• Title/Summary/Keyword: immune regulation

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Gene structure and expression characteristics of liver-expressed antimicrobial peptide-2 isoforms in mud loach (Misgurnus mizolepis, Cypriniformes)

  • Lee, Sang Yoon;Nam, Yoon Kwon
    • Fisheries and Aquatic Sciences
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    • v.20 no.12
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    • pp.31.1-31.11
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    • 2017
  • Background: Liver-expressed antimicrobial peptide-2 (LEAP-2) is an important component of innate immune system in teleosts. In order to understand isoform-specific involvement and regulation of LEAP-2 genes in mud loach (Misgurnus mizolepis, Cypriniformes), a commercially important food fish, this study was aimed to characterize gene structure and expression characteristics of two paralog LEAP-2 isoforms. Results: Mud loach LEAP-2 isoforms (LEAP-2A and LEAP-2B) showed conserved features in the core structure of mature peptides characterized by four Cys residues to form two disulfide bonds. The two paralog isoforms represented a tripartite genomic organization, known as a common structure of vertebrate LEAP-2 genes. Bioinformatic analysis predicted various transcription factor binding motifs in the 5'-flanking regions of mud loach LEAP-2 genes with regard to development and immune response. Mud loach LEAP-2A and LEAP-2B isoforms exhibited different tissue expression patterns and were developmentally regulated. Both isoforms are rapidly modulated toward upregulation during bacterial challenge in an isoform and/or tissue-dependent fashion. Conclusion: Both LEAP-2 isoforms play protective roles not only in embryonic and larval development but also in early immune response to bacterial invasion in mud loach. The regulation pattern of the two isoform genes under basal and stimulated conditions would be isoform-specific, suggestive of a certain degree of functional divergence between isoforms in innate immune system in this species.

Post-Translational Modifications in Transcription Factors that Determine T Helper Cell Differentiation

  • Kim, Hyo Kyeong;Jeong, Mi Gyeong;Hwang, Eun Sook
    • Molecules and Cells
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    • v.44 no.5
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    • pp.318-327
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    • 2021
  • CD4+ T helper (Th) cells play a crucial role in the modulation of innate and adaptive immune responses through the differentiation of Th precursor cells into several subsets, including Th1, Th2, Th17, and regulatory T (Treg) cells. Effector Th and Treg cells are distinguished by the production of signature cytokines and are important for eliminating intracellular and extracellular pathogens and maintaining immune homeostasis. Stimulation of naive Th cells by T cell receptor and specific cytokines activates master transcription factors and induces lineage specification during the differentiation of Th cells. The master transcription factors directly activate the transcription of signature cytokine genes and also undergo post-translational modifications to fine-tune cytokine production and maintain immune balance through cross-regulation with each other. This review highlights the post-translational modifications of master transcription factors that control the differentiation of effector Th and Treg cells and provides additional insights on the immune regulation mediated by protein argininemodifying enzymes in effector Th cells.

Epigenetic memory in gene regulation and immune response

  • Kim, Min Young;Lee, Ji Eun;Kim, Lark Kyun;Kim, TaeSoo
    • BMB Reports
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    • v.52 no.2
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    • pp.127-132
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    • 2019
  • Cells must fine-tune their gene expression programs for optimal cellular activities in their natural growth conditions. Transcriptional memory, a unique transcriptional response, plays a pivotal role in faster reactivation of genes upon environmental changes, and is facilitated if genes were previously in an active state. Hyper-activation of gene expression by transcriptional memory is critical for cellular differentiation, development, and adaptation. TREM (Transcriptional REpression Memory), a distinct type of transcriptional memory, promoting hyper-repression of unnecessary genes, upon environmental changes has been recently reported. These two transcriptional responses may optimize specific gene expression patterns, in rapidly changing environments. Emerging evidence suggests that they are also critical for immune responses. In addition to memory B and T cells, innate immune cells are transcriptionally hyperactivated by restimulation, with the same or different pathogens known as trained immunity. In this review, we briefly summarize recent progress in chromatin-based regulation of transcriptional memory, and its potential role in immune responses.

