• Title/Summary/Keyword: Dendritic cells (DCs)

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Prophylactic and Therapeutic Modulation of Innate and Adaptive Immunity Against Mucosal Infection of Herpes Simplex Virus

  • Uyangaa, Erdenebileg;Patil, Ajit Mahadev;Eo, Seong Kug
    • IMMUNE NETWORK
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    • v.14 no.4
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    • pp.187-200
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    • 2014
  • Herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) are the most common cause of genital ulceration in humans worldwide. Typically, HSV-1 and 2 infections via mucosal route result in a lifelong latent infection after peripheral replication in mucosal tissues, thereby providing potential transmission to neighbor hosts in response to reactivation. To break the transmission cycle, immunoprophylactics and therapeutic strategies must be focused on prevention of infection or reduction of infectivity at mucosal sites. Currently, our understanding of the immune responses against mucosal infection of HSV remains intricate and involves a balance between innate signaling pathways and the adaptive immune responses. Numerous studies have demonstrated that HSV mucosal infection induces type I interferons (IFN) via recognition of Toll-like receptors (TLRs) and activates multiple immune cell populations, including NK cells, conventional dendritic cells (DCs), and plasmacytoid DCs. This innate immune response is required not only for the early control of viral replication at mucosal sites, but also for establishing adaptive immune responses against HSV antigens. Although the contribution of humoral immune response is controversial, $CD4^+$ Th1 T cells producing IFN-${\gamma}$ are believed to play an important role in eradicating virus from the hosts. In addition, the recent experimental successes of immunoprophylactic and therapeutic compounds that enhance resistance and/or reduce viral burden at mucosal sites have accumulated. This review focuses on attempts to modulate innate and adaptive immunity against HSV mucosal infection for the development of prophylactic and therapeutic strategies. Notably, cells involved in innate immune regulations appear to shape adaptive immune responses. Thus, we summarized the current evidence of various immune mediators in response to mucosal HSV infection, focusing on the importance of innate immune responses.

Immunomodulation of Fungal β-Glucan in Host Defense Signaling by Dectin-1

  • Batbayar, Sainkhuu;Lee, Dong-Hee;Kim, Ha-Won
    • Biomolecules & Therapeutics
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    • v.20 no.5
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    • pp.433-445
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    • 2012
  • During the course of evolution, animals encountered the harmful effects of fungi, which are strong pathogens. Therefore, they have developed powerful mechanisms to protect themselves against these fungal invaders. ${\beta}$-Glucans are glucose polymers of a linear ${\beta}$(1,3)-glucan backbone with ${\beta}$(1,6)-linked side chains. The immunostimulatory and antitumor activities of ${\beta}$-glucans have been reported; however, their mechanisms have only begun to be elucidated. Fungal and particulate ${\beta}$-glucans, despite their large size, can be taken up by the M cells of Peyer's patches, and interact with macrophages or dendritic cells (DCs) and activate systemic immune responses to overcome the fungal infection. The sampled ${\beta}$-glucans function as pathogen-associated molecular patterns (PAMPs) and are recognized by pattern recognition receptors (PRRs) on innate immune cells. Dectin-1 receptor systems have been incorporated as the PRRs of ${\beta}$-glucans in the innate immune cells of higher animal systems, which function on the front line against fungal infection, and have been exploited in cancer treatments to enhance systemic immune function. Dectin-1 on macrophages and DCs performs dual functions: internalization of ${\beta}$-glucan-containing particles and transmittance of its signals into the nucleus. This review will depict in detail how the physicochemical nature of ${\beta}$-glucan contributes to its immunostimulating effect in hosts and the potential uses of ${\beta}$-glucan by elucidating the dectin-1 signal transduction pathway. The elucidation of ${\beta}$-glucan and its signaling pathway will undoubtedly open a new research area on its potential therapeutic applications, including as immunostimulants for antifungal and anti-cancer regimens.

