• IMMUNE NETWORK
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• v.1 no.2
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• pp.109-115
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• 2001

Background: The role of the interferon consensus sequence binding protein (ICSBP), a member of interferon regulatory factor family, in protecting against a vesicular stomatitis virus (VSV) infection has not been firmly elucidated. Thus, it was investigated utilizing the human promyelocytic leukemia HL-60 cells which do not express ICSBP. Methods: HL-60 cells were stably transfected with plasmid containing cDNA for either ICSBP or DNA binding domain (DBD) and tested for their VSV-susceptibilities. The susceptibility of each transfectant group to a VSV infection was determined by a plaque assay at 1 h, 24 h, and 48 h post-infection in the presence (500 IU/ml) or absence of interferon ${\alpha}$ ($IFN{\alpha}$). Results: In the absence of $IFN{\alpha}$, the three groups showed similar sensitivities to a VSV infection. However, when pre-treated with IFN, the viral titers in both the ICSBP and control clones steadily decreased over 48 h of incubation, indicating the existence of $IFN{\alpha}$-mediated protection against VSV infection. The $IFN{\alpha}$-treated ICSBP clones appeared to be more resistant to infection compared with the control clones, although the difference was not great. On the contrary, the viral titers in the $IFN{\alpha}$-treated DBD clones increased at 24 h then decreased by 48 h. Conclusion: The expression of truncated ICSBP (DBD) does not appear to underlie the impaired protection against a VSV infection in the DBD clones, since even the control clones lacking ICSBP were protected from a VSV infection. This suggests that ICSBP does not play a critical role in the $IFN{\alpha}$- mediated anti-VSV response of HL-60 cells, although it appears to confer some resistance to a VSV infection.

• IMMUNE NETWORK
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• v.4 no.3
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• pp.166-175
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• 2004

Background: Telomerase, a ribonucleoprotein enzyme capable of synthesizing telomeric repeats, attracts attention for its possible role in determining the replicative capacity of normal somatic cells, transformed cells, and cells of the germline lineage. Differently from normal somatic cells with no telomerase activity, normal lymphocytes has been reported to have telomerase activity comparable to that found in transformed cells during development and activation, which substantiate a role in supporting the capacity of lymphocytes for extensive clonal expansion. Methods: Here, in order to define the telomerase regulation in murine T lymphocytes, telomerase activity in cloned murine $CD8^+$ T cells and naive $CD8^+$ T cells isolated from C57BL/6 mice was examined. Next, the regulatory mechanism of telomerase activity at transcriptional and post- translational levels was investigated by determining the expression level of the TERT protein, a key component for telomerase activity. Results: It was demonstrated that telomerase activity was expressed in an inactivated state as well as in an activated state in the murine $CD8^+$ T lymphocytes by using TRAP assay. The increase of telomerase activity was partially dependent on the net increase of TERT expression. Also, telomerase activity was decreased after treatment with protein kinase inhibitors, indicating that telomerase activation was prevented by inhibition of phosphorylation. Conclusion: Therefore, these results suggest that telomerase activity is constitutively expressed in the murine resting T lymphocytes and controlled by both transcriptional regulation and post- ranslational modifications.

• IMMUNE NETWORK
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• v.11 no.3
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• pp.155-162
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• 2011

Background: Toll-like receptor 3 (TLR3) recognizes double-stranded RNA (dsRNA) and induces inflammation. In this study we attempted to ascertain if there are endogenous host molecules controlling the production of cytokines and chemokines. Two candidates, ribosomal protein L19 and L22, were analyzed to determine if they influence cytokine production followed by TLR3 activation. In this study we report that L19 acts upon production of IP-10 or IL-8 differently in glioblastoma cells. Methods: L19 or L22 was transfected into HEK293-TLR3, A549 or A172 cells. After treatment with several inhibitors of NF-${\kappa}B$, PI3K, p38 or ERK, production of IL-8 or IP-10 was measured by ELISA. siRNA was introduced to suppress expression of L19. After Vesicular stomatitis virus infection, viral multiplication was measured by western blot. Results: L19 increased ERK activation to produce IL-8. In A172 cells, in which TLR3 is expressed at endosomes, L19 inhibited interferon regulatory factor 3 (IRF3) activation and IP-10 production to facilitate viral multiplication, whereas L19 inhibited viral multiplication in A549 cells bearing TLR3 on their cell membrane. Conclusion: Our results suggest that L19 regulates TLR3 signaling, which is cell type specific and may be involved in pathogenesis of autoimmune diseases and chronic inflammatory diseases.

