• IMMUNE NETWORK
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• v.2 no.1
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• pp.41-48
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• 2002

Background: Viral antigens presented on the cell surface in association with MHC class I molecules are recognized by CD8+ T cells. MHC restricted peptides are important in eliciting cellular immune responses. As peptide antigens have a weak immunigenicity, pH-sensitive liposomes were used for peptide delivery to induce effective cytotoxic T lymphocyte (CTL) responses. In the previous study, as the HBx peptides could induce specific CTLs in vitro, we tested whether the HLA-A2/$K^b$ transgenic mice that were immunized by HBx-derived peptides could be protected from a viral challenge. Methods: HBx-peptides encapsulated by pH-sensitive liposomes were prepared. $A2K^b$ transgenic mice were immunized i.m. on days one and seven with the indicated concentrations of liposome-encapsulated peptides. Three weeks later, mice were infected with $1{\times}10^7pfu$/head of recombinant vaccinia virus (rVV)-HBx via i.p. administration. The ovaries were extracted from the mice, and the presence of rVV-HBx in the ovaries was analyzed using human TK-143B cells. IFN-${\gamma}$ secretion by these cells was directly assessed using a peptide-pulsed target cell stimulation assay with either peptide-pulsed antigen presenting cells (APCs), concanavalin A ($2{\mu}g/ml$), or a vehicle. To generate peptide-specific CTLs, splenocytes obtained from the immunized mice were stimulated with $20{\mu}g/ml$ of each peptide and restimulated with peptide-pulsed APC four times. The cytotoxic activity of the CTLs was assessed by standard $^{51}Cr$-release assay and intracellular IFN-${\gamma}$ assay. Results: Immunization of these peptides as a mixture in pH-sensitive liposomes to transgenic mice induced a good protective effect from a viral challenge by inducing the peptide-specific CD8+ T cells. Mice immunized with $50{\mu}g/head$ were much better protected against viral challenge compared to those immunized with $5{\mu}g$/head, whereas the mice immunized with empty liposomes were not protected at all. After in vitro CTL culture by peptide stimulation, however, specific cytotoxicity was much higher in the CTLs from mice immunized with $5{\mu}g/head$ than $50{\mu}g/head$ group. Increase of the number of cells that intracellular IFN-${\gamma}$ secreting cell among CD8+ T cells showed similar result. Conclusion: Mice immunized with XEPs within pH-sensitive liposome were protected against viral challenge. The protective effect depended on the amount of antigen used during immunization. XEP-3-specific CTLs could be induced by peptide stimulation in vitro from splenocytes obtained from immunized mice. The cytotoxic effect of CTLs was measured by $^{51}Cr$-release assay and the percentage of accumulated intracellular IFN-${\gamma}$ secreting cells after in vitro restimulation was measured by flow cytometric analysis. The result of $^{51}Cr$-release cytotoxicity test was well correlated with that of the flow cytometric analysis. Viral protection was effective in immunized group of $50{\mu}g/head$, while in the in vitro restimulation, it showed more spectific response in $5{\mu}g$/head group.

• Journal of Life Science
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• v.16 no.6
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• pp.904-910
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• 2006

Dendritic cells (DCs) are the only antigen presenting cells (APCs) capable of initiating immune responses, which is crucial for priming the specific cytotoxic T lymphocyte (CTL) response and tumor immunity. Upon activation by DCs, CD4+ helper T cells can cross-prime CD8+ CTLs via IL-12. However, recently activated DCs were described to prime in vitro strong T helper cell type 1 $(Th_1)$ responses, whereas at later time points, they preferentially prime $Th_2$ cells. Therfore, we examined in this study the optimum kinetic state of DCs activation impacted on in vivo priming of tumor-specific CTLs by using ovalbumin (OVA) tumor antigen model. Bone-marrow-derived DCs showed an appropriate expression of surface MHC and costimulatory molecules after 6 or 7-day differentiation. The 6-day differentiated DCs pulsed with OVA antigen for 8 h (8-h DC) and followed by restimulation with LPS for 24 h maintained high interleukin (IL)-12 production potential, accompanying the decreased level in their secretion by delayed re-exposure time to LPS. Furthermore, immunization with 8-h DC induced higher intracellular $interferon(IFN)-{\gamma}+/CD8+T$ cells and elicited more powerful cytotoxicity of splenocytes to EG7 cells, a clone of EL4 cells transfected with an OVA cDNA, than immunization with 24-h DC. In the animal study for the evaluation of therapeutic or protective antitumor immunity, immunization with 8-h DC induced an effective antitumor immunity against tumor of EG7 cells and completely protected mice from tumor formation and prolonged survival, respectively. The most commonly used and clinically applied DC-based vaccine is based on in vitro antigen loading for 24 h. However, our data indicated that antigen stimulation over 8 h decreased antitumor immunity with functional exhaustion of DCs, and that the 8-h DC would be an optimum activation state impacted on in vivo priming of tumor-specific CTLs and subsequently lead to induction of strong antitumor immunity.

