• IMMUNE NETWORK
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• 제4권1호
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• pp.38-43
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• 2004

Backgroud: Immunotherapy using dendritic cells (DC) loaded with tumor antigens may represent a potentially effective method for inducing antitumor immunity. We evaluated the effectiveness of DC-based antitumor immune response in various conditions. Methods: DC were cultured from peripheral blood mononuclear cells (PBMNC) in myelogenous leukemia (ML) and lysates of autologous leukemic cells are used as tumor antigen. The effectiveness of interleukin-12 (IL-12) and CD40L (CD154) on the antigen presenting function of lysates-loaded DC was analyzed by proliferation, cytokine production, and cytotoxicity tests with activated PBMNC (mainly lymphocytes). For generating antigen-loaded DC, direct fusion of DC with ML was studied. Results: Antigen loaded DC induced significantly effective antitumor immune response against autologous leukemic cells. Administration of IL-12 on the DC based antitumor immune response showed higher proliferation activity, IFN-$\gamma$ production, and cytotoxic activity of PBMNC. Also, fused cell has a potent antitumor immune response. Conclusion: We conclude that lysates-loaded DC with IL-12 may be effectively utilized as inducer of antitumor immune reaction in ML and in vivo application with DC-based antitumor immunotherapy or tumor vaccination seems to be feasible.

• IMMUNE NETWORK
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• 제16권1호
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• pp.44-51
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• 2016

Dendritic cells (DCs) are professional antigen presenting cells, and play an important role in the induction of antigen-specific adaptive immunity. However, some DC populations are involved in immune regulation and immune tolerance. These DC populations are believed to take part in the control of immune exaggeration and immune disorder, and maintain immune homeostasis in the body. Tolerogenic DCs (tolDCs) can be generated in vitro by genetic or pharmacological modification or by controlling the maturation stages of cytokine-derived DCs. These tolDCs have been investigated for the treatment of rheumatoid arthritis (RA) in experimental animal models. In the last decade, several in vitro and in vivo approaches have been translated into clinical trials. As of 2015, three tolDC trials for RA are on the list of ClinicalTrial.gov (www.clinicaltrials.gov). Other trials for RA are in progress and will be listed soon. In this review, we discuss the evolution of tolDC-based immunotherapy for RA and its limitations and future prospects.

• IMMUNE NETWORK
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• 제10권6호
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• pp.206-211
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• 2010

Background: Dendritic cell (DC)-based tumor vaccine is an attractive modality for the treatment of colon cancer because it has been recurred and produced few side effects in patients. Secretory glycoprotein 90K has been found at elevated level in various cancer tissues and sera. We investigated to establish a more effective DC vaccine for the treatment of colon cancer in which the levels of 90K are elevated. Methods: We obtained the concentrated 90K from 293T cells stably expressing 90K. DCs were cultured from peripheral blood monocytes, and a DC vaccine pulsed with tumor lysate was compared with a DC vaccine pulsed with 90K. We measured the functional activity for CTLs by using IFN-${\gamma}$-enzyme linked immunoabsorbent spot (ELISPOT) assay. Results: DCs pulsed with tumor lysate+90K exhibited the enhanced T cell stimulation, polarization of $\ddot{i}$ T cell toward Th1. The CTLs generated by DCs pulsed with 90K efficiently lysed HCT116 cells. The results indicate that 90K-speicifc-CTLs can recognize 90K proteins naturally presented by colon cancer cells. Conclusion: Our study suggests that 90K-specific CTLs generated by 90K-pulsed DCs could be useful effector cells for immunotherapy in colon cancer.

• IMMUNE NETWORK
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• 제5권3호
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• pp.163-171
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• 2005

Background: To perform the successful dendritic cell-based cancer immunotherapy one of the main issues to be solved is the source of antigen for DC pulsing. Limitations occur by using auto-tumor lysate due to the difficulties obtaining enough tumor tissue(s) quantitatively as well as qualitatively. In this study the possibility of allogeneic tumor cell lysate as a DC pulsing antigen has been tested in mouse melanoma pulmonary me tastasis model. Methods: B16F10 melanoma cells $(1{\timeS}10^5/mouse)$ were inoculated intra venously into the C57BL/6 mouse. Therapeutic DCs were cultured from the bone marrow myeloid lineage cells with GM-CSF and IL-4 (1,000 U/ml each) for 7 days and pulsed with lysate of either autologous B16F10 (B-DC), allogeneic K1735 (C3H/He origin; K-DC) or CloneM3 (DBA2 origin; C-DC) melanoma cells for 18 hrs. Pulsed-DCs $(1{\times}10^6/mouse)_{[CGP1]}$ were injected i.p. twice with one week interval starting from the day 1 after tumor cell inoculation. Results: Without observable toxicity, allogeneic tumor cell lysate pulsed-DC induced the significantly better anti-tumor response (tumor scale: $2.7{\pm}0.3,\;0.7{\pm}0.3\;and\;0.3{\pm}0.2$ for saline, B-DC and C-DC treated group, respectively). Along with increased tumor specific lymphocyte proliferations, induction of IFN-${\gamma}$ secretion against both auto- and allo-tumor cell lysates was observed from the DC treated mice. (w/B16F10-lysate: $44.97{\pm}10.31,\;1787.94{\pm}131.18,\;1257.15{\pm}48.27$, w/CloneM3 lysate: 0, $1591.13{\pm}1.83,\;1460.47{\pm}86.05pg/ml$ for saline, B-DC and C-DC treated group, respectively) Natural killer cell activity was also increased in the mice treated with tumor cell lysate pulsed-DC ($8.9{\pm}_{[CGP2]}0.1,\;11.6{\pm}0.8\;and\;12.6{\pm}0.7%$ specific NK activity for saline, B-DC and C-DC treated group, respectively). Conclusion: Conclusively, promising data were obtained that allogeneic-tumor cell lysate can be used as a tumor antigen for DC-based cancer immunotherapy.

