• Title/Summary/Keyword: host cells

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Host Cell-Intrinsic Antiviral Defense Induced by Type I Interferons

  • Asano, Atsushi
    • Korean Journal of Agricultural Science
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    • v.35 no.2
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    • pp.177-182
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    • 2008
  • Type I Interferons (IFNs) are potent antiviral cytokines that modulate both innate immunity and adaptive immunity. Type I IFNs are immediately induced by viral infection, and stimulate production of a broad range of gene products such as double-stranded RNA-activated protein kinase (PKR), 2' 5'-oligoadenylate synthetase (OAS)/RNaseL and Mx GTPases. These proteins inhibit viral replication in host cells. Type I IFNs, in turn, lead to antiviral state at early phase of viral infection. We provide an overview of the knowledge of IFN-inducible antiviral proteins conserved in vertebrates.

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US28, a Virally-Encoded GPCR as an Antiviral Target for Human Cytomegalovirus Infection

  • Lee, Sungjin;Chung, Yoon Hee;Lee, Choongho
    • Biomolecules & Therapeutics
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    • v.25 no.1
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    • pp.69-79
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    • 2017
  • Viruses continue to evolve a new strategy to take advantage of every aspect of host cells in order to maximize their survival. Due to their central roles in transducing a variety of transmembrane signals, GPCRs seem to be a prime target for viruses to pirate for their own use. Incorporation of GPCR functionality into the genome of herpesviruses has been demonstrated to be essential for pathogenesis of many herpesviruses-induced diseases. Here, we introduce US28 of human cytomegalovirus (HCMV) as the best-studied example of virally-encoded GPCRs to manipulate host GPCR signaling. In this review, we wish to summarize a number of US28-related topics including its regulation of host signaling pathways, its constitutive internalization, its structural and functional analysis, its roles in HCMV biology and pathogenesis, its proliferative activities and role in oncogenesis, and pharmacological modulation of its biological activities. This review will aid in our understanding of how pathogenic viruses usurp the host GPCR signaling for successful viral infection. This kind of knowledge will enable us to build a better strategy to control viral infection by normalizing the virally-dysregulated host GPCR signaling.

Evaluation of Mutagenicity with Gamgung-tang Using Host-Mediated Assay (Host-Mediated Assay를 이용한 감궁탕의 돌연변이원성 평가)

  • Shon, Yun-Hee;Kim, Cheorl-Ho;Nam, Kyung-Soo
    • Korean Journal of Pharmacognosy
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    • v.36 no.2 s.141
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    • pp.93-96
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    • 2005
  • Mutagenicity of Gamgung-tang (GGT) was tested using in vitro S-9 mixture in vitro host-mediated assay with Salmonella typhimurium. In the previous reports, GGT was tested for the safety using Ames(-S-9), Bacillus subtilis Rec, and umu gene expression mutagenicity tests. Mutagenic activity in any assays we tested was not found. In this report, we further investigated safety of GGT after metabolic activation in vivo. Ames test with S-9 mixture and host-mediated assay with Salmonella typhimurium TA98 were used to identify metagenic property of GGT. GGT was administered 3 times with i.m. to Balb/c mice did not induced mutagenic effect in Salmonella typhimurium TA98 recovered from the liver after 3.5h with i.p. treatment. Over the entire dose range $(3{\sim}150mg/mouse)$ tested no toxicity was detected to the bacterial cells. These results suggest that there was no DNA damage and mutagenicity by GGT.

Avian Somitic Cell Chimeras Using Surrogate Eggshell Technology

  • Mozdziak, Paul E.;Hodgson, Dee;Petitte, James N.
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.6
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    • pp.801-806
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    • 2008
  • A classical technique to study somitic cell fate is to employ the cross-transplantation of quail somites into a chick host. The densely stained nucleoli of the quail cells makes it possible to assess the fate of the donor quail cells in the chick host. Classical somite transplantation techniques have been hampered by the necessity of a small opening in the chick eggshell, difficulty in hatching the offspring and interspecies post-hatch graft rejection. With the advent of transgenic chicken technology, it is now possible to use embryos from transgenic chickens expressing reporter genes in somite cross-transplantation techniques to remove any possibility of interspecies graft rejection. This report describes using a surrogate eggshell system in conjunction with transgenic chick:chick somitic cell cross-transplantation to generate viable chimeric embryos and offspring. Greater than 40% of manipulated embryos survive past 10 days of incubation, and ~80% of embryos successfully cultured past 10 days of incubation hatched to produce viable offspring.

Extracellular Production of Alpha-Interferon by Recombinant Escherichia coli: Part II. The Growth Behavior of the Recombinant Cells (유전자 재조합 대장균을 사용한 Alpha-interferon의 생산과 분비: 제2부. 재조합 균주의 생장특성)

  • 노갑수;최차용
    • KSBB Journal
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    • v.5 no.3
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    • pp.195-200
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    • 1990
  • The growth behavior of recombinant Escherichia coli cells having plasmid pIF-III-B, which carries human alpha-interferon gene under the control of lpp promoter, lac promoter and lac operator, was studied by using of various E. coli host strains. Expression of the alpha-IFN gene is controllable by using inducer IPTG because the plasmid also contains lacI gene which produces lac regressors. The repressors block the transcription of alpha-IFN gene. There were considerable differences in cell growth according to the host strains used. Cell growth was inhibited not only by plasmid pIF-III-B itself but also by the induction of alph-a-IFN gene expression. Growth inhibition caused by the plasmid itself was more serious than that caused by the induction of alpha-IFN gene expression.

