Dendritic cell-based vaccines for therapy of HPV16-induced tumours

Czech Academy of Sciences Publication Activity Database

Bubeník, Jan; Šímová, Jana; Vonka, V.; Šmahel, M.; Mikyšková, Romana; Mendoza, Luis

2001-01-01

Roč. 495, - (2001), s. 359-363 ISSN 0065-2598 R&D Projects: GA MZd NC5526; GA ČR GA312/98/0826; GA ČR GA312/99/0542; GA ČR GA301/00/0114; GA ČR GA301/01/0985; GA AV ČR IAA7052002 Institutional research plan: CEZ:AV0Z5052915 Keywords : HPV16 * dendritic cell s * tumour vaccines Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.513, year: 2000

A novel cancer vaccine strategy based on HLA-A*0201 matched allogeneic plasmacytoid dendritic cells.

Directory of Open Access Journals (Sweden)

Caroline Aspord

Full Text Available BACKGROUND: The development of effective cancer vaccines still remains a challenge. Despite the crucial role of plasmacytoid dendritic cells (pDCs in anti-tumor responses, their therapeutic potential has not yet been worked out. We explored the relevance of HLA-A*0201 matched allogeneic pDCs as vectors for immunotherapy. METHODS AND FINDINGS: Stimulation of PBMC from HLA-A*0201(+ donors by HLA-A*0201 matched allogeneic pDCs pulsed with tumor-derived peptides triggered high levels of antigen-specific and functional cytotoxic T cell responses (up to 98% tetramer(+ CD8 T cells. The pDC vaccine demonstrated strong anti-tumor therapeutic in vivo efficacy as shown by the inhibition of tumor growth in a humanized mouse model. It also elicited highly functional tumor-specific T cells ex-vivo from PBMC and TIL of stage I-IV melanoma patients. Responses against MelA, GP100, tyrosinase and MAGE-3 antigens reached tetramer levels up to 62%, 24%, 85% and 4.3% respectively. pDC vaccine-primed T cells specifically killed patients' own autologous melanoma tumor cells. This semi-allogeneic pDC vaccine was more effective than conventional myeloid DC-based vaccines. Furthermore, the pDC vaccine design endows it with a strong potential for clinical application in cancer treatment. CONCLUSIONS: These findings highlight HLA-A*0201 matched allogeneic pDCs as potent inducers of tumor immunity and provide a promising immunotherapeutic strategy to fight cancer.

Unexpected High Response Rate to Traditional Therapy after Dendritic Cell-Based Vaccine in Advanced Melanoma: Update of Clinical Outcome and Subgroup Analysis

Directory of Open Access Journals (Sweden)

Laura Ridolfi

2010-01-01

Full Text Available We reviewed the clinical results of a dendritic cell-based phase II clinical vaccine trial in stage IV melanoma and analyzed a patient subgroup treated with standard therapies after stopping vaccination. From 2003 to 2009, 24 metastatic melanoma patients were treated with mature dendritic cells pulsed with autologous tumor lysate and keyhole limpet hemocyanin and low-dose interleukin-2. Overall response (OR to vaccination was 37.5% with a clinical benefit of 54.1%. All 14 responders showed delayed type hypersensitivity positivity. Median overall survival (OS was 15 months (95% CI, 8–33. Eleven patients underwent other treatments (3 surgery, 2 biotherapy, 2 radiotherapy, 2 chemotherapy, and 4 biochemotherapy after stopping vaccination. Of these, 2 patients had a complete response and 5 a partial response, with an OR of 63.6%. Median OS was 34 months (range 16–61. Our results suggest that therapeutic DC vaccination could favor clinical response in patients after more than one line of therapy.

Unexpected high response rate to traditional therapy after dendritic cell-based vaccine in advanced melanoma: update of clinical outcome and subgroup analysis.

Science.gov (United States)

Ridolfi, Laura; Petrini, Massimiliano; Fiammenghi, Laura; Granato, Anna Maria; Ancarani, Valentina; Pancisi, Elena; Scarpi, Emanuela; Guidoboni, Massimo; Migliori, Giuseppe; Sanna, Stefano; Tauceri, Francesca; Verdecchia, Giorgio Maria; Riccobon, Angela; Valmorri, Linda; Ridolfi, Ruggero

2010-01-01

We reviewed the clinical results of a dendritic cell-based phase II clinical vaccine trial in stage IV melanoma and analyzed a patient subgroup treated with standard therapies after stopping vaccination. From 2003 to 2009, 24 metastatic melanoma patients were treated with mature dendritic cells pulsed with autologous tumor lysate and keyhole limpet hemocyanin and low-dose interleukin-2. Overall response (OR) to vaccination was 37.5% with a clinical benefit of 54.1%. All 14 responders showed delayed type hypersensitivity positivity. Median overall survival (OS) was 15 months (95% CI, 8-33). Eleven patients underwent other treatments (3 surgery, 2 biotherapy, 2 radiotherapy, 2 chemotherapy, and 4 biochemotherapy) after stopping vaccination. Of these, 2 patients had a complete response and 5 a partial response, with an OR of 63.6%. Median OS was 34 months (range 16-61). Our results suggest that therapeutic DC vaccination could favor clinical response in patients after more than one line of therapy.

Efficacy of a therapeutic vaccine using mutated β-amyloid sensitized dendritic cells in Alzheimer's mice.

Science.gov (United States)

Luo, Zhongqiu; Li, Jialin; Nabar, Neel R; Lin, Xiaoyang; Bai, Ge; Cai, Jianfeng; Zhou, Shu-Feng; Cao, Chuanhai; Wang, Jinhuan

2012-09-01

Despite FDA suspension of Elan's AN-1792 amyloid beta (Aβ) vaccine in phase IIb clinical trials, the implications of this study are the guiding principles for contemporary anti-Aβ immunotherapy against Alzheimer's disease (AD). AN-1792 showed promising results with regards to Aβ clearance and cognitive function improvement, but also exhibited an increased risk of Th1 mediated meningoencephalitis. As such, vaccine development has continued with an emphasis on eliciting a notable anti-Aβ antibody titer, while avoiding the unwanted Th1 pro-inflammatory response. Previously, we published the first report of an Aβ sensitized dendritic cell vaccine as a therapeutic treatment for AD in BALB/c mice. Our vaccine elicited an anti-Aβ titer, with indications that a Th1 response was not present. This study is the first to investigate the efficacy and safety of our dendritic cell vaccine for the prevention of AD in transgenic mouse models (PDAPP) for AD. We also used Immunohistochemistry to characterize the involvement of LXR, ABCA1, and CD45 in order to gain insight into the potential mechanisms through which this vaccine may provide benefit. The results indicate that (1) the use of mutant Aβ1-42 sensitized dendritic cell vaccine results in durable antibody production, (2) the vaccine provides significant benefits with regards to cognitive function without the global (Th1) inflammation seen in prior Aβ vaccines, (3) histological studies showed an overall decrease in Aβ burden, with an increase in LXR, ABCA1, and CD45, and (4) the beneficial results of our DC vaccine may be due to the LXR/ABCA1 pathway. In the future, mutant Aβ sensitized dendritic cell vaccines could be an efficacious and safe method for the prevention or treatment of AD that circumvents problems associated with traditional anti-Aβ vaccines.

Dendritic Cell-Based Adjuvant Vaccination Targeting Wilms’ Tumor 1 in Patients with Advanced Colorectal Cancer

Directory of Open Access Journals (Sweden)

Shigetaka Shimodaira

2015-12-01

Full Text Available Despite significant recent advances in the development of immune checkpoint inhibitors, the treatment of advanced colorectal cancer involving metastasis to distant organs remains challenging. We conducted a phase I study to investigate the safety and immunogenicity of Wilms’ tumor (WT1 class I/II peptides-pulsed dendritic cell DC vaccination for patients with advanced colorectal cancer. Standard treatment comprising surgical resection and chemotherapy was followed by one course of seven biweekly administrations of 1–2 × 107 DCs with 1–2 KE of OK-432 (streptococcal preparation in three patients. Clinical efficacy was confirmed based on WT1 expression using immunohistochemistry on paraffin-embedded tissues and immune monitoring using tetramer analysis and enzyme-linked immunosorbent spot (ELISPOT assays. WT1 expression with human leukocyte antigen (HLA-class I molecules was detected in surgical resected tissues. Adverse reactions to DC vaccinations were tolerable under an adjuvant setting. WT1-specific cytotoxic T cells were detected by both modified WT1-peptide/HLA-A*24:02 tetramer analysis and/or interferon-γ-producing cells through the use of ELISPOT assays after the first DC vaccination. Immunity acquired from DC vaccination persisted for two years with prolonged disease-free and overall survival. The present study indicated that DC vaccination targeting WT1 demonstrated the safety and immunogenicity as an adjuvant therapy in patients with resectable advanced colorectal cancer.

Development of an epitope-based HIV-1 vaccine strategy from HIV-1 lipopeptide to dendritic-based vaccines.

Science.gov (United States)

Surenaud, Mathieu; Lacabaratz, Christine; Zurawski, Gérard; Lévy, Yves; Lelièvre, Jean-Daniel

2017-10-01

Development of a safe, effective and globally affordable Human Immunodeficiency Virus strain 1 (HIV-1) vaccine offers the best hope for future control of the HIV-1 pandemic. However, with the exception of the recent RV144 trial, which elicited a modest level of protection against infection, no vaccine candidate has shown efficacy in preventing HIV-1 infection or in controlling virus replication in humans. There is also a great need for a successful immunotherapeutic vaccine since combination antiretroviral therapy (cART) does not eliminate the reservoir of HIV-infected cells. But to date, no vaccine candidate has proven to significantly alter the natural history of an individual with HIV-1 infection. Areas covered: For over 25 years, the ANRS (France Recherche Nord&Sud Sida-HIV hépatites) has been committed to an original program combining basic science and clinical research developing an epitope-based vaccine strategy to induce a multiepitopic cellular response against HIV-1. This review describes the evolution of concepts, based on strategies using HIV-1 lipopeptides towards the use of dendritic cell (DC) manipulation. Expert commentary: Understanding the crucial role of DCs in immune responses allowed moving from the non-specific administration of HIV-1 sequences with lipopeptides to DC-based vaccines. These DC-targeting strategies should improve HIV-1 vaccine efficacy.

Therapeutic dendritic cell vaccination of patients with metastatic renal cell carcinoma: a clinical phase 1/2 trial

DEFF Research Database (Denmark)

Berntsen, Annika; Trepiakas, Redas; Wenandy, Lynn

2008-01-01

Therapeutic dendritic cell (DC) vaccination against cancer is a strategy aimed at activating the immune system to recognize and destroy tumor cells. In this nonrandomized phase 1/2 trial, we investigated the safety, feasibility, induction of T-cell response, and clinical response after treatment...... with a DC-based vaccine in patients with metastatic renal cell carcinoma. Twenty-seven patients with progressive cytokine-refractory metastatic renal cell carcinoma were vaccinated with DCs loaded with either a cocktail of survivin and telomerase peptides or tumor lysate depending on their HLA-A2 haplotype......, and low-dose IL-2 was administered concomitantly. Tumor response, immune response, and serum IL-6 and YKL-40 were measured during treatment. Vaccine generation was successful in all patients and no serious adverse events were observed. None of the patients had an objective response but 13/27 patients...

Vaccination with melanoma lysate-pulsed dendritic cells, of patients with advanced colorectal carcinoma: report from a phase I study

DEFF Research Database (Denmark)

Burgdorf, S K; Fischer, A; Claesson, M H

2006-01-01

Immune therapy have shown new and exciting perspectives for cancer treatment. Aim of our study was to evaluate toxicity and possible adverse effects from vaccination of patients with advanced colorectal cancer with autologous dendritic cells (DC) pulsed with lysate from a newly developed melanoma...... contained 3-5 x 10(6) DCs. Five of the six patients received all five vaccines. The treatment was well tolerated in all patients without any observed vaccine-correlated adverse effects. Treatment with this DC-based cancer vaccine proved safe and non-toxic.......Immune therapy have shown new and exciting perspectives for cancer treatment. Aim of our study was to evaluate toxicity and possible adverse effects from vaccination of patients with advanced colorectal cancer with autologous dendritic cells (DC) pulsed with lysate from a newly developed melanoma...... and selected melanoma cell line enriched in expression of MAGE-A antigens and deficient in expression of melanoma differentiation antigens: tyrosinase, MART-1 and gp100. Vaccinations were administered intradermally on the proximal thigh with a total of five given vaccines at 2 weeks intervals. Each vaccine...

Dendritic cell-tumor cell hybrids and immunotherapy

DEFF Research Database (Denmark)

Cathelin, Dominique; Nicolas, Alexandra; Bouchot, André

2011-01-01

Dendritic cells (DC) are professional antigen-presenting cells currently being used as a cellular adjuvant in cancer immunotherapy strategies. Unfortunately, DC-based vaccines have not demonstrated spectacular clinical results. DC loading with tumor antigens and DC differentiation and activation...

TAPCells, the Chilean dendritic cell vaccine against melanoma and prostate cancer

Directory of Open Access Journals (Sweden)

Flavio Salazar-Onfray

2013-01-01

Full Text Available Here we summarize 10 years of effort in the development of a biomedical innovation with global projections. This innovation consists of a novel method for the production of therapeutic dendritic-like cells called Tumor Antigen Presenting Cells (TAPCells®. TAPCells-based immunotherapy was tested in more than 120 stage III and IV melanoma patients and 20 castration-resistant prostate cancer patients in a series of phase I and I/II clinical trials. TAPCells vaccines induced T cell-mediated memory immune responses that correlated with increased survival in melanoma patients and prolonged prostate-specific antigen doubling time in prostate cancer patients. Importantly, more than 60% of tested patients showed a Delayed Type Hypersensitivity (DTH reaction against the lysates, indicating the development of anti-tumor immunological memory that correlates with clinical benefits. The in vitro analysis of the lysate mix showed that it contains damage-associated molecular patterns such as HMBG-1 protein which are capable to improve, through Toll-like receptor-4, maturation and antigen cross-presentation of the dendritic cells (DC. In fact, a Toll-like receptor-4 polymorphism correlates with patient clinical outcomes. Moreover, Concholepas concholepas hemocyanin (CCH used as adjuvant proved to be safe and capable of enhancing the immunological response. Furthermore, we observed that DC vaccination resulted in a three-fold increase of T helper-1 lymphocytes releasing IFN-γ and a two-fold increase of T helper-17 lymphocytes capable of producing IL-17 in DTH+ with respect to DTH- patients. Important steps have been accomplished for TAPCells technology transfer, including patenting, packaging and technology assessment. Altogether, our results indicate that TAPCells vaccines constitute an exceptional Chilean national innovation of international value.

