The Experts below are selected from a list of 1380 Experts worldwide ranked by ideXlab platform
Lingbing Zeng - One of the best experts on this subject based on the ideXlab platform.
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Bid is involved in apoptosis induced by Chinese Giant Salamander iridovirus and contributes to the viral replication in an amphibian cell line.
Developmental and comparative immunology, 2020Co-Authors: Li Yiqun, Yan Meng, Wenzhi Liu, Yuding Fan, Yong Zhou, Yanan Liu, Nan Jiang, Xue Mingyang, Lingbing ZengAbstract:Bid is a pro-apoptotic BH3-only member of the Bcl-2 superfamily that functions to link the extrinsic apoptotic pathway and the mitochondrial amplification loop of the intrinsic pathway. In this study, the expression and functions of Chinese Giant Salamander (Andrias davidianus) Bid (AdBid) were investigated. The AdBid cDNA sequence contains an open reading frame (ORF) of 576 nucleotides, encoding a putative protein of 191 aa. AdBid possesses the conserved BH3 interacting domain and shared 34-52% sequence identities with other amphibian Bid. mRNA expression of AdBid was most abundant in muscle. The expression level of AdBid in Chinese Giant Salamander muscle, kidney and spleen significantly increased after Chinese Giant Salamander iridovirus (GSIV) infection. Additionally, a plasmid expressing AdBid was constructed and transfected into the Chinese Giant Salamander muscle cell line (GSM cells). The morphology and cytopathic effect (CPE) and apoptotic process in AdBid over-expressed GSM cells was significantly enhanced during GSIV infection compared with that in control cells. Moreover, a higher level of the virus major capsid protein (MCP) gene copies and protein synthesis was confirmed in the AdBid over-expressed cells. These results indicated that AdBid played a positive role in GSIV induced apoptosis and the viral replication. This study may contribute to the better understanding on the infection mechanism of iridovirus-induced apoptosis.
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characterization expression pattern and antiviral activities of mx gene in chinese Giant Salamander andrias davidianus
International Journal of Molecular Sciences, 2020Co-Authors: Lingbing Zeng, Yuding Fan, Yanan Liu, Yongze Zhou, Nan JiangAbstract:Mx, Myxovirus resistance is an important interferon-stimulated protein that mediates antiviral responses. In this study, the expression and activities of Chinese Giant Salamander, Andrias davidianus Mx gene, AdMx, were investigated. The AdMx cDNA sequence contains an open reading frame (ORF) of 2112 nucleotides, encoding a putative protein of 703 aa. Meanwhile, AdMx possesses the conserved tripartite GTP binding motif and a dynamin family signature. qRT-PCR analysis revealed a broad expression of AdMx in vivo, with the highest expression levels in brain, kidney and spleen. The AdMx expression level in kidney, spleen and muscle significantly increased at 6 h after Chinese Giant Salamander iridovirus (GSIV) infection and peaked at 48 h, while that in muscle cell line (GSM) was not noticeably up-regulated until 72 h post infection. Additionally, a plasmid expressing AdMx was constructed and transfected into the Chinese Giant Salamander GSM cells. The virus load and gene copies in AdMx over-expressed cells were significantly reduced compared with those in the control cells. Moreover, compared to the control cells, a lower level of virus major capsid protein (MCP) synthesis in AdMx over-expressed cells was confirmed by Western blot. These results collectively suggest that Mx plays an important antiviral role in the immune responses against GSIV in Chinese Giant Salamander.
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chinese Giant Salamander andrias davidianus iridovirus infection leads to apoptotic cell death through mitochondrial damage caspases activation and expression of apoptotic related genes
International Journal of Molecular Sciences, 2019Co-Authors: Nan Jiang, Yan Meng, Wenzhi Liu, Yuding Fan, Yong Zhou, Mingyang Xue, Lingbing ZengAbstract:Chinese Giant Salamander iridovirus (GSIV) is the causative pathogen of Chinese Giant Salamander (Andrias davidianus) iridovirosis, leading to severe infectious disease and huge economic losses. However, the infection mechanism by GSIV is far from clear. In this study, a Chinese Giant Salamander muscle (GSM) cell line is used to investigate the mechanism of cell death during GSIV infection. Microscopy observation and DNA ladder analysis revealed that DNA fragmentation happens during GSIV infection. Flow cytometry analysis showed that apoptotic cells in GSIV-infected cells were significantly higher than that in control cells. Caspase 8, 9, and 3 were activated in GSIV-infected cells compared with the uninfected cells. Consistently, mitochondria membrane potential (MMP) was significantly reduced, and cytochrome c was released into cytosol during GSIV infection. p53 expression increased at an early stage of GSIV infection and then slightly decreased late in infection. Furthermore, mRNA expression levels of pro-apoptotic genes participating in the extrinsic and intrinsic pathway were significantly up-regulated during GSIV infection, while those of anti-apoptotic genes were restrained in early infection and then rose in late infection. These results collectively indicate that GSIV induces GSM apoptotic cell death involving mitochondrial damage, caspases activation, p53 expression, and pro-apoptotic molecules up-regulation.
