• Journal of Microbiology and Biotechnology
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• 제17권12호
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• pp.1955-1964
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• 2007

A recent report showed that analysis of CD154 expression in the presence of the secretion inhibitor Brefeldin A (Bref A) could be used to assess the entire repertoire of antigen-specific $CD4^+\;T$ helper cells. However, the capacity of intracellular CD154 expression to identify antigen-specific $CD8^+\;T$ cells has yet to be investigated. In this study, we compared the ability of intracellular CD154 expression to assess antigen-specific $CD8^+\;T$ cells with that of accepted standard assays, namely intracellular cytokine IFN-${\gamma}$ staining (ICS) and MHC class I tetramer staining. The detection of intracellular CD154 molecules in the presence of Bref A reflected the kinetic trend of antigen-specific $CD8^+\;T$ cell number, but unfortunately showed less sensitivity than ICS and tetramer staining. However, ICS levels peaked and saturated 8 h after antigenic stimulation in the presence of Bref A and then declined, whereas intracellular CD154 expression peaked by 8 h and maintained the saturated level up to 24 h post-stimulation. Moreover, intracellular CD154 expression in antigen-specific $CD8^+\;T$ cells developed in the absence of $CD4^+\;T$ cells changed little, whereas the number of IFN-${\gamma}$-producing $CD8^+\;T$ cells decreased abruptly. These results suggest that intracellular CD154 could aid the assessment of antigen-specific $CD8^+\;T$ cells, but does not have as much ability to identify heterogeneous $CD4^+\;T$ helper cells. Therefore, the combined analytical techniques of ICS and tetramer staining together with intracellular CD154 assays may be able to provide useful information on the accurate phenotype and functionality of antigen-specific $CD8^+\;T$ cells.

• IMMUNE NETWORK
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• 제3권3호
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• pp.169-175
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• 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.

• Journal of Korean Neurosurgical Society
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• 제66권4호
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• pp.356-381
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• 2023

Although immunotherapy has been broadly successful in the treatment of hematologic malignancies and a subset of solid tumors, its clinical outcomes for glioblastoma are still inadequate. The results could be due to neuroanatomical structures such as the blood-brain-barrier, antigenic heterogeneity, and the highly immunosuppressive microenvironment of glioblastomas. The antitumor efficacy of endogenously activated effector cells induced by peptide or dendritic cell vaccines in particular has been insufficient to control tumors. Effector cells, such as T cells and natural killer (NK) cells can be expanded rapidly ex vivo and transferred to patients. The identification of neoantigens derived from tumor-specific mutations is expanding the list of tumor-specific antigens for glioblastoma. Moreover, recent advances in gene-editing technologies enable the effector cells to not only have multiple biological functionalities, such as cytokine production, multiple antigen recognition, and increased cell trafficking, but also relieve the immunosuppressive nature of the glioblastoma microenvironment by blocking immune inhibitory molecules, which together improve their cytotoxicity, persistence, and safety. Allogeneic chimeric antigen receptor (CAR) T cells edited to reduce graft-versus-host disease and allorejection, or induced pluripotent stem cell-derived NK cells expressing CARs that use NK-specific signaling domain can be a good candidate for off-the-shelf products of glioblastoma immunotherapy. We here discuss current progress and future directions for T cell and NK cell therapy in glioblastoma.

• 대한수의학회지
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• 제40권1호
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• pp.130-137
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• 2000