TAPCells, the Chilean dendritic cell vaccine against melanoma and prostate cancer.

Science.gov (United States)

Salazar-Onfray, Flavio; Pereda, Cristián; Reyes, Diego; López, Mercedes N

2013-01-01

Here we summarize 10 years of effort in the development of a biomedical innovation with global projections. This innovation consists of a novel method for the production of therapeutic dendritic-like cells called Tumor Antigen Presenting Cells (TAPCells®). TAPCells-based immunotherapy was tested in more than 120 stage III and IV melanoma patients and 20 castration-resistant prostate cancer patients in a series of phase I and I/II clinical trials. TAPCells vaccines induced T cell-mediated memory immune responses that correlated with increased survival in melanoma patients and prolonged prostate-specific antigen doubling time in prostate cancer patients. Importantly, more than 60% of tested patients showed a Delayed Type Hypersensitivity (DTH) reaction against the lysates, indicating the development of anti-tumor immunological memory that correlates with clinical benefits. The in vitro analysis of the lysate mix showed that it contains damage-associated molecular patterns such as HMBG-1 protein which are capable to improve, through Toll-like receptor-4, maturation and antigen cross-presentation of the dendritic cells (DC). In fact, a Toll-like receptor-4 polymorphism correlates with patient clinical outcomes. Moreover, Concholepas concholepas hemocyanin (CCH) used as adjuvant proved to be safe and capable of enhancing the immunological response. Furthermore, we observed that DC vaccination resulted in a three-fold increase of T helper-1 lymphocytes releasing IFN-γ and a two-fold increase of T helper-17 lymphocytes capable of producing IL-17 in DTH+ with respect to DTH- patients. Important steps have been accomplished for TAPCells technology transfer, including patenting, packaging and technology assessment. Altogether, our results indicate that TAPCells vaccines constitute an exceptional Chilean national innovation of international value.

Exploiting the role of endogenous lymphoid-resident dendritic cells in the priming of NKT cells and CD8+ T cells to dendritic cell-based vaccines.

Directory of Open Access Journals (Sweden)

Troels R Petersen

2011-03-01

Full Text Available Transfer of antigen between antigen-presenting cells (APCs is potentially a physiologically relevant mechanism to spread antigen to cells with specialized stimulatory functions. Here we show that specific CD8+ T cell responses induced in response to intravenous administration of antigen-loaded bone marrow-derived dendritic cells (BM-DCs, were ablated in mice selectively depleted of endogenous lymphoid-resident langerin+ CD8α+ dendritic cells (DCs, suggesting that the antigen is transferred from the injected cells to resident APCs. In contrast, antigen-specific CD4+ T cells were primed predominantly by the injected BM-DCs, with only very weak contribution of resident APCs. Crucially, resident langerin+ CD8α+ DCs only contributed to the priming of CD8+ T cells in the presence of maturation stimuli such as intravenous injection of TLR ligands, or by loading the BM-DCs with the glycolipid α-galactosylceramide (α-GalCer to recruit the adjuvant activity of activated invariant natural killer-like T (iNKT cells. In fact, injection of α-GalCer-loaded CD1d-/- BM-DCs resulted in potent iNKT cell activation, suggesting that this glycolipid antigen can also be transferred to resident CD1d+ APCs. While iNKT cell activation per se was independent of langerin+ CD8α+ DCs, some iNKT cell-mediated activities were reduced, notably release of IL-12p70 and transactivation of NK cells. We conclude that both protein and glycolipid antigens can be exchanged between distinct DC species. These data suggest that the efficacy of DC-based vaccination strategies may be improved by the incorporation of a systemic maturation signal aimed to engage resident APCs in CD8+ T cell priming, and α-GalCer may be particularly well suited to this purpose.

Production of a Dendritic Cell-Based Vaccine Containing Inactivated Autologous Virus for Therapy of Patients with Chronic Human Immunodeficiency Virus Type 1 Infection▿

OpenAIRE

Whiteside, Theresa L.; Piazza, Paolo; Reiter, Amanda; Stanson, Joanna; Connolly, Nancy C.; Rinaldo, Charles R.; Riddler, Sharon A.

2008-01-01

In preparation for a pilot clinical trial in patients with chronic human immunodeficiency virus type 1 (HIV-1) infection, a novel dendritic cell (DC)-based vaccine is being manufactured. The trial will test the hypothesis that isolated endogenous virus presented by DCs serves as a potent immunogen for activation of CD8+ and CD4+ T cells specific for a broad range of autologous HIV-1 antigens. Production of the vaccine under good manufacture practice conditions involves (i) autologous virus is...

Specific microtubule-depolymerizing agents augment efficacy of dendritic cell-based cancer vaccines

Directory of Open Access Journals (Sweden)

Chang Wei-Ting

2011-06-01

Full Text Available Abstract Background Damage-associated molecular patterns (DAMPs are associated with immunogenic cell death and have the ability to enhance maturation and antigen presentation of dendritic cells (DCs. Specific microtubule-depolymerizing agents (MDAs such as colchicine have been shown to confer anti-cancer activity and also trigger activation of DCs. Methods In this study, we evaluated the ability of three MDAs (colchicine and two 2-phenyl-4-quinolone analogues to induce immunogenic cell death in test tumor cells, activate DCs, and augment T-cell proliferation activity. These MDAs were further evaluated for use as an adjuvant in a tumor cell lysate-pulsed DC vaccine. Results The three test phytochemicals considerably increased the expression of DAMPs including HSP70, HSP90 and HMGB1, but had no effect on expression of calreticulin (CRT. DC vaccines pulsed with MDA-treated tumor cell lysates had a significant effect on tumor growth, showed cytotoxic T-lymphocyte activity against tumors, and increased the survival rate of test mice. In vivo antibody depletion experiments suggested that CD8+ and NK cells, but not CD4+ cells, were the main effector cells responsible for the observed anti-tumor activity. In addition, culture of DCs with GM-CSF and IL-4 during the pulsing and stimulation period significantly increased the production of IL-12 and decreased production of IL-10. MDAs also induced phenotypic maturation of DCs and augmented CD4+ and CD8+ T-cell proliferation when co-cultured with DCs. Conclusions Specific MDAs including the clinical drug, colchicine, can induce immunogenic cell death in tumor cells, and DCs pulsed with MDA-treated tumor cell lysates (TCLs can generate potent anti-tumor immunity in mice. This approach may warrant future clinical evaluation as a cancer vaccine.

Low-Dose Cyclophosphamide Synergizes with Dendritic Cell-Based Immunotherapy in Antitumor Activity

Directory of Open Access Journals (Sweden)

Joris D. Veltman

2010-01-01

Full Text Available Clinical immunotherapy trials like dendritic cell-based vaccinations are hampered by the tumor's offensive repertoire that suppresses the incoming effector cells. Regulatory T cells are instrumental in suppressing the function of cytotoxic T cells. We studied the effect of low-dose cyclophosphamide on the suppressive function of regulatory T cells and investigated if the success rate of dendritic cell immunotherapy could be improved. For this, mesothelioma tumor-bearing mice were treated with dendritic cell-based immunotherapy alone or in combination with low-dose of cyclophosphamide. Proportions of regulatory T cells and the cytotoxic T cell functions at different stages of disease were analyzed. We found that low-dose cyclophosphamide induced beneficial immunomodulatory effects by preventing the induction of Tregs, and as a consequence, cytotoxic T cell function was no longer affected. Addition of cyclophosphamide improved immunotherapy leading to an increased median and overall survival. Future studies are needed to address the usefulness of this combination treatment for mesothelioma patients.

Dendritic cell-based immunotherapy.

Science.gov (United States)

Osada, Takuya; Clay, Timothy M; Woo, Christopher Y; Morse, Michael A; Lyerly, H Kim

2006-01-01

Dendritic cells (DCs) play a crucial role in the induction of antigen-specific T-cell responses, and therefore their use for the active immunotherapy of malignancies has been studied with considerable interest. More than a decade has passed since the publication of the first clinical data of DC-based vaccines, and through this and subsequent studies, a number of important developmental insights have been gleaned. These include the ideal source and type of DCs, the discovery of novel antigens and methods of loading DCs, the role of DC maturation, and the most efficient route of immunization. The generation of immune responses against tumor antigens after DC immunization has been demonstrated, and favorable clinical responses have been reported in some patients; however, it is difficult to pool the results as a whole, and thus the body of data remains inconclusive, in part because of varying DC preparation and vaccination protocols, the use of different forms of antigens, and, most importantly, a lack of rigorous criteria for defining clinical responses. As such, the standardization of clinical and immunologic criteria utilized, as well as DC preparations employed, will allow for the comparison of results across multiple clinical studies and is required in order for future trials to measure the true value and role of this treatment modality. In addition, issues regarding the optimal dose and clinical setting for the application of DC vaccines remain to be resolved, and recent clinical studies have been designed to begin to address these questions.

Clinical and Immunological Effects in Patients with Advanced Non-Small Cell Lung-Cancer after Vaccination with Dendritic Cells Exposed to an Allogeneic Tumor Cell Lysate*

DEFF Research Database (Denmark)

Engell-Noerregaard, Lotte; Kvistborg, Pia; Zocca, Mai-Britt

2013-01-01

Background: We evaluated the clinical and immunological effects of dendritic cell (DC) vaccination of patients with NSCLC. Autologous DCs were pulsed with a MAGE containing allogeneic melanoma cell lysate (MelCancerVac®, Dandrit Biotech, Copenhagen, Denmark). Imiquimod cream, proleukin and celeco......Background: We evaluated the clinical and immunological effects of dendritic cell (DC) vaccination of patients with NSCLC. Autologous DCs were pulsed with a MAGE containing allogeneic melanoma cell lysate (MelCancerVac®, Dandrit Biotech, Copenhagen, Denmark). Imiquimod cream, proleukin...... and celecoxib were used as adjuvants to the vaccines. The objective of the study was to evaluate specific T cell response in vitro by IFN EliSpot. Secondary objec- tives were overall survival, response and quality of life (QoL). Results: Twenty-two patients initiated the vaccination program consisting of ten...

Induction of indoleamine 2, 3-dioxygenase in human dendritic cells by a cholera toxin B subunit-proinsulin vaccine.

Directory of Open Access Journals (Sweden)

Jacques C Mbongue

Full Text Available Dendritic cells (DC interact with naïve T cells to regulate the delicate balance between immunity and tolerance required to maintain immunological homeostasis. In this study, immature human dendritic cells (iDC were inoculated with a chimeric fusion protein vaccine containing the pancreatic β-cell auto-antigen proinsulin linked to a mucosal adjuvant the cholera toxin B subunit (CTB-INS. Proteomic analysis of vaccine inoculated DCs revealed strong up-regulation of the tryptophan catabolic enzyme indoleamine 2, 3-dioxygenase (IDO1. Increased biosynthesis of the immunosuppressive enzyme was detected in DCs inoculated with the CTB-INS fusion protein but not in DCs inoculated with proinsulin, CTB, or an unlinked combination of the two proteins. Immunoblot and PCR analyses of vaccine treated DCs detected IDO1mRNA by 3 hours and IDO1 protein synthesis by 6 hours after vaccine inoculation. Determination of IDO1 activity in vaccinated DCs by measurement of tryptophan degradation products (kynurenines showed increased tryptophan cleavage into N-formyl kynurenine. Vaccination did not interfere with monocytes differentiation into DC, suggesting the vaccine can function safely in the human immune system. Treatment of vaccinated DCs with pharmacological NF-κB inhibitors ACHP or DHMEQ significantly inhibited IDO1 biosynthesis, suggesting a role for NF-κB signaling in vaccine up-regulation of dendritic cell IDO1. Heat map analysis of the proteomic data revealed an overall down-regulation of vaccinated DC functions, suggesting vaccine suppression of DC maturation. Together, our experimental data indicate that CTB-INS vaccine induction of IDO1 biosynthesis in human DCs may result in the inhibition of DC maturation generating a durable state of immunological tolerance. Understanding how CTB-INS modulates IDO1 activity in human DCs will facilitate vaccine efficacy and safety, moving this immunosuppressive strategy closer to clinical applications for prevention

A generic RNA-pulsed dendritic cell vaccine strategy for renal cell carcinoma

Science.gov (United States)

Geiger, Christiane; Regn, Sybille; Weinzierl, Andreas; Noessner, Elfriede; Schendel, Dolores J

2005-01-01

We present a generic dendritic cell (DC) vaccine strategy for patients with renal cell carcinoma (RCC) based on the use of RNA as a source of multiplex tumor-associated antigens (TAAs). Instead of preparing RNA from tumor tissue of each individual RCC patient, we propose to substitute RNA prepared from a well characterized highly immunogenic RCC cell line (RCC-26 tumor cells) as a generic source of TAAs for loading of DCs. We demonstrate here that efficient RNA transfer can be achieved using lipofection of immature DCs, which are subsequently matured with a cytokine cocktail to express high levels of MHC and costimulatory molecules as well as the chemokine receptor CCR7. Neither RNA itself nor the lipid component impacted on the phenotype or the cytokine secretion of mature DCs. Following RNA loading, DCs derived from HLA-A2-positive donors were able to activate effector-memory cytotoxic T lymphocytes (CTLs) specific for a TAA ligand expressed by the RCC-26 cell line. CTL responses to RNA-loaded DCs reached levels comparable to those stimulated directly by the RCC-26 tumor cells. Furthermore, DCs expressing tumor cell RNA primed naïve T cells, yielding T cell lines with cytotoxicity and cytokine secretion after contact with RCC tumor cells. RCC-26 cell lines are available as good manufacturing practice (GMP)-certified reagents enabling this source of RNA to be easily standardized and adapted for clinical testing. In addition, well defined immune monitoring tools, including the use of RNA expressing B cell lines, are available. Thus, this DC vaccine strategy can be directly compared with an ongoing gene therapy trial using genetically-engineered variants of the RCC-26 cell line as vaccines for RCC patients with metastatic disease. PMID:16045799

A generic RNA-pulsed dendritic cell vaccine strategy for renal cell carcinoma

Directory of Open Access Journals (Sweden)

Noessner Elfriede

2005-07-01

Full Text Available Abstract We present a generic dendritic cell (DC vaccine strategy for patients with renal cell carcinoma (RCC based on the use of RNA as a source of multiplex tumor-associated antigens (TAAs. Instead of preparing RNA from tumor tissue of each individual RCC patient, we propose to substitute RNA prepared from a well characterized highly immunogenic RCC cell line (RCC-26 tumor cells as a generic source of TAAs for loading of DCs. We demonstrate here that efficient RNA transfer can be achieved using lipofection of immature DCs, which are subsequently matured with a cytokine cocktail to express high levels of MHC and costimulatory molecules as well as the chemokine receptor CCR7. Neither RNA itself nor the lipid component impacted on the phenotype or the cytokine secretion of mature DCs. Following RNA loading, DCs derived from HLA-A2-positive donors were able to activate effector-memory cytotoxic T lymphocytes (CTLs specific for a TAA ligand expressed by the RCC-26 cell line. CTL responses to RNA-loaded DCs reached levels comparable to those stimulated directly by the RCC-26 tumor cells. Furthermore, DCs expressing tumor cell RNA primed naïve T cells, yielding T cell lines with cytotoxicity and cytokine secretion after contact with RCC tumor cells. RCC-26 cell lines are available as good manufacturing practice (GMP-certified reagents enabling this source of RNA to be easily standardized and adapted for clinical testing. In addition, well defined immune monitoring tools, including the use of RNA expressing B cell lines, are available. Thus, this DC vaccine strategy can be directly compared with an ongoing gene therapy trial using genetically-engineered variants of the RCC-26 cell line as vaccines for RCC patients with metastatic disease.

