• Journal of Korean Neurosurgical Society
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• 제38권2호
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• pp.126-131
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• 2005

Objective : The choice of tumor antigen for dendritic cell[DC]-loading has still been an unresolved problem in the DC-based vaccine strategies against malignant gliomas that has not been found well-characterized tumor specific antigens. In this study, we compare tumor-specific T cell response induced by glioma apoptotic body[GAB]-pulsed DCs to response induced by glioma cell lysate-pulsed ones quantitatively. Methods : DCs generated in the presence of granulocyte macrophage-colony stimulating factor and interleukin[IL]-4 from peripheral blood mononuclear cells[PBMCs] of HLA-A2 positive healthy donors were cultured. Each GABs and glioma cell lysate generated from HLA-A2 positive T98G glioblastoma cells were co-incubated with DCs. $CD8^+$ T lymphocytes isolated from PBMCs of same donors were cultured in media containing IL-2 and either stimulated by GAB- or lysate-pulsed DCs three times at a weekly interval. The interferon[IFN]-${\gamma}$ concentrations of each cell culture supernate were measured by enzyme immunoassay technique. Cytolytic activity of the generated cytotoxic $CD8^+$ T cells either stimulated with GAB- or lysate-pulsed DCs was determined by a standard 4-h $^{51}Cr$-release assay. Results : IFN-${\gamma}$ production and cytolytic activity of effector T cells stimulated by GAB-pulsed DCs were significantly higher than those of T cells stimulated by lysate-pulsed ones. Conclusion : These results indicate the choice of antigen is a critical determinant in the induction of antitumor immunity against malignant glioma. Antigen preparations from GABs represent a promising alternative to glioma cell lysate in DC-based glioma vaccine strategies.

• Journal of Veterinary Science
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• 제23권1호
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• pp.7.1-7.14
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• 2022

Background: Enterotoxigenic Escherichia coli (ETEC) infection is a primary cause of livestock diarrhea. Therefore, effective vaccines are needed to reduce the incidence of ETEC infection. Objectives: Our study aimed to develop a multivalent ETEC vaccine targeting major virulence factors of ETEC, including enterotoxins and fimbriae. Methods: SLS (STa-LTB-STb) recombinant enterotoxin and fimbriae proteins (F4, F5, F6, F18, and F41) were prepared to develop a multivalent vaccine. A total of 65 mice were immunized subcutaneously by vaccines and phosphate-buffered saline (PBS). The levels of specific immunoglobulin G (IgG) and pro-inflammatory cytokines were determined at 0, 7, 14 and 21 days post-vaccination (dpv). A challenge test with a lethal dose of ETEC was performed, and the survival rate of the mice in each group was recorded. Feces and intestine washes were collected to measure the concentrations of secretory immunoglobulin A (sIgA). Results: Anti-SLS and anti-fimbriae-specific IgG in serums of antigen-vaccinated mice were significantly higher than those of the control group. Immunization with the SLS enterotoxin and multivalent vaccine increased interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) concentrations. Compared to diarrheal symptoms and 100% death of mice in the control group, mice inoculated with the multivalent vaccine showed an 80% survival rate without any symptom of diarrhea, while SLS and fimbriae vaccinated groups showed 60 and 70% survival rates, respectively. Conclusions: Both SLS and fimbriae proteins can serve as vaccine antigens, and the combination of these two antigens can elicit stronger immune responses. The results suggest that the multivalent vaccine can be successfully used for preventing ETEC in important livestock.