In order to diagnose canine heartworm infection by antigen capture ELISA, the crude somatic(S), partial somatic(below 45kDa) and excretory/secretory(E/S) antigen of adult heartworm were identified and the antigenicity was examined by silver stain, immunoblot and ELISA. Then, production of monoclonal antibody to specific antigen carried out in this experiment. The bands to S antigen and E/S antigen were recognized between 10 and 200kDa and common bands were recognized strongly 14, 18, 28, 43kDa by silver stain. By western blot analysis, fractions to S antigen were recognized 14, 16, 18, 20, 24, 28, 32, 43, 50, 55kDa, etc. and only a 14kDa to E/S antigen in positive sera which were positive in modified Knott's test and necropsy. In ELISA, the positive sera reacted to antigens(SA, $SA_{45}$, E/S) were significantly different from negative sera by Student's t-test(p<0.05). Four hybridoma cell lines(14, 16, 17, 32kDa) than produce specific monoclonal antibodies for these antigens were obtained by immunizing BALB/c mice with a partially purified somatic antigen (below 45kDa) preparation, by fusing spleen cells with SP2/O cell myeloma cells, and by screening cell culture supernatants for antibody. In these results, it was confirmed that partial somatic antigen(below 45kDa) or E/S antigen can be used for serologic diagnosis of heartworm infection and monoclonal antibody reacting with specific antigen(14kDa) can be used for antigen capture ELISA in prepatent period of canine heartworm infection.

• 대한이식학회지
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• 제28권3호
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• pp.121-134
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• 2014

Current immunosuppressants have nonspecific immuosuppressive effects, and are not helpful for tolerance induction. Consequently, transplant patients cannot discontinue using them, and their nonspecific immunosuppressive effects result in many side effects, including infection and malignancy. However, most of cellular immunotherapy can have donor antigen-specific immunsuppressive effects. Therefore, cell therapy could be an alternative or adjunctive to nonspecific immunosuppressants. Polyclonal or antigen-specific Foxp3+ regulatory T cells have been actively tried for prevention of acute rejection, treatment of chronic rejection, or tolerance induction in clinical trials. Regulatory macrophages are also under clinical trials for kidney transplant patients. IL-10-secreting type 1 regulatory T cells and donor- or recipient-derived tolerogenic dendritic cells will also be used for immunoregulation in clinical trials of kidney transplantation. These cells have antigen-specific immunoregulatory effects. Mesenchymal stromal cells (MSCs) have good proliferative capacity and immunosuppressive actions independently of major histocompatibility complex; therefore, even third-party MSCs can be stored and used for many patients. Cell therapy using various immunoregulatory cells is now promising for not only reducing side effects of nonspecific immunosuppressants but also induction of immune tolerance, and is expected to contribute to better outcomes in transplant patients.

• Asian Pacific Journal of Cancer Prevention
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• 제16권7호
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• pp.2665-2669
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• 2015

CD4+CD25+regulatory T cells (Tregs) play a key role in regulation of immnue response and maintenance of self-tolerance. Studies have found Tregs could suppress tumor-specific T cell-mediated immune response and promote cancer progression. Depletion of Tregs can enhance antitumor immunity. Dendritic cells (DCs) are professional antigen-presenting cells and capable of activating antigen-specific immune responses, which make them ideal candidate for cancer immunotherapy. Now various DC vaccines are considered as effective treatment for cancers. The aim of this study was to evaluate variation of Tregs in BALB/C mice with hepatocellular carcinoma and investigate the interaction between tumor-derived Tregs, effector T cells (Teff) and splenic DCs. We found the percentages of Tregs/CD4+ in the peripheral blood of tumor-bearing mice were higher than in normal mice. Tumor-derived Tregs diminished the up-regulation of costimulatory molecule expression on splenic DCs, even in the presence of Teff cells and simultaneously inhibited IL-12 and $TNF-{\alpha}$ secretion by DCs.

• 대한약리학회지
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• 제23권1호
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• pp.45-49
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• 1987

Cytolytic T cell(CTL)에서는 표현되나 다른 세포에서는 표현되지 않는 유전자를 검색하여 최근 저자는 3종의 CTL 특이 cDNA를 cloning하였다. CTL 특이 cDNA의 기능을 규명하기 위하여 CTL L3 cell을 항원수용체를 통하여 혹은 interleukin 2(IL-2)로 자극하여 활성화시킨 후 RNA blot analysis로 각 cDNA clone의 상응전사체 표현양상을 관찰, CTL활성화과정과의 연관성을 실험하였다. 이중 2종의 cDNA상응전사체표현은 항원수용체자극에 의해 현저히 증가된 반면 IL-2는 전혀 영향을 미치지 않았으며 이 같은 전사체표현증가는 cyclosporin A 처리로 완전히 억제되었다. 이상의 결과는 항원수용체자극으로 활성화되는 유전자가 IL-2에 의해 활성화되는 유전자와는 상이함을 보여주는 것이며 또한 2종의 cDNA clone이 IL-2에 의해 활성화되지 않으나 항원수용체를 통하여 중개되며 cyclosporin A에 예민하게 반응하는 CTL활성화과정의 특정경로에 관여하는 것으로 사료된다.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.82-83
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• 2003

