• Title/Summary/Keyword: host defense

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Glycogen synthase kinase 3β in Toll-like receptor signaling

  • Ko, Ryeojin;Lee, Soo Young
    • BMB Reports
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    • v.49 no.6
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    • pp.305-310
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    • 2016
  • Toll-like receptors (TLRs) play a critical role in the innate immune response against pathogens. Each TLR recognizes specific pathogen-associated molecular patterns, after which they activate the adaptor protein MyD88 or TRIF-assembled signaling complex to produce immune mediators, including inflammatory cytokines and type I IFNs. Although the activation of TLR is important for host defense, its uncontrolled activation can damage the host. During the past decade, numerous studies have demonstrated that GSK3β is a key regulator of inflammatory cytokine production in MyD88-mediated TLR signaling via TLR2 and TLR4. Recently, GSK3β has also been implicated in the TRIF-dependent signaling pathway via TLR3. In this review, we describe current advances on the regulatory role of GSK3β in immune responses associated with various TLRs. A better understanding of the role of GSK3β in TLR signaling might lead to more effective anti-inflammatory interventions.

Characterization of Pathogenesis and Plant Defence-related Genes Against Potato virus X infection empolying Potato X virus expresssin vector

  • Park, Mi-Ri;Kwon, Sun-Jung;Kim, Kook-Hyung
    • Proceedings of the Korean Society of Plant Pathology Conference
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    • 2003.10a
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    • pp.74.1-74
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    • 2003
  • Differential display (DD) of mRNA is a technique in which mRNA species expressed by a cell population are reverse transcribed and then amplified by many separate polymerase chain reactions (PCR). Using DD-RT-PCR we obtained many genes that expressed differentially in healthy and PVX-infected Nicotiana benthamima, using total RNAs extracted from healthy and PVX-infected N. benthamiana plants. Three hundred and twenty-five DNA fragments isolated from DD-RT-PCR were cloned and sequenced for further characterization. Several host genes including SKPI-like protein, heat shock transcription factor and Avr9/Cf-9 rapidly elicited protein were selected to obtain full-length open reading frame and to characterize their potential involvement in virus disease development and/or host's defense against virus infection employing PVX-based expression vector. Transcrips from wild-type and clones containing each selected gene were inoculated onto N. benthamiana Levels of virus replication were confirmedby RT-PCR and RNA blot analysis, Expression profiles and potential role(s) of selected genes upon PVX infection will be discussed.

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Epigenetic Control of Oxidative Stresses by Histone Acetyltransferases in Candida albicans

  • Kim, Jueun;Park, Shinae;Lee, Jung-Shin
    • Journal of Microbiology and Biotechnology
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    • v.28 no.2
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    • pp.181-189
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    • 2018
  • Candida albicans is a major pathogenic fungus in humans, and meets at first the innate immune cells, such as macrophages, in its host. One important strategy of the host cell to kill C. albicans is to produce reactive oxygen species (ROS) by the macrophages. In response to ROS produced by the macrophages, C. albicans operates its defense mechanisms against them by expressing its oxidative stress response genes. Although there have been many research studies explaining the specific transcription factors and the expression of the oxidative stress genes in C. albicans, the regulation of the oxidative stress genes by chromatin structure is little known. Epigenetic regulation by the chromatin structure is very important for the regulation of eukaryotic gene expression, including the chromatin structure dynamics by histone modifications. Among various histone modifications, histone acetylation is reported for its direct relationship to the regulation of gene expression. Recent studies reported that histone acetyltransferases regulate genes to respond to the oxidative stress in C. albicans. In this review, we introduce all histone acetyltransferases that C. albicans contains and some papers that explain how histone acetyltransferases participate in the oxidative stress response in C. albicans.

Transcriptional Responses of Human Respiratory Epithelial Cells to Nontypeable Haemophilus influenzae Infection Analyzed by High Density cDNA Microarrays

  • Lee, Ji-Yeon;Lee, Na-Gyong
    • Journal of Microbiology and Biotechnology
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    • v.14 no.4
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    • pp.836-843
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    • 2004
  • Nontypeable H. influenzae (NTHi), a Gram-negative obligate human pathogen, causes pneumonia, chronic bronchitis, and otitis media, and the respiratory epithelium is the first line of defense that copes with the pathogen. In an effort to identify transcriptional responses of human respiratory epithelial cells to infection with NTHi, we examined its differential gene expression using high density cDNA microarrays. BEAS-2B human bronchial epithelial cells were exposed to NTHi for 3 hand 24 h, and the alteration of mRNA expression was analyzed using microarrays consisting of 8,170 human cDNA clones. The results indicated that approximately 2.6% of the genes present on the microarrays increased in expression over 2-fold and 3.8% of the genes decreased during the 24-h infection period. Upregulated genes included cytokines (granulocyte-macrophage colony stimulating factor 2, granulocyte chemotactic protein 2, IL-6, IL-10, IL-8), transcription factors (Kruppel-like factor 7, CCAAT/enhancer binding protein $\beta$, E2F-1, NF-$\kappa$B, cell surface molecules (CD74, ICAM-1, ICAM-2, HLA class I), as well as those involved in signal transduction and cellular transport. Selected genes were further confirmed by reverse-transcription-PCR. These data expand our knowledge of host cellular responses during NTHi infection and should provide a molecular basis for the study of host-NTHi interaction.