Induction of Peptide-specific CTL Activity and Inhibition of Tumor Growth Following Immunization with Nanoparticles Coated with Tumor Peptide-MHC-I Complexes

  • Sang-Hyun Kim;Ha-Eun Park;Seong-Un Jeong;Jun-Hyeok Moon;Young-Ran Lee;Jeong-Ki Kim;Hyunseok Kong;Chan-Su Park;Chong-Kil Lee
    • IMMUNE NETWORK
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    • v.21 no.6
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    • pp.44.1-44.15
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    • 2021
  • Tumor peptides associated with MHC class I molecules or their synthetic variants have attracted great attention for their potential use as vaccines to induce tumor-specific CTLs. However, the outcome of clinical trials of peptide-based tumor vaccines has been disappointing. There are various reasons for this lack of success, such as difficulties in delivering the peptides specifically to professional Ag-presenting cells, short peptide half-life in vivo, and limited peptide immunogenicity. We report here a novel peptide vaccination strategy that efficiently induces peptide-specific CTLs. Nanoparticles (NPs) were fabricated from a biodegradable polymer, poly(D,L-lactic-co-glycolic acid), attached to H-2Kb molecules, and then the natural peptide epitopes associated with the H-2Kb molecules were exchanged with a model tumor peptide, SIINFEKL (OVA257-268). These NPs were efficiently phagocytosed by immature dendritic cells (DCs), inducing DC maturation and activation. In addition, the DCs that phagocytosed SIINFEKL-pulsed NPs potently activated SIINFEKL-H2Kb complex-specific CD8+ T cells via cross-presentation of SIINFEKL. In vivo studies showed that intravenous administration of SIINFEKL-pulsed NPs effectively generated SIINFEKL-specific CD8+ T cells in both normal and tumor-bearing mice. Furthermore, intravenous administration of SIINFEKL-pulsed NPs into EG7.OVA tumor-bearing mice almost completely inhibited the tumor growth. These results demonstrate that vaccination with polymeric NPs coated with tumor peptide-MHC-I complexes is a novel strategy for efficient induction of tumor-specific CTLs.

Immunomodulatory Properties of Lactobacillus plantarum NC8 Expressing an Anti-CD11c Single-Chain Fv Fragment

  • Liu, Jing;Yang, Guilian;Gao, Xing;Zhang, Zan;Liu, Yang;Yang, Xin;Shi, Chunwei;Liu, Qiong;Jiang, Yanlong;Wang, Chunfeng
    • Journal of Microbiology and Biotechnology
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    • v.29 no.1
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    • pp.160-170
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    • 2019
  • The lactic acid bacteria species Lactobacillus plantarum (L. plantarum) has been used extensively for vaccine delivery. Considering to the critical role of dendritic cells in stimulating host immune response, in this study, we constructed a novel CD11c-targeting L. plantarum strain with surface-displayed variable fragments of anti-CD11c, single-chain antibody (scFv-CD11c). The newly designed L. plantarum strain, named 409-aCD11c, could adhere and invade more efficiently to bone marrow-derived DCs (BMDCs) in vitro due to the specific interaction between scFv-CD11c and CD11c located on the surface of BMDCs. After incubation with BMDCs, the 409-aCD11c strain harboring a eukaryotic vector pValac-GFP could lead to more efficient expression of GFP compared with wild-type strains shown by flow cytometry analysis, indicating the enhanced translocation of pValac-GFP from L. plantarum to BMDCs. Similar results were also observed in an in vivo study, which showed that oral administration resulted in efficient expression of GFP in both Peyer's patches (PP) and mesenteric lymph nodes (MLNs) within 7 days after the last administration. In addition, the CD11c-targeting strain significantly promoted the differentiation and maturation of DCs, the differentiation of $IL-4^+$ and $IL-17A^+$ T helper (Th) cells in MLNs, as well as production of $B220^+$ $IgA^+$ B cells in the PP. In conclusion, this study developed a novel DC-targeting L. plantarum strain which could increase the ability to deliver eukaryotic expression plasmid to host cells, indicating a promising approach for vaccine study.

Mechanism of T cell exhaustion in a chronic environment

  • Jin, Hyun-Tak;Jeong, Yun-Hee;Park, Hyo-Jin;Ha, Sang-Jun
    • BMB Reports
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    • v.44 no.4
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    • pp.217-231
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    • 2011
  • T cell exhaustion develops under conditions of antigen-persistence caused by infection with various chronic pathogens, such as human immunodeficiency virus (HIV) and myco-bacterium tuberculosis (TB), or by the development of cancer. T cell exhaustion is characterized by stepwise and progressive loss of T cell function, which is probably the main reason for the failed immunological control of chronic pathogens and cancers. Recent observations have detailed some of the intrinsic and extrinsic factors that influence the severity of T cell exhaustion. Duration and magnitude of antigenic activation of T cells might be associated with up-regulation of inhibitory receptors, which is a major intrinsic factor of T cell exhaustion. Extrinsic factors might include the production of suppressive cytokines, T cell priming by either non-professional antigenpresenting cells (APCs) or tolerogenic dendritic cells (DCs), and alteration of regulatory T (Treg) cells. Further investigation of the cellular and molecular processes behind the development of T cell exhaustion can reveal therapeutic targets and strategies for the treatment of chronic infections and cancers. Here, we report the properties and the mechanisms of T cell exhaustion in a chronic environment.