• IMMUNE NETWORK
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• 제6권3호
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• pp.154-162
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• 2006

Background: Dendritic cell (DC)-based cancer immunotherapy is studied for several years. However, it is mainly derived from autologous PBMC or leukapheresis from patient, which has limitations about yield and ability of DC production according to individual status. In order to solve these problems, inquiries about allogeneic DCs are performed but there are no preclinical trial answers for effect or toxicity of allogeneic DC to use for clinical trial. In this study, we compared the anti-tumor effect of allogeneic and autologous DCs from mouse bone marrow stem cells in mouse metastatic melanoma model. Methods: B16F10 melanoma cells ($5{\times}10^4$/mouse) were injected intravenously into the C57BL/6 mouse. Therapeutic DCs were differentiated from autologous (C57BL/6: CDC) or allogeneic (B6C3F1: BDC) bone marrow stem cells with GM-CSF, SCF and IL-4 for 13days and pulsed with B16F10 tumor cell lysate (Blys) for 18hrs. DC intra-peritoneal injections began on the 8th day after the tumor cell injection by twice with one week interval. Results: Anti-tumor response was observed by DC treatment without any toxicity especially in allogeneic DC treated mice (tumor burden score: $2.667{\pm}0.184,\;2.500{\pm}0.463,\;2.000{\pm}0.286,\;1.500{\pm}0.286,\;1.667 {\pm}0.297$ for saline, CDC/unpulsed-DC: U-DC, CDC/Blys-DC, BDC/U-DC and BDC/Blys-DC, respectively). IFN-${\gamma}$ secretion was significantly increased in allogeneic DC group stimulated with B16F10 cell lysate ($2,643.3{\pm}5,89.7,\;8,561.5{\pm}2,204.9.\;6,901.2{\pm}141.1pg/1{\times}10^6$ cells for saline, BDC/U-DC and BDC/Blys-DC, respectively) with increased NK cell activity. Conclusion: Conclusively, promising data was obtained that allogeneic DC can be used for DC-based cancer immunotherapy.

• IMMUNE NETWORK
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• 제6권2호
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• pp.102-110
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• 2006

Background: Dendritic cells (DC) are professional antigen-presenting cells in the immune system and can induce T cell response against virus infections, microbial pathogens, and tumors. Therefore, immunization using DC loaded with tumor-associated antigens (TAAs) is a powerful method of inducing anti-tumor immunity. For induction of effective anti-tumor immunity, antigens should be efficiently introduced into DC and presented on MHC class I molecules at high levels to activate antigen-specific $CD8^+$ T cells. We have been exploring methods for loading exogenous antigens into APC with high efficiency of Ag presentation. In this study, we tested the effect of the cationic liposome (Lipofectin) for transferring and loading exogenous model antigen (OVA protein) into BM-DC. Methods: Bone marrow-derived DC (EM-DC) were incubated with OVA-Lipofectin complexes and then co-cultured with B3Z cells. B3Z activation, which is expressed as the amount of ${\beta}$-galactosidase induced by TCR stimulation, was determined by an enzymatic assay using ${\beta}$-gal assay system. C57BL/6 mice were immunized with OVA-pulsed DC to monitor the in vivo vaccination effect. After vaccination, mice were inoculated with EG7-OVA tumor cells. Results: BM-DC pulsed with OVA-Lipofectin complexes showed more efficient presentation of OVA-peptide on MHC class I molecules than soluble OVA-pulsed DC. OVA-Lipofectin complexes-pulsed DC pretreated with an inhibitor of MHC class I-mediated antigen presentation, brefeldin A, showed reduced ability in presenting OVA peptide on their surface MHC class I molecules. Finally, immunization of OVA-Lipofectin complexes-pulsed DC protected mice against subsequent tumor challenge. Conclusion: Our data provide evidence that antigen-loading into DC using Lipofectin can promote MHC class I- restricted antigen presentation. Therefore, antigen-loading into DC using Lipofectin can be one of several useful tools for achieving efficient induction of antigen-specific immunity in DC-based immunotherapy.