Intermediate Node Mobility Management Technique by Real-Time Monitoring in CCN Environment (CCN 환경에서 실시간 모니터링에 의한 중간노드 이동성 관리 기법)

  • Ko, Seung-Beom;Kwon, Tae-Wook
    • The Journal of the Korea institute of electronic communication sciences
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    • v.17 no.5
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    • pp.783-790
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    • 2022
  • The development of SNS and video platforms provided an opportunity to explode the activation of content production and consumption. However, in the legacy system, due to the host-based location-oriented data transmission, there are inherent limitations in efficient operation and management. As an alternative to this, a Contents Centric Network (CCN) was studied. In this paper, when intermediate nodes located between the information provider and the information requester between the real-time streaming services in the CCN environment move or restrict their use, failure through monitoring of wireless reception strength to solve problems like disconnection of transmission quality at the information consumer. We propose a stable intermediate node management mechanism through active response before occurrence.

Complete genome sequence of Pediococcus acidilactici CACC 537 isolated from canine

  • Jung-Ae Kim;Hyun-Jun Jang;Dae-Hyuk Kim;Youn Kyoung Son;Yangseon Kim
    • Journal of Animal Science and Technology
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    • v.65 no.5
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    • pp.1105-1109
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    • 2023
  • Pedi coccus acidilactici CACC 537 was isolated from canine feces and reported to have probiotic properties. We aimed to characterize the potential probiotic properties of this strain by functional genomic analysis. Complete genome sequencing of P. acidilactici CACC 537 was performed using a PacBio RSII and Illumina platform, and contained one circular chromosome (2.0 Mb) with a 42% G + C content. The sequences were annotation revealed 1,897 protein-coding sequences, 15 rRNAs, and 56 tRNAs. It was determined that P. acidilactici CACC 537 genome carries genes known to be involved in the immune system, defense mechanisms, restriction-modification (R-M), and the CRISPR system. CACC 537 was shown to be beneficial in preventing pathogen infection during the fermentation process, help host immunity, and maintain intestinal health. These results provide for a comprehensive understanding of P. acidilactici and the development of industrial probiotic feed additives that can help improve host immunity and intestinal health.

The Counter-Terrorism Measures for International Sports Events in Korea (한국의 국제스포츠 행사에 대한 대 테러 전략)

  • Park, Dong-Kyun
    • Korean Security Journal
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    • no.22
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    • pp.65-90
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    • 2010
  • Recently, alarmed by the frequent international terrorism or safety accidents, the host countries of world sports events are focusing on security activities for the sake of the participants, facilities, events and competitions. They are alarmed because in case any happenings like international terrorism or safety accident, the contest itself can be criticized to be a failure as much as the international reliability of the host nation may well crash. We can see that any failure in coping with terrorism or safety matters can lead to a nation-wise crisis in the case of Indonesia where the October 12th of 2002 terrorist bomb attack in Bali damaged the image of the nation followed by the similar case in Philippine (Oct. 20th, 2002) where the same terrorist attack dramatically scared away the tourists to the nation. Korea is scheduled to hold the World Championship in Athletics in Daegu Metropolitan City in 2011. Also, it is slated to host various world sports events such as Yeosu International Exposition and Incheon Asian Games. In these contexts, this study analyzes counter-terrorism cases related with the recent international sports events that have been organized in a variety of manners in the era of globalization. This study aims to show alternatives for the safety management in these events. In other words, it is focusing on giving directions to the safety policies of the nation -which may become the future hub of north-east Asia and the world - for more perfect guard and defense, and counter-terrorism activities in all the conferences, sports events and international festivals where any private defense and guard companies are allowed to cooperate with the police force or public security agencies.

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Anthelmintic Natural Products against Clonorchis sinensis and the Analogues (간디스토마에 작용하는 천연물 및 그 유사체)

