Ruiz-Campillo M T, Molina-Hernández V, Pérez J, Pacheco I L, Pérez R, Escamilla A, Martínez-Moreno F J, Martínez-Moreno A, Zafra R
Department of Anatomy and Comparative Pathology, Faculty of Veterinary Medicine, University of Córdoba, Spain.
Department of Animal Health (Parasitology), Faculty of Veterinary Medicine, University of Córdoba, Spain.
Vet Parasitol. 2018 Jun 15;257:34-39. doi: 10.1016/j.vetpar.2018.05.019. Epub 2018 May 31.
During Fasciola hepatica infection, the parasite has the capability to modulate the host immune response towards a non-protector Th2 type instead of Th1. This type of immune response is closely related to the alternative activation of macrophages (M2 profile) as has been shown in vivo in murine models. In this study, an experiment was carried out in order to evaluate the expression of CD68, CD14, CD206 and iNOS in cells present in the peritoneal fluid of sheep during early stages of infection with F. hepatica (1, 3, 9 and 18 days post-infection, dpi) by immunocytochemistry. To the authors' knowledge, this is the first report that studies the in vivo immunophenotype of macrophages from the peritoneal fluid of sheep infected with F. hepatica. Throughout the experiments the absolute number of leucocytes progressively increased, reaching its highest value at 18 dpi, mainly due to the increase of eosinophils. This immunocytochemical study had two purposes: 1) CD68 expression was assessed with Hansel counterstaining, to optimally identify peritoneal macrophages, eosinophils and lymphocytes; 2) expression of CD14, CD206 and iNOS was evaluated to identify alternative or classical pathways of macrophage activation. The results showed a significant increase in CD14 from day 3 dpi compared with the non-infected group. CD206 expression at all time-points showed a significant and dramatic increase in comparison with the uninfected group. On the other hand, iNOS expression showed little variation, and was significantly decreased at 18 dpi in comparison with the uninfected group. These results suggest that F. hepatica induces an alternative activation of peritoneal macrophages of sheep from the first day post-infection, which may facilitate parasite survival. This is the first report describing M2 activation of peritoneal macrophages in ruminants infected with F. hepatica.
在肝片吸虫感染过程中，该寄生虫能够将宿主免疫反应调节为非保护性的Th2型而非Th1型。正如在小鼠模型体内所显示的那样，这种免疫反应类型与巨噬细胞的替代性激活（M2型）密切相关。在本研究中，开展了一项实验，旨在通过免疫细胞化学评估感染肝片吸虫早期（感染后1、3、9和18天，dpi）绵羊腹腔液中细胞内CD68、CD14、CD206和诱导型一氧化氮合酶（iNOS）的表达。据作者所知，这是首篇研究感染肝片吸虫的绵羊腹腔液巨噬细胞体内免疫表型的报告。在整个实验过程中，白细胞绝对数量逐渐增加，在18 dpi时达到最高值，主要是由于嗜酸性粒细胞增多。这项免疫细胞化学研究有两个目的：1）用汉塞尔复染法评估CD68表达，以最佳方式识别腹腔巨噬细胞、嗜酸性粒细胞和淋巴细胞；2）评估CD14、CD206和iNOS的表达，以识别巨噬细胞激活的替代性或经典途径。结果显示，与未感染组相比，感染后3天起CD14显著增加。与未感染组相比，所有时间点的CD206表达均显著且急剧增加。另一方面，iNOS表达变化不大，与未感染组相比，在18 dpi时显著下降。这些结果表明，肝片吸虫从感染后第一天起就诱导绵羊腹腔巨噬细胞的替代性激活，这可能有助于寄生虫存活。这是首篇描述感染肝片吸虫的反刍动物腹腔巨噬细胞M2激活的报告。
