Activation of plasmacytoid dendritic cells with TLR9 agonists initiates invariant NKT cell-mediated cross-talk with myeloid dendritic cells.

PubMed

Montoya, Carlos J; Jie, Hyun-Bae; Al-Harthi, Lena; Mulder, Candice; Patiño, Pablo J; Rugeles, María T; Krieg, Arthur M; Landay, Alan L; Wilson, S Brian

2006-07-15

CD1d-restricted invariant NK T (iNKT) cells and dendritic cells (DCs) have been shown to play crucial roles in various types of immune responses, including TLR9-dependent antiviral responses initiated by plasmacytoid DCs (pDCs). However, the mechanism by which this occurs is enigmatic because TLRs are absent in iNKT cells and human pDCs do not express CD1d. To explore this process, pDCs were activated with CpG oligodeoxyribonucleotides, which stimulated the secretion of several cytokines such as type I and TNF-alpha. These cytokines and other soluble factors potently induced the expression of activation markers on iNKT cells, selectively enhanced double-negative iNKT cell survival, but did not induce their expansion or production of cytokines. Notably, pDC-derived factors licensed iNKT cells to respond to myeloid DCs: an important downstream cellular target of iNKT cell effector function and a critical contributor to the initiation of adaptive immune responses. This interaction supports the notion that iNKT cells can mediate cross-talk between DC subsets known to express mutually exclusive TLR and cytokine profiles.

Dendritic cells rapidly undergo apoptosis in vitro following culture with activated CD4+ Vα24 natural killer T cells expressing CD40L

PubMed Central

Nieda, M; Kikuchi, A; Nicol, A; Koezuka, Y; Ando, Y; Ishihara, S; Lapteva, N; Yabe, T; Tokunaga, K; Tadokoro, K; Juji, T

2001-01-01

Human Vα24 natural killer T (Vα24NKT) cells are activated by α-glycosylceramide-pulsed dendritic cells (DCs) in a CD1d-dependent and T-cell receptor-mediated manner. There are two major subpopulations of Vα24NKT cells, CD4– CD8– Vα24NKT and CD4+ Vα24NKT cells. We have recently shown that activated CD4– CD8– Vα24NKT cells have cytotoxic activity against DCs, but knowledge of the molecules responsible for cytotoxicity of Vα24NKT cells is currently limited. We aimed to investigate whether CD4+ Vα24NKT cells also have cytotoxic activity against DCs and to determine the mechanisms underlying any observed cytotoxic activity. We demonstrated that activated CD4+ Vα24NKT cells [CD40 ligand (CD40L) -positive] have cytotoxic activity against DCs (strongly CD40-positive), but not against monocytes (weakly CD40-positive) or phytohaemagglutinin blast T cells (CD40-negative), and that apoptosis of DCs significantly contributes to the observed cytotoxicity. The apoptosis of DCs following culture with activated CD4+ Vα24NKT cells, but not with resting CD4+ Vα24NKT cells (CD40L-negative), was partially inhibited by anti-CD40L mAb. Direct ligation of CD40 on the DCs by the anti-CD40 antibody also induced apoptosis of DCs. Our results suggest that CD40–CD40L interaction plays an important role in the induction of apoptosis of DCs following culture with activated CD4+ Vα24NKT cells. The apoptosis of DCs from normal donors, triggered by the CD40–CD40L interaction, may contribute to the homeostatic regulation of the normal human immune system, preventing the interminable activation of activated CD4+ Vα24NKT cells by virtue of apoptosis of DCs. PMID:11260318

The emerging role of ASC in dendritic cell metabolism during Chlamydia infection

PubMed Central

McKeithen, Danielle N.; Ryans, Khamia; Mu, Jing; Xie, Zhonglin; Simoneaux, Tankya; Blas-machado, Uriel; Eko, Francis O.; Black, Carolyn M.; Igietseme, Joseph U.; He, Qing

2017-01-01

Chlamydia trachomatis is a bacterial agent that causes sexually transmitted infections worldwide. The regulatory functions of dendritic cells (DCs) play a major role in protective immunity against Chlamydia infections. Here, we investigated the role of ASC in DCs metabolism and the regulation of DCs activation and function during Chlamydia infection. Following Chlamydia stimulation, maturation and antigen presenting functions were impaired in ASC-/- DCs compared to wild type (WT) DCs, in addition, ASC deficiency induced a tolerant phenotype in Chlamydia stimulated DCs. Using real-time extracellular flux analysis, we showed that activation in Chlamydia stimulated WT DCs is associated with a metabolic change in which mitochondrial oxidative phosphorylation (OXPHOS) is inhibited and the cells become committed to utilizing glucose through aerobic glycolysis for differentiation and antigen presenting functions. However, in ASC-/- DCs Chlamydia-induced metabolic change was prevented and there was a significant effect on mitochondrial morphology. The mitochondria of Chlamydia stimulated ASC-/- DCs had disrupted cristae compared to the normal narrow pleomorphic cristae found in stimulated WT DCs. In conclusion, our results suggest that Chlamydia-mediated activation of DCs is associated with a metabolic transition in which OXPHOS is inhibited, thereby dedicating the DCs to aerobic glycolysis, while ASC deficiency disrupts DCs function by inhibiting the reprogramming of DCs metabolism within the mitochondria, from glycolysis to electron transport chain. PMID:29216217

Tumor exosomes block dendritic cells maturation to decrease the T cell immune response.

PubMed

Ning, Yongling; Shen, Kai; Wu, Qiyong; Sun, Xiao; Bai, Yu; Xie, Yewen; Pan, Jie; Qi, Chunjian

2018-07-01

Tumors can induce the generation and accumulation of immunosuppression in a tumor microenvironment, contributing to the tumor's escape from immunological surveillance. Although tumor antigen-pulsed dendritic cell can improve anti-tumor immune responses, tumor associated regulatory dendritic cells are involved in the induction of immune tolerance. The current study sought to investigate whether exosomes produced by tumor cells had any effect on DCs in immune suppression. In this study, we examined the effect of tumor exosomes on DCs and found that exosomes from LLC Lewis lung carcinoma or 4T1 breast cancer cell blocked the differentiation of myeloid precursor cells into CD11c + DCs and induced cell apoptosis. Tumor exosome treatment inhibited the maturation and migration of DCs and promoted the immune suppression of DCs. The treatment of tumor exosomes drastically decreased CD4 + IFN-γ + Th1 differentiation but increased the rates of regulatory T (Treg) cells. The immunosuppressive ability of tumor exosome-treated DCs were partially restored with PD-L1 blockage. These data suggested that PD-L1 played a role in tumor exosome-induced DC-associated immune suppression. Copyright © 2018 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

Leptin deficiency impairs maturation of dendritic cells and enhances induction of regulatory T and Th17 cells

PubMed Central

Moraes-Vieira, Pedro M.M.; Larocca, Rafael A.; Bassi, Enio J.; Peron, Jean Pierre S.; Andrade-Oliveira, Vinícius; Wasinski, Frederick; Araujo, Ronaldo; Thornley, Thomas; Quintana, Francisco J.; Basso, Alexandre S.; Strom, Terry B.; Câmara, Niels O.S.

2016-01-01

Leptin is an adipose-secreted hormone that plays an important role in both metabolism and immunity. Leptin has been shown to induce Th1-cell polarization and inhibit Th2-cell responses. Additionally, leptin induces Th17-cell responses, inhibits regulatory T (Treg) cells and modulates autoimmune diseases. Here, we investigated whether leptin mediates its activity on T cells by influencing dendritic cells (DCs) to promote Th17 and Treg-cell immune responses in mice. We observed that leptin deficiency (i) reduced the expression of DC maturation markers, (ii) decreased DC production of IL-12, TNF-α, and IL-6, (iii) increased DC production of TGF-β, and (iv) limited the capacity of DCs to induce syngeneic CD4+ T-cell proliferation. As a consequence of this unique phenotype, DCs generated under leptin-free conditions induced Treg or TH17 cells more efficiently than DCs generated in the presence of leptin. These data indicate important roles for leptin in DC homeostasis and the initiation and maintenance of inflammatory and regulatory immune responses by DCs. PMID:24271843

Effect of Different Titanium Surfaces on Maturation of Murine Bone Marrow-Derived Dendritic Cells

NASA Astrophysics Data System (ADS)

Zheng, Xiaofei; Zhou, Fengjuan; Gu, Yifei; Duan, Xiaobo; Mo, Anchun

2017-02-01

Dendritic cells (DCs) play a pivotal role in the host response to implanted biomaterials. Osseointegration of titanium (Ti) implant is an immunological and inflammatory-driven process. However, the role of DCs in this complex process is largely unknown. This study aimed to investigate the effect of different Ti surfaces on DC maturation, and evaluate its subsequent potential on osteogenic differentiation of preosteoblasts. Murine bone marrow-derived DCs were seeded on Ti disks with different surface treatments, including pretreatment (PT), sandblasted/acid-etched (SLA) and modified SLA (modSLA) surface. Compared with DCs cultured on PT and SLA surfaces, the cells seeded on modSLA surface demonstrated a more round morphology with lower expression of CD86 and MHC-II, the DC maturation markers. Those cells also secreted high levels of anti-inflammatory cytokine IL-10 and TGF-β. Notably, addition of conditioned medium (CM) from modSLA-induced DCs significantly increased the mRNA expression of Runx2 and ALP as well as ALP activity by murine preosteoblast MC3T3-E1 cells. Our data demonstrated that Ti disks with different surfaces lead to differential DCs responses. PT and SLA surfaces induce DCs mature, while DCs seeded on modSLA-Ti surface maintain an immature phenotype and exhibit a potential of promoting osteogenic differentiation of MC3T3-E1 cells.

Triggering through NOD-2 Differentiates Bone Marrow Precursors to Dendritic Cells with Potent Bactericidal activity

PubMed Central

Khan, Nargis; Aqdas, Mohammad; Vidyarthi, Aurobind; Negi, Shikha; Pahari, Susanta; Agnihotri, Tapan; Agrewala, Javed N.

2016-01-01

Dendritic cells (DCs) play a crucial role in bridging innate and adaptive immunity by activating naïve T cells. The role of pattern recognition receptors like Toll-Like Receptors and Nod-Like Receptors expressed on DCs is well-defined in the recognition of the pathogens. However, nothing is precisely studied regarding the impact of NOD-2 signaling during the differentiation of DCs. Consequently, we explored the role of NOD-2 signaling in the differentiation of DCs and therefore their capability to activate innate and adaptive immunity. Intriguingly, we observed that NOD-2 stimulated DCs (nDCs) acquired highly activated and matured phenotype and exhibited substantially greater bactericidal activity by robust production of nitric oxide. The mechanism involved in improving the functionality of nDCs was dependent on IFN-αβ signaling, leading to the activation of STAT pathways. Furthermore, we also observed that STAT-1 and STAT-4 dependent maturation and activation of DCs was under the feedback mechanism of SOCS-1 and SOCS-3 proteins. nDCs acquired enhanced potential to activate chiefly Th1 and Th17 immunity. Taken together, these results suggest that nDCs can be exploited as an immunotherapeutic agent in bolstering host immunity and imparting protection against the pathogens. PMID:27265209

Critical roles of conventional dendritic cells in promoting T cell‐dependent hepatitis through regulating natural killer T cells

PubMed Central

Wang, J.; Cao, X.; Zhao, J.; Zhao, H.; Wei, J.; Li, Q.; Qi, X.; Yang, Z.; Wang, L.; Zhang, H.; Bai, L.; Wu, Z.; Zhao, L.; Hong, Z.

2017-01-01

Summary Dendritic cells (DCs) play critical roles in initiating and regulating innate immunity as well as adaptive immune responses. However, the role of conventional dendritic cells (cDCs) in concanavalin A (ConA)‐induced fulminant hepatitis is unknown. In this study, we demonstrated that depletion of cDCs using either CD11c‐diphtheria toxin receptor transgenic mice (DTR Tg) mice or anti‐CD11c antibody reduced the severity of liver injury significantly, indicating a detrimental role of cDCs in ConA‐induced hepatitis. We elucidated further the pathological role of cDCs as being the critical source of interleukin (IL)‐12, which induced the secretion of interferon (IFN)‐γ by natural killer (NK) T cells. Reconstitution of cDCs‐depleted mice with IL‐12 restored ConA‐induced hepatitis significantly. Furthermore, we determined that NK T cells were the target of DC‐derived IL‐12, and NK T cells contributed to liver inflammation and injury through production of IFN‐γ. In summary, our study demonstrated a novel function of cDCs in mediating ConA‐induced hepatitis through regulating IFN‐γ secretion of NK T cells in an IL‐12‐dependent fashion. Targeting cDCs might provide potentially therapeutic applications in treating autoimmune related liver diseases. PMID:27891589

TNF-α and Tumor Lysate Promote the Maturation of Dendritic Cells for Immunotherapy for Advanced Malignant Bone and Soft Tissue Tumors

PubMed Central

Miwa, Shinji; Nishida, Hideji; Tanzawa, Yoshikazu; Takata, Munetomo; Takeuchi, Akihiko; Yamamoto, Norio; Shirai, Toshiharu; Hayashi, Katsuhiro; Kimura, Hiroaki; Igarashi, Kentaro; Mizukoshi, Eishiro; Nakamoto, Yasunari; Kaneko, Shuichi; Tsuchiya, Hiroyuki

2012-01-01

Background Dendritic cells (DCs) play a pivotal role in the immune system. There are many reports concerning DC-based immunotherapy. The differentiation and maturation of DCs is a critical part of DC-based immunotherapy. We investigated the differentiation and maturation of DCs in response to various stimuli. Methods Thirty-one patients with malignant bone and soft tissue tumors were enrolled in this study. All the patients had metastatic tumors and/or recurrent tumors. Peripheral blood mononuclear cells (PBMCs) were suspended in media containing interleukin-4 (IL-4) and granulocyte-macrophage colony stimulating factor (GM-CSF). These cells were then treated with or without 1) tumor lysate (TL), 2) TL + TNF-α, 3) OK-432. The generated DCs were mixed and injected in the inguinal or axillary region. Treatment courses were performed every week and repeated 6 times. A portion of the cells were analyzed by flow cytometry to determine the degree of differentiation and maturation of the DCs. Serum IFN-γ and serum IL-12 were measured in order to determine the immune response following the DC-based immunotherapy. Results Approximately 50% of PBMCs differentiated into DCs. Maturation of the lysate-pulsed DCs was slightly increased. Maturation of the TL/TNF-α-pulsed DCs was increased, commensurate with OK-432-pulsed DCs. Serum IFN-γ and serum IL-12 showed significant elevation at one and three months after DC-based immunotherapy. Conclusions Although TL-pulsed DCs exhibit tumor specific immunity, TL-pulsed cells showed low levels of maturation. Conversely, the TL/TNF-α-pulsed DCs showed remarkable maturation. The combination of IL-4/GM-CSF/TL/TNF-α resulted in the greatest differentiation and maturation for DC-based immunotherapy for patients with bone and soft tissue tumors. PMID:23300824

A role for the JAK-STAT1 pathway in blocking replication of HSV-1 in dendritic cells and macrophages

PubMed Central

Mott, Kevin R; UnderHill, David; Wechsler, Steven L; Town, Terrence; Ghiasi, Homayon

2009-01-01

Background Macrophages and dendritic cells (DCs) play key roles in host defense against HSV-1 infection. Although macrophages and DCs can be infected by herpes simplex virus type 1 (HSV-1), both cell types are resistant to HSV-1 replication. The aim of our study was to determine factor (s) that are involved in the resistance of DCs and macrophages to productive HSV-1 infection. Results We report here that, in contrast to bone marrow-derived DCs and macrophages from wild type mice, DCs and macrophages isolated from signal transducers and activators of transcription-1 deficient (STAT1-/-) mice were susceptible to HSV-1 replication and the production of viral mRNAs and DNA. There were differences in expression of immediate early, early, and late gene transcripts between STAT1+/+ and STAT1-/- infected APCs. Conclusion These results suggest for the first time that the JAK-STAT1 pathway is involved in blocking replication of HSV-1 in DCs and macrophages. PMID:19439086

Regulatory dendritic cells: there is more than just immune activation.

PubMed

Schmidt, Susanne V; Nino-Castro, Andrea C; Schultze, Joachim L

2012-01-01

The immune system exists in a delicate equilibrium between inflammatory responses and tolerance. This unique feature allows the immune system to recognize and respond to potential threats in a controlled but normally limited fashion thereby preventing a destructive overreaction against healthy tissues. While the adaptive immune system was the major research focus concerning activation vs. tolerance in the immune system more recent findings suggest that cells of the innate immune system are important players in the decision between effective immunity and induction of tolerance or immune inhibition. Among immune cells of the innate immune system dendritic cells (DCs) have a special function linking innate immune functions with the induction of adaptive immunity. DCs are the primary professional antigen presenting cells (APCs) initiating adaptive immune responses. They belong to the hematopoietic system and arise from CD34(+) stem cells in the bone marrow. Particularly in the murine system two major subgroups of DCs, namely myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) can be distinguished. DCs are important mediators of innate and adaptive immunity mostly due to their remarkable capacity to present processed antigens via major histocompatibility complexes (MHC) to T cells and B cells in secondary lymphoid organs. A large body of literature has been accumulated during the last two decades describing which role DCs play during activation of T cell responses but also during the establishment and maintenance of central tolerance (Steinman et al., 2003). While the concept of peripheral tolerance has been clearly established during the last years, the role of different sets of DCs and their particular molecular mechanisms of immune deviation has not yet fully been appreciated. In this review we summarize accumulating evidence about the role of regulatory DCs in situations where the balance between tolerance and immunogenicity has been altered leading to pathologic conditions such as chronic inflammation or malignancies.

Regulatory dendritic cells: there is more than just immune activation

PubMed Central

Schmidt, Susanne V.; Nino-Castro, Andrea C.; Schultze, Joachim L.

2012-01-01

The immune system exists in a delicate equilibrium between inflammatory responses and tolerance. This unique feature allows the immune system to recognize and respond to potential threats in a controlled but normally limited fashion thereby preventing a destructive overreaction against healthy tissues. While the adaptive immune system was the major research focus concerning activation vs. tolerance in the immune system more recent findings suggest that cells of the innate immune system are important players in the decision between effective immunity and induction of tolerance or immune inhibition. Among immune cells of the innate immune system dendritic cells (DCs) have a special function linking innate immune functions with the induction of adaptive immunity. DCs are the primary professional antigen presenting cells (APCs) initiating adaptive immune responses. They belong to the hematopoietic system and arise from CD34+ stem cells in the bone marrow. Particularly in the murine system two major subgroups of DCs, namely myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) can be distinguished. DCs are important mediators of innate and adaptive immunity mostly due to their remarkable capacity to present processed antigens via major histocompatibility complexes (MHC) to T cells and B cells in secondary lymphoid organs. A large body of literature has been accumulated during the last two decades describing which role DCs play during activation of T cell responses but also during the establishment and maintenance of central tolerance (Steinman et al., 2003). While the concept of peripheral tolerance has been clearly established during the last years, the role of different sets of DCs and their particular molecular mechanisms of immune deviation has not yet fully been appreciated. In this review we summarize accumulating evidence about the role of regulatory DCs in situations where the balance between tolerance and immunogenicity has been altered leading to pathologic conditions such as chronic inflammation or malignancies. PMID:22969767

Impaired IFN-α-mediated signal in dendritic cells differentiates active from latent tuberculosis.

PubMed

Parlato, Stefania; Chiacchio, Teresa; Salerno, Debora; Petrone, Linda; Castiello, Luciano; Romagnoli, Giulia; Canini, Irene; Goletti, Delia; Gabriele, Lucia

2018-01-01

Individuals exposed to Mycobacterium tuberculosis (Mtb) may be infected and remain for the entire life in this condition defined as latent tuberculosis infection (LTBI) or develop active tuberculosis (TB). Among the multiple factors governing the outcome of the infection, dendritic cells (DCs) play a major role in dictating antibacterial immunity. However, current knowledge on the role of the diverse components of human DCs in shaping specific T-cell response during Mtb infection is limited. In this study, we performed a comparative evaluation of peripheral blood circulating DC subsets as well as of monocyte-derived Interferon-α DCs (IFN-DCs) from patients with active TB, subjects with LTBI and healthy donors (HD). The proportion of circulating myeloid BDCA3+ DCs (mDC2) and plasmacytoid CD123+ DCs (pDCs) declined significantly in active TB patients compared to HD, whereas the same subsets displayed a remarkable activation in LTBI subjects. Simultaneously, the differentiation of IFN-DCs from active TB patients resulted profoundly impaired compared to those from LTBI and HD individuals. Importantly, the altered developmental trait of IFN-DCs from active TB patients was associated with down-modulation of IFN-linked genes, marked changes in molecular signaling conveying antigen (Ag) presentation and full inability to induce Ag-specific T cell response. Thus, these data reveal an important role of IFN-α in determining the induction of Mtb-specific immunity.

Impaired IFN-α-mediated signal in dendritic cells differentiates active from latent tuberculosis

PubMed Central

Parlato, Stefania; Chiacchio, Teresa; Salerno, Debora; Petrone, Linda; Castiello, Luciano; Romagnoli, Giulia; Canini, Irene; Goletti, Delia; Gabriele, Lucia

2018-01-01

Individuals exposed to Mycobacterium tuberculosis (Mtb) may be infected and remain for the entire life in this condition defined as latent tuberculosis infection (LTBI) or develop active tuberculosis (TB). Among the multiple factors governing the outcome of the infection, dendritic cells (DCs) play a major role in dictating antibacterial immunity. However, current knowledge on the role of the diverse components of human DCs in shaping specific T-cell response during Mtb infection is limited. In this study, we performed a comparative evaluation of peripheral blood circulating DC subsets as well as of monocyte-derived Interferon-α DCs (IFN-DCs) from patients with active TB, subjects with LTBI and healthy donors (HD). The proportion of circulating myeloid BDCA3+ DCs (mDC2) and plasmacytoid CD123+ DCs (pDCs) declined significantly in active TB patients compared to HD, whereas the same subsets displayed a remarkable activation in LTBI subjects. Simultaneously, the differentiation of IFN-DCs from active TB patients resulted profoundly impaired compared to those from LTBI and HD individuals. Importantly, the altered developmental trait of IFN-DCs from active TB patients was associated with down-modulation of IFN-linked genes, marked changes in molecular signaling conveying antigen (Ag) presentation and full inability to induce Ag-specific T cell response. Thus, these data reveal an important role of IFN-α in determining the induction of Mtb-specific immunity. PMID:29320502

Transforming growth factor-β1 deteriorates microrheological characteristics and motility of mature dendritic cells in concentration-dependent fashion.

PubMed

Zheng, Qinni; Long, Jinhua; Jia, Binbin; Xu, Xiaoli; Zhang, Chunlin; Li, Long; Wen, Zongyao; Jin, Feng; Yao, Weijuan; Zeng, Zhu

2014-01-01

Dendritic cells (DCs) are potent and specialized antigen-presenting cells that play a crucial role in initiating and amplifying both the innate and adaptive immune responses. Tumor cells can escape from immune attack by secreting suppressive cytokines which solely or cooperatively impair the immune function and microrheological properties of DCs. However, the underlying mechanisms are not fully defined. Transforming growth factor-β1 (TGF-β1) has been identified as a major cytokine in the tumor microenvironment. To determine the effects of TGF-β1 on mature DCs (mDCs) from microrheological viewpoint, cells were treated with different concentrations of TGF-β1. The results showed that the impaired microrheological parameters, including osmotic fragility, electrophoretic mobility, deformability, membrane fluidity, F-actin organization and so on, as well as motilities of mDCs relied heavily on TGF-β1 concentration. Moreover, these changes were correlated with the expression levels of fascin1, cofilin1, phosphorylated cofilin1 and profilin, this could be one of the crucial aspects of immune escape mechanisms of tumors, hinting that the signal pathway of TGF-β1 should be blocked in appropriate way before performing DCs-based immunotherapy against cancer. It is clinically important to understand the biological behavior of DCs and immune escape mechanism of tumor as well as how to improve efficiency of the anti-tumor therapy based on DCs.

Leucine-Rich Repeat Kinase 2 Controls the Ca2+/Nuclear Factor of Activated T Cells/IL-2 Pathway during Aspergillus Non-Canonical Autophagy in Dendritic Cells.

PubMed

Wong, Alicia Yoke Wei; Oikonomou, Vasilis; Paolicelli, Giuseppe; De Luca, Antonella; Pariano, Marilena; Fric, Jan; Tay, Hock Soon; Ricciardi-Castagnoli, Paola; Zelante, Teresa

2018-01-01

The Parkinson's disease-associated protein, Leucine-rich repeat kinase 2 (LRRK2), a known negative regulator of nuclear factor of activated T cells (NFAT), is expressed in myeloid cells such as macrophages and dendritic cells (DCs) and is involved in the host immune response against pathogens. Since, the Ca 2+ /NFAT/IL-2 axis has been previously found to regulate DC response to the fungus Aspergillus , we have investigated the role played by the kinase LRRK2 during fungal infection. Mechanistically, we found that in the early stages of the non-canonical autophagic response of DCs to the germinated spores of Aspergillus , LRRK2 undergoes progressive degradation and regulates NFAT translocation from the cytoplasm to the nucleus. Our results shed new light on the complexity of the Ca 2+ /NFAT/IL-2 pathway, where LRRK2 plays a role in controlling the immune response of DCs to Aspergillus .

Cell-free HTLV-1 infects dendritic cells leading to transmission and transformation of CD4(+) T cells.

PubMed

Jones, Kathryn S; Petrow-Sadowski, Cari; Huang, Ying K; Bertolette, Daniel C; Ruscetti, Francis W

2008-04-01

Cell-free human T-lymphotropic virus type 1 (HTLV-1) virions are poorly infectious in vitro for their primary target cells, CD4(+) T cells. Here, we show that HTLV-1 can efficiently infect myeloid and plasmacytoid dendritic cells (DCs). Moreover, DCs exposed to HTLV-1, both before and after being productively infected, can rapidly, efficiently and reproducibly transfer virus to autologous primary CD4(+) T cells. This DC-mediated transfer of HTLV-1 involves heparan sulfate proteoglycans and neuropilin-1 and results in long-term productive infection and interleukin-2-independent transformation of the CD4(+) T cells. These studies, along with observations of HTLV-1-infected DCs in the peripheral blood of infected individuals, indicate that DCs have a central role in HTLV-1 transmission, dissemination and persistence in vivo. In addition to altering the current paradigm concerning how HTLV-1 transmission occurs, these studies suggest that impairment of DC function after HTLV-1 infection plays a part in pathogenesis.

An investigation into IgE-facilitated allergen recognition and presentation by human dendritic cells

PubMed Central

2013-01-01

Background Allergen recognition by dendritic cells (DCs) is a key event in the allergic cascade leading to production of IgE antibodies. C-type lectins, such as the mannose receptor and DC-SIGN, were recently shown to play an important role in the uptake of the house dust mite glycoallergen Der p 1 by DCs. In addition to mannose receptor (MR) and DC-SIGN the high and low affinity IgE receptors, namely FcϵRI and FcϵRII (CD23), respectively, have been shown to be involved in allergen uptake and presentation by DCs. Objectives This study aims at understanding the extent to which IgE- and IgG-facilitated Der p 1 uptake by DCs influence T cell polarisation and in particular potential bias in favour of Th2. We have addressed this issue by using two chimaeric monoclonal antibodies produced in our laboratory and directed against a previously defined epitope on Der p 1, namely human IgE 2C7 and IgG1 2C7. Results Flow cytometry was used to establish the expression patterns of IgE (FcϵRI and FcϵRII) and IgG (FcγRI) receptors in relation to MR on DCs. The impact of FcϵRI, FcϵRII, FcγRI and mannose receptor mediated allergen uptake on Th1/Th2 cell differentiation was investigated using DC/T cell co-culture experiments. Myeloid DCs showed high levels of FcϵRI and FcγRI expression, but low levels of CD23 and MR, and this has therefore enabled us to assess the role of IgE and IgG-facilitated allergen presentation in T cell polarisation with minimal interference by CD23 and MR. Our data demonstrate that DCs that have taken up Der p 1 via surface IgE support a Th2 response. However, no such effect was demonstrable via surface IgG. Conclusions IgE bound to its high affinity receptor plays an important role in Der p 1 uptake and processing by peripheral blood DCs and in Th2 polarisation of T cells. PMID:24330349

An investigation into IgE-facilitated allergen recognition and presentation by human dendritic cells.

PubMed

Sharquie, Inas K; Al-Ghouleh, Abeer; Fitton, Patricia; Clark, Mike R; Armour, Kathryn L; Sewell, Herb F; Shakib, Farouk; Ghaemmaghami, Amir M

2013-12-13

Allergen recognition by dendritic cells (DCs) is a key event in the allergic cascade leading to production of IgE antibodies. C-type lectins, such as the mannose receptor and DC-SIGN, were recently shown to play an important role in the uptake of the house dust mite glycoallergen Der p 1 by DCs. In addition to mannose receptor (MR) and DC-SIGN the high and low affinity IgE receptors, namely FcεRI and FcεRII (CD23), respectively, have been shown to be involved in allergen uptake and presentation by DCs. This study aims at understanding the extent to which IgE- and IgG-facilitated Der p 1 uptake by DCs influence T cell polarisation and in particular potential bias in favour of Th2. We have addressed this issue by using two chimaeric monoclonal antibodies produced in our laboratory and directed against a previously defined epitope on Der p 1, namely human IgE 2C7 and IgG1 2C7. Flow cytometry was used to establish the expression patterns of IgE (FcεRI and FcεRII) and IgG (FcγRI) receptors in relation to MR on DCs. The impact of FcεRI, FcεRII, FcγRI and mannose receptor mediated allergen uptake on Th1/Th2 cell differentiation was investigated using DC/T cell co-culture experiments. Myeloid DCs showed high levels of FcεRI and FcγRI expression, but low levels of CD23 and MR, and this has therefore enabled us to assess the role of IgE and IgG-facilitated allergen presentation in T cell polarisation with minimal interference by CD23 and MR. Our data demonstrate that DCs that have taken up Der p 1 via surface IgE support a Th2 response. However, no such effect was demonstrable via surface IgG. IgE bound to its high affinity receptor plays an important role in Der p 1 uptake and processing by peripheral blood DCs and in Th2 polarisation of T cells.

Human dendritic cells in the severe combined immunodeficiency mouse model: their potentiating role in the allergic reaction.

PubMed

Hammad, H; Duez, C; Fahy, O; Tsicopoulos, A; André, C; Wallaert, B; Lebecque, S; Tonnel, A B; Pestel, J

2000-04-01

Dendritic cells (DCs) are present in the lungs and airways of healthy and allergic subjects where they are exposed to inhaled antigens. After the uptake of antigens, DCs migrate to lymphoid organs where T cells initiate and control the immune response. The migratory properties of DCs are an essential component of their function but remain unclear in the situation of allergic diseases. To better understand the role of DCs in response to allergens, we first investigated their presence in an original experimental model of allergic asthma: the humanized severe combined immunodeficiency (SCID) mouse reconstituted with peripheral blood mononuclear cells from patients sensitive to Dermatophagoides pteronyssinus (Dpt). Human DCs were detected in lungs of mice developing an inflammatory pulmonary infiltrate and appeared to be mainly located in the alveolar spaces. In a second step, human DCs were generated in vitro from monocytes and injected into naive SCID mice exposed or not exposed to Dpt aerosols. Their migratory behavior was explored, as well as their potential role in modulating the IgE production after exposure to Dpt. After exposure to Dpt, the number of DCs present in airways decreased, while it increased into the spleen and thymus of the mice. The IgE production increased in the presence of DCs as compared with mice not injected with DCs. These results suggest that DCs may play a role in the pulmonary allergic reaction developed in response to Dpt in SCID mice.

In situ targeting of dendritic cells sets tolerogenic environment and ameliorates CD4+ T-cell response in the postischemic liver.

PubMed

Funken, Dominik; Ishikawa-Ankerhold, Hellen; Uhl, Bernd; Lerchenberger, Maximilian; Rentsch, Markus; Mayr, Doris; Massberg, Steffen; Werner, Jens; Khandoga, Andrej

2017-11-01

CD4 + T cells recruited to the liver play a key role in the pathogenesis of ischemia/reperfusion (I/R) injury. The mechanism of their activation during alloantigen-independent I/R is not completely understood. We hypothesized that liver-resident dendritic cells (DCs) interact with CD4 + T cells in the postischemic liver and that modulation of DCs or T-cell-DC interactions attenuates liver inflammation. In mice, warm hepatic I/R (90/120-240 min) was induced. Tolerogenic DCs were generated in situ by pretreatment of animals with the vitamin D analog paricalcitol. A mAb-CD44 was used for blockade of CD4 + T-cell-DC interactions. As shown by 2-photon in vivo microscopy as well as confocal microscopy, CD4 + T cells were closely colocalized with DCs in the postischemic liver. Pretreatment with paricalcitol attenuated I/R-induced maturation of DCs (flow cytometry), CD4 + T-cell recruitment into the liver (intravital microscopy), and hepatocellular/microvascular damage (intravital microscopy, alanine aminotransferase/aspartate aminotransferase, histology). However, interruption of T-cell-DC interaction increased proinflammatory DC maturation and even enhanced tissue damage. Simultaneous treatment with an anti-CD44mAb completely abolished the beneficial effect of paricalcitol on T-cell migration and tissue injury. Our study demonstrates for the first time that hepatic DCs interact with CD4 + T cells in the postischemic liver in vivo ; modulation of DCs and/or generation of tolerogenic DCs attenuates intrahepatic CD4 + T-cell recruitment and reduces I/R injury; and interruption of CD44-dependent CD4 + T-cell-DC interactions enhances tissue injury by preventing the modulatory effect of hepatic DCs on T cells, especially type 1 T helper effector cells. Thus, hepatic DCs are strongly involved in the promotion of CD4 + T-cell-dependent postischemic liver inflammation.-Funken, D., Ishikawa-Ankerhold, H., Uhl, B., Lerchenberger, M., Rentsch, M., Mayr, D., Massberg, S., Werner, J., Khandoga, A. In situ targeting of dendritic cells sets tolerogenic environment and ameliorates CD4 + T-cell response in the postischemic liver. © FASEB.

CXCL4 Exposure Potentiates TLR-Driven Polarization of Human Monocyte-Derived Dendritic Cells and Increases Stimulation of T Cells.

PubMed

Silva-Cardoso, Sandra C; Affandi, Alsya J; Spel, Lotte; Cossu, Marta; van Roon, Joel A G; Boes, Marianne; Radstake, Timothy R D J

2017-07-01

Chemokines have been shown to play immune-modulatory functions unrelated to steering cell migration. CXCL4 is a chemokine abundantly produced by activated platelets and immune cells. Increased levels of circulating CXCL4 are associated with immune-mediated conditions, including systemic sclerosis. Considering the central role of dendritic cells (DCs) in immune activation, in this article we addressed the effect of CXCL4 on the phenotype and function of monocyte-derived DCs (moDCs). To this end, we compared innate and adaptive immune responses of moDCs with those that were differentiated in the presence of CXCL4. Already prior to TLR- or Ag-specific stimulation, CXCL4-moDCs displayed a more matured phenotype. We found that CXCL4 exposure can sensitize moDCs for TLR-ligand responsiveness, as illustrated by a dramatic upregulation of CD83, CD86, and MHC class I in response to TLR3 and TLR7/8-agonists. Also, we observed a markedly increased secretion of IL-12 and TNF-α by CXCL4-moDCs exclusively upon stimulation with polyinosinic-polycytidylic acid, R848, and CL075 ligands. Next, we analyzed the effect of CXCL4 in modulating DC-mediated T cell activation. CXCL4-moDCs strongly potentiated proliferation of autologous CD4 + T cells and CD8 + T cells and production of IFN-γ and IL-4, in an Ag-independent manner. Although the internalization of Ag was comparable to that of moDCs, Ag processing by CXCL4-moDCs was impaired. Yet, these cells were more potent at stimulating Ag-specific CD8 + T cell responses. Together our data support that increased levels of circulating CXCL4 may contribute to immune dysregulation through the modulation of DC differentiation. Copyright © 2017 by The American Association of Immunologists, Inc.

Accumulation and therapeutic modulation of 6-sulfo LacNAc(+) dendritic cells in multiple sclerosis.

PubMed

Thomas, Katja; Dietze, Kristin; Wehner, Rebekka; Metz, Imke; Tumani, Hayrettin; Schultheiß, Thorsten; Günther, Claudia; Schäkel, Knut; Reichmann, Heinz; Brück, Wolfgang; Schmitz, Marc; Ziemssen, Tjalf

2014-10-01

To examine the potential role of 6-sulfo LacNAc(+) (slan) dendritic cells (DCs) displaying pronounced proinflammatory properties in the pathogenesis of multiple sclerosis (MS). We determined the presence of slanDCs in demyelinated brain lesions and CSF samples of patients with MS. In addition, we explored the impact of methylprednisolone, interferon-β, glatiramer acetate, or natalizumab on the frequency of blood-circulating slanDCs in patients with MS. We also evaluated whether interferon-β modulates important proinflammatory capabilities of slanDCs. SlanDCs accumulate in highly inflammatory brain lesions and are present in the majority of CSF samples of patients with MS. Short-term methylprednisolone administration reduces the percentage of slanDCs in blood of patients with MS and the proportion of tumor necrosis factor-α- or CD150-expressing slanDCs. Long-term interferon-β treatment decreases the percentage of blood-circulating slanDCs in contrast to glatiramer acetate or natalizumab. Furthermore, interferon-β inhibits the secretion of proinflammatory cytokines by slanDCs and their capacity to promote proliferation and differentiation of T cells. Accumulation of slanDCs in highly inflammatory brain lesions and their presence in CSF indicate that slanDCs may play an important role in the immunopathogenesis of MS. The reduction of blood-circulating slanDCs and the inhibition of their proinflammatory properties by methylprednisolone and interferon-β may contribute to the therapeutic efficiency of these drugs in patients with MS.

Accumulation and therapeutic modulation of 6-sulfo LacNAc+ dendritic cells in multiple sclerosis

PubMed Central

Thomas, Katja; Dietze, Kristin; Wehner, Rebekka; Metz, Imke; Tumani, Hayrettin; Schultheiß, Thorsten; Günther, Claudia; Schäkel, Knut; Reichmann, Heinz; Brück, Wolfgang; Schmitz, Marc

2014-01-01

Objective: To examine the potential role of 6-sulfo LacNAc+ (slan) dendritic cells (DCs) displaying pronounced proinflammatory properties in the pathogenesis of multiple sclerosis (MS). Methods: We determined the presence of slanDCs in demyelinated brain lesions and CSF samples of patients with MS. In addition, we explored the impact of methylprednisolone, interferon-β, glatiramer acetate, or natalizumab on the frequency of blood-circulating slanDCs in patients with MS. We also evaluated whether interferon-β modulates important proinflammatory capabilities of slanDCs. Results: SlanDCs accumulate in highly inflammatory brain lesions and are present in the majority of CSF samples of patients with MS. Short-term methylprednisolone administration reduces the percentage of slanDCs in blood of patients with MS and the proportion of tumor necrosis factor-α– or CD150-expressing slanDCs. Long-term interferon-β treatment decreases the percentage of blood-circulating slanDCs in contrast to glatiramer acetate or natalizumab. Furthermore, interferon-β inhibits the secretion of proinflammatory cytokines by slanDCs and their capacity to promote proliferation and differentiation of T cells. Conclusion: Accumulation of slanDCs in highly inflammatory brain lesions and their presence in CSF indicate that slanDCs may play an important role in the immunopathogenesis of MS. The reduction of blood-circulating slanDCs and the inhibition of their proinflammatory properties by methylprednisolone and interferon-β may contribute to the therapeutic efficiency of these drugs in patients with MS. PMID:25340085

Human monocyte-derived dendritic cells exposed to microorganisms involved in hypersensitivity pneumonitis induce a Th1-polarized immune response.

PubMed

Bellanger, Anne-Pauline; Pallandre, Jean-René; Borg, Christophe; Loeffert, Sophie; Gbaguidi-Haore, Houssein; Millon, Laurence

2013-08-01

Hypersensitivity pneumonitis (HP) is an immunoallergic disease characterized by a prominent interstitial infiltrate composed predominantly of lymphocytes secreting inflammatory cytokines. Dendritic cells (DCs) are known to play a pivotal role in the lymphocytic response. However, their cross talk with microorganisms that cause HP has yet to be elucidated. This study aimed to investigate the initial interactions between human monocyte-derived DCs (MoDCs) and four microorganisms that are different in nature (Saccharopolyspora rectivirgula [actinomycetes], Mycobacterium immunogenum [mycobacteria], and Wallemia sebi and Eurotium amstelodami [filamentous fungi]) and are involved in HP. Our objectives were to determine the cross talk between MoDCs and HP-causative agents and to determine whether the resulting immune response varied according to the microbial extract tested. The phenotypic activation of MoDCs was measured by the increased expression of costimulatory molecules and levels of cytokines in supernatants. The functional activation of MoDCs was measured by the ability of MoDCs to induce lymphocytic proliferation and differentiation in a mixed lymphocytic reaction (MLR). E. amstelodami-exposed (EA) MoDCs expressed higher percentages of costimulatory molecules than did W. sebi-exposed (WS), S. rectivirgula-exposed (SR), or M. immunogenum-exposed (MI) MoDCs (P < 0.05, Wilcoxon signed-rank test). EA-MoDCs, WS-MoDCs, SR-MoDCs, and MI-MoDCs induced CD4(+) T cell proliferation and a Th1-polarized immune response. The present study provides evidence that, although differences were initially observed between MoDCs exposed to filamentous fungi and MoDCs exposed to bacteria, a Th1 response was ultimately promoted by DCs regardless of the microbial extract tested.

Benefits of gene transduction of granulocyte macrophage colony-stimulating factor in cancer vaccine using genetically modified dendritic cells.

PubMed

Ojima, Toshiyasu; Iwahashi, Makoto; Nakamura, Masaki; Matsuda, Kenji; Nakamori, Mikihito; Ueda, Kentaro; Naka, Teiji; Katsuda, Masahiro; Miyazawa, Motoki; Yamaue, Hiroki

2007-10-01

Granulocyte macrophage colony-stimulating factor (GM-CSF) is a key cytokine for the generation and stimulation of dendritic cells (DCs), and it may also play a pivotal role in promoting the survival of DCs. In this study, the feasibility of creating a cancer vaccine using DCs adenovirally transduced with the carcinoembryonic antigen (CEA) gene and the GM-CSF gene was examined. In addition, the effect of the co-transduction of GM-CSF gene on the lifespan of these genetically modified DCs was determined. A cytotoxic assay using peripheral blood mononuclear cell (PBMC)-derived cytotoxic T lymphocytes (CTLs) was performed in a 4-h 51Cr release assay. The apoptosis of DCs was examined by TdT-mediated dUTP-FITC nick end labeling (TUNEL) assay. CEA-specific CTLs were generated from PBMCs stimulated with genetically modified DCs expressing CEA. The cytotoxicity of these CTLs was augmented by co-transduction of DCs with the GM-CSF gene. Co-transduction of the GM-CSF gene into DCs inhibited apoptosis of these DCs themselves via up-regulation of Bcl-x(L) expression, leading to the extension of the lifespan of these DCs. Furthermore, the transduction of the GM-CSF gene into DCs also suppressed the incidence of apoptosis of DCs induced by transforming growth factor-beta1 (TGFbeta-1). Immunotherapy using these genetically modified DCs may therefore be useful with several advantages as follows: i) adenoviral toxicity to DCs can be reduced; ii) the lifespan of vaccinated DCs can be prolonged; and iii) GM-CSF may protect DCs from apoptosis induced by tumor-derived TGFbeta-1 in the regional lymph nodes.

Functions of TGF-β-exposed plasmacytoid dendritic cells.

PubMed

Saas, Philippe; Perruche, Sylvain

2012-01-01

Plasmacytoid dendritic cells (pDCs) belong to the family of dendritic cells and possess specific features that distinguish them from conventional dendritic cells. For instance, pDC are the main interferon-alpha-secreting cells. Plasmacytoid dendritic cells exert both proinflammatory and regulatory functions. This is attested by the involvement of pDC through interferon-alpha secretion in several autoimmune diseases, and by the implication of pDC in tolerance. The same is true for TGF-β that plays a dual role in inflammation. In this review, we discuss recent data on pDC and TGF-β interactions. As with many cell types, pDCs are able to respond to TGF-β using the classic Smad signaling pathway. In addition, pDCs are capable to secrete TGF-β, in particular in response to TGF-β exposure. Exposure of pDCs to TGF-β prevents type I interferon secretion in response to TLR7/9 ligands. In contrast, the consequences of TGF-β on the antigen-presenting cell capacities of pDC are less clear, since TGF-β-exposed pDCs may lead to both regulatory T-cell and interleukin-17-secreting cell polarization. Here, we discuss the factors that may influence this polarization. We also discuss how pDCs exposed to TGF-β may participate in tolerance induction and maintenance, or, on the contrary, in autoimmune diseases.

TGF-β of lung cancer microenvironment upregulates B7H1 and GITRL expression in dendritic cells and is associated with regulatory T cell generation.

PubMed

Ni, Xiao Yan; Sui, Hua Xiu; Liu, Yao; Ke, Shi Zhong; Wang, Yi Nan; Gao, Feng Guang

2012-08-01

The effects of TGF-β on dendritic cells (DCs) on the tumor microenvironment are not well understood. We report, here, the establishment of an in vitro lung cancer microenvironment by co-incubation of seminaphtharhodafluor (SNARF) labeled Lewis lung cancer (LLC) cells, carboxyfluorescein succinimidyl ester (CFSE) labeled fibroblasts and 4-chloromethyl-7-hydroxycoumarin (CMHC) labeled DCs. Raw 264.7, EL4 and NCI-H446 cells were able to synthesize TGF-β which was determined by flow cyto-metry and western blotting, respectively. Furthermore, TGF-β efficiently increased regulatory T-cell (Treg) expansion and upregulated DC B7H1 and GITRL expression. TGF-β and the co-incubation of LLC cells, fibroblasts with DCs could augment the expression of B7H1 and GITRL molecules of DCs. The data presented here indicate that the B7H1 and GITRL molecules may play an important role in TGF-β-induced Treg expansion of lung cancer microenvironment.

Involvement of dendritic cells in allograft rejection new implications of dendritic cell-endothelial cell interactions.

PubMed

Schlichting, C L; Schareck, W D; Kofler, S; Weis, M

2007-04-01

For almost half a century immunologists have tried to tear down the MHC barrier, which separates two unrelated individuals during transplantation. Latest experimental data suggest that a breakthrough in vitro is imminent. Dendritic cells (DCs), which activate naïve allo-reactive T-cells (TCs), play a central role in the establishment of allo-antigen-specific immunity. Allograft solid organ rejection is initiated at the foreign endothelial cell (EC) layer, which forms an immunogenic barrier for migrating DCs. Thus, DC/EC interactions might play a crucial role in antigen-specific allograft rejection. Organ rejection is mediated by host allo-reactive TCs, which are activated by donor DCs (direct activation) or host DCs (indirect activation). Direct allo-antigen presentation by regulatory dendritic cells (DCreg) can play an instructive role towards tolerance induction. Several groups established that, DCregs, if transplanted beforehand, enter host thymus, spleen, or bone marrow where they might eventually establish allo-antigen-specific tolerance. A fundamental aspect of DC function is migration throughout the entire organism. After solid organ transplantation, host DCs bind to ECs, invade allograft tissues, and finally transmigrate into lymphoid vessels and secondary lymphoid organs, where they present allo-antigens to naïve host TCs. Recent data suggest that in vitro manipulated DCregs may mediate allo-transplantation tolerance induction. However, the fundamental mechanisms on how such DCregs cause host TCs in the periphery towards tolerance remain unclear. One very promising experimental concept is the simultaneous manipulation of DC direct and indirect TC activation/suppression, towards donor antigen-specific allo-transplantation tolerance. The allo-antigen-specific long-term tolerance induction mediated by DCreg pre-transplantation (with simultaneous short-term immunosuppression) has become reproducible in the laboratory animal setting. Despite the shortcomings of laboratory animal studies, strong promises are deriving from these studies for clinical kidney, heart, and liver transplantation.

Effects of 12C6+ Heavy Ion Radiation on Dendritic Cells Function

PubMed Central

Zhang, Pei; Hu, Xuguang; Liu, Bin; Liu, Zhe; Liu, Cong; Cai, Jianming; Gao, Fu; Li, Bailong

2018-01-01

Background Carbon ion radiotherapy has been shown to be more effective in cancer radiotherapy than photon irradiation. Influence of carbon ion radiation on cancer microenvironment is very important for the outcomes of radiotherapy. Tumor-infiltrating dendritic cells (DCs) play critical roles in cancer antigen processing and antitumor immunity. However, there is scant literature covering the effects of carbon ion radiation on DCs. In this study, we aimed to uncover the impact of carbon ion irradiation on bone marrow derived DCs. Material/Methods Bone marrow cells were co-cultured with GM-CSF and IL-4 for seven days, and the population of DCs was confirmed with flow cytometry. We used an Annexin V and PI staining method to detect cell apoptosis. Endocytosis assay of DCs was determined by using a flow cytometry method. DCs migration capacity was tested by a Transwell method. We also used ELISA assay and western blotting assay to examine the cytokines and protein expression, respectively. Results Our data showed that carbon ion radiation induced apoptosis in both immature and mature DCs. After irradiation, the endocytosis and migration capacity of DCs was also impaired. Interestingly, carbon irradiation triggered a burst of IFN-γ and IL-12 in LPS or CpG treated DCs, which provide novel insights into the combination of immunotherapy and carbon ion radiotherapy. Finally, we found that carbon ion irradiation induced apoptosis and migration suppression was p38 dependent. Conclusions Our present study demonstrated that carbon ion irradiation induced apoptosis in DCs, and impaired DCs function mainly through the p38 signaling pathway. Carbon ion irradiation also triggered anti-tumor cytokines secretion. This work provides novel information of carbon ion radiotherapy in DCs, and also provides new insights on the combination of immune adjuvant and carbon ion radiotherapy. PMID:29525808

Activation and cytokine profile of monocyte derived dendritic cells in leprosy: in vitro stimulation by sonicated Mycobacterium leprae induces decreased level of IL-12p70 in lepromatous leprosy.

PubMed

Braga, André Flores; Moretto, Daniela Ferraz; Gigliotti, Patrícia; Peruchi, Mariela; Vilani-Moreno, Fátima Regina; Campanelli, Ana Paula; Latini, Ana Carla Pereira; Iyer, Anand; Das, Pranab Kumar; Souza, Vânia Nieto Brito de

2015-08-01

Dendritic cells (DCs) play a pivotal role in the connection of innate and adaptive immunity of hosts to mycobacterial infection. Studies on the interaction of monocyte-derived DCs (MO-DCs) using Mycobacterium leprae in leprosy patients are rare. The present study demonstrated that the differentiation of MOs to DCs was similar in all forms of leprosy compared to normal healthy individuals. In vitro stimulation of immature MO-DCs with sonicated M. leprae induced variable degrees of DC maturation as determined by the increased expression of HLA-DR, CD40, CD80 and CD86, but not CD83, in all studied groups. The production of different cytokines by the MO-DCs appeared similar in all of the studied groups under similar conditions. However, the production of interleukin (IL)-12p70 by MO-DCs from lepromatous (LL) leprosy patients after in vitro stimulation with M. leprae was lower than tuberculoid leprosy patients and healthy individuals, even after CD40 ligation with CD40 ligand-transfected cells. The present cumulative findings suggest that the MO-DCs of LL patients are generally a weak producer of IL-12p70 despite the moderate activating properties ofM. leprae. These results may explain the poor M. leprae-specific cell-mediated immunity in the LL type of leprosy.

Deciphering the message broadcast by tumor-infiltrating dendritic cells.

PubMed

Karthaus, Nina; Torensma, Ruurd; Tel, Jurjen

2012-09-01

Human dendritic cells (DCs) infiltrate solid tumors, but this infiltration occurs in favorable and unfavorable disease prognoses. The statistical inference is that tumor-infiltrating DCs (TIDCs) play no conclusive role in predicting disease progression. This is remarkable because DCs are highly specialized antigen-presenting cells linking innate and adaptive immunity. DCs either boost the immune system (enhancing immunity) or dampen it (leading to tolerance). This dual effect explains the dual outcomes of cancer progression. The reverse functional characteristics of DCs depend on their maturation status. This review elaborates on the markers used to detect DCs in tumors. In many cases, the identification of DCs in human cancers relies on staining for S-100 and CD1a. These two markers are mainly expressed by Langerhans cells, which are one of several functionally different DC subsets. The activation status of DCs is based on the expression of CD83, DC-SIGN, and DC-LAMP, which are nonspecific markers of DC maturation. The detection of TIDCs has not kept pace with the increased knowledge about the identification of DC subsets and their maturation status. Therefore, it is difficult to draw a conclusion about the performance of DCs in tumors. We suggest a novel selection of markers to distinguish human DC subsets and maturation states. The use of these biomarkers will be of pivotal importance to scrutinize the prognostic significance of TIDCs. Copyright © 2012 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Eosinophils Regulate Interferon Alpha Production in Plasmacytoid Dendritic Cells Stimulated with Components of Neutrophil Extracellular Traps.

PubMed

Skrzeczynska-Moncznik, Joanna; Zabieglo, Katarzyna; Bossowski, Jozef P; Osiecka, Oktawia; Wlodarczyk, Agnieszka; Kapinska-Mrowiecka, Monika; Kwitniewski, Mateusz; Majewski, Pawel; Dubin, Adam; Cichy, Joanna

2017-03-01

Eosinophils constitute an important component of helminth immunity and are not only associated with various allergies but are also linked to autoinflammatory disorders, including the skin disease psoriasis. Here we demonstrate the functional relationship between eosinophils and plasmacytoid dendritic cells (pDCs) as related to skin diseases. We previously showed that pDCs colocalize with neutrophil extracellular traps (NETs) in psoriatic skin. Here we demonstrate that eosinophils are found in psoriatic skin near neutrophils and NETs, suggesting that pDC responses can be regulated by eosinophils. Eosinophils inhibited pDC function in vitro through a mechanism that did not involve cell contact but depended on soluble factors. In pDCs stimulated by specific NET components, eosinophil-conditioned media attenuated the production of interferon α (IFNα) but did not affect the maturation of pDCs as evidenced by the unaltered expression of the costimulatory molecules CD80 and CD86. As pDCs and IFNα play a key role in autoimmune skin inflammation, these data suggest that eosinophils may influence autoinflammatory responses through their impact on the production of IFNα by pDCs.

Distribution of subpopulations of dendritic cells in peripheral blood of patients treated with exogenous thyrotropin

PubMed Central

2012-01-01

Background Dendritic cells (DCs) play a major role as regulators of inflammatory events associated with thyroid pathology. The immunoregulatory function of DCs depends strongly on their subtype, as well as maturation and activation status. Numerous hormonal factors modulate the immune properties of DCs, however, little is known about effects exerted by the hypothalamus-pituitary-thyroid-axis. Recently, we have shown a direct regulatory influence of thyroid hormones (TH) on human DCs function. The aim of the present study was to analyze the effect of systemically administered thyrotropin (TSH) on human blood DCs ex vivo. Methods Blood samples for the cytometric analysis of peripheral blood plasmacytoid and myeloid DCs subtypes were collected from patients subjected to total thyroidectomy because of differentiated thyroid carcinoma at 2 time points: (i) directly before the commencement of TSH administration and (ii) 5 days after first TSH injection. The whole blood quantitative and phenotypic analysis of plasmacytoid and myeloid DCs subtypes was performed by flow cytometry. Results Administration of TSH did not influence the percentage of plasmacytoid DCs in peripheral blood of study participants. Also the percentage of the two main myeloid DCs subpopulations – CD1c/BDCA1+ DCs and CD141/BDCA3+ DCs did not change significantly. TSH administration had no effect on the surface expression of CD86 – one of the major costimulatory molecules – neither in the whole peripheral blood mononuclear cell (PBMC) fraction nor in particular DCs subtypes. Conclusions In the present study, we demonstrated no influence of systemic TSH administration on human peripheral blood DCs subtypes. These results are in accordance with our previous work suggesting the direct effect of TH on human DCs ex vivo. PMID:23199104

Distribution of subpopulations of dendritic cells in peripheral blood of patients treated with exogenous thyrotropin.

PubMed

Stasiołek, Mariusz; Adamczewski, Zbigniew; Puła, Bartosz; Krawczyk-Rusiecka, Kinga; Zygmunt, Arkadiusz; Borowiecka, Magdalena; Dzięgiel, Piotr; Lewiński, Andrzej

2012-11-30

Dendritic cells (DCs) play a major role as regulators of inflammatory events associated with thyroid pathology. The immunoregulatory function of DCs depends strongly on their subtype, as well as maturation and activation status. Numerous hormonal factors modulate the immune properties of DCs, however, little is known about effects exerted by the hypothalamus-pituitary-thyroid-axis. Recently, we have shown a direct regulatory influence of thyroid hormones (TH) on human DCs function. The aim of the present study was to analyze the effect of systemically administered thyrotropin (TSH) on human blood DCs ex vivo. Blood samples for the cytometric analysis of peripheral blood plasmacytoid and myeloid DCs subtypes were collected from patients subjected to total thyroidectomy because of differentiated thyroid carcinoma at 2 time points: (i) directly before the commencement of TSH administration and (ii) 5 days after first TSH injection. The whole blood quantitative and phenotypic analysis of plasmacytoid and myeloid DCs subtypes was performed by flow cytometry. Administration of TSH did not influence the percentage of plasmacytoid DCs in peripheral blood of study participants. Also the percentage of the two main myeloid DCs subpopulations - CD1c/BDCA1+ DCs and CD141/BDCA3+ DCs did not change significantly. TSH administration had no effect on the surface expression of CD86 - one of the major costimulatory molecules - neither in the whole peripheral blood mononuclear cell (PBMC) fraction nor in particular DCs subtypes. In the present study, we demonstrated no influence of systemic TSH administration on human peripheral blood DCs subtypes. These results are in accordance with our previous work suggesting the direct effect of TH on human DCs ex vivo.

CD4+CD25+ Treg derived from hepatocellular carcinoma mice inhibits tumor immunity.

PubMed

Chen, Xin; Du, Yong; Huang, Zhiming

2012-01-01

CD4+CD25+ regulatory T cells (Tregs) play an essential role in the establishment and persistence of tumor immune suppression. Tregs can prevent anti-tumor-specific T cells from clearing the tumor, making Tregs a significant barrier for effective immunotherapy. An increase in the number of Tregs has been detected in the peripheral blood and tumor infiltrating lymphocytes of patients with hepatocellular carcinoma. Dendritic cells (DCs) are antigen-presenting cells that play a pivotal role in the initiation of immune responses. The evidence for their ability to act as natural adjuvant in the stimulation of specific anti-tumor cytotoxic T lymphocytes and in the induction of protective and therapeutic anti-tumor immunity is now overwhelming. The aim of our study was to investigate the variation of Tregs in hepatocellular carcinoma mice and how Tregs derived from the tumor mice affect DCs' function. We found that Tregs derived from the tumor mice down-regulated the expression of costimulatory molecules CD80/CD86 on DCs and inhibited the production of TNF-α and IL-12 from DCs. The suppressive function of Tregs was mediated by cell-to-cell contact, CTLA-4 expression and IL-10 secretion. In conclusion, these mechanisms acting in hepatocellular carcinoma may be necessary to better understand the immunosuppression of Tregs and helpful to the tumor immunotherapy. Copyright © 2012 Elsevier B.V. All rights reserved.

SH2 domain-containing adaptor protein B expressed in dendritic cells is involved in T-cell homeostasis by regulating dendritic cell-mediated Th2 immunity.

PubMed

Ahmed, Md Selim; Kang, Myeong-Ho; Lee, Ezra; Park, Yujin; Jeong, Yideul; Bae, Yong-Soo

2017-01-01

The Src homology 2 domain-containing adaptor protein B (SHB) is widely expressed in immune cells and acts as an important regulator for hematopoietic cell function. SHB silencing induces Th2 immunity in mice. SHB is also involved in T-cell homeostasis in vivo . However, SHB has not yet been studied and addressed in association with dendritic cells (DCs). The effects of SHB expression on the immunogenicity of DCs were assessed by Shb gene silencing in mouse bone marrow-derived DCs (BMDCs). After silencing, surface phenotype, cytokine expression profile, and T-cell stimulation capacity of BMDCs were examined. We investigated the signaling pathways involved in SHB expression during BMDC development. We also examined the immunogenicity of SHB-knockdown (SHB KD ) BMDCs in a mouse atopic dermatitis model. SHB was steadily expressed in mouse splenic DCs and in in vitro -generated BMDCs in both immature and mature stages. SHB expression was contingent on activation of the mitogen- activated protein kinase/Foxa2 signaling pathway during DC development. SHB KD increased the expression of MHC class II and costimulatory molecules without affecting the cytokine expression of BMDCs. When co-cultured with T cells, SHB KD in BMDCs significantly induced CD4 + T-cell proliferation and the expression of Th2 cytokines, while the regulatory T cell (Treg) population was downregulated. In mouse atopic dermatitis model, mice inoculated with SHB KD DCs developed more severe symptoms of atopic dermatitis compared with mice injected with control DCs. SHB expression in DCs plays an important role in T-cell homeostasis in vivo by regulating DC-mediated Th2 polarization.

Dendritic Cells Induce a Subpopulation of IL-12Rβ2-Expressing Treg that Specifically Consumes IL-12 to Control Th1 Responses

PubMed Central

Sela, Uri; Park, Chae Gyu; Park, Andrew; Olds, Peter; Wang, Shu; Fischetti, Vincent A.

2016-01-01

Cytokines secreted from dendritic cells (DCs) play an important role in the regulation of T helper (Th) cell differentiation and activation into effector cells. Therefore, controlling cytokine secretion from DCs may potentially regulate Th differentiation/activation. DCs also induce de-novo generation of regulatory T cells (Treg) that modulate the immune response. In the current study we used the mixed leukocyte reaction (MLR) to investigate the effect of allospecific Treg on IL-12, TNFα and IL-6 secretion by DCs. Treg cells were found to markedly down-regulate IL-12 secretion from DCs following stimulation with TLR7/8 agonist. This down-regulation of IL-12 was neither due to a direct suppression of its production by the DCs nor a result of marked DC death. We found that IL-12 was rather actively consumed by Treg cells. IL-12 consumption was mediated by a subpopulation of IL-12Rβ2-expressing Treg cells and was dependent on MHC class-II expressed on dendritic cells. Furthermore, IL-12 consumption by Tregs increased their suppressive effect on T cell proliferation and Th1 activation. These results provide a new pathway of Th1 response regulation where IL-12 secreted by DCs is consumed by a sub-population of IL-12Rβ2-expressing Treg cells. Consumption of IL-12 by Tregs not only reduces the availability of IL-12 to Th effector cells but also enhances the Treg immunosuppressive effect. This DC-induced IL-12Rβ2-expressing Treg subpopulation may have a therapeutic advantage in suppressing Th1 mediated autoimmunity. PMID:26745371

Antigen-Conjugated Human IgE Induces Antigen-Specific T Cell Tolerance in a Humanized Mouse Model

PubMed Central

Baravalle, Günther; Greer, Alexandra M.; LaFlam, Taylor N.; Shin, Jeoung-Sook

2015-01-01

Dendritic cells (DCs) play an important role in immune homeostasis through their ability to present Ags at steady state and mediate T cell tolerance. This characteristic renders DCs an attractive therapeutic target for the induction of tolerance against auto-antigens or allergens. Accordingly, Ag-conjugated DC–specific Abs have been proposed to be an excellent vehicle to deliver Ags to DCs for presentation and tolerance induction. However, this approach requires laborious reagent generation procedures and entails unpredictable side effects resulting from Ab-induced crosslinking of DC surface molecules. In this study, we examined whether IgE, a high-affinity, non–cross-linking natural ligand of FcεRI, could be used to target Ags to DCs and to induce Ag-specific T cell tolerance. We found that Ag-conjugated human IgE Fc domain (Fcε) effectively delivered Ags to DCs and enhanced Ag presentation by 1000- to 2500-fold in human FcεRIα-transgenic mice. Importantly, this presentation resulted in a systemic deletion of Ag-specific T cells and prevented these mice from developing delayed-type hypersensitivity, which is critically dependent on Ag-specific T cell immunity. Thus, targeting FcεRI on DCs via Ag-Fcε fusion protein may serve an alternative method to induce Ag-specific T cell tolerance in humans. PMID:24610015

Monocyte-derived dendritic cells induce a house dust mite-specific Th2 allergic inflammation in the lung of humanized SCID mice: involvement of CCR7.

PubMed

Hammad, Hamida; Lambrecht, Bart N; Pochard, Pierre; Gosset, Philippe; Marquillies, Philippe; Tonnel, André-Bernard; Pestel, Joël

2002-08-01

In rodents, airway dendritic cells (DCs) capture inhaled Ag, undergo maturation, and migrate to the draining mediastinal lymph nodes (MLN) to initiate the Ag-specific T cell response. However, the role of human DCs in the pathogenesis of the Th2 cell-mediated disease asthma remains to be clarified. Here, by using SCID mice engrafted with T cells from either house dust mite (HDM)-allergic patients or healthy donors, we show that DCs pulsed with Der p 1, one of the major allergens of HDM, and injected intratracheally into naive animals migrated into the MLN. In the MLN, Der p 1-pulsed DCs from allergic patients induced the proliferation of IL-4-producing CD4(+) T cells, whereas those from healthy donors induced IFN-gamma-secreting cells. In reconstituted human PBMC-reconstituted SCID mice primed with pulsed DCs from allergic patients, repeated exposure to aerosols of HDM induced 1) a strong pulmonary inflammatory reaction rich in T cells and eosinophils, 2) an increase in IL-4 and IL-5 production in the lung lavage fluid, and 3) increased IgE production compared with that in mice primed with unpulsed DCs. All these effects were reduced following in vivo neutralization of the CCR7 ligand secondary lymphoid tissue chemokine. These data in human PBMC-reconstituted SCID mice show that monocyte-derived DCs might play a key role in the pathogenesis of the pulmonary allergic response by inducing Th2 effector function following migration to the MLN.

Avoiding horror autotoxicus: The importance of dendritic cells in peripheral T cell tolerance

PubMed Central

Steinman, Ralph Marvin; Nussenzweig, Michel C.

2002-01-01

The immune system generally avoids horror autotoxicus or autoimmunity, an attack against the body's own constituents. This avoidance requires that self-reactive T cells be actively silenced or tolerized. We propose that dendritic cells (DCs) play a critical role in establishing tolerance, especially in the periphery, after functioning T cells have been produced in the thymus. In the steady state, meaning in the absence of acute infection and inflammation, DCs are in an immature state and not fully differentiated to carry out their known roles as inducers of immunity. Nevertheless, immature DCs continuously circulate through tissues and into lymphoid organs, capturing self antigens as well as innocuous environmental proteins. Recent experiments have provided direct evidence that antigen-loaded immature DCs silence T cells either by deleting them or by expanding regulatory T cells. This capacity of DCs to induce peripheral tolerance can work in two opposing ways in the context of infection. In acute infection, a beneficial effect should occur. The immune system would overcome the risk of developing autoimmunity and chronic inflammation if, before infection, tolerance were induced to innocuous environmental proteins as well as self antigens captured from dying infected cells. For chronic or persistent pathogens, a second but dire potential could take place. Continuous presentation of a pathogen by immature DCs, HIV-1 for example, may lead to tolerance and active evasion of protective immunity. The function of DCs in defining immunologic self provides a new focus for the study of autoimmunity and chronic immune-based diseases. PMID:11773639

Two photon microscopy intravital study of DC-mediated anti-tumor response of NK cells

NASA Astrophysics Data System (ADS)

Caccia, Michele; Gorletta, Tatiana; Sironi, Laura; Zanoni, Ivan; Salvetti, Cristina; Collini, Maddalena; Granucci, Francesca; Chirico, Giuseppe

2010-02-01

Recent studies have demonstrated that dendritic cells (DCs) play a crucial role in the activation of Natural Killer cells (NKs) that are responsible for anti-tumor innate immune responses. The focus of this report is on the role of pathogen associated molecular pattern (PAMP) activated-DCs in inducing NK cell-mediated anti-tumor responses. Mice transplanted sub-cute (s.c.) with AK7 cells, a mesothelioma cell line sensitive to NK cell responses, are injected with fluorescent NK cells and DC activation is then induced by s.c. injection of Lipopolysaccharide (LPS). Using 4 dimensional tracking we follow the kinetic behavior of NK cells at the Draining Lymph-Node (DLN). As control, noninflammatory conditions are also evaluated. Our data suggest that NK cells are recruited to the DLN where they can interact with activated-DCs with a peculiar kinetic behavior: short lived interactions interleaved by rarer longer ones. We also found that the changes in the NK dynamic behavior in inflammatory conditions clearly affect relevant motility parameters such as the instantaneous and average velocity and the effective diffusion coefficient. This observation suggests that NK cells and activated-DCs might efficiently interact in the DLN, where cells could be activated. Therefore the interaction between activated-DCs and NK cells in DLN is not only a reality but it may be also crucial for the start of the immune response of the NKs.

Role of Dendritic Cell-Specific ICAM-3-Grabbing Nonintegrin on Dendritic Cells in the Recognition of Hepatitis B Virus.

PubMed

Wang, Minxin; Zou, Xiaojing; Tian, Deying; Hu, Song; Jiang, Libin

2015-01-01

Dendritic cell-specific ICAM-3-grabbing nonintegrin (DC-SIGN) is an essential process for virus infection, such as HIV and hepatitis C, and plays a role in immune escape. However, the role of DC-SIGN in hepatitis B virus (HBV) infection is still unknown. The aim of this study was to investigate the role of DC-SIGN in mediating the maturation and activation of dendritic cells (DCs) when infected by HBV. Highly mannosylated HBV particles were obtained by treating HBV-producing HepG2.2.15 cells with the a-mannosidase I-inhibitor kifunensine. Highly mannosylated HBV or wild type HBV was added to infect the DCs of the DC-SIGN gene-silencing group and normal group, respectively. Then, the expression of CDla, CD80, CD83, CD86 and HLA-DR on DCs was detected by flow cytometry, the capacity of stimulating lymphocyte proliferation was tested by MTT assay, the level of IL-12p70 that was released by DCs was measured by enzyme-linked immunosorbent assay, and the expression of the proteins NF-κBp65 and p38 was detected by western blot. Both wild type and highly mannosylated HBV could promote DCs maturation and activation. However, the highly mannosylated HBV could promote DCs immune activation more strongly. The difference in the effect on DCs between the two types of HBV could be eliminated by DC-SIGN gene silencing. DC-SIGN can promote the maturation and activation of DCs when recognized HBV, but wild type HBV can escape recognition by DC-SIGN to a certain extent with the help of demannosylated modification, leading to defective DCs function and chronic HBV infection.

Amelioration of collagen-induced arthritis using antigen-loaded dendritic cells modified with NF-κB decoy oligodeoxynucleotides

PubMed Central

Jiang, Hongmei; Hu, Henggui; Zhang, Yali; Yue, Ping; Ning, Lichang; Zhou, Yan; Shi, Ping; Yuan, Rui

2017-01-01

Dendritic cells (DCs) play an important role in the initiation of autoimmunity in rheumatoid arthritis (RA); therefore, the use of DCs needs to be explored to develop new therapeutic approaches for RA. Here, we investigated the therapeutic effect of bovine type II collagen (BIIC)-loaded DCs modified with NF-κB decoy oligodeoxynucleotides (ODNs) on collagen-induced arthritis (CIA) in rats and explored the underlying mechanisms. DCs treated with BIIC and NF-κB decoy ODNs exhibited features of immature DCs with low levels of costimulatory molecule (CD80 and CD86) expression. The development of arthritis in rats with CIA injected with BIIC + NF-κB decoy ODN-propagated DCs (BIIC–decoy DCs) was significantly ameliorated compared to that in rats injected with BIIC-propagated DCs or phosphate-buffered saline. We also found that the BIIC–decoy DCs exerted antiarthritis effects by inhibiting self-lymphocyte proliferative response and suppressing IFN-γ and anti-BIIC antibody production and inducing IL-10 antibody production. Additionally, antihuman serum antibodies were successfully produced in the rats treated with BIIC–decoy DCs but not in those treated with NF-κB decoy ODN-propagated DCs; moreover, the BIIC–decoy DCs did not affect immune function in the normal rats. These findings suggested that NF-κB decoy ODN-modified DCs loaded with a specific antigen might offer a practical method for the treatment of human RA. PMID:29075103

Dendritic cell control of tolerogenic responses

PubMed Central

Manicassamy, Santhakumar; Pulendran, Bali

2011-01-01

Summary One of the most fundamental problems in immunology is the seemingly schizophrenic ability of the immune system to launch robust immunity against pathogens, while acquiring and maintaining a state of tolerance to the body’s own tissues and the trillions of commensal microorganisms and food antigens that confront it every day. A fundamental role for the innate immune system, particularly dendritic cells (DCs), in orchestrating immunological tolerance has been appreciated, but emerging studies have highlighted the nature of the innate receptors and the signaling pathways that program DCs to a tolerogenic state. Furthermore, several studies have emphasized the major role played by cellular interactions, and the microenvironment in programming tolerogenic DCs. Here we review these studies and suggest that the innate control of tolerogenic responses can be viewed as different hierarchies of organization, in which DCs, their innate receptors and signaling networks, and their interactions with other cells and local microenvironments represent different levels of the hierarchy. PMID:21488899

NKG2D is Required for Regulation of Lung Pathology and Dendritic Cell Function Following RSV Infection.

PubMed

Liu, Huan; Osterburg, Andrew R; Flury, Jennifer; Huang, Shuo; McCormack, Francis X; Cormier, Stephania A; Borchers, Michael T

2018-03-15

Respiratory syncytial virus (RSV) is a common cause of respiratory tract infection in vulnerable populations. Natural killer (NK) cells and dendritic cells (DC) are important for the effector functions of both cell types following infection. Wild type and NKG2D deficient mice were infected with RSV. Lung pathology, was assessed by histology. DC function and phenotype was evaluated by ELISA and flow cytometry. The expression of NKG2D ligands on lung and lymph node DCs was measured by immunostaining and flow cytometry. Adoptive transfer experiments were performed to assess the importance of NKG2D dependent DC function in RSV infection. NKG2D deficient mice exhibited greater lung pathology, marked by the accumulation of DCs following RSV infection.  DCs isolated from NKG2D deficient mice had impaired responses towards TLR ligands. DCs expressed NKG2D ligands on their surface, which was further increased in NKG2D deficient mice and during RSV infection. Adoptive transfer of DCs isolated from WT mice into the airways of NKG2D deficient mice ameliorated the enhanced inflammation in NKG2D deficient mice after RSV infection. NKG2D-dependent interactions with DCs control the phenotype and function of DCs and play a critical role in pulmonary host defenses against RSV infection.

Involvement of the mannose receptor in the uptake of Der p 1, a major mite allergen, by human dendritic cells.

PubMed

Deslée, Gaëtan; Charbonnier, Anne-Sophie; Hammad, Hamida; Angyalosi, Gerhild; Tillie-Leblond, Isabelle; Mantovani, Alberto; Tonnel, André-Bernard; Pestel, Joël

2002-11-01

Immature dendritic cells (DCs) take up antigens in peripheral tissues and, after antigen processing, mature to efficiently stimulate T cells in secondary lymph nodes. In allergic airway diseases DCs have been shown to be involved in the induction and maintenance of a T(H)2-type profile. The present study was undertaken to determine pathways of Der p 1 (a house dust mite allergen) uptake by human DCs and to compare Der p 1 uptake between DCs from patients with house dust mite allergy and DCs from healthy donors. Monocyte-derived DCs (MD-DCs) were obtained from patients with house dust mite allergy (n = 13) and healthy donors (n = 11). Der p 1 was labeled with rhodamine. Der p 1 uptake by MD-DCs was analyzed by means of flow cytometry and confocal microscopy. Rhodamine- labeled Der p 1 was demonstrated to be taken up by MD-DCs in a dose-, time-, and temperature- dependent manner. The involvement of the mannose receptor (MR) in the Der p 1 uptake was demonstrated by using (1) inhibitors of the MR- mediated endocytosis (mannan and blocking anti-MR mAb), which inhibited the Der p 1 uptake from 40 % to 50 %, and (2) confocal microscopy showing the colocalization of rhodamine-labeled Der p 1 with FITC-dextran. Interestingly, compared with DCs from healthy donors, DCs from allergic patients expressed more MR and were more efficient in Der p 1 uptake. These results suggest that the MR could play a key role in the Der p 1 allergen uptake by DCs and in the pathogenesis of allergic diseases in dust mite -sensitive patients.

Outer membrane protein A of Acinetobacter baumannii induces differentiation of CD4+ T cells toward a Th1 polarizing phenotype through the activation of dendritic cells.

PubMed

Lee, Jun Sik; Lee, Je Chul; Lee, Chang-Min; Jung, In Duk; Jeong, Young-Il; Seong, Eun-Young; Chung, Hae-Young; Park, Yeong-Min

2007-06-30

Acinetobacter baumannii is an increasing hospital-acquired pathogen that causes a various type of infections, but little is known about the protective immune response to this microorganism. Outer membrane protein A of A. baumannii (AbOmpA) is a major porin protein and plays an important role in pathogenesis. We analyzed interaction between AbOmpA and dendritic cells (DCs) to characterize the role of this protein in promoting innate and adaptive immune responses. AbOmpA functionally activates bone marrow-derived DCs by augmenting expression of the surface markers, CD40, CD54, B7 family (CD80 and CD86) and major histocompatibility complex class I and II. AbOmpA induces production of Th1-promoting interleukin-12 from DCs and augments the syngeneic and allogeneic immunostimulatory capacity of DCs. AbOmpA stimulates production of interferon-gamma from T cells in mixed lymphocyte reactions, which suggesting Th1-polarizing capacity. CD4(+) T cells stimulated by AbOmpA-stimulated DCs show a Th1-polarizing cytokine profile. The expression of surface markers on DCs is mediated by both mitogen-activated protein kinases and NF-kappaB pathways. Our findings suggest that AbOmpA induces maturation of DCs and drives Th1 polarization, which are important properties for determining the nature of immune response against A. baumannii.

Biophysical Properties and Motility of Human Mature Dendritic Cells Deteriorated by Vascular Endothelial Growth Factor through Cytoskeleton Remodeling

PubMed Central

Hu, Zu-Quan; Xue, Hui; Long, Jin-Hua; Wang, Yun; Jia, Yi; Qiu, Wei; Zhou, Jing; Wen, Zong-Yao; Yao, Wei-Juan; Zeng, Zhu

2016-01-01

Dendritic cells (DCs), the most potent antigen-presenting cells, play a central role in the initiation, regulation, and maintenance of the immune responses. Vascular endothelial growth factor (VEGF) is one of the important cytokines in the tumor microenvironment (TME) and can inhibit the differentiation and functional maturation of DCs. To elucidate the potential mechanisms of DC dysfunction induced by VEGF, the effects of VEGF on the biophysical characteristics and motility of human mature DCs (mDCs) were investigated. The results showed that VEGF had a negative influence on the biophysical properties, including electrophoretic mobility, osmotic fragility, viscoelasticity, and transmigration. Further cytoskeleton structure analysis by confocal microscope and gene expression profile analyses by gene microarray and real-time PCR indicated that the abnormal remodeling of F-actin cytoskeleton may be the main reason for the deterioration of biophysical properties, motility, and stimulatory capability of VEGF-treated mDCs. This is significant for understanding the biological behavior of DCs and the immune escape mechanism of tumors. Simultaneously, the therapeutic efficacies may be improved by blocking the signaling pathway of VEGF in an appropriate manner before the deployment of DC-based vaccinations against tumors. PMID:27809226

L Particles Transmit Viral Proteins from Herpes Simplex Virus 1-Infected Mature Dendritic Cells to Uninfected Bystander Cells, Inducing CD83 Downmodulation.

PubMed

Heilingloh, Christiane S; Kummer, Mirko; Mühl-Zürbes, Petra; Drassner, Christina; Daniel, Christoph; Klewer, Monika; Steinkasserer, Alexander

2015-11-01

Mature dendritic cells (mDCs) are known as the most potent antigen-presenting cells (APCs) since they are also able to prime/induce naive T cells. Thus, mDCs play a pivotal role during the induction of antiviral immune responses. Remarkably, the cell surface molecule CD83, which was shown to have costimulatory properties, is targeted by herpes simplex virus 1 (HSV-1) for viral immune escape. Infection of mDCs with HSV-1 results in downmodulation of CD83, resulting in reduced T cell stimulation. In this study, we report that not only infected mDCs but also uninfected bystander cells in an infected culture show a significant CD83 reduction. We demonstrate that this effect is independent of phagocytosis and transmissible from infected to uninfected mDCs. The presence of specific viral proteins found in these uninfected bystander cells led to the hypothesis that viral proteins are transferred from infected to uninfected cells via L particles. These L particles are generated during lytic replication in parallel with full virions, called H particles. L particles contain viral proteins but lack the viral capsid and DNA. Therefore, these particles are not infectious but are able to transfer several viral proteins. Incubation of mDCs with L particles indeed reduced CD83 expression on uninfected bystander DCs, providing for the first time evidence that functional viral proteins are transmitted via L particles from infected mDCs to uninfected bystander cells, thereby inducing CD83 downmodulation. HSV-1 has evolved a number of strategies to evade the host's immune system. Among others, HSV-1 infection of mDCs results in an inhibited T cell activation caused by degradation of CD83. Interestingly, CD83 is lost not only from HSV-1-infected mDCs but also from uninfected bystander cells. The release of so-called L particles, which contain several viral proteins but lack capsid and DNA, during infection is a common phenomenon observed among several viruses, such as human cytomegalovirus (HCMV), Epstein-Barr virus, and HSV-1. However, the detailed function of these particles is poorly understood. Here, we provide for the first time evidence that functional viral proteins can be transferred to uninfected bystander mDCs via L particles, revealing important biological functions of these particles during lytic replication. Therefore, the transfer of viral proteins by L particles to modulate uninfected bystander cells may represent an additional strategy for viral immune escape. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Targeting the Intratumoral Dendritic Cells by the Oncolytic Adenoviral Vaccine Expressing RANTES Elicits Potent Antitumor Immunity

PubMed Central

Lapteva, Natalia; Aldrich, Melissa; Weksberg, David; Rollins, Lisa; Goltsova, Tatiana; Chen, Si-Yi; Huang, Xue F.

2014-01-01

Summary Dendritic cells (DCs) are professional antigen (Ag)-presenting cells capable of inducing immune responses to tumor Ags and, therefore, play a central role in the induction of antitumor immunity. There is a large amount of evidence, however, about paucity of tumor-associated DCs and that DCs’ immunogenic functions are suppressed in a tumor environment. Here we describe a potent in situ vaccine targeting tumoral DCs in vivo. This vaccine comprised of an oncolytic adenovirus expressing RANTES (regulated upon activation, normally T expressed, and presumably secreted) (Ad-RANTES-E1A), enhanced tumor infiltration, and maturation of Ag-presenting cells in vivo. In this study, we show that intratumoral vaccinations with Ad-RANTES-E1A induced significant primary tumor growth regression and blocked metastasis formation in JC and E.G-7 murine tumor models. This vaccine recruited DCs, macrophages, natural killer cells, and CD8+ T cells to the tumor site, and thus enhanced Ag-specific cytotoxic T lymphocyte responses and natural killer cell responses. DCs purified from the Ad-RANTES-E1A–treated E.G-7 tumors secreted significantly higher levels of interferon-γ and interleukin-12, as compared with control groups and more efficiently enhanced CD8+ T-cell response. This in situ immunization strategy could be a potent antitumor immunotherapy approach for aggressive established tumors. PMID:19238013

Pattern response of dendritic cells in the tumor microenvironment and breast cancer

PubMed Central

da Cunha, Alessandra; Michelin, Marcia A; Murta, Eddie FC

2014-01-01

Breast cancer (BC) is the most common malignant neoplasm and the cause of death by cancer among women worldwide. Its development, including malignancy grade and patient prognosis, is influenced by various mutations that occur in the tumor cell and by the immune system’s status, which has a direct influence on the tumor microenvironment and, consequently, on interactions with non-tumor cells involved in the immunological response. Among the immune response cells, dendritic cells (DCs) play a key role in the induction and maintenance of anti-tumor responses owing to their unique abilities for antigen cross-presentation and promotion of the activation of specific lymphocytes that target neoplasic cells. However, the tumor microenvironment can polarize DCs, transforming them into immunosuppressive regulatory DCs, a tolerogenic phenotype which limits the activity of effector T cells and supports tumor growth and progression. Various factors and signaling pathways have been implicated in the immunosuppressive functioning of DCs in cancer, and researchers are working on resolving processes that can circumvent tumor escape and developing viable therapeutic interventions to prevent or reverse the expression of immunosuppressive DCs in the tumor microenvironment. A better understanding of the pattern of DC response in patients with BC is fundamental to the development of specific therapeutic approaches to enable DCs to function properly. Various studies examining DCs immunotherapy have demonstrated its great potential for inducing immune responses to specific antigens and thereby reversing immunosuppression and related to clinical response in patients with BC. DC-based immunotherapy research has led to immense scientific advances, both in our understanding of the anti-tumor immune response and for the treatment of these patients. PMID:25114862

Mesenchymal stem cells inhibit dendritic cell differentiation and function by preventing entry into the cell cycle.

PubMed

Ramasamy, Rajesh; Fazekasova, Henrietta; Lam, Eric W-F; Soeiro, Inês; Lombardi, Giovanna; Dazzi, Francesco

2007-01-15

Mesenchymal stem cells (MSCs) play a crucial role in hematopoietic development and have been shown to exert a powerful immunosuppressive effect. In this study, we investigated the effect of bone marrow MSC on the differentiation and function of peripheral blood monocytes into dendritic cells (DCs). Human MSCs, generated from normal bone marrow, were added to peripheral blood monocytes stimulated in vitro with granulocyte-macrophage colony stimulating factor and interleukin-4 to become DCs. Monocytes were then examined for the expression of markers characteristic of DCs and their ability to stimulate allogeneic T cells. In addition, the effect of MSCs on the cell cycle of monocyte-derived DCs and the expression of various cell cycle proteins were analyzed by cytometric analysis and Western blotting with specific antibodies. MSCs blocked the differentiation of monocytes into DCs and impaired their antigen-presenting ability. This resulted from a block of monocytes from entering the G1 phase of the cell cycle with a progressive number of cells accumulating in the G0 phase. Cyclin D2 was downregulated. However, differently from what was observed in T-cells stimulated in the presence of MSCs, the expression of p27 was found decreased, suggesting the involvement of similar but not identical pathways. We conclude that MSCs impair monocyte differentiation and function by interfering with the cell cycle. These findings imply that MSC-induced immunosuppression might be a side product of a more general antiproliferative effect.

Generation and Identification of GM-CSF Derived Alveolar-like Macrophages and Dendritic Cells From Mouse Bone Marrow

PubMed Central

Dong, Yifei; Arif, Arif A.; Poon, Grace F. T.; Hardman, Blair; Dosanjh, Manisha; Johnson, Pauline

2016-01-01

Macrophages and dendritic cells (DCs) are innate immune cells found in tissues and lymphoid organs that play a key role in the defense against pathogens. However, they are difficult to isolate in sufficient numbers to study them in detail, therefore, in vitro models have been developed. In vitro cultures of bone marrow-derived macrophages and dendritic cells are well-established and valuable methods for immunological studies. Here, a method for culturing and identifying both DCs and macrophages from a single culture of primary mouse bone marrow cells using the cytokine granulocyte macrophage colony-stimulating factor (GM-CSF) is described. This protocol is based on the established procedure first developed by Lutz et al. in 1999 for bone marrow-derived DCs. The culture is heterogeneous, and MHCII and fluoresceinated hyaluronan (FL-HA) are used to distinguish macrophages from immature and mature DCs. These GM-CSF derived macrophages provide a convenient source of in vitro derived macrophages that closely resemble alveolar macrophages in both phenotype and function. PMID:27404290

Regulation of the exopolysaccharide from an anamorph of Cordyceps sinensis on dendritic cell sarcoma (DCS) cell line.

PubMed

Song, Dan; He, Zhenyue; Wang, Chenhao; Yuan, Fengjiao; Dong, Ping; Zhang, Weiyun

2013-03-01

Cordyceps sinensis has been regarded as a precious tonic food and herbal medicine in China for thousands of years. The exopolysaccharide (EPS) from an anamorph of Cordyceps sinensis was found to have antitumor immunomodulatory activity. Mature dendritic cells play a role in initiating antitumor immunity, so we try to investigate the effects of EPS on the murine dendritic cell line DCS. Flow cytometry was used to assay the expression levels of cell surface molecules including major histocompatibility complex (MHC)-II, CD40, CD80, and CD86 of DCS cells and their ability to take up antigens. The ability of DCS cells to activate the proliferation of CTLL-2 T cells was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) method. IL-12 and TNF-α levels were detected using ELISA. Western blotting was performed to estimate the levels of phosphorylated Janus kinase 2 (p-JAK2), phosphorylated signal transducer and activator of transcription 3 (p-STAT3), nuclear factor-κB (NF-κB) p65 and p105. EPS increased the expressions of MHC-II, CD40, CD80, and CD86 of DCS cells and up-regulated their ability to take up antigens. EPS also enhanced their ability to activate the proliferation of CTLL-2 T cells. IL-12 and TNF-α secreted from DCS cells were up-regulated after EPS treatment. Furthermore, EPS significantly caused the decline of p-JAK2 and p-STAT3, significantly increased levels of NF-κB p65 in the nucleus and decreased levels of NF-κB p105 in the cytoplasm. EPS may induce DCS cells to exhibit mature characteristics, and the mechanism involved is probably related to the inhibition of the JAK2/STAT3 signal pathway and promotion of the NF-κB signal pathway.

CD40L Expression Allows CD8+ T Cells to Promote Their Own Expansion and Differentiation through Dendritic Cells

PubMed Central

Tay, Neil Q.; Lee, Debbie C. P.; Chua, Yen Leong; Prabhu, Nayana; Gascoigne, Nicholas R. J.; Kemeny, David M.

2017-01-01

CD8+ T cells play an important role in providing protective immunity against a wide range of pathogens, and a number of different factors control their activation. Although CD40L-mediated CD40 licensing of dendritic cells (DCs) by CD4+ T cells is known to be necessary for the generation of a robust CD8+ T cell response, the contribution of CD8+ T cell-expressed CD40L on DC licensing is less clear. We have previously shown that CD8+ T cells are able to induce the production of IL-12 p70 by DCs in a CD40L-dependent manner, providing some evidence that CD8+ T cell-mediated activation of DCs is possible. To better understand the role of CD40L on CD8+ T cell responses, we generated and characterized CD40L-expressing CD8+ T cells both in vitro and in vivo. We found that CD40L was expressed on 30–50% of effector CD8+ T cells when stimulated and that this expression was transient. The expression of CD40L on CD8+ T cells promoted the proliferation and differentiation of both the CD40L-expressing CD8+ T cells and the bystander effector CD8+ T cells. This process occurred via a cell-extrinsic manner and was mediated by DCs. These data demonstrate the existence of a mechanism where CD8+ T cells and DCs cooperate to maximize CD8+ T cell responses. PMID:29163545

Use of human antigen presenting cell gene array profiling to examine the effect of human T-cell leukemia virus type 1 Tax on primary human dendritic cells.

PubMed

Ahuja, Jaya; Kampani, Karan; Datta, Suman; Wigdahl, Brian; Flaig, Katherine E; Jain, Pooja

2006-02-01

Human T-cell leukemia virus type 1 (HTLV-1) is etiologically linked to adult T-cell leukemia and a progressive demyelinating disorder termed HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). One of the most striking features of the immune response in HAM/TSP centers on the expansion of HTLV-1-specific CD8(+) cytotoxic T lymphocyte (CTL) compartment in the peripheral blood and cerebrospinal fluid. More than 90% of the HTLV-1-specific CTLs are directed against the viral Tax (11-19) peptide implying that Tax is available for immune recognition by antigen presenting cells, such as dendritic cells (DCs). DCs obtained from HAM/TSP patients have been shown to be infected with HTLV-1 and exhibit rapid maturation. Therefore, we hypothesized that presentation of Tax peptides by activated DCs to naIve CD8(+) T cells may play an important role in the induction of a Tax-specific CTL response and neurologic dysfunction. In this study, a pathway-specific antigen presenting cell gene array was used to study transcriptional changes induced by exposure of monocyte-derived DCs to extracellular HTLV-1 Tax protein. Approximately 100 genes were differentially expressed including genes encoding toll-like receptors, cell surface receptors, proteins involved in antigen uptake and presentation and adhesion molecules. The differential regulation of chemokines and cytokines characteristic of functional DC activation was also observed by the gene array analyses. Furthermore, the expression pattern of signal transduction genes was also significantly altered. These results have suggested that Tax-mediated DC gene regulation might play a critical role in cellular activation and the mechanisms resulting in HTLV-1-induced disease.

TSPAN7, effector of actin nucleation required for dendritic cell-mediated transfer of HIV-1 to T cells.

PubMed

Ménager, Mickaël M

2017-06-15

Dendritic cells (DCs) have essential roles in early detection of pathogens and activation of both innate and adaptive immune responses. Whereas human DCs are resistant to productive HIV-1 replication, they have a unique ability to take up virus and transmit it efficiently to T lymphocytes. By doing that, HIV-1 may evade, at least in part, the first line of defense of the immune system, exploiting DCs instead to facilitate rapid infection of a large pool of immune cells. While performing an shRNA screen in human primary monocyte-derived DCs, to gain insights into this cell biological process, we discovered the role played by tetraspanin-7 (TSPAN7). This member of the tetraspanin family appears to be a positive regulator of actin nucleation and stabilization, through the ARP2/3 complex. By doing so, TSPAN7 limits HIV-1 endocytosis and maintains viral particles on actin-rich dendrites for an efficient transfer toward T lymphocytes. While studying the function of TSPAN7 in the control of actin nucleation, we also discovered the existence in DCs of two opposing forces at the plasma membrane: actin nucleation, a protrusive force which seems to counterbalance actomyosin contraction. © 2017 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.

Effective collaboration between marginal metallophilic macrophages and CD8+ dendritic cells in the generation of cytotoxic T cells

PubMed Central

Backer, Ronald; Schwandt, Timo; Greuter, Mascha; Oosting, Marije; Jüngerkes, Frank; Tüting, Thomas; Boon, Louis; O’Toole, Tom; Kraal, Georg; Limmer, Andreas; den Haan, Joke M. M.

2009-01-01

The spleen is the lymphoid organ that induces immune responses toward blood-borne pathogens. Specialized macrophages in the splenic marginal zone are strategically positioned to phagocytose pathogens and cell debris, but are not known to play a role in the activation of T-cell responses. Here we demonstrate that splenic marginal metallophilic macrophages (MMM) are essential for cross-presentation of blood-borne antigens by splenic dendritic cells (DCs). Our data demonstrate that antigens targeted to MMM as well as blood-borne adenoviruses are efficiently captured by MMM and exclusively transferred to splenic CD8+ DCs for cross-presentation and for the activation of cytotoxic T lymphocytes. Depletion of macrophages in the marginal zone prevents cytotoxic T-lymphocyte activation by CD8+ DCs after antibody targeting or adenovirus infection. Moreover, we show that tumor antigen targeting to MMM is very effective as antitumor immunotherapy. Our studies point to an important role for splenic MMM in the initial steps of CD8+ T-cell immunity by capturing and concentrating blood-borne antigens and the transfer to cross-presenting DCs which can be used to design vaccination strategies to induce antitumor cytotoxic T-cell immunity. PMID:20018690

Coxiella burnetii Induces Inflammatory Interferon-Like Signature in Plasmacytoid Dendritic Cells: A New Feature of Immune Response in Q Fever

PubMed Central

Ka, Mignane B.; Mezouar, Soraya; Ben Amara, Amira; Raoult, Didier; Ghigo, Eric; Olive, Daniel; Mege, Jean-Louis

2016-01-01

Plasmacytoid dendritic cells (pDCs) play a major role in antiviral immunity via the production of type I interferons (IFNs). There is some evidence that pDCs interact with bacteria but it is not yet clear whether they are protective or contribute to bacterial pathogenicity. We wished to investigate whether Coxiella burnetii, the agent of Q fever, interacts with pDCs. The stimulation of pDCs with C. burnetii increased the expression of activation and migratory markers (CD86 and CCR7) as determined by flow cytometry and modulated gene expression program as revealed by a microarray approach. Indeed, genes encoding for pro-inflammatory cytokines, chemokines, and type I INF were up-regulated. The up-regulation of type I IFN was correlated with an increase in IFN-α release by C. burnetii-stimulated pDCs. We also investigated pDCs in patients with Q fever endocarditis. Using flow cytometry and a specific gating strategy, we found that the number of circulating pDCs was significantly lower in patients with Q fever endocarditis as compared to healthy donors. In addition, the remaining circulating pDCs expressed activation and migratory markers. As a whole, our study identified non-previously reported activation of pDCs by C. burnetii and their modulation during Q fever. PMID:27446817

Enhanced Induction of T Cell Immunity Using Dendritic Cells Pulsed with HIV Tat and HCMV-pp65 Fusion Protein In Vitro

PubMed Central

Park, Jung-Sun; Park, Soo-Young; Cho, Hyun-Il; Sohn, Hyun-Jung

2011-01-01

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-γ 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. PMID:21860612

Immune responses of mature chicken bone-marrow-derived dendritic cells infected with Newcastle disease virus strains with differing pathogenicity.

PubMed

Xiang, Bin; Zhu, Wenxian; Li, Yaling; Gao, Pei; Liang, Jianpeng; Liu, Di; Ding, Chan; Liao, Ming; Kang, Yinfeng; Ren, Tao

2018-06-01

Infection of chickens with virulent Newcastle disease virus (NDV) is associated with severe pathology and increased morbidity and mortality. The innate immune response contributes to the pathogenicity of NDV. As professional antigen-presenting cells, dendritic cells (DCs) play a unique role in innate immunity. However, the contribution of DCs to NDV infection has not been investigated in chickens. In this study, we selected two representative NDV strains, i.e., the velogenic NDV strain Chicken/Guangdong/GM/2014 (GM) and the lentogenic NDV strain La Sota, to investigate whether NDVs could infect LPS-activated chicken bone-derived marrow DCs (mature chicken BM-DCs). We compared the viral titres and innate immune responses in mature chicken BM-DCs following infection with those strains. Both NDV strains could infect mature chicken BM-DC, but the GM strain showed stronger replication capacity than the La Sota strain in mature chicken BM-DCs. Gene expression profiling showed that MDA5, LGP2, TLR3, TLR7, IFN-α, IFN-β, IFN-γ, IL-1β, IL-6, IL-18, IL-8, CCL5, IL-10, IL-12, MHC-I, and MHC-II levels were altered in mature DCs after infection with NDVs at all evaluated times postinfection. Notably, the GM strain triggered stronger innate immune responses than the La Sota strain in chicken BM-DCs. However, both strains were able to suppress the expression of some cytokines, such as IL-6 and IFN-α, in mature chicken DCs at 24 hpi. These data provide a foundation for further investigation of the role of chicken DCs in NDV infection.

