• IMMUNE NETWORK
• /
• v.9 no.4
• /
• pp.115-121
• /
• 2009

Natural killer (NK) cells play key roles in innate and adaptive immune defenses. NK cell responses are mediated by two major mechanisms: the direct cytolysis of target cells, and immune regulation by production of various cytokines. Many previous reports show that the complex NK cell activation process requires de novo gene expression regulated at both transcriptional and post-transcriptional levels. Specialized un-translated regions (UTR) of mRNAs are the main mechanisms of post-transcriptional regulation. Analysis of posttranscriptional regulation is needed to clearly understand NK cell biology and, furthermore, harness the power of NK cells for therapeutic aims. This review summarizes the current understanding of mRNA metabolism during NK cell activation, focusing primarily on post-transcriptional regulation.

• IMMUNE NETWORK
• /
• v.3 no.3
• /
• pp.169-175
• /
• 2003

The intestinal immune system can discriminate between harmful and unharmful antigens and do not provoke productive immunity to unharmful antigen. Thus oral administration of antigen is one of classical methods for inducing antigen-specific immune tolerance in the periphery. Furthermore, oral tolerance has been investigated for the treatment of autoimmune disorders in human clinical trials. However, the detail mechanism of oral tolerance and contributing factors are not defined clearly at this time. Recent studies demonstrate unique types of immune cell that suppressing immune response, such as regulatory T cell and tolerogenic dendritic cell. This article reviews the factors involved in oral tolerance and discusses our current understanding base on the recent literatures and our works.

• YAKHAK HOEJI
• /
• v.35 no.5
• /
• pp.401-415
• /
• 1991

Effects of quercetin on the specific and non-specific immune responses were studied in vivo. Quercetin at a dose of 2.5, 5, 10, 20 and 40 mg/kg were orally administered to ICR male mice once daily for 28 consecutive days. Cyclophosphamide was injected intraperitoneally to ICR mice with a single dose of 5 mg/kg 2 days before secondary immunization. Mice were sensitized and challenged with sheep red blood cells (S-RBC). Immune responses were evaluated by humoral and cellular immune reponses and non-specific immune response. The results of this study were summarized as followings; 1. Quercetin significantly decreased the body weight, and introduced the atrophy of liver, spleen and thymus gland dose-dependently, but increased the numbers of white blood cell. 2. Querectin significantly depressed the hemagglutination titer, Arthus reaction and hemolytic plaque forming cell. 3. Quercetin significantly depressed the delayed type hypersensitivity and rosette forming cell. 4. Quercetin at a dose of 2.5, 5 and 40 mg/kg significantly depressed phagocytic activity. 5. Quercetin at a dose of 10 and 20 mg/kg significantly increased natural killer cell activity.

• Biomedical Science Letters
• /
• v.21 no.4
• /
• pp.172-180
• /
• 2015

It is well reported that tumor cells can regulate host immune systems. To identify the detailed changes of immune cells between tumor bearing mice and normal mice, we evaluated the systemic immune cell phenotype of B16F10 tumor bearing mice in a time dependent manner. The lymphocytic population (CD4+ and CD8+ T cells) of tumor bearing mice significantly decreased compared to that of normal mice. We found that the Foxp3+CD25+ CD4 T cell decreased, but the Foxp3+$CD25^{high}$ CD4 T cell significantly increased. All subpopulations of CD8 T cells decreased, except the CD62L-CD44+ CD8 T cell subpopulation. The myeloid cell population (CD11b+ and Gr-1+ cells) of tumor bearing mice significantly increased. Specifically, Foxp3+$CD25^{high}$ CD4 T cell and CD11b+Gr-1+ cells significantly increased in early phase of tumor progression. These results are helpful to understand the change of the systemic immune cell subpopulation of tumor bearing mice in a time-dependent manner.

• IMMUNE NETWORK
• /
• v.22 no.1
• /
• pp.10.1-10.17
• /
• 2022

Systemic autoimmune diseases arise from loss of self-tolerance and immune homeostasis between effector and regulator functions. There are many therapeutic modalities for autoimmune diseases ranging from conventional disease-modifying anti-rheumatic drugs and immunosuppressants exerting nonspecific immune suppression to targeted agents including biologic agents and small molecule inhibitors aiming at specific cytokines and intracellular signal pathways. However, such current therapeutic strategies can rarely induce recovery of immune tolerance in autoimmune disease patients. To overcome limitations of conventional treatment modalities, novel approaches using specific cell populations with immune-regulatory properties have been attempted to attenuate autoimmunity. Recently progressed biotechnologies enable sufficient in vitro expansion and proper manipulation of such 'tolerogenic' cell populations to be considered for clinical application. We introduce 3 representative cell types with immunosuppressive features, including mesenchymal stromal cells, Tregs, and myeloid-derived suppressor cells. Their cellular definitions, characteristics, mechanisms of immune regulation, and recent data about preclinical and clinical studies in systemic autoimmune diseases are reviewed here. Challenges and limitations of each cell therapy are also addressed.