• Journal of Periodontal and Implant Science
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• v.24 no.3
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• pp.472-482
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• 1994

Cytokines expressed specifically in leukocytes subsets and in activated cells, which are involved in chemotaxis and activation of leukocytes, are recently defined as chemokines. Macrophage inflammatory $protein-1{\alpha}(MIP-1{\alpha})$ and $MIP-1{\beta}$ are members of C-C chemokine subfamily which produces wide immunomodulatory, proinflammatory, and hematopoietic modulatory actions. We have studied their gene expression by using Northern blot analysis in various blood cells such as cytolytic T lymphocyte(CTL), helper T lymphocyte(HTL), macrophage, and B lymphocyte. Resting CTL line CTLL-R8 expressed $MIP-1{\alpha}$ mRNA which was downregulated by ConA stimulation. Both of resting and ConA stimulated HTL line Hut78 and Jurkat did not express $MIP-1{\alpha}$ mRNA. There was detectable $MIP-1{\alpha}$ transcript in HTL hybridoma 2B4.11 which was a little upstimulated by ConA stimulation. B cell line 230, and macrophage cell line RAW264.7 and WR19M.1 showed distinct $MIP-1{\alpha}$ message which were induced after LPS stimulation. Expression pattern of $MIP-1{\beta}$ in all cell lines or cell were almost identical to that of $MIP-1{\alpha}$. Also strategies employed to identify and characterize the biological functions was preceded by receptor cloning to trace the shorcut to the final goal of cytokine research. For the cloning of $MIP-1{\alpha}$ receptor(R), we used synthetic oligonucleotides of transmembrane(T) conserved sequences of already cloned human(h) IL-8-R, and performed reverse transcription-polymerase chain reaction(RT-PCR) amplification using murine(m) macrophage cell line mRNA. Among 5RT-PCR products, we isolated a homologous cDNA with hIL-8-R which were shown to be putative mIL-8-R cDNA.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.306.1-306.1
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• 2002

Cefodizime has originally been developed for treating infections as antibiotics. However. according to some of recent studies. cefodizime. a third generation cephalosporin. may potentially have the capability of stimulating chemotactic activity of neutrophils and monocytes as well as the strong immuno-modulator. In this study. we studied to learn about the expressive effect of dentritic cells and macrophage. With this background. We have studied to see if cefodizime can be a potential substance inducing an immunological function in dendritic cells and peritoneal macrophages. IL-12 activates NK cell and macrophage, and shows antiviral effect by excreting INF-${\gamma}$. In vitro. total RNAs were extracted from murine dentritic cell at 4, 8, 12, 24hr after the application of 10, 50, 100${\gamma}g$/ml of cefodizime wighout other stimulators. And we analyzed IL-12 mRNA using RT-PCR method. In conclusion. IL-12 mRNA was increased. and the results suggest that cefodizime activate TH1 cell induction, CTL differentiation as well as accelerating the increase of NK. LAK cell.

• Journal of Microbiology and Biotechnology
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• v.16 no.12
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• pp.1919-1927
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• 2006