Streptococcus suis Serotype 2 Infection Impairs Interleukin-12 Production and the MHC-II-Restricted Antigen Presentation Capacity of Dendritic Cells

PubMed Central

Letendre, Corinne; Auger, Jean-Philippe; Lemire, Paul; Galbas, Tristan; Gottschalk, Marcelo; Thibodeau, Jacques; Segura, Mariela

2018-01-01

Streptococcus suis is an important swine pathogen and emerging zoonotic agent. Encapsulated strains of S. suis modulate dendritic cell (DC) functions, leading to poorly activated CD4+ T cells. However, the antigen presentation ability of S. suis-stimulated DCs has not been investigated yet. In this work, we aimed to characterize the antigen presentation profiles of S. suis-stimulated DCs, both in vitro and in vivo. Upon direct activation in vitro, S. suis-stimulated murine bone marrow-derived DCs (bmDCs) preserved their antigen capture/processing capacities. However, they showed delayed kinetics of MHC-II expression compared to lipopolysaccharide-stimulated bmDCs. Meanwhile, splenic DCs from infected mice exhibited a compromised MHC-II expression, despite an appropriate expression of maturation markers. To identify potential interfering mechanisms, Class II Major Histocompatibility Complex Transactivator (CIITA) and membrane-associated RING-CH (MARCH)1/8 transcription were studied. S. suis-stimulated DCs maintained low levels of CIITA at early time points, both in vitro and in vivo, which could limit their ability to increase MHC-II synthesis. S. suis-stimulated DCs also displayed sustained/upregulated levels of MARCH1/8, thus possibly leading to MHC-II lysosomal degradation. The bacterial capsular polysaccharide played a partial role in this modulation. Finally, interleukin (IL)-12p70 production was inhibited in splenic DCs from infected mice, a profile compatible with DC indirect activation by pro-inflammatory compounds. Consequently, these cells induced lower levels of IL-2 and TNF-α in an antigen-specific CD4+ T cell presentation assay and blunted T cell CD25 expression. It remains unclear at this stage whether these phenotypical and transcriptional modulations observed in response to S. suis in in vivo infections are part of a bacterial immune evasion strategy or rather a feature common to systemic inflammatory response-inducing agents. However, it appears that the MHC-II-restricted antigen presentation and Th1-polarizing cytokine production capacities of DCs are impaired during S. suis infection. This study highlights the potential consequences of inflammation on the type and magnitude of the immune response elicited by a pathogen. PMID:29899744

Vascular endothelial growth factor-A enhances indoleamine 2,3-dioxygenase expression by dendritic cells and subsequently impacts lymphocyte proliferation

PubMed Central

Marti, Luciana Cavalheiro; Pavon, Lorena; Severino, Patricia; Sibov, Tatiana; Guilhen, Daiane; Moreira-Filho, Carlos Alberto

2013-01-01

Dendritic cells (DCs) are antigen (Ag)-presenting cells that activate and stimulate effective immune responses by T cells, but can also act as negative regulators of these responses and thus play important roles in immune regulation. Pro-angiogenic vascular endothelial growth factor (VEGF) has been shown to cause defective DC differentiation and maturation. Previous studies have demonstrated that the addition of VEGF to DC cultures renders these cells weak stimulators of Ag-specific T cells due to the inhibitory effects mediated by VEGF receptor 1 (VEGFR1) and/or VEGFR2 signalling. As the enzyme indoleamine 2,3-dioxygenase (IDO) is recognised as an important negative regulator of immune responses, this study aimed to investigate whether VEGF affects the expression of IDO by DCs and whether VEGF-matured DCs acquire a suppressor phenotype. Our results are the first to demonstrate that VEGF increases the expression and activity of IDO in DCs, which has a suppressive effect on Ag-specific and mitogen-stimulated lymphocyte proliferation. These mechanisms have broad implications for the study of immunological responses and tolerance under conditions as diverse as cancer, graft rejection and autoimmunity. PMID:24141959

Interleukin-10 reorganizes the cytoskeleton of mature dendritic cells leading to their impaired biophysical properties and motilities.

PubMed

Xu, Xiaoli; Liu, Xianmei; Long, Jinhua; Hu, Zuquan; Zheng, Qinni; Zhang, Chunlin; Li, Long; Wang, Yun; Jia, Yi; Qiu, Wei; Zhou, Jing; Yao, Weijuan; Zeng, Zhu

2017-01-01

Interlukin-10 (IL-10) is an immunomodulatory cytokine which predominantly induces immune-tolerance. It has been also identified as a major cytokine in the tumor microenvironment that markedly mediates tumor immune escape. Previous studies on the roles of IL-10 in tumor immunosuppression mainly focus on its biochemical effects. But the effects of IL-10 on the biophysical characteristics of immune cells are ill-defined. Dendritic cells (DCs) are the most potent antigen-presenting cells and play a key role in the anti-tumor immune response. IL-10 can affect the immune regulatory functions of DCs in various ways. In this study, we aim to explore the effects of IL-10 on the biophysical functions of mature DCs (mDCs). mDCs were treated with different concentrations of IL-10 and their biophysical characteristics were identified. The results showed that the biophysical properties of mDCs, including electrophoresis mobility, osmotic fragility and deformability, as well as their motilities, were impaired by IL-10. Meanwhile, the cytoskeleton (F-actin) of mDCs was reorganized by IL-10. IL-10 caused the alternations in the expressions of fasin1 and profilin1 as well as the phosphorylation of cofilin1 in a concentration-dependent fashion. Moreover, Fourier transformed infrared resonance data showed that IL-10 made the status of gene transcription and metabolic turnover of mDCs more active. These results demonstrate a new aspect of IL-10's actions on the immune system and represent one of the mechanisms for immune escape of tumors. It may provide a valuable clue to optimize and improve the efficiency of DC-based immunotherapy against cancer.

Nonspreading Rift Valley Fever Virus Infection of Human Dendritic Cells Results in Downregulation of CD83 and Full Maturation of Bystander Cells.

PubMed

Oreshkova, Nadia; Wichgers Schreur, Paul J; Spel, Lotte; Vloet, Rianka P M; Moormann, Rob J M; Boes, Marianne; Kortekaas, Jeroen

2015-01-01

Vaccines based on nonspreading Rift Valley fever virus (NSR) induce strong humoral and robust cellular immune responses with pronounced Th1 polarisation. The present work was aimed to gain insight into the molecular basis of NSR-mediated immunity. Recent studies have demonstrated that wild-type Rift Valley fever virus efficiently targets and replicates in dendritic cells (DCs). We found that NSR infection of cultured human DCs results in maturation of DCs, characterized by surface upregulation of CD40, CD80, CD86, MHC-I and MHC-II and secretion of the proinflammatory cytokines IFN-β, IL-6 and TNF. Interestingly, expression of the most prominent marker of DC maturation, CD83, was consistently downregulated at 24 hours post infection. Remarkably, NSR infection also completely abrogated CD83 upregulation by LPS. Downregulation of CD83 was not associated with reduced mRNA levels or impaired CD83 mRNA transport from the nucleus and could not be prevented by inhibition of the proteasome or endocytic degradation pathways, suggesting that suppression occurs at the translational level. In contrast to infected cells, bystander DCs displayed full maturation as evidenced by upregulation of CD83. Our results indicate that bystander DCs play an important role in NSR-mediated immunity.

Differential infection outcome of Chlamydia trachomatis in human blood monocytes and monocyte-derived dendritic cells

PubMed Central

2014-01-01

Background Chlamydia trachomatis is an intracellular bacteria which consist of three biovariants; trachoma (serovars A-C), urogenital (serovars D-K) and lymphogranuloma venereum (L1-L3), causing a wide spectrum of disease in humans. Monocytes are considered to disseminate this pathogen throughout the body while dendritic cells (DCs) play an important role in mediating immune response against bacterial infection. To determine the fate of C. trachomatis within human peripheral blood monocytes and monocyte-derived DCs, these two sets of immune cells were infected with serovars Ba, D and L2, representative of the three biovariants of C. trachomatis. Results Our study revealed that the different serovars primarily infect monocytes and DCs in a comparable fashion, however undergo differential infection outcome, serovar L2 being the only candidate to inflict active infection. Moreover, the C. trachomatis serovars Ba and D become persistent in monocytes while the serovars predominantly suffer degradation within DCs. Effects of persistence gene Indoleamine 2, 3-dioxygenase (IDO) was not clearly evident in the differential infection outcome. The heightened levels of inflammatory cytokines secreted by the chlamydial infection in DCs compared to monocytes seemed to be instrumental for this consequence. The immune genes induced in monocytes and DCs against chlamydial infection involves a different set of Toll-like receptors, indicating that distinct intracellular signalling pathways are adopted for immune response. Conclusion Our results demonstrate that the host pathogen interaction in chlamydia infection is not only serovar specific but manifests cell specific features, inducing separate immune response cascade in monocytes and DCs. PMID:25123797

Immune complexes stimulate CCR7-dependent dendritic cell migration to lymph nodes

PubMed Central

Clatworthy, Menna R.; Aronin, Caren E. Petrie; Mathews, Rebeccah J.; Morgan, Nicole; Smith, Kenneth G.C.; Germain, Ronald N.

2014-01-01

Antibodies are critical for defence against a variety of microbes but may also be pathogenic in some autoimmune diseases. Many effector functions of antibody are mediated by Fcγ receptors (FcγRs), which are found on most immune cells, including dendritic cells (DCs). DCs are important antigen presenting cells and play a central role in inducing antigen-specific tolerance or immunity1,2. Following antigen acquisition in peripheral tissues, DCs migrate to draining lymph nodes via lymphatics to present antigen to T cells. In this study we demonstrate that FcγR engagement by IgG immune complexes (IC) stimulates DC migration from peripheral tissues to the paracortex of draining lymph nodes. In vitro, IC-stimulated murine and human DCs showed enhanced directional migration in a CCL19 gradient and increased CCR7 expression. Using intravital two-photon microscopy, we observed that local administration of IC resulted in dermal DC mobilisation. We confirmed that dermal DC migration to lymph nodes was CCR7-dependent and increased in the absence of the inhibitory receptor, FcγRIIb. These observations have relevance to autoimmunity, because autoantibody-containing serum from mice and humans with SLE also increased dermal DC migration to lymph nodes in vivo, suggesting that this process may occur in lupus, potentially driving the inappropriate localisation of autoantigen-bearing DCs. PMID:25384086

Plasmacytoid Dendritic Cells in the Tumor Microenvironment: Immune Targets for Glioma Therapeutics12

PubMed Central

Candolfi, Marianela; King, Gwendalyn D; Yagiz, Kader; Curtin, James F; Mineharu, Yohei; Muhammad, AKM Ghulam; Foulad, David; Kroeger, Kurt M; Barnett, Nick; Josien, Regis; Lowenstein, Pedro R; Castro, Maria G

2012-01-01

Adenovirus-mediated delivery of the immune-stimulatory cytokine Flt3L and the conditionally cytotoxic thymidine kinase (TK) induces tumor regression and long-term survival in preclinical glioma (glioblastoma multiforme [GBM]) models. Flt3L induces expansion and recruitment of plasmacytoid dendritic cells (pDCs) into the brain. Although pDCs can present antigen and produce powerful inflammatory cytokines, that is, interferon α (IFN-α), their role in tumor immunology remains debated. Thus, we studied the role of pDCs and IFN-α in Ad.TK/GCV+ Ad.Flt3L-mediated anti-GBM therapeutic efficacy. Our data indicate that the combined gene therapy induced recruitment of plasmacytoid DCs (pDCs) into the tumor mass; which were capable of in vivo phagocytosis, IFN-α release, and T-cell priming. Thus, we next used either pDCs or an Ad vector encoding IFN-α delivered within the tumor microenvironment. When rats were treated with Ad.TK/GCV in combination with pDCs or Ad-IFN-α, they exhibited 35% and 50% survival, respectively. However, whereas intracranial administration of Ad.TK/GCV + Ad.Flt3L exhibited a high safety profile, Ad-IFN-α led to severe local inflammation, with neurologic and systemic adverse effects. To elucidate whether the efficacy of the immunotherapy was dependent on IFN-α-secreting pDCs, we administered an Ad vector encoding B18R, an IFN-α antagonist, which abrogated the antitumoral effect of Ad.TK/GCV + Ad.Flt3L. Our data suggest that IFN-α release by activated pDCs plays a critical role in the antitumor effect mediated by Ad.TK/GCV + Ad.Flt3L. In summary, taken together, our results demonstrate that pDCs mediate anti-GBM therapeutic efficacy through the production of IFN-α, thus manipulation of pDCs constitutes an attractive new therapeutic target for the treatment of GBM. PMID:22952428

Severe necroinflammatory reaction caused by natural killer cell-mediated Fas/Fas ligand interaction and dendritic cells in human hepatocyte chimeric mouse.

PubMed

Okazaki, Akihito; Hiraga, Nobuhiko; Imamura, Michio; Hayes, C Nelson; Tsuge, Masataka; Takahashi, Shoichi; Aikata, Hiroshi; Abe, Hiromi; Miki, Daiki; Ochi, Hidenori; Tateno, Chise; Yoshizato, Katsutoshi; Ohdan, Hideki; Chayama, Kazuaki

2012-08-01

The necroinflammatory reaction plays a central role in hepatitis B virus (HBV) elimination. Cluster of differentiation (CD)8-positive cytotoxic T lymphocytes (CTLs) are thought to be a main player in the elimination of infected cells, and a recent report suggests that natural killer (NK) cells also play an important role. Here, we demonstrate the elimination of HBV-infected hepatocytes by NK cells and dendritic cells (DCs) using urokinase-type plasminogen activator/severe combined immunodeficiency mice, in which the livers were highly repopulated with human hepatocytes. After establishing HBV infection, we injected human peripheral blood mononuclear cells (PBMCs) into the mice and analyzed liver pathology and infiltrating human immune cells with flow cytometry. Severe hepatocyte degeneration was observed only in HBV-infected mice transplanted with human PBMCs. We provide the first direct evidence that massive liver cell death can be caused by Fas/Fas ligand (FasL) interaction provided by NK cells activated by DCs. Treatment of mice with anti-Fas antibody completely prevented severe hepatocyte degeneration. Furthermore, severe hepatocyte death can be prevented by depletion of DCs, whereas depletion of CD8-positive CTLs did not disturb the development of massive liver cell apoptosis. Our findings provide the first direct evidence that DC-activated NK cells induce massive HBV-infected hepatocyte degeneration through the Fas/FasL system and may indicate new therapeutic implications for acute severe/fulminant hepatitis B. Copyright © 2012 American Association for the Study of Liver Diseases.

Characterization of porcine CD205

USDA-ARS?s Scientific Manuscript database

Dendritic cells (DC) express a cell-surface receptor, CD205, that plays a role in antigen capture and delivery to the endocytic pathway. Besides DCs, high CD205 expression is also detected on thymic epithelial cells, but B cells, macrophages, and T cells have limited or no expression. CD205 has be...

Dendritic Cell Response to HIV-1 Is Controlled by Differentiation Programs in the Cells and Strain-Specific Properties of the Virus.

PubMed

Nasi, Aikaterini; Amu, Sylvie; Göthlin, Mårten; Jansson, Marianne; Nagy, Noemi; Chiodi, Francesca; Réthi, Bence

2017-01-01

Dendritic cells (DCs) are potent antigen-presenting cells that might play contradictory roles during HIV-1 infection, contributing not only to antiviral immunity but also to viral dissemination and immune evasion. Although DCs are characterized by enormous functional diversity, it has not been analyzed how differentially programmed DCs interact with HIV-1. We have previously described the reprogramming of DC development by endogenously produced lactic acid that accumulated in a cell culture density-dependent manner and provided a long-lasting anti-inflammatory signal to the cells. By exploiting this mechanism, we generated immunostimulatory DCs characterized by the production of TH1 polarizing and inflammatory mediators or, alternatively, suppressed DCs that produce IL-10 upon activation, and we tested the interaction of these DC types with different HIV-1 strains. Cytokine patterns were monitored in HIV-1-exposed DC cultures. Our results showed that DCs receiving suppressive developmental program strongly upregulated their capacity to produce the TH1 polarizing cytokine IL-12 and the inflammatory chemokines CCL2 and CCL7 upon interaction with HIV-1 strains IIIB and SF162. On the contrary, HIV-1 abolished cytokine production in the more inflammatory DC types. Preincubation of the cells with the HIV-1 proteins gp120 and Nef could inhibit IL-12 production irrespectively of the tested DC types, whereas MyD88- and TRIF-dependent signals stimulated IL-12 production in the suppressed DC type only. Rewiring of DC cytokines did not require DC infections or ligation of the HIV-1 receptor CD209. A third HIV-1 strain, BaL, could not modulate DC cytokines in a similar manner indicating that individual HIV-1 strains can differ in their capacity to influence DCs. Our results demonstrated that HIV-1 could not induce definite and invariable modulatory programs in DCs. Instead, interaction with the virus triggered different responses in different DC types. Thus, the outcome of DC-HIV-1 interactions might be highly variable, shaped by endogenous features of the cells and diversity of the virus.

Dendritic Cell Response to HIV-1 Is Controlled by Differentiation Programs in the Cells and Strain-Specific Properties of the Virus

PubMed Central

Nasi, Aikaterini; Amu, Sylvie; Göthlin, Mårten; Jansson, Marianne; Nagy, Noemi; Chiodi, Francesca; Réthi, Bence

2017-01-01

Dendritic cells (DCs) are potent antigen-presenting cells that might play contradictory roles during HIV-1 infection, contributing not only to antiviral immunity but also to viral dissemination and immune evasion. Although DCs are characterized by enormous functional diversity, it has not been analyzed how differentially programmed DCs interact with HIV-1. We have previously described the reprogramming of DC development by endogenously produced lactic acid that accumulated in a cell culture density-dependent manner and provided a long-lasting anti-inflammatory signal to the cells. By exploiting this mechanism, we generated immunostimulatory DCs characterized by the production of TH1 polarizing and inflammatory mediators or, alternatively, suppressed DCs that produce IL-10 upon activation, and we tested the interaction of these DC types with different HIV-1 strains. Cytokine patterns were monitored in HIV-1-exposed DC cultures. Our results showed that DCs receiving suppressive developmental program strongly upregulated their capacity to produce the TH1 polarizing cytokine IL-12 and the inflammatory chemokines CCL2 and CCL7 upon interaction with HIV-1 strains IIIB and SF162. On the contrary, HIV-1 abolished cytokine production in the more inflammatory DC types. Preincubation of the cells with the HIV-1 proteins gp120 and Nef could inhibit IL-12 production irrespectively of the tested DC types, whereas MyD88- and TRIF-dependent signals stimulated IL-12 production in the suppressed DC type only. Rewiring of DC cytokines did not require DC infections or ligation of the HIV-1 receptor CD209. A third HIV-1 strain, BaL, could not modulate DC cytokines in a similar manner indicating that individual HIV-1 strains can differ in their capacity to influence DCs. Our results demonstrated that HIV-1 could not induce definite and invariable modulatory programs in DCs. Instead, interaction with the virus triggered different responses in different DC types. Thus, the outcome of DC-HIV-1 interactions might be highly variable, shaped by endogenous features of the cells and diversity of the virus. PMID:28348557

Engaging the CD40-CD40L pathway augments T-helper cell responses and improves control of Mycobacterium tuberculosis infection

PubMed Central

Bizzell, Erica; Madan-Lala, Ranjna

2017-01-01

Mycobacterium tuberculosis (Mtb) impairs dendritic cell (DC) functions and induces suboptimal antigen-specific CD4 T cell immune responses that are poorly protective. Mucosal T-helper cells producing IFN-γ (Th1) and IL-17 (Th17) are important for protecting against tuberculosis (TB), but the mechanisms by which DCs generate antigen-specific T-helper responses during Mtb infection are not well defined. We previously reported that Mtb impairs CD40 expression on DCs and restricts Th1 and Th17 responses. We now demonstrate that CD40-dependent costimulation is required to generate IL-17 responses to Mtb. CD40-deficient DCs were unable to induce antigen-specific IL-17 responses after Mtb infection despite the production of Th17-polarizing innate cytokines. Disrupting the interaction between CD40 on DCs and its ligand CD40L on antigen-specific CD4 T cells, genetically or via antibody blockade, significantly reduced antigen-specific IL-17 responses. Importantly, engaging CD40 on DCs with a multimeric CD40 agonist (CD40LT) enhanced antigen-specific IL-17 generation in ex vivo DC-T cell co-culture assays. Further, intratracheal instillation of Mtb-infected DCs treated with CD40LT significantly augmented antigen-specific Th17 responses in vivo in the lungs and lung-draining lymph nodes of mice. Finally, we show that boosting CD40-CD40L interactions promoted balanced Th1/Th17 responses in a setting of mucosal DC transfer, and conferred enhanced control of lung bacterial burdens following aerosol challenge with Mtb. Our results demonstrate that CD40 costimulation by DCs plays an important role in generating antigen-specific Th17 cells and targeting the CD40-CD40L pathway represents a novel strategy to improve adaptive immunity to TB. PMID:28767735

Versatile polyion complex micelles for peptide and siRNA vectorization to engineer tolerogenic dendritic cells.

PubMed

Mebarek, Naila; Vicente, Rita; Aubert-Pouëssel, Anne; Quentin, Julie; Mausset-Bonnefont, Anne-Laure; Devoisselle, Jean-Marie; Jorgensen, Christian; Bégu, Sylvie; Louis-Plence, Pascale

2015-05-01

Dendritic cells (DCs) are professional antigen-presenting cells that play a critical role in maintaining the balance between immunity and tolerance and, as such are a promising immunotherapy tool to induce immunity or to restore tolerance. The main challenge to harness the tolerogenic properties of DCs is to preserve their immature phenotype. We recently developed polyion complex micelles, formulated with double hydrophilic block copolymers of poly(methacrylic acid) and poly(ethylene oxide) blocks and able to entrap therapeutic molecules, which did not induce DC maturation. In the current study, the intrinsic destabilizing membrane properties of the polymers were used to optimize endosomal escape property of the micelles in order to propose various strategies to restore tolerance. On the first hand, we showed that high molecular weight (Mw) copolymer-based micelles were efficient to favor the release of the micelle-entrapped peptide into the endosomes, and thus to improve peptide presentation by immature (i) DCs. On the second hand, we put in evidence that low Mw copolymer-based micelles were able to favor the cytosolic release of micelle-entrapped small interfering RNAs, dampening the DCs immunogenicity. Therefore, we demonstrate the versatile use of polyionic complex micelles to preserve tolerogenic properties of DCs. Altogether, our results underscored the potential of such micelle-loaded iDCs as a therapeutic tool to restore tolerance in autoimmune diseases. Copyright © 2015 Elsevier B.V. All rights reserved.

Dendritic Cell Subset Distributions in the Aorta in Healthy and Atherosclerotic Mice

PubMed Central

Lutz, Manfred B.; Zernecke, Alma

2014-01-01

Dendritic cells (DCs) can be sub-divided into various subsets that play specialized roles in priming of adaptive immune responses. Atherosclerosis is regarded as a chronic inflammatory disease of the vessel wall and DCs can be found in non-inflamed and diseased arteries. We here performed a systematic analyses of DCs subsets during atherogenesis. Our data indicate that distinct DC subsets can be localized in the vessel wall. In C57BL/6 and low density lipoprotein receptor-deficient (Ldlr −/−) mice, CD11c+ MHCII+ DCs could be discriminated into CD103− CD11b+F4/80+, CD11b+F4/80− and CD11b−F4/80− DCs and CD103+ CD11b−F4/80− DCs. Except for CD103− CD11b− F4/80− DCs, these subsets expanded in high fat diet-fed Ldlr −/− mice. Signal-regulatory protein (Sirp)-α was detected on aortic macrophages, CD11b+ DCs, and partially on CD103− CD11b− F4/80− but not on CD103+ DCs. Notably, in FMS-like tyrosine kinase 3-ligand-deficient (Flt3l −/−) mice, a specific loss of CD103+ DCs but also CD103− CD11b+ F4/80− DCs was evidenced. Aortic CD103+ and CD11b+ F4/80− CD103− DCs may thus belong to conventional rather than monocyte-derived DCs, given their dependence on Flt3L-signalling. CD64, postulated to distinguish macrophages from DCs, could not be detected on DC subsets under physiological conditions, but appeared in a fraction of CD103− CD11b+ F4/80− and CD11b+ F4/80+ cells in atherosclerotic Ldlr −/− mice. The emergence of CD64 expression in atherosclerosis may indicate that CD11b+ F4/80− DCs similar to CD11b+ F4/80+ DCs are at least in part derived from immigrated monocytes during atherosclerotic lesion formation. Our data advance our knowledge about the presence of distinct DC subsets and their accumulation characteristics in atherosclerosis, and may help to assist in future studies aiming at specific DC-based therapeutic strategies for the treatment of chronic vascular inflammation. PMID:24551105

On/off TLR signaling decides proinflammatory or tolerogenic dendritic cell maturation upon CD1d-mediated interaction with invariant NKT cells.

PubMed

Caielli, Simone; Conforti-Andreoni, Cristina; Di Pietro, Caterina; Usuelli, Vera; Badami, Ester; Malosio, Maria Luisa; Falcone, Marika

2010-12-15

Invariant NKT (iNKT) cells play an effector/adjuvant function during antimicrobial and antitumoral immunity and a regulatory role to induce immune tolerance and prevent autoimmunity. iNKT cells that differentially modulate adaptive immunity do not bear a unique phenotype and/or specific cytokine secretion profile, thus opening questions on how a single T cell subset can exert opposite immunological tasks. In this study, we show that iNKT cells perform their dual roles through a single mechanism of action relying on the cognate interaction with myeloid dendritic cells (DCs) and leading to opposite effects depending on the presence of other maturation stimuli simultaneously acting on DCs. The contact of murine purified iNKT cells with immature autologous DCs directly triggers the tolerogenic maturation of DCs, rendering them able to induce regulatory T cell differentiation and prevent autoimmune diabetes in vivo. Conversely, the interaction of the same purified iNKT cells with DCs, in the presence of simultaneous TLR4 stimulation, significantly enhances proinflammatory DC maturation and IL-12 secretion. The different iNKT cell effects are mediated through distinct mechanisms and activation of different molecular pathways within the DC: CD1d signaling and activation of the ERK1/2 pathway for the tolerogenic action, and CD40-CD40L interaction and NF-κB activation for the adjuvant effect. Our data suggest that the DC decision to undergo proinflammatory or tolerogenic maturation results from the integration of different signals received at the time of iNKT cell contact and could have important therapeutic implications for exploiting iNKT cell adjuvant/regulatory properties in autoimmune diseases, infections, and cancer.

Intratumoral injection of IFN-alpha dendritic cells after dacarbazine activates anti-tumor immunity: results from a phase I trial in advanced melanoma.

PubMed

Rozera, Carmela; Cappellini, Giancarlo Antonini; D'Agostino, Giuseppina; Santodonato, Laura; Castiello, Luciano; Urbani, Francesca; Macchia, Iole; Aricò, Eleonora; Casorelli, Ida; Sestili, Paola; Montefiore, Enrica; Monque, Domenica; Carlei, Davide; Napolitano, Mariarosaria; Rizza, Paola; Moschella, Federica; Buccione, Carla; Belli, Roberto; Proietti, Enrico; Pavan, Antonio; Marchetti, Paolo; Belardelli, Filippo; Capone, Imerio

2015-05-02

Advanced melanoma patients have an extremely poor long term prognosis and are in strong need of new therapies. The recently developed targeted therapies have resulted in a marked antitumor effect, but most responses are partial and some degree of toxicity remain the major concerns. Dendritic cells play a key role in the activation of the immune system and have been typically used as ex vivo antigen-loaded cell drugs for cancer immunotherapy. Another approach consists in intratumoral injection of unloaded DCs that can exploit the uptake of a wider array of tumor-specific and individual unique antigens. However, intratumoral immunization requires DCs endowed at the same time with properties typically belonging to both immature and mature DCs (i.e. antigen uptake and T cell priming). DCs generated in presence of interferon-alpha (IFN-DCs), due to their features of partially mature DCs, capable of efficiently up-taking, processing and cross-presenting antigens to T cells, could successfully carry out this task. Combining intratumoral immunization with tumor-destructing therapies can induce antigen release in situ, facilitating the injected DCs in triggering an antitumor immune response. We tested in a phase I clinical study in advanced melanoma a chemo-immunotherapy approach based on unloaded IFN-DCs injected intratumorally one day after administration of dacarbazine. Primary endpoint of the study was treatment safety and tolerability. Secondary endpoints were immune and clinical responses of patients. Six patients were enrolled, and only three completed the treatment. The chemo-immunotherapy was well tolerated with no major side effects. Three patients showed temporary disease stabilization and two of them showed induction of T cells specific for tyrosinase, NY-ESO-1 and gp100. Of interest, one patient showing a remarkable long-term disease stabilization kept showing presence of tyrosinase specific T cells in PBMC and high infiltration of memory T cells in the tumor lesion at 21 months. We tested a chemo-immunotherapeutic approach based on IFN-DCs injected intratumorally one day after DTIC in advanced melanoma. The treatment was well tolerated, and clinical and immunological responses, including development of vitiligo, were observed, therefore warranting additional clinical studies aimed at evaluating efficacy of this approach. Trial Registration Number not publicly available due to EudraCT regulations: https://www.clinicaltrialsregister.eu/doc/EU_CTR_FAQ.pdf.

Adaptive Regulation of Osteopontin Production by Dendritic Cells Through the Bidirectional Interaction With Mesenchymal Stromal Cells.

PubMed

Scutera, Sara; Salvi, Valentina; Lorenzi, Luisa; Piersigilli, Giorgia; Lonardi, Silvia; Alotto, Daniela; Casarin, Stefania; Castagnoli, Carlotta; Dander, Erica; D'Amico, Giovanna; Sozzani, Silvano; Musso, Tiziana

2018-01-01

Mesenchymal stromal cells (MSCs) exert immunosuppressive effects on immune cells including dendritic cells (DCs). However, many details of the bidirectional interaction of MSCs with DCs are still unsolved and information on key molecules by which DCs can modulate MSC functions is limited. Here, we report that osteopontin (OPN), a cytokine involved in homeostatic and pathophysiologic responses, is constitutively expressed by DCs and regulated in the DC/MSC cocultures depending on the activation state of MSCs. Resting MSCs promoted OPN production, whereas the production of OPN was suppressed when MSCs were activated by proinflammatory cytokines (i.e., TNF-α, IL-6, and IL-1β). OPN induction required cell-to-cell contact, mediated at least in part, by β1 integrin (CD29). Conversely, activated MSCs inhibited the release of OPN via the production of soluble factors with a major role played by Prostaglandin E 2 (PGE 2 ). Accordingly, pretreatment with indomethacin significantly abrogated the MSC-mediated suppression of OPN while the direct addition of exogenous PGE 2 inhibited OPN production by DCs. Furthermore, DC-conditioned medium promoted osteogenic differentiation of MSCs with a concomitant inhibition of adipogenesis. These effects were paralleled by the repression of the adipogenic markers PPARγ, adiponectin, and FABP4, and induction of the osteogenic markers alkaline phosphatase, RUNX2, and of the bone-anabolic chemokine CCL5. Notably, blocking OPN activity with RGD peptides or with an antibody against CD29, one of the OPN receptors, prevented the effects of DC-conditioned medium on MSC differentiation and CCL5 induction. Because MSCs have a key role in maintenance of bone marrow (BM) hematopoietic stem cell niche through reciprocal regulation with immune cells, we investigated the possible MSC/DC interaction in human BM by immunohistochemistry. Although DCs (CD1c + ) are a small percentage of BM cells, we demonstrated colocalization of CD271 + MSCs with CD1c + DCs in normal and myelodysplastic BM. OPN reactivity was observed in occasional CD1c + cells in the proximity of CD271 + MSCs. Altogether, these results candidate OPN as a signal modulated by MSCs according to their activation status and involved in DC regulation of MSC differentiation.

Glycation of a food allergen by the Maillard reaction enhances its T-cell immunogenicity: role of macrophage scavenger receptor class A type I and II.

PubMed

Ilchmann, Anne; Burgdorf, Sven; Scheurer, Stephan; Waibler, Zoe; Nagai, Ryoji; Wellner, Anne; Yamamoto, Yasuhiko; Yamamoto, Hiroshi; Henle, Thomas; Kurts, Christian; Kalinke, Ulrich; Vieths, Stefan; Toda, Masako

2010-01-01

The Maillard reaction occurs between reducing sugars and proteins during thermal processing of foods. It produces chemically glycated proteins termed advanced glycation end products (AGEs). The glycation structures of AGEs are suggested to function as pathogenesis-related immune epitopes in food allergy. This study aimed at defining the T-cell immunogenicity of food AGEs by using ovalbumin (OVA) as a model allergen. AGE-OVA was prepared by means of thermal processing of OVA in the presence of glucose. Activation of OVA-specific CD4(+) T cells by AGE-OVA was evaluated in cocultures with bone marrow-derived murine myeloid dendritic cells (mDCs) as antigen-presenting cells. The uptake mechanisms of mDCs for AGE-OVA were investigated by using inhibitors of putative cell-surface receptors for AGEs, as well as mDCs deficient for these receptors. Compared with the controls (native OVA and OVA thermally processed without glucose), AGE-OVA enhanced the activation of OVA-specific CD4(+) T cells on coculture with mDCs, indicating that the glycation of OVA enhanced the T-cell immunogenicity of the allergen. The mDC uptake of AGE-OVA was significantly higher than that of the controls. We identified scavenger receptor class A type I and II (SR-AI/II) as a mediator of the AGE-OVA uptake, whereas the receptor for AGEs and galectin-3 were not responsible. Importantly, the activation of OVA-specific CD4(+) T cells by AGE-OVA was attenuated on coculture with SR-AI/II-deficient mDCs. SR-AI/II targets AGE-OVA to the MHC class II loading pathway in mDCs, leading to an enhanced CD4(+) T-cell activation. The Maillard reaction might thus play an important role in the T-cell immunogenicity of food allergens. Copyright 2010 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

Deletion of BCG Hip1 protease enhances dendritic cell and CD4 T cell responses.

PubMed

Bizzell, Erica; Sia, Jonathan Kevin; Quezada, Melanie; Enriquez, Ana; Georgieva, Maria; Rengarajan, Jyothi

2018-04-01

Dendritic cells (DCs) play a key role in the generation of CD4 T cell responses to pathogens. Mycobacterium tuberculosis (Mtb) harbors immune evasion mechanisms that impair DC responses and prevent optimal CD4 T cell immunity. The vaccine strain Mycobacterium bovis Bacille Calmette-Guérin (BCG) shares many of the immune evasion proteins utilized by Mtb, but the role of these proteins in DC and T cell responses elicited by BCG is poorly understood. We previously reported that the Mtb serine protease, Hip1, promotes sub-optimal DC responses during infection. Here, we tested the hypothesis that BCG Hip1 modulates DC functions and prevents optimal antigen-specific CD4 T cell responses that limit the immunogenicity of BCG. We generated a strain of BCG lacking hip1 (BCGΔhip1) and show that it has superior capacity to induce DC maturation and cytokine production compared with the parental BCG. Furthermore, BCGΔhip1-infected DCs were more effective at driving the production of IFN-γ and IL-17 from antigen-specific CD4 T cells in vitro. Mucosal transfer of BCGΔhip1-infected DCs into mouse lungs induced robust CD4 T cell activation in vivo and generated antigen-specific polyfunctional CD4 T cell responses in the lungs. Importantly, BCGΔhip1-infected DCs enhanced control of pulmonary bacterial burden following Mtb aerosol challenge compared with the transfer of BCG-infected DCs. These results reveal that BCG employs Hip1 to impair DC activation, leading to attenuated lung CD4 T cell responses with limited capacity to control Mtb burden after challenge. ©2017 Society for Leukocyte Biology.

Th2 polarization by Der p 1--pulsed monocyte-derived dendritic cells is due to the allergic status of the donors.

PubMed

Hammad, H; Charbonnier, A S; Duez, C; Jacquet, A; Stewart, G A; Tonnel, A B; Pestel, J

2001-08-15

The polarization of the immune response toward a Th2 or a Th1 profile can be mediated by dendritic cells (DCs) following antigen presentation and interaction with T cells. Costimulatory molecules such as CD80 and CD86 expressed by DCs, the polarizing cytokine environment during DC--T-cell interaction, and also the nature of the antigen are critical in the orientation of the immune response. In this study, the effect of the cysteine protease Der p 1, one of the major allergens of the house dust mite Dermatophagoides pteronyssinus, on these different parameters was evaluated comparatively on monocyte-derived DCs obtained from healthy donors, from pollen-sensitive patients, or from patients sensitive to Dermatophagoides pteronyssinus. Results showed that Der p 1 induced an increase in CD86 expression only on DCs from house dust mite--sensitive patients. This was also associated with a higher capacity to induce T-cell proliferation, a rapid increase in the production of proinflammatory cytokines, tumor necrosis factor--alpha and interleukin (IL)-1 beta, and the type 2 cytokine IL-10. No changes in the release of IL-12 p70 were induced by Der p 1. Finally, purified T cells from house dust mite-sensitive patients stimulated by autologous Der p 1--pulsed DCs preferentially produced IL-4 rather than interferon-gamma. These effects were abolished in the presence of the inactive precursor of Der p 1 (ProDer p 1). Taken together, these data suggest that DCs from house dust mite--sensitive patients, in contrast to DCs from healthy donors and from pollen-sensitive patients, exposed to Der p 1 play a pivotal role in the enhancement of the Th2 response associated with the allergic reaction developed in response to house dust mite exposure. (Blood. 2001;98:1135-1141)

Peripheral Dendritic Cells and CD4+CD25+Foxp3+ Regulatory T Cells in the First Trimester of Normal Pregnancy and in Women with Recurrent Miscarriage

PubMed Central

Kwiatek, Maciej; Gęca, Tomasz; Krzyżanowski, Arkadiusz; Malec, Agnieszka; Kwaśniewska, Anna

2015-01-01

The development of pregnancy is possible due to initiation of immune response in the body of the mother resulting in immune tolerance. Miscarriage may be caused by the impaired maternal immune response to paternal alloantigens located on the surface of trophoblast and fetal cells. The aim of the study was to compare the population of circulating dendritic cells (DCs) and CD4+CD25+Foxp3+ regulatory T cells (TREGs) in the first trimester of a normal pregnancy and in women with recurrent miscarriage and an attempt to determine the relationship between these cells and the role they may play in human reproductive failures. The study was conducted in a group of 33 first trimester pregnant women with recurrent miscarriage and in a group of 20 healthy pregnant women in the first trimester of normal pregnancy. Among mononuclear cells isolated from peripheral blood, the populations of DCs and TREGs were assessed by flow cytometry. The percentage of myeloid DCs and lymphoid DCs showed no significant difference between study and control group. Older maternal age and obesity significantly reduced the pool of circulating myeloid and lymphoid DCs (R=-0.39, p=0.02). In miscarriages the percentage of circulating TREGs was significantly lower compared to normal pregnancies (p=0.003). Among the analysed factors the percentage of TREGs was the most sensitive and the most specific parameter which correlated with the pregnancy loss. The reduction in the population of circulating TREGs suggests immunoregulatory mechanisms disorder in a pregnancy complicated by miscarriage. PMID:25945787

The role of T lymphocytes in cancer patients undergoing immunotherapy with autologous dendritic cells.

PubMed

Rodrigues, Cláudia M; Matias, Bruna F; Murta, Eddie F C; Michelin, Márcia A

2011-01-01

Cancer stems from mutations in specific genes that induce uncontrolled cell proliferation. Dendritic cells (DCs) are important immunologic cells and play a crucial role in the induction of an antitumour response. We examined the immune response mediated by T lymphocytes, helper T cells, cytotoxic T cells, and regulatory T cells, as well as the cytokines [interleukin (IL)-2, IL-12, interferon (IFN)-γ, tumour necrosis factor (TNF)-α and IL-10], produced by these cell populations, in cancer patients (N = 7) undergoing immunotheraphy with autologous DCs. We observed an initial increase in T helper cells (CD4+) expressing IL-2, IFN-γ, IL-12, TNF-α, and IL-10 after initiation of treatment, with statistically significant for the cytokines IL-2, TNF-α and IL-10. A similar significant effect was observed for IL-2-expressing cytotoxic T cells (CD8+). The percentage of total T cells (CD3+) remained elevated throughout immunotherapy. Regulatory T cells (CD25+/FOXP3+) only showed high percentage of their maximum value when analyzed the pretreatment levels, with statistically significant. Immunotherapy with DCs stimulated the immune response, as evidenced by an increase in percent fluorescence of most cell populations investigated during the specified treatment period.

Disruption of T-cell immunoglobulin and mucin domain molecule (TIM)-1/TIM4 interaction as a therapeutic strategy in a dendritic cell-induced peanut allergy model.

PubMed

Feng, Bai-Sui; Chen, Xiao; He, Shao-Heng; Zheng, Peng-Yuan; Foster, Jane; Xing, Zhou; Bienenstock, John; Yang, Ping-Chang

2008-07-01

Recent reports indicate that dendritic cell (DC)-derived T-cell immunoglobulin and mucin domain molecule (TIM)-4 plays an important role in the initiation of T(H)2 polarization. This study aims to elucidate the mechanisms of peanut allergy mediated by microbial products and DCs and the relationship between peanut allergy and TIM4. Mouse bone marrow-derived DCs (BMDCs) were generated and exposed to cholera toxin (CT) or/and peanut extract (PE) for 24 hours and then adoptively transferred to naive mice. After re-exposure to specific antigen PE, the mice were killed; intestinal allergic status was determined. Increased expression of TIM4 and costimulatory molecules was detected in BMDCs after concurrent exposure to CT and PE. Adoptively transferred CT/PE-conditioned BMDCs resulted in the increases in serum PE-specific IgE and skewed T(H)2 polarization in the intestine. Oral challenge with specific antigen PE induced mast cell activation in the intestine. Treating with Toll-like receptor 4 small interfering RNA abolished increased expression of TIM4 and costimulatory molecules by BMDCs. Pretreatment with anti-TIM1 or anti-TIM4 antibody abolished PE-specific T(H)2 polarization and allergy in the intestine. Concurrent exposure to microbial product CT and food antigen PE increases TIM4 expression in DCs and promotes DC maturation, which plays an important role in the initiation of PE-specific T(H)2 polarization and allergy in the intestine. Modulation of TIM4 production in DCs represents a novel therapeutic approach for the treatment of peanut allergy.

Co-operative suppression of inflammatory responses in human dendritic cells by plant proanthocyanidins and products from the parasitic nematode Trichuris suis.

PubMed

Williams, Andrew R; Klaver, Elsenoor J; Laan, Lisa C; Ramsay, Aina; Fryganas, Christos; Difborg, Rolf; Kringel, Helene; Reed, Jess D; Mueller-Harvey, Irene; Skov, Søren; van Die, Irma; Thamsborg, Stig M

2017-03-01

Interactions between dendritic cells (DCs) and environmental, dietary and pathogen antigens play a key role in immune homeostasis and regulation of inflammation. Dietary polyphenols such as proanthocyanidins (PAC) may reduce inflammation, and we therefore hypothesized that PAC may suppress lipopolysaccharide (LPS) -induced responses in human DCs and subsequent T helper type 1 (Th1) -type responses in naive T cells. Moreover, we proposed that, because DCs are likely to be exposed to multiple stimuli, the activity of PAC may synergise with other bioactive molecules that have anti-inflammatory activity, e.g. soluble products from the helminth parasite Trichuris suis (TsSP). We show that PAC are endocytosed by monocyte-derived DCs and selectively induce CD86 expression. Subsequently, PAC suppress the LPS-induced secretion of interleukin-6 (IL-6) and IL-12p70, while enhancing secretion of IL-10. Incubation of DCs with PAC did not affect lymphocyte proliferation; however, subsequent interferon-γ production was markedly suppressed, while IL-4 production was unaffected. The activity of PAC was confined to oligomers (degree of polymerization ≥ 4). Co-pulsing DCs with TsSP and PAC synergistically reduced secretion of tumour necrosis factor-α, IL-6 and IL-12p70 while increasing IL-10 secretion. Moreover, both TsSP and PAC alone induced Th2-associated OX40L expression in DCs, and together synergized to up-regulate OX40L. These data suggest that PAC induce an anti-inflammatory phenotype in human DCs that selectively down-regulates Th1 response in naive T cells, and that they also act cooperatively with TsSP. Our results indicate a novel interaction between dietary compounds and parasite products to influence immune function, and may suggest that combinations of PAC and TsSP can have therapeutic potential for inflammatory disorders. © 2016 John Wiley & Sons Ltd.

SLA-PGN-primed dendritic cell-based vaccination induces Th17-mediated protective immunity against experimental visceral leishmaniasis: a crucial role of PKCβ.

PubMed

Jawed, Junaid Jibran; Majumder, Saikat; Bandyopadhyay, Syamdas; Biswas, Satabdi; Parveen, Shabina; Majumdar, Subrata

2016-07-01

Emergence of drug resistance during visceral leishmaniasis (VL) is a major obstacle imposed during successful therapy. An effective vaccine strategy against this disease is therefore necessary. Our present study exploited the SLA (soluble leishmanial antigen) and PGN (peptidoglycan) stimulated bone marrow-derived dendritic cells (DCs) as a suitable vaccine candidate during experimental VL. SLA-PGN-stimulated DCs showed a significant decrease in hepatic and splenic parasite burden, which were associated with increased production of nitric oxide and pro-inflammatory cytokines such as IL-12, IFN-γ and IL-17. Elevated level of IL-17 was accompanied with the generation of more Th17 cells. Further studies on DC provided the evidence that these SLA-PGN-stimulated DCs played an important role in providing necessary cytokines such as IL-6, IL-23 and TGF-β for the generation of Th17 cells. Interestingly, inhibition of protein kinase C-β (PKCβ) in DCs led to decreased production of Th17 polarizing cytokines, causing reduction of the Th17 population size. Altogether, our finding highlighted the important role of DC-based PKCβ in regulation of the function and generation of Th17 cells. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Escape of HIV-1-infected dendritic cells from TRAIL-mediated NK cell cytotoxicity during NK-DC cross-talk--a pivotal role of HMGB1.

PubMed

Melki, Marie-Thérèse; Saïdi, Héla; Dufour, Alexandre; Olivo-Marin, Jean-Christophe; Gougeon, Marie-Lise

2010-04-15

Early stages of Human Immunodeficiency Virus-1 (HIV-1) infection are associated with local recruitment and activation of important effectors of innate immunity, i.e. natural killer (NK) cells and dendritic cells (DCs). Immature DCs (iDCs) capture HIV-1 through specific receptors and can disseminate the infection to lymphoid tissues following their migration, which is associated to a maturation process. This process is dependent on NK cells, whose role is to keep in check the quality and the quantity of DCs undergoing maturation. If DC maturation is inappropriate, NK cells will kill them ("editing process") at sites of tissue inflammation, thus optimizing the adaptive immunity. In the context of a viral infection, NK-dependent killing of infected-DCs is a crucial event required for early elimination of infected target cells. Here, we report that NK-mediated editing of iDCs is impaired if DCs are infected with HIV-1. We first addressed the question of the mechanisms involved in iDC editing, and we show that cognate NK-iDC interaction triggers apoptosis via the TNF-related apoptosis-inducing ligand (TRAIL)-Death Receptor 4 (DR4) pathway and not via the perforin pathway. Nevertheless, once infected with HIV-1, DC(HIV) become resistant to NK-induced TRAIL-mediated apoptosis. This resistance occurs despite normal amounts of TRAIL released by NK cells and comparable DR4 expression on DC(HIV). The escape of DC(HIV) from NK killing is due to the upregulation of two anti-apoptotic molecules, the cellular-Flice like inhibitory protein (c-FLIP) and the cellular inhibitor of apoptosis 2 (c-IAP2), induced by NK-DC(HIV) cognate interaction. High-mobility group box 1 (HMGB1), an alarmin and a key mediator of NK-DC cross-talk, was found to play a pivotal role in NK-dependent upregulation of c-FLIP and c-IAP2 in DC(HIV). Finally, we demonstrate that restoration of DC(HIV) susceptibility to NK-induced TRAIL killing can be obtained either by silencing c-FLIP and c-IAP2 by specific siRNA, or by inhibiting HMGB1 with blocking antibodies or glycyrrhizin, arguing for a key role of HMGB1 in TRAIL resistance and DC(HIV) survival. These findings provide evidence for a new strategy developed by HIV to escape immune attack, they challenge the question of the involvement of HMGB1 in the establishment of viral reservoirs in DCs, and they identify potential therapeutic targets to eliminate infected DCs.

Rapid Myeloid Cell Transcriptional and Proteomic Responses to Periodontopathogenic Porphyromonas gingivalis

PubMed Central

Nares, Salvador; Moutsopoulos, Niki M.; Angelov, Nikola; Rangel, Zoila G.; Munson, Peter J.; Sinha, Neha; Wahl, Sharon M.

2009-01-01

Long-lived monocytes, macrophages, and dendritic cells (DCs) are Toll-like receptor-expressing, antigen-presenting cells derived from a common myeloid lineage that play key roles in innate and adaptive immune responses. Based on immunohistochemical and molecular analyses of inflamed tissues from patients with chronic destructive periodontal disease, these cells, found in the inflammatory infiltrate, may drive the progressive periodontal pathogenesis. To investigate early transcriptional signatures and subsequent proteomic responses to the periodontal pathogen, Porphyromonas gingivalis, donor-matched human blood monocytes, differentiated DCs, and macrophages were exposed to P. gingivalis lipopolysaccharide (LPS) and gene expression levels were measured by oligonucleotide microarrays. In addition to striking differences in constitutive transcriptional profiles between these myeloid populations, we identify a P. gingivalis LPS-inducible convergent, transcriptional core response of more than 400 annotated genes/ESTs among these populations, reflected by a shared, but quantitatively distinct, proteomic response. Nonetheless, clear differences emerged between the monocytes, DCs, and macrophages. The finding that long-lived myeloid inflammatory cells, particularly DCs, rapidly and aggressively respond to P. gingivalis LPS by generating chemokines, proteases, and cytokines capable of driving T-helper cell lineage polarization without evidence of corresponding immunosuppressive pathways highlights their prominent role in host defense and progressive tissue pathogenesis. The shared, unique, and/or complementary transcriptional and proteomic profiles may frame the context of the host response to P. gingivalis, contributing to the destructive nature of periodontal inflammation. PMID:19264901

Dendritic cells modulate burn wound healing by enhancing early proliferation.

PubMed

Vinish, Monika; Cui, Weihua; Stafford, Eboni; Bae, Leon; Hawkins, Hal; Cox, Robert; Toliver-Kinsky, Tracy

2016-01-01

Adequate wound healing is vital for burn patients to reduce the risk of infections and prolonged hospitalization. Dendritic cells (DCs) are antigen presenting cells that release cytokines and are central for the activation of innate and acquired immune responses. Studies have showed their presence in human burn wounds; however, their role in burn wound healing remains to be determined. This study investigated the role of DCs in modulating healing responses within the burn wound. A murine model of full-thickness contact burns was used to study wound healing in the absence of DCs (CD11c promoter-driven diphtheria toxin receptor transgenic mice) and in a DC-rich environment (using fms-like tyrosine kinase-3 ligand, FL- a DC growth factor). Wound closure was significantly delayed in DC-deficient mice and was associated with significant suppression of early cellular proliferation, granulation tissue formation, wound levels of TGFβ1 and formation of CD31+ vessels in healing wounds. In contrast, DC enhancement significantly accelerated early wound closure, associated with increased and accelerated cellular proliferation, granulation tissue formation, and increased TGFβ1 levels and CD31+ vessels in healing wounds. We conclude that DCs play an important role in the acceleration of early wound healing events, likely by secreting factors that trigger the proliferation of cells that mediate wound healing. Therefore, pharmacological enhancement of DCs may provide a therapeutic intervention to facilitate healing of burn wounds. © 2016 by the Wound Healing Society.

Dendritic cells with increased expression of suppressor of cytokine signaling 1(SOCS1) gene ameliorate lipopolysaccharide/d-galactosamine-induced acute liver failure.

PubMed

Li, Shan-Shan; Yang, Min; Chen, Yong-Ping; Tang, Xin-Yue; Zhang, Sheng-Guo; Ni, Shun-Lan; Yang, Nai-Bin; Lu, Ming-Qin

2018-05-28

Acute liver failure is a devastating clinical syndrome with extremely terrible inflammation reaction, which is still lack of effective treatment in clinic. Suppressor of Cytokine Signaling 1 protein is inducible intracellular negative regulator of Janus kinases (JAK)/signal transducers and activators of transcription (STAT) pathway that plays essential role in inhibiting excessive intracellular signaling cascade and preventing autoimmune reaction. In this paper, we want to explore whether dendritic cells (DCs) with overexpression of SOCS1 have a therapeutic effect on experimental acute liver failure. Bone marrow derived dendritic cells were transfected with lentivirus encoding SOCS1 and negative control lentivirus, thereafter collected for costimulatory molecules analysis, allogeneic Mixed Lymphocyte Reaction and Western blot test of JAK/STAT pathway. C57BL/6 mice were randomly separated into normal control and treatment groups which respectively received tail vein injection of modified DCs, negative control DCs and normal saline 12 h earlier than acute liver failure induction. Our results indicated that DCs with overexpression of SOCS1 exhibited like regulatory DCs (DCregs) with low level of costimulatory molecules and poor allostimulatory ability in vitro, which was supposed to correlate with block of JAK2/STAT1 signaling. In vivo tests, we found that infusion of modified DCs increased survival rate of acute liver failure mice and alleviate liver injury via inhibition of TLR4/HMGB1 pathway. We concluded that DCs transduced with SOCS1 gene exhibit as DCregs through negative regulation of JAK2/STAT1 pathway and ameliorated lipopolysaccharide/d-galactosamine induced acute liver failure via inhibition of TLR4 pathway. Copyright © 2018 Elsevier Ltd. All rights reserved.

3-bromopyruvate ameliorate autoimmune arthritis by modulating Th17/Treg cell differentiation and suppressing dendritic cell activation.

PubMed

Okano, Takaichi; Saegusa, Jun; Nishimura, Keisuke; Takahashi, Soshi; Sendo, Sho; Ueda, Yo; Morinobu, Akio

2017-02-10

Recent studies have shown that cellular metabolism plays an important role in regulating immune cell functions. In immune cell differentiation, both interleukin-17-producing T (Th17) cells and dendritic cells (DCs) exhibit increased glycolysis through the upregulation of glycolytic enzymes, such as hexokinase-2 (HK2). Blocking glycolysis with 2-deoxyglucose was recently shown to inhibit Th17 cell differentiation while promoting regulatory T (Treg) cell generation. However, 2-DG inhibits all isoforms of HK. Thus, it is unclear which isoform has a critical role in Th17 cell differentiation and in rheumatoid arthritis (RA) pathogenesis. Here we demonstrated that 3-bromopyruvate (BrPA), a specific HK2 inhibitor, significantly decreased the arthritis scores and the histological scores in SKG mice, with a significant increase in Treg cells, decrease in Th17 cells, and decrease in activated DCs in the spleen. In vitro, BrPA facilitated the differentiation of Treg cells, suppressed Th17 cells, and inhibited the activation of DCs. These results suggested that BrPA may be a therapeutic target of murine arthritis. Although the role of IL-17 is not clarified in the treatment of RA, targeting cell metabolism to alter the immune cell functions might lead to a new therapeutic strategy for RA.

Dendritic cells in uninfected infants born to hepatitis B virus-positive mothers.

PubMed

Koumbi, Lemonica J; Papadopoulos, Nikolaos G; Anastassiadou, Vassiliki; Machaira, Maria; Kafetzis, Dimitris A; Papaevangelou, Vassiliki

2010-07-01

Plasmacytoid dendritic cells (pDCs) play a central role in antiviral immunity, detecting viruses via Toll-like receptors (TLR) and producing in response vast amounts of type I interferons (IFNs). Hepatitis B virus (HBV) causes chronic infection after vertical transmission. This study investigated whether an HBV-infected maternal environment might influence DC numbers and pDC function in uninfected infants. Blood was collected from inactive HBsAg carrier and control mothers and their infants at birth and 1 and 6 months of age. HBV DNA was measured in maternal and neonatal perinatal sera using real-time PCR. The circulating frequencies of myeloid DCs (mDCs) and pDCs were determined in the babies by flow cytometry. Peripheral blood mononuclear cells (PBMCs) and cord blood pDCs were stimulated with resiquimod, and alpha interferon (IFN-alpha) production and the pDC phenotype were assessed. The effect of the common-cold virus, rhinovirus (RV), on resiquimod stimulation was also determined. HBV DNA was detected in 62.3% of the mothers and 41% of their infants. DC numbers and pDC functions were similar between subjects and controls and were not correlated with maternal or neonatal viremia. RV infection did not induce pDC maturation until the age of 6 months, and it reduced TLR7-dependent resiquimod-induced IFN-alpha production similarly in both groups. Although the DC system is immature at birth, DCs of uninfected neonates of HBV-positive mothers are competent to initiate and maintain T-cell responses. RV is a weak inducer of IFN-alpha production until the age of 6 months and inhibits IFN-alpha responses triggered by the TLR7 pathway.

Mycobacterium tuberculosis impairs dendritic cell functions through the serine hydrolase Hip1.

PubMed

Madan-Lala, Ranjna; Sia, Jonathan Kevin; King, Rebecca; Adekambi, Toidi; Monin, Leticia; Khader, Shabaana A; Pulendran, Bali; Rengarajan, Jyothi

2014-05-01

Mycobacterium tuberculosis is a highly successful human pathogen that primarily resides in host phagocytes, such as macrophages and dendritic cells (DCs), and interferes with their functions. Although multiple strategies used by M. tuberculosis to modulate macrophage responses have been discovered, interactions between M. tuberculosis and DCs are less well understood. DCs are the primary APCs of the immune system and play a central role in linking innate and adaptive immune responses to microbial pathogens. In this study, we show that M. tuberculosis impairs DC cytokine secretion, maturation, and Ag presentation through the cell envelope-associated serine hydrolase, Hip1. Compared to wild-type, a hip1 mutant strain of M. tuberculosis induced enhanced levels of the key Th1-inducing cytokine IL-12, as well as other proinflammatory cytokines (IL-23, IL-6, TNF-α, IL-1β, and IL-18) in DCs via MyD88- and TLR2/9-dependent pathways, indicating that Hip1 restricts optimal DC inflammatory responses. Infection with the hip1 mutant also induced higher levels of MHC class II and costimulatory molecules CD40 and CD86, indicating that M. tuberculosis impairs DC maturation through Hip1. Further, we show that M. tuberculosis promotes suboptimal Ag presentation, as DCs infected with the hip1 mutant showed increased capacity to present Ag to OT-II- and early secreted antigenic target 6-specific transgenic CD4 T cells and enhanced Th1 and Th17 polarization. Overall, these data show that M. tuberculosis impairs DC functions and modulates the nature of Ag-specific T cell responses, with important implications for vaccination strategies.

The Role of T Lymphocytes in Cancer Patients Undergoing Immunotherapy with Autologous Dendritic Cells

PubMed Central

Rodrigues, Cláudia M.; Matias, Bruna F.; Murta, Eddie F.C.; Michelin, Márcia A.

2011-01-01

Introduction: Cancer stems from mutations in specific genes that induce uncontrolled cell proliferation. Dendritic cells (DCs) are important immunologic cells and play a crucial role in the induction of an antitumour response. Patients and methods: We examined the immune response mediated by T lymphocytes, helper T cells, cytotoxic T cells, and regulatory T cells, as well as the cytokines [interleukin (IL)-2, IL-12, interferon (IFN)-γ, tumour necrosis factor (TNF)-α and IL-10], produced by these cell populations, in cancer patients (N = 7) undergoing immunotheraphy with autologous DCs. Results: We observed an initial increase in T helper cells (CD4+) expressing IL-2, IFN-γ, IL-12, TNF-α, and IL-10 after initiation of treatment, with statistically significant for the cytokines IL-2, TNF-α and IL-10. A similar significant effect was observed for IL-2-expressing cytotoxic T cells (CD8+). The percentage of total T cells (CD3+) remained elevated throughout immunotherapy. Regulatory T cells (CD25+/FOXP3+) only showed high percentage of their maximum value when analyzed the pretreatment levels, with statistically significant. Conclusion: Immunotherapy with DCs stimulated the immune response, as evidenced by an increase in percent fluorescence of most cell populations investigated during the specified treatment period. PMID:21603246

Conventional and monocyte-derived CD11b(+) dendritic cells initiate and maintain T helper 2 cell-mediated immunity to house dust mite allergen.

PubMed

Plantinga, Maud; Guilliams, Martin; Vanheerswynghels, Manon; Deswarte, Kim; Branco-Madeira, Filipe; Toussaint, Wendy; Vanhoutte, Leen; Neyt, Katrijn; Killeen, Nigel; Malissen, Bernard; Hammad, Hamida; Lambrecht, Bart N

2013-02-21

Dendritic cells (DCs) are crucial for mounting allergic airway inflammation, but it is unclear which subset of DCs performs this task. By using CD64 and MAR-1 staining, we reliably separated CD11b(+) monocyte-derived DCs (moDCs) from conventional DCs (cDCs) and studied antigen uptake, migration, and presentation assays of lung and lymph node (LN) DCs in response to inhaled house dust mite (HDM). Mainly CD11b(+) cDCs but not CD103(+) cDCs induced T helper 2 (Th2) cell immunity in HDM-specific T cells in vitro and asthma in vivo. Studies in Flt3l(-/-) mice, lacking all cDCs, revealed that moDCs were also sufficient to induce Th2 cell-mediated immunity but only when high-dose HDM was given. The main function of moDCs was the production of proinflammatory chemokines and allergen presentation in the lung during challenge. Thus, we have identified migratory CD11b(+) cDCs as the principal subset inducing Th2 cell-mediated immunity in the LN, whereas moDCs orchestrate allergic inflammation in the lung. Copyright © 2013 Elsevier Inc. All rights reserved.

Kynurenic acid downregulates IL-17/1L-23 axis in vitro.

PubMed

Salimi Elizei, Sanam; Poormasjedi-Meibod, Malihe-Sadat; Wang, Xia; Kheirandish, Maryam; Ghahary, Aziz

2017-07-01

Exploring the function of interleukin (IL) 17 and related cytokine interactions have been proven useful toward understanding the role of inflammation in autoimmune diseases. Production of the inflammatory cytokine IL-23 by dendritic cells (DC's) has been shown to promote IL-17 expression by Th17 cells. It is well established that Th17 cells play an important role in several autoimmune diseases including psoriasis and alopecia. Our recent investigations have suggested that Kynurenine-rich environment can shift a pro-inflammatory response to an anti-inflammatory response, as is the case in the presence of the enzyme Indoleamine 2,3 dioxygenase (IDO), the rate-limiting enzyme in tryptophan degradation and Kynurenine (Kyn) production. In this study, we sought to explore the potential role of kynurenic acid (KynA), in modulating the expression of IL-23 and IL-17 by DCs and CD4 + cells, respectively. The result of flow cytometry demonstrated that the frequency of IL-23-producing DCs is reduced with 100 µg/ml of KynA as compared with that of LPS-stimulated DCs. KynA (100 μg/ml) addition to activated T cells significantly decreased the level of IL-17 mRNA and frequency of IL-17 + T cells as compared to that of concanavalin (Con) A-activated T cells. To examine the mechanism of the suppressive role of KynA on IL-23/IL-17 in these cells, cells were treated with 3 μM G-protein-coupled receptor35 (GPCR35) inhibitor (CID), for 60 min. The result showed that the reduction of both adenylate cyclase (AC) and cyclic adenosine monophosphate (cAMP) by KynA is involved in suppression of LPS-induced IL-23p19 expression. Since GPCR35 is also detected on T cells; therefore, it is concluded that KynA plays an important role in modulating the expression of IL-23 and IL-17 in DCs and Th17 cells through inhibiting GPCR35 and downregulation of both AC and cAMP.

Immunomodulatory function of regulatory dendritic cells induced by mesenchymal stem cells.

PubMed

Zhao, Zhi-Gang; Xu, Wen; Sun, Li; You, Yong; Li, Fang; Li, Qiu-Bai; Zou, Ping

2012-01-01

Mesenchymal stem cells (MSCs) provide an excellent model for development of stem cell therapeutics, and their potential treatment in the immunopathogenic diseases have gained further interest after demonstration of immunomodulatory effects on complicated interactions between T cells and even dendritic cells (DCs). However, the mechanisms underlying these immunoregulatory effects of MSCs are poorly understood. In this study, we show that bone marrow derived MSCs can differentiate mature DCs (mDCs) into a distinct regulatory DC population. Compared with mDCs, they have lower expression of CD1a, CD80, CD86 and CD40, but higher expression of CD11b. MSCs induced DCs (MSC-DCs) can hardly stimulate T-cell proliferation even when MSC-DCs are stimulated by LPS. In addition, high endocytosic capacity, low immunogenicity, and strong immunoregulatory function of MSC-DCs are also observed. Moreover, MSC-DCs can efficiently generate CD4+CD25+Foxp3+ Treg cells from CD4+CD25-Foxp3-T cells. The inhibitory function of MSC-DCs is mediated not only through TGF-β1, but also by inducing the production of Treg cells or T-cell anergy. These results demonstrate that the immunomodulatory effects of regulatory DCs induced by MSCs provide efficacious treatment for immunopathogenic diseases.

Genome-wide profiling of microRNAs reveals novel insights into the interactions between H9N2 avian influenza virus and avian dendritic cells.

PubMed

Lin, Jian; Xia, Jing; Zhang, Tian; Zhang, Keyun; Yang, Qian

2018-05-10

The antigen-presenting ability of dendritic cells (DCs) plays an important and irreplaceable role in recognising and clearing viruses. Antiviral responses must rapidly defend against infection while minimising inflammatory damage, but the mechanisms that regulate the magnitude of response within an infected cell are not well understood. MicroRNAs (microRNAs), small non-coding RNAs, can regulate mouse or avian DCs to inhibit the infection and replication of avian influenza virus (AIV). Here, we performed a global analysis to understand how avian DCs respond to H9N2 AIV and provide a potential mechanism to explain how avian microRNAs can defend against H9N2 AIV replication. First, we found that both active and inactive H9N2 AIV enhanced the ability of DCs to present antigens and activate T lymphocytes. Next, total microarray analyses suggested that H9N2 AIV stimulation involved protein localisation, nucleotide binding, leucocyte transendothelial migration and MAPK signalling. Moreover, we constructed 551 transcription factor (TF)-miRNA-mRNA loops based on the above analyses. Furthermore, we found that the haemagglutinin (HA) fragment, neither H5N1-HA or H9N2-HA, could not activate DCs, while truncated HA greatly increased the immune function of DCs by activating ERK and STAT3 signalling pathways. Lastly, our results not only suggested that gga-miR1644 targets muscleblind-like protein 2 (MBNL2) to enhance the ability of avian DCs to inhibit virus replication, but also suggested that gga-miR6675 targets the nuclear localisation sequence of polymerase basic protein 1 (PB1) to trigger the silencing of PB1 genes, resulting in the inhibition of H9N2 AIV replication. Altogether, our innovative study will shed new light on the role of avian microRNAs in evoking avian DCs and inhibiting virus replication.

Renal Denervation Prevents Immune Cell Activation and Renal Inflammation in Angiotensin II–Induced Hypertension

PubMed Central

Xiao, Liang; Kirabo, Annet; Wu, Jing; Saleh, Mohamed A.; Zhu, Linjue; Wang, Feng; Takahashi, Takamune; Loperena, Roxana; Foss, Jason D.; Mernaugh, Raymond L.; Chen, Wei; Roberts, Jackson; Osborn, John W.; Itani, Hana A.; Harrison, David G.

2015-01-01

Rationale Inflammation and adaptive immunity plays a crucial role in the development of hypertension. Angiotensin II and likely other hypertensive stimuli activate the central nervous system and promote T cell activation and end-organ damage in peripheral tissues. Objective To determine if renal sympathetic nerves mediate renal inflammation and T cell activation in hypertension. Methods and Results Bilateral renal denervation (RDN) using phenol application to the renal arteries reduced renal norepinephrine (NE) levels and blunted angiotensin II induced hypertension. Bilateral RDN also reduced inflammation, as reflected by decreased accumulation of total leukocytes, T cells and both CD4+ and CD8+ T cells in the kidney. This was associated with a marked reduction in renal fibrosis, albuminuria and nephrinuria. Unilateral RDN, which partly attenuated blood pressure, only reduced inflammation in the denervated kidney, suggesting that this effect is pressure independent. Angiotensin II also increased immunogenic isoketal-protein adducts in renal dendritic cells (DCs) and increased surface expression of costimulation markers and production of IL-1α, IL-1β, and IL-6 from splenic dendritic cells. NE also dose dependently stimulated isoketal formation in cultured DCs. Adoptive transfer of splenic DCs from angiotensin II-treated mice primed T cell activation and hypertension in recipient mice. RDN prevented these effects of hypertension on DCs. In contrast to these beneficial effects of ablating all renal nerves, renal afferent disruption with capsaicin had no effect on blood pressure or renal inflammation. Conclusions Renal sympathetic nerves contribute to dendritic cell activation, subsequent T cell infiltration and end-organ damage in the kidney in the development of hypertension. PMID:26156232

Antigen-specific IL-23/17 pathway activation by murine semi-mature DC-like cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nagasaka, Shinya; Iwasaki, Takumi; Okano, Tomoko

We analyzed the phenotype and function of bone marrow-derived dendritic cells (DCs) induced in vitro without using any serum during the late stage of cultivation. These 'serum-free' DCs (SF-DCs) possessed the ability to induce T cell proliferation as well as antibody responses, indicating that they were functional DCs. Surprisingly, the SF-DCs akin to semi-mature DCs in terms of both phenotypic and functional characteristics. The SF-DCs did not produce IL-12 but produced large amounts of IL-23 following lipopolysaccharide stimulation. The antigen-specific production of IL-17 by CD4{sup +} T cells co-cultured with OVA-loaded SF-DCs was significantly higher than that with OVA-loaded conventionalmore » DCs. These results suggest that SF-DCs tend to produce IL-23 and can consequently induce the IL-17 producing CD4{sup +} T cells. The semi-mature DC-like cells reported here will be useful vehicles for DC immunization and might contribute to studies on the possible involvement of semi-mature DCs in Th17 cell differentiation.« less

Desirable cytolytic immune effector cell recruitment by interleukin-15 dendritic cells.

PubMed

Van Acker, Heleen H; Beretta, Ottavio; Anguille, Sébastien; De Caluwé, Lien; Papagna, Angela; Van den Bergh, Johan M; Willemen, Yannick; Goossens, Herman; Berneman, Zwi N; Van Tendeloo, Viggo F; Smits, Evelien L; Foti, Maria; Lion, Eva

2017-02-21

Success of dendritic cell (DC) therapy in treating malignancies is depending on the DC capacity to attract immune effector cells, considering their reciprocal crosstalk is partially regulated by cell-contact-dependent mechanisms. Although critical for therapeutic efficacy, immune cell recruitment is a largely overlooked aspect regarding optimization of DC vaccination. In this paper we have made a head-to-head comparison of interleukin (IL)-15-cultured DCs and conventional IL-4-cultured DCs with regard to their proficiency in the recruitment of (innate) immune effector cells. Here, we demonstrate that IL-4 DCs are suboptimal in attracting effector lymphocytes, while IL15 DCs provide a favorable chemokine milieu for recruiting CD8+ T cells, natural killer (NK) cells and gamma delta (γδ) T cells. Gene expression analysis revealed that IL-15 DCs exhibit a high expression of chemokines involved in antitumor immune effector cell attraction, while IL-4 DCs display a more immunoregulatory profile characterized by the expression of Th2 and regulatory T cell-attracting chemokines. This is confirmed by functional data indicating an enhanced recruitment of granzyme B+ effector lymphocytes by IL-15 DCs, as compared to IL-4 DCs, and subsequent superior killing of tumor cells by the migrated lymphocytes. Elevated CCL4 gene expression in IL-15 DCs and lowered CCR5 expression on both migrated γδ T cells and NK cells, led to validation of increased CCL4 secretion by IL15 DCs. Moreover, neutralization of CCR5 prior to migration resulted in an important inhibition of γδ T cell and NK cell recruitment by IL-15 DCs. These findings further underscore the strong immunotherapeutic potential of IL-15 DCs.

Lead effects on development and function of bone marrow-derived dendritic cells promote Th2 immune responses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao Donghong; Mondal, Tapan K.; Lawrence, David A.

2007-07-01

Although lead (Pb) has significant effects on the development and function of macrophages, B cells, and T cells and has been suggested to promote allergic asthma in mice and humans, Pb modulation of bone marrow (BM)-derived dendritic cells (DCs) and the resultant DC effects on Th1 and Th2 development have not been examined. Accordingly, we cultured BM cells with murine granulocyte macrophage-colony stimulating factor (mGM-CSF) {+-} PbCl{sub 2}. At day 10, culture supernatant (SN) and non-adherent cells were harvested for analysis. Additionally, day 10 non-adherent BM-DCs were harvested and recultured with mGM-CSF + LPS {+-} Pb for 2 days. Themore » day 10 Pb exposure significantly inhibited BM-DC generation, based on CD11c expression. Although fewer DCs were generated with Pb, the existing Pb-exposed DCs had significantly greater MHC-II expression than did the non-Pb-exposed DCs. However, these differences diminished upon LPS stimulation. After LPS stimulation, CD80, CD86, CD40, CD54, and MHC-II were all up-regulated on both Pb-DCs and DCs, but Pb-DCs expressed significantly less CD80 than did DCs. The CD86:CD80 ratio suggests a Pb-DC potential for Th2 cell development. After LPS stimulation, IL-6, IL-10, IL-12 (p70), and TNF-{alpha} levels significantly increased with both Pb-DCs and DCs, but Pb-DCs produced significantly less cytokines than did DCs, except for IL-10, which further supports Pb-DC preferential skewing toward type-2 immunity. In vitro studies confirm that Pb-DCs have the ability to polarize antigen-specific T cells to Th2 cells. Pb-DCs also enhanced allogeneic and autologous T cell proliferation in vitro, and in vivo studies suggested that Pb-DCs inhibited Th1 effects on humoral and cell-mediated immunity. The Pb effect was mainly on DCs, rather than on T cells, and Pb's modification of DC function appears to be the main cause of Pb's promotion of type-2-related immunity, which may relate to Pb's enhanced activation of the Erk/MAP kinase pathway.« less

Paracoccidioides brasiliensis interferes on dendritic cells maturation by inhibiting PGE2 production.

PubMed

Fernandes, Reginaldo K; Bachiega, Tatiana F; Rodrigues, Daniela R; Golim, Marjorie de A; Dias-Melicio, Luciane A; Balderramas, Helanderson de A; Kaneno, Ramon; Soares, Ângela M V C

2015-01-01

Paracoccidioidomycosis (PCM) is a systemic mycosis, endemic in most Latin American countries, especially in Brazil, whose etiologic agent is the thermodimorphic fungus of the genus Paracoccidioides, comprising cryptic species of Paracoccidioides brasiliensis, S1, PS2, PS3 and Paracoccidioides lutzii. The mechanisms involved in the initial interaction of the fungus with cells of the innate immune response, as dendritic cells (DCs), deserve to be studied. Prostaglandins (PGs) are eicosanoids that play an important role in modulating functions of immune cells including DCs. Here we found that human immature DCs derived from the differentiation of monocytes cultured with GM-CSF and IL-4 release substantial concentrations of PGE2, which, however, were significantly inhibited after challenge with P. brasiliensis. In vitro blocking of pattern recognition receptors (PRRs) by monoclonal antibodies showed the involvement of mannose receptor (MR) in PGE2 inhibition by the fungus. In addition, phenotyping assays showed that after challenge with the fungus, DCs do not change their phenotype of immature cells to mature ones, as well as do not produce IL-12 p70 or adequate concentrations of TNF-α. Assays using exogenous PGE2 confirmed an association between PGE2 inhibition and failure of cells to phenotypically mature in response to P. brasiliensis. We conclude that a P. brasiliensis evasion mechanism exists associated to a dysregulation on DC maturation. These findings may provide novel information for the understanding of the complex interplay between the host and this fungus.

Enhanced IFN-α production is associated with increased TLR7 retention in the lysosomes of palasmacytoid dendritic cells in systemic lupus erythematosus.

PubMed

Murayama, Goh; Furusawa, Nanako; Chiba, Asako; Yamaji, Ken; Tamura, Naoto; Miyake, Sachiko

2017-10-19

Interferon-α (IFN-α) is increased and plays an important role in the pathogenesis of systemic lupus erythematosus (SLE). Plasmacytoid dendritic cells (pDCs) are the main producer of IFN-α, but their IFN-α producing capacity has been shown to be unchanged or reduced when stimulated with a Toll-like receptor 9 (TLR9) agonist in patients with SLE compared to in healthy individuals. In this study, we investigated the IFN-α-producing capacity of lupus pDCs under different stimulation. pDCs from patients with SLE and healthy controls (HC) were stimulated with TLR9 or TLR7 agonist, and their IFN-α producing capacity was examined by intracellular cytokine staining and flow cytometry. The correlation of IFN-α-producing capacity with serum IFN-α levels and disease activity was assessed. The effect of in vitro IFN-α exposure on IFN-α production by pDCs was examined. Localization of TLR7 in cellular compartments in pDCs was investigated. The IFN-α producing capacity of pDCs was reduced after TLR9 stimulation, but increased when stimulated with a TLR7 agonist in SLE compared to in HC. IFN-α production by pDCs upon TLR9 stimulation was reduced and the percentage of IFN-α + pDC was inversely correlated with disease activity and serum IFN-α levels. However, the TLR7 agonist-induced IFN-α producing capacity of lupus pDCs was enhanced and correlated with disease activity and serum IFN-α. Exposure to IFN-α enhanced IFN-α production of TLR7-stimulated pDCs, but reduced that of pDCs activated with a TLR9 agonist. TLR7 localization was increased in late endosome/lysosome compartments in pDCs from SLE patients. These findings indicate that enhanced TLR7 responses of lupus pDCs, owing to TLR7 retention in late endosome/lysosome and exposure to IFN-α, are associated with the pathogenesis of SLE.

Human dendritic cells produce TGF-beta 1 under the influence of lung carcinoma cells and prime the differentiation of CD4+CD25+Foxp3+ regulatory T cells.

PubMed

Dumitriu, Ingrid E; Dunbar, Donald R; Howie, Sarah E; Sethi, Tariq; Gregory, Christopher D

2009-03-01

Dendritic cells (DCs) have a central role in the development of adaptive immune responses, including antitumor immunity. Factors present in the tumor milieu can alter the maturation of DCs and inhibit their capacity to activate T cells. Using gene expression analysis, we found that human DCs increased the expression of TGF-beta1 transcripts following culture with human lung carcinoma cells (LCCs). These DCs produced increased amounts of TGF-beta1 protein compared with DCs not exposed to tumor cells. LCCs also decreased the expression of CD86 and HLA-DR by immature DCs. Furthermore, LCCs decreased CD86 expression and the production of TNF-alpha and IL-12 p70 by mature DCs. Moreover, LCCs also converted mature DCs into cells producing TGF-beta1. These TGF-beta1-producing DCs were poor at eliciting the activation of naive CD4(+) T cells and sustaining their proliferation and differentiation into Th1 (IFN-gamma(+)) effectors. Instead, TGF-beta1-producing DCs demonstrated an increased ability to generate CD4(+)CD25(+)Foxp3(+) regulatory T cells that suppress the proliferation of T lymphocytes. These results identify a novel mechanism by which the function of human DCs is altered by tumor cells and contributes to the evasion of the immune response.

Evaluation of the sensitizing potential of antibiotics in vitro using the human cell lines THP-1 and MUTZ-LC and primary monocyte‐derived dendritic cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sebastian, Katrin, E-mail: ksebastian@ukaachen.de; Ott, Hagen; Zwadlo-Klarwasser, Gabriele

Since the 7th amendment to the EU cosmetics directive foresees a complete ban on animal testing, alternative in vitro methods have been established to evaluate the sensitizing potential of small molecular weight compounds. To find out whether these novel in vitro assays are also capable to predict the sensitizing potential of small molecular weight drugs, model compounds such as beta-lactams and sulfonamides – which are the most frequent cause of adverse drug reactions – were co-incubated with THP-1, MUTZ-LC, or primary monocyte‐derived dendritic cells for 48 h and subsequent expression of selected marker genes (IL-8, IL-1β, CES1, NQO1, GCLM, PIRmore » and TRIM16) was studied by real time PCR. Benzylpenicillin and phenoxymethylpenicillin were recognized as sensitizing compounds because they are capable to induce the mRNA expression of these genes in moDCs and, except for IL-8, in THP-1 cells but not in MUTZ-LC. Ampicillin stimulated the expression of some marker genes in moDCs and THP-1 cells. SMX did not affect the expression of these genes in THP-1, however, in moDCs, at least PIR was enhanced and there was an increase of the release of IL-8. These data reveal that novel in vitro DC based assays might play a role in the evaluation of the allergenic potential of novel drug compounds, but these systems seem to lack the ability to detect the sensitizing potential of prohaptens that require metabolic activation prior to sensitization and moDCs seem to be superior with regard to the sensitivity compared with THP-1 and MUTZ-3 cell lines. -- Highlights: ► We tested the sensitizing potential of small molecular weight drugs in vitro. ► In vitro assays were performed with moDCs and THP-1 cells. ► Beta-lactam antibiotics can be recognized as sensitizing compounds. ► They affect the expression of metabolic enzymes, cytokines and transcription factors. ► Sulfamethoxazole has no measurable effect on THP-1 cells and moDCs.« less

Mycobacterium tuberculosis impairs dendritic cell functions through the serine hydrolase Hip1

PubMed Central

Madan-Lala, Ranjna; Sia, Jonathan Kevin; King, Rebecca; Adekambi, Toidi; Monin, Leticia; Khader, Shabaana A; Pulendran, Bali; Rengarajan, Jyothi

2014-01-01

Mycobacterium tuberculosis (Mtb) is a highly successful human pathogen that primarily resides in host phagocytes, such as macrophages and dendritic cells (DCs), and interferes with their functions. While multiple strategies used by Mtb to modulate macrophage responses have been discovered, interactions between Mtb and DCs are less well understood. DCs are the primary antigen presenting acells (APCs) of the immune system and play a central role in linking innate and adaptive immune responses to microbial pathogens. In this study we show that Mtb impairs DC cytokine secretion, maturation and antigen presentation through the cell envelope-associated serine hydrolase Hip1. Compared to wild type, a hip1 mutant strain of Mtb induced enhanced levels of the key T helper 1 (Th1)-inducing cytokine IL-12, as well as other proinflammatory cytokines (IL-23, IL-6, TNF-α, IL-1β, IL-18) in DCs via MyD88- and TLR2/9-dependent pathways, indicating that Hip1 restricts optimal DC inflammatory responses. Infection with the hip1 mutant also induced higher levels of MHC class II and co-stimulatory molecules, CD40 and CD86, indicating that Mtb impairs DC maturation through Hip1. Further, we show that Mtb promotes sub-optimal antigen presentation, as DCs infected with the hip1 mutant showed increased capacity to present antigen to OT-II- and early secreted antigenic target 6 (ESAT-6)-specific transgenic CD4 T cells and enhanced Th1 and Th17 polarization. Overall, these data show that Mtb impairs DC functions and modulates the nature of antigen-specific T cell responses, with important implications for vaccination strategies. PMID:24659689

Human dendritic cell subsets display distinct interactions with the pathogenic mould Aspergillus fumigatus.

PubMed

Lother, Jasmin; Breitschopf, Tanja; Krappmann, Sven; Morton, C Oliver; Bouzani, Maria; Kurzai, Oliver; Gunzer, Matthias; Hasenberg, Mike; Einsele, Hermann; Loeffler, Juergen

2014-11-01

The mould Aspergillus fumigatus is primarily an opportunistic pathogen of immunocompromised patients. Once fungal spores have been inhaled they encounter cells of the innate immune system, which include dendritic cells (DCs). DCs are the key antigen-presenting cells of the immune system and distinct subtypes, which differ in terms of origin, morphology and function. This study has systematically compared the interactions between A. fumigatus and myeloid DCs (mDCs), plasmacytoid DCs (pDCs) and monocyte-derived DCs (moDCs). Analyses were performed by time-lapse video microscopy, scanning electron microscopy, plating assays, flow cytometry, 25-plex ELISA and transwell assays. The three subsets of DCs displayed distinct responses to the fungus with mDCs and moDCs showing the greatest similarities. mDCs and moDCs both produced rough convolutions and occasionally phagocytic cups upon exposure to A. fumigatus whereas pDCs maintained a smooth appearance. Both mDCs and moDCs phagocytosed conidia and germ tubes, while pDCs did not phagocytose any fungi. Analysis of cytokine release and maturation markers revealed specific differences in pro- and anti-inflammatory patterns between the different DC subsets. These distinct characteristics between the DC subsets highlight their differences and suggest specific roles of moDCs, mDCs and pDCs during their interaction with A. fumigatus in vivo. Copyright © 2014 Elsevier GmbH. All rights reserved.

Plasmacytoid dendritic cells induce NK cell-dependent, tumor antigen-specific T cell cross-priming and tumor regression in mice.

PubMed

Liu, Chengwen; Lou, Yanyan; Lizée, Gregory; Qin, Hong; Liu, Shujuan; Rabinovich, Brian; Kim, Grace J; Wang, Yi-Hong; Ye, Yang; Sikora, Andrew G; Overwijk, Willem W; Liu, Yong-Jun; Wang, Gang; Hwu, Patrick

2008-03-01

A prerequisite for strong adaptive antiviral immunity is the robust initial activation of the innate immune system, which is frequently mediated by TLR-activated plasmacytoid DCs (pDCs). Natural antitumor immunity is often comparatively weak, potentially due to the lack of TLR-mediated activation signals within the tumor microenvironment. To assess whether pDCs are capable of directly facilitating effective antitumor immune responses, mice bearing established subcutaneous B16 melanoma tumors were administered TLR9-activated pDCs directly into the tumor. We found that TLR9-activated pDCs induced robust, spontaneous CTL cross-priming against multiple B16 tumor antigens, leading to the regression of both treated tumors and untreated tumors at distant contralateral sites. This T cell cross-priming was mediated by conventional DCs (cDCs) and was completely dependent upon the early recruitment and activation of NK cells at the tumor site. NK cell recruitment was mediated by CCR5 via chemokines secreted by pDCs, and optimal IFN-gamma production by NK cells was mediated by OX40L expressed by pDCs. Our data thus demonstrated that activated pDCs are capable of initiating effective and systemic antitumor immunity through the orchestration of an immune cascade involving the sequential activation of NK cells, cDCs, and CD8(+) T cells.

Modulation of CD11c+ lung dendritic cells in respect to TGF-β in experimental pulmonary fibrosis.

PubMed

Chakraborty, Kaustav; Chatterjee, Soumya; Bhattacharyya, Arindam

2017-09-01

Idiopathic pulmonary fibrosis (IPF) is a deadly, progressive lung disease with very few treatment options till now. Bleomycin-induced pulmonary fibrosis (BIPF) is a commonly used mice model in IPF research. TGF-β1 has been shown to play a key role in pulmonary fibrosis (PF). Dendritic cell (DC) acts as a bridge between innate and adaptive immune systems. The coexistence of chronic inflammation sustained by mature DCs with fibrosis suggests that inflammatory phenomenon has key importance in the pathogenesis of pulmonary fibrosis. Here, we investigated the modulation of DCs phenotypic maturation, accumulation in lung tissue, and expression of other lung DC subsets in respect to TGF-β in PF. First, we established BIPF model in mice and blocked TGF-β expression by the use of inhibitor SB431542. Accumulation of lung CD11c+ DCs is significantly higher in both inflammatory and fibrotic phases of the disease but that percentages got reduced in the absence of TGF-β. TGF-β initiates up-regulation of costimulatory molecules CD86 and CD80 in the inflammatory phases of the disease but not so at fibrotic stage. Expression of lung DC subset CD11c+CD103+ is significantly increased in inflammatory phase and also in fibrotic phase of BIPF. Blocking of TGF-β causes decreased expression of CD11c+CD103+ DCs. Another important lung DC subset CD11c+CD11b+ expression is suppressed by the absence of TGF-β after bleomycin administration. CD11c+CD103+ DCs might have anti-inflammatory as well as anti-fibrotic nature in PF. All these data demonstrate differential modulation of CD11c+ lung DCs by TGF-β in experimental PF. © 2017 International Federation for Cell Biology.

The early interaction of Leishmania with macrophages and dendritic cells and its influence on the host immune response.

PubMed

Liu, Dong; Uzonna, Jude E

2012-01-01

The complicated interactions between Leishmania and the host antigen-presenting cells (APCs) have fundamental effects on the final outcome of the disease. Two major APCs, macrophages and dendritic cells (DCs), play critical roles in mediating resistance and susceptibility during Leishmania infection. Macrophages are the primary resident cell for Leishmania: they phagocytose and permit parasite proliferation. However, these cells are also the major effector cells to eliminate infection. The effective clearance of parasites by macrophages depends on activation of appropriate immune response, which is usually initiated by DCs. Here, we review the early interaction of APCs with Leishmania parasites and how these interactions profoundly impact on the ensuing adaptive immune response. We also discuss how the current knowledge will allow further refinement of our understanding of the interplay between Leishmania and its hosts that leads to resistance or susceptibility.

The early interaction of Leishmania with macrophages and dendritic cells and its influence on the host immune response

PubMed Central

Liu, Dong; Uzonna, Jude E.

2012-01-01

The complicated interactions between Leishmania and the host antigen-presenting cells (APCs) have fundamental effects on the final outcome of the disease. Two major APCs, macrophages and dendritic cells (DCs), play critical roles in mediating resistance and susceptibility during Leishmania infection. Macrophages are the primary resident cell for Leishmania: they phagocytose and permit parasite proliferation. However, these cells are also the major effector cells to eliminate infection. The effective clearance of parasites by macrophages depends on activation of appropriate immune response, which is usually initiated by DCs. Here, we review the early interaction of APCs with Leishmania parasites and how these interactions profoundly impact on the ensuing adaptive immune response. We also discuss how the current knowledge will allow further refinement of our understanding of the interplay between Leishmania and its hosts that leads to resistance or susceptibility. PMID:22919674

Dendritic cell maturation, but not type I interferon exposure, restricts infection by HTLV-1, and viral transmission to T-cells

PubMed Central

Alais, Sandrine; Tanaka, Yuetsu; Journo, Chloé; Mahieux, Renaud; Dutartre, Hélène

2017-01-01

Human T lymphotropic Virus type 1 (HTLV-1) is the etiological agent of Adult T cell Leukemia/Lymphoma (ATLL) and HTLV-1-Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP). Both CD4+ T-cells and dendritic cells (DCs) infected with HTLV-1 are found in peripheral blood from HTLV-1 carriers. We previously demonstrated that monocyte-derived IL-4 DCs are more susceptible to HTLV-1 infection than autologous primary T-cells, suggesting that DC infection precedes T-cell infection. However, during blood transmission, breast-feeding or sexual transmission, HTLV-1 may encounter different DC subsets present in the blood, the intestinal or genital mucosa respectively. These different contacts may impact HTLV-1 ability to infect DCs and its subsequent transfer to T-cells. Using in vitro monocyte-derived IL-4 DCs, TGF-β DCs and IFN-α DCs that mimic DCs contacting HTLV-1 in vivo, we show here that despite their increased ability to capture HTLV-1 virions, IFN-α DCs restrict HTLV-1 productive infection. Surprisingly, we then demonstrate that it is not due to the antiviral activity of type–I interferon produced by IFN-α DCs, but that it is likely to be linked to a distinct trafficking route of HTLV-1 in IL-4 DCs vs. IFN-α DCs. Finally, we demonstrate that, in contrast to IL-4 DCs, IFN-α DCs are impaired in their capacity to transfer HTLV-1 to CD4 T-cells, both after viral capture and trans-infection and after their productive infection. In conclusion, the nature of the DCs encountered by HTLV-1 upon primo-infection and the viral trafficking route through the vesicular pathway of these cells determine the efficiency of viral transmission to T-cells, which may condition the fate of infection. PMID:28426803

The expression analysis of ICOS-L on activated T cells and immature dendritic cells as well as malignant B cells and Grave's-disease-derived thyroid tissues by two novel mAbs against human ICOS-L.

PubMed

Wang, F; Zhu, W; Liu, T; Sun, Z; Ju, S; Ju, S; Yu, G; Xie, W; Deng, Z; Lu, B; Zhang, X

2007-01-01

ICOS-L, a newly identified member of B7 superfamily, plays an important role in immune responses. In this article, we report on two novel mouse anti-human ICOS-L monoclonal antibodies (mAbs) named as 11C4 and 12B11, whose specificities were verified by methods of flow cytometry, western blotting, and epitope competition assay. The two mAbs bound to distinct ICOS-L epitopes on B cells. Interestingly, mAb 11C4 could well recognize ICOS-L molecule on activated T cells and Jurkat cell lines, which is different from commercial anti-ICOS-L mAb (clone number MIH12) and the other mAb 12B11. In addition, we found that the expression of ICOS-L molecule was only detected on the surface of immature monocyte-derived dendritic cells (Mo-DCs) and was sharply decreased after induction of mature Mo-DCs activated by tumor necrosis factor-alpha or CD40. Furthermore, we showed that 11C4 could effectively suppress the maturation of Mo-DCs in vitro as evidenced by the low expression of CD80, CD86, CD83, and human leukocyte antigen-DR, which suggested that ICOS-L may be involved in the maturation of Mo-DCs. Using immunohistochemistry staining with mAb 11C4, the expression of ICOS-L was found in B lymphoma tissues and thyroid tissues from the Grave's disease but not in thyroid adenoma and normal thyroid tissues.

The aryl hydrocarbon receptor and food allergy.

PubMed

Schulz, V J; Smit, J J; Pieters, R H H

2013-06-01

The immune system is important for protection against pathogens and malignant cells. However, malfunction of the immune system can also result in detrimental auto-immune diseases, inflammatory diseases, cancers and allergies. The aryl hydrocarbon receptor (AhR), present in numerous tissues and cell subsets, including cells of the immune system, plays an important role in the functioning of the immune system. Activation of the AhR is for example associated with various effects on dendritic cells (DCs), regulatory T cells and the Th1/Th2 cell balance. These cells play a major role in the development of food allergy. Food allergy is an increasing health problem in both humans and animals. Despite the knowledge in risk factors and cellular mechanisms for food allergy, no approved treatments are available yet. Recently, it has been shown that activation of the AhR by dioxin-like compounds suppresses allergic sensitization by suppressing the absolute number of precursor and effector T cells, by preserving CD4(+)CD25(+)Foxp3(+) Treg cells and by affecting DCs and their interaction with effector T cells. Future research should elucidate whether and how AhR activation can be used to interfere in food allergic responses in humans and in animals. This may lead to new prevention strategies and therapeutic possibilities for food allergy.

p21 Restricts HIV-1 in Monocyte-Derived Dendritic Cells through the Reduction of Deoxynucleoside Triphosphate Biosynthesis and Regulation of SAMHD1 Antiviral Activity.

PubMed

Valle-Casuso, Jose Carlos; Allouch, Awatef; David, Annie; Lenzi, Gina M; Studdard, Lydia; Barré-Sinoussi, Françoise; Müller-Trutwin, Michaela; Kim, Baek; Pancino, Gianfranco; Sáez-Cirión, Asier

2017-12-01

HIV-1 infection of noncycling cells, such as dendritic cells (DCs), is impaired due to limited availability of deoxynucleoside triphosphates (dNTPs), which are needed for HIV-1 reverse transcription. The levels of dNTPs are tightly regulated during the cell cycle and depend on the balance between dNTP biosynthesis and degradation. SAMHD1 potently blocks HIV-1 replication in DCs, although the underlying mechanism is still unclear. SAMHD1 has been reported to be able to degrade dNTPs and viral nucleic acids, which may both hamper HIV-1 reverse transcription. The relative contribution of these activities may differ in cycling and noncycling cells. Here, we show that inhibition of HIV-1 replication in monocyte-derived DCs (MDDCs) is associated with an increased expression of p21cip1/waf, a cell cycle regulator that is involved in the differentiation and maturation of DCs. Induction of p21 in MDDCs decreases the pool of dNTPs and increases the antiviral active isoform of SAMHD1. Although both processes are complementary in inhibiting HIV-1 replication, the antiviral activity of SAMHD1 in our primary cell model appears to be, at least partially, independent of its dNTPase activity. The reduction in the pool of dNTPs in MDDCs appears rather mostly due to a p21-mediated suppression of several enzymes involved in dNTP synthesis (i.e., RNR2, TYMS, and TK-1). These results are important to better understand the interplay between HIV-1 and DCs and may inform the design of new therapeutic approaches to decrease viral dissemination and improve immune responses against HIV-1. IMPORTANCE DCs play a key role in the induction of immune responses against HIV. However, HIV has evolved ways to exploit these cells, facilitating immune evasion and virus dissemination. We have found that the expression of p21, a cyclin-dependent kinase inhibitor involved in cell cycle regulation and monocyte differentiation and maturation, potentially can contribute to the inhibition of HIV-1 replication in monocyte-derived DCs through multiple mechanisms. p21 decreased the size of the intracellular dNTP pool. In parallel, p21 prevented SAMHD1 phosphorylation and promoted SAMHD1 dNTPase-independent antiviral activity. Thus, induction of p21 resulted in conditions that allowed the effective inhibition of HIV-1 replication through complementary mechanisms. Overall, p21 appears to be a key regulator of HIV infection in myeloid cells. Copyright © 2017 American Society for Microbiology.

Targeting MOG expression to dendritic cells delays onset of experimental autoimmune disease.

PubMed

Ko, Hyun-Ja; Chung, Jie-Yu; Nasa, Zeyad; Chan, James; Siatskas, Christopher; Toh, Ban-Hock; Alderuccio, Frank

2011-05-01

Haematopoietic stem cell (HSC) transfer coupled with gene therapy is a powerful approach to treating fatal diseases such as X-linked severe combined immunodeficiency. This ability to isolate and genetically manipulate HSCs also offers a strategy for inducing immune tolerance through ectopic expression of autoantigens. We have previously shown that retroviral transduction of bone marrow (BM) with vectors encoding the autoantigen, myelin oligodendrocyte glycoprotein (MOG), can prevent the induction of experimental autoimmune encephalomyelitis (EAE). However, ubiquitous cellular expression of autoantigen driven by retroviral promoters may not be the best approach for clinical translation and a targeted expression approach may be more acceptable. As BM-derived dendritic cells (DCs) play a major role in tolerance induction, we asked whether targeted expression of MOG, a target autoantigen in EAE, to DCs can promote tolerance induction and influence the development of EAE. Self-inactivating retroviral vectors incorporating the mouse CD11c promoter were generated and used to transduce mouse BM cells. Transplantation of gene-modified cells into irradiated recipients resulted in the generation of chimeric mice with transgene expression limited to DCs. Notably, chimeric mice transplanted with MOG-expressing BM cells manifest a significant delay in the development of EAE suggesting that targeted antigen expression to tolerogenic cell types may be a feasible approach to inducing antigen-specific tolerance.

Cyclooxygenase-2 Inhibition Enhances Proliferation of NKT Cells Derived from Patients with Laryngeal Cancer.

PubMed

Klatka, Janusz; Grywalska, Ewelina; Hymos, Anna; Guz, Małgorzata; Polberg, Krzysztof; Roliński, Jacek; Stepulak, Andrzej

2017-08-01

The aim of this study was to analyze whether inhibition of cyclooxygenase-2 by celecoxib and the subsequent enhancement in the proliferation of natural killer T (NKT) cells could play a role in dendritic cell (DC)-based laryngeal cancer (LC) immunotherapy. Peripheral blood mononuclear cells were obtained from 48 male patients diagnosed with LC and 30 control patients without cancer disease. Neoplastic cell lysate preparations were made from cancer tissues obtained after surgery and used for in vitro DCs generation. NKT cells proliferation assay was performed based on 3 H-thymidine incorporation assay. An increased proliferation of NKT cells was obtained from control patients compared to NKT cells obtained from LC patients regardless of the type of stimulation or treatment. In the patient group diagnosed with LC, COX-2 inhibition resulted in a significantly enhanced proliferation of NKT cells when stimulated with autologous DCs than NKT cells stimulated with DCs without COX-2 inhibition. These correlations were not present in the control group. Higher proliferation rate of NKT cells was also observed in non-metastatic and highly differentiated LC, which was independent of the type of stimulation or treatment. COX-2 inhibition could be regarded as immunotherapy-enhancing tool in patients with LC. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Minocycline promotes the generation of dendritic cells with regulatory properties.

