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Search Results: 1 - 10 of 80837 matches for " Shengwang Liu "
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Identification, Expression and Activity Analyses of Five Novel Duck Beta-Defensins
Deying Ma, Kexin Zhang, Mingyue Zhang, Shengnan Xin, Xiaoli Liu, Zongxi Han, Yuhao Shao, Shengwang Liu
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0047743
Abstract: In the current study, five novel avian β-defensins (AvBDs) were identified and characterized in tissues from Peking ducks (Anas platyrhynchos). The nucleotide sequences of these cDNAs comprised 198 bp, 182 bp, 201 bp, 204 bp, and 168 bp, and encoded 65, 60, 66, 67, and 55 amino acids, respectively. Homology, characterization and comparison of these genes with AvBD from other avian species confirmed that they were Apl_AvBD1, 3, 5, 6, and 16. Recombinant AvBDs were produced and purified by expressing these genes in Escherichia coli. In addition, peptides were synthesized according to the respective AvBD sequences. Investigation of the antibacterial activity of the Apl_AvBDs showed that all of them exhibited antibacterial activity against all 12 bacteria investigated (P<0.05 or P<0.01). In addition, the antibacterial activity of all of the AvBDs against M. tetragenus and P. multocida decreased significantly in the presence of 150 mM NaCl (P<0.01). None of the AvBDs showed hemolytic activity. Consistent with their broad-spectrum antibacterial activity, the five novel Apl_AvBDs inhibited replication of duck hepatitis virus (DHV) in vitro significantly (P<0.05). The mRNA expression of all five Apl_AvBD in most tissues, including immune organs and the liver, was upregulated in response to DHV infection at different time points. These findings provide evidence that these defensins activate the immune response to combat microbial infection.
Proteomics analysis of differentially expressed proteins in chicken trachea and kidney after infection with the highly virulent and attenuated coronavirus infectious bronchitis virus in vivo
Zhongzan Cao, Zongxi Han, Yuhao Shao, Xiaoli Liu, Junfeng Sun, Demin Yu, Xiangang Kong, Shengwang Liu
Proteome Science , 2012, DOI: 10.1186/1477-5956-10-24
Abstract: Fifty-eight differentially expressed proteins were identified. Results demonstrated that some proteins which had functions in cytoskeleton organization, anti-oxidative stress, and stress response, showed different change patterns in abundance from chicken infected with the highly virulent ck/CH/LDL/97I P5 strain and those given the embryo-passaged, attenuated P115 stain. In addition, the dynamic transcriptional alterations of 12 selected proteins were analyzed by the real-time RT-PCR, and western blot analysis confirmed the change in abundance of heat shock proteins (HSP) beta-1, annexin A2, and annexin A5.The proteomic alterations described here may suggest that these changes to protein expression correlate with IBV virus' virulence in chicken, hence provides valuable insights into the interactions of IBV with its host and may also assist with investigations of the pathogenesis of IBV and other coronavirus infections.Coronaviruses (CoVs) are enveloped single-stranded positive sense RNA viruses that belong to the family Coronaviridae in the order Nidovirales. They are able to infect humans as well as other animals, including cows, pigs, mice, and chickens, they generally cause respiratory infection, gastrointestinal, and neurological disorders of varying severity. Infectious bronchitis virus (IBV) was the first coronavirus to be discovered, and is classed among the Gamma coronaviruses on the basis of antigenic and genetic relatedness [1]. It is a major poultry pathogen and is probably endemic in all chicken-raising regions; it has a severe impact on poultry production, causing heavy economic losses. All strains of IBV are capable of infecting a large range of epithelial surfaces of chickens, such as those of the trachea, kidney, oviduct and proventriculus [2].Coronavirus infection has dramatic effects on host cell morphology, transcription and translation patterns, the cell cycle, cytoskeleton, suppression of interferon, and apoptosis pathways. Coronavirus infection
Different linkages in the long and short regions of the genomes of duck enteritis virus Clone-03 and VAC Strains
Xiaoli Liu, Zongxi Han, Yuhao Shao, Yang Li, Huixin Li, Xiangang Kong, Shengwang Liu
Virology Journal , 2011, DOI: 10.1186/1743-422x-8-200
Abstract: A 42,897-bp fragment located downstream of the LOFR11 gene was amplified from the Clone-03 strain of DEV by using 'targeted gene walking PCR'. Twenty-two open reading frames (ORFs) were predicted and determined in the following order: 5'-LORF11-RLORF1-ORF1-ICP4-S1-S2-US1-US10-SORF3-US2-MDV091.5-like-US3-US4-US5-US6-US7-US8-ORFx-US1-S2-S1-ICP4 -3'. This was different from that of the published VAC strain, both in the linkage of the L region and S region, and in the length of the US10 and US7 proteins. The MDV091.5-like gene, ORFx gene, S1 gene and S2 gene were first observed in the DEV genome. The lengths of DEV US10 and US7 were determined to be 311 and 371 amino acids, respectively, in the Clone-03 strain of DEV, and these were different from those of other strains. The comparison of genomic organization in the fragment studied herein with those of other herpesviruses showed that DEV possesses some unique characteristics, such as the duplicated US1 at each end of the US region, and the US5, which showed no homology with those of other herpesviruses. In addition, the results of phylogenetic analysis of ORFs in the represented fragment indicated that DEV is closest to its counterparts VZV (Varicellovirus) and other avian herpesviruses.The molecular characteristics of the 42,897-bp fragment of Clone-03 have been found to be different from those of the VAC strain. The phylogenetic analysis of genes in this region showed that DEV should be a separate member of the subfamily Alphaherpesvirinae.Herpesviruses are among the most persistent of all pathogens because they have coevolved with their hosts over a long period of time, and they are relatively harmless in immunocompetent hosts [1]. The family Herpesviridae comprises approximately 100 members; these viruses infect a range of host species from humans and other mammals to birds, amphibians, and reptiles [2]. On the basis of differences in cellular tropism, genome organization, and gene content, herpesviruses have been