• Journal of Environmental Health Sciences
• /
• v.14 no.1
• /
• pp.115-122
• /
• 1988

Captafol (1H-Isoindole-1.3(2H)-dione, 3a, 4, 7, 7a-tetrahydro-2-[1, 1, 2, 2-tetrahydroethyltkio]) is widely used as fungicide in agriculture. Immune modulatory effects of captafol and ethanol were studied in mice. Mice administered captafol intra peritoneally every other day for 5 times, and ethanol per os as captafol. Mice were sensitized and challenged with sheep red blood cells, serum antibody titer, foot pad swelling, and rosette forming cell number were mediated immune response. 1. The result show that humoral immune response and cell mediatea response were suppressed by captafol. 2. Especially effect of ethanol on the captafol immune response were significantly suppressed the humoral immune response and cell mediated immune response.

• Journal of Microbiology and Biotechnology
• /
• v.16 no.4
• /
• pp.584-589
• /
• 2006

Bifidobacteria has been suggested to exert health promoting effects on the host by maintaining microbial flora and modulating immune functions in the human intestine. We assessed modulatory effects of the different cell fractions of Bifidobacterium sp. BGN4 on macrophage cells and other immune cells from the spleen and Peyer's patches (PP) of mouse. Cell free extracts (CFE) of the BGN4 fractions induced well-developed morphological changes in the macrophages and increased the phagocytic activity more effectively than other fractions in the mouse peritoneal cells. Nitric oxide (NO) production was significantly reduced by both the cell walls (CW) and CFE in the cultured cells from the spleen and PP. The production of interleukin-6 (IL-6) and interleukin-10 (IL-10) was eminent in the spleen cells treated with experimental BGN4 cell fractions. However, in the PP cells, IL-6 was slightly decreased by the treatment with the whole cell (WC) and CW, whereas IL-10 was significantly increased by the treatment with the CW and CFE. These results suggest that different types of bifidobacterial cell fractions may have differential immunomodulatory activities depending on their location within the host immune system.

• IMMUNE NETWORK
• /
• v.16 no.1
• /
• pp.33-43
• /
• 2016

Cell-penetrating peptides (CPPs) are short amino acids that have been widely used to deliver macromolecules such as proteins, peptides, DNA, or RNA, to control cellular behavior for therapeutic purposes. CPPs have been used to treat immunological diseases through the delivery of immune modulatory molecules in vivo. Their intracellular delivery efficiency is highly synergistic with the cellular characteristics of the dendritic cells (DCs), which actively uptake foreign antigens. DC-based vaccines are primarily generated by pulsing DCs ex vivo with various immunomodulatory antigens. CPP conjugation to antigens would increase DC uptake as well as antigen processing and presentation on both MHC class II and MHC class I molecules, leading to antigen specific CD4⁺ and CD8⁺ T cell responses. CPP-antigen based DC vaccination is considered a promising tool for cancer immunotherapy due to the enhanced CTL response. In this review, we discuss the various applications of CPPs in immune modulation and DC vaccination, and highlight the advantages and limitations of the current CPP-based DC vaccination.

• Interdisciplinary Bio Central
• /
• v.2 no.2
• /
• pp.1.1-1.8
• /
• 2010

Microdevices have been used as effective experimental tools for the rapid and multiplexed analysis of individual cells in single-cell assays. Technological advances for miniaturizing such systems and the optimization of delicate controls in micron-sized space homing cells have motivated many researchers from diverse fields (e.g., cancer research, stem cell research, therapeutic agent development, etc.) to employ microtools in their scientific research. Microtools allow high-throughput, multiplexed analysis of single cells, and they are not limited by the lack of large samples. These characteristics may significantly benefit the study of immune cells, where the number of cells available for testing is usually limited. In this review, I present an overview of several microtools that are currently available for single-cell analyses in two popular formats: microarrays and microfluidic microdevices. Then, I discuss the potential to study human immunology on the single-cell level, and I highlight several recent examples of immunoassays performed with single-cell microdevice assays. Finally, I discuss the outlook for the development of optimized assay platforms to study human immune cells. The development and application of microdevices for studies on single immune cells presents novel opportunities for the qualitative and quantitative characterization of immune cells and may lead to a comprehensive understanding of fundamental aspects of human immunology.

• YAKHAK HOEJI
• /
• v.46 no.6
• /
• pp.472-476
• /
• 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.