Tumor cells genetically engineered to secrete cytokines are effective in tumor therapy, but various unexpected side effects are observed, which may result from the bulk activation of various bystander cells. In this study, we tested tumor vaccines expressing various membrane-bound forms of IL-2 (mbIL-2) on MethA fibrosarcoma cells to focus antitumor immune responses to CTL. Chimeric forms of IL-2 with whole CD4, deletion forms of CD4, and TNF were expressed on the tumor cell surface, respectively. Tumor clones expressing mbIL-2 or secretory form of IL-2 were able to support the cell growth of CTLL-2, an IL-2-dependent T cell line, and the proliferation of spleen cells from 2C TCR transgenic mice that are responsive to the $p2Ca/L^d$ MHC class I complex. Expression of mbIL-2 on tumor cells reduced the tumorigenicity of tumor cells, and the mice that once rejected the live IL-2/TNF tumor clone acquired systemic immunity against wild-type MethA cells. The IL-2/TNF clone was inferior to other clones in tumor formation, and superior in the stimulation of the CD8+ T cell population in vitro. These results suggest that the IL-2/TNF clone is the best tumor vaccine, and may stimulate CD8+ T cells by direct priming. Expression of IL-2/TNF on tumor cells may serve as an effective gene therapy method to ameliorate the side effects encountered in the recombinant cytokine therapy and the conventional cytokine gene therapy using the secretory form of IL-2.

• Herbal Formula Science
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• v.11 no.2
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• pp.95-110
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• 2003

Alzheimer's disease(AD) is a geriatric dementia that is widespread in old age. In the near future AD will be the biggest problem in public health service. Although a variety of oriental prescriptions in study Jeonmaedan have been traditionally utilized for the treatment of AD, their pharmacological effects and action mechanisms have not yet fully elucidated. It has been widely believed that A${\beta}$ peptide devided from APP causes apoptotic neurotoxicity in AD brain. However, recent evidence suggests that CTl05(carboxy terminal 105 amino acid peptide fragment of APP) may be an important factor causing neurotoxicity in AD. In addition, AD is one of brain degeneration disease. So we studied on herbal medicine that have a relation of brain degeneration. In Oriental Medicine, Jeonmaedan has been used for disease in relation to brain degeneration. As the result of this study, in Jeonmaedan the apoptosis in the nervous system is inhibited, the repair against the degerneration of SK-N-SH cell lines by CT105 expression is promoted. So Jeonmaedan may be beneficial for the treatment of AD.

• IMMUNE NETWORK
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• v.11 no.3
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• pp.182-189
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• 2011

Background: Cytotoxic T lymphocytes (CTLs) appear to play an important role in the control and prevention of human cytomegalovirus (HCMV) infection. The pp65 antigen is a structural protein, which has been defined as a potential target for effective immunity against HCMV infection. Incorporation of an 11 amino acid region of the HIV TAT protein transduction domain (Tat) into protein facilitates rapid, efficient entry into cells. Methods: To establish a strategy for the generation of HCMV-specific CTLs in vitro, recombinant truncated N- and C-terminal pp65 protein (pp65 N&C) and N- and C-terminal pp65 protein fused with Tat (Tat/pp65 N&C) was produced in E.coli system. Peripheral blood mononuclear cells were stimulated with dendritic cells (DCs) pulsed with pp65 N&C or Tat/pp65 N&C protein and immune responses induced was examined using IFN-${\gamma}$ ELISPOT assay, cytotoxicity assay and tetramer staining. Results: DCs pulsed with Tat/pp65N&C protein could induce higher T-cell responses in vitro compared with pp65N&C. Moreover, the DCs pulsed with Tat/pp65 N&C could stimulate both of $CD8^+$ and $CD4^+$ T-cell responses. The T cells induced by DCs pulsed with Tat/pp65 N&C showed higher cytotoxicity than that of pp65-pulsed DCs against autologous lymphoblastoid B-cell line (LCL) expressing the HCMV-pp65 antigen. Conclusion: Our results suggest that DCs pulsed with Tat/pp65 N&C protein effectively induced pp65-specific CTL in vitro. Tat fusion recombinant protein may be useful for the development of adoptive T-cell immunotherapy and DC-based vaccines.

• IMMUNE NETWORK
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• v.3 no.2
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• pp.96-102
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• 2003