• IMMUNE NETWORK
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• v.7 no.1
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• pp.10-17
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• 2007

Autoimmune arthritis, such as rheumatoid arthritis (RA), is a chronic inflammatory disorder that primarily affects the joints and then results in their progressive destruction. Effector Th cells have been classified as Th1 and Th2 subsets based on their cytokine expression profiles and immune regulatory function. Another subset of T cells termed Th17 was recendy discovered and known to selectively produce IL-17. Also, Th17 was shown to be generated by TGF${\beta}$ and IL-6 and maintained by IL-23. IL-17 is a proinflammatory cytokine that is considered to involve the development of various inflammatory autoimmune diseases such as RA, asthma, lupus, and allograft rejection. IL-17 is present in the sera, synovial fluids and synovial biopsies of most RA patient. IL-17 activates RA synovial fibroblasts to synthesize IL-6, IL-8 and VEGF via PI3K/Akt and NF-${\kappa}B$ dependent pathway. IL-17 increases IL-6 production, collagen destruction and collagen synthesis. In addition, it not only causes bone resorption but also increases osteoclastogenesis and fetal cartilage destruction. Inhibition of the IL-17 production may contribute a novel therapeutic approach along with potent anti-inflammatory effect and with less immunosuppressive effect on host defenses.

• IMMUNE NETWORK
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• v.8 no.4
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• pp.130-136
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• 2008

Background: Human cytomegalovirus UL18, a MHC class I homologue, has been considered a natural killer (NK) cell decoy. It ligates LIR-1/ILT2 (CD85j), an NK inhibitory receptor, to prevent lysis of infected target cells. However, precise role of UL18 to NK cell cytotoxicity is yet elusive. Difficulty in clarifying the function of UL18 lies in complication in detecting UL18 mainly due to low level expression of UL18 on the surface and gradual loss of its expression. Methods: To overcome this hurdle, cDNA of cytoplasmic tail-less UL18 was constructed and expressed in swine endothelial cell (SEC). The expression level and its stability in the cell surface were monitored with FACS analysis. Results: Surface expression of UL18 is up-regulated by removing cytoplasmic tail portion from UL18F (a full sequence of UL18). SECs transfected with a cDNA of UL18CY (a cytoplasmic tail-less UL18) stably expressed UL18 molecule on the surface without gradual loss of its expression during 6 week continuous cultures. In the NK cytotoxicity assay, UL18 functions either inhibiting or activating NK cell cytotoxicity according to the source of NK cells. We found that there is individual susceptibility in determining whether the engagement of NK cell and UL18 results in overall inhibiting or activating NK cell cytotoxicity. Conclusion: In this study, we found that cytoplasmic tail is closely related to the regulatory function for controlling surface expression of UL18. Furthermore, by constructing stable cell line in which UL18 expression is up-regulated and stable, we provided a useful tool to clarify exact functions of UL18 on various immune cells having ILT2 receptor.

• Journal of Microbiology and Biotechnology
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• v.18 no.8
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• pp.1368-1376
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• 2008

In our previous study, the expression of active H-ferritins in Saccharomyces cerevisiae was found to reduce cell growth and reactive oxygen species (ROS) generation upon exposure to oxidative stress; such expression enhanced that of high-affinity iron transport genes (FET3 and FTR1). The results suggested that the recombinant cells expressing H-ferritins induced cytosolic iron depletion. The present study analyzes metabolic changes under these circumstances via proteomic methods. The YGH2 yeast strain expressing A-ferritin, the YGH2-KG (E62K and H65G) mutant strain, and the YGT control strain were used. Comparative proteomic analysis showed that the synthesis of 34 proteins was at least stimulated in YGH2, whereas the other 37 proteins were repressed. Among these, the 31 major protein spots were analyzed via nano-LC/MS/MS. The increased proteins included major heat-shock proteins and proteins related to endoplasmic reticulum-associated degradation (ERAD). On the other hand, the proteins involved with folate metabolism, purine and methionine biosynthesis, and translation were reduced. In addition, we analyzed the insoluble protein fractions and identified the fragments of Idh1p and Pgk1p, as well as several ribosomal assembly-related proteins. This suggests that intracellular iron depletion induces imperfect translation of proteins. Although the proteins identified above result from changes in iron metabolism (i.e., iron deficiency), definitive evidence for iron-related proteins remains insufficient. Nevertheless, this study is the first to present a molecular model for iron deficiency, and the results may provide valuable information on the regulatory network of iron metabolism.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.7
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• pp.903-912
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• 2012

