• Title/Summary/Keyword: host defense

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Innate Lymphoid Cells in Tissue Homeostasis and Disease Pathogenesis

  • Kim, Jihyun;Ryu, Seungwon;Kim, Hye Young
    • Molecules and Cells
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    • v.44 no.5
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    • pp.301-309
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    • 2021
  • Innate lymphoid cells (ILCs) are the most recently discovered family of innate immune cells. ILCs can be categorized into three groups on the basis of the transcription factors that direct their functions and the cytokines they produce. Notably, these functions parallel the effector functions of T lymphocytes. ILCs play a frontline role in host defense and tissue homeostasis by responding rapidly to environmental factors, conducting effector responses in a tissue-specific manner, and interacting with hematopoietic and non-hematopoietic cells throughout the body. Moreover, recent studies reveal that ILCs are involved in development of various inflammatory diseases, such as respiratory diseases, autoimmune diseases, or cancer. In this review, we discuss the recent findings regarding the biology of ILCs in health and inflammatory diseases.

Unsupervised learning with hierarchical feature selection for DDoS mitigation within the ISP domain

  • Ko, Ili;Chambers, Desmond;Barrett, Enda
    • ETRI Journal
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    • v.41 no.5
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    • pp.574-584
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    • 2019
  • A new Mirai variant found recently was equipped with a dynamic update ability, which increases the level of difficulty for DDoS mitigation. Continuous development of 5G technology and an increasing number of Internet of Things (IoT) devices connected to the network pose serious threats to cyber security. Therefore, researchers have tried to develop better DDoS mitigation systems. However, the majority of the existing models provide centralized solutions either by deploying the system with additional servers at the host site, on the cloud, or at third party locations, which may cause latency. Since Internet service providers (ISP) are links between the internet and users, deploying the defense system within the ISP domain is the panacea for delivering an efficient solution. To cope with the dynamic nature of the new DDoS attacks, we utilized an unsupervised artificial neural network to develop a hierarchical two-layered self-organizing map equipped with a twofold feature selection for DDoS mitigation within the ISP domain.

Identification of a novel $Ca^{2+}$-independent Phospholipase $A_2$ in Bovine Brain

  • Jeong, Eui-Man;Jun, Hyung-Jin;Kim, Ha-Dong;Lee, Ho-Sup;Min, Pil-Gi;Jo, Dong-Hwan;Jung, Sung-Yun;Kim, Dea-Kyong
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.102.1-102.1
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    • 2003
  • Phospholipase A$_2$(PLA$_2$) catalyzes the hydrolysis of the sn-2 position of membrane glycerophospholipids to liberate arachidonic acid(AA), a precursor of eicosanoids including prostaglandins(PGs) and leukotrienes (LTs). The same reaction also produces lyso-phospholipids. So far, at least 19 enzymes that possess PLA2 activity have been identified, consists of low-molecular-weight, Ca$\^$2+/-requiring, secretory enzymes that have been implicated in a number of biological processes, such as modification of eicosanoid generation, inflammation, host defense, and atherosclerosis. (omitted)

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Managing oral biofilms to avoid enamel demineralization during fixed orthodontic treatment

  • Jung-Sub An;Bum-Soon Lim;Sug-Joon Ahn
    • The korean journal of orthodontics
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    • v.53 no.6
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    • pp.345-357
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    • 2023
  • Enamel demineralization represents the most prevalent complication arising from fixed orthodontic treatment. Its main etiology is the development of cariogenic biofilms formed around orthodontic appliances. Ordinarily, oral biofilms exist in a dynamic equilibrium with the host's defense mechanisms. However, the equilibrium can be disrupted by environmental changes, such as the introduction of a fixed orthodontic appliance, resulting in a shift in the biofilm's microbial composition from non-pathogenic to pathogenic. This alteration leads to an increased prevalence of cariogenic bacteria, notably mutans streptococci, within the biofilm. This article examines the relationships between oral biofilms and orthodontic appliances, with a particular focus on strategies for effectively managing oral biofilms to mitigate enamel demineralization around orthodontic appliances.

