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CD8+ T Cell-mediated Immunity Induced by Heterologous Prime-boost Vaccination Based on DNA Vaccine and Recombinant Vaccinia Virus Expressing Epitope (Epitope발현 DNA Vaccine과 Recombinant Vaccinia Virus를 이용한 Heterologous Prime-boost Vaccination에 의하여 유도되는 CD8+ T 세포 매개성 면역)

  • Park, Seong-Ok;Yoon, Hyun-A;Aleyas, Abi George;Lee, John-Hwa;Chae, Joon-Seok;Eo, Seong-Kug
    • IMMUNE NETWORK
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    • v.5 no.2
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    • pp.89-98
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    • 2005
  • Background: DNA vaccination represents an anticipated approach for the control of numerous infectious diseases. Used alone, however, DNA vaccine is weak immunogen inferior to viral vectors. In recent, heterologous prime-boost vaccination leads DNA vaccines to practical reality. Methods: We assessed prime-boost immunization strategies with a DNA vaccine (minigene, $gB_{498-505}$ DNA) and recombinant vaccinia virus $(vvgB_{498-505})$ expressing epitope $gB_{498-505}$ (SSIEF ARL) of CD8+ T cells specific for glycoprotein B (gB) of herpes simplex virus (HSV). Animals were immunized primarily with $gB_{498-505}$ epitope-expressing DNA vaccine/recombinant vaccinia virus and boosted with alternative vaccine type expressing entire Ag. Results: In prime-boost protocols using vvgBw (recombinant vaccinia virus expressing entire Ag) and $vvgB_{498-505}$, CD8+ T cell-mediated immunity was induced maximally at both acute and memory stages if primed with vvgBw and boosted with $vvgB_{498-505}$ as evaluated by CTL activity, intracellular IFN-staining, and MHC class I tetramer staining. Similarly $gB_{498-505}$ DNA prime-gBw DNA (DNA vaccine expressing entire Ag) boost immunization elicited the strongest CD8+ T cell responses in protocols based on DNA vaccine. However, the level of CD8+ T cell-mediated immunity induced with prime-boost vaccination using DNA vaccine expressing epitope or entire Ag was inferior to those based on vvgBw and $vvgB_{498-505}$. Of particular interest CD8+ T cell-mediated immunity was optimally induced when $vvgB_{498-505}$ was used to prime and gB DNA was used as alternative boost. Especially CD7+ T cell responses induced by such protocol was longer lasted than other protocols. Conclusion: These facts direct to search for the effective strategy to induce optimal CD8+ T cell-mediated immunity against cancer and viral infection.

Insights into the Role of Follicular Helper T Cells in Autoimmunity

  • Park, Hong-Jai;Kim, Do-Hyun;Lim, Sang-Ho;Kim, Won-Ju;Youn, Jeehee;Choi, Youn-Soo;Choi, Je-Min
    • IMMUNE NETWORK
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    • v.14 no.1
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    • pp.21-29
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    • 2014
  • Follicular helper T ($T_{FH}$) cells are recently highlighted as their crucial role for humoral immunity to infection as well as their abnormal control to induce autoimmune disease. During an infection, na$\ddot{i}$ve T cells are differentiating into $T_{FH}$ cells which mediate memory B cells and long-lived plasma cells in germinal center (GC). $T_{FH}$ cells are characterized by their expression of master regulator, Bcl-6, and chemokine receptor, CXCR5, which are essential for the migration of T cells into the B cell follicle. Within the follicle, crosstalk occurs between B cells and $T_{FH}$ cells, leading to class switch recombination and affinity maturation. Various signaling molecules, including cytokines, surface molecules, and transcription factors are involved in $T_{FH}$ cell differentiation. IL-6 and IL-21 cytokine-mediated STAT signaling pathways, including STAT1 and STAT3, are crucial for inducing Bcl-6 expression and $T_{FH}$ cell differentiation. $T_{FH}$ cells express important surface molecules such as ICOS, PD-1, IL-21, BTLA, SAP and CD40L for mediating the interaction between T and B cells. Recently, two types of microRNA (miRNA) were found to be involved in the regulation of $T_{FH}$ cells. The miR-17-92 cluster induces Bcl-6 and $T_{FH}$ cell differentiation, whereas miR-10a negatively regulates Bcl-6 expression in T cells. In addition, follicular regulatory T ($T_{FR}$) cells are studied as thymus-derived $CXCR5^+PD-1^+Foxp3^+\;T_{reg}$ cells that play a significant role in limiting the GC response. Regulation of $T_{FH}$ cell differentiation and the GC reaction via miRNA and $T_{FR}$ cells could be important regulatory mechanisms for maintaining immune tolerance and preventing autoimmune diseases such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Here, we review recent studies on the various factors that affect $T_{FH}$ cell differentiation, and the role of $T_{FH}$ cells in autoimmune diseases.

