BACKGROUNDCystic echinococcosis due to Echinococcus granulosus (E. granulosus) is one of the most important chronic helminthic diseases, especially in sheep/cattle-raising regions. The larval stage of the parasite forms a cyst that grows in the liver, lung, or other organs of the host. To ensure a long life in the host tissues, the parasite establishes complex inter-cellular communication systems between its host to allow its differentiation toward each larval stage. Recent studies have reported that this communication is associated with the extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase cascade in helminth parasites, and in particular that these protein kinases might serve as effective targets for a novel chemotherapy for cystic echinococcosis. The aim of the present study investigated the biological function of a novel ERK ortholog from E. granulosus, EgERK.

METHODSDNA encoding EgERK was isolated from protoscolices of E. granulosus and analyzed using the LA Taq polymerase chain reaction (PCR) approach and bioinformatics. Reverse transcription PCR (RT-PCR) was used to determine the transcription level of the gene at two different larval tissues. Western blotting was used to detect levels of EgERK protein. The expression profile of EgERK in protoscolices was examined by immunofluorescence.

RESULTSWe cloned the entire Egerk genomic locus from E. granulosus. In addition, two alternatively spliced transcripts of Egerk, Egerk-A, and Egerk-B were identified. Egerk-A was found to constitutively expressed at the transcriptional and protein levels in two different larval tissues (cyst membranes and protoscolices). Egerk-A was expressed in the tegumental structures, hooklets, and suckers and in the tissue surrounding the rostellum of E. granulosus protoscolices.

CONCLUSIONSWe have cloned the genomic DNA of a novel ERK ortholog from E. granulosus, EgERK (GenBank ID HQ585923), and found that it is constitutively expressed in cyst membrane and protoscolex. These findings will be useful in further study of the biological functions of the gene in the growth and development of Echinococcus and will contribute to research on novel anti-echinococcosis drug targets.

Animals ; Blotting, Western ; Computational Biology ; DNA, Helminth ; genetics ; Echinococcus granulosus ; enzymology ; genetics ; Genome, Helminth ; genetics ; Helminth Proteins ; genetics ; metabolism ; Polymerase Chain Reaction

During the past several decades, researches on parasite genetics have progressed from biochemical and serodiagnostic studies to protein chemistry, molecular biology, and functional gene studies. Nowadays, bioinformatics, genomics, and proteomics approaches are being applied by Korean parasitology researchers. As for Clonorchis sinensis, investigations have been carried out to identify its functional genes using forward and reverse genetic approaches and to characterize the biochemical and biological properties of its gene products. The authors review the proteins of cloned genes, which include antigenic proteins, physiologic and metabolic enzymes, and the gene expression profile of Clonorchis sinensis.
Animals ; Clonorchiasis/parasitology ; Clonorchis sinensis/enzymology/*genetics/*metabolism ; Gene Expression Regulation ; Helminth Proteins/*genetics/*metabolism ; Humans

To express recombinant Ancylostoma caninum anticoagulant peptide-c2 (AcAPc2), a whole cDNA fragment encoding AcAPc2 was achieved by ligation- PCR and inserted into prokaryotic expression vector pTWIN1 for constructing the specific self-splicing prokaryotic expression vector, pTWIN1-AcAPc2; positive recombinants were transformed into E. coli ER2566 for expression research. The recombinant protein, AcAPc2-intein2-CBD, was soluble and expressed in E. coli ER2566 (about 30.1% fusion protein in total protein). AcAPc2-intein2-CBD was characterized to be 41 KD by SDS-PAGE and identified by Western-blot. The recombinant fusion protein was purified to a efficiently high degree by chitin affinity chromatography. After the process of specific self-splicing induced by beta-Mercaptoethanol, the target protein, AcAPc2, was obtained, characterized to be 21 KD by SDS-PAGE and migrated as a dimmer. Molecular weight of AcAPc2 conformed to native dimmer. Bio-information analysis indicated relationship between secondary construction of AcAPc2 and biologic function. These findings greatly facilitate the purification of AcAPc2 and are very important for the additional studies on its anti-coagulation mechanism and its clinical application as anti-coagulation medicine.
Animals ; Dogs ; Escherichia coli ; genetics ; metabolism ; Gene Expression ; Genes, Helminth ; Genetic Vectors ; Helminth Proteins ; biosynthesis ; genetics ; Plasmids ; genetics ; Prokaryotic Cells ; metabolism ; RNA Splicing ; Recombinant Fusion Proteins ; chemistry ; pharmacology