PubMed

Kim, Narae; Park, Chan-Su; Im, Sun-A; Kim, Ji-Wan; Lee, Jae-Hee; Park, Young-Jun; Song, Sukgil; Lee, Chong-Kil

2016-08-16

Minocycline, which has long been used as a broad-spectrum antibiotic, also exhibits non-antibiotic properties such as inhibition of inflammation and angiogenesis. In this study, we show that minocycline significantly enhances the generation of dendritic cells (DCs) from mouse bone marrow (BM) cells when used together with GM-CSF and IL-4. DCs generated from BM cells in the presence of minocycline (Mino-DCs) demonstrate the characteristics of regulatory DCs. Compared with control DCs, Mino-DCs are resistant to subsequent maturation stimuli, impaired in MHC class II-restricted exogenous Ag presentation, and show decreased cytokine secretion. Mino-DCs also show decreased ability to prime allogeneic-specific T cells, while increasing the expansion of CD4+CD25+Foxp3+ T regulatory cells both in vitro and in vivo. In addition, pretreatment with MOG35-55 peptide-pulsed Mino-DCs ameliorates clinical signs of experimental autoimmune encephalitis induced by MOG peptide injection. Our study identifies minocycline as a new pharmacological agent that could be potentially used to increase the production of regulatory DCs for cell therapy to treat autoimmune disorders, allergy, and transplant rejection.

RUNX2 Mediates Plasmacytoid Dendritic Cell Egress from the Bone Marrow and Controls Viral Immunity.

PubMed

Chopin, Michaël; Preston, Simon P; Lun, Aaron T L; Tellier, Julie; Smyth, Gordon K; Pellegrini, Marc; Belz, Gabrielle T; Corcoran, Lynn M; Visvader, Jane E; Wu, Li; Nutt, Stephen L

2016-04-26

Plasmacytoid dendritic cells (pDCs) represent a unique immune cell type that responds to viral nucleic acids through the rapid production of type I interferons. Within the hematopoietic system, the transcription factor RUNX2 is exclusively expressed in pDCs and is required for their peripheral homeostasis. Here, we show that RUNX2 plays an essential role in promoting pDC localization and function. RUNX2 is required for the appropriate expression of the integrin-mediated adhesion machinery, as well as for the down-modulation of the chemokine receptor CXCR4, which allows pDC egress into the circulation. RUNX2 also facilitates the robust response to viral infection through the control of IRF7, the major regulator of type I interferon production. Mice lacking one copy of Runx2 have reduced numbers of peripheral pDCs and IFN-α expression, which might contribute to the reported difficulties of individuals with cleidocranial dysplasia, who are haploinsufficient for RUNX2, to clear viral infections. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Functional Analysis of Dendritic Cells Generated from T-iPSCs from CD4+ T Cell Clones of Sjögren's Syndrome.

PubMed

Iizuka-Koga, Mana; Asashima, Hiromitsu; Ando, Miki; Lai, Chen-Yi; Mochizuki, Shinji; Nakanishi, Mahito; Nishimura, Toshinobu; Tsuboi, Hiroto; Hirota, Tomoya; Takahashi, Hiroyuki; Matsumoto, Isao; Otsu, Makoto; Sumida, Takayuki

2017-05-09

Although it is important to clarify the pathogenic functions of T cells in human samples, their examination is often limited due to difficulty in obtaining sufficient numbers of dendritic cells (DCs), used as antigen-presenting cells, especially in autoimmune diseases. We describe the generation of DCs from induced pluripotent stem cells derived from T cells (T-iPSCs). We reprogrammed CD4+ T cell clones from a patient with Sjögren's syndrome (SS) into iPSCs, which were differentiated into DCs (T-iPS-DCs). T-iPS-DCs had dendritic cell-like morphology, and expressed CD11c, HLA-DR, CD80, CD86, and also BDCA-3. Compared with monocyte-derived DCs, the capacity for antigen processing was similar, and T-iPS-DCs induced the proliferative response of autoreactive CD4+ T cells. Moreover, we could evaluate T cell functions of the patient with SS. In conclusion, we obtained adequate numbers of DCs from T-iPSCs, which could be used to characterize pathogenic T cells in autoimmune diseases such as SS. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Human CD1c+ dendritic cells drive the differentiation of CD103+ CD8+ mucosal effector T cells via the cytokine TGF-β

PubMed Central

Yu, Chun I; Becker, Christian; Wang, Yuanyuan; Marches, Florentina; Helft, Julie; Leboeuf, Marylene; Anguiano, Esperanza; Pourpe, Stephane; Goller, Kristina; Pascual, Virginia; Banchereau, Jacques; Merad, Miriam; Palucka, Karolina

2013-01-01

Summary In comparison to murine dendritic cells (DCs), less is known about the function of human DCs in tissues. Here, we analyzed, using lung tissues from humans and humanized mice, the role of human CD1c+ and CD141+ DCs in determining the type of CD8+ T cell immunity generated to live-attenuated influenza virus (LAIV) vaccine. We found that both lung DC subsets acquired influenza antigens in vivo and expanded specific cytotoxic CD8+ T cells in vitro. However, lung-tissue-resident CD1c+ DCs but not CD141+ DCs were able to drive CD103 expression on CD8+ T cells and promoted CD8+ T cell accumulation in lung epithelia in vitro and in vivo. CD1c+ DCs induction of CD103 expression was dependent on membrane-bound cytokine TGF-β1. Thus, CD1c+ and CD141+ DCs generate CD8+ T cells with different properties, and CD1c+ DCs specialize in the regulation of mucosal CD8+ T cells. PMID:23562160

Chromatin remodeling modulates radiosensitivity of the daughter cells derived from cell population exposed to low- and high-LET irradiation

PubMed Central

Chen, Xiaoyan; Zhu, Lin; Zhang, Hang; Wang, Chen; Shao, Chunlin

2017-01-01

Radiation effects are dependent of linear energy transfer (LET), but it is still obscure whether the daughter cells (DCs) derived from irradiated population are radioresistance and much less the underlying mechanism. With the measurements of survival, proliferation and γH2AX foci, this study shows that the DCs from γ-ray irradiated cells (DCs-γ) became more radioresistant than its parent control without irradiation, but the radiosensitivity of DCs from α-particle irradiated cells (DCs-α) was not altered. After irradiation with equivalent doses of γ-rays and α-particles, the foci number of histone H3 lysine 9 dimethylation (H3K9me3) and the activity of histone deacetylase (HDAC) in DCs-γ was extensively higher than these in DCs-α and its parent control, indicating that a higher level of heterochromatin was formed in DCs-γ but not in DCs-α. Treatment of cells with SAHA (an inhibitor of HDAC) decreased the level of heterochromatin domains by inhibiting the expressions of H3K9m3 and HP-1a proteins and triggering the expression of acetylated core histone H3 (Ac-H3). When cells were treated with SAHA, the radioresistance phenotype of DCs-γ was eliminated so that the radiosensitivities of DCs-γ, DCs-α and their parent cells approached to same levels. Our current results reveal that γ-rays but not α-particles could induce chromatin remodeling and heterochromatinization which results in the occurrence of radioresistance of DCs, indicating that the combination treatment of irradiation and HDAC inhibitor could serve as a potential cancer therapy strategy, especially for the fraction radiotherapy of low-LET irradiation. PMID:28881774

Differential lower airway dendritic cell patterns may reveal distinct endotypes of RSV bronchiolitis.

PubMed

Kerrin, Aoife; Fitch, Paul; Errington, Claire; Kerr, Dennis; Waxman, Liz; Riding, Kay; McCormack, Jon; Mehendele, Felicity; McSorley, Henry; MacKenzie, Karen; Wronski, Sabine; Braun, Armin; Levin, Richard; Theilen, Ulf; Schwarze, Jürgen

2017-07-01

The pathogenesis of respiratory syncytial virus (RSV) bronchiolitis in infants remains poorly understood. Mouse models implicate pulmonary T cells in the development of RSV disease. T cell responses are initiated by dendritic cells (DCs), which accumulate in lungs of RSV-infected mice. In infants with RSV bronchiolitis, previous reports have shown that DCs are mobilised to the nasal mucosa, but data on lower airway DC responses are lacking. To determine the presence and phenotype of DCs and associated immune cells in bronchoalveolar lavage (BAL) and peripheral blood samples from infants with RSV bronchiolitis. Infants intubated and ventilated due to severe RSV bronchiolitis or for planned surgery (controls with healthy lungs) underwent non-bronchoscopic BAL. Immune cells in BAL and blood samples were characterised by flow cytometry and cytokines measured by Human V-Plex Pro-inflammatory Panel 1 MSD kit. In RSV cases, BAL conventional DCs (cDCs), NK T cells, NK cells and pro-inflammatory cytokines accumulated, plasmacytoid DCs (pDCs) and T cells were present, and blood cDCs increased activation marker expression. When stratifying RSV cases by risk group, preterm and older (≥4 months) infants had fewer BAL pDCs than term born and younger (<4 months) infants, respectively. cDCs accumulate in the lower airways during RSV bronchiolitis, are activated systemically and may, through activation of T cells, NK T cells and NK cells, contribute to RSV-induced inflammation and disease. In addition, the small population of airway pDCs in preterm and older infants may reveal a distinct endotype of RSV bronchiolitis with weak antiviral pDC responses. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

miRNomes of haematopoietic stem cells and dendritic cells identify miR-30b as a regulator of Notch1

PubMed Central

Su, Xiaoping; Qian, Cheng; Zhang, Qian; Hou, Jin; Gu, Yan; Han, Yanmei; Chen, Yongjian; Jiang, Minghong; Cao, Xuetao

2013-01-01

Dendritic cells (DCs) are critical to initiate the immune response and maintain tolerance, depending on different status and subsets. The expression profiles of microRNAs (miRNAs) in various DC subsets and haematopoietic stem cells (HSCs), which generate DCs, remain to be fully identified. Here we examine miRNomes of mouse bone marrow HSCs, immature DCs, mature DCs and IL-10/NO-producing regulatory DCs by deep sequencing. We identify numerous stage-specific miRNAs and histone modification in HSCs and DCs at different differentiation stages. miR-30b, significantly upregulated via a TGF-beta/Smad3-mediated epigenetic pathway in regulatory DCs, can target Notch1 to promote IL-10 and NO production, suggesting that miR-30b is a negative regulator of immune response. We also identify miRNomes of in vivo counterparts of mature DCs and regulatory DCs and systematically compare them with DCs cultured in vitro. These results provide a resource for studying roles of miRNAs in stem cell biology, development and functional regulation of DC subsets. PMID:24309499

GM-CSF Monocyte-Derived Cells and Langerhans Cells As Part of the Dendritic Cell Family

PubMed Central

Lutz, Manfred B.; Strobl, Herbert; Schuler, Gerold; Romani, Nikolaus

2017-01-01

Dendritic cells (DCs) and macrophages (Mph) share many characteristics as components of the innate immune system. The criteria to classify the multitude of subsets within the mononuclear phagocyte system are currently phenotype, ontogeny, transcription patterns, epigenetic adaptations, and function. More recently, ontogenetic, transcriptional, and proteomic research approaches uncovered major developmental differences between Flt3L-dependent conventional DCs as compared with Mphs and monocyte-derived DCs (MoDCs), the latter mainly generated in vitro from murine bone marrow-derived DCs (BM-DCs) or human CD14+ peripheral blood monocytes. Conversely, in vitro GM-CSF-dependent monocyte-derived Mphs largely resemble MoDCs whereas tissue-resident Mphs show a common embryonic origin from yolk sac and fetal liver with Langerhans cells (LCs). The novel ontogenetic findings opened discussions on the terminology of DCs versus Mphs. Here, we bring forward arguments to facilitate definitions of BM-DCs, MoDCs, and LCs. We propose a group model of terminology for all DC subsets that attempts to encompass both ontogeny and function. PMID:29109731

Fc receptor-targeting of immunogen as a strategy for enhanced antigen loading, vaccination, and protection using intranasally administered antigen-pulsed dendritic cells.

PubMed

Pham, Giang H; Iglesias, Bibiana V; Gosselin, Edmund J

2014-09-08

Dendritic cells (DCs) play a critical role in the generation of adaptive immunity via the efficient capture, processing, and presentation of antigen (Ag) to naïve T cells. Administration of Ag-pulsed DCs is also an effective strategy for enhancing immunity to tumors and infectious disease organisms. Studies have also demonstrated that targeting Ags to Fcγ receptors (FcγR) on Ag presenting cells can enhance humoral and cellular immunity in vitro and in vivo. Specifically, our studies using a Francisella tularensis (Ft) infectious disease vaccine model have demonstrated that targeting immunogens to FcγR via intranasal (i.n.) administration of monoclonal antibody (mAb)-inactivated Ft (iFt) immune complexes (ICs) enhances protection against Ft challenge. Ft is the causative agent of tularemia, a debilitating disease of humans and other mammals and a category A biothreat agent for which there is no approved vaccine. Therefore, using iFt Ag as a model immunogen, we sought to determine if ex vivo targeting of iFt to FcγR on DCs would enhance the potency of i.n. administered iFt-pulsed DCs. In this study, bone marrow-derived DCs (BMDCs) were pulsed ex vivo with iFt or mAb-iFt ICs. Intranasal administration of mAb-iFt-pulsed BMDCs enhanced humoral and cellular immune responses, as well as protection against Ft live vaccine strain (LVS) challenge. Increased protection correlated with increased iFt loading on the BMDC surface as a consequence of FcγR-targeting. However, the inhibitory FcγRIIB had no impact on this enhancement. In conclusion, targeting Ag ex vivo to FcγR on DCs provides a method for enhanced Ag loading of DCs ex vivo, thereby reducing the amount of Ag required, while also avoiding the inhibitory impact of FcγRIIB. Thus, this represents a simple and less invasive strategy for increasing the potency of ex vivo-pulsed DC vaccines against chronic infectious diseases and cancer. Copyright © 2014 Elsevier Ltd. All rights reserved.

Fc Receptor-Targeting of Immunogen as a Strategy for Enhanced Antigen Loading, Vaccination, and Protection Using Intranasally-Administered Antigen-Pulsed Dendritic Cells

PubMed Central

Pham, Giang H.; Iglesias, Bibiana V.; Gosselin, Edmund J.

2014-01-01

Dendritic cells (DCs) play a critical role in the generation of adaptive immunity via the efficient capture, processing, and presentation of antigen (Ag) to naïve T cells. Administration of Ag-pulsed DCs is also an effective strategy for enhancing immunity to tumors and infectious disease organisms. Studies have also demonstrated that targeting Ags to Fcγ receptors (FcγR) on Ag presenting cells can enhance humoral and cellular immunity in vitro and in vivo. Specifically, our studies using an F. tularensis (Ft) infectious disease vaccine model have demonstrated that targeting immunogens to FcγR via intranasal (i.n.) administration of monoclonal antibody (mAb)-inactivated Ft (iFt) immune complexes (ICs) enhances protection against Ft challenge. Ft is the causative agent of tularemia, a debilitating disease of humans and other mammals and a category A biothreat agent for which there is no approved vaccine. Therefore, using iFt Ag as a model immunogen, we sought to determine if ex vivo targeting of iFt to FcγR on DCs would enhance the potency of i.n. administered iFt-pulsed DCs. In this study, bone marrow-derived DCs (BMDCs) were pulsed ex vivo with iFt or mAb-iFt ICs. Intranasal administration of mAb-iFt-pulsed BMDCs enhanced humoral and cellular immune responses, as well as protection against Ft live vaccine strain (LVS) challenge. Increased protection correlated with increased iFt loading on the BMDC surface as a consequence of FcγR targeting. However, the inhibitory FcγRIIB had no impact on this enhancement. In conclusion, targeting Ag ex vivo to FcγR on DCs provides a method for enhanced Ag loading of DCs ex vivo, thereby reducing the amount of Ag required, while also avoiding the inhibitory impact of FcγRIIB. Thus, this represents a simple and less invasive strategy for increasing the potency of ex vivo-pulsed DC vaccines against chronic infectious diseases and cancer. PMID:25068496

Effect of porcine circovirus type 2 (PCV2) on the function of splenic CD11c+ dendritic cells in mice.

PubMed

Wang, Xiaobo; Chen, Ligong; Yuan, Wanzhe; Li, Yanqin; Li, Limin; Li, Tanqing; Li, Huanrong; Song, Qinye

2017-05-01

Porcine circovirus-associated disease (PCVAD) caused by porcine circovirus type 2 (PCV2) is an important disease in the global pig industry. Dendritic cells (DCs) are the primary immune cells capable of initiating adaptive immune responses as well as major target cells of PCV2. To determine whether PCV2 affects the immune functions of DCs, we evaluated the expression of endocytosis and co-stimulatory molecules on DCs (CD11c + ) from PCV2-infected mouse spleen by flow cytometry (FCM). We also analyzed the main cytokines secreted by DCs (CD11c + ) and activation of CD4 + and CD8 + T cells by DCs (CD11c + ) through measurement of cytokine secretion, using ELISA. Compared with control mice, PCV2 did not affect the endocytic activity of DCs but it significantly enhanced TNF-α secretion and markedly decreased IFN-α secretion. Subsets of CD40 + , MHCII + CD40 + and CD137L + CD86 + DCs did not increase obviously, but MHCII + CD40 - and CD137L - CD80 + /CD86 + DCs increased significantly in PCV2-infected mouse spleen. Under the stimulation of DCs from PCV2-infected mouse, secretion of IFN-γ by CD4 + and CD8 + T cells and of IL-12 by CD8 + T cells was significantly lower than in control mice, while secretion of IL-4 by CD4 + T cells was remarkably higher. These results indicate that PCV2 modulates cytokine secretion and co-stimulatory molecule expression of DCs, and alters activation of CD4 + and CD8 + T cells by DCs. The immunomodulatory effects of PCV2 on DCs might be related to the host's immune dysfunction and persistent infection with this virus.

A Tec kinase BTK inhibitor ibrutinib promotes maturation and activation of dendritic cells.

PubMed

Natarajan, Gayathri; Oghumu, Steve; Terrazas, Cesar; Varikuti, Sanjay; Byrd, John C; Satoskar, Abhay R

2016-06-01

Ibrutinib, a BTK inhibitor, is currently used to treat various hematological malignancies. We evaluated whether ibrutinib treatment during development of murine bone marrow-derived dendritic cells (DCs) modulates their maturation and activation. Ibrutinib treatment increased the proportion of CD11c(+) DCs, upregulated the expression of MHC-II and CD80 and downregulated Ly6C expression by DCs. Additionally, ibrutinib treatment led to an increase in MHC-II(+), CD80(+) and CCR7(+) DCs but a decrease in CD86(+) DCs upon LPS stimulation. LPS/ibrutinib-treated DCs displayed increased IFNβ and IL-10 synthesis and decreased IL-6, IL-12 and NO production compared to DCs stimulated with LPS alone. Finally, LPS/ibrutinib-treated DCs promoted higher rates of CD4(+) T cell proliferation and cytokine production compared to LPS only stimulated DCs. Taken together, our results indicate that ibrutinib enhances the maturation and activation of DCs to promote CD4(+) T cell activation which could be exploited for the development of DC-based cancer therapies.

IFNγ Signaling Endows DCs with the Capacity to Control Type I Inflammation during Parasitic Infection through Promoting T-bet+ Regulatory T Cells

PubMed Central

Lee, Hyang-Mi; Fleige, Anne; Forman, Ruth; Cho, Sunglim; Khan, Aly Azeem; Lin, Ling-Li; Nguyen, Duc T.; O'Hara-Hall, Aisling; Yin, Zhinan; Hunter, Christopher A.; Muller, Werner; Lu, Li-Fan

2015-01-01

IFNγ signaling drives dendritic cells (DCs) to promote type I T cell (Th1) immunity. Here, we show that activation of DCs by IFNγ is equally crucial for the differentiation of a population of T-bet+ regulatory T (Treg) cells specialized to inhibit Th1 immune responses. Conditional deletion of IFNγ receptor in DCs but not in Treg cells resulted in a severe defect in this specific Treg cell subset, leading to exacerbated immune pathology during parasitic infections. Mechanistically, IFNγ-unresponsive DCs failed to produce sufficient amount of IL-27, a cytokine required for optimal T-bet induction in Treg cells. Thus, IFNγ signalling endows DCs with the ability to efficiently control a specific type of T cell immunity through promoting a corresponding Treg cell population. PMID:25658840

Human 6-sulfo LacNAc (slan) dendritic cells have molecular and functional features of an important pro-inflammatory cell type in lupus erythematosus.

PubMed

Hänsel, Anja; Günther, Claudia; Baran, Wojciech; Bidier, Mona; Lorenz, Hanns-Martin; Schmitz, Marc; Bachmann, Michael; Döbel, Thomas; Enk, Alexander H; Schäkel, Knut

2013-02-01

Lupus erythematosus (LE) is an autoimmune disease with evidence for an IL-23- and IL-17-induced immunopathology. Little is known about the type of dendritic cells supporting this immune response. We recently demonstrated the strong Th1- and Th17-T-cell inducing capacity of human 6-sulfo LacNAc-dendritic cells (slanDCs), and identified slanDCs as inflammatory dermal dendritic cells in psoriasis locally expressing IL-23, TNF-α and inducible nitric oxide synthase (iNOS). In this study, we investigated the role of slanDCs in LE. Using immunohistochemistry, we identified slanDCs at increased frequency in affected skin lesions of cutaneous and systemic LE. slanDCs were found scattered in the dermal compartment and also clustered in lymph follicle-like structures. Here, they colocalized with T cells in the periphery but not with B cells in the center. The positive staining of dermal slanDCs for TNF-α indicated their pro-inflammatory status. In vitro the production of TNF-α was induced when slanDCs were cultured in the presence of serum from patients with LE. Stimulatory components of LE serum were previously identified as autoimmune complexes with ssRNA binding to TLR7 and TLR8. We found that slanDCs express mRNA for TLR7 and TLR8. slanDCs stimulated with ssRNA, selective TLR7 or TLR8 ligands responded with high-level TNF-α and IL-12 production. In contrast to slanDCs, the population of CD1c(+) DCs and plasmacytoid DCs (pDCs) expressed either TLR7 or TLR8, and their production of TNF-α and IL-12 to respective ligands was far less pronounced. We conclude that slanDCs have molecular and functional features of a pro-inflammatory myeloid DC type relevant for the immunopathogenesis of LE. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

The role of DAMPS in ALA-PDT for skin squamous cell carcinoma (Conference Presentation)

NASA Astrophysics Data System (ADS)

Wang, Xiuli; Wang, Xiaojie; Ji, Jie; Zhang, Haiyan; Shi, Lei

2016-03-01

5-Aminolevulinic acid mediated photodynamic therapy (ALA-PDT) is an established local approach for skin squamous cell carcinoma. It is believed that dangerous signals damage-associated molecular patterns (DAMPs) play an important role in ALA-PDT. In this study, we evaluated in vitro and in vivo expressions of major DAMPs, calreticulin (CRT), heat shock proteins 70 (HSP70), and high mobility group box 1 (HMGB1), induced by ALA-PDT using immunohistochemistry, western blot, and ELISA in a squamous cell carcinoma (SCC) mouse model. The role of DAMPs in the maturation of DCs potentiated by ALA-PDT-treated tumor cells was detected by FACS and ELISA. Our results showed that ALA-PDT enhanced the expression of CRT, HSP70, and HMGB1. These induced DAMPs played an important role in activating DCs by PDT-treated tumor cells, including phenotypic maturation (upregulation of surface expression of MHC-II, CD80, and CD86) and functional maturation (enhanced capability to secrete IFN-γ and IL-12). Furthermore, injecting ALA-PDT-treated tumor cells into naïve mice resulted in complete protection against cancer cells of the same origin. Our findings indicate that ALA-PDT can upregulate DAMPs and enhance tumor immunogenicity, providing a promising strategy for inducing a systemic anticancer immune response.

[Dopamine receptor signaling regulates human osteoclastogenesis].

PubMed

Hanami, Kentaro; Nakano, Kazuhisa; Tanaka, Yoshiya

2013-01-01

Although the central nervous system and the neurotransmitters are known to control not only the immune system but also the homeostasis of bone mass, their pathological relevance to bone disorders remains unclear. Osteoclasts in the synovium of rheumatoid arthritis (RA) play an important role in bone destruction. It is known that increased sympathetic nervous activity increases both differentiation and function of osteoclasts, which leads to bone loss. Dopamine, a major neurotransmitter, transmits signals via five different seven-transmembrane G protein-coupled receptors termed D1 to D5. We previously reported that dopamine plays an important role in IL-6-IL-17 axis and subsequent joint destruction in RA. The major source of dopamine in the synovial tissue of RA was dendritic cells (DCs) that stored and secreted dopamine. Dopamine released by DCs bounded to D1-like dopamine receptors on T cells and induced activation of cAMP and differentiation to Th17 cells via IL-6 production We here overview the interplay among the immune system, bone metabolism and neurologic system shedding light upon dopaminergic signals upon osteoclastogenesis.

Mesenchymal stem cells induce mature dendritic cells into a novel Jagged-2-dependent regulatory dendritic cell population.

PubMed

Zhang, Bin; Liu, Rui; Shi, Dan; Liu, Xingxia; Chen, Yuan; Dou, Xiaowei; Zhu, Xishan; Lu, Chunhua; Liang, Wei; Liao, Lianming; Zenke, Martin; Zhao, Robert C H

2009-01-01

Mesenchymal stem cells (MSCs), in addition to their multilineage differentiation, exert immunomodulatory effects on immune cells, even dendritic cells (DCs). However, whether they influence the destiny of full mature DCs (maDCs) remains controversial. Here we report that MSCs vigorously promote proliferation of maDCs, significantly reduce their expression of Ia, CD11c, CD80, CD86, and CD40 while increasing CD11b expression. Interestingly, though these phenotypes clearly suggest their skew to immature status, bacterial lipopolysaccharide (LPS) stimulation could not reverse this trend. Moreover, high endocytosic capacity, low immunogenicity, and strong immunoregulatory function of MSC-treated maDCs (MSC-DCs) were also observed. Furthermore we found that MSCs, partly via cell-cell contact, drive maDCs to differentiate into a novel Jagged-2-dependent regulatory DC population and escape their apoptotic fate. These results further support the role of MSCs in preventing rejection in organ transplantation and treatment of autoimmune disease.

DNA and protein co-administration induces tolerogenic dendritic cells through DC-SIGN mediated negative signals.

PubMed

Li, Jinyao; Geng, Shuang; Liu, Xiuping; Liu, Hu; Jin, Huali; Liu, Chang-Gong; Wang, Bin

2013-10-01

We previously demonstrated that DNA and protein co-administration induced differentiation of immature dendritic cells (iDCs) into CD11c(+)CD40(low)IL-10(+) regulatory DCs (DCregs) via the caveolin-1 (Cav-1) -mediated signal pathway. Here, we demonstrate that production of IL-10 and the low expression of CD40 play a critical role in the subsequent induction of regulatory T cells (Tregs) by the DCregs. We observed that DNA and protein were co-localized with DC-SIGN in caveolae and early lysosomes in the treated DCs, as indicated by co-localization with Cav-1 and EEA-1 compartment markers. DNA and protein also co-localized with LAMP-2. Gene-array analysis of gene expression showed that more than a thousand genes were significantly changed by the DC co-treatment with DNA + protein compared with controls. Notably, the level of DC-SIGN expression was dramatically upregulated in pOVA + OVA co-treated DCs. The expression levels of Rho and Rho GNEF, the down-stream molecules of DC-SIGN mediated signal pathway, were also greatly upregulated. Further, the level of TLR9, the traditional DNA receptor, was significantly downregulated. These results suggest that DC-SIGN as the potential receptor for DNA and protein might trigger the negative pathway to contribute the induction of DCreg combining with Cav-1 mediated negative signal pathway.

DNA and protein co-administration induces tolerogenic dendritic cells through DC-SIGN mediated negative signals

PubMed Central

Li, Jinyao; Geng, Shuang; Liu, Xiuping; Liu, Hu; Jin, Huali; Liu, Chang-Gong; Wang, Bin

2013-01-01

We previously demonstrated that DNA and protein co-administration induced differentiation of immature dendritic cells (iDCs) into CD11c+CD40lowIL-10+ regulatory DCs (DCregs) via the caveolin-1 (Cav-1) -mediated signal pathway. Here, we demonstrate that production of IL-10 and the low expression of CD40 play a critical role in the subsequent induction of regulatory T cells (Tregs) by the DCregs. We observed that DNA and protein were co-localized with DC-SIGN in caveolae and early lysosomes in the treated DCs, as indicated by co-localization with Cav-1 and EEA-1 compartment markers. DNA and protein also co-localized with LAMP-2. Gene-array analysis of gene expression showed that more than a thousand genes were significantly changed by the DC co-treatment with DNA + protein compared with controls. Notably, the level of DC-SIGN expression was dramatically upregulated in pOVA + OVA co-treated DCs. The expression levels of Rho and Rho GNEF, the down-stream molecules of DC-SIGN mediated signal pathway, were also greatly upregulated. Further, the level of TLR9, the traditional DNA receptor, was significantly downregulated. These results suggest that DC-SIGN as the potential receptor for DNA and protein might trigger the negative pathway to contribute the induction of DCreg combining with Cav-1 mediated negative signal pathway. PMID:24051433

Transcriptome profile of lung dendritic cells after in vitro porcine reproductive and respiratory syndrome virus (PRRSV) infection

PubMed Central

Pröll, Maren Julia; Neuhoff, Christiane; Schellander, Karl; Uddin, Muhammad Jasim; Cinar, Mehmet Ulas; Sahadevan, Sudeep; Qu, Xueqi; Islam, Md. Aminul; Poirier, Mikhael; Müller, Marcel A.; Drosten, Christian; Tesfaye, Dawit; Tholen, Ernst; Große-Brinkhaus, Christine

2017-01-01

The porcine reproductive and respiratory syndrome (PRRS) is an infectious disease that leads to high financial and production losses in the global swine industry. The pathogenesis of this disease is dependent on a multitude of factors, and its control remains problematic. The immune system generally defends against infectious diseases, especially dendritic cells (DCs), which play a crucial role in the activation of the immune response after viral infections. However, the understanding of the immune response and the genetic impact on the immune response to PRRS virus (PRRSV) remains incomplete. In light of this, we investigated the regulation of the host immune response to PRRSV in porcine lung DCs using RNA-sequencing (RNA-Seq). Lung DCs from two different pig breeds (Pietrain and Duroc) were collected before (0 hours) and during various periods of infection (3, 6, 9, 12, and 24 hours post infection (hpi)). RNA-Seq analysis revealed a total of 20,396 predicted porcine genes, which included breed-specific differentially expressed immune genes. Pietrain and Duroc infected lung DCs showed opposite gene expression courses during the first time points post infection. Duroc lung DCs reacted more strongly and distinctly than Pietrain lung DCs during these periods (3, 6, 9, 12 hpi). Additionally, cluster analysis revealed time-dependent co-expressed groups of genes that were involved in immune-relevant pathways. Key clusters and pathways were identified, which help to explain the biological and functional background of lung DCs post PRRSV infection and suggest IL-1β1 as an important candidate gene. RNA-Seq was also used to characterize the viral replication of PRRSV for each breed. PRRSV was able to infect and to replicate differently in lung DCs between the two mentioned breeds. These results could be useful in investigations on immunity traits in pig breeding and enhancing the health of pigs. PMID:29140992

A novel CD4-CD8alpha+CD205+CD11b- murine spleen dendritic cell line: establishment, characterization and functional analysis in a model of vaccination to toxoplasmosis.

PubMed

Ruiz, Sophie; Beauvillain, Céline; Mévélec, Marie-Noëlle; Roingeard, Philippe; Breton, Pascal; Bout, Daniel; Dimier-Poisson, Isabelle

2005-11-01

Dendritic cells (DCs) play an essential role in the induction of immune responses to pathogen infections. Native DCs are difficult to obtain in large numbers and consequently the vast majority of DCs employed in all experiments are derived from bone marrow progenitors. In an attempt to solve this problem, we have established a novel CD8alpha(+) DC line (H-2(k)) from spleen, which we have named SRDC line, and which is easy to culture in vitro. These cells display similar morphology, phenotype and activity to CD4(-)CD8alpha(+)CD205(+)CD11b(-) DCs purified ex vivo. Toxoplasma gondii antigen was shown to be taken up by these cells and to increase class I and class II major histocompatibility complex (MHC), CD40, CD80 and CD86 surface expression. We report that vaccination with T. gondii antigen-pulsed SRDCs, which synthesize large amounts of interleukin-12, induced protective immune responses against this intracellular pathogen in syngeneic CBA/J mice. This protection was associated with strong cellular and humoral immune responses at systemic and intestinal levels. Spleen and mesenteric lymph node cell proliferations were correlated with a Th1/Th2-type response and a specific SRDC homing to spleen and intestine was observed. The SRDC or CD4(-)CD8alpha(+)CD205(+)CD11b(-) DC line can be expected to be a very useful tool for immunobiology studies of DC.

Influenza A Virus Infection of Human Primary Dendritic Cells Impairs Their Ability to Cross-Present Antigen to CD8 T Cells

PubMed Central

Smed-Sörensen, Anna; Chalouni, Cécile; Chatterjee, Bithi; Cohn, Lillian; Blattmann, Peter; Nakamura, Norihiro; Delamarre, Lélia; Mellman, Ira

2012-01-01

Influenza A virus (IAV) infection is normally controlled by adaptive immune responses initiated by dendritic cells (DCs). We investigated the consequences of IAV infection of human primary DCs on their ability to function as antigen-presenting cells. IAV was internalized by both myeloid DCs (mDCs) and plasmacytoid DCs but only mDCs supported viral replication. Although infected mDCs efficiently presented endogenous IAV antigens on MHC class II, this was not the case for presentation on MHC class I. Indeed, cross-presentation by uninfected cells of minute amounts of endocytosed, exogenous IAV was ∼300-fold more efficient than presentation of IAV antigens synthesized by infected cells and resulted in a statistically significant increase in expansion of IAV-specific CD8 T cells. Furthermore, IAV infection also impaired cross-presentation of other exogenous antigens, indicating that IAV infection broadly attenuates presentation on MHC class I molecules. Our results suggest that cross-presentation by uninfected mDCs is a preferred mechanism of antigen-presentation for the activation and expansion of CD8 T cells during IAV infection. PMID:22412374

Human Plasmacytoid Dendritic Cells Display and Shed B Cell Maturation Antigen upon TLR Engagement.

PubMed

Schuh, Elisabeth; Musumeci, Andrea; Thaler, Franziska S; Laurent, Sarah; Ellwart, Joachim W; Hohlfeld, Reinhard; Krug, Anne; Meinl, Edgar

2017-04-15

The BAFF-APRIL system is best known for its control of B cell homeostasis, and it is a target of therapeutic intervention in autoimmune diseases and lymphoma. By analyzing the expression of the three receptors of this system, B cell maturation Ag (BCMA), transmembrane activator and CAML interactor, and BAFF receptor, in sorted human immune cell subsets, we found that BCMA was transcribed in plasmacytoid dendritic cells (pDCs) in both blood and lymphoid tissue. Circulating human pDCs contained BCMA protein without displaying it on the cell surface. After engagement of TLR7/8 or TLR9, BCMA was detected also on the cell surface of pDCs. The display of BCMA on the surface of human pDCs was accompanied by release of soluble BCMA (sBCMA); inhibition of γ-secretase enhanced surface expression of BCMA and reduced the release of sBCMA by pDCs. In contrast with human pDCs, murine pDCs did not express BCMA, not even after TLR9 activation. In this study, we extend the spectrum of BCMA expression to human pDCs. sBCMA derived from pDCs might determine local availability of its high-affinity ligand APRIL, because sBCMA has been shown to function as an APRIL-specific decoy. Further, therapeutic trials targeting BCMA in patients with multiple myeloma should consider possible effects on pDCs. Copyright © 2017 by The American Association of Immunologists, Inc.

Evaluation of the skin sensitization potential of chemicals using expression of co-stimulatory molecules, CD54 and CD86, on the naive THP-1 cell line.

PubMed

Yoshida, Y; Sakaguchi, H; Ito, Y; Okuda, M; Suzuki, H

2003-04-01

It has been known that dendritic cells (DCs) including Langerhans cells (LCs) play a critical role in the skin sensitization process. Many attempts have been made to develop in vitro sensitization tests that employ DCs derived from peripheral blood mononuclear cells (PBMC-DC) or CD34+ hematopoietic progenitor cells (CD34+ HPC) purified from cord blood or bone marrow. However, the use of the DCs in in vitro methods has been difficult due to the nature of these cells such as low levels in the source and/or donor-to-donor variability. In our studies, we employed the human monocytic leukemia cell line, THP-1, in order to avoid some of these difficulties. At the start, we examined whether treatment of the cells with various cytokines could produce DCs from THP-1. Treatment of THP-1 cells with cytokines such as GM-CSF, IL-4, TNF-alpha, and/or PMA did induce some phenotypic changes in THP-1 cells that were characteristic of DCs. Subsequently, responses to a known sensitizer, dinitrochlorobenzene (DNCB), and a non-sensitizer, dimethyl sulfoxide (DMSO) or sodium lauryl sulfate (SLS), on the expression of co-stimulatory molecules, CD54 and CD86, were examined between the naive cells and the cytokine-treated cells. Interestingly, the naive THP-1 cells responded only to DNCB and the response to the sensitizer was more distinct than cytokine-treated THP-1 cells. Similar phenomena were also observed in the human myeloid leukemia cell line, KG-1. Furthermore, with treatment of DNCB, naive THP-1 cells showed augmented expression of HLA, CD80 and secretion of IL-1 beta. The response of THP-1 cells to a sensitizer was similar to that of LCs/DCs. Upon demonstrating the differentiation of monocyte cells in our system, we then evaluated a series of chemicals, including known sensitizers and non-sensitizers, for their potential to augment CD54 and CD86 expression on naive THP-1 cells. Indeed, known sensitizers such as PPD and 2-MBT significantly augmented CD54 and CD86 expression in a dose-dependent manner while non-sensitizers, such as SLS and methyl salicylate (MS), did not. To note, the metal allergens such as (NH(4))(2)[PtCl(4)], NiSO(4) and CoSO(4) augmented significantly only CD54 expression. Taking advantage of a cultured cell line, measurement of the co-stimulatory molecules, CD54 and CD86, on naive THP-1 cells following chemical exposure shows promise for the development of a simple, short-term in vitro sensitization test.

Prominent role for plasmacytoid dendritic cells in mucosal T cell-independent IgA induction.

PubMed

Tezuka, Hiroyuki; Abe, Yukiko; Asano, Jumpei; Sato, Taku; Liu, Jiajia; Iwata, Makoto; Ohteki, Toshiaki

2011-02-25

Although both conventional dendritic cells (cDCs) and plasmacytoid dendritic cells (pDCs) are present in the gut-associated lymphoid tissues (GALT), the roles of pDCs in the gut remain largely unknown. Here we show a critical role for pDCs in T cell-independent (TI) IgA production by B cells in the GALT. When pDCs of the mesenteric lymph nodes (MLNs) and Peyer's patches (PPs) (which are representative GALT) were cultured with naive B cells to induce TI IgA class switch recombination (CSR), IgA production was substantially higher than in cocultures of these cells with cDCs. IgA production was dependent on APRIL and BAFF production by pDCs. Importantly, pDC expression of APRIL and BAFF was dependent on stromal cell-derived type I IFN signaling under steady-state conditions. Our findings provide insight into the molecular basis of pDC conditioning to induce mucosal TI IgA production, which may lead to improvements in vaccination strategies and treatment for mucosal-related disorders. Copyright © 2011 Elsevier Inc. All rights reserved.

Antitumor Effects of Epidrug/IFNα Combination Driven by Modulated Gene Signatures in Both Colorectal Cancer and Dendritic Cells.

PubMed

Fragale, Alessandra; Romagnoli, Giulia; Licursi, Valerio; Buoncervello, Maria; Del Vecchio, Giorgia; Giuliani, Caterina; Parlato, Stefania; Leone, Celeste; De Angelis, Marta; Canini, Irene; Toschi, Elena; Belardelli, Filippo; Negri, Rodolfo; Capone, Imerio; Presutti, Carlo; Gabriele, Lucia

2017-07-01

Colorectal cancer results from the progressive accumulation of genetic and epigenetic alterations. IFN signaling defects play an important role in the carcinogenesis process, in which the inability of IFN transcription regulatory factors (IRF) to access regulatory sequences in IFN-stimulated genes (ISG) in tumors and in immune cells may be pivotal. We reported that low-dose combination of two FDA-approved epidrugs, azacytidine (A) and romidepsin (R), with IFNα2 (ARI) hampers the aggressiveness of both colorectal cancer metastatic and stem cells in vivo and triggers immunogenic cell death signals that stimulate dendritic cell (DC) function. Here, we investigated the molecular signals induced by ARI treatment and found that this drug combination increased the accessibility to regulatory sequences of ISGs and IRFs that were epigenetically silenced in both colorectal cancer cells and DCs. Likewise, specific ARI-induced histone methylation and acetylation changes marked epigenetically affected ISG promoters in both metastatic cancer cells and DCs. Analysis by ChIP-seq confirmed such ARI-induced epigenetically regulated IFN signature. The activation of this signal endowed DCs with a marked migratory capability. Our results establish a direct correlation between reexpression of silenced ISGs by epigenetic control and ARI anticancer activity and provide new knowledge for the development of innovative combined therapeutic strategies for colorectal cancer. Cancer Immunol Res; 5(7); 604-16. ©2017 AACR . ©2017 American Association for Cancer Research.

Frequency of Dendritic Cells and Their Expression of Costimulatory Molecules in Children with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Saad, Khaled; Zahran, Asmaa M.; Elsayh, Khalid I.; Abdel-Rahman, Ahmed A.; Al-Atram, Abdulrahman A.; Hussein, Almontaser; El-Gendy, Yasmin G.

2017-01-01

The aim of our study was to evaluate the frequencies of myeloid dendritic cells (mDCs) and plasmacytoid dendritic cells (pDCs) in children with ASD. Subjects were 32 children with ASD and 30 healthy children as controls. The numbers of mDCs and pDCs and the expression of CD86 and CD80 on the entire DCs were detected by flow cytometry. ASD children…

Lymphoid tissue and plasmacytoid dendritic cells and macrophages do not share a common macrophage-dendritic cell-restricted progenitor.

PubMed

Sathe, Priyanka; Metcalf, Donald; Vremec, David; Naik, Shalin H; Langdon, Wallace Y; Huntington, Nicholas D; Wu, Li; Shortman, Ken

2014-07-17

The relationship between dendritic cells (DCs) and macrophages is often debated. Here we ask whether steady-state, lymphoid-tissue-resident conventional DCs (cDCs), plasmacytoid DCs (pDCs), and macrophages share a common macrophage-DC-restricted precursor (MDP). Using new clonal culture assays combined with adoptive transfer, we found that MDP fractions isolated by previous strategies are dominated by precursors of macrophages and monocytes, include some multipotent precursors of other hematopoietic lineages, but contain few precursors of resident cDCs and pDCs and no detectable common precursors restricted to these DC types and macrophages. Overall we find no evidence for a common restricted MDP leading to both macrophages and FL-dependent, resident cDCs and pDCs. Copyright © 2014 Elsevier Inc. All rights reserved.

Chronic Fibro-Inflammatory Responses in Autoimmune Pancreatitis Depend on IFN-α and IL-33 Produced by Plasmacytoid Dendritic Cells.

PubMed

Watanabe, Tomohiro; Yamashita, Kouhei; Arai, Yasuyuki; Minaga, Kosuke; Kamata, Ken; Nagai, Tomoyuki; Komeda, Yoriaki; Takenaka, Mamoru; Hagiwara, Satoru; Ida, Hiroshi; Sakurai, Toshiharu; Nishida, Naoshi; Strober, Warren; Kudo, Masatoshi

2017-05-15

In previous studies, we found that human IgG4-related autoimmune pancreatitis (AIP) and murine AIP are driven by activation of plasmacytoid dendritic cells (pDCs) producing IFN-α. In the present studies we examined additional roles of pDC-related mechanisms in AIP pathogenesis, particularly those responsible for induction of fibrosis. We found that in murine AIP (MRL/Mp mice treated with polyinosinic-polycytidylic acid) not only the pancreatic infiltration of immune cells but also the development of fibrosis were markedly reduced by the depletion of pDCs or blockade of type I IFN signaling; moreover, such treatment was accompanied by a marked reduction of pancreatic expression of IL-33. Conversely, polyinosinic-polycytidylic acid-induced inflamed pancreatic tissue in murine AIP exhibited increased expression of type I IFNs and IL-33 (and downstream IL-33 cytokines such as IL-13 and TGF-β1). pDCs stimulated by type I IFN were the source of the IL-33 because purified populations of these cells isolated from the inflamed pancreas produced a large amount of IL-33 upon activation by TLR9 ligands, and such production was abrogated by the neutralization of type I IFN. The role of IL-33 in murine AIP pathogenesis was surprisingly important because blockade of IL-33 signaling by anti-ST2 Ab attenuated both pancreatic inflammation and accompanying fibrosis. Finally, whereas patients with both conventional pancreatitis and IgG4-related AIP exhibited increased numbers of acinar cells expressing IL-33, only the latter also exhibited pDCs producing this cytokine. These data thus suggest that pDCs producing IFN-α and IL-33 play a pivotal role in the chronic fibro-inflammatory responses underlying murine AIP and human IgG4-related AIP. Copyright © 2017 by The American Association of Immunologists, Inc.

Mechanisms of Oral Tolerance.

PubMed

Tordesillas, Leticia; Berin, M Cecilia

2018-02-27

Oral tolerance is a state of systemic unresponsiveness that is the default response to food antigens in the gastrointestinal tract, although immune tolerance can also be induced by other routes, such as the skin or inhalation. Antigen can be acquired directly by intestinal phagocytes, or pass through enterocytes or goblet cell-associated passages prior to capture by dendritic cells (DCs) in the lamina propria. Mucin from goblet cells acts on DCs to render them more tolerogenic. A subset of regulatory DCs expressing CD103 is responsible for delivery of antigen to the draining lymph node and induction of Tregs. These DCs also imprint gastrointestinal homing capacity, allowing the recently primed Tregs to home back to the lamina propria where they interact with macrophages that produce IL-10 and expand. Tregs induced by dietary antigen include Foxp3 + Tregs and Foxp3 - Tregs. In addition to Tregs, T cell anergy can also contribute to oral tolerance. The microbiota plays a key role in the development of oral tolerance, through regulation of macrophages and innate lymphoid cells that contribute to the regulatory phenotype of gastrointestinal dendritic cells. Absence of microbiota is associated with a susceptibility to food allergy, while presence of Clostridia strains can suppress development of food allergy through enhancement of Tregs and intestinal barrier function. It is not clear if feeding of antigens can also induce true immune tolerance after a memory immune response has been generated, but mechanistic studies of oral immunotherapy trials demonstrate shared pathways in oral tolerance and oral immunotherapy, with a role for Tregs and anergy. An important role for IgA and IgG antibodies in development of immune tolerance is also supported by studies of oral tolerance in humans. The elucidation of key pathways in oral tolerance could identify new strategies to increase efficacy of immunotherapy treatments for food allergy.

CXCL16-positive dendritic cells enhance invariant natural killer T cell-dependent IFNγ production and tumor control

PubMed Central

Veinotte, Linnea; Gebremeskel, Simon; Johnston, Brent

2016-01-01

ABSTRACT Crosstalk interactions between dendritic cells (DCs) and invariant natural killer T (iNKT) cells are important in regulating antitumor responses elicited by glycolipid antigens. iNKT cells constitutively express the chemokine receptor CXCR6, while cytokine-activated DCs upregulate the transmembrane chemokine ligand, CXCL16. This study examined the co-stimulatory role of CXCR6/CXCL16 interactions in glycolipid-dependent iNKT cell activation and tumor control. Spleen and liver DCs in wild-type mice, but not iNKT cell deficient (Jα18−/−) mice, transiently upregulated surface CXCL16 following in vivo administration of the glycolipid antigen α-galactosylceramide. Recombinant CXCL16 did not directly induce iNKT cell activation in vitro but enhanced interferon (IFN)-γ production when mouse or human iNKT cells were stimulated with plate-bound anti-CD3. Compared with glycolipid-loaded CXCL16neg DCs, CXCL16hi DCs induced higher levels of IFNγ production in iNKT cell cultures and following adoptive transfer in vivo. The number of IFNγ+ iNKT cells and expansion of T-bet+ iNKT cells were reduced in vivo when CXCL16−/− DCs were used to activate iNKT cells. Enhanced IFNγ production in vivo was not dependent on CXCR6 expression on natural killer (NK) cells. Adoptive transfer of glycolipid-loaded CXCL16hi DCs provided superior protection against tumor metastasis compared to CXCL16neg DC transfers. Similarly, wild-type DCs provided superior protection against metastasis compared with CXCL16−/− DCs. These experiments implicate an important role for CXCR6/CXCL16 interactions in regulating iNKT cell IFNγ production and tumor control. The selective use of CXCL16hi DCs in adoptive transfer immunotherapies may prove useful for enhancing T helper (Th) type 1 responses and clinical outcomes in cancer patients. PMID:27471636

Vitamin C treatment of mouse bone marrow-derived dendritic cells enhanced CD8(+) memory T cell production capacity of these cells in vivo.

PubMed

Jeong, Young-Joo; Kim, Jin-Hee; Hong, Jun-Man; Kang, Jae Seung; Kim, Hang-Rae; Lee, Wang Jae; Hwang, Young-il

2014-07-01

Vitamin C has been found to stimulate dendritic cells (DCs) to secrete more IL-12 and thereby drive naïve CD4(+) T cells to differentiate into Th1 cells. In the present study, we evaluated the effect of these vitamin C-treated DCs on CD8(+) T cell differentiation both in vitro and in vivo. Mouse bone marrow-derived DCs were prepared in the presence of GM-CSF and IL-15. With vitamin C treatment, these DCs, when LPS-stimulated, secreted more IL-12p70 and IL-15 than did untreated DCs. And when co-cultured with T cells, they yielded a higher frequency of IFN-γ(+) CD8(+) T cells. Moreover, we found that administering vitamin C-treated and tumor lysate-loaded DCs into mice yielded a higher frequency of CD44(high) CD62L(low) CD8(+) effector and effector memory T cells, which showed an increased ex vivo killing effect of the tumor cells. These DCs also elicited enhanced protective effects against inoculated tumor cells, most probably by way of the increased cytotoxic T cells, as was revealed by the decreased growth of the inoculated tumor cells in these mice. This ex vivo vitamin C treatment effect on DCs can be considered as a strategy for boosting DC vaccination potency against tumors. Copyright © 2014 Elsevier GmbH. All rights reserved.

Epifluorescence Intravital Microscopy of Murine Corneal Dendritic Cells

PubMed Central

Rosenbaum, James T.; Planck, Stephen R.

2010-01-01

Purpose. Dendritic cells (DCs) are antigen-presenting cells vital for initiating immune responses. In this study the authors examined the in vivo migratory capability of resident corneal DCs to various stimuli. Methods. The authors used mice expressing enhanced yellow fluorescent protein (eYFP) under control of the CD11c promoter to visualize corneal DCs. To assess the distribution and mobility of DCs, normal corneas were imaged in vivo and ex vivo with fluorescence microscopy. Intravital microscopy was used to examine the responses of resident central and peripheral corneal DCs to silver nitrate injury, lipopolysaccharide, microspheres, and tumor necrosis factor (TNF-α). In some experiments, TNF-α injection was used to first induce centripetal migration of DCs to the central cornea, which was subsequently reinjected with microspheres. Results. In normal corneas, DCs were sparsely distributed centrally and were denser in the periphery, with epithelial-level DCs extending into the epithelium. Videomicroscopy showed that though cell processes were in continuous movement, cells generally did not migrate. Within the first 6 hours after stimulation, neither central nor peripheral corneal DCs exhibited significant lateral migration, but central corneal DCs assumed extreme morphologic changes. An increased number of DCs in the TNF-α–stimulated central cornea were responsive to subsequent microsphere injection by adopting a migratory behavior, but not with increased speed. Conclusions. In vivo imaging reveals minimal lateral migration of corneal DCs after various stimuli. In contrast, DCs within the central cornea after initial TNF-α injection are more likely to respond to a secondary insult with lateral migration. PMID:20007837

Dendritic cell modification of neutrophil responses to infection after burn injury.

PubMed

Bohannon, Julia; Cui, Weihua; Sherwood, Edward; Toliver-Kinsky, Tracy

2010-09-01

Burn patients are highly susceptible to infections due to increased exposure through wounds and impairments in a number of immune functions. Dendritic cells (DCs) are important in activation of numerous immune responses that are essential for the clearance of infections. We have found that prophylactic treatment of burn-injured mice with the DC growth factor FLT3 ligand (FL) significantly increases resistance to burn wound infections in a DC-dependent manner that is correlated closely with enhanced bacterial clearance. However, as DCs are not typically microbicidal, the mechanisms by which DC modulation enhances bacterial clearance are not known. Due to the rapid response of neutrophils to cutaneous wounds, and the reported interactions between DCs and neutrophils, we investigated the role of neutrophils in FL-mediated resistance to burn wound infection. This was examined both in vivo and in vitro through neutrophil depletion, supplementation of neutrophils, and assessment of neutrophil chemotaxis following FL treatment. To test the involvement of DCs, CD11c-diphtheria toxin receptor transgenic mice were used to deplete DCs during FL treatment. Studies revealed that neutrophils do play a critical role in FL-mediated resistance to a burn wound infection. Additionally, treatment with FL after a burn injury enhances neutrophil-mediated control of bacterial spread, neutrophil migratory capacity, and myeloperoxidase production in a DC-dependent manner. The results of this study provide new insight into immunological mechanisms that can offer protection against infection after burn injury.

Distinct Phenotype, Longitudinal Changes of Numbers and Cell-Associated Virus in Blood Dendritic Cells in SIV-Infected CD8-Lymphocyte Depleted Macaques

PubMed Central

Soulas, Caroline; Autissier, Patrick J.; Burdo, Tricia H.; Lifson, Jeffrey D.; Williams, Kenneth C.

2015-01-01

Loss of circulating CD123+ plasmacytoid dendritic cells (pDCs) during HIV infection is well established. However, changes of myeloid DCs (mDCs) are ambiguous since they are studied as a homogeneous CD11c+ population despite phenotypic and functional heterogeneity. Heterogeneity of CD11c+ mDCs in primates is poorly described in HIV and SIV infection. Using multiparametric flow cytometry, we monitored longitudinally cell number and cell-associated virus of CD123+ pDCs and non-overlapping subsets of CD1c+ and CD16+ mDCs in SIV-infected CD8-depleted rhesus macaques. The numbers of all three DC subsets were significantly decreased by 8 days post-infection. Whereas CD123+ pDCs were persistently depleted, numbers of CD1c+ and CD16+ mDCs rebounded. Numbers of CD1c+ mDCs significantly increased by 3 weeks post-infection while numbers of CD16+ mDCs remained closer to pre-infection levels. We found similar changes in the numbers of all three DC subsets in CD8 depleted animals as we found in animals that were SIV infected animals that were not CD8 lymphocyte depleted. CD16+ mDCs and CD123+ pDCs but not CD1c+ mDCs were significantly decreased terminally with AIDS. All DC subsets harbored SIV RNA as early as 8 days and then throughout infection. However, SIV DNA was only detected in CD123+ pDCs and only at 40 days post-infection consistent with SIV RNA, at least in mDCs, being surface-bound. Altogether our data demonstrate that SIV infection differently affects CD1c+ and CD16+ mDCs where CD16+ but not CD1c+ mDCs are depleted and might be differentially regulated in terminal AIDS. Finally, our data underline the importance of studying CD1c+ and CD16+ mDCs as discrete populations, and not as total CD11c+ mDCs. PMID:25915601

Mast Cells Condition Dendritic Cells to Mediate Allograft Tolerance

PubMed Central

de Vries, Victor C.; Pino-Lagos, Karina; Nowak, Elizabeth C.; Bennett, Kathy A.; Oliva, Carla; Noelle, Randolph J.

2013-01-01

SUMMARY Peripheral tolerance orchestrated by regulatory T cells, dendritic cells (DCs), and mast cells (MCs) has been studied in several models including skin allograft tolerance. We now define a role for MCs in controlling DC behavior (“conditioning”) to facilitate tolerance. Under tolerant conditions, we show that MCs mediated a marked increase in tumor necrosis factor (TNFα)-dependent accumulation of graft-derived DCs in the dLN compared to nontolerant conditions. This increase of DCs in the dLN is due to the local production of granulocyte macrophage colony-stimulating factor (GM-CSF) by MCs that induces a survival advantage of graft-derived DCs. DCs that migrated to the dLN from the tolerant allograft were tolerogenic; i.e., they dominantly suppress T cell responses and control regional immunity. This study underscores the importance of MCs in conditioning DCs to mediate peripheral tolerance and shows a functional impact of peripherally produced TNFα and GM-CSF on the migration and function of tolerogenic DCs. PMID:22035846

Phenotypic and functional comparison of two distinct subsets of programmable cell of monocytic origin (PCMOs)-derived dendritic cells with conventional monocyte-derived dendritic cells

PubMed Central

Beikzadeh, Babak; Delirezh, Nowruz

2016-01-01

Dendritic cells (DCs) are professional antigen-presenting cells with the ability to induce primary T-cell responses. They are commonly produced by culturing monocytes in the presence of IL-4 and GM-CSF (cells produced in this manner are called conventional DCs). Here we report the generation of two functionally distinct subsets of DCs derived from programmable cells of monocytic origin (PCMOs) in the presence of IL-3 or tumor necrosis factor alpha (TNF-α). Monocytes were treated with macrophage colony-stimulating factor (M-CSF) and IL-3 for 6 days and then incubated with IL-4 and IL-3 (for IL-3 DCs) or with IL-4, GM-CSF and TNF-α (for TNF-α DCs) for 7 days. Monocytes were then loaded with tumor lysate (used as antigen), and poly (I∶C) was added. The maturation factors TNF-α and monocyte conditioned medium (MCM) were added on days 4 and 5, respectively. The phenotypes of the DCs generated were characterized by flow cytometry, and the cells' phagocytic activities were measured using FITC-conjugated latex bead uptake. T-cell proliferation and cytokine release were assayed using MTT and commercially available ELISA kits, respectively. We found that either IL-3DCs or TNF-α DCs induce T-cell proliferation and cytokine secretion; the cytokine release pattern showed reduced IL-12/IL-10 and IFN-γ/IL-4 ratios in both types of DCs and in DC-primed T-cell supernatant, respectively, which confirmed that the primed T cells were polarized toward aTh2-type immune response. We concluded that PCMOs are a new cell source that can develop into two functionally distinct DCs that both induce a Th2-type response in vitro. This modality can be used as a DC-based immunotherapy for autoimmune diseases. PMID:25661728

Downregulation of ILT4+ dendritic cells in recurrent miscarriage and recurrent implantation failure.

PubMed

Liu, Su; Wei, Hongxia; Li, Yuye; Huang, Chunyu; Lian, Ruochun; Xu, Jian; Chen, Lanna; Zeng, Yong

2018-06-14

The role of ILT4 + DCs in healthy fertile controls and patients with recurrent miscarriages (RM) and recurrent implantation failure (RIF) is unclear. We studied the expression of ILT4 from peripheral blood and endometrial samples from healthy controls and patients with RM and RIF by flow cytometry and immunohistochemistry analysis. Endometrial Foxp3 expression was also investigated using immunohistochemistry. In peripheral blood, there was a significant increase in the percentage of ILT4 + DCs in healthy fertile controls compared with patients with RM and RIF. The presence of ILT4 + DC is even more prominent in the endometrium of healthy fertile controls compared with patients with RM and RIF. Moreover, there was a strong correlation between the number of ILT4 + cells and Foxp3 + Tregs in healthy fertile controls, but not in patients with RM and RIF. Our data indicate that ILT4 + DCs play an important role in the maintenance of immune tolerance during pregnancy, probably through the induction of Foxp3 + Treg cells, a process which is impaired in RM and RIF. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

B-cell activating factor detected on both naïve and memory B cells in bullous pemphigoid.

PubMed

Qian, Hua; Kusuhara, Masahiro; Li, Xiaoguang; Tsuruta, Daisuke; Tsuchisaka, Atsunari; Ishii, Norito; Koga, Hiroshi; Hayakawa, Taihei; Ohara, Koji; Karashima, Tadashi; Ohyama, Bungo; Ohata, Chika; Furumura, Minao; Hashimoto, Takashi

2014-08-01

B-cell activating factor (BAFF), an important immune regulatory cytokine, is involved in development of autoimmune diseases. Although BAFF is expressed in various cells, including dendritic cells (DCs) and monocytes, BAFF expression on B cells has not been well documented. In the present study, BAFF molecules on DCs and naïve and memory B cells in autoimmune bullous diseases, including pemphigus vulgaris, pemphigus foliaceus and bullous pemphigoid (BP), were analysed by flow cytometry. Compared with healthy controls (HC), BAFF expression on naïve and memory B cells increased significantly in BP. No difference in BAFF receptor expression in naïve and memory B cells was shown among all study groups. Furthermore, BAFF expression in both naïve and memory B cells of BP, but not HC, was detected by confocal microscopic analysis. These results implied that BAFF expressed by B cells may play a pathogenic role in autoimmune bullous diseases, particularly BP. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The varieties of immunological experience: of pathogens, stress, and dendritic cells.

PubMed

Pulendran, Bali

2015-01-01

In the 40 years since their discovery, dendritic cells (DCs) have been recognized as central players in immune regulation. DCs sense microbial stimuli through pathogen-recognition receptors (PRRs) and decode, integrate, and present information derived from such stimuli to T cells, thus stimulating immune responses. DCs can also regulate the quality of immune responses. Several functionally specialized subsets of DCs exist, but DCs also display functional plasticity in response to diverse stimuli. In addition to sensing pathogens via PRRs, emerging evidence suggests that DCs can also sense stress signals, such as amino acid starvation, through ancient stress and nutrient sensing pathways, to stimulate adaptive immunity. Here, I discuss these exciting advances in the context of a historic perspective on the discovery of DCs and their role in immune regulation. I conclude with a discussion of emerging areas in DC biology in the systems immunology era and suggest that the impact of DCs on immunity can be usefully contextualized in a hierarchy-of-organization model in which DCs, their receptors and signaling networks, cell-cell interactions, tissue microenvironment, and the host macroenvironment represent different levels of the hierarchy. Immunity or tolerance can then be represented as a complex function of each of these hierarchies.

Dynamic Imaging of CD8(+) T cells and dendritic cells during infection with Toxoplasma gondii.

PubMed

John, Beena; Harris, Tajie H; Tait, Elia D; Wilson, Emma H; Gregg, Beth; Ng, Lai Guan; Mrass, Paulus; Roos, David S; Dzierszinski, Florence; Weninger, Wolfgang; Hunter, Christopher A

2009-07-01

To better understand the initiation of CD8(+) T cell responses during infection, the primary response to the intracellular parasite Toxoplasma gondii was characterized using 2-photon microscopy combined with an experimental system that allowed visualization of dendritic cells (DCs) and parasite specific CD8(+) T cells. Infection with T. gondii induced localization of both these populations to the sub-capsular/interfollicular region of the draining lymph node and DCs were required for the expansion of the T cells. Consistent with current models, in the presence of cognate antigen, the average velocity of CD8(+) T cells decreased. Unexpectedly, infection also resulted in modulation of the behavior of non-parasite specific T cells. This TCR-independent process correlated with the re-modeling of the lymph node micro-architecture and changes in expression of CCL21 and CCL3. Infection also resulted in sustained interactions between the DCs and CD8(+) T cells that were visualized only in the presence of cognate antigen and were limited to an early phase in the response. Infected DCs were rare within the lymph node during this time frame; however, DCs presenting the cognate antigen were detected. Together, these data provide novel insights into the earliest interaction between DCs and CD8(+) T cells and suggest that cross presentation by bystander DCs rather than infected DCs is an important route of antigen presentation during toxoplasmosis.

Dynamic Imaging of CD8+ T Cells and Dendritic Cells during Infection with Toxoplasma gondii

PubMed Central

John, Beena; Harris, Tajie H.; Tait, Elia D.; Wilson, Emma H.; Gregg, Beth; Ng, Lai Guan; Mrass, Paulus; Roos, David S.; Dzierszinski, Florence; Weninger, Wolfgang; Hunter, Christopher A.

2009-01-01

To better understand the initiation of CD8+ T cell responses during infection, the primary response to the intracellular parasite Toxoplasma gondii was characterized using 2-photon microscopy combined with an experimental system that allowed visualization of dendritic cells (DCs) and parasite specific CD8+ T cells. Infection with T. gondii induced localization of both these populations to the sub-capsular/interfollicular region of the draining lymph node and DCs were required for the expansion of the T cells. Consistent with current models, in the presence of cognate antigen, the average velocity of CD8+ T cells decreased. Unexpectedly, infection also resulted in modulation of the behavior of non-parasite specific T cells. This TCR-independent process correlated with the re-modeling of the lymph node micro-architecture and changes in expression of CCL21 and CCL3. Infection also resulted in sustained interactions between the DCs and CD8+ T cells that were visualized only in the presence of cognate antigen and were limited to an early phase in the response. Infected DCs were rare within the lymph node during this time frame; however, DCs presenting the cognate antigen were detected. Together, these data provide novel insights into the earliest interaction between DCs and CD8+ T cells and suggest that cross presentation by bystander DCs rather than infected DCs is an important route of antigen presentation during toxoplasmosis. PMID:19578440

The Adjuvant Effects of High-Molecule-Weight Polysaccharides Purified from Antrodia cinnamomea on Dendritic Cell Function and DNA Vaccines

PubMed Central

Lin, Chi-Chen; Pan, I-Hong; Li, Yi-Rong; Pan, Yi-Gen; Lin, Ming-Kuem; Lu, Yi-Huang; Wu, Hsin-Chieh; Chu, Ching-Liang

2015-01-01

The biological activity of the edible basidiomycete Antrodia cinnamomea (AC) has been studied extensively. Many effects, such as anti-cancer, anti-inflammatory, and antioxidant activities, have been reported from either crude extracts or compounds isolated from AC. However, research addressing the function of AC in enhancing immunity is rare. The aim of the present study is to investigate the active components and the mechanism involved in the immunostimulatory effect of AC. We found that polysaccharides (PS) in the water extract of AC played a major role in dendritic cell (DC) activation, which is a critical leukocyte in initiating immune responses. We further size purified and identified that the high-molecular weight PS fraction (greater than 100 kDa) exhibited the activating effect. The AC high-molecular weight PSs (AC hmwPSs) promoted pro-inflammatory cytokine production by DCs and the maturation of DCs. In addition, DC-induced antigen-specific T cell activation and Th1 differentiation were increased by AC hmwPSs. In studying the molecular mechanism, we confirmed the activation of the MAPK and NF-κB pathways in DCs after AC hmwPSs treatment. Furthermore, we demonstrated that TLR2 and TLR4 are required for the stimulatory activity of AC hmwPSs on DCs. In a mouse tumor model, we demonstrated that AC hmwPSs enhanced the anti-tumor efficacy of the HER-2/neu DNA vaccine by facilitating specific Th1 responses. Thus, we conclude that hmwPSs are the major components of AC that stimulate DCs via the TLR2/TLR4 and NF-κB/MAPK signaling pathways. The AC hmwPSs have potential to be applied as adjuvants. PMID:25723174

Glycolipid presentation to natural killer T cells differs in an organ-dependent fashion

NASA Astrophysics Data System (ADS)

Schmieg, John; Yang, Guangli; Franck, Richard W.; van Rooijen, Nico; Tsuji, Moriya

2005-01-01

It has been shown that dendritic cells (DCs) are able to present glycolipids to natural killer (NK) T cells in vivo. However, the essential role of DCs, as well as the role of other cells in glycolipid presentation, is unknown. Here, we show that DCs are the crucial antigen-presenting cells (APCs) for splenic NK T cells, whereas Kupffer cells are the key APCs for hepatic NK T cells. Both cell types stimulate cytokine production by NK T cells within 2 h of glycolipid administration, but only DCs are involved in the systemic, downstream responses to glycolipid administration. More specifically, CD8+ DCs produce IL-12 in response to glycolipid presentation, which stimulates secondary IFN- production by NK cells in different organs. Different APCs participate in glycolipid presentation to NK T cells in vivo but differ in their involvement in the overall glycolipid response. dendritic cell | Kupffer cell

CD8+ T Cells Orchestrate pDC-XCR1+ Dendritic Cell Spatial and Functional Cooperativity to Optimize Priming.

PubMed

Brewitz, Anna; Eickhoff, Sarah; Dähling, Sabrina; Quast, Thomas; Bedoui, Sammy; Kroczek, Richard A; Kurts, Christian; Garbi, Natalio; Barchet, Winfried; Iannacone, Matteo; Klauschen, Frederick; Kolanus, Waldemar; Kaisho, Tsuneyasu; Colonna, Marco; Germain, Ronald N; Kastenmüller, Wolfgang

2017-02-21

Adaptive cellular immunity is initiated by antigen-specific interactions between T lymphocytes and dendritic cells (DCs). Plasmacytoid DCs (pDCs) support antiviral immunity by linking innate and adaptive immune responses. Here we examined pDC spatiotemporal dynamics during viral infection to uncover when, where, and how they exert their functions. We found that pDCs accumulated at sites of CD8 + T cell antigen-driven activation in a CCR5-dependent fashion. Furthermore, activated CD8 + T cells orchestrated the local recruitment of lymph node-resident XCR1 chemokine receptor-expressing DCs via secretion of the XCL1 chemokine. Functionally, this CD8 + T cell-mediated reorganization of the local DC network allowed for the interaction and cooperation of pDCs and XCR1 + DCs, thereby optimizing XCR1 + DC maturation and cross-presentation. These data support a model in which CD8 + T cells upon activation create their own optimal priming microenvironment by recruiting additional DC subsets to the site of initial antigen recognition. Published by Elsevier Inc.

A BTLA-mediated bait-and-switch strategy permits Listeria expansion in CD8α+ DCs to promote long term T cell responses

PubMed Central

Yang, Xuanming; Zhang, Xunmin; Sun, Yonglian; Tu, Tony; Fu, May Lynne; Miller, Mendy; Fu, Yang-Xin

2014-01-01

SUMMARY Listeria monocytogenes infected CD8α+ DCs in the spleen are essential for CD8+ T cell generation. CD8α+ DCs are also necessary for Listeria expansion and dissemination within the host. The mechanisms that regulate CD8α+ DCs to allow Listeria expansion are unclear. We find that activating the B and T lymphocyte attenuator (BTLA), a co-inhibitory receptor on CD8α+ DCs, suppresses, while blocking BTLA enhances both the primary and memory CD8 T cell responses against Listeria. Btla−/− mice have lower effector and memory CD8+ T cells while paradoxically also being more resistant to Listeria. Although bacterial entry into Btla−/− CD8α+ DCs is unaffected, Listeria fails to expand within these cells. BTLA signaling limits Fas/FasL-mediated suppression of Listeria expansion within CD8α+ DCs to more effectively alert adaptive immune cells. This study uncovers a BTLA-mediated strategy used by the host that permits Listeria proliferation to enable increasing T cell responses for long-term protection. PMID:25011109

Flt3L controls the development of radiosensitive dendritic cells in the meninges and choroid plexus of the steady-state mouse brain

PubMed Central

Anandasabapathy, Niroshana; Victora, Gabriel D.; Meredith, Matthew; Feder, Rachel; Dong, Baojun; Kluger, Courtney; Yao, Kaihui; Dustin, Michael L.; Nussenzweig, Michel C.; Steinman, Ralph M.

2011-01-01

Antigen-presenting cells in the disease-free brain have been identified primarily by expression of antigens such as CD11b, CD11c, and MHC II, which can be shared by dendritic cells (DCs), microglia, and monocytes. In this study, starting with the criterion of Flt3 (FMS-like receptor tyrosine kinase 3)-dependent development, we characterize the features of authentic DCs within the meninges and choroid plexus in healthy mouse brains. Analyses of morphology, gene expression, and antigen-presenting function established a close relationship between meningeal and choroid plexus DCs (m/chDCs) and spleen DCs. DCs in both sites shared an intrinsic requirement for Flt3 ligand. Microarrays revealed differences in expression of transcripts encoding surface molecules, transcription factors, pattern recognition receptors, and other genes in m/chDCs compared with monocytes and microglia. Migrating pre-DC progenitors from bone marrow gave rise to m/chDCs that had a 5–7-d half-life. In contrast to microglia, DCs actively present self-antigens and stimulate T cells. Therefore, the meninges and choroid plexus of a steady-state brain contain DCs that derive from local precursors and exhibit a differentiation and antigen-presenting program similar to spleen DCs and distinct from microglia. PMID:21788405

Flt3L controls the development of radiosensitive dendritic cells in the meninges and choroid plexus of the steady-state mouse brain.

PubMed

Anandasabapathy, Niroshana; Victora, Gabriel D; Meredith, Matthew; Feder, Rachel; Dong, Baojun; Kluger, Courtney; Yao, Kaihui; Dustin, Michael L; Nussenzweig, Michel C; Steinman, Ralph M; Liu, Kang

2011-08-01

Antigen-presenting cells in the disease-free brain have been identified primarily by expression of antigens such as CD11b, CD11c, and MHC II, which can be shared by dendritic cells (DCs), microglia, and monocytes. In this study, starting with the criterion of Flt3 (FMS-like receptor tyrosine kinase 3)-dependent development, we characterize the features of authentic DCs within the meninges and choroid plexus in healthy mouse brains. Analyses of morphology, gene expression, and antigen-presenting function established a close relationship between meningeal and choroid plexus DCs (m/chDCs) and spleen DCs. DCs in both sites shared an intrinsic requirement for Flt3 ligand. Microarrays revealed differences in expression of transcripts encoding surface molecules, transcription factors, pattern recognition receptors, and other genes in m/chDCs compared with monocytes and microglia. Migrating pre-DC progenitors from bone marrow gave rise to m/chDCs that had a 5-7-d half-life. In contrast to microglia, DCs actively present self-antigens and stimulate T cells. Therefore, the meninges and choroid plexus of a steady-state brain contain DCs that derive from local precursors and exhibit a differentiation and antigen-presenting program similar to spleen DCs and distinct from microglia.

Ikaros-Notch axis in host hematopoietic cells regulates experimental graft-versus-host disease

PubMed Central

Toubai, Tomomi; Sun, Yaping; Tawara, Isao; Friedman, Ann; Liu, Chen; Evers, Rebecca; Nieves, Evelyn; Malter, Chelsea; Chockley, Peter; Maillard, Ivan; Winandy, Susan

2011-01-01

Host hematopoietically derived APCs play a vital role in the initiation of GVH responses. However, the APC autonomous molecular mechanisms that are critical for the induction of GVHD are not known. We report here that the Ikaros-Notch axis in host hematopoietically derived APCs regulates the severity of acute GVHD across multiple clinically relevant murine models of experimental bone marrow transplantation. In the present study, Ikaros deficiency (Ik−/−) limited to host hematopoietically derived APCs enhanced donor T-cell expansion and intensified acute GVHD, as determined by survival and other GVHD-specific parameters. The Ik−/− conventional CD8+ and CD8−CD11c+ dendritic cells (DCs), the most potent APCs, showed no increase in the expression of activation markers or in response to TLR stimulation compared with wild-type controls. However, Ik−/− DCs demonstrated an enhanced stimulation of allogeneic T cells. Deficiency of Ikaros in the conventional CD8+ and CD8−CD11c+ DCs was associated with an increase in Notch signaling, the blockade of which mitigated the enhanced in vitro and in vivo allostimulatory capacity. Therefore, the Ikaros-Notch axis is a novel pathway that modulates DC biology in general, and targeting this pathway in host hematopoietically derived APCs may reduce GVHD. PMID:21471527

Depletion of host CCR7(+) dendritic cells prevented donor T cell tissue tropism in anti-CD3-conditioned recipients.

PubMed

He, Wei; Racine, Jeremy J; Johnston, Heather F; Li, Xiaofan; Li, Nainong; Cassady, Kaniel; Liu, Can; Deng, Ruishu; Martin, Paul; Forman, Stephen; Zeng, Defu

2014-07-01

We reported previously that anti-CD3 mAb treatment before hematopoietic cell transplantation (HCT) prevented graft-versus-host disease (GVHD) and preserved graft-versus-leukemia (GVL) effects in mice. These effects were associated with downregulated donor T cell expression of tissue-specific homing and chemokine receptors, marked reduction of donor T cell migration into GVHD target tissues, and deletion of CD103(+) dendritic cells (DCs) in mesenteric lymph nodes (MLN). MLN CD103(+) DCs and peripheral lymph node (PLN) DCs include CCR7(+) and CCR7(-) subsets, but the role of these DC subsets in regulating donor T cell expression of homing and chemokine receptors remain unclear. Here, we show that recipient CCR7(+), but not CCR7(-), DCs in MLN induced donor T cell expression of gut-specific homing and chemokine receptors in a retinoid acid-dependent manner. CCR7 regulated activated DC migration from tissue to draining lymph node, but it was not required for the ability of DCs to induce donor T cell expression of tissue-specific homing and chemokine receptors. Finally, anti-CD3 treatment depleted CCR7(+) but not CCR7(-) DCs by inducing sequential expansion and apoptosis of CCR7(+) DCs in MLN and PLN. Apoptosis of CCR7(+) DCs was associated with DC upregulation of Fas expression and natural killer cell but not T, B, or dendritic cell upregulation of FasL expression in the lymph nodes. These results suggest that depletion of CCR7(+) host-type DCs, with subsequent inhibition of donor T cell migration into GVHD target tissues, can be an effective approach in prevention of acute GVHD and preservation of GVL effects. Copyright © 2014 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Oral dendritic cells mediate antigen-specific tolerance by stimulating TH1 and regulatory CD4+ T cells.

PubMed

Mascarell, Laurent; Lombardi, Vincent; Louise, Anne; Saint-Lu, Nathalie; Chabre, Henri; Moussu, Hélène; Betbeder, Didier; Balazuc, Anne-Marie; Van Overtvelt, Laurence; Moingeon, Philippe

2008-09-01

A detailed characterization of oral antigen-presenting cells is critical to improve second-generation sublingual allergy vaccines. To characterize oral dendritic cells (DCs) within lingual and buccal tissues from BALB/c mice with respect to their surface phenotype, distribution, and capacity to polarize CD4(+) T-cell responses. In situ analysis of oral DCs was performed by immunohistology. Purified DCs were tested in vitro for their capacity to capture, process, and present the ovalbumin antigen to naive CD4(+) T cells. In vivo priming of ovalbumin-specific T cells adoptively transferred to BALB/c mice was analyzed by cytofluorometry in cervical lymph nodes after sublingual administration of mucoadhesive ovalbumin. Three subsets of oral DCs with a distinct tissue distribution were identified: (1) a minor subset of CD207(+) Langerhans cells located in the mucosa itself, (2) a major subpopulation of CD11b(+)CD11c(-) and CD11b(+)CD11c(+) myeloid DCs at the mucosal/submucosal interface, and (3) B220(+)120G8(+) plasmacytoid DCs found in submucosal tissues. Purified myeloid and plasmacytoid oral DCs capture and process the antigen efficiently and are programmed to elicit IFN-gamma and/or IL-10 production together with a suppressive function in naive CD4(+) T cells. Targeting the ovalbumin antigen to oral DCs in vivo by using mucoadhesive particles establishes tolerance in the absence of cell depletion through the stimulation of IFN-gamma and IL-10-producing CD4(+) regulatory T cells in cervical lymph nodes. The oral immune system is composed of various subsets of tolerogenic DCs organized in a compartmentalized manner and programmed to induce T(H)1/regulatory T-cell responses.

MiR-29b antagonizes the pro-inflammatory tumor-promoting activity of multiple myeloma-educated dendritic cells

PubMed Central

Botta, C; Cucè, M; Pitari, M R; Caracciolo, D; Gullà, A; Morelli, E; Riillo, C; Biamonte, L; Gallo Cantafio, M E; Prabhala, R; Mignogna, C; Di Vito, A; Altomare, E; Amodio, N; Di Martino, M T; Correale, P; Rossi, M; Giordano, A; Munshi, N C; Tagliaferri, P; Tassone, P

2018-01-01

Dendritic cells (DCs) have a key role in regulating tumor immunity, tumor cell growth and drug resistance. We hypothesized that multiple myeloma (MM) cells might recruit and reprogram DCs to a tumor-permissive phenotype by changes within their microRNA (miRNA) network. By analyzing six different miRNA-profiling data sets, miR-29b was identified as the only miRNA upregulated in normal mature DCs and significantly downregulated in tumor-associated DCs. This finding was validated in primary DCs co-cultured in vitro with MM cell lines and in primary bone marrow DCs from MM patients. In DCs co-cultured with MM cells, enforced expression of miR-29b counteracted pro-inflammatory pathways, including signal transducer and activator of transcription 3 and nuclear factor-κB, and cytokine/chemokine signaling networks, which correlated with patients’ adverse prognosis and development of bone disease. Moreover, miR-29b downregulated interleukin-23 in vitro and in the SCID-synth-hu in vivo model, and antagonized a Th17 inflammatory response. All together, these effects translated into strong anti-proliferative activity and reduction of genomic instability of MM cells. Our study demonstrates that MM reprograms the DCs functional phenotype by downregulating miR-29b whose reconstitution impairs DCs ability to sustain MM cell growth and survival. These results underscore miR-29b as an innovative and attractive candidate for miRNA-based immune therapy of MM. PMID:29158557

Characterization of human DNGR-1+ BDCA3+ leukocytes as putative equivalents of mouse CD8α+ dendritic cells

PubMed Central

Poulin, Lionel Franz; Salio, Mariolina; Griessinger, Emmanuel; Anjos-Afonso, Fernando; Craciun, Ligia; Chen, Ji-Li; Keller, Anna M.; Joffre, Olivier; Zelenay, Santiago; Nye, Emma; Le Moine, Alain; Faure, Florence; Donckier, Vincent; Sancho, David; Cerundolo, Vincenzo; Bonnet, Dominique

2010-01-01

In mouse, a subset of dendritic cells (DCs) known as CD8α+ DCs has emerged as an important player in the regulation of T cell responses and a promising target in vaccination strategies. However, translation into clinical protocols has been hampered by the failure to identify CD8α+ DCs in humans. Here, we characterize a population of human DCs that expresses DNGR-1 (CLEC9A) and high levels of BDCA3 and resembles mouse CD8α+ DCs in phenotype and function. We describe the presence of such cells in the spleens of humans and humanized mice and report on a protocol to generate them in vitro. Like mouse CD8α+ DCs, human DNGR-1+ BDCA3hi DCs express Necl2, CD207, BATF3, IRF8, and TLR3, but not CD11b, IRF4, TLR7, or (unlike CD8α+ DCs) TLR9. DNGR-1+ BDCA3hi DCs respond to poly I:C and agonists of TLR8, but not of TLR7, and produce interleukin (IL)-12 when given innate and T cell–derived signals. Notably, DNGR-1+ BDCA3+ DCs from in vitro cultures efficiently internalize material from dead cells and can cross-present exogenous antigens to CD8+ T cells upon treatment with poly I:C. The characterization of human DNGR-1+ BDCA3hi DCs and the ability to grow them in vitro opens the door for exploiting this subset in immunotherapy. PMID:20479117

Depletion of CD11c⁺ cells in the CD11c.DTR model drives expansion of unique CD64⁺ Ly6C⁺ monocytes that are poised to release TNF-α.

PubMed

Sivakumaran, Shivajanani; Henderson, Stephen; Ward, Sophie; Sousa, Pedro Santos E; Manzo, Teresa; Zhang, Lei; Conlan, Thomas; Means, Terry K; D'Aveni, Maud; Hermine, Olivier; Rubio, Marie-Thérèse; Chakraverty, Ronjon; Bennett, Clare L

2016-01-01

Dendritic cells (DCs) play a vital role in innate and adaptive immunities. Inducible depletion of CD11c(+) DCs engineered to express a high-affinity diphtheria toxin receptor has been a powerful tool to dissect DC function in vivo. However, despite reports showing that loss of DCs induces transient monocytosis, the monocyte population that emerges and the potential impact of monocytes on studies of DC function have not been investigated. We found that depletion of CD11c(+) cells from CD11c.DTR mice induced the expansion of a variant CD64(+) Ly6C(+) monocyte population in the spleen and blood that was distinct from conventional monocytes. Expansion of CD64(+) Ly6C(+) monocytes was independent of mobilization from the BM via CCR2 but required the cytokine, G-CSF. Indeed, this population was also expanded upon exposure to exogenous G-CSF in the absence of DC depletion. CD64(+) Ly6C(+) monocytes were characterized by upregulation of innate signaling apparatus despite the absence of inflammation, and an increased capacity to produce TNF-α following LPS stimulation. Thus, depletion of CD11c(+) cells induces expansion of a unique CD64(+) Ly6C(+) monocyte population poised to synthesize TNF-α. This finding will require consideration in experiments using depletion strategies to test the role of CD11c(+) DCs in immunity. © 2015 The Authors. European Journal of Immunology published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

OX62+OX6+OX35+ rat dendritic cells are unable to prime CD4+ T cells for an effective immune response following acute burn injury.

PubMed

Fazal, Nadeem

2013-01-01

Co-stimulatory molecules expressed on Dendritic Cells (DCs) function to coordinate an efficient immune response by T cells in the peripheral lymph nodes. We hypothesized that CD4+ T cell-mediated immune suppression following burn injury may be related to dysfunctional DCs residing in gut associated lymphoid tissues (GALT), such as Mesenteric Lymph Nodes (MLN). Therefore, we studied co-stimulatory molecules expressed on burn rat MLN DCs as an index of functional DCs that would mount an effective normal CD4+ T cell immune response. In a rat model of 30% Total Body Surface Area (TBSA) scald burn, OX62+OX6+OX35+ DCs and CD4+ T cells were isolated from MLN of day 3 post-burn and sham control rats. DCs were tested for their expression of co-stimulatory molecules, and prime CD4+ T cell (DC:CD4+T cell co-culture assays) to determine an effector immune response such as CD4+ T cell proliferation. The surface receptor expressions of MLN DCs co-stimulatory molecules, i.e., MHC-II, CD40, CD80 (B7-1), and CD86 (B7-2) were determined by Flow cytometry (quantitatively) and confocal microscopy (qualitatively). Tritiated thymidine and CFDA-SE determined CD4+ T cell proliferation following co-incubation with DCs. Cytokine milieu of MLN (IL-12 and IL-10) was assessed by mRNA determination by RT-PCR. The results showed down-regulated expressions of co-stimulatory markers (CD80, CD86, CD40 and MHC-II) of MLN DCs obtained from burn-injured rats, as well as lack of ability of these burn-induced DCs to stimulate CD4+ T cell proliferation in co-culture assays, as compared to the sham rats. Moreover, anti-CD40 stimulation of affected burn MLN DCs did not reverse this alteration. Furthermore, a marked up-regulation of mRNA IL-10 and down-regulation of mRNA IL-12 in burn MLN as compared to sham animals was also observed. To surmise, the data indicated that dysfunctional OX62+OX6+OX35+ rat MLN DCs may contribute to CD4+ T-cell-mediated immune suppression observed following acute burn injury.

OX62+OX6+OX35+ rat dendritic cells are unable to prime CD4+ T cells for an effective immune response following acute burn injury☆

PubMed Central

Fazal, Nadeem

2013-01-01

Co-stimulatory molecules expressed on Dendritic Cells (DCs) function to coordinate an efficient immune response by T cells in the peripheral lymph nodes. We hypothesized that CD4+ T cell-mediated immune suppression following burn injury may be related to dysfunctional DCs residing in gut associated lymphoid tissues (GALT), such as Mesenteric Lymph Nodes (MLN). Therefore, we studied co-stimulatory molecules expressed on burn rat MLN DCs as an index of functional DCs that would mount an effective normal CD4+ T cell immune response. In a rat model of 30% Total Body Surface Area (TBSA) scald burn, OX62+OX6+OX35+ DCs and CD4+ T cells were isolated from MLN of day 3 post-burn and sham control rats. DCs were tested for their expression of co-stimulatory molecules, and prime CD4+ T cell (DC:CD4+T cell co-culture assays) to determine an effector immune response such as CD4+ T cell proliferation. The surface receptor expressions of MLN DCs co-stimulatory molecules, i.e., MHC-II, CD40, CD80 (B7-1), and CD86 (B7-2) were determined by Flow cytometry (quantitatively) and confocal microscopy (qualitatively). Tritiated thymidine and CFDA-SE determined CD4+ T cell proliferation following co-incubation with DCs. Cytokine milieu of MLN (IL-12 and IL-10) was assessed by mRNA determination by RT-PCR. The results showed down-regulated expressions of co-stimulatory markers (CD80, CD86, CD40 and MHC-II) of MLN DCs obtained from burn-injured rats, as well as lack of ability of these burn-induced DCs to stimulate CD4+ T cell proliferation in co-culture assays, as compared to the sham rats. Moreover, anti-CD40 stimulation of affected burn MLN DCs did not reverse this alteration. Furthermore, a marked up-regulation of mRNA IL-10 and down-regulation of mRNA IL-12 in burn MLN as compared to sham animals was also observed. To surmise, the data indicated that dysfunctional OX62+OX6+OX35+ rat MLN DCs may contribute to CD4+ T-cell-mediated immune suppression observed following acute burn injury. PMID:24600560

Dendritic Cell-Based Genetic Immunotherapy for Ovarian Cancer

DTIC Science & Technology

2008-12-01

transduction of dendritic cells (DCs) is inefficient because of the lack of the primary Ad receptor, CAR. CD40 is a surface marker expressed by DCs that...ligands or antibodies that can bind to the cell surface markers expressed by DCs. The tumor antigen or peptides are linked to the ligands...thus pose the risk of insertional mutagenesis and oncogenesis. The various cell- surface markers that have been exploited for targeting DCs have

The involvement of plasmacytoid cells in HIV infection and pathogenesis.

PubMed

Aiello, Alessandra; Giannessi, Flavia; Percario, Zulema A; Affabris, Elisabetta

2018-04-01

Plasmacytoid dendritic cells (pDCs) are a unique dendritic cell subset that are specialized in type I interferon (IFN) production. pDCs are key players in the antiviral immune response and serve as bridge between innate and adaptive immunity. Although pDCs do not represent the main reservoir of the Human Immunodeficiency Virus (HIV), they are a crucial subset in HIV infection as they influence viral transmission, target cell infection and antigen presentation. pDCs act as inflammatory and immunosuppressive cells, thus contributing to HIV disease progression. This review provides a state of art analysis of the interactions between HIV and pDCs and their potential roles in HIV transmission, chronic immune activation and immunosuppression. A thorough understanding of the roles of pDCs in HIV infection will help to improve therapeutic strategies to fight HIV infection, and will further increase our knowledge on this important immune cell subset. Copyright © 2018 Elsevier Ltd. All rights reserved.

The Dox-pDC - A murine conditionally immortalized plasmacytoid dendritic cell line with native immune profile

PubMed Central

Wiedemuth, Ralf; Binner, Aline; Navratiel, Katrin; Anastassiadis, Konstantinos; Brenner, Sebastian

2018-01-01

Plasmacytoid dendritic cells (pDC) constitute a very rare blood cell population and play a significant role in immune response and immune-mediated disorders. Investigations on primary pDCs are hindered not only due to their rarity but also because they represent a heterogeneous cell population which is difficult to culture ex vivo. We generated a conditionally immortalized pDC line (Dox-pDC) from mice with Doxycycline-inducible SV40 Large T Antigen with a comparable immune profile to primary pDCs. The Dox-pDC secrete pro- and anti-inflammatory cytokines upon Toll-like receptor 9 stimulation and upregulate their MHCI, MHCII and costimulatory molecules. Further, the Dox-pDC activate and polarize naïve T cells in vivo and in vitro in response to the model antigen Ovalbumin. Due to their long-term culture stability and their robust proliferation Dox-pDC represent a reliable alternative to primary mouse pDC. PMID:29489861

The Dox-pDC - A murine conditionally immortalized plasmacytoid dendritic cell line with native immune profile.

PubMed

Thieme, Sebastian; Holzbaur, Alexander; Wiedemuth, Ralf; Binner, Aline; Navratiel, Katrin; Anastassiadis, Konstantinos; Brenner, Sebastian; Richter, Cornelia

2018-01-01

Plasmacytoid dendritic cells (pDC) constitute a very rare blood cell population and play a significant role in immune response and immune-mediated disorders. Investigations on primary pDCs are hindered not only due to their rarity but also because they represent a heterogeneous cell population which is difficult to culture ex vivo. We generated a conditionally immortalized pDC line (Dox-pDC) from mice with Doxycycline-inducible SV40 Large T Antigen with a comparable immune profile to primary pDCs. The Dox-pDC secrete pro- and anti-inflammatory cytokines upon Toll-like receptor 9 stimulation and upregulate their MHCI, MHCII and costimulatory molecules. Further, the Dox-pDC activate and polarize naïve T cells in vivo and in vitro in response to the model antigen Ovalbumin. Due to their long-term culture stability and their robust proliferation Dox-pDC represent a reliable alternative to primary mouse pDC.

PQBP1 Is a Proximal Sensor of the cGAS-Dependent Innate Response to HIV-1.

PubMed

Yoh, Sunnie M; Schneider, Monika; Seifried, Janna; Soonthornvacharin, Stephen; Akleh, Rana E; Olivieri, Kevin C; De Jesus, Paul D; Ruan, Chunhai; de Castro, Elisa; Ruiz, Pedro A; Germanaud, David; des Portes, Vincent; García-Sastre, Adolfo; König, Renate; Chanda, Sumit K

2015-06-04

Dendritic cells (DCs) play a critical role in the immune response to viral infection through the facilitation of cell-intrinsic antiviral activity and the activation of adaptive immunity. HIV-1 infection of DCs triggers an IRF3-dependent innate immune response, which requires the activity of cyclic GAMP synthase (cGAS). We report the results of a targeted RNAi screen utilizing primary human monocyte-derived DCs (MDDCs) to identify immune regulators that directly interface with HIV-1-encoded features to initiate this innate response. Polyglutamine binding protein 1 (PQBP1) emerged as a strong candidate through this analysis. We found that PQBP1 directly binds to reverse-transcribed HIV-1 DNA and interacts with cGAS to initiate an IRF3-dependent innate response. MDDCs derived from Renpenning syndrome patients, who harbor mutations in the PQBP1 locus, possess a severely attenuated innate immune response to HIV-1 challenge, underscoring the role of PQBP1 as a proximal innate sensor of a HIV-1 infection. Copyright © 2015 Elsevier Inc. All rights reserved.

A short protocol using dexamethasone and monophosphoryl lipid A generates tolerogenic dendritic cells that display a potent migratory capacity to lymphoid chemokines

PubMed Central

2013-01-01

Background Generation of tolerogenic dendritic cells (TolDCs) for therapy is challenging due to its implications for the design of protocols suitable for clinical applications, which means not only using safe products, but also working at defining specific biomarkers for TolDCs identification, developing shorter DCs differentiation methods and obtaining TolDCs with a stable phenotype. We describe here, a short-term protocol for TolDCs generation, which are characterized in terms of phenotypic markers, cytokines secretion profile, CD4+ T cell-stimulatory ability and migratory capacity. Methods TolDCs from healthy donors were generated by modulation with dexamethasone plus monophosphoryl lipid A (MPLA-tDCs). We performed an analysis of MPLA-tDCs in terms of yield, viability, morphology, phenotypic markers, cytokines secretion profile, stability, allogeneic and antigen-specific CD4+ T-cell stimulatory ability and migration capacity. Results After a 5-day culture, MPLA-tDCs displayed reduced expression of costimulatory and maturation molecules together to an anti-inflammatory cytokines secretion profile, being able to maintain these tolerogenic features even after the engagement of CD40 by its cognate ligand. In addition, MPLA-tDCs exhibited reduced capabilities to stimulate allogeneic and antigen-specific CD4+ T cell proliferation, and induced an anti-inflammatory cytokine secretion pattern. Among potential tolerogenic markers studied, only TLR-2 was highly expressed in MPLA-tDCs when compared to mature and immature DCs. Remarkable, like mature DCs, MPLA-tDCs displayed a high CCR7 and CXCR4 expression, both chemokine receptors involved in migration to secondary lymphoid organs, and even more, in an in vitro assay they exhibited a high migration response towards CCL19 and CXCL12. Conclusion We describe a short-term protocol for TolDC generation, which confers them a stable phenotype and migratory capacity to lymphoid chemokines, essential features for TolDCs to be used as therapeutics for autoimmunity and prevention of graft rejection. PMID:23706017

The XC chemokine receptor 1 is a conserved selective marker of mammalian cells homologous to mouse CD8α+ dendritic cells

PubMed Central

Crozat, Karine; Guiton, Rachel; Contreras, Vanessa; Feuillet, Vincent; Dutertre, Charles-Antoine; Ventre, Erwan; Vu Manh, Thien-Phong; Baranek, Thomas; Storset, Anne K.; Marvel, Jacqueline; Boudinot, Pierre; Hosmalin, Anne; Schwartz-Cornil, Isabelle

2010-01-01

Human BDCA3+ dendritic cells (DCs) were suggested to be homologous to mouse CD8α+ DCs. We demonstrate that human BDCA3+ DCs are more efficient than their BDCA1+ counterparts or plasmacytoid DCs (pDCs) in cross-presenting antigen and activating CD8+ T cells, which is similar to mouse CD8α+ DCs as compared with CD11b+ DCs or pDCs, although with more moderate differences between human DC subsets. Yet, no specific marker was known to be shared between homologous DC subsets across species. We found that XC chemokine receptor 1 (XCR1) is specifically expressed and active in mouse CD8α+, human BDCA3+, and sheep CD26+ DCs and is conserved across species. The mRNA encoding the XCR1 ligand chemokine (C motif) ligand 1 (XCL1) is selectively expressed in natural killer (NK) and CD8+ T lymphocytes at steady-state and is enhanced upon activation. Moreover, the Xcl1 mRNA is selectively expressed at high levels in central memory compared with naive CD8+ T lymphocytes. Finally, XCR1−/− mice have decreased early CD8+ T cell responses to Listeria monocytogenes infection, which is associated with higher bacterial loads early in infection. Therefore, XCR1 constitutes the first conserved specific marker for cell subsets homologous to mouse CD8α+ DCs in higher vertebrates and promotes their ability to activate early CD8+ T cell defenses against an intracellular pathogenic bacteria. PMID:20479118

Inhibitory effects of chloroquine on the activation of plasmacytoid dendritic cells in SIVmac239-infected Chinese rhesus macaques

PubMed Central

Ma, Jian-Ping; Xia, Hou-Jun; Zhang, Gao-Hong; Han, Jian-Bao; Zhang, Li-Guo; Zheng, Yong-Tang

2012-01-01

It is currently widely accepted that immune activation in HIV-infected individuals leads to a severe loss of CD4+ T cells and the progression to AIDS. However, the underlying mechanism of this immune activation remains unclear. Experimental data suggest that the activation of plasmacytoid dendritic cells (pDCs) by plasma viremia may play a critical role in HIV-induced immune activation. In this study, we found that the level of immune activation was higher in the late phase of SIVmac239 infection compared with chronic infection, which suggests that immune activation might be related to disease progression in SIVmac239-infected non-human primate models. Our work also showed that chloroquine could effectively inhibit the activation of pDCs in vitro and in vivo. However, chloroquine treatment of SIVmac239-infected macaques had no significant influence on the Cellular composition of peripheral blood in these animals. PMID:22885523

Biological effect of OK-432 (picibanil) and possible application to dendritic cell therapy.