Etiologic and Immunologic Characteristics of Thoroughbred Horses with Bacterial Infectious Upper Respiratory Disease at the Seoul Race Park

  • Ryu, Seung-Ho;Koo, Hye-Cheong;Park, Young-Kyung;Kim, Jun-Man;Jung, Woo-Kyung;Davis, William C.;Park, Yong-Ho;Lee, Chang-Woo
    • Journal of Microbiology and Biotechnology
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    • v.19 no.9
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    • pp.1041-1050
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    • 2009
  • Equine respiratory disease is a common cause of poor performance and training interruptions. The higher incidence rate of infectious upper respiratory disease (IURD) in thoroughbred racehorses at the Seoul Race Park coincided with the frequent stabling season, shorter stabling periods, and younger ages in this study. Incidence rates were also correlated with significantly lower proportions of cells expressing MHC class II-, CD2 antigen-, $CD4^+$- or $CD8^+$-T lymphocyte-, and B lymphocyte in IURD patients compared with healthy control groups in the summer and fall and in 2-and-3-year-old groups. The data suggested that movement and new environments may have resulted in immunosuppression and inappropriate responses to respiratory pathogens in IURD patients. The IURD incidence decreased with age, perhaps by the acquisition of immunity, and study results suggested that immunologic protection was associated with IURD, particularly in young thoroughbred racehorses. Streptococci isolates were identified in 11 of 72 IURD horses, and 3 of these isolates were identified as Streptococcus. equi subsp. equi. S. equi subsp. zooepidemicus was isolated from 2 of 23 IURD horses in the spring (8.7%), 5 of 23 in the summer (21.7%), and 1 of 6 in winter (16.7%). S. equi subsp. zooepidemicus (5%) was also identified in 3 of 61 isolates from clinically normal horses. Racetracks should implement anti-IURD protective measures by assessing the capacity of equine immunologic protection at the Park and by limiting the introduction of specific respiratory pathogens (such as S. equi subsp. equi) by preventing the access of infected but subclinical horses with a specified respiratory pathogen-free certification system prior to Park entry.

Landscape Analysis of Habitat Fragmentation in the North and South Korean Border (남북한 접경지역 개발에 따른 서식지 파편화에 대한 경관생태학적 분석)

  • Sung, Chan-Yong;Cho, Woo
    • Korean Journal of Environment and Ecology
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    • v.26 no.6
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    • pp.952-959
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    • 2012
  • This study examined habitat fragmentation that has occurred in Paju and Yeoncheon, the two border municipalities between North and South Korea in Gyeonggi-do (province) during the last 17 years using various landscape metrics. We 1) classified grass and agricultural habitats and forest habitats from two Landsat TM images collected in 1990 and 2007, and 2) compared the percentage of class area, patch density, mean patch area, and mean perimeter area ratio for the two habitat types between the two time points. Both types of habitats has been severely fragmented due to urban development in the last 17 years. The increased patch density and decreased mean habitat area are attributed to the construction of roads and railroads that separate a large habitat to many small pieces. The increased mean perimeter area ratio also indicates that the habitat fragmentation extended areas that are affected by the edge effect and so less suitable for interior species. A habitat conservation plan is urgently needed to minimize habitat fragmentation from developments that are expected to soon occur in the north and south Korean border.