Naive helper T cells from BCG-vaccinated volunteers produce IFN-gamma and IL-5 to mycobacterial antigen-pulsed dendritic cells.

Directory of Open Access Journals (Sweden)

JoĂŤl Pestel

2008-06-01

Full Text Available Mycobacterium bovis bacillus Calmette-GuĂŠrin (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.

Naive helper T cells from BCG-vaccinated volunteers produce IFN-gamma and IL-5 to mycobacterial antigen-pulsed dendritic cells.

Science.gov (United States)

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.

Co-culture of apoptotic breast cancer cells with immature dendritic cells: a novel approach for DC-based vaccination in breast cancer

Energy Technology Data Exchange (ETDEWEB)

Zheng, Jin [Department of Oncology, State Key Discipline of Cell Biology, Xijing Hospital, the Fourth Military Medical University, Xi' an, Shaanxi (China); Department of Traditional Chinese and Western Medicine of Oncology, Tangdu Hospital, the Fourth Military Medical University, Xi' an, Shaanxi (China); Liu, Qiang [Department of Hematology, Tangdu Hospital, the Fourth Military Medical University, Xi' an, Shaanxi (China); Yang, Jiandong [Department of Hepatobiliary Surgery, Xijing Hospital, the Fourth Military Medical University, Xi' an, Shaanxi (China); Ren, Qinyou [Department of Traditional Chinese and Western Medicine of Oncology, Tangdu Hospital, the Fourth Military Medical University, Xi' an, Shaanxi (China); Cao, Wei [Department of Interventional Radiology, Tangdu Hospital, the Fourth Military Medical University, Xi' an, Shaanxi (China); Yang, Jingyue; Yu, Zhaocai [Department of Oncology, State Key Discipline of Cell Biology, Xijing Hospital, the Fourth Military Medical University, Xi' an, Shaanxi (China); Yu, Fang [Department of Gastrointestinal Surgery, Xijing Hospital of Digestive Diseases, the Fourth Military Medical University, Xi' an, Shaanxi (China); Wu, Yanlan [Department of Infectious Diseases, Tangdu Hospital, the Fourth Military Medical University, Xi' an, Shaanxi (China); Shi, Hengjun [Department of Traditional Chinese and Western Medicine of Oncology, Tangdu Hospital, the Fourth Military Medical University, Xi' an, Shaanxi (China); Liu, Wenchao [Department of Oncology, State Key Discipline of Cell Biology, Xijing Hospital, the Fourth Military Medical University, Xi' an, Shaanxi (China)

2012-04-27

A dendritic cell (DC)-based vaccine strategy could reduce the risk of recurrence and improve the survival of breast cancer patients. However, while therapy-induced apoptosis of hepatocellular and colorectal carcinoma cells can enhance maturation and antigen presentation of DCs, whether this effect occurs in breast cancer is currently unknown. In the present study, we investigated the effect of doxorubicin (ADM)-induced apoptotic MCF-7 breast cancer cells on the activation of DCs. ADM-induced apoptotic MCF-7 cells could effectively induce immature DC (iDC) maturation. The mean fluorescence intensity (MFI) of DC maturity marker CD83 was 23.3 in the ADM-induced apoptotic MCF-7 cell group compared with 8.5 in the MCF-7 cell group. The MFI of DC co-stimulatory marker CD86 and HLA-DR were also increased after iDCs were treated with ADM-induced apoptotic MCF-7 cells. Furthermore, the proliferating autologous T-lymphocytes increased from 14.2 to 40.3% after incubated with DCs induced by apoptotic MCF-7 cells. The secretion of interferon-γ by these T-lymphocytes was also increased. In addition, cell-cell interaction between apoptotic MCF-7 cells and iDCs, but not soluble factors released by apoptotic MCF-7 cells, was crucial for the maturation of iDCs. These findings constitute a novel in vitro DC-based vaccine strategy for the treatment of breast cancer by ADM-induced apoptotic MCF-7 cells.

Co-culture of apoptotic breast cancer cells with immature dendritic cells: a novel approach for DC-based vaccination in breast cancer

International Nuclear Information System (INIS)

Zheng, Jin; Liu, Qiang; Yang, Jiandong; Ren, Qinyou; Cao, Wei; Yang, Jingyue; Yu, Zhaocai; Yu, Fang; Wu, Yanlan; Shi, Hengjun; Liu, Wenchao

2012-01-01

A dendritic cell (DC)-based vaccine strategy could reduce the risk of recurrence and improve the survival of breast cancer patients. However, while therapy-induced apoptosis of hepatocellular and colorectal carcinoma cells can enhance maturation and antigen presentation of DCs, whether this effect occurs in breast cancer is currently unknown. In the present study, we investigated the effect of doxorubicin (ADM)-induced apoptotic MCF-7 breast cancer cells on the activation of DCs. ADM-induced apoptotic MCF-7 cells could effectively induce immature DC (iDC) maturation. The mean fluorescence intensity (MFI) of DC maturity marker CD83 was 23.3 in the ADM-induced apoptotic MCF-7 cell group compared with 8.5 in the MCF-7 cell group. The MFI of DC co-stimulatory marker CD86 and HLA-DR were also increased after iDCs were treated with ADM-induced apoptotic MCF-7 cells. Furthermore, the proliferating autologous T-lymphocytes increased from 14.2 to 40.3% after incubated with DCs induced by apoptotic MCF-7 cells. The secretion of interferon-γ by these T-lymphocytes was also increased. In addition, cell-cell interaction between apoptotic MCF-7 cells and iDCs, but not soluble factors released by apoptotic MCF-7 cells, was crucial for the maturation of iDCs. These findings constitute a novel in vitro DC-based vaccine strategy for the treatment of breast cancer by ADM-induced apoptotic MCF-7 cells

Investigations of the functional states of dendritic cells under different conditioned microenvironments by Fourier transformed infrared spectroscopy.

Science.gov (United States)

Dong, Rong; Long, Jinhua; Xu, Xiaoli; Zhang, Chunlin; Wen, Zongyao; Li, Long; Yao, Weijuan; Zeng, Zhu

2014-01-10

Dendritic cells are potent and specialized antigen presenting cells, which play a crucial role in initiating and amplifying both the innate and adaptive immune responses. The dendritic cell-based vaccination against cancer has been clinically achieved promising successes. But there are still many challenges in its clinical application, especially for how to identify the functional states. The CD14+ monocytes were isolated from human peripheral blood after plastic adherence and purified to approximately 98% with cocktail immunomagnetic beads. The immature dendritic cells and mature dendritic cells were induced by traditional protocols. The resulting dendritic cells were cocultured with normal cells and cancer cells. The functional state of dendritic cells including immature dendritic cells (imDCs) and mature dendritic cells (mDCs) under different conditioned microenvironments were investigated by Fourier transformed infrared spectroscopy (FTIR) and molecular biological methods. The results of Fourier transformed infrared spectroscopy showed that the gene transcription activity and energy states of dendritic cells were specifically suppressed by tumor cells (P Fourier transformed infrared spectroscopy at given wave numbers were closely correlated with the expression levels of NF-κB (R2:0.69 and R2:0.81, respectively). Our results confirmed that the ratios of absorption intensities of Fourier transformed infrared spectroscopy at given wave numbers were positively correlated with the expression levels of NF-κB, suggesting that Fourier transformed infrared spectroscopy technology could be clinically applied to identify the functional states of dendritic cell when performing dendritic cell-based vaccination. It's significant for the simplification and standardization of dendritic cell-based vaccination clinical preparation protocols.

Three-day dendritic cells for vaccine development: Antigen uptake, processing and presentation

Directory of Open Access Journals (Sweden)

Schendel Dolores J

2010-09-01

Full Text Available Abstract Background Antigen-loaded dendritic cells (DC are capable of priming naïve T cells and therefore represent an attractive adjuvant for vaccine development in anti-tumor immunotherapy. Numerous protocols have been described to date using different maturation cocktails and time periods for the induction of mature DC (mDC in vitro. For clinical application, the use of mDC that can be generated in only three days saves on the costs of cytokines needed for large scale vaccine cell production and provides a method to produce cells within a standard work-week schedule in a GMP facility. Methods In this study, we addressed the properties of antigen uptake, processing and presentation by monocyte-derived DC prepared in three days (3d mDC compared with conventional DC prepared in seven days (7d mDC, which represent the most common form of DC used for vaccines to date. Results Although they showed a reduced capacity for spontaneous antigen uptake, 3d mDC displayed higher capacity for stimulation of T cells after loading with an extended synthetic peptide that requires processing for MHC binding, indicating they were more efficient at antigen processing than 7d DC. We found, however, that 3d DC were less efficient at expressing protein after introduction of in vitro transcribed (ivtRNA by electroporation, based on published procedures. This deficit was overcome by altering electroporation parameters, which led to improved protein expression and capacity for T cell stimulation using low amounts of ivtRNA. Conclusions This new procedure allows 3d mDC to replace 7d mDC for use in DC-based vaccines that utilize long peptides, proteins or ivtRNA as sources of specific antigen.

Saponin-based adjuvants induce cross-presentation in dendritic cells by intracellular lipid body formation

NARCIS (Netherlands)

Brok, M.H. den; Bull, C.; Wassink, M.; Graaf, A.M.A. de; Wagenaars, J.A.L.; Minderman, M.; Thakur, M.; Amigorena, S.; Rijke, E.O.; Schrier, C.C.; Adema, G.J.

2016-01-01

Saponin-based adjuvants (SBAs) are being used in animal and human (cancer) vaccines, as they induce protective cellular immunity. Their adjuvant potency is a factor of inflammasome activation and enhanced antigen cross-presentation by dendritic cells (DCs), but how antigen cross-presentation is

Chimeric Vaccine Stimulation of Human Dendritic Cell Indoleamine 2, 3-Dioxygenase Occurs via the Non-Canonical NF-κB Pathway.

Directory of Open Access Journals (Sweden)

Nan-Sun Kim

Full Text Available A chimeric protein vaccine composed of the cholera toxin B subunit fused to proinsulin (CTB-INS was shown to suppress type 1 diabetes onset in NOD mice and upregulate biosynthesis of the tryptophan catabolic enzyme indoleamine 2, 3-dioxygenase (IDO1 in human dendritic cells (DCs. Here we demonstrate siRNA inhibition of the NF-κB-inducing kinase (NIK suppresses vaccine-induced IDO1 biosynthesis as well as IKKα phosphorylation. Chromatin immunoprecipitation (ChIP analysis of CTB-INS inoculated DCs showed that RelB bound to NF-κB consensus sequences in the IDO1 promoter, suggesting vaccine stimulation of the non-canonical NF-κB pathway activates IDO1 expression in vivo. The addition of Tumor Necrosis Factor Associated Factors (TRAF TRAF 2, 3 and TRAF6 blocking peptides to vaccine inoculated DCs was shown to inhibit IDO1 biosynthesis. This experimental outcome suggests vaccine activation of the TNFR super-family receptor pathway leads to upregulation of IDO1 biosynthesis in CTB-INS inoculated dendritic cells. Together, our experimental data suggest the CTB-INS vaccine uses a TNFR-dependent signaling pathway of the non-canonical NF-κB signaling pathway resulting in suppression of dendritic cell mediated type 1 diabetes autoimmunity.

Changes in peripheral blood level of regulatory T cells in patients with malignant melanoma during treatment with dendritic cell vaccination and low-dose IL-2

DEFF Research Database (Denmark)

Bjoern, J; Brimnes, M K; Andersen, M H

2011-01-01

In this study, changes in peripheral blood regulatory T cell (Treg) levels were evaluated in 46 progressive patients with melanoma treated with a dendritic cell-based vaccine and concomitant low-dose IFN-α and IL-2. The regulatory subset of CD4 T cells, characterized by CD25(high......) , was prospectively analysed in fresh blood, and treatment-associated quantitative and qualitative changes were analysed. By the 4th vaccine, patients showed a marked increase in CD4+ CD25(high) T cell subset from 6% to 22% (P...

Changes in peripheral blood level of regulatory T cells in patients with malignant melanoma during treatment with dendritic cell vaccination and low-dose IL-2

DEFF Research Database (Denmark)

Bjoern, J; Brimnes, M K; Andersen, M H

2011-01-01

In this study, changes in peripheral blood regulatory T cell (Treg) levels were evaluated in 46 progressive patients with melanoma treated with a dendritic cell-based vaccine and concomitant low-dose IFN-a and IL-2. The regulatory subset of CD4 T cells, characterized by CD25(high......) , was prospectively analysed in fresh blood, and treatment-associated quantitative and qualitative changes were analysed. By the 4th vaccine, patients showed a marked increase in CD4+ CD25(high) T cell subset from 6% to 22% (P...

