The coagulation system helps control infection caused by the ciliate parasite Philasterides dicentrarchi in the turbot Scophthalmus maximus (L.)

• Published in: Developmental & Comparative Immunology
• Main Authors: Blanco Abad, Verónica, Noia Guldrís, Manuel, Valle Cao, Alejandra, Fontenla Iglesias, Francisco, Folgueira López, Iria, Felipe González, Ana Paula de, Pereiro González, Patricia, Leiro Vidal, José Manuel, Lamas Fernández, Jesús
• Other Authors: Universidade de Santiago de Compostela. Departamento de Bioloxía Funcional, Universidade de Santiago de Compostela. Departamento de Microbioloxía e Parasitoloxía, Universidade de Santiago de Compostela. Instituto de Acuicultura
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier
• Subjects: Fish; Philasterides dicentrarchi; Coagulation system; Neutrophils; Plasma; Complement; Blanco; Scophthalmus maximus; Turbot
• Online Access: http://hdl.handle.net/10347/18167; https://doi.org/10.1016/j.dci.2018.06.001

This is the accepted manuscript of the following article: Blanco-Abad, V., Noia, M., Valle, A., Fontenla, F., Folgueira, I., & De Felipe, A. et al. (2018). The coagulation system helps control infection caused by the ciliate parasite Philasterides dicentrarchi in the turbot Scophthalmus maximus (L.). Developmental & Comparative Immunology, 87, 147-156. doi:10.1016/j.dci.2018.06.001 Many studies have shown that coagulation systems play an important role in the defence against pathogens in invertebrates and vertebrates. In vertebrates, particularly in mammals, it has been established that the coagulation system participates in the entrapment of pathogens and activation of the early immune response. However, functional studies investigating the importance of the fish coagulation system in host defence against pathogens are scarce. In the present study, injection of turbot (Scopthalamus maximus) with the pathogenic ciliate Philasterides dicentrarchi led to the formation of macroscopic intraperitoneal clots in the fish. The clots contained abundant, immobilized ciliates, many of which were lysed. We demonstrated that the plasma clots immobilize and kill the ciliates in vitro. To test the importance of plasma clotting in ciliate killing, we inhibited the process by adding a tetrapeptide known to inhibit fibrinogen/thrombin clotting in mammals. Plasma tended to kill P. dicentrarchi slightly faster when clotting was inhibited by the tetrapeptide, although the total mortality of ciliates was similar. We also found that kaolin, a particulate activator of the intrinsic pathway in mammals, accelerates plasma clotting in turbot. In addition, PMA-stimulated neutrophils, living ciliates and several ciliate components such as cilia, proteases and DNA also displayed procoagulant activity in vitro. Injection of fish with the ciliates generated the massive release of neutrophils to the peritoneal cavity, with formation of large aggregates in those fish with live ciliates in the peritoneum. We observed, by SEM, numerous ...