Epigenetic control of LTR retrotransposons in plant germline and somatic cells

  • Lee, Seung Cho;Parent, Jean-Sebastien;Ernst, Evan;Berger, Frederic;Grimanelli, Daniel;Martienssen, Robert A.
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.20-20
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    • 2017
  • Plant genomes include heterochromatic loci that consist of repetitive sequences and transposable elements. LTR retrotransposon is the major class of transposons in advanced plants in terms of proportion in plant genome. The elements contribute not only to genome size but also to genome stability and gene expression. A number of cases have been reported transposon insertions near genic regions affect crop traits such as fruit pigments, stress tolerance, and yields. Functional LTR retrotransposons produce extrachromosomal DNA from genomic RNA by reverse transcription that takes place within virus-like-particles (VLPs). DECREASED DNA METHYLATION 1 (DDM1) plays important roles in maintaining DNA methylation of heterochromatin affecting all sequence contexts, CG, CHG, and CHH. Previous studies showed that ddm1 mutant exhibits massive transcription of retrotransposons in Arabidopsis, but only few of them were able to create new insertions into the genome. RNA-dependent RNA POLYMERASE 6 (RDR6) is known to function in restricting accumulation of transposon RNA by processing the transcripts into 21-22 nt epigenetically activated small interfering RNA (easiRNA). We purified VLPs and sequence cDNA to identify functional LTR retrotransposons in Arabidopsis ddm1 and ddm1rdr6 plants. Over 20 LTR copia and gypsy families were detected in ddm1 and ddm1rdr6 sequencing libraries and most of them were not reported for mobility. In ddm1rdr6, short fragments of ATHILA gypsy elements were detected. It suggests easiRNAs might regulate reverse transcription steps. The highest enriched element among transposon loci was previously characterized EVADE element. It has been reported that active EVADE element is more efficiently silenced through female germline than male germline. By genetic analyses, we found ddm1 and rdr6 mutation affect maternal silencing of active EVADE elements. DDM1-GFP protein accumulated in megaspore mother cell but was not found in mature egg cell. The fusion protein was also found in early embryo and maternal DDM1-GFP allele was more dominantly expressed in the embryo. We observed localization of DDM1-GFP in Arabidopsis and DDM1-YFP in maize and found the proteins accumulated in dividing zone of root tips. Currently we are looking at cell cycle dependency of DDM1 expression using maize system. Among 10 AGO proteins in Arabidopsis, AGO9 is specifically expressed in egg cell and shoot meristematic cells. In addition, mutation of AGO9 and RDR6 caused failure in maternal silencing, implying 21-22 nt easiRNA pathway is important for retrotransposon silencing in female gametophyte or/and early embryo. On the other hand, canonical 24 nt sRNA-directed DNA methylation (RdDM) pathways did not contribute to maternal silencing as confirmed by this study. Heat-activated LTR retrotransposon, ONSEN, was not silenced by DDM1 but the silencing mechanisms require RdDM pathways in somatic cells. We will propose distinct mechanisms of LTR retrotransposons in germline and somatic stages.

