Echinococcus granulosus fatty acid binding proteins subcellular localization

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

Nuclear receptors are ligand-activated transcription factors capable of regulating the expression of complex gene networks. The family includes seven subfamilies of protein with a wide phylogenetic distribution. A novel subfamily with two DNA-binding domains (2DBDs) has been first reported in Schistosoma mansoni (Platyhelminth, Trematoda). Employing an ab initio protocol and homology modeling methods, the full-length 3D structure of the Eg2DBDα.1 nuclear receptor from Echinococcus granulosus (Platyhelminth, Cestoda) was generated. The model analysis reveals the presence of the conserved three-layered alpha-helical sandwich structure in the ligand binding domain, and a particularly long and flexible hinge region. Molecular dynamics simulations were performed previous to dock a conformational library of fatty acids and retinoic acids. Our results indicate that oleic and linoleic acids are suitable ligands to this receptor. The ligand-protein complex is stabilized mainly by hydrogen bonds and hydrophobic interactions. The fact that 2DBD nuclear receptors have not been identified in vertebrates confers particular interest to these nuclear receptors, not only concerning their structure and function but as targets of new anthelmintic drugs.Communicated by Ramaswamy H. Sarma.

Design of a Novel Multi-Epitope Vaccine Against Echinococcus granulosus in Immunoinformatics

All the time, echinococcosis is a global zoonotic disease which seriously endangers public health all over the world. In order to speed up the development process of anti-Echinococcus granulosus vaccine, at the same time, it can also save economic cost. In this study, immunoinformatics tools and molecular docking methods were used to predict and screen the antigen epitopes of Echinococcus granulosus, to design a multi-epitope vaccine containing B- and T-cell epitopes. The multi-epitope vaccine could activate B lymphocytes to produce specific antibodies theoretically, which could protect the human body against Echinococcus granulosus infection. It also could activate T lymphocytes and clear the infected parasites in the body. In this study, four CD8+ T-cell epitopes, three CD4+ T-cell epitopes and four B-cell epitopes of Protein EgTeg were identified by immunoinformatics methods. Meanwhile, three CD8+ T-cell epitopes, two CD4+ T-cell epitopes and four B-cell epitopes of Protein EgFABP1 were identified. We constructed the multi-epitope vaccine using linker proteins. The study based on the traditional methods of antigen epitope prediction, further optimized the prediction results combined with molecular docking technology and improved the precision and accuracy of the results. Finally, in vivo and in vitro experiments had verified that the vaccine designed in this study had good antigenicity and immunogenicity.

Zone of Interaction Between the Parasite and the Host: Protein Profile of the Body Cavity Fluid of Gasterosteus aculeatus L. Infected with the Cestode Schistocephalus solidus (Muller, 1776)

PURPOSE

During infection, the host and the parasite "communicate" with each other through various molecules, including proteins. The aim of this study was to describe the excretory-secretory proteins from the helminth Schistocephalus solidus and its intermediate host, the three-spined stickleback Gasterosteus aculeatus L., which are likely to be involved in interactions between them.

METHODS

Combined samples of washes from the G. aculeatus sticklebacks cavity infected with the S. solidus, and washes from the parasite surface were used as experimental samples, while washes from the uninfected fish body cavity were used as control. The obtained samples were analyzed using mass-spectrometry nLC-MS/MS.

RESULTS

As a result of mass-spectrometry analysis 215 proteins were identified. Comparative quantitative analysis revealed significant differences in LFQ intensity between experimental and control samples for 20 stickleback proteins. In the experimental samples, we found an increase in the content of serpins, plasminogen, angiotensin 1-10, complement component C9, and a decrease in the content of triosephosphate isomerase, creatine kinase, fructose-biphosphate aldolase, superoxide dismutase, peroxidoxin-1, homocysteine-binding and fatty acid-binding proteins, compared to uninfected fish samples. In the experimental group washes, 30 S. solidus proteins were found, including malate dehydrogenase, annexin family proteins, serpins, peptidyl-prolyl cis-trans isomerase and fatty acid-binding protein.

CONCLUSIONS

Thus, the protein composition of washes from the helminth S. solidus surface and the body cavity of infected and uninfected stickleback G. aculeatus were studied. As a result, it was shown that various components of the immune defense system predominated in the washes of infected fish and helminths.

Bioinformatic analysis of a novel Echinococcus granulosus nuclear receptor with two DNA binding domains

Nuclear receptors are ligand-activated transcription factors capable of regulating the expression of complex gene networks. The family includes seven subfamilies of proteins with a wide phylogenetic distribution. A novel subfamily with two DNA-binding domains (2DBDs) has been reported in Schistosoma mansoni (Platyhelminth, Trematoda). This work describes the cDNA cloning and bioinformatics analysis of Eg2DBDα, a 2DBD nuclear receptor isoform from the parasite Echinococcus granulosus (Platyhelminth, Cestoda). The Eg2DBDα gene coding domain structure was analysed. Although two additional 2DBD nuclear receptors are reported in the parasite database GeneDB, they are unlikely to be expressed in the larval stage. Phylogenetic relationships between these atypical proteins from different cestodes are also analysed including S. mansoni 2DBD nuclear receptors. The presence of two DNA binding domains confers particular interest to these nuclear receptors, not only concerning their function but to the development of new antihelminthic drugs.