PubMed

Ryoma, Yoshiki; Moriya, Yoichiro; Okamoto, Masato; Kanaya, Isao; Saito, Motoo; Sato, Mitsunobu

2004-01-01

OK-432 (Picibanil), a streptococcal preparation with potent biological response modifying activities, was approved in Japan as an anticancer agent in 1975. In the ensuing 30 years, since then, a significant amount of data, including clinical as well as experimental studies, has been accumulated. OK-432 has been reported to induce various cytokines, activate immunological cells and thus augment anticancer immunity. Recently, the interrelation between innate immunity and adaptive immunity has become clear and it was reported that OK-432 acts, at least in part, via Toll-like receptor (TLR) 4-MD2 signaling pathway. In addition, dendritic cells (DCs) are considered to play a pivotal role in immunological response and it is reported that OK-432 induced maturation of DCs both in vitro and in vivo. These results suggest that OK-432 is a useful adjuvant in DC-based anticancer immunotherapy. Clinical studies of DC therapy with OK-432 are under way.

Exposure to apoptotic activated CD4+ T cells induces maturation and APOBEC3G-mediated inhibition of HIV-1 infection in dendritic cells.

PubMed

Mohanram, Venkatramanan; Johansson, Ulrika; Sköld, Annette E; Fink, Joshua; Kumar Pathak, Sushil; Mäkitalo, Barbro; Walther-Jallow, Lilian; Spetz, Anna-Lena

2011-01-01

Dendritic cells (DCs) are activated by signaling via pathogen-specific receptors or exposure to inflammatory mediators. Here we show that co-culturing DCs with apoptotic HIV-infected activated CD4(+) T cells (ApoInf) or apoptotic uninfected activated CD4(+) T cells (ApoAct) induced expression of co-stimulatory molecules and cytokine release. In addition, we measured a reduced HIV infection rate in DCs after co-culture with ApoAct. A prerequisite for reduced HIV infection in DCs was activation of CD4(+) T cells before apoptosis induction. DCs exposed to ApoAct or ApoInf secreted MIP-1α, MIP-1β, MCP-1, and TNF-α; this effect was retained in the presence of exogenous HIV. The ApoAct-mediated induction of co-stimulatory CD86 molecules and reduction of HIV infection in DCs were partially abrogated after blocking TNF-α using monoclonal antibodies. APOBEC3G expression in DCs was increased in co-cultures of DCs and ApoAct but not by apoptotic resting CD4(+) T cells (ApoRest). Silencing of APOBEC3G in DC abrogated the HIV inhibitory effect mediated by ApoAct. Sequence analyses of an env region revealed significant induction of G-to-A hypermutations in the context of GG or GA dinucleotides in DNA isolated from DCs exposed to HIV and ApoAct. Thus, ApoAct-mediated DC maturation resulted in induction of APOBEC3G that was important for inhibition of HIV-infection in DCs. These findings underscore the complexity of differential DC responses evoked upon interaction with resting as compared with activated dying cells during HIV infection.

Der p 1 suppresses indoleamine 2, 3-dioxygenase in dendritic cells from house dust mite-sensitive patients with asthma.

PubMed

Maneechotesuwan, Kittipong; Wamanuttajinda, Valla; Kasetsinsombat, Kanda; Huabprasert, Sukit; Yaikwawong, Metha; Barnes, Peter J; Wongkajornsilp, Adisak

2009-01-01

Indoleamine 2, 3-dioxygenase (IDO), a tryptophan-degrading enzyme in dendritic cells (DCs), mediates an immunosuppressive effect on activated T lymphocytes. However, little is known about the effect of Der p 1 on IDO in human DCs. The aim was to investigate the effect of Der p 1 on the expression and activity of IDO in monocyte-derived DCs from house dust mite (HDM)-sensitive patients with asthma. Using real-time RT-PCR and HPLC, the expression and activity of IDO were assessed in TNF-alpha-induced mature DCs from HDM-sensitive and nonatopic patients with asthma in response to Der p 1 exposure ex vivo. We also monitored the alteration of IDO activity in Der p 1-pulsed DCs after the coincubation with autologous T cells. With a reliance on its protease activity, Der p 1 suppressed functional IDO in DCs from HDM-sensitive patients with asthma but enhanced IDO activity in DCs from nonatopic patients with asthma. This suppression was maintained by the reciprocally induced IL-4 from the coculturing autologous HDM-sensitive T cells. Conversely, the upregulation of IDO activity in Der p 1-pulsed DCs was maintained by IFN-gamma released from autologous nonatopic T cells and the regulatory T-cell subset. Der p 1 pulsation to sensitive DCs failed to raise regulatory T cells but raised progenitor fractions from cloned HDM-sensitive CD4(+) cells through direct contact and soluble mediators. House dust mite-sensitive DCs exposed to Der p 1 downregulated IDO activity and tipped the T(H)1/T(H)2 cytokine balance toward IL-4, resulting in sustainable IDO suppression.

Preventive antitumor activity against hepatocellular carcinoma (HCC) induced by immunization with fusions of dendritic cells and HCC cells in mice.

PubMed

Homma, S; Toda, G; Gong, J; Kufe, D; Ohno, T

2001-11-01

The prevention of recurrence of hepatocellular carcinoma (HCC) after treatment is very important for improvement of the prognosis of HCC patients. Dendritic cells (DCs) are potent antigen-presenting cells that can prime naive T cells to induce a primary immune response. We attempted to induce preventive antitumor immunity against HCC by immunizing BALB/c mice with fusions of DCs and HCC cells. Murine bone marrow-derived DCs and a murine HCC cell line. BNL cells, were fused by treatment with 50% polyethyleneglvcol (PEG). Fusion efficacy was assessed by the analysis of fusions of BNL cells stained with red fluorescent dye and DCs stained with green fluorescent dye. Mice injected intravenously with DC/BNL fusions were challenged by BNL cell inoculation. About 30% of the PEG-treated non-adherent cells with both fluorescences were considered to be fusion cells. The cell fraction of DC/BNL fusions showed phenotypes of DCs, MHC class II, CD80, CD86, and intercellular adhesion molecule (ICAM)-1, which were not expressed on BNL cells. Mice immunized with the fusions were protected against the inoculation of BNL tumor cells, whereas injection with a mixture of DCs and BNL cells not treated with PEG did not provide significant resistance against BNL cell inoculation. Splenocytes from DC/BNL fusion-immunized mice showed lytic activity against BNL cells. These results demonstrate that immunization with fusions of DCs and HCC cells is capable of inducing preventive antitumor immunity against HCC.

GM-CSF Inhibits c-Kit and SCF Expression by Bone Marrow-Derived Dendritic Cells

PubMed Central

Barroeta Seijas, Amairelys Belen; Simonetti, Sonia; Vitale, Sara; Runci, Daniele; Quinci, Angela Caterina; Soriani, Alessandra; Criscuoli, Mattia; Filippi, Irene; Naldini, Antonella; Sacchetti, Federico Maria; Tarantino, Umberto; Oliva, Francesco; Piccirilli, Eleonora; Santoni, Angela; Di Rosa, Francesca

2017-01-01

Stem cell factor (SCF), the ligand of c-kit, is a key cytokine for hematopoiesis. Hematopoietic precursors express c-kit, whereas differentiated cells of hematopoietic lineage are negative for this receptor, with the exception of NK cells, mast cells, and a few others. While it has long been recognized that dendritic cells (DCs) can express c-kit, several questions remain concerning the SCF/c-kit axis in DCs. This is particularly relevant for DCs found in those organs wherein SCF is highly expressed, including the bone marrow (BM). We characterized c-kit expression by conventional DCs (cDCs) from BM and demonstrated a higher proportion of c-kit+ cells among type 1 cDC subsets (cDC1s) than type 2 cDC subsets (cDC2s) in both humans and mice, whereas similar levels of c-kit expression were observed in cDC1s and cDC2s from mouse spleen. To further study c-kit regulation, DCs were generated with granulocyte-macrophage colony-stimulating factor (GM-CSF) from mouse BM, a widely used protocol. CD11c+ cells were purified from pooled non-adherent and slightly adherent cells collected after 7 days of culture, thus obtaining highly purified BM-derived DCs (BMdDCs). BMdDCs contained a small fraction of c-kit+ cells, and by replating them for 2 days with GM-CSF, we obtained a homogeneous population of c-kit+ CD40hi MHCIIhi cells. Not only did BMdDCs express c-kit but they also produced SCF, and both were striking upregulated if GM-CSF was omitted after replating. Furthermore, a small but significant reduction in BMdDC survival was observed upon SCF silencing. Incubation of BMdDCs with SCF did not modulate antigen presentation ability of these cells, nor it did regulate their membrane expression of the chemokine receptor CXCR4. We conclude that the SCF/c-kit-mediated prosurvival circuit may have been overlooked because of the prominent use of GM-CSF in DC cultures in vitro, including those human DC cultures destined for the clinics. We speculate that DCs more prominently rely on SCF in vivo in some microenvironments, with potential implications for graft-versus-host disease and antitumor immunity. PMID:28261209

The Polyunsaturated Fatty Acids Arachidonic Acid and Docosahexaenoic Acid Induce Mouse Dendritic Cells Maturation but Reduce T-Cell Responses In Vitro

PubMed Central

Carlsson, Johan A.; Wold, Agnes E.; Sandberg, Ann-Sofie; Östman, Sofia M.

2015-01-01

Long-chain polyunsaturated fatty acids (PUFAs) might regulate T-cell activation and lineage commitment. Here, we measured the effects of omega-3 (n-3), n-6 and n-9 fatty acids on the interaction between dendritic cells (DCs) and naïve T cells. Spleen DCs from BALB/c mice were cultured in vitro with ovalbumin (OVA) with 50 μM fatty acids; α-linolenic acid, arachidonic acid (AA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), linoleic acid or oleic acid and thereafter OVA-specific DO11.10 T cells were added to the cultures. Fatty acids were taken up by the DCs, as shown by gas chromatography analysis. After culture with arachidonic acid or DHA CD11c+ CD11b+ and CD11c+ CD11bneg DCs expressed more CD40, CD80, CD83, CD86 and PDL-1, while IAd remained unchanged. However, fewer T cells co-cultured with these DCs proliferated (CellTrace Violetlow) and expressed CD69 or CD25, while more were necrotic (7AAD+). We noted an increased proportion of T cells with a regulatory T cell (Treg) phenotype, i.e., when gating on CD4+ FoxP3+ CTLA-4+, CD4+ FoxP3+ Helios+ or CD4+ FoxP3+ PD-1+, in co-cultures with arachidonic acid- or DHA-primed DCs relative to control cultures. The proportion of putative Tregs was inversely correlated to T-cell proliferation, indicating a suppressive function of these cells. With arachidonic acid DCs produced higher levels of prostaglandin E2 while T cells produced lower amounts of IL-10 and IFNγ. In conclusion arachidonic acid and DHA induced up-regulation of activation markers on DCs. However arachidonic acid- and DHA-primed DCs reduced T-cell proliferation and increased the proportion of T cells expressing FoxP3, indicating that these fatty acids can promote induction of regulatory T cells. PMID:26619195

Effect of oxygen levels on the physiology of dendritic cells: implications for adoptive cell therapy.

PubMed

Futalan, Diahnn; Huang, Chien-Tze; Schmidt-Wolf, Ingo G H; Larsson, Marie; Messmer, Davorka

2011-01-01

Dendritic cell (DC)-based adoptive tumor immunotherapy approaches have shown promising results, but the incidence of tumor regression is low and there is an evident call for identifying culture conditions that produce DCs with a more potent Th1 potential. Routinely, DCs are differentiated in CO(2) incubators under atmospheric oxygen conditions (21% O(2)), which differ from physiological oxygen levels of only 3-5% in tissue, where most DCs reside. We investigated whether differentiation and maturation of DCs under physiological oxygen levels could produce more potent T-cell stimulatory DCs for use in adoptive immunotherapy. We found that immature DCs differentiated under physiological oxygen levels showed a small but significant reduction in their endocytic capacity. The different oxygen levels did not influence their stimuli-induced upregulation of cluster of differentiation 54 (CD54), CD40, CD83, CD86, C-C chemokine receptor type 7 (CCR7), C-X-C chemokine receptor type 4 (CXCR4) and human leukocyte antigen (HLA)-DR or the secretion of interleukin (IL)-6, tumor necrosis factor (TNF)-α and IL-10 in response to lipopolysaccharide (LPS) or a cytokine cocktail. However, DCs differentiated under physiological oxygen level secreted higher levels of IL-12(p70) after exposure to LPS or CD40 ligand. Immature DCs differentiated at physiological oxygen levels caused increased T-cell proliferation, but no differences were observed for mature DCs with regard to T-cell activation. In conclusion, we show that although DCs generated under atmospheric or physiological oxygen conditions are mostly similar in function and phenotype, DCs differentiated under physiological oxygen secrete larger amounts of IL-12(p70). This result could have implications for the use of ex vivo-generated DCs for clinical studies, since DCs differentiated at physiological oxygen could induce increased Th1 responses in vivo.

Immature, Semi-Mature, and Fully Mature Dendritic Cells: Toward a DC-Cancer Cells Interface That Augments Anticancer Immunity

PubMed Central

Dudek, Aleksandra M.; Martin, Shaun; Garg, Abhishek D.; Agostinis, Patrizia

2013-01-01

Dendritic cells (DCs) are the sentinel antigen-presenting cells of the immune system; such that their productive interface with the dying cancer cells is crucial for proper communication of the “non-self” status of cancer cells to the adaptive immune system. Efficiency and the ultimate success of such a communication hinges upon the maturation status of the DCs, attained following their interaction with cancer cells. Immature DCs facilitate tolerance toward cancer cells (observed for many apoptotic inducers) while fully mature DCs can strongly promote anticancer immunity if they secrete the correct combinations of cytokines [observed when DCs interact with cancer cells undergoing immunogenic cell death (ICD)]. However, an intermediate population of DC maturation, called semi-mature DCs exists, which can potentiate either tolerogenicity or pro-tumorigenic responses (as happens in the case of certain chemotherapeutics and agents exerting ambivalent immune reactions). Specific combinations of DC phenotypic markers, DC-derived cytokines/chemokines, dying cancer cell-derived danger signals, and other less characterized entities (e.g., exosomes) can define the nature and evolution of the DC maturation state. In the present review, we discuss these different maturation states of DCs, how they might be attained and which anticancer agents or cell death modalities (e.g., tolerogenic cell death vs. ICD) may regulate these states. PMID:24376443

Rapid Pathogen-Induced Apoptosis: A Mechanism Used by Dendritic Cells to Limit Intracellular Replication of Legionella pneumophila

PubMed Central

Nogueira, Catarina V.; Lindsten, Tullia; Jamieson, Amanda M.; Case, Christopher L.; Shin, Sunny; Thompson, Craig B.; Roy, Craig R.

2009-01-01

Dendritic cells (DCs) are specialized phagocytes that internalize exogenous antigens and microbes at peripheral sites, and then migrate to lymphatic organs to display foreign peptides to naïve T cells. There are several examples where DCs have been shown to be more efficient at restricting the intracellular replication of pathogens compared to macrophages, a property that could prevent DCs from enhancing pathogen dissemination. To understand DC responses to pathogens, we investigated the mechanisms by which mouse DCs are able to restrict replication of the intracellular pathogen Legionella pneumophila. We show that both DCs and macrophages have the ability to interfere with L. pneumophila replication through a cell death pathway mediated by caspase-1 and Naip5. L. pneumophila that avoided Naip5-dependent responses, however, showed robust replication in macrophages but remained unable to replicate in DCs. Apoptotic cell death mediated by caspase-3 was found to occur much earlier in DCs following infection by L. pneumophila compared to macrophages infected similarly. Eliminating the pro-apoptotic proteins Bax and Bak or overproducing the anti-apoptotic protein Bcl-2 were both found to restore L. pneumophila replication in DCs. Thus, DCs have a microbial response pathway that rapidly activates apoptosis to limit pathogen replication. PMID:19521510

Generation of dendritic cells from positively selected CD14+ monocytes for anti-tumor immunotherapy.

PubMed

Curti, Antonio; Isidori, Alessandro; Ferri, Elisa; Terragna, Carolina; Neyroz, Paolo; Cellini, Claudia; Ratta, Marina; Baccarani, Michele; Lemoli, Roberto M

2004-07-01

Peripheral blood CD14+ monocytes from multiple myeloma (MM) patients can be induced to differentiate into fully functional, mature, CD83+ dendritic cells (DCs) which are highly efficient in priming autologous T lymphocytes in response to the patient-specific tumor idiotype (Id). We have recently scaled up our manufacturing protocol for application in a phase I-II clinical trial of anti-Id vaccination with DCs in MM patients. Elegible patients received a series of by-monthly immunizations consisting of three subcutaneous and two intravenous injections of Id-keyhole limpet hemocyanin (KLH)-pulsed DCs (5 x -, 10 x -, 50 x 10(6) cells and 10 x -, 50 x 10(6) cells, respectively). To generate DCs, monocytes were labeled with clinical grade anti-CD14 conjugates and positively selected by immunomagnetic separation. Cells were then cultured, according to Good Manufacturing Practice guidelines, in FCS-free medium in cell culture bags, and differentiated to DCs with GM-CSF plus IL-4 followed by TNF-alpha or, more recently, by a cocktail of IL-1beta, IL-6, TNF-alpha and prostaglandin-E2. Before maturation, Mo-DCs were pulsed with the autologous Id as whole protein or Id (VDJ)-derived HLA class I restricted peptides. Ten MM patients, who had been treated with two courses of high-dose chemotherapy with peripheral blood stem cell support, entered into the clinical study. CD14+ monocytes were enriched from 16.1+/-5.7% to 95.5+/-3.2% (recovery 67.9+/-15%, viability > 97%). After cell culture, phenotypic analysis showed that 89.6+/-6.6% of the cells were mature DCs. We obtained 2.89+/-1 x 10(8) DCs/leukapheresis which represented 24.5+/-9% of the initial number of CD14+ cells. Notably, the cytokine cocktail induced a significantly higher percentage and yield (31+/-10.9 of initial CD14+ cells) of DCs than TNF-alpha alone, secretion of larger amounts of IL-12, potent stimulatory activity on allogeneic and autologous T cells. Storage in liquid nitrogen did not modify the phenotype or functional characteristics of pre-loaded DCs. The recovery of thawed, viable DCs, was 78+/-10%. Thus, positive selection of CD14+ monocytes allows the generation of a uniform population of mature pre-loaded DCs which can be cryopreserved with no effects on phenotype and function and are suitable for clinical trials. Based on these results, a DCs-based phase II trial of anti-Id vaccination with VDJ-derived HLA class I-restricted peptides and KLH is underway for lymphoma patients.

Nrf2 suppresses the function of dendritic cells to facilitate the immune escape of glioma cells.

PubMed

Wang, Jialiang; Liu, Peng; Xin, Shaoyan; Wang, Zongbao; Li, Jun

2017-11-15

Nrf2 is presented in dendritic cells (DCs) and contributes to the maintenance of redox homeostasis. However, the expression pattern and function of Nrf2 in the maturation of DCs in the glioma-infiltrated microenvironment remain unrevealed. Our study aims to investigate the roles of Nrf2 in glioma cell-tamed DCs and their impact on the downstream T cell proliferation and cytotoxicity to glioma cells. It was showed that the inducible maturation of DCs was significantly suppressed after stimulation with tumor-conditioned medium (TCM) prepared from glioma cells (LN-18 and U118MG), as suggested by the decreased CD80, CD86 and IL-12 p70 expression and higher levels of IL-10 than the normal astrocyte medium treated DCs. Moreover, the TCM-exposed DCs had significantly increased expression and transcriptional activity of Nrf2 compared to the negative control. Nrf2 inhibition in DC cells substantially antagonized the inhibitory effects of TCM on the maturation and activation of DC cells, reflected by the elevated maturation markers and IL-12 p70. We further confirmed that Nrf2 inhibition in TCM-exposed DC cells promoted the proliferation of T cells as evaluated by the CFSE-labeled assay and Th1 response shown by the elevated production of IFN-γ. The cytotoxic T lymphocyte assay revealed that Nrf2 genetic suppression in DC cells greatly enhanced the capacity of T cells in the cytotoxicity to glioma cells dependent on the E:T ratio. Collectively, our study demonstrated that Nrf2 inhibition in DCs in glioma-exposed microenvironment could enhance the maturation of DCs and the subsequent activation of T cells and their cytotoxicity on glioma cells. Copyright © 2017. Published by Elsevier Inc.

Clinical significance of circulating immune cells in left- and right-sided colon cancer.

PubMed

Di, Jiabo; Zhuang, Meng; Yang, Hong; Jiang, Beihai; Wang, Zaozao; Su, Xiangqian

2017-01-01

Left-sided and right-sided colon cancers (LCCs and RCCs, respectively) differ in their epidemiology, pathogenesis, genetic and epigenetic alterations, molecular pathways and prognosis. Notably, immune response gene expression profiles have been shown to differ between patients with LCC and patients with RCC. The immune system plays an important role in tumor immunosurveillance, and there is increasing evidence that peripheral blood immune cells have a profound influence on tumor prognosis. This study aimed to determine the clinical significance of circulating immune cells with respect to colon tumor locations. Different types of circulating immune cells were separated and analysed based on their surface markers by flow cytometry. We compared the numbers of dendritic cells (DCs) and T cell subsets in the peripheral blood of 94 patients with RCC or LCC and analysed the proportions of these immune cells in relation to tumor stage, tumor differentiation and lymphatic metastasis. We show that at later tumor stages, patients with LCC had higher levels of circulating myeloid DCs ( P  = 0.049) and plasmacytoid DCs ( P  = 0.018) than patients with RCC. In poorly differentiated tumors, LCC patients had significantly higher amount of plasmacytoid DCs ( P  = 0.036), CD4 + memory T (Tm) cells ( P  = 0.012), CD4 + T cells ( P  = 0.028), Tm cells ( P  = 0.014), and regulatory T cells ( P  = 0.001) than RCC patients. The levels of circulating CD4 + T cells, Tm cells and CD4 + Tm cells were significantly elevated at later stages in patients with LCC or RCC, while these cells decreased in poorly differentiated tumors in patients with RCC. Moreover, CD4 + Tm cell and CD4 + T cell levels are significantly associated with lymph node metastasis in patients with LCC and RCC. Circulating immune cells were associated with tumor location, tumor stage and tumor differentiation, and can be used to predict lymphatic metastasis in patients with colon cancer. This variation in systemic immunity could contribute to the differential prognosis of patients with colon cancer.

Role and contribution of pulmonary CD103+ dendritic cells in the adaptive immune response to Mycobacterium tuberculosis.

PubMed

Koh, Vanessa Hui Qi; Ng, See Liang; Ang, Michelle Lay Teng; Lin, Wenwei; Ruedl, Christiane; Alonso, Sylvie

2017-01-01

Despite international control programmes, the global burden of tuberculosis remains enormous. Efforts to discover novel drugs have largely focused on targeting the bacterium directly. Alternatively, manipulating the host immune response may represent a valuable approach to enhance immunological clearance of the bacilli, but necessitates a deeper understanding of the immune mechanisms associated with protection against Mycobacterium tuberculosis infection. Here, we examined the various dendritic cells (DC) subsets present in the lung and draining lymph nodes (LN) from mice intra-tracheally infected with M. tuberculosis. We showed that although limited in number, pulmonary CD103 + DCs appeared to be involved in the initial transport of mycobacteria to the draining mediastinal LN and subsequent activation of T cells. Using CLEC9A-DTR transgenic mice enabling the inducible depletion of CD103 + DCs, we established that this DC subset contributes to the control of mycobacterial burden and plays a role in the early activation of T cells, in particular CD8 + T cells. Our findings thus support a previously unidentified role for pulmonary CD103 + DCs in the rapid mobilization of mycobacteria from the lungs to the draining LN soon after exposure to M. tuberculosis, which is a critical step for the development of the host adaptive immune response. Copyright © 2016 Elsevier Ltd. All rights reserved.

A benzenediamine derivate FC-99 attenuates lupus nephritis in MRL/lpr mice via inhibiting myeloid dendritic cell-secreted BAFF

PubMed Central

Ji, Jianjian; Xu, Jingjing; Li, Fanlin; Li, Xiaojing; Gong, Wei; Song, Yuxian; Dou, Huan; Hou, Yayi

2016-01-01

Myeloid dendritic cells (DCs) can produce B-cell-activating factor (BAFF) that modulates survival and differentiation of B cells and plays a pivotal role in the pathogenesis of systemic lupus erythematosus (SLE). Toll-like receptor 4 (TLR4) signaling has important functions in the process of BAFF production. Our previous study showed that a benzenediamine derivate FC-99 possesses anti-inflammation activity and directly interacts with interleukin-1 receptor-associated kinase 4 (IRAK4), which was a pivotal molecule in TLR4 signaling. In this study, we demonstrated that FC-99 attenuated lupus nephritis in the MRL/lpr mice. FC-99 also decreased the levels of total immunoglobulin G (IgG), total IgG2a and IgM in sera, as well as the activation of B cells in the spleens of MRL/lpr mice. Moreover, FC-99 inhibited abnormal activation of myeloid DCs in spleens and reduced the levels of BAFF in sera, spleens, and kidneys of MRL/lpr mice. Furthermore, upon TLR4 stimulation with lipopolysaccharide in vitro, FC-99 inhibited IRAK4 phosphorylation, as well as the activation and BAFF production in murine bone marrow-derived DCs. These data indicate that FC-99 attenuates lupus nephritis in MRL/lpr mice via inhibiting DC-secreted BAFF, suggesting that FC-99 may be a potential therapeutic candidate for the treatment of SLE. PMID:27121231

Immunostimulatory activities of dendritic cells loaded with adenovirus vector carrying HBcAg/HBsAg

PubMed Central

Jia, Hongyu; Li, Chunling; Zhang, Yimin; Yu, Liang; Xiang, Dairong; Liu, Jun; Chen, Fengzhe; Han, Xiaochun

2015-01-01

Objective: This study is to investigate the immunostimulatory activities of dendritic cells (DCs) transfected with HBcAg and/or HBsAg recombinant adenovirus (rAd). Methods: DCs were transfected with rAd (DC/Ad-C+Ad-S, DC/Ad-C, and DC/Ad-S), or pulsed with HBcAg antigen (DC/HBcAg). Flow cytometry was used to detect the phenotype of DCs and the cytokine production of T lymphocytes. Mice were vaccinated with DCs transfected with rAd or pulsed with antigen, and DNA vaccine. Mixed lymphocyte reaction (MLR) was used to evaluate the T-cell stimulatory capacity, and HBcAg-specific cytotoxic T lymphocyte (CTL) activity was assessed. Results: Phenotypic analysis showed that DCs transfected with rAd or pulsed with HBcAg antigen exhibited mature phenotypes. MLR indicated no significant differences in stimulating T-cell proliferation between the DC/rAd and DC/HBcAg groups. When mixed with DCs, Th and Tc cells mainly secreted IFN-γ, indicating type I immune responses. In vaccinated mice, DCs transduced with rAd and pulsed with HBcAg induced significantly more IFN-γ secretion from Th cells, compared with DNA vaccine, indicating stronger Th1 response. Moreover, DCs transduced with rAd stimulated Tc cells to produce more IFN-γ, indicating stronger Tc1 response. In vaccinated mice, HBcAg-specific CTL activities were decreased in the following order: the DC/Ad-C+Ad-S, DC/Ad-C, DC/Ad-S, DC/HBcAg, and DNA vaccine groups. Conclusion: DCs transfected with rAd induce stronger Th1/Tc1 (type I) cell immune responses and specific CTL response than HBcAg-pulsed DCs or DNA vaccine. Our findings suggest that DCs transfected with rAd-C/rAd-S might provide an effective approach in the treatment of persistent hepatitis B virus infection. PMID:26064236

A short-term increase of the postoperative naturally circulating dendritic cells subsets in flurbiprofen-treated patients with esophageal carcinoma undergoing thoracic surgery

PubMed Central

Chai, Xiao-qing; Shu, Shu-hua; Zhang, Xiao-lin; Xie, Yan-hu; Wei, Xin; Wu, Yu-jing; Wei, Wei

2016-01-01

The present study evaluated whether flurbiprofen increased the naturally circulating dendritic cells (DCs) subsets in patients with esophageal squamous cell carcinoma (ESCC) undergoing esophageal resection. Compared to healthy donors (n=20), the significantly depressed percentages of plasmacytoid DCs (pDCs), CD1c+ myeloid DCs (mDCs), and CD141+ mDCs among ESCC patients (n=60) were confirmed. Flurbiprofen was administered before skin incision and at the end of operation in group F (n=30), as well as placebo in group C (n=30). The postoperative suppressed percentages of pDCs, CD1c+ mDCs, and CD141+ mDCs increased significantly following the perioperative treatment with flurbiprofen. Flurbiprofen also significantly stimulated the postoperative IFN-f and IL-17 production, but inhibited the immunosuppressive IL-10 and TGF-β levels. Furthermore, flurbiprofen exerted a similar analgesic effect and brought a significantly less sufentanil consumption compared to group C. Taken together, flurbiprofen provided a short-term increase of postoperative naturally circulating DCs in ESCC patients. PMID:26959879

A short-term increase of the postoperative naturally circulating dendritic cells subsets in flurbiprofen-treated patients with esophageal carcinoma undergoing thoracic surgery.

PubMed

Wang, Di; Yang, Xin-lu; Chai, Xiao-qing; Shu, Shu-hua; Zhang, Xiao-lin; Xie, Yan-hu; Wei, Xin; Wu, Yu-jing; Wei, Wei

2016-04-05

The present study evaluated whether flurbiprofen increased the naturally circulating dendritic cells (DCs) subsets in patients with esophageal squamous cell carcinoma (ESCC) undergoing esophageal resection. Compared to healthy donors (n=20), the significantly depressed percentages of plasmacytoid DCs (pDCs), CD1c+ myeloid DCs (mDCs), and CD141+ mDCs among ESCC patients (n=60) were confirmed. Flurbiprofen was administered before skin incision and at the end of operation in group F (n=30), as well as placebo in group C (n=30). The postoperative suppressed percentages of pDCs, CD1c+ mDCs, and CD141+ mDCs increased significantly following the perioperative treatment with flurbiprofen. Flurbiprofen also significantly stimulated the postoperative IFN-f and IL-17 production, but inhibited the immunosuppressive IL-10 and TGF-β levels. Furthermore, flurbiprofen exerted a similar analgesic effect and brought a significantly less sufentanil consumption compared to group C. Taken together, flurbiprofen provided a short-term increase of postoperative naturally circulating DCs in ESCC patients.

Notch-ligand expression by NALT dendritic cells regulates mucosal Th1- and Th2-type responses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fukuyama, Yoshiko; Tokuhara, Daisuke; Division of Mucosal Immunology, Institute of Medical Science, University of Tokyo, Tokyo 108-8639

Highlights: Black-Right-Pointing-Pointer Nasal Ad-FL effectively up-regulates APC function by CD11c{sup +} DCs in mucosal tissues. Black-Right-Pointing-Pointer Nasal Ad-FL induces Notch ligand (L)-expressing CD11c{sup +} DCs. Black-Right-Pointing-Pointer Notch L-expressing DCs support the induction of Th1- and Th2-type cytokine responses. -- Abstract: Our previous studies showed that an adenovirus (Ad) serotype 5 vector expressing Flt3 ligand (Ad-FL) as nasal adjuvant activates CD11c{sup +} dendritic cells (DCs) for the enhancement of antigen (Ag)-specific IgA antibody (Ab) responses. In this study, we examined the molecular mechanism for activation of CD11c{sup +} DCs and their roles in induction of Ag-specific Th1- and Th2-cell responses. Ad-FLmore » activated CD11c{sup +} DCs expressed increased levels of the Notch ligand (L)-expression and specific mRNA. When CD11c{sup +} DCs from various mucosal and systemic lymphoid tissues of mice given nasal OVA plus Ad-FL were cultured with CD4{sup +} T cells isolated from non-immunized OVA TCR-transgenic (OT II) mice, significantly increased levels of T cell proliferative responses were noted. Furthermore, Ad-FL activated DCs induced IFN-{gamma}, IL-2 and IL-4 producing CD4{sup +} T cells. Of importance, these APC functions by Ad-FL activated DCs were down-regulated by blocking Notch-Notch-L pathway. These results show that Ad-FL induces CD11c{sup +} DCs to the express Notch-ligands and these activated DCs regulate the induction of Ag-specific Th1- and Th2-type cytokine responses.« less

Circulating dendritic cells of multiple sclerosis patients are proinflammatory and their frequency is correlated with MS-associated genetic risk factors.

PubMed

Thewissen, Kristof; Nuyts, Amber H; Deckx, Nathalie; Van Wijmeersch, Bart; Nagels, Guy; D'hooghe, Marie; Willekens, Barbara; Cras, Patrick; Eijnde, Bert O; Goossens, Herman; Van Tendeloo, Viggo F I; Stinissen, Piet; Berneman, Zwi N; Hellings, Niels; Cools, Nathalie

2014-04-01

The role of the adaptive immune system and more specifically T cells in the pathogenesis of multiple sclerosis (MS) has been studied extensively. Emerging evidence suggests that dendritic cells (DCs), which are innate immune cells, also contribute to MS. This study aimed to characterize circulating DC populations in MS and to investigate the contribution of MS-associated genetic risk factors to DCs. Ex vivo analysis of conventional (cDCs) and plasmacytoid DCs (pDCs) was carried out on peripheral blood of MS patients (n = 110) and age- and gender-matched healthy controls (n = 112). Circulating pDCs were significantly decreased in patients with chronic progressive MS compared to relapsing-remitting MS and healthy controls. While no differences in cDCs frequency were found between the different study groups, HLA-DRB1*1501(+) MS patients and patients not carrying the protective IL-7Rα haplotype 2 have reduced frequencies of circulating cDCs and pDCs, respectively. MS-derived DCs showed enhanced IL-12p70 production upon TLR ligation and had an increased expression of the migratory molecules CCR5 and CCR7 as well as an enhanced in vitro chemotaxis. DCs in MS are in a pro-inflammatory state, have a migratory phenotype and are affected by genetic risk factors, thereby contributing to pathogenic responses.

Immunoglobulin-like transcript receptors on human dermal CD14+ dendritic cells act as a CD8-antagonist to control cytotoxic T cell priming

PubMed Central

Banchereau, Jacques; Zurawski, Sandra; Thompson-Snipes, LuAnn; Blanck, Jean-Philippe; Clayton, Sandra; Munk, Adiel; Cao, Yanying; Wang, Zhiqing; Khandelwal, Sunaina; Hu, Jiancheng; McCoy, William H.; Palucka, Karolina A.; Reiter, Yoram; Fremont, Daved H.; Zurawski, Gerard; Colonna, Marco; Shaw, Andrey S.; Klechevsky, Eynav

2012-01-01

Human Langerhans cells (LCs) are highly efficient at priming cytolytic CD8+ T cells compared with dermal CD14+ dendritic cells (DCs). Here we show that dermal CD14+ DCs instead prime a fraction of naïve CD8+ T cells into cells sharing the properties of type 2 cytokine-secreting CD8+ T cells (TC2). Differential expression of the CD8-antagonist receptors on dermal CD14+ DCs, the Ig-like transcript (ILT) inhibitory receptors, explains the difference between the two types of DCs. Inhibition of CD8 function on LCs inhibited cytotoxic T lymphocytes (CTLs) and enhanced TC2 generation. In addition, blocking ILT2 or ILT4 on dermal CD14+ DCs enhanced the generation of CTLs and inhibited TC2 cytokine production. Lastly, addition of soluble ILT2 and ILT4 receptors inhibited CTL priming by LCs. Thus, ILT receptor expression explains the polarization of CD8+ T-cell responses by LCs vs. dermal CD14+ DCs. PMID:23112154

Capsaicin-mediated apoptosis of human bladder cancer cells activates dendritic cells via CD91.

PubMed

Gilardini Montani, Maria Saveria; D'Eliseo, Donatella; Cirone, Mara; Di Renzo, Livia; Faggioni, Alberto; Santoni, Angela; Velotti, Francesca

2015-04-01

Immunostimulation by anticancer cytotoxic drugs is needed for long-term therapeutic success. Activation of dendritic cells (DCs) is crucial to obtain effective and long-lasting anticancer T-cell mediated immunity. The aim of this study was to explore the effect of capsaicin-mediated cell death of bladder cancer cells on the activation of human monocyte-derived CD1a+ immature DCs. Immature DCs (generated from human peripheral blood-derived CD14+ monocytes cultured with granulocyte-macrophage colony stimulating factor and interleukin-4) were cocultured with capsaicin (CPS)-induced apoptotic bladder cancer cells. DC activation was investigated using immunofluorescence and flow cytometric analysis for key surface molecules. In some experiments, CD91 was silenced in immature DCs. We found that capsaicin-mediated cancer cell apoptosis upregulates CD86 and CD83 expression on DCs, indicating the induction of DC activation. Moreover, silencing of CD91 (a common receptor for damage-associated molecular patterns, such as calreticulin and heat-shock protein-90/70) in immature DCs led to the inhibition of DC activation. Our data show that CPS-mediated cancer cell apoptosis activates DCs via CD91, suggesting CPS as an attractive candidate for cancer therapy. Copyright © 2015 Elsevier Inc. All rights reserved.

PD-1 expression on dendritic cells suppresses CD8+ T cell function and antitumor immunity.

PubMed

Lim, Tong Seng; Chew, Valerie; Sieow, Je Lin; Goh, Siting; Yeong, Joe Poh-Sheng; Soon, Ai Ling; Ricciardi-Castagnoli, Paola

2016-03-01

Programmed death one (PD-1) is a well-established co-inhibitory regulator that suppresses proliferation and cytokine production of T cells. Despite remarkable progress in delineating the functional roles of PD-1 on T lymphocytes, little is known about the regulatory role of PD-1 expressed on myeloid cells such as dendritic cells (DCs). Here, we show that CD8 + T cells can be more potently activated to secrete IL-2 and IFNγ by PD-1-deficient DCs compared to wild-type DCs. Adoptive transfer of PD-1-deficient DCs demonstrated their superior capabilities in inducing antigen-specific CD8 + T cell proliferation in vivo . In addition, we provide first evidence demonstrating the existence of peripheral blood DCs and CD11c + tumor-infiltrating myeloid cells that co-express PD-1 in patients with hepatocellular carcinoma (HCC). The existence of PD-1-expressing HCC-infiltrating DCs (HIDCs) was further supported in a mouse model of HCC. Intratumoral transfer of PD-1-deficient DCs rendered recipient mice resistant to the growth of HCC by promoting tumor-infiltrating CD8 + effector T cells to secrete perforin and granzyme B. This novel finding provides a deeper understanding of the role of PD-1 in immune regulation and has significant implications for cancer immunotherapies targeting PD-1.

PD-1 expression on dendritic cells suppresses CD8+ T cell function and antitumor immunity

PubMed Central

Lim, Tong Seng; Chew, Valerie; Sieow, Je Lin; Goh, Siting; Yeong, Joe Poh-Sheng; Soon, Ai Ling; Ricciardi-Castagnoli, Paola

2016-01-01

ABSTRACT Programmed death one (PD-1) is a well-established co-inhibitory regulator that suppresses proliferation and cytokine production of T cells. Despite remarkable progress in delineating the functional roles of PD-1 on T lymphocytes, little is known about the regulatory role of PD-1 expressed on myeloid cells such as dendritic cells (DCs). Here, we show that CD8+ T cells can be more potently activated to secrete IL-2 and IFNγ by PD-1-deficient DCs compared to wild-type DCs. Adoptive transfer of PD-1-deficient DCs demonstrated their superior capabilities in inducing antigen-specific CD8+ T cell proliferation in vivo. In addition, we provide first evidence demonstrating the existence of peripheral blood DCs and CD11c+ tumor-infiltrating myeloid cells that co-express PD-1 in patients with hepatocellular carcinoma (HCC). The existence of PD-1-expressing HCC-infiltrating DCs (HIDCs) was further supported in a mouse model of HCC. Intratumoral transfer of PD-1-deficient DCs rendered recipient mice resistant to the growth of HCC by promoting tumor-infiltrating CD8+ effector T cells to secrete perforin and granzyme B. This novel finding provides a deeper understanding of the role of PD-1 in immune regulation and has significant implications for cancer immunotherapies targeting PD-1. PMID:27141339

Avian dark cells

NASA Technical Reports Server (NTRS)

Hara, J.; Plymale, D. R.; Shepard, D. L.; Hara, H.; Garry, Robert F.; Yoshihara, T.; Zenner, Hans-Peter; Bolton, M.; Kalkeri, R.; Fermin, Cesar D.

2002-01-01

Dark cells (DCs) of mammalian and non-mammalian species help to maintain the homeostasis of the inner ear fluids in vivo. Although the avian cochlea is straight and the mammalian cochlea is coiled, no significant difference in the morphology and/or function of mammalian and avian DCs has been reported. The mammalian equivalent of avian DCs are marginal cells and are located in the stria vascularis along a bony sheet. Avian DCs hang free from the tegmentum vasculosum (TV) of the avian lagena between the perilymph and endolymph. Frame averaging was used to image the fluorescence emitted by several fluorochromes applied to freshly isolated dark cells (iDCs) from chickens (Gallus domesticus) inner ears. The viability of iDCs was monitored via trypan blue exclusion at each isolation step. Sodium Green, BCECF-AM, Rhodamine 123 and 9-anthroyl ouabain molecules were used to test iDC function. These fluorochromes label iDCs ionic transmembrane trafficking function, membrane electrogenic potentials and Na+/K+ ATPase pump's activity. Na+/K+ ATPase pump sites, were also evaluated by the p-nitrophenyl phosphatase reaction. These results suggest that iDCs remain viable for several hours after isolation without special culturing requirements and that the number and functional activity of Na+/K+ ATPase pumps in the iDCs were indistinguishable from in vivo DCs. Primary cultures of freshly iDCs were successfully maintained for 28 days in plastic dishes with RPMI 1640 culture medium. The preparation of iDCs overcomes the difficulty of DCs accessability in vivo and the unavoidable contamination that rupturing the inner ear microenvironments induces.

CD40 ligation and phagocytosis differently affect the differentiation of monocytes into dendritic cells.

PubMed

Rosenzwajg, Michelle; Jourquin, Frédéric; Tailleux, Ludovic; Gluckman, Jean Claude

2002-12-01

That monocytes can differentiate into macrophages or dendritic cells (DCs) makes them an essential link between innate and adaptive immunity. However, little is known about how interactions with pathogens or T cells influence monocyte engagement toward DCs. We approached this point in cultures where granulocyte macrophage-colony stimulating factor (GM-CSF) and interleukin (IL)-4 induced monocytes to differentiate into immature DCs. Activating monocytes with soluble CD40 ligand (CD40L) led to accelerated differentiation toward mature CD83(+) DCs with up-regulated human leukocyte antigen-DR, costimulatory molecules and CD116 (GM-CSF receptor), and down-regulation of molecules involved in antigen capture. Monocytes primed by phagocytosis of antibody-opsonized, killed Escherichia coli differentiated into DCs with an immature phenotype, whereas Zymosan priming yielded active DCs with an intermediate phenotype. Accordingly, DCs obtained from cultures with CD40L or after Zymosan priming had a decreased capacity to endocytose dextran, but only DCs cultured with CD40L had increased capacity to stimulate allogeneic T cells. DCs obtained after E. coli or Zymosan priming of monocytes produced high levels of proinflammatory tumor necrosis factor alpha and IL-6 as well as of regulatory IL-10, but they produced IL-12p70 only after secondary CD40 ligation. Thus, CD40 ligation on monocytes accelerates the maturation of DCs in the presence of GM-CSF/IL-4, whereas phagocytosis of different microorganisms does not alter and even facilitates their potential to differentiate into immature or active DCs, the maturation of which can be completed upon CD40 ligation. In vivo, such differences may correspond to DCs with different trafficking and T helper cell-stimulating capacities that could differently affect induction of adaptive immune responses to infections.

Dendritic cells from the elderly display an intrinsic defect in the production of IL-10 in response to lithium chloride.

PubMed

Agrawal, Sudhanshu; Gollapudi, Sastry; Gupta, Sudhir; Agrawal, Anshu

2013-11-01

Chronic, low grade inflammation is a characteristic of old age. Innate immune system cells such as dendritic cells (DCs) from the elderly display a pro-inflammatory phenotype associated with increased reactivity to self. Lithium is a well-established anti-inflammatory agent used in the treatment of bipolar disorders. It has also been reported to reduce inflammation in DCs. Here, we investigated whether Lithium is effective in reducing the inflammatory responses in DCs from the elderly. The effect of Lithium Chloride (LiCl) was compared on the response of TLR4 agonist, LPS and TLR2 agonist, PAM3CSK4 stimulated aged and young DCs. LiCl enhanced the production of IL-10 in LPS stimulated young DCs. However, it did not affect TNF-α and IL-6 production. In contrast, in aged DCs, LiCl reduced the secretion of TNF-α and IL-6 in LPS stimulated DCs but did not increase IL-10. LiCl had no significant effect on PAM3CSK4 responses in aged and young DCs. LiCl treated DCs also displayed differences at the level of CD4 T cell priming and polarization. LPS-stimulated young DCs reduced IFN-γ secretion and biased the Th cell response towards Th2/Treg while LiCl treated aged DCs only reduced IFN-γ secretion but did not bias the response towards Th2/Treg. In summary, our data suggests that LiCl reduces inflammation in aged and young DCs via different mechanisms. Furthermore, the effect of LiCl is different on LPS and PAM3CSK4 responses. © 2013.

Human spleen contains different subsets of dendritic cells and regulatory T lymphocytes

PubMed Central

Velásquez-Lopera, M M; Correa, L A; García, L F

2008-01-01

Most knowledge about dendritic cells (DCs) and regulatory T cells in humans has been gathered from circulating cells but little is known about their frequency and distribution in lymphoid organs. This report shows the frequency, phenotype and location of DCs and regulatory T cells in deceased organ donors' spleens. As determined by flow cytometry, conventional/myeloid DCs (cDCs) CD11chighHLA-DR+CD123−/low were 2·3 ± 0·9% and LIN- HLA-DR+CD11chigh 2·1 ± 0·3% of total spleen cells. Mature CD11chighHLA-DR+CD83+ were 1·5 ± 0·8% and 1·0 ± 1·6% immature CD11chighHLA-DR+CD83- cDC. There were 0·3 ± 0·3% plasmacytoid DCs (pDC) CD11c−/lowHLA-DR+CD123high and 0·3 ± 0·1% LIN-HLA-DR+CD123high. Cells expressing cDCs markers, BDCA-1 and BDCA-3, and pDCs markers BDCA-2 and BDCA-4 were observed in higher frequencies than DCs with other phenotypes evaluated. CD11c+, CD123+ and CD83+ cells were located in subcapsular zone, T cells areas and B-cell follicles. CD4+CD25high Tregs were 0·2 ± 0·2% and CD8+CD28- comprised 11·5 ± 8·1% of spleen lymphocytes. FOXP3+ cells were found in T- and B-cell areas. The improvement in cell separation, manipulation and expansion techniques, will facilitate the manipulation of donor spleen cells as a part of protocols for induction and maintenance of allograft tolerance or treatment of autoimmune diseases. PMID:18727627

The Rho-ROCK pathway as a new pathological mechanism of innate immune subversion in chronic myeloid leukaemia.

PubMed

Basbous, Sara; Levescot, Anaïs; Piccirilli, Nathalie; Brizard, Françoise; Guilhot, François; Roy, Lydia; Bourmeyster, Nicolas; Gombert, Jean-Marc; Herbelin, André

2016-11-01

CD1d-restricted invariant natural killer T (iNKT) cells are believed to play a key role in cancer immune surveillance, and are functionally deficient in patients with chronic myeloid leukaemia (CML). Herein, we have hypothesized that this defect might originate from BCR-ABL-dependent dysfunctions in myeloid dendritic cells (mDCs). Indeed, flow cytometry and confocal microscopy revealed that cell surface expression of CD1d was downregulated in CML mDCs, relative to healthy donor (HD) controls. The decreased cell surface display of CD1d could not be ascribed to defective mDC differentiation, as attested by normal expression of HLA-DR and the CD86 maturation marker. On the other hand, reduced membrane expression was not associated with decreased intracytoplasmic levels of CD1d or its mRNA transcripts, consistent with intracellular retention. In vitro treatment of CML mDCs with the Rho-associated protein kinase (ROCK) inhibitor Y-27632 partially restored both cell surface CD1d expression and CD1d-mediated antigen presentation, whereas it had no effect on HD mDCs. An inhibitor of BCR-ABL tyrosine kinase (TK), imatinib mesylate (IM), had no such activity. Similar recovery of CD1d expression occurred with fasudil, another ROCK inhibitor that is commonly used in clinical trials. Our data support the conclusion that BCR-ABL-dependent ROCK, but not TK, is involved in CD1d downregulation. We propose that ROCK, which is most likely activated by the DH/PH domain of BCR-ABL, mediates iNKT-cell immune subversion in CML patients by downregulating CD1d expression on CML mDCs. Our study reveals the ROCK-mDC axis as a new potential target to restore immune surveillance in patients with CML, offering new therapeutic perspectives for CML treatment. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

HIV-1-infected monocyte-derived dendritic cells do not undergo maturation but can elicit IL-10 production and T cell regulation

NASA Astrophysics Data System (ADS)

Granelli-Piperno, Angela; Golebiowska, Angelika; Trumpfheller, Christine; Siegal, Frederick P.; Steinman, Ralph M.

2004-05-01

Dendritic cells (DCs) undergo maturation during virus infection and thereby become potent stimulators of cell-mediated immunity. HIV-1 replicates in immature DCs, but we now find that infection is not accompanied by many components of maturation in either infected cells or uninfected bystanders. The infected cultures do not develop potent stimulating activity for the mixed leukocyte reaction (MLR), and the DCs producing HIV-1 gag p24 do not express CD83 and DC-lysosome-associated membrane protein maturation markers. If different maturation stimuli are applied to DCs infected with HIV-1, the infected cells selectively fail to mature. When DCs from HIV-1-infected patients are infected and cultured with autologous T cells, IL-10 was produced in 6 of 10 patients. These DC-T cell cocultures could suppress another immune response, the MLR. The regulation was partially IL-10-dependent and correlated in extent with the level of IL-10 produced. Suppressor cells only developed from infected patients, rather than healthy controls, and the DCs had to be exposed to live virus rather than HIV-1 gag peptides or protein. These results indicate that HIV-1-infected DCs have two previously unrecognized means to evade immune responses: maturation can be blocked reducing the efficacy of antigen presentation from infected cells, and T cell-dependent suppression can be induced.

Ursodeoxycholic acid suppresses eosinophilic airway inflammation by inhibiting the function of dendritic cells through the nuclear farnesoid X receptor.

PubMed

Willart, M A M; van Nimwegen, M; Grefhorst, A; Hammad, H; Moons, L; Hoogsteden, H C; Lambrecht, B N; Kleinjan, A

2012-12-01

Ursodeoxycholic acid (UDCA) is the only known beneficial bile acid with immunomodulatory properties. Ursodeoxycholic acid prevents eosinophilic degranulation and reduces eosinophil counts in primary biliary cirrhosis. It is unknown whether UDCA would also modulate eosinophilic inflammation outside the gastrointestinal (GI) tract, such as eosinophilic airway inflammation seen in asthma. The working mechanism for its immunomodulatory effect is unknown. The immunosuppressive features of UDCA were studied in vivo, in mice, in an ovalbumin (OVA)-driven eosinophilic airway inflammation model. To study the mechanism of action of UDCA, we analyzed the effect of UDCA on eosinophils, T cells, and dendritic cell (DCs). DC function was studied in greater detail, focussing on migration and T-cell stimulatory strength in vivo and interaction with T cells in vitro as measured by time-lapse image analysis. Finally, we studied the capacity of UDCA to influence DC/T cell interaction. Ursodeoxycholic acid treatment of OVA-sensitized mice prior to OVA aerosol challenge significantly reduced eosinophilic airway inflammation compared with control animals. DCs expressed the farnesoid X receptor for UDCA. Ursodeoxycholic acid strongly promoted interleukin (IL)-12 production and enhanced the migration in DCs. The time of interaction between DCs and T cells was sharply reduced in vitro by UDCA treatment of the DCs resulting in a remarkable T-cell cytokine production. Ursodeoxycholic acid-treated DCs have less capacity than saline-treated DCs to induce eosinophilic inflammation in vivo in Balb/c mice. Ursodeoxycholic acid has the potency to suppress eosinophilic inflammation outside the GI tract. This potential comprises to alter critical function of DCs, in essence, the effect of UDCA on DCs through the modulation of the DC/T cell interaction. © 2012 John Wiley & Sons A/S.

Tumor cell apoptosis induces tumor-specific immunity in a CC chemokine receptor 1- and 5-dependent manner in mice.

PubMed

Iida, Noriho; Nakamoto, Yasunari; Baba, Tomohisa; Kakinoki, Kaheita; Li, Ying-Yi; Wu, Yu; Matsushima, Kouji; Kaneko, Shuichi; Mukaida, Naofumi

2008-10-01

The first step in the generation of tumor immunity is the migration of dendritic cells (DCs) to the apoptotic tumor, which is presumed to be mediated by various chemokines. To clarify the roles of chemokines, we induced apoptosis using suicide gene therapy and investigated the immune responses following tumor apoptosis. We injected mice with a murine hepatoma cell line, BNL 1ME A.7R.1 (BNL), transfected with HSV-thymidine kinase (tk) gene and then treated the animals with ganciclovir (GCV). GCV treatment induced massive tumor cell apoptosis accompanied with intratumoral DC infiltration. Tumor-infiltrating DCs expressed chemokine receptors CCR1 and CCR5, and T cells and macrophages expressed CCL3, a ligand for CCR1 and CCR5. Moreover, tumor apoptosis increased the numbers of DCs migrating into the draining lymph nodes and eventually generated a specific cytotoxic cell population against BNL cells. Although GCV completely eradicated HSV-tk-transfected BNL cells in CCR1-, CCR5-, or CCL3-deficient mice, intratumoral and intranodal DC infiltration and the subsequent cytotoxicity generation were attenuated in these mice. When parental cells were injected again after complete eradication of primary tumors by GCV treatment, the wild-type mice completely rejected the rechallenged cells, but the deficient mice exhibited impairment in rejection. Thus, we provide definitive evidence indicating that CCR1 and CCR5 and their ligand CCL3 play a crucial role in the regulation of intratumoral DC accumulation and the subsequent establishment of tumor immunity following induction of tumor apoptosis by suicide genes.

Role of Inflammatory Reponse in Experimental Decompression Sickness

NASA Technical Reports Server (NTRS)

Butler, B. D.; Little, T.

1999-01-01

Decompression to altitude can result in gas bubble formation both in tissues and in the systemic veins. The venous gas emboli (VGE) are often monitored during decompression exposures to assess risk for decompression sickness (DCS). Astronauts are at risk for DCS during extravehicular activities (EVA), where decompression occurs from the Space Shuttle or Space Station atmospheric pressure of 14.7 pounds per square inch (PSI) to that of the space suit pressure of 4.3 PSI. DCS symptoms include diffuse pain, especially around joints, inflammation and edema. Pathophysiological effects include interstitial inflammatory responses and recurring injury to the vascular endothelium. Such responses can result in vasoconstriction and associated hemodynamic changes.The granulocyte cell activation and chemotaxin release results in the formation of vasoactive and microvascular permeability altering mediators, especially from the lungs which are the principal target organ for the venous bubbles, and from activated cells (neutrophils, platelets, macrophages). Such mediators include free arachidonic acid and the byproducts of its metabolism via the cyclooxygenase and lipoxygenase pathways (see figure). The cyclooxygenase pathway results in formation of prostacyclin and other prostaglandins and thromboxanes that cause vasoconstriction, bronchoconstriction and platelet aggregation. Leukotrienes produced by the alternate pathway cause pulmonary and bronchial smooth muscle contraction and edema. Substances directly affecting vascular tone such as nitric oxide may also play a role in the respose to DCS. We are studying the role and consequent effects of the release inflammatory bioactive mediators as a result of DCS and VGE. More recent efforts are focused on identifying the effects of the body's circadian rhythm on these physiological consequences to decompression stress. al

Identification of immune factors regulating anti-tumor immunity using polymeric vaccines with multiple adjuvants

PubMed Central

Ali, Omar A.; Verbeke, Catia; Johnson, Chris; Sands, Warren; Lewin, Sarah A.; White, Des; Doherty, Edward; Dranoff, Glenn; Mooney, David J.

2014-01-01

The innate cellular and molecular components required to mediate effective vaccination against weak tumor-associated antigens remain unclear. In this study we utilized polymeric cancer vaccines incorporating different classes of adjuvants to induce tumor protection, in order to identify dendritic cell subsets and cytokines critical to this efficacy. Three-dimensional, porous polymer matrices loaded with tumor lysates and presenting distinct combinations of GM-CSF and various TLR agonists effected 70–90% prophylactic tumor protection in B16-F10 melanoma models. In aggressive, therapeutic B16 models, the vaccine systems incorporating GM-CSF in combination with P(I:C) or CpG-ODN induced the complete regression of solid tumors (≤40mm2) resulting in 33% long-term survival. Regression analysis revealed that the numbers of vaccine-resident CD8(+) DCs and plasmacytoid DCs, along with local IL-12, and G-CSF concentrations correlated strongly to vaccine efficacy regardless of adjuvant type. Further, vaccine studies in Batf3−/− mice revealed that CD8(+) DCs are required to effect tumor protection, as vaccines in these mice were deficient in cytotoxic T cell priming, and IL-12 induction in comparison to wild-type. These studies broadly demonstrate that three-dimensional polymeric vaccines provide a potent platform for prophylactic and therapeutic protection, and can be used as a tool to identify critical components of a desired immune response. Specifically, these results suggest that CD8(+) DCs, plasmacytoid DCs, IL-12, and G-CSF play important roles in priming effective anti-tumor responses with these vaccines. PMID:24480625

MyD88-dependent dendritic and epithelial cell crosstalk orchestrates immune responses to allergens.

PubMed

Thomas, S Y; Whitehead, G S; Takaku, M; Ward, J M; Xu, X; Nakano, K; Lyons-Cohen, M R; Nakano, H; Gowdy, K M; Wade, P A; Cook, D N

2018-05-01

Sensitization to inhaled allergens is dependent on activation of conventional dendritic cells (cDCs) and on the adaptor molecule, MyD88. However, many cell types in the lung express Myd88, and it is unclear how signaling in these different cell types reprograms cDCs and leads to allergic inflammation of the airway. By combining ATAC-seq with RNA profiling, we found that MyD88 signaling in cDCs maintained open chromatin at select loci even at steady state, allowing genes to be rapidly induced during allergic sensitization. A distinct set of genes related to metabolism was indirectly controlled in cDCs through MyD88 signaling in airway epithelial cells (ECs). In mouse models of asthma, Myd88 expression in ECs was critical for eosinophilic inflammation, whereas Myd88 expression in cDCs was required for Th17 cell differentiation and consequent airway neutrophilia. Thus, both cell-intrinsic and cell-extrinsic MyD88 signaling controls gene expression in cDCs and orchestrates immune responses to inhaled allergens.

Early SIV and HIV infection promotes the LILRB2/MHC-I inhibitory axis in cDCs.

PubMed

Alaoui, Lamine; Palomino, Gustavo; Zurawski, Sandy; Zurawski, Gerard; Coindre, Sixtine; Dereuddre-Bosquet, Nathalie; Lecuroux, Camille; Goujard, Cecile; Vaslin, Bruno; Bourgeois, Christine; Roques, Pierre; Le Grand, Roger; Lambotte, Olivier; Favier, Benoit

2018-05-01

Classical dendritic cells (cDCs) play a pivotal role in the early events that tip the immune response toward persistence or viral control. In vitro studies indicate that HIV infection induces the dysregulation of cDCs through binding of the LILRB2 inhibitory receptor to its MHC-I ligands and the strength of this interaction was proposed to drive disease progression. However, the dynamics of the LILRB2/MHC-I inhibitory axis in cDCs during early immune responses against HIV are yet unknown. Here, we show that early HIV-1 infection induces a strong and simultaneous increase of LILRB2 and MHC-I expression on the surface of blood cDCs. We further characterized the early dynamics of LILRB2 and MHC-I expression by showing that SIVmac251 infection of macaques promotes coordinated up-regulation of LILRB2 and MHC-I on cDCs and monocytes/macrophages, from blood and lymph nodes. Orientation towards the LILRB2/MHC-I inhibitory axis starts from the first days of infection and is transiently induced in the entire cDC population in acute phase. Analysis of the factors involved indicates that HIV-1 replication, TLR7/8 triggering, and treatment by IL-10 or type I IFNs increase LILRB2 expression. Finally, enhancement of the LILRB2/MHC-I inhibitory axis is specific to HIV-1 and SIVmac251 infections, as expression of LILRB2 on cDCs decreased in naturally controlled chikungunya virus infection of macaques. Altogether, our data reveal a unique up-regulation of LILRB2 and its MHC-I ligands on cDCs in the early phase of SIV/HIV infection, which may account for immune dysregulation at a critical stage of the anti-viral response.

Preparation of triple-negative breast cancer vaccine through electrofusion with day-3 dendritic cells.

PubMed

Zhang, Peng; Yi, Shuhong; Li, Xi; Liu, Ruilei; Jiang, Hua; Huang, Zenan; Liu, Yu; Wu, Juekun; Huang, Yong

2014-01-01

Dendritic cells (DCs) are professional antigen-presenting cells (APCs) in human immune system. DC-based tumor vaccine has met with some success in specific malignancies, inclusive of breast cancer. In this study, we electrofused MDA-MB-231 breast cancer cell line with day-3 DCs derived from peripheral blood monocytes, and explored the biological characteristics of fusion vaccine and its anti-tumor effects in vitro. Day-3 mature DCs were generated from day-2 immature DCs by adding cocktails composed of TNF-α, IL-1β, IL-6 and PEG2. Day-3 mature DCs were identified and electofused with breast cancer cells to generate fusion vaccine. Phenotype of fusion cells were identified by fluorescence microscope and flow cytometer. The fusion vaccine was evaluated for T cell proliferation, secretion of IL-12 and IFN-γ, and induction of tumor-specific CTL response. Despite differences in morphology, day-3 and day-7 DC expressed similar surface markers. The secretion of IL-12 and IFN-γ in fusion vaccine group was much higher than that in the control group. Compared with control group, DC-tumor fusion vaccine could better stimulate the proliferation of allogeneic T lymphocytes and kill more breast cancer cells (MDA-MB-231) in vitro. Day-3 DCs had the same function as the day-7 DCs, but with a shorter culture period. Our findings suggested that day-3 DCs fused with whole apoptotic breast cancer cells could elicit effective specific antitumor T cell responses in vitro and may be developed into a prospective candidate for adoptivet immunotherapy.

Immunohistochemical detection of receptor activator nuclear κB ligand and osteoprotegerin in odontogenic cysts and tumors.

PubMed

de Matos, Felipe Rodrigues; de Moraes, Maiara; das Neves Silva, Emília Beatriz; Galvão, Hébel Cavalcanti; de Almeida Freitas, Roseana

2013-11-01

The aim of the present study was to compare the immunohistochemical detection of receptor activator nuclear κB ligand (RANKL) and osteoprotegerin (OPG) in radicular cysts (RCs), dentigerous cysts (DCs), solid ameloblastomas (SAs), and keratocystic odontogenic tumors (KOTs). A total of 20 RCs, 20 DCs, 20 KOTs, 14 dental follicles (DFs), and 18 SAs were evaluated by immunohistochemistry using anti-RANKL and anti-OPG antibodies. The analysis was quantitative, and the number of positive cells was counted in 10 microscopic high-power fields (400×). The DFs, KOTs, and SAs showed higher expression of RANKL than did the RCs and DCs in the epithelium (P < .05). The epithelial expression of OPG was higher in the DFs, KOTs, RCs, and DCs than in the SAs (P < .05). The ratio of OPG less than RANKL was more frequent in SAs and OPG greater than RANKL in DCs (P < .05). Our results have shown differences in RANKL and OPG detection in the odontogenic cysts and tumors studied. The higher RANKL and lower OPG detection in SA could play a role in bone resorption, compatible with the tumor's biologic behavior. Copyright © 2013 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Dendritic Cells in the Gut: Interaction with Intestinal Helminths

PubMed Central

Mendlovic, Fela; Flisser, Ana

2010-01-01

The mucosal environment in mammals is highly tolerogenic; however, after exposure to pathogens or danger signals, it is able to shift towards an inflammatory response. Dendritic cells (DCs) orchestrate immune responses and are highly responsible, through the secretion of cytokines and expression of surface markers, for the outcome of such immune response. In particular, the DC subsets found in the intestine have specialized functions and interact with different immune as well as nonimmune cells. Intestinal helminths primarily induce Th2 responses where DCs have an important yet not completely understood role. In addition, this cross-talk results in the induction of regulatory T cells (T regs) as a result of the homeostatic mucosal environment. This review highlights the importance of studying the particular relation “helminth-DC-milieu” in view of the significance that each of these factors plays. Elucidating the mechanisms that trigger Th2 responses may provide the understanding of how we might modulate inflammatory processes. PMID:20224759

Administration of interleukin-12 enhances the therapeutic efficacy of dendritic cell-based tumor vaccines in mouse hepatocellular carcinoma.

PubMed

Tatsumi, T; Takehara, T; Kanto, T; Miyagi, T; Kuzushita, N; Sugimoto, Y; Jinushi, M; Kasahara, A; Sasaki, Y; Hori, M; Hayashi, N

2001-10-15

Dendritic cells (DCs) are potent antigen-presenting cells that are capable of priming systemic antitumor immune response. Here, we evaluated the combined effectiveness of tumor lysate-pulsed DC immunization and interleukin (IL)-12 administration on the induction of antitumor immunity in a mouse hepatocellular carcinoma (HCC) model. Mouse DCs were pulsed with lysate of BNL 1ME A.7R.1 (BNL), a BALB/c-derived HCC cell line, and then injected into syngeneic mice in combination with systemic administration of IL-12. Lymphocytes from mice treated with BNL lysate-pulsed DCs and IL-12 showed stronger cytolytic activity and produced higher amounts of IFN-gamma than those from mice treated with BNL lysate-pulsed DCs alone. Although immunization with BNL lysate-pulsed DCs alone did not lead to complete regression of established tumors, it significantly inhibited tumor growth compared with vehicle injection. Importantly, the combined therapy of BNL lysate-pulsed DCs and IL-12 resulted in tumor rejection or significant inhibition of tumor growth compared with mice treated with BNL lysate-pulsed DCs alone. In vivo lymphocyte depletion experiments demonstrated that this combination was dependent on both CD8+ and CD4+ T cells, but not natural killer cells. These results demonstrated that IL-12 administration enhanced the therapeutic effect of immunization of tumor lysate-pulsed DCs against HCC in mice. This combination of IL-12 and DCs may be useful for suppressing the growth of residual tumor after primary therapy of human HCC.

Disarmed by density: A glycolytic break for immunostimulatory dendritic cells?

PubMed

Nasi, Aikaterini; Rethi, Bence

2013-12-01

We observed a cell concentration-dependent differentiation switch among cultured dendritic cells (DCs) triggered by lactic acid, a product of glycolytic metabolism. In particular, while interleukin (IL)-12, IL-23, and tumor necrosis factor α (TNFα)-producing, migratory DCs developed in sparse cultures, IL-10-producing, non-migratory DCs differentiated in dense cultures. This points to a novel opportunity for tailoring DC-based anticancer therapies through metabolism modulation in developing DCs.

Separation of plasmacytoid dendritic cells from B-cell-biased lymphoid progenitor (BLP) and Pre-pro B cells using PDCA-1.

PubMed

Medina, Kay L; Tangen, Sarah N; Seaburg, Lauren M; Thapa, Puspa; Gwin, Kimberly A; Shapiro, Virginia Smith

2013-01-01

B-cell-biased lymphoid progenitors (BLPs) and Pre-pro B cells lie at a critical juncture between B cell specification and commitment. However, both of these populations are heterogenous, which hampers investigation into the molecular changes that occur as lymphoid progenitors commit to the B cell lineage. Here, we demonstrate that there are PDCA-1(+)Siglec H(+) plasmacytoid dendritic cells (pDCs) that co-purify with BLPs and Pre-pro B cells, which express little or no CD11c or Ly6C. Removal of PDCA-1(+) pDCs separates B cell progenitors that express high levels of a Rag1-GFP reporter from Rag1-GFP(low/neg) pDCs within the BLP and Pre-pro B populations. Analysis of Flt3-ligand knockout and IL-7Rα knockout mice revealed that there is a block in B cell development at the all-lymphoid progenitor (ALP) stage, as the majority of cells within the BLP or Pre-pro B gates were PDCA-1(+) pDCs. Thus, removal of PDCA-1(+) pDCs is critical for analysis of BLP and Pre-pro B cell populations. Analysis of B cell potential within the B220(+)CD19(-) fraction demonstrated that AA4.1(+)Ly6D(+)PDCA-1(-) Pre-pro B cells gave rise to CD19(+) B cells at high frequency, while PDCA-1(+) pDCs in this fraction did not. Interestingly, the presence of PDCA-1(+) pDCs within CLPs may help to explain the conflicting results regarding the origin of these cells.

Effects of mesenchymal stem cells from human induced pluripotent stem cells on differentiation, maturation, and function of dendritic cells.

PubMed

Gao, Wen-Xiang; Sun, Yue-Qi; Shi, Jianbo; Li, Cheng-Lin; Fang, Shu-Bin; Wang, Dan; Deng, Xue-Quan; Wen, Weiping; Fu, Qing-Ling

2017-03-02

Mesenchymal stem cells (MSCs) have potent immunomodulatory effects on multiple immune cells and have great potential in treating immune disorders. Induced pluripotent stem cells (iPSCs) serve as an unlimited and noninvasive source of MSCs, and iPSC-MSCs have been reported to have more advantages and exhibit immunomodulation on T lymphocytes and natural killer cells. However, the effects of iPSC-MSCs on dendritic cells (DCs) are unclear. The aim of this study is to investigate the effects of iPSC-MSCs on the differentiation, maturation, and function of DCs. Human monocyte-derived DCs were induced and cultured in the presence or absence of iPSC-MSCs. Flow cytometry was used to analyze the phenotype and functions of DCs, and enzyme-linked immunosorbent assay (ELISA) was used to study cytokine production. In this study, we successfully induced MSCs from different clones of human iPSCs. iPSC-MSCs exhibited a higher proliferation rate with less cell senescence than BM-MSCs. iPSC-MSCs inhibited the differentiation of human monocyte-derived DCs by both producing interleukin (IL)-10 and direct cell contact. Furthermore, iPSC-MSCs did not affect immature DCs to become mature DCs, but modulated their functional properties by increasing their phagocytic ability and inhibiting their ability to stimulate proliferation of lymphocytes. More importantly, iPSC-MSCs induced the generation of IL-10-producing regulatory DCs in the process of maturation, which was mostly mediated by a cell-cell contact mechanism. Our results indicate an important role for iPSC-MSCs in the modulation of DC differentiation and function, supporting the clinical application of iPSC-MSCs in DC-mediated immune diseases.

Lung dendritic cells are stimulated by ultrafine particles and play a key role in particle adjuvant activity.

PubMed

de Haar, Colin; Kool, Mirjam; Hassing, Ine; Bol, Marianne; Lambrecht, Bart N; Pieters, Raymond

2008-05-01

The adjuvant activity of air pollution particles on allergic airway sensitization is well known, but the cellular mechanisms underlying this adjuvant potential are not clear. We sough to study the role of dendritic cells and the costimulatory molecules CD80 and CD86 in the adjuvant activity of ultrafine carbon black particles (CBP). The proliferation of CFSE-labeled DO11.10 CD4 cells was studied after intranasal exposure to particles and ovalbumin (OVA). Next the frequency of myeloid dendritic cells (mDCs) and plasmacytoid dendritic cells and their expression of CD80 and CD86 were studied in the peribronchial lymph nodes (PBLNs). The expression of costimulatory molecules was also studied on bone marrow-derived mDCs after exposure to CBPs in vitro, and the importance of costimulation in CBP adjuvant activity was assessed by using CD80/CD86-deficient mice or cytotoxic T lymphocyte-associated antigen 4 (CTLA4)-Ig in vivo. Our data show that CBPs plus OVA caused proliferation of DO11.10 CD4 cells and high levels of cytokine production in the PBLNs. Furthermore, the combined CBP plus OVA exposure increased the number of mDCs and expression of costimulatory molecules in the PBLNs. In addition, CBPs upregulated the expression of CD80/CD86 molecules on dendritic cells in vitro, which are necessary for the particle adjuvant effects in vivo. Together this study shows the importance of dendritic cells and costimulation in particle adjuvant activity. Furthermore, we show for the first time that CBPs can also directly induce maturation of dendritic cells.

Identification of Cellular Sources of IL-2 Needed for Regulatory T Cell Development and Homeostasis.

PubMed

Owen, David L; Mahmud, Shawn A; Vang, Kieng B; Kelly, Ryan M; Blazar, Bruce R; Smith, Kendall A; Farrar, Michael A

2018-06-15

The cytokine IL-2 is critical for promoting the development, homeostasis, and function of regulatory T (Treg) cells. The cellular sources of IL-2 that promote these processes remain unclear. T cells, B cells, and dendritic cells (DCs) are known to make IL-2 in peripheral tissues. We found that T cells and DCs in the thymus also make IL-2. To identify cellular sources of IL-2 in Treg cell development and homeostasis, we used Il2 FL/FL mice to selectively delete Il2 in T cells, B cells, and DCs. Because IL-15 can partially substitute for IL-2 in Treg cell development, we carried out the majority of these studies on an Il15 -/- background. Deletion of Il2 in B cells, DCs, or both these subsets had no effect on Treg cell development, either in wild-type (WT) or Il15 -/- mice. Deletion of Il2 in T cells had minimal effects in WT mice but virtually eliminated developing Treg cells in Il15 -/- mice. In the spleen and most peripheral lymphoid organs, deletion of Il2 in B cells, DCs, or both subsets had no effect on Treg cell homeostasis. In contrast, deletion of Il2 in T cells led to a significant decrease in Treg cells in either WT or Il15 -/- mice. The one exception was the mesenteric lymph nodes where significantly fewer Treg cells were observed when Il2 was deleted in both T cells and DCs. Thus, T cells are the sole source of IL-2 needed for Treg cell development, but DCs can contribute to Treg cell homeostasis in select organs. Copyright © 2018 by The American Association of Immunologists, Inc.

Peripheral CD103+ dendritic cells form a unified subset developmentally related to CD8α+ conventional dendritic cells

PubMed Central

Edelson, Brian T.; KC, Wumesh; Juang, Richard; Kohyama, Masako; Benoit, Loralyn A.; Klekotka, Paul A.; Moon, Clara; Albring, Jörn C.; Ise, Wataru; Michael, Drew G.; Bhattacharya, Deepta; Stappenbeck, Thaddeus S.; Holtzman, Michael J.; Sung, Sun-Sang J.; Murphy, Theresa L.; Hildner, Kai

2010-01-01

Although CD103-expressing dendritic cells (DCs) are widely present in nonlymphoid tissues, the transcription factors controlling their development and their relationship to other DC subsets remain unclear. Mice lacking the transcription factor Batf3 have a defect in the development of CD8α+ conventional DCs (cDCs) within lymphoid tissues. We demonstrate that Batf3−/− mice also lack CD103+CD11b− DCs in the lung, intestine, mesenteric lymph nodes (MLNs), dermis, and skin-draining lymph nodes. Notably, Batf3−/− mice displayed reduced priming of CD8 T cells after pulmonary Sendai virus infection, with increased pulmonary inflammation. In the MLNs and intestine, Batf3 deficiency resulted in the specific lack of CD103+CD11b− DCs, with the population of CD103+CD11b+ DCs remaining intact. Batf3−/− mice showed no evidence of spontaneous gastrointestinal inflammation and had a normal contact hypersensitivity (CHS) response, despite previous suggestions that CD103+ DCs were required for immune homeostasis in the gut and CHS. The relationship between CD8α+ cDCs and nonlymphoid CD103+ DCs implied by their shared dependence on Batf3 was further supported by similar patterns of gene expression and their shared developmental dependence on the transcription factor Irf8. These data provide evidence for a developmental relationship between lymphoid organ–resident CD8α+ cDCs and nonlymphoid CD103+ DCs. PMID:20351058

Polysaccharide purified from Ganoderma atrum induced activation and maturation of murine myeloid-derived dendritic cells.

PubMed

Wang, Hui; Yu, Qiang; Nie, Shao-Ping; Xiang, Quan-Dan; Zhao, Ming-Ming; Liu, Shi-Yu; Xie, Ming-Yong; Wang, Shun-Qi

2017-10-01

Ganoderma atrum (G. atrum), a member of the genus Ganoderma, is an edible and medicinal fungus. In this study, we investigated the direct and indirect effects of G. atrum polysaccharide (PSG-1) on dendritic cells (DCs). Firstly, flow cytometric and ELISA analysis showed that PSG-1 increased cell surface molecule expression of MHC-II, CD80 and CD86, and enhanced the production of IL-12 p70, IL-6, IL-10, RANTES, MIP-1α and MCP-1 in DCs. PSG-1-treated DCs promoted the proliferation of splenic T lymphocyte of mouse in mixed lymphocyte reaction. The above results demonstrated that PSG-1 induced the maturation of DCs. Secondly, PSG-1 increased the phosphorylation of p38, ERK and JNK determined by western blot. Inhibitors of p38, ERK and JNK decreased PSG-1-induced expression of MHC-II, CD80 and CD86 and production of IL-6 and IL-10 by DCs. These results suggested that PSG-1 induced mitogen-activated protein kinase (MAPK) activation was involved in the regulation of maturation markers and cytokines expression in DCs. Finally, PSG-1 increased expression of MHC-II of DCs in a DCs-Caco-2 co-culture model, suggesting that PSG-1 could indirectly influence DCs. In summary, our data suggested that PSG-1 directly induced DCs maturation via activating MAPK pathways, and indirectly stimulated DCs separated by intestinal epithelial cells. Copyright © 2017. Published by Elsevier Ltd.

Type I interferon dependence of plasmacytoid dendritic cell activation and migration

PubMed Central

Asselin-Paturel, Carine; Brizard, Géraldine; Chemin, Karine; Boonstra, Andre; O'Garra, Anne; Vicari, Alain; Trinchieri, Giorgio

2005-01-01

Differential expression of Toll-like receptor (TLR) by conventional dendritic cells (cDCs) and plasmacytoid DC (pDCs) has been suggested to influence the type of immune response induced by microbial pathogens. In this study we show that, in vivo, cDCs and pDCs are equally activated by TLR4, -7, and -9 ligands. Type I interferon (IFN) was important for pDC activation in vivo in response to all three TLR ligands, whereas cDCs required type I IFN signaling only for TLR9- and partially for TLR7-mediated activation. Although TLR ligands induced in situ migration of spleen cDC into the T cell area, spleen pDCs formed clusters in the marginal zone and in the outer T cell area 6 h after injection of TLR9 and TLR7 ligands, respectively. In vivo treatment with TLR9 ligands decreased pDC ability to migrate ex vivo in response to IFN-induced CXCR3 ligands and increased their response to CCR7 ligands. Unlike cDCs, the migration pattern of pDCs required type I IFN for induction of CXCR3 ligands and responsiveness to CCR7 ligands. These data demonstrate that mouse pDCs differ from cDCs in the in vivo response to TLR ligands, in terms of pattern and type I IFN requirement for activation and migration. PMID:15795237

DNA sensing via the Stimulator of Interferon Genes (STING) adaptor in myeloid dendritic cells induces potent tolerogenic responses1

PubMed Central

Huang, Lei; Li, Lingqian; Lemos, Henrique; Chandler, Phillip R.; Pacholczyk, Gabriela; Baban, Babak; Barber, Glen N.; Hayakawa, Yoshihiro; McGaha, Tracy L.; Ravishankar, Buvana; Munn, David H.; Mellor, Andrew L.

2013-01-01

Cytosolic DNA sensing via the STING adaptor incites autoimmunity by inducing type I IFN (IFNαβ). Here we show that DNA is also sensed via STING to suppress immunity by inducing indoleamine 2,3 dioxygenase (IDO). STING gene ablation abolished IFNαβ and IDO induction by dendritic cells (DCs) after DNA nanoparticle (DNP) treatment. Marginal zone macrophages, some DCs and myeloid cells ingested DNPs but CD11b+ DCs were the only cells to express IFNβ, while CD11b+ non-DCs were major IL-1β producers. STING ablation also abolished DNP-induced regulatory responses by DCs and regulatory T cells (Tregs), and hallmark regulatory responses to apoptotic cells were also abrogated. Moreover, systemic cyclic diguanylate monophosphate (c-diGMP) treatment to activate STING induced selective IFNβ expression by CD11b+ DCs and suppressed Th1 responses to immunization. Thus, previously unrecognized functional diversity amongst physiologic innate immune cells regarding DNA sensing via STING is pivotal in driving immune responses to DNA. PMID:23986532

Uptake of donor lymphocytes treated with 8-methoxypsoralen and ultraviolet A light by recipient dendritic cells induces CD4{sup +}CD25{sup +}Foxp3{sup +} regulatory T cells and down-regulates cardiac allograft rejection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, De-Hua; Dou, Li-Ping; Wei, Yu-Xiang

Extracorporeal photopheresis (ECP) is an effective immunomodulatory therapy and has been demonstrated to be beneficial for graft-vs-host disease and solid-organ allograft rejection. ECP involves reinfusion of a patient's autologous peripheral blood leukocytes treated ex vivo with 8-methoxypsoralen and UVA light radiation (PUVA). Previous studies focused only on ECP treatment of recipient immune cells. Our study is the first to extend the target of ECP treatment to donor immune cells. The results of in vitro co-culture experiments demonstrate uptake of donor PUVA-treated splenic lymphocytes (PUVA-SPs) by recipient immature dendritic cells (DCs). Phagocytosis of donor PUVA-SPs does not stimulate phenotype maturation ofmore » recipient DCs. In the same co-culture system, donor PUVA-SPs enhanced production of interleukin-10 and interferon-{gamma} by recipient DCs and impaired the subsequent capability of recipient DCs to stimulate recipient naive T cells. Phagocytosis of donor PUVA-SP (PUVA-SP DCs) by recipient DCs shifted T-cell responses in favor of T helper 2 cells. Infusion of PUVA-SP DCs inhibited cardiac allograft rejection in an antigen-specific manner and induced CD4{sup +}CD25{sup high}Foxp3{sup +} regulatory T cells. In conclusion, PUVA-SP DCs simultaneously deliver the donor antigen and the regulatory signal to the transplant recipient, and thus can be used to develop a novel DC vaccine for negative immune regulation and immune tolerance induction.« less

A Dual Role for Corneal Dendritic Cells in Herpes Simplex Keratitis: Local Suppression of Corneal Damage and Promotion of Systemic Viral Dissemination

PubMed Central

Hu, Kai; Harris, Deshea L.; Yamaguchi, Takefumi; von Andrian, Ulrich H.; Hamrah, Pedram

2015-01-01

The cornea is the shield to the foreign world and thus, a primary site for peripheral infections. However, transparency and vision are incompatible with inflammation and scarring that may result from infections. Thus, the cornea is required to perform a delicate balance between fighting infections and preserving vision. To date, little is known about the specific role of antigen-presenting cells in viral keratitis. In this study, utilizing an established murine model of primary acute herpes simplex virus (HSV)-1 keratitis, we demonstrate that primary HSV keratitis results in increased conventional dendritic cells (cDCs) and macrophages within 24 hours after infection. Local depletion of cDCs in CD11c-DTR mice by subconjuntival diphtheria toxin injections, led to increased viral proliferation, and influx of inflammatory cells, resulting in increased scarring and clinical keratitis. In addition, while HSV infection resulted in significant corneal nerve destruction, local depletion of cDCs resulted in a much more severe loss of corneal nerves. Further, local cDC depletion resulted in decreased corneal nerve infection, and subsequently decreased and delayed systemic viral transmission in the trigeminal ganglion and draining lymph node, resulting in decreased mortality of mice. In contrast, sham depletion or depletion of macrophages through local injection of clodronate liposomes had neither a significant impact on the cornea, nor an effect on systemic viral transmission. In conclusion, we demonstrate that corneal cDCs may play a primary role in local corneal defense during viral keratitis and preserve vision, at the cost of inducing systemic viral dissemination, leading to increased mortality. PMID:26332302

Prolonged expression of MHC class I - peptide expression in bone marrow derived retrovirus transfected matured dendritic cells by continuous centrifugation in the presence of IL-4.

PubMed

Hettihewa, L M

2011-11-01

Dendritic cells (DCs) are potent antigen presenting cells which proceed from immature to a mature stage during their differentiation. There are several methods of obtaining long lasting mature antigen expressing DCs and different methods show different levels of antigen expressions. We investigated bone marrow derived DCs for the degree of maturation and genetically engineered antigen presentation in the presence of interleukin-4 (IL-4) as a maturity enhancer. DCs and transfected retrovirus were cultured together in the presence of granulocyte-macrophage colony stimulating factor (GMCSF)-IL4, GMCSF +IL4, lipopolysaccharide (LPS). B 7.1, B7.2 and CD11c were measured by the degree of immune fluorescence using enhanced green fluorescent protein (EGFP) shuttled retrovirus transfected antigen. Degree of MHC class I molecule with antigen presentation of antigen was also evaluated by fluorescence activated cell sorting. The antigen presenting capacity of transfected DCs was investigated. Bone marrow DCs were generated in the presence of GMCSF and IL-4 in vitro. Dividing bone marrow cells were infected with EGFP shuttled retrovirus expressing SSP2 by prolonged centrifugation for three consecutive days from day 5, 6 and 7 and continued to culture in the presence of GMSCF and IL-4 until day 8. IL-4 as a cytokine increased the maturation of retrovirus transfected DCs by high expression of B 7-1 and B 7-2. Also, IL-4 induced DC enhanced by the prolonged centrifugation and it was shown by increased antigen presentation of these dendric cells as antigen presenting cell (APC). Cytolytic effects were significantly higher in cytotoxic T cell response (CTLs) mixed with transfected DCs than CTLs mixed with pulsed DCs. There was an enhanced antigen presentation by prolonged expression of antigen loaded MHC class I receptors in DCs in the presence of IL-4 by prolonged centrifugation.

Adenoviral-transduced dendritic cells are susceptible to suppression by T regulatory cells and promote interleukin 17 production.

PubMed

Wang, Adele Y; Crome, Sarah Q; Jenkins, Kristina M; Medin, Jeffrey A; Bramson, Jonathan L; Levings, Megan K

2011-03-01

Dendritic cell (DC) vaccines offer a robust platform for the development of cancer vaccines, but their effectiveness is thought to be limited by T regulatory cells (Tregs). Recombinant adenoviruses (RAdV) have been used successfully to engineer tumor antigen expression in DCs, but the impact of virus transduction on susceptibility to suppression by Tregs is unknown. We investigated the functional consequences of exposure to adenovirus on interactions between human monocyte-derived DCs and Tregs. Since the development of Tregs is linked to that of pro-inflammatory Th17 cells, the role of Th17 cells and IL-17-producing Tregs in the context of DC-based immunotherapies was also investigated. We found that Tregs potently suppressed the co-stimulatory capacity of RAdV-transduced DCs, regardless of whether the DCs were maturated by inflammatory cytokines or by exposure to Th1 or Th17 cells. Furthermore, exposure of Tregs to RAdV-exposed DCs increased IL-17 production and suppressive capacity, and correlated with enhanced secretion of IL-1β and IL-6 by DCs. The findings that DCs exposed to RAdV are suppressed by Tregs, promote Treg plasticity, and enhance Treg suppression indicates that strategies to limit Tregs will be required to enhance the efficacy of such DC-based immunotherapies.

Anodal Transcranial Direct Current Stimulation Enhances Survival and Integration of Dopaminergic Cell Transplants in a Rat Parkinson Model.

PubMed

Winkler, Christian; Reis, Janine; Hoffmann, Nadin; Gellner, Anne-Kathrin; Münkel, Christian; Curado, Marco Rocha; Furlanetti, Luciano; Garcia, Joanna; Döbrössy, Máté D; Fritsch, Brita

2017-01-01

Restorative therapy concepts, such as cell based therapies aim to restitute impaired neurotransmission in neurodegenerative diseases. New strategies to enhance grafted cell survival and integration are still needed to improve functional recovery. Anodal direct current stimulation (DCS) promotes neuronal activity and secretion of the trophic factor BDNF in the motor cortex. Transcranial DCS applied to the motor cortex transiently improves motor symptoms in Parkinson's disease (PD) patients. In this proof-of-concept study, we combine cell based therapy and noninvasive neuromodulation to assess whether neurotrophic support via transcranial DCS would enhance the restitution of striatal neurotransmission by fetal dopaminergic transplants in a rat Parkinson model. Transcranial DCS was applied daily for 20 min on 14 consecutive days following striatal transplantation of fetal ventral mesencephalic (fVM) cells derived from transgenic rat embryos ubiquitously expressing GFP. Anodal but not cathodal transcranial DCS significantly enhanced graft survival and dopaminergic reinnervation of the surrounding striatal tissue relative to sham stimulation. Behavioral recovery was more pronounced following anodal transcranial DCS, and behavioral effects correlated with the degree of striatal innervation. Our results suggest anodal transcranial DCS may help advance cell-based restorative therapies in neurodegenerative diseases. In particular, such an assistive approach may be beneficial for the already established cell transplantation therapy in PD.

Regulation of dendritic cell function through toll-like receptors.

PubMed

Kaisho, Tsuneyasu; Akira, Shizuo

2003-12-01

Higher animals establish host defense by orchestrating innate and adaptive immunity. This is mediated by professional antigen presenting cells, i.e. dendritic cells (DCs). DCs can incorporate pathogens, produce a variety of cytokines, maturate, and present pathogen-derived peptides to T cells, thereby inducing T cell activation and differentiation. These responses are triggered by microbial recognition through type I transmembrane proteins, Toll-like receptors (TLRs) on DCs. TLRs consist of ten members and each TLR is involved in recognizing a variety of microorganism-derived molecular structures. TLR ligands include cell wall components, proteins, nucleic acids, and synthetic chemical compounds, all of which can activate DCs as immune adjuvants.

INAM plays a critical role in IFN-γ production by NK cells interacting with polyinosinic-polycytidylic acid-stimulated accessory cells.

PubMed

Kasamatsu, Jun; Azuma, Masahiro; Oshiumi, Hiroyuki; Morioka, Yuka; Okabe, Masaru; Ebihara, Takashi; Matsumoto, Misako; Seya, Tsukasa

2014-11-15

Polyinosinic-polycytidylic acid strongly promotes the antitumor activity of NK cells via TLR3/Toll/IL-1R domain-containing adaptor molecule 1 and melanoma differentiation-associated protein-5/mitochondrial antiviral signaling protein pathways. Polyinosinic-polycytidylic acid acts on accessory cells such as dendritic cells (DCs) and macrophages (Mφs) to secondarily activate NK cells. In a previous study in this context, we identified a novel NK-activating molecule, named IFN regulatory factor 3-dependent NK-activating molecule (INAM), a tetraspanin-like membrane glycoprotein (also called Fam26F). In the current study, we generated INAM-deficient mice and investigated the in vivo function of INAM. We found that cytotoxicity against NK cell-sensitive tumor cell lines was barely decreased in Inam(-/-) mice, whereas the number of IFN-γ-producing cells was markedly decreased in the early phase. Notably, deficiency of INAM in NK and accessory cells, such as CD8α(+) conventional DCs and Mφs, led to a robust decrease in IFN-γ production. In conformity with this phenotype, INAM effectively suppressed lung metastasis of B16F10 melanoma cells, which is controlled by NK1.1(+) cells and IFN-γ. These results suggest that INAM plays a critical role in NK-CD8α(+) conventional DC (and Mφ) interaction leading to IFN-γ production from NK cells in vivo. INAM could therefore be a novel target molecule for cancer immunotherapy against IFN-γ-suppressible metastasis. Copyright © 2014 by The American Association of Immunologists, Inc.

Dendritic Cell Transmigration through Brain Microvessel Endothelium Is Regulated by MIP-1α Chemokine and Matrix Metalloproteinases1

PubMed Central

Zozulya, Alla L.; Reinke, Emily; Baiu, Dana C.; Karman, Jozsef; Sandor, Matyas; Fabry, Zsuzsanna

2007-01-01

Dendritic cells (DCs) accumulate in the CNS during inflammatory diseases, but the exact mechanism regulating their traffic into the CNS remains to be defined. We now report that MIP-1α increases the transmigration of bone marrow-derived, GFP-labeled DCs across brain microvessel endothelial cell monolayers. Furthermore, occludin, an important element of endothelial tight junctions, is reorganized when DCs migrate across brain capillary endothelial cell monolayers without causing significant changes in the barrier integrity as measured by transendothelial electrical resistance. We show that DCs produce matrix metalloproteinases (MMP) -2 and -9 and GM6001, an MMP inhibitor, decreases both baseline and MIP-1α -induced DC transmigration. These observations suggest that DC transmigration across brain endothelial cell monolayers is partly MMP dependent. The migrated DCs express higher levels of CD40, CD80, and CD86 costimulatory molecules and induce T cell proliferation, indicating that the transmigration of DCs across brain endothelial cell monolayers contributes to the maintenance of DC Ag-presenting function. The MMP dependence of DC migration across brain endothelial cell monolayers raises the possibility that MMP blockers may decrease the initiation of T cell recruitment and neuroinflammation in the CNS. PMID:17182592

Uptake routes of tumor-antigen MAGE-A3 by dendritic cells determine priming of naïve T-cell subtypes.

PubMed

Moeller, Ines; Spagnoli, Giulio C; Finke, Jürgen; Veelken, Hendrik; Houet, Leonora

2012-11-01

Induction of tumor-antigen-specific T cells in active cancer immunotherapy is generally difficult due to the very low anti-tumoral precursor cytotoxic T cells. By improving tumor-antigen uptake and presentation by dendritic cells (DCs), this problem can be overcome. Focusing on MAGE-A3 protein, frequently expressed in many types of tumors, we analyzed different DC-uptake routes after additional coating the recombinant MAGE-A3 protein with either a specific monoclonal antibody or an immune complex formulation. Opsonization of the protein with antibody resulted in increased DC-uptake compared to the uncoated rhMAGE-A3 protein. This was partly due to Fcγ receptor-dependent internalization. However, unspecific antigen internalization via macropinocytosis also played a role. When analyzing DC-uptake of MAGE-A3 antigen expressed in multiple myeloma cell line U266, pretreatment with proteasome inhibitor bortezomib resulted in increased apoptosis compared to γ-irradiation. Bortezomib-mediated immunogenic apoptosis, characterized by elevated surface expression of hsp90, triggered higher phagocytosis of U266 cells by DCs involving specific DC-derived receptors. We further investigated the impact of antigen delivery on T-cell priming. Induction of CD8(+) T-cell response was favored by stimulating naïve T cells with either antibody-opsonized MAGE-A3 protein or with the bortezomib-pretreated U266 cells, indicating that receptor-mediated uptake favors cross-presentation of antigens. In contrast, CD4(+) T cells were preferentially induced after stimulation with the uncoated protein or protein in the immune complex, both antigen formulations were preferentially internalized by DCs via macropinocytosis. In summary, receptor-mediated DC-uptake mechanisms favored the induction of CD8(+) T cells, relevant for clinical anti-tumor response.

Isolation of Human Skin Dendritic Cell Subsets.

PubMed

Gunawan, Merry; Jardine, Laura; Haniffa, Muzlifah

2016-01-01

Dendritic cells (DCs) are specialized leukocytes with antigen-processing and antigen-presenting functions. DCs can be divided into distinct subsets by anatomical location, phenotype and function. In human, the two most accessible tissues to study leukocytes are peripheral blood and skin. DCs are rare in human peripheral blood (<1 % of mononuclear cells) and have a less mature phenotype than their tissue counterparts (MacDonald et al., Blood. 100:4512-4520, 2002; Haniffa et al., Immunity 37:60-73, 2012). In contrast, the skin covering an average total surface area of 1.8 m(2) has approximately tenfold more DCs than the average 5 L of total blood volume (Wang et al., J Invest Dermatol 134:965-974, 2014). DCs migrate spontaneously from skin explants cultured ex vivo, which provide an easy method of cell isolation (Larsen et al., J Exp Med 172:1483-1493, 1990; Lenz et al., J Clin Invest 92:2587-2596, 1993; Nestle et al., J Immunol 151:6535-6545, 1993). These factors led to the extensive use of skin DCs as the "prototype" migratory DCs in human studies. In this chapter, we detail the protocols to isolate DCs and resident macrophages from human skin. We also provide a multiparameter flow cytometry gating strategy to identify human skin DCs and to distinguish them from macrophages.

Impairment of regulatory capacity of CD4+CD25+ regulatory T cells mediated by dendritic cell polarization and hyperthyroidism in Graves' disease.

PubMed

Mao, Chaoming; Wang, Shu; Xiao, Yichuan; Xu, Jingwei; Jiang, Qian; Jin, Min; Jiang, Xiaohua; Guo, Hua; Ning, Guang; Zhang, Yanyun

2011-04-15

Graves' disease (GD) is one of the most common autoimmune diseases. The immune dysfunction in GD involves the generation of thyroid-stimulating hormone receptor (TSHR) autoantibodies that presumably arise consequent to interactions among dendritic cells (DCs), T cells, and regulatory T (Treg) cells. However, the immunological mechanisms of interactions between them that lead to the induction and regulation of this autoimmune disease are poorly defined. In this study, we investigated whether DCs are the main cause of the defective activity of Treg cells in GD patients. We found a significant decrease in the percentage of circulating CD4(+)CD25(+)FOXP3(+) Treg cells in untreated GD patients (uGD), which was negatively correlated with the concentration of TSHR autoantibodies. uGD-derived DCs were polarized to increase the number of plasmacytoid DCs (pDCs) and conferred the ability to abrogate the suppressive function of Treg cells through inducing apoptosis of CD4(+)CD25(+) Treg cells in an IFN-α-dependent manner, and elevated thyroid hormones further exacerbated the effect. The nucleotide UDP, which inhibits IFN-α secretion of pDCs through P2Y6 receptor signaling, restored the suppressive function of CD4(+)CD25(+) Treg cells. Collectively, uGD-derived DCs through pDC polarization and elevated thyroid hormones act in concert to impair the regulatory capacity of Treg cells, facilitating the production of TSHR autoantibodies in the pathogenesis of GD.

The detailed analysis of the changes of murine dendritic cells (DCs) induced by thymic peptide

PubMed Central

Hu, Xiaofang; Zheng, Wei; Wang, Lu; Wan, Nan; Wang, Bing; Li, Weiwei; Hua, Hui; Hu, Xu; Shan, Fengping

2012-01-01

The aim of present research is to analyze the detailed changes of dendritic cells (DCs) induced by pidotimod(PTD). These impacts on DCs of both bone marrow derived DCs and established DC2.4 cell line were assessed with use of conventional scanning electron microscopy (SEM), flow cytometry (FCM), transmission electron microscopy (TEM), cytochemistry assay FITC-dextran, bio-assay and enzyme linked immunosorbent assay (ELISA). We demonstrated the ability of PTD to induce DC phynotypic and functional maturation as evidenced by higher expression of key surface molecules such as MHC II, CD80 and CD86. The functional tests proved the downregulation of ACP inside the DCs, occurred when phagocytosis of DCs decreased, with simultaneously antigen presentation increased toward maturation. Finally, PTD also stimulated production of more cytokine IL-12 and less TNF-α. Therefore it is concluded that PTD can markedly exert positive induction to murine DCs. PMID:22863756

Transspinal direct current stimulation modulates migration and proliferation of adult newly born spinal cells in mice.

