• The Korean Journal of Physiology and Pharmacology
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• 제14권1호
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• pp.11-14
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• 2010

Human tumors, including those of the hepatobiliary system, express a number of specific antigens that can be recognized by T cells, and may provide potential targets for cancer immunotherapy. Dendritic cells (DCs) are rare leucocytes that are uniquely potent in their ability to capture, process and present antigens to T cells. The ability to culture sufficient numbers of DCs from human bone marrow or blood progenitors has attracted a great deal of interest in their potential utilization in human tumor vaccination. $CD34^+$ peripheral blood stem cells (PBSCs) were obtained from a patient with a hepatocellular carcinoma. The PBSCs were cultured in the X-VIVO 20 medium supplemented with the Flt-3 Ligand (FL), GM-CSF, IL-4 and TNF-$\alpha$ for 12 days. The morphology and functions of the cells were examined. The generated cells had the typical morphology of DCs. When the DCs were reinjected into the same patient, an augmentation of the cytotoxic T lymphocyte (CTL) activity was observed. Concomitantly, an increase in the natural killer (NK) cell activity was also detected in the patient. These results suggest that DCs-based cancer immunotherapy may become an important treatment option for cancer patients in the future.

• 생명과학회지
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• 제16권6호
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• pp.904-910
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• 2006

수지상세포는 종양면역에서 필수적인 강력한 CTL 반응을 개시할 수 있는 유일한 세포이다 . 특히 외인성 종양항원에 대한 CTL 반응 유도는 활성화된 수지상세포의 IL-12 분비를 통한 CD4+ helper T세포의 cross-priming을 필요로 한다. 그러나 최근에 활성화된 수지상세포는 $Th_1$ 면역반응을 유도하지만 활성화 시간이 경과함에 따라 오히려 $Th_2$반응을 유도 할 수 있다. 따라서 본 연구에서는 OVA를 종양항원 모델로 설정하여 종양특이적인 CTL 반응을 형성하기 위한 최적의 수지상세포 활성화 조건을 조사하였다. 마우스 골수세포에 서 수지상세포로의 분화는 항원제시 기능을 위한 표면분자의 발현 측면에서 볼 때 배양 6일-7일 정도가 적합하였다. 수지상세포의 IL-12 생성능은 배양 6일 이상, OVA 항원 탑재 8시간 이상의 경우에 연이은 LPS 성숙자극으로 오히려 감소하는 경향을 보였다. 즉 배양 6일의 수지상세포에 OVA 항원 탑재를 8시간 수행한 경우(8-h DC)가 in vitro에서의 IL-12생성능, ex vivo에서의 세포내 $IFN-{\gamma}$를 발현하는 CD8+ T세포의 증가 및 OVA 특이적인 세포독성효과 등에서 가장 좋은 결과를 보였다. 또한 in vivo에서 종양 치료 및 예방효과에서도 8-h DC로 면역한 경우에 가장 우수한 종양형성 억제 효과와 생존기간 연장효과를 보였다. 현재 대부분의 수지상 세포를 이용한 항종양 백신에서 항원 탑재반응을 24시간 동안 수행하고 있으나, 본 실험의 결과로 볼 때, 8시간의 in vitro 항원 탑재가 보다 효과적인 종양특이적 CTL 반응과 항종양 면역반응을 유도함을 알 수 있다. 결론적으로 본 연구를 통하여 8시간 이상의 항원접촉은 수지상세포의 기능적 활성능력을 오히려 고갈시킬 수 있음을 제시한다.

• Archives of Pharmacal Research
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• 제22권4호
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• pp.340-347
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• 1999

Dendritic cells (DCs) are potent professional antigen-presenting cells (APC) capable of inducing the primary T cell response to antigen. Although tumor cells express target antigens, they are incapable of stimulating a tumor-specific immune response due to a defect in the costimulatory signal that is required for optimal activation of T cells. In this work, we describe a new approach using tumor-DC coculture to improve the antigen presenting capacity of tumor cells which does not require a source of tumor-associated antigen. Immunization of a weakly immunogenic and progressive tumor cocultured with none marrow-derived DCs generated an effective tumor vaccine. Immunization with the cocutured DCs was able to induce complete protectiv immunity against tumor challenges and was effective for the induction of tumor-specific CTL (cytotoxic T lymphocyte) activity. Furthermore, high NK cell activity was observed in mice in which tumors were rejected. In addition, immunization with tumor-pulsed DC s induced delayed tumor growth, but not tumor eradication in tumor-bearing mice. Our results demonstrate that coculture of DCs with tumors generated antitumor immunity due to the NK cell activation as well as tumor-specific T cell. This approach would be used for designing tumor vaccines using DCs when the information about tumor antigens is limited.

