자연살해세포의 시너지 활성을 조절하는 신호전달 기전

학위논문 (박사)-- 서울대학교 대학원 : 협동과정 농업생물공학전공, 2016. 8. 유상렬.Natural Killer (NK) cells are discriminated among innate lymphoid cells (ILCs) with their cytolytic activity that has a key role in the control of viral infection and tumorigenesis. NK cells not only kill virus-infected or transformed cells including cancer stem cells by releasing cytotoxic granules, but also contribute to modulate diverse immune responses by secretion of cytokines (e.g., IFN-γ and TNF-α) and chemokines (e.g., MIP-1α and MIP-1β). Therefore, the malfunction of NK cells is linked various diseases, and the manipulation of NK cells function have hold promise in therapeutic applications. However, the limited information for the mechanisms regulating activation of NK cells has hampered the progression toward therapeutic strategies. Accordingly, understanding accurate activating and inhibitory receptors signaling mechanisms controlling NK cells function can augment successful NK cell-based therapies. The triggering of NK cell effector functions relies on the engagement of activating or inhibitory receptors for ligands on their target cells. The balanced signals from activating and inhibitory receptors are known to dictate NK cells activity. However, even in the case of inhibitory signal is absent, activating signal from single coactivation receptor is insufficient to induce enough activation of resting NK cells. Signals from multiple activating receptors, not a single receptor, are required for NK cell functions. And only specific combinations among them can induce additive or synergistic enhancement of NK cells activity. For this reason, the study of signaling mechanisms modulating synergistic activation of NK cells is critical for harnessing the arm of NK cells for clinical purposes. In this study, two critical signaling molecules for immune cell functions, glycogen synthase kinase (GSK)-3β and NF-κB are examined for regulation of synergistic activation of NK cells, and their interaction mechanisms with other signaling pathways are investigated. In a synergistic activation model of NK cells that combines NKG2D and 2B4 activating receptors, representative non-ITAM-associated activating receptors, GSK-3β negatively regulated the synergistic activation of both cytotoxicity and cytokine secretion. The individual or combinational stimulation of NKG2D and 2B4 induced inhibitory phosphorylation of GSK-3, and the extent of phosphorylation in accordance with the level of NK cell activity. The inhibition of GSK-3β by siRNA knockdown or pharmacological inhibition increased NK cell function, but GSK-3α knockdown had no effect. This negative role of GSK-3β was dependent on its kinase activity. The regulation of NK cell function by GSK-3β was a common mechanism for both NKL cell line and primary NK cells. And NK cell activations by either ITAM-associated or non-ITAM activating receptors were regulated by GSK-3β. NF-κB is a well-known transcription factor that is critical for diverse immune responses. Nevertheless, its role in NK cells activated by multiple activating receptors during target cell recognition is not defined. Synergistic combination of NKG2D, 2B4, or DNAM-1 induced synergistic and sufficient activation of NF-κB pathway that is linked to synergistic NK cell activity, whereas single receptor stimulation was insufficient. Receptors cooperation for NF-κB activation was regulated at the level of Vav1 phosphorylation, the 1st checkpoint, and this Vav1-dependent synergistic signal also cooperates with separate PI3K-Akt signal for synergistic p65 phosphorylation, the 2nd checkpoint, in a stepwise manner. As confirmed with a X-linked lymphoproliferative disease (XLP) NK cells model that is