PubMed

Samaddar, Sreyashi; Vazquez, Kizzy; Ponkia, Dipen; Toruno, Pedro; Sahbani, Karim; Begum, Sultana; Abouelela, Ahmed; Mekhael, Wagdy; Ahmed, Zaghloul

2017-02-01

Direct current electrical fields have been shown to be a major factor in the regulation of cell proliferation, differentiation, migration, and survival, as well as in the maturation of dividing cells during development. During adulthood, spinal cord cells are continuously produced in both animals and humans, and they hold great potential for neural restoration following spinal cord injury. While the effects of direct current electrical fields on adult-born spinal cells cultured ex vivo have recently been reported, the effects of direct current electrical fields on adult-born spinal cells in vivo have not been characterized. Here, we provide convincing findings that a therapeutic form of transspinal direct current stimulation (tsDCS) affects the migration and proliferation of adult-born spinal cells in mice. Specifically, cathodal tsDCS attracted the adult-born spinal cells, while anodal tsDCS repulsed them. In addition, both tsDCS polarities caused a significant increase in cell number. Regarding the potential mechanisms involved, both cathodal and anodal tsDCS caused significant increases in expression of brain-derived neurotrophic factor, while expression of nerve growth factor increased and decreased, respectively. In the spinal cord, both anodal and cathodal tsDCS increased blood flow. Since blood flow and angiogenesis are associated with the proliferation of neural stem cells, increased blood flow may represent a major factor in the modulation of newly born spinal cells by tsDCS. Consequently, we propose that the method and novel findings presented in the current study have the potential to facilitate cellular, molecular, and/or bioengineering strategies to repair injured spinal cords. NEW & NOTEWORTHY Our results indicate that transspinal direct current stimulation (tsDCS) affects the migratory pattern and proliferation of adult newly born spinal cells, a cell population which has been implicated in learning and memory. In addition, our results suggest a potential mechanism of action regarding the functional effects of applying direct current. Thus tsDCS may represent a novel method by which to manipulate the migration and cell number of adult newly born cells and restore functions following brain or spinal cord injury. Copyright © 2017 the American Physiological Society.

In vivo immunogenicity of Tax 11-19 epitope in HLA-A2/DTR transgenic mice: implication for dendritic cell-based anti-HTLV-1 vaccine

PubMed Central

Sagar, Divya; Masih, Shet; Schell, Todd; Jacobson, Steven; Comber, Joseph D.; Philip, Ramila; Wigdahl, Brian; Jain, Pooja; Khan, Zafar K.

2014-01-01

Viral oncoprotein Tax plays key roles in transformation of human T-cell leukemia virus (HTLV-1)-infected T cells leading to adult T-cell leukemia (ATL), and is the key antigen recognized during HTLV-associated myelopathy (HAM). In HLA-A2+ asymptomatic carriers as well as ATL and HAM patients, Tax(11-19) epitope exhibits immunodominance. Here, we evaluate CD8 T-cell immune response against this epitope in the presence and absence of dendritic cells (DCs) given the recent encouraging observations made with Phase 1 DC-based vaccine trial for ATL. To facilitate these studies, we first generated an HLA-A2/DTR hybrid mouse strain carrying the HLA-A2.1 and CD11c-DTR genes. We then studied CD8 T-cell immune response against Tax(11-19) epitope delivered in the absence or presence of Freund’s adjuvant and/or DCs. Overall results demonstrate that naturally presented Tax epitope could initiate an antigen-specific CD8 T cell response in vivo but failed to do so upon DC depletion. Presence of adjuvant potentiated Tax(11-19)-specific response. Elevated serum IL-6 levels coincided with depletion of DCs whereas decreased TGF-β was associated with adjuvant use. Thus, Tax(11-19) epitope is a potential candidate for the DC-based anti-HTLV-1 vaccine and the newly hybrid mouse strain could be used for investigating DC involvement in human class-I-restricted immune responses. PMID:24739247

Mycobacterium tuberculosis Controls MicroRNA-99b (miR-99b) Expression in Infected Murine Dendritic Cells to Modulate Host Immunity*

PubMed Central

Singh, Yogesh; Kaul, Vandana; Mehra, Alka; Chatterjee, Samit; Tousif, Sultan; Dwivedi, Ved Prakash; Suar, Mrutyunjay; Van Kaer, Luc; Bishai, William R.; Das, Gobardhan

2013-01-01

Mycobacterium tuberculosis resides and replicates within host phagocytes by modulating host microbicidal responses. In addition, it suppresses the production of host protective cytokines to prevent activation of and antigen presentation by M. tuberculosis-infected cells, causing dysregulation of host protective adaptive immune responses. Many cytokines are regulated by microRNAs (miRNAs), a newly discovered class of small noncoding RNAs, which have been implicated in modulating host immune responses in many bacterial and viral diseases. Here, we show that miRNA-99b (miR-99b), an orphan miRNA, plays a key role in the pathogenesis of M. tuberculosis infection. We found that miR-99b expression was highly up-regulated in M. tuberculosis strain H37Rv-infected dendritic cells (DCs) and macrophages. Blockade of miR-99b expression by antagomirs resulted in significantly reduced bacterial growth in DCs. Interestingly, knockdown of miR-99b in DCs significantly up-regulated proinflammatory cytokines such as IL-6, IL-12, and IL-1β. Furthermore, mRNA and membrane-bound protein data indicated that inhibition of miR-99b augments TNF-α and TNFRSF-4 production. Thus, miR-99b targets TNF-α and TNFRSF-4 receptor genes. Treatment of anti-miR-99b-transfected DCs with anti-TNF-α antibody resulted in increased bacterial burden. Thus, our findings unveil a novel host evasion mechanism adopted by M. tuberculosis via miR-99b, which may open up new avenues for designing miRNA-based vaccines and therapies. PMID:23233675

Mapping the accumulation of co-infiltrating CNS dendritic cells and encephalitogenic T cells during EAE

PubMed Central

Clarkson, Benjamin D; Walker, Alec; Harris, Melissa; Rayasam, Aditya; Sandor, Matyas; Fabry, Zsuzsanna

2014-01-01

Evidence from experimental autoimmune encephalomyelitis (EAE) suggests that CNS-infiltrating dendritic cells (DCs) are crucial for restimulation of coinfiltrating T cells. Here we systematically quantified and visualized the distribution and interaction of CNS DCs and T cells during EAE. We report marked periventricular accumulation of DCs and myelin-specific T cells during EAE disease onset prior to accumulation in the spinal cord, indicating that the choroid plexus-CSF axis is a CNS entry portal. Moreover, despite emphasis on spinal cord inflammation in EAE and in correspondence with MS pathology, inflammatory lesions containing interacting DCs and T cells are present in specific brain regions. PMID:25288303

Molecular control of steady-state dendritic cell maturation and immune homeostasis.

PubMed

Hammer, Gianna Elena; Ma, Averil

2013-01-01

Dendritic cells (DCs) are specialized sentinels responsible for coordinating adaptive immunity. This function is dependent upon coupled sensitivity to environmental signs of inflammation and infection to cellular maturation-the programmed alteration of DC phenotype and function to enhance immune cell activation. Although DCs are thus well equipped to respond to pathogens, maturation triggers are not unique to infection. Given that immune cells are exquisitely sensitive to the biological functions of DCs, we now appreciate that multiple layers of suppression are required to restrict the environmental sensitivity, cellular maturation, and even life span of DCs to prevent aberrant immune activation during the steady state. At the same time, steady-state DCs are not quiescent but rather perform key functions that support homeostasis of numerous cell types. Here we review these functions and molecular mechanisms of suppression that control steady-state DC maturation. Corruption of these steady-state operatives has diverse immunological consequences and pinpoints DCs as potent drivers of autoimmune and inflammatory disease.

Regulation of PGE2 signaling pathways and TNF-alpha signaling pathways on the function of bone marrow-derived dendritic cells and the effects of CP-25.

PubMed

Li, Ying; Sheng, Kangliang; Chen, Jingyu; Wu, Yujing; Zhang, Feng; Chang, Yan; Wu, Huaxun; Fu, Jingjing; Zhang, Lingling; Wei, Wei

2015-12-15

This study was to investigate PGE2 and TNF-alpha signaling pathway involving in the maturation and activation of bone marrow dendritic cells (DCs) and the effect of CP-25. Bone marrow DCs were isolated and stimulated by PGE2 and TNF-alpha respectively. The markers of maturation and activation expressed on DCs, such as CD40, CD80, CD83, CD86, MHC-II, and the ability of antigen uptake of DCs were analyzed by flow cytometry. The proliferation of T cells co-cultured with DCs, the signaling pathways of PGE2-EP4-cAMP and TNF-alpha-TRADD-TRAF2-NF-κB in DCs were analyzed. The results showed that both PGE2 and TNF-alpha up-regulated the expressions of CD40, CD80, CD83, CD86, and MHC-II, decreased the antigen uptake of DCs, and DCs stimulated by PGE2 or TNF-alpha could increase T cell proliferation. CP-25 (10(-5), 10(-6), and 10(-7)mol/l) decreased significantly the expressions of CD40, CD80, CD83, CD86 and MHC-II, increased the antigen uptake of DCs, and suppressed T cell proliferation induced by DCs. PGE2 increased the expressions of EP4, NF-κB and down-regulated cAMP level of DCs. TNF-alpha could also up-regulate TNFR1, TRADD, TRAF2, and NF-κB expression of DCs. CP-25 (10(-5), 10(-6), and 10(-7)mol/l) decreased the expressions of EP4 and NF-κB, increased cAMP level in DCs stimulated by PGE2. CP-25 (10(-5), 10(-6), and 10(-7)mol/l) also could down-regulate significantly TNFR1, TRADD, TRAF2, and NF-κB expression in DCs stimulated by TNF-alpha. These results demonstrate that PGE2 and TNF-alpha could enhance DCs functions by mediating PGE2-EP4-cAMP pathway, TNF-alpha-TNFR1-TRADD-TRAF2-NF-κB pathway respectively. CP-25 might inhibit the function of DCs through regulating PGE2-EP4-cAMP and TNF-alpha-TNFR1-TRADD-TRAF2-NF-κB pathways. Copyright © 2015 Elsevier B.V. All rights reserved.

Enhancement of dendritic cell-based vaccine potency by anti-apoptotic siRNAs targeting key pro-apoptotic proteins in cytotoxic CD8(+) T cell-mediated cell death.

PubMed

Kim, Jin Hee; Kang, Tae Heung; Noh, Kyung Hee; Bae, Hyun Cheol; Kim, Seok-Ho; Yoo, Young Do; Seong, Seung-Yong; Kim, Tae Woo

2009-01-29

Dendritic cells (DCs) have become an important measure for the treatment of malignancies. Current DC preparations, however, generate short-lived DCs because they are subject to cell death from various apoptotic pressures. Antigen-specific CD8(+) cytotoxic T lymphocytes (CTLs) is one of the main obstacles to limit the DC-mediated immune priming since CTLs can recognize the target antigen expressing DCs as target cells and kill the DCs. CTLs secret perforin and serine protease granzymes during CTL killing. Perforin and serine protease granzymes induce the release of a number of mitochondrial pro-apoptotic factors, which are controlled by members of the BCL-2 family, such as BAK, BAX and BIM. FasL linking to Fas on DCs triggers the activation of caspase-8, which eventually leads to mitochondria-mediated apoptosis via truncation of BID. In this study, we tried to enhance the DC priming capacity by prolonging DC survival using anti-apoptotic siRNA targeting these key pro-apoptotic molecules in CTL killing. Human papillomavirus (HPV)-16 E7 antigen presenting DCs that were transfected with these anti-apoptotic siRNAs showed increased resistance to T cell-mediated death, leading to enhanced E7-specific CD8(+) T cell activation in vitro and in vivo. Among them, siRNA targeting BIM (siBIM) generated strongest E7-specific E7-specific CD8(+) T cell immunity. More importantly, vaccination with E7 presenting DCs transfected with siBIM was capable of generating a marked therapeutic effect in vaccinated mice. Our data indicate that ex vivo manipulation of DCs with siBIM may represent a plausible strategy for enhancing dendritic cell-based vaccine potency.

MLN4924 sensitizes monocytes and maturing dendritic cells for TNF-dependent and -independent necroptosis.

PubMed

El-Mesery, Mohamed; Seher, Axel; Stühmer, Thorsten; Siegmund, Daniela; Wajant, Harald

2015-03-01

MLN4924 prevents the formation of active cullin-RING ubiquitin ligase complexes and thus inhibits NF-κB signalling. Here, we evaluated the effects of this compound on monocytes and dendritic cells (DCs). Monocytes and DCs were challenged with TNF or LPS in the presence and absence of MLN4924. The effects of MLN4924 on cellular viability, pro-inflammatory gene induction and DC maturation were investigated using the MTT assay, elisa and FACS analysis. Mechanisms of cell death induction were evaluated by using inhibitors of caspases, RIPK1 and MLKL. MLN4924 inhibited NF-κB activation and sensitized monocytes and immature DCs (iDCs) for TNFR1-induced cell death. Neither the caspase inhibitor zVAD-fmk, the RIPK1 inhibitor necrostatin-1 (nec-1) nor the MLKL inhibitor necrosulfonamide (NSA) alone prevented TNF-induced cell death. A combination of zVAD-fmk and nec-1 or NSA, however, rescued monocytes and iDCs from MLN4924/TNF-induced cell death indicating that MLN4924 affects anti-apoptotic and anti-necrotic activities in TNFR1 signalling. MLN4924 also converted the response of iDCs to LPS from maturation to cell death. LPS-induced cell death in MLN4924-treated iDCs was again only effectively blocked by cotreatment with zVAD-fmk and nec-1 or NSA. Noteworthy, MLN4924/LPS-induced cell death was almost completely independent of endogenous TNF. MLN4924 also strongly inhibited maturation and activation of iDCs that were rescued from cell death by zVAD-fmk and nec-1. Our data reveal a strong dual suppressive effect of MLN4924 on DC activity. The targeting of NAE by MLN4924 could be a new way to treat inflammatory diseases. © 2014 The British Pharmacological Society.

Dendritic cells loaded with HeLa-derived exosomes simulate an antitumor immune response.

PubMed

Ren, Guoping; Wang, Yanhong; Yuan, Shexia; Wang, Baolian

2018-05-01

The aim of the present study was to investigate the effect of loading dendritic cells (DCs) with HeLa-derived exosomes on cytotoxic T-lymphocyte (CTL) responses, and the cytotoxic effects of CTL responses on the HeLa cell line. Ultrafiltration centrifugation combined with sucrose density gradient ultracentrifugation was applied to isolate exosomes (HeLa-exo) from the supernatant of HeLa cells. Morphological features of HeLa-exo were identified by transmission electron microscopy (TEM), and the expression of cluster of differentiation (CD)63 was detected by western blotting. Next, monocytes were isolated from peripheral blood and cultured with the removal of adherent cells to induce DC proliferation. DCs were then phenotypically characterized by flow cytometry. Finally, MTT assays were performed to analyze the effects of DCs loaded with HeLa-exo on T cell proliferation and cytotoxicity assays to evaluate the effect of CTL responses on HeLa cells. TEM revealed that HeLa-exo exhibit typical cup-shaped morphology with a diameter range of 30-100 nm. It was also identified that the CD63 surface antigen is expressed on HeLa-exo. Furthermore, monocyte-derived DCs were able to express CD1a, suggesting that DC induction was a success. DCs exhibited hair-like protrusions and other typical dendritic cell morphology. Furthermore, DCs loaded with HeLa-exo could enhance CTL proliferation and the cytotoxic activity of CTLs compared with DCs without HeLa-exo (P<0.05). In conclusion, DCs loaded with HeLa-exo may promote T cell proliferation and induce CTL responses to inhibit the growth of cervical cancer cells in vitro .

Inorganic arsenic impairs differentiation and functions of human dendritic cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Macoch, Mélinda; Morzadec, Claudie; Fardel, Olivier

2013-01-15

Experimental studies have demonstrated that the antileukemic trivalent inorganic arsenic prevents the development of severe pro-inflammatory diseases mediated by excessive Th1 and Th17 cell responses. Differentiation of Th1 and Th17 subsets is mainly regulated by interleukins (ILs) secreted from dendritic cells (DCs) and the ability of inorganic arsenic to impair interferon-γ and IL-17 secretion by interfering with the physiology of DCs is unknown. In the present study, we demonstrate that high concentrations of sodium arsenite (As(III), 1–2 μM) clinically achievable in plasma of arsenic-treated patients, block differentiation of human peripheral blood monocytes into immature DCs (iDCs) by inducing their necrosis.more » Differentiation of monocytes in the presence of non-cytotoxic concentrations of As(III) (0.1 to 0.5 μM) only slightly impacts endocytotic activity of iDCs or expression of co-stimulatory molecules in cells activated with lipopolysaccharide. However, this differentiation in the presence of As(III) strongly represses secretion of IL-12p70 and IL-23, two major regulators of Th1 and Th17 activities, from iDCs stimulated with different toll-like receptor (TLR) agonists in metalloid-free medium. Such As(III)-exposed DCs also exhibit reduced mRNA levels of IL12A and/or IL12B genes when activated with TLR agonists. Finally, differentiation of monocytes with non-cytotoxic concentrations of As(III) subsequently reduces the ability of activated DCs to stimulate the release of interferon-γ and IL-17 from Th cells. In conclusion, our results demonstrate that clinically relevant concentrations of inorganic arsenic markedly impair in vitro differentiation and functions of DCs, which may contribute to the putative beneficial effects of the metalloid towards inflammatory autoimmune diseases. Highlights: ► Inorganic arsenic impairs differentiation and functions of human dendritic cells (DCs) ► Arsenite (> 1 μM) blocks differentiation of dendritic cells by inducing necrosis ► Arsenite (0.1 to 0.5 μM) slightly reduces endocytotic activity of immature DCs ► Arsenite (0.1 to 0.5 μM) represses expression of IL-12p70 and IL-23 in activated DCs ► Arsenite (0.1 to 0.5 μM) reduces the ability of DCs to activate human T lymphocytes.« less

CD22 expression on blastic plasmacytoid dendritic cell neoplasms and reactivity of anti-CD22 antibodies to peripheral blood dendritic cells.

PubMed

Reineks, Edmunds Z; Osei, Ebenezer S; Rosenberg, Arlene; Auletta, Jeffrey; Meyerson, Howard J

2009-07-01

We identified CD22 expression on a blastic plasmacytoid dendritic cell (pDC) neoplasm presenting as a leukemia in a child. CD22 expression, as determined by the antibody s-HCL-1, was also noted on the neoplastic cells from three additional patients with blastic pDC tumors identified at our institution. Subsequently we determined that peripheral blood pDCs react with the s-HCL-1 antibody demonstrating that normal pDCs express CD22. Evaluation of five additional anti-CD22 antibodies indicated that staining of pDCs with these reagents was poor except for s-HCL-1. Therefore, the detection of CD22 on pDCs is best demonstrated with the use of this specific antibody clone. All anti-CD22 antibodies stained conventional DCs. We also evaluated the reactivity of the anti-CD22 antibodies with basophils and noted that the pattern of staining was similar to that seen with pDCs. The studies demonstrate that normal DCs and pDC neoplasms express CD22, and highlight clone specific differences in anti-CD22 antibody reactivity patterns on pDCs and basophils. (c) 2009 Clinical Cytometry Society.

Protective antitumor activity through dendritic cell immunization is mediated by NK cell as well as CTL activation.

PubMed

Kim, K D; Kim, J K; Kim, S J; Choe, I S; Chung, T H; Choe, Y K; Lim, J S

1999-08-01

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 bone marrow-derived DCs generated an effective tumor vaccine. Immunization with the cocultured DCs was able to induce complete protective 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 DCs 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 useful for designing tumor vaccines using DCs when the information about tumor antigens is limited.

Role for Dendritic Cells in Immunoregulation during Experimental Vaginal Candidiasis

PubMed Central

LeBlanc, Dana M.; Barousse, Melissa M.; Fidel, Paul L.

2006-01-01

Vulvovaginal candidiasis (VVC) caused by the commensal organism Candida albicans remains a significant problem among women of childbearing age, with protection against and susceptibility to infection still poorly understood. While cell-mediated immunity by CD4+ Th1-type cells is protective against most forms of mucosal candidiasis, no protective role for adaptive immunity has been identified against VVC. This is postulated to be due to immunoregulation that prohibits a more profound Candida-specific CD4+ T-cell response against infection. The purpose of this study was to examine the role of dendritic cells (DCs) in the induction phase of the immune response as a means to understand the initiation of the immunoregulatory events. Immunostaining of DCs in sectioned murine lymph nodes draining the vagina revealed a profound cellular reorganization with DCs becoming concentrated in the T-cell zone throughout the course of experimental vaginal Candida infection consistent with cell-mediated immune responsiveness. However, analysis of draining lymph node DC subsets revealed a predominance of immunoregulation-associated CD11c+ B220+ plasmacytoid DCs (pDCs) under both uninfected and infected conditions. Staining of vaginal DCs showed the presence of both DEC-205+ and pDCs, with extension of dendrites into the vaginal lumen of infected mice in close contact with Candida. Flow cytometric analysis of draining lymph node DC costimulatory molecules and activation markers from infected mice indicated a lack of upregulation of major histocompatibility complex class II, CD80, CD86, and CD40 during infection, consistent with a tolerizing condition. Together, the results suggest that DCs are involved in the immunoregulatory events manifested during a vaginal Candida infection and potentially through the action of pDCs. PMID:16714548

Down-regulation of RBP-J mediated by microRNA-133a suppresses dendritic cells and functions as a potential tumor suppressor in osteosarcoma.

PubMed

Gao, Xuren; Han, Dong; Fan, Weimin

2016-12-10

In recent years, immunotherapy for the treatment of tumors have been established. Dendritic cells (DCs) are extremely efficient and professional antigen presenting cells (APCs), which are an important target for immune therapeutic interventions in cancer. In present study, we investigated whether RBP-J signaling regulated by miR-133a was involved in the DCs mediated tumor suppressor in osteosarcoma. DCs were isolated from 30 osteosarcoma patients and 30 healthy subjects. Mouse macrophage-like cell line RAW264.7 were cultured and osteosarcoma mouse model with injection of murine osteosarcoma cell line S180 were established. In osteosarcoma patients, miR-133a expression level of DCs was increased, and RBP-J expression in mRNA and protein levels were decreased. MiR-133a inhibitor promoted maturation and activation of DCs in osteosarcoma patients. In osteosarcoma mouse model, miR-133a mimic suppressed the maturation and activation of spleen DCs, while miR-133a inhibitor promoted them. Overexpression of miR-133a decreased therapeutic effect of DCs on osteosarcoma mice. In RAW264.7 cells, miR-133a was observed to target RBP-J and regulate its expression. MiR-133a mimic inhibited the maturation of DCs in cells exposed to LPS, the effect of which was reversed by overexpression of RBP-J. RBP-J mediated by miR-133a probably contributed to the regulation of DCs maturation and activation in osteosarcoma, which functioned as a therapeutic target for the immunotherapy in cancers. Copyright © 2016. Published by Elsevier Inc.

Suppression of dendritic cells' maturation and functions by daidzein, a phytoestrogen

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yum, Min Kyu; Jung, Mi Young; Cho, Daeho

2011-12-15

Isoflavones are ubiquitous compounds in foods and in the environment in general. Daidzein and genistein, the best known of isoflavones, are structurally similar to 17{beta}-estradiol and known to exert estrogenic effects. They also evidence a broad variety of biological properties, including antioxidant, anti-carcinogenic, anti-atherogenic and anti-osteoporotic activities. Previously, daidzein was reported to increase the phagocytic activity of peritoneal macrophages and splenocyte proliferation, and to inhibit nitric oxide (NO) production in macrophages. However, its potential impacts on immune response in dendritic cells (DCs), antigen-presenting cells that link innate and adaptive immunity, have yet to be clearly elucidated. In this study, wemore » evaluated the effects of isoflavones on the maturation and activation of DCs. Isoflavones (formononetin, daidzein, equol, biochanin A, genistein) were found to differentially affect the expression of CD86, a costimulatory molecule, on lipopolysaccharide (LPS)-stimulated DCs. In particular, daidzein significantly and dose-dependently inhibited the expression levels of maturation-associated cell surface markers including CD40, costimulatory molecules (CD80, CD86), and major histocompatibility complex class II (I-A{sup b}) molecule on LPS-stimulated DCs. Daidzein also suppressed pro-inflammatory cytokine production such as IL-12p40, IL-6 and TNF-{alpha}, whereas it didn't affect IL-10 and IL-1{beta} expression. Furthermore, daidzein enhanced endocytosis and inhibited the allo-stimulatory ability of LPS-stimulated DCs on T cells, indicating that daidzein treatment can inhibit the functional maturation of DCs. These results demonstrate that daidzein may exhibit immunosuppressive activity by inhibiting the maturation and activation of DCs. -- Highlights: Black-Right-Pointing-Pointer Daidzein inhibited expression of maturation-associated cell surface markers in DCs. Black-Right-Pointing-Pointer Daidzein suppressed expression of pro-inflammatory cytokines in LPS-stimulated DCs. Black-Right-Pointing-Pointer Daidzein enhanced endocytosis and inhibited allo-stimulatory ability of DCs. Black-Right-Pointing-Pointer Daidzein exhibited immunosuppressive activity by inhibiting the activation of DCs.« less

Butyrate Conditions Human Dendritic Cells to Prime Type 1 Regulatory T Cells via both Histone Deacetylase Inhibition and G Protein-Coupled Receptor 109A Signaling

PubMed Central

Kaisar, Maria M. M.; Pelgrom, Leonard R.; van der Ham, Alwin J.; Yazdanbakhsh, Maria; Everts, Bart

2017-01-01

Recently, it has become clear that short-chain fatty acids (SCFAs), and in particular butyrate, have anti-inflammatory properties. Murine studies have shown that butyrate can promote regulatory T cells via the induction of tolerogenic dendritic cells (DCs). However, the effects of SCFAs on human DCs and how they affect their capacity to prime and polarize T-cell responses have not been addressed. Here, we report that butyrate suppresses LPS-induced maturation and metabolic reprogramming of human monocyte-derived DCs (moDCs) and conditions them to polarize naive CD4+ T cells toward IL-10-producing type 1 regulatory T cells (Tr1). This effect was dependent on induction of the retinoic acid-producing enzyme retinaldehyde dehydrogenase 1 in DCs. The induction of retinaldehyde dehydrogenase activity and Tr1 cell differentiation by butyrate was dependent on simultaneous inhibition of histone deacetylases and signaling through G protein-coupled receptor 109A. Taken together, we reveal that butyrate is a potent inducer of tolerogenic human DCs, thereby shedding new light on the cellular and molecular mechanisms through which SCFAs can exert their immunomodulatory effects in humans. PMID:29163504

Dendritic cells from CML patients have altered actin organization, reduced antigen processing, and impaired migration.

PubMed

Dong, Rong; Cwynarski, Kate; Entwistle, Alan; Marelli-Berg, Federica; Dazzi, Francesco; Simpson, Elizabeth; Goldman, John M; Melo, Junia V; Lechler, Robert I; Bellantuono, Ilaria; Ridley, Anne; Lombardi, Giovanna

2003-05-01

Chronic myeloid leukemia (CML) is characterized by expression of the BCR-ABL fusion gene that encodes a 210-kDa protein, which is a constitutively active tyrosine kinase. At least 70% of the oncoprotein is localized to the cytoskeleton, and several of the most prominent tyrosine kinase substrates for p210(BCR-ABL) are cytoskeletal proteins. Dendritic cells (DCs) are bone marrow-derived antigen-presenting cells responsible for the initiation of immune responses. In CML patients, up to 98% of myeloid DCs generated from peripheral blood mononuclear cells are BCR-ABL positive. In this study we have compared the morphology and behavior of myeloid DCs derived from CML patients with control DCs from healthy individuals. We show that the actin cytoskeleton and shape of CML-DCs of myeloid origin adherent to fibronectin differ significantly from those of normal DCs. CML-DCs are also defective in processing and presentation of exogenous antigens such as tetanus toxoid. The antigen-processing defect may be a consequence of the reduced capacity of CML-DCs to capture antigen via macropinocytosis or via mannose receptors when compared with DCs generated from healthy individuals. Furthermore, chemokine-induced migration of CML-DCs in vitro was significantly reduced. These observations cannot be explained by a difference in the maturation status of CML and normal DCs, because phenotypic analysis by flow cytometry showed a similar surface expression of maturation makers. Taken together, these results suggest that the defects in antigen processing and migration we have observed in CML-DCs may be related to underlying cytoskeletal changes induced by the p210(BCR-ABL) fusion protein.

Ex vivo generation of dendritic cells from cryopreserved, post-induction chemotherapy, mobilized leukapheresis from pediatric patients with medulloblastoma.

PubMed

Nair, Smita K; Driscoll, Timothy; Boczkowski, David; Schmittling, Robert; Reynolds, Renee; Johnson, Laura A; Grant, Gerald; Fuchs, Herbert; Bigner, Darell D; Sampson, John H; Gururangan, Sridharan; Mitchell, Duane A

2015-10-01

Generation of patient-derived, autologous dendritic cells (DCs) is a critical component of cancer immunotherapy with ex vivo-generated, tumor antigen-loaded DCs. An important factor in the ability to generate DCs is the potential impact of prior therapies on DC phenotype and function. We investigated the ability to generate DCs using cells harvested from pediatric patients with medulloblastoma for potential evaluation of DC-RNA based vaccination approach in this patient population. Cells harvested from medulloblastoma patient leukapheresis following induction chemotherapy and granulocyte colony stimulating factor mobilization were cryopreserved prior to use in DC generation. DCs were generated from the adherent CD14+ monocytes using standard procedures and analyzed for cell recovery, phenotype and function. To summarize, 4 out of 5 patients (80%) had sufficient monocyte recovery to permit DC generation, and we were able to generate DCs from 3 out of these 4 patient samples (75%). Overall, we successfully generated DCs that met phenotypic requisites for DC-based cancer therapy from 3 out of 5 (60%) patient samples and met both phenotypic and functional requisites from 2 out of 5 (40%) patient samples. This study highlights the potential to generate functional DCs for further clinical treatments from refractory patients that have been heavily pretreated with myelosuppressive chemotherapy. Here we demonstrate the utility of evaluating the effect of the currently employed standard-of-care therapies on the ex vivo generation of DCs for DC-based clinical studies in cancer patients.

Linking innate to adaptive immunity through dendritic cells.

PubMed

Steinman, Ralph M

2006-01-01

The function of dendritic cells (DCs) in linking innate to adaptive immunity is often summarized with two terms. DCs are sentinels, able to capture, process and present antigens and to migrate to lymphoid tissues to select rare, antigen-reactive T cell clones. DCs are also sensors, responding to a spectrum of environmental cues by extensive differentiation or maturation. The type of DC and the type of maturation induced by different stimuli influences the immunological outcome, such as the differentiation of Thl vs. Th2 T cells. Here we summarize the contributions of DCs to innate defences, particularly the production of immune enhancing cytokines and the activation of innate lymphocytes. Then we outline three innate features of DCs that influence peripheral tolerance and lead to adaptive immunity: a specialized endocytic system for antigen capture and processing, location and movements in vivo, and maturation in response to an array of stimuli. A new approach to the analysis of DC biology is to target antigens selectively to maturing DCs in vivo. This leads to stronger, more prolonged and broader (many immunogenic peptides) immunity by both T cells and B cells.

Microbiota-activated CD103+ DCs stemming from microbiota adaptation specifically drive γδT17 proliferation and activation.

PubMed

Fleming, Chris; Cai, Yihua; Sun, Xuan; Jala, Venkatakrishna R; Xue, Feng; Morrissey, Samantha; Wei, Yu-Ling; Chien, Yueh-Hsiu; Zhang, Huang-Ge; Haribabu, Bodduluri; Huang, Jian; Yan, Jun

2017-04-24

IL-17-producing γδT cells (γδT17) promote autoinflammatory diseases and cancers. Yet, γδT17 peripheral regulation has not been thoroughly explored especially in the context of microbiota-host interaction. The potent antigen-presenting CD103 + dendritic cell (DC) is a key immune player in close contact with both γδT17 cells and microbiota. This study presents a novel cellular network among microbiota, CD103 + DCs, and γδT17 cells. Immunophenotyping of IL-17r -/- mice and IL-17r -/- IRF8 -/- mice were performed by ex vivo immunostaining and flow cytometric analysis. We observed striking microbiome differences in the oral cavity and gut of IL-17r -/- mice by sequencing 16S rRNA gene (v1-v3 region) and analyzed using QIIME 1.9.0 software platform. Principal coordinate analysis of unweighted UniFrac distance matrix showed differential clustering for WT and IL-17r -/- mice. We found drastic homeostatic expansion of γδT17 in all major tissues, most prominently in cervical lymph nodes (cLNs) with monoclonal expansion of Vγ6 γδT17 in IL-17r -/- mice. Ki-67 staining and in vitro CFSE assays showed cellular proliferation due to cell-to-cell contact stimulation with microbiota-activated CD103 + DCs. A newly developed double knockout mice model for IL-17r and CD103 + DCs (IL-17r -/- IRF8 -/- ) showed a specific reduction in Vγ6 γδT17. Vγ6 γδT17 expansion is inhibited in germ-free mice and antibiotic-treated specific pathogen-free (SPF) mice. Microbiota transfer using cohousing of IL-17r -/- mice with wildtype mice induces γδT17 expansion in the wildtype mice with increased activated CD103 + DCs in cLNs. However, microbiota transfer using fecal transplant through oral gavage to bypass the oral cavity showed no difference in colon or systemic γδT17 expansion. These findings reveal for the first time that γδT17 cells are regulated by microbiota dysbiosis through cell-to-cell contact with activated CD103 + DCs leading to drastic systemic, monoclonal expansion. Microbiota dysbiosis, as indicated by drastic bacterial population changes at the phylum and genus levels especially in the oral cavity, was discovered in mice lacking IL-17r. This network could be very important in regulating both microbiota and immune players. This critical regulatory pathway for γδT17 could play a major role in IL-17-driven inflammatory diseases and needs further investigation to determine specific targets for future therapeutic intervention.

Autophagy-related protein Vps34 controls the homeostasis and function of antigen cross-presenting CD8α+ dendritic cells.

PubMed

Parekh, Vrajesh V; Pabbisetty, Sudheer K; Wu, Lan; Sebzda, Eric; Martinez, Jennifer; Zhang, Jianhua; Van Kaer, Luc

2017-08-01

The class III PI3K Vacuolar protein sorting 34 (Vps34) plays a role in both canonical and noncanonical autophagy, key processes that control the presentation of antigens by dendritic cells (DCs) to naive T lymphocytes. We generated DC-specific Vps34 -deficient mice to assess the contribution of Vps34 to DC functions. We found that DCs from these animals have a partially activated phenotype, spontaneously produce cytokines, and exhibit enhanced activity of the classic MHC class I and class II antigen-presentation pathways. Surprisingly, these animals displayed a defect in the homeostatic maintenance of splenic CD8α + DCs and in the capacity of these cells to cross-present cell corpse-associated antigens to MHC class I-restricted T cells, a property that was associated with defective expression of the T-cell Ig mucin (TIM)-4 receptor. Importantly, mice deficient in the Vps34-associated protein Rubicon, which is critical for a noncanonical form of autophagy called "Light-chain 3 (LC3)-associated phagocytosis" (LAP), lacked such defects. Finally, consistent with their defect in the cross-presentation of apoptotic cells, DC-specific Vps34 -deficient animals developed increased metastases in response to challenge with B16 melanoma cells. Collectively, our studies have revealed a critical role of Vps34 in the regulation of CD8α + DC homeostasis and in the capacity of these cells to process and present antigens associated with apoptotic cells to MHC class I-restricted T cells. Our findings also have important implications for the development of small-molecule inhibitors of Vps34 for therapeutic purposes.

Targeting of tolerogenic dendritic cells towards heat-shock proteins: a novel therapeutic strategy for autoimmune diseases?

PubMed

Jansen, Manon A A; Spiering, Rachel; Broere, Femke; van Laar, Jacob M; Isaacs, John D; van Eden, Willem; Hilkens, Catharien M U

2018-01-01

Tolerogenic dendritic cells (tolDCs) are a promising therapeutic tool to restore immune tolerance in autoimmune diseases. The rationale of using tolDCs is that they can specifically target the pathogenic T-cell response while leaving other, protective, T-cell responses intact. Several ways of generating therapeutic tolDCs have been described, but whether these tolDCs should be loaded with autoantigen(s), and if so, with which autoantigen(s), remains unclear. Autoimmune diseases, such as rheumatoid arthritis, are not commonly defined by a single, universal, autoantigen. A possible solution is to use surrogate autoantigens for loading of tolDCs. We propose that heat-shock proteins may be a relevant surrogate antigen, as they are evolutionarily conserved between species, ubiquitously expressed in inflamed tissues and have been shown to induce regulatory T cells, ameliorating disease in various arthritis mouse models. In this review, we provide an overview on how immune tolerance may be restored by tolDCs, the problem of selecting relevant autoantigens for loading of tolDCs, and why heat-shock proteins could be used as surrogate autoantigens. © 2017 John Wiley & Sons Ltd.

Impact of cladribine therapy on changes in circulating dendritic cell subsets, T cells and B cells in patients with multiple sclerosis.

PubMed

Mitosek-Szewczyk, Krystyna; Tabarkiewicz, Jacek; Wilczynska, Barbara; Lobejko, Katarzyna; Berbecki, Jerzy; Nastaj, Marcin; Dworzanska, Ewa; Kolodziejczyk, Beata; Stelmasiak, Zbigniew; Rolinski, Jacek

2013-09-15

Cladribine causes sustained reduction in peripheral T and B cell populations while sparing other immune cells. We determined two populations of dendritic cells (DCs): namely CD1c(+)/CD19(-) (myeloid DCs) and CD303(+)/CD123(+) (plasmacytoid DCs), CD19(+) B lymphocytes, CD3(+) T lymphocytes and CD4(+) or CD8(+) subpopulations in patients with multiple sclerosis after cladribine therapy. We examined 50 patients with secondary progressive multiple sclerosis (SP MS) according to McDonalds et al.'s criteria, 2001 [15]. Blood samples were collected before the initiation of cladribine therapy and after 1st, 2nd, 3th, 4th and 5th courses of treatment. DC subsets, T and B cells were analyzed by flow cytometry. During cladribine treatment the myeloid DCs CD1c(+)/CD19(-) did not change (p=0.73175), and the plasmacytoid DCs CD303(+)/CD123(+) significantly increased (p=0.00034) which resulted in significant changes in the ratio of myeloid DCs to plasmacytoid DCs (p=0.00273). During therapy, B lymphocyte CD19(+) significantly decreased (p=0.00005) and significant changes in CD4(+) cells (p=0.00191), changes in CD8(+) cells (p=0.05760) and significant changes in CD3(+) (p=0.01822) were found. We noticed significant trend to increase the CD303(+) circulating the dendritic cells. This population produces large amounts of IFN-alfa. We found significant and rapid decrease in B cells and CD4(+) Th cells. Our results suggest two possible ways of beneficial cladribine influence on immune system in MS. Induction of IFN-alfa producing cells and their predominance over BDCA-1(+) DCs, which are associated with cytotoxic response. Additionally, cladribine could influence two populations of lymphocytes: B cells and Th lymphocytes responsible for induction of immune response against myelin antigens. Copyright © 2013 Elsevier B.V. All rights reserved.

Live attenuated yellow fever 17D infects human DCs and allows for presentation of endogenous and recombinant T cell epitopes.

PubMed

Barba-Spaeth, Giovanna; Longman, Randy S; Albert, Matthew L; Rice, Charles M

2005-11-07

The yellow fever (YF) 17D vaccine is one of the most successful live attenuated vaccines available. A single immunization induces both long-lasting neutralizing antibody and YF-specific T cell responses. Surprisingly, the mechanism for this robust immunity has not been addressed. In light of several recent reports suggesting flavivirus interaction with dendritic cells (DCs), we investigated the mechanism of YF17D interaction with DCs and the importance of this interaction in generating T cell immunity. Our results show that YF17D can infect immature and mature human DCs. Viral entry is Ca(2+) dependent, but it is independent of DC-SIGN as well as multiple integrins expressed on the DC surface. Similar to infection of cell lines, YF infection of immature DCs is cytopathic. Although infection itself does not induce DC maturation in vitro, TNF-alpha-induced maturation protects DCs from YF-induced cytopathogenicity. Furthermore, we show that DCs infected with YF17D or YF17D carrying a recombinant epitope can process and present antigens for CD8(+) T cell stimulation. These findings offer insight into the immunologic mechanisms associated with the highly capable YF17D vaccine that may guide effective vaccine design.

Cyclophosphamide induces bone marrow to yield higher numbers of precursor dendritic cells in vitro capable of functional antigen presentation to T cells in vivo

PubMed Central

Salem, Mohamed L.; El-Naggar, Sabry A.; Cole, David J.

2009-01-01

We have shown recently that cyclophosphamide (CTX) treatment induced a marked increase in the numbers of immature dendritic cells (DCs) in blood, coinciding with enhanced antigen-specific responses of the adoptively transferred CD8+ T cells. Because this DC expansion was preceded by DC proliferation in bone marrow (BM), we tested whether BM post CTX treatment can generate higher numbers of functional DCs. BM was harvested three days after treatment of C57BL/6 mice with PBS or CTX and cultured with GM-CSF/IL-4 in vitro. Compared with control, BM from CTX-treated mice showed faster generation and yielded higher numbers of DCs with superior activation in response to toll-like receptor (TLR) agonists. Vaccination with peptide-pulsed DCs generated from BM from CTX-treated mice induced comparable adjuvant effects to those induced by control DCs. Taken together, post CTX BM harbors higher numbers of DC precursors capable of differentiating into functional DCs, which be targeted to create host microenvironment riches in activated DCs upon treatment with TLR agonists. PMID:20036354

Decline in Immunological Responses Mediated by Dendritic Cells in Mice Treated with 18α-Glycyrrhetinic Acid.

PubMed

Ebrahimnezhad, Salimeh; Amirghofran, Zahra; Karimi, Mohammad Hossein

2016-01-01

18α-Glycyrrhetinic acid (18α-GA), a bioactive component of Glycyrrhiza glabra, has been shown in vitro immunomodulatory effects on dendritic cells (DCs). The aim of the present study is to evaluate the in vivo effect of 18α-GA on DCs and T cell responses. 18α-GA was intraperitoneally administered to mice and splenic DCs were evaluated for expression of co-stimulatory molecules using flow cytometry. Isolated DCs were added to mixed lymphocyte reaction (MLR) and the proliferation of T cells was measured using BrdU assay. The level of IFN-γ in the MLR supernatant was determined by enzyme-linked immunosorbent assay. The in vivo effect of isolated DCs on antigen-specific delayed type hypersensitivity (DTH) response, and the number of regulatory T (Treg) cells in mice spleen by flow cytometry, were investigated. DCs isolated from 18α-GA-treated mice expressed lower levels of CD40 (p < 0.05) and MHC II (p < 0.01) compared to those of control group. In MLR assay isolated DCs decreased T cell proliferation to 83.54% ± 4.3% of control (p < 0.05). The level of IFN-γ in the MLR supernatant was declined to 25.2% ± 6.8% of control. In DTH test, DCs isolated from 18α-GA-treated mice significantly suppressed antigen-specific cell mediated immune response (3.3 ± 1 mm in test group versus 6.5 ± 1.2 mm in control group, ρ < 0.01). The percentage of Treg cells in spleen of 18α-GA-treated mice (6.37% ± 2.3%) was lower than that of control group (13.85% ± 0.4%, ρ < 0.05). In vivo administration of 18α-GA resulted in inhibition of DCs maturation and T cell-mediated responses, the effects that may candidate this compound for its possible benefits in immune-mediated diseases.

The IDO1 selective inhibitor epacadostat enhances dendritic cell immunogenicity and lytic ability of tumor antigen-specific T cells.

PubMed

Jochems, Caroline; Fantini, Massimo; Fernando, Romaine I; Kwilas, Anna R; Donahue, Renee N; Lepone, Lauren M; Grenga, Italia; Kim, Young-Seung; Brechbiel, Martin W; Gulley, James L; Madan, Ravi A; Heery, Christopher R; Hodge, James W; Newton, Robert; Schlom, Jeffrey; Tsang, Kwong Y

2016-06-21

Epacadostat is a novel inhibitor of indoleamine-2,3-dioxygenase-1 (IDO1) that suppresses systemic tryptophan catabolism and is currently being evaluated in ongoing clinical trials. We investigated the effects of epacadostat on (a) human dendritic cells (DCs) with respect to maturation and ability to activate human tumor antigen-specific cytotoxic T-cell (CTL) lines, and subsequent T-cell lysis of tumor cells, (b) human regulatory T cells (Tregs), and (c) human peripheral blood mononuclear cells (PBMCs) in vitro. Simultaneous treatment with epacadostat and IFN-γ plus lipopolysaccharide (LPS) did not change the phenotype of matured human DCs, and as expected decreased the tryptophan breakdown and kynurenine production. Peptide-specific T-cell lines stimulated with DCs pulsed with peptide produced significantly more IFN-γ, TNFα, GM-CSF and IL-8 if the DCs were treated with epacadostat. These T cells also displayed higher levels of tumor cell lysis on a per cell basis. Epacadostat also significantly decreased Treg proliferation induced by IDO production from IFN-γ plus LPS matured human DCs, although the Treg phenotype did not change. Multicolor flow cytometry was performed on human PBMCs treated with epacadostat; analysis of 123 discrete immune cell subsets revealed no changes in major immune cell types, an increase in activated CD83+ conventional DCs, and a decrease in immature activated Tim3+ NK cells. These studies show for the first time several effects of epacadostat on human DCs, and subsequent effects on CTL and Tregs, and provide a rationale as to how epacadostat could potentially increase the efficacy of immunotherapeutics, including cancer vaccines.

Immunomodulation of Hyperthermia for Recurrent Prostate Cancer

DTIC Science & Technology

2005-03-01

immature DCs have efficient antigen uptake capability. Previously we have shown that immature BM DCs can engulf flurochrome labeled hepatocellular ... carcinoma cells (HCC) and after engulfment efficient maturation signals are provided to them and mature DCs induce the expression of cell surface

Mycobacterium tuberculosis PstS1 amplifies IFN-γ and induces IL-17/IL-22 responses by unrelated memory CD4+ T cells via dendritic cell activation.

PubMed

Palma, Carla; Schiavoni, Giovanna; Abalsamo, Laura; Mattei, Fabrizio; Piccaro, Giovanni; Sanchez, Massimo; Fernandez, Carmen; Singh, Mahavir; Gabriele, Lucia

2013-09-01

The immunological mechanisms that modulate protection during Mycobacterium tuberculosis (Mtb) infection or vaccination are not fully understood. Secretion of IFN-γ and, to a lesser extent, of IL-17 by CD4(+) T cells plays a major role both in protection and immunopathology. Few Mtb Ags interacting with DCs affect priming, activation, and regulation of Ag-unrelated CD4(+) T-cell responses. Here we demonstrate that PstS1, a 38 kDa-lipoprotein of Mtb, promotes Ag-independent activation of memory T lymphocytes specific for Ag85B or Ag85A, two immunodominant protective Ags of Mtb. PstS1 expands CD4(+) and CD8(+) memory T cells, amplifies secretion of IFN-γ and IL-22 and induces IL-17 production by effector memory cells in an Ag-unrelated manner in vitro and in vivo. These effects were mediated through the stimulation of DCs, particularly of the CD8α(-) subtype, which respond to PstS1 by undergoing phenotypic maturation and by secreting IL-6, IL-1β and, to a lower extent, IL-23. IL-6 secretion by PstS1-stimulated DCs was required for IFN-γ, and to a lesser extent for IL-22 responses by Ag85B-specific memory T cells. These results may open new perspectives for immunotherapeutic strategies to control Th1/Th17 immune responses in Mtb infections and in vaccinations against tuberculosis. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

In vivo approaches reveal a key role for DCs in CD4+ T cell activation and parasite clearance during the acute phase of experimental blood-stage malaria.

PubMed

Borges da Silva, Henrique; Fonseca, Raíssa; Cassado, Alexandra Dos Anjos; Machado de Salles, Érika; de Menezes, Maria Nogueira; Langhorne, Jean; Perez, Katia Regina; Cuccovia, Iolanda Midea; Ryffel, Bernhard; Barreto, Vasco M; Marinho, Cláudio Romero Farias; Boscardin, Silvia Beatriz; Álvarez, José Maria; D'Império-Lima, Maria Regina; Tadokoro, Carlos Eduardo

2015-02-01

Dendritic cells (DCs) are phagocytes that are highly specialized for antigen presentation. Heterogeneous populations of macrophages and DCs form a phagocyte network inside the red pulp (RP) of the spleen, which is a major site for the control of blood-borne infections such as malaria. However, the dynamics of splenic DCs during Plasmodium infections are poorly understood, limiting our knowledge regarding their protective role in malaria. Here, we used in vivo experimental approaches that enabled us to deplete or visualize DCs in order to clarify these issues. To elucidate the roles of DCs and marginal zone macrophages in the protection against blood-stage malaria, we infected DTx (diphtheria toxin)-treated C57BL/6.CD11c-DTR mice, as well as C57BL/6 mice treated with low doses of clodronate liposomes (ClLip), with Plasmodium chabaudi AS (Pc) parasites. The first evidence suggesting that DCs could contribute directly to parasite clearance was an early effect of the DTx treatment, but not of the ClLip treatment, in parasitemia control. DCs were also required for CD4+ T cell responses during infection. The phagocytosis of infected red blood cells (iRBCs) by splenic DCs was analyzed by confocal intravital microscopy, as well as by flow cytometry and immunofluorescence, at three distinct phases of Pc malaria: at the first encounter, at pre-crisis concomitant with parasitemia growth and at crisis when the parasitemia decline coincides with spleen closure. In vivo and ex vivo imaging of the spleen revealed that DCs actively phagocytize iRBCs and interact with CD4+ T cells both in T cell-rich areas and in the RP. Subcapsular RP DCs were highly efficient in the recognition and capture of iRBCs during pre-crisis, while complete DC maturation was only achieved during crisis. These findings indicate that, beyond their classical role in antigen presentation, DCs also contribute to the direct elimination of iRBCs during acute Plasmodium infection.

In Vivo Approaches Reveal a Key Role for DCs in CD4+ T Cell Activation and Parasite Clearance during the Acute Phase of Experimental Blood-Stage Malaria

PubMed Central

Borges da Silva, Henrique; Fonseca, Raíssa; Cassado, Alexandra dos Anjos; Machado de Salles, Érika; de Menezes, Maria Nogueira; Langhorne, Jean; Perez, Katia Regina; Cuccovia, Iolanda Midea; Ryffel, Bernhard; Barreto, Vasco M.; Marinho, Cláudio Romero Farias; Boscardin, Silvia Beatriz; Álvarez, José Maria; D’Império-Lima, Maria Regina; Tadokoro, Carlos Eduardo

2015-01-01

Dendritic cells (DCs) are phagocytes that are highly specialized for antigen presentation. Heterogeneous populations of macrophages and DCs form a phagocyte network inside the red pulp (RP) of the spleen, which is a major site for the control of blood-borne infections such as malaria. However, the dynamics of splenic DCs during Plasmodium infections are poorly understood, limiting our knowledge regarding their protective role in malaria. Here, we used in vivo experimental approaches that enabled us to deplete or visualize DCs in order to clarify these issues. To elucidate the roles of DCs and marginal zone macrophages in the protection against blood-stage malaria, we infected DTx (diphtheria toxin)-treated C57BL/6.CD11c-DTR mice, as well as C57BL/6 mice treated with low doses of clodronate liposomes (ClLip), with Plasmodium chabaudi AS (Pc) parasites. The first evidence suggesting that DCs could contribute directly to parasite clearance was an early effect of the DTx treatment, but not of the ClLip treatment, in parasitemia control. DCs were also required for CD4+ T cell responses during infection. The phagocytosis of infected red blood cells (iRBCs) by splenic DCs was analyzed by confocal intravital microscopy, as well as by flow cytometry and immunofluorescence, at three distinct phases of Pc malaria: at the first encounter, at pre-crisis concomitant with parasitemia growth and at crisis when the parasitemia decline coincides with spleen closure. In vivo and ex vivo imaging of the spleen revealed that DCs actively phagocytize iRBCs and interact with CD4+ T cells both in T cell-rich areas and in the RP. Subcapsular RP DCs were highly efficient in the recognition and capture of iRBCs during pre-crisis, while complete DC maturation was only achieved during crisis. These findings indicate that, beyond their classical role in antigen presentation, DCs also contribute to the direct elimination of iRBCs during acute Plasmodium infection. PMID:25658925

Inhibition of human dendritic cell activation by hydroethanolic but not lipophilic extracts of turmeric (Curcuma longa).

PubMed

Krasovsky, Joseph; Chang, David H; Deng, Gary; Yeung, Simon; Lee, Mavis; Leung, Ping Chung; Cunningham-Rundles, Susanna; Cassileth, Barrie; Dhodapkar, Madhav V

2009-03-01

Turmeric has been extensively utilized in Indian and Chinese medicine for its immune-modulatory properties. Dendritic cells (DCs) are antigen-presenting cells specialized to initiate and regulate immunity. The ability of DCs to initiate immunity is linked to their activation status. The effects of turmeric on human DCs have not been studied. Here we show that hydroethanolic (HEE) but not lipophilic "supercritical" extraction (SCE) of turmeric inhibits the activation of human DCs in response to inflammatory cytokines. Treatment of DCs with HEE also inhibits the ability of DCs to stimulate the mixed lymphocyte reaction (MLR). Importantly, the lipophilic fraction does not synergize with the hydroethanolic fraction for the ability of inhibiting DC maturation. Rather, culturing of DCs with the combination of HEE and SCE leads to partial abrogation of the effects of HEE on the MLR initiated by DCs. These data provide a mechanism for the anti-inflammatory properties of turmeric. However, they suggest that these extracts are not synergistic and may contain components with mutually antagonistic effects on human DCs. Harnessing the immune effects of turmeric may benefit from specifically targeting the active fractions.

Inhibition of Human Dendritic Cell Activation by Hydroethanolic But Not Lipophilic Extracts of Turmeric (Curcuma longa)

PubMed Central

Krasovsky, Joseph; Chang, David H.; Deng, Gary; Yeung, Simon; Lee, Mavis; Leung, Ping Chung; Cunningham-Rundles, Susanna; Cassileth, Barrie; Dhodapkar, Madhav V.

2015-01-01

Turmeric has been extensively utilized in Indian and Chinese medicine for its immune-modulatory properties. Dendritic cells (DCs) are antigen-presenting cells specialized to initiate and regulate immunity. The ability of DCs to initiate immunity is linked to their activation status. The effects of turmeric on human DCs have not been studied. Here we show that hydroethanolic (HEE) but not lipophilic “supercritical” extraction (SCE) of turmeric inhibits the activation of human DCs in response to inflammatory cytokines. Treatment of DCs with HEE also inhibits the ability of DCs to stimulate the mixed lymphocyte reaction (MLR). Importantly, the lipophilic fraction does not synergize with the hydroethanolic fraction for the ability of inhibiting DC maturation. Rather, culturing of DCs with the combination of HEE and SCE leads to partial abrogation of the effects of HEE on the MLR initiated by DCs. These data provide a mechanism for the anti-inflammatory properties of turmeric. However, they suggest that these extracts are not synergistic and may contain components with mutually antagonistic effects on human DCs. Harnessing the immune effects of turmeric may benefit from specifically targeting the active fractions. PMID:19034830

The Closely Related CD103+ Dendritic Cells (DCs) and Lymphoid-Resident CD8+ DCs Differ in Their Inflammatory Functions

PubMed Central

Jiao, Zhijun; Bedoui, Sammy; Brady, Jamie L.; Walter, Anne; Chopin, Michael; Carrington, Emma M.; Sutherland, Robyn M.; Nutt, Stephen L.; Zhang, Yuxia; Ko, Hyun-Ja; Wu, Li

2014-01-01

Migratory CD103+ and lymphoid-resident CD8+ dendritic cells (DCs) share many attributes, such as dependence on the same transcription factors, cross-presenting ability and expression of certain surface molecules, such that it has been proposed they belong to a common sub-lineage. The functional diversity of the two DC types is nevertheless incompletely understood. Here we reveal that upon skin infection with herpes simplex virus, migratory CD103+ DCs from draining lymph nodes were more potent at inducing Th17 cytokine production by CD4+ T cells than CD8+ DCs. This superior capacity to drive Th17 responses was also evident in CD103+ DCs from uninfected mice. Their differential potency to induce Th17 differentiation was reflected by higher production of IL-1β and IL-6 by CD103+ DCs compared with CD8+ DCs upon stimulation. The two types of DCs from isolated lymph nodes also differ in expression of certain pattern recognition receptors. Furthermore, elevated levels of GM-CSF, typical of those found in inflammation, substantially increased the pool size of CD103+ DCs in lymph nodes and skin. We argue that varied levels of GM-CSF may explain the contrasting reports regarding the positive role of GM-CSF in regulating development of CD103+ DCs. Together, we find that these two developmentally closely-related DC subsets display functional differences and that GM-CSF has differential effect on the two types of DCs. PMID:24637385

Anodal Transcranial Direct Current Stimulation Enhances Survival and Integration of Dopaminergic Cell Transplants in a Rat Parkinson Model

PubMed Central

Winkler, Christian; Reis, Janine; Hoffmann, Nadin; Gellner, Anne-Kathrin; Münkel, Christian; Curado, Marco Rocha

2017-01-01

Abstract Restorative therapy concepts, such as cell based therapies aim to restitute impaired neurotransmission in neurodegenerative diseases. New strategies to enhance grafted cell survival and integration are still needed to improve functional recovery. Anodal direct current stimulation (DCS) promotes neuronal activity and secretion of the trophic factor BDNF in the motor cortex. Transcranial DCS applied to the motor cortex transiently improves motor symptoms in Parkinson’s disease (PD) patients. In this proof-of-concept study, we combine cell based therapy and noninvasive neuromodulation to assess whether neurotrophic support via transcranial DCS would enhance the restitution of striatal neurotransmission by fetal dopaminergic transplants in a rat Parkinson model. Transcranial DCS was applied daily for 20 min on 14 consecutive days following striatal transplantation of fetal ventral mesencephalic (fVM) cells derived from transgenic rat embryos ubiquitously expressing GFP. Anodal but not cathodal transcranial DCS significantly enhanced graft survival and dopaminergic reinnervation of the surrounding striatal tissue relative to sham stimulation. Behavioral recovery was more pronounced following anodal transcranial DCS, and behavioral effects correlated with the degree of striatal innervation. Our results suggest anodal transcranial DCS may help advance cell-based restorative therapies in neurodegenerative diseases. In particular, such an assistive approach may be beneficial for the already established cell transplantation therapy in PD. PMID:28966974

HMGB1, an alarmin promoting HIV dissemination and latency in dendritic cells

PubMed Central

Gougeon, M-L; Melki, M-T; Saïdi, H

2012-01-01

Dendritic cells (DCs) initiate immune responses by transporting antigens and migrating to lymphoid tissues to initiate T-cell responses. DCs are located in the mucosal surfaces that are involved in human immunodeficiency virus (HIV) transmission and they are probably among the earliest targets of HIV-1 infection. DCs have an important role in viral transmission and dissemination, and HIV-1 has evolved different strategies to evade DC antiviral activity. High mobility group box 1 (HMGB1) is a DNA-binding nuclear protein that can act as an alarmin, a danger signal to alert the innate immune system for the initiation of host defense. It is the prototypic damage-associated molecular pattern molecule, and it can be secreted by innate cells, including DCs and natural killer (NK) cells. The fate of DCs is dependent on a cognate interaction with NK cells, which involves HMGB1 expressed at NK–DC synapse. HMGB1 is essential for DC maturation, migration to lymphoid tissues and functional type-1 polarization of naïve T cells. This review highlights the latest advances in our understanding of the impact of HIV on the interactions between HMGB1 and DCs, focusing on the mechanisms of HMGB1-dependent viral dissemination and persistence in DCs, and discussing the consequences on antiviral innate immunity, immune activation and HIV pathogenesis. PMID:22033335

Type of monocyte immunomagnetic separation affects the morphology of monocyte-derived dendritic cells, as investigated by scanning electron microscopy.

PubMed

Kowalewicz-Kulbat, M; Ograczyk, E; Krawczyk, K; Rudnicka, W; Fol, M

2016-12-01

Dendritic cells (DCs) are increasingly being used for multiple applications and are useful tools for many immunotherapeutic strategies. The understanding of the possible impact of the DCs-generation methods on the biological capacities of these cells is therefore essential. Although the immunomagnetic separation is regarded as a fast and accurate method yielding cells with the high purity and efficiency, still little is known about its impact on the properties of the generated DCs. The aim of this study was to compare the morphology of the monocyte derived dendritic cells (MoDCs), generated from monocytes selected with anti-CD14 mAbs (positive separation) and treated with anti-CD3, -CD7, -CD16, -CD19, -CD56, -CD123, glycophorin A (negative separation), using laser scanning microscopy. We found that the type of the immunomagnetic separation method used strongly influences the shape and cell dimension of the MoDCs. We observed that the height of both immature and LPS-matured DCs generated from monocytes isolated by negative separation was significantly higher compared to the cells obtained by positive separation. Copyright © 2016 Elsevier B.V. All rights reserved.

CC chemokine receptor 4 is required for experimental autoimmune encephalomyelitis by regulating GM-CSF and IL-23 production in dendritic cells

PubMed Central

Poppensieker, Karola; Otte, David-Marian; Schürmann, Britta; Limmer, Andreas; Dresing, Philipp; Drews, Eva; Schumak, Beatrix; Klotz, Luisa; Raasch, Jennifer; Mildner, Alexander; Waisman, Ari; Scheu, Stefanie; Knolle, Percy; Förster, Irmgard; Prinz, Marco; Maier, Wolfgang; Zimmer, Andreas; Alferink, Judith

2012-01-01

Dendritic cells (DCs) are pivotal for the development of experimental autoimmune encephalomyelitis (EAE). However, the mechanisms by which they control disease remain to be determined. This study demonstrates that expression of CC chemokine receptor 4 (CCR4) by DCs is required for EAE induction. CCR4−/− mice presented enhanced resistance to EAE associated with a reduction in IL-23 and GM-CSF expression in the CNS. Restoring CCR4 on myeloid cells in bone marrow chimeras or intracerebral microinjection of CCR4-competent DCs, but not macrophages, restored EAE in CCR4−/− mice, indicating that CCR4+ DCs are cellular mediators of EAE development. Mechanistically, CCR4−/− DCs were less efficient in GM-CSF and IL-23 production and also TH-17 maintenance. Intraspinal IL-23 reconstitution restored EAE in CCR4−/− mice, whereas intracerebral inoculation using IL-23−/− DCs or GM-CSF−/− DCs failed to induce disease. Thus, CCR4-dependent GM-CSF production in DCs required for IL-23 release in these cells is a major component in the development of EAE. Our study identified a unique role for CCR4 in regulating DC function in EAE, harboring therapeutic potential for the treatment of CNS autoimmunity by targeting CCR4 on this specific cell type. PMID:22355103

DOWNREGULATION OF THE SYK SIGNALLING PATHWAY IN INTESTINAL DENDRITIC CELLS IS SUFFICIENT TO INDUCE DENDRITIC CELLS THAT INHIBIT COLITIS

PubMed Central

Hang, Long; Blum, Arthur M; Kumar, Sangeeta; Urban, Joseph F.; Mitreva, Makedonka; Geary, Timothy G.; Jardim, Armando; Stevenson, Mary M; Lowell, Clifford A.; Weinstock, Joel V.

2016-01-01

Helminthic infections modulate host immunity and may protect people in less developed countries from developing immunological diseases. In a murine colitis model, the helminth Heligmosomoides polygyrus bakeri (Hpb) prevents colitis via induction of regulatory dendritic cells (DCs). The mechanism driving the development of these regulatory DCs is unexplored. There is decreased expression of the intracellular signaling pathway spleen tyrosine kinase (Syk) in intestinal DCs from Hp- infected mice. To explore the importance of this observation, it was shown that intestinal DCs from DC-specific Syk −/− mice were powerful inhibitors of murine colitis suggesting that loss of Syk was sufficient to convert these cells into their regulatory phenotype. DCs sense gut flora and damaged epithelium via expression of C-type lectin receptors many of which signal through the Syk signaling pathway. It was observed that gut DCs express mRNA encoding for CLEC7A, 9A, 12A and 4N. Hpb infection down modulated CLEC mRNA expression in these cells. Focusing on CLEC7A, which encodes for the dectin-1 receptor, flow analysis showed that Hpb decreases dectin-1 display on the intestinal DC subsets that drive Th1/Th17 development. DCs become unresponsive to the dectin-1 agonist curdlan and fail to phosphorylate Syk after agonist stimulation. Soluble worm products can block CLEC7A and Syk mRNA expression in gut DCs from uninfected mice after a brief in vitro exposure. Thus, down-modulation of Syk expression and phosphorylation in intestinal DCs could be an important mechanism through which helminths induce regulatory DCs that limit colitis. PMID:27559049

Reduced numbers of mucosal DR(int) macrophages and increased numbers of CD103(+) dendritic cells during anti-TNF-α treatment in patients with Crohn's disease.

PubMed

Dige, Anders; Magnusson, Maria K; Öhman, Lena; Hvas, Christian Lodberg; Kelsen, Jens; Wick, Mary Jo; Agnholt, Jørgen

2016-01-01

Anti-TNF-α treatment constitutes a mainstay in the treatment of Crohn's disease (CD), but its mechanisms of action are not fully understood. We aimed to investigate the effects of adalimumab, a human monoclonal TNF-α antibody, on macrophage (MQ) and dendritic cell (DC) subsets in mucosal biopsies and peripheral blood. Intestinal biopsies and blood samples were obtained from 12 different CD patients both before and 4 weeks after the initiation of the induction of adalimumab treatment. Endoscopic disease activity was estimated by the Simple Endoscopic Score for Crohn's Disease. Biopsies were obtained from inflamed and non-inflamed areas. The numbers of lamina propria CD14 (+) DR(int) and CD14 (+) DR(hi) MQs, CD141(+), CD141(-) and CD103(+) DCs subsets, and circulating monocytes and DCs were analyzed using flow cytometry. At baseline, we observed higher numbers of DR(int) MQs and lower numbers of CD103(+) DCs in inflamed versus non-inflamed mucosa [843 vs. 391/10(5) lamina propria mononuclear cells (LPMCs) (p < 0.05) and 9 vs. 19 × 10(5) LPMCs (p = 0.01), respectively]. After four weeks of adalimumab treatment, the numbers of DR(int) MQs decreased [843 to 379/10(5) LPMCs (p = 0.03)], whereas the numbers of CD103(+) DCs increased [9-20 × 10(5) LPMCs (p = 0.003)] compared with baseline. In peripheral blood, no alterations were observed in monocyte or DC numbers between baseline and week 4. In CD, mucosal inflammation is associated with high numbers of DR(int) MQs and low numbers of CD103(+) DCs. This composition of intestinal myeloid subsets is reversed by anti-TNF-α treatment. These results suggest that DR(int) MQs play a pivotal role in CD inflammation.

Maturation and upregulation of functions of murine dendritic cells (DCs) under the influence of purified aromatic-turmerone (AR).

PubMed

Yonggang, Tan; Yiming, Meng; Heying, Zhang; Cheng, Sun; Qiushi, Wang; Xianghong, Yang; Wei, Zheng; Huawei, Zhou; Shan, Fengping

2012-10-01

The aim of this work is to evaluate the effects of purified aromatic-turmerone (ar-turmerione, AR) on murine dendritic cells (DCs). These impacts of AR on DCs from bone marrow derived DCs(BMDCs) were assessed with use of conventional scanning electron microscopy (SEM), fluorescence activated cell sorting (FACS), transmission electron microscopy (TEM), cytochemistry assay, FITC-dextran, bio-assay and enzyme linked immunosorbent assay (ELISA). We found that AR induced phenotypic maturation as evidenced by increased expression of CD86, CD40, CD83, CD80 and major histocompatibility complex II (MHC II). The functional tests showed the activity of acidic phosphatase (ACP) inside the DCs were downregulated after treatment with AR (which occurs when phagocytosis of DCs were decreased). Finally, we proved that AR increased the production of IL-12 and tumor necrosis factor α (TNF-α). These data suggested that AR could promote phenotypic and functional maturation of DCs and this adjuvant-like activity may have potential therapeutic value. It is therefore concluded that AR could exert positive modulation on murine DCs.

Maturation and upregulation of functions of murine dendritic cells (DCs) under the influence of purified Aromatic-Turmerone (AR)

PubMed Central

Yonggang, Tan; Yiming, Meng; Heying, Zhang; Cheng, Sun; Qiushi, Wang; Xianghong, Yang; Wei, Zheng; Huawei, Zhou; Shan, Fengping

2012-01-01

The aim of this work is to evaluate the effects of purified aromatic-turmerone(ar-turmerione, AR) on murine dendritic cells (DCs). These impacts of AR on DCs from bone marrow derived DCs(BMDCs) were assessed with use of conventional scanning electron microscopy (SEM), fluorescence activated cell sorting (FACS), transmission electron microscopy (TEM), cytochemistry assay, FITC-dextran, bio-assay and enzyme linked immunosorbent assay (ELISA). We found that AR induced phenotypic maturation as evidenced by increased expression of CD86, CD40, CD83, CD80 and major histocompatibility complex II (MHC II). The functional tests showed the activity of acidic phosphatase (ACP) inside the DCs were downregulated after treatment with AR (which occurs when phagocytosis of DCs were decreased). Finally, we proved that AR increased the production of IL-12 and tumor necrosis factor α (TNF-α). These data suggested that AR could promote phenotypic and functional maturation of DCs and this adjuvant-like activity may have potential therapeutic value. It is therefore concluded that AR could exert positive modulation on murine DCs. PMID:23095866

Intravital imaging of multicolor-labeled tumor immune microenvironment through skin-fold window chamber

NASA Astrophysics Data System (ADS)

Qi, Shuhong; Zhang, Zhihong

2015-03-01

Tumor immune microenvironment became very important for the tumor immunotherapy. There were several kinds of immune cells in tumor stromal, and they played very different roles in tumor growth. In order to observe the behaviors of multiple immune cells in tumor microenvironment and the interaction between immune cells and tumor cells at the same time, we generated a multicolor-labeled tumor immune microenvironment model. The tumor cells and immune cells were labeled by different fluorescent proteins. By using of skin-fold window chamber implanted into mice and intravital imaging technology, we could dynamically observe the different immune cells in tumor microenvironment. After data analysis from the video, we could know the behavior of TILs, DCs and Tregs in tumor immune microenvironment; furthermore, we could know these immune cells play different roles in the tumor microenvironment.

Ablation of CD11c(hi) dendritic cells exacerbates Japanese encephalitis by regulating blood-brain barrier permeability and altering tight junction/adhesion molecules.

PubMed

Kim, Jin Hyoung; Hossain, Ferdaus Mohd Altaf; Patil, Ajit Mahadev; Choi, Jin Young; Kim, Seong Bum; Uyangaa, Erdenebelig; Park, Sang-Youel; Lee, John-Hwa; Kim, Bumseok; Kim, Koanhoi; Eo, Seong Kug

2016-10-01

Japanese encephalitis (JE), characterized by extensive neuroinflammation following infection with neurotropic JE virus (JEV), is becoming a leading cause of viral encephalitis due to rapid changes in climate and demography. The blood-brain barrier (BBB) plays an important role in restricting neuroinvasion of peripheral leukocytes and virus, thereby regulating the progression of viral encephalitis. In this study, we explored the role of CD11c(hi) dendritic cells (DCs) in regulating BBB integrity and JE progression using a conditional depletion model of CD11c(hi) DCs. Transient ablation of CD11c(hi) DCs resulted in markedly increased susceptibility to JE progression along with highly increased neuro-invasion of JEV. In addition, exacerbated JE progression in CD11c(hi) DC-ablated hosts was closely associated with increased expression of proinflammatory cytokines (IFN-β, IL-6, and TNF-α) and CC chemokines (CCL2, CCL3, CXCL2) in the brain. Moreover, our results revealed that the exacerbation of JE progression in CD11c(hi) DC-ablated hosts was correlated with enhanced BBB permeability and reduced expression of tight junction and adhesion molecules (claudin-5, ZO-1, occluding, JAMs). Ultimately, our data conclude that the ablation of CD11c(hi) DCs provided a subsidiary impact on BBB integrity and the expression of tight junction/adhesion molecules, thereby leading to exacerbated JE progression. These findings provide insight into the secondary role of CD11c(hi) DCs in JE progression through regulation of BBB integrity and the expression of tight junction/adhesion molecules. Copyright © 2016 Elsevier Ltd. All rights reserved.

Critical role for TNF in the induction of human antigen-specific regulatory T cells by tolerogenic dendritic cells.

PubMed

Kleijwegt, Fleur S; Laban, Sandra; Duinkerken, Gaby; Joosten, Antoinette M; Zaldumbide, Arnaud; Nikolic, Tatjana; Roep, Bart O

2010-08-01

TNF is a pleiotropic cytokine with differential effects on immune cells and diseases. Anti-TNF therapy was shown to be effective in rheumatoid arthritis but proved inefficient or even detrimental in other autoimmune diseases. We studied the role of TNF in the induction of Ag-specific regulatory T cells (Tregs) by tolerogenic vitamin D3-modulated human dendritic cells (VD3-DCs), which previously were shown to release high amounts of soluble TNF (sTNF) upon maturation with LPS. First, production of TNF by modulated VD3-DCs was analyzed upon maturation with LPS or CD40L with respect to both secreted (cleaved) TNF (sTNF) and expression of the membrane-bound (uncleaved) form of TNF (mTNF). Next, TNF antagonists were tested for their effect on induction of Ag-specific Tregs by modulated DCs and the subsequent functionality of these Tregs. VD3-DCs expressed greater amounts of mTNF than did control DCs (nontreated DCs), independent of the maturation protocol. Inhibition of TNF with anti-TNF Ab (blocking both sTNF and mTNF) during the priming of Tregs with VD3-DCs prevented generation of Tregs and their suppression of proliferation of CD4(+) T cells. In contrast, sTNF receptor II (sTNFRII), mainly blocking sTNF, did not change the suppressive capacity of Tregs. Blocking of TNFRII by anti-CD120b Ab during Treg induction similarly abrogated their subsequent suppressive function. These data point to a specific role for mTNF on VD3-DCs in the induction of Ag-specific Tregs. Interaction between mTNF and TNFRII instructs the induction of suppressive Tregs by VD3-DCs. Anti-TNF therapy may therefore act adversely in different patients or disease pathways.

IgE in lupus pathogenesis: Friends or foes?

PubMed

Augusto, Jean-François; Truchetet, Marie-Elise; Charles, Nicolas; Blanco, Patrick; Richez, Christophe

2018-04-01

Systemic lupus erythematosus (SLE) is a complex autoimmune disease involving multiple immunological pathways. Recently, several studies have suggested an implication of Immunoglobulin E (IgE) in the pathophysiology of SLE. In the Lyn -/- and FcγIIB -/- .Yaa lupus mouse models, autoreactive IgE activate basophils, and promote a Th2 environment with, subsequently, production of autoantibodies by plasma cells. Autoreactive IgE has been also shown to play a role in the activation of human plasmacytoid dendritic cells (pDCs), in synergy with IgG, which results in an increase of interferon-alpha (IFN-α) production. In contrast, a protective effect of total non-autoreactive IgE has also been suggested, through a decreased ability of FcεRI-triggered pDCs to secrete IFN-α. This review summarizes in a comprehensive manner the emerging recent literature in the field, and propose new concepts to reconcile the observations. Copyright © 2018 Elsevier B.V. All rights reserved.

Evaluation of selected biomarkers for the detection of chemical sensitization in human skin: a comparative study applying THP-1, MUTZ-3 and primary dendritic cells in culture.

PubMed

Hitzler, Manuel; Bergert, Antje; Luch, Andreas; Peiser, Matthias

2013-09-01

Dendritic cells (DCs) exhibit the unique capacity to induce T cell differentiation and proliferation, two processes that are crucially involved in allergic reactions. By combining the exclusive potential of DCs as the only professional antigen-presenting cells of the human body with the well known handling advantages of cell lines, cell-based alternative methods aimed at detecting chemical sensitization in vitro commonly apply DC-like cells derived from myeloid cell lines. Here, we present the new biomarkers programmed death-ligand 1 (PD-L1), DC immunoreceptor (DCIR), IL-16, and neutrophil-activating protein-2 (NAP-2), all of which have been detectable in primary human DCs upon exposure to chemical contact allergens. To evaluate the applicability of DC-like cells in the prediction of a chemical's sensitization potential, the expression of cell surface PD-L1 and DCIR was analyzed. In contrast to primary DCs, only minor subpopulations of MUTZ-3 and THP-1 cells presented PD-L1 or DCIR at their surface. After exposure to increasing concentrations of nickel and cinnamic aldehyde, the expression level of PD-L1 and DCIR revealed much stronger affected on monocyte-derived DCs (MoDCs) or Langerhans cells (MoLCs) when compared to THP-1 and MUTZ-3 cells. Applying protein profiler arrays we further identified the soluble factors NAP-2, IL-16, IL-8 and MIP-1α as sensitive biomarkers showing the capacity to discriminate sensitizing from non-sensitizing chemicals or irritants. An allergen-specific release of IL-8 and MIP-1α could be detected in the supernatants of MoDCs and MoLCs and also in MUTZ-3 and THP-1 cells, though at much lower levels. On the protein and transcriptional level, NAP-2 and IL-16 indicated sensitizers most sensitively and specifically in MoDCs. Altogether, we have proven the reciprocal regulated surface molecules PD-L1 and DCIR and the soluble factors MIP-1α, NAP-2 and IL-16 as reliable biomarkers for chemical sensitization. We further show that primary DCs are significantly different in their phenotype and function compared to DC-like cell lines. Since they demonstrated higher absolute values and a broader range in biomarker expression, we propose that MoDCs represent an optimal and robust sensor test system well suited to identify and classify chemicals with an allergic potential. Copyright © 2013 Elsevier Ltd. All rights reserved.

A Marked Reduction in Priming of Cytotoxic CD8+ T Cells Mediated by Stress-Induced Glucocorticoids Involves Multiple Deficiencies in Cross-Presentation by Dendritic Cells

PubMed Central

Hunzeker, John T.; Elftman, Michael D.; Mellinger, Jennifer C.; Princiotta, Michael F.; Bonneau, Robert H.; Truckenmiller, Mary E.; Norbury, Christopher C.

2013-01-01

Protracted psychological stress elevates circulating glucocorticoids, which can suppress CD8+ T cell-mediated immunity, but the mechanisms are incompletely understood. Dendritic cells (DCs), required for initiating CTL responses, are vulnerable to stress/corticosterone, which can contribute to diminished CTL responses. Cross-priming of CD8+ T cells by DCs is required for initiating CTL responses against many intracellular pathogens that do not infect DCs. We examined the effects of stress/corticosterone on MHC class I (MHC I) cross-presentation and priming and show that stress/corticosterone-exposed DCs have a reduced ability to cross-present OVA and activate MHC I-OVA257–264-specific T cells. Using a murine model of psychological stress and OVA-loaded β2-microglobulin knockout “donor” cells that cannot present Ag, DCs from stressed mice induced markedly less Ag-specific CTL proliferation in a glucocorticoid receptor-dependent manner, and endogenous in vivo T cell cytolytic activity generated by cross-presented Ag was greatly diminished. These deficits in cross-presentation/priming were not due to altered Ag donation, Ag uptake (phagocytosis, receptor-mediated endocytosis, or fluid-phase uptake), or costimulatory molecule expression by DCs. However, proteasome activity in corticosterone-treated DCs or splenic DCs from stressed mice was partially suppressed, which limits formation of antigenic peptide-MHC I complexes. In addition, the lymphoid tissue-resident CD11b−CD24+CD8α+ DC subset, which carries out cross-presentation/priming, was preferentially depleted in stressed mice. At the same time, CD11b−CD24+CD8α− DC precursors were increased, suggesting a block in development of CD8α+ DCs. Therefore, glucocorticoid-induced changes in both the cellular composition of the immune system and intracellular protein degradation contribute to impaired CTL priming in stressed mice. PMID:21098225

Disarmed by density

PubMed Central

Nasi, Aikaterini; Rethi, Bence

2013-01-01

We observed a cell concentration-dependent differentiation switch among cultured dendritic cells (DCs) triggered by lactic acid, a product of glycolytic metabolism. In particular, while interleukin (IL)-12, IL-23, and tumor necrosis factor α (TNFα)-producing, migratory DCs developed in sparse cultures, IL-10-producing, non-migratory DCs differentiated in dense cultures. This points to a novel opportunity for tailoring DC-based anticancer therapies through metabolism modulation in developing DCs. PMID:24575378

Neurokinin-1 receptor agonists bias therapeutic dendritic cells to induce type 1 immunity by licensing host dendritic cells to produce IL-12

PubMed Central

Janelsins, Brian M.; Sumpter, Tina L.; Tkacheva, Olga A.; Rojas-Canales, Darling M.; Erdos, Geza; Mathers, Alicia R.; Shufesky, William J.; Storkus, Walter J.; Falo, Louis D.; Morelli, Adrian E.; Larregina, Adriana T.

2013-01-01

Substance-P and hemokinin-1 are proinflammatory neuropeptides with potential to promote type 1 immunity through agonistic binding to neurokinin-1 receptor (NK1R). Dendritic cells (DCs) are professional antigen-presenting cells that initiate and regulate the outcome of innate and adaptive immune responses. Immunostimulatory DCs are highly desired for the development of positive immunization techniques. DCs express functional NK1R; however, regardless of their potential DC-stimulatory function, the ability of NK1R agonists to promote immunostimulatory DCs remains unexplored. Here, we demonstrate that NK1R signaling activates therapeutic DCs capable of biasing type 1 immunity by inhibition of interleukin-10 (IL-10) synthesis and secretion, without affecting their low levels of IL-12 production. The potent type 1 effector immune response observed following cutaneous administration of NK1R-signaled DCs required their homing in skin-draining lymph nodes (sDLNs) where they induced inflammation and licensed endogenous-conventional sDLN-resident and -recruited inflammatory DCs to secrete IL-12. Our data demonstrate that NK1R signaling promotes immunostimulatory DCs, and provide relevant insight into the mechanisms used by neuromediators to regulate innate and adaptive immune responses. PMID:23365459

Identification of proteins derived from Listeria monocytogenes inducing human dendritic cell maturation.

PubMed

Mirzaei, Reza; Saei, Azad; Torkashvand, Fatemeh; Azarian, Bahareh; Jalili, Ahmad; Noorbakhsh, Farshid; Vaziri, Behrouz; Hadjati, Jamshid

2016-08-01

Dendritic cells (DCs) are potent antigen-presenting cells (APCs) that can promote antitumor immunity when pulsed with tumor antigens and then matured by stimulatory agents. Despite apparent progress in DC-based cancer immunotherapy, some discrepancies were reported in generating potent DCs. Listeria monocytogenes as an intracellular microorganism is able to effectively activate DCs through engaging pattern-recognition receptors (PRRs). This study aimed to find the most potent components derived from L. monocytogenes inducing DC maturation. The preliminary results demonstrated that the ability of protein components is higher than DNA components to promote DC maturation and activation. Protein lysate fractionation demonstrated that fraction 2 HIC (obtained by hydrophobic interaction chromatography) was able to efficiently mature DCs. F2HIC-matured DCs are able to induce allogeneic CD8(+) T cells proliferation better than LPS-matured DCs and induce IFN-γ producing CD8(+) T cells. Mass spectrometry results showed that F2HIC contains 109 proteins. Based on the bioinformatics analysis for these 109 proteins, elongation factor Tu (EF-Tu) could be considered as a PRR ligand for stimulating DC maturation.

Human primary myeloid dendritic cells interact with the opportunistic fungal pathogen Aspergillus fumigatus via the C-type lectin receptor Dectin-1.

PubMed

Hefter, Maike; Lother, Jasmin; Weiß, Esther; Schmitt, Anna Lena; Fliesser, Mirjam; Einsele, Hermann; Loeffler, Juergen

2017-07-01

Aspergillus fumigatus is an opportunistic fungal pathogen causing detrimental infections in immunocompromised individuals. Dendritic cells (DCs) are potent antigen-presenting cells and recognize the A. fumigatus cell wall component β-1,3 glucan via Dectin-1, followed by DC maturation and cytokine release. Here, we demonstrate that human primary myeloid DCs (mDCs) interact with different morphotypes of A. fumigatus. Dectin-1 is expressed on mDCs and is down-regulated after contact with A. fumigatus, indicating that mDCs recognize A. fumigatus via this receptor. Blocking of Dectin-1, followed by stimulation with depleted zymosan diminished the up-regulation of the T-cell co-stimulatory molecules CD40, CD80, HLA-DR and CCR7 on mDCs and led to decreased release of the cytokines TNF-α, IL-8, IL-1β and IL-10. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Immature Renal Dendritic Cells Recruit Regulatory CXCR6+ Invariant Natural Killer T Cells to Attenuate Crescentic GN

PubMed Central

Riedel, Jan-Hendrik; Paust, Hans-Joachim; Turner, Jan-Eric; Tittel, André P.; Krebs, Christian; Disteldorf, Erik; Wegscheid, Claudia; Tiegs, Gisa; Velden, Joachim; Mittrücker, Hans-Willi; Garbi, Natalio; Stahl, Rolf A.K.; Steinmetz, Oliver M.; Kurts, Christian

2012-01-01

Immature renal dendritic cells (DCs) are protective early in murine crescentic GN, but the mechanisms underlying this protection are unknown. Here, depletion of DCs reduced the recruitment of invariant natural killer T (iNKT) cells, which attenuate GN, into the kidney in the early stage of experimental crescentic GN. More than 90% of renal iNKT cells expressed the chemokine receptor CXCR6, and renal DCs produced high amounts of the cognate ligand CXCL16 early after induction of nephritis, suggesting that renal DC-derived CXCL16 might attract protective CXCR6+ iNKT cells. Consistent with this finding, CXCR6-deficient mice exhibited less iNKT cell recruitment and developed nephritis that was more severe, similar to the aggravated nephritis observed in mice depleted of immature DCs. Finally, adoptive transfer of CXCR6-competent NKT cells ameliorated nephritis. Taken together, these results suggest an immunoprotective mechanism involving immature DCs, CXCL16, CXCR6, and regulatory iNKT cells, which might stimulate the development of new therapeutic strategies for GN. PMID:23138484

Immature renal dendritic cells recruit regulatory CXCR6(+) invariant natural killer T cells to attenuate crescentic GN.

PubMed

Riedel, Jan-Hendrik; Paust, Hans-Joachim; Turner, Jan-Eric; Tittel, André P; Krebs, Christian; Disteldorf, Erik; Wegscheid, Claudia; Tiegs, Gisa; Velden, Joachim; Mittrücker, Hans-Willi; Garbi, Natalio; Stahl, Rolf A K; Steinmetz, Oliver M; Kurts, Christian; Panzer, Ulf

2012-12-01

Immature renal dendritic cells (DCs) are protective early in murine crescentic GN, but the mechanisms underlying this protection are unknown. Here, depletion of DCs reduced the recruitment of invariant natural killer T (iNKT) cells, which attenuate GN, into the kidney in the early stage of experimental crescentic GN. More than 90% of renal iNKT cells expressed the chemokine receptor CXCR6, and renal DCs produced high amounts of the cognate ligand CXCL16 early after induction of nephritis, suggesting that renal DC-derived CXCL16 might attract protective CXCR6(+) iNKT cells. Consistent with this finding, CXCR6-deficient mice exhibited less iNKT cell recruitment and developed nephritis that was more severe, similar to the aggravated nephritis observed in mice depleted of immature DCs. Finally, adoptive transfer of CXCR6-competent NKT cells ameliorated nephritis. Taken together, these results suggest an immunoprotective mechanism involving immature DCs, CXCL16, CXCR6, and regulatory iNKT cells, which might stimulate the development of new therapeutic strategies for GN.

Dendritic cell MST1 inhibits Th17 differentiation

PubMed Central

Li, Chunxiao; Bi, Yujing; Li, Yan; Yang, Hui; Yu, Qing; Wang, Jian; Wang, Yu; Su, Huilin; Jia, Anna; Hu, Ying; Han, Linian; Zhang, Jiangyuan; Li, Simin; Tao, Wufan; Liu, Guangwei

2017-01-01

Although the differentiation of CD4+T cells is widely studied, the mechanisms of antigen-presenting cell-dependent T-cell modulation are unclear. Here, we investigate the role of dendritic cell (DC)-dependent T-cell differentiation in autoimmune and antifungal inflammation and find that mammalian sterile 20-like kinase 1 (MST1) signalling from DCs negatively regulates IL-17 producing-CD4+T helper cell (Th17) differentiation. MST1 deficiency in DCs increases IL-17 production by CD4+T cells, whereas ectopic MST1 expression in DCs inhibits it. Notably, MST1-mediated DC-dependent Th17 differentiation regulates experimental autoimmune encephalomyelitis and antifungal immunity. Mechanistically, MST1-deficient DCs promote IL-6 secretion and regulate the activation of IL-6 receptor α/β and STAT3 in CD4+T cells in the course of inducing Th17 differentiation. Activation of the p38 MAPK signal is responsible for IL-6 production in MST1-deficient DCs. Thus, our results define the DC MST1–p38MAPK signalling pathway in directing Th17 differentiation. PMID:28145433

Cytoskeletal stabilization of inhibitory interactions in immunologic synapses of mature human dendritic cells with natural killer cells

PubMed Central

Barreira da Silva, Rosa; Graf, Claudine

2011-01-01

Human mature dendritic cells (DCs) can efficiently stimulate natural killer (NK)–cell responses without being targeted by their cytotoxicity. To understand this important regulatory crosstalk, we characterized the development of the immunologic synapse between mature DCs and resting NK cells. Conjugates between these 2 innate leukocyte populations formed rapidly, persisted for prolonged time periods and matured with DC-derived f-actin polymerization at the synapse. Polarization of IL-12 and IL-12R to the synapse coincided with f-actin polymerization, while other activating and inhibitory molecules were enriched at the interface between DCs and NK cells earlier. Functional assays revealed that inhibition of f-actin polymerization in mature synapses led to an increase of IFN-γ secretion and cytotoxicity by NK cells. This elevated NK-cell reactivity resulted from decreased inhibitory signaling in the absence of MHC class I polarization at the interface, which was observed on inhibition of f-actin polymerization in DCs. Thus, inhibitory signaling is stabilized by f-actin at the synapse between mature DCs and resting NK cells. PMID:21917751

Cell death induced by the application of alternating magnetic fields to nanoparticle-loaded dendritic cells.

PubMed

Marcos-Campos, I; Asín, L; Torres, T E; Marquina, C; Tres, A; Ibarra, M R; Goya, G F

2011-05-20

In this work, the capability of primary, monocyte-derived dendritic cells (DCs) to uptake iron oxide magnetic nanoparticles (MNPs) is assessed and a strategy to induce selective cell death in these MNP-loaded DCs using external alternating magnetic fields (AMFs) is reported. No significant decrease in the cell viability of MNP-loaded DCs, compared to the control samples, was observed after five days of culture. The number of MNPs incorporated into the cytoplasm was measured by magnetometry, which confirmed that 1-5 pg of the particles were uploaded per cell. The intracellular distribution of these MNPs, assessed by transmission electron microscopy, was found to be primarily inside the endosomic structures. These cells were then subjected to an AMF for 30 min and the viability of the blank DCs (i.e. without MNPs), which were used as control samples, remained essentially unaffected. However, a remarkable decrease of viability from approximately 90% to 2-5% of DCs previously loaded with MNPs was observed after the same 30 min exposure to an AMF. The same results were obtained using MNPs having either positive (NH(2)(+)) or negative (COOH(-)) surface functional groups. In spite of the massive cell death induced by application of AMF to MNP-loaded DCs, the number of incorporated magnetic particles did not raise the temperature of the cell culture. Clear morphological changes at the cell structure after magnetic field application were observed using scanning electron microscopy. Therefore, local damage produced by the MNPs could be the main mechanism for the selective cell death of MNP-loaded DCs under an AMF. Based on the ability of these cells to evade the reticuloendothelial system, these complexes combined with an AMF should be considered as a potentially powerful tool for tumour therapy.

Elderly dendritic cells respond to LPS/IFN-γ and CD40L stimulation despite incomplete maturation

PubMed Central

Musk, Arthur W.; Alvarez, John; Mamotte, Cyril D. S.; Jackaman, Connie; Nowak, Anna K.; Nelson, Delia J.

2018-01-01

There is evidence that dendritic cells (DCs) undergo age-related changes that modulate their function with their key role being priming antigen-specific effector T cells. This occurs once DCs develop into antigen-presenting cells in response to stimuli/danger signals. However, the effects of aging on DC responses to bacterial lipopolysaccharide (LPS), the pro-inflammatory cytokine interferon (IFN)-γ and CD40 ligand (CD40L) have not yet been systematically evaluated. We examined responses of blood myeloid (m)DC1s, mDC2s, plasmacytoid (p)DCs, and monocyte-derived DCs (MoDCs) from young (21–40 years) and elderly (60–84 years) healthy human volunteers to LPS/IFN-γ or CD40L stimulation. All elderly DC subsets demonstrated comparable up-regulation of co-stimulatory molecules (CD40, CD80 and/or CD86), intracellular pro-inflammatory cytokine levels (IFN-γ, tumour necrosis factor (TNF)-α, IL-6 and/or IL-12), and/or secreted cytokine levels (IFN-α, IFN-γ, TNF-α, and IL-12) to their younger counterparts. Furthermore, elderly-derived LPS/IFN-γ or CD40L-activated MoDCs induced similar or increased levels of CD8+ and CD4+ T cell proliferation, and similar T cell functional phenotypes, to their younger counterparts. However, elderly LPS/IFN-γ-activated MoDCs were unreliable in their ability to up-regulate chemokine (IL-8 and monocyte chemoattractant protein (MCP)-1) and IL-6 secretion, implying an inability to dependably induce an inflammatory response. A key age-related difference was that, unlike young-derived MoDCs that completely lost their ability to process antigen, elderly-derived MoDCs maintained their antigen processing ability after LPS/IFN-γ maturation, measured using the DQ-ovalbumin assay; this response implies incomplete maturation that may enable elderly DCs to continuously present antigen. These differences may impact on the efficacy of anti-pathogen and anti-tumour immune responses in the elderly. PMID:29652910

A benzenediamine derivate FC-99 attenuates lupus nephritis in MRL/lpr mice via inhibiting myeloid dendritic cell-secreted BAFF.

PubMed

Ji, Jianjian; Xu, Jingjing; Li, Fanlin; Li, Xiaojing; Gong, Wei; Song, Yuxian; Dou, Huan; Hou, Yayi

2016-05-01

Myeloid dendritic cells (DCs) can produce B-cell-activating factor (BAFF) that modulates survival and differentiation of B cells and plays a pivotal role in the pathogenesis of systemic lupus erythematosus (SLE). Toll-like receptor 4 (TLR4) signaling has important functions in the process of BAFF production. Our previous study showed that a benzenediamine derivate FC-99 possesses anti-inflammation activity and directly interacts with interleukin-1 receptor-associated kinase 4 (IRAK4), which was a pivotal molecule in TLR4 signaling. In this study, we demonstrated that FC-99 attenuated lupus nephritis in the MRL/lpr mice. FC-99 also decreased the levels of total immunoglobulin G (IgG), total IgG2a and IgM in sera, as well as the activation of B cells in the spleens of MRL/lpr mice. Moreover, FC-99 inhibited abnormal activation of myeloid DCs in spleens and reduced the levels of BAFF in sera, spleens, and kidneys of MRL/lpr mice. Furthermore, upon TLR4 stimulation with lipopolysaccharide in vitro, FC-99 inhibited IRAK4 phosphorylation, as well as the activation and BAFF production in murine bone marrow-derived DCs. These data indicate that FC-99 attenuates lupus nephritis in MRL/lpr mice via inhibiting DC-secreted BAFF, suggesting that FC-99 may be a potential therapeutic candidate for the treatment of SLE. © The Author 2016. Published by ABBS Editorial Office in association with Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences.

Acute aerobic exercise induces a preferential mobilisation of plasmacytoid dendritic cells into the peripheral blood in man.

PubMed

Brown, Frankie F; Campbell, John P; Wadley, Alex J; Fisher, James P; Aldred, Sarah; Turner, James E

2018-05-31

Dendritic cells (DCs) are important sentinel cells of the immune system responsible for presenting antigen to T cells. Exercise is known to cause an acute and transient increase in the frequency of DCs in the bloodstream in humans, yet there are contradictory findings in the literature regarding the phenotypic composition of DCs mobilised during exercise, which may have implications for immune regulation and health. Accordingly, we sought to investigate the composition of DC sub-populations mobilised in response to acute aerobic exercise. Nine healthy males (age, 21.9 ± 3.6 years; height, 177.8 ± 5.4 cm; body mass, 78.9 ± 10.8 kg; body mass index, 24.9 ± 3.3 kg·m 2 ; V̇O 2 MAX , 41.5 ± 5.1 mL·kg·min -1 ) cycled for 20 min at 80% V̇O 2 MAX . Blood was sampled at baseline, during the final minute of exercise and 30 min later. Using flow cytometry, total DCs were defined as Lineage- (CD3, CD19, CD20, CD14, CD56) HLA-DR+ and subsequently identified as plasmacytoid DCs (CD303+) and myeloid DCs (CD303-). Myeloid DCs were analysed for expression of CD1c and CD141 to yield four sub-populations; CD1c-CD141+; CD1c+CD141+; CD1c+CD141- and CD1c-CD141-. Expression of CD205 was also analysed on all DC sub-populations to identify DCs capable of recognising apoptotic and necrotic cells. Total DCs increased by 150% during exercise (F (1,10)  = 60; p < 0.05, η 2  = 0.9). Plasmacytoid DCs mobilised to a greater magnitude than myeloid DCs (195 ± 131% vs. 131 ± 100%; p < 0.05). Among myeloid DCs, CD1c-CD141- cells showed the largest exercise-induced mobilisation (167 ± 122%), with a stepwise pattern observed among the remaining sub-populations: CD1c+CD141- (79 ± 50%), followed by CD1c+CD141+ (44 ± 41%), with the smallest response shown by CD1c-CD141+ cells (23 ± 54%) (p < 0.05). Among myeloid DCs, CD205- cells were the most exercise responsive. All DC subsets returned to resting levels within 30 min of exercise cessation. These results show that there is a preferential mobilisation of plasmacytoid DCs during exercise. Given the functional repertoire of plasmacytoid DCs, which includes the production of interferons against viral and bacterial pathogens, these findings indicate that exercise may augment immune-surveillance by preferentially mobilising effector cells; these findings have general implications for the promotion of exercise for health, and specifically for the optimisation of DC harvest for cancer immunotherapy. Copyright © 2018 Elsevier Inc. All rights reserved.

Activated natural killer cell-mediated immunity is required for the inhibition of tumor metastasis by dendritic cell vaccination.

PubMed

Kim, Aeyung; Noh, Young-Woock; Kim, Kwang Dong; Jang, Yong-Suk; Choe, Yong-Kyung; Lim, Jong-Seok

2004-10-31

Immunization with dendritic cells (DCs) pulsed with tumor antigen can activate tumor-specific cytotoxic T lymphocytes (CTL), which is responsible for tumor protection and regression. In this study, we examined whether DCs pulsed with necrotic tumor lysates can efficiently prevent malignant melanoma tumor cell metastasis to the lung. DCs derived from mouse bone marrow were found to produce remarkably elevated levels of IL-12 after being pulsed with the tumor lysates. Moreover, immunization with these DCs induced CTL activation and protected mice from metastasis development by intravenously inoculated tumor cells. In addition, these DCs activated NK cells in vitro in a contact-dependent manner, and induced NK activities in vivo. Furthermore, NK cell depletion before DC vaccination significantly reduced the tumor-specific CTL activity, IFN-gamma production, and IFN-gamma- inducible gene expression, and eventually interfered with the antitumor effect of tumor-pulsed DCs. Finally, similar findings with respect to NK cell dependency were obtained in the C57BL/ 6J-bg/bg mice, which have severe deficiency in cytolytic activity of NK cells. These data suggest that the antitumor effect elicited by DC vaccination, at least in a B16 melanoma model, requires the participation of both cytolytic NK and CD8(+) T cells. The findings of this study would provide important data for the effective design of DC vaccines for cancer immunotherapy.

