• 통합자연과학논문집
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• 제17권2호
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• pp.59-65
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• 2024

Dendritic cells play a very important role in the immune response as antigen-presenting cells that are critical for initiating both innate and acquired immunity. They recognize, process and present foreign antigens to other key immune cells to trigger and regulate the immune response. The ability to activate these dendritic cells can be used as a treatment for various immune diseases. Maqui berry has been reported to have anticancer, antibacterial and anti-inflammatory properties. However, its effect on the activity of dendritic cells has not been studied. In this study, we investigated the efficacy of maqui berry extract in modulating dendritic cell activity. Treatment of dendritic cells with maqui berry extract induced the costimulatory molecules CD80, CD86, and MHC class I and II in a concentration-dependent manner. Furthermore, the antigen-presenting capacity of dendritic cells was inhibited, which confirms their ability to present antigens, and the production of Interleukin (IL)-12, which is important for dendritic cell activity, was increased. These results indicated that Maqui berry extract activates dendritic cells maturation by inducing the production of co-stimulatory molecules and IL-12. These results suggest that maqui berry extract may act as an effective adjuvant to enhance dendritic cell-based immune responses.

• Biomolecules & Therapeutics
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• 제13권3호
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• pp.174-180
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• 2005

Antigen presenting cells (APCs), dendritic cells (DCs) and macrophages, 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 APC function, we searched for and characterized APC function modulators from natural products. Bifidobacterium pseudocatenulatum SPM1204 (SPM1204) isolated from feces of healthy Korean in the age of 20s was used in this experiment. DCs and macrophages were cultured in the presence of supernatants of SPM 1204 and then examined for their activities for the presentation exogenous antigen in association with major histocompatibility complexes (MHC) and macrophage activation. SPM1204 increased class I MHC-restricted presentation of exogenous antigen (cross-presentation) in a DC cell line, DC2.4 cells. The RAW 264.7 cell line was used to test the nonspecific effect of immune reinforcement of SPM1204 as a source of biological regulating modulator for the macrophage activation, include nitric oxide (NO) production and cytokine production. Results showed that the production of NO, tumor necrosis factor (TNF)-$\alpha$, interleukin 1 (IL-1)-$\beta$ and morphological changes in macrophages were largely affected by SPM1204 in a dose-dependent manner. Our results demonstrated that SPM1204 promote cross-presentation of dendritic cells as well as the induction of NO, TNF-$\alpha$ production, and activation of macrophage.

• Molecules and Cells
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• 제37권5호
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• pp.365-371
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• 2014

Recent findings, notably on adipokines and adipose tissue inflammation, have revised the concept of adipose tissues being a mere storage depot for body energy. Instead, adipose tissues are emerging as endocrine and immunologically active organs with multiple effects on the regulation of systemic energy homeostasis. Notably, compared with other metabolic organs such as liver and muscle, various inflammatory responses are dynamically regulated in adipose tissues and most of the immune cells in adipose tissues are involved in obesity-mediated metabolic complications, including insulin resistance. Here, we summarize recent findings on the key roles of innate (neutrophils, macrophages, mast cells, eosinophils) and adaptive (regulatory T cells, type 1 helper T cells, CD8 T cells, B cells) immune cells in adipose tissue inflammation and metabolic dysregulation in obesity. In particular, the roles of natural killer T cells, one type of innate lymphocyte, in adipose tissue inflammation will be discussed. Finally, a new role of adipocytes as antigen presenting cells to modulate T cell activity and subsequent adipose tissue inflammation will be proposed.

• IMMUNE NETWORK
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• 제13권2호
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• pp.63-69
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• 2013

