OBJECTIVETo identify the egg antigens related to the formation of hepatic granulomas and fibrosis of Schistosomiasis japonica.

METHODSThe egg cDNA library of Schistosoma japonicum (S. japonicum) was constructed and screened by immunological methods with the pooled sera of advanced schistosomiasis patients. The inserted foreign DNA fragments of positive clones were sequenced. The sequence data were analyzed using Wdnasis 2.5 and compared with Genebank data using blast software.

RESULTSEighty-one clones containing recombinant DNA fragments were obtained from the egg cDNA library of S. japonicum by immunological screening. The DNA sequences of all clones belonged to the miracidial antigen family. The longest cDNA fragment was 1604 bp, which contained an open reading frame of 351 bp, which encoded a protein of 1 2913.35 daltons.

CONCLUSIONThe cDNA sequence of the miracidial antigen of S. japonicum (Chinese strain) was obtained for the first time.

Animals ; Antigens, Helminth ; genetics ; Base Sequence ; China ; DNA, Complementary ; analysis ; Ovum ; Schistosoma japonicum ; genetics ; immunology

OBJECTIVE: To obtain the coding genes related to Schistosoma japonicum (Sj) cercariae 66 to approximately 68 kD antigens,and to provide antigens for diagnosis and vaccine of schistosomiasis. METHODS: Sj cercariae cDNA library was screened using the monospecific anti-sera of rabbit against soluble cercariae 66 to approximately 68 kD antigens as probes.The inserted cDNA fragments of the positive clones were amplified with PCR and identified by agarose gel electrophoresis. Four strong positive clones were further sequenced and analyzed through the internet NCBI/BLAST software. RESULTS: Twenty-one positive clones were obtained, 10 of which revealed a single band (0.5 to approximately 3.0 kb).The 4 strong positive clones showed high identity to SJCHGC05187,SJCHGC05173,SJCHGC06989, and SJCHGC01894 at the nucleotide level. CONCLUSION Four coding genes related with Sj antigens are obtained.
Animals ; Antibodies, Helminth ; immunology ; Antigens, Helminth ; immunology ; Cercaria ; genetics ; immunology ; DNA, Complementary ; genetics ; Gene Library ; Immune Sera ; immunology ; Schistosoma japonicum ; genetics ; immunology

OBJECTIVE: To clone and characterize new genes of Schistosoma japonicum, Sj, and to provide efficient vaccine candidates. METHODS: Sj adult cDNA library was screened with rabbit sera raised against male worm soluble antigen. The inserted cDNA fragments from the positively selected clones were amplified with PCR and further sequenced, as well as characterized through internet NCBI GenBank software. RESULTS: Eleven positive clones were obtained and two were verified by GenBank as new, including a novel gene designated as Sj-P8 (GenBank accession No. AF517843) and a new partial cDNA of Sj myosin (GenBank accession No. AY770506). The two new genes encoded a transmembrane protein of 75 amino acids and a myosin protein fragment of 212 amino acids respectively. CONCLUSION The newly obtained genes may provide useful information for the research on Sj vaccine.
Amino Acid Sequence ; Animals ; Antigens, Helminth ; genetics ; immunology ; Base Sequence ; Cloning, Molecular ; DNA, Complementary ; genetics ; DNA, Helminth ; genetics ; Gene Library ; Genes, Helminth ; genetics ; Male ; Molecular Sequence Data ; Rabbits ; Schistosoma japonicum ; genetics ; Schistosomiasis japonica ; prevention & control ; Vaccines, Synthetic

OBJECTIVETo prepare Sj14-3-3 DNA vaccine and observe its immunoprotection against Schistosoma japonicum in mice.

METHODSThe Sj14-3-3 gene was amplified by reverse transcription-polymerase chain reaction (RT-PCR) and subcloned into eukaryotic expression vector pBK. The recombinant plasmid pBK-Sj14-3-3 was extracted, purified and inoculated into BALB/c mice by intramuscular injection. Mice were attacked by Schistosoma japonicum cercariae and then killed. Adult worm and egg were counted, respectively. Diameter of the egg granulomas in the liver of infected mice was measured.