Naive helper T cells from BCG-vaccinated volunteers produce IFN-gamma and IL-5 to mycobacterial antigen-pulsed dendritic cells.

PubMed

Kowalewicz-Kulbat, Magdalena; Kaźmierczak, Dominik; Donevski, Stefan; Biet, Franck; Pestel, Joël; Rudnicka, Wiesława

2008-01-01

Mycobacterium bovis bacillus Calmette-Guérin (BCG) is a live vaccine that has been used in routine vaccination against tuberculosis for nearly 80 years. However, its efficacy is controversial. The failure of BCG vaccination may be at least partially explained by the induction of poor or inappropriate host responses. Dendritic cells (DCs) are likely to play a key role in the induction of immune response to mycobacteria by polarizing the reactivity of T lymphocytes toward a Th1 profile, contributing to the generation of protective cellular immunity against mycobacteria. In this study we aimed to investigate the production of Th1 and Th2 cytokines by naive CD4+ T cells to mycobacterial antigen-pulsed DCs in the group of young, healthy BCG vaccinated volunteers. The response of naive helper T cells was compared with the response of total blood lymphocytes. Our present results clearly showed that circulating naive CD45RA+CD4+ lymphocytes from BCG-vaccinated subjects can become effector helper cells producing IFN-gamma and IL-5 under the stimulation by autologous dendritic cells presenting mycobacterial protein antigen-PPD or infected with live M. bovis BCG bacilli.

Dendritic cell reprogramming by endogenously produced lactic acid.

PubMed

Nasi, Aikaterini; Fekete, Tünde; Krishnamurthy, Akilan; Snowden, Stuart; Rajnavölgyi, Eva; Catrina, Anca I; Wheelock, Craig E; Vivar, Nancy; Rethi, Bence

2013-09-15

The demand for controlling T cell responses via dendritic cell (DC) vaccines initiated a quest for reliable and feasible DC modulatory strategies that would facilitate cytotoxicity against tumors or tolerance in autoimmunity. We studied endogenous mechanisms in developing monocyte-derived DCs (MoDCs) that can induce inflammatory or suppressor programs during differentiation, and we identified a powerful autocrine pathway that, in a cell concentration-dependent manner, strongly interferes with inflammatory DC differentiation. MoDCs developing at low cell culture density have superior ability to produce inflammatory cytokines, to induce Th1 polarization, and to migrate toward the lymphoid tissue chemokine CCL19. On the contrary, MoDCs originated from dense cultures produce IL-10 but no inflammatory cytokines upon activation. DCs from high-density cultures maintained more differentiation plasticity and can develop to osteoclasts. The cell concentration-dependent pathway was independent of peroxisome proliferator-activated receptor γ (PPARγ), a known endogenous regulator of MoDC differentiation. Instead, it acted through lactic acid, which accumulated in dense cultures and induced an early and long-lasting reprogramming of MoDC differentiation. Our results suggest that the lactic acid-mediated inhibitory pathway could be efficiently manipulated in developing MoDCs to influence the immunogenicity of DC vaccines.

Zinc Induces Dendritic Cell Tolerogenic Phenotype and Skews Regulatory T cell – Th17 Balance

PubMed Central

George, Mariam Mathew; Vignesh, Kavitha Subramanian; Landero Figueroa, Julio A.; Caruso, Joseph A.; Deepe, George S.

2016-01-01

Zn is an essential metal for development and maintenance of both the innate and adaptive compartments of the immune system. Zn homeostasis impacts maturation of dendritic cells (DCs) that are important in shaping T cell responses. The mechanism by which Zn regulates the tolerogenic phenotype of DCs remains largely unknown. In this study, we investigated the effect of Zn on DC phenotype and the generation of forkhead box P3 (FoxP3+) regulatory T cells (Tregs) using a model of Histoplasma capsulatum fungal infection. Exposure of bone marrow derived DCs to Zn in vitro induced a tolerogenic phenotype by diminishing surface major histocompatibility complex (MHC)II and promoting the tolerogenic markers, programmed death-ligand (PD-L)1, PD-L2 and the tryptophan degrading enzyme, indoleamine 2,3 dioxygenase (IDO). Zn triggered tryptophan degradation by IDO and kynurenine production by DCs and strongly suppressed the proinflammatory response to stimulation by toll like receptor (TLR) ligands. In vivo, Zn supplementation and subsequent H. capsulatum infection supressed MHCII on DCs, enhanced PD-L1 and PD-L2 expression on MHCIIlo DCs and skewed the Treg - Th17 balance in favour of FoxP3+ Tregs while decreasing Th17 cells. Thus, Zn shapes the tolerogenic potential of DCs in vitro and in vivo and promotes Tregs during fungal infection. PMID:27465530

Immune Cell Profiling of IFN-λ Response Shows pDCs Express Highest Level of IFN-λR1 and Are Directly Responsive via the JAK-STAT Pathway.

PubMed

Kelly, Aoife; Robinson, Mark W; Roche, Gerard; Biron, Christine A; O'Farrelly, Cliona; Ryan, Elizabeth J

2016-12-01

The interferon lambda (IFN-λ) cytokines have well-known antiviral properties, yet their contribution to immune regulation is not well understood. Epithelial cells represent the major target cell of IFN-λ; peripheral blood mononuclear cells are generally considered nonresponsive, with the exception of plasmacytoid dendritic cells (pDCs). In this study we aimed to define the potential for discrete subpopulations of cells to directly respond to IFN-λ. Analysis of peripheral blood leukocytes reveals that, while pDCs uniformly express the highest levels of IFN-λ receptor, a small proportion of B cells and monocytes also express the receptor. Nevertheless, B cells and monocytes respond poorly to IFN-λ stimulation in vitro, with minimal STAT phosphorylation and interferon-stimulated gene (ISG) induction observed. We confirm that pDCs respond to IFN-λ in vitro, upregulating their expression of pSTAT1, pSTAT3, and pSTAT5. However, we found that pDCs do not upregulate pSTAT6 in response to IFN-λ treatment. Our results highlight unique aspects of the response to IFN-λ and confirm that while the IFN-λ receptor is expressed by a small proportion of several different circulating immune cell lineages, under normal conditions only pDCs respond to IFN-λ stimulation with robust STAT phosphorylation and ISG induction. The difference in STAT6 responsiveness of pDCs to type I and type III interferons may help explain the divergence in their biological activities.

Dendritic cells: In vitro culture in two- and three-dimensional collagen systems and expression of collagen receptors in tumors and atherosclerotic microenvironments.

PubMed

Sprague, Leslee; Muccioli, Maria; Pate, Michelle; Singh, Manindra; Xiong, Chengkai; Ostermann, Alexander; Niese, Brandon; Li, Yihan; Li, Yandi; Courreges, Maria Cecilia; Benencia, Fabian

2014-04-15

Dendritic cells (DCs) are immune cells found in the peripheral tissues where they sample the organism for infections or malignancies. There they take up antigens and migrate towards immunological organs to contact and activate T lymphocytes that specifically recognize the antigen presented by these antigen presenting cells. In the steady state there are several types of resident DCs present in various different organs. For example, in the mouse, splenic DC populations characterized by the co-expression of CD11c and CD8 surface markers are specialized in cross-presentation to CD8 T cells, while CD11c/SIRP-1α DCs seem to be dedicated to activating CD4 T cells. On the other hand, DCs have also been associated with the development of various diseases such as cancer, atherosclerosis, or inflammatory conditions. In such disease, DCs can participate by inducing angiogenesis or immunosuppression (tumors), promoting autoimmune responses, or exacerbating inflammation (atherosclerosis). This change in DC biology can be prompted by signals in the microenvironment. We have previously shown that the interaction of DCs with various extracellular matrix components modifies the immune properties and angiogenic potential of these cells. Building on those studies, herewith we analyzed the angiogenic profile of murine myeloid DCs upon interaction with 2D and 3D type-I collagen environments. As determined by PCR array technology and quantitative PCR analysis we observed that interaction with these collagen environments induced the expression of particular angiogenic molecules. In addition, DCs cultured on collagen environments specifically upregulated the expression of CXCL-1 and -2 chemokines. We were also able to establish DC cultures on type-IV collagen environments, a collagen type expressed in pathological conditions such as atherosclerosis. When we examined DC populations in atherosclerotic veins of Apolipoprotein E deficient mice we observed that they expressed adhesion molecules capable of interacting with collagen. Finally, to further investigate the interaction of DCs with collagen in other pathological conditions, we determined that both murine ovarian and breast cancer cells express several collagen molecules that can contribute to shape their particular tumor microenvironment. Consistently, tumor-associated DCs were shown to express adhesion molecules capable of interacting with collagen molecules as determined by flow cytometry analysis. Of particular relevance, tumor-associated DCs expressed high levels of CD305/LAIR-1, an immunosuppressive receptor. This suggests that signaling through this molecule upon interaction with collagen produced by tumor cells might help define the poorly immunogenic status of these cells in the tumor microenvironment. Overall, these studies demonstrate that through interaction with collagen proteins, DCs can be capable of modifying the microenvironments of inflammatory disease such as cancer or atherosclerosis. Copyright © 2014. Published by Elsevier Inc.

Immunoglobulins drive terminal maturation of splenic dendritic cells

PubMed Central

Ziętara, Natalia; Łyszkiewicz, Marcin; Puchałka, Jacek; Pei, Gang; Gutierrez, Maximiliano Gabriel; Lienenklaus, Stefan; Hobeika, Elias; Reth, Michael; Martins dos Santos, Vitor A. P.; Krueger, Andreas; Weiss, Siegfried

2013-01-01

Nature and physiological status of antigen-presenting cells, such as dendritic cells DCs, are decisive for the immune reactions elicited. Multiple factors and cell interactions have been described that affect maturation of DCs. Here, we show that DCs arising in the absence of immunoglobulins (Ig) in vivo are impaired in cross-presentation of soluble antigen. This deficiency was due to aberrant cellular targeting of antigen to lysosomes and its rapid degradation. Function of DCs could be restored by transfer of Ig irrespective of antigen specificity and isotype. Modulation of cross-presentation by Ig was inhibited by coapplication of mannan and, thus, likely to be mediated by C-type lectin receptors. This unexpected dependency of splenic DCs on Ig to cross-present antigen provides insights into the interplay between cellular and humoral immunity and the immunomodulatory capacity of Ig. PMID:23345431

CpG Oligodeoxynucleotides Facilitate Delivery of Whole Inactivated H9N2 Influenza Virus via Transepithelial Dendrites of Dendritic Cells in Nasal Mucosa

PubMed Central

Qin, Tao; Yin, Yinyan; Yu, Qinghua; Huang, Lulu; Wang, Xiaoqing; Lin, Jian

2015-01-01

ABSTRACT The spread of the low-pathogenicity avian H9N2 influenza virus has seriously increased the risk of a new influenza pandemic. Although whole inactivated virus (WIV) vaccine via intranasal pathway is the effective method of blocking virus transmission, the mucosal barrier seems to be a major factor hampering its development. CpG oligodeoxynucleotides, a known adjuvant, can target downstream dendritic cells (DCs) and effectively enhance the mucosal and systemic immune responses. However, the ability of CpGs to assist H9N2 WIV in transepithelial transport remains unknown. Here, in vitro and in vivo, we showed that CpGs provided assistance for H9N2 WIV in recruiting DCs to the nasal epithelial cells (ECs) and forming transepithelial dendrites (TEDs) to capture luminal viruses. CD103+ DCs participated in this process. Chemokine CCL20 from nasal ECs played a key role in driving DC recruitment and TED formation. Virus-loaded DCs quickly migrated into the draining cervical lymph nodes (CLNs) for antigen presentation. In addition, the competence of CpGs was independent of direct epithelial transport via the transcellular or paracellular pathway. Taken together, our data demonstrated that CpGs enhanced the transport of H9N2 WIV via TEDs of nasal DCs, which might be a novel mechanism for optimal adaptive immune responses. IMPORTANCE This paper demonstrates by both an in vivo and an in vitro coculture model that CpG oligodeoxynucleotides, known as an adjuvant generally targeting downstream immune responses, also are crucial for the transport of H9N2 WIV across nasal epithelial cells (ECs) via the uptake of transepithelial dendrites (TEDs). Our results prove for the first time to our knowledge that the immune-potentiating mechanism of CpGs is based on strengthening the transepithelial uptake of H9N2 WIV in nasal mucosa. These findings provide a fresh perspective for further improvement of intranasal influenza vaccines, which are urgently needed in the face of the potential threat of H9N2 influenza. PMID:25810544

Ebola virus infection induces irregular dendritic cell gene expression.

PubMed

Melanson, Vanessa R; Kalina, Warren V; Williams, Priscilla

2015-02-01

Filoviruses subvert the human immune system in part by infecting and replicating in dendritic cells (DCs). Using gene arrays, a phenotypic profile of filovirus infection in human monocyte-derived DCs was assessed. Monocytes from human donors were cultured in GM-CSF and IL-4 and were infected with Ebola virus Kikwit variant for up to 48 h. Extracted DC RNA was analyzed on SuperArray's Dendritic and Antigen Presenting Cell Oligo GEArray and compared to uninfected controls. Infected DCs exhibited increased expression of cytokine, chemokine, antiviral, and anti-apoptotic genes not seen in uninfected controls. Significant increases of intracellular antiviral and MHC I and II genes were also noted in EBOV-infected DCs. However, infected DCs failed to show any significant difference in co-stimulatory T-cell gene expression from uninfected DCs. Moreover, several chemokine genes were activated, but there was sparse expression of chemokine receptors that enabled activated DCs to home to lymph nodes. Overall, statistically significant expression of several intracellular antiviral genes was noted, which may limit viral load but fails to stop replication. EBOV gene expression profiling is of vital importance in understanding pathogenesis and devising novel therapeutic treatments such as small-molecule inhibitors.

Blocking of p38 and transforming growth factor β receptor pathways impairs the ability of tolerogenic dendritic cells to suppress murine arthritis.

PubMed

Gárate, David; Rojas-Colonelli, Nicole; Peña, Corina; Salazar, Lorena; Abello, Paula; Pesce, Bárbara; Aravena, Octavio; García-González, Paulina; Ribeiro, Carolina H; Molina, María C; Catalán, Diego; Aguillón, Juan C

2013-01-01

Dendritic cells (DCs) modulated with lipopolysaccharide (LPS) are able to reduce inflammation when therapeutically administered into mice with collagen-induced arthritis (CIA). The aim of this study was to uncover the mechanisms that define the tolerogenic effect of short-term LPS-modulated DCs on CIA. Bone marrow-derived DCs were stimulated for 4 hours with LPS and characterized for their expression of maturation markers and their cytokine secretion profiles. Stimulated cells were treated with SB203580 or SB431542 to inhibit the p38 or transforming growth factor β (TGFβ) receptor pathway, respectively, or were left unmodified and, on day 35 after CIA induction, were used to inoculate mice. Disease severity was evaluated clinically. CD4+ T cell populations were counted in the spleen and lymph nodes from inoculated or untreated mice with CIA. CD4+ splenic T cells were transferred from mice with CIA treated with LPS-stimulated DCs or from untreated mice with CIA into other mice with CIA on day 35 of arthritis. Treatment with LPS-stimulated DCs increased the numbers of interleukin-10 (IL-10)-secreting and TGFβ-secreting CD4+ T cells, but decreased the numbers of Th17 cells. Adoptive transfer of CD4+ T cells from treated mice with CIA reproduced the inhibition of active CIA accomplished with LPS-stimulated DCs. The therapeutic effect of LPS-stimulated DCs and their influence on T cell populations were abolished when the p38 and the TGFβ receptor pathways were inhibited. DCs modulated short-term (4 hours) with LPS are able to confer a sustained cure in mice with established arthritis by re-educating the CD4+ T cell populations. This effect is dependent on the p38 and the TGFβ receptor signaling pathways, which suggests the participation of IL-10 and TGFβ in the recovery of tolerance. Copyright © 2013 by the American College of Rheumatology.

Culture supernatants of oral cancer cells induce impaired IFN-α production of pDCs partly through the down-regulation of TLR-9 expression.

PubMed

Han, Nannan; Zhang, Zun; Jv, Houyu; Hu, Jingzhou; Ruan, Min; Zhang, Chenping

2018-06-05

The aim of the present study was to investigate whether tumor-derived supernatants down-regulate the immune function of plasmacytoid dendritic cells (pDCs) in oral cancer and the potential molecular mechanisms of this effect. Immunohistochemistry (IHC) and flow cytometry were used to detect tumor-infiltrating and peripheral blood pDCs. MTS and flow cytometry were employed to evaluate the immune response of CD4 + T cells. Real-time PCR and ELISA assays were used to identify TLR-7 and TLR-9 expression, IFN-α production and tumor-secreted soluble cytokines. The proportion of pDCs (0.121%±0.043%) was significantly higher in Oral squamous cell carcinoma (OSCC) samples than in normal tissue (0.023%±0.016%) (P = 0.021). TLR9 mRNA was significantly lower in tumor-infiltrating pDCs and positively correlated to low IFN-α production (r = 0.956; P<0.01). The supernatant of oral cancer cells negatively regulated TLR9 mRNA expression and the subsequent IFN-α production of pDCs, which inhibited the immune response of CD4 + T cells. The neutralizing antibodies blocking assay showed that the specific inhibitory effect of pDC functionality was associated with the soluble fraction of the oral cancer environment, which is mainly mediated by IL-10 and TGF-β cooperation. Tumor-derived supernatants may impair the function of tumor-infiltrating pDCs, which subsequently decreases the immune response of CD4 + T cells in human oral cancer through TGF-β- and IL-10- dependent mechanisms. Careful manipulation of these impaired pDCs may help develop an important alternative immunotherapy for the treatment of oral cancer. Copyright © 2018 Elsevier Ltd. All rights reserved.

Radiation- and Age-Associated Changes in Peripheral Blood Dendritic Cell Populations among Aging Atomic Bomb Survivors in Japan.

PubMed

Kajimura, Junko; Lynch, Heather E; Geyer, Susan; French, Benjamin; Yamaoka, Mika; Shterev, Ivo D; Sempowski, Gregory D; Kyoizumi, Seishi; Yoshida, Kengo; Misumi, Munechika; Ohishi, Waka; Hayashi, Tomonori; Nakachi, Kei; Kusunoki, Yoichiro

2017-11-30

Previous immunological studies in atomic bomb survivors have suggested that radiation exposure leads to long-lasting changes, similar to immunological aging observed in T-cell-adaptive immunity. However, to our knowledge, late effects of radiation on dendritic cells (DCs), the key coordinators for activation and differentiation of T cells, have not yet been investigated in humans. In the current study, we hypothesized that numerical and functional decreases would be observed in relationship to radiation dose in circulating conventional DCs (cDCs) and plasmacytoid DCs (pDCs) among 229 Japanese A-bomb survivors. Overall, the evidence did not support this hypothesis, with no overall changes in DCs or functional changes observed with radiation dose. Multivariable regression analysis for radiation dose, age and gender effects revealed that total DC counts as well as subpopulation counts decreased in relationship to increasing age. Further analyses revealed that in women, absolute numbers of pDCs showed significant decreases with radiation dose. A hierarchical clustering analysis of gene expression profiles in DCs after Toll-like receptor stimulation in vitro identified two clusters of participants that differed in age-associated expression levels of genes involved in antigen presentation and cytokine/chemokine production in cDCs. These results suggest that DC counts decrease and expression levels of gene clusters change with age. More than 60 years after radiation exposure, we also observed changes in pDC counts associated with radiation, but only among women.

Radiation- and Age-Associated Changes in Peripheral Blood Dendritic Cell Populations among Aging Atomic Bomb Survivors in Japan.

PubMed

Kajimura, Junko; Lynch, Heather E; Geyer, Susan; French, Benjamin; Yamaoka, Mika; Shterev, Ivo D; Sempowski, Gregory D; Kyoizumi, Seishi; Yoshida, Kengo; Misumi, Munechika; Ohishi, Waka; Hayashi, Tomonori; Nakachi, Kei; Kusunoki, Yoichiro

2018-01-01

Previous immunological studies in atomic bomb survivors have suggested that radiation exposure leads to long-lasting changes, similar to immunological aging observed in T-cell-adaptive immunity. However, to our knowledge, late effects of radiation on dendritic cells (DCs), the key coordinators for activation and differentiation of T cells, have not yet been investigated in humans. In the current study, we hypothesized that numerical and functional decreases would be observed in relationship to radiation dose in circulating conventional DCs (cDCs) and plasmacytoid DCs (pDCs) among 229 Japanese A-bomb survivors. Overall, the evidence did not support this hypothesis, with no overall changes in DCs or functional changes observed with radiation dose. Multivariable regression analysis for radiation dose, age and gender effects revealed that total DC counts as well as subpopulation counts decreased in relationship to increasing age. Further analyses revealed that in women, absolute numbers of pDCs showed significant decreases with radiation dose. A hierarchical clustering analysis of gene expression profiles in DCs after Toll-like receptor stimulation in vitro identified two clusters of participants that differed in age-associated expression levels of genes involved in antigen presentation and cytokine/chemokine production in cDCs. These results suggest that DC counts decrease and expression levels of gene clusters change with age. More than 60 years after radiation exposure, we also observed changes in pDC counts associated with radiation, but only among women.

Concurrent CCR7 Overexpression and RelB Knockdown in Immature Dendritic Cells Induces Immune Tolerance and Improves Skin-Graft Survival in a Murine Model.

PubMed

Dong, Zhiwei; Chen, Yajie; Peng, Yuan; Wang, Fan; Yang, Zichen; Huang, Guangtao; Chen, Yu; Yuan, Zhiqiang; Cao, Tongtong; Peng, Yizhi

2017-01-01

Skin transplantation aims to cover skin defects but often fails due to immune rejection of the transplantated tissue. Immature dendritic cells (imDCs) induce immune tolerance but have a low migration rate. After stimulation, imDCs transform into mature DCs, which activate immune rejection. Thus, inducing imDC to obtain a high migration counteracts development of immune tolerance. We transfected imDCs with a recombinant adenovirus carrying the CCR7 gene (Ad-CCR7) and a small interfering RNA targeting RelB (RelB-siRNA) to concurrently overexpress CCR7 and downregulate RelB expression. Functionally, such cells showed a significantly enhanced migration rate in the chemotactic assay and decreased T-cell proliferation after lipopolysaccharide stimulation in mixed lymphocyte reactions. Cotransfected cells showed an increased ability to induce immune tolerance by upregulating T regulatory (Treg) cells and shifting the Th1/Th2 ratio. Cotransfection of Ad-CCR7 and RelB-siRNA endowed imDCs with resistance to apoptosis and cell death. CCR7 overexpression and RelB knockdown (KD) in imDCs improve skin-graft survival in a murine skin-transplantation model. Transfection with Ad-CCR7 and RelB KD in imDCs may be an effective approach inducing immune tolerance, thus being potentially valuable for inhibiting allograft rejection. © 2017 The Author(s). Published by S. Karger AG, Basel.

OK-432 synergizes with IFN-γ to confer dendritic cells with enhanced antitumor immunity.

PubMed

Pan, Ke; Lv, Lin; Zheng, Hai-xia; Zhao, Jing-jing; Pan, Qiu-zhong; Li, Jian-jun; Weng, De-sheng; Wang, Dan-dan; Jiang, Shan-shan; Chang, Alfred E; Li, Qiao; Xia, Jian-chuan

2014-03-01

Generation of functional dendritic cells (DCs) with boosted immunity after the withdrawal of initial activation/maturation conditions remains a significant challenge. In this study, we investigated the impact of a newly developed maturation cocktail consisting of OK-432 and interferon-gamma (IFN-γ) on the function of human monocyte-derived DCs (MoDCs). We found that OK-432 plus IFN-γ stimulation could induce significantly stronger expression of surface molecules, production of cytokines, as well as migration of DCs compared with OK-432 stimulation alone. Most importantly, DCs matured with OK-432 plus IFN-γ-induced maintained secretion of interleukin-12 (IL-12)p70 in secondary culture after stimulus withdrawal. Functionally, OK-432 plus IFN-γ-conditioned DCs induce remarkable Th1 and Tc1 responses more effectively than OK-432 alone, even more than the use of α-type-1 cytokine cocktail. As a result, DCs matured with OK-432 plus IFN-γ can prime stronger cytotoxic lymphocyte (CTL) and natural killer (NK) cell response against tumor cells in vitro. Peripheral blood mononuclear cells activated by DCs matured with OK-432 plus IFN-γ also showed greater tumor growth inhibition in vivo in null mice. Molecular mechanistic analysis showed that DC maturation using IFN-γ in concert with OK-432 involves the activation of p38 and nuclear factor-kappa B (NF-κB) pathways. This study provided a novel strategy to generate more potent immune segments in DC vaccine.

Defective IL-10 signaling in hyper-IgE syndrome results in impaired generation of tolerogenic dendritic cells and induced regulatory T cells

PubMed Central

Saito, Masako; Nagasawa, Masayuki; Takada, Hidetoshi; Hara, Toshiro; Tsuchiya, Shigeru; Agematsu, Kazunaga; Yamada, Masafumi; Kawamura, Nobuaki; Ariga, Tadashi; Tsuge, Ikuya; Nonoyama, Shigeaki; Karasuyama, Hajime

2011-01-01

Hyper-IgE syndrome (HIES) is a primary immunodeficiency characterized by recurrent staphylococcal infections and atopic dermatitis associated with elevated serum IgE levels. Although defective differentiation of IL-17–producing CD4+ T cells (Th17) partly accounts for the susceptibility to staphylococcal skin abscesses and pneumonia, the pathogenesis of atopic manifestations in HIES still remains an enigma. In this study, we examined the differentiation and function of Th1, Th2, regulatory T cells (Treg cells), and dendritic cells (DCs) in HIES patients carrying either STAT3 or TYK2 mutations. Although the in vitro differentiation of Th1 and Th2 cells and the number and function of Treg cells in the peripheral blood were normal in HIES patients with STAT3 mutations, primary and monocyte-derived DCs showed defective responses to IL-10 and thus failed to become tolerogenic. When treated with IL-10, patient DCs showed impaired up-regulation of inhibitory molecules on their surface, including PD-L1 and ILT-4, compared with control DCs. Moreover, IL-10–treated DCs from patients displayed impaired ability to induce the differentiation of naive CD4+ T cells to FOXP3+ induced Treg cells (iTreg cells). These results suggest that the defective generation of IL-10–induced tolerogenic DCs and iTreg cells may contribute to inflammatory changes in HIES. PMID:21300911

Dendritic cells limit fibroinflammatory injury in nonalcoholic steatohepatitis in mice.

PubMed

Henning, Justin R; Graffeo, Christopher S; Rehman, Adeel; Fallon, Nina C; Zambirinis, Constantinos P; Ochi, Atsuo; Barilla, Rocky; Jamal, Mohsin; Deutsch, Michael; Greco, Stephanie; Ego-Osuala, Melvin; Bin-Saeed, Usama; Rao, Raghavendra S; Badar, Sana; Quesada, Juan P; Acehan, Devrim; Miller, George

2013-08-01

Nonalcoholic steatohepatitis (NASH) is the most common etiology of chronic liver dysfunction in the United States and can progress to cirrhosis and liver failure. Inflammatory insult resulting from fatty infiltration of the liver is central to disease pathogenesis. Dendritic cells (DCs) are antigen-presenting cells with an emerging role in hepatic inflammation. We postulated that DCs are important in the progression of NASH. We found that intrahepatic DCs expand and mature in NASH liver and assume an activated immune phenotype. However, rather than mitigating the severity of NASH, DC depletion markedly exacerbated intrahepatic fibroinflammation. Our mechanistic studies support a regulatory role for DCs in NASH by limiting sterile inflammation through their role in the clearance of apoptotic cells and necrotic debris. We found that DCs limit CD8(+) T-cell expansion and restrict Toll-like receptor expression and cytokine production in innate immune effector cells in NASH, including Kupffer cells, neutrophils, and inflammatory monocytes. Consistent with their regulatory role in NASH, during the recovery phase of disease, ablation of DC populations results in delayed resolution of intrahepatic inflammation and fibroplasia. Our findings support a role for DCs in modulating NASH. Targeting DC functional properties may hold promise for therapeutic intervention in NASH. Copyright © 2013 American Association for the Study of Liver Diseases.

Differential regulation of interleukin 12 and interleukin 23 production in human dendritic cells

PubMed Central

Gerosa, Franca; Baldani-Guerra, Barbara; Lyakh, Lyudmila A.; Batoni, Giovanna; Esin, Semih; Winkler-Pickett, Robin T.; Consolaro, Maria Rita; De Marchi, Mario; Giachino, Daniela; Robbiano, Angela; Astegiano, Marco; Sambataro, Angela; Kastelein, Robert A.; Carra, Giuseppe; Trinchieri, Giorgio

2008-01-01

We analyzed interleukin (IL) 12 and IL-23 production by monocyte-derived dendritic cells (mono-DCs). Mycobacterium tuberculosis H37Rv and zymosan preferentially induced IL-23. IL-23 but not IL-12 was efficiently induced by the combination of nucleotide-binding oligodimerization domain and Toll-like receptor (TLR) 2 ligands, which mimics activation by M. tuberculosis, or by the human dectin-1 ligand β-glucan alone or in combination with TLR2 ligands, mimicking induction by zymosan. TLR2 ligands inhibited IL-12 and increased IL-23 production. DC priming with interferon (IFN) γ strongly increased IL-12 production, but was not required for IL-23 production and inhibited IL-23 production induced by β-glucan. The pattern of IL-12 and IL-23 induction was reflected in accumulation of the IL-12p35 and IL-23p19 transcripts, respectively, but not IL-12/23p40. Although IL-23, transforming growth factor β, and IL-6 contained in the supernatants of activated mono-DCs played a role in the induction of IL-17 by human CD4+ T cells, IL-1β, in combination with one or more of those factors, was required for IL-17 production, and its production determined the differential ability of the stimuli used to elicit mono-DCs to produce soluble factors directing IL-17 production. Thus, the differential ability of pathogens to induce antigen-presenting cells to produce cytokines regulates the immune response to infection. PMID:18490488

Coregulatory Interactions among CD8α Dendritic Cells, the Latency-Associated Transcript, and Programmed Death 1 Contribute to Higher Levels of Herpes Simplex Virus 1 Latency

PubMed Central

Mott, Kevin R.; Allen, Sariah J.; Zandian, Mandana

2014-01-01

ABSTRACT The latency-associated transcript (LAT) of herpes simplex virus 1 (HSV-1), CD8α+ dendritic cells (DCs), and programmed death 1 (PD-1) have all been implicated in the HSV-1 latency-reactivation cycle. It is not known, however, whether an interaction between LAT and CD8α+ DCs regulates latency and T-cell exhaustion. To address this question, we used LAT-expressing [LAT(+)] and LAT-negative [LAT(−)] viruses. Depletion of DCs in mice ocularly infected with LAT(+) virus resulted in a reduction in the number of T cells expressing PD-1 in the trigeminal ganglia (TG), whereas depletion of DCs in mice similarly infected with LAT(−) virus did not alter PD-1 expression. CD8α+ DCs, but not CD4+ DCs, infected with LAT(+) virus had higher levels of ICP0, ICP4, thymidine kinase (TK), and PD-1 ligand 1 (PD-L1) transcripts than those infected with LAT(−) virus. Coculture of infected bone marrow (BM)-derived DCs from wild-type (WT) mice, but not infected DCs from CD8α−/− mice, with WT naive T cells contributed to an increase in PD-1 expression. Transfer of bone marrow from WT mice but not CD8α−/− mice to recipient Rag1−/− mice increased the number of latent viral genomes in reconstituted mice infected with the LAT(+) virus. Collectively, these data indicated that a reduction in latency correlated with a decline in the levels of CD8α+ DCs and PD-1 expression. In summary, our results demonstrate an interaction among LAT, PD-1, and CD11c CD8α+ cells that regulates latency in the TG of HSV-1-infected mice. IMPORTANCE Very little is known regarding the interrelationship of LAT, PD-1, and CD8α+ DCs and how such interactions might contribute to relative numbers of latent viral genomes. We show here that (i) in both in vivo and in vitro studies, deficiency of CD8α+ DCs significantly reduced T-cell exhaustion in the presence of LAT(+) virus but not LAT(−) virus; (ii) HSV-1 infectivity was significantly lower in LAT(−)-infected DCs than in their LAT(+)-infected counterparts; and (iii) adoptive transfer of bone marrow (BM) from WT but not CD8α−/− mice to recipient Rag1−/− mice restored latency to the level in WT mice following infection with LAT(+) virus. These studies point to a key role for CD8α+ DCs in T-cell exhaustion in the presence of LAT, which leads to larger numbers of latent viral genomes. Thus, altering this negative function of CD8α+ DCs can potentially be used to generate a more effective vaccine against HSV infection. PMID:24672046

Macrophages are required for dendritic cell uptake of respiratory syncytial virus from an infected epithelium.

PubMed

Ugonna, Kelechi; Bingle, Colin D; Plant, Karen; Wilson, Kirsty; Everard, Mark L

2014-01-01

We have previously shown that the respiratory syncytial virus [RSV] can productively infect monocyte derived dendritic cells [MoDC] and remain dormant within the same cells for prolonged periods. It is therefore possible that infected dendritic cells act as a reservoir within the airways of individuals between annual epidemics. In the present study we explored the possibility that sub-epithelial DCs can be infected with RSV from differentiated bronchial epithelium and that in turn RSV from DCs can infect the epithelium. A dual co-culture model was established in which a differentiated primary airway epithelium on an Air Liquid Interface (ALI) was cultured on a transwell insert and MoDCs were subsequently added to the basolateral membrane of the insert. Further experiments were undertaken using a triple co-culture model in which in which macrophages were added to the apical surface of the differentiated epithelium. A modified RSV [rr-RSV] expressing a red fluorescent protein marker of replication was used to infect either the MoDCs or the differentiated epithelium and infection of the reciprocal cell type was assessed using confocal microscopy. Our data shows that primary epithelium became infected when rr-RSV infected MoDCs were introduced onto the basal surface of the transwell insert. MoDCs located beneath the epithelium did not become infected with virus from infected epithelial cells in the dual co-culture model. However when macrophages were present on the apical surface of the primary epithelium infection of the basal MoDCs occurred. Our data suggests that RSV infected dendritic cells readily transmit infection to epithelial cells even when they are located beneath the basal layer. However macrophages appear to be necessary for the transmission of infection from epithelial cells to basal dendritic cells.

The Role of Dendritic Cell Maturation in the Induction of Insulin-Dependent Diabetes Mellitus.

PubMed

Mbongue, Jacques C; Nieves, Hector A; Torrez, Timothy W; Langridge, William H R

2017-01-01

Dendritic cells (DCs) are the dominant class of antigen-presenting cells in humans and are largely responsible for the initiation and guidance of innate and adaptive immune responses involved in maintenance of immunological homeostasis. Immature dendritic cells (iDCs) phagocytize pathogens and toxic proteins and in endosomal vesicles degrade them into small fragments for presentation on major histocompatibility complex (MHC) II receptor molecules to naïve cognate T cells (Th0). In addition to their role in stimulation of immunity, DCs are involved in the induction and maintenance of immune tolerance toward self-antigens. During activation, the iDCs become mature. Maturation begins when the DCs cease taking up antigens and begin to migrate from their location in peripheral tissues to adjacent lymph nodes or the spleen where during their continued maturation the DCs present stored antigens on surface MHCII receptor molecules to naive Th0 cells. During antigen presentation, the DCs upregulate the biosynthesis of costimulatory receptor molecules CD86, CD80, CD83, and CD40 on their plasma membrane. These activated DC receptor molecules bind cognate CD28 receptors presented on the Th0 cell membrane, which triggers DC secretion of IL-12 or IL-10 cytokines resulting in T cell differentiation into pro- or anti-inflammatory T cell subsets. Although basic concepts involved in the process of iDC activation and guidance of Th0 cell differentiation have been previously documented, they are poorly defined. In this review, we detail what is known about the process of DC maturation and its role in the induction of insulin-dependent diabetes mellitus autoimmunity.

Dexmedetomidine Inhibits Maturation and Function of Human Cord Blood-Derived Dendritic Cells by Interfering with Synthesis and Secretion of IL-12 and IL-23

PubMed Central

Chen, Gong; Le, Yuan; Zhou, Lei; Gong, Li; Li, Xiaoxiao; Li, Yunli; Liao, Qin; Duan, Kaiming; Tong, Jianbin; Ouyang, Wen

2016-01-01

Aims To investigate the effects and underlying mechanism of dexmedetomidine on the cultured human dendritic cells (DCs). Methods Human DCs and cytotoxic T lymphocytes (CTLs) were obtained from human cord blood mononuclear cells by density gradient centrifugation. Cultured DCs were divided into three groups: dexmedetomidine group, dexmedetomidine plus yohimbine (dexmedetomidine inhibitor) group and control group. DCs in the three groups were treated with dexmedetomidine, dexmedetomidine plus yohimbine and culture medium, respectively. After washing, the DCs were co-incubated with cultured CTLs. The maturation degree of DCs was evaluated by detecting (1) the ratios of HLA-DR-, CD86-, and CD80-positive cells (flow cytometry), and (2) expression of IL-12 and IL-23 (PCR and Elisa). The function of DCs was evaluated by detecting the proliferation (MTS assay) and cytotoxicity activity (the Elisa of IFN-γ) of CTLs. In addition, in order to explore the mechanisms of dexmedetomidine modulating DCs, α2-adrenergic receptor and its downstream signals in DCs were also detected. Results The ratios of HLA-DR-, CD86-, and CD80-positive cells to total cells were similar among the three groups (P>0.05). Compared to the control group, the protein levels of IL-12 and IL-23 in the culture medium and the mRNA levels of IL-12 p35, IL-12 p40 and IL-23 p19 in the DCs all decreased in dexmedetomidine group (P<0.05). In addition, the proliferation of CTLs and the secretion of IFN-γ also decreased in the dexmedetomidine group, compared with the control group (P<0.05). Moreover, these changes induced by dexmedetomidine in the dexmedetomidine group were reversed by α2-adrenergic receptor inhibitor yohimbine in the dexmedetomidine plus yohimbine group. It was also found the decrease of mRNA levels of IL-12 p35, IL-12 p40 and IL-23 p19 in the dexmedetomidine group could be reversed by ERK1/2 or AKT inhibitors. Conclusion Dexmedetomidine could negatively modulate human immunity by inhibiting the maturation of DCs and then decreasing the proliferation and cytotoxicity activity of CTLs. The α2-adrenergic receptors and its downstream molecules ERK1/2 and AKT are closely involved in the modulation of dexmedetomidine on DCs. PMID:27054340

Dendritic cells induce specific cytotoxic T lymphocytes against prostate cancer TRAMP-C2 cells loaded with freeze- thaw antigen and PEP-3 peptide.

PubMed

Liu, Xiao-Qi; Jiang, Rong; Li, Si-Qi; Wang, Jing; Yi, Fa-Ping

2015-01-01

Prostate cancer is the most common cancer in men. In this study, we investigated immune responses of cytotoxic T lymphocytes (CTLs) against TRAMP-C2 prostate cancer cells after activation by dendritic cells (DCs) loaded with TRAMP-C2 freeze-thaw antigen and/or PEP-3 peptide in vitro. Bone marrow-derived DC from the bone marrow of the C57BL/6 were induced to mature by using the cytokine of rhGM-CSF and rhIL-4, and loaded with either the freeze-thaw antigen or PEP-3 peptide or both of them. Maturation of DCs was detected by flow cytometry. The killing efficiency of the CTLs on TRAMP-C2 cells were detected by flow cytometry, CCK8, colony formation, transwell migration, and wound-healing assay. The levels of the IFN-γ, TNF-β and IL-12 were measured by enzyme-linked immunosorbent assay (ELISA). Compared with the unloaded DCs, the loaded DCs had significantly increased expression of several phenotypes related to DC maturation. CTLs activated by DCs loaded with freeze-thaw antigen and PEP-3 peptide had more evident cytotoxicity against TRAMP-C2 cells in vitro. The secretion levels of IFN-γ, TNF-β and IL-12, secreted by DCs loaded with antigen and PEP-3 and interaction with T cells, were higher than in the other groups. Our results suggest that the CTLs activated by DCs loaded with TRAMP-C2 freeze-thaw antigen and PEP-3 peptide exert a remarkable killing efficiency against TRAMP-C2 cells in vitro.

Induction of anti-HBs in HB vaccine nonresponders in vivo by hepatitis B surface antigen-pulsed blood dendritic cells.

PubMed

Fazle Akbar, Sk Md; Furukawa, Shinya; Yoshida, Osamu; Hiasa, Yoichi; Horiike, Norio; Onji, Morikazu

2007-07-01

Antigen-pulsed dendritic cells (DCs) are now used for treatment of patients with cancers, however, the efficacy of these DCs has never been evaluated for prophylactic purposes. The aim of this study was (1) to prepare hepatitis B surface antigen (HBsAg)-pulsed human blood DCs, (2) to assess immunogenicity of HBsAg-pulsed DCs in vitro and (3) to evaluate the efficacy of HBsAg-pulsed DCs in hepatitis B (HB) vaccine nonresponders. Human peripheral blood DCs were cultured with HBsAg to prepare HBsAg-pulsed DCs. The expression of immunogenic epitopes of HBsAg on HBsAg-pulsed DCs was assessed in vitro. Finally, HBsAg-pulsed DCs were administered, intradermally to six HB vaccine nonresponders and the levels of antibody to HBsAg (anti-HBs) in the sera were assessed. HB vaccine nonresponders did not exhibit features of immediate, early or delayed adverse reactions due to administration of HBsAg-pulsed DCs. Anti-HBs were detected in the sera of all HB vaccine nonresponders within 28 days after administration of HBsAg-pulsed DCs. This study opens a new field of application of antigen-pulsed DCs for prophylactic purposes when adequate levels of protective antibody cannot be induced by traditional vaccination approaches.

3D Microfluidic model for evaluating immunotherapy efficacy by tracking dendritic cell behaviour toward tumor cells.

PubMed

Parlato, Stefania; De Ninno, Adele; Molfetta, Rosa; Toschi, Elena; Salerno, Debora; Mencattini, Arianna; Romagnoli, Giulia; Fragale, Alessandra; Roccazzello, Lorenzo; Buoncervello, Maria; Canini, Irene; Bentivegna, Enrico; Falchi, Mario; Bertani, Francesca Romana; Gerardino, Annamaria; Martinelli, Eugenio; Natale, Corrado; Paolini, Rossella; Businaro, Luca; Gabriele, Lucia

2017-04-24

Immunotherapy efficacy relies on the crosstalk within the tumor microenvironment between cancer and dendritic cells (DCs) resulting in the induction of a potent and effective antitumor response. DCs have the specific role of recognizing cancer cells, taking up tumor antigens (Ags) and then migrating to lymph nodes for Ag (cross)-presentation to naïve T cells. Interferon-α-conditioned DCs (IFN-DCs) exhibit marked phagocytic activity and the special ability of inducing Ag-specific T-cell response. Here, we have developed a novel microfluidic platform recreating tightly interconnected cancer and immune systems with specific 3D environmental properties, for tracking human DC behaviour toward tumor cells. By combining our microfluidic platform with advanced microscopy and a revised cell tracking analysis algorithm, it was possible to evaluate the guided efficient motion of IFN-DCs toward drug-treated cancer cells and the succeeding phagocytosis events. Overall, this platform allowed the dissection of IFN-DC-cancer cell interactions within 3D tumor spaces, with the discovery of major underlying factors such as CXCR4 involvement and underscored its potential as an innovative tool to assess the efficacy of immunotherapeutic approaches.

Antigen-specific immature dendritic cell vaccine ameliorates anti-dsDNA antibody-induced renal damage in a mouse model.

PubMed

Xia, Yumin; Jiang, Shan; Weng, Shenhong; Lv, Xiaochun; Cheng, Hong; Fang, Chunhong

2011-12-01

Dendritic cells (DCs) can inhibit immune response by clonal anergy when immature. Recent studies have shown that immature DCs (iDCs) may serve as a live cell vaccine after specific antigen pulse based on its potential of blocking antibody production. In this study, we aimed to investigate the effects of nuclear antigen-pulsed iDCs in the treatment of lupus-like renal damages induced by anti-dsDNA antibodies. iDCs were generated from haemopoietic stem cells in bone marrow and then pulsed in vitro with nuclear antigen. The iDC vaccine and corresponding controls were injected into mice with lupus-like renal damages. The evaluation of disease was monitored by biochemical parameters and histological scores. Anti-dsDNA antibody isotypes and T-lymphocyte-produced cytokines were analysed for elucidating therapeutic mechanisms. RESULTS; The mice treated with antigen-pulsed iDCs had a sustained remission of renal damage compared with those injected with non-pulsed iDCs or other controls, including decreased anti-dsDNA antibody level, less proteinuria, lower blood urea nitrogen and serum creatinine values, and improved histological evaluation. Analysis on isotypes of anti-dsDNA antibody showed that iDC vaccine preferentially inhibited the production of IgG3, IgG2b and IgG2a. Furthermore, administration of antigen-treated iDCs to mice resulted in significantly reduced IL-2, IL-4 and IL-12 and IFN-γ produced by T-memory cells. Conversely, the vaccination of antigen-pulsed mature DCs led to increased anti-dsDNA antibody production and an aggravation of lupus-like disease in the model. CONCLUSIONS; These results suggested the high potency of iDC vaccine in preventing lupus-like renal injuries induced by pathogenic autoantibodies.

Dendritic cell chimerism in oral mucosa of transplanted patients affected by graft-versus-host disease.

PubMed

Pérez, Claudio A; Rabanales, Ramón; Rojas-Alcayaga, Gonzalo; Larrondo, Milton; Escobar, Alejandro F; López, Mercedes N; Salazar-Onfray, Flavio; Alfaro, Jorge I; González, Fermín E

2016-02-01

Graft-versus-host disease (GVHD) is one of the main complications after haematopoietic stem cell transplantation. Clinical features of GVHD include either an acute (aGVHD) or a chronic (cGVHD) condition that affects locations such as the oral mucosa. While the involvement of the host's dendritic cells (DCs) has been demonstrated in aGVHD, the origin (donor/host) and mechanisms underlying oral cGVHD have not been completely elucidated. In this study, we intend to determine the origin of DCs present in mucosal tissue biopsies from the oral cavity of transplanted patients affected by cGVHD. We purified DCs, from oral biopsies of three patients with cGVHD, through immunobeads and subsequently performed DNA extraction. The origin of the obtained DCs was determined by PCR amplification of 13 informative short tandem repeat (STR) alleles. We also characterised the DCs phenotype and the inflammatory infiltrate from biopsies of two patients by immunohistochemistry. Clinical and histological features of the biopsies were concordant with oral cGVHD. We identified CD11c-, CD207- and CD1a-positive cells in the epithelium and beneath the basal layer. Purification of DCs from the mucosa of patients affected by post-transplantation cGVHD was >95%. PCR-STR data analysis of DCs DNA showed that 100% of analysed cells were of donor origin in all of the evaluated patients. Our results demonstrate that resident DCs isolated from the oral tissue of allotransplanted patients affected by cGVHD are originated from the donor. Further research will clarify the role of DCs in the development and/or severity of oral cGVHD. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Dual TLR2/9 Recognition of Herpes Simplex Virus Infection Is Required for Recruitment and Activation of Monocytes and NK Cells and Restriction of Viral Dissemination to the Central Nervous System

PubMed Central

Uyangaa, Erdenebileg; Choi, Jin Young; Patil, Ajit Mahadev; Hossain, Ferdaus Mohd Altaf; Park, Sung OK; Kim, Bumseok; Kim, Koanhoi; Eo, Seong Kug

2018-01-01

The importance of TLR2 and TLR9 in the recognition of infection with herpes simplex virus (HSV) and HSV-caused diseases has been described, but some discrepancies remain concerning the benefits of these responses. Moreover, the impact of TLR2/9 on innate and adaptive immune responses within relevant mucosal tissues has not been elucidated using natural mucosal infection model of HSV. Here, we demonstrate that dual TLR2/9 recognition is essential to provide resistance against mucosal infection with HSV via an intravaginal route. Dual TLR2/9 ablation resulted in the highly enhanced mortality with exacerbated symptoms of encephalitis compared with TLR2 or TLR9 deficiency alone, coinciding with highly increased viral load in central nervous system tissues. TLR2 appeared to play a minor role in providing resistance against mucosal infection with HSV, since TLR2-ablated mice showed higher survival rate compared with TLR9-ablated mice. Also, the high mortality in dual TLR2/9-ablated mice was closely associated with the reduction in early monocyte and NK cell infiltration in the vaginal tract (VT), which was likely to correlate with low expression of cytokines and CCR2 ligands (CCL2 and CCL7). More interestingly, our data revealed that dual TLR2/9 recognition of HSV infection plays an important role in the functional maturation of TNF-α and iNOS-producing dendritic cells (Tip-DCs) from monocytes as well as NK cell activation in VT. TLR2/9-dependent maturation of Tip-DCs from monocytes appeared to specifically present cognate Ag, which effectively provided functional effector CD4+ and CD8+ T cells specific for HSV Ag in VT and its draining lymph nodes. TLR2/9 expressed in monocytes was likely to directly facilitate Tip-DC-like features after HSV infection. Also, dual TLR2/9 recognition of HSV infection directly activated NK cells without the aid of dendritic cells through activation of p38 MAPK pathway. Taken together, these results indicate that dual TLR2/9 recognition plays a critical role in providing resistance against mucosal infection with HSV, which may involve a direct regulation of Tip-DCs and NK cells in VT. Therefore, our data provide a more detailed understanding of TLR2/9 role in conferring antiviral immunity within relevant mucosal tissues after mucosal infection with HSV. PMID:29760708

Dual TLR2/9 Recognition of Herpes Simplex Virus Infection Is Required for Recruitment and Activation of Monocytes and NK Cells and Restriction of Viral Dissemination to the Central Nervous System.

PubMed

Uyangaa, Erdenebileg; Choi, Jin Young; Patil, Ajit Mahadev; Hossain, Ferdaus Mohd Altaf; Park, Sung Ok; Kim, Bumseok; Kim, Koanhoi; Eo, Seong Kug

2018-01-01

The importance of TLR2 and TLR9 in the recognition of infection with herpes simplex virus (HSV) and HSV-caused diseases has been described, but some discrepancies remain concerning the benefits of these responses. Moreover, the impact of TLR2/9 on innate and adaptive immune responses within relevant mucosal tissues has not been elucidated using natural mucosal infection model of HSV. Here, we demonstrate that dual TLR2/9 recognition is essential to provide resistance against mucosal infection with HSV via an intravaginal route. Dual TLR2/9 ablation resulted in the highly enhanced mortality with exacerbated symptoms of encephalitis compared with TLR2 or TLR9 deficiency alone, coinciding with highly increased viral load in central nervous system tissues. TLR2 appeared to play a minor role in providing resistance against mucosal infection with HSV, since TLR2-ablated mice showed higher survival rate compared with TLR9-ablated mice. Also, the high mortality in dual TLR2/9-ablated mice was closely associated with the reduction in early monocyte and NK cell infiltration in the vaginal tract (VT), which was likely to correlate with low expression of cytokines and CCR2 ligands (CCL2 and CCL7). More interestingly, our data revealed that dual TLR2/9 recognition of HSV infection plays an important role in the functional maturation of TNF-α and iNOS-producing dendritic cells (Tip-DCs) from monocytes as well as NK cell activation in VT. TLR2/9-dependent maturation of Tip-DCs from monocytes appeared to specifically present cognate Ag, which effectively provided functional effector CD4 + and CD8 + T cells specific for HSV Ag in VT and its draining lymph nodes. TLR2/9 expressed in monocytes was likely to directly facilitate Tip-DC-like features after HSV infection. Also, dual TLR2/9 recognition of HSV infection directly activated NK cells without the aid of dendritic cells through activation of p38 MAPK pathway. Taken together, these results indicate that dual TLR2/9 recognition plays a critical role in providing resistance against mucosal infection with HSV, which may involve a direct regulation of Tip-DCs and NK cells in VT. Therefore, our data provide a more detailed understanding of TLR2/9 role in conferring antiviral immunity within relevant mucosal tissues after mucosal infection with HSV.

Lung dendritic cells imprint T cell lung homing and promote lung immunity through the chemokine receptor CCR4

PubMed Central

Strassner, James P.

2013-01-01

T cell trafficking into the lung is critical for lung immunity, but the mechanisms that mediate T cell lung homing are not well understood. Here, we show that lung dendritic cells (DCs) imprint T cell lung homing, as lung DC–activated T cells traffic more efficiently into the lung in response to inhaled antigen and at homeostasis compared with T cells activated by DCs from other tissues. Consequently, lung DC–imprinted T cells protect against influenza more effectively than do gut and skin DC–imprinted T cells. Lung DCs imprint the expression of CCR4 on T cells, and CCR4 contributes to T cell lung imprinting. Lung DC–activated, CCR4-deficient T cells fail to traffic into the lung as efficiently and to protect against influenza as effectively as lung DC–activated, CCR4-sufficient T cells. Thus, lung DCs imprint T cell lung homing and promote lung immunity in part through CCR4. PMID:23960189

Synovial T cell hyporesponsiveness to myeloid dendritic cells is reversed by preventing PD-1/PD-L1 interactions.

PubMed

Moret, Frederique M; van der Wurff-Jacobs, Kim M G; Bijlsma, Johannes W J; Lafeber, Floris P J G; van Roon, Joel A G

2014-11-30

The aim of this study was to investigate PD-1/PD-L1 involvement in the hyporesponsiveness of rheumatoid arthritis (RA) synovial fluid (SF) CD4 T cells upon stimulation by thymic stromal lymphopoietin (TSLP)-primed CD1c myeloid dendritic cells (mDCs). Expression of PD-1 on naïve (Tn), central memory (Tcm) and effector memory (Tem) CD4 T cell subsets was assessed by flow cytometry. PD-L1 expression and its regulation upon TSLP stimulation of mDCs from peripheral blood (PB) and SF of RA patients were investigated by quantitative RT-PCR and flow cytometry. The involvement of PD-1/PD-L1 interactions in SF T cell hyporesponsiveness upon (TSLP-primed) mDC activation was determined by cell culture in the presence of PD-1 blocking antibodies, with or without interleukin 7 (IL-7) as a recognized suppressor of PD-1 expression. PD-1 expression was increased on CD4 T cells derived from SF compared with PB of RA patients. TSLP increased PD-L1 mRNA expression in both PB and SF mDCs. PD-L1 protein expression was increased on SF mDCs compared with PB mDCs and was associated with T cell hyporesponsiveness. Blockade of PD-1, as well as IL-7 stimulation, during cocultures of memory T cells and (TSLP-primed) mDCs from RA patients significantly recovered T cell proliferation. SF T cell hyporesponsiveness upon (TSLP-primed) mDC stimulation in RA joints is partially dependent on PD-1/PD-L1 interactions, as PD-1 and PD-L1 are both highly expressed on SF T cells and mDCs, respectively, and inhibiting PD-1 availability restores T cell proliferation. The potential of IL-7 to robustly reverse this hyporesponsiveness suggests that such proinflammatory cytokines in RA joints strongly contribute to memory T cell activation.

Ibrutinib enhances IL-17 response by modulating the function of bone marrow derived dendritic cells

PubMed Central

Natarajan, Gayathri; Terrazas, Cesar; Oghumu, Steve; Varikuti, Sanjay; Dubovsky, Jason A; Byrd, John C; Satoskar, Abhay R

2016-01-01

Ibrutinib (PCI-32765) is an irreversible dual Btk/Itk inhibitor shown to be effective in treating several B cell malignancies. However, limited studies have been conducted to study the effect of this drug on myeloid cell function. Hence, we studied the effect of ibrutinib treatment on TLR-4 mediated activation of bone marrow derived dendritic cell culture (DCs). Upon ibrutinib treatment, LPS-treated DCs displayed lower synthesis of TNF-α and nitric oxide (NO) and higher induction of IL-6, TGF-β, IL-10 and IL-18. While ibrutinib dampened MHC-II and CD86 expression on DCs, CD80 expression was upregulated. Further, ibrutinib-treated DCs promoted T cell proliferation and enhanced IL-17 production upon co-culture with nylon wool enriched T cells. Taken together, our results indicate that ibrutinib modulates TLR-4 mediated DC activation to promote an IL-17 response. We describe a novel mode of action for ibrutinib on DCs which should be explored to treat other forms of cancer besides B cell malignancies. PMID:26942065

Intracerebral dendritic cells critically modulate encephalitogenic versus regulatory immune responses in the CNS

PubMed Central

Zozulya, Alla L.; Ortler, Sonja; Lee, JangEun; Weidenfeller, Christian; Sandor, Matyas; Wiendl, Heinz; Fabry, Zsuzsanna

2010-01-01

Dendritic cells (DCs) appear in higher numbers within the CNS as a consequence of inflammation associated with autoimmune disorders, such as multiple sclerosis (MS), but the contribution of these cells to the outcome of disease is not yet clear. Here we show that stimulatory or tolerogenic functional states of intracerebral DCs regulate the systemic activation of neuroantigen-specific T cells, the recruitment of these cells into the CNS and the onset and progression of experimental autoimmune encephalomyelitis (EAE). Intracerebral microinjection of stimulatory DCs exacerbated the onset and clinical course of EAE, accompanied with an early T-cell infiltration and a decreased proportion of regulatory FoxP3-expressing cells in the brain. In contrast, the intracerebral microinjection of DCs modified by tumor necrosis factor alpha (TNF-α) induced their tolerogenic functional state and delayed or prevented EAE onset. This triggered the generation of interleukin 10 (IL-10)-producing neuroantigen-specific lymphocytes in the periphery and restricted IL-17 production in the CNS. Our findings suggest that DCs are a rate-limiting factor for neuroinflammation. PMID:19129392

Ibrutinib enhances IL-17 response by modulating the function of bone marrow derived dendritic cells.

PubMed

Natarajan, Gayathri; Terrazas, Cesar; Oghumu, Steve; Varikuti, Sanjay; Dubovsky, Jason A; Byrd, John C; Satoskar, Abhay R

Ibrutinib (PCI-32765) is an irreversible dual Btk/Itk inhibitor shown to be effective in treating several B cell malignancies. However, limited studies have been conducted to study the effect of this drug on myeloid cell function. Hence, we studied the effect of ibrutinib treatment on TLR-4 mediated activation of bone marrow derived dendritic cell culture (DCs). Upon ibrutinib treatment, LPS-treated DCs displayed lower synthesis of TNF-α and nitric oxide (NO) and higher induction of IL-6, TGF-β, IL-10 and IL-18. While ibrutinib dampened MHC-II and CD86 expression on DCs, CD80 expression was upregulated. Further, ibrutinib-treated DCs promoted T cell proliferation and enhanced IL-17 production upon co-culture with nylon wool enriched T cells. Taken together, our results indicate that ibrutinib modulates TLR-4 mediated DC activation to promote an IL-17 response. We describe a novel mode of action for ibrutinib on DCs which should be explored to treat other forms of cancer besides B cell malignancies.

Multi-session transcranial direct current stimulation (tDCS) elicits inflammatory and regenerative processes in the rat brain.

PubMed

Rueger, Maria Adele; Keuters, Meike Hedwig; Walberer, Maureen; Braun, Ramona; Klein, Rebecca; Sparing, Roland; Fink, Gereon Rudolf; Graf, Rudolf; Schroeter, Michael

2012-01-01

Transcranial direct current stimulation (tDCS) is increasingly being used in human studies as an adjuvant tool to promote recovery of function after stroke. However, its neurobiological effects are still largely unknown. Electric fields are known to influence the migration of various cell types in vitro, but effects in vivo remain to be shown. Hypothesizing that tDCS might elicit the recruitment of cells to the cortex, we here studied the effects of tDCS in the rat brain in vivo. Adult Wistar rats (n = 16) were randomized to either anodal or cathodal stimulation for either 5 or 10 consecutive days (500 µA, 15 min). Bromodeoxyuridine (BrdU) was given systemically to label dividing cells throughout the experiment. Immunohistochemical analyses ex vivo included stainings for activated microglia and endogenous neural stem cells (NSC). Multi-session tDCS with the chosen parameters did not cause a cortical lesion. An innate immune response with early upregulation of Iba1-positive activated microglia occurred after both cathodal and anodal tDCS. The involvement of adaptive immunity as assessed by ICAM1-immunoreactivity was less pronounced. Most interestingly, only cathodal tDCS increased the number of endogenous NSC in the stimulated cortex. After 10 days of cathodal stimulation, proliferating NSC increased by ∼60%, with a significant effect of both polarity and number of tDCS sessions on the recruitment of NSC. We demonstrate a pro-inflammatory effect of both cathodal and anodal tDCS, and a polarity-specific migratory effect on endogenous NSC in vivo. Our data suggest that tDCS in human stroke patients might also elicit NSC activation and modulate neuroinflammation.

HMGB1 Is Involved in IFN-α Production and TRAIL Expression by HIV-1-Exposed Plasmacytoid Dendritic Cells: Impact of the Crosstalk with NK Cells.

PubMed

Saïdi, Héla; Bras, Marlène; Formaglio, Pauline; Melki, Marie-Thérèse; Charbit, Bruno; Herbeuval, Jean-Philippe; Gougeon, Marie-Lise

2016-02-01

Plasmacytoid dendritic cells (pDCs) are innate sensors of viral infections and important mediators of antiviral innate immunity through their ability to produce large amounts of IFN-α. Moreover, Toll-like receptor 7 (TLR7) and 9 (TLR9) ligands, such as HIV and CpG respectively, turn pDCs into TRAIL-expressing killer pDCs able to lyse HIV-infected CD4+ T cells. NK cells can regulate antiviral immunity by modulating pDC functions, and pDC production of IFN-α as well as cell-cell contact is required to promote NK cell functions. Impaired pDC-NK cell crosstalk was reported in the setting of HIV-1 infection, but the impact of HIV-1 on TRAIL expression and innate antiviral immunity during this crosstalk is unknown. Here, we report that low concentrations of CCR5-tropic HIV-1Ba-L promote the release of pro-inflammatory cytokines such as IFN-α, TNF-α, IFN-γ and IL-12, and CCR5-interacting chemokines (MIP-1α and MIP-1β) in NK-pDCs co-cultures. At high HIV-1BaL concentrations, the addition of NK cells did not promote the release of these mediators, suggesting that once efficiently triggered by the virus, pDCs could not integrate new activating signals delivered by NK cells. However, high HIV-1BaL concentrations were required to trigger IFN-α-mediated TRAIL expression at the surface of both pDCs and NK cells during their crosstalk. Interestingly, we identified the alarmin HMGB1, released at pDC-NK cell synapse, as an essential trigger for the secretion of IFN-α and IFN-related soluble mediators during the interplay of HIV-1 exposed pDCs with NK cells. Moreover, HMGB1 was found crucial for mTRAIL translocation to the plasma membrane of both pDCs and NK cells during their crosstalk following pDC exposure to HIV-1. Data from serum analyses of circulating HMGB1, HMGB1-specific antibodies, sTRAIL and IP-10 in a cohort of 67 HIV-1+ patients argue for the in vivo relevance of these observations. Altogether, these findings identify HMGB1 as a trigger for IFN-α-mediated TRAIL expression at the surface of pDCs and NK cells, and they suggest a novel mechanism of innate control of HIV-1 infection.

Murine CD103+ dendritic cells protect against steatosis progression towards steatohepatitis.

PubMed

Heier, Eva-Carina; Meier, Anna; Julich-Haertel, Henrike; Djudjaj, Sonja; Rau, Monica; Tschernig, Thomas; Geier, Andreas; Boor, Peter; Lammert, Frank; Lukacs-Kornek, Veronika

2017-06-01

Non-alcoholic fatty liver (NAFL) is the hepatic consequence of metabolic syndrome and can progress to non-alcoholic steatohepatitis (NASH). The identification of molecular and cellular factors that determine the progression of NASH and lead to irreversible hepatocellular damage are crucial. Dendritic cells (DCs) represent a heterogeneous cell population among which CD103 + DCs play a significant role in immunity and tolerance. We aimed to clarify the role of this DC subset in the pathomechanism of NASH. Steatosis progression towards steatohepatitis was analysed using multicolor FACS analyses, cytokine and qPCR array in high sucrose diet (HSD) and methionine and choline deficient diet (MCD) fed wild-type and basic leucine zipper transcription factor, ATF-Like-3 (Batf3) deficient animals, which lack CD103 + DCs (classical type-1 DC, cDC1s). Metabolic challenge of Batf3 -/- animals resulted in the progression of steatosis towards steatohepatitis, manifesting by an increased influx of inflammatory cells into the liver and elevated inflammatory cytokine production of myeloid cells upon innate stimuli. However, the lack of cDC1s did not affect cellular apoptosis and fibrosis progression but altered genes involved in lipid metabolism. The adoptive transfer of CD103 + cDC1s to Batf3 deficient animals reversed these observed changes and more importantly could attenuate cellular damage and inflammation in established murine steatohepatitis. Here, we have identified the murine CD103 + cDC1s as a protective DC subtype that influences the pro-anti-inflammatory balance and protects the liver from metabolic damage. As guardians of liver integrity, they play a key role in the inflammatory process during the development of steatohepatitis in mice. Non-alcoholic fatty liver (NAFL) is the hepatic consequence of metabolic syndrome and can lead to non-alcoholic steatohepatitis (NASH). The current study demonstrated that a specific murine dendritic cell subtype possesses a potent regulatory role to influence the inflammatory milieu of the liver in this process. Copyright © 2017 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Progress of dendritic cell-based cancer vaccines for patients with hematological malignancies.

PubMed

Ni, Ming; Hoffmann, Jean-Marc; Schmitt, Michael; Schmitt, Anita

2016-09-01

Dendritic cells (DCs) are the most professional antigen-presenting cells eliciting cellular and humoral immune responses against cancer cells by expressing these antigens on MHC class I/II complexes to T cells. Therefore, they have been employed in many clinical trials as cancer vaccines for patients with cancer. This review focuses on the use of DCs in leukemia patients expressing leukemia-associated antigens (LAAs). The contribution of both stimulating vs. tolerogenic DCs as well as of other factors to the milieu of anti-leukemia immune responses are discussed. Several DC vaccination strategies like leukemia lysate, proteins and peptides have been developed. Next generation DC vaccines comprise transduction of DCs with retroviral vectors encoding for LAAs, cytokines and costimulatory molecules as well as transfection of DCs with naked RNA encoding for LAAs. Published as well as ongoing clinical trials are reported and critically reviewed. Future results will demonstrate whether next-generation DCs are really superior to conventional pulsing with peptide, protein or tumor lysate. However, currently available methods based on nucleic acid transfection/transduction are tempting in terms of material production costs and time for clinical application according to good manufacturing practice (GMP).

Topoisomerase I peptide-loaded dendritic cells induce autoantibody response as well as skin and lung fibrosis.

PubMed

Mehta, Heena; Goulet, Philippe-Olivier; Nguyen, Vinh; Pérez, Gemma; Koenig, Martial; Senécal, Jean-Luc; Sarfati, Marika

2016-12-01

DNA Topoisomerase I (TopoI) is a candidate autoantigen for diffuse cutaneous systemic sclerosis (dcSSc) associated with fatal lung disease. Dendritic cells (DCs) contribute to bleomycin-induced lung fibrosis. However, the possibility that TopoI-loaded DCs are involved in the initiation and/or perpetuation of dcSSc has not been explored. Here, we show that immunization with TopoI peptide-loaded DCs induces anti-TopoI autoantibody response and long-term fibrosis. Mice were repeatedly immunized with unpulsed DCs or DCs loaded with either TOPOIA or TOPOIB peptides, selected from different regions of TopoI. At week 12 after initial DC immunization, TOPOIA DCs but not TOPOIB DCs immunization induced mixed inflammation and fibrosis in lungs and skin. At a late time point (week 18), both TOPOIA DCs and TOPOIB DCs groups displayed increased alpha-smooth muscle actin expression in lungs and dermis along with skin fibrosis distal from the site of injection when compared with unpulsed DCs. Both TopoI peptide-DC-immunized groups developed IgG2a anti-TopoI autoantibody response. At week 10, signs of perivascular, peribronchial, and parenchymal pulmonary inflammation were already observed in the TOPOIA DCs group, together with transient elevation in bronchoalveolar lavage cell counts, IL-17A expression, and CXCL4 production, a biomarker of early human dcSSc. Collectively, TopoI peptide DCs induce progressive autoantibody response as well as development of protracted skin and lung dcSSc-like disease. Pronounced lung inflammation, transient IL-17A, and CXCL4 expression precede fibrosis development. Our immunization strategy, that uses self immune system and autoantigen, will help to further investigate the pathogenesis of this complex autoimmune disorder with unmet medical needs.

CD301b⁺ dermal dendritic cells drive T helper 2 cell-mediated immunity.

PubMed

Kumamoto, Yosuke; Linehan, Melissa; Weinstein, Jason S; Laidlaw, Brian J; Craft, Joseph E; Iwasaki, Akiko

2013-10-17

Unlike other types of T helper (Th) responses, whether the development of Th2 cells requires instruction from particular subset of dendritic cells (DCs) remains unclear. By using an in vivo depletion approach, we have shown that DCs expressing CD301b were required for the generation of Th2 cells after subcutaneous immunization with ovalbumin (OVA) along with papain or alum. CD301b⁺ DCs are distinct from epidermal or CD207⁺ dermal DCs (DDCs) and were responsible for transporting antigen injected subcutaneously with Th2-type adjuvants. Transient depletion of CD301b⁺ DCs resulted in less effective accumulation and decreased expression of CD69 by polyclonal CD4⁺ T cells in the lymph node. Moreover, despite intact cell division and interferon-γ production, CD301b⁺ DC depletion led to blunted interleukin-4 production by OVA-specific OT-II transgenic CD4⁺ T cells and significantly impaired Th2 cell development upon infection with Nippostrongylus brasiliensis. These results reveal CD301b⁺ DDCs as the key mediators of Th2 immunity. Copyright © 2013 Elsevier Inc. All rights reserved.

Intestinal lamina propria dendritic cells maintain T cell homeostasis but do not affect commensalism

PubMed Central

Welty, Nathan E.; Staley, Christopher; Ghilardi, Nico; Sadowsky, Michael J.; Igyártó, Botond Z.

2013-01-01

Dendritic cells (DCs) in the intestinal lamina propria (LP) are composed of two CD103+ subsets that differ in CD11b expression. We report here that Langerin is expressed by human LP DCs and that transgenic human langerin drives expression in CD103+CD11b+ LP DCs in mice. This subset was ablated in huLangerin-DTA mice, resulting in reduced LP Th17 cells without affecting Th1 or T reg cells. Notably, cognate DC–T cell interactions were not required for Th17 development, as this response was intact in huLangerin-Cre I-Aβfl/fl mice. In contrast, responses to intestinal infection or flagellin administration were unaffected by the absence of CD103+CD11b+ DCs. huLangerin-DTA x BatF3−/− mice lacked both CD103+ LP DC subsets, resulting in defective gut homing and fewer LP T reg cells. Despite these defects in LP DCs and resident T cells, we did not observe alterations of intestinal microbial communities. Thus, CD103+ LP DC subsets control T cell homeostasis through both nonredundant and overlapping mechanisms. PMID:24019552

pDC therapy induces recovery from EAE by recruiting endogenous pDC to sites of CNS inflammation

PubMed Central

Duraes, Fernanda V.; Lippens, Carla; Steinbach, Karin; Dubrot, Juan; Brighouse, Dale; Bendriss-Vermare, Nathalie; Issazadeh-Navikas, Shohreh; Merkler, Doron; Hugues, Stephanie

2016-01-01

Plasmacytoid dendritic cells (pDCs) exhibit both innate and adaptive functions. In particular they are the main source of type I IFNs and directly impact T cell responses through antigen presentation. We have previously demonstrated that during experimental autoimmune encephalomyelitis (EAE) initiation, myelin-antigen presentation by pDCs is associated with suppressive Treg development and results in attenuated EAE. Here, we show that pDCs transferred during acute disease phase confer recovery from EAE. Clinical improvement is associated with migration of injected pDCs into inflamed CNS and is dependent on the subsequent and selective chemerin-mediated recruitment of endogenous pDCs to the CNS. The protective effect requires pDC pre-loading with myelin antigen, and is associated with the modulation of CNS-infiltrating pDC phenotype and inhibition of CNS encephalitogenic T cells. This study may pave the way for novel pDC-based cell therapies in autoimmune diseases, aiming at specifically modulating pathogenic cells that induce and sustain autoimmune inflammation. PMID:26341385

Interleukin 10 (IL-10)-mediated Immunosuppression

PubMed Central

Mittal, Sharad K.; Cho, Kyung-Jin; Ishido, Satoshi; Roche, Paul A.

2015-01-01

Efficient immune responses require regulated antigen presentation to CD4 T cells. IL-10 inhibits the ability of dendritic cells (DCs) and macrophages to stimulate antigen-specific CD4 T cells; however, the mechanisms by which IL-10 suppresses antigen presentation remain poorly understood. We now report that IL-10 stimulates expression of the E3 ubiquitin ligase March-I in activated macrophages, thereby down-regulating MHC-II, CD86, and antigen presentation to CD4 T cells. By contrast, IL-10 does not stimulate March-I expression in DCs, does not suppress MHC-II or CD86 expression on either resting or activated DCs, and does not affect antigen presentation by activated DCs. IL-10 does, however, inhibit the process of DC activation itself, thereby reducing the efficiency of antigen presentation in a March-I-independent manner. Thus, IL-10 suppression of antigen presenting cell function in macrophages is March-I-dependent, whereas in DCs, suppression is March- I-independent. PMID:26408197

Ficus carica Polysaccharides Promote the Maturation and Function of Dendritic Cells

PubMed Central

Tian, Jie; Zhang, Yue; Yang, Xiaomin; Rui, Ke; Tang, Xinyi; Ma, Jie; Chen, Jianguo; Xu, Huaxi; Lu, Liwei; Wang, Shengjun

2014-01-01

Various polysaccharides purified from plants are considered to be biological response modifiers and have been shown to enhance immune responses. Ficus carica L. is a Chinese traditional plant and has been widely used in Asian countries for its anti-tumor properties. Ficus carica polysaccharides (FCPS), one of the most essential and effective components in Ficus carica L., have been considered to be a beneficial immunomodulator and may be used in immunotherapy. However, the immunologic mechanism of FCPS is still unclear. Dectin-1 is a non-toll-like pattern recognition receptor, predominately expressed on dendritic cells (DCs). Activation of DCs through dectin-1 signaling can lead to the maturation of DC, thus inducing both innate and adaptive immune responses against tumor development and microbial infection. In our study, we found that FCPS could effectively stimulate DCs, partially through the dectin-1/Syk pathway, and promote their maturation, as shown by the up-regulation of CD40, CD80, CD86, and major histocompatibility complex II (MHCII). FCPS also enhanced the production of cytokines by DCs, including IL-12, IFN-γ, IL-6, and IL-23. Moreover, FCPS-treated DCs showed an enhanced capability to stimulate T cells and promote T cell proliferation. Altogether, these results demonstrate that FCPS are able to activate and maturate DCs, thereby up-regulating the immunostimulatory capacity of DCs, which leads to enhanced T cell responses. PMID:25026176

Type-1 polarised dendritic cells are a potent immunogen against Mycobacterium tuberculosis.

PubMed

Satake, Y; Nakamura, Y; Kono, M; Hozumi, H; Nagata, T; Tsujimura, K; Enomoto, N; Fujisawa, T; Inui, N; Fujiyama, T; Tokura, Y; Matsui, T; Yokomura, K; Shirai, M; Hayakawa, H; Suda, T

2017-05-01

Application of immunotherapy using dendritic cells (DCs) is considered an effective treatment strategy against persistent Mycobacterium tuberculosis infection. With the goal of developing improved therapeutic vaccination strategies for patients with tuberculosis (TB), we tested the ability of ex vivo-generated DCs to induce an effective TB antigen-specific type-1 immune response. Monocyte-derived DCs from TB patients were induced to mature using a 'standard' cytokine cocktail (interleukin [IL] 1β, tumour necrosis factor alpha [TNF-α], IL-6 and prostaglandin E2) or a type 1-polarised DC (DC1) cocktail (IL-1β, TNF-α, interferon [IFN] α, IFN-γ and polyinosinic:polycytidylic acid), and were loaded with the established TB antigen 6-kDa early secretory antigenic target protein (ESAT-6). Although DC1s from TB patients expressed the same levels of multiple co-stimulatory molecules (CD83, CD86, CD80 and CD40) as the standard DCs (sDCs), DC1s secreted substantially higher levels of IL-12p70. Furthermore, when DCs pulsed with or without ESAT-6 were cultured with lymphocytes from the same patients, DC1s induced much higher numbers of ESAT-6-specific IFN-γ-producing T-cells than sDCs, as manifested by their superior induction of natural killer cell activation and antigen-independent suppression of regulatory T-cells. TB antigen-loaded DC1s are potent inducers of antigen-specific T-cells, which could be used to develop improved immunotherapies of TB.

Antigen Cross-Presentation of Immune Complexes

PubMed Central

Platzer, Barbara; Stout, Madeleine; Fiebiger, Edda

2014-01-01

The ability of dendritic cells (DCs) to cross-present tumor antigens has long been a focus of interest to physicians, as well as basic scientists, that aim to establish efficient cell-based cancer immune therapy. A prerequisite for exploiting this pathway for therapeutic purposes is a better understanding of the mechanisms that underlie the induction of tumor-specific cytotoxic T-lymphocyte (CTL) responses when initiated by DCs via cross-presentation. The ability of humans DC to perform cross-presentation is of utmost interest, as this cell type is a main target for cell-based immunotherapy in humans. The outcome of a cross-presentation event is guided by the nature of the antigen, the form of antigen uptake, and the subpopulation of DCs that performs presentation. Generally, CD8α+ DCs are considered to be the most potent cross-presenting DCs. This paradigm, however, only applies to soluble antigens. During adaptive immune responses, immune complexes form when antibodies interact with their specific epitopes on soluble antigens. Immunoglobulin G (IgG) immune complexes target Fc-gamma receptors on DCs to shuttle exogenous antigens efficiently into the cross-presentation pathway. This receptor-mediated cross-presentation pathway is a well-described route for the induction of strong CD8+ T cell responses. IgG-mediated cross-presentation is intriguing because it permits the CD8− DCs, which are commonly considered to be weak cross-presenters, to efficiently cross-present. Engaging multiple DC subtypes for cross-presentation might be a superior strategy to boost CTL responses in vivo. We here summarize our current understanding of how DCs use IgG-complexed antigens for the efficient induction of CTL responses. Because of its importance for human cell therapy, we also review the recent advances in the characterization of cross-presentation properties of human DC subsets. PMID:24744762

Attenuated Listeria monocytogenes vectors overcome suppressive plasma factors during HIV infection to stimulate myeloid dendritic cells to promote adaptive immunity and reactivation of latent virus.

PubMed

Miller, Elizabeth A; Spadaccia, Meredith R; Norton, Thomas; Demmler, Morgan; Gopal, Ramya; O'Brien, Meagan; Landau, Nathaniel; Dubensky, Thomas W; Lauer, Peter; Brockstedt, Dirk G; Bhardwaj, Nina

2015-01-01

HIV-1 infection is characterized by myeloid dendritic cell (DC) dysfunction, which blunts the responsiveness to vaccine adjuvants. We previously showed that nonviral factors in HIV-seropositive plasma are partially responsible for mediating this immune suppression. In this study we investigated recombinant Listeria monocytogenes (Lm) vectors, which naturally infect and potently activate DCs from seronegative donors, as a means to overcome DC dysfunction associated with HIV infection. Monocyte-derived DCs were cocultured with plasma from HIV-infected donors (HIV-moDCs) to induce a dysregulated state and infected with an attenuated, nonreplicative vaccine strain of Lm expressing full length clade B consensus gag (KBMA Lm-gag). Lm infection stimulated cytokine secretion [interleukin (IL)-12p70, tumor necrosis factor (TNF)-α, and IL-6] and Th-1 skewing of allogeneic naive CD4 T cells by HIV-moDCs, in contrast to the suppressive effects observed by HIV plasma on moDCs on toll-like receptor ligand stimulation. Upon coculture of "killed" but metabolically active (KBMA) Lm-gag-infected moDCs from HIV-infected donors with autologous cells, expansion of polyfunctional, gag-specific CD8(+) T cells was observed. Reactivation of latent proviruses by moDCs following Lm infection was also observed in models of HIV latency in a TNF-α-dependent manner. These findings reveal the unique ability of Lm vectors to contend with dysregulation of HIV-moDCs, while simultaneously possessing the capacity to activate latent virus. Concurrent stimulation of innate and adaptive immunity and disruption of latency may be an approach to reduce the pool of latently infected cells during HIV infection. Further study of Lm vectors as part of therapeutic vaccination and eradication strategies may advance this evolving field.

Activated dendritic cells delivered in tissue compatible biomatrices induce in-situ anti-tumor CTL responses leading to tumor regression

PubMed Central

Verma, Vivek; Kim, Young; Lee, Min-Cheol; Lee, Jae-Tae; Cho, Sunghoon; Park, In-Kyu; Min, Jung Joon; Lee, Je Jung; Lee, Shee Eun; Rhee, Joon Haeng

2016-01-01

Dendritic cell (DC) based anti-cancer immunotherapy is well tolerated in patients with advanced cancers. However, the clinical responses seen after adoptive DC therapy have been suboptimal. Several factors including scarce DC numbers in tumors and immunosuppressive tumor microenvironments contribute to the inefficacy of DCs as cellular vaccines. Hence DC based vaccines can benefit from novel methods of cell delivery that would prevent the direct exposure of immune cells to suppressive tumor microenvironments. Here we evaluated the ability of DCs harbored in biocompatible scaffolds (referred to as biomatrix entrapped DCs; beDCs) in activating specific anti-tumor immune responses against primary and post-surgery secondary tumors. Using a preclinical cervical cancer and a melanoma model in mice, we show that single treatment of primary and post-surgery secondary tumors using beDCs resulted in significant tumor growth retardation while multiple inoculations were required to achieve a significant anti-tumor effect when DCs were given in free form. Additionally, we found that, compared to the tumor specific E6/E7 peptide vaccine, total tumor lysate induced higher expression of CD80 and CD40 on DCs that induced increased levels of IFNγ production upon interaction with host lymphocytes. Remarkably, a strong immunocyte infiltration into the host-implanted DC-scaffold was observed. Importantly, the host-implanted beDCs induced the anti-tumor immune responses in the absence of any stromal cell support, and the biomatrix structure was eventually absorbed into the surrounding host tissue. Collectively, these data indicate that the scaffold-based DC delivery may provide an efficient and safe way of delivering cell-based vaccines for treatment of primary and post-surgery secondary tumors. PMID:27223090

The Effects of T4 and A3/R Bacteriophages on Differentiation of Human Myeloid Dendritic Cells

PubMed Central

Bocian, Katarzyna; Borysowski, Jan; Zarzycki, Michał; Pacek, Magdalena; Weber-Dąbrowska, Beata; Machcińska, Maja; Korczak-Kowalska, Grażyna; Górski, Andrzej

2016-01-01

Bacteriophages (phages) are viruses of bacteria. Here we evaluated the effects of T4 and A3/R bacteriophages, as well as phage-generated bacterial lysates, on differentiation of human myeloid dendritic cells (DCs) from monocytes. Neither of the phages significantly reduced the expression of markers associated with differentiation of DCs and their role in the activation of T cells (CD40, CD80, CD83, CD86, CD1c, CD11c, MHC II, PD-L1, PD-L2, TLR2, TLR4, and CCR7) and phagocytosis receptors (CD64 and DEC-205). By contrast, bacterial lysate of T4 phage significantly decreased the percentages of DEC-205- and CD1c-positive cells. The percentage of DEC-205-positive cells was also significantly reduced in DCs differentiated in the presence of lysate of A3/R phage. Thus while bacteriophages do not substantially affect differentiation of DCs, some products of phage-induced lysis of bacterial cells may influence the differentiation and potentially also some functions of DCs. Our results have important implications for phage therapy of bacterial infections because during infections monocytes recruited to the site of inflammation are an important source of inflammatory DCs. PMID:27582733

Involvement of suppressors of cytokine signaling in toll-like receptor-mediated block of dendritic cell differentiation.

PubMed

Bartz, Holger; Avalos, Nicole M; Baetz, Andrea; Heeg, Klaus; Dalpke, Alexander H

2006-12-15

Dendritic cells (DCs) are important sentinels within innate immunity, monitoring the presence of infectious microorganisms. They operate in 2 different maturation stages, with transition from immature to mature DCs being induced by activation of toll-like receptors (TLRs). However, TLRs are also expressed on precursor cells of DCs. Here we analyzed the effects of TLR stimulation during the process of granulocyte-macrophage-colony-stimulating factor (GM-CSF)-mediated in vitro generation of immature DCs from precursor cells. We show that TLR triggering deviated phenotypic and functional differentiation from CD14+ monocytes to CD1a+ DCs. Similar results were obtained when differentiation of murine myeloid DCs from bone marrow cells was analyzed. The inhibitory effects were independent of soluble factors. TLR stimulation in DC precursor cells induced proteins of the suppressor of cytokine signaling family (SOCS), which correlated with loss of sensitivity to GM-CSF. Overexpression of SOCS-1 abolished GM-CSF signal transduction. Moreover, forced SOCS-1 expression in DC precursors mimicked the inhibitory effects on DC generation observed for TLR stimulation. The results indicate that TLR stimulation during the period of DC generation interferes with and deviates DC differentiation and that these effects are mediated particularly by SOCS-1.

HMGB1 Is Involved in IFN-α Production and TRAIL Expression by HIV-1-Exposed Plasmacytoid Dendritic Cells: Impact of the Crosstalk with NK Cells

PubMed Central

Formaglio, Pauline; Melki, Marie-Thérèse; Charbit, Bruno; Herbeuval, Jean-Philippe; Gougeon, Marie-Lise

2016-01-01

Plasmacytoid dendritic cells (pDCs) are innate sensors of viral infections and important mediators of antiviral innate immunity through their ability to produce large amounts of IFN-α. Moreover, Toll-like receptor 7 (TLR7) and 9 (TLR9) ligands, such as HIV and CpG respectively, turn pDCs into TRAIL-expressing killer pDCs able to lyse HIV-infected CD4+ T cells. NK cells can regulate antiviral immunity by modulating pDC functions, and pDC production of IFN-α as well as cell–cell contact is required to promote NK cell functions. Impaired pDC-NK cell crosstalk was reported in the setting of HIV-1 infection, but the impact of HIV-1 on TRAIL expression and innate antiviral immunity during this crosstalk is unknown. Here, we report that low concentrations of CCR5-tropic HIV-1Ba-L promote the release of pro-inflammatory cytokines such as IFN-α, TNF-α, IFN-γ and IL-12, and CCR5-interacting chemokines (MIP-1α and MIP-1β) in NK-pDCs co-cultures. At high HIV-1BaL concentrations, the addition of NK cells did not promote the release of these mediators, suggesting that once efficiently triggered by the virus, pDCs could not integrate new activating signals delivered by NK cells. However, high HIV-1BaL concentrations were required to trigger IFN-α-mediated TRAIL expression at the surface of both pDCs and NK cells during their crosstalk. Interestingly, we identified the alarmin HMGB1, released at pDC-NK cell synapse, as an essential trigger for the secretion of IFN-α and IFN-related soluble mediators during the interplay of HIV-1 exposed pDCs with NK cells. Moreover, HMGB1 was found crucial for mTRAIL translocation to the plasma membrane of both pDCs and NK cells during their crosstalk following pDC exposure to HIV-1. Data from serum analyses of circulating HMGB1, HMGB1-specific antibodies, sTRAIL and IP-10 in a cohort of 67 HIV-1+ patients argue for the in vivo relevance of these observations. Altogether, these findings identify HMGB1 as a trigger for IFN-α-mediated TRAIL expression at the surface of pDCs and NK cells, and they suggest a novel mechanism of innate control of HIV-1 infection. PMID:26871575

Bioactive grape proanthocyanidins enhance immune reactivity in UV-irradiated skin through functional activation of dendritic cells in mice

PubMed Central

Vaid, Mudit; Singh, Tripti; Prasad, Ram; Elmets, Craig A.; Xu, Hui; Katiyar, Santosh K.

2013-01-01

Ultraviolet (UV) radiation-induced immunosuppression has been implicated in skin carcinogenesis. Grape seed proanthocyanidins (GSPs) have anti-skin carcinogenic effects in mice and GSPs-fed mice exhibit a reduction in UV-induced suppression of allergic contact hypersensitivity (CHS), a prototypic T cell-mediated response. Here, we report that dietary GSPs did not inhibit UVB-induced suppression of CHS in xeroderma pigmentosum complementation group A (XPA)-deficient mice, which lack nucleotide excision repair mechanisms. GSPs enhanced repair of UVB-induced DNA damage (cyclobutane pyrimidine dimers) in wild-type, but not XPA-deficient, dendritic cells (DCs). Co-culture of CD4+ T cells with DCs from UVB-irradiated wild-type mice resulted in suppression of T-cell proliferation and secretion of Th-1 type cytokines that was ameliorated when the DCs were obtained from GSPs-fed mice; whereas, DCs obtained from GSPs-fed XPA-KO mice failed to restore T-cell proliferation. In adoptive transfer experiments, donor DCs were positively selected from the draining lymph nodes of UVB-exposed donor mice that were sensitized to 2,4, dinitrofluorobenzene were transferred into naïve recipient mice and the CHS response assessed. Naïve recipients that received DCs from UVB-exposed wild-type donors that had been fed GSPs exhibited a full CHS response, whereas no significant CHS was observed in mice that received DCs from XPA-KO mice fed GSPs. These results suggest that GSPs prevent UVB-induced immunosuppression through DNA repair-dependent functional activation of dendritic cells in mice. PMID:23321928

Use of antigen-primed dendritic cells for inducing antitumor immune responses in vitro in patients with non-small cell lung cancer

PubMed Central

Obleukhova, Irina; Kiryishina, Nataliya; Falaleeva, Svetlana; Lopatnikova, Julia; Kurilin, Vasiliy; Kozlov, Vadim; Vitsin, Aleksander; Cherkasov, Andrey; Kulikova, Ekaterina; Sennikov, Sergey

2018-01-01

Cancer is associated with a reduction in immature and mature circulating dendritic cells (DCs), and with an impaired migratory capacity, compared with healthy donors. Therefore, modern approaches to the in vitro generation of DCs loaded with tumor antigens and their use for inducing antitumor immune responses in vivo are being investigated. The purpose of the present study was to investigate the phenotypic and functional characteristics of peripheral blood DC subsets in patients with non-small cell lung cancer (NSCLC), and the development of an antitumor cytotoxic response by mononuclear cells (MNCs) from patients using in vitro generated antigen-primed DCs. Heparinized peripheral venous blood samples were obtained from 10 healthy donors and 20 patients with a histologically verified diagnosis of NSCLC. The ability of antigen-activated DCs to stimulate the activity of MNCs against autologous tumor cells was evaluated using a cytotoxic test. Peripheral blood DC subsets from patients with NSCLC were identified to be decreased and to exhibit an impaired ability to mature, compared with healthy donors. Furthermore, DCs generated from MNCs from patients with NSCLC were able to stimulate a specific cytotoxic response when loaded with autologous tumor lysates or RNA and matured, in vitro. A perforin and granzyme B-dependent mode of cytotoxicity was primarily induced. The ability of DCs loaded with tumor antigens to increase the cytotoxic activity of MNCs against NSCLC cells in vitro indicates the effective induction and co-stimulation of T lymphocytes by the generated DCs. PMID:29399182

TCF4-Targeting miR-124 is Differentially Expressed amongst Dendritic Cell Subsets

PubMed Central

Han, Sun Murray; Na, Hye Young; Ham, Onju; Choi, Wanho; Sohn, Moah; Ryu, Seul Hye; In, Hyunju; Hwang, Ki-Chul

2016-01-01

Dendritic cells (DCs) are professional antigen-presenting cells that sample their environment and present antigens to naïve T lymphocytes for the subsequent antigen-specific immune responses. DCs exist in a range of distinct subpopulations including plasmacytoid DCs (pDCs) and classical DCs (cDCs), with the latter consisting of the cDC1 and cDC2 lineages. Although the roles of DC-specific transcription factors across the DC subsets have become understood, the posttranscriptional mechanisms that regulate DC development are yet to be elucidated. MicroRNAs (miRNAs) are pivotal posttranscriptional regulators of gene expression in a myriad of biological processes, but their contribution to the immune system is just beginning to surface. In this study, our in-house probe collection was screened to identify miRNAs possibly involved in DC development and function by targeting the transcripts of relevant mouse transcription factors. Examination of DC subsets from the culture of mouse bone marrow with Flt3 ligand identified high expression of miR-124 which was able to target the transcript of TCF4, a transcription factor critical for the development and homeostasis of pDCs. Further expression profiling of mouse DC subsets isolated from in vitro culture as well as via ex vivo purification demonstrated that miR-124 was outstandingly expressed in CD24+ cDC1 cells compared to in pDCs and CD172α+ cDC2 cells. These results imply that miR-124 is likely involved in the processes of DC subset development by posttranscriptional regulation of a transcription factor(s). PMID:26937233

Increased plasmacytoid dendritic cells in Guillain-Barré syndrome.

PubMed

Wang, Yu-Zhong; Feng, Xun-Gang; Wang, Qian; Xing, Chun-Ye; Shi, Qi-Guang; Kong, Qing-Xia; Cheng, Pan-Pan; Zhang, Yong; Hao, Yan-Lei; Yuki, Nobuhiro

2015-06-15

Guillain-Barré syndrome (GBS) is a post-infectious autoimmune disease. Dendritic cells (DCs) can recognize the pathogen and modulate the host immune response. Exploring the role of DCs in GBS will help our understanding of the disease development. In this study, we aimed to analyze plasmacytoid and conventional DCs in peripheral blood of patients with GBS at different stages of the disease: acute phase as well as early and late recovery phases. There was a significant increase of plasmacytoid DCs in the acute phase (p=0.03 vs healthy donors). There was a positive correlation between percentage of plasmacytoid DCs and the clinical severity of patients with GBS (r=0.61, p<0.001). Quantitative polymerase chain reaction and flow cytometry confirmed the aberrant plasmacytoid DCs in GBS. Thus, plasmacytoid DCs may participate in the development of GBS. Copyright © 2015 Elsevier B.V. All rights reserved.

Chemokine programming dendritic cell antigen response: part II - programming antigen presentation to T lymphocytes by partially maintaining immature dendritic cell phenotype.

PubMed

Park, Jaehyung; Bryers, James D

2013-05-01

In a companion article to this study,(1) the successful programming of a JAWSII dendritic cell (DC) line's antigen uptake and processing was demonstrated based on pre-treatment of DCs with a specific 'cocktail' of select chemokines. Chemokine pre-treatment modulated cytokine production before and after DC maturation [by lipopolysaccharide (LPS)]. After DC maturation, it induced an antigen uptake and processing capacity at levels 36% and 82% higher than in immature DCs, respectively. Such programming proffers a potential new approach to enhance vaccine efficiency. Unfortunately, simply enhancing antigen uptake does not guarantee the desired activation and proliferation of lymphocytes, e.g. CD4(+) T cells. In this study, phenotype changes and antigen presentation capacity of chemokine pre-treated murine bone marrow-derived DCs were examined in long-term co-culture with antigen-specific CD4(+) T cells to quantify how chemokine pre-treatment may impact the adaptive immune response. When a model antigen, ovalbumin (OVA), was added after intentional LPS maturation of chemokine-treated DCs, OVA-biased CD4(+) T-cell proliferation was initiated from ~ 100% more undivided naive T cells as compared to DCs treated only with LPS. Secretion of the cytokines interferon-γ, interleukin-1β, interleukin-2 and interleukin-10 in the CD4(+) T cell : DC co-culture (with or without chemokine pre-treatment) were essentially the same. Chemokine programming of DCs with a 7 : 3 ratio of CCL3 : CCL19 followed by LPS treatment maintained partial immature phenotypes of DCs, as indicated by surface marker (CD80 and CD86) expression over time. Results here and in our companion paper suggest that chemokine programming of DCs may provide a novel immunotherapy strategy to obviate the natural endocytosis limit of DC antigen uptake, thus potentially increasing DC-based vaccine efficiency. © 2012 Blackwell Publishing Ltd.

Bone marrow CD11b(+)F4/80(+) dendritic cells ameliorate collagen-induced arthritis through modulating the balance between Treg and Th17.

PubMed

Zhang, Lingling; Fu, Jingjing; Sheng, Kangliang; Li, Ying; Song, Shanshan; Li, Peipei; Song, Shasha; Wang, Qingtong; Chen, Jingyu; Yu, Jianhua; Wei, Wei

2015-03-01

Tolerogenic dendritic cells (DCs) are well-known to show an immunosuppressive function. In this study we determine the therapeutic effects and potential mechanisms of transferred bone marrow (BM) CD11b(+)F4/80(+) DCs on collagen-induced arthritis (CIA) in mice. Murine BM CD11b(+)F4/80(+) DCs were generated under the stimulation of GM-CSF and IL-4, and the function of BM CD11b(+) F4/80(+) DCs was identified by measuring the levels of IL-10, TGF-beta and indoleamine 2,3-dioxygenase (IDO). BM CD11b(+)F4/80(+) DCs were transferred to CIA mice by intravenous injections. The histopathology of joint and spleen were evaluated. T lymphocyte proliferation, Treg and Th17 subsets were analyzed. The expressions of Foxp3, Helios and RORγt in T lymphocytes co-cultured with BM CD11b(+)F4/80(+) DCs were measured in vitro. We found that BM CD11b(+)F4/80(+) DCs induced by GM-CSF and IL-4 could express high levels of IL-10, TGF-beta and IDO. BM CD11b(+)F4/80(+) DCs significantly reduced the pathologic scores in joints and spleens, which correlated significantly with the reduced T lymphocyte proliferation and Th17 cell number, and with the increased Tregs number. In vitro, OVA-pulsed BM CD11b(+)F4/80(+) DCs promoted Treg cell expansion, enhanced IL-10 and CTLA-4 protein expression, augmented Foxp3 and Helios mRNA expression, and inhibited RORγt and IL-17 mRNA expression. Taken together, BM CD11b(+)F4/80(+) DCs are able to ameliorate the development and severity of CIA, at least partly by inducing Foxp3(+) Treg cell expansion and suppressing Th17 function. The BM CD11b(+)F4/80(+) DCs might have a promising immunotherapeutic potential for autoimmune arthritis. Copyright © 2015 Elsevier B.V. All rights reserved.

Despite Increased Type 1 IFN, Autoimmune Nonobese Diabetic Mice Display Impaired Dendritic Cell Response to CpG and Decreased Nuclear Localization of IFN-Activated STAT1.

