Molecular cloing and bioinformatics analysis of lactate dehydrogenase from Taenia multiceps

Cloning, expression and serodiagnostic potential of HSP70 of Taenia multiceps in sheep

The aim of this study was to determine the efficacy of the recombinant protein expressed by the T. multiceps HSP70 gene in the immunodiagnosis of sheep coenurosis. Specific primers were designed to amplify the gene encoding HSP70 from the whole genome sequence of T. multiceps, mRNA was isolated from C. cerebralis cysts obtained from an infected sheep's brain, and then, cDNA was isolated. The gene region related to the designed primers was amplified by PCR, and the obtained product was cloned and expressed. The specificity of the recombinant protein purified afterwards was demonstrated by Western Blot using known positive and negative sheep sera. Additionally, the efficiency of the recombinant protein in ELISA was determined with sera collected from 1207 sheep. Finally, the sensitivity and specificity values ​of the recombinant TmHSP70 antigen in the Western Blot were 100 %, while the sensitivity and specificity rates of the ELISA were 66.6 % and 52.6 %, respectively. At the same time, 567 (46.97 %) of the 1207 analyzed serum samples were found to be positive by ELISA. In conclusion, the Western Blot technique had a higher quality than ELISA in detecting the TmHSP70 antigen for the serodiagnosis of sheep coenurosis.

Expression and serodiagnostic potential of antigen B and thioredoxin peroxidase from Taenia multiceps

Coenurosis is a serious parasitic disease of herbivorous animals caused by the metacestode of Taenia multiceps (Coenurus cerebralis). Accordingly, a significant amount of research is currently dedicated to the development of appropriate antigens for use in rapid and accurate coenurosis diagnosis kits. In the present study, antigen B (AgB) and thioredoxin peroxidase (TPx) from T. multiceps were cloned and expressed using a prokaryotic system, molecular characterization of Tm-AgB was determined by bioinformatical analyses. The serological diagnostic potentials of rTm-AgB and rTm-TPx were evaluated by indirect ELISA and compared with those of previously reported rTm-AnxB2, rTm-HSP70, and rTm-GST. The results showed that Tm-AgB is a specific lipoprotein of cestodes with good thermal stability. The ELISA assay showed that rTm-AgB exhibited a sensitivity of 95.8% and a specificity of 87.5%, indicating its strong potential for serological diagnosis of T. multiceps.

Cloning, expression, characterization, and immunological properties of citrate synthase from Echinococcus granulosus

The larval stages of the tapeworm Echinococcus granulosus (Cestoda: Taeniidae) are the causative agent of cystic echinococcosis, one of the most important parasitic zoonoses worldwide. E. granulosus has a complete pathway for the tricarboxylic acid cycle (TCA), in which citrate synthase (CS) is the key enzyme. Here, we cloned and expressed CS from E. granulosus (Eg-CS) and report its molecular characterization. The localization of this protein during different developmental stages and mRNA expression patterns during H₂O₂ treatment were determined. We found that Eg-CS is a highly conserved protein, consisting of 466 amino acids. In western blotting assays, recombinant Eg-CS (rEg-CS) reacted with E. granulosus-positive sheep sera and anti-rEg-CS rabbit sera, indicating that Eg-CS has good antigenicity and immunoreactivity. Localization studies, performed using immunohistochemistry, showed that Eg-CS is ubiquitously expressed in the larva, germinal layer, and adult worm sections of E. granulosus. Eg-CS mRNA expression levels increased following H₂O₂ exposure. In conclusion, citrate synthase might be involved in the metabolic process in E. granulosus. An assessment of the serodiagnostic potential of rEg-CS based on indirect ELISA showed that, although sensitivity (93.55%) and specificity (80.49%) are high, cross-reactivity with other parasites precludes its use as a diagnostic antigen.

Molecular characterisation and expression analysis of two heat-shock proteins in Taenia multiceps

Background

Taenia multiceps is a harmful tapeworm and its larval form (coenurus cerebralis) is the causative agent of coenurosis, a disease affecting the health of herbivores, resulting in great economic loss to animal husbandry. Heat-shock proteins (HSPs), expressed in all prokaryotes and eukaryotes, act as molecular chaperones and can affect pathogenicity.

Methods

Herein, cDNAs of T. multiceps genes Tm-HSP60 and Tm-p36 were cloned and molecularly characterised by bioinformatics analyses. The immunogenicity and immunoreactivity of recombinant rTm-HSP60 and rTm-p36 proteins were investigated by immunoblotting and indirect ELISA was established to evaluate their serodiagnostic potential. Tissue localisation and transcriptional level at different life stages of T. multiceps were determined by immunohistochemical and quantitative real-time PCR analyses.

Result

The 533 residue rTm-HSP60 and the 314 residue rTm-p36 proteins share typical highly conserved features of HSPs. Tm-p36 shares structural characteristics with metazoan small HSPs, with two N-terminal α-crystallin domains. Compared with Tm-p36, Tm-HSP60 displayed stronger immunogenicity, and the indirect ELISA based on rTm-HSP60 exhibited a sensitivity of 83.3% and a specificity of 87.5%, while rTm-p36 was not suitable to develop indirect ELISA. Tm-HSP60 was widely distributed in all stages of T. multiceps, albeit at relatively low levels, while Tm-p36 was specifically distributed in the protoscolex and oncosphere.

Conclusions

The sequence, structural and functional analyses of these two HSPs indicates that they may play important roles in the life-cycle of T. multiceps as molecular chaperones. Tm-HSP60 displayed stronger immunogenicity compare to Tm-p36, and has the potential for antibody detection. Tm-p36 was strongly associated with the activation of oncospheres and has potential interest for vaccination.

Electronic supplementary material

The online version of this article (10.1186/s13071-019-3352-8) contains supplementary material, which is available to authorized users.

Molecular Characterization of Annexin B2, B3 and B12 in Taenia multiceps

Coenurus cerebralis, the metacestode of Taenia multiceps, causes coenurosis, a disease severely affecting goat, sheep, cattle and yak farming and resulting in huge economic losses annually. Annexins bind calcium ions and play an important role in flatworm parasite development. To explore potential functions of annexins in T. multiceps, three homologous genes, namely, TmAnxB2, TmAnxB3 and TmAnxB12, were screened from the transcriptome dataset, amplified from C. cerebralis cDNA and subjected to bioinformatics analysis. Then, polyclonal antibodies recognizing the recombinant TmAnxB2 (rTmAnxB2) and rTmAnxB3 were prepared for localization of TmAnxB2 and TmAnxB3 in different tissues and developmental stages by immunofluorescence. The transcription of all three genes was also measured by relative fluorescent quantitative PCR. The sizes of rTmAnxB2, rTmAnxB3 and rTmAnxB12 were 58.00, 53.06 and 53.51 kDa, respectively, and rTmAnxB12 was unstable. Both rTmAnxB2 and rTmAnxB3 were recognized by goat-positive T. multiceps sera in Western blots. Immunofluorescence revealed that TmAnxB2 and TmAnxB3 were localized in the protoscolex and cyst wall and TmAnxB3 was also detected in adult cortex. TmAnxB2 and TmAnxB12 mRNA levels were determined to be highest in oncospheres and protoscolex, whereas transcription of TmAnxB3 was highest in scolex and immature segments. Taken together, these findings indicate that TmAnxB2 and TmAnxB12 may play critical roles in T. multiceps larvae, while TmAnxB3 may have important functions in adults. These results will lay the foundation for functional research of annexins in T. multiceps.