• Clinical and Experimental Pediatrics
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• 제48권3호
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• pp.251-259
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• 2005

Atopy is a highly prevalent and serious health problem. The prevalence and severity of asthma and allergic diseases have increased over recent decades, particularly in industrialized nations. Early life infections may protect against the development of atopy and allergic diseases like asthma. The inverse relationship between the incidence of atopy and childhood infections has led to the 'hygiene hypothesis', which suggests that diminished exposure to childhood infections in modern society has led to decreased Th1-type responses. Th1 and Th2 responses are counter-regulatory. Reduced Th1 may lead to enhanced Th2-type inflammation, which is important in promoting asthma and allergic disease via up-regulation of IL-4, IL-5, and IL-13. It is now widely accepted that altered regulation of Th2 responses(and possibly the balance between Th1 and Th2 responses) is an important factor in the development of atopy. CpG DNA represent a novel class of drugs with substantial immunomodulatory properties. CpG DNA contain unmethylated motifs centered on the CpG dinucleotides, like bacterial DNA. These CpG DNA promote Th1 and regulatory type immune responses and suppress Th2 responses. In murine studies, CpG DNA are effective in prevention and treatment of asthma and allergic diseases. CpG DNA are just beginning to be tested in human asthma. While its precise mechanisms continue to be fully studied, CpG DNA offers considerable promise as a novel treatment for atopic inflammation. It may prove to be an important disease modifying therapy, or even curative therapeutic agent for asthma and allergic diseases.

• BMB Reports
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• 제46권9호
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• pp.448-453
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• 2013

CpG-DNA has various immunomodulatory effects in dendritic cells, B cells, and macrophages. While induction of cytokines by CpG-DNA has been well documented in macrophages, the expression of costimulatory molecules in CpG-DNA treated macrophages has not yet been defined. Therefore, we investigated the effects of CpG-DNA on the expression of costimulatory molecules in RAW 264.7 cells. The surface expression of CD80 was slightly increased and CD83 expression was significantly increased in response to CpG-DNA. However, the expression of CD86 and MHC class II was not changed. As expression of CD83 mRNA was also increased by CpG-DNA, CD83 expression is regulated at a transcriptional level. To understand the contribution of signaling pathways to CD83 induction, we used pathway specific inhibitors. The NF-${\kappa}B$ inhibitor significantly reduced surface expression of CD83 as well as phagocytic activity of RAW 264.7 cells. Therefore, CD83 expression may contribute to the immunostimulatory effects of CpG-DNA in macrophage cells.

• BMB Reports
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• 제52권11호
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• pp.635-640
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• 2019

CpG-DNA triggers the proliferation and differentiation of B cells which results in the increased production of antibodies. The presence of bacteria-reactive IgM in normal serum was reported; however, the relevance of CpG-DNA with the production of bacteria-reactive IgM has not been investigated. Here, we proved the function of CpG-DNA for the production of bacteria-reactive IgM. CpG-DNA administration led to increased production of bacteria-reactive IgM both in the peritoneal fluid and serum through TLR9 signaling pathway. When we stimulated B cells with CpG-DNA, production of bacteria-reactive IgM was reproduced in vitro. We established a bacteria-reactive monoclonal IgM antibody using CpG-DNA stimulated-peritoneal B cells. The monoclonal IgM antibody enhanced the phagocytic activity of RAW 264.7 cells against S. aureus MW2 infection. Therefore, we suggest that CpG-DNA enhances the antibacterial activity of the immune system by triggering the production of bacteria-reactive IgM. We also suggest the possible application of the antibodies for the treatment of antibiotics-resistant bacterial infections.