• Nuclear Medicine and Molecular Imaging
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• 제40권2호
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• pp.74-81
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• 2006

Molecular targeting may be defined as the specific concentration of a diagnostic or therapeutic tracer by its Interaction with a molecular species that is distinctly present or absent in a disease state. Monoclonal antibody (mAb) is one of the successful agents for targeted therapy in cancer. To enhance the therapeutic effect, the concept of targeting radionuclides to tumors using radiolabeled mAbs against tumor-associated antigens, radioimmunotherapy, was proposed. The efficacy of radioimmunotherapy, however, has to be further optimized. Several strategies to improve targeting of tumors with radiolabeled mAbs have been developed, such as the use of mAb fragments, the use of high-affinity mAbs, the use of labeling techniques that are stable in vivo, active removal of the radiolabeled mAb from the circulation, and pretargeting strategies. Until now, however, there are many kinds of obstacles to be solved in the use of mAb for the targeted therapy. Major technical challenges to molecular targeting are related to the rapid and specific delivery of tracers to the target, the elimination of unwanted background activity, and the development of more specific targets to create a cytocidal effect. further development of this field will be determined by success in solving these challenges.

• Asian Pacific Journal of Cancer Prevention
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• 제15권14호
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• pp.5909-5916
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• 2014

Human papillomavirus infection (HPV) and HPV related immune perturbation play important roles in the development of cervical cancer. Since mature dendritic cells (DCs) are potent antigen-presenting cells (APC), they could be primed by HPV antigens against cervical cancers. In this study we were able to generate, maintain and characterize, both phenotypically and functionally, patient specific dendritic cells in vitro. A randomized Phase I trial with three arms - saline control (arm I), unprimed mature DC (arm II) and autologous tumor lysate primed mature DC (arm III) and fourteen patients was conducted. According to WHO criteria, grade 0 or grade one toxicity was observed in three patients. One patient who received tumor lysate primed dendritic cells and later cis-platin chemotherapy showed a complete clinical response of her large metastatic disease and remained disease free for more than 72 months. Our findings indicate that DC vaccines hold promise as adjuvant sfor cervical cancer treatment and further studies to improve their efficacy need to be conducted.

• IMMUNE NETWORK
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• 제9권5호
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• pp.169-178
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• 2009

DNA immunization induces B and T cell responses to various pathogens and tumors. However, these responses are known to be relatively weak and often transient. Thus, novel strategies are necessary for enhancing immune responses induced by DNA immunization. Here, we demonstrated that co-immunization of influenza virus nucleoprotein (NP) gene significantly enhances humoral and cell-mediated responses to codelivered antigens in mice. We also found that NP DNA coimmunization augments in vivo proliferation of adoptively transferred antigen-specific CD4 and CD8 T cells, which enhanced protective immunity against tumor challenge. Our results suggest that NP DNA can serve as a novel genetic adjuvant in cocktail DNA vaccination.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권2호
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• pp.97-108
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• 2011

Cancer stem cells have stem cell-like features, such as the ability for self-renewal and differentiation but show unlimited growth because they have the lost normal regulation of cell growth. Cancer stem cells and normal stem cells have similar features. They show high motility, diversity of progeny, robust proliferative potential, association with blood vessels, immature expression profiles, nestin expression, epidermal growth factor (EGF)-receptor expression, phosphatase and tensin homolog (PTEN) expression, hedgehog pathway activity, telomerase activity, and Wnt pathway activity. On the other hand, with cancer cells, some of these signaling pathways are abnormally modified. In 1875, Cohnheim suggested the concept of cancer stem cells. Recently, evidence for the existence of cancer stem cells was identified. In 1994, the cancer stem cells' specific cell surface marker for leukemia was identified. Since then, other specific cell surface markers for cancer stem cells in solid tumors (e.g. breast and colon cancer) have been identified. In oral cancer, studies on cancer stem cells have been performed mainly with squamous cell carcinomas. Oral cancer specific cell surface markers, which are genes strongly expressed in oral cancer and cancer stem cell specific side populations, have been identified. Cancer stem cells are resistant to radiotherapy and chemotherapy. Therefore, to eliminate malignant tumors efficiently and reduce the recurrence rate, therapy targeting cancer stem cells needs to be performed. Currently, studies targeting the cancer stem cells' specific signaling pathways, telomerase and tumor vasculatures are being done.

