• Title/Summary/Keyword: Defense mechanism

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Pathogenesis and Host Interaction of Foot-and-mouth Disease (구제역의 병인론과 숙주와의 상호작용)

  • Park, Jong-Hyeon;Lee, Kwang-Nyeong;Kim, Su-Mi;Ko, Young-Joon;Lee, Hyang-Sim;Cho, In-Soo
    • Journal of Veterinary Clinics
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    • v.28 no.1
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    • pp.113-121
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    • 2011
  • Foot-and-mouth disease (FMD) is a severe vesicular disease of cloven-hoofed animals including domesticated ruminants and pigs. Acute clinical signs may be mild in sheep and goats but are associated with lameness in pigs and mouth lesions with vesicles in cattle. The required condition for a successful pathogen appears to be the ability to counteract both the host innate and adaptive immune response. FMD virus (FMDV) inhibits the induction of antiviral molecules and interferes with the secretory pathway in the infected cell. The surface expression of Major Histocompatibility Complex (MHC) class I molecules is reduced in infected cells. Thus, the ability of the host to recognize and eliminate virus infected cells is decreased. Furthermore, FMDV infection results in a rapid, but transient lymphopenia, reducing the number of T and B cells, and affecting T cell function. The virus appears to premature apoptosis-mediated cell death because it has a very short replication cycle and is able to rapidly produce large amounts of virus. FMDV engages the host protective response at multiple steps to ensure its effective replication and pathogenesis. This review describes the recent pathological and immunological studies to overcome the powerful abilities of FMDV to counteract defense mechanism of host.

Vitamin C Up-regulates Expression of CD80, CD86 and MHC Class II on Dendritic Cell Line, DC-1 Via the Activation of p38 MAPK

  • Kim, Hyung Woo;Cho, Su In;Bae, Seyeon;Kim, Hyemin;Kim, Yejin;Hwang, Young-Il;Kang, Jae Seung;Lee, Wang Jae
    • IMMUNE NETWORK
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    • v.12 no.6
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    • pp.277-283
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    • 2012
  • Vitamin C is an essential water-soluble nutrient which primarily exerts its effect on host defense mechanisms and immune homeostasis, but the mechanism related to immune-potentiation is poorly understood. Since dendritic cells (DCs) are known as a potent antigen presenting cell (APC) that could enhance the antigen specific immune responses, we investigate the effects of vitamin C on activation of DCs and its related mechanism by using dendritic cell lines, DC-1. First, we found that there was no damage on DC-1 by 2.5 mM of vitamin C. In the presence of vitamin C, the expression of CD80, CD86, and MHC molecules was increased, but it was decreased by the pre-treatment of SB203580, p38 MAPK-specific inhibitor. We confirmed the phosphorylation of p38 MAPK was increased by the treatment of vitamin C. Taken together, these results suggest that vitamin C could enhance the activity of dendritic cells via the up-regulation of the expression of CD80, CD86, and MHC molecules and the activation of p38 MAPK is related to this process.

Gene Expression Analysis for Statin-induced Cytotoxicity from Rat Primary Hepatocytes

  • Ko, Moon-Jeong;Ahn, Joon-Ik;Shin, Hee-Jung;Kim, Hye-Soo;Chung, Hye-Joo;Jeong, Ho-Sang
    • Genomics & Informatics
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    • v.8 no.1
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    • pp.41-49
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    • 2010
  • Statins are competitive inhibitors of hydroxy-3-methyl glutaryl coenzyme A (HMG-CoA) reductase and used most frequently to reduce plasma cholesterol levels and to decrease cardiovascular events. However, statins also have been reported to have undesirable side effects such as myotoxicity and hepatotoxicity associated with their intrinsic efficacy mechanisms. Clinical studies recurrently reported that statin therapy elevated the level of liver enzymes such as ALT and AST in patients suggesting possible liver toxicity due to statins. This observation has been drawn great attention since statins are the most prescribed drugs and statin-therapy was extended to a larger number of high-risk patients. Here we employed rat primary hepatocytes and microarray technique to understand underlying mechanism responsible for statin-induced liver toxicity on cell level. We isolated genes whose expressions were commonly modulated by statin treatments and examined their biological functions. It is of interest that those genes have function related to response to stress in particular immunity and defense in cells. Our study provided the basic information on cellular mechanism of statin-induced cytotoxicity and may serve for finding indicator genes of statin -induced toxicity in rat primary hepatocytes.

