• Title/Summary/Keyword: Adaptive immunity

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Emerging roles of neutrophils in immune homeostasis

  • Lee, Mingyu;Lee, Suh Yeon;Bae, Yoe-Sik
    • BMB Reports
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    • v.55 no.10
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    • pp.473-480
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    • 2022
  • Neutrophils, the most abundant innate immune cells, play essential roles in the innate immune system. As key innate immune cells, neutrophils detect intrusion of pathogens and initiate immune cascades with their functions; swarming (arresting), cytokine production, degranulation, phagocytosis, and projection of neutrophil extracellular trap. Because of their short lifespan and consumption during immune response, neutrophils need to be generated consistently, and generation of newborn neutrophils (granulopoiesis) should fulfill the environmental/systemic demands for training in cases of infection. Accumulating evidence suggests that neutrophils also play important roles in the regulation of adaptive immunity. Neutrophil-mediated immune responses end with apoptosis of the cells, and proper phagocytosis of the apoptotic body (efferocytosis) is crucial for initial and post resolution by producing tolerogenic innate/adaptive immune cells. However, inflammatory cues can impair these cascades, resulting in systemic immune activation; necrotic/pyroptotic neutrophil bodies can aggravate the excessive inflammation, increasing inflammatory macrophage and dendritic cell activation and subsequent TH1/TH17 responses contributing to the regulation of the pathogenesis of autoimmune disease. In this review, we briefly introduce recent studies of neutrophil function as players of immune response.

Immune-mediated Liver Injury in Hepatitis B Virus Infection

  • Oh, In Soo;Park, Su-Hyung
    • IMMUNE NETWORK
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    • v.15 no.4
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    • pp.191-198
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    • 2015
  • Hepatitis B virus (HBV) is responsible for approximately 350 million chronic infections worldwide and is a leading cause of broad-spectrum liver diseases such as hepatitis, cirrhosis and liver cancer. Although it has been well established that adaptive immunity plays a critical role in viral clearance, the pathogenetic mechanisms that cause liver damage during acute and chronic HBV infection remain largely known. This review describes our current knowledge of the immune-mediated pathogenesis of HBV infection and the role of immune cells in the liver injury during hepatitis B.

Role of Th17 Cell and Autoimmunity in Chronic Obstructive Pulmonary Disease

  • Hong, Seok Chan;Lee, Seung-Hyo
    • IMMUNE NETWORK
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    • v.10 no.4
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    • pp.109-114
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    • 2010
  • The molecular mechanisms involved in the pathogenesis of chronic obstructive pulmonary disease (COPD) are poorly defined. Accumulating evidences indicate that chronic inflammatory responses and adaptive immunity play important roles in the development and progression of the disease. Recently, it has been shown that IL-17 producing CD4 T cells, named Th17 cells, which have been implicated in the pathogenesis of several inflammatory and autoimmune diseases, are involved in airway inflammation and COPD. In addition, we and others suggest that autoimmunity may play a critical role in the pathogenesis of COPD. Here, we will review the current understanding of roles of Th17 cells and autoimmune responses in COPD.

Regulation of the Immune System by NF-κB and IκB

  • Liou, Hsiou-Chi
    • BMB Reports
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    • v.35 no.6
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    • pp.537-546
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    • 2002
  • NF-${\kappa}B$/Rel transcription factor family participates in diverse biological processes including embryo development, hematopoiesis, immune regulation, as well as neuronal functions. In this review, the NF-${\kappa}B$/Rel signal transduction pathways and their important roles in the regulation of immune system will be discussed. NF-${\kappa}B$/Rel members execute distinct functions in multiple immune cell types via the regulation of target genes essential for cell proliferation, survival, effector functions, cell trafficking and communication, as well as the formation of lymphoid architecture. Consequently, proper activation of NF-${\kappa}B$/Rel during immune responses to allergens, auto-antigens, allo-antigens, and pathogenic infection is crucial for the integrity of host innate and adaptive immunity.

Dead cell phagocytosis and innate immune checkpoint

  • Yoon, Kyoung Wan
    • BMB Reports
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    • v.50 no.10
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    • pp.496-503
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    • 2017
  • The human body loses several billions of cells daily. When cells die in vivo, the corpse of each dead cell is immediately cleared. Specifically, dead cells are efficiently recognized and cleared by multiple types of neighboring phagocytes. Early research on cell death focused more on molecular mechanisms of cell death regulation while the cellular corpses were merely considered cellular debris. However, it has come to light that various biological stimuli following cell death are important for immune regulation. Clearance of normal dead cells occurs silently in immune tolerance. Exogenous or mutated antigens of malignant or infected cells can initiate adaptive immunity, thereby inducing immunogenicity by adjuvant signals. Several pathogens and cancer cells have strategies to limit the adjuvant signals and escape immune surveillance. In this review, we present an overview of the mechanisms of dead cell clearance and its immune regulations.