• 동의생리병리학회지
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• 제18권1호
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• pp.230-235
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• 2004

We previously reported that the phytoprotein extracted from Acanthopanax senticosus (PA) had anti-carcinogenic anti-metastatic activity via increase of inhibition of gap junctional intercellular communication. In the present study investigated the immunomodulatory mechanism of phytoprotein isolated from the stem bark of Acanthopanax sentic (PA). PA was found to significantly stimulate macrophages producing TNF-α and IL-1β in vitro. It also showed tumori activity indicating that PA had the ability to stimulate macrophage directly. Moreover, PA induced the CDB/sup +/ CTL cy responses to recognize antigen on the B16-BL6 melanoma cells. Treatment of PA with B16-BL6 melanoma cells increased the proliferation of splenocytes compared with untreated control. These results demonstrate that PA immunomodulatory activity suggesting a useful anti-tumor agent applicable to treatment and prevention of cancer.

• IMMUNE NETWORK
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• 제11권3호
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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.

• 생약학회지
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• 제40권1호
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• pp.35-40
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• 2009

The immunomodulatory activities of the ethanol extract of Gynostemma pentaphyllum, termed hereafter as GPE, were examined in immunosuppressed mice as well as in normal mice in the present study. Oral administration of GPE into mice prevented dexamethasone (DEX)-induced immunosuppression as determined by the mitogen-induced proliferation of the splenocytes and the the cytokine production (TNF-$\alpha$, IL-$1{\beta}$) in the whole blood culture. In addition, oral administration of GPE increased antitumor host defense in mice implanted with sarcoma-180 tumor cells. The immunoaugmenting activity of orally administered GPE was also confirmed in mice immunized with ovalbumin (OVA). Mice that were orally administered with GPE generated much more potent OVA-specific cytotoxic T lymphocyte (CTL) responses upon intravenous OVA injection compared to the untreated controls. These results demonstrate that oral administration of the ethanol extract of Gynostemma pentaphyllum could be useful to increase host defense in immunocompromised situations such as stress- or tumor-induced immunosuppression.

• IMMUNE NETWORK
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• 제21권5호
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• pp.33.1-33.19
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• 2021

IL-1β plays critical roles in the priming and effector phases of immune responses such as the differentiation, commitment, and memory formation of T cells. In this context, several reports have suggested that the IL-1β signal is crucial for CTL-mediated immune responses to viral infections and tumors. However, little is known regarding whether IL-1β acts directly on CD8⁺ T cells and what the molecular mechanisms underlying expression of IL-1 receptors (IL-1Rs) on CD8⁺ T cells and features of IL-1R⁺ CD8⁺ T cells are. Here, we provide evidence that the expression of IL-1R type I (IL-1RI), the functional receptor of IL-1β, is preferentially induced by IL-21 on TCR-stimulated CD8⁺ T cells. Further, IL-1β enhances the effector function of CD8⁺ T cells expressing IL-21-induced IL-1RI by increasing cytokine production and release of cytotoxic granules containing granzyme B. The IL-21-IL-1RI-IL-1β axis is involved in an augmented effector function through regulation of transcription factors BATF, Blimp-1, and IRF4. Moreover, this axis confers a unique effector function to CD8⁺ T cells compared to conventional type 1 cytotoxic T cells differentiated with IL-12. Chemical inhibitor and immunoprecipitation assay demonstrated that IL-21 induces a unique pattern of STAT activation with the formation of both STAT1:STAT3 and STAT3:STAT5 heterodimers, which are critical for the induction of IL-1RI on TCR-stimulated CD8⁺ T cells. Taken together, we propose that induction of a novel subset of IL-1RI-expressing CD8⁺ T cells by IL-21 may be beneficial to the protective immune response against viral infections and is therefore important to consider for vaccine design.