In the past it was thought that autoimmunity is mediated by antibodies and immune complexes. It has now become clear that many diseases, especially tissue specific, are T cell mediated or at least T cell dependent. The pathogenesis of cell-mediated autoimmune diseases, such as multiple sclerosis, uveitis, diabetes, arthritis, and others, is thought to be in a large measure driven by interferon-gamma-producing antigen-specific T cells polarized toward the Th1 phenotype. (omitted)

• 미생물학회지
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• 제50권2호
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• pp.169-172
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• 2014

최근 인간 간암세포주(human hepatoma cells)를 이용하여 C형 간염 바이러스(hepatitis C virus, HCV)의 복제가 가능한 세포배양모델(cell culture system)이 확립되었다. 본 연구에서는 인간 간암세포주 중 huh7.5 cell (human hepatoma 7.5 cells)과 C형 간염 바이러스인 J6/JFH1 clone (2a 유전자형)를 이용하여 감염 가능한 세포배양모델을 확립하였다. 또한, HCV 감염 간암세포주의 HCV 특이 T 림프구에 대한 항원제시(antigen presentation) 가능성을 살펴보았다. 외부에서 전달된 HCV 항원일 경우 간암세포주의 HCV 특이 T 림프구에 대한 항원제시로 T 림프구의 활성이 가능하였으나, HCV 감염 간암세포주의 경우 T 림프구의 활성을 억제하였다. 이러한 HCV 특이 T 림프구의 활성억제와 HCV 감염 간암세포주 항원제시능의 상관성을 알아보기 위해 HCV 감염 간암세포주의 주조직적합성복합체(major histocompatibility complex, MHC) 발현변화를 측정하였으나 HCV 감염은 간암세포주의 MHC 발현변화에 영향을 미치지 않았다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권2호
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• pp.611-616
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• 2014

Objectives: Dendritic cell (DC)-based tumor immunotherapy needs an immunogenic tumor associated antigen (TAA) and an effective approach for its presentation to lymphocytes. In this study we explored whether transduction of DCs with lentiviruses (LVs) expressing the human interleukin-12 gene could stimulate antigen-specific cytotoxic T cells (CTLs) against human lung cancer cells in vitro. Methods: Peripheral blood monocyte-derived DCs were transduced with a lentiviral vector encoding human IL-12 gene (LV-12). The anticipated target of the human IL-12 gene was detected by RT-PCR. The concentration of IL-12 in the culture supernatant of DCs was measured by ELISA.Transduction efficiencies and CD83 phenotypes of DCs were assessed by flow cytometry. DCs were pulsed with tumor antigen of lung cancer cells (DC+Ag) and transduced with LV-12 (DC-LV-12+Ag). Stimulation of T lymphocyte proliferation by DCs and activation of cytotoxic T-lymphocytes (CTL) stimulated by LV-12 transduced DCs pulsed with tumor antigen against A549 lung cancer cells were assessed with methyl thiazolyltetrazolium (MTT). Results: A recombinant lentivirus expressing the IL-12 gene was successfully constructed. DC transduced with LV-12 produced higher levels of IL-12 and expressed higher levels of CD83 than non-transduced. The DC modified by interleukin -12 gene and pulsed with tumor antigen demonstrated good stimulation of lymphocyte proliferation, induction of antigen-specific cytotoxic T lymphocytes and antitumor effects. Conclusions: Dendritic cells transduced with a lentivirus-mediated interleukin-12 gene have an enhanced ability to kill lung cancer cells through promoting T lymphocyte proliferation and cytotoxicity.