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rag1 and rag2 gene expressions identify lymphopoietic tissues in juvenile and adult chinese Giant Salamander andrias davidianus
Developmental and Comparative Immunology, 2018Co-Authors: Nan Jiang, Wenzhi Liu, Yuding Fan, Yong Zhou, Jacques Robert, Lingbing ZengAbstract:Rag1 and rag2 are two closely linked recombination activating genes required for V(D)J recombination of antigen receptors in immature lymphocytes, whose expression can serve as marker to identify the lymphopoietic tissues. To study the development of lymphopoietic tissues in Chinese Giant Salamander (Andrias davidianus), the Chinese Giant Salamander rag1 and rag2 coding sequences were cloned and determined. High transcript levels of rag1 and rag2 were co-detected in the thymus before 14 months of age, whereas levels were lower in spleen, liver and kidney at all stage of development. The spatial expression patterns of rag1 and rag2 were studied in combination with igY and tcrβ gene expression using in situ hybridization. Significant transcript signals for rag1, rag2, tcrβ and igY were detected not only in the thymus and spleen but also the liver and kidney of juvenile and adult Chinese Giant Salamanders, which suggests that cells of lymphocyte lineage are present in multiple tissues of the Chinese Giant Salamander. This implies that lymphopoiesis may take place in these tissues. The tissue morphology of thymus suggested that the branched thymic primordium developed into mature organ with the development of thymocyte from juvenile to adult. These results not only confirm that as expected the thymus and spleen are primordial lymphopoietic tissues but also suggest that the liver and kidney provide site of lymphocyte differentiation in Chinese Giant Salamander.
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Transcriptomic analysis of the host response to an iridovirus infection in Chinese Giant Salamander, Andrias davidianus
Veterinary Research, 2015Co-Authors: Yuding Fan, Scott E Lapatra, Lili Huang, Pin Nie, Ming Xian Chang, Lingbing ZengAbstract:AbstractThe emergence of an infectious viral disease caused by the Chinese Giant Salamander iridovirus (GSIV) has led to substantial economic losses. However, no more molecular information is available for the understanding of the mechanisms associated with virus–host interaction. In this study, de novo sequencing was used to obtain abundant high-quality ESTs and investigate differentially-expressed genes in the spleen of Chinese Giant Salamanders that were either infected or mock infected with GSIV. Comparative expression analysis indicated that 293 genes were down-regulated and 220 genes were up-regulated. Further enrichment analysis showed that the most enriched pathway is “complement and coagulation cascades”, and significantly enriched diseases include “inherited thrombophilia”, “immune system diseases”, “primary immunodeficiency”, “complement regulatory protein defects”, and “disorders of nucleotide excision repair”. Additionally, 30 678 simple sequence repeats (SSRs) from all spleen samples, 26 355 single nucleotide polymorphisms (SNPs) from the spleens of uninfected animals and 36 070 SNPs from the spleens of infected animals were detected. The large amount of variation was specific for the Chinese Giant Salamanders that were infected with GSIV. The results reported herein provided significant and new EST information that could contribute greatly in investigations into the molecular functions of immune genes in the Chinese Giant Salamander.
Yuding Fan - One of the best experts on this subject based on the ideXlab platform.
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Bid is involved in apoptosis induced by Chinese Giant Salamander iridovirus and contributes to the viral replication in an amphibian cell line.
Developmental and comparative immunology, 2020Co-Authors: Li Yiqun, Yan Meng, Wenzhi Liu, Yuding Fan, Yong Zhou, Yanan Liu, Nan Jiang, Xue Mingyang, Lingbing ZengAbstract:Bid is a pro-apoptotic BH3-only member of the Bcl-2 superfamily that functions to link the extrinsic apoptotic pathway and the mitochondrial amplification loop of the intrinsic pathway. In this study, the expression and functions of Chinese Giant Salamander (Andrias davidianus) Bid (AdBid) were investigated. The AdBid cDNA sequence contains an open reading frame (ORF) of 576 nucleotides, encoding a putative protein of 191 aa. AdBid possesses the conserved BH3 interacting domain and shared 34-52% sequence identities with other amphibian Bid. mRNA expression of AdBid was most abundant in muscle. The expression level of AdBid in Chinese Giant Salamander muscle, kidney and spleen significantly increased after Chinese Giant Salamander iridovirus (GSIV) infection. Additionally, a plasmid expressing AdBid was constructed and transfected into the Chinese Giant Salamander muscle cell line (GSM cells). The morphology and cytopathic effect (CPE) and apoptotic process in AdBid over-expressed GSM cells was significantly enhanced during GSIV infection compared with that in control cells. Moreover, a higher level of the virus major capsid protein (MCP) gene copies and protein synthesis was confirmed in the AdBid over-expressed cells. These results indicated that AdBid played a positive role in GSIV induced apoptosis and the viral replication. This study may contribute to the better understanding on the infection mechanism of iridovirus-induced apoptosis.