RESULTSElectrophoresis on 1% agarose gel showed that the product of RT-PCR and the inserted fragment of recombinant plasmid digested with EcoR I and Xho I had the same size, about 765 bp, confirming the latter was the 14-3-3 encoding gene by nucleotide sequencing. Adult worm load declined by 27%, average egg load of per gram (EPG) of the liver tissues by 79%, average egg production per couple of adult worm (EPWP) by 51%, and mean diameter of egg granulomas by 29% in vaccinated mice.

CONCLUSIONThe recombinant plasmid pBK-Sj14-3-3 was successfully constructed, which had some immunoprotection against Schistosoma japonicum in infected mice, indicating its potential to be vaccine candidate molecule of Schistosoma japonicum.

14-3-3 Proteins ; genetics ; immunology ; Animals ; Antibodies, Helminth ; blood ; Antigens, Helminth ; genetics ; immunology ; Cloning, Molecular ; DNA, Helminth ; genetics ; Female ; Helminth Proteins ; genetics ; immunology ; Membrane Proteins ; genetics ; immunology ; Mice ; Mice, Inbred BALB C ; Parasite Egg Count ; Rabbits ; Recombinant Proteins ; biosynthesis ; genetics ; immunology ; Schistosoma japonicum ; genetics ; immunology ; Schistosomiasis japonica ; immunology ; prevention & control ; Vaccines, DNA ; immunology

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

OBJECTIVETo discuss the optimal immunization dose by observing the immunoprotective effects of different doses of recombinant Schistosoma japonicum (Chinese strain) signaling protein 14-3-3 (rSj14-3-3).

METHODSSj14-3-3 gene was amplified by reverse transcriptase PCR (RT-PCR), subcloned into prokaryotic expression vector pET28a, then transformed into E.coli to express by inducing. Purified rSj14-3-3 was prepared through SDS polyacrylamide gel electrophoresis (SDS-PAGE), electroelution, dialysis, then BALB/c mice were divided into 5 groups and immunized in rSj14-3-3 protein followed by challenging infection (the 1st, 2nd, and 3rd groups were immunized in 50 microg, 100 microg and 300 microg antigen, respectively. The 4th, 5th groups were immunized in Freund's adjuvant and normal saline controls). After 6 weeks of challenging infection, the mice were killed and the worm and egg reduction rates were calculated. And the mice sera in different time were taken to examine the specific anti-Sj14-3-3 IgG.

RESULTSrSj14-3-3 protein was expressed successfully. After immunizing and challenging, worm reduction was found to be 28.20% in the 1st group, 43.10% in the 2nd group, 40.00% in the 3rd group, respectively. Number of eggs in liver tissue was reduced by 41.80%, 57.50%, 55.70%, respectively. Compared the results of the tested groups to the controls, the differences were of significance by t-test (worm reduction rate: t = 6.8 in the 1st group, t = 8.7 in the 2nd group, t = 7.3 in the 3rd group, P < 0.01 in all tested groups. Egg reduction rate at the group's number above: t = 11.23, t = 11.54, t = 7.99, P < 0.01 in all tested groups). As compared the results between the tested groups by chi(2), the differences were of significance between the 1st and the 2nd groups (worm reduction rate: chi(2) = 8.96, P < 0.05; egg reduction rate: chi(2) = 15.69, P < 0.05), between the 1st and the 3rd groups, the differences were also of significance (worm reduction rate: chi(2) = 6.52, P < 0.05; egg reduction rate: chi(2) = 12.52, P < 0.05). The difference was not of significance between the 2nd and the 3rd groups (worm reduction rate: chi(2) = 1.20, P > 0.05; egg reduction rate: chi(2) = 0.93, P > 0.05). In all tested groups, total anti-Sj14-3-3 specific IgG rose markedly. IgG(1) and IgG(2a) subtypes were high, but IgG(2b) and IgG(3) were near the background in four subtypes tested.

