[Show abstract][Hide abstract] ABSTRACT: Water buffalo are less susceptible to Schistosoma japonicum infection than yellow cattle. The factors that affect such differences in susceptibility remain unknown. A Bos taurus genome-wide gene chip was used to analyze gene expression profiles in the peripheral blood of water buffalo and yellow cattle pre- and post-infection with S. japonicum. This study showed that most of the identified differentially expressed genes(DEGs) between water buffalo and yellow cattle pre- and post-infection were involved in immune-related processes, and the expression level of immune genes was lower in water buffalo. The unique DEGs (390) in yellow cattle were mainly associated with inflammation pathways, while the unique DEGs (2,114) in water buffalo were mainly associated with immune-related factors. The 83 common DEGs may be the essential response genes during S. japonicum infection, the highest two gene ontology (GO) functions were associated with the regulation of fibrinolysis. The pathway enrichment analysis showed that the DEGs constituted similar immune-related pathways pre- and post-infection between the two hosts. This first analysis of the transcriptional profiles of natural hosts has enabled us to gain new insights into the mechanisms that govern their susceptibility or resistance to S. japonicum infections.
PLoS ONE 06/2015; 10(6):e0130344. DOI:10.1371/journal.pone.0130344 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Wnt signaling is a key pathway involving the regulation of cell development and growth in metazoa. An analysis of Wnt signaling in Schistosoma japonicum might provide information regarding the molecular mechanisms underlying parasite development, which might be useful for vaccine screening and identification of pharmaceutical targets. The SjWnt5 gene, a member of the Wnt gene family, contained an 1149-bp open reading frame that encoded a 382-aa protein. Analysis of the SjWnt5 amino acid sequence revealed a domain that was conserved among members of the Wnt protein family. Expression of SjWnt5 was observed at all of the developmental stages in definitive hosts, and the highest level of SjWnt5 messenger RNA (mRNA) was detected at the schistosomula stage. Higher levels of SjWnt5 mRNA and protein were observed in mature male worms, compared with those in mature females. SjWnt5 mRNA was expressed at higher levels in maldeveloped worms from nonpermissive host or single-sex infection than in normal worms from permissive host and mixed-sex infection. The immunohistochemical analysis showed that SjWnt5 protein was expressed in the subtegumental musculature and acetabulum musculature of schistosomulum and adult worms, suggesting that SjWnt5 may play a role in regulation of parasite muscle development. Furthermore, SjWnt5 was found prominently expressed in the testes of the male and the ovary as well as the vitellarium of the female, suggesting that SjWnt5 may involve in the development of the reproductive organs of both sexes.
Parasitology Research 06/2015; 114(9). DOI:10.1007/s00436-015-4545-5 · 2.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Schistosomiasis is a worldwide parasitic disease, and while it can be successfully treated with chemotherapy, this does not prevent reinfection with the parasite. Adenovirus vectors have been widely used for vaccine delivery, and a vaccination approach has the potential to prevent infection with Schistosoma. Here, we developed a recombinant adenoviral vector that expresses Schistosoma japonicum inhibitor apoptosis protein (Ad-SjIAP) and assessed its immunoprotective functions against schistosomiasis in mice. Murine immune responses following vaccination were investigated using enzyme-linked immunosorbent assays (ELISA), lymphocyte proliferation, and cytokine assays. The protective immunity in mice was evaluated by challenging with S. japonicum cercariae. Our results indicated that immunization with the Ad-SjIAP in mice induced a strong serum IgG response against IAP including IgG1, IgG2a, and IgG2b. In addition, lymphocyte proliferation experiments showed that mice treated with Ad-SjIAP significantly increased the lymphocyte response upon stimulation with recombinant Schistosoma japonicum inhibitor apoptosis protein (rSjIAP). Moreover, cytokine assays indicated that vaccination of Ad-SjIAP significantly increased the production of interferon (IFN)-γ and IL-2 as compared to the corresponding control group. Furthermore, following the challenge with S. japonicum cercariae, the vaccine conferred moderate protection, with an average rate of 37.95 % for worm reduction and 31.7 % for egg reduction. Taken together, our preliminarily results suggested that schistosoma IAP may be a potential vaccine against S. japonicum and that adenoviral vectors may serve as an alternative delivery vehicle for schistosome vaccine development.