Regulation of Th2 Cell Immunity by Dendritic Cells

  • Hyeongjin Na;Minkyoung Cho;Yeonseok Chung
    • IMMUNE NETWORK
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    • v.16 no.1
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    • pp.1-12
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    • 2016
  • Th2 cell immunity is required for host defense against helminths, but it is detrimental in allergic diseases in humans. Unlike Th1 cell and Th17 cell subsets, the mechanism by which dendritic cells modulate Th2 cell responses has been obscure, in part because of the inability of dendritic cells to provide IL-4, which is indispensable for Th2 cell lineage commitment. In this regard, immune cells other than dendritic cells, such as basophils and innate lymphoid cells, have been suggested as Th2 cell inducers. More recently, multiple independent researchers have shown that specialized subsets of dendritic cells mediate Th2 cell responses. This review will discuss the current understanding related to the regulation of Th2 cell responses by dendritic cells and other immune cells.

The Innate Immune Viral Sensors and Their Functional Crosstalk

  • Ji-Seung Yoo
    • Microbiology and Biotechnology Letters
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    • v.52 no.2
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    • pp.105-113
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    • 2024
  • The precise and elaborate regulation of signaling cascades by diverse cytoplasmic and endosomal antiviral sensors is crucial for maintaining immune homeostasis and defending against viral pathogens. Receptors and enzymes that recognize foreign nucleic acids play a pivotal role in inducing antiviral interferon programs, serving as the first line of defense against various DNA and RNA viruses. Recent research has increasingly highlighted the crosstalk between nucleic acid sensors in detecting multiple virus invasions, resulting in amplified antiviral signals and compensating for any missing roles. This review provides an update on recent findings regarding the interplay of RNA sensors for DNA virus recognition.

Modulated Gene Expression of Toxoplasma gondii Infected Retinal Pigment Epithelial Cell Line (ARPE-19) via PI3K/Akt or mTOR Signal Pathway

  • Zhou, Wei;Quan, Juan-Hua;Gao, Fei-Fei;Ismail, Hassan Ahmed Hassan Ahmed;Lee, Young-Ha;Cha, Guang-Ho
    • Parasites, Hosts and Diseases
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    • v.56 no.2
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    • pp.135-145
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    • 2018
  • Due to the critical location and physiological activities of the retinal pigment epithelial (RPE) cell, it is constantly subjected to contact with various infectious agents and inflammatory mediators. However, little is known about the signaling events in RPE involved in Toxoplasma gondii infection and development. The aim of the study is to screen the host mRNA transcriptional change of 3 inflammation-related gene categories, PI3K/Akt pathway regulatory components, blood vessel development factors and ROS regulators, to prove that PI3K/Akt or mTOR signaling pathway play an essential role in regulating the selected inflammation-related genes. The selected genes include PH domain and leucine- rich-repeat protein phosphatases (PHLPP), casein kinase2 (CK2), vascular endothelial growth factor (VEGF), pigment epithelium-derived factor (PEDF), glutamate-cysteine ligase (GCL), glutathione S-transferase (GST), and NAD(P)H: quinone oxidoreductase (NQO1). Using reverse transcription polymerase chain reaction (RT-PCR) and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR), we found that T. gondii up-regulates PHLPP2, $CK2{\beta}$, VEGF, GCL, GST and NQO1 gene expression levels, but down-regulates PHLPP1 and PEDF mRNA transcription levels. PI3K inhibition and mTOR inhibition by specific inhibitors showed that most of these host gene expression patterns were due to activation of PI3K/Akt or mTOR pathways with some exceptional cases. Taken together, our results reveal a new molecular mechanism of these gene expression change dependent on PI3K/Akt or mTOR pathways and highlight more systematical insight of how an intracellular T. gondii can manipulate host genes to avoid host defense.