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characterization expression pattern and antiviral activities of mx gene in chinese Giant Salamander andrias davidianus
International Journal of Molecular Sciences, 2020Co-Authors: Lingbing Zeng, Yuding Fan, Yanan Liu, Yongze Zhou, Nan JiangAbstract:Mx, Myxovirus resistance is an important interferon-stimulated protein that mediates antiviral responses. In this study, the expression and activities of Chinese Giant Salamander, Andrias davidianus Mx gene, AdMx, were investigated. The AdMx cDNA sequence contains an open reading frame (ORF) of 2112 nucleotides, encoding a putative protein of 703 aa. Meanwhile, AdMx possesses the conserved tripartite GTP binding motif and a dynamin family signature. qRT-PCR analysis revealed a broad expression of AdMx in vivo, with the highest expression levels in brain, kidney and spleen. The AdMx expression level in kidney, spleen and muscle significantly increased at 6 h after Chinese Giant Salamander iridovirus (GSIV) infection and peaked at 48 h, while that in muscle cell line (GSM) was not noticeably up-regulated until 72 h post infection. Additionally, a plasmid expressing AdMx was constructed and transfected into the Chinese Giant Salamander GSM cells. The virus load and gene copies in AdMx over-expressed cells were significantly reduced compared with those in the control cells. Moreover, compared to the control cells, a lower level of virus major capsid protein (MCP) synthesis in AdMx over-expressed cells was confirmed by Western blot. These results collectively suggest that Mx plays an important antiviral role in the immune responses against GSIV in Chinese Giant Salamander.
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chinese Giant Salamander andrias davidianus iridovirus infection leads to apoptotic cell death through mitochondrial damage caspases activation and expression of apoptotic related genes
International Journal of Molecular Sciences, 2019Co-Authors: Nan Jiang, Yan Meng, Wenzhi Liu, Yuding Fan, Yong Zhou, Mingyang Xue, Lingbing ZengAbstract:Chinese Giant Salamander iridovirus (GSIV) is the causative pathogen of Chinese Giant Salamander (Andrias davidianus) iridovirosis, leading to severe infectious disease and huge economic losses. However, the infection mechanism by GSIV is far from clear. In this study, a Chinese Giant Salamander muscle (GSM) cell line is used to investigate the mechanism of cell death during GSIV infection. Microscopy observation and DNA ladder analysis revealed that DNA fragmentation happens during GSIV infection. Flow cytometry analysis showed that apoptotic cells in GSIV-infected cells were significantly higher than that in control cells. Caspase 8, 9, and 3 were activated in GSIV-infected cells compared with the uninfected cells. Consistently, mitochondria membrane potential (MMP) was significantly reduced, and cytochrome c was released into cytosol during GSIV infection. p53 expression increased at an early stage of GSIV infection and then slightly decreased late in infection. Furthermore, mRNA expression levels of pro-apoptotic genes participating in the extrinsic and intrinsic pathway were significantly up-regulated during GSIV infection, while those of anti-apoptotic genes were restrained in early infection and then rose in late infection. These results collectively indicate that GSIV induces GSM apoptotic cell death involving mitochondrial damage, caspases activation, p53 expression, and pro-apoptotic molecules up-regulation.