• Genomics & Informatics
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• 제8권1호
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• pp.58-61
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• 2010

CpG is the pair of nucleotides C and G, appearing successively, in this order, along one DNA strand. It is known that due to biochemical considerations CpG is relatively rare in most DNA sequences. However, in particular subsequences, which are a few hundred to a few thousand nucleotides long, the couple CpG is more frequent. These subsequences, called CpG islands, are known to appear in biologically more significant parts of the genome. The ability to identify CpG islands along a chromosome will therefore help us spot its more significant regions of interest, such as the promoters or 'start' regions of many genes. In this respect, I developed the CpG islands search tool, CpG Islands Detector, which was implemented in JAVA to be run on any platform. The window-based graphical user interface of CpG Islands Detector may facilitate the end user to employ this tool to pinpoint CpG islands in a genomic DNA sequence. In addition, this tool can be used to highlight potential genes in genomic sequences since CpG islands are very often found in the 5' regions of vertebrate genes.

• BMB Reports
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• 제43권3호
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• pp.164-169
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• 2010

CpG-DNA, which contains unmethylated CpG dinucleotides in the context of specific sequences, has remarkable and diverse immunological effects, including induction of proinflammatory cytokine expression and regulation of the Th1/Th2 immune response. Here, we examined the immunostimulatory activities of double-stranded (ds) CpG-DNA in the human B cell line RPMI8226. To investigate whether dsCpG-DNA stimulates immune cells, we constructed a plasmid containing repeated dsCpG-DNA and produced dsCpG-DNA by PCR amplification and EcoR I digestion. PCR-amplified dsCpG-DNA alone did not have immmunostimulatory activity. However, dsCpGDNA encapsulated with lipofectin induced IL-8 promoter activation, HLA-DRA expression, and IL-8 expression in a CG sequence-independent manner. The effects of encapsulated dsCpGDNA were independent of minor endotoxin contamination. These findings suggest the potential use of dsCpG-DNA as a therapy for immune response regulation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권6호
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• pp.636-642
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• 2007

Background: CpG DNA plays an important role in immune cell function. This study examined whether the temporal control of toll-like receptor (TLR)9 by CpG DNA can regulate the expression of matrix metalloproteinase-9(MMP-9). Methods and materials: Macrophages were cultured in the presence of 10% FBS. For the various MMP genes analysis, RT-PCR and real-time PCR were performed. In addition, zymography assay performed for the MMP activity. The phosphorylation assay did for the ERK1/2 and NF${\kappa}B$ activation, and luciferase promoter assay was for the NF${\kappa}B$ activity. Results: CpG DNA induced the mRNA expression of MMP-2, MMP-9, and MMP-13, but not of MMP-7, MMP-8, and MMP-12, in a time-dependent manner. Especially, the mRNA expression of MMP-9 was strongly induced by CpG DNA using real-time RT-PCR. The TLR9 inhibitor, chloroquine, suppressed CpG DNA-induced MMP-9 expression and its activity. Moreover, CpG DNA induced the phosphorylation of ERK and the inhibition of ERK by U0126 suppressed CpG DNA-induced MMP-9 expression and its activity. CpG DNA stimulated $I{\kappa}B-{\alpha}$ degradation and luciferase activity. In addition, pretreatment of SN-50, the inhibitor of NF${\kappa}B$, strongly blocked the CpG DNA-induced MMP-9 expression and activity. Conclusion: These observations suggest that CpG DNA may play important roles in the activation of macrophages by regulating the production of MMP-9 via the sequential TLR9-ERK-NF${\kappa}B$ signaling pathway.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제30권3호
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• pp.302-309
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• 2008

DNA 메틸화는 histone modification과 함께 DNA의 염기서열이 유지되면서 유전기능이 변화되고 자손까지 전달 될 수 있는 후생 유전의 중요한 한 부분이다. DNA 메틸화는 크로마틴의 구조를 변경시키는 과정을 통하여 유전자와 repetitive sequence의 표현을 억제시킬 수 있다. DNA 메틸화는 X-불활성화, 유전체 각인, 유전자 발현조절, 암 생성 등에 중요한 역할을 하는 것으로 밝혀졌고, DNA 메틸화 표지자 (DNA methylation marker)들은 종양의 진단과 치료에 대한 반응을 예측하는 지표로 활용되고 있다. 지금까지 많은 연구 성과에도 불구하고 DNA메틸화, 메틸화에 의한 gene silencing, DNA 메틸화의 표적부위 등에 대한 명확한 기전이 아직도 밝혀지지 않고 있어 향후 더 많은 기초적 연구가 필요할 것이다. 최근에는 후생 유전적 변화는 가역적이기 때문에 종양억제유전자를 억압하는 후생 유전적 변화를 제거한다면 그 종양억제유전자를 다시 활성화시킬 수 있다는 개념의 후생유전 치료법 연구로 DNA 메틸화 억제제와 histone deacetyaltion에 관여하는 HDAC의 억제제들이 항암제로서 개발되어 사용되고 있는데 향후 더 많은 약제 개발과 임상적 연구가 진행되어야 할 것이다.