Ischemic Time Associated with Activation of Rejection-Related Immune Responses (허혈 시간과 거부반응 관련 면역반응)

  • Nam, Hyun-Suk;Choi, Jin-Yeung;Kim, Yoon-Tai;Kang, Kyung-Sun;Kwon, Hyuk-Moo;Hong, Chong-Hae;Kim, Doo;Han, Tae-Wook;Moon, Tae-Young;Kim, Jee-Hee;Cho, Byung-Ryul;Woo, Heung-Myong
    • 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.

Formulation and Characterization of Antigen-loaded PLGA Nanoparticles for Efficient Cross-priming of the Antigen

  • Lee, Young-Ran;Lee, Young-Hee;Im, Sun-A;Kim, Kyung-Jae;Lee, Chong-Kil
    • IMMUNE NETWORK
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    • v.11 no.3
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    • pp.163-168
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    • 2011
  • Background: Nanoparticles (NPs) prepared from biodegradable polymers, such as poly (D,L-lactic acid-co-glycolic acid) (PLGA), have been studied as vehicles for the delivery of antigens to phagocytes. This paper describes the preparation of antigen-loaded PLGA-NPs for efficient cross-priming. Methods: NPs containing a similar amount of ovalbumin (OVA) but different sizes were produced using a micromixer-based W/O/W solvent evaporation procedure, and the efficiency of the NPs to induce the cross-presentation of OVA peptides were examined in dendritic cells (DCs). Cellular uptake and biodistribution studies were performed using fluorescein isothiocyanate (FITC)-loaded NPs in mice. Results: The NPs in the range of $1.1{\sim}1.4{\mu}m$ in size were the most and almost equally efficient in inducing the cross-presentation of OVA peptides via $H-2K^b$ molecules. Cellular uptake and biodistribution studies showed that opsonization of the NPs with mouse IgG greatly increased the percentage of FITC-positive cells in the spleen and lymph nodes. The major cell type of FITC-positive cells in the spleen was macrophages, whereas that of lymph nodes was DCs. Conclusion: These results show that IgG-opsonized PLGA-NPs with a mean size of $1.1{\mu}m$ would be the choice of biodegradable carriers for the targeted-delivery of protein antigens for cross-priming in vivo.

Effects of AEBSF on the Delay of Spontaneous Apoptosis and the Trans-Differentiation of Human Neutrophils into Dendritic Cells (Serine pretease 억제제인 4-(2-aminoethyl) benzensulfonylfluoride (AEBSF)에 의한 호중구의 자연 세포사멸의 지연과 수지상 세포로의 전이분화 연구)

  • Park, Hae-Young;Kwak, Jong-Young
    • Journal of Life Science
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    • v.17 no.7 s.87
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    • pp.948-955
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    • 2007
  • Neutrophils play a key role as a first line of defense and are known to acquire the characteristics of dendritic cells (DCs) under the appropriate conditions. The spontaneous apoptosis of neutrophils was delayed by treatment with 4-(2-aminoethyl) benzensulfonylfluoride (AEBSF), a serine protease inhibitor. AEBSF inhibited both caspase-3 and serine protease activities, whereas ZVAD-fmk, a pancaspase inhibitor, inhibited only caspase-3 activity. The life span of neutrophils was prolonged up to 5 days by AEBSF in the presence or absence of granulocyte macrophage colony stimulating factor(CM-CSF). DC surface markers, such as CD80, CD83, and MHC class ll were not expressed on neutrophils treated with AEBSF alone. CM-CSF failed to prolong the survival time of neutrophils up to3 days but increased the expression levels of DC markers on neutrophils in the presence of AEBSF. Expression levels of DC markers were the highest on neutrophils treated with CM-CSF and AEBSF for 3 days. AEBSF and CM-CSF-treated neutrophils stimulated proliferation of T cells in the presence of a superantigen, Staphylococcal enterotoxin B (SEB) but produced $interferon-{\gamma}$ ($IFN{\gamma}$) in the absence of SEB. These results suggest that the inhibition of serine protease activity prolonged the life span of human neutrophils and combined treatment of neukophils with CM-CSF and serine protease inhibitor induced differentiation of neutrophils into DC-like cells.