defective for 2B4 receptor signaling because of mutations of SAP adaptor, stepwise checkpoint signaling mechanism for NF-κB activation was suggested. These newly uncovered signaling mechanisms during multiple receptor stimulation provides new insights of receptor cooperation to determine specificity and magnitude of NK cell activation and bases for establishing NK cell-based therapeutic strategies.Chapter I. General Introduction 1 I-1. Research background 2 I-1-1. Cancer therapies 2 I-1-2. NK cell-based cancer therapy 3 I-2. Innate lymphoid cells 5 I-2-1. Classification of innate lymphoid cells 5 I-2-2. Differences of NK cells from other ILCs 6 I-3. Functional characteristics of NK cells 7 I-3-1. NK cells 7 I-3-2. Anti-cancer activity of NK cells 8 I-3-3. Anti-viral activity of NK cells 9 I-3-4. Crosstalk of NK cells with other immune cells 9 I-4. Inhibitory and activating receptors of NK cells 11 I-4-1. Inhibitory receptors and signaling 11 I-4-2. Activating receptors and signaling 12 I-5. Signaling for synergistic activation of NK cells 15 I-6. X-linked lymphoproliferative disease 17 I-7. Purpose of study and rationale for study design 18 I-8. References 19 Chapter II. NK cell function triggered by multiple activating receptors is negatively regulated by glycogen synthase kinase-3β 32 II-1. Abstract 33 II-2. Introduction 35 II-3. Materials and Methods 38 II-3-1. Cell lines and reagents 38 II-3-2. NK cell expansion 38 II-3-3. Antibodies (Abs) 39 II-3-4. Flow cytometric analysis of NK cell activation 40 II-3-5. Cell stimulation 40 II-3-6. Measurement of cytokine secretion 40 II-3-7. Immunoblot analysis 41 II-3-8. RNA interference 41 II-3-9. RT-PCR 42 II-3-10. Cytotoxicity assay 43 II-3-11. Flow cytometric analysis of Ca2+ mobilization 43 II-3-12. Retroviral transduction 44 II-3-13. Statistical analysis 45 II-4. Results 46 II-4-1. Effector functions of NK cells are enhanced by pharmacological inhibition of GSK-3 46 II-4-2. GSK-3 phosphorylation correlates with the activation status of NK cells 52 II-4-3. GSK-3 phosphorylation by PI3K- and MAPK-dependent Pathways 60 II-4-4. GSK-3β-dependent regulation of NK cell effector functions 63 II-4-5. GSK-3β regulates calcium-dependent signaling for NK cell Activation 68 II-4-6. Regulation of NK cell function by GSK-3β is dependent on its kinase activity 72 II-4-7. Role of GSK-3β in primary NK cell activation 79 II-5. Discussion 85 II-6. References 91 Chapter III. Stepwise phosphorylation of p65 promotes NF-κB activation and NK cell responses during target cell recognition 100 III-1. Abstract 101 III-2. Introduction 102 III-3. Materials and Methods 106 III-3-1. Cells and reagents 106 III-3-2. Patient samples 107 III-3-3. Abs 107 III-3-4. Cellular assays 108 III-3-5. Receptor crosslinking and cell mixing experiments 110 III-3-6. Assessment of NF-κB activation by EMSA 111 III-3-7. NF-κB reporter assay 111 III-3-8. RNA interference 112 III-3-9. Ex vivo expansion of NK cells 113 III-3-10. DNA constructs and transfections 114 III-3-11. Immunoblotting 114 III-3-12. Cell conjugation and immunofluorescence 115 III-3-13. Real-time PCR 116 III-3-14. Flow cytometric analysis of p65 phosphorylation 117 III-3-15. Statistical analyses 117 III-3-16. Data availability 117 III-4. Results 118 III-4-1. Synergistic activation of NF-κB by NKG2D and 2B4 118 III-4-2. NF-κB is required for NK cell functions by NKG2D and 2B4 127 III-4-3. Disparate signals converge on the NF-κB p65 subunit 142 III-4-4. Signal amplification is insufficient for NF-κB activation 157 III-4-5. Defective NF-κB activation in XLP1 NK cells by NKG2D and 2B4 162 III-4-6. Vav1 is required for the synergistic activation of NF-κB 179 III-5. Discussion 184 III-6. References 195 국문 초록 202Docto