• BMB Reports
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• 제44권9호
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• pp.607-612
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• 2011

Several investigators have shown that CpG-DNA has outstanding effects as a Th1-responsive adjuvant and that its potent adjuvant effects are enhanced by encapsulation with a liposome of proper composition. In this study, we showed that encapsulation with phosphatidyl-${\beta}$-oleoyl-${\gamma}$-palmitoyl ethanolamine (DOPE): cholesterol hemisuccinate (CHEMS) complex enhances the immunostimulatory activity of CpG DNA and the binding of CpG-DNA to TLR9. We also examined involvement of myeloid differentiation protein (MyD88) and NF-${\kappa}B$ activation in liposome-encapsulated CpG-DNA-induced IL-8 promoter activation. In this manuscript, the natural phosphodiester bond CpG-DNA encapsulated by DOPE : CHEMS complex is designated as Lipoplex(O). Importantly, we successfully screened B cell epitopes of envelope protein (E protein) of hepatitis C virus (HCV-E) and attachment glycoprotein G of human respiratory syncytial virus (HRSV-G) by immunization with complexes of several peptides and Lipoplex(O) without carriers. Therefore, Lipoplex(O) is potentially applicable as a universal adjuvant for peptide-based epitope screening and antibody production.

• BMB Reports
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• 제43권4호
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• pp.250-256
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• 2010

Natural phosphodiester bond CpG-DNA that contains immunomodulatory CpG motifs (PO-DNA) upregulates the expression of proinflammatory cytokines and induces an Ag-driven Th1 response in a CG sequence-dependent manner in mice. In humans, only phosphorothioate backbone-modified CpG-DNA (PS-DNA) and not PO-DNA has immunomodulatory activity. In this study, we found that liposome-encapsulated PO-DNA upregulated the expression of human $\beta$-defensin-2 (hBD-2) and major histocompatibility class II molecules (HLA-DRA) in a CG sequence-dependent and liposome- dependent manner in human B cells. Of the three different liposomes, DOTAP has the unique ability to enhance the immunomodulatory activity of PO-DNA. In contrast, HLA-DRA and hBD-2 promoter activation can be induced by liposome-encapsulated PS-DNA in a CG sequence-independent manner, depending on the CpG-DNA species. Our observations demonstrate that, when encapsulated with a proper liposome in the immune system, natural PO-DNA has the potential to be a useful therapy for the regulation of the innate immune response.

• Interdisciplinary Bio Central
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• 제1권1호
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• pp.4.1-4.7
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• 2009

Introduction: Histone modifications and DNA methylation are the major factors in epigenetic gene regulation. Especially, revealing how histone modifications are related to DNA methylation is one of the challenging problems in this field. In this paper, we address this issue and propose several plausible mechanisms for precise controlling of DNA methylation status at CpG islands. Materials and Methods: To establish the regulatory relationships, we used 38 histone modification types including H2A.Z and CTCF, and DNA methylation status at CpG islands across chromosome 6, 20, and 22 of human CD4+ T cell. We utilized Bayesian network to construct regulatory network. Results and Discussion: We found several meaningful relationships supported by previous studies. In addition, our results show that histone modifications can be clustered into several groups with different regulatory properties. Based on those findings we predicted the status of methylation level at CpG islands with high accuracy, and suggested core-regulatory network to control DNA methylation status.