• Toxicological Research
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• v.23 no.2
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• pp.97-105
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• 2007

Toll-like receptors (TLRs) playa crucial role in initiating and regulating innate and adaptive immune responses by detecting invading microbial pathogens. TLRs can also respond to non-microbial molecules derived from damaged tissue. Accumulating evidence suggests that deregulation of TLRs results in the dysfunction of immune system and ultimately increases the risk of many immune and inflammatory diseases including infectious diseases, allergy, and autoimmune diseases. Therefore, understanding how the immune system is controlled by TLRs will provide new insight to find the way to prevent or treat infectious diseases and immune disorders.

• Food Science of Animal Resources
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• v.30 no.1
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• pp.1-12
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• 2010

The immune system is generally divided into the innate and the adopted immune systems, both protecting the body from pathogens. Recently, allergies, a disease associated with an imbalanced immune system, have increased rapidly in developed countries. Prevailing symptoms of allergic diseases are eczema, allergic rhinitis, asthma, inflammatory bowel disease, and food allergy. Probiotic bacteria, mainly consisting of lactic acid bacteria, are used in the prevention and treatment of allergic diseases. The function of them is to stimulate the intestinal immune cells and form a complex signal network to activate other immune cells. Beneficial health effects of probiotics are based on the hygiene hypothesis, which suggests that sanitary environment is important for health, but limited exposure to environmental factors increases allergic diseases. An immunoregulatory effect of probiotic bacteria is demonstrated by controlled trial, animal model, in vitro, in vivo and ex vivo designs. However, the immunoregulatory effect of probiotic bacteria is controversial because it depends on probiotic strains, a dose and a type of diseases. In this review, we discussed clinical evidences on immunoregulatory effects of probiotic bacteria.

• IMMUNE NETWORK
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• v.14 no.1
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• pp.1-6
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• 2014

Epstein-Barr virus (EBV) is etiologically associated with a variety of diseases including lymphoproliferative diseases, lymphomas, carcinomas, and autoimmune diseases. Humans are the only natural host of EBV and limited species of new-world monkeys can be infected with the virus in experimental conditions. Small animal models of EBV infection, required for evaluation of novel therapies and vaccines for EBV-associated diseases, have not been available. Recently the development of severely immunodeficient mouse strains enabled production of humanized mice in which human immune system components are reconstituted and express their normal functions. Humanized mice can serve as infection models for human-specific viruses such as EBV that target cells of the immune system. This review summarizes recent studies by the author's group addressing reproduction of EBV infection and pathogenesis in humanized mice.

• IMMUNE NETWORK
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• v.19 no.1
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• pp.4.1-4.16
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• 2019

Long noncoding RNAs (lncRNAs) are non-protein coding RNAs of more than 200 nucleotides in length. Despite the term "noncoding", lncRNAs have been reported to be involved in gene expression. Accumulating evidence suggests that lncRNAs play crucial roles in the regulation of immune system and the development of autoimmunity. lncRNAs are expressed in various immune cells including T lymphocytes, B lymphocytes, macrophages, neutrophils, dendritic cells, and NK cells, and are also involved in the differentiation and activation of these immune cells. Here, we review recent studies on the role of lncRNAs in immune regulation and the differential expression of lncRNAs in various autoimmune diseases.

• IMMUNE NETWORK
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• v.22 no.3
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• pp.21.1-21.21
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• 2022

As far the current severe coronavirus disease 2019 (COVID-19), respiratory disease is still the biggest threat to human health. In addition, infectious respiratory diseases are particularly prominent. In addition to killing and clearing the infection pathogen directly, regulating the immune responses against the pathogens is also an important therapeutic modality. Sirtuins belong to NAD+-dependent class III histone deacetylases. Among 7 types of sirtuins, silent information regulator type-1 (SIRT1) played a multitasking role in modulating a wide range of physiological processes, including oxidative stress, inflammation, cell apoptosis, autophagy, antibacterial and antiviral functions. It showed a critical effect in regulating immune responses by deacetylation modification, especially through high-mobility group box 1 (HMGB1), a core molecule regulating the immune system. SIRT1 was associated with many respiratory diseases, including COVID-19 infection, bacterial pneumonia, tuberculosis, and so on. Here, we reviewed the latest research progress regarding the effects of SIRT1 on immune system in respiratory diseases. First, the structure and catalytic characteristics of SIRT1 were introduced. Next, the roles of SIRT1, and the mechanisms underlying the immune regulatory effect through HMGB1, as well as the specific activators/inhibitors of SIRT1, were elaborated. Finally, the multitasking roles of SIRT1 in several respiratory diseases were discussed separately. Taken together, this review implied that SIRT1 could serve as a promising specific therapeutic target for the treatment of respiratory diseases.