• IMMUNE NETWORK
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• 제3권2호
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• pp.118-125
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• 2003

Background: Disialoganglioside GD2 is a tumor-associated antigen that is overexpressed on tumor cells of neuroectodermal origin, such as melanoma and neuroblastoma. Anti-idiotypic antibodies that mimic GD2 may induce more effective immune responses than GD2 antigen itself, because they are protein antigens and are known to be able to break immune tolerance. In this study, to explore the potential of anti-idiotypic antibodies as tumor vaccines, the ability of anti-idiotypic antibodies (Ab2) to induce anti-anti-idiotypic antibodies (Ab3) that bind to the original antigen GD2 was investigated. Methods: Six monoclonal anti-idiotypic antibodies (1A8, 1G5, 2B6, 3A4, 3D6, 3H9) to monoclonal antibody M2058, which is a monoclonal antibody to GD2, were produced in mice. Three (1A8, 3A4, 3H9) of them were selected based on their ability to inhibit the binding of Ab1 to D142.34 (murine melanoma cell expressing GD2). These 3 different Ab2 were injected into rabbits, and rabbit Ab3 induced by each of them were characterized. Results: Ab3-containing sera from two rabbits immunized with 1A8, 3A4, or 3H9 bound significantly (P<0.05) to D142.34 but not to B78.96 (GD2-negative cell), and bound significantly (P<0.05) to isolated GD2 but not to GD1a. Ab3-containing sera from two rabbits immunized with 3A4 or 3H9 inhibited significantly (P<0.05) the binding of Ab1 M2058 to D142.34, and inhibited significantly (P<0.05) the binding of Ab1 M2058 to the Ab2. Conclusion: These results suggest that anti-idiotypic antibodies 3A4 and 3H9 have a potential to be used as vaccines against tumors expressing GD2 by inducing GD2-specific antibodies (Ab3).

• Asian Pacific Journal of Cancer Prevention
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• 제17권3호
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• pp.1023-1035
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• 2016

The purpose of this study was to investigate the role of colon cancer stem cells (CSCs) during chemically-induced rat multi-step colon carcinogenesis with or without the treatment with a specific cyclooxygenase-2 inhibitor drug (celecoxib). Two experiments were performed, the first, a short term 12 week colon carcinogenesis bioassay in which only surrogate markers for colon cancer, aberrant crypt foci (ACF) lesions, were formed. The other experiment was a medium term colon cancer rat assay in which tumors had developed after 32 weeks. Treatment with celecoxib lowered the numbers of ACF, as well as the tumor volumes and multiplicities after 32 weeks. Immunohistochemical proliferating cell nuclear antigen (PCNA) labeling indexes LI (%) were downregulated after treatment by celecoxib. Also different cell surface antigens known to associate with CSCs such as the epithelial cell adhesion molecule (EpCAM), CD44 and CD133 were compared between the two experiments and showed differential expression patterns depending on the stage of carcinogenesis and treatment with celecoxib. Flow cytometric analysis demonstrated that the numbers of CD133 cells were increased in the colonic epithelium after 12 weeks while those of CD44 but not CD133 cells were increased after 32 weeks. Moreover, aldehyde dehydrogenase-1 activity levels in the colonic epithelium (a known CSC marker) detected by ELISA assay were found down-regulated after 12 weeks, but were up-regulated after 32 weeks. The data have also shown that the protective effect of celecoxib on these specific markers and populations of CSCs and on other molecular processes such as apoptosis targeted by this drug may vary depending on the genetic and phenotypic stages of carcinogenesis. Therefore, uncovering these distinction roles of CSCs during different phases of carcinogenesis and during specific treatment could be useful for targeted therapy.

