• Title/Summary/Keyword: Immune Functions

검색결과 565건 처리시간 0.026초

Recent Advances in the Innate Immunity of Invertebrate Animals

  • Iwanaga, Sadaaki;Lee, Bok-Luel
    • BMB Reports
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    • 제38권2호
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    • pp.128-150
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    • 2005
  • Invertebrate animals, which lack adaptive immune systems, have developed other systems of biological host defense, so called innate immunity, that respond to common antigens on the cell surfaces of potential pathogens. During the past two decades, the molecular structures and functions of various defense components that participated in innate immune systems have been established in Arthropoda, such as, insects, the horseshoe crab, freshwater crayfish, and the protochordata ascidian. These defense molecules include phenoloxidases, clotting factors, complement factors, lectins, protease inhibitors, antimicrobial peptides, Toll receptors, and other humoral factors found mainly in hemolymph plasma and hemocytes. These components, which together compose the innate immune system, defend invertebrate from invading bacterial, fungal, and viral pathogens. This review describes the present status of our knowledge concerning such defensive molecules in invertebrates.

Activation-induced Cytidine Deaminase in B Cell Immunity and Cancers

  • Park, Seok-Rae
    • IMMUNE NETWORK
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    • 제12권6호
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    • pp.230-239
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    • 2012
  • Activation-induced cytidine deaminase (AID) is an enzyme that is predominantly expressed in germinal center B cells and plays a pivotal role in immunoglobulin class switch recombination and somatic hypermutation for antibody (Ab) maturation. These two genetic processes endow Abs with protective functions against a multitude of antigens (pathogens) during humoral immune responses. In B cells, AID expression is regulated at the level of either transcriptional activation on AID gene loci or post-transcriptional suppression of AID mRNA. Furthermore, AID stabilization and targeting are determined by post-translational modifications and interactions with other cellular/nuclear factors. On the other hand, aberrant expression of AID causes B cell leukemias and lymphomas, including Burkitt's lymphoma caused by c-myc/IgH translocation. AID is also ectopically expressed in T cells and non-immune cells, and triggers point mutations in relevant DNA loci, resulting in tumorigenesis. Here, I review the recent literatures on the function of AID, regulation of AID expression, stability and targeting in B cells, and AID-related tumor formation.

유산균체와 유단백질 유래 Peptide의 면역조절 기능 연구 동향

  • 김철현
    • 한국유가공학회:학술대회논문집
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    • 한국유가공기술과힉회 2008년도 추계학술대회 논문집
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    • pp.39-50
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    • 2008
  • The immune system of mammals includes a complex array of cells and molecules, which interact to provide protection from pathogenic microorganisms. The beneficial role played by lactic acid bacteria and milk-derived peptide in the humans, including the effects on the immune system, has been extensively reported. They are present in dairy products and are frequently used as nutraceuticals to some improve some biological functions in the host. The activation of the systemic and secretory immune response by lactic acid bacteria and milk-derived peptide requires many complex interactions among th different constituents of the intestinal ecosystem. The aim of this review was to make the point about the immunological potential of lactic acid bacteria and milk-derived peptide.

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Aflatoxin B1의 면역억제작용 (Immunosuppressive Effect of Aflatoxin B1)

  • 문은미;이동권;표석능
    • Biomolecules & Therapeutics
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    • 제4권2호
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    • pp.190-195
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    • 1996
  • Aflatoxin B1 (AFB1) has been reported to directly suppress the immune responses. In the present study, the effect of AFB1 on immune functions was investigated. Splenic lymphocytes were treated with various doses of the mitogens (lipopolysaccharide, concanavalin A) in the presence of AFB1. AFB1 pretretment decreased the number of plaque forming cells (PFC) in a dose-dependent manner. Antibody production of IgM and IgG class was significantly decreased in AFB1-treated splenic cells. In addition, when animals were exposed to AFB1, the susceptibility of bacterial infection as well as the growth of tumor cells was increased. These data suggest that AFB1 affected the immune function and humoral immunity impaired by AFB1 treatment contributed to pathological process.

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The Roles of RUNX Family Proteins in Development of Immune Cells

  • Seo, Wooseok;Taniuchi, Ichiro
    • Molecules and Cells
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    • 제43권2호
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    • pp.107-113
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    • 2020
  • The Runt-related transcription factors (RUNX) transcription factors have been known for their critical roles in numerous developmental processes and diseases such as autoimmune disorders and cancer. Especially, RUNX proteins are best known for their roles in hematopoiesis, particularly during the development of T cells. As scientists discover more types of new immune cells, the functional diversity of RUNX proteins also has been increased over time. Furthermore, recent research has revealed complicated transcriptional networks involving RUNX proteins by the current technical advances. Databases established by next generation sequencing data analysis has identified ever increasing numbers of potential targets for RUNX proteins and other transcription factors. Here, we summarize diverse functions of RUNX proteins mainly on lymphoid lineage cells by incorporating recent discoveries.

Immunomodulatory Response Induced by Ginseng

  • Kumar Ashok
    • 고려인삼학회:학술대회논문집
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    • 고려인삼학회 2002년도 학술대회지
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    • pp.366-375
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    • 2002
  • There has been continuing interest in the development of synthetic and natural compounds that modify the immune response particularly for the treatment of AIDS and cancer. During the past fifty years, numerous scientific studies have been published on ginseng (Foster and Chongxi, 1992). Modern human studies have investigated preventive effect of ginseng on several kinds of cancer (Yun et al, 1993,Yun, 1995,Yun and Choi, 1998), its long term immunological effect on HIV patients (Sankang, 1989, Cho et al, 1997), its effect on cell mediated immune functions in healthy volunteers (Scaglione et al, 1990). Similarly non clinical studies on animal model system have studied the chemopreventive action of ginseng on cancer (Kumar, 1993,98) and immunological properties of ginseng (Kim et al, 1990, Tomoda et al, 1993, Yun et al, 1993, Mizuno et al, 1994,Lee et al, 1997, Park et al, 2001,Yoshikawa et al, 2001, Wang et al, 2001). The precise mechanism of action of ginseng, however, not clearly understood. Considering its wide-ranging therapeutic effects, this study is being undertaken to elucidate the general mode of action of ginseng, especially to test our hypothesis that its biological action may be mediated by the immune system.

