Fasciola hepatica induces an alternative activation of peritoneal macrophages of sheep from the first day post-infection, facilitating parasite survival.

Results of a study carried out by partner 10 (University of Córdoba) revealed that peritoneal macrophages from sheep experimentally infected by F. hepatica showed a dramatic increase of CD206 (alternative macrophage activation marker) expression at 1, 3, 9 and 18 days postinfection and no significant changes in iNOS (classical macrophage activation marker) expression. These results suggest that F. hepatica infection in sheep induces since very early stages of infection alternative activation of peritoneal macrophages. Since this type of macrophages is ineffective to kill parasites, it facilitates the larval survival during the peritoneal migration. The paper entitled: Study of peritoneal macrophage immunophenotype in sheep experimentally infected with Fasciola hepatica. Ruiz-Campillo MT, Molina-Hernández V, Pérez J, Pacheco IL, Pérez R, Escamilla A, Martínez-Moreno FJ, Martínez-Moreno A, Zafra R. Vet Parasitol. 2018 Jun 15;257:34-39. doi: 10.1016/j.vetpar.2018.05.019.

https://www.sciencedirect.com/science/article/pii/S0304401718302127?via%3Dihub

Fig. 1. Peritoneal smear stained with anti-CD206 polyclonal antibody showing mild cytoplasmic immunolabelling (brown colour) in macrophages (arrows) from uninfected control (A) and very severe immunolabelling in macrophages at 1 day post-infection (dpi) (B), 9 dpi (C), and 18 dpi (D). ABC method-haematoxylin counterstain. ×400.

Fig. 1. Peritoneal smear stained with anti-CD206 polyclonal antibody showing mild cytoplasmic immunolabelling (brown colour) in macrophages (arrows) from uninfected control (A) and very severe immunolabelling in macrophages at 1 day post-infection (dpi) (B), 9 dpi (C), and 18 dpi (D). ABC method-haematoxylin counterstain. ×400.