In Erhualian and Yorkshire reciprocal cross $F_1$ pig populations, we examined the mRNA expression characteristic of liver-derived IGF-1, IGF-1R, IGF-2, IGF-2R and IGFBP-3 during the embryonic and postnatal developmental periods (E50, E70, E90, D1, D20, D70, D120 and D180). Our results demonstrated that the IGF-system genes mRNA levels exhibited an ontogenetic expression pattern, which was potentially associated with the porcine embryonic development, postnatal growth, organogenesis and even the initiation and acceleration of puberty. The expression pattern of IGF-system genes showed variation in the reciprocal cross ($F_1$ YE and EY pigs). This study also involved the expression features of imprinted genes IGF-2 and IGF-2R. The parent-of-origin effect of imprinted genes was reflected by their differential expression between the reciprocal crosses populations. The correlation analysis also indicated that the regulatory network and mechanisms involved in the IGF system were a complex issue that needs to be more fully explored. A better understanding of IGF system components and their interactive mechanisms will enable researchers to gain insights not only into animal organogenesis but also into somatic growth development and even reproduction.

• Journal of Microbiology and Biotechnology
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• v.8 no.4
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• pp.325-332
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• 1998

In vitro phosphorylation experiments with a cell extract of Streptomyces coelicolor A3(2) M130 in the presence of ${\gamma}-[^32P]$]ATP revealed the presence of multiple phosphorylated proteins, including the AfsR/AfsK kinases which control the biosynthesis of A-factor, actinorhodin, and undecylprodigiosin. Phosphorylation of AfsR by a cell extract as an AfsK source was significantly inhibited by Ser/Thr protein kinase inhibitors, staurosporine and K-252a, at concentrations giving 50% inhibition ($IC_50$) of $1{\mu}M\;and\;0.1{\mu}M$, respectively. Further in vitro experiments with the cell extracts showed that phosphorylation of multiple proteins was inhibited by various protein kinase inhibitors with different inhibitory profiles. Manganese and calcium ions in the reaction mixture also modulate phosphorylation of multiple proteins. Manganese at 10 mM greatly enhanced the phosphorylation and partially circumvented the inhibition caused by staurosporine and K-252a. A calcium-activated protein kinase(s) was little affected by these inhibitors. Herbimycin and radicicol, which are known as tyrosine kinase inhibitors, did not show any significant inhibition of AfsR phosphorylation. Consistent with the in vitro effect of the kinase inhibitors, they inhibited aerial mycelium formation and pigmented antibiotic production on solid media. On the contrary, when assayed in liquid culture, the amount of actinorhodin produced was increased by staurosporine and K-252a and greatly decreased by manganese. All of these data clearly show that the genus Streptomyces possesses several protein kinases of eukaryotic types which are involved in the regulatory network for morphogenesis and secondary metabolism.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.1
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• pp.79-86
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• 2015

Cognitive radio networks (CRNs) offer the promise of intelligent radios that can learn from and adapt to their environment. CRN permits unlicensed users to utilize the idle spectrum as long as it does not introduce interference to the primary users due to the Federal Communications Commission's recent regulatory policies. Thereby, the security aspects in CRNs should be different with the other networks. The purpose of this paper is to devise a new delegation-based authentication protocol (NDAP) by extracting out the security aspects for unlicensed user authentication over CRNs from Tsai et al's delegation-based authentication protocol (TDAP). First of all, we will provide security analyses on the TDAP and set design goal for unlicensed user authentication. Then, we will propose a NDAP as a remedy mechanism for the TDAP and a new protocol for CRNs. The NDAP could be used as a security building block for the CRNs and various convergence applications.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.1
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• pp.1-8
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• 2016

The Nuclear Power Plants(: NPP) are being protected as national infrastructure, and instrumentation and control(: I&C) systems are one of the principle facilities of the NPP, which perform the protection, control, and monitoring function. The I&C systems are being evolved into digitalization based on computer and network technology from analog system. In addition, the I&C systems are mostly employ the specialized logic controllers which are dedicated for the NPP, but the usage of generalized IT resources are steadily increased. The cyber security issues for the NPP are being emerged due to cyber incidents by Stuxnet and various accidents in the NPP. In this paper, hybrid access control model is proposed which are applicable to I&C system by analyzing the access control requirements specified in regulatory guides. The safety of in-service and under construction of NPP are effectively increased by applying proposed hybrid model.