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rag1 and rag2 gene expressions identify lymphopoietic tissues in juvenile and adult chinese Giant Salamander andrias davidianus
Developmental and Comparative Immunology, 2018Co-Authors: Nan Jiang, Wenzhi Liu, Yuding Fan, Yong Zhou, Jacques Robert, Lingbing ZengAbstract:Rag1 and rag2 are two closely linked recombination activating genes required for V(D)J recombination of antigen receptors in immature lymphocytes, whose expression can serve as marker to identify the lymphopoietic tissues. To study the development of lymphopoietic tissues in Chinese Giant Salamander (Andrias davidianus), the Chinese Giant Salamander rag1 and rag2 coding sequences were cloned and determined. High transcript levels of rag1 and rag2 were co-detected in the thymus before 14 months of age, whereas levels were lower in spleen, liver and kidney at all stage of development. The spatial expression patterns of rag1 and rag2 were studied in combination with igY and tcrβ gene expression using in situ hybridization. Significant transcript signals for rag1, rag2, tcrβ and igY were detected not only in the thymus and spleen but also the liver and kidney of juvenile and adult Chinese Giant Salamanders, which suggests that cells of lymphocyte lineage are present in multiple tissues of the Chinese Giant Salamander. This implies that lymphopoiesis may take place in these tissues. The tissue morphology of thymus suggested that the branched thymic primordium developed into mature organ with the development of thymocyte from juvenile to adult. These results not only confirm that as expected the thymus and spleen are primordial lymphopoietic tissues but also suggest that the liver and kidney provide site of lymphocyte differentiation in Chinese Giant Salamander.
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Transcriptomic analysis of the host response to an iridovirus infection in Chinese Giant Salamander, Andrias davidianus
Veterinary Research, 2015Co-Authors: Yuding Fan, Scott E Lapatra, Lili Huang, Pin Nie, Ming Xian Chang, Lingbing ZengAbstract:AbstractThe emergence of an infectious viral disease caused by the Chinese Giant Salamander iridovirus (GSIV) has led to substantial economic losses. However, no more molecular information is available for the understanding of the mechanisms associated with virus–host interaction. In this study, de novo sequencing was used to obtain abundant high-quality ESTs and investigate differentially-expressed genes in the spleen of Chinese Giant Salamanders that were either infected or mock infected with GSIV. Comparative expression analysis indicated that 293 genes were down-regulated and 220 genes were up-regulated. Further enrichment analysis showed that the most enriched pathway is “complement and coagulation cascades”, and significantly enriched diseases include “inherited thrombophilia”, “immune system diseases”, “primary immunodeficiency”, “complement regulatory protein defects”, and “disorders of nucleotide excision repair”. Additionally, 30 678 simple sequence repeats (SSRs) from all spleen samples, 26 355 single nucleotide polymorphisms (SNPs) from the spleens of uninfected animals and 36 070 SNPs from the spleens of infected animals were detected. The large amount of variation was specific for the Chinese Giant Salamanders that were infected with GSIV. The results reported herein provided significant and new EST information that could contribute greatly in investigations into the molecular functions of immune genes in the Chinese Giant Salamander.
Yan Meng - One of the best experts on this subject based on the ideXlab platform.
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Bid is involved in apoptosis induced by Chinese Giant Salamander iridovirus and contributes to the viral replication in an amphibian cell line.
Developmental and comparative immunology, 2020Co-Authors: Li Yiqun, Yan Meng, Wenzhi Liu, Yuding Fan, Yong Zhou, Yanan Liu, Nan Jiang, Xue Mingyang, Lingbing ZengAbstract:Bid is a pro-apoptotic BH3-only member of the Bcl-2 superfamily that functions to link the extrinsic apoptotic pathway and the mitochondrial amplification loop of the intrinsic pathway. In this study, the expression and functions of Chinese Giant Salamander (Andrias davidianus) Bid (AdBid) were investigated. The AdBid cDNA sequence contains an open reading frame (ORF) of 576 nucleotides, encoding a putative protein of 191 aa. AdBid possesses the conserved BH3 interacting domain and shared 34-52% sequence identities with other amphibian Bid. mRNA expression of AdBid was most abundant in muscle. The expression level of AdBid in Chinese Giant Salamander muscle, kidney and spleen significantly increased after Chinese Giant Salamander iridovirus (GSIV) infection. Additionally, a plasmid expressing AdBid was constructed and transfected into the Chinese Giant Salamander muscle cell line (GSM cells). The morphology and cytopathic effect (CPE) and apoptotic process in AdBid over-expressed GSM cells was significantly enhanced during GSIV infection compared with that in control cells. Moreover, a higher level of the virus major capsid protein (MCP) gene copies and protein synthesis was confirmed in the AdBid over-expressed cells. These results indicated that AdBid played a positive role in GSIV induced apoptosis and the viral replication. This study may contribute to the better understanding on the infection mechanism of iridovirus-induced apoptosis.