Study of Separation Mechanism According to the Constraint Condition of Explosive Bolts (폭발볼트의 구속환경에 따른 분리메커니즘 연구)

  • Jeong, Donghee;Lee, Youngwoo
    • Journal of the Korean Society of Propulsion Engineers
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    • v.20 no.2
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    • pp.67-74
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    • 2016
  • Explosive bolt is one of separation device that uses high explosive charge, and is separated by pressure formed by an explosion and the resulting shock waves. Explosive bolt having such a mechanism would have to be designed to minimize shock and debris formation generated during separation. In this study, separation tests were carried out with distance as variable for restraining the explosive bolt (Air Gap). Bolt release and its separating shape with variation of air gap is observed, and we used accelerometer to measure the shock wave transmitted through a bound object. In addition, separation behavior of explosive bolt is analyzed using ANSYS AUOTODYN program. By comparing the results of previously performed experiments and analysis, we could confirm the effects of air gap to the release behavior of explosive bolt, and decide optimum constraining environment for specific separation bolts.

Yangkyuksanhwa-tang effected to Atopic Dermatitis (양격산화탕(凉膈散火湯)이 Atopy 피부염(皮膚炎)에 미치는 영향(影響))

  • Yun, Bo-Hyun;Park, Seong-Sik
    • Journal of Sasang Constitutional Medicine
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    • v.16 no.2
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    • pp.84-98
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    • 2004
  • 1. Objectives Yangkyuksanhwa-tang is used mush in pruritus and dermatopathy of Soyangin. It is suggested this prescription is effective on atopy dermatitis. 2. Methods For observation of Yangkyuksanhwa-tang effected to atopic dermatitis, extract of Yangkyuksanhwa-tang has been dispensed to the stratum corneum of epithelium in dermatome of murine after making damage to its defense mechanism against fat and causing atopic dermatitis artificially. After that, the change in outer dermatome and minute mechanism of epidermis, the change of eosinophil, the change in distribution of soybean agglutinin, the change in distribution of fat and ceramide in stratum corneum, the change in inflammation in dermatome, the change of cell accrementition and apoptosis, and the effect on anaphylaxis and Staphylococcus aureus was observed. 3. Results After administration of Yangkyuksanhwa-tang, severe skin damage such as eczema and psoriasis, that was observed in the case of atopy dermatitis, was decreased and the increase of eosinophil in serum was suppressed. Lipid lamella was recovered, so epidermal demage was relieved. The distribution of HSP70 in the outer skin was decreased. Yangkyuksanhwa-tang suppressed activation of $NF-_{\kappa}B$ p50, induced CD11/18b not to be generated, and suppressed inflammatory response of skin. Anaphylaxis and groth of Staphylococcus aureus was suppressed. 4. Conclusions Yangkyuksanhwa-tang decreased skin damage of atopy dermatitis. It has antibiosis about Staphylococcus aureus, it can be medicinal substances on atopy dermatitis. In addition, it is possible that it can be medicinal substances on regional skin allergy.

