• 한국안광학회지
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• 제5권2호
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• pp.15-20
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• 2000

성체 소의 망막에 존재하는 doparminergic 신경세포의 형태를 연구하였다. Dopaminerglc 세포는 항체면역세포화학적 방법을 이용하여 확인하였다. Tyrosine hydroxylase 면역 반응 신경 세포의 대부분은 내핵층의 가장 깊은 부분에 위치했다. 이들 세포들의 돌기들은 단층이었으며 그리고 내망상층의 1층내에 위치했다. Tyrosine-hydroxylase 면역 반응되는 두 번째 주요 세포 집단은 치환된 amacrine 세포들이다. 치환된 tyrosine-hydroxylase 면역 반응 amacrine 세포의 돌기들도 역시 내망상층의 1층내에 나타났다. 소수의 신경 세포의 돌기들은 외망상층에서 나타났다. 매우 낮은 밀도의 신경세포들은 내망상층의 중간과 깊은 층에서 tyrosine-hydroxylase 면역 반응 돌기들의 추가적인 층을 가졌다. Doparminergic 신경세포의 돌기들은 방사선형으로 넓게 신장되어 큰 모양을 형성하였고 수상돌기의 가지들은 적당하게 뻗어 있었다. 이러한 돌기들은 때때로 varicosity를 가지지만 "dendritic rings"을 형성하지는 않았다. 본연구의 결과는 doparminergic 세포는 소의 망막내 특이 신경세포 형태를 구성하는 것을 알 수 있었다.

• 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.

• 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.

• 대한화학회지
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• 제43권4호
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• pp.393-400
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• 1999

Hyperbranched polymer를 이용한 나뭇가지꼴 카보실란 거대분자를 합성하였다 Hyperbranched polymer의 영세대 화합물의 합성은 $HSiMe_{3-n}$$(CH_2CH=CH_2)_n$(n=2; $AB_2$,3;$AB_3$형)의 수소화규소첨가반응 방법을 이용하여 합성하였다. Hyperbranched polymer $AB_2$와 $AB_3$형 고분자 화합물은 수소화규소첨가반응과 알켄첨가반응에 의해 Gn+1형 나뭇가지꼴 거대분자로 성장하였다. Gn+2P세대 화합물은 $HSiMeCl_2$와의 수소화규소첨가반응 방법에 의해 모든 가지가 동일형 화합물을 형성하지 못했다. Gn과 Gn+1형 고분자 화합물은 9-BBN과의 반응과 반응생성물의 산화반응에 의해서 polysilol을 형성하였다. 반응의 정도는 NMR에 의해서 확인할 수 있었다.

• Journal of Ginseng Research
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• 제36권4호
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• pp.375-382
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• 2012

Ginsenoside Rp1 (G-Rp1) is a saponin derivate that provides anti-metastatic activities through inhibition of the NF-${\kappa}B$ pathway. In this study, we examined the effects of G-Rp1 on regulatory T cell (Treg) activation. After treatment of splenocytes with G-Rp1, Tregs exhibited upregulation of IL-10 expression, and along with dendritic cells (DCs), these Tregs showed increased cell number compared to other cell populations. The effect of G-Rp1 on Treg number was augmented in the presence of lipopolysaccharide (LPS), which mimics pathological changes that occur during inflammation. However, depletion of DCs prevented the increase in Treg number in the presence of G-Rp1 and/or LPS. In addition, G-Rp1 promoted the differentiation of the memory types of $CD4^+Foxp3^+CD62L^{low}$ Tregs rather than the generation of new Tregs. In vivo experiments also demonstrated that Tregs and DCs from mice that were fed G-Rp1 for 7 d and then injected with LPS exhibited increased activation compared with those from mice that were injected with LPS alone. Expression of TGF-${\beta}$ and CTLA4 in Tregs was increased, and upregulation of IL-2 and CD80/CD86 expression by DCs affected the suppressive function of Tregs through IL-2 receptors and CTLA4. These data demonstrate that G-Rp1 exerts anti-inflammatory effects by activating Tregs in vitro and in vivo.

• IMMUNE NETWORK
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• 제14권3호
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• pp.128-137
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• 2014

Respiratory viruses can induce acute respiratory disease. Clinical symptoms and manifestations are dependent on interactions between the virus and host immune system. Dendritic cells (DCs), along with alveolar macrophages, constitute the first line of sentinel cells in the innate immune response against respiratory viral infection. DCs play an essential role in regulating the immune response by bridging innate and adaptive immunity. In the steady state, lung DCs can be subdivided into $CD103^+$ conventional DCs (cDCs), $CD11b^+$ cDCs, and plasmacytoid DCs (pDCs). In the inflammatory state, like a respiratory viral infection, monocyte-derived DCs (moDCs) are recruited to the lung. In inflammatory lung, discrimination between moDCs and $CD11b^+$ DCs in the inflamed lung has been a critical challenge in understanding their role in the antiviral response. In particular, $CD103^+$ cDCs migrate from the intraepithelial base to the draining mediastinal lymph nodes to primarily induce the $CD8^+$ T cell response against the invading virus. Lymphoid $CD8{\alpha}^+$ cDCs, which have a developmental relationship with $CD103^+$ cDCs, also play an important role in viral antigen presentation. Moreover, pDCs have been reported to promote an antiviral response by inducing type I interferon production rather than adaptive immunity. However, the role of these cells in respiratory infections remains unclear. These different DC subsets have functional specialization against respiratory viral infection. Under certain viral infection, contextually controlling the balance of these specialized DC subsets is important for an effective immune response and maintenance of homeostasis.

