• IMMUNE NETWORK
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• 제15권1호
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• pp.1-8
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• 2015

Innate immune cells survey antigenic materials beneath our body surfaces and provide a front-line response to internal and external danger signals. Dendritic cells (DCs), a subset of innate immune cells, are critical sentinels that perform multiple roles in immune responses, from acting as principal modulators to priming an adaptive immune response through antigen-specific signaling. In the gut, DCs meet exogenous, non-harmful food antigens as well as vast commensal microbes under steady-state conditions. In other instances, they must combat pathogenic microbes to prevent infections. In this review, we focus on the function of intestinal DCs in maintaining intestinal immune homeostasis. Specifically, we describe how intestinal DCs affect IgA production from B cells and influence the generation of unique subsets of T cell.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.137.2-137.2
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• 2003

Dendritic cells (DCs) are known to professional antigen presenting cell (APC). Due to the role as an effective activator of cytotoxic T Lymphocytes by expressing MHC, adhesion and co-stimulatory molecules, DCs are now widely recognized to play an important role in the immune responses to tumors.We investigated the effect of cultured DCs in murine melanoma pulmonary metastasis model. To follow the metastasis protocol, syngenic melanoma cells were inoculated intra-venously into the mouse (B16F10 into the C57BL/6)8 days prior to the first DC injection (1$\times$106 DCs/ mouse, i.p.) and the autologous tumor cell lysate pulsed-DCs were injected as a therapeutic module twice in two weeks. (omitted)

• IMMUNE NETWORK
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• 제11권1호
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• pp.79-94
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• 2011

Background: Dendritic cell (DC)-based vaccines are currently being evaluated as a novel strategy for tumor vaccination and immunotherapy. However, inducing long-term regression in established tumor-implanted mice is difficult. Here, we show that deoxypohophyllotoxin (DPT) induces maturation and activation of bone marrow-derived DCs via Toll-like receptor (TLR) 4 activation of MAPK and NF-${\kappa}B$. Methods: The phenotypic and functional maturation of DPT-treated DCs was assessed by flow cytometric analysis and cytokine production, respectively. DPT-treated DCs was also used for mixed leukocyte reaction to evaluate T cell-priming capacity and for tumor regression against melanoma. Results: DPT promoted the activation of $CD8^+$ T cells and the Th1 immune response by inducing IL-12 production in DCs. In a B16F10 melanoma-implanted mouse model, we demonstrated that DPT-treated DCs (DPT-DCs) enhance immune priming and regression of an established tumor in vivo. Furthermore, migration of DPT-DCs to the draining lymph nodes was induced via CCR7 upregulation. Mice that received DPT-DCs displayed enhanced antitumor therapeutic efficacy, which was associated with increased IFN-${\gamma}$ production and induction of cytotoxic T lymphocyte activity. Conclusion: These findings strongly suggest that the adjuvant effect of DPT in DC vaccination is associated with the polarization of T effector cells toward a Th1 phenotype and provides a potential therapeutic antitumor immunity.

• 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.

• IMMUNE NETWORK
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• 제5권3호
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• pp.150-156
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• 2005

Background: Dendritic cells (DCs) playa critical role not only in the initiation of immune responses, but also in the induction of immune tolerance. In an effort to regulate immune responses through the modulation of antigen presenting cell (APC) function of DCs, we searched for and characterized APC function modulators from natural products. Methods: DCs were cultured in the presence of propolis components, WP and CP, and then examined for their ability to present exogenous antigen in association with major histocompatibility complexes (MHC). Results: WP and CP inhibited class I MHC-restricted presentation of exogenous antigen (cross-presentation) in a DC cell line, DC2.4 cells, and DCs generated from bone marrow cells with GM-CSF and IL-4. The inhibitory activity of WP and CP appeared to be due not only to inhibition of phagocytic activity of DCs, but also to suppression of expression of MHC molecules on DCs. We also examined the effects of WP and CP on T cells. Interestingly, WP and CP increased IL-2 production from T cells. Conclusion: These results demonstrate that WP and CP inhibit MHC-restricted presentation of exogenous antigen through down-regulation of phagocytic activity and suppression of expression of MHC molecules on DCs.

• BMB Reports
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• 제54권1호
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• pp.31-43
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• 2021

Dendritic cells (DC), which consist of several different subsets, specialize in antigen presentation and are critical for mediating the innate and adaptive immune responses. DC subsets can be classified into conventional, plasmacytoid, and monocyte-derived DC in the tumor microenvironment, and each subset plays a different role. Because of the role of intratumoral DCs in initiating antitumor immune responses with tumor-derived antigen presentation to T cells, DCs have been targeted in the treatment of cancer. By regulating the functionality of DCs, several DC-based immunotherapies have been developed, including administration of tumor-derived antigens and DC vaccines. In addition, DCs participate in the mechanisms of classical cancer therapies, such as radiation therapy and chemotherapy. Thus, regulating DCs is also important in improving current cancer therapies. Here, we will discuss the role of each DC subset in antitumor immune responses, and the current status of DC-related cancer therapies.