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A Study on Methodology for Standardized Platform Design to Build Network Security Infrastructure (네트워크 보안 인프라 구성을 위한 표준화된 플랫폼 디자인 방법론에 관한 연구)

  • Seo, Woo-Seok;Park, Jae-Pyo;Jun, Moon-Seog
    • The Journal of the Korea institute of electronic communication sciences
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    • v.7 no.1
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    • pp.203-211
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    • 2012
  • Network security infrastructure is constantly developing based on the combination and blending of various types of devices. From the form of distributed control, the phased defense policy such as fire walls, virtual private communication network, invasion prevention system, invasion detection system, corporate security management, and TSM (Telebiometrics System Mechanism), now it consolidates security devices and solutions to be developed to the step of concentration and artificial intelligence. Therefore, this article suggests network security infrastructure design types concentrating security devices and solutions as platform types and provides network security infrastructure design selecting methodology, the foundational data to standardize platform design according to each situation so as to propose methodology that can realize and build the design which is readily applied and realized in the field and also can minimize the problems by controlling the interferences from invasion.

Investigating the Induced Systemic Resistance Mechanism of 2,4-Diacetylphloroglucinol (DAPG) using DAPG Hydrolase-Transgenic Arabidopsis

  • Chae, Dae-Han;Kim, Da-Ran;Cheong, Mi Sun;Lee, Yong Bok;Kwak, Youn-Sig
    • The Plant Pathology Journal
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    • v.36 no.3
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    • pp.255-266
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    • 2020
  • Plant immune responses can be triggered by chemicals, microbes, pathogens, insects, or abiotic stresses. In particular, induced systemic resistance (ISR) refers to the activation of the immune system due to a plant's interaction with beneficial microorganisms. The phenolic compound, 2,4-diacetylphloroglucinol (DAPG), which is produced by beneficial Pseudomonas spp., acts as an ISR elicitor, yet DAPG's mechanism in ISR remains unclear. In this study, transgenic Arabidopsis thaliana plants overexpressing the DAPG hydrolase gene (phlG) were generated to investigate the functioning of DAPG in ISR. DAPG was applied onto 3-week-old A. thaliana Col-0 and these primed plants showed resistance to the pathogens Botrytis cinerea and Pseudomonas syringae pv. tomato DC3000. However, in the phlG transgenic A. thaliana, the ISR was not triggered against these pathogens. The DAPG-mediated ISR phenotype was impaired in transgenic A. thaliana plants overexpressing phlG, thus showing similar disease severity when compared to untreated control plants. Furthermore, the DAPG-treated A. thaliana Col-0 showed an increase in their gene expression levels of PDF1.2 and WRKY70 but this failed to occur in the phlG transgenic lines. Collectively, these experimental results indicate that jasmonic acid/ethylene signal-based defense system is effectively disabled in phlG transgenic A. thaliana lines.

Characteristics of AlN Thin Films by Magnetron Sputtering System Using Reactive Gases of N2 and NH3 (N2와 NH3 반응성가스를 사용하여 마그네트론 스퍼터링법으로 제작한 AlN박막의 특성)

  • Han, Chang-Suk
    • Korean Journal of Materials Research
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    • v.25 no.3
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    • pp.138-143
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    • 2015
  • Aluminum nitride, a compound semiconductor, has a Wurtzite structure; good material properties such as high thermal conductivity, great electric conductivity, high dielectric breakdown strength, a wide energy band gap (6.2eV), a fast elastic wave speed; and excellent in thermal and chemical stability. Furthermore, the thermal expansion coefficient of the aluminum nitride is similar to those of Si and GaAs. Due to these characteristics, aluminum nitride can be applied to electric packaging components, dielectric materials, SAW (surface acoustic wave) devices, and photoelectric devices. In this study, we surveyed the crystallization and preferred orientation of AlN thin films with an X-ray diffractometer. To fabricate the AlN thin film, we used the magnetron sputtering method with $N_2$, NH3 and Ar. According to an increase in the partial pressures of $N_2$ and $NH_3$, Al was nitrified and deposited onto a substrate in a molecular form. When AlN was fabricated with $N_2$, it showed a c-axis orientation and tended toward a high orientation with an increase in the temperature. On the other hand, when AlN was fabricated with $NH_3$, it showed a-axis orientation. This result is coincident with the proposed mechanism. We fabricated AlN thin films with an a-axis orientation by controlling the sputtering electric power, $NH_3$ pressure, deposition speed, and substrate temperature. According to the proposed mechanism, we also fabricated AlN thin films which demonstrated high a-axis and c-axis orientations.