Identification of a novel linear B-cell epitope in the UL26 and UL26.5 proteins of Duck Enteritis Virus
Xiaoli Liu, Zongxi Han, Yuhao Shao, Dan Yu, Huixin Li, Yu Wang, Xiangang Kong, Shengwang Liu
Virology Journal , 2010, DOI: 10.1186/1743-422x-7-223
Abstract: A mAb (designated 1C8) was generated against the DEV UL26c protein, and a series of 17 partially overlapping fragments that spanned the DEV UL26c were expressed with GST tags. These peptides were subjected to enzyme-linked immunosorbent assay (ELISA) and western blotting analysis using mAb 1C8 to identify the epitope. A linear motif, 520IYYPGE525, which was located at the C-terminus of the DEV UL26 and UL26.5 proteins, was identified by mAb 1C8. The result of the ELISA showed that this epitope could be recognized by DEV-positive serum from mice. The 520IYYPGE525 motif was the minimal requirement for reactivity, as demonstrated by analysis of the reactivity of 1C8 with several truncated peptides derived from the motif. Alignment and comparison of the 1C8-defined epitope sequence with those of other alphaherpesviruses indicated that the motif 521YYPGE525 in the epitope sequence was conserved among the alphaherpesviruses.A mAb, 1C8, was generated against DEV UL26c and the epitope-defined minimal sequence obtained using mAb 1C8 was 520IYYPGE525. The mAb and the identified epitope may be useful for further study of the design of diagnostic reagents for DEV.Herpesviruses exist widely in nature. The genomes of herpesviruses consist of linear double-stranded DNA; they differ in size (from approximately 124 to 235 kb), sequence arrangement and base composition [1], and vary significantly with respect to the presence and arrangement of inverted and directly repeated sequences. The genomes of most of the alphaherpesviruses, such as herpes simplex virus 2 (HSV-2) [2] and Marek's disease virus 1 (MDV-1) [3], encode more than 70 proteins; some of these proteins are not essential for the replication of the viruses. Only limited information is available about the structures and functions of these 70 proteins, although some studies of the antigenic determinants of the glycoproteins have been reported [4,5]. Three types of capsid, named A-, B-, and C-capsids, are needed in the assemb
Proteomic analysis of chicken embryonic trachea and kidney tissues after infection in ovo by avian infectious bronchitis coronavirus
Zhongzan Cao, Zongxi Han, Yuhao Shao, Heyuan Geng, Xiangang Kong, Shengwang Liu
Proteome Science , 2011, DOI: 10.1186/1477-5956-9-11
Abstract: 17 differentially expressed proteins from tracheal tissues and 19 differentially expressed proteins from kidney tissues were identified. These proteins mostly related to the cytoskeleton, binding of calcium ions, the stress response, anti-oxidative, and macromolecular metabolism. Some of these altered proteins were confirmed further at the mRNA level using real-time RT-PCR. Moreover, western blotting analysis further confirmed the changes of annexin A5 and HSPB1 during IBV infection.To the best of our knowledge, we have performed the first analysis of the proteomic changes in chicken embryonic trachea and kidney tissues during IBV infection in ovo. The data obtained should facilitate a better understanding of the pathogenesis of IBV infection.Avian infectious bronchitis (IB) is one of the most serious diseases of chickens. It is of economic importance in the poultry industry worldwide and is associated with respiratory disease, reduction in weight gain, poor egg production and quality, and decreased feed conversion efficiency. Its etiologic agent is the avian infectious bronchitis coronavirus (IBV), which is a Gamma coronavirus of the coronavirus genus and replicates primarily in the upper respiratory tract, kidney, and oviduct of chickens [1-3].Knowledge of the interactions between virus and host is critical in order to understand the pathogenesis of viral infection. On the one hand, the virus usurps the biological processes of the host to evade the innate immune response of the host; on the other hand, the host mounts a variety of defensive responses against the viral infection. These virus-host interactions can cause changes in the level of expression of host genes. Alteration of gene expression in the host after infection with coronavirus (CoV) has been investigated mainly with regard to infection with mouse hepatitis virus (MHV) and severe acute respiratory syndrome coronavirus (SARS-CoV) [4]. Limited studies have been performed to analyze host gene expression
Comparative analysis of the genes UL1 through UL7 of the duck enteritis virus and other herpesviruses of the subfamily Alphaherpesvirinae
Li, Huixin;Liu, Shengwang;Han, Zongxi;Shao, Yuhao;Chen, Shuhong;Kong, Xiangang;
Genetics and Molecular Biology , 2009, DOI: 10.1590/S1415-47572009005000003
Abstract: keywords : duck enteritis virus; ul1-ul7 genes; phylogenetic analysis.
