• Journal of Microbiology and Biotechnology
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• 제27권10호
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• pp.1727-1735
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• 2017

Hepatitis E virus (HEV) infections cause epidemic or sporadic acute hepatitis, which are mostly self-limiting. However, viral infection in immunocompromised patients and pregnant women may result in serious consequences, such as chronic hepatitis and liver damage, mortality of the latter of which reaches up to 20-30%. Type I interferon (IFN)-induced antiviral immunity is known to be the first-line defense against virus infection. Upon HEV infection in the cell, the virus genome is recognized by pathogen recognition receptors, leading to rapid activation of intracellular signaling cascades. Expression of type I IFN triggers induction of a barrage of IFN-stimulated genes, helping the cells cope with viral infection. Interestingly, some of the HEV-encoded genes seem to be involved in disrupting signaling cascades for antiviral immune responses, and thus crippling cytokine/chemokine production. Antagonistic mechanisms of type I IFN responses by HEV have only recently begun to emerge, and in this review, we summarize known HEV evasion strategies and compare them with those of other hepatitis viruses.

• IMMUNE NETWORK
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• 제14권4호
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• pp.201-206
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• 2014

IL-33 is a member of the IL-1 cytokine family and plays a role in the host defense against bacteria, viruses, and fungi. In this study, we investigated the function of IL-33 and its receptor in in vitro macrophage responses to Candida albicans. Our results demonstrate that pre-sensitization of isolated peritoneal macrophages with IL-33 enhanced their pro-inflammatory cytokine production and phagocytic activity in response to C. albicans. These macrophage activities were entirely dependent on the ST2-MyD88 signaling pathway. In addition, pre-sensitization with IL-33 also increased ROS production and the subsequent killing ability of macrophages following C. albicans challenge. These results indicate that IL-33 may increase anti-fungal activity against Candida through macrophage-mediated resistance mechanisms.

• Asian-Australasian Journal of Animal Sciences
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• 제22권6호
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• pp.885-892
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• 2009

To investigate host defense mechanisms for protecting the mammary gland from mastitis infection, the membrane fraction of mammary tissues from Holstein cows was purified by differential velocity centrifugation, and then the sodium dodecyl sulfate-polyacrylamid gel electrophoresis (SDS-PAGE) separated proteins were identified by ion trap mass spectrometer equipped with a Surveyor high performance liquid chromatography (HPLC) system. A total of 183 proteins were identified. Bioinformatics software was applied to analyse physicochemical characteristics of the identified proteins and to predict biochemical function. These data may provide valuable information to investigate the mechanisms of mammary gland milk secretion and infectious disease, and enable a clear identification of proteins and potential protein targets for therapies.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2017년도 춘계학술발표대회
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• pp.217-219
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• 2017

나날이 증가하는 해킹의 위협에 따라 이를 방어하기 위한 침임 탐지 시스템과 로그 수집 분야에서 많은 연구가 진행되고 있다. 이러한 연구들로 인해 다양한 종류의 침임 탐지 시스템이 생겨났으며, 이는 다양한 종류의 침입 탐지 시스템에서 서로의 단점을 보안할 필요성이 생기게 되었다. 따라서 본 논문에서는 네트워크 기반인 NIDS(Network-based IDS)와 호스트 기반인 HIDS(Host-based IDS)의 장단점을 가진 Hybrid IDS을 구성하기 위해 NIDS와 HIDS의 로그 데이터 통합을 위해 실시간 로그 처리에 특화된 Kafka를 이용하고, 실시간 분석에 Spark Streaming을 이용하여 통합된 로그를 분석하게 되며, 실시간 전송 도중에 발생되는 데이터 유실에 대해 별도로 저장되는 Hadoop의 HDFS에서는 데이터 유실에 대한 보장을 하는 실시간 Hybrid IDS 분석 시스템에 대한 설계를 제안한다.