Parasitology Research 09/2014; 113(11). DOI:10.1007/s00436-014-4104-5 · 2.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Water buffalo and goats are natural hosts for S. japonicum in endemic areas of China. The susceptibility of these two hosts to schistosome infection is different, as water buffalo are less conducive to S. japonicum growth and development. To identify genes that may affect schistosome development and survival, we compared gene expression profiles of schistosomes derived from these two natural hosts using high-throughput microarray technology.
The worm recovery rate was lower and the length and width of worms from water buffalo were smaller compared to those from goats following S. japonicum infection for 7 weeks. Besides obvious morphological difference between the schistosomes derived from the two hosts, differences were also observed by scanning and transmission electron microscopy. Microarray analysis showed differentially expressed gene patterns for parasites from the two hosts, which revealed that genes related to lipid and nucleotide metabolism, as well as protein folding, sorting, and degradation were upregulated, while others associated with signal transduction, endocrine function, development, immune function, endocytosis, and amino acid/carbohydrate/glycan metabolism were downregulated in schistosomes from water buffalo. KEGG pathway analysis deduced that the differentially expressed genes mainly involved lipid metabolism, the MAPK and ErbB signaling pathways, progesterone-mediated oocyte maturation, dorso-ventral axis formation, reproduction, and endocytosis, etc.
The microarray gene analysis in schistosomes derived from water buffalo and goats provide a useful platform to disclose differences determining S. japonicum host compatibility to better understand the interplay between natural hosts and parasites, and identify schistosome target genes associated with susceptibility to screen vaccine candidates.
PLoS ONE 08/2013; 8(8):e70367. DOI:10.1371/journal.pone.0070367 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: DNA damage tolerance consisting of template switching and translesion synthesis is a major cellular mechanism in response to unrepaired DNA lesions during replication. The Rev1 pathway constitutes the major mechanism of translesion synthesis and base damage-induced mutagenesis in model cell systems. Rev1 is a dCMP transferase, but additionally plays non-catalytic functions in translesion synthesis. Using the yeast model system, we attempted to gain further insights into the non-catalytic functions of Rev1. Rev1 stably interacts with Rad5 (a central component of the template switching pathway) via the C-terminal region of Rev1 and the N-terminal region of Rad5. Supporting functional significance of this interaction, both the Rev1 pathway and Rad5 are required for translesion synthesis and mutagenesis of 1,N(6)-ethenoadenine. Furthermore, disrupting the Rev1-Rad5 interaction by mutating Rev1 did not affect its dCMP transferase, but led to inactivation of the Rev1 non-catalytic function in translesion synthesis of UV-induced DNA damage. Deletion analysis revealed that the C-terminal 21-amino acid sequence of Rev1 is uniquely required for its interaction with Rad5 and is essential for its non-catalytic function. Deletion analysis additionally implicated a C-terminal region of Rev1 in its negative regulation. These results show that a non-catalytic function of Rev1 in translesion synthesis and mutagenesis is mediated by its interaction with Rad5.
DNA repair 11/2012; 12(1). DOI:10.1016/j.dnarep.2012.10.003 · 3.11 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Water buffalo and yellow cattle are the two of the most important natural reservoir hosts for Schistosoma japonicum in endemic areas of China, although their susceptibility differs, with water buffalo being less conducive to the growth and development of S. japonicum. Results from the current study show that the general morphology and ultrastructure of adult schistosomes derived from the two hosts also differed. Using high-throughput microarray technology, we also compared the gene expression profiles of adult schistosomes derived from the two hosts. We identified genes that were differentially expressed in worms from the two natural hosts. Further analysis revealed that genes associated with protein kinase and phosphatase, the stimulus response, and lipid and nucleotide metabolism were overexpressed, whereas genes associated with reproduction, anatomical structure morphogenesis and multifunctional motif were underexpressed in schistosomes from water buffalo. These differentially expressed genes were mainly involved in nucleotide, energy, lipid metabolism, energy metabolism, transcription, transport and signaling pathway. This suggests that they are key molecules affecting the survival and development of schistosomes in different natural host species. The results of this study add to current understanding of the interplay between parasites and their natural hosts, and provide valuable information for the screening of vaccine candidates or new drug targets against schistosomiasis in the natural reservoir hosts in endemic areas.