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chinese Giant Salamander andrias davidianus iridovirus infection leads to apoptotic cell death through mitochondrial damage caspases activation and expression of apoptotic related genes
International Journal of Molecular Sciences, 2019Co-Authors: Nan Jiang, Yan Meng, Wenzhi Liu, Yuding Fan, Yong Zhou, Mingyang Xue, Lingbing ZengAbstract:Chinese Giant Salamander iridovirus (GSIV) is the causative pathogen of Chinese Giant Salamander (Andrias davidianus) iridovirosis, leading to severe infectious disease and huge economic losses. However, the infection mechanism by GSIV is far from clear. In this study, a Chinese Giant Salamander muscle (GSM) cell line is used to investigate the mechanism of cell death during GSIV infection. Microscopy observation and DNA ladder analysis revealed that DNA fragmentation happens during GSIV infection. Flow cytometry analysis showed that apoptotic cells in GSIV-infected cells were significantly higher than that in control cells. Caspase 8, 9, and 3 were activated in GSIV-infected cells compared with the uninfected cells. Consistently, mitochondria membrane potential (MMP) was significantly reduced, and cytochrome c was released into cytosol during GSIV infection. p53 expression increased at an early stage of GSIV infection and then slightly decreased late in infection. Furthermore, mRNA expression levels of pro-apoptotic genes participating in the extrinsic and intrinsic pathway were significantly up-regulated during GSIV infection, while those of anti-apoptotic genes were restrained in early infection and then rose in late infection. These results collectively indicate that GSIV induces GSM apoptotic cell death involving mitochondrial damage, caspases activation, p53 expression, and pro-apoptotic molecules up-regulation.
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protective immunity of a pichia pastoris expressed recombinant iridovirus major capsid protein in the chinese Giant Salamander andrias davidianus
Vaccine, 2015Co-Authors: Yan Meng, Scott E Lapatra, Yuding Fan, Yong Zhou, Nan Jiang, Lingbing ZengAbstract:The major capsid protein (MCP) is the main immunogenic protein of iridoviruses, that has been widely used as an immunogen in vaccination trials. In this study, the codon-optimized Giant Salamander iridovirus (GSIV) MCP gene (O-MCP) was synthesized and cloned into a pPICZα B vector for secretory expression in the methylotrophic yeast Pichia pastoris after methanol induction. The expression of the O-MCP protein was detected by the Bradford protein assay, SDS-PAGE, Western blotting and electron microscopy. The Bradford protein assay indicated that the concentration of the O-MCP expressed was about 40 μg/ml in culture supernatants. SDS-PAGE analysis revealed that the O-MCP had a molecular weight of about 66 kDa and reacted with a His-specific MAb that was confirmed by Western blotting. Electron microscopy observations revealed that the purified O-MCP could self-assemble into virus-like particles. Healthy Giant Salamanders were vaccinated by intramuscular injection with the O-MCP antigen at a dose of 20 μg/individual. The numbers of erythrocytes and leukocytes in the peripheral blood of immunized Chinese Giant Salamanders increased significantly at day 3 and reached a peak at day 5 post-immunization. Meanwhile, the differential leukocyte counts of monocytes and neutrophils increased significantly at day 5 post-immunization compared to that of the control group. The percentage of lymphocytes was 71.33 ± 3.57% at day 21 post-immunization. The neutralization assay showed that the serum neutralizing antibody titer reached 321 at day 21 post-immunization. The GSIV challenge test revealed that the relative percent survival of Chinese Giant Salamanders vaccinated with O-MCP was 78%. These results indicated that the O-MCP antigen expressed by the Pichia pastoris system elicited significant immune response in the Chinese Giant Salamander against GSIV and might represent a potential yeast-derived vaccine candidate that could be used for the control of disease caused by the Giant Salamander iridovirus.
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cloning sequence analysis and expression profiles of toll like receptor 7 from chinese Giant Salamander andrias davidianus
Comparative Biochemistry and Physiology B, 2015Co-Authors: Lili Huang, Lingbing Zeng, Yan Meng, Wenzhi Liu, Yuding Fan, Yong Zhou, Nan JiangAbstract:The Chinese Giant Salamander, Andrias davidianus, is the largest extant amphibian species in the world, which is of significance due to its specific position in the evolutionary history of vertebrates. Currently, limited information about the innate immune system of this animal is known. In this study, the toll-like receptor 7 (TLR7), designated CgsTLR7, was cloned from Chinese Giant Salamander, A. davidianus. The full-length cDNA of CgsTLR7 is 3747 bp, with an open reading frame of 3150 bp, encoding 1049 amino acids. The TLR family motifs, including the leucine-rich repeat (LRR) and Toll/interleukin (IL)-1 receptor (TIR) domain are conserved in CgsTLR7, which includes 19 LRRs and a TIR domain. The predicted amino acid sequence of CgsTLR7 has 71%, 65%, 63% and 55% identity with turtle, chicken, human and fugu TLR7 homologues, respectively. Phylogenetic analysis showed that CgsTLR7 is closest to that of frog TLR7 among the examined species. Quantitative real-time PCR analysis revealed broad expression of CgsTLR7 in tissues from apparently healthy Chinese Giant Salamanders with the highest expression in the liver and the lowest expression in the intestine. The mRNA expression was up-regulated and reached a peak level in the kidney, liver and spleen at 12 h, 24 h and 48 h after infecting the animals with the Giant Salamander iridovirus (GSIV), respectively. These results suggest that CgsTLR7 has a conserved gene structure and might play an important role in immune regulation against viral infections in the Chinese Giant Salamander.