IL-12 is a secretory heterodimeric cytokine composed of p35 and p40 subunits. IL-12 p35 and p40 subunits are sometimes produced as monomers or homodimers. IL-12 is also produced as a membrane-bound form in some cases. In this study, we hypothesized that the membrane-bound form of IL-12 subunits may function as a costimulatory signal for selective activation of TAA-specific CTL through direct priming without involving antigen presenting cells and helper T cells. MethA fibrosarcoma cells were transfected with expression vectors of membrane-bound form of IL-12p35 (mbIL-12p35) or IL-12p40 subunit (mbIL-12p40) and were selected under G418-containing medium. The tumor cell clones were analyzed for the expression of mbIL-12p35 or p40 subunit and for their stimulatory effects on macrophages. The responsible T-cell subpopulation for antitumor activity of mbIL-12p35 expressing tumor clone was also analyzed in T cell subset-depleted mice. Expression of transfected membranebound form of IL-12 subunits was stable during more than 3 months of in vitro culture, and the chimeric molecules were not released into culture supernatants. Neither the mbIL-12p35-expressing tumor clones nor mbIL-12p40-expressing tumor clones activated macrophages to secrete TNF-${\alpha}$. Growth of mbIL-12p35-expressing tumor clones was more accelerated in the $CD8^+$ T cell-depleted mice than in $CD4^+$ T cell-depleted or normal mice. These results suggest that $CD8^+$ T cells could be responsible for the rejection of mbIL-12p35-expressing tumor clone, which may bypass activation of antigen presenting cells and $CD4^+$ helper T cells.

• 약학회지
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• 제46권6호
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• pp.477-481
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• 2002

Ellagitannins have been reported to enhance the immune system. In this study, the effects of pedunculagin on langerhans cells were examined. Pedunculagin, an ellagitannin from Alnus hirsuta var. microphylla. Betulaceae, is a novel immunomodulator. Langerhans cell are known as the potent antigen presenting cell and elicit the Contact Hypersensitivity (CHS) response by presenting Ag to trafficking Ag-specific T cells within the skin. For determining the effects af pedunculagin on murine langerhans cell, the expression of TNF-$\alpha$ mRNA was examined by RT-PCR. As a result, the expression of TNF-$\alpha$ mRNA was upregulated by pedunculagin. These results suggest that pedunculagin enhances TNF-$\alpha$ and could be used as an immunomodulator in skin immune system.

• Archives of Plastic Surgery
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• 제35권4호
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• pp.367-372
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• 2008

Purpose: Prevention of acute rejection in skin allografts without continuous immunosuppression lacks reports in worldwide literature. Needs for chronic immunosuppression preclude the use of tissue allograft as a routine surgical reconstructive option. Recently dendritic cells(DC) gained considerable attention as antigen presenting cells that are also capable of immunologic tolerance induction. This study assesses the effects of alloantigen-pulsed dendritic cells in induction of survival increase in a rat skin allograft model. Methods: Recipient-derived dendritic cells were harvested from rat whole blood and cultured with GM-CSF(200 ng/mL) and IL-4(8 ng/mL) for 2 weeks. Then donor-specific alloantigen pulsed dendritic cells were reinjected into tail vein before skin graft. The rat dorsal skin allografts were transplanted in 5 subgroups. Groups: I) untreated, II) anti-lymphocyte serum(ALS, 0.5 mL), III) FK-506(2 mg/kg), IV) DCp, VI) DCp and FK-506. Graft appearance challenges were assessed postoperatively. Results: The group V(DC and FK-506 treated) showed longest graft survival rate(23.5 days) than other groups; untreated(5.8 days), ALS(7.2 days), FK-506 (17.5 days), DCp(12.2 days). Conclusion: Donor antigen pulsed host dendritic cell combined with short-term immunosuppression prolong skin allograft survival and has potential therapeutic application for induction of donor antigen specific tolerance.

• IMMUNE NETWORK
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• 제15권3호
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• pp.111-120
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• 2015

Dendritic cells (DCs) play a significant role in establishing self-tolerance through their ability to present self-antigens to developing T cells in the thymus. DCs are predominantly localized in the medullary region of thymus and present a broad range of self-antigens, which include tissue-restricted antigens expressed and transferred from medullary thymic epithelial cells, circulating antigens directly captured by thymic DCs through coticomedullary junction blood vessels, and peripheral tissue antigens captured and transported by peripheral tissue DCs homing to the thymus. When antigen-presenting DCs make a high affinity interaction with antigen-specific thymocytes, this interaction drives the interacting thymocytes to death, a process often referred to as negative selection, which fundamentally blocks the self-reactive thymocytes from differentiating into mature T cells. Alternatively, the interacting thymocytes differentiate into the regulatory T (Treg) cells, a distinct T cell subset with potent immune suppressive activities. The specific mechanisms by which thymic DCs differentiate Treg cells have been proposed by several laboratories. Here, we review the literatures that elucidate the contribution of thymic DCs to negative selection and Treg cell differentiation, and discusses its potential mechanisms and future directions.

