• Proceedings of the PSK Conference
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• 2003.10b
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• pp.130.1-130.1
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• 2003

As a potent antigen presenting cells and a powerful inducer of antigen specific immunity including cytotoxic T cell activity, dendritic cells(DCs) are being considered as a promising anti-tumor therapeutic module. Unlike solid tumors, leukemia is the hematologic malignancy involving immune effector cells. The expected usage of DCs in leukemia is the treatment of minimal residual disease(MRD) after the remission or stem cell transplantation. In this study, syngeneic leukemia cells were inoculated intra-venously into the mouse (WEHI-3 into the Balb/c), and the autologous tumor cell lysate pulsed DCs were injected as a therapeutic module twice in two weeks. (omitted)

• BMB Reports
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• v.48 no.2
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• pp.103-108
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• 2015

Trichomoniasis caused by the parasitic protozoan Trichomonas vaginalis is the most common sexually transmitted disease in the world. Dendritic cells are antigen presenting cells that initiate immune responses by directing the activation and differentiation of naive T cells. In this study, we analyzed the effect of Trichomonas vaginalis-derived Secretory Products on the differentiation and function of dendritic cells. Differentiation of bone marrow-derived dendritic cells in the presence of T. vaginalis-derived Secretory Products resulted in inhibition of lipopolysaccharide-induced maturation of dendritic cells, down-regulation of IL-12, and up-regulation of IL-10. The protein components of T. vaginalis-derived Secretory Products were shown to be responsible for altered function of bone marrow-derived dendritic cells. Chromatin immunoprecipitation assay demonstrated that IL-12 expression was regulated at the chromatin level in T. vaginalis-derived Secretory Products-treated dendritic cells. Our results demonstrated that T. vaginalis- derived Secretory Products modulate the maturation and cytokine production of dendritic cells leading to immune tolerance.

• IMMUNE NETWORK
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• v.11 no.3
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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.

• Parasites, Hosts and Diseases
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• v.49 no.2
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• pp.191-194
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• 2011

Sparganosis is a tissue invading helminthiasis infecting intermediate hosts, including humans. Strong immune responses are expected to occur in early phases of infection. Thus, we investigated cytokine expressions in splenic dendritic cells and in sera after experimental infection of mice. In splenic dendritic cells, TNF-${\alpha}$ and IL-$1{\beta}$ expression peaked at week 1 and week 3 post -infection (PI), respectively, and also early phase (week 2 PI) depressed cytokine expression was noticed. Serum IL-$1{\beta}$ concentration increased significantly at week 2 PI and peaked at week 6 PI, and that of TNF-${\alpha}$ peaked at week 6 PI. These results showed that pro-inflammatory cytokines, TNF-${\alpha}$ and IL-$1{\beta}$, are chronologically regulated in mouse sparganosis.

• Journal of Microbiology and Biotechnology
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• v.27 no.4
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• pp.709-717
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• 2017

Mucosal tissues are the initial site through which most pathogens invade. As such, vaccines and adjuvants that modulate mucosal immune functions have emerged as important agents for disease prevention. Herein, we investigated the immunomodulatory mechanisms of the B subunit of Escherichia coli heat-labile enterotoxin type IIa ($LT-IIa-B_5$), a potent non-toxic mucosal adjuvant. Alternations in gene expression in response to $LT-IIa-B_5$ were identified using a genome-wide transcriptional microarray that focused on dendritic cells (DC), a type of cell that broadly orchestrates adaptive and innate immune responses. We found that $LT-IIa-B_5$ enhanced the homing capacity of DC into the lymph nodes and selectively regulated transcription of pro-inflammatory cytokines, chemokines, and cytokine receptors. These data are consistent with a model in which directional activation and differentiation of immune cells by $LT-IIa-B_5$ serve as a critical mechanism whereby this potent adjuvant amplifies mucosal immunity to co-administered antigens.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.7
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• pp.2665-2669
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• 2015

