Wei Si

Kunming University of Science and Technology, Yün-nan, Yunnan, China

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Publications (45)193.2 Total impact

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    ABSTRACT: Circulation of genotype VII Newcastle disease virus (NDV) has posed a great threat for the poultry industry worldwide. Antibodies against Hemagglutinin-neuraminidase (HN), a membrane protein of NDV with critical roles in NDV infection, have been reported to provide chickens protection from NDV infection. In this study, we comprehensively analyzed the in vivo antibody responses against the linear antigenic domains of the HN protein from genotype VII NDV using a yeast surface display system. The results revealed four distinct regions of HN, P1 (1-52aa), P2 (53-192aa), P3 (193-302aa) and P4 (303-571aa), respectively, according to their antigenic potency. Analysis by FACS and ELISA assay indicated P2 to be the dominant linear antigenic domain, with the immunogenic potency to protect the majority of chickens from NDV challenge. In contrast, the P1, P3 and P4 domains showed weak antigenicity in vivo and could not protect chickens from NDV challenge. These results provide important insight into the characteristic of humoral immune responses elicited by HN of NDV in vivo.
    PLoS ONE 06/2015; 10(6):e0131723. DOI:10.1371/journal.pone.0131723 · 3.23 Impact Factor
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    ABSTRACT: Because of their similarity to humans, non-human primates are important models for studying human disease and developing therapeutic strategies. Establishment of chimeric animals using embryonic stem cells (ESCs) could help with these investigations, but has not so far been achieved. Here, we show that cynomolgus monkey ESCs (cESCs) grown in adjusted culture conditions are able to incorporate into host embryos and develop into chimeras with contribution in all three germ layers and in germ cell progenitors. Under the optimized culture conditions, which are based on an approach developed previously for naive human ESCs, the cESCs displayed altered growth properties, gene expression profiles, and self-renewal signaling pathways, suggestive of an altered naive-like cell state. Thus our findings show that it is feasible to generate chimeric monkeys using ESCs and open up new avenues for the use of non-human primate models to study both pluripotency and human disease. Copyright © 2015 Elsevier Inc. All rights reserved.
    Cell stem cell 06/2015; 17(1). DOI:10.1016/j.stem.2015.06.004 · 22.15 Impact Factor
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    ABSTRACT: Salmonella enterica serovar Enteritidis (Salmonella Enteritidis) is a facultative intracellular pathogen that causes huge losses in poultry industry and also food poisoning in humans due to its being a food-borne pathogen. Functions of Invasion-related genes need to be explored, as invasion is a key step for Salmonella infection. In this study, a transposon mutant library of Salmonella Enteritidis isolate SM6 was constructed and screened for the invasion-related genes via incubation with Caco-2 cells. Three stably attenuated mutants were identified for significantly reduced invasion with insertions all in hilA (hyperinvasive locus A) gene. We constructed and evaluated the hilA deletion mutant in vivo and in vitro. SM6△hilA showed significantly reduced ability to invade Caco-2 cells and decreased pathogenicity in chicks. However, the bacterial load and pathological damage in the cecum were significantly higher than those in the SM6 in vivo. Present results provide new evidences for pathogenicity research on Salmonella Enteritidis. Copyright © 2015 Elsevier B.V. All rights reserved.
    Research in Veterinary Science 05/2015; 101. DOI:10.1016/j.rvsc.2015.05.004 · 1.51 Impact Factor
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    ABSTRACT: During March 25-May 5, 2014, we investigated 11 outbreaks of peste des petits ruminants in Heilongjiang Province, China. We found that the most likely source of the outbreaks was animals from livestock markets in Shandong. Peste des petits ruminants viruses belonging to lineages II and IV were detected in sick animals.
    Emerging infectious diseases 04/2015; 21(4). DOI:10.3201/eid2104.141627 · 7.33 Impact Factor
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    ABSTRACT: To construct a novel live, attenuated Salmonella vaccine, the lon, cpxR and cpdB genes were deleted from a wild-type Salmonella enterica serovar Enteritidis-6 (SM-6) strain using the phage λ Red homologous recombination system, resulting in SM-△CpxR, SM-△C/Lon and SM-△C/L/CpdB. The growth curves of strain SM-△C/Lon grew more rapidly than the other strains and had OD 600 values higher than the other strains starting at the 4 h time point. The growth curves of strain SM-△C/L/CpdB were relatively flat. The colonization time of SM-△C/L/CpdB is about 8-10 days. Deleting the lon/cpxR/cpdB (SM-6) genes resulted in an approximate 10(3)-fold attenuation in virulence assessed by the analysis of the LD50 of specific pathogen-free (SPF) chicks. This result indicated that the deletion of the lon, cpxR and cpdB genes induced significant virulence attenuation. The protective effects of SM-△C/L/CpdB vaccination in SPF chicks against 5 × 10(9) colony forming units (CFU) of S. Enteritidis were a result of the induction of an effective immune response. These findings demonstrate the potential of mutant SM-△C/L/CpdB to be used as an effective vaccine. Copyright © 2015. Published by Elsevier Ltd.