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identification of type i ifn in chinese Giant Salamander andrias davidianus and the response to an iridovirus infection
Molecular Immunology, 2015Co-Authors: Yan Meng, Wenzhi Liu, Yuding Fan, Yong Zhou, Qian Chen, Xianhui Zeng, Lingbing ZengAbstract:Abstract The type I IFNs play a major role in the first line of defense against virus infections. In this study, the type I IFN gene designated gsIFN was identified and characterized in the Chinese Giant Salamander (Andrias davidianus). The genomic DNA of gsIFN contains 5 exons and 4 introns and has a total length of 5622 bp. The full-length cDNA sequence of gsIFN is 1113 bp and encodes a putative protein of 186 amino acids that has a 43% identity to type I IFN of Xenopus tropicalis. The deduced amino acid sequence has the C-terminal CAWE motif, that is mostly conserved in the higher vertebrate type I IFNs. Real-time fluorescence quantitative RT-PCR analysis revealed broad expression of gsIFN in vivo and the highest level expression in blood, kidney and spleen. Additionally, the expression of gsIFN at the mRNA level was significantly induced in peripheral blood leucocytes after stimulation with poly I:C and after infection with the Chinese Giant Salamander iridovirus (GSIV). A plasmid expressing gsIFN was constructed and transfected into the Chinese Giant Salamander muscle cell line. Expression of the IFN-inducible gene Mx was up-regulated in the gsIFN-overexpressing cells after GSIV infection. The virus load and titer were significantly reduced compared with that in control cells. Additionally, a lower level of virus major capsid protein synthesis was confirmed by immunofluorescence assay compared to the control cells. These results suggest that the gsIFN gene plays an important role in the antiviral innate immune response.
Yong Zhou - One of the best experts on this subject based on the ideXlab platform.
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Bid is involved in apoptosis induced by Chinese Giant Salamander iridovirus and contributes to the viral replication in an amphibian cell line.
Developmental and comparative immunology, 2020Co-Authors: Li Yiqun, Yan Meng, Wenzhi Liu, Yuding Fan, Yong Zhou, Yanan Liu, Nan Jiang, Xue Mingyang, Lingbing ZengAbstract:Bid is a pro-apoptotic BH3-only member of the Bcl-2 superfamily that functions to link the extrinsic apoptotic pathway and the mitochondrial amplification loop of the intrinsic pathway. In this study, the expression and functions of Chinese Giant Salamander (Andrias davidianus) Bid (AdBid) were investigated. The AdBid cDNA sequence contains an open reading frame (ORF) of 576 nucleotides, encoding a putative protein of 191 aa. AdBid possesses the conserved BH3 interacting domain and shared 34-52% sequence identities with other amphibian Bid. mRNA expression of AdBid was most abundant in muscle. The expression level of AdBid in Chinese Giant Salamander muscle, kidney and spleen significantly increased after Chinese Giant Salamander iridovirus (GSIV) infection. Additionally, a plasmid expressing AdBid was constructed and transfected into the Chinese Giant Salamander muscle cell line (GSM cells). The morphology and cytopathic effect (CPE) and apoptotic process in AdBid over-expressed GSM cells was significantly enhanced during GSIV infection compared with that in control cells. Moreover, a higher level of the virus major capsid protein (MCP) gene copies and protein synthesis was confirmed in the AdBid over-expressed cells. These results indicated that AdBid played a positive role in GSIV induced apoptosis and the viral replication. This study may contribute to the better understanding on the infection mechanism of iridovirus-induced apoptosis.
