The tapeworm Taenia solium is an important human zoonotic parasite that causes great economic loss and also endangers public health. At present, an effective vaccine that will prevent infection and chemotherapy without any side effect remains to be developed. In this study, codon usage patterns in the T. solium genome were examined through 8,484 protein-coding genes. Neutrality analysis showed that T. solium had a narrow GC distribution, and a significant correlation was observed between GC12 and GC3. Examination of an NC (ENC vs GC3s)-plot showed a few genes on or close to the expected curve, but the majority of points with low-ENC (the effective number of codons) values were detected below the expected curve, suggesting that mutational bias plays a major role in shaping codon usage. The Parity Rule 2 plot (PR2) analysis showed that GC and AT were not used proportionally. We also identified 26 optimal codons in the T. solium genome, all of which ended with either a G or C residue. These optimal codons in the T. solium genome are likely consistent with tRNAs that are highly expressed in the cell, suggesting that mutational and translational selection forces are probably driving factors of codon usage bias in the T. solium genome.
Animals ; Base Sequence ; Codon/*genetics ; Evolution, Molecular ; *Genome, Helminth ; Helminth Proteins/*genetics ; Molecular Sequence Data ; Taenia solium/*genetics

TSO18 gene was subcloned into the Pichia pastoris expression vector pPIC9K. The recombinant plasmid pPIC9K-TSO18 was transformed into P. pastoris GS115 by electroporation so that the plasmid will be integrated with chromosome of P. pastoris. The P. pastoris strains containing multi-copy recombinant were screened by G418 and induced by methanol. The expression product was analyzed by SDS-PAGE, Western blot, deglycosylation, and purified by Sephadex column, and was used to immunize mice. The results indicated that the target protein was efficiently expressed in P. pastoris, and glycosylated moderately, and had immunological activity. In a 5 liter fermentor, the expression level of the target protein was up to 2.54 mg/mL. These results will benefit for the development of genetically engineering vaccine.
Animals ; Antigens, Helminth ; biosynthesis ; genetics ; immunology ; Cloning, Molecular ; Electroporation ; Gene Expression ; Genetic Vectors ; genetics ; Mice ; Pichia ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; immunology ; Swine ; Taenia solium ; genetics ; immunology

OBJECTIVE: To conduct eukaryotic expression of the leucine-rich repeat containing 15 (LRRC15), a differentially expressed protein in excretory secretory antigens of Taenia solium cysticercus, and predict its antigen epitope. METHODS: The molecular weight, stability, amino acid sequence composition, isoelectric point and T lymphocyte epitope of the LRRC15 protein were predicted using the bioinformatics online softwares ExPASy-PortParam and Protean. The full-length splicing primers were designed using PCR-based accurate synthesis, and the LRRC15 gene was synthesized. The recombinant pcDNA3.4-LRRC15 plasmid was constructed and transfected into HEK293 cells to express the LRRC15 protein. In addition, the LRRC15 protein was characterized by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting. RESULTS: The recombinant pcDNA3.4-LRRC15 plasmid was successfully constructed, which expressed the target LRRC15 protein with an approximately molecular weight of 70 kDa. Bioinformatics prediction with the ExPASy-PortParam software showed that LRRC15 was a hydrophilic protein, which was consisted of 644 amino acids and had a molecular weight of 69.89 kDa and an isoelectric point of 5.6. The molecular formula of the LRRC15 protein was C₃₀₇₃H₄₉₄₂N₈₄₆O₉₅₃S₂₈ and had an instability coefficient is 50.3, indicating that LRRC15 was an instable protein. Bioinformatics prediction with the Protean software showed that the dominant T-cell antigen epitopes were located in 292 to 295, 353 to 361, 521 to 526 and 555 to 564 amino acids of the LRRC15 protein, and the T-cell antigen epitopes with a high hydrophilicity, good flexibility, high surface accessibility and high antigenicity index were found in 122 to 131, 216 to 233, 249 to 254, 333 to 343, 358 to 361, 368 to 372, 384 to 386, 407 to 412, 445 to 450, 469 to 481, 553 to 564, 588 to 594, 607 to 617 and 624 to 639 amino acids. Following transfection of the recombinant pcDNA3.4-LRRC15 plasmid into HEK293 cells, SDS-PAGE and Western blotting identified LRRC15 proteins in cell secretory culture media, cell lysis supernatants and sediments. The LRRC15-His fusion protein was purified from the cell culture medium, and SDS-PAGE identified a remarkable band at approximately 70 kDa, while Western blotting successfully recognized the band of the recombinant LRRC15 protein. CONCLUSIONS The eukaryotic expression and antigen epitope prediction of the LRRC15 protein in the excretory secretory antigens of T. solium cysticercus have been successfully performed, which provides insights into further understandings of its biological functions.
Amino Acids ; Animals ; Antigens, Helminth/genetics* ; Cysticercus/genetics* ; Epitopes/genetics* ; Eukaryota ; HEK293 Cells ; Humans ; Leucine-Rich Repeat Proteins ; Membrane Proteins ; Taenia solium/genetics*

OBJECTIVETo clone the coding gene of the stage-specific antigen cC1 from Cysticercus cellulosae and express high levels of soluble cC1 in E.coli.

