Li Z.-Y.,Key Laboratory of Tropical Diseases and Control |
Li Z.-Y.,Sun Yat Sen University |
Lv Z.-Y.,Key Laboratory of Tropical Diseases and Control |
Lv Z.-Y.,Sun Yat Sen University |
And 8 more authors.
Parasitology Research | Year: 2012
Angiostrongylus cantonensis is the most common infectious cause of eosinophilic meningitis or meningoen-cephalitis. A novel gene (AC16) was isolated from a cDNA library of A. cantonensis fourth-stage larvae. The putative 16-kDa protein has 149 amino acids and is homologous to an immunodominant hypodermal antigen (IHA16) from Ancylostoma caninum (identities057%). In this paper, we cloned the gene and purified the recombinant Ac16 (rAC16) protein. Real-time quantitative PCR revealed that Ac16 was expressed significantly higher in the fourth-stage larvae and adult worms derived from rats than that in the fourth-stage larvae derived from mice. Moreover, sera from rat (permissive host) infected with A. cantonensis detected Ac16 by Western blot, while sera from infected mouse (non-permissive host) could not. The results implied that Ac16 was related to the parasitic adaptation of A. cantonensis in different hosts and non-permissive host mouse had no circulating antibody to the antigen Ac16 from A. cantonensis and thus might contribute to understanding the mechanism of parasite immune evasion. Furthermore, we evaluated the ability of Ac16 antibody diagnosing A. cantonensis infection by an indirect enzyme-linked immunosorbent assay. The results showed that the Ac16 antibody had a 79.17% sensitivity to rAC16 and 83.33% to crude adult worm antigens (CA) (P>0.05), while the specificity to rAC16 and to CA were 95.89% and 86.30% respectively (P<0.05), thus implying that rAc16 may constitute a putative serodiagnostic antigen for Angiostrongyliasis cantonensis. © Springer-Verlag 2011.
Li Z.,Key Laboratory of Tropical Diseases and Control |
Li Z.,Sun Yat Sen University |
Chen X.,Key Laboratory of Tropical Diseases and Control |
Chen X.,Sun Yat Sen University |
And 12 more authors.
Parasitology Research | Year: 2014
The pathogenesis of angiostrongyliasis, resulting from the third-stage and the fourth-stage Angiostrongylus cantonensis larvae invasion of the human central nervous system, remains elusive. MicroRNAs are important regulators of gene expression and involved in many biological processes. The aim of this study was to determine and characterize miRNAs of third (L3) and fourth (L4) larvae of A. cantonensis by Solex deep sequencing. A total of 629 conserved miRNAs (526 and 376 miRNAs in L3 and L4 larvae of A. cantonensis, respectively) and three novel candidate miRNA from L3 and L4 larva of A. cantonensis were identified with bioinformatic analysis. There were 163 miRNAs upregulated and 54 miRNAs downregulated (fold changes ≥5.0) in the L4 of A. cantonensis compared with that of L3 of A. cantonensis. Interestingly, Gene Ontology "biological process" classifications revealed that 26 miRNAs of significantly differential expression are associated with the immune system, which implies that these miRNAs might participate in the pathogenesis of angiostrongyliasis by regulating genes involved in immune response pathways. Furthermore, the differential expression patterns of 26 conserved miRNAs between L3 and L4 of A. cantonensis were verified. The results of real-time PCR and Northern blot showed that the aca-miR-124 and aca-miR-146a-5p have a low level expression in L3 larvae but high level expression in L4 larvae. Transfection of aca-miR-124 mimics alone significantly downregulated the mRNA expression of IL-6 and IL-1β and TNF-a in the N9 cells, compared to the combination transfection of aca-miR-124 mimics and inhibitor (P<0.05), suggesting that miR-124 of A. cantonensis have an important role in the suppression of microglia activation. In conclusion, the study presents a general picture of the expression of small RNAs in L3 and L4 of A. cantonensis and highlights conserved miRNAs differentially expressed between L3 and L4 larvae. Our data revealed that miRNAs of parasite may mediate important roles in A. cantonensis immune evasion and aca-miR-146a-5p can serve as a potential biomarker to diagnose angiostrongyliasis. © 2014 Springer-Verlag.
Shen J.,Key Laboratory of Tropical Diseases and Control |
Shen J.,Sun Yat Sen University |
Xu L.,Key Laboratory of Tropical Diseases and Control |
Xu L.,Sun Yat Sen University |
And 13 more authors.
Parasitology Research | Year: 2014
Sj16, a 16-kDa protein secreted from Schistosoma japonicum, has been demonstrated an anti-inflammatory effect in vitro and in vivo, but its mechanism is still not clear. In this study, microarray analysis was performed to investigate the effects of recombinant Sj16 (rSj16) on the gene expression of the lipopolysaccharide (LPS)-stimulated dendritic cells (DCs). Immature DCs were treated with LPS, LPS+recombinant Sj16 (rSj16), or rSj16 alone for 24 h, and the gene expression profiles were examined using complementary DNA (cDNA) microarrays. With the cutoff value of 2-fold change in the expression, 509 genes were affected, 226 genes upregulated, and 283 genes downregulated after adding rSj16. Analysis by functional annotation clustering tool showed that rSj16-affected genes mainly associated with inflammatory response, defense response, regulation of immune system process, apoptosis, and cell migration. The results revealed that rSj16 reduced the LPS-induced pro-inflammatory genes such as cytokines (e.g., IL6, IL18, IFN-γ, IL12a, IL1b), chemokines, and receptors (e.g., CXCL1, CXCL9, CCL5, CCR5, CCR1, CCR2, CXCR3) and increased the anti-inflammatory gene IL-10. Further data mining of these genes by pathway analysis showed that genes regulated by rSj16 were significantly involved in cytokine-cytokine receptor interaction, NOD-like receptor signaling pathway, Toll-like receptor signaling pathway, antigen processing and presentation, and Jak-STAT signaling pathway. In addition, quantitative real-time PCR (qRT-PCR) and Western blot analysis showed that rSj16 downregulated the expression of inhibitor of nuclear factor kappa-β kinase subunit beta (IKKβ) and nuclear factor-kappa β p65 (NF-κβ) messenger RNA (mRNA) and inhibited the phosphorylation of IKKβ and the NF-κB p65 protein, which implied that rSj16 exerting immunomodulatory effects by suppressing NF-κB signaling pathway. These results provide useful information in further understanding of the immunoregulation mechanisms of Sj16, and it is indicated that Sj16 could be as a potential molecule for the immunosuppressant drug development. © 2014 Springer-Verlag.