Helminthic cysteine proteases are well known to play critical roles in tissue invasion, nutrient uptake, and immune evasion of the parasites. In the same manner, the sparganum, the plerocercoid of Spirometra mansoni, is also known to secrete a large amount of cysteine proteases. However, cysteine protease inhibitors regulating the proteolytic activities of the cysteine protease are poorly illustrated. In this regard, we partially purified an endogenous cysteine protease inhibitor from spargana and characterized its biochemical properties. The cysteine protease inhibitor was purified by sequential chromatographies using Resource Q anion exchanger and Superdex 200 HR gel filtration from crude extracts of spargana. The molecular weight of the purified protein was estimated to be about 11 kD on SDS-PAGE. It was able to inhibit papain and 27 kDa cysteine protease of spargana with the ratio of 25.7% and 49.1%, respectively, while did not inhibit chymotrypsin. This finding suggests that the cysteine protease inhibitor of spargana may be involved in regulation of endogenous cysteine proteases of the parasite, rather than interact with cysteine proteases from their hosts.
Animals ; Cystatins/pharmacology ; Cysteine Endopeptidases/metabolism ; Cysteine Proteinase Inhibitors/chemistry/*metabolism/*pharmacology ; Helminth Proteins/*metabolism/*pharmacology ; Spirometra/*metabolism

Calcium-binding protein is an indispensable protein which performs extensive and important functions in the growth of Schistosoma japonicum. Based on our primary study on tegument surface proteins of S. japonicun, a cDNA encoding a 66 kDa calcium-binding protein of S. japonicum (Chinese strain) was cloned, sequence analysis revealed that it was identical with that of SjIrV1 of Philippines strains S. japonicum. The expression of SjIrV1 were detected by Real-time PCR, using cDNA templates isolated from 7, 14, 21, 28, 35 and 42 days worms and the results revealed that the gene was expressed in all investigated stages, and the mRNA level of SjIrV1 is much higher in 42 d female worms than that in 42 d male worms. The cDNA containing the open reading frame of IrV1 was subcloned into a pET28a (+) vector and transformed into competent Escherichia coli BL21 for expression. The recombinant protein was purified using a Ni-NTA purification system, and confirmed by high performance liquid chromatography (RP-HPLC) and tandem mass spectrometry (MS/MS). Western blotting analysis showed that recombinant SjIrV1 (rSjIrV1) could be recognized by the S. japonicum infected mouse serum and the mouse serum specific to rSjIrV1, respectively. Immunofluorescence observation exhibited that SjIrV1 was mainly distributed on the tegument of the 35-day adult worms. ELISA test revealed that IgG, IgG1 and IgG2a antibodies are significantly increased in the serum of rSjIrV1 vaccinated mice. The study suggested that rSjIrV1 might play an important role in the development of S. japonicum.
Animals ; Antibodies, Helminth ; blood ; Calcium-Binding Proteins ; genetics ; metabolism ; Cloning, Molecular ; Escherichia coli ; metabolism ; Female ; Genetic Vectors ; Helminth Proteins ; genetics ; metabolism ; Male ; Mice ; Recombinant Proteins ; genetics ; metabolism ; Schistosoma japonicum ; genetics ; metabolism

OBJECTIVETo examine the expression profile and immunofluorescence localization of the major egg antigen p40 of Schistosoma japonicum (Sjp40) during granuloma formation in the liver of infected New Zealand white rabbits.

METHODSNew Zealand white rabbits were infected with S. japonicum cercariae, and the livers were harvested at 29 and 45 days post-infection (dpi). The total RNA of the liver tissues was extracted for expression profiling of Sjp40 by quantitative reverse transcription-PCR (qRT-PCR) with GAPDH of S. japonicum as the endogenous reference gene. The expression of Sjp40 in the liver were detected by Western blotting using anti-Sjp40 monoclonal antibody (mAb) 9G7 or anti-Toxoplasma gondii tSAG1 mAb Y3A8 (control) as the primary antibody. Paraffin sections of the liver were prepared for observing egg granuloma formation using HE staining and for indirect immunofluorescence assay of Sjp40 location in the trapped eggs and egg granulomas.

RESULTSThe level of Sjp40 mRNA in the eggs trapped in rabbit livers was significantly higher at 45 dpi than that at 29 dpi (P<0.05), and Western blotting confirmed the presence of Sjp40 protein in the rabbit livers at both 29 and 45 dpi. Immunofluorescence assay demonstrated localized expression of Sjp40 in the immature eggs in the rabbit liver at 29 dpi, but at 45 dpi fluorescence was detected in clusters of mature eggs containing miracidium and in the surrounding egg granulomas.

CONCLUSIONSThe transcriptional levels of Sjp40 significantly increased with the maturation of eggs trapped in the rabbit livers. Sjp40 protein spread from the eggs to the surrounding egg granuloma at 45 dpi when acute liver granulomatous lesions occur, suggesting that Sjp40 plays a key role in egg granulomas formation in the livers of infected New Zealand white rabbits.

Animals ; Antibodies, Monoclonal ; Antigens, Helminth ; metabolism ; Fluorescent Antibody Technique ; Gene Expression Profiling ; Granuloma ; parasitology ; Helminth Proteins ; metabolism ; Liver ; parasitology ; RNA, Messenger ; Rabbits ; Schistosoma japonicum ; Schistosomiasis japonica

OBJECTIVETo establish and optimize the proteomic analysis of protoscoleces-specific antigens from Echinococcus granulosus. To provide a foundation for identifying specific antigens in the soluble proteins of E. granulosus protoscoleces for further research.