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chinese Giant Salamander andrias davidianus iridovirus infection leads to apoptotic cell death through mitochondrial damage caspases activation and expression of apoptotic related genes
International Journal of Molecular Sciences, 2019Co-Authors: Nan Jiang, Yan Meng, Wenzhi Liu, Yuding Fan, Yong Zhou, Mingyang Xue, Lingbing ZengAbstract:Chinese Giant Salamander iridovirus (GSIV) is the causative pathogen of Chinese Giant Salamander (Andrias davidianus) iridovirosis, leading to severe infectious disease and huge economic losses. However, the infection mechanism by GSIV is far from clear. In this study, a Chinese Giant Salamander muscle (GSM) cell line is used to investigate the mechanism of cell death during GSIV infection. Microscopy observation and DNA ladder analysis revealed that DNA fragmentation happens during GSIV infection. Flow cytometry analysis showed that apoptotic cells in GSIV-infected cells were significantly higher than that in control cells. Caspase 8, 9, and 3 were activated in GSIV-infected cells compared with the uninfected cells. Consistently, mitochondria membrane potential (MMP) was significantly reduced, and cytochrome c was released into cytosol during GSIV infection. p53 expression increased at an early stage of GSIV infection and then slightly decreased late in infection. Furthermore, mRNA expression levels of pro-apoptotic genes participating in the extrinsic and intrinsic pathway were significantly up-regulated during GSIV infection, while those of anti-apoptotic genes were restrained in early infection and then rose in late infection. These results collectively indicate that GSIV induces GSM apoptotic cell death involving mitochondrial damage, caspases activation, p53 expression, and pro-apoptotic molecules up-regulation.
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rag1 and rag2 gene expressions identify lymphopoietic tissues in juvenile and adult chinese Giant Salamander andrias davidianus
Developmental and Comparative Immunology, 2018Co-Authors: Nan Jiang, Wenzhi Liu, Yuding Fan, Yong Zhou, Jacques Robert, Lingbing ZengAbstract:Rag1 and rag2 are two closely linked recombination activating genes required for V(D)J recombination of antigen receptors in immature lymphocytes, whose expression can serve as marker to identify the lymphopoietic tissues. To study the development of lymphopoietic tissues in Chinese Giant Salamander (Andrias davidianus), the Chinese Giant Salamander rag1 and rag2 coding sequences were cloned and determined. High transcript levels of rag1 and rag2 were co-detected in the thymus before 14 months of age, whereas levels were lower in spleen, liver and kidney at all stage of development. The spatial expression patterns of rag1 and rag2 were studied in combination with igY and tcrβ gene expression using in situ hybridization. Significant transcript signals for rag1, rag2, tcrβ and igY were detected not only in the thymus and spleen but also the liver and kidney of juvenile and adult Chinese Giant Salamanders, which suggests that cells of lymphocyte lineage are present in multiple tissues of the Chinese Giant Salamander. This implies that lymphopoiesis may take place in these tissues. The tissue morphology of thymus suggested that the branched thymic primordium developed into mature organ with the development of thymocyte from juvenile to adult. These results not only confirm that as expected the thymus and spleen are primordial lymphopoietic tissues but also suggest that the liver and kidney provide site of lymphocyte differentiation in Chinese Giant Salamander.
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protective immunity of a pichia pastoris expressed recombinant iridovirus major capsid protein in the chinese Giant Salamander andrias davidianus
Vaccine, 2015Co-Authors: Yan Meng, Scott E Lapatra, Yuding Fan, Yong Zhou, Nan Jiang, Lingbing ZengAbstract:The major capsid protein (MCP) is the main immunogenic protein of iridoviruses, that has been widely used as an immunogen in vaccination trials. In this study, the codon-optimized Giant Salamander iridovirus (GSIV) MCP gene (O-MCP) was synthesized and cloned into a pPICZα B vector for secretory expression in the methylotrophic yeast Pichia pastoris after methanol induction. The expression of the O-MCP protein was detected by the Bradford protein assay, SDS-PAGE, Western blotting and electron microscopy. The Bradford protein assay indicated that the concentration of the O-MCP expressed was about 40 μg/ml in culture supernatants. SDS-PAGE analysis revealed that the O-MCP had a molecular weight of about 66 kDa and reacted with a His-specific MAb that was confirmed by Western blotting. Electron microscopy observations revealed that the purified O-MCP could self-assemble into virus-like particles. Healthy Giant Salamanders were vaccinated by intramuscular injection with the O-MCP antigen at a dose of 20 μg/individual. The numbers of erythrocytes and leukocytes in the peripheral blood of immunized Chinese Giant Salamanders increased significantly at day 3 and reached a peak at day 5 post-immunization. Meanwhile, the differential leukocyte counts of monocytes and neutrophils increased significantly at day 5 post-immunization compared to that of the control group. The percentage of lymphocytes was 71.33 ± 3.57% at day 21 post-immunization. The neutralization assay showed that the serum neutralizing antibody titer reached 321 at day 21 post-immunization. The GSIV challenge test revealed that the relative percent survival of Chinese Giant Salamanders vaccinated with O-MCP was 78%. These results indicated that the O-MCP antigen expressed by the Pichia pastoris system elicited significant immune response in the Chinese Giant Salamander against GSIV and might represent a potential yeast-derived vaccine candidate that could be used for the control of disease caused by the Giant Salamander iridovirus.