Whole tumor antigen vaccination using dendritic cells: Comparison of RNA electroporation and pulsing with UV-irradiated tumor cells

Directory of Open Access Journals (Sweden)

Benencia Fabian

2008-04-01

Full Text Available Abstract Because of the lack of full characterization of tumor associated antigens for solid tumors, whole antigen use is a convenient approach to tumor vaccination. Tumor RNA and apoptotic tumor cells have been used as a source of whole tumor antigen to prepare dendritic cell (DC based tumor vaccines, but their efficacy has not been directly compared. Here we compare directly RNA electroporation and pulsing of DCs with whole tumor cells killed by ultraviolet (UV B radiation using a convenient tumor model expressing human papilloma virus (HPV E6 and E7 oncogenes. Although both approaches led to DCs presenting tumor antigen, electroporation with tumor cell total RNA induced a significantly higher frequency of tumor-reactive IFN-gamma secreting T cells, and E7-specific CD8+ lymphocytes compared to pulsing with UV-irradiated tumor cells. DCs electroporated with tumor cell RNA induced a larger tumor infiltration by T cells and produced a significantly stronger delay in tumor growth compared to DCs pulsed with UV-irradiated tumor cells. We conclude that electroporation with whole tumor cell RNA and pulsing with UV-irradiated tumor cells are both effective in eliciting antitumor immune response, but RNA electroporation results in more potent tumor vaccination under the examined experimental conditions.

Clinical Benefit of Allogeneic Melanoma Cell Lysate-Pulsed Autologous Dendritic Cell Vaccine in MAGE-Positive Colorectal Cancer Patients

DEFF Research Database (Denmark)

Toh, Han Chong; Wang, Who-Whong; Chia, Whay Kuang

2009-01-01

PURPOSE: We evaluated the clinical benefit of an allogeneic melanoma cell lysate (MCL)-pulsed autologous dendritic cell (DC) vaccine in advanced colorectal cancer patients expressing at least one of six MAGE-A antigens overexpressed by the cell line source of the lysate. EXPERIMENTAL DESIGN: DCs...... were cultured from peripheral blood mononuclear cells (PBMC), pulsed with the allogeneic MCL, and matured using cytokines that achieved high CD83- and CCR7-expressing DCs. Each patient received up to 10 intradermal vaccinations (3-5 x 10(6) cells per dose) at biweekly intervals. RESULTS: Twenty......-free for >27 and >37 months, respectively. This result is particularly meaningful as all patients had progressive disease before treatment. Overall, DC vaccination was associated with a serial decline in regulatory T cells. Using an antibody array, we characterized plasma protein profiles in responding...

Primary Human Blood Dendritic Cells for Cancer Immunotherapy—Tailoring the Immune Response by Dendritic Cell Maturation

Directory of Open Access Journals (Sweden)

Simone P. Sittig

2015-12-01

Full Text Available Dendritic cell (DC-based cancer vaccines hold the great promise of tipping the balance from tolerance of the tumor to rejection. In the last two decades, we have gained tremendous knowledge about DC-based cancer vaccines. The maturation of DCs has proven indispensable to induce immunogenic T cell responses. We review the insights gained from the development of maturation cocktails in monocyte derived DC-based trials. More recently, we have also gained insights into the functional specialization of primary human blood DC subsets. In peripheral human blood, we can distinguish at least three primary DC subsets, namely CD1c+ and CD141+ myeloid DCs and plasmacytoid DCs. We reflect the current knowledge on maturation and T helper polarization by these blood DC subsets in the context of DC-based cancer vaccines. The maturation stimulus in combination with the DC subset will determine the type of T cell response that is induced. First trials with these natural DCs underline their excellent in vivo functioning and mark them as promising tools for future vaccination strategies.

Preclinical evaluation of NF-kappa B-triggered dendritic cells expressing the viral oncogenic driver of Merkel cell carcinoma for therapeutic vaccination

DEFF Research Database (Denmark)

Gerer, Kerstin F.; Erdmann, Michael; Hadrup, Sine Reker

2017-01-01

Background: Merkel cell carcinoma (MCC) is a rare but very aggressive skin tumor that develops after integration of a truncated form of the large T-antigen (truncLT) of the Merkel cell polyomavirus (MCV) into the host's genome. Therapeutic vaccination with dendritic cells (DCs) loaded with tumor ...

Survival of metastatic melanoma patients after dendritic cell vaccination correlates with expression of leukocyte phosphatidylethanolamine-binding protein 1/Raf kinase inhibitory protein

DEFF Research Database (Denmark)

Buschow, Sonja I; Ramazzotti, Matteo; Reinieren-Beeren, Inge M J

2017-01-01

-based biomarkers are of particular interest because of their straightforward implementation in routine clinical care. We sought to identify markers for dendritic cell (DC) vaccine-based immunotherapy against metastatic melanoma through gene expression analysis of peripheral blood mononuclear cells. A large....... Intriguingly, this was only the case for expression of PEBP1 after, but not prior to, DC vaccination. Moreover, the change in PEBP1 expression upon vaccination correlated well with survival. Further analyses revealed that PEBP1 expression positively correlated with genes involved in T cell responses...... but inversely correlated with genes associated with myeloid cells and aberrant inflammation including STAT3, NOTCH1, and MAPK1. Concordantly, PEBP1 inversely correlated with the myeloid/lymphoid-ratio and was suppressed in patients suffering from chronic inflammatory disease....

Immunotherapeutic efficacy of vaccines generated by fusion of dendritic cells and HPV16-associated tumour cells

Czech Academy of Sciences Publication Activity Database

Bubeník, Jan; Šímová, Jana; Bieblová, Jana; Reiniš, Milan; Indrová, Marie

2005-01-01

Roč. 16, Suppl. 1 (2005), s. 101 ISSN 1107-3756. [World Congress on Advances in Oncology /10./ and International Symposium on Molecular Medicine /8./. 05.10.13-05.10.15, Hersonissos] R&D Projects: GA ČR(CZ) GA301/04/0492; GA MZd(CZ) NR8004 Institutional research plan: CEZ:AV0Z50520514 Keywords : HPV16 * dendritic cells * vaccines Subject RIV: EC - Immunology

Breast Cancer Vaccines Based on Dendritic Cells and the Chemokines

National Research Council Canada - National Science Library

Mule, James

1998-01-01

The major objective of this project is to establish a new modality for the treatment of breast cancer that employs the combination of chemokine gene-modified fibroblasts with breast tumor-pulsed dendritic cells (DC...

Breast Cancer Vaccines Based on Dendritic Cells and the Chemokines

National Research Council Canada - National Science Library

Mule, James

1997-01-01

The major objective of this project is to establish a new modality for the treatment of breast cancer that employs the combination of chemokine gene modified fibroblasts with breast tumor pulsed dendritic cells (DC...

Self-Amplifying Replicon RNA Vaccine Delivery to Dendritic Cells by Synthetic Nanoparticles

Directory of Open Access Journals (Sweden)

Kenneth C. McCullough

2014-10-01

Full Text Available Dendritic cells (DC play essential roles determining efficacy of vaccine delivery with respect to immune defence development and regulation. This renders DCs important targets for vaccine delivery, particularly RNA vaccines. While delivery of interfering RNA oligonucleotides to the appropriate intracellular sites for RNA-interference has proven successful, the methodologies are identical for RNA vaccines, which require delivery to RNA translation sites. Delivery of mRNA has benefitted from application of cationic entities; these offer value following endocytosis of RNA, when cationic or amphipathic properties can promote endocytic vesicle membrane perturbation to facilitate cytosolic translocation. The present review presents how such advances are being applied to the delivery of a new form of RNA vaccine, replicons (RepRNA carrying inserted foreign genes of interest encoding vaccine antigens. Approaches have been developed for delivery to DCs, leading to the translation of the RepRNA and encoded vaccine antigens both in vitro and in vivo. Potential mechanisms favouring efficient delivery leading to translation are discussed with respect to the DC endocytic machinery, showing the importance of cytosolic translocation from acidifying endocytic structures. The review relates the DC endocytic pathways to immune response induction, and the potential advantages for these self-replicating RNA vaccines in the near future.

Identification of human tissue cross-presenting dendritic cells

OpenAIRE

Haniffa, Muzlifah; Collin, Matthew; Ginhoux, Florent

2013-01-01

Dendritic cells (DCs) are a heterogeneous group of functionally specialized antigen-presenting cells. We recently characterized the human tissue cross-presenting DCs and aligned the human and mouse DC subsets. Our findings will facilitate the translation of murine DC studies to the human setting and aid the design of DC-based vaccine strategies for infection and cancer immunotherapy.

Oral Delivery of Probiotics Expressing Dendritic Cell-Targeting Peptide Fused with Porcine Epidemic Diarrhea Virus COE Antigen: A Promising Vaccine Strategy against PEDV.

Science.gov (United States)

Wang, Xiaona; Wang, Li; Huang, Xuewei; Ma, Sunting; Yu, Meiling; Shi, Wen; Qiao, Xinyuan; Tang, Lijie; Xu, Yigang; Li, Yijing

2017-10-25

Porcine epidemic diarrhea virus (PEDV), an enteric coronavirus, is the causative agent of porcine epidemic diarrhea (PED) that damages intestinal epithelial cells and results in severe diarrhea and dehydration in neonatal suckling pigs with up to 100% mortality. The oral vaccine route is reported as a promising approach for inducing protective immunity against PEDV invasion. Furthermore, dendritic cells (DCs), professional antigen-presenting cells, link humoral and cellular immune responses for homeostasis of the intestinal immune environment. In this study, in order to explore an efficient oral vaccine against PEDV infection, a mucosal DC-targeting oral vaccine was developed using Lactobacillus casei to deliver the DC-targeting peptide (DCpep) fused with the PEDV core neutralizing epitope (COE) antigen. This probiotic vaccine could efficiently elicit secretory immunoglobulin A (SIgA)-based mucosal and immunoglobulin G (IgG)-based humoral immune responses via oral vaccination in vivo. Significant differences ( p targeting peptide fused with PEDV COE antigen. This mucosal DC-targeting oral vaccine delivery effectively enhances vaccine antigen delivery efficiency, providing a useful strategy to induce efficient immune responses against PEDV infection.

mRNA-transfected dendritic cell vaccine in combination with metronomic cyclophosphamide as treatment for patients with advanced malignant melanoma

DEFF Research Database (Denmark)

Borch, Troels Holz; Engell-Noerregaard, Lotte; Iversen, Trine Zeeberg

2016-01-01

Introduction: Vaccination with dendritic cells (DCs) has generally not fulfilled its promise in cancer immunotherapy due to ineffective translation of immune responses into clinical responses. A proposed reason for this is intrinsic immune regulatory mechanisms, such as regulatory T cells (Tregs......th vaccines. Immune monitoring consisted of IFNγ ELISpot assay, proliferation assay, and flow cytometry for enumeration of immune cell subsets.  Results: Toxicity was manageable. Eighteen patients were evaluable after six cycles. Of these, nine patients had progressive disease as best response...

Systemic Administration of Interleukin 2 Enhances the Therapeutic Efficacy of Dendritic Cell-Based Tumor Vaccines

Science.gov (United States)

Shimizu, K.; Fields, R. C.; Giedlin, M.; Mule, J. J.

1999-03-01

We have reported previously that murine bone marrow-derived dendritic cells (DC) pulsed with whole tumor lysates can mediate potent antitumor immune responses both in vitro and in vivo. Because successful therapy was dependent on host immune T cells, we have now evaluated whether the systemic administration of the T cell stimulatory/growth promoting cytokine interleukin-2 (IL-2) could enhance tumor lysate-pulsed DC-based immunizations to further promote protective immunity toward, and therapeutic rejection of, syngeneic murine tumors. In three separate approaches using a weakly immunogenic sarcoma (MCA-207), the systemic administration of non-toxic doses of recombinant IL-2 (20,000 and 40,000 IU/dose) was capable of mediating significant increases in the potency of DC-based immunizations. IL-2 could augment the efficacy of tumor lysate-pulsed DC to induce protective immunity to lethal tumor challenge as well as enhance splenic cytotoxic T lymphocyte activity and interferon-γ production in these treated mice. Moreover, treatment with the combination of tumor lysate-pulsed DC and IL-2 could also mediate regressions of established pulmonary 3-day micrometastases and 7-day macrometastases as well as established 14- and 28-day s.c. tumors, leading to either significant cure rates or prolongation in overall survival. Collectively, these findings show that nontoxic doses of recombinant IL-2 can potentiate the antitumor effects of tumor lysate-pulsed DC in vivo and provide preclinical rationale for the use of IL-2 in DC-based vaccine strategies in patients with advanced cancer.

Treatment of transplanted CT26 tumour with dendritic cell vaccine in combination with blockade of vascular endothelial growth factor receptor 2 and CTLA-4

DEFF Research Database (Denmark)

Pedersen, Anders Elm; Buus, S; Claesson, M H

2005-01-01

We investigated the anti CT26 tumour effect of dendritic cell based vaccination with the MuLV gp70 envelope protein-derived peptides AH1 and p320-333. Vaccination lead to generation of AH1 specific cytotoxic lymphocytes (CTL) and some decrease in tumour growth of simultaneously inoculated CT26...... cells. After combination with an antibody against VEGF receptor 2 (DC101), a significant increase in survival of the tumour cell recipients was observed. Also, monotherapy with an antibody against CTLA-4 (9H10), led to approximately 100% survival of tumour cell recipients. However, effective treatment...

Novel dendritic cell-based vaccination in late stage melanoma.

Science.gov (United States)

Schneble, Erika J; Yu, Xianzhong; Wagner, T E; Peoples, George E

2014-01-01

Dendritic cells (DCs) are professional antigen-presenting cells (APCs) that play an important role in stimulating an immune response of both CD4(+) T helper cells and CD8(+) cytotoxic T lymphocytes (CTLs). As such, DCs have been studied extensively in cancer immunotherapy for their capability to induce a specific anti-tumor response when loaded with tumor antigens. However, when the most relevant antigens of a tumor remain to be identified, alternative approaches are required. Formation of a dentritoma, a fused DC and tumor cells hybrid, is one strategy. Although initial studies of these hybrid cells are promising, several limitations interfere with its clinical and commercial application. Here we present early experience in clinical trials and an alternative approach to manufacturing this DC/tumor cell hybrid for use in the treatment of late stage and metastatic melanoma.

Preclinical Evaluation of Novel Dendritic Cell-Based Prostate Cancer Vaccines

Science.gov (United States)

2008-01-01

payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this...in melanoma patients is determined by their maturation state. Cancer Res 2003;63:12–7. 34. Nestle FO, Banchereau J, Hart D. Dendritic cells: on the

Metastatic melanoma patients treated with dendritic cell vaccination, Interleukin-2 and metronomic cyclophosphamide

DEFF Research Database (Denmark)

Ellebaek, Eva; Engell-Noerregaard, Lotte; Iversen, Trine Zeeberg

2012-01-01

Dendritic cells (DC) are the most potent antigen presenting cells and have proven effective in stimulation of specific immune responses in vivo. Competing immune inhibition could limit the clinical efficacy of DC vaccination. In this phase II trial, metronomic Cyclophosphamide and a Cox-2 inhibitor...... have been added to a DC vaccine with the intend to dampen immunosuppressive mechanisms. Twenty-eight patients with progressive metastatic melanoma were treated with autologous DCs pulsed with survivin, hTERT, and p53-derived peptides (HLA-A2(+)) or tumor lysate (HLA-A2(-)). Concomitantly the patients...... were treated with IL-2, Cyclophosphamide, and Celecoxib. The treatment was safe and tolerable. Sixteen patients (57 %) achieved stable disease (SD) at 1st evaluation and 8 patients had prolonged SD (7-13.7 months). The median OS was 9.4 months. Patients with SD had an OS of 10.5 months while patients...