Cohyponormal operators with the single valued extension property
Ridgley Lange,Shengwang Wang
International Journal of Mathematics and Mathematical Sciences , 1986, DOI: 10.1155/s0161171286000820
Abstract: It is proved that in order to find a nontrivial hyperinvariant subspace for a cohyponormal operator it suffices to make the further assumption that the operator have the single-valued extension property.
Narrow-Band Biphoton Generation near Atomic Resonance
Shengwang Du,Jianming Wen,Morton H. Rubin
Physics , 2008, DOI: 10.1364/JOSAB.25.000C98
Abstract: Generating nonclassical light offers a benchmark tool for the fundamental research and potential applications in quantum optics. Conventionally, it has become a standard technique to produce the nonclassical light through the nonlinear optical processes occurring in nonlinear crystals. In this review we describe using cold atomic-gas media to generate such nonclassical light, especially focusing on narrow-band biphoton generation. Compared with the standard procedure, the new biphoton source has such properties as long coherence time, long coherence length, high spectral brightness, and high conversion efficiency. In this paper we concentrate on the theoretical aspect of the entangled two-photon state produced from the four-wave mixing in a multilevel atomic ensemble. We show that both linear and nonlinear optical responses to the generated fields play an important role in determining the biphoton waveform and, consequently on the two-photon temporal correlation. There are two characteristic regimes determined by whether the linear or nonlinear coherence time is dominant. In addition, our model provides a clear physical picture that brings insight into understanding biphoton optics with this new source. We apply our model to recent work on generating narrow-band (and even subnatural linewidth) paired photons using the technique of electromagnetically induced transparency and slow-light effect in cold atoms, and find good agreements with experimental results.
Narrowband biphoton generation in the group delay regime
Luwei Zhao,Yumian Su,Shengwang Du
Physics , 2014,
Abstract: We study narrow-band biphoton generation from spontaneous four-wave mixing with electromagnetically induced transparency in a laser cooled atomic ensemble. We compare two formalisms in the interaction and Heisenberg pictures, and find that they agree in the low gain regime but disagree in the high gain regime. We extend both formalisms accounting the non-uniformity in atomic density and the driving laser fields. We find that for a fixed optical depth and a weak and far-detuned pump laser beam, the two-photon waveform is independent of the atomic density distribution. However, the spatial profiles of the two driving laser beams have significant effects on the biphoton temporal waveform. We predict that waveform shaping in time domain can be achieved by controlling the spatial profiles of the driving laser fields.
Isolation, identification and bioactivity characterization of goose avian beta-defensin 3

Mingyue Zhang,Caiyuan Zhou,Zongxi Han,Tanhao Shao,Shengwang Liu,Deying Ma,

生物工程学报 , 2011,
Abstract: The objective of the study was to clone avian beta-defensin (AvBD) 3 gene from goose tissues, express the recombinant AvBD3 protein in Escherichia coli, and determine its antimicrobial activity. The mRNA of goose AvBD3 was cloned from spleen and bursa of Fabricius of the gooses by RT-PCR. The sequence analysis showed that the genefragment of AvBD3 contained 182 bp, and encoded 60 amino acids. Homology analysis showed that goose AvBD3 shared the highest percentage of amino acid homology (100%) with chicken AvBD3. The cDNA of goose AvBD3 was sub-cloned into BamH I and Sal I sites of pGEX-6p-1 vector to construct recombinant plasmid pGEX-goose AvBD3. The recombinant plasmid was transformed into E. coli BL21 and the bacteria was induced with IPTG It was demonstrated by SDS-PAGE that a 31 kDa protein which was equal to goose AvBD3 protein in molecular weight was highly expressed. The purified recombinant goose AvBD3 exhibited extensive antimicrobial activity against twelve bacteria strains, including Gram-positive and Gram-negative investigated. At high salt ions conditions, antimicrobial activity of recombinant goose AvBD3 protein against both Staphylococcus aureus and Pasteurella multocida decreased significantly. In addition, hemolysis activity of the recombinant protein was extremely low, and the recombinant protein remained antimicrobial activity under different pH values.
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