• Parasites, Hosts and Diseases
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• v.61 no.2
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• pp.138-146
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• 2023

Toxoplasma gondii is an intracellular protozoan parasite which can infect most warm-blooded animals and humans. Among the different mouse models, C57BL/6 mice are more susceptible to T. gondii infection compared to BALB/c mice, and this increased susceptibility has been attributed to various factors, including T-cell responses. Dendritic cells (DCs) are the most prominent type of antigen-presenting cells and regulate the host immune response, including the response of T-cells. However, differences in the DC responses of these mouse strains to T. gondii infection have yet to be characterized. In this study, we cultured bone marrow-derived DCs (BMDCs) from BALB/c and C57BL/6 mice. These cells were infected with T. gondii. The activation of the BMDCs was assessed based on the expression of cell surface markers and cytokines. In the BMDCs of both mouse strains, we detected significant increases in the expression of cell surface T-cell co-stimulatory molecules (major histocompatibility complex (MHC) II, CD40, CD80, and CD86) and cytokines (tumor necrosis factor (TNF)-α, interferon (IFN)-γ, interleukin (IL)-12p40, IL-1β, and IL-10) from 3 h post-T. gondii infection. The expression of MHC II, CD40, CD80, CD86, IFN-γ, IL-12p40, and IL-1β was significantly higher in the T. gondii-infected BMDCs obtained from the C57BL/6 mice than in those from the BALB/c mice. These findings indicate that differences in the activation status of the BMDCs in the BALB/c and C57BL/6 mice may account for their differential susceptibility to T. gondii.

• IMMUNE NETWORK
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• v.22 no.2
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• pp.16.1-16.20
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• 2022

The gastrointestinal tract is the first organ directly affected by fasting. However, little is known about how fasting influences the intestinal immune system. Intestinal dendritic cells (DCs) capture antigens, migrate to secondary lymphoid organs, and provoke adaptive immune responses. We evaluated the changes of intestinal DCs in mice with short-term fasting and their effects on protective immunity against Listeria monocytogenes (LM). Fasting induced an increased number of CD103⁺CD11b^- DCs in both small intestinal lamina propria (SILP) and mesenteric lymph nodes (mLN). The SILP CD103⁺CD11b^- DCs showed proliferation and migration, coincident with increased levels of GM-CSF and C-C chemokine receptor type 7, respectively. At 24 h post-infection with LM, there was a significant reduction in the bacterial burden in the spleen, liver, and mLN of the short-term-fasted mice compared to those fed ad libitum. Also, short-term-fasted mice showed increased survival after LM infection compared with ad libitum-fed mice. It could be that significantly high TGF-β2 and Aldh1a2 expression in CD103⁺CD11b^- DCs in mice infected with LM might affect to increase of Foxp3⁺ regulatory T cells. Changes of major subset of DCs from CD103⁺ to CD103^- may induce the increase of IFN-γ-producing cells with forming Th1-biased environment. Therefore, the short-term fasting affects protection against LM infection by changing major subset of intestinal DCs from tolerogenic to Th1 immunogenic.

• Journal of Life Science
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• v.21 no.12
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• pp.1789-1794
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• 2011

Dendritic cells (DCs) are professional antigen-presenting cells playing key roles in immune sentinels as initiators of T-cell responses against microbial pathogens and tumors. Sarijang, a folk sauce containing extracts of Rhynchosia nulubilis, Ulmus davidiana roots, Allium sativum, and Rhus Verniaiflura bark, has been used as a nonspecific immunostimulant for cancer patients. However, little is known about its immunomodulating effects or their mechanisms. In this study, we investigated whether sarijang induces phenotypic and functional maturation of DCs. For this study, murine bone marrow-derived myeloid DCs were cultured in the presence of interleukin-4 (IL-4) and granulocyte-macrophage colony stimulating factor (GM-CSF), and the generated immature DCs were stimulated with sarijang or lipopolysaccharide (LPS). Our data indicated that sarijang significantly enhanced the expression of co-stimulatory molecules (CD80 and CD86) as well as major histocompatibility complex (MHC) II, as did LPS. The results provide new insight into the immunopharmacology of sarijang and suggest a novel approach to the manipulation of DC for therapeutic application.