Allograft Immune Reaction of Kidney Transplantation Part 1. Mechanism of Allograft Rejection (신이식 후 면역반응의 이해 - 1부. 이식 거부 반응의 기전 -)

  • Kang, Hee-Gyung
    • Childhood Kidney Diseases
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    • v.12 no.1
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    • pp.23-29
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    • 2008
  • Kidney allograft transplantation is the most effective method of renal replacement for end stage renal disease patients. Still, it is another kind of 'disease', requiring immunosuppression to keep the allograft from rejection(allograft immune reaction). Immune system of the allograft recipient recognizes the graft as a 'pathogen (foreign or danger)', and the allograft-recognizing commanderin-chief of adaptive immune system, T cell, recruits all the components of immune system for attacking the graft. Proper activation and proliferation of T cell require signals from recognizing proper epitope(processed antigen by antigen presenting cell) via T cell receptor, costimulatory stimuli, and cytokines(IL-2). Thus, most of the immunosuppressive agents suppress the process of T cell activation and proliferation.

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Comparison and Analysis of the MC DS-CDMA/MPSK and DS-CDMA/MPSK Systems in Nakagami Fading (나카가미 감쇄에서 MC DS-CDMA/MPSK와 DS-CDMA/MPSK 시스템 비교 분석)

  • 이정도;강희조
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.10 no.6
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    • pp.951-958
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    • 1999
  • Multicarrier modulation or orthogonal frequency division multiplexing(OFDM) is a promising technique for mobile communications systems, since it has a strong immunity to multipath fading without employing complicated adaptive equalization. In this paper, performance of MC DS-CDMA/MPSK(multi-carrier direct sequence-code division multiple access/mary phase shift keying) and DS-CDMA/MPSK(direct sequence-code division multiple access/mary phase shift keying) with coherent detection for a CDMA system over Nakagami fading channel analysis. For a given bandwidth, it is shown that MC DS-CDMA/MPSK eventually outperforms DS-CDMA MPSK with random sequences.

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Temporal interpolator based on spatial filtering (공간 필터링에 근거한 시간축 내삽기)

  • 김종훈
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.33B no.8
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    • pp.60-67
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    • 1996
  • In this paper, we propose a new temporal interpolation method based on spatial filtering. Compared with the conventional method, the proposed one may use a few adjacent frames and apply temporal lowpass filtering. To develop this method, we follow the basic approach of sampling rate conversion. Additionally, we use some assumption of video sequence : moving object has constant velocity rigid translational motion. From them, spatial filtering for temporal sampling rate conversion is described. This method has a lot of noise immunity on a motion vector and doesn't make a great difference from the original frame. The interpolated frame shows moderate change even there is a great time difference. This method has exactly same description of motion adaptive spatial filter which has an efficient temporal band-limiting characteristics. It imposes the possibility to make video sequence with good pictural quality.

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Asthma has an adverse effect on the production of antibody to vaccines (천식이 예방접종 후 항체 형성에 미치는 영향)

  • Sheen, Youn Ho
    • Allergy, Asthma & Respiratory Disease
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    • v.6 no.6
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    • pp.279-283
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    • 2018
  • Asthma is considered a chronic inflammatory airway disease. Mounting evidence reports that patients with asthma are at significantly higher risk of developing communicable diseases such as invasive pneumococcal disease, Haemophilus influenza, varicella, measles, pertussis and tetanus. While impaired innate immunity may play a role in increased risk of developing these infections, suboptimal adaptive immune responses have also been reported to play a role in asthmatic subjects with regard to increased risk of infections. This review discusses the currently underrecognized immunological effect of asthma on antibody to vaccines and recommends that clinicians be aware of less optimal antibody production in response to vaccines in subjects with asthma.

Backbone assignment and structural analysis of anti-CRISPR AcrIF7 from Pseudomonas aeruginosa prophages

  • Kim, Iktae;Suh, Jeong-Yong
    • Journal of the Korean Magnetic Resonance Society
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    • v.25 no.3
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    • pp.39-44
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    • 2021
  • The CRISPR-Cas system provides adaptive immunity for bacteria and archaea against invading phages and foreign plasmids. In the Class 1 CRISPR-Cas system, multi-subunit Cas proteins assemble with crRNA to bind to DNA targets. To disarm the bacterial defense system, bacteriophages evolved anti-CRISPR (Acr) proteins that actively inhibit the host CRISPR-Cas function. Here we report the backbone resonance assignments of AcrIF7 protein that inhibits the type I-F CRISPR-Cas system of Pseudomonas aeruginosa using triple-resonance nuclear magnetic resonance spectroscopy. We employed various computational methods to predict the structure and binding interface of AcrIF7, and assessed the model with experimental data. AcrIF7 binds to Cas8f protein via flexible loop regions to inhibit target DNA binding, suggesting that conformational heterogeneity is important for the Cas-Acr interaction.