CONCLUSIONImmunoprotection of rSj14-3-3 should have some relations with immunization dose, and the protection obtained from immunizing mice by using 100 microg antigen was the best.

14-3-3 Proteins ; administration & dosage ; immunology ; Animals ; Antibodies, Helminth ; immunology ; Antibody Formation ; Antigens, Helminth ; blood ; Female ; Helminth Proteins ; immunology ; Immunoglobulin G ; blood ; Mice ; Mice, Inbred BALB C ; Recombinant Proteins ; Schistosoma japonicum ; genetics ; immunology ; Signal Transduction ; Vaccination

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 express and purify Schistosoma japonicum ribosomal protein S4(SjRPS4) in Escherichia coli, and assess its value in immunodiagnosis of Schistosomiasis japonica.

METHODSGene fragment of SjRPS4 was amplified by screening the cercaria cDNA library of Schistosoma japonicum. The target gene was cloned into the expressive vector pQE30 and transformed into E. coli M15. The recombinant protein expression was induced by isopropylthio-β-D-galactoside (IPTG). This fusion protein was purified by Ni(2+)-NTA chromatography and identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), Western blot and ELISA.

RESULTSThe plasmid pQE30/SjRPS4 was constructed successfully and expressed a SjRPS4 fusion protein in E. coli as showing a single special band on SDS-PAGE gel at Mr 30 × 10(3) position. It reached a purity of above 90% after purification. The Western blot result confirmed that the recombinant protein could specifically react with the serum samples from patients of schistosomiasis. Detecting the serum of Schistosomiasis japonica patients by ELISA, the sensitivity and specificity of the ELISA method were 90.91% (70/77) and 92.59% (25/27), the positive rate of recombinant protein expression was 67.30% (70/104). There was no cross-reaction with paragonimiasis patients' serum.

CONCLUSIONProtein SjRPS4 was successfully cloned and expressed, and it was confirmed that SjRPS4 antibodies were valuable in the diagnosis of Schistosomiasis japonica.

Amino Acid Sequence ; Animals ; Antibodies, Helminth ; blood ; Antigens, Helminth ; Cloning, Molecular ; Enzyme-Linked Immunosorbent Assay ; Gene Library ; Humans ; Molecular Sequence Data ; Plasmids ; Recombinant Proteins ; genetics ; Ribosomal Proteins ; genetics ; Schistosoma japonicum ; genetics ; Schistosomiasis japonica ; diagnosis ; genetics ; Sensitivity and Specificity

The cDNA fragments of interest were amplified using Sj lambda ZipLox library as the templates by PCR and then cloned into a eukaryotic expression vector p-CMV-GH; A small number of DNA fragments inserted in the recombinants was identified by restriction cleavage, EST sequencing and bioinformatical analysis; mice were injected intramuscularly with the expression library (L-CMV-SjR) or sublibraries(L-CMV-SjR1, L-CMV-SjR2 and L-CMV-SjR3), immunized mice were challenged with Schistosoma japonicum cercariae on day 35, the levels of IgG antibodies in sera from the immunized mice were detected by ELISA. The results demonstrated that a partial cDNA expression library of S.j, with approximately 10(5) transformants, was constructed, most of the recombinants contained the insert DNA fragments of interest, and these fragments had the features of protein-coding sequences for Schistosome. There were no significant differences for the levels of IgG antibodies in sera from all of the immunized groups. Mice immunized with L-CMV-SjR, L-CMV-SjR1 and L-CMV-SjR2 developed significant protective effect against Sj infection compared to control mice injected with the empty plasmid, the rate of worm reduction was about 30%.
Animals ; Antibodies, Helminth ; blood ; immunology ; Antigens, Helminth ; genetics ; immunology ; DNA, Complementary ; Disease Models, Animal ; Gene Expression ; Gene Library ; Mice ; Schistosoma japonicum ; genetics ; immunology ; Schistosomiasis japonica ; prevention & control ; Vaccination ; methods ; Vaccines, DNA ; genetics ; immunology

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