Modeling, molecular dynamics and docking studies of a full-length Echinococcus granulosus 2DBD nuclear receptor

Weighted gene co-expression network analysis reveals immune evasion related genes in Echinococcus granulosus sensu stricto

Cystic echinococcosis (CE) is a zoonotic disease caused by the tapeworm Echinococcus granulosus sensu lato (s.l). In the intermediate host, this disease is characterized by the growth of cysts in viscera such as liver and lungs, inside of which the parasite develops to the next infective stage known as protoscoleces. There are records that the infected viscera affect the development and morphology of E. granulosus s.l. protoscolex in hosts such as buffalo or humans. However, the molecular mechanisms that drive these differences remains unknown. Weighted gene co-expression network analysis (WGCNA) using a set of RNAseq data obtained from E. granulosus sensu stricto (s.s.) protoscoleces found in liver and lung cysts reveals 34 modules in protoscoleces of liver origin, of which 12 have differential co-expression from protoscoleces of lung origin. Three of these twelve modules contain hub genes related to immune evasion: tegument antigen, tegumental protein, ubiquitin hydrolase isozyme L3, COP9 signalosome complex subunit 3, tetraspanin CD9 antigen, and the methyl-CpG-binding protein Mbd2. Also, two of the twelve modules contain only hypothetical proteins with unknown orthology, which means that there are a group of unknown function proteins co-expressed inside the protoscolex of liver CE cyst origin. This is the first evidence of gene expression differences in protoscoleces from CE cysts found in different viscera, with co-expression networks that are exclusive to protoscoleces from liver CE cyst samples. This should be considered in the control strategies of CE, as intermediate hosts can harbor CE cysts in liver, lungs, or both organs simultaneously.

Dimerization, host-parasite communication and expression studies of an Echinococcus granulosus 2DBD nuclear receptor

Nuclear receptors (NRs) are ligand-modulated transcription factors that regulate various biological processes, such as metabolism, development and reproduction. Although NRs with two DNA-binding domains (2DBD) were identified in Schistosoma mansoni (Platyhelminth, Trematoda) more than fifteen years ago, these proteins have been poorly studied. 2DBD-NRs could become attractive therapeutic targets to combat parasitic diseases such as cystic echinococcosis since this type of protein is absent in vertebrate hosts. Cystic echinococcosis is a worldwide zoonosis caused by the larval stage of the parasitic platyhelminth Echinococcus granulosus (Cestoda) that generates an important public health problem and a significant economic loss. Recently, our research group identified four 2DBD-NRs in E. granulosus, named Eg2DBDα, Eg2DBDα.1 (an isoform of Eg2DBDα), Eg2DBDβ, and Eg2DBDγ. This work demonstrated that Eg2DBDα.1 forms homodimers through the E and F regions, whereas its interaction with EgRXRβa could not be detected. In addition, the stimulation of Eg2DBDα.1 homodimerization by intermediate host serum was shown, suggesting that at least one lipophilic molecule from bovine serum could bind to Eg2DBDα.1. Finally, Eg2DBDs expression studies in the protoscolex larval stage were performed, indicating that Eg2dbdγ is not expressed, whereas Eg2dbdα has the highest expression level followed by Eg2dbdβ and Eg2dbdα.1 in decreased order. Overall, these findings provide new insights into the mechanism of action of Eg2DBDα.1 and its potential role in host-parasite communication.