Publications (10)27.32 Total impact
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Article: Two Litopenaeus vannamei HMGB proteins interact with transcription factors LvSTAT and LvDorsal to activate the promoter of white spot syndrome virus immediate-early gene ie1.
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ABSTRACT: White spot syndrome virus (WSSV) has caused great economic damage to shrimp aquaculture. Previous studies have shown that WSSV successfully usurps the immunity system of the host for its own gene regulation. To investigate the role of shrimp high mobility group box (HMGB) proteins in WSSV gene regulation, two Litopenaeus vannamei HMGB genes, LvHMGBa and LvHMGBb, were isolated by rapid amplification of cDNA ends (RACE). Recombinant LvHMGBa/b proteins were present in the nucleus of transfected Drosophila Schneider 2 (S2) cells. Luciferase reporter assays revealed that LvHMGBa/b upregulated the WSSV immediate-early (IE) gene (ie1) in a NF-κB and STAT binding site-dependent manner. GST pull-down assays demonstrated that LvHMGBa/b interacted with L. vannamei Dorsal (LvDorsal) and L. vannamei STAT (LvSTAT), respectively. LvHMGBa was highly expressed in hepatopancreas while HMGBb was highly expressed in stomach, intestine, heart, antennal gland, and epidermis. Moreover, an immune challenge assay demonstrated that the expression of LvHMGBa/b was upregulated by WSSV infection and that both mRNAs reached peak values at 24 h post-infection. To our knowledge, this is the first report that invertebrate HMGB proteins participates in viral gene regulation.Molecular Immunology 02/2011; 48(5):793-9. · 2.90 Impact Factor -
Article: Cloning and characterization of a shrimp ML superfamily protein.
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ABSTRACT: ML superfamily proteins, including MD-1, MD-2, Niemann-Pick type C2 (Npc2) protein, GM2 activator protein, phosphatidylinositol/phosphatidylglycerol transfer protein (PG/PI-TP) and mite allergen Der p 2, bind to specific lipids and play important roles in lipid-recognition and metabolism. Among these ML (MD-2-related lipid-recognition) proteins, MD-2 is essential for lipopolysaccharide (LPS) signaling and the following secretion of proinflammatory factors. In this report, we identified the cDNA and gene of an ML protein from an important white shrimp Litopenaeus vannamei and named it LvML. The gene consists of four exons and three introns. The putative LvML contains 6 cysteines which may form 3 disulfide bonds that are conserved in ML proteins. Reverse transcription PCR analysis showed that in the examined tissues LvML mRNA is only expressed in the hepatopancreas, while not in hemocytes, eyestalk, gill, heart, stomach, intestine, nerve core, muscle or pyloric caecum. Its expression is positively regulated after injection of LPS. Then enzyme-linked immunosorbent assay showed that the recombinant LvML possessed activity of binding to LPS, and that the binding was inhibited by pre-incubation with LPS. We suggested that the LvML may play roles in the shrimp innate immunity.Fish & Shellfish Immunology 02/2011; 30(2):713-9. · 3.32 Impact Factor -
Article: Shrimp NF-κB binds to the immediate-early gene ie1 promoter of white spot syndrome virus and upregulates its activity.
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ABSTRACT: The immediate-early gene ie1 carried by white spot syndrome virus (WSSV) exhibits very strong promoter activity and expresses highly throughout the infection cycle. Here we identified a NF-κB binding motif in the ie1 promoter region. Electrophoretic mobility shift assays indicated that the recombinant Rel homology domain (RHD) of shrimp NF-κB homolog LvRelish bound to the putative NF-κB site in the ie1 promoter. A transactivity assay of the WSSV ie1 promoter in Drosophila Schneider 2 cells demonstrated that LvRelish could increase ie1 promoter activity. These results show that shrimp NF-κB homolog LvRelish transactivates WSSV ie1 gene expression and contributes to its high promoter activity. Further transactivation assays showed that WSSV IE1 protein expression upregulated the promoter activities of WSSV ie1 gene and antimicrobial peptide genes regulated by the NF-κB system. We suggested that WSSV may annex the shrimp NF-κB system, which it uses to enhance the expression of viral immediate-early genes.Virology 10/2010; 406(2):176-80. · 3.35 Impact Factor -
Article: Identification and functional study of a shrimp Dorsal homologue.