• IMMUNE NETWORK
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• 제16권1호
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• pp.33-43
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• 2016

Cell-penetrating peptides (CPPs) are short amino acids that have been widely used to deliver macromolecules such as proteins, peptides, DNA, or RNA, to control cellular behavior for therapeutic purposes. CPPs have been used to treat immunological diseases through the delivery of immune modulatory molecules in vivo. Their intracellular delivery efficiency is highly synergistic with the cellular characteristics of the dendritic cells (DCs), which actively uptake foreign antigens. DC-based vaccines are primarily generated by pulsing DCs ex vivo with various immunomodulatory antigens. CPP conjugation to antigens would increase DC uptake as well as antigen processing and presentation on both MHC class II and MHC class I molecules, leading to antigen specific CD4⁺ and CD8⁺ T cell responses. CPP-antigen based DC vaccination is considered a promising tool for cancer immunotherapy due to the enhanced CTL response. In this review, we discuss the various applications of CPPs in immune modulation and DC vaccination, and highlight the advantages and limitations of the current CPP-based DC vaccination.

• KSBB Journal
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• 제19권6호
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• pp.415-420
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• 2004

전 세계적으로 암의 발병률의 증가하고 있고 또한 그 수는 해마다 증가하는 실정이다. 암은 성장양상에 따라 악성종양과 양성종양으로 나뉘는데 암으로 구분되는 악성종양을 치료하기 위한 여러 가지 치료법들이 시행되고 또 개발되고 있다. 그중에서 dendritic cells (DCs)는 인체 내 면역반응을 이용하여 암을 치료하는 방법으로 적응면역에 관여하는 cytotoxic T cell (CTL)에 항원을 제시하여 CTL로 하여금 종양세포를 직접적으로 공격하도록 도움을 주는 역할을 한다. 그러나 여기에는 여러 가지 단점이 있다. 이 단점을 보완하기 위한 새로운 방법으로 artificial antigen-presenting cell (aAPC)을 이용한 치료법이 개발되고 있다. 가용성의 human leukocyte antigen-immunoglobulin fusion protein (HLA-Ig)를 기초한 aAPC은 DCs의 단점을 보완한 항원제시세포로써 DCs보다 더욱 효과적으로 CTL반응을 유도해 낼 것으로 기대한다. 본 총설에서는 이 DCs의 역할과 이들을 이용한 암 치료법에 대해서 논하고 그 개발 가능성에 대해서 알아보도록 하겠다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권5호
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• pp.3109-3116
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• 2013

The majority of hepatocellular carcinoma (HCC) patients have a poor prognosis with current therapies, and new approaches are urgently needed. We have developed a novel therapeutic cancer vaccine platform based on tumor cell derived autophagosomes (DRibbles) for cancer immunotherapy. We here evaluated the effectiveness of DRibbles-pulsed dendritic cell (DC) immunization to induce anti-tumor immunity in BALB/c mouse HCC and humanized HCC mouse models generated by transplantation of human HCC cells (HepG2) into BALB/c-nu mice. DRibbles were enriched from H22 or BNL cells, BALB/c-derived HCC cell lines, by inducing autophagy and blocking protein degradation. DRibbles-pulsed DC immunization induced a specific T cell response against HCC and resulted in significant inhibition of tumor growth compared to mice treated with DCs alone. Antitumor efficacy of the DCs-DRibbles vaccine was also demonstrated in a humanized HCC mouse model. The results indicated that HCC/DRibbles-pulsed DCs immunotherapy might be useful for suppressing the growth of residual tumors after primary therapy of human HCC.

• IMMUNE NETWORK
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• 제4권1호
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• pp.44-52
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• 2004

Background: As a potent antigen presenting cell and a powerful inducer of antigen specific immunity, dendritic cells (DCs) are being considered as a promising anti-tumor therapeutic module. The expected therapeutic effect of DCs in renal cell carcinoma was tested in the mouse model. Established late-stage tumor therapeutic (E-T) and minimal residual disease (MRD) model was considered in the in vivo experiments. Methods: Syngeneic renal cell carcinoma cells (RENCA) were inoculated either subcutaneously (E-T) or intravenously (MRD) into the Balb/c mouse. Tumor cell lysate pulsed-DCs were injected twice in two weeks. Intraperitoneal DC injection was started 3 week (E-T model) or one day (MRD model) after tumor cell inoculation. Two weeks after the final DC injection, the tumor growth and the systemic immunity were observed. Therapeutic DCs were cultured from the bone marrow myeloid lineage cells with GM-CSF and IL-4 for 7 days and pulsed with RENCA cell lysate for 18 hrs. Results: Compared to the saline treated group, tumor growth (E-T model) or formation (MRD model) was suppressed in pulsed-DC treated group. RENCA specific lymphocyte proliferation was observed in the RENCA tumor-bearing mice treated with pulsed-DCs. Primary cytotoxic T cell activity against RENCA cells was increased in pulsed-DC treated group. Conclusion: The data suggest the possible anti-tumor effect of cultured DCs in established or minimal residual disease/metastasis state of renal cell carcinoma. Systemic tumor specific immunity including cytotoxic T cell activity was modulated also in pulsed-DC treated group.