METHODSBrood capsules were collected aseptically from fertile E. granulosus cysts from the livers of an infected patient. The fertile E. granulosus cysts were fractured, and protoscoleces were collected by centrifugation. The soluble proteins of protoscoleces were acquired using the 2D Quant kit according to the manufacturer's instructions. We employed two-dimensional electrophoresis (2-DE) combined with immunoblot assay (Western blot) to analyze the soluble components of E. granulosus protoscoleces antigens. The 2-DE and immunoblot maps obtained were analyzed with PDQuest 8.0 image analysis software.

RESULTSAbout 233 soluble protein spots were identified with Coomassie-stained gels. Most of the proteins had a molecular weight of 16,000 Da to 117,000 Da, and an isoelectric point value of 3.0 to 10.0. 2-DE immunoblot was conducted and 57 specific antigen spots were observed, among which 23 spots were identified.

CONCLUSION2-DE combined with Western blot is the key to successful proteomic analysis and presents a new possibility for searching the specific E. granulosus protoscoleces antigens.

Animals ; Antigens, Helminth ; chemistry ; metabolism ; Blotting, Western ; methods ; Echinococcus granulosus ; classification ; metabolism ; Electrophoresis, Gel, Two-Dimensional ; Gene Expression Regulation ; Helminth Proteins ; isolation & purification ; Proteomics ; methods

Nematode sperm undergo a drastic physiological change during spermiogenesis (sperm activation). Unlike mammalian flagellated sperm, nematode sperm are amoeboid cells and their motility is driven by the dynamics of a cytoskeleton composed of major sperm protein (MSP) rather than actin found in other crawling cells. This review focuses on sperm from Caenorhabditis elegans and Ascaris suum to address the roles of external and internal factors that trigger sperm activation and power sperm motility. Nematode sperm can be activated in vitro by several factors, including Pronase and ionophores, and in vivo through the TRY-5 and SPE-8 pathways. Moreover, protease and protease inhibitors are crucial regulators of sperm maturation. MSP-based sperm motility involves a coupled process of protrusion and retraction, both of which have been reconstituted in vitro. Sperm motility is mediated by phosphorylation signals, as illustrated by identification of several key components (MPOP, MFPs and MPAK) in Ascaris and the characterization of GSP-3/4 in C. elegans.
Animals ; Helminth Proteins ; metabolism ; Male ; Nematoda ; cytology ; growth & development ; metabolism ; Phosphorylation ; Signal Transduction ; Sperm Motility ; Spermatozoa ; cytology ; growth & development ; metabolism

The WD40-repeat proteins serve as a platform coordinating partner proteins and are involved in a range of regulatory cellular functions. A WD40-repeat protein (CsWD1) of Clonorchis sinensis previously cloned is expressed stage-specifically in the tegumental syncytium of C. sinensis metacercariae. In the present study, interacting proteins with the CsWD1 protein was purified by immunoprecipitation and 2 dimension gel electrophoresis from the C. sinensis metacercaria soluble extract, and tryptic peptides were analyzed by LC/ESI-MS. Putative partner proteins were annotated to be actin-2, glyceraldehyde-3-phosphate dehydrogenase, and hypothetical and unmanned proteins. The CsWD1 protein was predicted to contain 3 conserved actin-interacting residues on its functional surface. With these results, the CsWD1 protein is suggested to be an actin-interacting protein of C. sinensis.
Animals ; Antibodies, Helminth/metabolism ; Clonorchis sinensis/*physiology ; Electrophoresis, Gel, Two-Dimensional/veterinary ; Helminth Proteins/chemistry/*isolation & purification/metabolism ; Hydrogen-Ion Concentration ; Immunoglobulin G/chemistry ; Microfilament Proteins/chemistry/*isolation & purification/metabolism

A complete cDNA sequence encoding a pore-forming subunit (Kir6.2) of ATP-senstive potassium channel in the adult worm, Clonorchis sinensis, termed CsKir6.2, was isolated from an adult cDNA library. The cDNA contained a single open-reading frame of 333 amino acids, which has a structural motif (a GFG-motif) of the putative pore-forming loop of the Kir6.2. Peculiarly, the CsKir6.2 shows a lack-sequence structure, which deleted 57 amino acids were deleted from its N-terminus. The predicted amino acid sequence revealed a highly conserved sequence as other known other Kir6.2 subunits. The mRNA was weekly expressed in the adult worm.
Adenosine Triphosphate/metabolism ; Amino Acid Sequence ; Animals ; Base Sequence ; Cloning, Molecular ; Clonorchis sinensis/*genetics/metabolism ; Helminth Proteins/*genetics/metabolism ; Human ; Molecular Sequence Data ; Potassium Channels, Inwardly Rectifying/*genetics/metabolism ; RNA, Helminth/chemistry/genetics ; Sequence Alignment ; Support, Non-U.S. Gov't