Association between Tuberculosis Case and CD44 Gene Polymorphism (결핵 발병과 CD44 유전자 다형성사이의 연관성 연구)

  • Lim, Hee-Seon;Lee, Sang-In;Park, Sangjung
    • Korean Journal of Clinical Laboratory Science
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    • v.51 no.3
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    • pp.323-328
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    • 2019
  • Tuberculosis, a chronic bacterial infection caused by Mycobacterium tuberculosis (MTB), differs in its status latency and activity because of the characteristics of MTB, immune status of the host, and genetic susceptibility. The host defense mechanism against MTB is caused mainly by interactions between macrophages, T cells, and dendritic cells. CD44 is expressed in activated T cells when infected with MTB and regulates lymphocyte migration. In addition, CD44 mediates leukocyte adhesion to the ECM and plays a role in attracting macrophages and $CD4^+$ T cells to the lungs. Therefore, genetic polymorphism of the CD44 gene will inhibit the host cell immune mechanisms against MTB. This study examined whether the genetic polymorphism of the CD44 gene affects the susceptibility of tuberculosis. A total of 237 SNPs corresponding to the CD44 genes were analyzed using the genotype data of 443 tuberculosis cases and 3,228 healthy controls from the Korean Association Resource (KARE). Of these, 17 SNPs showed a significant association with the tuberculosis case. The most significant SNP was rs75137824 (OR=0.231, CI: 1.51~3.56, $P=1.3{\times}10^{-4}$). In addition, rs10488809, one of the 17 significant SNPs, is important for the tuberculosis outbreak can bind to the JUND and FOS transcription factors and can affect CD44 gene expression. This study suggests that polymorphism of the CD44 gene modulates the host susceptibility to tuberculosis in a variety of ways, resulting in differences in the status of tuberculosis.

Transcriptomic Profile in Pear Leave with Resistance Against Venturia nashicola Infection (배 검은별무늬병 감염과 저항성 방어반응 연관 전사체 프로파일)

  • Il Sheob Shin;Jaean Chun;Sehee Kim;Kanghee Cho;Kyungho Won;Haewon Jung;Keumsun Kim
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2022.09a
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    • pp.36-36
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    • 2022
  • The molecular understanding of resistance and susceptibility of host plants to scab, a most threatful disease to pome fruit production worldwide, is very limited. Comparing resistant line '93-3-98' to susceptible one 'Sweet Skin' at seven time points of 0, 0.5, 1, 2, 3, 4, 8 days post inoculation, RNA-sequencing data derived from infected and mock-inoculated young leaves were analyzed to evaluate the tolerant response and to mine candidate genes of pear to the scab pathogen Venturia nashicola. Analysis of the mapped reads showed that the infection of V. nashicola led to significant differential expression of 17,827 transcripts with more than 3-fold change in the seven pairs of libraries, of which 9,672 (54%) are up- and 8,155(46%) are down-regulated. These included mainly receptor (NB-ARC domains-containing, CC-NBS-LRR, TIR-NBS-LRR, seven transmembrane MLO family protein) and transcription factor (ethylene responsive element binding, WRKY DNA-binding protein) related gene. An arsenal of defense response of highly resistant pear accessions derived from European pear was probably supposed no sooner had V. nashicola infected its host than host genes related to disease suppression like Polyketide cyclase/dehydrase and lipid transport protein, WRKY family transcription factor, lectin protein kinase, cystein-rich RLK, calcium-dependent phospholipid-binding copine protein were greatly boosted and eradicated cascade reaction induced by pathogen within 24 hours. To identify transcripts specifically expressed in response to V. nashicola, RT-PCRs were conducted and compare to the expression patterns of seven cultivars with a range of highly resistant to highly susceptible symptom. A DEG belonging to the PR protein family genes that were higher expressed in response to V. nashicola suggesting extraordinary role in the resistance response were led to the identification. This study provides the first transcriptional profile by RNA-seq of the host plant during scab disease and insights into the response of tolerant pear plants to V. nashicola.

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