  • 안병준;이재구
    • YAKHAK HOEJI
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    • v.30 no.5
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    • pp.253-265
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    • 1986
  • Among 230 species of herbal drugs screened, thirty one show the anthelmintic activities in vitro against Clonorchis sinensis, the chinese liver fluke. The active substances have been isolated and their structures identified. Some of the active substances and their derivatives have been synthesized, followed by anthelmintic activity tests. The extracts from the active drugs cause damages in organs of the adult worm in the hepatic duct of rabbit. Some fresh water fish, which function as bad hosts for the fluke, excrete defense substances against the cercaria of the fluke. The defense substances have been isolated from Cyprinus carpio and Cyprinus carpio nudus, followed by structural identification. The results are summarized as follows: l) The bark of Machilus thunbergii as well as the seed of Schizandra chinensis contain meso-dihydro-guaiaretic acid as the anthelmintic component. Among derivatives synthesized, 4-phenyl-1-((3, 4-dihydroxyphenyl)-, 4-phenyl-1-(3-hydroxy-4-methoxy phenyl)-and 4-phenyl-1-(4-hydroxy-3-methoxy phenyl)-2, 3-dimethyl butanes show considerable activities. Administration of the bark extract mainly damages the bladder of the adult worm. 2) The active substance from the roasted fruit of Prunus mume is 2-hydroxymethylfurfural. This substance is produced during the roasting process. Administration of the fruitextract causes a damage of the bladder of the adult worm. 3) The active substance from the root of Scutellaria baicalensis is 5.2'-dihydroxy-6, 7, 8, 6'-tetramethoxyflavone. 4) Beside alantolactone, a very strong anthelmintic component is contained in the root of Inula helenium. Administration of the root extract causes irreversible damage on the worm, affecting mainly the reproductive organs. 5) The cercaricidal substances from the epidermis of C. carpio and C. carpio nudus are ethyl linoleate and linoleic acid, respertively. 6) The cercaricidal substances from various kinds of fresh water fish have different $R_f$ values, implying that the defense substances are species-specific. Unexpectedly, the fish with good host function, for example Pseudorasbora parva, excrete the defense substances, too. The defense substances are possibly organ-specific in individual species; the organs essenstial for the existence of the species excrete the defense substances, allowing other parts to be invaded by the cercaria. 7) The cercaricidal fraction of Carassius carassius is detected only in the fish which have been collected during the summer time from May to September, Its secretion is not dependent on water temperature. Thus, it seems to be possible that the secretion of the defense substance would be stimulated through a contact between the fish and cercaria.

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Helicobacter pylori Infection and Vitamin C: Past, Present and Future Perspectives (Helicobacter pylori 감염과 비타민 C: 과거, 현재, 미래)

  • Youn, Hee-Shang;Rhee, Kwang-Ho
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.11 no.sup1
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    • pp.83-92
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    • 2008
  • Helicobacter pylori is the causative agent of chronic gastritis and has a role in the pathogenesis of peptic ulcer diseases, and gastric cancer. There have been reports suggesting a close link between these gastroduodenal disorders and a state of vitamin C deficiency. In this paper, the past, present and future perspectives on H. pylori infection and vitamin C will be discussed under the following view points. Since the ecological niche of H. pylori is the mucus layer and intercellular junctions of the gastric epithelium, the various kinds of host inflammatory cells motivated by the local and systemic immune responses cannot eliminate the microorganisms. When the invading foreign body is not removed, despite full activation of defense mechanisms, adverse consequences of the immune responses develop on the host gastric mucosa. The reasons for the body vitamin C depletion could be explained as follows; 1) the increased vitamin C consumption by increased oxygen free radical production through the prolonged hypersensitivity reactions in the gastric mucosa, 2) the increased vitamin C oxidation by the nitrite which is formed from nitrate reduction by the intragastric bacteria proliferated in the hypochlorhydric gastric cavity, 3) the strong ${\gamma}$-glutamyltranspeptidase activity of H. pylori which depletes the glutathiones in gastric mucosa. Depletion of glutathiones in the stomach favors irreversible oxidative destruction of ascorbic acid. Both persistent inflammatory burdens in the stomach by H. pylori and resultant vitamin C depletions synergistically and uninhibitedly might aggravate the hypothetical sequence of gastric carcinogenesis: atrophic gastritis${\rightarrow}$intestinal metaplasia${\rightarrow}$dysplasia${\rightarrow}$gastric adenocarcinoma. High intake of vitamin C could reverse the hypothetical sequence of the gastric carcinogenesis via direct and indirect effects on H. pylori and host-parasite relationships.

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Ultrastructures of Colletotrichum orbiculare in the Leaves of Cucumber Plants Expressing Induced Systemic Resistance Mediated by Glomus intraradices BEG110

  • Jeun, Yong-Chull;Lee, Yun-Jung;Kim, Ki-Woo;Kim, Su-Jung;Lee, Sang-Woo
    • Mycobiology
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    • v.36 no.4
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    • pp.236-241
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    • 2008
  • The colonization of an arbuscular mycorrhizal fungus Glomus intraradices BEG110 in the soil caused a decrease in disease severity in cucumber plants after fungal inoculation with Colletotrichum orbiculare. In order to illustrate the resistance mechanism mediated by G. intraradices BEG110, infection patterns caused by C. orbiculare in the leaves of cucumber plants and the host cellular responses were characterized. These properties were characterized using transmission electron microscopy on the leaves of cucumber plants grown in soil colonized with G. intraradices BEG110. In the untreated plants, inter- and intra-cellular fungal hyphae were observed throughout the leaf tissues during both the biotrophic and necrotrophic phases of infection. The cytoplasm of fungal hyphae appeared intact during the biotrophic phase, suggesting no defense response against the fungus. However, several typical resistance responses were observed in the plants when treated with G. intraradices BEG110 including the formation of sheaths around the intracellular hyphae or a thickening of host cell walls. These observations suggest that the resistance mediated by G. intraradices BEG110 most often occurs in the symplast of the host cells rather than in the apoplast. In addition, this resistance is similar to those mediated by biotic inducers such as plant growth promoting rhizobacteria.