    Microbial Pathogenesis 03/2015; 83-84. DOI:10.1016/j.micpath.2015.03.018 · 2.00 Impact Factor
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    ABSTRACT: Enterohemorrhagic Escherichia coli (EHEC) strains cause serious gastrointestinal disease, which can lead to potentially life-threatening systemic complications such as hemolytic uremic syndrome. Although the ehx gene is established as a major virulence factor of EHEC, the role of this gene in colonization and biofilm formation remains to be elucidated. We constructed recombinant isogenic mutants of the ehxA locus of E. coli HLJ1122 (serotype O82) using the λ Red homologous recombination system. Significantly higher levels of adherence to human epithelial cells (HEp-2) cells were observed for strain HLJ1122 compared with the mutant strain HLJ1122-ΔehxA (P < 0.05). Strain HLJ1122 also exhibited significantly higher levels of biofilm formation than strain HLJ1122-ΔehxA (P < 0.05). Mice infected with strain HLJ1122 showed severe destruction of the intestinal and gastric mucosa; in contrast, mice infected with HLJ1122-ΔehxA showed limited intestinal pathology, displaying minimal inflammatory infiltrates compared with mock-infected mice. These results showed the multifunctional role of Ehx in E. coli virulence.
    Canadian Journal of Microbiology 03/2015; 61(5):1-7. DOI:10.1139/cjm-2014-0824 · 1.18 Impact Factor
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    Food Control 02/2015; 53. DOI:10.1016/j.foodcont.2014.12.026 · 2.82 Impact Factor
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    ABSTRACT: Salmonella enterica serovar Pullorum (S. Pullorum) is a worldwide poultry pathogen of considerable economic importance, particularly in those countries with a developing poultry industry. A variety of genes that affect S. Pullorum colonization in chickens had been indentified. 2',3'-cyclic phosphodiesterase (cpdB) is the bifunctional enzyme which possess 2',3'-cyclic phosphodiesterase as well as 3'-nucleotidase activity. To assess the role of cpdB of S. Pullorum in colonization of cecum and internal organs in poultry, seven-day-old chicks were infected with 10(9) CFU of a cpdB mutant and wild type strain. High number of cpdB mutant and wild type strain colonized the internal organs shortly after infection, but no colonization of cpdB mutant were observed from internal organs at day 10 post-infection, meanwhile, wild type bacteria in internal organs were observed at day 16 post-infection. Furthermore, the colonization of cpdB mutant in the cecum was seriously decreased from 6 days post-infection simultaneously wild type strain was increased and seriously decreased at day 8 post-infection. At day 12 post-infection, no cpdB mutant was observed from cecum, however high numbers of wild type strain were isolated at day 16 post-infection. It is concluded that cpdB is involved in long-term colonization of S. Pullorum in the chicks' cecum and internal organs. In addition, deletion of cpdB from S. Pullorum was not affect the morphology and growth of bacteria. Copyright © 2015. Published by Elsevier Ltd.