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Glutathione Reductase and Thioredoxin Reductase: Novel Antioxidant Enzymes from Plasmodium berghei

  • Kapoor, Gaurav;Banyal, Harjeet Singh
    • Parasites, Hosts and Diseases
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    • v.47 no.4
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    • pp.421-424
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    • 2009
  • Malaria parasites adapt to the oxidative stress during their erythrocytic stages with the help of vital thioredoxin redox system and glutathione redox system. Glutathione reductase and thioredoxin reductase are important enzymes of these redox systems that help parasites to maintain an adequate intracellular redox environment. In the present study, activities of glutathione reductase and thioredoxin reductase were investigated in normal and Plasmodium berghei-infected mice red blood cells and their fractions. Activities of glutathione reductase and thioredoxin reductase in P. berghei-infected host erythrocytes were found to be higher than those in normal host cells. These enzymes were mainly confined to the cytosolic part of cell-free P. berghei. Full characterization and understanding of these enzymes may promise advances in chemotherapy of malaria.

Molecular and Cellular Mechanisms of Syndecans in Tissue Injury and Inflammation

  • Bartlett, Allison H.;Hayashida, Kazutaka;Park, Pyong Woo
    • Molecules and Cells
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    • v.24 no.2
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    • pp.153-166
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    • 2007
  • The syndecan family of heparan sulfate proteoglycans is expressed on the surface of all adherent cells. Syndecans interact with a wide variety of molecules, including growth factors, cytokines, proteinases, adhesion receptors and extracellular matrix components, through their heparan sulfate chains. Recent studies indicate that these interactions not only regulate key events in development and homeostasis, but also key mechanisms of the host inflammatory response. This review will focus on the molecular and cellular aspects of how syndecans modulate tissue injury and inflammation, and how syndecans affect the outcome of inflammatory diseases in vivo.

Helicoverpa armigera Nucleopolyhedrovirus ORF80 Encodes a Late, Nonstructural Protein

  • Wang, Dun;Zhang, Chuan-Xi
    • BMB Reports
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    • v.40 no.1
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    • pp.65-71
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    • 2007
  • The Helicoverpa armigera nucleopolyhedrovirus (HearNPV) ORF80 (ha80) has 765 bp encoding a protein with approximately 254 amino acids and a predicted molecular weight of 30.8 kDa. Homologues of ha80 are found in most baculovirus sequences, including those from lepidopteran NPVs, lepidopteran granuloviruses (GVs), hymenopteran baculoviruses, and one dipteran baculovirus, yet their functions remain unclear. In this study we characterized ha80, and showed that it was transcribed late in infected host cells (HzAM1). The product of ha80 was a 31 kDa protein that was not a structural protein of budded virus (BV) or occlusion-derived virus (ODV) particles. Ha80 was first detected in the cytoplasm of infected HzAM1 cells at 12 h p.i., and was observed in the nucleus at later stages of infection, suggesting that it may be involved in transporting viral proteins into the host cell nucleus or play its roles in the nucleus.

Proteomic Identification and Characterization of Vibrio vulnificus Proteins Induced upon Exposure to INT-407 Intestinal Epithelial Cells

  • Oh, Man-Hwan;Jeong, Hee-Gon;Choi, Sang-Ho
    • Journal of Microbiology and Biotechnology
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    • v.18 no.5
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    • pp.968-974
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    • 2008
  • Proteomic analysis led to identification of the proteins of Vibrio vulnificus that were induced upon exposure to INT-407 cells, and 7 of which belong to the functional categories such as amino acid transport/metabolism, nucleotide transport/metabolism, posttranslational modification/protein turnover/chaperones, and translation. Among the genes encoding the host-induced proteins, disruption of purH, trpD, tsaA, and groEL2 resulted in reduced cytotoxicity. The purH, trpD, and tsuA mutants showed impaired growth in the INT-407 lysate; however, the growth rate of the groEL2 mutant was not significantly changed, indicating that the possible roles of the host-induced proteins in the virulence of V. vulnificus are rather versatile.

Stable Isotope Labeling of Proteins in Mammalian Cells

  • Lee, KyungRyun;Lee, Jung Ho
    • Journal of the Korean Magnetic Resonance Society
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    • v.24 no.3
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    • pp.77-85
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    • 2020
  • Stable isotope enrichment in proteins is necessary for high-resolution nuclear magnetic resonance (NMR) experiments. Although methods for 13C, 15N and 2H-enrichment in prokaryotic cells are well established, full processing and correct folding of complex protein systems require higher organisms as the expression host. In the present study, we review recent efforts to enrich stable isotopes in mammalian cells for protein NMR studies.