Interleukin-32 in Inflammatory Autoimmune Diseases

  • Kim, Soohyun
    • IMMUNE NETWORK
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    • v.14 no.3
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    • pp.123-127
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    • 2014
  • Interleukin-32 (IL-32) is a cytokine inducing crucial inflammatory cytokines such as tumor necrosis factor-${\alpha}(TNF{\alpha})$ and IL-6 and its expression is elevated in various inflammatory autoimmune diseases, certain cancers, as well as viral infections. IL-32 gene was first cloned from activated T cells, however IL-32 expression was also found in other immune cells and non-immune cells. IL-32 gene was identified in most mammals except rodents. It is transcribed as multiple-spliced variants in the absence of a specific activity of each isoform. IL-32 has been studied mostly in clinical fields such as infection, autoimmune, cancer, vascular disease, and pulmonary diseases. It is difficult to investigate the precise role of IL-32 in vivo due to the absence of IL-32 gene in mouse. The lack of mouse IL-32 gene restricts in vivo studies and restrains further development of IL-32 research in clinical applications although IL-32 new cytokine getting a spotlight as an immune regulatory molecule processing important roles in autoimmune, infection, and cancer. In this review, we discuss the regulation and function of IL-32 in inflammatory bowel diseases and rheumatoid arthritis.

Emerging role of Hippo pathway in the regulation of hematopoiesis

  • Inyoung Kim;Taeho Park;Ji-Yoon Noh;Wantae Kim
    • BMB Reports
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    • v.56 no.8
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    • pp.417-425
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    • 2023
  • In various organisms, the Hippo signaling pathway has been identified as a master regulator of organ size determination and tissue homeostasis. The Hippo signaling coordinates embryonic development, tissue regeneration and differentiation, through regulating cell proliferation and survival. The YAP and TAZ (YAP/TAZ) act as core transducers of the Hippo pathway, and they are tightly and exquisitely regulated in response to various intrinsic and extrinsic stimuli. Abnormal regulation or genetic variation of the Hippo pathway causes a wide range of human diseases, including cancer. Recent studies have revealed that Hippo signaling plays a pivotal role in the immune system and cancer immunity. Due to pathophysiological importance, the emerging role of Hippo signaling in blood cell differentiation, known as hematopoiesis, is receiving much attention. A number of elegant studies using a genetically engineered mouse (GEM) model have shed light on the mechanistic and physiological insights into the Hippo pathway in the regulation of hematopoiesis. Here, we briefly review the function of Hippo signaling in the regulation of hematopoiesis and immune cell differentiation.

Alloferon Alleviates Dextran Sulfate Sodium-induced Colitis

  • Kim, Hyemin;Im, Jong Pil;Kim, Joo Sung;Kang, Jae Seung;Lee, Wang Jae
    • IMMUNE NETWORK
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    • v.15 no.3
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    • pp.135-141
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    • 2015
  • Dysfunction of gut immune regulation is involved in mucosal damage in inflammatory bowel disease (IBD). However, there is still no efficacious immune-regulator for the treatment of IBD. Alloferon is a novel immune-modulatory peptide that was originally isolated from infected insects. It shows anti-inflammatory effects by the regulation of cytokine production by immune cells and their activities. Therefore, we investigated the effect of alloferon in a mouse model of colitis using dextran sulfate sodium (DSS). Colitis was induced by administration of DSS in drinking water for 7 consecutive days. It was confirmed by the presence of weight loss, diarrhea, hematochezia, and colon contraction. Alloferon was injected 4 days after DSS administration. We found that alloferon improved the pathogenesis of IBD based on the reduced disease activity index (DAI) and colon contraction. Edema, epithelial erosion, and immune cell infiltration were found in mice administered DSS, but the phenomena were reduced following alloferon treatment. The plasma level of IL-6, a classical pro-inflammatory cytokine in colitis, was also decreased by alloferon. Moreover, alloferon inhibited the TNF-${\alpha}$-induced degradation and phosphorylation of $I{\kappa}B$ in Colo205 colon cancer cells. Taken together, these results show that alloferon has anti-inflammatory effects and attenuates DSS-induced colitis.