Inhibitory Effects of a New Herbal Composition (HemoHIM) on UVB-Induced Suppression of Langerhans Cell's Accessory Cell Function (생약복합조성물(HemoHIM)의 자외선 조사로 억제된 랑게르한스 세포의 항원제시기능 방호효과)

  • Kim, Jong-Jin;Jo, Sung-Kee;Jung, U-Hee;Park, Hae-Ran;Yee, Sung-Tae
    • Journal of Life Science
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    • v.21 no.12
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    • pp.1761-1771
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    • 2011
  • In the previous results, we developed an effective products to apply as functional foods for overcome of radiation damage and reduction of side effects in radiotherapy. To verify the prevention of UVB-induced immunosuppression of immune cell function by HemoHIM, we studied on the mechanism of the skin immune function for the protection in UVB irradiation. In studies presented here, we showed that HemoHIM can prevent UVB-induced impairment of skin immune cell function by in vitro and in vivo assay. Exposure of freshly cultured murine dendritic cells (DCs) with IL-4/GM-CSF to UVB irradiation resulted in impairment of accessory function. This suppression could be prevented by addition of HemoHIM before or after to the cultures of UVB-irradiated DCs. We also tested the effects of HemoHIM on the suppression of contact hypersensitivity (CHS) treated oral or intraperitoneal administration. This UVB-suppressed CHS was prevented by administration of HemoHIM to UVB-irradiated mice. These results suggest that HemoHIM may prevent UVB-induced immune suppression in the skin.

Anti-cancer Effect of Hematopoietic Stem Cell-derived Allogeneic-DC Vaccine in Melanoma Metastasis Model (마우스 동종 줄기세포 유래 수지상 세포를 이용한 백신의 흑색종 폐암 전이 모델에서의 항암 효과 및 기전 연구)

  • Kim, Myoung-Joo;Shon, Hye-Jin;Baek, So-Young;Lee, Kang-Eun;Lee, Young-Joon;Lee, Hyun-Ah
    • IMMUNE NETWORK
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    • v.6 no.3
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    • pp.154-162
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    • 2006
  • Background: Dendritic cell (DC)-based cancer immunotherapy is studied for several years. However, it is mainly derived from autologous PBMC or leukapheresis from patient, which has limitations about yield and ability of DC production according to individual status. In order to solve these problems, inquiries about allogeneic DCs are performed but there are no preclinical trial answers for effect or toxicity of allogeneic DC to use for clinical trial. In this study, we compared the anti-tumor effect of allogeneic and autologous DCs from mouse bone marrow stem cells in mouse metastatic melanoma model. Methods: B16F10 melanoma cells ($5{\times}10^4$/mouse) were injected intravenously into the C57BL/6 mouse. Therapeutic DCs were differentiated from autologous (C57BL/6: CDC) or allogeneic (B6C3F1: BDC) bone marrow stem cells with GM-CSF, SCF and IL-4 for 13days and pulsed with B16F10 tumor cell lysate (Blys) for 18hrs. DC intra-peritoneal injections began on the 8th day after the tumor cell injection by twice with one week interval. Results: Anti-tumor response was observed by DC treatment without any toxicity especially in allogeneic DC treated mice (tumor burden score: $2.667{\pm}0.184,\;2.500{\pm}0.463,\;2.000{\pm}0.286,\;1.500{\pm}0.286,\;1.667 {\pm}0.297$ for saline, CDC/unpulsed-DC: U-DC, CDC/Blys-DC, BDC/U-DC and BDC/Blys-DC, respectively). IFN-${\gamma}$ secretion was significantly increased in allogeneic DC group stimulated with B16F10 cell lysate ($2,643.3{\pm}5,89.7,\;8,561.5{\pm}2,204.9.\;6,901.2{\pm}141.1pg/1{\times}10^6$ cells for saline, BDC/U-DC and BDC/Blys-DC, respectively) with increased NK cell activity. Conclusion: Conclusively, promising data was obtained that allogeneic DC can be used for DC-based cancer immunotherapy.