Cellular based cancer vaccines

DEFF Research Database (Denmark)

Hansen, M; Met, Ö; Svane, I M

2012-01-01

Cancer vaccines designed to re-calibrate the existing host-tumour interaction, tipping the balance from tumor acceptance towards tumor control holds huge potential to complement traditional cancer therapies. In general, limited success has been achieved with vaccines composed of tumor...... to transiently affect in vitro migration via autocrine receptor-mediated endocytosis of CCR7. In the current review, we discuss optimal design of DC maturation focused on pre-clinical as well as clinical results from standard and polarized dendritic cell based cancer vaccines....

Asymptomatic Changes in Cardiac Function Can Occur in DCIS Patients Following Treatment with HER-2/neu Pulsed Dendritic Cell Vaccines

Science.gov (United States)

Bahl, Susan; Roses, Robert; Sharma, Anupama; Koldovsky, Ursula; Xu, Shuwen; Weinstein, Susan; Nisenbaum, Harvey; Fox, Kevin; Pasha, Theresa; Zhang, Paul; Araujo, Louis; Carver, Joseph; Czerniecki, Brian J

2009-01-01

Background Targeting HER-2/neu with Trastuzumab has been associated with development of cardiac toxicity. Methods Twenty-seven patients with ductal carcinoma in situ (DCIS) of the breast completed an IRB approved clinical trial of a HER-2/neu targeted dendritic cell based vaccine. Four weekly vaccinations were administered prior to surgical resection. All subjects underwent pre- and post-vaccine cardiac monitoring by MUGA/ECHO scanning allowing for a comparison of cardiac function. Results In 3 of 27 vaccinated patients (11%) transient asymptomatic decrements in ejection fraction of greater than 15% were noted after vaccination. Notably, evidence of circulating anti-HER-2/neu antibody was found prior to vaccination in all three patients, but cardiac toxicity was not noted until induction of cellular mediated immune responses. Conclusions This is the first description of HER-2/neu targeted vaccination associated with an incidence of cardiac changes, and the induction of cellular immune responses combined with antibody may contribute to changes in cardiac function. PMID:19800453

Tumor-Mediated Suppression of Dendritic Cell Vaccines

National Research Council Canada - National Science Library

Akporiaye, Emmanuel

2004-01-01

.... One of these factors is Transforming Growth Factor-beta (TGF-beta). TGF-beta is produced in large quantities by different types of cancer including breast cancer and inhibits the actions of several immune cells including dendritic cells (DC...

Exosomes as potent cell-free peptide-based vaccine. II. Exosomes in CpG adjuvants efficiently prime naive Tc1 lymphocytes leading to tumor rejection.

NARCIS (Netherlands)

Chaput, N.; Schartz, N.E.; Andre, F.; Taieb, J.; Novault, S.; Bonnaventure, P.; Aubert, N.; Bernard, J.; Lemonnier, F.; Merad, M.; Adema, G.J.; Adams, M.; Ferrantini, M.; Carpentier, A.F.; Escudier, B.; Tursz, T.; Angevin, E.; Zitvogel, L.

2004-01-01

Ideal vaccines should be stable, safe, molecularly defined, and out-of-shelf reagents efficient at triggering effector and memory Ag-specific T cell-based immune responses. Dendritic cell-derived exosomes could be considered as novel peptide-based vaccines because exosomes harbor a discrete set of

NOD/scid IL-2Rgnull mice: a preclinical model system to evaluate human dendritic cell-based vaccine strategies in vivo

Directory of Open Access Journals (Sweden)

Spranger Stefani

2012-02-01

Full Text Available Abstract Background To date very few systems have been described for preclinical investigations of human cellular therapeutics in vivo. However, the ability to carry out comparisons of new cellular vaccines in vivo would be of substantial interest for design of clinical studies. Here we describe a humanized mouse model to assess the efficacy of various human dendritic cell (DC preparations. Two reconstitution regimes of NOD/scid IL2Rgnull (NSG mice with adult human peripheral blood mononuclear cells (PBMC were evaluated for engraftment using 4-week and 9-week schedules. This led to selection of a simple and rapid protocol for engraftment and vaccine evaluation that encompassed 4 weeks. Methods NSG recipients of human PBMC were engrafted over 14 days and then vaccinated twice with autologous DC via intravenous injection. Three DC vaccine formulations were compared that varied generation time in vitro (3 days versus 7 days and signals for maturation (with or without Toll-like receptor (TLR3 and TLR7/8 agonists using MART-1 as a surrogate antigen, by electroporating mature DC with in vitro transcribed RNA encoding full length protein. After two weekly vaccinations, the splenocyte populations containing human lymphocytes were recovered 7 days later and assessed for MART-1-specific immune responses using MHC-multimer-binding assays and functional assessment of specific killing of melanoma tumor cell lines. Results Human monocyte-derived DC generated in vitro in 3 days induced better MART-1-specific immune responses in the autologous donor T cells present in the humanized NSG mice. Moreover, consistent with our in vitro observations, vaccination using mature DC activated with TLR3 and TLR7/8 agonists resulted in enhanced immune responses in vivo. These findings led to a ranking of the DC vaccine effects in vivo that reflected the hierarchy previously found for these mature DC variations in vitro. Conclusions This humanized mouse model system enables

Dendritic cell vaccination in combination with docetaxel for patients with metastatic castration-resistant prostate cancer

DEFF Research Database (Denmark)

Kongsted, Per; Borch, Troels Holz; Ellebaek, Eva

2017-01-01

Background aims  We investigated whether the addition of an autologous dendritic cell–based cancer vaccine (DCvac) induces an immune response in patients with metastatic castration-resistant prostate cancer treated with docetaxel.  Methods  Forty-three patients were randomized 1:1 to receive up...... twice through treatment cycles 1–4 and once through treatment cycles 5–10. Immune cell composition and antigen-specific responses were analyzed using flow cytometry, ELISpot and delayed type hypersensitivity (DTH) tests. Toxicity was graded according to Common Terminology Criteria for Adverse Events...... to local reactions. Decline in myeloid-derived suppressor cells at the third treatment cycle was found to be an independent predictor of DSS.  Conclusions  The addition of DCvac was safe. Immune responses were detected in approximately half of the patients investigated....

Dendritic cells exposed to MVA-based HIV-1 vaccine induce highly functional HIV-1-specific CD8(+ T cell responses in HIV-1-infected individuals.

Directory of Open Access Journals (Sweden)

Núria Climent

Full Text Available Currently, MVA virus vectors carrying HIV-1 genes are being developed as HIV-1/AIDS prophylactic/therapeutic vaccines. Nevertheless, little is known about the impact of these vectors on human dendritic cells (DC and their capacity to present HIV-1 antigens to human HIV-specific T cells. This study aimed to characterize the interaction of MVA and MVA expressing the HIV-1 genes Env-Gag-Pol-Nef of clade B (referred to as MVA-B in human monocyte-derived dendritic cells (MDDC and the subsequent processes of HIV-1 antigen presentation and activation of memory HIV-1-specific T lymphocytes. For these purposes, we performed ex vivo assays with MDDC and autologous lymphocytes from asymptomatic HIV-infected patients. Infection of MDDC with MVA-B or MVA, at the optimal dose of 0.3 PFU/MDDC, induced by itself a moderate degree of maturation of MDDC, involving secretion of cytokines and chemokines (IL1-ra, IL-7, TNF-α, IL-6, IL-12, IL-15, IL-8, MCP-1, MIP-1α, MIP-1β, RANTES, IP-10, MIG, and IFN-α. MDDC infected with MVA or MVA-B and following a period of 48 h or 72 h of maturation were able to migrate toward CCL19 or CCL21 chemokine gradients. MVA-B infection induced apoptosis of the infected cells and the resulting apoptotic bodies were engulfed by the uninfected MDDC, which cross-presented HIV-1 antigens to autologous CD8(+ T lymphocytes. MVA-B-infected MDDC co-cultured with autologous T lymphocytes induced a highly functional HIV-specific CD8(+ T cell response including proliferation, secretion of IFN-γ, IL-2, TNF-α, MIP-1β, MIP-1α, RANTES and IL-6, and strong cytotoxic activity against autologous HIV-1-infected CD4(+ T lymphocytes. These results evidence the adjuvant role of the vector itself (MVA and support the clinical development of prophylactic and therapeutic anti-HIV vaccines based on MVA-B.

Immunogenic Properties of a BCG Adjuvanted Chitosan Nanoparticle-Based Dengue Vaccine in Human Dendritic Cells.

Directory of Open Access Journals (Sweden)

Taweewun Hunsawong

2015-09-01

Full Text Available Dengue viruses (DENVs are among the most rapidly and efficiently spreading arboviruses. WHO recently estimated that about half of the world's population is now at risk for DENV infection. There is no specific treatment or vaccine available to treat or prevent DENV infections. Here, we report the development of a novel dengue nanovaccine (DNV composed of UV-inactivated DENV-2 (UVI-DENV and Mycobacterium bovis Bacillus Calmette-Guerin cell wall components (BCG-CWCs loaded into chitosan nanoparticles (CS-NPs. CS-NPs were prepared by an emulsion polymerization method prior to loading of the BCG-CWCs and UVI-DENV components. Using a scanning electron microscope and a zetasizer, DNV was determined to be of spherical shape with a diameter of 372.0 ± 11.2 nm in average and cationic surface properties. The loading efficacies of BCG-CWCs and UVI-DENV into the CS-NPs and BCG-CS-NPs were up to 97.2 and 98.4%, respectively. THP-1 cellular uptake of UVI-DENV present in the DNV was higher than soluble UVI-DENV alone. DNV stimulation of immature dendritic cells (iDCs resulted in a significantly higher expression of DCs maturation markers (CD80, CD86 and HLA-DR and induction of various cytokine and chemokine productions than in UVI-DENV-treated iDCs, suggesting a potential use of BCG- CS-NPs as adjuvant and delivery system for dengue vaccines.

Priming anticancer active specific immunotherapy with dendritic cells.

Science.gov (United States)

Mocellin, Simone

2005-06-01

Dendritic cells (DCs) probably represent the most powerful naturally occurring immunological adjuvant for anticancer vaccines. However, the initial enthusiasm for DC-based vaccines is being tempered by clinical results not meeting expectations. The partial failure of current vaccine formulations is explained by the extraordinary complexity of the immune system, which makes the task of exploiting the potential of such a biotherapeutic approach highly challenging. Clinical findings obtained in humans so far indicate that the immune system can be actively polarized against malignant cells by means of DC-based active specific immunotherapy, and that in some cases this is associated with tumor regression. This implies that under some unique circumstances, the naturally 'dormant' immune effectors can actually be employed as endogenous weapons against malignant cells. Only the thorough understanding of DC biology and tumor-host immune system interactions will allow researchers to reproduce, in a larger set of patients, the cellular/molecular conditions leading to an effective immune-mediated eradication of cancer.

Langerin negative dendritic cells promote potent CD8+ T-cell priming by skin delivery of live adenovirus vaccine microneedle arrays.

Science.gov (United States)

Bachy, Veronique; Hervouet, Catherine; Becker, Pablo D; Chorro, Laurent; Carlin, Leo M; Herath, Shanthi; Papagatsias, Timos; Barbaroux, Jean-Baptiste; Oh, Sea-Jin; Benlahrech, Adel; Athanasopoulos, Takis; Dickson, George; Patterson, Steven; Kwon, Sung-Yun; Geissmann, Frederic; Klavinskis, Linda S

2013-02-19

Stabilization of virus protein structure and nucleic acid integrity is challenging yet essential to preserve the transcriptional competence of live recombinant viral vaccine vectors in the absence of a cold chain. When coupled with needle-free skin delivery, such a platform would address an unmet need in global vaccine coverage against HIV and other global pathogens. Herein, we show that a simple dissolvable microneedle array (MA) delivery system preserves the immunogenicity of vaccines encoded by live recombinant human adenovirus type 5 (rAdHu5). Specifically, dried rAdHu5 MA immunization induced CD8(+) T-cell expansion and multifunctional cytokine responses equipotent with conventional injectable routes of immunization. Intravital imaging demonstrated MA cargo distributed both in the epidermis and dermis, with acquisition by CD11c(+) dendritic cells (DCs) in the dermis. The MA immunizing properties were attributable to CD11c(+) MHCII(hi) CD8α(neg) epithelial cell adhesion molecule (EpCAM(neg)) CD11b(+) langerin (Lang; CD207)(neg) DCs, but neither Langerhans cells nor Lang(+) DCs were required for CD8(+) T-cell priming. This study demonstrates an important technical advance for viral vaccine vectors progressing to the clinic and provides insights into the mechanism of CD8(+) T-cell priming by live rAdHu5 MAs.

Precision cancer immunotherapy: optimizing dendritic cell-based strategies to induce tumor antigen-specific T-cell responses against individual patient tumors.

Science.gov (United States)

Osada, Takuya; Nagaoka, Koji; Takahara, Masashi; Yang, Xiao Yi; Liu, Cong-Xiao; Guo, Hongtao; Roy Choudhury, Kingshuk; Hobeika, Amy; Hartman, Zachary; Morse, Michael A; Lyerly, H Kim

2015-05-01

Most dendritic cell (DC)-based vaccines have loaded the DC with defined antigens, but loading with autologos tumor-derived antigens would generate DCs that activate personalized tumor-specific T-cell responses. We hypothesized that DC matured with an optimized combination of reagents and loaded with tumor-derived antigens using a clinically feasible electroporation strategy would induce potent antitumor immunity. We first studied the effects on DC maturation and antigen presentation of the addition of picibanil (OK432) to a combination of zoledronic acid, tumor necrosis factor-α, and prostaglandin E2. Using DC matured with the optimized combination, we tested 2 clinically feasible sources of autologous antigen for electroloading, total tumor mRNA or total tumor lysate, to determine which stimulated more potent antigen-specific T cells in vitro and activated more potent antitumor immunity in vivo. The combination of tumor necrosis factor-α/prostaglandin E2/zoledronic acid/OK432 generated DC with high expression of maturation markers and antigen-specific T-cell stimulatory function in vitro. Mature DC electroloaded with tumor-derived mRNA [mRNA electroporated dendritic cell (EPDC)] induced greater expansion of antigen-specific T cells in vitro than DC electroloaded with tumor lysate (lysate EPDC). In a therapeutic model of MC38-carcinoembryonic antigen colon cancer-bearing mice, vaccination with mRNA EPDC induced the most efficient anti-carcinoembryonic antigen cellular immune response, which significantly suppressed tumor growth. In conclusion, mature DC electroloaded with tumor-derived mRNA are a potent cancer vaccine, especially useful when specific tumor antigens for vaccination have not been identified, allowing autologous tumor, and if unavailable, allogeneic cell lines to be used as an unbiased source of antigen. Our data support clinical testing of this strategy.

