• BMB Reports
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• 제39권6호
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• pp.788-793
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• 2006

Bacterial DNA containing immunostimulatory CpG motifs can stimulate antigen-presenting cells to express co-stimulatory molecules and to produce various cytokines in vivo and in vitro. In this study, we fragmented macromolecular E.coli genomic DNA with DNase I, and analyzed the ability of the resulting DNA fragments to induce the NF-${\kappa}B$ activation and humoral immune response. Furthermore, using computational analysis and luciferase assay for synthetic ODNs based on the sequence of the immunostimulatory DNA fragments (DF-ODNs), an active component of DF-ODNs sequences was investigated. Experimental results demonstrated that DF-ODN is optimal for the NF-${\kappa}B$-responsive promoter activation in the mouse macrophage cell line and the humoral immune response in vivo. In agreement with the activity of the DF-ODNs processed by DNase I, a synthetic ODN based on the DF-ODN sequences is potent at inducing IL-12 mRNA expression in primary dendritic cells. These results suggest that the discovery and characterization of a highly active natural CpG-ODN may be achieved by the analyses of bacterial DNA fragments generated by a nuclease activity.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권1호
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• pp.29-33
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• 2005

A DNA vaccine methodology using eukaryote expression vectors to produce immunizing proteins in the vaccinated hosts is a novel approach to the development of vaccine and immuno-therapeutics, and it has achieved considerable success over several infectious diseases and various cancers. To further enhance its efficiency, attempts were made to develop novel plasmid vectors containing multiple immunostimulatory CpG motifs, for rapid and strong immune response. First, a 2.9 kb compact plasmid vector (pVAC), containing CMV promoter, polycloning site, BGH poly(A) terminator, ampicillin resistance gene and pBR322 origin was constructed. A pVAC-hEPO was also constructed, which contained a human erythropoietin gene, for evaluating the transfection efficiency of naked plasmid DNA both in vitro and in vivo. To examine the adjuvant effect of multi-CpG motifs on naked plasmid DNA, 22 and 44 enriched and unmethylated CpG motifs were introduced into pVAC to generate pVAC-ISS1 and pVAC-ISS2, respectively. $100{\mu}g$ of pSecTagB, pVAC, pVAC-ISS1 or pVAC-ISS2 were each injected intramuscularly into the tibilias anterior muscle of Balb/c mice. The level of interleukin-6 induced in the mice injected with pVAC-ISS1 and pVAC-ISS2 were significantly elevated after 12 hours, which were almost 2 and 2.5 times higher than that in the mice injected with pSecTagB, respectively. These results suggest that DNA vaccine plasmids with enriched CpG motifs can induce rapid secretion of interleukin-6 by lymphocytes. In conclusion, these vectors can contribute to the development of adjuvant-free DNA vaccinations against infectious diseases and various cancers.

• 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 Dairy Science and Biotechnology
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• 제30권1호
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• pp.31-36
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• 2012

Lactobacillus rhamnosus GG(ATCC 53103) is one of the best researched probiotic strains in the world. Studies in children have shown that Lactobacillus rhamnosus GG effectively prevents early atopic disease in patients with high risk. The active molecules associated with the immunostimulatory sequence and anti-allergy effects of L. rhamnosus GG have not yet been identified. Unmethylated CpG motifs in bacterial DNA have a mitogenic effect in mouse immune cells, CpG-containing ISS oligodeoxynucleotides are potent Th1 adjuvants, effective in both preventing and reversing Th2-biased immune deviation in allergy models. The genomic DNA of L. rhamnosus GG is a potent inducer of murine B cell and dendritic cell immunoactivation. In L. rhamnosus GG genomic DNA, ID35 shows high activity in ISS assays in both mice and humans. The effects of ID35 result from a unique TTTCGTT motif located at its 5'-end, and its effects are comparable with murine prototype CpG 1826. L. rhamnosus GG is known to secrete proteinaceous pili encoded by the spaCBA gene cluster. The presence of pili structures may be essential for its adhesion to human intestinal mucus, explaining the prolonged duration of intestinal residence of this bacterium, compared to that of non-piliated lactobacilli.

