• Title/Summary/Keyword: Host Defense

검색결과 315건 처리시간 0.025초

Glycogen synthase kinase 3β in Toll-like receptor signaling

  • Ko, Ryeojin;Lee, Soo Young
    • BMB Reports
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    • 제49권6호
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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
    • 한국식물병리학회:학술대회논문집
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    • 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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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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    • 제28권2호
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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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    • 제14권4호
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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.

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

  • 고승범;권태욱
    • 한국전자통신학회논문지
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    • 제17권5호
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    • pp.783-790
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    • 2022
  • SNS와 동영상 플랫폼의 발전은 콘텐츠의 생산과 소비의 활성화를 폭발시키는 계기를 마련하였다. 하지만 Legacy system에서는 Host 기반의 위치 중심의 데이터 전송으로 인해 효율적 운용과 관리에 있어서 태생적 한계가 발생하게 되었다. 이에 대한 대안으로써 콘텐츠 중심 네트워크(CCN, Contents Centric Network)가 연구되었다. 본 논문에서는 CCN 환경에서 실시간 스트리밍 서비스 간 정보제공자와 정보요청자 사이 위치한 중간노드들이 이동 또는 사용 제한 시 정보요청자 측에서 단절 또는 전송 품질의 저하 등의 문제를 해결하고자 무선 수신 세기에 대한 모니터링을 통해 장애 발생 이전 적극적 대응을 통해 안정적 중간노드 관리 메커니즘을 제안한다.

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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    • 제65권5호
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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.

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

  • 박동균
    • 시큐리티연구
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    • 제22호
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    • pp.65-90
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    • 2010
  • 세계사적인 측면에서 볼 때, 국가마다 위기상황은 존재하게 마련이다. 이와 같이 국가가 경험하게 되는 각종 위기 상황은 대부분이 전쟁과 관련된 것들이 많았다. 그러나 최근에는 국가(정부)가 관심을 기울여야 할 위기의 영역이 다양해지고 또한 폭이 넓어졌다. 즉 탈냉전이후 국가가 대비하고, 관리해야 할 위기의 근원과 위협요인들이 급증하기 시작한 것이다. 국제정치의 현재 패러다임으로 볼 때, 세계대전의 위험성은 줄었지만 지역차원의 무장분쟁이나 갈등사례는 오히려 증가했다. 특히 테러는 이제 전쟁 이상의 위협으로 다가오고 있고, 또한 많은 국가에서 여러 형태의 테러가 발생하고 있다. 최근에 올림픽이나 월드컵 등 각종 국제스포츠 행사들이 전세계인들의 주목을 받아가며 개최되고 있다. 이와 같이, 국제 스포츠 행사를 개최하고 있는 개최국들은 빈발하고 있는 국제 테러 및 안전사고 등에 대비하여 참가인원, 시설, 행사 및 경기에 대한 안전 활동에 집중하고 있다. 이는 대회 기간 중에 국제테러, 안전사고 등 위기상황이 발생하게 되면, 대회 자체가 실패한 대회로 평가받는 것은 물론 개최국가의 국제 신뢰도 저하가 필연적으로 수반되기 때문이다. 이러한 맥락에서, 본 연구는 최근 세계화 시대에 다양하게 개최되고 있는 각종 국제스포츠 행사에 대한 테러대응 사례를 분석하여 안전관리 대책을 제시하였다. 즉, 향후 동북아 세계의 중심국가로서의 각종 국제스포츠 행사시 민간경비 경호 업체가 경찰력이나 공안기관과의 협조를 이루어 보다 완벽한 경호경비 대테러 활동을 수행하기 위한 정책적 방향 제시에 중점을 두고 있다. 한국은 86 아시안게임, 88 올림픽, 2002 월드컵 등 다양한 국제스포츠 행사를 주최한 경험이 있다. 또한 앞으로 2011년 대구국제육상경기대회, 인천 아시안게임 등 전세계인들이 주목하는 국제행사를 준비하고 있다. 이러한 행사준비는 국가적인 차원에서만 대응해서는 안 된다. 모든 국민들이 언제, 어디서도 테러의 목표물이나 대상이 될 수 있다는 가정하에서 이에 대비한다면 테러로부터의 피해를 최소화할 수 있기 때문이다.

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

  • 안병준;이재구
    • 약학회지
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    • 제30권5호
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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 감염과 비타민 C: 과거, 현재, 미래 (Helicobacter pylori Infection and Vitamin C: Past, Present and Future Perspectives)

  • 윤희상;이광호
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • 제11권sup1호
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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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    • 제36권4호
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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.