Induction of systemic CTL responses in melanoma patients by dendritic cell vaccination: Cessation of CTL responses is associated with disease progression

DEFF Research Database (Denmark)

Andersen, M.H.; Keikavoussi, P.; Brocker, E.B.

2001-01-01

Two HLA-A2-positive patients with advanced stage IV melanoma were treated with monocyte-derived dendritic cells (DC) pulsed with either tumor peptide antigens from gp100, MART-1 and MAGE- 3 alone or in combination with autologous oncolysates. Clinically, the rapid progression of disease...... by Western blotting was decreased in PBL at this time. In summary, our data confirm that DC-based vaccinations induce peptide-specific T cells in the peripheral blood of advanced-stage melanoma patients. Although successful induction of systemic tumor antigen-specific CTL may not lead to objective clinical...

Targeting nanoparticles to dendritic cells for immunotherapy.

NARCIS (Netherlands)

Cruz, L.J.; Tacken, P.J.; Rueda, F.; Domingo, J.C.; Albericio, F.; Figdor, C.G.

2012-01-01

Dendritic cells (DCs) are key players in the initiation of adaptive immune responses and are currently exploited in immunotherapy for treatment of cancer and infectious diseases. Development of targeted nanodelivery systems carrying vaccine components, including antigens and adjuvants, to DCs in

A Francisella tularensis live vaccine strain that improves stimulation of antigen-presenting cells does not enhance vaccine efficacy.

Directory of Open Access Journals (Sweden)

Deanna M Schmitt

Full Text Available Vaccination is a proven strategy to mitigate morbidity and mortality of infectious diseases. The methodology of identifying and testing new vaccine candidates could be improved with rational design and in vitro testing prior to animal experimentation. The tularemia vaccine, Francisella tularensis live vaccine strain (LVS, does not elicit complete protection against lethal challenge with a virulent type A Francisella strain. One factor that may contribute to this poor performance is limited stimulation of antigen-presenting cells. In this study, we examined whether the interaction of genetically modified LVS strains with human antigen-presenting cells correlated with effectiveness as tularemia vaccine candidates. Human dendritic cells infected with wild-type LVS secrete low levels of proinflammatory cytokines, fail to upregulate costimulatory molecules, and activate human T cells poorly in vitro. One LVS mutant, strain 13B47, stimulated higher levels of proinflammatory cytokines from dendritic cells and macrophages and increased costimulatory molecule expression on dendritic cells compared to wild type. Additionally, 13B47-infected dendritic cells activated T cells more efficiently than LVS-infected cells. A deletion allele of the same gene in LVS displayed similar in vitro characteristics, but vaccination with this strain did not improve survival after challenge with a virulent Francisella strain. In vivo, this mutant was attenuated for growth and did not stimulate T cell responses in the lung comparable to wild type. Therefore, stimulation of antigen-presenting cells in vitro was improved by genetic modification of LVS, but did not correlate with efficacy against challenge in vivo within this model system.

Vaccination with apoptosis colorectal cancer cell pulsed autologous ...

African Journals Online (AJOL)

To investigate vaccination with apoptosis colorectal cancer (CRC) cell pulsed autologous dendritic cells (DCs) in advanced CRC, 14 patients with advanced colorectal cancer (CRC) were enrolled and treated with DCs vaccine to assess toxicity, tolerability, immune and clinical responses to the vaccine. No severe toxicity ...

Dendritic cell vaccination for metastatic melanoma: a 14-year monoinstitutional experience.

Science.gov (United States)

de Rosa, Francesco; Ridolfi, Laura; Fiammenghi, Laura; Petrini, Massimiliano; Granato, Anna M; Ancarani, Valentina; Pancisi, Elena; Soldati, Valentina; Cassan, Serena; Bulgarelli, Jenny; Framarini, Massimo; Tauceri, Francesca; Migliori, Giuseppe; Brolli, Claudia; Gentili, Giorgia; Petracci, Elisabetta; Nanni, Oriana; Riccobon, Angela; Ridolfi, Ruggero; Guidoboni, Massimo

2017-08-01

Although immunomodulating antibodies are highly effective in metastatic melanoma, their toxicity, related to the activation of T lymphocytes, can be severe. Anticancer vaccines promote a fairly specific response and are very well tolerated, but their effectiveness has yet to be demonstrated. We have been treating patients with advanced melanoma with an autologous dendritic cell vaccine since 2001; to better characterize the safety and efficacy of our product, we designed a retrospective study on all of our patients treated with the vaccine to date. We retrospectively reviewed both case report forms of patients included in clinical trials and medical records of those treated within a compassionate use program. Response was assessed according to the Response Evaluation Criteria In Solid Tumors criteria and toxicity has been graded according to CTCAE 4.0. Although the response rate has been rather low, the median overall survival of 11.4 months and the 1-year survival rate of 46.9% are encouraging, especially considering the fact that data were obtained in a heavily pretreated population and only about one quarter of the patients had received ipilimumab and/or BRAF inhibitors. Multivariate analysis confirmed that the development of an immune response was significantly correlated with a better prognosis (hazard ratio 0.54; P=0.019). The adverse events observed were generally mild and self-limiting. Our analysis confirms the excellent tolerability of our vaccine, making it a potential candidate for combination therapies. As efficacy seems largely restricted to immunoresponsive patients, future strategies should aim to increase the number of these patients.

Comparison of monocyte-derived dendritic cells from colorectal cancer patients, non-small-cell-lung-cancer patients and healthy donors

DEFF Research Database (Denmark)

Kvistborg, P; Bechmann, C M; Pedersen, A W

2009-01-01

Dendritic cells (DCs) are bone marrow-derived professional antigen presenting cells. Due to their role as potent inducers of immune responses, these cells are widely used as adjuvant in experimental clinical settings for cancer immune therapy. We have developed a DC-based vaccine using autologous......-small-cell-lung-cancer (NSCLC). In the present paper we retrospectively compare the maturation profile based on surface marker expression on DCs generated from the three patient cohorts and between cancer patient cohorts and a cohort of healthy donors. Vaccines were generated under cGMP conditions and phenotypic profiles of DC...

[Imiquimod combined with dendritic cell vaccine decreases Treg proportion and enhances anti-tumor responses in mice bearing melanoma].

Science.gov (United States)

Ren, Shurong; Wang, Qiubo; Zhang, Yanli; Lu, Cuixiu; Li, Ping; Li, Yumei

2017-02-01

Objective To investigate the therapeutic effect of Toll-like receptor 7 (TLR7) agonist imiquimod combined with dendritic cell (DC)-based tumor vaccine on melanoma in mice and the potential mechanism. Methods Melanoma-bearing mouse models were established by subcutanous injection of B16-OVA cells into C57BL/6 mice. DCs were isolated from mouse bone marrow and propagated in culture medium with recombinant mouse granulocyte-macrophage colony-stimulating factor (rmGM-CSF) and recombinant mouse interleukin-4 (rmIL-4). DC vaccine (OVA-DC) was prepared by overnight incubation of DCs added with chicken ovalbumin. C57BL/6 mice were separated into four groups which were treated with PBS, topical imiquimod application, OVA-DC intradermal injection and imiquimod plus OVA-DC, respectively. The tumor size was calculated by digital vernier caliper. Peripheral blood CD4 + FOXP3 + Tregs of the tumor-bearing mice was detected by flow cytometry. The cytotoxicity of splenic lymphocyte against B16-OVA was assessed in vitro by CCK-8 assay. Results Compared with the other three groups, B16-OVA-bearing mice treated with imiquimod plus DC vaccine had the smallest tumor volume. The percentage of CD4 + FOXP3 + Tregs decreased significantly in the combined treated mice. The combined treatment enhanced significantly cytotoxicity of splenic lymphocytes against B16-OVA cells. Conclusion Imiquimod combined with antigen-pulsed-DC vaccine could reduce CD4 + FOXP3 + Treg proportion and promote anti-tumor effect in mice with melanoma.

Laser Adjuvant-Assisted Peptide Vaccine Promotes Skin Mobilization of Dendritic Cells and Enhances Protective CD8+ TEM and TRM Cell Responses against Herpesvirus Infection and Disease.

Science.gov (United States)

Lopes, Patricia P; Todorov, George; Pham, Thanh T; Nesburn, Anthony B; Bahraoui, Elmostafa; BenMohamed, Lbachir

2018-04-15

There is an urgent need for chemical-free and biological-free safe adjuvants to enhance the immunogenicity of vaccines against widespread viral pathogens, such as herpes simplex virus 2 (HSV-2), that infect a large proportion of the world human population. In the present study, we investigated the safety, immunogenicity, and protective efficacy of a laser adjuvant-assisted peptide (LAP) vaccine in the B6 mouse model of genital herpes. This LAP vaccine and its laser-free peptide (LFP) vaccine analog contain the immunodominant HSV-2 glycoprotein B CD8 + T cell epitope (HSV-gB 498-505 ) covalently linked with the promiscuous glycoprotein D CD4 + T helper cell epitope (HSV-gD 49-89 ). Prior to intradermal delivery of the LAP vaccine, the lower-flank shaved skin of B6 or CD11c/eYFP transgenic mice received a topical skin treatment with 5% imiquimod cream and then was exposed for 60 s to a laser, using the FDA-approved nonablative diode. Compared to the LFP vaccine, the LAP vaccine (i) triggered mobilization of dendritic cells (DCs) in the skin, which formed small spots along the laser-treated areas, (ii) induced phenotypic and functional maturation of DCs, (iii) stimulated long-lasting HSV-specific effector memory CD8 + T cells (T EM cells) and tissue-resident CD8 + T cells (T RM cells) locally in the vaginal mucocutaneous tissues (VM), and (iv) induced protective immunity against genital herpes infection and disease. As an alternative to currently used conventional adjuvants, the chemical- and biological-free laser adjuvant offers a well-tolerated, simple-to-produce method to enhance mass vaccination for widespread viral infections. IMPORTANCE Herpes simplex viruses 1 and 2 (HSV-1 and HSV-2) infect a large proportion of the world population. There is an urgent need for chemical-free and biological-free safe adjuvants that would advance mass vaccination against the widespread herpes infections. The present study demonstrates that immunization with a laser

Targeting vaccines to dendritic cells

DEFF Research Database (Denmark)

Foged, Camilla; Sundblad, Anne; Hovgaard, Lars

2002-01-01

delivery systems (DDS) with adjuvant effect that target DC directly and induce optimal immune responses. This paper will review the current knowledge of DC physiology as well as the progress in the field of novel vaccination strategies that directly or indirectly aim at targeting DC....... to be far superior to that of B-cells and macrophages. DC are localized at strategic places in the body at sites used by pathogens to enter the organism, and are thereby in an optimal position to capture antigens. In general, vaccination strategies try to mimic the invasiveness of the pathogens. DC...

Vaccination with apoptosis colorectal cancer cell pulsed autologous ...

African Journals Online (AJOL)

user

2011-02-18

Feb 18, 2011 ... with DCs vaccine to assess toxicity, tolerability, immune and clinical responses to the vaccine. No ... Key words: Dendritic cells, immunotherapy, colorectal cancer. .... color analyses of DCs, cells were labeled simultaneously with ..... promote CD8+ Tc1 cell survival, memory response, tumor localization and ...

Induction of CML28-specific cytotoxic T cell responses using co-transfected dendritic cells with CML28 DNA vaccine and SOCS1 small interfering RNA expression vector

International Nuclear Information System (INIS)

Zhou Hongsheng; Zhang Donghua; Wang Yaya; Dai Ming; Zhang Lu; Liu Wenli; Liu Dan; Tan Huo; Huang Zhenqian

2006-01-01

CML28 is an attractive target for antigen-specific immunotherapy. SOCS1 represents an inhibitory control mechanism for DC antigen presentation and the magnitude of adaptive immunity. In this study, we evaluated the potential for inducing CML28-specific cytotoxic T lymphocytes (CTL) responses by dendritic cells (DCs)-based vaccination. We constructed a CML28 DNA vaccine and a SOCS1 siRNA vector and then cotransfect monocyte-derived DCs. Flow cytometry analysis showed gene silencing of SOCS1 resulted in higher expressions of costimulative moleculars in DCs. Mixed lymphocyte reaction (MLR) indicated downregulation of SOCS1 stronger capability to stimulate proliferation of responder cell in DCs. The CTL assay revealed transfected DCs effectively induced autologous CML28-specific CTL responses and the lytic activities induced by SOCS1-silenced DCs were significantly higher compared with those induced by SOCS1-expressing DCs. These results in our study indicates gene silencing of SOCS1 remarkably enhanced the cytotoxicity efficiency of CML28 DNA vaccine in DCs

ALA-PDT mediated DC vaccine for skin squamous cell carcinoma

Science.gov (United States)

Ji, Jie; Fan, Zhixia; Zhou, Feifan; Wang, Xiaojie; Shi, Lei; Zhang, Haiyan; Wang, Peiru; Yang, Degang; Zhang, Linglin; Wang, Xiuli; Chen, Wei R.

2015-03-01

Dendritic cell (DC) based vaccine has emerged as a promising immunotherapy for cancers. However, most DC vaccines so far have only achieved limited success in cancer treatment. Photodynamic therapy (PDT), an established cancer treatment strategy, can cause immunogenic apoptosis to induce an effective antitumor immune response. In this study, we developed a DC-based cancer vaccine using immunogenic apoptotic tumor cells induced by 5-aminolevulinic acid (ALA) mediated PDT. The maturation of DCs induced by PDT-treated apoptotic cells was evaluated. The anti-tumor immunity of ALA-PDT-DC vaccine was tested with mouse model. We observed the maturations of DCs potentiated by ALA-PDT treated tumor cells, including phenotypic maturation (upregulation of surface expression of MHC-II, DC80, and CD86), and functional maturation (enhanced capability to secret INF-Υ and IL-12). ALA-PDT-DC vaccine mediated by apoptotic cells provided protection against tumor in mice, far stronger than that of DC vaccine obtained from freeze/thaw treated tumor cells. Our results indicate that immunogenic apoptotic tumor cells can be more effective in enhancing DC-based cancer vaccine, which could improve the clinical application of PDT- DC vaccines.