• Journal of Sleep Medicine
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• 제15권2호
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• pp.37-42
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• 2018

Objectives: To assess the effect and safety of transcranial direct-current stimulation (tDCS) in primary chronic insomnia. Methods: A one-month, double-blind, randomized, sham-controlled trial was performed. A total of 7 patients with primary chronic insomnia received tDCS using anodal (n=3), cathodal (n=2), or sham stimulation (n=2). They were followed up at 1 week and 1 month after treatment. The primary outcome measures included improvement in total sleep time (TST), sleep latency (SL), and sleep efficiency (SE) at 1 month follow-up. Results: TST and SE were improved with tDCS at 1 month follow-up in all patients (100%) of the anodal group, one (50%) of the cathodal group, and one (50%) of the sham group. tDCS improved SL at 1 month follow-up in two patients (67%) of the anodal group, one (50%) of the cathodal group, and none (0%) of the sham group. With respect to adverse events, transient itching sensation occurred in one patient of the anodal group. None of the other groups reported adverse events. Conclusions: Our results suggest that tDCS may be effective and safe for treatment of primary chronic insomnia. A larger controlled study needs to be further investigated.

• Journal of Ginseng Research
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• 제30권3호
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• pp.117-127
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• 2006

본 연구에서는 정관장 홍삼의 물(water) extract, 식용발효 주정 extract 및 홍삼 추출물로부터 분리 제조한 crude saponin을 이용하여 면역반응을 매개하는 수지상세포의 활성 효과에 대하여 알아보았다. 그 결과 홍삼시료 중, crude saponin $100\;{\mu}g/ml$을 처리하였을 때 수지상세포의 세포표면 분자인 MHC class II, CD40, CD80, CD86의 발현이 증가하였으며, phagocytosis는 감소하였다. 또한 홍삼시료를 처리한 수지상세포와 allogeneic T세포를 함께 배양하였을 때, 홍삼시료의 물 extract, 식용발효주정 extract, crude saponin 모두 allogeneic T세포의 증식반응을 유도하였고, IL-2와 $IFN-{\gamma}$의 생산량을 증가시키는 것을 확인하였다. 또한 $CD4^+$ syngeneic T세포와 $CD8^+$ syngeneic T세포의 반응에서도 T세포의 증식반응을 높게 유도하였으며, $CD4^+$ syngeneic T세포에서 IL-2와 $IFN-{\gamma}$의 생산량을 증가시키고, $CD8^+$ syngeneic T세포에서는 $IFN-{\gamma}$ 생산량을 증가시키는 것을 확인하였다. 이상의 결과로 crude saponin의 경우 수지상세포 의 세포표면 공동자극분자의 발현을 유도하고 성숙을 유도함으로써 T세포의 활성을 증진시키는 것으로 생각되며, 물 extract와 식용발효주정 extract는 crude saponin과는 다른 기작으로 T세포 활성화를 유도하는 것을 알 수 있었다. 따라서 실험에 사용한 홍삼시료, 즉 물 extract, 식용발효주정 extract, crude saponin 모두 수지상세포의 활성을 유도하는 물질로써 암항원 특이적 T세포 활성화를 이용한 항암치료에 이용할 수 있는 가능성이 있다고 사료된다.

• 생명과학회지
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• 제17권3호통권83호
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• pp.427-434
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• 2007

본 실험에서는 일부 한약재를 이용하여 수지상세포의 활성화에 미치는 영향을 알아보았다. 그 결과, 실험에 사용한 여섯 가지 한약재 중 선별된 천궁과 당귀는 수지상세포의 항원 제시 능력에 영향을 미쳐, T 세포 증식 반응을 증가시켰고, IL-2와 IFN-r의 분비를 증가시키는 것으로 나타났다. 또한 이러한 T 세포의 활성은 수지상세포의 세포표면 단백질인 MHC classII와 CD86, 그리고 CD11c의 발현 증가에 의한 것임을 확인 할 수 있었다. 이상의 실험 결과, 본 실험에서 선별된 천궁과 당귀는 수지상세포를 활성화시키는 효과가 있는 것으로 생각된다.

• IMMUNE NETWORK
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• 제10권6호
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• pp.188-197
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• 2010

Background: Lichen-derived glucans have been known to stimulate the functions of immune cells. However, immunostimulatory activity of glucan obtained from edible lichen, Umbilicaria esculenta, has not been reported. Thus we evaluated the phenotype and functional maturation of dendritic cells (DCs) following treatment of extracted glucan (PUE). Methods: The phenotypic and functional maturation of PUE-treated DCs was assessed by flow cytometric analysis and cytokine production, respectively. PUE-treated DCs was also used for mixed leukocyte reaction to evaluate T cell-priming capacity. Finally we detected the activation of MAPK and NF-${\kappa}B$ by immunoblot. Results: Phenotypic maturation of DCs was shown by the elevated expressions of CD40, CD80, CD86, and MHC class I/II molecules. Functional activation of DCs was proved by increased cytokine production of IL-12, IL-$1{\beta}$, TNF-${\alpha}$, and IFN-${\alpha}/{\beta}$, decreased endocytosis, and enhanced proliferation of allogenic T cells. Polymyxin B, specific inhibitor of lipopolysaccharide (LPS), did not affect PUE activity, which suggested that PUE was free of LPS contamination. As a mechanism of action, PUE increased phosphorylation of ERK, JNK, and p38 MAPKs, and enhanced nuclear translocation of NF-${\kappa}B$ p50/p65 in DCs. Conclusion: These results indicate that PUE induced DC maturation via MAPK and NF-${\kappa}B$ signaling pathways.