    Microbial Pathogenesis 01/2015; 80. DOI:10.1016/j.micpath.2015.01.002 · 2.00 Impact Factor
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    ABSTRACT: Parkinson's disease (PD) is an age-dependent neurodegenerative disease that can be caused by genetic mutations in α-synuclein (α-syn) or duplication of wild-type α-syn; PD is characterized by the deposition of α-syn aggregates, indicating a gain of toxicity from accumulation of α-syn. Although the major neuropathologic feature of PD is the degeneration of dopaminergic (DA) neurons in the substantia nigra, non-motor symptoms including anxiety, cognitive defect, and sleep disorder precede the onset of motor impairment, and many clinical symptoms of PD are not caused by degeneration of DA neurons. Non-human primate models of PD are important for revealing the early pathology in PD and identifying effective treatments. We established transgenic PD rhesus monkeys that express mutant α-syn (A53T). Six transgenic A53T monkeys were produced via lentiviral vector expressing A53T in fertilized monkey eggs and subsequent embryo transfer to surrogates. Transgenic A53T is expressed in the monkey brain and causes age-dependent non-motor symptoms, including cognitive defects and anxiety phenotype, without detectable sleeping disorders. The transgenic α-syn monkeys demonstrate the specific early symptoms caused by mutant α-syn and provide insight into treatment of early Parkinson's disease. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
    Human Molecular Genetics 12/2014; 24(8). DOI:10.1093/hmg/ddu748 · 6.68 Impact Factor
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    ABSTRACT: Male macaques produce faster sperm than male humans due to a higher pressure of sperm competition in macaques. To explore the molecular basis of this biological difference, we firstly constructed macaque and human sperm proteomes using liquid chromatography−tandem mass spectrometry. We then detected the positively selected genes specifically on the branch of macaque based on branch−site likelihood method. We identified 197 positively selected genes specifically on the branch of macaque which are unselected in corresponding human orthologs. These genes are highly associated with mitochondria and axoneme which directly drive sperm motility. We further compared the ultrastructural differences of the mid−piece between macaque and human sperms to provide evidence for our findings using transmission electron microscopy. In conclusion, our results provide potential molecular targets for explaining the different phenotypes under sperm competition between macaques and humans, and also provide resources for the analysis of male fertility.This article is protected by copyright. All rights reserved
    Proteomics 12/2014; 15(9). DOI:10.1002/pmic.201400248 · 3.97 Impact Factor
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    ABSTRACT: This study evaluated maternal immunity against Salmonella enterica serovar Enteritidis acquired through the egg yolk. Two-hundred 19-week-old specific pathogen free (SPF) broiler breeders which were randomly divided into two groups of equal size were injected with S. Enteritidis ghosts (5 x 109 colony forming units in 0.1 ml per hen) and phosphate-buffered saline (PBS, 0.01 mol⋅L-1, pH 7.4) twice, respectively, with an interval of 2 weeks. An indirect Enzyme-Linked Immunosorbent Assay (ELISA) was applied to detect specific antibodies against S. Enteritidis. S. Enteritidis-specific antibody levels in the vaccinated group increased over time and were significantly higher than those of the control group on day 28 (p < 0.001) and 35 (p < 0.001) post-vaccination. Ten 7-day-old chicks from hens that were vaccinated with a S. Enteritidis ghost vaccine were challenged at 14 days of age with 5 x 109 CFU of S. Enteritidis DH091 (homologous to the vaccine strain), 8/10 (80%) chicks from vaccinated hens survived, whereas 3/10 (30%) chicks from unvaccinated hens survived. The chicks acquired high levels of serum antibodies against S. Enteritidis. These results reveal that maternal antibodies in chicks acquired from vaccinated hens through eggs can confer a significant protection against S. Enteritidis infection.
    Research in Veterinary Science 10/2014; 97(2). DOI:10.1016/j.rvsc.2014.08.001 · 1.51 Impact Factor
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    ABSTRACT: Newcastle disease virus (NDV) is a member of the Paramyxovirinae subfamily and can infect most species of birds. It has been a great threat for the poultry industry all around the world. In this report, we successfully produced infectious pseudotyped pNL4-3-Luc-R-E- (HIV-Luc) viruses with the HN and F envelope proteins of NDV. Further investigation revealed the cytoplasmic domains of HN and F, especially HN, plays a significant role in the infection efficiency of these pseudotyped HIV-Luc viruses. Replacement of, or direct fusion to the cytoplasmic domain of the HN protein by that of vesicular stomatitis virus G (VSV-G) could greatly enhance or destroy the infective potential of HN and F-pseudotyped (NDV-pseudotyped) HIV-Luc virus. We further established a novel neutralization assay to evaluate neutralizing antibodies against NDV with the NDV-pseudotyped HIV-Luc viruses. Comparative neutralization data indicate that the results determined by using the NDV-pseudotyped HIV-Luc viruses are as reliable as those by the conventional virus-neutralization assay (VN test) with native NDV. Moreover, the results show that the novel neutralization assay is more sensitive than the VN test.
    PLoS ONE 06/2014; 9(6):e99905. DOI:10.1371/journal.pone.0099905 · 3.23 Impact Factor
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    ABSTRACT: Recent advances in gene editing technology have introduced the potential for application of mutagenesis approaches in nonhuman primates to model human development and disease. Here we report successful TALEN-mediated mutagenesis of an X-linked, Rett syndrome (RTT) gene, methyl-CpG binding protein 2 (MECP2), in both rhesus and cynomolgus monkeys. Microinjection of MECP2-targeting TALEN plasmids into rhesus and cynomolgus zygotes leads to effective gene editing of MECP2 with no detected off-target mutagenesis. Male rhesus (2) and cynomolgous (1) fetuses carrying MECP2 mutations in various tissues including testes were miscarried during midgestation, consistent with RTT-linked male embryonic lethality in humans. One live delivery of a female cynomolgus monkey occurred after 162 days of gestation, with abundant MECP2 mutations in peripheral tissues. We conclude that TALEN-mediated mutagenesis can be an effective tool for genetic modeling of human disease in nonhuman primates.