A Study on Influence Factors of the Continuous Use of In-house Web2.0 Services in Public Enterprises

학위논문 (석사)-- 서울대학교 행정대학원 : 공기업정책학과, 2015. 8. 김순은.사내의 원활한 커뮤니케이션은 조직의 성과와 효율성의 향상에 직결된다. 또한 조직 구성원 각자가 소유하고 있는 지식과 경험을 공유하여 조직차원에서 축척하고 관리하는 일은 회사전체의 경영성과 달성에 매우 중요하다. 이를 위해 대다수의 기업과 공공기관들은 조직 구성원 개개인의 자발적 참여와 공유를 통해 서비스 되는 개방형 웹서비스인 웹2.0 또는 엔터프라이즈2.0 활성화를 위해 적극적으로 노력하고 있다. 그러나 이러한 사용자 참여형 웹서비스가 성공을 거두기 위해서는 사용자들의 자발적 동기에 의한 지속적인 사용과 참여가 필수적이라 할 수 있다. 이를 위해 본 연구에서는 한국전력공사를 중심으로 사용자 참여형 웹서비스의 지속사용의도에 미치는 영향요인에 대한 실증적인 연구를 수행하였다. 연구방법은 정보시스템 지속사용의도에 관한 연구에 많이 적용되고 있는 외생변수(독립변수)를 추가한 확장된 TAM 모형을 기반으로 하였으며, 선행연구와 문헌검토를 통해 정보기술, 정보보안, 조직신뢰, 유희성, 자기효능감을 독립변수로 선정하였고 매개변수와 종속변수는 기존 TAM 모형에서 제시한 변수들을 사용하였으며, 즉 유용성, 사용용이성을 매개변수로 지속사용의도를 종속변수로 선정하였다. 연구결과 지속사용의도에는 정보보안 요인을 제외한 정보기술, 조직신뢰, 유희성, 자기효능감 요인이 영향을 미치는 것으로 검증되었다. 또한 기존 TAM 모형의 사용용이성과 유용성의 매개효과도 검증되었다. 이번 연구가 사내의 사용자 참여형 웹서비스를 활성화시키기 위한 전략수립에 기본 방침을 정하는데 중요한 역할을 할 수 있을 것으로 기대한다. 주요어 : TAM, 웹2.0, 엔터프라이즈2.0, 정보기술, 사용자참여형 학 번 : 2014-23596제 1 장 서 론 1 제 1 절 연구의 목적 및 배경 1 제 2 절 연구의 범위 및 방법 4 제 2 장 이론적 배경 6 제 1 절 사용자 참여형 웹서비스 6 1.1 웹2.0 및 엔터프라이즈2.0 서비스의 개념 6 1.2 주요 웹2.0서비스 9 1.3 한국전력공사 웹2.0서비스 12 1.3.1 i-board 12 1.3.2 웹2.0 플랫폼 서비스 14 1.3.3 지식경영시스템(Knowledge Management System) 16 1.3.4 KEPCO-EP Communicator 17 제 2 절 ICT 서비스 지속사용의도 18 2.1 정보시스템 지속사용의도 18 2.2 정보시스템 지속사용모델 18 2.2.1 정보시스템 기술수용모델(TAM : Technology Acceptance Model) 19 2.2.2 정보시스템 기대일치모델(Expectation Confirmation Theory-IT) 22 2.2.3 확장된 정보시스템 기대일치모델(Extended ECM-IT) 23 2.2.4 정보시스템 지속사용모델 비교 24 제 3 절 선행연구 26 3.1 상용 정보시스템 지속사용의도 26 3.2 사내 웹2.0서비스 지속사용의도 29 3.3 정보시스템 지속사용의도에 관한 연구결과 요약 34 제 3 장 연구의 틀 37 제 1 절 연구의 대상 37 제 2 절 연구모형 38 제 3 절 연구가설 39 제 4 장 연구분석 방법 48 제 1 절 조사 설계 48 제 2 절 연구변수의 조작적 정의 49 제 3 절 분석 방법 52 제 5 장 실증분석 54 제 1 절 조사대상자 일반적 특성 분석 54 1.1 인구통계학적 분석 54 1.2 변수별 빈도분석 56 1.3 기초통계 분석 62 제 2 절 측정도구의 타당성 및 신뢰성 검증 63 2.1 타당성 검증 63 2.1.1 독립변수 요인분석 64 2.1.2 매개변수 요인분석 67 2.1.3 종속변수 요인분석 68 2.2 신뢰성 검증 69 제 3 절 상관관계분석 71 제 4 절 가설의 검증 74 4.1 사용용이성과의 관계 74 4.2 유용성과의 관계 77 4.3 사용용이성/유용성과 지속사용의도와의 관계 79 4.4 매개효과 분석 83 4.4.1 사용용이성의 매개효과 분석 84 4.4.2 유용성의 매개효과 분석 85 4.4.3 매개효과 요약 86 제 6 장 결 론 89 제 1 절 연구결과 요약 89 제 2 절 연구의 시사점 92 제 3 절 연구의 한계 95 참 고 문 헌 97 설 문 지 105 Abstarct 110Maste