Transcriptome Analysis to Characterize the Immune Response of NecroX-7 in Mouse CD4+ T Cells

  • Kim, Eun-Jung
    • Biomedical Science Letters
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    • v.21 no.2
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    • pp.60-68
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    • 2015
  • NecroX-7 is a novel small compound of the NecroX series based on the indole moiety, which has potent cytoprotective and antioxidant properties. We previously detected potential immune regulatory effects of NecroX-7 in immune related diseases like Graft-versus-Host Disease. However, the function and the underlying mechanisms of immunological effects of NecroX-7 in the immune system have not been well established. In this study, we investigated the immune response characterization of differentially expressed genes of NecroX-7 administration in $CD4^+$ T cells by microarray analysis. $CD4^+$ T cells stimulated with NecroX-7 ($40{\mu}M$) or vehicle for 72 hours resulted in the identification of 337 differentially expressed genes (1.5 fold, P<0.05) by expression profiling analysis. Twenty eight of the explored NecroX-7-regulated genes were related to immune system processes. These genes were validated by quantitative real-time PCR. The most significant genes were glutathione reductase, eukaryotic translation elongation factor 1, lymphotoxin-alpha, heat shock protein 9 and chloride intracellular channel protein 4. These findings demonstrate the strongly immune response of NecroX-7 in $CD4^+$ T cells, suggesting that cytoprotection and immune regulation may underlie the critical aspects of NecroX-7 exposure.

Effect of Pedunculagin on IL-1$\beta$ mRNA Expression in Langerhans cells (랑게르한스세포에서 IL-1$\beta$ mRNA 발현에 대한 Pedunculagin의 효과)

  • 주성수;권희승;강희철;이도익
    • YAKHAK HOEJI
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    • v.46 no.6
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    • pp.472-476
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    • 2002
  • Contact hypersensitivity (CHS) serves as a good model of cell-mediated reaction. Epidermal langerhans cell (LC) are thought to playa crucial role in the regulation of immune reaction of the skin, which elicit the CHS response by presenting Antigen to trafficking Ag-specific T cells within the skin. However, contact hypersensitivity is regarded as a negative side of immunities, caused by increased damaging immune response. Therefore, the study of effector molecule causing immune suppression is thought to be meaningful in the skin immune response. For this aim, this study investigated the influence of pedunculagin on cytokine, IL-$\beta$ expression from langerhans cell (LC). In vitro and in vivo, pedunculagin up-regulated the expression of IL-1$\beta$ mRNA. After PMA stimulation in vitro and DNFB sensitization in vivo, the expression of IL-1$\beta$ mRNA was down-regulated. This results suggested that pedunculagin could be immuno-modulator in skin immune system by modulating IL-1$\beta$ expression.

Molecular Mechanisms Governing IL-24 Gene Expression

  • Sahoo, Anupama;Im, Sin-Hyeog
    • IMMUNE NETWORK
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    • v.12 no.1
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    • pp.1-7
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    • 2012
  • Interleukin-24 (IL-24) belongs to the IL-10 family of cytokines and is well known for its tumor suppressor activity. This cytokine is released by both immune and nonimmune cells and acts on non-hematopoietic tissues such as skin, lung and reproductive tissues. Apart from its ubiquitous tumor suppressor function, IL-24 is also known to be involved in the immunopathology of autoimmune diseases like psoriasis and rheumatoid arthritis. Although the cellular sources and functions of IL-24 are being increasingly investigated, the molecular mechanisms of IL-24 gene expression at the levels of signal transduction, epigenetics and transcription factor binding are still unclear. Understanding the specific molecular events that regulate the production of IL-24 will help to answer the remaining questions that are important for the design of new strategies of immune intervention involving IL-24. Herein, we briefly review the signaling pathways and transcription factors that facilitate, induce, or repress production of this cytokine along with the cellular sources and functions of IL-24.

Innate immune response to oral bacteria and the immune evasive characteristics of periodontal pathogens

  • Ji, Suk;Choi, Youngnim
    • Journal of Periodontal and Implant Science
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    • v.43 no.1
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    • pp.3-11
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    • 2013
  • Periodontitis is a chronic inflammation of periodontal tissue caused by subgingival plaque-associated bacteria. Periodontitis has long been understood to be the result of an excessive host response to plaque bacteria. In addition, periodontal pathogens have been regarded as the causative agents that induce a hyperinflammatory response from the host. In this brief review, host-microbe interaction of nonperiodontopathic versus periodontopathic bacteria with innate immune components encountered in the gingival sulcus will be described. In particular, we will describe the susceptibility of these microbes to antimicrobial peptides (AMPs) and phagocytosis by neutrophils, the induction of tissue-destructive mediators from neutrophils, the induction of AMPs and interleukin (IL)-8 from gingival epithelial cells, and the pattern recognition receptors that mediate the regulation of AMPs and IL-8 in gingival epithelial cells. This review indicates that true periodontal pathogens are poor activators/suppressors of a host immune response, and they evade host defense mechanisms.