• IMMUNE NETWORK
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• 제11권6호
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• pp.383-389
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• 2011

Background: EY-6 is one of the newly synthesized indoledione derivatives to induce tumor cell-specific cell death. In this study, we investigated the mechanism of immunological death induced by EY-6 at mouse colon cancer cell as well as at the normal immune cell represented by dendritic cell. Methods: C57BL/6 mouse syngeneic colon cancer cell MC38 was treated with EY-6, and analyzed by MTT for viability test, flow cytometry for confirming surface expressing molecules and ELISA for detection of cytokine secretion. Normal myeloid-dendritic cell (DC) was ex vivo cultured from bone marrow hematopoietic stem cells of C57BL/6 mice with GM-CSF and IL-4 to analyze the DC uptake of dead tumor cells and to observe the effect of EY-6 on the normal DC. Results: EY-6 killed the MC38 tumor cells in a dose dependent manner (25, 50 and $100{\mu}M$) with carleticulin induction. And EY-6 induced the secretion of IFN-${\gamma}$ but not of TNF-${\alpha}$ from the MC38 tumor cells. EY-6 did not kill the ex-vivo cultured DCs at the dose killing tumor cells and did slightly but not significantly induced the DC maturation. The OVA-specific cross-presentation ability of DC was not induced by chemical treatment (both MHC II and MHC I-restricted antigen presentation). Conclusion: Data indicate that the EY-6 induced tumor cell specific and immunological cell death by modulation of tumor cell phenotype and cytokine secretion favoring induction of specific immunity eliminating tumor cells.

• Parasites, Hosts and Diseases
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• 제58권2호
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• pp.185-189
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• 2020

Immunogenicity of dendritic cell-derived exosomes stimulated with Toxoplasma gondii lysates (TLA exo), mixed with cholera toxin as an adjuvant, was investigated in mice immunized via 2 mucosal routes (ocular vs intranasal). BALB/c mice were injected 3 times with TLA exo vaccine at 2 week interval, and the levels of IgG in serum and IgA in tear, saliva, feces, and vaginal wash were measured. To observe the expression of T. gondii-specific B1 gene, mice infected with ME49 T. gondii cysts were immunized with TLA exo or PBS exo (not stimulated with TLA), and their brain tissues were examined. The mice vaccinated via intranasal route elicited significantly higher humoral and mucosal immune responses compared with mice treated with PBS alone. Also, mice immunized via ocular route (by eyedrop) induced significantly higher T. gondii-specific IgG in serum and IgA in tear and feces in comparison with PBS controls. B1 gene expression was significantly lower in TLA exo vaccinated mice than in PBS or PBS exo vaccinated mice. These results demonstrated that ocular immunization of mice with TLA exo vaccine has the potential to stimulate systemic or local antibody responses. This study also highlighted an advantage of an eyedrop vaccine as an alternative for T. gondii intranasal vaccines.

• Molecules and Cells
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• 제38권1호
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• pp.89-94
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• 2015

The shape and activity of mitochondria are tightly regulated by fusion and fission processes that are essential for maintaining normal cellular function. However, little is known about the involvement of mitochondrial dynamics in the development of the immune system. In this study, we demonstrate that mitochondrial dynamics play a role in the differentiation and migration of immature dendritic cells (imDCs). We show that mitochondrial elongation is induced during GM-CSF-stimulated differentiation of bone marrow progenitors to imDCs accompanied by upregulation of mitochondrial fusion proteins. These processes precede the changes in mitochondrial morphology and connectivity that occur during differentiation. Mfn2 and OPA1, but not Mfn1, are transcriptionally upregulated during differentiation; however, knockdown of Mfn2 and OPA1 does not induce any change in expression of CD11c, CDC80, or CD86. Notably, knockdown of Mfn2 or OPA1 by siRNA in imDCs significantly reduces CCR7 expression and CCL19-mediated migration. These results suggest that the mitochondrial fusion-related proteins Mfn2 and OPA1 are upregulated during bone marrow progenitor differentiation and promote the migration of imDCs by regulating the expression of CCR7.

• 한국표면공학회지
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• 제37권5호
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• pp.296-300
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• 2004

The defects of partial denture frameworks are mainly shrinkage porosity, inclusions, micro-crack, particles from investment, and dendritic structure. In order to investigate a good casting condition of partial denture frameworks, the three casting alloys and casting methods were used and detected casting defects were analyzed by using electrochemical methods. Three casting alloys (63Co-27Cr-5.5Mo, 63Ni-16Cr, 63Co-30Cr-5Mo) were prepared for fabricating partial denture frameworks with various casting methods; centrifugal casting (Kerr, USA), high frequency induction casting (Jelenko Eagle, USA), vacuum pressure casting (Bego, Germany). The casting temperature was $1,380^{\circ}C$ (63Co-27Cr-5.5Mo and 63Ni-16Cr) and $1,420^{\circ}C$ (63Co-30Cr-5Mo). The casting morphologies were analyzed using FE-SEM and EDX. The corrosion test of the dendritic structure was performed through potentiodynamic method in 0.9% NaCl solutions at $36.5^{\circ}C$ and corrosion surface was observed using SEM. The defects of partial denture frameworks improved in the order of centrifugal casting, high frequency induction casting, and vacuum pressure casting method, especially, pore defects were found at part of clasp in the case of centrifugal casting method. The structure of casting showed dendritic structure for three casting alloys. In the 63Co-27Cr-5.5Mo and 63Co-30Cr-5Mo, $\alpha$-Co and $\varepsilon$-Co phases were identified at matrix and $${\gamma}$-Ni_2$Cr second phase were shown in 63Ni-16Cr. Also, the corrosion resistance of cast structure increased in the order of vacuum pressure casting, high frequency induction casting, and centrifugal casting method.