in the acute stage. Higher and stable levels were detected in the chronic stage. Western Blot showed bands from 102 to 38 kDa detected by specific IgM and IgG. More immunogenic bands were identified by specific IgG. In the chronic stage of infection a band near 31 kDa was the only band detected by IgM until 150 d. p.i. Specific IgG recognized bands between 102 and 31 kDa. This study demonstrates how the humoral immune response evolves in the acute and chronic stages of infection and provides evidence on the role of the pig as a paratenic host of T. cati.
猫弓首蛔虫是人类弓首蛔虫病的病原体之一。血清学方法用于像人类这样的中间宿主的诊断，但这种寄生虫引发的体液免疫反应尚不清楚。我们在感染的急性和慢性阶段，以猪作为动物模型，对猫弓首蛔虫排泄分泌抗原（TES）的体液免疫反应进行了特征描述。ELISA 和 Western Blot 技术用于确定抗体反应。猪用 100,000 个感染性猫弓首蛔虫卵进行实验接种。在接种后 7、14、21 和 28 天（d.p.i.）采集血液，以评估感染的急性阶段，在 90、120 和 180 d.p.i. 时进行慢性阶段分析。ELISA 显示，在 7 d.p.i.时，特异性 IgM 和 IgG 的值高于截止值，并且在 0 和 7 d.p.i.时，IgM 和在 14、21 和 28 d.p.i.时，IgG 的差异具有统计学意义。在慢性阶段，检测到更高且稳定的水平。Western Blot 显示特异性 IgM 和 IgG 检测到 102 至 38 kDa 的条带。特异性 IgG 鉴定出更多的免疫原性条带。在感染的慢性阶段，直到 150 d.p.i.，IgM 仅检测到 31 kDa 附近的一条带。特异性 IgG 识别 102 至 31 kDa 之间的条带。这项研究表明了体液免疫反应在感染的急性和慢性阶段如何演变，并提供了猪作为猫弓首蛔虫的中间宿主的证据。