CD4+CD25+regulatory T cells (Tregs) play a key role in regulation of immnue response and maintenance of self-tolerance. Studies have found Tregs could suppress tumor-specific T cell-mediated immune response and promote cancer progression. Depletion of Tregs can enhance antitumor immunity. Dendritic cells (DCs) are professional antigen-presenting cells and capable of activating antigen-specific immune responses, which make them ideal candidate for cancer immunotherapy. Now various DC vaccines are considered as effective treatment for cancers. The aim of this study was to evaluate variation of Tregs in BALB/C mice with hepatocellular carcinoma and investigate the interaction between tumor-derived Tregs, effector T cells (Teff) and splenic DCs. We found the percentages of Tregs/CD4+ in the peripheral blood of tumor-bearing mice were higher than in normal mice. Tumor-derived Tregs diminished the up-regulation of costimulatory molecule expression on splenic DCs, even in the presence of Teff cells and simultaneously inhibited IL-12 and $TNF-{\alpha}$ secretion by DCs.

• Toxicological Research
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• v.20 no.4
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• pp.315-320
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• 2004

In this study we assessed the influences of ultraviolet (UV) light B radiation on epidermal ATPase-positive dendritic cell (DC) and the effect of green tea treatment in ICR mouse. The extent of changes following 200 mJ/$cm^2$ (0.5 mW/sec) was studied at 0, 6, 12, 18, 24, 30 or 36 hours after exposure. SBCs were decreased by 6 hours after irradiation. There was tendency to decrease from 6 hours to 24 hours and had little further change from then to 36 hours after irradiation. The mice that received 0, 50, 100, 200, 300 or 400 mJ/$cm^2$ of UVB were examined 24 hours after irradiation. The DCs were decreased as the radiation dose increases from 100 to 400 mJ/$cm^2$. The frequency of UVB (200 mJ/$cm^2$)-induced DC decrease was reduced by treatment of green tea (i.p. and topical application, p<0.01).

• Proceedings of the PSK Conference
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• 2003.10b
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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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• v.3 no.3
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• pp.176-181
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• 2003

Background: The molecular basis of follicular dendritic cells (FDC)-germinal center (GC) B cell interaction is largely unknown, although this cellular interaction is thought to be important for the whole process of GC B cell differentiation. Methods: Using FDC-like cells, HK, and highly purified GC B cells, we attempted to identify the molecules that play critical roles in the interactions between FDC and B cells. GC B cells were co-cultured with HK cells and soluble CD154 in the presence or absence of various function-blocking monoclonal antibodies to examine their effect on GC B cell binding to HK cells and B cell proliferation. Results: Anti-CD11a and anti-CD54 antibodies inhibited GC B cell binding to HK cells while anti-CD49d and anti-CD106 antibodies did not. GC B cell proliferation was not impaired by the disruption of GC B cell-HK cell adherence. Conclusion: Our results suggest that CD11a/CD18-CD54 interactions play an important roles in the initial binding of GC B cells to FDC and diffusible growth factors from FDC may be responsible the massive proliferation of GC B cells.

• Journal of Microbiology and Biotechnology
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• v.25 no.10
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• pp.1687-1696
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• 2015

Supplementation with probiotics can protect against the development of food allergies by modulating the host immune response; however, the mechanisms are not fully understood. The objective of this study was to investigate the allergy-reducing effects of regulatory dendritic cells (regDCs) induced by Lactobacillus paracasei L9 (L9) in β-lactoglobulin (BLG)-sensitized mice. The L9 supplement suppressed the aberrant balance of Th1/Th2 responses to BLG in mice, via upregulation of the CD4+CD25+Foxp3+Treg cell responses. The amount of CD4+CD25+Foxp3+Treg cells in mesenteric lymph nodes increased by 51.85%. Furthermore, administration of L9 significantly induced the expression of CD103 and reduced the maturation status of DCs in mesenteric lymph nodes, Peyer's patches, and spleen. Bone marrow-derived dendritic cells (BM-DCs) were activated by L9 in vitro, with an approximate 1.31-fold and 19.57-fold increase in expression of CD103 in CD11c+DCs and the level of IL-10 production, respectively, while the expression of CD86 did not change significantly. These data demonstrate that L9 reduced the BLG allergic sensitization, likely through regDCs mediated active suppression.