PubMed

Rahman, M Jubayer; Rahir, Gwendoline; Dong, Matthew B; Zhao, Yongge; Rodrigues, Kameron B; Hotta-Iwamura, Chie; Chen, Ye; Guerrero, Alan; Tarbell, Kristin V

2016-03-01

Innate immune signals help break self-tolerance to initiate autoimmune diseases such as type 1 diabetes, but innate contributions to subsequent regulation of disease progression are less clear. Most studies have measured in vitro innate responses of GM-CSF dendritic cells (DCs) that are functionally distinct from conventional DCs (cDCs) and do not reflect in vivo DC subsets. To determine whether autoimmune NOD mice have alterations in type 1 IFN innate responsiveness, we compared cDCs from prediabetic NOD and control C57BL/6 (B6) mice stimulated in vivo with the TLR9 ligand CpG, a strong type 1 IFN inducer. In response to CpG, NOD mice produce more type 1 IFN and express higher levels of CD40, and NOD monocyte DCs make more TNF. However, the overall CpG-induced transcriptional response is muted in NOD cDCs. Of relevance the costimulatory proteins CD80/CD86, signals needed for regulatory T cell homeostasis, are upregulated less on NOD cDCs. Interestingly, NOD Rag1(-/-) mice also display a defect in CpG-induced CD86 upregulation compared with B6 Rag1(-/-), indicating this particular innate alteration precedes adaptive autoimmunity. The impaired response in NOD DCs is likely downstream of the IFN-α/β receptor because DCs from NOD and B6 mice show similar CpG-induced CD86 levels when anti-IFN-α/β receptor Ab is added. IFN-α-induced nuclear localization of activated STAT1 is markedly reduced in NOD CD11c(+) cells, consistent with lower type 1 IFN responsiveness. In conclusion, NOD DCs display altered innate responses characterized by enhanced type 1 IFN and activation of monocyte-derived DCs but diminished cDC type 1 IFN response.

Three-dimensional culture and interaction of cancer cells and dendritic cells in an electrospun nano-submicron hybrid fibrous scaffold

PubMed Central

Kim, Tae-Eon; Kim, Chang Gun; Kim, Jin Soo; Jin, Songwan; Yoon, Sik; Bae, Hae-Rahn; Kim, Jeong-Hwa; Jeong, Young Hun; Kwak, Jong-Young

2016-01-01

An artificial three-dimensional (3D) culture system that mimics the tumor microenvironment in vitro is an essential tool for investigating the cross-talk between immune and cancer cells in tumors. In this study, we developed a 3D culture system using an electrospun poly(ε-caprolactone) (PCL) nanofibrous scaffold (NFS). A hybrid NFS containing an uninterrupted network of nano- and submicron-scale fibers (400 nm to 2 µm) was generated by deposition onto a stainless steel mesh instead of an aluminum plate. The hybrid NFS contained multiplanar pores in a 3D structure. Surface-seeded mouse CT26 colon cancer cells and bone marrow-derived dendritic cells (BM-DCs) were able to infiltrate the hybrid NFS within several hours. BM-DCs cultured on PCL nanofibers showed a baseline inactive form, and lipopolysaccharide (LPS)-activated BM-DCs showed increased expression of CD86 and major histocompatibility complex Class II. Actin and phosphorylated FAK were enriched where unstimulated and LPS-stimulated BM-DCs contacted the fibers in the 3D hybrid NFS. When BM-DCs were cocultured with mitoxantrone-treated CT26 cells in a 3D hybrid NFS, BM-DCs sprouted cytoplasm to, migrated to, synapsed with, and engulfed mitoxantrone-treated CT26 cancer cells, which were similar to the naturally occurring cross-talk between these two types of cells. The 3D hybrid NFS developed here provides a 3D structure for coculture of cancer and immune cells. PMID:27042051

Three-dimensional culture and interaction of cancer cells and dendritic cells in an electrospun nano-submicron hybrid fibrous scaffold.

PubMed

Kim, Tae-Eon; Kim, Chang Gun; Kim, Jin Soo; Jin, Songwan; Yoon, Sik; Bae, Hae-Rahn; Kim, Jeong-Hwa; Jeong, Young Hun; Kwak, Jong-Young

2016-01-01

An artificial three-dimensional (3D) culture system that mimics the tumor microenvironment in vitro is an essential tool for investigating the cross-talk between immune and cancer cells in tumors. In this study, we developed a 3D culture system using an electrospun poly(ε-caprolactone) (PCL) nanofibrous scaffold (NFS). A hybrid NFS containing an uninterrupted network of nano- and submicron-scale fibers (400 nm to 2 µm) was generated by deposition onto a stainless steel mesh instead of an aluminum plate. The hybrid NFS contained multiplanar pores in a 3D structure. Surface-seeded mouse CT26 colon cancer cells and bone marrow-derived dendritic cells (BM-DCs) were able to infiltrate the hybrid NFS within several hours. BM-DCs cultured on PCL nanofibers showed a baseline inactive form, and lipopolysaccharide (LPS)-activated BM-DCs showed increased expression of CD86 and major histocompatibility complex Class II. Actin and phosphorylated FAK were enriched where unstimulated and LPS-stimulated BM-DCs contacted the fibers in the 3D hybrid NFS. When BM-DCs were cocultured with mitoxantrone-treated CT26 cells in a 3D hybrid NFS, BM-DCs sprouted cytoplasm to, migrated to, synapsed with, and engulfed mitoxantrone-treated CT26 cancer cells, which were similar to the naturally occurring cross-talk between these two types of cells. The 3D hybrid NFS developed here provides a 3D structure for coculture of cancer and immune cells.

Nuclear DAMP complex-mediated RAGE-dependent macrophage cell death

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Ruochan; Department of Infectious Diseases and State Key Lab of Viral Hepatitis, Xiangya Hospital, Central South University, Changsha, Hunan 410008; Fu, Sha

High mobility group box 1 (HMGB1), histone, and DNA are essential nuclear components involved in the regulation of chromosome structure and function. In addition to their nuclear function, these molecules act as damage-associated molecular patterns (DAMPs) alone or together when released extracellularly. The synergistic effect of these nuclear DNA-HMGB1-histone complexes as DAMP complexes (nDCs) on immune cells remains largely unexplored. Here, we demonstrate that nDCs limit survival of macrophages (e.g., RAW264.7 and peritoneal macrophages) but not cancer cells (e.g., HCT116, HepG2 and Hepa1-6). nDCs promote production of inflammatory tumor necrosis factor α (TNFα) release, triggering reactive oxygen species-dependent apoptosis andmore » necrosis. Moreover, the receptor for advanced glycation end products (RAGE), but not toll-like receptor (TLR)-4 and TLR-2, was required for Akt-dependent TNFα release and subsequent cell death following treatment with nDCs. Genetic depletion of RAGE by RNAi, antioxidant N-Acetyl-L-cysteine, and TNFα neutralizing antibody significantly attenuated nDC-induced cell death. These findings provide evidence supporting novel signaling mechanisms linking nDCs and inflammation in macrophage cell death. - Highlights: • Nuclear DAMP complexes (nDCs) selectively induce cell death in macrophages, but not cancer cells. • TNFα-mediated oxidative stress is required for nDC-induced death. • RAGE-mediated Akt activation is required for nDC-induced TNFα release. • Blocking RAGE and TNFα inhibits nDC-induced macrophage cell death.« less

HIV-1 Env and Nef Cooperatively Contribute to Plasmacytoid Dendritic Cell Activation via CD4-Dependent Mechanisms.

PubMed

Reszka-Blanco, Natalia J; Sivaraman, Vijay; Zhang, Liguo; Su, Lishan

2015-08-01

Plasmacytoid dendritic cells (pDCs) are the major source of type I IFN (IFN-I) in response to human immunodeficiency virus type 1 (HIV-1) infection. pDCs are rapidly activated during HIV-1 infection and are implicated in reducing the early viral load, as well as contributing to HIV-1-induced pathogenesis. However, most cell-free HIV-1 isolates are inefficient in activating human pDCs, and the mechanisms of HIV-1 recognition by pDCs and pDC activation are not clearly defined. In this study, we report that two genetically similar HIV-1 variants (R3A and R3B) isolated from a rapid progressor differentially activated pDCs to produce alpha interferon (IFN-α). The highly pathogenic R3A efficiently activated pDCs to induce robust IFN-α production, while the less pathogenic R3B did not. The viral determinant for efficient pDC activation was mapped to the V1V2 region of R3A Env, which also correlated with enhanced CD4 binding activity. Furthermore, we showed that the Nef protein was also required for the activation of pDCs by R3A. Analysis of a panel of R3A Nef functional mutants demonstrated that Nef domains involved in CD4 downregulation were necessary for R3A to activate pDCs. Our data indicate that R3A-induced pDC activation depends on (i) the high affinity of R3A Env for binding the CD4 receptor and (ii) Nef activity, which is involved in CD4 downregulation. Our findings provide new insights into the mechanism by which HIV-1 induces IFN-α in pDCs, which contributes to pathogenesis. Plasmacytoid dendritic cells (pDCs) are the major type I interferon (IFN-I)-producing cells, and IFN-I actually contributes to pathogenesis during chronic viral infections. How HIV-1 activates pDCs and the roles of pDCs/IFN-I in HIV-1 pathogenesis remain unclear. We report here that the highly pathogenic HIV R3A efficiently activated pDCs to induce IFN-α production, while most HIV-1 isolates are inefficient in activating pDCs. We have discovered that R3A-induced pDC activation depends on (i) the high affinity of R3A Env for binding the CD4 receptor and (ii) Nef activity, which is involved in CD4 downregulation. Our findings thus provide new insights into the mechanism by which HIV-1 induces IFN-α in pDCs and contributes to HIV-1 pathogenesis. These novel findings will be of great interest to those working on the roles of IFN and pDCs in HIV-1 pathogenesis in general and on the interaction of HIV-1 with pDCs in particular. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Zoledronic acid modulates maturation of human monocyte-derived dendritic cells.

PubMed

Orsini, Giulia; Failli, Alessandra; Legitimo, Annalisa; Adinolfi, Barbara; Romanini, Antonella; Consolini, Rita

2011-12-01

Zoledronic acid (ZA) is a drug of the bisphosphonate class, which is widely used for the treatment of both osteoporosis and skeletal metastasis. Besides its main bone antiresorptive activity, ZA displays antitumor properties, by triggering the expansion and activation of γδ T-cells, which exert an antitumor effect through dendritic cells (DCs). Several studies have reported the interaction between ZA and γδ T-cells, but the potential immunoregulatory activity of this drug on DCs has scarcely been investigated. Therefore, in this paper, we evaluated the effects of a therapeutic dose of ZA on the in vitro generation and maturation of DCs derived from peripheral blood monocytes of healthy adult donors. We demonstrate that ZA treatment did not affect DC differentiation, but inhibited DC maturation on lipopolysaccharide activation, as shown by the impaired expression of maturation surface markers and reduced ability to induce allogeneic T-cell proliferation. Interestingly, IL-10 secretion by mature DCs was significantly lower in ZA-treated cells than in controls. We conclude that ZA exerts its immunological in vitro activity also by modulating the maturation of DCs.

Enhancement of Tumor-Specific T Cell–Mediated Immunity in Dendritic Cell–Based Vaccines by Mycobacterium tuberculosis Heat Shock Protein X

PubMed Central

Jung, In Duk; Shin, Sung Jae; Lee, Min-Goo; Kang, Tae Heung; Han, Hee Dong; Lee, Seung Jun; Kim, Woo Sik; Kim, Hong Min; Park, Won Sun; Kim, Han Wool; Yun, Cheol-Heui; Lee, Eun Kyung; Wu, T.-C.

2014-01-01

Despite the potential for stimulation of robust antitumor immunity by dendritic cells (DCs), clinical applications of DC-based immunotherapy are limited by the low potency in generating tumor Ag-specific T cell responses. Therefore, optimal conditions for generating potent immunostimulatory DCs that overcome tolerance and suppression are key factors in DC-based tumor immunotherapy. In this study, we demonstrate that use of the Mycobacterium tuberculosis heat shock protein X (HspX) as an immunoadjuvant in DC-based tumor immunotherapy has significant potential in therapeutics. In particular, the treatment aids the induction of tumor-reactive T cell responses, especially tumor-specific CTLs. The HspX protein induces DC maturation and proinflammatory cytokine production (TNF-α, IL-1β, IL-6, and IFN-β) through TLR4 binding partially mediated by both the MyD88 and the TRIF signaling pathways. We employed two models of tumor progression and metastasis to evaluate HspX-stimulated DCs in vivo. The administration of HspX-stimulated DCs increased the activation of naive T cells, effectively polarizing the CD4+ and CD8+ T cells to secrete IFN-γ, as well as enhanced the cytotoxicity of splenocytes against HPV-16 E7 (E7)–expressing TC-1 murine tumor cells in therapeutic experimental animals. Moreover, the metastatic capacity of B16-BL6 melanoma cancer cells toward the lungs was remarkably attenuated in mice that received HspX-stimulated DCs. In conclusion, the high therapeutic response rates with tumor-targeted Th1-type T cell immunity as a result of HspX-stimulated DCs in two models suggest that HspX harnesses the exquisite immunological power and specificity of DCs for the treatment of tumors. PMID:24990079

Cross-talk between T Cells and Hematopoietic Stem Cells during Adoptive Cellular Therapy for Malignant Glioma.

PubMed

Wildes, Tyler J; Grippin, Adam; Dyson, Kyle A; Wummer, Brandon M; Damiani, David J; Abraham, Rebecca S; Flores, Catherine T; Mitchell, Duane A

2018-04-30

Purpose: Adoptive T-cell immunotherapy (ACT) has emerged as a viable therapeutic for peripheral and central nervous system (CNS) tumors. In peripheral cancers, optimal efficacy of ACT is reliant on dendritic cells (DCs) in the tumor microenvironment. However, the CNS is largely devoid of resident migratory DCs to function as antigen-presenting cells during immunotherapy. Herein, we demonstrate that cellular interactions between adoptively transferred tumor-reactive T cells and bone marrow-derived hematopoietic stem and progenitor cells (HSPCs) lead to the generation of potent intratumoral DCs within the CNS compartment. Experimental Design: We evaluated HSPC differentiation during ACT in vivo in glioma-bearing hosts and HSPC proliferation and differentiation in vitro using a T-cell coculture system. We utilized FACS, ELISAs, and gene expression profiling to study the phenotype and function of HSPC-derived cells ex vivo and in vivo. To demonstrate the impact of HSPC differentiation and function on antitumor efficacy, we performed survival experiments. Results: Transfer of HSPCs with concomitant ACT led to the production of activated CD86 + CD11c + MHCII + cells consistent with DC phenotype and function within the brain tumor microenvironment. These intratumoral DCs largely supplanted abundant host myeloid-derived suppressor cells. We determined that during ACT, HSPC-derived cells in gliomas rely on T-cell-released IFNγ to differentiate into DCs, activate T cells, and reject intracranial tumors. Conclusions: Our data support the use of HSPCs as a novel cellular therapy. Although DC vaccines induce robust immune responses in the periphery, our data demonstrate that HSPC transfer uniquely generates intratumoral DCs that potentiate T-cell responses and promote glioma rejection in situ Clin Cancer Res; 1-12. ©2018 AACR. ©2018 American Association for Cancer Research.

Induction of antigen-specific cytotoxic T-cell response by dendritic cells generated from ecto-mesenchymal stem cells infected with an adenovirus containing the MAGE-D4a gene.

PubMed

Hu, Shijie; Li, Bing; Shen, Xuefeng; Zhang, Rui; Gao, Dakuan; Guo, Qingdong; Jin, Yan; Fei, Zhou

2016-04-01

The present study aimed to investigate the feasibility of using ecto-mesenchymal stem cell (EMSC)-derived dendritic cells (DCs) for glioma immunotherapy following infection by a recombinant adenovirus containing the melanoma-associated antigen D4a (MAGE-D4a) gene. The ex vivo cultured EMSCs were infected by the adenoviral plasmid containing MAGE-D4a (pAd/MAGE-D4a). Efficiency of transfection was evaluated through the detection of green fluorescent protein-marked MAGE-D4a. The MAGE-EMSCs were induced to differentiate into DCs, termed as MAGE-EMSCs-DCs. The morphology was subsequently analyzed under a microscope, and methyl thiazolyl tetrazolium (MTT) and interferon-γ (IFN-γ) assays were performed to analyze the cytotoxicity of the MAGE-EMSC-DCs on the human glioma U251 cell line. Following purification by magnetic-activated cell sorting, the EMSCs grew into swirls, with a long spindle shape and were fibroblast-like. The gene transfected with recombinant adenovirus vectors maintained high and stable expression levels of MAGE-D4a, and its efficiency was increased in a multiplicity of infection-dependent manner. The results of the MTT assay indicated that the T cells, primed by the recombinant MAGE-D4a-infected EMSC-DCs in vitro , recognized MAGE-D4a-expressing tumor cell lines in a human leukocyte antigen class I-restricted manner, and evoked a higher cytotoxic T cell (CTL) response. The CTL response induced by the MAGE-EMSC-DCs, co-cultured with the U251 cells for 24 h, produced 765.0 pg/ml IFN-γ, which was significantly greater when compared to the control wells. T lymphocytes stimulated by MAGE-EMSC-DCs evoke a higher CTL response to human glioma cell lines, and may serve as a promising therapeutic modality for the treatment of MAGE-D4a-expressing glioma.

Electroconvection in one-dimensional liquid crystal cells

NASA Astrophysics Data System (ADS)

Huh, Jong-Hoon

2018-04-01

We investigate the alternating current (ac) -driven electroconvection (EC) in one-dimensional cells (1DCs) under the in-plane switching mode. In 1DCs, defect-free EC can be realized. In the presence and absence of external multiplicative noise, the features of traveling waves (TWs), such as their Hopf frequency fH and velocity, are examined in comparison with those of conventional two-dimensional cells (2DCs) accompanying defects of EC rolls. In particular, we show that the defects significantly contribute to the features of the TWs. Additionally, owing to the defect-free EC in the 1DCs, the effects of the ac and noise fields on the TW are clarified. The ac field linearly increases fH, independent of the ac frequency f . The noise increases fH monotonically, but fH does not vary below a characteristic noise intensity VN*. In addition, soliton-like waves and unfamiliar oscillation of EC vortices in 1DCs are observed, in contrast to the localized EC (called worms) and the oscillation of EC rolls in 2DCs.

Classical dendritic cells mediate fibrosis directly via the retinoic acid pathway in severe eye allergy

PubMed Central

Ahadome, Sarah D.; Mathew, Rose; Reyes, Nancy J.; Mettu, Priyatham S.; Cousins, Scott W.; Calder, Virginia L.; Saban, Daniel R.

2016-01-01

Fibrosis is a shared end-stage pathway to lung, liver, and heart failure. In the ocular mucosa (conjunctiva), fibrosis leads to blindness in trachoma, pemphigoid, and allergy. The indirect fibrogenic role of DCs via T cell activation and inflammatory cell recruitment is well documented. However, here we demonstrate that DCs can directly induce fibrosis. In the mouse model of allergic eye disease (AED), classical CD11b+ DCs in the ocular mucosa showed increased activity of aldehyde dehydrogenase (ALDH), the enzyme required for retinoic acid synthesis. In vitro, CD11b+ DC–derived ALDH was associated with 9-cis-retinoic acid ligation to retinoid x receptor (RXR), which induced conjunctival fibroblast activation. In vivo, stimulating RXR led to rapid onset of ocular mucosal fibrosis, whereas inhibiting ALDH activity in DCs or selectively depleting DCs markedly reduced fibrosis. Collectively, these data reveal a profibrotic ALDH-dependent pathway by DCs and uncover a role for DC retinoid metabolism. PMID:27595139

The multifaceted biology of plasmacytoid dendritic cells

PubMed Central

Swiecki, Melissa; Colonna, Marco

2015-01-01

Plasmacytoid dendritic cells (pDCs) are a unique dendritic cell subset that specializes in the production of type I interferons (IFNs). pDCs promote antiviral immune responses and have been implicated in the pathogenesis of autoimmune diseases characterized by a type I IFN signature. However, pDCs can also induce tolerogenic immune responses. Here, we review recent progress from the field of pDC biology, focusing on: the molecular mechanisms that regulate pDC development and functions; the pathways involved in their sensing of pathogens and endogenous nucleic acids; the function of pDCs at mucosal sites; and their roles in infections, autoimmunity and cancer. PMID:26160613

Inhibition of HBV Replication in HepG2.2.15 Cells by Human Peripheral Blood Mononuclear Cell-Derived Dendritic Cells.

PubMed

Liu, Tao; Song, Hong-Li; Zheng, Wei-Ping; Shen, Zhong-Yang

2015-01-01

Anti-HBV therapy is essential for patients awaiting liver transplantation. This study aimed to explore the effects of dendritic cells (DCs) derived from the peripheral blood of hepatitis B patients on the replication of HBV in vivo and to evaluate the biosafety of DCs in clinical therapy. Peripheral blood mononuclear cells (PBMCs) were isolated from HBV-infected patients and maturation-promoting factors and both HBsAg and HBcAg were used to induce DC maturation. Mature DCs and lymphocytes were co-cultured with human hepatocyte cell HL-7702 or HBV-producing human hepatocellular carcinoma cell HepG2.2.15. We found that mature lymphocytes exposed to DCs in vitro did not influence morphology or activities of HL-7702 and HepG2.2.15 cells. Liver function indexes and endotoxin levels in the cell supernatants did not change in these co-cultures. Additionally, supernatant and intracellular HBV DNA levels were reduced when HepG2.2.15 cells were co-cultured with mature lymphocytes that had been cultured with DCs, and HBV covalently closed circular DNA (cccDNA) levels in HepG2.2.15 cells also decreased. Importantly, DC-mediated immunotherapy had no mutagenic effect on HBV genomic DNA by gene sequencing of the P, S, X, and C regions of HBV genomic DNA. We conclude that PBMC-derived DCs from HBV-infected patients act on autologous lymphocytes to suppress HBV replication and these DC clusters showed favorable biosafety. © 2015 by the Association of Clinical Scientists, Inc.

MIF Promotes Classical Activation and Conversion of Inflammatory Ly6Chigh Monocytes into TipDCs during Murine Toxoplasmosis

PubMed Central

Ruiz-Rosado, Juan de Dios; Olguín, Jonadab E.; Juárez-Avelar, Imelda; Saavedra, Rafael; Terrazas, Luis I.; Robledo-Avila, Frank H.; Vazquez-Mendoza, Alicia; Fernández, Jacquelina; Satoskar, Abhay R.; Partida-Sánchez, Santiago; Rodriguez-Sosa, Miriam

2016-01-01

Macrophage migration inhibitory factor (MIF) mediates immunity against Toxoplasma gondii infection by inducing inflammatory cytokines required to control the parasite replication. However, the role of this inflammatory mediator in the cell-mediated immune response against this infection is still poorly understood. Here, we used T. gondii-infected WT and Mif −/− mice to analyze the role of MIF in the maturation of CD11b+ and CD8α + dendritic cells (DCs). We found that MIF promotes maturation of CD11b+ but not CD8α + DCs, by inducing IL-12p70 production and CD86 expression. Infected Mif −/− mice showed significantly lower numbers of TNF and inducible nitric oxide synthase- (iNOS-) producing DCs (TipDCs) compared to infected WT mice. The adoptive transfer of Ly6Chigh monocytes into infected WT or Mif −/− mice demonstrated that MIF participates in the differentiation of Ly6Chigh monocytes into TipDCs. In addition, infected Mif −/− mice display a lower percentage of IFN-γ-producing natural killer (NK) cells compared to WT mice, which is associated with reducing numbers of TipDCs in Mif −/− mice. Furthermore, administration of recombinant MIF (rMIF) into T. gondii-infected Mif −/− mice restored the numbers of TipDCs and reversed the susceptible phenotype of Mif −/− mice. Collectively, these results demonstrate an important role for MIF inducing cell-mediated immunity to T. gondii infection. PMID:27057101

Profiling dendritic cell subsets in head and neck squamous cell tonsillar cancer and benign tonsils.

PubMed

Abolhalaj, Milad; Askmyr, David; Sakellariou, Christina Alexandra; Lundberg, Kristina; Greiff, Lennart; Lindstedt, Malin

2018-05-23

Dendritic cells (DCs) have a key role in orchestrating immune responses and are considered important targets for immunotherapy against cancer. In order to develop effective cancer vaccines, detailed knowledge of the micromilieu in cancer lesions is warranted. In this study, flow cytometry and human transcriptome arrays were used to characterize subsets of DCs in head and neck squamous cell tonsillar cancer and compare them to their counterparts in benign tonsils to evaluate subset-selective biomarkers associated with tonsillar cancer. We describe, for the first time, four subsets of DCs in tonsillar cancer: CD123 + plasmacytoid DCs (pDC), CD1c + , CD141 + , and CD1c - CD141 - myeloid DCs (mDC). An increased frequency of DCs and an elevated mDC/pDC ratio were shown in malignant compared to benign tonsillar tissue. The microarray data demonstrates characteristics specific for tonsil cancer DC subsets, including expression of immunosuppressive molecules and lower expression levels of genes involved in development of effector immune responses in DCs in malignant tonsillar tissue, compared to their counterparts in benign tonsillar tissue. Finally, we present target candidates selectively expressed by different DC subsets in malignant tonsils and confirm expression of CD206/MRC1 and CD207/Langerin on CD1c + DCs at protein level. This study descibes DC characteristics in the context of head and neck cancer and add valuable steps towards future DC-based therapies against tonsillar cancer.

Purified Dendritic Cell-Tumor Fusion Hybrids Supplemented with Non-Adherent Dendritic Cells Fraction Are Superior Activators of Antitumor Immunity

PubMed Central

Wang, Yucai; Liu, Yunyan; Zheng, Lianhe

2014-01-01

Background Strong evidence supports the DC-tumor fusion hybrid vaccination strategy, but the best fusion product components to use remains controversial. Fusion products contain DC-tumor fusion hybrids, unfused DCs and unfused tumor cells. Various fractions have been used in previous studies, including purified hybrids, the adherent cell fraction or the whole fusion mixture. The extent to which the hybrids themselves or other components are responsible for antitumor immunity or which components should be used to maximize the antitumor immunity remains unknown. Methods Patient-derived breast tumor cells and DCs were electro-fused and purified. The antitumor immune responses induced by the purified hybrids and the other components were compared. Results Except for DC-tumor hybrids, the non-adherent cell fraction containing mainly unfused DCs also contributed a lot in antitumor immunity. Purified hybrids supplemented with the non-adherent cell population elicited the most powerful antitumor immune response. After irradiation and electro-fusion, tumor cells underwent necrosis, and the unfused DCs phagocytosed the necrotic tumor cells or tumor debris, which resulted in significant DC maturation. This may be the immunogenicity mechanism of the non-adherent unfused DCs fraction. Conclusions The non-adherent cell fraction (containing mainly unfused DCs) from total DC/tumor fusion products had enhanced immunogenicity that resulted from apoptotic/necrotic tumor cell phagocytosis and increased DC maturation. Purified fusion hybrids supplemented with the non-adherent cell population enhanced the antitumor immune responses, avoiding unnecessary use of the tumor cell fraction, which has many drawbacks. Purified hybrids supplemented with the non-adherent cell fraction may represent a better approach to the DC-tumor fusion hybrid vaccination strategy. PMID:24466232

Comparison of cytotoxic T lymphocyte responses against pancreatic cancer induced by dendritic cells transfected with total tumor RNA and fusion hybrided with tumor cell

PubMed Central

Chen, Jiang; Li, Hong-Yu; Wang, Di; Shao, Xiao-Dong

2015-01-01

Pancreatic cancer (PC) is a deadly human malignancy. Dendritic cell (DC)-based immunotherapy with whole tumor antigens demonstrates potential efficiency in cancer treatment. Tumor RNA and tumor fusion hybrid cells are sources of whole tumor antigens for preparing DC tumor vaccines. However, the efficacy of these sources in eliciting immune responses against PC has not yet to be directly compared. In the present study, patient-derived PC cells and DCs were fused (DC–tumor hybrids) and primary cultured PC cell-derived total RNA was electroporated into autologous DCs (DC–tumor RNA). The antitumor immune responses induced by DC–tumor hybrids and DC–tumor RNA were compared directly. The results showed that both RNA and hybrid methodologies could induce tumor-specific cytotoxic T lymphocyte (CTL) responses, but pulsing DCs with total tumor RNA could induce a higher frequency of activated CTLs and T-helper cells than fusing DCs with autologous tumor cells. In addition, DC–tumor RNA triggered stronger autologous tumor cell lysis than DC–tumor hybrids. It could be concluded that DCs pulsed with whole tumor RNA are superior to those fused with tumor cells in priming anti-PC CTL responses. Electroporation with total tumor RNA may be more suitable for DC-based PC vaccination. PMID:25736302

Functional modulation of human intestinal epithelial cell responses by Bifidobacterium infantis and Lactobacillus salivarius

PubMed Central

O'Hara, Ann M; O'Regan, Padraig; Fanning, Áine; O'Mahony, Caitlin; MacSharry, John; Lyons, Anne; Bienenstock, John; O'Mahony, Liam; Shanahan, Fergus

2006-01-01

Intestinal epithelial cells (IECs) and dendritic cells (DCs) play a pivotal role in antigen sampling and the maintenance of gut homeostasis. However, the interaction of commensal bacteria with the intestinal surface remains incompletely understood. Here we investigated immune cell responses to commensal and pathogenic bacteria. HT-29 human IECs were incubated with Bifidobacterium infantis 35624, Lactobacillus salivarius UCC118 or Salmonella typhimurium UK1 for varying times, or were pretreated with a probiotic for 2 hr prior to stimulation with S. typhimurium or flagellin. Gene arrays were used to examine inflammatory gene expression. Nuclear factor (NF)-κB activation, interleukin (IL)-8 secretion, pathogen adherence to IECs, and mucin-3 (MUC3) and E-cadherin gene expression were assayed by TransAM assay, enzyme-linked immunosorbent assay (ELISA), fluorescence, and real-time reverse transcriptase–polymerase chain reaction (RT-PCR), respectively. IL-10 and tumour necrosis factor (TNF)-α secretion by bacteria-treated peripheral blood-derived DCs were measured using ELISA. S. typhimurium increased expression of 36 of the 847 immune-related genes assayed, including NF-κB and IL-8. The commensal bacteria did not alter expression levels of any of the 847 genes. However, B. infantis and L. salivarius attenuated both IL-8 secretion at baseline and S. typhimurium-induced pro-inflammatory responses. B. infantis also limited flagellin-induced IL-8 protein secretion. The commensal bacteria did not increase MUC3 or E-cadherin expression, or interfere with pathogen binding to HT-29 cells, but they did stimulate IL-10 and TNF-α secretion by DCs. The data demonstrate that, although the intestinal epithelium is immunologically quiescent when it encounters B. infantis or L. salivarius, these commensal bacteria exert immunomodulatory effects on intestinal immune cells that mediate host responses to flagellin and enteric pathogens. PMID:16771855

Failure To Recruit Anti-Inflammatory CD103+ Dendritic Cells and a Diminished CD4+ Foxp3+ Regulatory T Cell Pool in Mice That Display Excessive Lung Inflammation and Increased Susceptibility to Mycobacterium tuberculosis

PubMed Central

Leepiyasakulchai, Chaniya; Ignatowicz, Lech; Pawlowski, Andrzej; Källenius, Gunilla

2012-01-01

Susceptibility to Mycobacterium tuberculosis is characterized by excessive lung inflammation, tissue damage, and failure to control bacterial growth. To increase our understanding of mechanisms that may regulate the host immune response in the lungs, we characterized dendritic cells expressing CD103 (αE integrin) (αE-DCs) and CD4+ Foxp3+ regulatory T (Treg) cells during M. tuberculosis infection. In resistant C57BL/6 and BALB/c mice, the number of lung αE-DCs increased dramatically during M. tuberculosis infection. In contrast, highly susceptible DBA/2 mice failed to recruit αE-DCs even during chronic infection. Even though tumor necrosis factor alpha (TNF-α) is produced by multiple DCs and macrophage subsets and is required for control of bacterial growth, αE-DCs remained TNF-α negative. Instead, αE-DCs contained a high number of transforming growth factor beta-producing cells in infected mice. Further, we show that Treg cells in C57BL/6 and DBA/2 mice induce gamma interferon during pulmonary tuberculosis. In contrast to resistant mice, the Treg cell population was diminished in the lungs, but not in the draining pulmonary lymph nodes (PLN), of highly susceptible mice during chronic infection. Treg cells have been reported to inhibit M. tuberculosis-specific T cell immunity, leading to increased bacterial growth. Still, despite the reduced number of lung Treg cells in DBA/2 mice, the bacterial load in the lungs was increased compared to resistant animals. Our results show that αE-DCs and Treg cells that may regulate the host immune response are increased in M. tuberculosis-infected lungs of resistant mice but diminished in infected lungs of susceptible mice. PMID:22215739

Toxoplasma gondii infection shifts dendritic cells into an amoeboid rapid migration mode encompassing podosome dissolution, secretion of TIMP-1, and reduced proteolysis of extracellular matrix.

PubMed

Ólafsson, Einar B; Varas-Godoy, Manuel; Barragan, Antonio

2018-03-01

Dendritic cells (DCs) infected by Toxoplasma gondii rapidly acquire a hypermigratory phenotype that promotes systemic parasite dissemination by a "Trojan horse" mechanism in mice. Recent paradigms of leukocyte migration have identified the amoeboid migration mode of DCs as particularly suited for rapid locomotion in extracellular matrix and tissues. Here, we have developed a microscopy-based high-throughput approach to assess motility and matrix degradation by Toxoplasma-challenged murine and human DCs. DCs challenged with T. gondii exhibited dependency on metalloproteinase activity for hypermotility and transmigration but, strikingly, also dramatically reduced pericellular proteolysis. Toxoplasma-challenged DCs up-regulated expression and secretion of tissue inhibitor of metalloproteinases-1 (TIMP-1) and their supernatants impaired matrix degradation by naïve DCs and by-stander DCs dose dependently. Gene silencing of TIMP-1 by short hairpin RNA restored matrix degradation activity in Toxoplasma-infected DCs. Additionally, dissolution of podosome structures in parasitised DCs coincided with abrogated matrix degradation. Toxoplasma lysates inhibited pericellular proteolysis in a MyD88-dependent fashion whereas abrogated proteolysis persevered in Toxoplasma-infected MyD88-deficient DCs. This indicated that both TLR/MyD88-dependent and TLR/MyD88-independent signalling pathways mediated podosome dissolution and the abrogated matrix degradation. We report that increased TIMP-1 secretion and cytoskeletal rearrangements encompassing podosome dissolution are features of Toxoplasma-induced hypermigration of DCs with an impact on matrix degradation. Jointly, the data highlight how an obligate intracellular parasite orchestrates key regulatory cellular processes consistent with non-proteolytic amoeboid migration of the vehicle cells that facilitate its dissemination. © 2017 John Wiley & Sons Ltd.

Type I and Type II Interferon Coordinately Regulate Suppressive Dendritic Cell Fate and Function during Viral Persistence

PubMed Central

Cunningham, Cameron R.; Champhekar, Ameya; Tullius, Michael V.; Dillon, Barbara Jane; Zhen, Anjie; de la Fuente, Justin Rafael; Herskovitz, Jonathan; Elsaesser, Heidi; Snell, Laura M.; Wilson, Elizabeth B.; de la Torre, Juan Carlos; Kitchen, Scott G.; Horwitz, Marcus A.; Bensinger, Steven J.; Smale, Stephen T.; Brooks, David G.

2016-01-01

Persistent viral infections are simultaneously associated with chronic inflammation and highly potent immunosuppressive programs mediated by IL-10 and PDL1 that attenuate antiviral T cell responses. Inhibiting these suppressive signals enhances T cell function to control persistent infection; yet, the underlying signals and mechanisms that program immunosuppressive cell fates and functions are not well understood. Herein, we use lymphocytic choriomeningitis virus infection (LCMV) to demonstrate that the induction and functional programming of immunosuppressive dendritic cells (DCs) during viral persistence are separable mechanisms programmed by factors primarily considered pro-inflammatory. IFNγ first induces the de novo development of naive monocytes into DCs with immunosuppressive potential. Type I interferon (IFN-I) then directly targets these newly generated DCs to program their potent T cell immunosuppressive functions while simultaneously inhibiting conventional DCs with T cell stimulating capacity. These mechanisms of monocyte conversion are constant throughout persistent infection, establishing a system to continuously interpret and shape the immunologic environment. MyD88 signaling was required for the differentiation of suppressive DCs, whereas inhibition of stimulatory DCs was dependent on MAVS signaling, demonstrating a bifurcation in the pathogen recognition pathways that promote distinct elements of IFN-I mediated immunosuppression. Further, a similar suppressive DC origin and differentiation was also observed in Mycobacterium tuberculosis infection, HIV infection and cancer. Ultimately, targeting the underlying mechanisms that induce immunosuppression could simultaneously prevent multiple suppressive signals to further restore T cell function and control persistent infections. PMID:26808628

Efficacy of Dendritic Cells Matured Early with OK-432 (Picibanil®), Prostaglandin E2, and Interferon-α as a Vaccine for a Hormone Refractory Prostate Cancer Cell Line

PubMed Central

Yoo, Changhee; Do, Hyun-Ah; Jeong, In Gab; Park, Hongzoo; Hwang, Jung-Jin; Hong, Jun Hyuk; Cho, Jin Seon; Choo, Myong-Soo; Ahn, Hanjong

2010-01-01

Dendritic cells (DCs) are potent antigen-presenting cells. OK432 (Picibanil®) was introduced as a potent stimulator of DC maturation in combination with prostaglandin-E2 and interferon-α. We compared the efficacy of a DC-prostate cancer vaccine using early-mature DCs stimulated with OK432, PGE2 and INF-α (OPA) with that of vaccines using other methods. On days 3 or 7 of DC culture, TNF-α (T), TNF-α and LPS (TL) or OPA were employed as maturation stimulators. DU145 cells subjected to heat stress were hybridized with mature DCs using polyethyleneglycol. T cells were sensitized by the hybrids, and their proliferative and cytokine secretion activities and cytotoxicity were measured. The yields of early-mature DCs were higher, compared to yields at the conventional maturation time (P<0.05). In the early maturation setting, the mean fusion ratios, calculated from the fraction of dual-positive cells, were 13.3%, 18.6%, and 39.9%, respectively (P=0.051) in the T only, TL, and OPA-treated groups. The function of cytotoxic T cells, which were sensitized with the hybrids containing DCs matured early with OPA, was superior to that using other methods. The antitumor effects of DC-DU145 hybrids generated with DCs subjected to early maturation with the OPA may be superior to that of the hybrids using conventional maturation methods. PMID:20808670

Efficacy of dendritic cells matured early with OK-432 (Picibanil), prostaglandin E2, and interferon-alpha as a vaccine for a hormone refractory prostate cancer cell line.

PubMed

Yoo, Changhee; Do, Hyun-Ah; Jeong, In Gab; Park, Hongzoo; Hwang, Jung-Jin; Hong, Jun Hyuk; Cho, Jin Seon; Choo, Myong-Soo; Ahn, Hanjong; Kim, Choung-Soo

2010-09-01

Dendritic cells (DCs) are potent antigen-presenting cells. OK432 (Picibanil) was introduced as a potent stimulator of DC maturation in combination with prostaglandin-E(2) and interferon-alpha. We compared the efficacy of a DC-prostate cancer vaccine using early-mature DCs stimulated with OK432, PGE2 and INF-alpha (OPA) with that of vaccines using other methods. On days 3 or 7 of DC culture, TNF-alpha (T), TNF-alpha and LPS (TL) or OPA were employed as maturation stimulators. DU145 cells subjected to heat stress were hybridized with mature DCs using polyethyleneglycol. T cells were sensitized by the hybrids, and their proliferative and cytokine secretion activities and cytotoxicity were measured. The yields of early-mature DCs were higher, compared to yields at the conventional maturation time (P<0.05). In the early maturation setting, the mean fusion ratios, calculated from the fraction of dual-positive cells, were 13.3%, 18.6%, and 39.9%, respectively (P=0.051) in the T only, TL, and OPA-treated groups. The function of cytotoxic T cells, which were sensitized with the hybrids containing DCs matured early with OPA, was superior to that using other methods. The antitumor effects of DC-DU145 hybrids generated with DCs subjected to early maturation with the OPA may be superior to that of the hybrids using conventional maturation methods.

The Herpes Simplex Virus Type 1 Latency-Associated Transcript Inhibits Phenotypic and Functional Maturation of Dendritic Cells

PubMed Central

Dervillez, Xavier; Dasgupta, Gargi; Nguyen, Chelsea; Kabbara, Khaled W.; Jiang, Xianzhi; Nesburn, Anthony B.; Wechsler, Steven L.

2012-01-01

Abstract We recently found that the herpes simplex virus-1 (HSV-1) latency-associated transcript (LAT) results in exhaustion of virus-specific CD8+ T cells in latently-infected trigeminal ganglia (TG). In this study we sought to determine if this impairment may involve LAT directly and/or indirectly interfering with DC maturation. We found that a small number of HSV-1 antigen-positive DCs are present in the TG of latently-infected CD11c/eYFP mice; however, this does not imply that these DCs are acutely or latently infected. Some CD8+ T cells are adjacent to DCs, suggesting possible interactions. It has previously been shown that wild-type HSV-1 interferes with DC maturation. Here we show for the first time that this is associated with LAT expression, since compared to LAT(−) virus: (1) LAT(+) virus interfered with expression of MHC class I and the co-stimulatory molecules CD80 and CD86 on the surface of DCs; (2) LAT(+) virus impaired DC production of the proinflammatory cytokines IL-6, IL-12, and TNF-α; and (3) DCs infected in vitro with LAT(+) virus had significantly reduced the ability to stimulate HSV-specific CD8+ T cells. While a similar number of DCs was found in LAT(+) and LAT(−) latently-infected TG of CD11c/eYFP transgenic mice, more HSV-1 Ag-positive DCs and more exhausted CD8 T cells were seen with LAT(+) virus. Consistent with these findings, HSV-specific cytotoxic CD8+ T cells in the TG of mice latently-infected with LAT(+) virus produced less IFN-γ and TNF-α than those from TG of LAT(−)-infected mice. Together, these results suggest a novel immune-evasion mechanism whereby the HSV-1 LAT increases the number of HSV-1 Ag-positive DCs in latently-infected TG, and interferes with DC phenotypic and functional maturation. The effect of LAT on TG-resident DCs may contribute to the reduced function of HSV-specific CD8+ T cells in the TG of mice latently infected with LAT(+) virus. PMID:22512280

The Gene Expression Profile of CD11c+CD8α− Dendritic Cells in the Pre-Diabetic Pancreas of the NOD Mouse

PubMed Central

Beumer, Wouter; Welzen-Coppens, Jojanneke M. C.; van Helden-Meeuwsen, Cornelia G.; Gibney, Sinead M.; Drexhage, Hemmo A.; Versnel, Marjan A.

2014-01-01

Two major dendritic cell (DC) subsets have been described in the pancreas of mice: The CD11c+CD8α− DCs (strong CD4+ T cell proliferation inducers) and the CD8α+CD103+ DCs (T cell apoptosis inducers). Here we analyzed the larger subset of CD11c+CD8α− DCs isolated from the pancreas of pre-diabetic NOD mice for genome-wide gene expression (validated by Q-PCR) to elucidate abnormalities in underlying gene expression networks. CD11c+CD8α− DCs were isolated from 5 week old NOD and control C57BL/6 pancreas. The steady state pancreatic NOD CD11c+CD8α− DCs showed a reduced expression of several gene networks important for the prime functions of these cells, i.e. for cell renewal, immune tolerance induction, migration and for the provision of growth factors including those for beta cell regeneration. A functional in vivo BrdU incorporation test showed the reduced proliferation of steady state pancreatic DC. The reduced expression of tolerance induction genes (CD200R, CCR5 and CD24) was supported on the protein level by flow cytometry. Also previously published functional tests on maturation, immune stimulation and migration confirm the molecular deficits of NOD steady state DC. Despite these deficiencies NOD pancreas CD11c+CD8α− DCs showed a hyperreactivity to LPS, which resulted in an enhanced pro-inflammatory state characterized by a gene profile of an enhanced expression of a number of classical inflammatory cytokines. The enhanced up-regulation of inflammatory genes was supported by the in vitro cytokine production profile of the DCs. In conclusion, our data show that NOD pancreatic CD11c+CD8α− DCs show various deficiencies in steady state, while hyperreactive when encountering a danger signal such as LPS. PMID:25166904

Abnormal costimulatory phenotype and function of dendritic cells before and after the onset of severe murine lupus

PubMed Central

Colonna, Lucrezia; Dinnall, Joudy-Ann; Shivers, Debra K; Frisoni, Lorenza; Caricchio, Roberto; Gallucci, Stefania

2006-01-01

We analyzed the activation and function of dendritic cells (DCs) in the spleens of diseased, lupus-prone NZM2410 and NZB-W/F1 mice and age-matched BALB/c and C57BL/6 control mice. Lupus DCs showed an altered ex vivo costimulatory profile, with a significant increase in the expression of CD40, decreased expression of CD80 and CD54, and normal expression of CD86. DCs from young lupus-prone NZM2410 mice, before the development of the disease, expressed normal levels of CD80 and CD86 but already overexpressed CD40. The increase in CD40-positive cells was specific for DCs and involved the subset of myeloid and CD8α+ DCs before disease onset, with a small involvement of plasmacytoid DCs in diseased mice. In vitro data from bone marrow-derived DCs and splenic myeloid DCs suggest that the overexpression of CD40 is not due to a primary alteration of CD40 regulation in DCs but rather to an extrinsic stimulus. Our analyses suggest that the defect of CD80 in NZM2410 and NZB-W/F1 mice, which closely resembles the costimulatory defect found in DCs from humans with systemic lupus erythematosus, is linked to the autoimmune disease. The increase in CD40 may instead participate in disease pathogenesis, being present months before any sign of autoimmunity, and its downregulation should be explored as an alternative to treatment with anti-CD40 ligand in lupus. PMID:16507174

Identification of Barramundi (Lates calcarifer) DC-SCRIPT, a Specific Molecular Marker for Dendritic Cells in Fish

PubMed Central

Zoccola, Emmanuelle; Delamare-Deboutteville, Jérôme; Barnes, Andrew C.

2015-01-01

Antigen presentation is a critical step bridging innate immune recognition and specific immune memory. In mammals, the process is orchestrated by dendritic cells (DCs) in the lymphatic system, which initiate clonal proliferation of antigen-specific lymphocytes. However, fish lack a classical lymphatic system and there are currently no cellular markers for DCs in fish, thus antigen-presentation in fish is poorly understood. Recently, antigen-presenting cells similar in structure and function to mammalian DCs were identified in various fish, including rainbow trout (Oncorhynchus mykiss) and zebrafish (Danio rerio). The present study aimed to identify a potential molecular marker for DCs in fish and therefore targeted DC-SCRIPT, a well-conserved zinc finger protein that is preferentially expressed in all sub-types of human DCs. Putative dendritic cells were obtained in culture by maturation of spleen and pronephros-derived monocytes. DC-SCRIPT was identified in barramundi by homology using RACE PCR and genome walking. Specific expression of DC-SCRIPT was detected in barramundi cells by Stellaris mRNA FISH, in combination with MHCII expression when exposed to bacterial derived peptidoglycan, suggesting the presence of DCs in L. calcarifer. Moreover, morphological identification was achieved by light microscopy of cytospins prepared from these cultures. The cultured cells were morphologically similar to mammalian and trout DCs. Migration assays determined that these cells have the ability to move towards pathogens and pathogen associated molecular patterns, with a preference for peptidoglycans over lipopolysaccharides. The cells were also strongly phagocytic, engulfing bacteria and rapidly breaking them down. Barramundi DCs induced significant proliferation of responder populations of T-lymphocytes, supporting their role as antigen presenting cells. DC-SCRIPT expression in head kidney was higher 6 and 24 h following intraperitoneal challenge with peptidoglycan and lipopolysaccharide and declined after 3 days relative to PBS-injected controls. Relative expression was also lower in the spleen at 3 days post challenge but increased again at 7 days. As DC-SCRIPT is a constitutively expressed nuclear receptor, independent of immune activation, this may indicate initial migration of immature DCs from head kidney and spleen to the injection site, followed by return to the spleen for maturation and antigen presentation. DC-SCRIPT may be a valuable tool in the investigation of antigen presentation in fish and facilitate optimisation of vaccines and adjuvants for aquaculture. PMID:26173015

Dendritic Cell Activity Driven by Recombinant Mycobacterium bovis BCG Producing Human IL-18, in Healthy BCG Vaccinated Adults.

PubMed

Szpakowski, Piotr; Biet, Franck; Locht, Camille; Paszkiewicz, Małgorzata; Rudnicka, Wiesława; Druszczyńska, Magdalena; Allain, Fabrice; Fol, Marek; Pestel, Joël; Kowalewicz-Kulbat, Magdalena

2015-01-01

Tuberculosis remains an enormous global burden, despite wide vaccination coverage with the Bacillus Calmette-Guérin (BCG), the only vaccine available against this disease, indicating that BCG-driven immunity is insufficient to protect the human population against tuberculosis. In this study we constructed recombinant BCG producing human IL-18 (rBCGhIL-18) and investigated whether human IL-18 produced by rBCGhIL-18 modulates DC functions and enhances Th1 responses to mycobacterial antigens in humans. We found that the costimulatory CD86 and CD80 molecules were significantly upregulated on rBCGhIL-18-infected DCs, whereas the stimulation of DCs with nonrecombinant BCG was less effective. In contrast, both BCG strains decreased the DC-SIGN expression on human DCs. The rBCGhIL-18 increased IL-23, IL-10, and IP-10 production by DCs to a greater extent than nonrecombinant BCG. In a coculture system of CD4(+) T cells and loaded DCs, rBCGhIL-18 favoured strong IFN-γ but also IL-10 production by naive T cells but not by memory T cells. This was much less the case for nonrecombinant BCG. Thus the expression of IL-18 by recombinant BCG increases IL-23, IP-10, and IL-10 expression by human DCs and enhances their ability to induce IFN-γ and IL-10 expression by naive T cells, without affecting the maturation phenotype of the DCs.

Dendritic Cell Activity Driven by Recombinant Mycobacterium bovis BCG Producing Human IL-18, in Healthy BCG Vaccinated Adults

PubMed Central

Biet, Franck; Rudnicka, Wiesława; Druszczyńska, Magdalena; Fol, Marek; Pestel, Joël

2015-01-01

Tuberculosis remains an enormous global burden, despite wide vaccination coverage with the Bacillus Calmette-Guérin (BCG), the only vaccine available against this disease, indicating that BCG-driven immunity is insufficient to protect the human population against tuberculosis. In this study we constructed recombinant BCG producing human IL-18 (rBCGhIL-18) and investigated whether human IL-18 produced by rBCGhIL-18 modulates DC functions and enhances Th1 responses to mycobacterial antigens in humans. We found that the costimulatory CD86 and CD80 molecules were significantly upregulated on rBCGhIL-18-infected DCs, whereas the stimulation of DCs with nonrecombinant BCG was less effective. In contrast, both BCG strains decreased the DC-SIGN expression on human DCs. The rBCGhIL-18 increased IL-23, IL-10, and IP-10 production by DCs to a greater extent than nonrecombinant BCG. In a coculture system of CD4+ T cells and loaded DCs, rBCGhIL-18 favoured strong IFN-γ but also IL-10 production by naive T cells but not by memory T cells. This was much less the case for nonrecombinant BCG. Thus the expression of IL-18 by recombinant BCG increases IL-23, IP-10, and IL-10 expression by human DCs and enhances their ability to induce IFN-γ and IL-10 expression by naive T cells, without affecting the maturation phenotype of the DCs. PMID:26339658

Impact of HBeAg on the maturation and function of dendritic cells.

PubMed

Lan, Songsong; Wu, Lecan; Wang, Xiuyan; Wu, Jinming; Lin, Xianfan; Wu, Wenzhi; Huang, Zhiming

2016-05-01

HBV infection typically leads to chronic hepatitis in newborns and some adults with weakened immune systems. The mechanisms by which virus escapes immunity remain undefined. Regulatory dendritic cells (DCregs) contributing to immune escape have been described. We wondered whether or not HBeAg as an immunomodulatory protein could induce DCreg which might subsequently result into HBV persistence. The immunophenotyping, T-cell activation and cytokine production were analyzed in HBeAg-treated DCs from normal or cyclophosphamide (Cy)-induced immunocompromised mice. HBeAg tended to promote bone marrow derived DCs (BMDCs) from Cy-treated mice into CD11b(high)PIR-B(+) regulatory DCs exhibiting the lowest T-cell stimulatory capacity and interleukin (IL)-12p70 production compared with controls. Neutralization of IL-10 significantly inhibited the regulatory effect of these DCs on T-cell stimulation of mature DCs. After lipopolysaccharides (LPS) stimulation, marked phosphorylation of Akt was detected in HBeAg treated DCs from immunocompromised mice. Blocking the PI3K-Akt pathway by LY294002 led to an enhancement of IL-12 production. PI3K signalling pathway appears to be involved in the decreased IL-12 secretion by HBeAg treated DCs. These findings suggest that HBeAg may program the generation of a new DC subset with regulatory capacity under the condition of immunosuppression, which may presumably contribute to the persistent HBV infection. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Propolis modulates miRNAs involved in TLR-4 pathway, NF-κB activation, cytokine production and in the bactericidal activity of human dendritic cells.

PubMed

Conti, Bruno J; Santiago, Karina B; Cardoso, Eliza O; Freire, Paula P; Carvalho, Robson F; Golim, Marjorie A; Sforcin, José M

2016-12-01

Dendritic cells (DCs) are antigen-presenting cells, essential for recognition and presentation of pathogens to T cells. Propolis, a resinous material produced by bees from various plants, exhibits numerous biological properties, highlighting its immunomodulatory action. Here, we assayed the effects of propolis on the maturation and function of human DCs. DCs were generated from human monocytes and incubated with propolis and LPS. NF-κB and cytokines production were determined by ELISA. microRNA's expression was analysed by RT-qPCR and cell markers detection by flow cytometry. Colony-forming units were obtained to assess the bactericidal activity of propolis-treated DCs. Propolis activated DCs in the presence of LPS, inducing NF-kB, TNF-α, IL-6 and IL-10 production. The inhibition of hsa-miR-148a and hsa-miR-148b abolished the inhibitory effects on HLA-DR and pro-inflammatory cytokines. The increased expression of hsa-miR-155 may be correlated to the increase in TLR-4 and CD86 expression, maintaining LPS-induced expression of HLA-DR and CD40. Such parameters may be involved in the increased bactericidal activity of DCs against Streptococcus mutans. Propolis modulated the maturation and function of DCs and may be useful in the initial steps of the immune response, providing a novel approach to the development of DC-based strategies and for the discovery of new immunomodulators. © 2016 Royal Pharmaceutical Society.

Deficiency in plasmacytoid dendritic cells and type I interferon signalling prevents diet-induced obesity and insulin resistance in mice.

PubMed

Hannibal, Tine D; Schmidt-Christensen, Anja; Nilsson, Julia; Fransén-Pettersson, Nina; Hansen, Lisbeth; Holmberg, Dan

2017-10-01

Obesity is associated with glucose intolerance and insulin resistance and is closely linked to the increasing prevalence of type 2 diabetes. In mouse models of diet-induced obesity (DIO) and type 2 diabetes, an increased fat intake results in adipose tissue expansion and the secretion of proinflammatory cytokines. The innate immune system not only plays a crucial role in obesity-associated chronic low-grade inflammation but it is also proposed to play a role in modulating energy metabolism. However, little is known about how the modulation of metabolism by the immune system may promote increased adiposity in the early stages of increased dietary intake. Here we aimed to define the role of type I IFNs in DIO and insulin resistance. Mice lacking the receptor for IFN-α (IFNAR -/- ) and deficient in plasmacytoid dendritic cells (pDCs) (B6.E2-2 fl/fl .Itgax-cre) were fed a diet with a high fat content or normal chow. The mice were analysed in vivo and in vitro using cellular, biochemical and molecular approaches. We found that the development of obesity was inhibited by an inability to respond to type I IFNs. Furthermore, the development of obesity and insulin resistance in this model was associated with pDC recruitment to the fatty tissues and liver of obese mice (a 4.3-fold and 2.7-fold increase, respectively). Finally, we demonstrated that the depletion of pDCs protects mice from DIO and from developing obesity-associated metabolic complications. Our results provide genetic evidence that pDCs, via type I IFNs, regulate energy metabolism and promote the development of obesity.

Cross-linking of CD81 by HCV-E2 protein inhibits human intrahepatic plasmacytoid dendritic cells response to CpG-ODN

PubMed Central

Tu, Zhengkun; Zhang, Ping; Li, Haijun; Niu, Junqi; Jin, Xia; Su, Lishan

2014-01-01

Plasmacytoid dendritic cells (pDCs) are reported to be defective in HCV-infected patients, the mechanisms of which remain poorly understood. We isolated liver derived mononuclear cells (LMNCs) and pDCs from normal liver tissues of benign tumor dissections and liver transplant donors. Isolated pDCs and LMNCs were cultured with precoated HCV envelop protein E2 (HCV-E2) or anti-CD81 mAb in the presence of CpG-ODN. Our results show that cross-linking of CD81 by either HCV-E2 or anti-CD81 mAb inhibits IFN-α secretion in CpG-induced pDCs; down-regulates HLA-DR, CD80 and CD86 expression in pDCs; and suppresses CpG-ODN induced proliferation and survival of pDCs. The blockade of CD81 by soluble anti-CD81 antibody restores pDCs response to CpG-ODN. These results suggest that HCV E2 protein interacts with CD81 to inhibit pDC maturation, activation, and IFN-α production, and may thereby contribute to the impaired innate anti-viral immune response in HCV infection. PMID:23954883

Dendritic Cell Activation by Glucan Isolated from Umbilicaria Esculenta

PubMed Central

Kim, Hyung Sook; Kim, Jee Youn; Lee, Hong Kyung; Kim, Moo Sung; Lee, Sang Rin; Kang, Jong Soon; Kim, Hwan Mook; Lee, Kyung-Ae; Hong, Jin Tae; Kim, Youngsoo

2010-01-01

Background Lichen-derived glucans have been known to stimulate the functions of immune cells. However, immunostimulatory activity of glucan obtained from edible lichen, Umbilicaria esculenta, has not been reported. Thus we evaluated the phenotype and functional maturation of dendritic cells (DCs) following treatment of extracted glucan (PUE). Methods The phenotypic and functional maturation of PUE-treated DCs was assessed by flow cytometric analysis and cytokine production, respectively. PUE-treated DCs was also used for mixed leukocyte reaction to evaluate T cell-priming capacity. Finally we detected the activation of MAPK and NF-κB by immunoblot. Results Phenotypic maturation of DCs was shown by the elevated expressions of CD40, CD80, CD86, and MHC class I/II molecules. Functional activation of DCs was proved by increased cytokine production of IL-12, IL-1β, TNF-α, and IFN-α/β, decreased endocytosis, and enhanced proliferation of allogenic T cells. Polymyxin B, specific inhibitor of lipopolysaccharide (LPS), did not affect PUE activity, which suggested that PUE was free of LPS contamination. As a mechanism of action, PUE increased phosphorylation of ERK, JNK, and p38 MAPKs, and enhanced nuclear translocation of NF-κB p50/p65 in DCs. Conclusion These results indicate that PUE induced DC maturation via MAPK and NF-κB signaling pathways. PMID:21286379

Enhanced glucocorticoid-induced leucine zipper in dendritic cells induces allergen-specific regulatory CD4(+) T-cells in respiratory allergies.

PubMed

Karaki, S; Garcia, G; Tcherakian, C; Capel, F; Tran, T; Pallardy, M; Humbert, M; Emilie, D; Godot, V

2014-05-01

Respiratory allergies rely on a defect of IL-10-secreting regulatory CD4(+) T-cells (IL-10-Tregs ) leading to excessive Th2-biased immune responses to allergens. According to clinical data, the restoration of allergen-specific IL-10-Tregs is required to control respiratory allergies and cure patients. The discovery of mechanisms involved in the generation of IL-10-Tregs will thus help to provide effective treatments. We previously demonstrated that dendritic cells (DCs) expressing high levels of the glucocorticoid-induced leucine zipper protein (GILZ) generate antigen-specific IL-10-Tregs . We suspect a defective expression of GILZ in the DCs of respiratory allergic patients and speculate that increasing its expression might restore immune tolerance against allergens through the induction of IL-10-Tregs . We assessed GILZ expression in blood DCs of patients and healthy nonallergic donors by qPCR. We compared the ability of patients' DCs to induce allergen-specific IL-10-Tregs before and after an in vivo up-regulation of GILZ expression by steroid administration, steroids being inducers of GILZ. We report lower levels of GILZ in DCs of respiratory allergic patients that return to normal levels after steroid administration. We show that patients' DCs with increased levels of GILZ generate allergen-specific IL-10-Tregs again. We further confirm unequivocally that GILZ is required in patients' DCs to activate these IL-10-Tregs . This proof of concept study shows that the re-establishment of GILZ expression in patients' DCs to normal levels restores their capacity to activate allergen-specific IL-10-Tregs . We thus highlight the up-regulation of GILZ in DCs as a new interventional approach to restore the immune tolerance to allergens. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Brucella discriminates between mouse dendritic cell subsets upon in vitro infection.

PubMed

Papadopoulos, Alexia; Gagnaire, Aurélie; Degos, Clara; de Chastellier, Chantal; Gorvel, Jean-Pierre

2016-01-01

Brucella is a Gram-negative bacterium responsible for brucellosis, a worldwide re-emerging zoonosis. Brucella has been shown to infect and replicate within Granulocyte macrophage colony-stimulating factor (GMCSF) in vitro grown bone marrow-derived dendritic cells (BMDC). In this cell model, Brucella can efficiently control BMDC maturation. However, it has been shown that Brucella infection in vivo induces spleen dendritic cells (DC) migration and maturation. As DCs form a complex network composed by several subpopulations, differences observed may be due to different interactions between Brucella and DC subsets. Here, we compare Brucella interaction with several in vitro BMDC models. The present study shows that Brucella is capable of replicating in all the BMDC models tested with a high infection rate at early time points in GMCSF-IL15 DCs and Flt3l DCs. GMCSF-IL15 DCs and Flt3l DCs are more activated than the other studied DC models and consequently intracellular bacteria are not efficiently targeted to the ER replicative niche. Interestingly, GMCSF-DC and GMCSF-Flt3l DC response to infection is comparable. However, the key difference between these 2 models concerns IL10 secretion by GMCSF DCs observed at 48 h post-infection. IL10 secretion can explain the weak secretion of IL12p70 and TNFα in the GMCSF-DC model and the low level of maturation observed when compared to GMCSF-IL15 DCs and Flt3l DCs. These models provide good tools to understand how Brucella induce DC maturation in vivo and may lead to new therapeutic design using DCs as cellular vaccines capable of enhancing immune response against pathogens.

Liver-primed memory T cells generated under noninflammatory conditions provide anti-infectious immunity.

PubMed

Böttcher, Jan P; Schanz, Oliver; Wohlleber, Dirk; Abdullah, Zeinab; Debey-Pascher, Svenja; Staratschek-Jox, Andrea; Höchst, Bastian; Hegenbarth, Silke; Grell, Jessica; Limmer, Andreas; Atreya, Imke; Neurath, Markus F; Busch, Dirk H; Schmitt, Edgar; van Endert, Peter; Kolanus, Waldemar; Kurts, Christian; Schultze, Joachim L; Diehl, Linda; Knolle, Percy A

2013-03-28

Development of CD8(+) T cell (CTL) immunity or tolerance is linked to the conditions during T cell priming. Dendritic cells (DCs) matured during inflammation generate effector/memory T cells, whereas immature DCs cause T cell deletion/anergy. We identify a third outcome of T cell priming in absence of inflammation enabled by cross-presenting liver sinusoidal endothelial cells. Such priming generated memory T cells that were spared from deletion by immature DCs. Similar to central memory T cells, liver-primed T cells differentiated into effector CTLs upon antigen re-encounter on matured DCs even after prolonged absence of antigen. Their reactivation required combinatorial signaling through the TCR, CD28, and IL-12R and controlled bacterial and viral infections. Gene expression profiling identified liver-primed T cells as a distinct Neuropilin-1(+) memory population. Generation of liver-primed memory T cells may prevent pathogens that avoid DC maturation by innate immune escape from also escaping adaptive immunity through attrition of the T cell repertoire. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

Critical role of dendritic cells in T cell retention in the interfollicular region of Peyer's patches.

PubMed

Obata, Takashi; Shibata, Naoko; Goto, Yoshiyuki; Ishikawa, Izumi; Sato, Shintaro; Kunisawa, Jun; Kiyono, Hiroshi

2013-07-15

Peyer's patches (PPs) simultaneously initiate active and quiescent immune responses in the gut. The immunological function is achieved by the rigid regulation of cell distribution and trafficking, but how the cell distribution is maintained remains to be elucidated. In this study, we show that binding of stromal cell-derived lymphoid chemokines to conventional dendritic cells (cDCs) is essential for the retention of naive CD4(+) T cells in the interfollicular region (IFR) of PPs. Transitory depletion of CD11c(high) cDCs in mice rapidly impaired the IFR structure in the PPs without affecting B cell follicles or germinal centers, lymphoid chemokine production from stromal cells, or the immigration of naive T cells into the IFRs of PPs. The cDC-orchestrated retention of naive T cells was mediated by heparinase-sensitive molecules that were expressed on cDCs and bound the lymphoid chemokine CCL21 produced from stromal cells. These data collectively reveal that interactions among cDCs, stromal cells, and naive T cells are necessary for the formation of IFRs in the PPs.

Targeting dendritic cells--why bother?

PubMed

Kreutz, Martin; Tacken, Paul J; Figdor, Carl G

2013-04-11

Vaccination is among the most efficient forms of immunotherapy. Although sometimes inducing lifelong protective B-cell responses, T-cell-mediated immunity remains challenging. Targeting antigen to dendritic cells (DCs) is an extensively explored concept aimed at improving cellular immunity. The identification of various DC subsets with distinct functional characteristics now allows for the fine-tuning of targeting strategies. Although some of these DC subsets are regarded as superior for (cross-) priming of naive T cells, controversies still remain about which subset represents the best target for immunotherapy. Because targeting the antigen alone may not be sufficient to obtain effective T-cell responses, delivery systems have been developed to target multiple vaccine components to DCs. In this Perspective, we discuss the pros and cons of targeting DCs: if targeting is beneficial at all and which vaccine vehicles and immunization routes represent promising strategies to reach and activate DCs.

R5 HIV-1 envelope attracts dendritic cells to cross the human intestinal epithelium and sample luminal virions via engagement of the CCR5

PubMed Central

Cavarelli, Mariangela; Foglieni, Chiara; Rescigno, Maria; Scarlatti, Gabriella

2013-01-01

The gastrointestinal tract is a principal route of entry and site of persistence of human immunodeficiency virus type 1 (HIV-1). The intestinal mucosa, being rich of cells that are the main target of the virus, represents a primary site of viral replication and CD4+ T-cell depletion. Here, we show both in vitro and ex vivo that HIV-1 of R5 but not X4 phenotype is capable of selectively triggering dendritic cells (DCs) to migrate within 30 min between intestinal epithelial cells to sample virions and transfer infection to target cells. The engagement of the chemokine receptor 5 on DCs and the viral envelope, regardless of the genetic subtype, drive DC migration. Viruses penetrating through transient opening of the tight junctions likely create a paracellular gradient to attract DCs. The formation of junctions with epithelial cells may initiate a haptotactic process of DCs and at the same time favour cell-to-cell viral transmission. Our findings indicate that HIV-1 translocation across the intestinal mucosa occurs through the selective engagement of DCs by R5 viruses, and may guide the design of new prevention strategies. PMID:23606583

R5 HIV-1 envelope attracts dendritic cells to cross the human intestinal epithelium and sample luminal virions via engagement of the CCR5.

PubMed

Cavarelli, Mariangela; Foglieni, Chiara; Rescigno, Maria; Scarlatti, Gabriella

2013-05-01

The gastrointestinal tract is a principal route of entry and site of persistence of human immunodeficiency virus type 1 (HIV-1). The intestinal mucosa, being rich of cells that are the main target of the virus, represents a primary site of viral replication and CD4(+) T-cell depletion. Here, we show both in vitro and ex vivo that HIV-1 of R5 but not X4 phenotype is capable of selectively triggering dendritic cells (DCs) to migrate within 30 min between intestinal epithelial cells to sample virions and transfer infection to target cells. The engagement of the chemokine receptor 5 on DCs and the viral envelope, regardless of the genetic subtype, drive DC migration. Viruses penetrating through transient opening of the tight junctions likely create a paracellular gradient to attract DCs. The formation of junctions with epithelial cells may initiate a haptotactic process of DCs and at the same time favour cell-to-cell viral transmission. Our findings indicate that HIV-1 translocation across the intestinal mucosa occurs through the selective engagement of DCs by R5 viruses, and may guide the design of new prevention strategies. Copyright © 2013 The Authors. Published by John Wiley and Sons, Ltd on behalf of EMBO.

Tumor-Derived Microvesicles Modulate Antigen Cross-Processing via Reactive Oxygen Species-Mediated Alkalinization of Phagosomal Compartment in Dendritic Cells.

PubMed

Battisti, Federico; Napoletano, Chiara; Rahimi Koshkaki, Hassan; Belleudi, Francesca; Zizzari, Ilaria Grazia; Ruscito, Ilary; Palchetti, Sara; Bellati, Filippo; Benedetti Panici, Pierluigi; Torrisi, Maria Rosaria; Caracciolo, Giulio; Altieri, Fabio; Nuti, Marianna; Rughetti, Aurelia

2017-01-01

Dendritic cells (DCs) are the only antigen-presenting cells able to prime naïve T cells and cross-prime antigen-specific CD8 + T cells. Their functionality is a requirement for the induction and maintenance of long-lasting cancer immunity. Albeit intensively investigated, the in vivo mechanisms underlying efficient antigen cross-processing and presentation are not fully understood. Several pieces of evidence indicate that antigen transfer to DCs mediated by microvesicles (MVs) enhances antigen immunogenicity. This mechanism is also relevant for cross-presentation of those tumor-associated glycoproteins such as MUC1 that are blocked in HLA class II compartment when internalized by DCs as soluble molecules. Here, we present pieces of evidence that the internalization of tumor-derived MVs modulates antigen-processing machinery of DCs. Employing MVs derived from ovarian cancer ascites fluid and established tumor cell lines, we show that MV uptake modifies DC phagosomal microenvironment, triggering reactive oxygen species (ROS) accumulation and early alkalinization. Indeed, tumor MVs carry radical species and the MV uptake by DCs counteracts the chemically mediated acidification of the phagosomal compartment. Further pieces of evidence suggest that efficacious antigen cross-priming of the MUC1 antigen carried by the tumor MVs results from the early signaling induced by MV internalization and the function of the antigen-processing machinery of DCs. These results strongly support the hypothesis that tumor-derived MVs impact antigen immunogenicity by tuning the antigen-processing machinery of DCs, besides being carrier of tumor antigens. Furthermore, these findings have important implications for the exploitation of MVs as antigenic cell-free immunogen for DC-based therapeutic strategies.

Existence of CD8α-like dendritic cells with a conserved functional specialization and a common molecular signature in distant mammalian species.

PubMed

Contreras, Vanessa; Urien, Céline; Guiton, Rachel; Alexandre, Yannick; Vu Manh, Thien-Phong; Andrieu, Thibault; Crozat, Karine; Jouneau, Luc; Bertho, Nicolas; Epardaud, Mathieu; Hope, Jayne; Savina, Ariel; Amigorena, Sebastian; Bonneau, Michel; Dalod, Marc; Schwartz-Cornil, Isabelle

2010-09-15

The mouse lymphoid organ-resident CD8alpha(+) dendritic cell (DC) subset is specialized in Ag presentation to CD8(+) T cells. Recent evidence shows that mouse nonlymphoid tissue CD103(+) DCs and human blood DC Ag 3(+) DCs share similarities with CD8alpha(+) DCs. We address here whether the organization of DC subsets is conserved across mammals in terms of gene expression signatures, phenotypic characteristics, and functional specialization, independently of the tissue of origin. We study the DC subsets that migrate from the skin in the ovine species that, like all domestic animals, belongs to the Laurasiatheria, a distinct phylogenetic clade from the supraprimates (human/mouse). We demonstrate that the minor sheep CD26(+) skin lymph DC subset shares significant transcriptomic similarities with mouse CD8alpha(+) and human blood DC Ag 3(+) DCs. This allowed the identification of a common set of phenotypic characteristics for CD8alpha-like DCs in the three mammalian species (i.e., SIRP(lo), CADM1(hi), CLEC9A(hi), CD205(hi), XCR1(hi)). Compared to CD26(-) DCs, the sheep CD26(+) DCs show 1) potent stimulation of allogeneic naive CD8(+) T cells with high selective induction of the Ifngamma and Il22 genes; 2) dominant efficacy in activating specific CD8(+) T cells against exogenous soluble Ag; and 3) selective expression of functional pathways associated with high capacity for Ag cross-presentation. Our results unravel a unifying definition of the CD8alpha(+)-like DCs across mammalian species and identify molecular candidates that could be used for the design of vaccines applying to mammals in general.

Dendritic cells infected by Ad-sh-SOCS1 enhance cytokine-induced killer (CIK) cell immunotherapeutic efficacy in cervical cancer models.

PubMed

Zheng, Yi; Hu, Bicheng; Xie, Shenggao; Chen, Xiaofan; Hu, Yuqian; Chen, Wanping; Li, Shanshan; Hu, Bo

2017-05-01

Cervical cancer constitutes a major problem in women's health worldwide, but the efficacy of the standard therapy is unsatisfactory. Cytokine-induced killer (CIK) cells exhibit antitumor activity against a variety of malignancies in preclinical models and have proven safe and effective in clinical trials. However, current CIK therapy has limitations and needs to be improved to meet the clinical requirements. The aim of this study was to investigate whether suppressing the expression of cytokine signaling 1 (SOCS1) in dendritic cells (DCs) can shorten in vitro CIK culture time and improve its antitumor efficacy. DCs were pre-cultured for 3 days before infected with adenovirus-mediated-SOCS1 short hairpin RNA (Ad-sh-SOCS1) and pulsed with CTL epitope peptides E7. The DCs infected by Ad-sh-SOCS1 (gmDCs) and CIKs were then co-cultured for 5 or 9 days, and CIK proliferation and antitumor activity were evaluated both in vitro and in vivo. Our data show that gmDCs significantly stimulated the expansion of co-cultured CIKs and increased the secretion of interferon-γ and interleukin-12. Moreover, gmDCs-activated CIKs showed higher cytotoxic activity against TC-1 cells expressing HPV16E6 and E7. Our in vivo study showed that the mice infused with gmDCs-activated CIKs on day 10 had an increased survival rate and prolonged survival time compared with the controls. Taken together, these results indicate that DCs modified by adenovirus-mediated SOCS1 silencing can promote CIKs expansion and enhance the efficacy of antitumor immunotherapy both in vitro and in vivo, which represents an effective therapeutic approach for cervical cancer and other tumors. Copyright © 2017 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

Adoptive transfer of dendritic cells expressing CD11c reduces the immunological response associated with experimental colitis in BALB/c mice.

PubMed

Paiatto, Lisiery N; Silva, Fernanda G D; Yamada, Áureo T; Tamashiro, Wirla M S C; Simioni, Patricia U

2018-01-01

In addition to conventional therapies, several new strategies have been proposed for modulating autoimmune diseases, including the adoptive transfer of immunological cells. In this context, dendritic cells (DCs) appear to be one of the most promising treatments for autoimmune disorders. The present study aimed to evaluate the effects of adoptive transfer of DCs obtained from both naïve and ovalbumin (OVA)-tolerant mice on the severity of TNBS induced colitis and analyze the eventual protective mechanisms. To induce oral tolerance, BALB/c mice were fed 4mg/mL OVA solution for seven consecutive days. Spleen DCs were isolated from tolerant (tDC) and naïve (nDC) mice, and then adoptively transferred to syngeneic mice. Three days later, colitis was induced in DC treated mice by intrarectal instillation of 100μg2,4,6-trinitrobenzenesulfonic acid (TNBS) dissolved in 50% ethanol. Control subjects received only intrarectal instillation of either TNBS solution or a vehicle. Five days later, mice from all groups were euthanized and examined for physiological and immunological parameters. Regarding the phenotype, we observed that the frequencies of CD11+ MHC II+ and CD11+ MHCII+ CD86+ cells were significantly lower in DCs isolated from tolerant mice than in those from naive mice. However, pretreatment with both types of DCs was able to significantly reduce clinical signs of colitis such as diarrhea, rectal prolapse, bleeding, and cachexia, although only treatment with tDCs was able to prevent weight loss from instillation of TNBS. In vitro proliferation of spleen cells from mice treated with either type of DCs was significantly lower than that observed in splenic cell cultures of naïve mice. Although no significant difference was observed in the frequencies of Treg cells in the experimental groups, the frequency of Th17+CD4+cellsand the secretion of IL-17 were more reduced in the cultures of spleen cells from mice treated with either type of DCs. The levels of IL-9 and IFN-γ were lower in supernatants of cells from mice treated with nDCs. The results allow us to conclude that the adoptive transfer of cells expressing CD11c is able to reduce the clinical and immunological signs of drug-induced colitis. Adoptive transfer of CD11c+DC isolated from both naive and tolerant mice altered the proliferative and T cell responses. To the best of our knowledge, there is no previously published data showing the protective effects of DCs from naïve or tolerant mice in the treatment of colitis.

Langerhans cells utilize CD1a and langerin to efficiently present nonpeptide antigens to T cells

PubMed Central

Hunger, Robert E.; Sieling, Peter A.; Ochoa, Maria Teresa; Sugaya, Makoto; Burdick, Anne E.; Rea, Thomas H.; Brennan, Patrick J.; Belisle, John T.; Blauvelt, Andrew; Porcelli, Steven A.; Modlin, Robert L.

2004-01-01

Langerhans cells (LCs) constitute a subset of DCs that initiate immune responses in skin. Using leprosy as a model, we investigated whether expression of CD1a and langerin, an LC-specific C-type lectin, imparts a specific functional role to LCs. LC-like DCs and freshly isolated epidermal LCs presented nonpeptide antigens of Mycobacterium leprae to T cell clones derived from a leprosy patient in a CD1a-restricted and langerin-dependent manner. LC-like DCs were more efficient at CD1a-restricted antigen presentation than monocyte-derived DCs. LCs in leprosy lesions coexpress CD1a and langerin, placing LCs in position to efficiently present a subset of antigens to T cells as part of the host response to human infectious disease. PMID:14991068

Integrative analysis reveals CD38 as a therapeutic target for plasma cell-rich pre-disease and established rheumatoid arthritis and systemic lupus erythematosus.

PubMed

Cole, Suzanne; Walsh, Alice; Yin, Xuefeng; Wechalekar, Mihir D; Smith, Malcolm D; Proudman, Susanna M; Veale, Douglas J; Fearon, Ursula; Pitzalis, Costantino; Humby, Frances; Bombardieri, Michele; Axel, Amy; Adams, Homer; Chiu, Christopher; Sharp, Michael; Alvarez, John; Anderson, Ian; Madakamutil, Loui; Nagpal, Sunil; Guo, Yanxia

2018-05-02

Plasmablasts and plasma cells play a key role in many autoimmune diseases, such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). This study was undertaken to evaluate the potential of targeting CD38 as a plasma cell/plasmablast depletion mechanism by daratumumab in the treatment of patients with RA and SLE. RNA-sequencing analysis of synovial biopsies from various stages of RA disease progression, flow cytometry analysis of peripheral blood mononuclear cells (PBMC) from patients with RA or SLE and healthy donors, immunohistochemistry assessment (IHC) of synovial biopsies from patients with early RA, and ex vivo immune cell depletion assays using daratumumab (an anti-CD38 monoclonal antibody) were used to assess CD38 as a therapeutic target. We demonstrated that the plasma cell/plasmablast-related genes CD38, XBP1, IRF4, PRDM1, IGJ and TNFSF13B are significantly up-regulated in synovial biopsies from patients with arthralgia, undifferentiated arthritis (UA), early RA and established RA as compared to healthy controls and control patients with osteoarthritis. In addition, the highest CD38 expression was observed on plasma cells and plasmablasts compared to natural killer (NK) cells, classical dendritic cells (DCs), plasmacytoid DCs (pDCs) and T cells, in blood from healthy controls and patients with SLE and RA. Furthermore, IHC showed CD38 staining in the same region as CD3 and CD138 staining in synovial tissue biopsies from patients with early RA. Most importantly, our data show for the first time that daratumumab effectively depletes plasma cells/plasmablasts in PBMC from patients with SLE and RA in a dose-dependent manner ex vivo. These results indicate that CD38 may be a potential target for RA disease interception and daratumumab should be evaluated clinically for the treatment of both RA and SLE.

Modulatory effects of Echinacea purpurea extracts on human dendritic cells: a cell- and gene-based study.

PubMed

Wang, Chien-Yu; Chiao, Ming-Tsang; Yen, Po-Jen; Huang, Wei-Chou; Hou, Chia-Chung; Chien, Shih-Chang; Yeh, Kuo-Chen; Yang, Wen-Ching; Shyur, Lie-Fen; Yang, Ning-Sun

2006-12-01

Echinacea spp. are popularly used as an herbal medicine or food supplement for enhancing the immune system. This study shows that plant extracts from root [R] and stem plus leaf [S+L] tissues of E. purpurea exhibit opposite (enhancing vs inhibitory) modulatory effects on the expression of the CD83 marker in human dendritic cells (DCs), which are known as professional antigen-presenting cells. We developed a function-targeted DNA microarray system to characterize the effects of phytocompounds on human DCs. Down-regulation of mRNA expression of specific chemokines (e.g., CCL3 and CCL8) and their receptors (e.g., CCR1 and CCR9) was observed in [S+L]-treated DCs. Other chemokines and regulatory molecules (e.g., CCL4 and CCL2) involved in the c-Jun pathway were found to be up-regulated in [R]-treated DCs. This study, for the first time, demonstrates that E. purpurea extracts can modulate DC differentiation and expression of specific immune-related genes in DCs.

Generation of CTL responses against pancreatic cancer in vitro using dendritic cells co-transfected with MUC4 and survivin RNA.

PubMed

Chen, Jiang; Guo, Xiao-Zhong; Li, Hong-Yu; Liu, Xu; Ren, Li-Nan; Wang, Di; Zhao, Jia-Jun

2013-09-23

Pancreatic cancer (PC) is one of the most devastating human malignancies without effective therapies. Tumor vaccine based on RNA-transfected dendritic cells (DCs) has emerged as an alternative therapeutic approach for a variety of human cancers including advanced PC. In the present study we compared the cytotoxic T lymphocyte (CTL) responses against PC cells in vitro, which were induced by DCs co-transfected with two mRNAs of tumor associated-antigens (TAA) MUC4 and survivin, versus DCs transfected with a single mRNA encoding either MUC4 or survivin. DCs co-transfected with two TAA mRNAs were found to induce stronger CTL responses against PC target cells in vitro, compared with the DCs transfected with a single mRNA. Moreover, the antigen-specific CTL responses were MHC class I-restricted. These results provide an experimental foundation for further clinical investigations of DC vaccines encoding multiple TAA epitopes for metastatic PC. Copyright © 2013 Elsevier Ltd. All rights reserved.

Collecting lymphatic vessel permeability facilitates adipose tissue inflammation and distribution of antigen to lymph node-homing adipose tissue dendritic cells.

PubMed

Kuan, Emma L; Ivanov, Stoyan; Bridenbaugh, Eric A; Victora, Gabriel; Wang, Wei; Childs, Ed W; Platt, Andrew M; Jakubzick, Claudia V; Mason, Robert J; Gashev, Anatoliy A; Nussenzweig, Michel; Swartz, Melody A; Dustin, Michael L; Zawieja, David C; Randolph, Gwendalyn J

2015-06-01

Collecting lymphatic vessels (CLVs), surrounded by fat and endowed with contractile muscle and valves, transport lymph from tissues after it is absorbed into lymphatic capillaries. CLVs are not known to participate in immune responses. In this study, we observed that the inherent permeability of CLVs allowed broad distribution of lymph components within surrounding fat for uptake by adjacent macrophages and dendritic cells (DCs) that actively interacted with CLVs. Endocytosis of lymph-derived Ags by these cells supported recall T cell responses in the fat and also generated Ag-bearing DCs for emigration into adjacent lymph nodes (LNs). Enhanced recruitment of DCs to inflammation-reactive LNs significantly relied on adipose tissue DCs to maintain sufficient numbers of Ag-bearing DCs as the LN expanded. Thus, CLVs coordinate inflammation and immunity within adipose depots and foster the generation of an unexpected pool of APCs for Ag transport into the adjacent LN. Copyright © 2015 by The American Association of Immunologists, Inc.

[Preparation and characterization of nanoemulsion].

PubMed

Sun, Yu-Jing; Wu, Dao-Cheng; Cao, Yun-Xin; Sui, Yan-Fang

2005-01-01

To prepare nanoemulsion-encapsulated BSA-FITC (NEBSA-FITC), study its characteristics, and measure its uptake by dendritic cells (DCs) and peritoneal macrophages. NEBSA-FITC was prepared by a method of interfacial polymerization.The encapsulation rate, drug-carrying capacity and stability of the nanoemulsion were determined by Sephadex-G100 chromatography. The shape and size of NEBSA-FITC were observed under electron microscope. The uptake of NEBSA-FITC by DCs and macrophage cells was detected by FACS and laser confocal microscopy. The mean size of NEBSA-FITC was (25+/-10) nm. The encapsulation rate was 91%, the drug-carrying capacity was 0.091 g/L and NEBSA-FITC had a good stability. The FACS analysis showed that DCs and macrophage cells could take in more NEBSA-FITC than free BSA. The observation under laser confocal microscope found that NEBSA-FITC was located in the cytoplasm of DCs. Nanoemulsion can be efficiently taken by DCs and macrophage cells, and therefore may be promising efficient carrier of APCs-targeted antitumor vaccine.

Invariant natural killer T-cell control of type 1 diabetes: a dendritic cell genetic decision of a silver bullet or Russian roulette.

PubMed

Driver, John P; Scheuplein, Felix; Chen, Yi-Guang; Grier, Alexandra E; Wilson, S Brian; Serreze, David V

2010-02-01

In part, activation of invariant natural killer T (iNKT)-cells with the superagonist alpha-galactosylceramide (alpha-GalCer) inhibits the development of T-cell-mediated autoimmune type 1 diabetes in NOD mice by inducing the downstream differentiation of antigen-presenting dendritic cells (DCs) to an immunotolerogenic state. However, in other systems iNKT-cell activation has an adjuvant-like effect that enhances rather than suppresses various immunological responses. Thus, we tested whether in some circumstances genetic variation would enable activated iNKT-cells to support rather than inhibit type 1 diabetes development. We tested whether iNKT-conditioned DCs in NOD mice and a major histocompatibility complex-matched C57BL/6 (B6) background congenic stock differed in capacity to inhibit type 1 diabetes induced by the adoptive transfer of pathogenic AI4 CD8 T-cells. Unlike those of NOD origin, iNKT-conditioned DCs in the B6 background stock matured to a state that actually supported rather than inhibited AI4 T-cell-induced type 1 diabetes. The induction of a differing activity pattern of T-cell costimulatory molecules varying in capacity to override programmed death-ligand-1 inhibitory effects contributes to the respective ability of iNKT-conditioned DCs in NOD and B6 background mice to inhibit or support type 1 diabetes development. Genetic differences inherent to both iNKT-cells and DCs contribute to their varying interactions in NOD and B6.H2(g7) mice. This great variability in the interactions between iNKT-cells and DCs in two inbred mouse strains should raise a cautionary note about considering manipulation of this axis as a potential type 1 diabetes prevention therapy in genetically heterogeneous humans.

Activation of chicken bone marrow-derived dendritic cells induced by a Salmonella Enteritidis ghost vaccine candidate.

PubMed

Kamble, N M; Jawale, C V; Lee, J H

2016-10-01

Bacterial Ghost-based vaccine development has been applied to a variety of gram-negative bacteria. Developed Salmonella Enteritidis (S. Enteritidis) ghost are promising vaccine candidates because of their immunogenic and enhanced biosafety potential. In this study, we aimed to evaluate the immunostimulatory effect of a S. Enteritidis ghost vaccine on the maturation of chicken bone marrow-derived dendritic cells (chBM-DCs) in vitro The immature chBM-DCs were stimulated with S. Enteritidis ghost vaccine candidate. The vaccine efficiently stimulated maturation events in chBM-DCs, indicated by up-regulated expression of CD40, CD80, and MHC-II molecules. Immature BM-DCs responded to stimulation with S. Enteritidis ghost by increased expression of IL-6 and IL-12p40 cytokines. Also, S. Enteritidis ghost stimulated chBM-DCs induced the significant expression of IFN-γ and IL-2 in co-cultured autologous CD4+ T cells. In conclusion, our data suggest that S. Enteritidis ghost vaccine candidate is capable of activating and interacting with chBM-DCs. The results from current study may help for rational designing of Salmonella ghost based heterologous antigen delivery platforms to dendritic cells. © 2016 Poultry Science Association Inc.

Leishmania-infected MHC class IIhigh dendritic cells polarize CD4+ T cells toward a nonprotective T-bet+ IFN-γ+ IL-10+ phenotype.

PubMed

Resende, Mariana; Moreira, Diana; Augusto, Jorge; Cunha, Joana; Neves, Bruno; Cruz, Maria Teresa; Estaquier, Jérôme; Cordeiro-da-Silva, Anabela; Silvestre, Ricardo

2013-07-01

A differential behavior among infected and bystander dendritic cells (DCs) has been explored in different infection models. We have analyzed both populations sorted on contact with visceral Leishmania infantum on a susceptible mice model evaluating the subsequent repercussions on adaptive immune response. Our results demonstrate a clear dichotomy between the immunomodulatory abilities of bystander and infected DCs. The bystander population presents increased levels of IL-12p40 and costimulatory molecules being capable to induce CD4(+) T cell activation with immune protective capabilities. In contrast, infected DCs, which express lower costimulatory molecules and higher levels of IL-10, promote the development of Leishmania Ag-specific, nonprotective T-bet(+)IFN-γ(+)IL-10(+) CD4(+) T cells with an effector phenotype. This specific polarization was found to be dependent on IL-12p70. Splenic infected DCs recovered from chronic infected animals are similarly capable to polarize ex vivo syngeneic naive CD4(+) T cells toward a T-bet(+)IFN-γ(+)IL-10(+) phenotype. Further analysis revealed that only MHC class II(high)-infected DCs were responsible for this polarization. The adoptive transfer of such polarized CD4(+) T cells facilitates visceral leishmaniasis in BALB/c mice in a clear contrast with their counterpart generated with bystander DCs that significantly potentiate protection. Further, we demonstrated that CD4(+) T cells primed by infected DCs in an IL-10 free system, thus deprived of T-bet(+)IFN-γ(+)IL-10(+) population, restore the immune response and reduce parasite load, supporting a deleterious role of IFN-γ(+)IL-10(+) T cells in the maintenance of infection. Overall, our results highlight novel subversion mechanisms by which nonprotective T-bet(+)IFN-γ(+)IL-10(+) T cells are associated with chronicity and prolonged parasite persistence.

pDC therapy induces recovery from EAE by recruiting endogenous pDC to sites of CNS inflammation.

PubMed

Duraes, Fernanda V; Lippens, Carla; Steinbach, Karin; Dubrot, Juan; Brighouse, Dale; Bendriss-Vermare, Nathalie; Issazadeh-Navikas, Shohreh; Merkler, Doron; Hugues, Stephanie

2016-02-01

Plasmacytoid dendritic cells (pDCs) exhibit both innate and adaptive functions. In particular they are the main source of type I IFNs and directly impact T cell responses through antigen presentation. We have previously demonstrated that during experimental autoimmune encephalomyelitis (EAE) initiation, myelin-antigen presentation by pDCs is associated with suppressive Treg development and results in attenuated EAE. Here, we show that pDCs transferred during acute disease phase confer recovery from EAE. Clinical improvement is associated with migration of injected pDCs into inflamed CNS and is dependent on the subsequent and selective chemerin-mediated recruitment of endogenous pDCs to the CNS. The protective effect requires pDC pre-loading with myelin antigen, and is associated with the modulation of CNS-infiltrating pDC phenotype and inhibition of CNS encephalitogenic T cells. This study may pave the way for novel pDC-based cell therapies in autoimmune diseases, aiming at specifically modulating pathogenic cells that induce and sustain autoimmune inflammation. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

The melanocortin receptor agonist NDP-MSH impairs the allostimulatory function of dendritic cells.

PubMed

Rennalls, La'Verne P; Seidl, Thomas; Larkin, James M G; Wellbrock, Claudia; Gore, Martin E; Eisen, Tim; Bruno, Ludovica

2010-04-01

As alpha-melanocyte-stimulating hormone (alpha-MSH) is released by immunocompetent cells and has potent immunosuppressive properties, it was determined whether human dendritic cells (DCs) express the receptor for this hormone. Reverse transcription-polymerase chain reaction detected messenger RNA specific for all of the known melanocortin receptors in DCs. Mixed lymphocyte reactions also revealed that treatment with [Nle(4), DPhe(7)]-alpha-MSH (NDP-MSH), a potent alpha-MSH analogue, significantly reduced the ability of DCs to stimulate allogeneic T cells. The expression of various cell surface adhesion, maturation and costimulatory molecules on DCs was also investigated. Although treatment with NDP-MSH did not alter the expression of CD83 and major histocompatibility complex class I and II, the surface expression of CD86 (B7.2), intercellular adhesion molecule (ICAM-1/CD54) and CD1a was reduced. In summary, our data indicate that NDP-MSH inhibits the functional activity of DCs, possibly by down-regulating antigen-presenting and adhesion molecules and that these events may be mediated via the extracellular signal-regulated kinase 1 and 2 pathway.

Vinpocetine Inhibited the CpG Oligodeoxynucleotide-induced Immune Response in Plasmacytoid Dendritic Cells.

PubMed

Feng, Xungang; Wang, Yuzhong; Hao, Yanlei; Ma, Qun; Dai, Jun; Liang, Zhibo; Liu, Yantao; Li, Xiangyuan; Song, Yan; Si, Chuanping

2017-04-01

Plasmacytoid dendritic cells (pDCs) exert dual roles in immune responses through inducing inflammation and maintaining immune tolerance. A switch of pDC phenotype from pro-inflammation to tolerance has therapeutic promise in the treatment of autoimmune diseases. Vinpocetine, a vasoactive vinca alkaloid extracted from the periwinkle plant, has recently emerged as an immunomodulatory agent. In this study, we evaluated the effect of vinpocetine on phenotype of pDCs isolated from C57BL/6 mice and explored its possible mechanism. Our data showed that vinpocetine significantly downregulated the expression of CD40, CD80, and CD86 on pDCs and increased the expression of translocator protein (TSPO), the specific receptor of vinpocetine, in pDCs. Vinpocetine significantly inhibited the Toll-like receptor 9 signaling pathway and reduced the secretion of related cytokines in pDCs through TSPO. Furthermore, viability of pDCs was significantly promoted by vinpocetine. These findings imply that vinpocetine serves as an immunomodulatory agent for pDCs and may be applied for the treatment of pDCs-related autoimmune diseases.

Dendritic cells combined with tumor cells and α-galactosylceramide induce a potent, therapeutic and NK-cell dependent antitumor immunity in B cell lymphoma.

PubMed

Escribà-Garcia, Laura; Alvarez-Fernández, Carmen; Tellez-Gabriel, Marta; Sierra, Jorge; Briones, Javier

2017-05-26

Invariant natural killer T (iNKT) cells are a small population of lymphocytes with unique specificity for glycolipid antigens presented by non-polymorphic CD1d receptor on dendritic cells (DCs). iNKT cells play a central role in tumor immunology since they are implicated in the coordination of innate and adaptive immune responses. These cells can be activated with the prototypic lipid α-galactosylceramide (α-GalCer), stimulating interferon gamma (IFN-γ) production and cytokine secretion, which contribute to the enhancement of T cell activation. We evaluated the antitumor effect of a combination of dendritic cells (DCs) and tumor cells with the iNKT cell agonist α-GalCer in a therapeutic model of B cell lymphoma. iNKT, NK and T cell phenotype was determined by flow cytometry. Serum cytokines were analyzed by Luminex technology. Significant differences between survival curves were assessed by the log-rank test. For all other data, Mann-Whitney test was used to analyze the differences between groups. This vaccine induced a potent (100% survival), long-lasting and tumor-specific antitumor immune response, that was associated with an increase of both Th1 cytokines and IFN-γ secreting iNKT cells (4.59 ± 0.41% vs. 0.92 ± 0.12% in control group; p = 0.01) and T cells (CD4 IFN-γ + : 3.75 ± 0.59% vs. 0.66 ± 0.18% p = 0.02; CD8 IFN-γ + : 10.61 ± 0.84% vs. 0.47 ± 0.03% p = 0.002). Importantly, natural killer (NK) cells played a critical role in the antitumor effect observed after vaccination. This study provides clinically relevant data for the development of iNKT-cell based immunotherapy treatments for patients with B cell malignancies.

Sphingosine 1-Phosphate- and C-C Chemokine Receptor 2-Dependent Activation of CD4+ Plasmacytoid Dendritic Cells in the Bone Marrow Contributes to Signs of Sepsis-Induced Immunosuppression

PubMed Central

Smirnov, Anna; Pohlmann, Stephanie; Nehring, Melanie; Ali, Shafaqat; Mann-Nüttel, Ritu; Scheu, Stefanie; Antoni, Anne-Charlotte; Hansen, Wiebke; Büettner, Manuela; Gardiasch, Miriam J.; Westendorf, Astrid M.; Wirsdörfer, Florian; Pastille, Eva; Dudda, Marcel; Flohé, Stefanie B.

2017-01-01

Sepsis is the dysregulated response of the host to systemic, mostly bacterial infection, and is associated with an enhanced susceptibility to life-threatening opportunistic infections. During polymicrobial sepsis, dendritic cells (DCs) secrete enhanced levels of interleukin (IL) 10 due to an altered differentiation in the bone marrow and contribute to the development of immunosuppression. We investigated the origin of the altered DC differentiation using murine cecal ligation and puncture (CLP), a model for human polymicrobial sepsis. Bone marrow cells (BMC) were isolated after sham or CLP operation, the cellular composition was analyzed, and bone marrow-derived DCs (BMDCs) were generated in vitro. From 24 h on after CLP, BMC gave rise to BMDC that released enhanced levels of IL-10. In parallel, a population of CD11chiMHCII+CD4+ DCs expanded in the bone marrow in a MyD88-dependent manner. Prior depletion of the CD11chiMHCII+CD4+ DCs from BMC in vitro reversed the increased IL-10 secretion of subsequently differentiating BMDC. The expansion of the CD11chiMHCII+CD4+ DC population in the bone marrow after CLP required the function of sphingosine 1-phosphate receptors and C-C chemokine receptor (CCR) 2, the receptor for C-C chemokine ligand (CCL) 2, but was not associated with monocyte mobilization. CD11chiMHCII+CD4+ DCs were identified as plasmacytoid DCs (pDCs) that had acquired an activated phenotype according to their increased expression of MHC class II and CD86. A redistribution of CD4+ pDCs from MHC class II− to MHC class II+ cells concomitant with enhanced expression of CD11c finally led to the rise in the number of CD11chiMHCII+CD4+ DCs. Enhanced levels of CCL2 were found in the bone marrow of septic mice and the inhibition of CCR2 dampened the expression of CD86 on CD4+ pDCs after CLP in vitro. Depletion of pDCs reversed the bias of splenic DCs toward increased IL-10 synthesis after CLP in vivo. Thus, during polymicrobial sepsis, CD4+ pDCs are activated in the bone marrow and induce functional reprogramming of differentiating BMDC toward an immunosuppressive phenotype. PMID:29218051

Engineering Immunity: Modulating Dendritic Cell Subsets and Lymph Node Response to Direct Immune-polarization and Vaccine Efficacy

PubMed Central

Leleux, Jardin; Atalis, Alexandra; Roy, Krishnendu

2017-01-01

While successful vaccines have been developed against many pathogens, there are still many diseases and pathogenic infections that are highly evasive to current vaccination strategies. Thus, more sophisticated approaches to control the type and quality of vaccine-induced immune response must be developed. Dendritic cells (DCs) are the sentinels of the body and play a critical role in immune response generation and direction by bridging innate and adaptive immunity. It is now well recognized that DCs can be separated into many subgroups, each of which has a unique function. Better understanding of how various DC subsets, in lymphoid organs and in the periphery, can be targeted through controlled delivery; and how these subsets modulate and control the resulting immune response could greatly enhance our ability to develop new, effective vaccines against complex diseases. In this review, we provide an overview of DC subset biology and discuss current immunotherapeutic strategies that utilize DC targeting to modulate and control immune responses. PMID:26489733

Differential Recruitment of Dendritic Cells Subsets to Lymph Nodes Correlates with a Protective or Permissive T-Cell Response during Leishmania (Viannia) Braziliensis or Leishmania (Leishmania) Amazonensis Infection.