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Epigenetic control of LTR retrotransposons in plant germline and somatic cells

  • Lee, Seung Cho;Parent, Jean-Sebastien;Ernst, Evan;Berger, Frederic;Grimanelli, Daniel;Martienssen, Robert A.
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.97-97
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    • 2017
  • Plant genomes include heterochromatic loci that consist of repetitive sequences and transposable elements. LTR retrotransposon is the major class of transposons in advanced plants in terms of proportion in plant genome. The elements contribute not only to genome size but also to genome stability and gene expression. A number of cases have been reported transposon insertions near genic regions affect crop traits such as fruit pigments, stress tolerance, and yields. Functional LTR retrotransposons produce extrachromosomal DNA from genomic RNA by reverse transcription that takes place within virus-like-particles (VLPs). DECREASED DNA METHYLATION 1 (DDM1) plays important roles in maintaining DNA methylation of heterochromatin affecting all sequence contexts, CG, CHG, and CHH. Previous studies showed that ddm1 mutant exhibits massive transcription of retrotransposons in Arabidopsis, but only few of them were able to create new insertions into the genome. RNA-dependent RNA POLYMERASE 6 (RDR6) is known to function in restricting accumulation of transposon RNA by processing the transcripts into 21-22 nt epigenetically activated small interfering RNA (easiRNA). We purified VLPs and sequence cDNA to identify functional LTR retrotransposons in Arabidopsis ddm1 and ddm1rdr6 plants. Over 20 LTR copia and gypsy families were detected in ddm1 and ddm1rdr6 sequencing libraries and most of them were not reported for mobility. In ddm1rdr6, short fragments of ATHILA gypsy elements were detected. It suggests easiRNAs might regulate reverse transcription steps. The highest enriched element among transposon loci was previously characterized EVADE element. It has been reported that active EVADE element is more efficiently silenced through female germline than male germline. By genetic analyses, we found ddm1 and rdr6 mutation affect maternal silencing of active EVADE elements. DDM1-GFP protein accumulated in megaspore mother cell but was not found in mature egg cell. The fusion protein was also found in early embryo and maternal DDM1-GFP allele was more dominantly expressed in the embryo. We observed localization of DDM1-GFP in Arabidopsis and DDM1-YFP in maize and found the proteins accumulated in dividing zone of root tips. Currently we are looking at cell cycle dependency of DDM1 expression using maize system. Among 10 AGO proteins in Arabidopsis, AGO9 is specifically expressed in egg cell and shoot meristematic cells. In addition, mutation of AGO9 and RDR6 caused failure in maternal silencing, implying 21-22 nt easiRNA pathway is important for retrotransposon silencing in female gametophyte or/and early embryo. On the other hand, canonical 24 nt sRNA-directed DNA methylation (RdDM) pathways did not contribute to maternal silencing as confirmed by this study. Heat-activated LTR retrotransposon, ONSEN, was not silenced by DDM1 but the silencing mechanisms require RdDM pathways in somatic cells. We will propose distinct mechanisms of LTR retrotransposons in germline and somatic stages.

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The Effects of Student-Centered Instruction Using Analogy for Middle School Students' Learning of the Photosynthesis Concept (학생 중심 비유 활용 수업이 중학생의 광합성 개념 이해에 미치는 영향)

  • Byun, Chun-Su;Kim, Heui-Baik
    • Journal of The Korean Association For Science Education
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    • v.30 no.2
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    • pp.304-322
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    • 2010
  • The purpose of this study is to explore the effects of student-centered instruction using analogies for middle school students' learning of the photosynthesis concept. Participants in this study were 8th grade students at a middle school in Seoul (N=132). The students were divided into two groups for implementation. In the experimental group the teaching materials containing analogies were used while the contents of a science textbook were taught in the control group. The results of this study indicated that student-centered instruction using analogies was more effective than traditional methods of instruction for understanding photosynthesis concepts and the students' attitude toward the science class. Analogies were also found to contribute to developing an understanding of the photosynthesis concept through activating students' prior knowledge, focusing on structural features of the target concept and elaborating knowledge. In addition, analogies play an important role in activating small group discussions, improving students' meta-cognitive skills, and revealing and revising of misconceptions about photosynthesis. Moreover, analogies can help improve students' interests and self-efficiency in science classes.