• IMMUNE NETWORK
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• 제21권6호
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• pp.44.1-44.15
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• 2021

Tumor peptides associated with MHC class I molecules or their synthetic variants have attracted great attention for their potential use as vaccines to induce tumor-specific CTLs. However, the outcome of clinical trials of peptide-based tumor vaccines has been disappointing. There are various reasons for this lack of success, such as difficulties in delivering the peptides specifically to professional Ag-presenting cells, short peptide half-life in vivo, and limited peptide immunogenicity. We report here a novel peptide vaccination strategy that efficiently induces peptide-specific CTLs. Nanoparticles (NPs) were fabricated from a biodegradable polymer, poly(D,L-lactic-co-glycolic acid), attached to H-2K^b molecules, and then the natural peptide epitopes associated with the H-2K^b molecules were exchanged with a model tumor peptide, SIINFEKL (OVA_257-268). These NPs were efficiently phagocytosed by immature dendritic cells (DCs), inducing DC maturation and activation. In addition, the DCs that phagocytosed SIINFEKL-pulsed NPs potently activated SIINFEKL-H2K^b complex-specific CD8⁺ T cells via cross-presentation of SIINFEKL. In vivo studies showed that intravenous administration of SIINFEKL-pulsed NPs effectively generated SIINFEKL-specific CD8⁺ T cells in both normal and tumor-bearing mice. Furthermore, intravenous administration of SIINFEKL-pulsed NPs into EG7.OVA tumor-bearing mice almost completely inhibited the tumor growth. These results demonstrate that vaccination with polymeric NPs coated with tumor peptide-MHC-I complexes is a novel strategy for efficient induction of tumor-specific CTLs.

• Asian Pacific Journal of Cancer Prevention
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• 제16권9호
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• pp.3843-3847
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• 2015

Background: Cervical cancer is the second most common cause of cancer related death of women. Persistent HPV infection, especially with high-risk types such as HPV16 and HPV18, has been identified to be the primary cause of cervical cancer. E6 and E7 are the major oncoproteins of high-risk HPVs, which are expressed exclusively in HPV infected tissues, and thereby represent ideal therapeutic targets for immunotherapy of cervical cancer. Materials and Methods: In this work, we used recombinant adenovirus expressing coden-optimized HPV16 E6 and E7 fusion protein (Ad-ofE6E7) to prime dendritic cells (DC-ofE6E7), to investigate the ability of primed DC vaccine in eliciting antitumor immunity in vitro and vivo. Results: Our results indicated that DC-ofE6E7 vaccine co-culturing with splenocytes could strongly induce a tumor-specific cytotoxic T lymphocyte (CTL) response and kill the TC-1 cells effectively in vitro. Moreover, DC-ofE6E7 vaccine induced protective immunity against the challenge of TC-1 cancer cells in vivo. Conclusions: The results suggested that the HPV16 ofE6E7 primed DC vaccine has potential application for cervical cancer immunotherapy.

• IMMUNE NETWORK
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• 제4권1호
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• pp.31-37
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• 2004

Background: 1-8D gene is a member of human 1-8 interferon inducible gene family and is shown to be overexpressed in fresh colon cancer tissues. Three peptides 1-6, 3-5 and 3-7 derived from 1-8D gene were shown to have immunogenicity against colon cancer. Methods: To study tumor immunotherapy of these peptides we established an adoptive transfer model. $D^{b-/-}{\times}{\beta}2$ microglobulin (${\beta}2m$) null mice transgenic for a chimeric HLA-A2.1/$D^b-{\beta}2m$ single chain (HHD mice) were immunized with irradiated peptide-loaded RMA-S/HHD/B7.1 transfectants. Spleens were removed after last immunization, and splenocytes were re-stimulated in vitro. Lymphocytes from vaccinated HHD mice were transferred together with IL-2 to the tumor bearing nude mice that were challenged S.C. with the HCT/HHD/B7 colon carcinoma cell line that was found to grow in these mice. Results: Peptide 3-5 was found to be highly effective in CTL activity. Adoptively transferred anti-peptide 3-5 cytolytic T lymphocytes caused significant retardation in tumor growth. Conclusion: This study shows that peptide 3-5 can be the most effective candidate for the vaccine of adoptive immunotherapy against colon cancer.