PubMed

Carvalho, A K; Carvalho, K; Passero, L F D; Sousa, M G T; da Matta, V L R; Gomes, C M C; Corbett, C E P; Kallas, G E; Silveira, F T; Laurenti, M D

2016-01-01

Leishmania (L.) amazonensis (La) and L. (V.) braziliensis (Lb) are responsible for a large clinical and immunopathological spectrum in human disease; while La may be responsible for anergic disease, Lb infection leads to cellular hypersensitivity. To better understand the dichotomy in the immune response caused by these Leishmania species, we evaluated subsets of dendritic cells (DCs) and T lymphocyte in draining lymph nodes during the course of La and Lb infection in BALB/c mice. Our results demonstrated a high involvement of DCs in La infection, which was characterized by the greater accumulation of Langerhans cells (LCs); conversely, Lb infection led to an increase in dermal DCs (dDCs) throughout the infection. Considering the T lymphocyte response, an increase of effector, activated, and memory CD4(+) T-cells was observed in Lb infection. Interleukin- (IL-) 4- and IL-10-producing CD4(+)and CD8(+) T-cells were present in both La and Lb infection; however, interferon- (IFN-) γ-producing CD4(+)and CD8(+) T-cells were detected only in Lb infection. The results suggest that during Lb infection, the dDCs were the predominant subset of DCs that in turn was associated with the development of Th1 immune response; in contrast La infection was associated with a preferential accumulation of LCs and total blockage of the development of Th1 immune response.

Reprogramming tumor-infiltrating dendritic cells for CD103+ CD8+ mucosal T-cell differentiation and breast cancer rejection.

PubMed

Wu, Te-Chia; Xu, Kangling; Banchereau, Romain; Marches, Florentina; Yu, Chun I; Martinek, Jan; Anguiano, Esperanza; Pedroza-Gonzalez, Alexander; Snipes, G Jackson; O'Shaughnessy, Joyce; Nishimura, Stephen; Liu, Yong-Jun; Pascual, Virginia; Banchereau, Jacques; Oh, Sangkon; Palucka, Karolina

2014-05-01

Our studies showed that tumor-infiltrating dendritic cells (DC) in breast cancer drive inflammatory Th2 (iTh2) cells and protumor inflammation. Here, we show that intratumoral delivery of the β-glucan curdlan, a ligand of dectin-1, blocks the generation of iTh2 cells and prevents breast cancer progression in vivo. Curdlan reprograms tumor-infiltrating DCs via the ligation of dectin-1, enabling the DCs to become resistant to cancer-derived thymic stromal lymphopoietin (TSLP), to produce IL-12p70, and to favor the generation of Th1 cells. DCs activated via dectin-1, but not those activated with TLR-7/8 ligand or poly I:C, induce CD8+ T cells to express CD103 (αE integrin), a ligand for cancer cells, E-cadherin. Generation of these mucosal CD8+ T cells is regulated by DC-derived integrin αvβ8 and TGF-β activation in a dectin-1-dependent fashion. These CD103+ CD8+ mucosal T cells accumulate in the tumors, thereby increasing cancer necrosis and inhibiting cancer progression in vivo in a humanized mouse model of breast cancer. Importantly, CD103+ CD8+ mucosal T cells elicited by reprogrammed DCs can reject established cancer. Thus, reprogramming tumor-infiltrating DCs represents a new strategy for cancer rejection.

Silymarin inhibits ultraviolet radiation-induced immune suppression through DNA repair-dependent activation of dendritic cells and stimulation of effector T cells

PubMed Central

Vaid, Mudit; Prasad, Ram; Singh, Tripti; Elmets, Craig A.; Xu, Hui; Katiyar, Santosh K.

2013-01-01

Silymarin inhibits UVB-induced immunosuppression in mouse skin. To identify the molecular mechanisms underlying this effect, we used an adoptive transfer approach in which dendritic cells (DCs) from the draining lymph nodes of donor mice that had been UVB-exposed and sensitized to 2,4,-dinitrofluorobenzene (DNFB) were transferred into naïve recipient mice. The contact hypersensitivity (CHS) response of the recipient mice to DNFB was then measured. When DCs were obtained from UVB-exposed donor mice that were not treated with silymarin, the CHS response was suppressed confirming the role of DCs in the UVB-induced immunosuppression. Silymarin treatment of UVB-exposed donor mice relieved this suppression of the CHS response in the recipients. Silymarin treatment was associated with rapid repair of UVB-induced cyclobutane pyrimidine dimers (CPDs) in DCs and silymarin treatment did not prevent UV-induced immunosuppression in XPA-deficient mice which are unable to repair UV-induced DNA damage. The CHS response in mice receiving DCs from silymarin-treated UV-exposed donor mice also was associated with enhanced secretion of Th1-type cytokines and stimulation of T cells. Adoptive transfer of T cells revealed that transfer of either CD8+ or CD4+ cells from silymarin-treated, UVB-exposed donors resulted in enhancement of the CHS response. Cell culture study showed enhanced secretion of IL-2 and IFNγ by CD8+ T cells, and reduced secretion of Th2 cytokines by CD4+ cells, obtained from silymarin-treated UVB-exposed mice. These data suggest that DNA repair-dependent functional activation of DCs, a reduction in CD4+ regulatory T-cell activity, and stimulation of CD8+ effector T cells contribute to silymarin-mediated inhibition of UVB-induced immunosuppression. PMID:23395695

The diffuse chemosensory system: exploring the iceberg toward the definition of functional roles.

PubMed

Sbarbati, Andrea; Bramanti, Placido; Benati, Donatella; Merigo, Flavia

2010-05-01

The diffuse chemosensory system (DCS) is an anatomical structure composed of solitary chemosensory cells (SCCs, also called solitary chemoreceptor cells), which have analogies with taste cells but are not aggregated in buds. The concept of DCS has been advanced, after the discovery that cells similar to gustatory elements are present in several organs. The elements forming the DCS share common morphological and biochemical characteristics with the taste cells located in taste buds of the oro-pharyngeal cavity but they are localized in internal organs. In particular, they may express molecules of the chemoreceptorial cascade (e.g. trans-membrane taste receptors, the G-protein alpha-gustducin, PLCbeta2, TRPM5). This article will focus on the mammalian DCS in apparatuses of endodermic origin (i.e. digestive and respiratory systems), which is composed of an enormous number of sensory elements and presents a multiplicity of morphological aspects. Recent research has provided an adequate description of these elements, but the functional role for the DCS in these apparatuses is unknown. The initial findings led to the definition of a DCS structured like an iceberg, with a mysterious "submerged" portion localized in the distal part of endodermic apparatuses. Recent work has focussed on the discovery of this submerged portion, which now appears less puzzling. However, the functional roles of the different cytotypes belonging to the DCS are not well known. Recent studies linked chemosensation of the intraluminal content to local control of absorptive and secretory (exocrine and endocrine) processes. Control of the microbial population and detection of irritants seem to be other possible functions of the DCS. In the light of these new findings, the DCS might be thought to be involved in a wide range of diseases of both the respiratory (e.g. asthma, chronic obstructive pulmonary disease, cystic fibrosis) and digestive apparatuses (absorptive or secretive diseases, dysmicrobism), as well as in systemic diseases (e.g. obesity, diabetes). A description of the functional roles of the DCS might be a first step toward the discovery of therapeutic approaches which target chemosensory mechanisms. Copyright 2010 Elsevier Ltd. All rights reserved.

From The Cover: Induction of antiviral immunity requires Toll-like receptor signaling in both stromal and dendritic cell compartments

NASA Astrophysics Data System (ADS)

Sato, Ayuko; Iwasaki, Akiko

2004-11-01

Pattern recognition by Toll-like receptors (TLRs) is known to be important for the induction of dendritic cell (DC) maturation. DCs, in turn, are critically important in the initiation of T cell responses. However, most viruses do not infect DCs. This recognition system poses a biological problem in ensuring that most viral infections be detected by pattern recognition receptors. Furthermore, it is unknown what, if any, is the contribution of TLRs expressed by cells that are infected by a virus, versus TLRs expressed by DCs, in the initiation of antiviral adaptive immunity. Here we address these issues using a physiologically relevant model of mucosal infection with herpes simplex virus type 2. We demonstrate that innate immune recognition of viral infection occurs in two distinct stages, one at the level of the infected epithelial cells and the other at the level of the noninfected DCs. Importantly, both TLR-mediated recognition events are required for the induction of effector T cells. Our results demonstrate that virally infected tissues instruct DCs to initiate the appropriate class of effector T cell responses and reveal the critical importance of the stromal cells in detecting infectious agents through their own pattern recognition receptors. mucosal immunity | pattern recognition | viral infection

The study on specific umbilical blood Dc vaccine for Beige nude mice loaded human colorectal carcinoma to induce anti-tumor immunity.

PubMed

Fu, Z-X; Han, J-S; Liu, F; Zhao, Z-L; Li, D-B; Shi, L; Dong, J-T; Zhou, Y; Cai, J-H

2017-05-01

This study is to observe the immunosuppression of CD137L transfected umbilical blood Dcs (Dendritic cell) vaccine to tumor development of SCID/ Beige nude mice. Samples of umbilical blood in the childbirth pregnant women were collected by density gradient centrifugation. Umbilical cord blood dendritic cells (Dcs) were transfected by specific CD137L via LipofectamineTM method and cells were harvested. Meanwhile, the peripheral blood of volunteers was collected to isolate Dcs, the Dcs were cultured for 5 days and hatched with SW-1116 cells antigen. The mature Dcs were harvested. The male SCID/Beige nude mice were subcutaneously injected with human SW-1116 cells in axillary to build colorectal carcinoma model as blank control (Blank). The naked peripheral blood Dc vaccine group (cPBMCs), the SW-1116 antigen-specific peripheral blood Dc vaccine group (pDcs) and the CD137L specific umbilical blood Dc vaccine group (tuDcs) were injected 24 h before tumor cells injection, respectively to recur the humanized immune reconstruction. The general life, living habits changes, tumor growing time and tumor size were observed. The nude mice were sacrificed 18 days after tumor formation. The tumor size, mice weight, in vitro tumor weight, liver weight and spleen weight of mice were recorded to evaluate the anti-tumor effect of the specific immune cells. The nude mice in pDcs group showed better general living condition, slower tumor growth, smaller tumor volume and no ulceration, necrosis, and death in nude mice. The tumor formation time in different groups was 4.71 ± 0.18 ds (blank), 7.71 ± 0.29 ds (cPBMCs), 7.86 ± 0.26 ds (pDcs) and 8.14 ± 0.69 ds (tuDcs) respectively. There were significant differences between blank and other three groups (F = 40.96, p < 0.01). Compared to mice in blank group, the tumor volume of cPBMCs group was significantly smaller (201.43 ± 69.84 mm³ vs. 436.04 ± 54.50 mm³, p < 0.01) and the tumor weight were significantly smaller (1.25 ± 0.12 g vs. 2.83 ± 0.24 g, p < 0.01). The tumor volume of tuDcs mice was significantly smaller than that of blank (92.11 ± 11.55 mm³ vs. 436.04 ± 54.50 mm³, p < 0.01) and cPBMCs mice (92.11 ± 11.55 mm³ vs. 201.43 ± 69.84 mm³, p < 0.01). Similarly, the tumor weight of tuDcs mice was significantly smaller than that of blank (0.66 ± 0.07 g vs. 2.83 ± 0.24 g, p < 0.01) and cPBMCs mice (0.66 ± 0.07 g vs. 1.25 ± 0.12 g, p < 0.01). There was no significant difference in tumor volume (92.11 ± 11.55 mm³ vs. 85.61 ± 11.59 mm³, p = 0.69) and tumor weight (0.66 ± 0.07 g vs. 0.63 ± 0.09 g, p = 0.75) between tuDcs group and pDcs group. The specific CD137L transfected umbilical blood Dc vaccine had significant anti-tumor effect against human colon cancer in nude mice via increasing the number of immune effector cell in tumor microenvironment.

Native cellulose nanofibrills induce immune tolerance in vitro by acting on dendritic cells

NASA Astrophysics Data System (ADS)

Tomić, Sergej; Kokol, Vanja; Mihajlović, Dušan; Mirčić, Aleksandar; Čolić, Miodrag

2016-08-01

Cellulose nanofibrills (CNFs) are attractive biocompatible, natural nanomaterials for wide biomedical applications. However, the immunological mechanisms of CNFs have been poorly investigated. Considering that dendritic cells (DCs) are the key immune regulatory cells in response to nanomaterials, our aim was to investigate the immunological mechanisms of CNFs in a model of DC-mediated immune response. We found that non-toxic concentrations of CNFs impaired the differentiation, and subsequent maturation of human monocyte-derived (mo)-DCs. In a co-culture with CD4+T cells, CNF-treated mo-DCs possessed a weaker allostimulatory and T helper (Th)1 and Th17 polarizing capacity, but a stronger capacity to induce Th2 cells and CD4+CD25hiFoxP3hi regulatory T cells. This correlated with an increased immunoglobulin-like transcript-4 and indolamine dioxygenase-1 expression by CNF-treated mo-DCs, following the partial internalization of CNFs and the accumulation of CD209 and actin bundles at the place of contacts with CNFs. Cumulatively, we showed that CNFs are able to induce an active immune tolerance by inducing tolerogenic DCs, which could be beneficial for the application of CNFs in wound healing and chronic inflammation therapies.

Dectin-1/TLR2 and NOD2 Agonists Render Dendritic Cells Susceptible to Infection by X4-Using HIV-1 and Promote cis-Infection of CD4+ T Cells

PubMed Central

Tremblay, Michel J.

2013-01-01

HIV-1 pathogenesis is intimately linked with microbial infections and innate immunity during all stages of the disease. While the impact of microbial-derived products in transmission of R5-using virus to CD4+ T cells by dendritic cells (DCs) has been addressed before, very limited data are available on the effect of such compounds on DC-mediated dissemination of X4-tropic variant. Here, we provide evidence that treatment of DCs with dectin-1/TLR2 and NOD2 ligands increases cis-infection of autologous CD4+ T cells by X4-using virus. This phenomenon is most likely associated with an enhanced permissiveness of DCs to productive infection with X4 virus, which is linked to increased surface expression of CXCR4 and the acquisition of a maturation profile by DCs. The ensuing DC maturation enhances susceptibility of CD4+ T cells to productive infection with HIV-1. This study highlights the crucial role of DCs at different stages of HIV-1 infection and particularly in spreading of viral strains displaying a X4 phenotype. PMID:23844079

A mucin-like peptide from Fasciola hepatica instructs dendritic cells with parasite specific Th1-polarizing activity.

PubMed

Noya, Verónica; Brossard, Natalie; Rodríguez, Ernesto; Dergan-Dylon, L Sebastián; Carmona, Carlos; Rabinovich, Gabriel A; Freire, Teresa

2017-01-12

Fasciolosis is a trematode zoonosis of interest in public health and cattle production. We report here the immunostimulatory effect of a 66 mer mucin-like peptide from Fasciola hepatica (Fhmuc), which synergizes with lipopolysaccharide (LPS) to promote dendritic cell (DC) maturation, endowing these cells with Th1-polarizing capacity. Exposure of DCs to Fhmuc in presence of LPS induced enhanced secretion of pro-inflammatory cytokines and expression of co-stimulatory molecules by DCs, promoting their T cell stimulatory capacity and selectively augmenting IFN-γ secretion by allogeneic T cells. Furthermore, exposure of DCs to Fhmuc augmented LPS-induced Toll-like receptor (TLR) 4 expression on the cell surface. Finally, Fhmuc-conditioned DCs induced parasite specific-adaptive immunity with increased levels of IFN-γ secreted by splenocytes from vaccinated animals, and higher parasite-specific IgG antibodies. However, Fhmuc-treated DC conferred modest protection against F. hepatica infection highlighting the potent immuno-regulatory capacity of the parasite. In summary, this work highlights the capacity of a mucin-derived peptide from F. hepatica to enhance LPS-maturation of DCs and induce parasite-specific immune responses with potential implications in vaccination and therapeutic strategies.

A mucin-like peptide from Fasciola hepatica instructs dendritic cells with parasite specific Th1-polarizing activity

PubMed Central

Noya, Verónica; Brossard, Natalie; Rodríguez, Ernesto; Dergan-Dylon, L. Sebastián; Carmona, Carlos; Rabinovich, Gabriel A.; Freire, Teresa

2017-01-01

Fasciolosis is a trematode zoonosis of interest in public health and cattle production. We report here the immunostimulatory effect of a 66 mer mucin-like peptide from Fasciola hepatica (Fhmuc), which synergizes with lipopolysaccharide (LPS) to promote dendritic cell (DC) maturation, endowing these cells with Th1-polarizing capacity. Exposure of DCs to Fhmuc in presence of LPS induced enhanced secretion of pro-inflammatory cytokines and expression of co-stimulatory molecules by DCs, promoting their T cell stimulatory capacity and selectively augmenting IFN-γ secretion by allogeneic T cells. Furthermore, exposure of DCs to Fhmuc augmented LPS-induced Toll-like receptor (TLR) 4 expression on the cell surface. Finally, Fhmuc-conditioned DCs induced parasite specific-adaptive immunity with increased levels of IFN-γ secreted by splenocytes from vaccinated animals, and higher parasite-specific IgG antibodies. However, Fhmuc-treated DC conferred modest protection against F. hepatica infection highlighting the potent immuno-regulatory capacity of the parasite. In summary, this work highlights the capacity of a mucin-derived peptide from F. hepatica to enhance LPS-maturation of DCs and induce parasite-specific immune responses with potential implications in vaccination and therapeutic strategies. PMID:28079156

Antifungal Activity of Plasmacytoid Dendritic Cells and the Impact of Chronic HIV Infection.

PubMed

Maldonado, Samuel; Fitzgerald-Bocarsly, Patricia

2017-01-01

Due to the effectiveness of combined antiretroviral therapy, people living with HIV can control viral replication and live longer lifespans than ever. However, HIV-positive individuals still face challenges to their health and well-being, including dysregulation of the immune system resulting from years of chronic immune activation, as well as opportunistic infections from pathogenic fungi. This review focuses on one of the key players in HIV immunology, the plasmacytoid dendritic cell (pDC), which links the innate and adaptive immune response and is notable for being the body's most potent producer of type-I interferons (IFNs). During chronic HIV infection, the pDC compartment is greatly dysregulated, experiencing a substantial depletion in number and compromise in function. This immune dysregulation may leave patients further susceptible to opportunistic infections. This is especially important when considering a new role for pDCs currently emerging in the literature: in addition to their role in antiviral immunity, recent studies suggest that pDCs also play an important role in antifungal immunity. Supporting this new role, pDCs express C-type lectin receptors including dectin-1, dectin-2, dectin-3, and mannose receptor, and toll-like receptors-4 and -9 that are involved in recognition, signaling, and response to a wide variety of fungal pathogens, including Aspergillus fumigatus, Cryptococcus neoformans, Candida albicans , and Pneumocystis jirovecii . Accordingly, pDCs have been demonstrated to recognize and respond to certain pathogenic fungi, measured via activation, cytokine production, and fungistatic activity in vitro , while in vivo mouse models indicated a strikingly vital role for pDCs in survival against pulmonary Aspergillus challenge. Here, we discuss the role of the pDC compartment and the dysregulation it undergoes during chronic HIV infection, as well as what is known so far about the role and mechanisms of pDC antifungal activity.

Identifying Regulators of the Immune Response to Dying Cells | Center for Cancer Research

Cancer.gov

Cytotoxic T cells are responsible for carrying out antigen-mediated immune responses against virally-infected and malignant cells. In both cases, cytotoxic T cells are stimulated by interacting with antigen presenting cells, such as dendritic cells (DCs). Infected cells produce virus-specific antigens and pathogen associated molecular patterns, which are recognized by DCs and

Phenotype and function of nasal dendritic cells

PubMed Central

Lee, Haekyung; Ruane, Darren; Law, Kenneth; Ho, Yan; Garg, Aakash; Rahman, Adeeb; Esterházy, Daria; Cheong, Cheolho; Goljo, Erden; Sikora, Andrew G.; Mucida, Daniel; Chen, Benjamin; Govindraj, Satish; Breton, Gaëlle; Mehandru, Saurabh

2015-01-01

Intranasal vaccination generates immunity across local, regional and distant sites. However, nasal dendritic cells (DC), pivotal for the induction of intranasal vaccine- induced immune responses, have not been studied in detail. Here, using a variety of parameters, we define nasal DCs in mice and humans. Distinct subsets of “classical” DCs, dependent on the transcription factor zbtb46 were identified in the murine nose. The murine nasal DCs were FLT3 ligand-responsive and displayed unique phenotypic and functional characteristics including the ability to present antigen, induce an allogeneic T cell response and migrate in response to LPS or live bacterial pathogens. Importantly, in a cohort of human volunteers, BDCA-1+ DCs were observed to be the dominant nasal DC population at steady state. During chronic inflammation, the frequency of both BDCA-1+ and BDCA-3hi DCs was reduced in the nasal tissue, associating the loss of these immune sentinels with chronic nasal inflammation. The present study is the first detailed description of the phenotypic, ontogenetic and functional properties of nasal DCs and will inform the design of preventative immunization strategies as well as therapeutic modalities against chronic rhinosinusitis. PMID:25669151

Novel allergic asthma model demonstrates ST2-dependent dendritic cell targeting by cypress pollen.

PubMed

Gabriele, Lucia; Schiavoni, Giovanna; Mattei, Fabrizio; Sanchez, Massimo; Sestili, Paola; Butteroni, Cinzia; Businaro, Rita; Mirchandani, Ananda; Niedbala, Wanda; Liew, Foo Y; Afferni, Claudia

2013-09-01

Cypress pollen causes respiratory syndromes with different grades of severity, including asthma. IL-33, its receptor ST2, and dendritic cells (DCs) have been implicated in human respiratory allergy. We sought to define a new mouse model of allergy to cypress pollen that recapitulates clinical parameters in allergic patients and to evaluate the implications of DCs and the IL-33/ST2 pathway in this pathology. BALB/c mice, either wild-type or ST2 deficient (ST2(-/-)), were sensitized and challenged with the Cupressus arizonica major allergen nCup a 1. Local and systemic allergic responses were evaluated. Pulmonary cells were characterized by means of flow cytometry. DCs were stimulated with nCup a 1 and tested for their biological response to IL-33 in coculture assays. nCup a 1 causes a respiratory syndrome closely resembling human pollinosis in BALB/c mice. nCup a 1-treated mice exhibit the hallmarks of allergic pathology associated with pulmonary infiltration of eosinophils, T cells, and DCs and a dominant TH2-type immune response. IL-33 levels were increased in lungs and sera of nCup a 1-treated mice and in subjects with cypress allergy. The allergen-specific reaction was markedly reduced in ST2(-/-) mice, which showed fewer infiltrating eosinophils, T cells, and DCs in the lungs. Finally, stimulation of DCs with nCup a 1 resulted in ST2 upregulation that endowed DCs with increased ability to respond to IL-33-mediated differentiation of IL-5- and IL-13-producing CD4 T cells. Our findings define a novel preclinical model of allergy to cypress pollen and provide the first evidence of a functionally relevant linkage between pollen allergens and TH2-polarizing activity by DCs through IL-33/ST2. Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

MERTK as negative regulator of human T cell activation

PubMed Central

Cabezón, Raquel; Carrera-Silva, E. Antonio; Flórez-Grau, Georgina; Errasti, Andrea E.; Calderón-Gómez, Elisabeth; Lozano, Juan José; España, Carolina; Ricart, Elena; Panés, Julián; Rothlin, Carla Vanina; Benítez-Ribas, Daniel

2015-01-01

The aim of this study was to test the hypothesis whether MERTK, which is up-regulated in human DCs treated with immunosuppressive agents, is directly involved in modulating T cell activation. MERTK is a member of the TAM family and contributes to regulating innate immune response to ACs by inhibiting DC activation in animal models. However, whether MERTK interacts directly with T cells has not been addressed. Here, we show that MERTK is highly expressed on dex-induced human tol-DCs and participates in their tolerogenic effect. Neutralization of MERTK in allogenic MLR, as well as autologous DC–T cell cultures, leads to increased T cell proliferation and IFN-γ production. Additionally, we identify a previously unrecognized noncell-autonomous regulatory function of MERTK expressed on DCs. Mer-Fc protein, used to mimic MERTK on DCs, suppresses naïve and antigen-specific memory T cell activation. This mechanism is mediated by the neutralization of the MERTK ligand PROS1. We find that MERTK and PROS1 are expressed in human T cells upon TCR activation and drive an autocrine proproliferative mechanism. Collectively, these results suggest that MERTK on DCs controls T cell activation and expansion through the competition for PROS1 interaction with MERTK in the T cells. In conclusion, this report identified MERTK as a potent suppressor of T cell response. PMID:25624460

A Lipid Based Antigen Delivery System Efficiently Facilitates MHC Class-I Antigen Presentation in Dendritic Cells to Stimulate CD8+ T Cells

NASA Astrophysics Data System (ADS)

Maji, Mithun; Mazumder, Saumyabrata; Bhattacharya, Souparno; Choudhury, Somsubhra Thakur; Sabur, Abdus; Shadab, Md.; Bhattacharya, Pradyot; Ali, Nahid

2016-06-01

The most effective strategy for protection against intracellular infections such as Leishmania is vaccination with live parasites. Use of recombinant proteins avoids the risks associated with live vaccines. However, due to low immunogenicity, they fail to trigger T cell responses particularly of CD8+ cells requisite for persistent immunity. Previously we showed the importance of protein entrapment in cationic liposomes and MPL as adjuvant for elicitation of CD4+ and CD8+ T cell responses for long-term protection. In this study we investigated the role of cationic liposomes on maturation and antigen presentation capacity of dendritic cells (DCs). We observed that cationic liposomes were taken up very efficiently by DCs and transported to different cellular sites. DCs activated with liposomal rgp63 led to efficient presentation of antigen to specific CD4+ and CD8+ T cells. Furthermore, lymphoid CD8+ T cells from liposomal rgp63 immunized mice demonstrated better proliferative ability when co-cultured ex vivo with stimulated DCs. Addition of MPL to vaccine enhanced the antigen presentation by DCs and induced more efficient antigen specific CD8+ T cell responses when compared to free and liposomal antigen. These liposomal formulations presented to CD8+ T cells through TAP-dependent MHC-I pathway offer new possibilities for a safe subunit vaccine.

Phenotype of dendritic cells generated in the presence of non-small cell lung cancer antigens - preliminary report.

PubMed

Jankowska, Olga; Krawczyk, Paweł; Wojas-Krawczyk, Kamila; Sagan, Dariusz; Milanowski, Janusz; Roliński, Jacek

2008-01-01

Therapeutic outcomes of definitively treated non-small-cell lung cancer (NSCLC) are unacceptably poor. It has been proposed that the manipulation of dendritic cells (DCs) as a "natural" vaccine adjuvant may prove to be a particularly effective way to stimulate antitumor immunity. Presently, there is no standardized methodology for preparing vaccines and many questions concerning the optimal source and type of antigens as well as maturation state and activity of DCs are still unsolved. The study population comprised of ten patients with histologically confirmed NSCLC (mean age: 67.63 +/- 6.15 years). Resected small tumor pieces were placed in tissue culture dishes containing different growth factors in order to obtain pure cancer cells. Seven days after the operation, the PBMC were collected and monocytes were purified by the adherence to culture dishes. Monocytes were cultured in RPMI 1640 medium supplemented with 10% of autologous plasma in the presence of rhIL-4 and rhGM-CSF to generate immature autologous (DCs). TNF-alpha with or without tumor cells' lysate were added to maturation of DCs. After 7 days of culture, DCs were harvested and the expression of CD1a, CD83, CD80, CD86 and HLA-DR antigens were analyzed by flow cytometry. We discovered higher (p=0.07) percentage of semimature DCs in tumor cell lysate culture in comparison with TNF-alpha culture (21.22 +/- 16.82% versus 11.27 +/- 11.64%). The expression of co-stimulatory and maturation markers (CD86, CD83 and HLA-DR) was higher on DCs from the culture with tumor cell lysate compared with TNF-alpha culture as a control. Specimen of NSCLC's culture prepared in this way could generate differences in DCs phenotype, which may have an influence on the therapeutic and protective antitumor immunity of the vaccine. Our research seems to be the next step in the development of DC-based vaccine. We are going to continue the investigation to start the preparation of a pattern of immunological vaccine against lung cancer.

Structure and enzyme expression in photosynthetic organs of the atypical C4 grass Arundinella hirta.

PubMed

Wakayama, Masataka; Ohnishi, Jun-ichi; Ueno, Osamu

2006-05-01

In its leaf blade, Arundinella hirta has unusual Kranz cells that lie distant from the veins (distinctive cells; DCs), in addition to the usual Kranz units composed of concentric layers of mesophyll cells (MCs) and bundle sheath cells (BSCs; usual Kranz cells) surrounding the veins. We examined whether chlorophyllous organs other than leaf blades--namely, the leaf sheath, stem, scale leaf, and constituents of the spike--also have this unique anatomy and the C4 pattern of expression of photosynthetic enzymes. All the organs developed DCs to varying degrees, as well as BSCs. The stem, rachilla, and pedicel had C4-type anatomy with frequent occurrence of DCs, as in the leaf blade. The leaf sheath, glume, and scale leaf had a modified C4 anatomy with MCs more than two cells distant from the Kranz cells; DCs were relatively rare. An immunocytochemical study of C3 and C4 enzymes revealed that all the organs exhibited essentially the same C4 pattern of expression as in the leaf blade. In the scale leaf, however, intense expression of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) occurred in the MCs as well as in the BSCs and DCs. In the leaf sheath, the distant MCs also expressed Rubisco. In Arundinella hirta, it seems that the ratio of MC to Kranz cell volumes, and the distance from the Kranz cells, but not from the veins, affects the cellular expression of photosynthetic enzymes. We suggest that the main role of DCs is to keep a constant quantitative balance between the MCs and Kranz cells, which is a prerequisite for effective C4 pathway operation.

Evaluating maturation and genetic modification of human dendritic cells in a new polyolefin cell culture bag system.

PubMed

Macke, Lars; Garritsen, Henk S P; Meyring, Wilhelm; Hannig, Horst; Pägelow, Ute; Wörmann, Bernhard; Piechaczek, Christoph; Geffers, Robert; Rohde, Manfred; Lindenmaier, Werner; Dittmar, Kurt E J

2010-04-01

Dendritic cells (DCs) are applied worldwide in several clinical studies of immune therapy of malignancies, autoimmune diseases, and transplantations. Most legislative bodies are demanding high standards for cultivation and transduction of cells. Closed-cell cultivating systems like cell culture bags would simplify and greatly improve the ability to reach these cultivation standards. We investigated if a new polyolefin cell culture bag enables maturation and adenoviral modification of human DCs in a closed system and compare the results with standard polystyrene flasks. Mononuclear cells were isolated from HLA-A*0201-positive blood donors by leukapheresis. A commercially available separation system (CliniMACS, Miltenyi Biotec) was used to isolate monocytes by positive selection using CD14-specific immunomagnetic beads. The essentially homogenous starting cell population was cultivated in the presence of granulocyte-macrophage-colony-stimulating factor and interleukin-4 in a closed-bag system in parallel to the standard flask cultivation system. Genetic modification was performed on Day 4. After induction of maturation on Day 5, mature DCs could be harvested and cryopreserved on Day 7. During the cultivation period comparative quality control was performed using flow cytometry, gene expression profiling, and functional assays. Both flasks and bags generated mature genetically modified DCs in similar yields. Surface membrane markers, expression profiles, and functional testing results were comparable. The use of a closed-bag system facilitated clinical applicability of genetically modified DCs. The polyolefin bag-based culture system yields DCs qualitatively and quantitatively comparable to the standard flask preparation. All steps including cryopreservation can be performed in a closed system facilitating standardized, safe, and reproducible preparation of therapeutic cells.

The active translation of MHCII mRNA during dendritic cells maturation supplies new molecules to the cell surface pool.

PubMed

Malanga, Donatella; Barba, Pasquale; Harris, Paul E; Maffei, Antonella; Del Pozzo, Giovanna

2007-04-01

The transition of human dendritic cells (DCs) from the immature to the mature phenotype is characterized by an increased density of MHC class II (MHCII) molecules on the plasma membrane, a key requirement of their competence as professional antigen presenting cells (APCs). MHCII molecules on the cell surface derive from newly synthesized as well as from preexisting proteins. So far, all the studies done on DCs during maturation, to establish the relative contribution of newly synthesized MHCII molecules to the cell surface pool did not produced a clear, unified scenario. We report that, in human DCs stimulated ex vivo with LPS, the changes in the RNA accumulation specific for at least two MHCII genes (HLA-DRA and HLA-DQA1) due to transcriptional upregulation, is associated with the active translation at high rate of these transcripts. Our finding reveals that, across the 24h of the maturation process in human DCs, newly synthesized MHCII proteins are supplied to the APCs cell surface pool.

Dendritic cell targeted vaccines: Recent progresses and challenges

PubMed Central

Chen, Pengfei; Liu, Xinsheng; Sun, Yuefeng; Zhou, Peng; Wang, Yonglu; Zhang, Yongguang

2016-01-01

ABSTRACT Dendritic cells (DCs) are known to be a set of morphology, structure and function of heterogeneous professional antigen presenting cells (APCs), as well as the strongest functional antigen presenting cells, which can absorb, process and present antigens. As the key regulators of innate and adaptive immune responses, DCs are at the center of the immune system and capable of interacting with both B cells and T cells, thereby manipulating the humoral and cellular immune responses. DCs provide an essential link between the innate and adaptive immunity, and the strong immune activation function of DCs and their properties of natural adjuvants, make them a valuable target for antigen delivery. Targeting antigens to DC-specific endocytic receptors in combination with the relevant antibodies or ligands along with immunostimulatory adjuvants has been recently recognized as a promising strategy for designing an effective vaccine that elicits a strong and durable T cell response against intracellular pathogens and cancer. This opinion article provides a brief summary of the rationales, superiorities and challenges of existing DC-targeting approaches. PMID:26513200

Trichinella spiralis Excretory–Secretory Products Induce Tolerogenic Properties in Human Dendritic Cells via Toll-Like Receptors 2 and 4

PubMed Central

Ilic, Nataša; Gruden-Movsesijan, Alisa; Cvetkovic, Jelena; Tomic, Sergej; Vucevic, Dragana Bozidar; Aranzamendi, Carmen; Colic, Miodrag; Pinelli, Elena; Sofronic-Milosavljevic, Ljiljana

2018-01-01

Trichinella spiralis, as well as its muscle larvae excretory–secretory products (ES L1), given either alone or via dendritic cells (DCs), induce a tolerogenic immune microenvironment in inbred rodents and successfully ameliorate experimental autoimmune encephalomyelitis. ES L1 directs the immunological balance away from T helper (Th)1, toward Th2 and regulatory responses by modulating DCs phenotype. The ultimate goal of our work is to find out if it is possible to translate knowledge obtained in animal model to humans and to generate human tolerogenic DCs suitable for therapy of autoimmune diseases through stimulation with ES L1. Here, the impact of ES L1 on the activation of human monocyte-derived DCs is explored for the first time. Under the influence of ES L1, DCs acquired tolerogenic (semi-matured) phenotype, characterized by low expression of HLA-DR, CD83, and CD86 as well as moderate expression of CD40, along with the unchanged production of interleukin (IL)-12 and elevated production of IL-10 and transforming growth factor (TGF)-β, compared to controls. The interaction with DCs involved toll-like receptors (TLR) 2 and 4, and this interaction was mainly responsible for the phenotypic and functional properties of ES L1-treated DCs. Importantly, ES L1 potentiated Th2 polarizing capacity of DCs, and impaired their allo-stimulatory and Th1/Th17 polarizing properties. Moreover, ES L1-treated DCs promoted the expansion of IL-10- and TGF-β- producing CD4+CD25hiFoxp3hi T cells in indolamine 2, 3 dioxygenase (IDO)-1-dependent manner and increased the suppressive potential of the primed T cell population. ES L1-treated DCs retained the tolerogenic properties, even after the challenge with different pro-inflammatory stimuli, including those acting via TLR3 and, especially TLR4. These results suggest that the induction of tolerogenic properties of DCs through stimulation with ES L1 could represent an innovative approach for the preparation of tolerogenic DC for treatment of inflammatory and autoimmune disorders. PMID:29416536

Effects of a dynamic core stability program on the biomechanics of cutting maneuvers: A randomized controlled trial.

PubMed

Whyte, E F; Richter, C; O'Connor, S; Moran, K A

2018-02-01

Deficits in trunk control predict ACL injuries which frequently occur during high-risk activities such as cutting. However, no existing trunk control/core stability program has been found to positively affect trunk kinematics during cutting activities. This study investigated the effectiveness of a 6-week dynamic core stability program (DCS) on the biomechanics of anticipated and unanticipated side and crossover cutting maneuvers. Thirty-one male, varsity footballers participated in this randomized controlled trial. Three-dimensional trunk and lower limb biomechanics were captured in a motion analysis laboratory during the weight acceptance phase of anticipated and unanticipated side and crossover cutting maneuvers at baseline and 6-week follow-up. The DCS group performed a DCS program three times weekly for 6 weeks in a university rehabilitation room. Both the DCS and control groups concurrently completed their regular practice and match play. Statistical parametric mapping and repeated measures analysis of variance were used to determine any group (DCS vs control) by time (pre vs post) interactions. The DCS resulted in greater internal hip extensor (P=.017, η 2 =0.079), smaller internal knee valgus (P=.026, η 2 =0.076), and smaller internal knee external rotator moments (P=.041, η 2 =0.066) during anticipated side cutting compared with the control group. It also led to reduced posterior ground reaction forces for all cutting activities (P=.015-.030, η 2 =0.074-0.105). A 6-week DCS program did not affect trunk kinematics, but it did reduce a small number of biomechanical risk factors for ACL injury, predominantly during anticipated side cutting. A DCS program could play a role in multimodal ACL injury prevention programs. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Comparative analysis of signature genes in PRRSV-infected porcine monocyte-derived cells at differential activation statuses

USDA-ARS?s Scientific Manuscript database

Activation statuses of monocytic cells are critically important for antiviral immunity. Devastating viruses like porcine reproductive and respiratory syndrome virus (PRRSV) are capable of directly infecting these cells, subverting host immunity. Monocyte-derived DCs (mDCs) are major target cells in ...

Different Expression of Interferon-Stimulated Genes in Response to HIV-1 Infection in Dendritic Cells Based on Their Maturation State

PubMed Central

Calonge, Esther; Bermejo, Mercedes; Diez-Fuertes, Francisco; Mangeot, Isabelle; González, Nuria; Coiras, Mayte; Jiménez Tormo, Laura; García-Perez, Javier; Dereuddre-Bosquet, Nathalie; Le Grand, Roger

2017-01-01

ABSTRACT Dendritic cells (DCs) are professional antigen-presenting cells whose functions are dependent on their degree of differentiation. In their immature state, DCs capture pathogens and migrate to the lymph nodes. During this process, DCs become resident mature cells specialized in antigen presentation. DCs are characterized by a highly limiting environment for human immunodeficiency virus type 1 (HIV-1) replication due to the expression of restriction factors such as SAMHD1 and APOBEC3G. However, uninfected DCs capture and transfer viral particles to CD4 lymphocytes through a trans-enhancement mechanism in which chemokines are involved. We analyzed changes in gene expression with whole-genome microarrays when immature DCs (IDCs) or mature DCs (MDCs) were productively infected using Vpx-loaded HIV-1 particles. Whereas productive HIV infection of IDCs induced expression of interferon-stimulated genes (ISGs), such induction was not produced in MDCs, in which a sharp decrease in ISG- and CXCR3-binding chemokines was observed, lessening trans-infection of CD4 lymphocytes. Similar patterns of gene expression were found when DCs were infected with HIV-2 that naturally expresses Vpx. Differences were also observed under conditions of restrictive HIV-1 infection, in the absence of Vpx. ISG expression was not modified in IDCs, whereas an increase of ISG- and CXCR3-binding chemokines was observed in MDCs. Overall these results suggest that sensing and restriction of HIV-1 infection are different in IDCs and MDCs. We propose that restrictive infection results in increased virulence through different mechanisms. In IDCs avoidance of sensing and induction of ISGs, whereas in MDCs increased production of CXCR3-binding chemokines, would result in lymphocyte attraction and enhanced infection at the immune synapse. IMPORTANCE In this work we describe for the first time the activation of a different genetic program during HIV-1 infection depending on the state of maturation of DCs. This represents a breakthrough in the understanding of the restriction to HIV-1 infection of DCs. The results show that infection of DCs by HIV-1 reprograms their gene expression pattern. In immature cells, productive HIV-1 infection activates interferon-related genes involved in the control of viral replication, thus inducing an antiviral state in surrounding cells. Paradoxically, restriction of HIV-1 by SAMHD1 would result in lack of sensing and IFN activation, thus favoring initial HIV-1 escape from the innate immune response. In mature DCs, restrictive infection results in HIV-1 sensing and induction of ISGs, in particular CXCR3-binding chemokines, which could favor the transmission of HIV to lymphocytes. Our data support the hypothesis that genetic DC reprograming by HIV-1 infection favors viral escape and dissemination, thus increasing HIV-1 virulence. PMID:28148784

Strong adhesion by regulatory T cells induces dendritic cell cytoskeletal polarization and contact-dependent lethargy.

PubMed

Chen, Jiahuan; Ganguly, Anutosh; Mucsi, Ashley D; Meng, Junchen; Yan, Jiacong; Detampel, Pascal; Munro, Fay; Zhang, Zongde; Wu, Mei; Hari, Aswin; Stenner, Melanie D; Zheng, Wencheng; Kubes, Paul; Xia, Tie; Amrein, Matthias W; Qi, Hai; Shi, Yan

2017-02-01

Dendritic cells are targeted by regulatory T (T reg) cells, in a manner that operates as an indirect mode of T cell suppression. In this study, using a combination of single-cell force spectroscopy and structured illumination microscopy, we analyze individual T reg cell-DC interaction events and show that T reg cells exhibit strong intrinsic adhesiveness to DCs. This increased DC adhesion reduces the ability of contacted DCs to engage other antigen-specific cells. We show that this unusually strong LFA-1-dependent adhesiveness of T reg cells is caused in part by their low calpain activities, which normally release integrin-cytoskeleton linkage, and thereby reduce adhesion. Super resolution imaging reveals that such T reg cell adhesion causes sequestration of Fascin-1, an actin-bundling protein essential for immunological synapse formation, and skews Fascin-1-dependent actin polarization in DCs toward the T reg cell adhesion zone. Although it is reversible upon T reg cell disengagement, this sequestration of essential cytoskeletal components causes a lethargic state of DCs, leading to reduced T cell priming. Our results reveal a dynamic cytoskeletal component underlying T reg cell-mediated DC suppression in a contact-dependent manner. © 2017 Chen et al.

Infection of chicken bone marrow mononuclear cells with subgroup J avian leukosis virus inhibits dendritic cell differentiation and alters cytokine expression.

PubMed

Liu, Di; Qiu, Qianqian; Zhang, Xu; Dai, Manman; Qin, Jianru; Hao, Jianjong; Liao, Ming; Cao, Weisheng

2016-10-01

Subgroup J avian leukosis virus (ALV-J) is an oncogenic retrovirus known to induce tumor formation and immunosuppression in infected chickens. One of the organs susceptible to ALV-J is the bone marrow, from which specialized antigen-presenting cells named dendritic cells (BM-DCs) are derived. Notably, these cells possess the unique ability to induce primary immune responses. In the present study, a method of cultivating and purifying DCs from chicken bone marrow in vitro was established to investigate the effects of ALV-J infection on BM-DC differentiation or generation. The results indicated that ALV-J not only infects the chicken bone marrow mononuclear cells but also appears to inhibit the differentiation and maturation of BM-DCs and to trigger apoptosis. Moreover, substantial reductions in the mRNA expression of TLR1, TLR2, TLR3, MHCI, and MHCII and in cytokine production were detected in the surviving BM-DCs following ALV-J infection. These findings indicate that ALV-J infection disrupts the process of bone marrow mononuclear cell differentiation into BM-DCs likely via altered antigen presentation, resulting in a downstream immune response in affected chickens. Copyright © 2016 Elsevier B.V. All rights reserved.

In Situ Modulation of Dendritic Cells by Injectable Thermosensitive Hydrogels for Cancer Vaccines in Mice

PubMed Central

2014-01-01

Attempts to develop cell-based cancer vaccines have shown limited efficacy, partly because transplanted dendritic cells (DCs) do not survive long enough to reach the lymph nodes. The development of biomaterials capable of modulating DCs in situ to enhance antigen uptake and presentation has emerged as a novel method toward developing more efficient cancer vaccines. Here, we propose a two-step hybrid strategy to produce a more robust cell-based cancer vaccine in situ. First, a significant number of DCs are recruited to an injectable thermosensitive mPEG–PLGA hydrogel through sustained release of chemoattractants, in particular, granulocyte-macrophage colony-stimulating factor (GM-CSF). Then, these resident DCs can be loaded with cancer antigens through the use of viral or nonviral vectors. We demonstrate that GM-CSF-releasing mPEG–PLGA hydrogels successfully recruit and house DCs and macrophages, allowing the subsequent introduction of antigens by vectors to activate the resident cells, thus, initiating antigen presentation and triggering immune response. Moreover, this two-step hybrid strategy generates a high level of tumor-specific immunity, as demonstrated in both prophylactic and therapeutic models of murine melanoma. This injectable thermosensitive hydrogel shows great promise as an adjuvant for cancer vaccines, potentially providing a new approach for cell therapies through in situ modulation of cells. PMID:25207465

Rapid activation of spleen dendritic cell subsets following lymphocytic choriomeningitis virus infection of mice: analysis of the involvement of type 1 IFN.

PubMed

Montoya, Maria; Edwards, Matthew J; Reid, Delyth M; Borrow, Persephone

2005-02-15

In this study, we report the dynamic changes in activation and functions that occur in spleen dendritic cell (sDC) subsets following infection of mice with a natural murine pathogen, lymphocytic choriomeningitis virus (LCMV). Within 24 h postinfection (pi), sDCs acquired the ability to stimulate naive LCMV-specific CD8+ T cells ex vivo. Conventional (CD11chigh CD8+ and CD4+) sDC subsets rapidly up-regulated expression of costimulatory molecules and began to produce proinflammatory cytokines. Their tendency to undergo apoptosis ex vivo simultaneously increased, and in vivo the number of conventional DCs in the spleen decreased markedly, dropping approximately 2-fold by day 3 pi. Conversely, the number of plasmacytoid (CD11clowB220+) DCs in the spleen increased, so that they constituted almost 40% of sDCs by day 3 pi. Type 1 IFN production was up-regulated in plasmacytoid DCs by 24 h pi. Analysis of DC activation and maturation in mice unable to respond to type 1 IFNs implicated these cytokines in driving infection-associated phenotypic activation of conventional DCs and their enhanced tendency to undergo apoptosis, but also indicated the existence of type 1 IFN-independent pathways for the functional maturation of DCs during LCMV infection.

Fast Mechanically Driven Daughter Cell Separation Is Widespread in Actinobacteria.

PubMed

Zhou, Xiaoxue; Halladin, David K; Theriot, Julie A

2016-08-30

Dividing cells of the coccoid Gram-positive bacterium Staphylococcus aureus undergo extremely rapid (millisecond) daughter cell separation (DCS) driven by mechanical crack propagation, a strategy that is very distinct from the gradual, enzymatically driven cell wall remodeling process that has been well described in several rod-shaped model bacteria. To determine if other bacteria, especially those in the same phylum (Firmicutes) or with similar coccoid shapes as S. aureus, might use a similar mechanically driven strategy for DCS, we used high-resolution video microscopy to examine cytokinesis in a phylogenetically wide range of species with various cell shapes and sizes. We found that fast mechanically driven DCS is rather rare in the Firmicutes (low G+C Gram positives), observed only in Staphylococcus and its closest coccoid relatives in the Macrococcus genus, and we did not observe this division strategy among the Gram-negative Proteobacteria In contrast, several members of the high-G+C Gram-positive phylum Actinobacteria (Micrococcus luteus, Brachybacterium faecium, Corynebacterium glutamicum, and Mycobacterium smegmatis) with diverse shapes ranging from coccoid to rod all undergo fast mechanical DCS during cell division. Most intriguingly, similar fast mechanical DCS was also observed during the sporulation of the actinobacterium Streptomyces venezuelae Much of our knowledge on bacterial cytokinesis comes from studying rod-shaped model organisms such as Escherichia coli and Bacillus subtilis Less is known about variations in this process among different bacterial species. While cell division in many bacteria has been characterized to some extent genetically or biochemically, few species have been examined using video microscopy to uncover the kinetics of cytokinesis and daughter cell separation (DCS). In this work, we found that fast (millisecond) DCS is exhibited by species in two independent clades of Gram-positive bacteria and is particularly prevalent among the Actinobacteria, a diverse group that includes significant pathogens as well as bacteria that generate medically important antibiotics. Copyright © 2016 Zhou et al.

Varying Effects of Different β-Glucans on the Maturation of Porcine Monocyte-Derived Dendritic Cells ▿

PubMed Central

Sonck, Eva; Devriendt, Bert; Goddeeris, Bruno; Cox, Eric

2011-01-01

β-Glucans are well known for their immunomodulatory capacities in humans and mice. For this reason, together with the European ban on growth-promoting antibiotics, β-glucans are intensively used in pig feed. However, as shown in the present study, there is much variation in the stimulatory capacities of β-glucans from different sources. Since dendritic cells (DCs) are the first cells that are encountered after an antigen is taken up by the intestinal epithelial cell barrier, we decided to investigate the effect of two concentrations (5 and 10 μg/ml) of five commercial β-glucan preparations, differing in structure and source, on porcine monocyte-derived dendritic cells (MoDCs). Although all β-glucans gave rise to a significant reduction of the phagocytic activity of DCs, only Macrogard induced a significant phenotypic maturation. In addition to Macrogard, zymosan, another β-glucan derived from Saccharomyces cerevisiae, and curdlan also significantly improved the T-cell-stimulatory capacity of MoDCs. Most interesting, however, is the cytokine secretion profile of curdlan-stimulated MoDCs, since only curdlan induced significant higher expression levels of interleukin-1β (IL-1β), IL-6, IL-10, and IL-12/IL-23p40. Since the cytokine profile of DCs influences the outcome of the ensuing immune response and thus may prove valuable in intestinal immunity, a careful choice is necessary when β-glucans are used as dietary supplement. PMID:21752950

Tolerogenic Dendritic Cells Generated by In Vitro Treatment With SAHA Are Not Stable In Vivo.

PubMed

Thewissen, Kristof; Broux, Bieke; Hendriks, Jerome J A; Vanhees, Mandy; Stinissen, Piet; Slaets, Helena; Hellings, Niels

2016-01-01

The aim of this study is to examine whether the histone deacetylase inhibitor, suberoylanilide hydroxamic acid (SAHA), can generate dendritic cells (DCs) with a stable tolerogenic phenotype to counteract autoimmune responses in an animal model of multiple sclerosis. We investigated if the tolerogenic potency of DCs could be increased by continuous treatment during in vitro differentiation toward DCs compared to standard 24-h in vitro treatment of already terminally differentiated DCs. We show that in vitro treatment with SAHA reduces the generation of new CD11c(+) DCs out of mouse bone marrow. SAHA-generated DCs show reduced antigen-presenting function as evidenced by a reduction in myelin endocytosis, a decreased MHC II expression, and a failure to upregulate costimulatory molecules upon LPS challenge. In addition, SAHA-generated DCs display a reduction in proinflammatory cytokines and molecules involved in apoptosis induction, inflammatory migration, and TLR signaling, and they are less immunostimulatory compared to untreated DCs. We demonstrated that the underlying mechanism involves a diminished STAT1 phosphorylation and was independent of STAT6 activation. Although in vitro results were promising, SAHA-generated DCs were not able to alleviate the development of experimental autoimmune encephalomyelitis in mice. In vitro washout experiments demonstrated that the tolerogenic phenotype of SAHA-treated DCs is reversible. Taken together, while SAHA potently boosts tolerogenic properties in DCs during the differentiation process in vitro, SAHA-generated DCs were unable to reduce autoimmunity in vivo. Our results imply that caution needs to be taken when developing DC-based therapies to induce tolerance in the context of autoimmune disease.

Alternate Reading Frame Protein (F Protein) of Hepatitis C Virus: Paradoxical Effects of Activation and Apoptosis on Human Dendritic Cells Lead to Stimulation of T Cells

PubMed Central

Samrat, Subodh Kumar; Li, Wen; Singh, Shakti; Kumar, Rakesh; Agrawal, Babita

2014-01-01

Hepatitis C virus (HCV) leads to chronic infection in the majority of infected individuals due to lack, failure, or inefficiency of generated adaptive immune responses. In a minority of patients, acute infection is followed by viral clearance. The immune correlates of viral clearance are not clear yet but have been extensively investigated, suggesting that multispecific and multifunctional cellular immunity is involved. The generation of cellular immunity is highly dependent upon how antigen presenting cells (APCs) process and present various viral antigens. Various structural and non-structural HCV proteins derived from the open reading frame (ORF) have been implicated in modulation of dendritic cells (DCs) and APCs. Besides the major ORF proteins, the HCV core region also encodes an alternate reading frame protein (ARFP or F), whose function in viral pathogenesis is not clear. In the current studies, we sought to determine the role of HCV-derived ARFP in modulating dendritic cells and stimulation of T cell responses. Recombinant adenovirus vectors containing F or core protein derived from HCV (genotype 1a) were prepared and used to endogenously express these proteins in dendritic cells. We made an intriguing observation that endogenous expression of F protein in human DCs leads to contrasting effects on activation and apoptosis of DCs, allowing activated DCs to efficiently internalize apoptotic DCs. These in turn result in efficient ability of DCs to process and present antigen and to prime and stimulate F protein derived peptide-specific T cells from HCV-naive individuals. Taken together, our findings suggest important aspects of F protein in modulating DC function and stimulating T cell responses in humans. PMID:24475147

Different protein of Echinococcus granulosus stimulates dendritic induced immune response.

PubMed

Wang, Yana; Wang, Qiang; Lv, Shiyu; Zhang, Shengxiang

2015-06-01

Cystic echinococcosis is a chronic infectious disease that results from a host/parasite interaction. Vaccination with ferritin derived from Echinococcus granulosus is a potential preventative treatment. To understand whether ferritin is capable of inducing a host immune response, we investigated the response of dendritic cells (DCs) to both recombinant ferritin protein and the hydatid fluid (HF) of E. granulosus. We evaluated the immunomodulatory potential of these antigens by performing, immunocytochemistry, electron microscopy and in vivo imaging of monocyte-derived murine DCs. During antigen stimulation of DCs, ferritin cause DCs maturation and induced higher levels of surface marker expression and activated T-cell proliferation and migration. On contrary, HF failed to induce surface marker expression and to stimulate T-cell proliferation. In response to HF, DCs produced interleukin-6 (IL-6), but no IL-12 and IL-10. DCs stimulated with ferritin produced high levels of cytokines. Overall, HF appears to induce host immunosuppression in order to ensure parasite survival via inhibits DC maturation and promotes Th2-dependent secretion of cytokines. Although ferritin also promoted DC maturation and cytokine release, it also activates CD4+T-cell proliferation, but regard of the mechanism of the Eg.ferritin induce host to eradicate E. granulosus were not clear.

Donor-derived, tolerogenic dendritic cells suppress immune rejection in the indirect allosensitization-dominant setting of corneal transplantation.

PubMed

Hattori, Takaaki; Saban, Daniel R; Emami-Naeini, Parisa; Chauhan, Sunil K; Funaki, Toshinari; Ueno, Hiroki; Dana, Reza

2012-04-01

Significant interest has been focused on the use of ex vivo-manipulated DCs to optimally induce transplant tolerance and promote allograft survival. Although it is understood that donor-derived, tolerogenic DCs suppress the direct pathway of allosensitization, whether such DCs can similarly suppress the indirect pathway remains unclear. We therefore used the murine model of corneal transplantation to address this, as these allografts are rejected in an indirect pathway-dominant manner. Interestingly, recipients administered with donor bone marrow-derived DCregs, generated via culturing with GM-CSF, IL-10, and TGF-β1, significantly prolonged survival of corneal allografts. Correspondingly, these recipients demonstrated a potent reduction in the frequency of indirectly allosensitized T cells, as determined by ELISPOT. Examination of DCregs relative to mDCs or iDCs showed a resistance to up-regulation of MHC-II and costimulatory molecules, as well as an impaired capacity to stimulate MLRs. In vivo, DCreg administration in corneal-allografted recipients led to inhibition of CD4(+)IFN-γ(+) T cell frequencies and an associated increase in Foxp3 expression in the Treg compartment. We conclude that donor-derived, tolerogenic DCs significantly suppress the indirect pathway, thereby identifying a novel regulatory mechanism for these cells in transplantation.

Donor-derived, tolerogenic dendritic cells suppress immune rejection in the indirect allosensitization-dominant setting of corneal transplantation

PubMed Central

Hattori, Takaaki; Saban, Daniel R.; Emami-naeini, Parisa; Chauhan, Sunil K.; Funaki, Toshinari; Ueno, Hiroki; Dana, Reza

2012-01-01

Significant interest has been focused on the use of ex vivo-manipulated DCs to optimally induce transplant tolerance and promote allograft survival. Although it is understood that donor-derived, tolerogenic DCs suppress the direct pathway of allosensitization, whether such DCs can similarly suppress the indirect pathway remains unclear. We therefore used the murine model of corneal transplantation to address this, as these allografts are rejected in an indirect pathway-dominant manner. Interestingly, recipients administered with donor bone marrow-derived DCregs, generated via culturing with GM-CSF, IL-10, and TGF-β1, significantly prolonged survival of corneal allografts. Correspondingly, these recipients demonstrated a potent reduction in the frequency of indirectly allosensitized T cells, as determined by ELISPOT. Examination of DCregs relative to mDCs or iDCs showed a resistance to up-regulation of MHC-II and costimulatory molecules, as well as an impaired capacity to stimulate MLRs. In vivo, DCreg administration in corneal-allografted recipients led to inhibition of CD4+IFN-γ+ T cell frequencies and an associated increase in Foxp3 expression in the Treg compartment. We conclude that donor-derived, tolerogenic DCs significantly suppress the indirect pathway, thereby identifying a novel regulatory mechanism for these cells in transplantation. PMID:22291211

Neurotrophin Receptor p75NTR Regulates Immune Function of Plasmacytoid Dendritic Cells.

PubMed

Bandoła, Joanna; Richter, Cornelia; Ryser, Martin; Jamal, Arshad; Ashton, Michelle P; von Bonin, Malte; Kuhn, Matthias; Dorschner, Benjamin; Alexopoulou, Dimitra; Navratiel, Katrin; Roeder, Ingo; Dahl, Andreas; Hedrich, Christian M; Bonifacio, Ezio; Brenner, Sebastian; Thieme, Sebastian

2017-01-01

Plasmacytoid dendritic cells (pDCs) regulate innate and adaptive immunity. Neurotrophins and their receptors control the function of neuronal tissue. In addition, they have been demonstrated to be part of the immune response but little is known about the effector immune cells involved. We report, for the first time, the expression and immune-regulatory function of the low affinity neurotrophin receptor p75 neurotrophin receptor (p75NTR) by the antigen-presenting pDCs, mediated by toll-like receptor (TLR) 9 activation and differential phosphorylation of interferon regulatory factor 3 and 7. The modulation of p75NTR on pDCs significantly influences disease progression of asthma in an ovalbumin-induced mouse model mediated by the TLR9 signaling pathway. p75NTR activation of pDCs from patients with asthma increased allergen-specific T cell proliferation and cytokine secretion in nerve growth factor concentration-dependent manner. Further, p75NTR activation of pDCs delayed the onset of autoimmune diabetes in RIP-CD80GP mice and aggravated graft-versus-host disease in a xenotransplantation model. Thus, p75NTR signaling on pDCs constitutes a new and critical mechanism connecting neurotrophin signaling and immune response regulation with great therapeutic potential for a variety of immune disorders.

Neurotrophin Receptor p75NTR Regulates Immune Function of Plasmacytoid Dendritic Cells

PubMed Central

Bandoła, Joanna; Richter, Cornelia; Ryser, Martin; Jamal, Arshad; Ashton, Michelle P.; von Bonin, Malte; Kuhn, Matthias; Dorschner, Benjamin; Alexopoulou, Dimitra; Navratiel, Katrin; Roeder, Ingo; Dahl, Andreas; Hedrich, Christian M.; Bonifacio, Ezio; Brenner, Sebastian; Thieme, Sebastian

2017-01-01

Plasmacytoid dendritic cells (pDCs) regulate innate and adaptive immunity. Neurotrophins and their receptors control the function of neuronal tissue. In addition, they have been demonstrated to be part of the immune response but little is known about the effector immune cells involved. We report, for the first time, the expression and immune-regulatory function of the low affinity neurotrophin receptor p75 neurotrophin receptor (p75NTR) by the antigen-presenting pDCs, mediated by toll-like receptor (TLR) 9 activation and differential phosphorylation of interferon regulatory factor 3 and 7. The modulation of p75NTR on pDCs significantly influences disease progression of asthma in an ovalbumin-induced mouse model mediated by the TLR9 signaling pathway. p75NTR activation of pDCs from patients with asthma increased allergen-specific T cell proliferation and cytokine secretion in nerve growth factor concentration-dependent manner. Further, p75NTR activation of pDCs delayed the onset of autoimmune diabetes in RIP-CD80GP mice and aggravated graft-versus-host disease in a xenotransplantation model. Thus, p75NTR signaling on pDCs constitutes a new and critical mechanism connecting neurotrophin signaling and immune response regulation with great therapeutic potential for a variety of immune disorders. PMID:28861085

Fever-like thermal conditions regulate the activation of maturing dendritic cells.

PubMed

Tournier, Jean-Nicolas; Hellmann, Anne Quesnel; Lesca, Gaëtan; Jouan, Alain; Drouet, Emmanuel; Mathieu, Jacques

2003-04-01

Fever is one of the most frequent clinical signs encountered in pathology, especially with respect to infectious diseases. It is currently thought that the role of fever on immunity is limited to activation of innate immunity; however, its relevance to activation of adaptive immunity remains unclear. Dendritic cells (DCs) that behave as sentinels of the immune system provide an important bridge between innate and adaptive immunity. To highlight the role of fever on adaptive immunity, we exposed murine bone marrow-derived lipopolysaccharide (LPS)- or live bacteria-maturing DCs over a 3-h period to 37 degrees C or to fever-like thermal conditions (39 degrees C or 40 degrees C). At these three temperatures, we measured the kinetics of cytokine production and the ability of DCs to induce an allogeneic mixed lymphocyte reaction. Our results show that short exposure of DCs to temperatures of 39 degrees C or 40 degrees C differentially increased the secretion of interleukin (IL)-12p70 and decreased the secretion of IL-10 and tumor necrosis factor alpha by maturing DCs. These fever-like conditions induced a regulation of cytokine production at the single-cell level. In addition, short-term exposed LPS-maturing DCs to 39 degrees C induced a stronger reaction with allogeneic CD4(+) T cells than maturing DCs incubated at 37 degrees C. These results provide evidence that temperature regulates cytokine secretion and DC functions, both of which are of particular importance in bacterial diseases.

Strong adhesion by regulatory T cells induces dendritic cell cytoskeletal polarization and contact-dependent lethargy

PubMed Central

Mucsi, Ashley D.; Meng, Junchen; Yan, Jiacong; Zhang, Zongde; Wu, Mei; Hari, Aswin; Stenner, Melanie D.; Zheng, Wencheng; Kubes, Paul; Xia, Tie; Amrein, Matthias W.

2017-01-01

Dendritic cells are targeted by regulatory T (T reg) cells, in a manner that operates as an indirect mode of T cell suppression. In this study, using a combination of single-cell force spectroscopy and structured illumination microscopy, we analyze individual T reg cell–DC interaction events and show that T reg cells exhibit strong intrinsic adhesiveness to DCs. This increased DC adhesion reduces the ability of contacted DCs to engage other antigen-specific cells. We show that this unusually strong LFA-1–dependent adhesiveness of T reg cells is caused in part by their low calpain activities, which normally release integrin–cytoskeleton linkage, and thereby reduce adhesion. Super resolution imaging reveals that such T reg cell adhesion causes sequestration of Fascin-1, an actin-bundling protein essential for immunological synapse formation, and skews Fascin-1–dependent actin polarization in DCs toward the T reg cell adhesion zone. Although it is reversible upon T reg cell disengagement, this sequestration of essential cytoskeletal components causes a lethargic state of DCs, leading to reduced T cell priming. Our results reveal a dynamic cytoskeletal component underlying T reg cell–mediated DC suppression in a contact-dependent manner. PMID:28082358

IL-23 (Interleukin-23)-Producing Conventional Dendritic Cells Control the Detrimental IL-17 (Interleukin-17) Response in Stroke.

PubMed

Gelderblom, Mathias; Gallizioli, Mattia; Ludewig, Peter; Thom, Vivien; Arunachalam, Priyadharshini; Rissiek, Björn; Bernreuther, Christian; Glatzel, Markus; Korn, Thomas; Arumugam, Thiruma Valavan; Sedlacik, Jan; Gerloff, Christian; Tolosa, Eva; Planas, Anna M; Magnus, Tim

2018-01-01

Inflammatory mechanisms can exacerbate ischemic tissue damage and worsen clinical outcome in patients with stroke. Both αβ and γδ T cells are established mediators of tissue damage in stroke, and the role of dendritic cells (DCs) in inducing the early events of T cell activation and differentiation in stroke is not well understood. In a murine model of experimental stroke, we defined the immune phenotype of infiltrating DC subsets based on flow cytometry of surface markers, the expression of ontogenetic markers, and cytokine levels. We used conditional DC depletion, bone marrow chimeric mice, and IL-23 (interleukin-23) receptor-deficient mice to further explore the functional role of DCs. We show that the ischemic brain was rapidly infiltrated by IRF4 + /CD172a + conventional type 2 DCs and that conventional type 2 DCs were the most abundant subset in comparison with all other DC subsets. Twenty-four hours after ischemia onset, conventional type 2 DCs became the major source of IL-23, promoting neutrophil infiltration by induction of IL-17 (interleukin-17) in γδ T cells. Functionally, the depletion of CD11c + cells or the genetic disruption of the IL-23 signaling abrogated both IL-17 production in γδ T cells and neutrophil infiltration. Interruption of the IL-23/IL-17 cascade decreased infarct size and improved neurological outcome after stroke. Our results suggest a central role for interferon regulatory factor 4-positive IL-23-producing conventional DCs in the IL-17-dependent secondary tissue damage in stroke. © 2017 American Heart Association, Inc.

microRNAs in the regulation of dendritic cell functions in inflammation and atherosclerosis.

PubMed

Busch, Martin; Zernecke, Alma

2012-08-01

Atherosclerosis has been established as a chronic inflammatory disease of the vessel wall. Among the mononuclear cell types recruited to the lesions, specialized dendritic cells (DCs) have gained increasing attention, and their secretory products and interactions shape the progression of atherosclerotic plaques. The regulation of DC functions by microRNAs (miRNAs) may thus be of primary importance in disease. We here systematically summarize the biogenesis and functions of miRNAs and provide an overview of miRNAs in DCs, their targets, and potential implications for atherosclerosis, with a particular focus on the best characterized miRNAs in DCs, namely, miR-155 and miR-146. MiRNA functions in DCs range from regulation of lipid uptake to cytokine production and T cell responses with a complex picture emerging, in which miRNAs cooperate or antagonize DC behavior, thereby promoting or counterbalancing inflammatory responses. As miRNAs regulate key functions of DCs known to control atherosclerotic vascular disease, their potential as a therapeutic target holds promise and should be attended to in future research.

Mechanistic studies of systemic immune responses induced by laser-nanotechnology

NASA Astrophysics Data System (ADS)

Chen, Wei R.; Zhou, Feifan; Henderson, Brock; Vasquez, Bailey; Liu, Hong; Hode, Tomas; Nordquist, Robert E.

2014-02-01

With the help of the specific absorption spectrum of carbon nanotubes, we achieved selective photothermal tumor cell destruction, particularly using a near-infrared laser to reduce potential damage to untargeted tissues. Combined with immunological stimulation, using a novel adjuvant, we also observed the anti-tumor immune responses when treating animal tumors using the laser-nano treatment. In fact, the local application of laser-nano-immunotherapy appeared to result in a systemic curative effect. In our mechanistic study, we found that the laser-nano-immuno treatment can activate antigen-presenting cells, such as dendritic cells (DCs). More importantly, the uptake and presentation of antigens by these antigen presenting cells were significantly enhanced, as shown by the strong binding of tumor cells and DCs as well as the proliferation of T cells caused by the DCs after the DCs had been incubated with laser-nano-immuno treated tumors. These cellular observations provide evidence that a systemic anti-tumor immune response was induced by the combination of laser and nanotechnology.

Genome-wide STAT3 binding analysis after histone deacetylase inhibition reveals novel target genes in dendritic cells

PubMed Central

Sun, Yaping; Iyer, Matthew; McEachin, Richard; Zhao, Meng; Wu, Yi-Mi; Cao, Xuhong; Oravecz-Wilson, Katherine; Zajac, Cynthia; Mathewson, Nathan; Wu, Shin-Rong Julia; Rossi, Corinne; Toubai, Tomomi; Qin, Zhaohui S.; Chinnaiya, Arul M.; Reddy, Pavan

2016-01-01

STAT3 is a master transcriptional regulator that plays an important role in the induction of both immune activation and immune tolerance in dendritic cells (DCs). The transcriptional targets of STAT3 in promoting DC activation are becoming increasingly understood; however, the mechanisms underpinning its role in causing DC suppression remain largely unknown. To determine the functional gene targets of STAT3, we compared the genome-wide binding of STAT3 using ChIP-seq coupled with gene expression microarrays to determine STAT3-dependent gene regulation in DCs after histone deacetylase (HDAC) inhibition. HDAC inhibition boosted the ability of STAT3 to bind to distinct DNA targets and regulate gene expression. Among the top 500 STAT3 binding sites, the frequency of canonical motifs was significantly higher than that of non-canonical motifs. Functional analysis revealed that after treatment with an HDAC inhibitor, the upregulated STAT3 target genes were those that were primarily the negative regulators of pro-inflammatory cytokines and those in the IL-10 signaling pathway. The downregulated STAT3-dependent targets were those involved in immune effector processes and antigen processing/presentation. The expression and functional relevance of these genes were validated. Specifically, functional studies confirmed that the upregulation of IL-10Ra by STAT3 contributed to the suppressive function of DCs following HDAC inhibition. PMID:27866206

Arc/Arg3.1 governs inflammatory dendritic cell migration from the skin and thereby controls T cell activation.

PubMed

Ufer, Friederike; Vargas, Pablo; Engler, Jan Broder; Tintelnot, Joseph; Schattling, Benjamin; Winkler, Hana; Bauer, Simone; Kursawe, Nina; Willing, Anne; Keminer, Oliver; Ohana, Ora; Salinas-Riester, Gabriela; Pless, Ole; Kuhl, Dietmar; Friese, Manuel A

2016-09-23

Skin-migratory dendritic cells (migDCs) are pivotal antigen-presenting cells that continuously transport antigens to draining lymph nodes and regulate immune responses. However, identification of migDCs is complicated by the lack of distinguishing markers, and it remains unclear which molecules determine their migratory capacity during inflammation. We show that, in the skin, the neuronal plasticity molecule activity-regulated cytoskeleton-associated protein/activity-regulated gene 3.1 (Arc/Arg3.1) was strictly confined to migDCs. Mechanistically, Arc/Arg3.1 was required for accelerated DC migration during inflammation because it regulated actin dynamics through nonmuscle myosin II. Accordingly, Arc/Arg3.1-dependent DC migration was critical for mounting T cell responses in experimental autoimmune encephalomyelitis and allergic contact dermatitis. Thus, Arc/Arg3.1 was restricted to migDCs in the skin and drove fast DC migration by exclusively coordinating cytoskeletal changes in response to inflammatory challenges. These findings commend Arc/Arg3.1 as a universal switch in migDCs that may be exploited to selectively modify immune responses. Copyright © 2016, American Association for the Advancement of Science.

Candida albicans induces selective development of macrophages and monocyte derived dendritic cells by a TLR2 dependent signalling.

PubMed

Yáñez, Alberto; Megías, Javier; O'Connor, José-Enrique; Gozalbo, Daniel; Gil, M Luisa

2011-01-01

As TLRs are expressed by haematopoietic stem and progenitor cells (HSPCs), these receptors may play a role in haematopoiesis in response to pathogens during infection. We have previously demonstrated that in in vitro defined conditions inactivated yeasts and hyphae of Candida albicans induce HSPCs proliferation and differentiation towards the myeloid lineage by a TLR2/MyD88 dependent pathway. In this work, we showed that C. albicans invasive infection with a low virulence strain results in a rapid expansion of HSPCs (identified as LKS cells: Lin(-) c-Kit(+) Sca-1(+) IL-7Rα(-)), that reach the maximum at day 3 post-infection. This in vivo expansion of LKS cells in TLR2(-/-) mice was delayed until day 7 post- infection. Candidiasis was, as expected, accompanied by an increase in granulopoiesis and decreased lymphopoiesis in the bone marrow. These changes were more pronounced in TLR2(-/-) mice correlating with their higher fungal burden. Accordingly, emigration of Ly6C(high) monocytes and neutrophils to spleen was increased in TLR2(-/-) mice, although the increase in macrophages and inflammatory macrophages was completely dependent on TLR2. Similarly, we detected for the first time, in the spleen of C. albicans infected control mice, a newly generated population of dendritic cells that have the phenotype of monocyte derived dendritic cells (moDCs) that were not generated in TLR2(-/-) infected mice. In addition, C. albicans signalling through TLR2/MyD88 and Dectin-1 promotes in vitro the differentiation of Lin(-) cells towards moDCs that secrete TNF-α and are able to kill the microorganism. Therefore, our results indicate that during infection C. albicans can directly stimulate progenitor cells through TLR2 and Dectin-1 to generate newly formed inflammatory macrophages and moDCs that may fulfill an essential role in defense mechanisms against the pathogen.

Candida albicans Induces Selective Development of Macrophages and Monocyte Derived Dendritic Cells by a TLR2 Dependent Signalling

PubMed Central

Yáñez, Alberto; Megías, Javier; O'Connor, José-Enrique; Gozalbo, Daniel; Gil, M. Luisa

2011-01-01

As TLRs are expressed by haematopoietic stem and progenitor cells (HSPCs), these receptors may play a role in haematopoiesis in response to pathogens during infection. We have previously demonstrated that in in vitro defined conditions inactivated yeasts and hyphae of Candida albicans induce HSPCs proliferation and differentiation towards the myeloid lineage by a TLR2/MyD88 dependent pathway. In this work, we showed that C. albicans invasive infection with a low virulence strain results in a rapid expansion of HSPCs (identified as LKS cells: Lin− c-Kit+ Sca-1+ IL-7Rα−), that reach the maximum at day 3 post-infection. This in vivo expansion of LKS cells in TLR2−/− mice was delayed until day 7 post- infection. Candidiasis was, as expected, accompanied by an increase in granulopoiesis and decreased lymphopoiesis in the bone marrow. These changes were more pronounced in TLR2−/− mice correlating with their higher fungal burden. Accordingly, emigration of Ly6Chigh monocytes and neutrophils to spleen was increased in TLR2−/− mice, although the increase in macrophages and inflammatory macrophages was completely dependent on TLR2. Similarly, we detected for the first time, in the spleen of C. albicans infected control mice, a newly generated population of dendritic cells that have the phenotype of monocyte derived dendritic cells (moDCs) that were not generated in TLR2−/− infected mice. In addition, C. albicans signalling through TLR2/MyD88 and Dectin-1 promotes in vitro the differentiation of Lin− cells towards moDCs that secrete TNF-α and are able to kill the microorganism. Therefore, our results indicate that during infection C. albicans can directly stimulate progenitor cells through TLR2 and Dectin-1 to generate newly formed inflammatory macrophages and moDCs that may fulfill an essential role in defense mechanisms against the pathogen. PMID:21935459

Efficacy of DHMEQ, a NF-κB inhibitor, in islet transplantation: II. Induction DHMEQ treatment ameliorates subsequent alloimmune responses and permits long-term islet allograft acceptance.

PubMed

Watanabe, Masaaki; Yamashita, Kenichiro; Kamachi, Hirofumi; Kuraya, Daisuke; Koshizuka, Yasuyuki; Shibasaki, Susumu; Asahi, Yoh; Ono, Hitoshi; Emoto, Shin; Ogura, Masaomi; Yoshida, Tadashi; Ozaki, Michitaka; Umezawa, Kazuo; Matsushita, Michiaki; Todo, Satoru

2013-09-15

Long-term graft deterioration remains a major obstacle in the success of pancreatic islet transplantation (PITx). Antigen-independent inflammatory and innate immune responses strengthen subsequent antigen-dependent immunity; further, activation of nuclear factor (NF)-κB plays a key role during these responses. In this study, we tested our hypothesis that, by the inhibition of NF-κB activation, the suppression of these early responses after PITx could facilitate graft acceptance. Full major histocompatibility complex (MHC)-mismatched BALB/c (H-2) mice islets were transplanted into streptozotocin-induced diabetic C57BL/6 (B6: H-2) mice. The NF-κB inhibitor dehydroxymethylepoxyquinomicin (DHMEQ) was administered for either 3 or 14 days after PITx. To some PITx recipients, tacrolimus was also administered. Islet allograft survival, alloimmune responses, and in vitro effects of DHMEQ on dendritic cells (DCs) were assessed. With a vehicle treatment, 600 islet allografts were promptly rejected after PITx. In contrast, 3-day treatment with DHMEQ, followed by 2-week treatment with tacrolimus, allowed permanent acceptance of islet allografts. The endogenous danger-signaling molecule high mobility group complex 1 (HMGB1) was elevated in sera shortly after PITx, whereas DHMEQ administration abolished this elevation. DHMEQ suppressed HMGB1-driven cellular activation and proinflammatory cytokine secretion in mouse bone marrow-derived DCs and significantly reduced the capacity of DCs to prime allogeneic T-cell proliferation in vitro. Finally, the DHMEQ plus tacrolimus regimen reverted the diabetic state with only 300 islet allografts. Inhibition of NF-κB activation by DHMEQ shortly after PITx suppresses HMGB1, which activates DCs and strengthens the magnitude of alloimmune responses; this permits long-term islet allograft acceptance, even in case of fewer islet allografts.

Distinctive TLR7 signaling, type I IFN production, and attenuated innate and adaptive immune responses to yellow fever virus in a primate reservoir host.

PubMed

Mandl, Judith N; Akondy, Rama; Lawson, Benton; Kozyr, Natalia; Staprans, Silvija I; Ahmed, Rafi; Feinberg, Mark B

2011-06-01

Why cross-species transmissions of zoonotic viral infections to humans are frequently associated with severe disease when viruses responsible for many zoonotic diseases appear to cause only benign infections in their reservoir hosts is unclear. Sooty mangabeys (SMs), a reservoir host for SIV, do not develop disease following SIV infection, unlike nonnatural HIV-infected human or SIV-infected rhesus macaque (RM) hosts. SIV infections of SMs are characterized by an absence of chronic immune activation, in association with significantly reduced IFN-α production by plasmacytoid dendritic cells (pDCs) following exposure to SIV or other defined TLR7 or TLR9 ligands. In this study, we demonstrate that SM pDCs produce significantly less IFN-α following ex vivo exposure to the live attenuated yellow fever virus 17D strain vaccine, a virus that we show is also recognized by TLR7, than do RM or human pDCs. Furthermore, in contrast to RMs, SMs mount limited activation of innate immune responses and adaptive T cell proliferative responses, along with only transient antiviral Ab responses, following infection with yellow fever vaccine 17D strain. However, SMs do raise significant and durable cellular and humoral immune responses comparable to those seen in RMs when infected with modified vaccinia Ankara, a virus whose immunogenicity does not require TLR7/9 recognition. Hence, differences in the pattern of TLR7 signaling and type I IFN production by pDCs between primate species play an important role in determining their ability to mount and maintain innate and adaptive immune responses to specific viruses, and they may also contribute to determining whether disease follows infection.

Effects of Transcranial Direct Current Stimulation over Left Dorsolateral pFC on the Attentional Blink Depend on Individual Baseline Performance.

PubMed

London, Raquel E; Slagter, Heleen A

2015-12-01

Selection mechanisms that dynamically gate only relevant perceptual information for further processing and sustained representation in working memory are critical for goal-directed behavior. We examined whether this gating process can be modulated by anodal transcranial direct current stimulation (tDCS) over left dorsolateral pFC (DLPFC)--a region known to play a key role in working memory and conscious access. Specifically, we examined the effects of tDCS on the magnitude of the so-called "attentional blink" (AB), a deficit in identifying the second of two targets presented in rapid succession. Thirty-four participants performed a standard AB task before (baseline), during, and after 20 min of 1-mA anodal and cathodal tDCS in two separate sessions. On the basis of previous reports linking individual differences in AB magnitude to individual differences in DLPFC activity and on suggestions that effects of tDCS depend on baseline brain activity levels, we hypothesized that anodal tDCS over left DLPFC would modulate the magnitude of the AB as a function of individual baseline AB magnitude. Indeed, individual differences analyses revealed that anodal tDCS decreased the AB in participants with a large baseline AB but increased the AB in participants with a small baseline AB. This effect was only observed during (but not after) stimulation, was not found for cathodal tDCS, and could not be explained by regression to the mean. Notably, the effects of tDCS were not apparent at the group level, highlighting the importance of taking individual variability in performance into account when evaluating the effectiveness of tDCS. These findings support the idea that left DLPFC plays a critical role in the AB and in conscious access more generally. They are also in line with the notion that there is an optimal level of prefrontal activity for cognitive function, with both too little and too much activity hurting performance.

Daphnoretin modulates differentiation and maturation of human dendritic cells through down-regulation of c-Jun N-terminal kinase.

PubMed

Chen, Chien-An; Liu, Chien-Kuo; Hsu, Ming-Ling; Chi, Chih-Wen; Ko, Chun-Chuan; Chen, Jian-Syun; Lai, Cheng-Ta; Chang, Hen-Hong; Lee, Tzung-Yan; Lai, Yuen-Liang; Chen, Yu-Jen

2017-10-01

Daphnoretin, an active constituent of Wikstroemia indica C.A. Meys, has been shown possessing anti-cancer activity. In this study, we examined the effect of daphnoretin on differentiation and maturation of human myeloid dendritic cells (DCs). After treatment with daphnoretin (0, 1.1, 3.3, 10 and 30μM) to initiate monocytes, the recovery rate of DCs was reduced in a dose-dependent manner. The mature DCs differentiated in the presence of daphnoretin had fewer and shorter dendrites. Daphnoretin modulated DCs differentiation and maturation in terms of lower expression of CD1a, CD40, CD83, DC-SIGN, and HLA-DR. Daphnoretin inhibited the allostimulatory activity of DCs on proliferation of naive CD4 + CD45 + RA + T cell. On the mitogen-activated protein kinase, daphnoretin down-regulated the lipopolysaccharide-augmented expression of phosphorylated c-Jun N-terminal kinase (pJNK), but not p38 and extracellular signal-regulated kinase 1/2 (ERK1/2). Activation of JNK by anisomycin reversed the effect of daphnoretin on daphnoretin-inhibited pJNK expression and dendrite formation of DCs. In disease model related to maturation of DCs, daphnoretin suppressed the acute rejection of skin allografts in mice. Our results suggest that daphnoretin modulated differentiation and maturation of DCs toward a state of atypical maturation with impaired allostimulatory function and this effect may go through down-regulation of phosphorylated JNK. Copyright © 2017 Elsevier B.V. All rights reserved.

Ex Vivo Induction of Multiple Myeloma-specific Immune Responses by Monocyte-derived Dendritic Cells Following Stimulation by Whole-tumor Antigen of Autologous Myeloma Cells.

PubMed

Vasileiou, Spyridoula; Baltadakis, Ioannis; Delimpasi, Sosanna; Karatza, Maria-Helena; Liapis, Konstantinos; Garofalaki, Maria; Tziotziou, Eirini; Poulopoulou, Zoe; Karakasis, Dimitri; Harhalakis, Nicholas

2017-09-01

The introduction of novel agents has significantly expanded treatment options for multiple myeloma (MM), albeit long-term disease control cannot be achieved in the majority of patients. Vaccination with MM antigen-loaded dendritic cells (DCs) represents an alternative strategy that is currently being explored. The aim of this study was to assess the immunogenic potential of ex vivo-generated monocyte-derived DCs (moDCs), following stimulation with the whole-antigen array of autologous myeloma cells (AMC). MoDCs were loaded with antigens of myeloma cells by 2 different methods: phagocytosis of apoptotic bodies from γ-irradiated AMC, or transfection with AMC total RNA by square-wave electroporation. Twenty patients with MM were enrolled in the study. Following stimulation and maturation, moDCs were tested for their capacity to induce T-helper 1 and cytotoxic T lymphocyte responses in vitro. Both strategies were effective in the induction of myeloma-specific cytotoxic T lymphocyte and T-helper 1 cells, as demonstrated by cytotoxicity and ELISpot assays. On the whole, T-cell responses were observed in 18 cases by either method of DC pulsing. We conclude that both whole-tumor antigen approaches are efficient in priming autologous antimyeloma T-cell responses and warrant further study aiming at the development of individualized DC vaccines for MM patients.

Cross-Priming of Naive Cd8 T Cells against Melanoma Antigens Using Dendritic Cells Loaded with Killed Allogeneic Melanoma Cells

PubMed Central

Berard, Frederic; Blanco, Patrick; Davoust, Jean; Neidhart-Berard, Eve-Marie; Nouri-Shirazi, Mahyar; Taquet, Nicolas; Rimoldi, Donata; Cerottini, Jean Charles; Banchereau, Jacques; Palucka, A. Karolina

2000-01-01

The goal of tumor immunotherapy is to elicit immune responses against autologous tumors. It would be highly desirable that such responses include multiple T cell clones against multiple tumor antigens. This could be obtained using the antigen presenting capacity of dendritic cells (DCs) and cross-priming. That is, one could load the DC with tumor lines of any human histocompatibility leukocyte antigen (HLA) type to elicit T cell responses against the autologous tumor. In this study, we show that human DCs derived from monocytes and loaded with killed melanoma cells prime naive CD45RA+CD27+CD8+ T cells against the four shared melanoma antigens: MAGE-3, gp100, tyrosinase, and MART-1. HLA-A201+ naive T cells primed by DCs loaded with HLA-A201− melanoma cells are able to kill several HLA-A201+ melanoma targets. Cytotoxic T lymphocyte priming towards melanoma antigens is also obtained with cells from metastatic melanoma patients. This demonstration of cross-priming against shared tumor antigens builds the basis for using allogeneic tumor cell lines to deliver tumor antigens to DCs for vaccination protocols. PMID:11104796

The regulation of autoreactive B cells during innate immune responses.

PubMed

Vilen, Barbara J; Rutan, Jennifer A

2008-01-01

Systemic lupus erythematosus (SLE) highlights the dangers of dysregulated B cells and the importance of initiating and maintaining tolerance. In addition to central deletion, receptor editing, peripheral deletion, receptor revision, anergy, and indifference, we have described a new mechanism of B cell tolerance wherein dendritic cells (DCs) and macrophages (MPhis) regulate autoreactive B cells during innate immune responses. In part, DCs and MPhis repress autoreactive B cells by releasing IL-6 and soluble CD40L (sCD40L). This mechanism is selective in that IL-6 and sCD40L do not affect Ig secretion by naïve cells during innate immune responses, allowing immunity in the absence of autoimmunity. In lupus-prone mice, DCs and MPhis are defective in secretion of IL-6 and sCD40L and cannot effectively repress autoantibody secretion suggesting that defects in DC/MPhi-mediated tolerance may contribute to the autoimmune phenotype. Further, these studies suggest that reconstituting DCs and MPhis in SLE patients might restore regulation of autoreactive B cells and provide an alternative to immunosuppressive therapies.

Fucosylated clusterin in semen promotes the uptake of stress-damaged proteins by dendritic cells via DC-SIGN.

PubMed

Merlotti, A; Dantas, E; Remes Lenicov, F; Ceballos, A; Jancic, C; Varese, A; Rubione, J; Stover, S; Geffner, J; Sabatté, J

2015-07-01

Could seminal plasma clusterin play a role in the uptake of stress-damaged proteins by dendritic cells? Seminal plasma clusterin, but not serum clusterin, promotes the uptake of stress-damaged proteins by dendritic cells via DC-SIGN. Clusterin is one of the major extracellular chaperones. It interacts with a variety of stressed proteins to prevent their aggregation, guiding them for receptor-mediated endocytosis and intracellular degradation. The concentration of clusterin in semen is almost 20-fold higher than that found in serum, raising the question about the role of seminal plasma clusterin in reproduction. No previous studies have analyzed whether seminal plasma clusterin has chaperone activity. We have previously shown that seminal plasma clusterin, but not serum clusterin, expresses an extreme abundance of fucosylated glycans. These motifs enable seminal plasma clusterin to bind DC-SIGN with very high affinity. In vitro experiments were performed to evaluate the ability of seminal plasma clusterin to inhibit the precipitation of stressed proteins, promoting their uptake by dendritic cells via DC-SIGN (a C-type lectin receptor selectively expressed on dendritic cells (DC)). Moreover, the ability of seminal plasma clusterin to modulate the phenotype and function of DCs was also assessed. Clusterin was purified from human semen and human serum. Catalase, bovine serum albumin, glutathione S-transferase, and normal human serum were stressed and the ability of seminal plasma clusterin to prevent the precipitation of these proteins, guiding them to DC-SIGN expressed by DCs, was evaluated using a fluorescence-activated cell sorter (FACS). Endocytosis of stressed proteins was analyzed by confocal microscopy and the ability of seminal plasma clusterin-treated DCs to stimulate the proliferation of CD25+FOXP3+CD4+ T cells was also evaluated by FACS. Seminal plasma clusterin interacts with stressed proteins, inhibits their aggregation (P < 0.01) and efficiently targets them to dendritic cells via DC-SIGN (P < 0.01). DCs efficiently endocytosed clusterin-client complexes and sorted them to degradative compartments involved in antigen processing and presentation. Moreover, we also found that the interaction of seminal plasma clusterin with DC-SIGN did not change the phenotype of DCs, but stimulates their ability to induce the expansion of CD25+FOXP3+CD4+ T lymphocytes (P < 0.05 versus control). All the experiments were performed in vitro; hence the relevance of our observations should be validated in vivo. Our results suggest that by inducing the endocytosis of stress-damaged proteins by DCs via DC-SIGN, seminal plasma clusterin might promote a tolerogenic response to male antigens, thereby contributing to female tolerance to seminal antigens. The present research was supported by the Consejo Nacional de Investigaciones Científicas y Técnicas, the Buenos Aires University School of Medicine, and the Agencia Nacional de Promoción Científica y Tecnológica (Argentina). The authors have no conflicts of interest to declare. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Accumulation of BDCA1⁺ dendritic cells in interstitial fibrotic lung diseases and Th2-high asthma.

PubMed

Greer, Alexandra M; Matthay, Michael A; Kukreja, Jasleen; Bhakta, Nirav R; Nguyen, Christine P; Wolters, Paul J; Woodruff, Prescott G; Fahy, John V; Shin, Jeoung-Sook

2014-01-01

Dendritic cells (DCs) significantly contribute to the pathology of several mouse lung disease models. However, little is known of the contribution of DCs to human lung diseases. In this study, we examined infiltration with BDCA1⁺ DCs of human lungs in patients with interstitial lung diseases or asthma. Using flow cytometry, we found that these DCs increased by 5∼6 fold in the lungs of patients with idiopathic pulmonary fibrosis or hypersensitivity pneumonitis, which are both characterized by extensive fibrosis in parenchyma. The same DC subset also significantly increased in the lung parenchyma of patients with chronic obstructive pulmonary disease, although the degree of increase was relatively modest. By employing immunofluorescence microscopy using FcεRI and MHCII as the specific markers for BDCA1⁺ DCs, we found that the numbers of BDCA1⁺ DCs also significantly increased in the airway epithelium of Th2 inflammation-associated asthma. These findings suggest a potential contribution of BDCA1⁺ DCs in human lung diseases associated with interstitial fibrosis or Th2 airway inflammation.

Regulation of dendritic cell function through Toll-like receptors.

PubMed

Kaisho, Tsuneyasu; Akira, Shizuo

2003-06-01

Higher animals establish host defense by orchestrating innate and adaptive immunity. This is mediated by professional antigen presenting cells, i.e. dendritic cells (DCs). DCs can incorporate pathogens, produce a variety of cytokines, maturate, and present pathogen-derived peptides to T cells, thereby inducing T cell activation and differentiation. These responses are triggered by microbial recognition through type I transmembrane proteins, Toll-like receptors (TLRs) on DCs. TLRs consist of ten members and each TLR is involved in recognizing a variety of microorganism-derived molecular structures. TLR ligands include cell wall components, proteins, nucleic acids, and synthetic chemical compounds, all of which can activate DCs as immune adjuvants. Each TLR can activate DCs in a similar, but distinct manner. For example, TLRs can be divided into subgroups according to their type I interferon (IFN) inducing ability. TLR2 cannot induce IFN-alpha or IFN-beta, but TLR4 can lead to IFN-beta production. Meanwhile, TLR3, TLR7, and TLR9 can induce both IFN-alpha and IFN-beta. Recent evidences suggest that cytoplamic adapters for TLRs are especially crucial for this functional heterogeneity. Clarifying how DC function is regulated by TLRs should provide us with critical information for manipulating the host defense against a variety of diseases.

Size-Dependent Effects of Gold Nanoparticles Uptake on Maturation and Antitumor Functions of Human Dendritic Cells In Vitro

PubMed Central

Tomić, Sergej; Đokić, Jelena; Vasilijić, Saša; Ogrinc, Nina; Rudolf, Rebeka; Pelicon, Primož; Vučević, Dragana; Milosavljević, Petar; Janković, Srđa; Anžel, Ivan; Rajković, Jelena; Rupnik, Marjan Slak; Friedrich, Bernd; Čolić, Miodrag

2014-01-01

Gold nanoparticles (GNPs) are claimed as outstanding biomedical tools for cancer diagnostics and photo-thermal therapy, but without enough evidence on their potentially adverse immunological effects. Using a model of human dendritic cells (DCs), we showed that 10 nm- and 50 nm-sized GNPs (GNP10 and GNP50, respectively) were internalized predominantly via dynamin-dependent mechanisms, and they both impaired LPS-induced maturation and allostimulatory capacity of DCs, although the effect of GNP10 was more prominent. However, GNP10 inhibited LPS-induced production of IL-12p70 by DCs, and potentiated their Th2 polarization capacity, while GNP50 promoted Th17 polarization. Such effects of GNP10 correlated with a stronger inhibition of LPS-induced changes in Ca2+ oscillations, their higher number per DC, and more frequent extra-endosomal localization, as judged by live-cell imaging, proton, and electron microscopy, respectively. Even when released from heat-killed necrotic HEp-2 cells, GNP10 inhibited the necrotic tumor cell-induced maturation and functions of DCs, potentiated their Th2/Th17 polarization capacity, and thus, impaired the DCs' capacity to induce T cell-mediated anti-tumor cytotoxicity in vitro. Therefore, GNP10 could potentially induce more adverse DC-mediated immunological effects, compared to GNP50. PMID:24802102

Quantitative immunophenotypic analysis of antigen-presenting cells involved in ectromelia virus antigen presentation in BALB/c and C57BL/6 mice.

PubMed

Szulc-Dąbrowska, Lidia; Gieryńska, Małgorzata; Boratyńska-Jasińska, Anna; Martyniszyn, Lech; Winnicka, Anna; Niemiałtowski, Marek G

2013-08-01

During mousepox in resistant (C57BL/6) or susceptible (BALB/c) strains of mice, stimulation of Th1 or Th2 cytokine immune response, respectively, is observed. Because mechanisms of different polarization of T cells remain elusive, in this study, we quantitatively assessed the phenotype of antigen-presenting cells (APCs) involved in ectromelia virus (ECTV) antigen presentation and cluster formation with effector cells in secondary lymphoid organs of BALB/c and C57BL/6 mice. We showed that both strains of mice display similar dynamics and kinetics of viral antigen presentation by CD11c(+) , CD11b(+) , and CD19(+) cells. CD11c(+) and CD11b(+) cells highly participated in viral antigen presentation during all stages of mousepox, whereas CD19(+) cells presented viral peptides later in infection. The main population of dendritic cells (DCs) engaged in ECTV antigen presentation and cell junction formation with effector cells was a population of myeloid CD11b(+) DCs (mDCs). We suggest that, on the one hand, ECTV may differentially affect the functions of APCs depending on the strain of mice. On the other hand, we suggest that some types of APCs, such as mDCs or other DCs subsets, have different abilities to direct the shape of immune response depending on the host resistance to mousepox. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Effect of ginseng polysaccharides and dendritic cells on the balance of Th1/Th2 T helper cells in patients with non-small cell lung cancer.

PubMed

Ma, Junjie; Liu, Huiping; Wang, Xiaolong

2014-12-01

To investigate the effect of thorascopic administration.of ginseng polysaccharides (GPS) plus dendritic cells (DC) on T helper cell type 1/T helper cell type 2 (Th1/Th2) balance in patients with non-small cell lung cancer (NSCLC). A total of 96 NSCLC patients were divided evenly into two groups. The control group was treated with DCs alone and the treatment group was treated with DCs plus GPS. After DCs and GPS were administered thoracoscopically, once a week, 4 times for 30 days, the patients' quality of life was measured with the Functional Assessment of Cancer Treatment-Lung (FACT-L) questionnaire before and after treatment. Serum interferon-γ (INF-γ), interleukin-4 (IL-4), IL-2 and IL-5 were examined before and after treatments. The level of Th1 cytokines (INF-γ, IL-2) and the ratio of Th1/Th2 cytokines (INF-γ/IL-4, IL-2/ IL-5) increased in both treatment groups, while Th2 cytokines (IL-4, IL-5) and FACT-L scores decreased (P < 0.01). Furthermore, after treatment Th1 cytokines (INF-γ, IL-2) and the ratio of Th1/Th2 cytokines (INF-γ/IL-4, IL-2/IL-5) were higher in the DCs + GPS group than in the control group (P < 0.05). Conversely, FACT-L scores and Th2 cytokines (IL-4, IL-5) were higher in the control group than in the DCs + GPS group (P < 0.05). The treatment regime of DCs plus GPS had a greater effect on NSCLC patients' immune function as compared with DCs alone. This was evident by increased expression of Th1 cytokines (INF-γ, IL-2) and the ratio of Th1/Th2 (INF-γ/IL-4, IL-2/IL-5), as well as by decreased FACT-L scores and the expression of Th2 cytokines (IL-4, IL-5).