Production of a Dendritic Cell-Based Vaccine Containing Inactivated Autologous Virus for Therapy of Patients with Chronic Human Immunodeficiency Virus Type 1 Infection▿

Science.gov (United States)

Whiteside, Theresa L.; Piazza, Paolo; Reiter, Amanda; Stanson, Joanna; Connolly, Nancy C.; Rinaldo, Charles R.; Riddler, Sharon A.

2009-01-01

In preparation for a pilot clinical trial in patients with chronic human immunodeficiency virus type 1 (HIV-1) infection, a novel dendritic cell (DC)-based vaccine is being manufactured. The trial will test the hypothesis that isolated endogenous virus presented by DCs serves as a potent immunogen for activation of CD8+ and CD4+ T cells specific for a broad range of autologous HIV-1 antigens. Production of the vaccine under good manufacture practice conditions involves (i) autologous virus isolation; (ii) superinfection of CD4+ T cells with the virus; (iii) inactivation of the virus in CD4+ T cells, T-cell apoptosis, and coincubation of T cells with autologous DCs; and (iv) product testing and release. Endogenous virus was isolated from peripheral blood-derived CD4+ T cells of three HIV-1-positive subjects by coincubation with autologous OKT-3-stimulated CD4+ T cells. CD4+ T-cell supernatants were tested for p24 levels by enzyme-linked immunosorbent assay (>25 ng/ml) and for the 50% tissue culture infective doses (TCID50; which ranged from 4,642 to 46,416/ml on day 19 of culture). Autologous CD4+ T cells that were separated on immunobeads (>95% purity) and superinfected with virus-expressed p24 (28 to 54%) had TCID50 of >400/ml on days 5 to 10. Virus inactivation with psoralen (20 μg/ml) and UVB irradiation (312 nm) reduced the TCID50 of the supernatants from 199,986 to 11/ml (>99%). 7-Amino-actinomycin D-positive, annexin V-positive CD4+ T cells were fed to autologous DCs generated by using the Elutra cell separation system and the Aastrom system. Flow analysis showed that DC loading was complete in 24 h. On the basis of these translational results and experience with the generation of DCs from HIV-1-infected patients in a previous clinical trial, the Investigational New Drug application for clinical vaccination was submitted and approved by the FDA (application no. BB-IND-13137). PMID:19038780

Production of a dendritic cell-based vaccine containing inactivated autologous virus for therapy of patients with chronic human immunodeficiency virus type 1 infection.

Science.gov (United States)

Whiteside, Theresa L; Piazza, Paolo; Reiter, Amanda; Stanson, Joanna; Connolly, Nancy C; Rinaldo, Charles R; Riddler, Sharon A

2009-02-01

In preparation for a pilot clinical trial in patients with chronic human immunodeficiency virus type 1 (HIV-1) infection, a novel dendritic cell (DC)-based vaccine is being manufactured. The trial will test the hypothesis that isolated endogenous virus presented by DCs serves as a potent immunogen for activation of CD8(+) and CD4(+) T cells specific for a broad range of autologous HIV-1 antigens. Production of the vaccine under good manufacture practice conditions involves (i) autologous virus isolation; (ii) superinfection of CD4(+) T cells with the virus; (iii) inactivation of the virus in CD4(+) T cells, T-cell apoptosis, and coincubation of T cells with autologous DCs; and (iv) product testing and release. Endogenous virus was isolated from peripheral blood-derived CD4(+) T cells of three HIV-1-positive subjects by coincubation with autologous OKT-3-stimulated CD4(+) T cells. CD4(+) T-cell supernatants were tested for p24 levels by enzyme-linked immunosorbent assay (>25 ng/ml) and for the 50% tissue culture infective doses (TCID(50); which ranged from 4,642 to 46,416/ml on day 19 of culture). Autologous CD4(+) T cells that were separated on immunobeads (>95% purity) and superinfected with virus-expressed p24 (28 to 54%) had TCID(50) of >400/ml on days 5 to 10. Virus inactivation with psoralen (20 microg/ml) and UVB irradiation (312 nm) reduced the TCID(50) of the supernatants from 199,986 to 11/ml (>99%). 7-Amino-actinomycin D-positive, annexin V-positive CD4(+) T cells were fed to autologous DCs generated by using the Elutra cell separation system and the Aastrom system. Flow analysis showed that DC loading was complete in 24 h. On the basis of these translational results and experience with the generation of DCs from HIV-1-infected patients in a previous clinical trial, the Investigational New Drug application for clinical vaccination was submitted and approved by the FDA (application no. BB-IND-13137).

Antigen-specific immature dendritic cell vaccine ameliorates anti-dsDNA antibody-induced renal damage in a mouse model.

Science.gov (United States)

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.

Vaccination with poly(IC:LC and peptide-pulsed autologous dendritic cells in patients with pancreatic cancer

Directory of Open Access Journals (Sweden)

Shikhar Mehrotra

2017-04-01

Full Text Available Abstract Background Dendritic cells (DCs enhance the quality of anti-tumor immune response in patients with cancer. Thus, we posit that DC-based immunotherapy, in conjunction with toll-like receptor (TLR-3 agonist poly-ICLC, is a promising approach for harnessing immunity against metastatic or locally advanced unresectable pancreatic cancer (PC. Methods We generated autologous DCs from the peripheral blood of HLA-A2+ patients with PC. DCs were pulsed with three distinct A2-restricted peptides: 1 human telomerase reverse transcriptase (hTERT, TERT572Y, 2 carcinoembryonic antigen (CEA; Cap1-6D, and 3 survivin (SRV.A2. Patients received four intradermal injections of 1 × 107 peptide-pulsed DC vaccines every 2 weeks (Day 0, 14, 28, and 42. Concurrently, patients received intramuscular administration of Poly-ICLC at 30 μg/Kg on vaccination days (i.e., day 0, 14, 28, and 42, as well as on days 3, 17, 21, 31, 37, and 45. Our key objective was to assess safety and feasibility. The effect of DC vaccination on immune response was measured at each DC injection time point by enumerating the phenotype and function of patient T cells. Results Twelve patients underwent apheresis: nine patients with metastatic disease, and three patients with locally advanced unresectable disease. Vaccines were successfully manufactured from all individuals. We found that this treatment was well-tolerated, with the most common symptoms being fatigue and/or self-limiting flu-like symptoms. Among the eight patients who underwent imaging on day 56, four patients experienced stable disease while four patients had disease progression. The median overall survival was 7.7 months. One patient survived for 28 months post leukapheresis. MHC class I –tetramer analysis before and after vaccination revealed effective generation of antigen-specific T cells in three patients with stable disease. Conclusion Vaccination with peptide-pulsed DCs in combination with poly-ICLC is safe and

Characterization of monocyte-derived dendritic cells maturated with IFN-alpha

DEFF Research Database (Denmark)

Svane, I M; Nikolajsen, K; Walter, M R

2006-01-01

Dendritic cells (DC) are promising candidates for cancer immunotherapy. These cells can be generated from peripheral blood monocytes cultured with granulocyte macrophage-colony stimulating factor (GM-CSF) and interleukin-4 (IL-4). In order to obtain full functional capacity, maturation is required......, maturation with IFN-alpha has only a small effect on induction of autologous T-cell stimulatory capacity of the DC. However, an increase in DC allogeneic T-cell stimulatory capacity was observed. These data suggest that IFN-alpha has a potential as a maturation agent used in DC-based cancer vaccine trials...

Comparison of alpha-Type-1 polarizing and standard dendritic cell cytokine cocktail for maturation of therapeutic monocyte-derived dendritic cell preparations from cancer patients

DEFF Research Database (Denmark)

Trepiakas, Redas; Pedersen, Anders Elm; Met, Ozcan

2008-01-01

The current "gold standard" for generation of dendritic cell (DC) used in DC-based cancer vaccine studies is maturation of monocyte-derived DCs with tumor necrosis factor-alpha (TNF-alpha)/IL-1beta/IL-6 and prostaglandin E(2) (PGE(2)). Recently, a protocol for producing so-called alpha-Type-1...... polarized dendritic cells (alphaDC1) in serum-free medium was published based on maturation of monocyte-derived DCs with TNF-alpha/IL-1-beta/polyinosinic:polycytidylic acid (poly-I:C)/interferon (IFN)-alpha and IFN-gamma. This DC maturation cocktail was described to fulfill the criteria for optimal DC......-regulation of inhibitory molecules such as PD-L1, ILT2, ILT3 as compared to sDC. Although alphaDC1 matured DCs secreted more IL-12p70 and IL-23 these DCs had lower or similar stimulatory capacity compared to sDCs when used as stimulating cells in mixed lymphocyte reaction (MLR) or for induction of autologous influenza...

Low-dose temozolomide before dendritic-cell vaccination reduces (specifically) CD4+CD25++Foxp3+ regulatory T-cells in advanced melanoma patients.

Science.gov (United States)

Ridolfi, Laura; Petrini, Massimiliano; Granato, Anna Maria; Gentilcore, Giusy; Simeone, Ester; Ascierto, Paolo Antonio; Pancisi, Elena; Ancarani, Valentina; Fiammenghi, Laura; Guidoboni, Massimo; de Rosa, Francesco; Valmorri, Linda; Scarpi, Emanuela; Nicoletti, Stefania Vittoria Luisa; Baravelli, Stefano; Riccobon, Angela; Ridolfi, Ruggero

2013-05-31

In cancer immunotherapy, dendritic cells (DCs) play a fundamental role in the dialog between innate and adaptive immune response, but several immunosuppressive mechanisms remain to be overcome. For example, a high number of CD4+CD25++Foxp3+ regulatory T-cells (Foxp3+Tregs) have been observed in the peripheral blood and tumor microenvironment of cancer patients. On the basis of this, we conducted a study on DC-based vaccination in advanced melanoma, adding low-dose temozolomide to obtain lymphodepletion. Twenty-one patients were entered onto our vaccination protocol using autologous DCs pulsed with autologous tumor lysate and keyhole limpet hemocyanin. Patients received low-dose temozolomide before vaccination and 5 days of low-dose interleukin-2 (IL-2) after vaccination. Circulating Foxp3+Tregs were evaluated before and after temozolomide, and after IL-2. Among the 17 evaluable patients we observed 1 partial response (PR), 6 stable disease (SD) and 10 progressive disease (PD). The disease control rate (PR+SD = DCR) was 41% and median overall survival was 10 months. Temozolomide reduced circulating Foxp3+Treg cells in all patients. A statistically significant reduction of 60% was observed in Foxp3+Tregs after the first cycle, whereas the absolute lymphocyte count decreased by only 14%. Conversely, IL-2 increased Foxp3+Treg cell count by 75.4%. Of note the effect of this cytokine, albeit not statistically significant, on the DCR subgroup led to a further 33.8% reduction in Foxp3+Treg cells. Our results suggest that the combined immunological therapy, at least as far as the DCR subgroup is concerned, effectively reduced the number of Foxp3+Treg cells, which exerted a blunting effect on the growth-stimulating effect of IL-2. However, this regimen, with its current modality, would not seem to be capable of improving clinical outcome.

Closing the manufacturing process of dendritic cell vaccines transduced with adenovirus vectors.

Science.gov (United States)

Gulen, Dumrul; Abe, Fuminori; Maas, Sarah; Reed, Elizabeth; Cowan, Kenneth; Pirruccello, Samuel; Wisecarver, James; Warkentin, Phyllis; Northam, Matt; Turken, Orhan; Coskun, Ugur; Senesac, Joe; Talmadge, James E

2008-12-20

Anticancer immunotherapy using dendritic cell (DC) based vaccines provides an adjuvant therapeutic strategy that is not cross reactive with conventional therapeutics. However, manufacturing of DC vaccines requires stringent adherence to Good Manufacturing Practice (GMP) methods and rigorous standardization. Optimally this includes a closed system for monocyte isolation, in combination with closed culture and washing systems and an effective vector transduction strategy. In this study, we used the Gambro Elutra to enrich monocytes from non-mobilized leukapheresis products collected from healthy donors. This approach enriched monocytes from an average frequency of 13.6+3.2% (mean+SEM), to an average frequency of 79.5+4.3% following enrichment with a yield of 79 to 100%. The monocytes were then cultured in a closed system using gas permeable Vuelife fluoroethylene propylene (FEP) bags and X-vivo-15 media containing 10 ng/ml granulocyte-macrophage colony-stimulation factor (GM-CSF) and 5 ng/ml Interleukin (IL) 4. The cultures were re-fed on days two and four, with a 25% media volume and cytokines. Following culture for seven days, the cells were harvested using a Cobe-2991 and concentrated using a bench centrifuge retrofitted with blocks to allow centrifugation of 72 ml bags and supernatant removed using a plasma extractor. This approach reduced the media volume to an average of 17.4 ml and an average DC concentration of 6.3+1.0x10(7) cells/ml, a viability of 93.8+2.2%, a purity of 88.9+3.3% and a total yield of 8.5+1.4x10(8) DCs. Based on the identification of DR+ cells as DCs we had an average yield of 46+8% using a calculation based on the number of monocytes in the apheresis product and the resulting DCs differentiated from monocytes. The use of DCs as a vaccine, required transduction with an adenovirus (Adv) vector with the tumor suppressor, p53 transgene (Adv5CMV-p53) as the antigen at a DC concentration of 9x10(6) DCs/ml at an Ad5CMV-p53: DC ratio of 20

Clinical outcomes of a novel therapeutic vaccine with Tax peptide-pulsed dendritic cells for adult T cell leukaemia/lymphoma in a pilot study.

