Cystic echinococcosis in cattle: histological and proteomic features of inflammation

Cystic echinococcosis (CE) is caused by the larval stage of Echinococcus granulosus and is a widespread zoonotic disease. The World Health Organization (WHO) included CE in the list of Neglected Tropical Diseases in order to eliminate the disease and support the affected countries. The aim of the study was to compare fertile and infertile cysts from naturally infected cattle by means of histological and proteomic analysis in order to elucidate the molecular cross-talk between host and parasite and obtain further information on the bovine host immune response against E. granulosus. In this study, 70 hydatid cysts were removed from parasitized bovine lungs and livers. Each cyst was ranked as fertile or infertile and processed through histologic, immuno-histochemical, biomolecular, and statistical analysis. After that, 27 pulmonary tissues and 10 hydatid fluid samples were analysed with a Tandem Mass Tag (TMT)-based quantitative proteomics approach. As a result, four degrees of inflammation were detected, and thousands of proteins were identified in both tissues and fluids. Based on ontology and pathway analysis, several differential proteins are involved in the modulation or activation of host defence mechanisms. In conclusion, the combination of histological and proteomic approaches applied in this work provided a better understanding of the host-parasite interplay and of the bovine host immune response against E. granulosus