How to extract value from poverty? : an institutional ethnographic critique on the Community Redevelopment Agency of the City of Los Angeles (빈곤으로부터 가치 짜내는 방법 -로스앤젤레스 도시재개발국에 대한 제도민족지적 비판-)

  • Park, Kyong-Hwan
    • Journal of the Korean association of regional geographers
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    • v.12 no.2
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    • pp.305-322
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    • 2006
  • An increasing number of cities employ rescaling strategies that not only construct metropolitan production network scaled down from national context, but also tune up new governance to effectively control local geographies of the city. In this context, urban redevelopment has emerged a key 'global' strategy to empower governmental institutions of the city, which not only eliminate such threatening spatial variables as deteriorated housing, working-class ghettos, and crime areas, but also increase and extract exchange value of those spaces. I view such practices a process of 'glurbanization'. This paper investigates how state/city government employs the discourse of urban re/development for 'inventing' poverty at an urban scale: how it institutionalizes the discourse for implementing concrete projects: and how urban institutional apparatus appropriate their discursive practices of redevelopment for their own ends in the city. By particularly focusing on the California Redevelopment Law and the Community Redevelopment Agency of the City of Los Angeles, this paper analyzes the ways in which the law and the agency extract value from what they define 'blight areas' by means of eminent domain and tax increment revenues. For empirical analysis I employ discourse analysis and institutional ethnography. I conclusively argue that the urban spaces stigmatized as 'blight areas' are increasingly entrapped by the urban redevelopment agency, which extracts increased exchange value from the areas and redirects it for supporting external investors, private developers, and the body of the agency itself.

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Development and Application of Remote Observatory System for Elementary School Gifted Students in Science (초등과학영재를 위한 원격천문대 시스템의 개발 및 적용)

  • Lee, Jaeho;Baek, Sang Ho
    • Journal of Gifted/Talented Education
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    • v.25 no.5
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    • pp.697-709
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    • 2015
  • This paper aims at shaping remote observatory system environment for schools, developing astronomical observation program using that system and applying it to science-gifted elementary students in order to figure out effects on their scientific investigation ability and attitude. in order to figure out effects of astronomical observation program using remote observatory program on scientific investigation ability and attitude of science-gifted elementary students, test was conducted on gifted students class of 5th grade in A Elementary School(15) and those of 5th grade in B Elementary School(20). The summary of this paper's results are as follows. First, in order to compose remote observatory system, an astronomical telescope available for remote control to transfer actual observed images in real-time was manufactured. Second, learning program for using remote observatory system wad developed by selecting contents through analysis of the curriculum. Third, in order to figure out effects of astronomical observation program using remote observatory program on scientific investigation ability and attitude of science-gifted elementary students. As a result, both of basic investigation ability and integrated investigation abilit, sub-elements of scientific investigation ability, showed significant differences and scientific investigation ability combining basic and integrated investigation abilities showed significant differences as well. Effects of astronomical observation program applying remote observatory also showed significant differences and its sub-elements, openness, collaboration, patience and creativeness did not show significant differences while curiosity, critics and volunteering showed significant differences.

Study of English Teaching Method by Convergence of Project-based Learning and Problem-based Learning for English Communication (프로젝트 기반과 문제해결 기반 융합 학습을 통한 영어 의사소통 교수법에 관한 연구)

  • Shin, Myeong-Hee
    • Journal of the Korea Convergence Society
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    • v.10 no.2
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    • pp.83-88
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    • 2019
  • This study examines the effects of student-centered project-based learning for the development of creative problem-solving skills, communication skills, critical thinking skills, and cooperation. A college students' creative personality test was used and pre-and post-test were performed. and TOEIC Speaking practice test by Educational Testing Service were selected to measure the English communication skills. The SPSS 18.0 was used and validated at a significance level of 5%. The result of this study shows that in the case of 'independence', the post-test average of the experimental group was statistically significant at the significant level (p<.01), which also showed statistically significant difference. There was statistically significant difference between the control group ($M=127{\pm}08.2$) and in the experimental group ($M=132{\pm}18.7$) applying project-based and problem-based convergent learning to English class were positively changed.