• Parasites, Hosts and Diseases
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• v.55 no.4
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• pp.375-384
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• 2017

Trichomonas vaginalis is a pathogen that triggers severe immune responses in hosts. T. vaginalis ${\alpha}$-actinin 2, $Tv{\alpha}$-actinin 2, has been used to diagnose trichomoniasis. This study was undertaken to examine the role of $Tv{\alpha}$-actinin 2 as an antigenic molecule to induce immune responses from humans. Western blot analysis using anti-$Tv{\alpha}$-actinin 2 antibodies indicated its presence in the secreted proteins of T. vaginalis. ELISA was employed to measure cytokine production by vaginal epithelial cells, prostate cells, mouse dendritic cells (DCs), or T cells stimulated with T. vaginalis or $Tv{\alpha}$-actinin 2 protein. Both T. vaginalis and $rTv{\alpha}$-actinin 2 induced cytokine production from epithelial cell lines, including IL-10. Moreover, $CD4^+CD25^-$ regulatory T cells (Treg cells) incubated with $rTv{\alpha}$-actinin 2-treated DCs produced high levels of IL-10. These data indicate that $Tv{\alpha}$-actinin 2 modulates immune responses via IL-10 production by Treg cells.

• Journal of Veterinary Clinics
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• v.26 no.2
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• pp.138-143
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• 2009

Ischemia/reperfusion injury(I/RI) is the major cause of acute renal failure and delayed graft function(DGF) unavoidable in renal transplantation. Enormous studies on ischemia damage playing a role in activating graft rejection factors, such as T cells or macrophages, are being reported. Present study was performed to determine whether ischemia time would play an important role in activating rejection-related factors or not in rat models of I/RI. Male Sprague-Dawley rats were submitted to 30, 45, and 60 minutes of warm renal ischemia with nephrectomy or control animals underwent sham operation(unilateral nephrectomy). Renal function and survival rates were evaluated on day 0, 1, 2, 3, 5 and 7. Immunofluorescence staining of dendritic cells(DCs), natural killer(NK) cells, macrophages, B cells, CD4+ and CD8+ T cells were measured on day 1 and 7 after renal I/RI. Survival rates dropped below 50% after day 3 in 45 minutes ischemia. Histologic analysis of ischemic kidneys revealed a significant loss of tubular architecture and infiltration of inflammatory cells. DCs, NK cells, macrophages, CD4+ and CD8+ T cells were infiltrated from a day after I/RI depending on ischemia time. Antigen presenting cells(DCs, NK cells or macrophages) and even T cells were infiltrated 24 hours post-I/RI, which is at the time of acute tubular necrosis. During the regeneration phase, not only these cells increased but B cells also appeared in more than 45 minutes ischemia. The numbers of the innate and the adaptive immune cells increased depending on ischemia as well as reperfusion time. These changes of infiltrating cells resulting from each I/RI model show that ischemic time plays a role in activating rejection related immune factors and have consequences on progression of renal disease in transplanted and native kidneys.

• IMMUNE NETWORK
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• v.23 no.5
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• pp.41.1-41.21
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• 2023

CD4 and CD8 T cells are key players in the immune response against both pathogenic infections and cancer. CD4 T cells provide help to CD8 T cells via multiple mechanisms, including licensing dendritic cells (DCs), co-stimulation, and cytokine production. During acute infection and vaccination, CD4 T cell help is important for the development of CD8 T cell memory. However, during chronic viral infection and cancer, CD4 helper T cells are critical for the sustained effector CD8 T cell response, through a variety of mechanisms. In this review, we focus on T cell responses in conditions of chronic Ag stimulation, such as chronic viral infection and cancer. In particular, we address the significant role of CD4 T cell help in promoting effector CD8 T cell responses, emerging techniques that can be utilized to further our understanding of how these interactions may take place in the context of tertiary lymphoid structures, and how this key information can be harnessed for therapeutic utility against cancer.

• Journal of Life Science
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• v.27 no.4
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• pp.482-499
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• 2017

Allergic diseases have increased over the past several decade worldwide including developing countries. Allergic inflammatory responses are caused by Th (T helper)2 immune responses, triggered by allergen ingestion by antigen presenting cells such as dendritic cells (DCs). Intestinal microorganisms control the metabolism and physiological functions of the host, contribute to early immune system maturation during the early life, and homeostasis and epithelial integrity during life. Bifidobacteria have strain-specific immunostimulatory properties in the Th1/Th2 balance, inhibit TSLP (thymic stromal lymphopoietin) and IgE expression, and promote Flg (Filaggrin) and FoxP3 (Treg) expression to alleviate allergies. In addition, unmethylated CpG motif ODN (oligodeoxynucleotides) is recognized by TLR (toll-like receptors)9 of B cells and plasmacytoid dendritic cells (pDCs) to induce innate and adaptive immune responses, while the butyrate produced by Clostridium butyricum activates the GPR (G-protein coupled receptors)109a signaling pathway to induce the expression of anti-inflammatory gene of pDCs, and directly stimulates the proliferation of thymically derived regulatory T (tTreg) cells through the activation of GPR43 or inhibits the activity of HADC (histone deacetylase) to differentiate naive $CD4^+$ T cells into pTreg cells through the histone H3 acetylation of Foxp3 gene intronic enhancer.