    Cell stem cell 02/2014; 14(3). DOI:10.1016/j.stem.2014.01.018 · 22.15 Impact Factor
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    ABSTRACT: Monkeys serve as important model species for studying human diseases and developing therapeutic strategies, yet the application of monkeys in biomedical researches has been significantly hindered by the difficulties in producing animals genetically modified at the desired target sites. Here, we first applied the CRISPR/Cas9 system, a versatile tool for editing the genes of different organisms, to target monkey genomes. By coinjection of Cas9 mRNA and sgRNAs into one-cell-stage embryos, we successfully achieve precise gene targeting in cynomolgus monkeys. We also show that this system enables simultaneous disruption of two target genes (Ppar-γ and Rag1) in one step, and no off-target mutagenesis was detected by comprehensive analysis. Thus, coinjection of one-cell-stage embryos with Cas9 mRNA and sgRNAs is an efficient and reliable approach for gene-modified cynomolgus monkey generation.
    Cell 01/2014; 156(4). DOI:10.1016/j.cell.2014.01.027 · 33.12 Impact Factor
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    ABSTRACT: Ovarian physiology and pathology are important areas of scientific research. Efforts have been made to identify the ovary-related transcriptomes in different species. However, the proteomic studies are limited. The rhesus monkey is very similar to humans, and it is widely used in the study of reproductive biology and medicine. In this study, using an optimized proteomics platform, we successfully identified 5723 rhesus ovarian proteins, of which 4325 proteins were consistently identified in all three replicates and with at least 2 unique peptides. The 4325 proteins were chosen for further analysis. Through gene ontology and pathway analyses, we obtained a preliminary understanding of the function of these proteins. A random immunohistochemistry analysis was used to determine the expression of proteins in various cell types. By comparing the genes identified in this study with genes that were reported to have relatively high levels of expression in human oocytes, we obtained genes that were predicted to play roles in maintenance of normal ovarian physiology. Searching the identified genes from this study against the MGI database gave us a list of proteins those exist in the rhesus monkey ovary and are important for female mouse reproduction as well. The overlap of genes in this study and the genes whose abnormal expression or dysfunction were reported to be associated with human polycystic ovary syndrome (PCOS) and premature ovarian failure (POF) prompted us to use the rhesus monkey to study these two common causes of female infertility. This study may provide a basis for future studies of human reproductive disorders using the rhesus monkey as a model.
    Molecular BioSystems 01/2014; 10(3). DOI:10.1039/c3mb70312f · 3.18 Impact Factor
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    ABSTRACT: During mammalian development, placental growth needs to be tightly controlled by apoptosis. However, despite the potentially significant problems, the strategies used to balance growth and apoptosis have remained elusive. Here we report that activation of the Notch1 signal pathway inhibits transduction of transforming growth factor (TGF)-β signaling, which leads to cell cycle arrest and apoptosis in rabbit trophoblast stem cells. The subcellular location of NICD1 appears to determine if TGF-β signaling will be inhibited or not. Moreover, changes in NICD1 subcellular location are regulated by intracellular calcium distribution. Collectively, these results establish a potential mechanism whereby trophoblast stem cells can balance growth and apoptosis, and thus guarantee the development of the fetus.
    Stem cells and development 11/2013; DOI:10.1089/scd.2013.0280 · 4.20 Impact Factor
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    ABSTRACT: The occurrence and counts of Listeria monocytogenes were investigated in a total of 526 retail raw food samples. All L. monocytogenes isolates were further analyzed by serotyping and antimicrobial susceptibility assays. The molecular basis of tetracycline resistance of each isolate and the genetic relatedness were determined. L. monocytogenes isolates were found in 12.4% (65/526) of the samples, with counts below 102 CFU/g. L. monocytogenes was most commonly isolated from pork (20%, 20/100), seafood (13.8%, 15/109), chicken (13.2%, 14/106), and beef (10.3%, 11/107). In addition, L. monocytogenes was also detected in 4.8% (5/104) of raw mutton samples. Four serogroups were identified among the 65 L. monocytogenes isolates, with serogroups 1/2a-3a (60%) and 4b-4d-4e (24.6%) being dominant. Most L. monocytogenes isolates were resistant to cefotaxime (54.6%), fosfomycin (51.5%), and clarithromycin (36.4%). Some isolates showed intermediate resistance to streptomycin (12.1%), norfloxacin (13.6%), ciprofloxacin (13.6%), and nitrofurantoin (9.1%). Multiple resistances were observed in 72.3% of isolates. Genetic relatedness analysis revealed that there were no prominent associations between specific food types, serotypes, antimicrobial susceptibility profiles and Pulsed-field gel electrophoresis (PFGE) patterns. In addition, these isolates were multiresistant and belonged to the epidemiologically important serotypes 1/2a and 4b, implying a potential public health risk.