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ABSTRACT: Rel/NF-kappaB transcription factors play central roles in induction and regulation of innate immune responses. Here, identification and functional analysis of LvDorsal, a Dorsal homologue from the Pacific white shrimp Litopenaeus vannamei, were described. The full-length cDNA of LvDorsal is 2204bp with an open reading frame that encodes 400 amino acids. The deduced LvDorsal contains a conserved Rel homology domain (RHD), an IPT (Ig-like, plexins and transcription factors) domain and a nucleus localization signal, suggesting that it belongs to the class II NF-kappaB. RT-PCR analysis showed that LvDorsal mRNAs were expressed in all the tissues tested, including gill, epidermis, hemocytes, intestine, stomach, eyestalk, brain, hepatopancreas, muscle, heart and pyloric caecum. Immunofluorescence assay showed that recombinant LvDorsal was translocated into the nucleus of Drosophila S2 cells. Electrophoretic mobility shift assay illustrated that recombinant LvDorsal RHD from S2 cells bound specifically with D. melanogaster kappaB motifs. Additionally, the dual-luciferase reporter assays indicated that LvDorsal could transactivate the reporter gene controlled by the 5' flanking region of shrimp penaeidin-4 and Drosophila attacin genes, suggesting that LvDorsal can regulate the transcription of shrimp penaeidin-4 gene. Study of LvDorsal will help us to better understand shrimp immunity and may help to obtain more effective methods to prevent shrimp diseases.Developmental and comparative immunology 10/2009; 34(2):107-13. · 3.29 Impact Factor -
Article: Identification and functional study of a shrimp Relish homologue.
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ABSTRACT: Rel/NF-kappaB transcription factors play central roles in induction and regulation of innate immune responses. Here we describe the identification and functional analysis of a Relish homologue, LvRelish and its shorter isoform sLvRelish, from the Pacific white shrimp, Litopenaeus vannamei. The LvRelish gene has 22 exons in approximately 15 kb genomic sequence. The full-length cDNA of LvRelish is 4071 bp with an open reading frame that encodes 1207 amino acids. LvRelish contains a conserved Rel homology domain (RHD), a nucleus localization signal, an IkappaB-like domain (six ankyrin repeats), and a death domain, suggesting that it belongs to the class I NF-kappaB. sLvRelish cDNA is 1051 bp encoding 317 amino acids. It shares the RHD region with LvRelish. RT-PCR analysis showed that LvRelish and sLvRelish mRNAs were expressed at different levels in tissues. Western blot analysis showed that recombinant intact LvRelish could be cleaved into two fragments in S2 cells, and immunofluorescence assay showed that the plasmid-expressed LvRelish protein was seen both in the cytoplasm and the nucleus. Electrophoretic mobility shift assay showed that recombinant RHD of LvRelish in S2 cells bound specifically with Drosophila melanogaster kappaB motifs in vitro. Both the LvRelish and its RHD domain transactivated the reporter gene controlled by the 5' flanking region of penaeidin 4, an antibacterial peptide of shrimp, suggesting that LvRelish can regulate the transcription of penaeidin 4 gene. Identification of LvRelish will help us better understand shrimp immunity and may help obtain more effective methods to prevent shrimp diseases.Fish & Shellfish Immunology 06/2009; 27(2):230-8. · 3.32 Impact Factor -
Article: An immune deficiency homolog from the white shrimp, Litopenaeus vannamei, activates antimicrobial peptide genes.