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.1
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• pp.79-86
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• 2001

Recent clinical studies have shown that a high proportion of patients with acute promyelocytic leukemia (APL) achieve complete remission after treatment with all-trans retinoic acid (ATRA). However, most patients who receive continuous treatment with ATRA relapse and develop ATRA-resistant leukemia. Dendritic cells (DCs) are important antigen-presenting cells in the development of antileukemic T-cell responses. In this study, we investigated the strategies to overcome ATRA resistance of APL cells by inducing the differentiation of DCs from human leukemic cell lines for the developtment of adoptive immunotherapy. CD83 was used as a mature DC marker in this study and the expression of CD83 mRNA was determined by RT-PCR method. The promyelocytic leukemic cell line HL-60, B lymphoblast cell lines RPMI 7666 and NC-37 could be induced to dendritic cells in vitro. Treatment of HL-60 with phorbol 12-myristate 13-acetate (PMA) resulted in the expression of myeloid-related DC phenotypes, while treatment of RPMI 7666 with fms-like tyrosine kinase 3 ligand (Flt3-ligand, FL) and treatment of NC-37 with PMA and FL led to the expression of lymphoid-related DC phenotypes. In conclusion, myeloid-related DC phenotypes and lymphoid-related DC phenotypes could be generated from HL-60, NC-37 and RPMI 7666 cell lines, respectively. These DC phenotypes can potentially be used to generate antileukemic T cells in vitro for adoptive immunotherapy.

• IMMUNE NETWORK
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• v.5 no.1
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• pp.36-44
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• 2005

Background: The anti-tumor therapeutic effect of autologous tumor cell lysate pulseddendritic cells (DCs) was studied for non-immunogenic and immune suppressive lung cancer model. To test the possibility as an adjuvant therapy, minimal residual disease model was considered in mouse in vivo experiments. Methods: Syngeneic 3LL lung cancer cells were inoculated intravenously into the C57BL/6 mouse. Autologous tumor cell (3LL) or allogeneic leukemia cell (WEHI-3) lysate pulsed-DCs were injected twice in two weeks. Intraperitoneal DC injection was started one day (MRD model) after tumor cell inoculation. Two weeks after the final DC injection, tumor formation in the lung and the tumor-specific systemic immunity were observed. Tumor-specific lymphocyte proliferation and the IFN-${\gamma}$ secretion were analyzed for the immune monitoring. Therapeutic DCs were cultured from the bone marrow myeloid lineage cells with GM-CSF and IL-4 for 7 days and pulsed with tumor cell lysate for 18 hrs. Results: Compared to the saline treated group, tumor formation was suppressed in 3LL tumor cell lysate pulsed-DC treated group, while 3LL-specific immune stimulation was minimum. WEHI-3-specific immune stimulation occurred in WEHI-3 lysate-pulsed DC treated group, which had no correlation with tumor regression. Conclusion: The data suggest the possible anti-tumor effect of cultured DCs as an adjuvant therapy for minimal residual disease state of lung cancer. The significance of immune modulation in DC therapy including the possible involvement of NK cell as well as antigen-specific cytotoxic T cell activity induction was discussed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.12
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• pp.2744-2754
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• 1997

Recently, the Multi-Layer Restoration(MLR) algorithm was proposed by British Telecom(BT) to restore the network failures in Digital Cross-connect System(DCS) mesh survival network[1, 2]. This algorithm has multi restoration stage which is composed of the pre-planned and dynamic restoration. This algorithm is effective its ability in link or node failures. This reason is that it does not restore in the pre-planned rstoration stage but in dynamic restoration stage. In this paper, we propose the MLR with pre-planned Multi-Chooser(PMC) and successive restoration ratio algorithm. This proposed algorithm has a excellent performance for restortion time and ratio, spare channel availability and fast restoration from multiple link failure or node failure. This paper proposed the modeling and restoration algorithm, and analyzed the performance of the algorithm by simulation using OPNET(OPtimized Network Engineering Tools).