• Journal of Life Science
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• v.13 no.2
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• pp.236-240
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• 2003

Human immune system acts to protect the host from infectious agents (bacteria, viruses, fungi, parasites) and from other noxious insults. However, immune diseases are sometimes caused by the impairment of immune system leading to abnormal immune response. Especially, autoimmune diseases are very diverse and often bring serious damage Although many active investigations to reveal the etiological mechanisms concerning the autoimmune diseases, it still remains unclear. After proposing a HERV (human endogenous retrovirus) as a candidate autoimmune gene in type I diabetes, it is newly attracting our attention for demonstrating that an endogenous human retroviral superantigen can be transactivated by interferon-$\alpha$ (IFN- $\alpha$) or Epstein-Barr virus (EBV) infection. These might provide us with powerful clues to carry out further studies to overcome autoimmune diseases as the presentation of a relatively clear connection between endogenous superantigens and human diseases.

• IMMUNE NETWORK
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• v.3 no.4
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• pp.261-267
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• 2003

The periodontal diseases are infections caused by bacteria in oral biofilm, a gelatinous mat commonly called dental plaque, which is a complex microbial community that forms and adhere to tooth surfaces. Host immune-pathogen interaction in periodontal disease appears to be a complex process, which is regulated not only by the acquired immunity to deal with ever-growing and -invading microorganisms in periodontal pockets, but also by genetic and/or environmental factors. However, our understanding of the pathogenesis in human periodontal diseases is limited by the lack of specific and sensitive tools or models to study the complex microbial challenges and their interactions with the host's immune system. Recent advances in cellular and molecular biology research have demonstrated the importance of the acquired immune system in fighting the virulent periodontal pathogens and in protecting the host from developing further devastating conditions in periodontal infections. The use of genetic knockout and immunodeficient mouse strains has shown that the acquired immune response, in particular, $CD4^+$ T-cells plays a pivotal role in controlling the ongoing infection, the immune/inflammatory responses, and the subsequent host's tissue destruction.

• Tuberculosis and Respiratory Diseases
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• v.87 no.1
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• pp.22-30
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• 2024

Tumor immune evasion is a complex process that involves various mechanisms, such as antigen recognition restriction, immune system suppression, and T cell exhaustion. The tumor microenvironment contains various immune cells involved in immune evasion. Recent studies have demonstrated that granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) induce immune evasion in lung cancer by modulating neutrophils and myeloid-derived suppressor cells. Here we describe the origin and function of G-CSF and GM-CSF, particularly their role in immune evasion in lung cancer. In addition, their effects on programmed death-ligand 1 expression and clinical implications are discussed.

• Journal of Ginseng Research
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• v.45 no.1
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• pp.32-40
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• 2021

Traditional medicinal practices have used natural products such as adaptogens to treat inflammatory, autoimmune, neurodegenerative, bacterial, and viral diseases since the early days of civilization. Panax ginseng Myer is a common herb used in East Asian countries for millennia, especially in Korea, China, and Japan. Numerous studies indicate that ginseng can modulate the immune system and thereby prevent diseases. Although the human immune system comprises many different types of cells, multiple studies suggest that each type of immune cell can be controlled or stimulated by ginseng or its derivatives. Provisional lists of ginseng's potential for use against viruses, bacteria, and other microorganisms suggest it may prove to be a valuable pharmaceutical resource, particularly if higher-quality evidence can be found. Here, we reviewed the role of ginseng as an immune-modulating agent in attempt to provide a valuable starting point for future studies on the herb and the human immune system.

• IMMUNE NETWORK
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• v.16 no.5
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• pp.261-270
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• 2016

The human immune system has evolved to fight against foreign pathogens. It plays a central role in the body's defense mechanism. However, the immune memory geared to fight off a previously recognized pathogen, tends to remember an original form of the pathogen when a variant form subsequently invades. This has been termed 'original antigenic sin'. This adverse immunological effect can alter vaccine effectiveness and sometimes cause enhanced pathogenicity or additional inflammatory responses, according to the type of pathogen and the circumstances of infection. Here we aim to give a simplified conceptual understanding of virus infection and original antigenic sin by comparing and contrasting the two examples of recurring infections such as influenza and dengue viruses in humans.