PLoS ONE 10/2012; 7(10):e47660. DOI:10.1371/journal.pone.0047660 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Yellow cattle and water buffalo are two of the most important natural hosts for Schistosoma japonicum in China. Previous observation has revealed that yellow cattle are more suited to the development of S. japonicum than water buffalo. Understanding more about the molecular mechanisms involved in worm development, as well as the pathological and immunological differences between yellow cattle and water buffalo post infection with S japonicum will provide useful information for the vaccine design and its delivery procedure.
The worm length (p < 0.01), worm recovery rate (p < 0.01) and the percentage of paired worms (p < 0.01) were significantly greater in yellow cattle than those in water buffalo. There were many white egg granulomas in the livers of yellow cattle, but fewer were observed in water buffalo at 7 weeks post infection. The livers of infected yellow cattle contained significantly increased accumulation of inflammatory cells, and the schistosome eggs were surrounded with large amounts of eosinophil infiltration. In contrast, no hepatocyte swelling or lymphocyte infiltration, and fewer white blood cells, was observed in water buffalo. The percentage of CD4⁺ T cells was higher in yellow cattle, while the percentage of CD8⁺ T cells was higher in water buffalo from pre-infection to 7 w post infection. The CD4/CD8 ratios were decreased in both species after challenge with schistosomes. Comparing with water buffalo, the IFN-γ level was higher and decreased significantly, while the IL-4 level was lower and increased gradually in yellow cattle from pre-infection to 7 w post infection.
In this study, we confirmed that yellow cattle were more suited to the development of S. japonicum than water buffalo, and more serious pathological damage was observed in infected yellow cattle. Immunological analysis suggested that CD4⁺ T cells might be an integral component of the immune response and might associate with worm development in yellow cattle. A shift from Th1 to Th2 type polarized immunity was only shown clearly in schistosome-infected yellow cattle, but no shift in water buffalo. The results provide valuable information for increased understanding of host-schistosome interactions, and for control of schistosomiasis.
BMC Veterinary Research 03/2012; 8(1):25. DOI:10.1186/1746-6148-8-25 · 1.78 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Wnt signaling regulates a diverse array of eukaryotic development processes, which are mediated by the Frizzled family receptors. However, the role of this signaling pathway in the development of Schistosoma japonicum remains poorly understood. We isolated a novel S. japonicum Frizzled member (SjFz9), which encodes a 923 amino acid protein, sharing the general feature of Frizzled proteins. We investigated its mRNA and protein expression patterns during different life stages in definitive hosts. Quantitative real-time PCR analysis revealed that SjFz9 transcripts were highly expressed in the schistosomulum. In adult stages, SjFz9 expression exhibited high level at day 23 and day 42 in both male and female, compared to other adult stages. The immunohistochemical localization pattern of the SjFz9 protein showed a broad tissue distribution in the subtegumental musculature and acetabulum musculature of schistosomulum and adult worms. Furthermore, SjFz9 was found prominently expressed in the testes of the male and the ovary as well as the vitellarium of the female. Our data suggest that SjFz9 may be an important Wnt receptor with potential functions in regulating the cell differentiation and proliferation within the musculature, as well as the development of the reproductive organs of both sexes.
