ANCAROLA MarÍa eugenia
congresos y reuniones científicas
Tegument ultrastructural insight in Echinococcus granulosus protoscoleces
SEBASTIÁN MILES; MAREK CYRKLAFF; JAVIER MAGNONE; JOAQUÍN GARCÍA-LUNA; MARIA EUGENIA ANCAROLA; MARCELA CUCHER; SYLVIA DEMATTEIS; FRIEDRICH FRISCHKNECHT; GUSTAVO MOURGLIA ETTLIN
Congreso; Segundo Congreso Nacional de Biociencias; 2019
Echinococcus granulosus is the cestode parasite responsible for cystic echinococcosis, a worldwide distributed zoonosis listed as a Neglected Tropical Disease by the WHO. In spite of its health and economic relevance, scarce information is available on E. granulosus structural biology in different developmental stages. In this sense, protoscoleces (PSC) are an extremely interesting parasite stage due to their developmental plasticity, since they are able to differentiate either into adult worms or secondary cysts within definitive or intermediate hosts, respectively. The most external cellular layer of PSC is called the tegument, which is remarkably important in determining the infection outcome through its immunomodulating activities. In the present work, we have analyzed through several microscopy techniques the tegument ultrastructure from both freshly-obtained and 96h-cultured PSC. Firstly, parasite glycocalyx and general tegumental morphology was analyzed by Scanning Electron Microscopy (SEM); and then, tegumental ultrastructural characteristics were assessed through Transmission Electron Microscopy (TEM). In this regard, TEM studies evidenced the presence of vesicles within PSC glycocalyx, tegument and interior structures, exhibiting similar morphological characteristics resembling extracellular vesicles (EVs). Since PSC are known to secret EVs to the extracellular medium, their morphological properties -as well as the general tegumental ultrastructure- were analyzed through Tomography Electron Microscopy (tomoEM) followed by further 3D reconstruction. VEs existence was confirmed by TEM using different fixation and embedding techniques which reduce potential artifacts. Finally, the presence of selected parasite proteins known to exert immunomodulating activities, e.g. GST, FABP, AgB and Annexin, within PSC tegument and EVs was studied by immunolabeling with gold nanoparticles (ImmunoTEM). Furthermore, the presence of host IgGs -known to be present within hydatid fluid- was also assessed through ImmunoTEM. At the end, novel data on PSC tegumental ultrastructure and composition was obtained, contributing to a better understanding of E. granulosus structural biology.