• IMMUNE NETWORK
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• 제9권1호
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• pp.27-33
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• 2009

Macrophages generated in vitro using macrophage-colony stimulating factor (M-CSF) and interleukin (IL)-6 from bone marrow cells (BM-Mp) are defective in antigen presenting cell (APC) function as shown by their ability to induce the proliferation of anti-CD3 mAb-primed syngeneic T cells. However, they do express major histocompatibility (MHC) class I and II molecules. accessory molecules and intracellular adhesion molecules. Here we demonstrate that the defective APC function of macrophages is mainly due to production of $TGF-{\beta}1$ by BM-Mp. Methods: Microarray analysis showed that $TGF-{\beta}1$ was highly expressed in BM-Mp, compared to a macrophage cell line, B6D. which exerted efficient APC function. Production of $TGF-{\beta}1$ by BM-Mp was confirmed by neutralization experiments of $TGF-{\beta}1$ as well as by real time-polymerase chain reaction (PCR). Results: Addition of $anti-TGF-{\beta}1$ monoclonal antibody to cultures of BM-Mp and anti-CD3 mAb-primed syngeneic T cells efficiently induced the proliferation of syngeneic T cells. Conversely, the APC function of B6D cells was almost completely suppressed by addition of $TGF-{\beta}1$. Quantitative real time-PCR analysis also confirmed the enhanced expression of $TGF-{\beta}1$ in BM-Mp. Conclusion: The defective APC function of macrophages generated in vitro with M-CSF and IL-6 was mainly due to the production of $TGF-{\beta}1$ by macrophages.

• Biomolecules & Therapeutics
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• 제18권4호
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• pp.463-468
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• 2010

T-cell activation depends on signals received by the T-cell receptor and CD28 co-stimulatory receptor. Since B7.1 and B7.2 molecules expressed on the surface of antigen presenting cells provide co-stimulatory signals through CD28 to T-cells, an inhibitor of CD28-B7.1/B7.2 binding has been proposed as a therapeutic agent for suppression of excessive T-cell activity. Although anti-B7.1/B7.2 antibodies are known to block B7.1 and B7.2 molecules, their effects on intracellular events in antigen presenting cells remain unclear. In this study, anti-B7.1/B7.2 antibodies decreased secretion of nitric oxide and pro-inflammatory cytokines such as TNF-$\alpha$, IL-$1{\beta}$, and IL-12 in LPS-activated RAW264.7 macrophage-like cells and peritoneal macrophages. Moreover, anti-B7.1/B7.2 antibodies inhibited $I{\kappa}B{\alpha}$ phosphorylation and down-regulated expression of co-stimulatory molecules including B7.1, B7.2, and PD-L1 in LPS-stimulated peritoneal macrophages. These findings suggest that CTLA4-Ig and anti-B7.1/B7.2 antibodies may be candidates to treat chronic inflammatory diseases and autoimmune responses caused by excessive activation of both T-cells and macrophages.

• The Korean Journal of Physiology and Pharmacology
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• 제13권3호
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• pp.169-173
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• 2009

Ginsan, a Panax ginseng polysaccharide that contains glucopyranoside and fructofuranoside, has immunomodulatory effects. Although several biologic studies of ginsan have been performed, its effects on dendritic cells (DCs), which are antigen-presenting cells of the immune system, have not been studied. We investigated the immunomodulatory effects of ginsan on DCs. Ginsan had little effect on DC viability, even when used at high concentrations. Ginsan markedly increased the levels of production by DCs of IL-12 and TNF-${\alpha}$, as measured by ELISA. To examine the maturation-inducing activity of ginsan, we measured the surface expression levels of the maturation markers MHC class II and CD86 (B7.2) on DCs. It is interesting that ginsan profoundly enhanced the expression of CD86 on DC surfaces, whereas it increased that of MHC class II only marginally. In $^3H$-thymidine incorporation assays, ginsan-treated DCs stimulated significantly higher proliferation of allogeneic $CD4^+$ T lymphocytes than did medium-treated DCs. Taken together, our data demonstrate that ginsan stimulates DCs by inducing maturation. Because DCs are critical antigen-presenting cells in immune responses, this study provides valuable information on the activities of ginsan.