• Tuberculosis and Respiratory Diseases
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• 제46권2호
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• pp.229-240
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• 1999

연구배경: HSVtk/GCV를 이용한 유전자치료에서 면역반응은 1) adenovirus 혹은 retrovirus와 같이 벡타로 사용된 virus의 단백질, 2) 치료목적으로 이입된 HSVtk 유전자의 생성물, 3) 암세포에 대해서 일어날 수 있다. 그리고 이러한 면역반응은 cytokines의 생성 혹은 cytotoxic tumor-specific T-cell의 생성을 초래하여 bystander effect에 의한 살상효과를 증가시키거나, anti-tumor immunity를 유도하여 tumor vaccine의 효과를 나타낼 수 있다. 한편 이와는 대조적으로 면역반응용 HSVtk 유전자를 발현하는 세포들을 파괴하여 이입된 HSVtk 유전자의 발현기간을 제한함으로서 유전자치료의 효과를 감소시킬 수도 있다. 본 연구는 retrovirus 벡타로 이입한 HSVtk 유전자치료에서 면역체계가 bystander effect에 의한 살상효과에 미치는 영향을 규명하고 면역체계가 이입한 유전자의 발현에 미치는 영향을 조사하고자 하였다. 방 법: Immunocompetent mice인 Balb/c mouse와 immunodeficient mouse인 Balb/c-nude 및 SCID mouse에서 retrovirus 벡타를 사용하여 HSVtk 유전자를 이입하고 치료효과를 조사하였다. 그리고 Balb/c mouse에 면역억제제인 cyclosporin을 투여하여 면역억제제가 bystander effect 및 유전자치료 효과와 유전자의 발현기간에 미치는 영향을 조사하였다. 결 과: Balb/c mouse에 HSVtk 유전자를 이입하고 GCV를 투여한 군은 GCV를 투여하지 않은 대조군에 비해 종양의 성장이 유의하게 억제되었으나 Balb/c-nude mouse와 SCID mouse의 경우 GCV를 투여한 군과 대조군 사이에 유의한 차이가 없었다. 면역억제제인 cyclosporin을 투여한 군에서 유전자 치료 효과가 cyclosporin을 투여하지 않은 정상 mouse에 비해 치료효과가 유의하게 작았다. Cyclosporin 투여에 따른 유전자의 발현기간에는 유의한 차이가 없었다. 결 론: Retrovirus 벡타를 사용한 HSVtk 유전자치료에는 면역증강이 치료효과를 증가시킬 것으로 생각된다.

• Tuberculosis and Respiratory Diseases
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• 제53권3호
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• pp.265-274
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• 2002

배 경 :종양 특이 항원인 MAGE 유전자는 여러 종류의 암조직에서 발현되지만 정상조직에서는 고환의 생식 세포를 제외하고는 발현이 없다. 본 연구에서는 MAGE 유전자의 암 특이적 발현을 폐암의 진단에 활용할 수 있는지를 유도객담을 이용하여 알아보고자 하였다. 방 법 :조직학적으로 폐암으로 진단된 환자 30명, 대조군으로 기타 폐질환 환자 14명에서 얻은 유도객담을 3cc의 보존제(guanidinium isothiocyanate, Triton X-100)와 잘 섞어 냉장보관 후 당일 MAGE A 1-6를 동시에 발견할 수 있도록 고안된 2종류의 primer(MAGE common primer C1/C2, C3/C4)를 이용하여 nested PT PCR를 실시하여 MAGE 유전자의 발현 유무를 조사하였다. 결 과 : MAGE common primer를 이용한 nested RT-PCR에서 폐암환자 30 명 중 24명 (80%)에서 MAGE가 양성으로 발현되었고 대조군에서는 전례에서 발견되지 않았다(p=0.001). 편평세포암 17례 중 13례(76.5%), 선암 9례 중 7례 (77.8%)에서 소세포암은 4례에서 모두 MAGE 양성이었으며 각 군간에 발현율의 차이는 없었다(p=0.56). MAGE양성인 환자 24명 중 약 반수인 11 명에서는 기관지 내시경검사에서 육안적으로 종양 병변이 발견되지 않는 경우였다. 결 론 : 유도객담에서 MAGE 유전자는 암 환자에서 선택적으로 높은 빈도의 발현을 보이는 것을 확인하였다. 이러한 결과로 객담을 이용한 MAGE 검사법이 폐암의 검색, 조기진단 그리고 치료 후 경과 관찰에 유용하게 사용될 수 있을 것으로 생각된다.