[Show abstract][Hide abstract] ABSTRACT: More than 40 kinds of mammals in China are known to be naturally infected with Schistosoma japonicum (S. japonicum); Microtus fortis (M. fortis), a species of vole, is the only mammal in which the schistosomes cannot mature or cause significant pathogenic changes. In the current study, we compared the differences in pathology by Hematoxylin-eosin staining and in changes in the T cell subsets with flow cytometry as well as gene expression using genome oligonucleotide microarrays in the lung and liver, before challenge and 10 days post-infection with schistosomes in a S. japonicum-susceptible mouse model of infection, a non-susceptible rat model and the non-permissive host, M. fortis. The results demonstrated that S. japonicum promoted a more intensive immune response and more pathological lesions in M. fortis and rats than in mice. Hematoxylin-eosin staining revealed that the immune effector cells involved were mainly eosinophilic granulocytes supplemented with heterophilic granulocytes and macrophages. The analysis of splenic T cell subsets showed that CD4(+) T cell subsets and the CD4(+)/CD8(+) ratio were increased, while the CD8(+) T cell subsets decreased remarkably in rats; whereas the CD8(+) T cell subsets were increased, but the CD4(+)/CD8(+) ratio was decreased significantly in mice. The analysis of the pattern of gene expression suggested that some immune-associated genes and apoptosis-inducing genes up-regulated, while some development-associated genes were down-regulated in the infected M. fortis compared to the uninfected controls; the three different hosts have different response mechanisms to schistosome infection. The results of this study will be helpful for identifying the key molecules in the immune response to S. japonicum in M. fortis and for understanding more about the underlying mechanism of the response, as well as for elucidating the interaction between S. japonicum and its hosts.
PLoS ONE 10/2010; 5(10):e13494. DOI:10.1371/journal.pone.0013494 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Enolase is a key enzyme in the glycolytic pathway; recent studies have also shown that enolase is found on the surface of several parasites, where it acts as a plasminogen-binding protein. In the present study, the enolase of Schistosoma japonicum has been cloned and expressed. In western blot analysis, the recombinant enolase from S. japonicum ( rSjENO) was recognized by rabbit sera directed against an antigen preparation from adult worms. Kinetic measurement revealed that rSjENO possesses good enzymatic activity. The real-time PCR showed that the enolase gene was highly expressed at 18-28 days of the life cycle. Immunofluorescence testing showed that SjENO was located mainly on the surface as well as in the inner tissues of the worms. Ligand-blotting analysis indicated that rSjENO could bind to human plasminogen as its receptor. In addition, a 24.28% reduction in the liver egg count and a reduction of 21.45% in the fecal egg count were observed in BALB/c mice vaccinated with rSjENO when compared with blank control mice. An ELISA assay suggested that high levels of specific IgG antibody could be induced by rSjENO in vaccinated mice.
Parasitology Research 08/2010; 107(3):667-77. DOI:10.1007/s00436-010-1913-z · 2.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Apoptosis is a normal process for regulating cellular death of many organisms. Here, we molecularly characterized an inhibitor of apoptosis from Schistosoma japonicum (SjIAP). The transcription of the SjIAP predominantly occurred at the developmental stages in a final host. Functional assay indicated that the SjIAP could inhibit caspase activity either in 293T cell or in schistosome lysates. Additionally, there were differently expressed profiles of the SjIAP in S. japonicum living in different hosts. Our preliminary results suggest that the SjIAP may play important roles in parasitic living and development as well as in the host-parasite interactions, and drug target of SjIAP might be a potential for controlling schistosomiasis.
Parasitology Research 02/2010; 106(4):967-76. DOI:10.1007/s00436-010-1752-y · 2.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Schistosome parasites require a complex lifecycle requiring two hosts and aquatic phases of development. The schistosomula is a key phase of parasite development within the mammalian host, however relatively little is understood about the molecular processes underlying this stage. In this study 5723 subtractive expressed sequence tags (ESTs) were randomly selected from a 7 day hepatic schistosomula enriched library constructed using suppression subtractive hybridization method. Sequence analysis of these ESTs identified 1762 unique genes (contigs). Among them, 989 contigs were annotated with known genes, 311 contigs were homologous to established genes, 101 contigs were similar to established genes, 72 contigs were weakly similar to established genes and 289 sequences did not match any published sequences. Genes identified related to metabolism, cellular development, immune evasion and host-parasite interactions were identified as enriched in the hepatic schistosomula stage. The future identification of poorly annotated but stage-specific genes may potentially represent new drugs or vaccine targets, applicable for the future controlling of schistosomiasis.