Projecting Public Expenditures for Long-Term Care in Korea

Public expenditures on long-term care are a matter of concern for Korea as in many other countries. The expenditure is expected to accelerate and to put pressure on public budgets, adding to that arising from insufficient retirement schemes and other forms of social spending. This study tried to foresee how much health care spending could increase in the future considering demographic and non-demographic factors as the drivers of expenditure. Previous projections of future long-term expenditure were mainly based on a given relation between spending and age structure. However, although demographic factors will surely put upward pressure on long-term care costs, other non-demographic factors, such as labor cost increase and availability of informal care, should be taken into account as well. Also, the possibility of dynamic link between health status and longevity gains needs to be considered. The model in this study is cell-base and consists of three main parts. The first part estimated the numbers of elderly people with different levels of health status by age group, gender, household type. The second part estimated the levels of long-term care services required, by attaching a probability of receiving long-term care services to each cell using from the sample from current year. The third part of the model estimated long-term care expenditure, along the demographic and non-demographic factors` change in various scenarios. Public spending on long-term care could rise from the current level of 0.2~0.3% of GDP to around 0.44~2.30% by 2040.2

POLYNOMINAL THROUGHPUT METHOD AND A DEVICE THEREOF AT A FINITE FIELD

본 발명은 유한 필드에서의 긴 다항식 나눗셈 알고리즘과 그에 따른 하드웨어 아키텍쳐에 관한 것으로 특히, 룩어헤드(Lookahead) 기법과 부분 분할(Partial-Division)을 바탕으로 그룹 단위의 병렬 프로세싱에 의해 유한 필드 심볼간의 승산이 전혀 필요 없게 되어 단위시간당 생성해내는 제산 결과(Throughput)가 기존 방식에 비하여 상대적으로 매우 많아지도록 하기 위한 유한 필드에서의 긴 다항식 제산 장치를 제공하여 향상된 속도가 수십배 정도의 이득을 가지므로 전체적인 파워 딜레이 프로덕트는 아주 낮아지게 되어 이를 활용하면 고속 또는 저전력 소모 또는 둘다 요구되어지는 상황에서도 사용되어질 수 있는 장점을 갖는다

고속/저전력소비 응용을 위한 에러정정 코드의 VLSI 구현에 관한 연구

학위논문(박사) - 한국과학기술원 : 전기및전자공학과, 1998.8, [ iii, 136 p. ]In this dissertation we present a construction method of BCH and RS encoder/decoder with special emphasis on minimizing power consumption and increasing the throughput per unit time to reduce the energy-delay product. A new long polynomial division algorithm in finite field based on the lookahead of partial-remainder(LAPR), is proposed. Since our algorithm is based on partial-division on orthogonal group basis and lookahead technique exploiting the linearity in finite field arithmetic, it is possible to completely eliminate polynomial multiplications leading to highly increased throughput per unit time. The inherent regularity and feed-forward nature of our algorithm make it possible to be fully pipelined. When pipelined, its throughput is 1 quotient and 1 remainder per clock cycle regardless of the degree of dividend polynomial, which is orders of magnitude faster than the conventional architecture using LFSR(Linear Feedback Shift Register). An area efficient sequential architecture based on LAPR is also presented. Although, the throughput rate of sequential architecture is rather lower than that of the pipelined one, as far as the authors know, it is still higher than that of any division architecture ever reported. Those will be shown to be efficient, regular and easily expandable, hence, naturally suitable for VLSI implementation. We verified the general validity of the division algorithm based on LAPR by mathematical manipulation and simulation. To verify the relative performance of the proposed division architectures over the conventional one using LFSR, we designed three popularly used BCH/RS coding applications 1) (32,28) RS encoder, 2) (63,51) BCH encoder 3) syndrome generator for (63,51) BCH decoder construction in COMPASS ASIC development environment using $0.8 \mu m$ double metal CMOS technology. Experimental verification for three benchmark circuits show that at identical throughput, pipelined architectures based on LAPR consumes about 32, 65, 67 t...한국과학기술원 : 전기및전자공학과

A design of the digital data processor for a mobile telephone system

학위논문(석사) - 한국과학기술원 : 전기 및 전자공학과, 1994.2, [ ii, 85 p. ]한국과학기술원 : 전기 및 전자공학과