METHODSThe cC1 gene was amplified from Cysticercus cellulosae by RT-PCR and cloned into pMD18-T vector, followed by subcloning into the prokaryotic expression plasmid pET28a. The recombinant plasmid was transformed into E.coli BL21(DE3) and the expression conditions were optimized. The expressed product was purified by Ni(+)-affinity chromatography, analyzed by high-performance liquid chromatography (HPLC), and identified with SDS-PAGE and Western blotting.

RESULTSThe fragment length of the amplification product by RT-PCR was 1056 bp. Comparison of the amplified gene sequence with the cC1 gene in Genbank identified a samesense point mutation at 423 position in the gene cloned into the expression plasmids. After a 6-h induction with 0.05 mmol/L IPTG at 37 degrees celsius;, the expression of the 40 kd soluble fusion protein exceeded 60% of the total bacterial protein, and the fusion protein was recognized by Cysticercus-infected human sera. The purity of the fusion protein was about 94% after purification by affinity chromatography.

CONCLUSIONThe stage-specific antigen cC1 from Cysticercus cellulosae has been successfully cloned and the soluble protein efficiently expressed in E.coli, which provides the basis for its further study and application.

Animals ; Antigens, Helminth ; biosynthesis ; genetics ; immunology ; Cloning, Molecular ; Cysticercus ; immunology ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; Humans ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Solubility ; Swine ; Taenia solium ; immunology

Wnt proteins are a family of secreted glycoproteins that are evolutionarily conserved and considered to be involved in extensive developmental processes in metazoan organisms. The characterization of wnt genes may improve understanding the parasite's development. In the present study, a wnt4 gene encoding 491amino acids was amplified from cDNA of metacestodes of Taenia solium using reverse transcription PCR (RT-PCR). Bioinformatics tools were used for sequence analysis. The conserved domain of the wnt gene family was predicted. The expression profile of Wnt4 was investigated using real-time PCR. Wnt4 expression was found to be dramatically increased in scolex evaginated cysticerci when compared to invaginated cysticerci. In situ hybridization showed that wnt4 gene was distributed in the posterior end of the worm along the primary body axis in evaginated cysticerci. These findings indicated that wnt4 may take part in the process of cysticerci evagination and play a role in scolex/bladder development of cysticerci of T. solium.
Animals ; Base Sequence ; Cysticercosis/pathology ; Cysticercus/enzymology/*genetics ; DNA, Helminth/*genetics ; Gene Expression Regulation ; Humans ; In Situ Hybridization ; Real-Time Polymerase Chain Reaction ; Sequence Analysis, DNA ; Sus scrofa ; Swine ; Swine Diseases ; Taenia solium/embryology/enzymology/*genetics ; Wnt4 Protein/*genetics

A male patient with neurocysticercosis was identified in Montai Village, Xay District, Oudomxay Province, Lao PDR in February 2004. He had a history of diagnosis for neurocysticercosis by a CT scan in Thailand after an onset of epileptic seizure in 1993. A pig in the same district was found to contain Taenia solium metacestodes (=cysticerci); the slaughtered pig body contained more than 2,000 cysticerci. In addition to morphological identification, molecular identification was also performed on the cysticerci by DNA sequencing analysis of the mitochondrial cox1 gene; they were confirmed as T. solium metacestodes. The patient is regarded as an indigenous case of neurocysticercosis infected in an endemic focus of T. solium taeniasis/cysticercosis in Oudomxay Province, Lao PDR.
Animals ; Cysticercus ; Electron Transport Complex IV/genetics ; Humans ; Laos/epidemiology ; Male ; Mitochondria/genetics ; Neurocysticercosis/*epidemiology/parasitology/radiography ; Risk Factors ; Sequence Analysis, DNA ; Swine ; Swine Diseases/*epidemiology/parasitology/radiography ; Taenia solium/classification/genetics/*isolation & purification