• Journal of Korean Neurosurgical Society
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• 제44권6호
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• pp.382-384
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• 2008

Gas forming brain abscess is a rare disease caused by Klebsiella pneumoniae occurring in patients with impaired host defense mechanism such as diabetes mellitus or liver cirrhosis. A 59-year-old man with 2-year history of diabetes mellitus and 20-year history of liver cirrhosis presented to the hospital with headache. On the day after admission, severe headache was developed and he deteriorated rapidly. Brain CT showed a non-enhanced mass including multiple air density as well as surrounding edema seen in the right occipital lobe, and isodensity air-fluid level seen in the right lateral ventricle. Despite emergent ventricular drainage and intraventricular and intravenous administration of antibiotics, his condition progressively worsened to sepsis and to death after 5 days. Bacterial culture of blood and ventricular fluids disclosed a Gram (-) rod, Klebsiella pneumoniae. In this report we review the pathogenic mechanism and its management.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.268.2-269
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• 2003

Prostaglandins (PGs) and NO (nitric oxide) are important elements to keep homeostasis and host defense system in human beings. When PGs and NO are overproduced by cyclooxygenase-2(COX-2) and inducible nitric oxide synthase (iNOS), respectively, they can cause chronic inflammation, tissue damage, and carcinogenesis. On this line, we are interested in finding agents that can inhibit the production of PGs and NO from natural products for devloping anti-inflammatory and cancer chemopreventive agents. (omitted)

• International Journal of Oral Biology
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• 제40권4호
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• pp.217-221
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• 2015

Cariogenic Streptococcus mutans encounters a variety of host defense factors produced in oral cavity. Nitric oxide (NO) and NO-mediated reactive nitrogen species are potential antimicrobials of innate immunity that can threaten the fitness of S. mutans in their ecological niches. Streptococcal strategies to detoxify cytotoxic NO, which allow S. mutans to persist in caries or other environments of the oral cavity, remain unknown. In this study, we directly measured NO consumption rates of S. mutans isolated in Korea. Surprisingly, all S. mutans strains were unable to consume exogenous NO efficiently, while an intracellular parasite Salmonella enterica serovar Typhimurium expressing the NO-metabolizing enzyme flavohemoglobin consumed most of the NO. This result suggested that S. mutans has alternative detoxification systems for tolerating NO-induced nitrosative stresses.

• Natural Product Sciences
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• 제2권1호
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• pp.43-47
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• 1996

Macrophages play an important role in host defense against tumors by killing tumor cells. Our work is directed toward studying the effect of the extracts of Salvia plebeia on induction of antitumor activity in macrophages, since it has been usezd as a folk-medicine for the treatment of hepatitis and tumors. The ability of macrophage treated with the plant extracts to inhibit the growth of tumor cells was assessed. The Extracts of the plant induced antitumor activity and could enhance the tumoricidal activity of macrophages when used in combination with $IFN-{\gamma}$. These results suggest that Salvia plebeia extract contain immunomodulatory factors responsible for the induction of the antitumor activity.

• 대한수의학회지
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• 제49권2호
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• pp.167-172
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• 2009

Human granulocytic anaplasmosis (HGA) is caused by the obligate intracellular bacterium Anaplasma (A.) phagocytophilum. Natural killer T (NKT) cells are key players in host defense against various microbial infections. We investigated the role of NKT cells in immune response to A. phagocytophilum infection using NKT-knockout ($J\alpha$18-/-) mice. $J\alpha$18-/- and wild-type (WT) mice were infected with low-passage A. phagocytophilum and assayed for hepatic histopathology and cytokine production during 7 days post-infection. Compared to WT controls, the infected $J\alpha$18 -/- mice had much less histopathologic lesions and less apoptosis through day 7, and lower concentrations of ${IFN\gamma}$ and IL- 12, but not of IL-10. This result suggests that NKT cells are major components in the pathogenesis of HGA.

• 공업화학
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• 제23권5호
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• pp.429-432
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• 2012

최근 항생제에 대한 내성이 빠르게 확산됨에 따라 이를 극복하기 위해 새로운 항생제들을 찾기 위한 노력이 많은 연구자들에 의해 이루어지고 있다. 미생물의 외부공격에 대해 모든 생명체들은 방어물질을 분비하거나 내재하고 있는 데 그 중 하나가 항균 펩타이드이며, 전 세계적으로 활발한 연구가 이루어지고 있고 새로운 차세대 항생제로써 인식 되어진다. 이에 본 총설에서는 항균 펩타이드의 미생물에 대한 항생활성, 작용기작과 개발현황에 대해 고찰하고자 한다.