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Roles of heterogenous hepatic macrophages in the progression of liver diseases

  • Lee, Kyeong-Jin;Kim, Mi-Yeon;Han, Yong-Hyun
    • BMB Reports
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    • 제55권4호
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    • pp.166-174
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    • 2022
  • Hepatic macrophages are key immune cells associated with the broad ranges of liver diseases including steatosis, inflammation and fibrosis. Hepatic macrophages interact with other immune cells and orchestrate hepatic immune circumstances. Recently, the heterogenous populations of hepatic macrophages have been discovered termed residential Kupffer cells and monocyte-derived macrophages, and identified their distinct population dynamics during the progression of various liver diseases. Liver injury lead to Kupffer cells activation with induction of inflammatory cytokines and chemokines, which triggers recruitment of inflammatory monocyte-derived macrophages. To understand liver pathology, the functions of different subtypes of liver macrophages should be regarded with different perspectives. In this review, we summarize recent advances in the roles of hepatic macrophages under liver damages and suggest hepatic macrophages as promising therapeutic targets for treating liver diseases.

Current Understanding of Cytotoxic T Lymphocyte Antigen-4 (CTLA-4) Signaling in T-Cell Biology and Disease Therapy

  • Kim, Gil-Ran;Choi, Je-Min
    • Molecules and Cells
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    • 제45권8호
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    • pp.513-521
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    • 2022
  • Cytotoxic T lymphocyte antigen-4 (CTLA-4) is an immune checkpoint molecule that is mainly expressed on activated T cells and regulatory T (Treg) cells that inhibits T-cell activation and regulates immune homeostasis. Due to the crucial functions of CTLA-4 in T-cell biology, CTLA-4-targeted immunotherapies have been developed for autoimmune disease as well as cancers. CTLA-4 is known to compete with CD28 to interact with B7, but some studies have revealed that its downstream signaling is independent of its ligand interaction. As a signaling domain of CTLA-4, the tyrosine motif plays a role in inhibiting T-cell activation. Recently, the lysine motif has been shown to be required for the function of Treg cells, emphasizing the importance of CTLA-4 signaling. In this review, we summarize the current understanding of CTLA-4 biology and molecular signaling events and discuss strategies to target CTLA-4 signaling for immune modulation and disease therapy.

Integration of the Innate and Adaptive Immunity by CD137-CD137L Bidirectional Signals: Implications in Allograft Rejection

  • Park, Sang June;Lee, Jong Soo;Kwon, Byungsuk;Cho, Hong Rae
    • 대한이식학회지
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    • 제28권3호
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    • pp.113-120
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    • 2014
  • Two-signal models are useful in explaining various types of immune responses. In particular, secondary, so-called costimulatory, signals are critically required for the process of T-cell activation, survival, differentiation, and memory formation. Early studies in rodent models showed that targeting T-cell costimulatory pathways elicits immunological tolerance, providing a basis for development of costimulatory therapeutics in allograft rejection. However, as the classic definition of T-cell costimulation continues to evolve, simple blockade of costimulatory pathways has limitations in prevention of allograft rejection. Furthermore, functions of costimulatory molecules are much more diverse than initially anticipated and beyond T cells. In this mini-review, we will discuss CD137-CD137L bidirectional signals as examples showing that two-signals can be applicable to multiple phases of immune responses.

C4orf47 is a Novel Prognostic Biomarker and Correlates with Infiltrating Immune Cells in Hepatocellular Carcinoma

  • Hye-Ran Kim;Choong Won Seo;Sang Jun Han;Jongwan Kim
    • 대한의생명과학회지
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    • 제29권1호
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    • pp.11-25
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    • 2023
  • In hepatocellular carcinoma (HCC), chromosome 4 open-reading frame 47 (C4orf47) has not been so far investigated for its prognostic value or association with infiltrating immune cells. We performed bioinformatics analysis on HCC data and analyzed the data using online databases such as TIMER, UALCAN, Kaplan-Meier plotter, LinkedOmics, and GEPIA2. We found that C4orf47 expression in HCC was higher compared to normal tissues. High C4orf47 expression was associated with a worse prognosis in HCC. The correlation between C4orf47 and infiltrating immune cells is positively associated with CD4+T cells, B cells, neutrophils, macrophages, and dendritic cells in HCC. Moreover, high C4orf47 expression was correlated with a poor prognosis of infiltrating immune cells. Analysis of C4orf47 gene co-expression networks revealed that 12501 genes were positively correlated with C4orf47, whereas 7200 genes were negatively correlated. The positively related genes of C4orf47 are associated with a high hazard ratio in different types of cancer, including HCC. Regarding the biological functions of C4orf47 gene, it mainly regulates RNA metabolic process, DNA replication, and cell cycle. The C4orf47 gene may play a prognostic role by regulating the global transcriptome process in HCC. Our findings demonstrate that high C4orf47 expression correlates with poor prognosis and tumor-infiltrating immune cells in HCC. We suggest that C4orf47 is a novel prognostic biomarker and potential immune therapeutic target for HCC.