Background: Granulocyte-macrophage colony-stimulating factor (GM-CSF) gene-transduced tumor cell vaccines induce very potent systemic anti-tumor immunity in preclinical and clinical models. Our previous phase I clinical trial in patients with metastatic renal cell carcinoma (RCC) has demonstrated both immune cell infiltration at vaccine sites and T cell-mediated delayed-type hypersensitivity (DTH) response to whole tumor cell vaccines. Methods: To investigate the immune responses to autologous genetically- modified tumor cell vaccines, tumor-specific $CD8^+$ T cell lines were generated from peripheral blood lymphocytes (PBL) of a RCC patient 1.24 by repeated in vitro stimulation with either B7.1-transduced autologous RCC tumor cells or B7.1-transduced autologous tumor cells treated with interferon gamma ($IFN{\gamma}$), and cloned by limiting dilution. Results: Among several RCC-specific cytotoxic T lymphocytes (CTLs), a $CD4^+/CD8^+$ double positive T cell clone (17/A2) appeared to recognize $IFN{\gamma}$-treated autologous RCC restricted by HLA-B39. The 17/A2 also recognized other HLA-B39 positive RCC tumor cells after $IFN{\gamma}$ treatment. Conclusion: These results demonstrate that autologous RCC vaccination successfully generates the tumor-specific CTL 17/A2, and suggest that the presentation and recognition of the tumor antigen by the 17/A2 might be upregulated by $IFN{\gamma}$.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.109.2-109.2
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• 2010

세라믹 필터는 여러 종류의 분진제거 시스템에서 연소 배가스 정제를 위한 가장 적절한 소재로 알려져 있다. 현재까지 다양한 형태의 세라믹 필터가 개발되고 있는데, 캔들 타입(candle type), 튜브 타입(tubular type), 평판 타입(parallel flow type) 등이 그 예이다. 통상적으로 세라믹 캔들 필터는 가압유동층복합발전(PFBC, Pressurize Fluidized-Bed Combustion), 석탄가스화복합발전(IGCC, Integrated coal Gasification Combined Cycle), 석탄가스화연료전지복합발전(IGFC, Integrated coal Gasification Fuel cell Combined cycle)에서 고온 배가스 정제용으로 사용되고 있다. 일반적으로 IGCC나 CTL 합성가스 정제시스템의 경우에는 높은 고압(약 25기압)과 미세분진이 함유되어 있는 분위기에서 운전된다. 그러므로 이때 사용되는 초청정용 세라믹 집진필터는 고온, 고압 및 부식 환경에서 50 MPa 이상을 갖는 높은 강도와 내식성을 갖도록 개발되어야 하기 때문에 SiC(Silicon Carbide)가 가장 적절한 캔들 필터 소재로 적용되고 있다. 이에 따라 집진용 SiC 세라믹 캔들 필터를 개발하기 위해서는 고온에서 내산화성이 우수하고, 부피팽창에 의한 균열이 발생하지 않는 무기결합재의 선정 및 이를 통한 소재의 특성 최적화가 가장 중요한 부분이라 할 수 있다. 본 연구에서는 IGCC나 CTL 공정에 적용하기 위한 SiC 캔들 필터 소재 개발을 위해 래밍성형 공정으로 1m급의 탄화규소 캔들 필터 시작품을 제작하여 SiC 출발입자 크기와 무기계 결합재인 스트론튬 카보네이트의 첨가량 변화에 따른 필터 소재의 특성 평가를 수행하였다.

• IMMUNE NETWORK
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• v.15 no.2
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• pp.73-82
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• 2015

Respiratory syncytial virus (RSV) infection is recognized by the innate immune system through Toll like receptors (TLRs) and retinoic acid inducible gene I. These pathways lead to the activation of type I interferons and resistance to infection. In contrast to TLRs, very few studies have examined the role of NOD-like receptors in viral recognition and induction of adaptive immune responses to RSV. Caspase-1 plays an essential role in the immune response via the maturation of the proinflammatory cytokines IL-$1{\beta}$ and IL-18. However, the role of caspase-1 in RSV infection in vivo is unknown. We demonstrate that RSV infection induces IL-$1{\beta}$ secretion and that caspase-1 deficiency in bone marrow derived dendritic cells leads to defective IL-$1{\beta}$ production, while normal RSV viral clearance and T cell responses are observed in caspase-1 deficient mice following respiratory infection with RSV. The frequencies of IFN-${\gamma}$ producing or RSV specific T cells in lungs from caspase-1 deficient mice are not impaired. In addition, we demonstrate that caspase-1 deficient neonatal or young mice also exhibit normal immune responses. Furthermore, we find that IL-1R deficient mice infected with RSV exhibit normal Th1 and cytotoxic T lymphocytes (CTL) immune responses. Collectively, these results demonstrate that in contrast to TLR pathways, caspase-1 might not play a central role in the induction of Th1 and CTL immune responses to RSV.