    Food Control 07/2013; 32(1):153–158. DOI:10.1016/j.foodcont.2012.11.032 · 2.82 Impact Factor
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    ABSTRACT: The collagenase cathepsin K has been shown important in the pathogenesis of rheumatoid arthritis (RA). Icariin is the major pharmacologically active flavonol diglycoside of Herba Epimedii, an herb used in Chinese traditional medicine to treat arthritis. We investigated whether icariin can inhibit the protease activity of cathepsin K and its effects on a murine model of collagen-induced arthritis (CIA). Six-week old female BALB/C mice were immunized with type II collagen and treated with vehicle alone icariin (25mg/kg) for 21 days; a control remained untreated. Serum concentrations of type I collagen C-terminal telopeptide (CTX-I) and cartilage oligomeric matrix protein (COMP) and urinary concentrations of deoxypyridinoline (DPD) were measured, and disease severity was assessed. Compared with immunized, untreated mice, immunized icariin-treated mice had significantly lower urinary DPD (~25%, p<0.01) and serum COMP (~11.9%, p<0.01) concentrations, with serum CTX-1 (RatLaps) concentrations being significantly lower in immunized, icariin treated mice than in immunized, vehicle treated (p<0.01) and non-immunized (p<0.005) mice. Icariin also reduced the clinical signs of arthritis. Icariin inhibited cathpesin K activity in vitro and was effective in a mouse model of CIA similar to human RA, suggesting that this agent may have promise in the treatment of patients with RA.
    Phytomedicine: international journal of phytotherapy and phytopharmacology 06/2013; 20(11). DOI:10.1016/j.phymed.2013.04.019 · 2.88 Impact Factor
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    ABSTRACT: Commercial bacterins for Glässers disease are widely used for prevention this disease caused by Haemophilus parasuis, however, the protective efficacy varied depending on the strains and serovars. Bacterial ghosts (BGs) are empty bacterial envelopes, unlike classical bacterins, suffer no denaturing steps during their production. These properties may lead to a superior protection. In this study, a BGs vaccine generated from the Haemophilus parasuis serovar 5 reference strain Nagasaki was prepared and used to inoculate piglets. The efficacy of the BGs vaccine was evaluated by clinical, bacteriological, serological, and post-mortem examinations. Inactivated bacterin (IB) and a placebo control (PC) were compared with the BGs vaccine in this study. The results showed that the piglets inoculated with the BGs vaccine developed a higher antibody activity and higher IFN-γ and IL-4 levels than those vaccinated with IB or the PC group after primary and secondary exposure to the antigens and challenge. The CD4(+) T lymphocytes were observed to increase following secondary immunization in the BGs-vaccinated group more than in the IB (p<0.05) and PC (p<0.05) groups. The CD8(+) T lymphocytes increased dramatically in all three groups after challenge, and the differences between each group all were significant (p<0.05). There were fewer tissue lesions and lower bacterial load in the tissue homogenates observed in the BGs group after challenge. The results suggested that higher CD4(+) T lymphocytes rate and both the CD4(+) MHC-II restricted Th1 type and Th2 type immune responses in the BGs group appear relevant to protection.
    Clinical and vaccine Immunology: CVI 03/2013; 20(6). DOI:10.1128/CVI.00676-12 · 2.37 Impact Factor

Publication Stats

411 Citations
193.20 Total Impact Points

Institutions

  • 2015
    • Kunming University of Science and Technology
      Yün-nan, Yunnan, China
  • 2009–2015
    • Harbin Veterinary Research Institute
      Charbin, Heilongjiang Sheng, China
    • Georgia Health Sciences University
      • Institute of Molecular Medicine and Genetics
      Augusta, Georgia, United States
  • 2014
    • Northeast Agricultural University
      Charbin, Heilongjiang Sheng, China
  • 2000–2014
    • Kunming Institute of Zoology CAS
      Yün-nan, Yunnan, China
  • 2006–2011
    • Chinese Academy of Sciences
      Peping, Beijing, China