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ABSTRACT: Invertebrates rely on innate immunity as the first line defense against microbes. In Drosophila, the inducible antimicrobial peptides (AMPs) regulated by the Toll and immune deficiency (Imd) pathways are important effectors in innate immunity. Here we report an immune deficiency homolog (LvIMD) from the white shrimp, Litopenaeus vannamei. The full-length cDNA of LvIMD is 758 bp with an open reading frame of 483 bp that encodes a putative protein of 160 amino acids including a death domain at the C-terminus. LvIMD death domain shows similarity to that of Drosophila IMD and human receptor interacting protein 1 (RIP1) of the tumor necrosis factor receptor (TNFR) pathway, with 27.9% and 26.4% identity, respectively. Phylogenetic analysis shows that LvIMD clusters with a predicted protein from the starlet sea anemone (Nematostella vectensis) independent to insect IMDs and vertebrates RIP1s. LvIMD mRNA is expressed in most tissues and is induced in hepatopancreas and hemocytes after immune challenge. Luciferase reporter assays confirm that LvIMD is able to induce the expression of AMP genes, including Drosophila Attacin A and shrimp Penaeidin 4 in S2 cells. To our knowledge, this is the first report that LvIMD participates in innate signaling to activate the expression of AMP genes in shrimp.Molecular Immunology 03/2009; 46(8-9):1897-904. · 2.90 Impact Factor -
Article: A novel prophenoloxidase 2 exists in shrimp hemocytes.
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ABSTRACT: The prophenoloxidase (proPO)-activating system in crustaceans and other arthropods is regarded as a constituent of the immune system and plays an important role in defense against pathogens. Hitherto in crustaceans, only one proPO gene per species has been identified. Here we report the identification of a novel proPO-2 (LvproPO-2) from the hemocytes of Litopenaeus vannamei, which shows 72% identity to proPO-1 (LvproPO-1) cloned previously. Northern blotting analysis and quantitative real-time PCR reveal that LvproPO-2 is mainly expressed in the hemocytes, and its expression is down-regulated in shrimp challenged with white spot syndrome virus (WSSV). Western blotting analysis shows that most LvproPO-2/LvPO-2 (L. vannamei phenoloxidase-2) exists in the hemocytes, but not in plasma of L. vannamei. LvproPO-2/LvPO-2 could be detected on the hemocyte surface and the nucleus of hemocytes by indirect immunofluorescence assay (IFA). These findings provide insight into the molecular biological basis for further studying on the defense mechanism of shrimp innate immunity, especially on the proPO-activating system and melanization cascade of shrimp.Developmental & Comparative Immunology 10/2008; 33(1):59-68. · 3.27 Impact Factor -
Article: Molecular cloning of two C1q-like cDNAs in mandarin fish Siniperca chuatsi.
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ABSTRACT: C1q, a subunit of the C1 complex, plays a key role in the recognition of immune complexes to initiate the classical complement pathway. In this study, we reported two C1q-like cDNAs from mandarin fish (Siniperca chuatsi), mC1q-like-1 (mC1qL1) and mC1q-like-2 (mC1qL2). The full-length cDNA of mC1qL1was 990bp, containing a 71bp 5'-untranslated region (UTR), an open reading frame (ORF) of 723bp, and a 196bp long 3'-UTR. mC1qL2 cDNA was 1193bp, containing a 100bp 5'-UTR, followed by an ORF of 756bp and a 3'-UTR of 337bp. mC1qL1 and mC1qL2 share 29% identity in amino acid sequence. Both mC1qL1 and mC1qL2 contained three parts: a short amino-terminal region, a collagen-like region and a carboxyl-terminal globular C1q domain. The phylogenetic analysis showed that mC1qL1 clustered with two Danio rerio hypothetical proteins and further grouped with C1q proteins, while mC1qL2 clustered with C1qA proteins from other species. In healthy mandarin fish, mC1qL1 and mC1qL2 were expressed in all tissues tested, including liver, spleen, head kidney, caudal kidney, intestine and gill. mC1qL1 was highly expressed in head kidney, while mC1qL2 was mainly expressed in spleen. The expression level of mC1qL1 and mC1qL2 in liver were not changed obviously and mC1qL2 was significantly changed (p<0.05) in spleen after infectious spleen and kidney necrosis virus (ISKNV) infection. Mandarin fish C1q may play a role in response to ISKNV infection.Veterinary Immunology and Immunopathology 06/2008; 125(1-2):37-46. · 2.08 Impact Factor -
Article: A Toll receptor in shrimp.