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cloning sequence analysis and expression profiles of toll like receptor 7 from chinese Giant Salamander andrias davidianus
Comparative Biochemistry and Physiology B, 2015Co-Authors: Lili Huang, Lingbing Zeng, Yan Meng, Wenzhi Liu, Yuding Fan, Yong Zhou, Nan JiangAbstract:The Chinese Giant Salamander, Andrias davidianus, is the largest extant amphibian species in the world, which is of significance due to its specific position in the evolutionary history of vertebrates. Currently, limited information about the innate immune system of this animal is known. In this study, the toll-like receptor 7 (TLR7), designated CgsTLR7, was cloned from Chinese Giant Salamander, A. davidianus. The full-length cDNA of CgsTLR7 is 3747 bp, with an open reading frame of 3150 bp, encoding 1049 amino acids. The TLR family motifs, including the leucine-rich repeat (LRR) and Toll/interleukin (IL)-1 receptor (TIR) domain are conserved in CgsTLR7, which includes 19 LRRs and a TIR domain. The predicted amino acid sequence of CgsTLR7 has 71%, 65%, 63% and 55% identity with turtle, chicken, human and fugu TLR7 homologues, respectively. Phylogenetic analysis showed that CgsTLR7 is closest to that of frog TLR7 among the examined species. Quantitative real-time PCR analysis revealed broad expression of CgsTLR7 in tissues from apparently healthy Chinese Giant Salamanders with the highest expression in the liver and the lowest expression in the intestine. The mRNA expression was up-regulated and reached a peak level in the kidney, liver and spleen at 12 h, 24 h and 48 h after infecting the animals with the Giant Salamander iridovirus (GSIV), respectively. These results suggest that CgsTLR7 has a conserved gene structure and might play an important role in immune regulation against viral infections in the Chinese Giant Salamander.
Qi-ya Zhang - One of the best experts on this subject based on the ideXlab platform.
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Establishment of three cell lines from Chinese Giant Salamander and their sensitivities to the wild-type and recombinant ranavirus
Veterinary Research, 2015Co-Authors: Jiang-di Yuan, Zhong-yuan Chen, Xing Huang, Xiao-chan Gao, Qi-ya ZhangAbstract:AbstractKnown as lethal pathogens, Ranaviruses have been identified in diseased fish, amphibians (including Chinese Giant Salamander Andrias davidianus, the world’s largest amphibian) and reptiles, causing organ necrosis and systemic hemorrhage. Here, three Chinese Giant Salamander cell lines, thymus cell line (GSTC), spleen cell line (GSSC) and kidney cell line (GSKC) were initially established. Their sensitivities to ranaviruses, wild-type Andrias davidianus ranavirus (ADRV) and recombinant Rana grylio virus carrying EGFP gene (rRGV-EGFP) were tested. Temporal transcription pattern of ranavirus major capsid protein (MCP), fluorescence and electron microscopy observations showed that both the wild-type and recombinant ranavirus could replicate in the cell lines.
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thymus cdna library survey uncovers novel features of immune molecules in chinese Giant Salamander andrias davidianus
Developmental and Comparative Immunology, 2014Co-Authors: Rong Zhu, Jiang-di Yuan, Zhong-yuan Chen, Jun Wang, Xiangyong Liao, Jianfang Gui, Qi-ya ZhangAbstract:A ranavirus-induced thymus cDNA library was constructed from Chinese Giant Salamander, the largest extant amphibian species. Among the 137 putative immune-related genes derived from this library, these molecules received particular focus: immunoglobulin heavy chains (IgM, IgD, and IgY), IFN-inducible protein 6 (IFI6), and T cell receptor beta chain (TCRβ). Several unusual features were uncovered: IgD displays a structure pattern distinct from those described for other amphibians by having only four constant domains plus a hinge region. A unique IgY form (IgY(ΔFc)), previously undescribed in amphibians, is present in serum. Alternative splicing is observed to generate IgH diversification. IFI6 is newly-identified in amphibians, which occurs in two forms divergent in subcelluar distribution and antiviral activity. TCRβ immunoscope profile follows the typical vertebrate pattern, implying a polyclonal T cell repertoire. Collectively, the pioneering survey of ranavirus-induced thymus cDNA library from Chinese Giant Salamander reveals immune components and characteristics in this primitive amphibian.