[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 01/2013; 8(8):e70367. · 3.73 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; 8:25. · 1.86 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 01/2012; 7(10):e47660. · 3.73 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: 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. · 2.85 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. · 2.85 Impact Factor
[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 01/2010; 5(10):e13494. · 3.73 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.
Molecular and Biochemical Parasitology 08/2009; 166(1):62-9. · 2.73 Impact Factor