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ABSTRACT: Outbreaks of infectious diseases have resulted in high mortality and huge economic losses in penaeid shrimp culture. Interest in understanding shrimp immunity has increased because of its importance in disease control. Here we report cDNA cloning of a Toll receptor from the white shrimp Litopenaeus vannamei. L. vannamei Toll (lToll) is 926 residues, with a putative signal peptide of 19 residues. The protein contains distinct structural/functional motifs of the Toll like receptor (TLR) family, including an extracellular domain containing 16 leucine-rich repeats (LRRs) flanked by cysteine-rich motifs and a cytoplasmic Toll/interleukin-1 receptor (TIR) domain. The lToll TIR domain showed high similarity to Apis mellifer Toll and Drosophila melanogaster Toll, with 59.9% and 54.3% identity, respectively. Reverse-transcription polymerase chain reaction (RT-PCR) analysis showed that lToll was expressed in hemocyte, gill, heart, brain, stomach, intestine, pyloric caecum, muscle, nerve and spermary, with a lower expression level in eyestalk and hepatopancreas. Identification of lToll will help to elucidate the Toll pathway in shrimp innate immunity.Molecular Immunology 04/2007; 44(8):1999-2008. · 2.90 Impact Factor -
Article: Characterization of WSSV resistance in selected families of Litopenaeus vannamei
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ABSTRACT: Disease outbreaks caused by the white spot syndrome virus (WSSV) have resulted in high economic losses in the shrimp-culture industry worldwide. After three generations of selective breeding for WSSV resistance, 29 families of Litopenaeus vannamei (G3) were selected and divided into three groups: relatively high-resistance, moderate-resistance, and susceptible families, which had average survival rates of 22.7 ± 12.30, 9.08 ± 1.46, and 0.78 ± 1.70%, respectively, after WSSV infection. Appearance of the mortality peak in the relatively high-resistance families was postponed by 2–3 days compared to the same in susceptible families and unselected shrimps. Using real-time quantitative polymerase chain reaction, the copy number of WSSV DNA in the muscles of surviving shrimps from the relatively high-resistance family 14 was significantly lower than that of the moderate-resistance family 17, the susceptible family 4, and the unselected family of shrimps at 36 hours postinfection (hpi) and thereafter; for example, at 48 hpi, the DNA copy number was (23.87 ± 2.56) × 106 copies g−1 in the high-resistance families against (40.03 ± 2.54) × 106, (65.70 ± 3.44) × 106, and (47.87 ± 3.95) × 106 copies g−1 body weight, respectively, in the other groups. The WSSV copy number in the muscles of dead shrimps from the relatively high-resistance family 14 was significantly higher than that of the moderate-resistance family 17, the susceptible family 4, and the unselected family of shrimps at 48 hpi and thereafter; for example, at 72 hpi, the DNA copy number was (54.1 ± 3.9) × 106 copies g−1 compared to values of (31.5 ± 2.6) × 106, (11.6 ± 2.9) × 106, and (25.4 ± 2.7) × 106 copies g−1 body weight in the other groups, respectively. The results indicated that shrimps from the relatively high-resistance families could inhibit the replication of WSSV and therefore had apparent WSSV resistance. These results provide a direction for the future selective breeding of shrimps for WSSV resistance.Aquaculture.
Top co-authors
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Institutions
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2008–2011
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Sun Yat-Sen University
- School of Life Sciences
Guangzhou, Guangdong Sheng, China
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2007
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Zhongshan University
Zhongshan, Guangdong Sheng, China
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