We collected fecal samples from 21 individuals infected with Taenia tapeworms in Koh Kong Province, Cambodia, and performed nucleotide sequencing of the cox1 gene and multiplex PCR on the eggs for DNA differential diagnosis of human Taenia tapeworms. Genomic DNA was extracted from the eggs of a minimum number of 10 isolated from fecal samples. Using oligonucleotide primers Ta7126F, Ts7313F, Tso7466F, and Rev7915, the multiplex PCR assay proved useful for differentially diagnosing Taenia solium, Taenia saginata, and Taenia asiatica based on 706, 629, and 474 bp bands, respectively. All of the Taenia specimens from Kho Kong, Cambodia, were identified as either T. saginata (n=19) or T. solium (n=2) by cox1 sequencing and multiplex PCR.
Adolescent ; Adult ; Animals ; Cambodia ; Child ; Cyclooxygenase 1/*genetics ; DNA Primers/genetics ; DNA, Helminth/chemistry/genetics ; Feces/parasitology ; Female ; Helminth Proteins/*genetics ; Humans ; Male ; Middle Aged ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; Taenia saginata/*enzymology/*genetics/isolation & purification ; Taenia solium/*enzymology/*genetics/isolation & purification ; Taeniasis/*parasitology ; Young Adult

Epidemiological situation of taeniasis in Mongolia was assessed based on mitochondrial DNA identification of the parasite species. Multiplex PCR was used on a total of 194 proglottid specimens of Taenia species and copro-PCR and loop-mediated isothermal amplification (LAMP) assays were utilized for detection of copro-DNA of 37 fecal samples from taeniasis patients submitted to the Mongolian National Center for Communicable Diseases (NCCD) from 2002 to 2012. In addition, 4 out of 44 calcified cysts in beef kept in formalin since 2003 were evaluated for histopathological confirmation of cattle cysticercosis. All proglottid specimens and stool samples were confirmed to be Taenia saginata by multiplex PCR and by copro-PCR and LAMP, respectively. Cysts collected from cattle were morphologically confirmed to be metacestodes of Taenia species. T. saginata taeniasis was identified from almost all ages from a 2-year-old boy up to a 88-year-old woman and most prominently in 15-29 age group (37%, 74/198) followed by 30-44 age group (34.8%, 69/198 ) from 15 of Mongolia's 21 provinces, while cattle cysticerci were found from 12 provinces. The highest proportion of taeniasis patients was in Ulaanbaatar, the capital of Mongolia.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Animals ; Cattle/parasitology ; Child ; Child, Preschool ; Cysticercosis/*epidemiology/parasitology ; DNA, Helminth/*genetics ; DNA, Mitochondrial/*genetics ; Feces/parasitology ; Female ; Geography ; Humans ; Male ; Meat/parasitology ; Middle Aged ; Mitochondria/genetics ; Mongolia/epidemiology ; Neglected Diseases/epidemiology ; Nucleic Acid Amplification Techniques/veterinary ; Questionnaires ; Taenia saginata/*genetics ; Taenia solium/genetics ; Taeniasis/*epidemiology/parasitology ; Young Adult

Species identification of Taenia tapeworms was performed using morphologic observations and multiplex PCR and DNA sequencing of the mitochondrial cox1 gene. In 2008 and 2009, a total of 1,057 fecal samples were collected from residents of Kongwa district of Dodoma region, Tanzania, and examined microscopically for helminth eggs and proglottids. Of these, 4 Taenia egg positive cases were identified, and the eggs were subjected to DNA analysis. Several proglottids of Taenia solium were recovered from 1 of the 4 cases. This established that the species were T. solium (n=1) and T. saginata (n=3). One further T. solium specimen was found among 128 fecal samples collected from Mbulu district in Arusha, and this had an intact strobila with the scolex. Phylegenetic analysis of the mtDNA cox1 gene sequences of these 5 isolates showed that T. saginata was basal to the T. solium clade. The mitochondrial cox1 gene sequences of 3 of these Tanzanian isolates showed 99% similarity to T. saginata, and the other 2 isolates showed 100% similarity to T. solium. The present study has shown that Taenia tapeworms are endemic in Kongwa district of Tanzania, as well as in a previously identified Mbulu district. Both T. solium isolates were found to have an "African/Latin American" genotype (cox1).
Adolescent ; Adult ; Animals ; DNA, Helminth/chemistry/genetics ; DNA, Mitochondrial/chemistry/genetics ; Diagnosis, Differential ; Feces/parasitology ; Genotype ; Humans ; Male ; Multiplex Polymerase Chain Reaction ; Phylogeny ; Sequence Analysis, DNA ; Species Specificity ; Taenia saginata/classification/genetics/*isolation & purification ; Taenia solium/classification/genetics/*isolation & purification ; Taeniasis/*parasitology ; Tanzania