Computational approaches for prediction of protein-protein interaction between Foot-and-mouth disease virus and Sus scrofa based on RNA-Seq

  • Park, Tamina;Kang, Myung-gyun;Nah, Jinju;Ryoo, Soyoon;Wee, Sunghwan;Baek, Seung-hwa;Ku, Bokkyung;Oh, Yeonsu;Cho, Ho-seong;Park, Daeui
    • Korean Journal of Veterinary Service
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    • v.42 no.2
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    • pp.73-83
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    • 2019
  • Foot-and-Mouth Disease (FMD) is a highly contagious trans-boundary viral disease caused by FMD virus, which causes huge economic losses. FMDV infects cloven hoofed (two-toed) mammals such as cattle, sheep, goats, pigs and various wildlife species. To control the FMDV, it is necessary to understand the life cycle and the pathogenesis of FMDV in host. Especially, the protein-protein interaction between FMDV and host will help to understand the survival cycle of viruses in host cell and establish new therapeutic strategies. However, the computational approach for protein-protein interaction between FMDV and pig hosts have not been applied to studies of the onset mechanism of FMDV. In the present work, we have performed the prediction of the pig's proteins which interact with FMDV based on RNA-Seq data, protein sequence, and structure information. After identifying the virus-host interaction, we looked for meaningful pathways and anticipated changes in the host caused by infection with FMDV. A total of 78 proteins of pig were predicted as interacting with FMDV. The 156 interactions include 94 interactions predicted by sequence-based method and the 62 interactions predicted by structure-based method using domain information. The protein interaction network contained integrin as well as STYK1, VTCN1, IDO1, CDH3, SLA-DQB1, FER, and FGFR2 which were related to the up-regulation of inflammation and the down-regulation of cell adhesion and host defense systems such as macrophage and leukocytes. These results provide clues to the knowledge and mechanism of how FMDV affects the host cell.

Bacterial Stringent Signal Directs Virulence and Survival in Vibrio cholerae.

  • Oh, Young Taek;Kim, Hwa Young;Yoon, Sang Sun
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2019.10a
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    • pp.8-8
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    • 2019
  • The stringent response (SR) is characterized as a bacterial defense mechanism in response to various growth-inhibiting stresses. It is activated by accumulation of a small nucleotide regulator, (p)ppGpp, and induces global changes in bacterial transcription and translation. Recent work from our group has shown that (p)ppGpp plays a critical role in virulence and survival in Vibrio cholerae. The genes, relA and relV, are involved in the production of (p)ppGpp, while the spoT gene encodes an enzyme that hydrolyzes it in V. cholerae. A mutant strain defective in (p)ppGpp production (i.e. ${\Delta}relA{\Delta}relV{\Delta}spoT$ mutant) lost the ability to produce cholera toxin (CT) and lost their viability due to uncontrolled production of organic acids, when grown with extra glucose. In contrast, the ${\Delta}relA{\Delta}spoT$ mutant, a (p)ppGpp overproducer strain, produced enhanced level of CT and exhibited better growth in glucose supplemented media via glucose metabolic switch from organic fermentation to acetoin, a neutral fermentation end product, fermentation. These findings indicates that (p)ppGpp, in addition to its well-known role as a SR mediator, positively regulates CT production and maintenance of growth fitness in V. cholerae. This implicates SR as a promising drug target, inhibition of which may possibly downregulate V. cholerae virulence and survival fitness. Therefore, we screened a chemical library and identified a compound that induces medium acidification (termed iMAC) and thereby loss of wild type V. cholerae viability under glucose-rich conditions. Further, we present a potential mechanism by which the compound inhibits (p)ppGpp accumulation. Together, these results indicate that iMAC treatment causes V. cholerae cells to produce significantly less (p)ppGpp, an important regulator of the bacterial virulence and survival response, and further suggesting that it has a therapeutic potential to be developed as a novel antibacterial agent against cholera.

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