• 한국수산과학회지
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• 제50권3호
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• pp.302-310
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• 2017

Interferon regulatory factor 8 (IRF8) is essential for the development of B and T cells, as well as for the activity of dendritic cells and macrophages. We performed molecular characterization of IRF8 from rock fish, Sebastes schlegelii (Ss), and investigated the spatial and temporal profile of mRNA expression after challenge with lipopolysaccharide (LPS), polyinosinic:polycytidylic acid (poly I:C), or Streptococcus iniae. The full-length cDNA sequence of SsIRF8 was 1,657 bp, containing an ORF of 1,266 bp. The gene had a predicted molecular mass of 47.7 kDa and an isoelectric point of 5.99. The amino acid sequence coded by this gene showed the highest degree of identity (90.8%) and similarity (96.2%) with IRF8 from Oplegnathus fasciatus. The SsIRF8 mRNA was expressed ubiquitously, at varying levels, with the highest level of expression observed in the spleen. To confirm the role of SsIRF8 in mediating the immune response, we measured SsIRF8 mRNA expression in the splenic tissue at different time points after injection with LPS, poly I:C, or S. iniae. The qRT-PCR results showed that SsIRF8 mRNA expression in the poly I:C-injected group was highly upregulated 6 hr after exposure (P<0.05). Expression of SsIRF8 mRNA in the S. iniae-injected group peaked at 24 hr. These results suggest that SsIRF8 might be important in regulating the strength of the rockfish immune response to immunostimulatory agents.

• BMB Reports
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• 제40권4호
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• pp.486-493
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• 2007

Atopic dermatitis (AD) is a chronic inflammatory skin disease and the pathogenesis of AD is associated with the release of various cytokines/chemokines due to activated $Th_2$ immune responses. Synthetic oligodeoxynucleotides (ODNs) containing unmethylated CpG dinucleotide in the context of particular base sequence (CpG motifs) are known to have the immunostimulatory activities in mice and to convert from Th2 to Th1 immune responses in AD. We aimed to investigate that CpG ODN, especially phosphodiester form, can stimulate the protective immunity in NC/Nga mice with AD. We isolated BMDCs from NC/Nga mice and then, cultured with GM-CSF and IL-4 for 6 days, and treated for 2 days by either phosphorothioate ODN or phosphodiester ODN. CpG ODN-treated DCs resulted in more production of IL-12. When CpG ODN-treated DCs were intravenously injected into the NC/Nga mice, the NC/Nga mice with CpG ODN-treated DCs showed significant improvement of AD symptoms and decrease of IgE level. Histopathologically, the NC/Nga mice skin with CpG ODN-treated DCs showed the decreased IL-4 and TARC expression comparing with non-injected mice. These results may suggest that phosphodiester CpG ODN-treated DCs might function as a potent adjuvant for AD in a mouse model.

• BMB Reports
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• 제44권11호
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• pp.758-763
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• 2011

Immunostimulatory CpG-DNA targeting TLR9 is one of the most extensively evaluated vaccine adjuvants. Previously, we found that a particular form of natural phosphodiester bond CpG-DNA (PO-ODN) encapsulated in a phosphatidyl-${\beta}$-oleoyl-${\gamma}$-palmitoyl ethanolamine (DOPE) : cholesterol hemisuccinate (CHEMS) (1 : 1 ratio) complex (Lipoplex(O)) is a potent adjuvant. Complexes containing peptide and Lipoplex(O) are extremely useful for B cell epitope screening and antibody production without carriers. Here, we showed that IL-12 production was increased in bone marrow derived dendritic cells in a CpG sequence-dependent manner when PO-ODN was encapsulated in Lipoplex(O), DOTAP or lipofectamine. However, the effects of Lipoplex(O) surpassed those of PO-ODN encapsulated in DOTAP or lipofectamine and also other various forms of liposome-encapsulated CpG-DNA in terms of potency for protein antigen-specific IgG production and Th1- associated IgG2a production. Therefore, Lipoplex(O) may have a unique potent immunoadjuvant activity which can be useful for various applications involving protein antigens as well as peptides.