Science.gov (United States)

Suehiro, Youko; Hasegawa, Atsuhiko; Iino, Tadafumi; Sasada, Amane; Watanabe, Nobukazu; Matsuoka, Masao; Takamori, Ayako; Tanosaki, Ryuji; Utsunomiya, Atae; Choi, Ilseung; Fukuda, Tetsuya; Miura, Osamu; Takaishi, Shigeo; Teshima, Takanori; Akashi, Koichi; Kannagi, Mari; Uike, Naokuni; Okamura, Jun

2015-05-01

Adult T cell leukaemia/lymphoma (ATL) is a human T cell leukaemia virus type-I (HTLV-I)-infected T cell malignancy with poor prognosis. We herein developed a novel therapeutic vaccine designed to augment an HTLV-I Tax-specific cytotoxic T lymphocyte (CTL) response that has been implicated in anti-ATL effects, and conducted a pilot study to investigate its safety and efficacy. Three previously treated ATL patients, classified as intermediate- to high-risk, were subcutaneously administered with the vaccine, consisting of autologous dendritic cells (DCs) pulsed with Tax peptides corresponding to the CTL epitopes. In all patients, the performance status improved after vaccination without severe adverse events, and Tax-specific CTL responses were observed with peaks at 16-20 weeks. Two patients achieved partial remission in the first 8 weeks, one of whom later achieved complete remission, maintaining their remission status without any additional chemotherapy 24 and 19 months after vaccination, respectively. The third patient, whose tumour cells lacked the ability to express Tax at biopsy, obtained stable disease in the first 8 weeks and later developed slowly progressive disease although additional therapy was not required for 14 months. The clinical outcomes of this pilot study indicate that the Tax peptide-pulsed DC vaccine is a safe and promising immunotherapy for ATL. © 2015 John Wiley & Sons Ltd.

Evaluation of in vivo labelled dendritic cell migration in cancer patients.

Science.gov (United States)

Ridolfi, Ruggero; Riccobon, Angela; Galassi, Riccardo; Giorgetti, Gianluigi; Petrini, Massimiliano; Fiammenghi, Laura; Stefanelli, Monica; Ridolfi, Laura; Moretti, Andrea; Migliori, Giuseppe; Fiorentini, Giuseppe

2004-07-30

BACKGROUND: Dendritic Cell (DC) vaccination is a very promising therapeutic strategy in cancer patients. The immunizing ability of DC is critically influenced by their migration activity to lymphatic tissues, where they have the task of priming naïve T-cells. In the present study in vivo DC migration was investigated within the context of a clinical trial of antitumor vaccination. In particular, we compared the migration activity of mature Dendritic Cells (mDC) with that of immature Dendritic Cells (iDC) and also assessed intradermal versus subcutaneous administration. METHODS: DC were labelled with 99mTc-HMPAO or 111In-Oxine, and the presence of labelled DC in regional lymph nodes was evaluated at pre-set times up to a maximum of 72 h after inoculation. Determinations were carried out in 8 patients (7 melanoma and 1 renal cell carcinoma). RESULTS: It was verified that intradermal administration resulted in about a threefold higher migration to lymph nodes than subcutaneous administration, while mDC showed, on average, a six-to eightfold higher migration than iDC. The first DC were detected in lymph nodes 20-60 min after inoculation and the maximum concentration was reached after 48-72 h. CONCLUSIONS: These data obtained in vivo provide preliminary basic information on DC with respect to their antitumor immunization activity. Further research is needed to optimize the therapeutic potential of vaccination with DC.

HER-2 Pulsed Dendritic Cell Vaccine Can Eliminate HER-2 Expression and Impact DCIS

Science.gov (United States)

Sharma, Anupama; Koldovsky, Ursula; Xu, Shuwen; Mick, Rosemarie; Roses, Robert; Fitzpatrick, Elizabeth; Weinstein, Susan; Nisenbaum, Harvey; Levine, Bruce L; Fox, Kevin; Zhang, Paul; Koski, Gary; Czerniecki, Brian J

2011-01-01

Background HER-2/neu over-expression plays a critical role in breast cancer development and its expression in ductal carcinoma in situ (DCIS) is associated with development of invasive breast cancer. A vaccine targeting HER-2/neu expression in DCIS may initiate immunity against invasive cancer. Methods A HER-2/neu dendritic cell (DC) vaccine was administered to 27 patients with HER-2/neu over-expressing DCIS. The HER-2/neu vaccine was administered prior to surgical resection and pre- and post-vaccination analysis was conducted to assess clinical results. Results At surgery, 5 of 27 (18.5%) vaccinated subjects had no evidence of remaining disease, while among 22 subjects with residual DCIS, HER-2/neu expression was eradicated in 11 (50%). When comparing ERneg with ERpos DCIS lesions, vaccination was more effective in hormone-independent DCIS. Following vaccination, no residual DCIS was found in 40% of ERneg subjects compared to 5.9% in ERpos subject. Sustained HER-2/neu expression was found in 10% of ERneg subjects compared to 47.1% in ERpos subjects (p=0.04). Post-vaccination phenotypes were significantly different between ERpos and ERneg subjects (p=0.01), with 7 of 16 (43.8%) initially presenting with ERpos HER-2/neupos Luminal B phenotype finishing with the ERpos HER-2/neuneg Luminal A phenotype, and 3 of 6 (50%) with the ERneg HER-2/neupos phenotype changing to the ERneg HER-2/neuneg phenotype. Conclusions Results suggest vaccination against HER-2/neu is safe, well-tolerated and induces decline and or eradication of HER-2/neu expression. These findings warrant further exploration of HER-2/neu vaccination in estrogen-independent breast cancer and highlight the need to target additional tumor associated antigens and pathways. PMID:22252842

Therapy of HPV 16-associated carcinoma with dendritic cell-based vaccines: In vitro priming of the effector cell responses by DC pulsed with tumour lysates and synthetic RAHYNIVTF peptide

Czech Academy of Sciences Publication Activity Database

Indrová, Marie; Bubeník, Jan; Šímová, Jana; Vonka, V.; Němečková, Š.; Mendoza, Luis; Reiniš, Milan

2001-01-01

Roč. 7, č. 1 (2001), s. 97-100 ISSN 1107-3756 R&D Projects: GA MZd NC5526; GA MZd NC45011; GA ČR GA312/98/0826; GA ČR GA312/99/0542; GA ČR GA301/00/0114; GA AV ČR IAA7052002 Institutional research plan: CEZ:AV0Z5052915 Keywords : tumour vaccines * HPV 16 * dendritic cells Subject RIV: FD - Oncology ; Hematology Impact factor: 1.689, year: 2001

PD-L1 peptide co-stimulation increases immunogenicity of a dendritic cell-based cancer vaccine

DEFF Research Database (Denmark)

Munir Ahmad, Shamaila; Martinenaite, Evelina; Hansen, Morten

2016-01-01

elicited by the DC vaccine even further. Consequently, we observed a significant increase in the number of vaccine-reacting T cells in vitro. In conclusion, activation of PD-L1-specific T cells may directly modulate immunogenicity of DC vaccines. Addition of PD-L1 epitopes may thus be an easily applicable...... and attractive option to augment the effectiveness of cancer vaccines and other immunotherapeutic agents....

Pros and Cons of Antigen-Presenting Cell Targeted Tumor Vaccines

Directory of Open Access Journals (Sweden)

Cleo Goyvaerts

2015-01-01

Full Text Available In therapeutic antitumor vaccination, dendritic cells play the leading role since they decide if, how, when, and where a potent antitumor immune response will take place. Since the disentanglement of the complexity and merit of different antigen-presenting cell subtypes, antitumor immunotherapeutic research started to investigate the potential benefit of targeting these subtypes in situ. This review will discuss which antigen-presenting cell subtypes are at play and how they have been targeted and finally question the true meaning of targeting antitumor-based vaccines.

Recombinant invasive Lactococcus lactis can transfer DNA vaccines either directly to dendritic cells or across an epithelial cell monolayer.

Science.gov (United States)

de Azevedo, Marcela; Meijerink, Marjolein; Taverne, Nico; Pereira, Vanessa Bastos; LeBlanc, Jean Guy; Azevedo, Vasco; Miyoshi, Anderson; Langella, Philippe; Wells, Jerry M; Chatel, Jean-Marc

2015-09-11

Lactococcus lactis (L. lactis), a generally regarded as safe (GRAS) bacterium has recently been investigated as a mucosal delivery vehicle for DNA vaccines. Because of its GRAS status, L. lactis represents an attractive alternative to attenuated pathogens. Previous studies showed that eukaryotic expression plasmids could be delivered into intestinal epithelial cells (IECs) by L. lactis, or recombinant invasive strains of L. lactis, leading to heterologous protein expression. Although expression of antigens in IECs might lead to vaccine responses, it would be of interest to know whether uptake of L. lactis DNA vaccines by dendritic cells (DCs) could lead to antigen expression as they are unique in their ability to induce antigen-specific T cell responses. To test this, we incubated mouse bone marrow-derived DCs (BMDCs) with invasive L. lactis strains expressing either Staphylococcus aureus Fibronectin Binding Protein A (LL-FnBPA+), or Listeria monocytogenes mutated Internalin A (LL-mInlA+), both strains carrying a plasmid DNA vaccine (pValac) encoding for the cow milk allergen β-lactoglobulin (BLG). We demonstrated that they can transfect BMDCs, inducing the secretion of the pro-inflammatory cytokine IL-12. We also measured the capacity of strains to invade a polarized monolayer of IECs, mimicking the situation encountered in the gastrointestinal tract. Gentamycin survival assay in these cells showed that LL-mInlA+ is 100 times more invasive than L. lactis. The cross-talk between differentiated IECs, BMDCs and bacteria was also evaluated using an in vitro transwell co-culture model. Co-incubation of strains in this model showed that DCs incubated with LL-mInlA+ containing pValac:BLG could express significant levels of BLG. These results suggest that DCs could sample bacteria containing the DNA vaccine across the epithelial barrier and express the antigen. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Therapy of MHC Class I+ and Class I- HPV 16-Associated Tumours with Cytokines, Genetically Modified Tumour Vaccines and Dendritic Cells

Czech Academy of Sciences Publication Activity Database

Bubeník, Jan; Šímová, Jana; Mikyšková, Romana; Vonka, V.

2004-01-01

Roč. 27, č. 4 (2004), s. 161D ISSN 0147-958X. [International Congress of Immunology /12./ and Annual Conference of FOCIS /4./. Montreal, 18.07.2004-23.07.2004] Institutional research plan: CEZ:AV0Z5052915 Keywords : HPV 16 * tumour vaccines * dendritic cells Subject RIV: EC - Immunology Impact factor: 1.051, year: 2004

Evaluation of in vivo labelled dendritic cell migration in cancer patients

Directory of Open Access Journals (Sweden)

Ridolfi Laura

2004-07-01

Full Text Available Abstract Background Dendritic Cell (DC vaccination is a very promising therapeutic strategy in cancer patients. The immunizing ability of DC is critically influenced by their migration activity to lymphatic tissues, where they have the task of priming naïve T-cells. In the present study in vivo DC migration was investigated within the context of a clinical trial of antitumor vaccination. In particular, we compared the migration activity of mature Dendritic Cells (mDC with that of immature Dendritic Cells (iDC and also assessed intradermal versus subcutaneous administration. Methods DC were labelled with 99mTc-HMPAO or 111In-Oxine, and the presence of labelled DC in regional lymph nodes was evaluated at pre-set times up to a maximum of 72 h after inoculation. Determinations were carried out in 8 patients (7 melanoma and 1 renal cell carcinoma. Results It was verified that intradermal administration resulted in about a threefold higher migration to lymph nodes than subcutaneous administration, while mDC showed, on average, a six-to eightfold higher migration than iDC. The first DC were detected in lymph nodes 20–60 min after inoculation and the maximum concentration was reached after 48–72 h. Conclusions These data obtained in vivo provide preliminary basic information on DC with respect to their antitumor immunization activity. Further research is needed to optimize the therapeutic potential of vaccination with DC.

Dendritic cell immunotherapy for HIV infection: from theory to reality.

Science.gov (United States)

Oshiro, Telma Miyuki; de Almeida, Alexandre; da Silva Duarte, Alberto José

2009-11-01

Knowledge concerning the immunology of dendritic cells (DCs) accumulated over the last few decades and the development of methodologies to generate and manipulate these cells in vitro has made their therapeutic application a reality. Currently, clinical protocols for DC-based therapeutic vaccine in HIV-infected individuals show that it is a safe and promising approach. Concomitantly, important advances continue to be made in the development of methodologies to optimize DC acquisition, as well as the selection of safe, immunogenic HIV antigens and the evaluation of immune response in treated individuals.

Novel vaccines targeting dendritic cells by coupling allergoids to nonoxidized mannan enhance allergen uptake and induce functional regulatory T cells through programmed death ligand 1.

Science.gov (United States)

Sirvent, Sofía; Soria, Irene; Cirauqui, Cristina; Cases, Bárbara; Manzano, Ana I; Diez-Rivero, Carmen M; Reche, Pedro A; López-Relaño, Juan; Martínez-Naves, Eduardo; Cañada, F Javier; Jiménez-Barbero, Jesús; Subiza, Javier; Casanovas, Miguel; Fernández-Caldas, Enrique; Subiza, José Luis; Palomares, Oscar

2016-08-01

Allergen immunotherapy (AIT) is the only curative treatment for allergy. AIT faces pitfalls related to efficacy, security, duration, and patient compliance. Novel vaccines overcoming such inconveniences are in demand. We sought to study the immunologic mechanisms of action for novel vaccines targeting dendritic cells (DCs) generated by coupling glutaraldehyde-polymerized grass pollen allergoids to nonoxidized mannan (PM) compared with glutaraldehyde-polymerized allergoids (P) or native grass pollen extracts (N). Skin prick tests and basophil activation tests with N, P, or PM were performed in patients with grass pollen allergy. IgE-blocking experiments, flow cytometry, confocal microscopy, cocultures, suppression assays, real-time quantitative PCR, ELISAs, and ELISpot assays were performed to assess allergen capture by human DCs and T-cell responses. BALB/c mice were immunized with PM, N, or P. Antibody levels, cytokine production by splenocytes, and splenic forkhead box P3 (FOXP3)(+) regulatory T (Treg) cells were quantified. Experiments with oxidized PM were also performed. PM displays in vivo hypoallergenicity, induces potent blocking antibodies, and is captured by human DCs much more efficiently than N or P by mechanisms depending on mannose receptor- and dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin-mediated internalization. PM endorses human DCs to generate functional FOXP3(+) Treg cells through programmed death ligand 1. Immunization of mice with PM induces a shift to nonallergic responses and increases the frequency of splenic FOXP3(+) Treg cells. Mild oxidation impairs these effects in human subjects and mice, demonstrating the essential role of preserving the carbohydrate structure of mannan. Allergoids conjugated to nonoxidized mannan represent suitable vaccines for AIT. Our findings might also be of the utmost relevance to development of therapeutic interventions in other immune tolerance-related diseases. Copyright �

Antigen-Specific Polyclonal Cytotoxic T Lymphocytes Induced by Fusions of Dendritic Cells and Tumor Cells

Directory of Open Access Journals (Sweden)

Shigeo Koido

2010-01-01

Full Text Available The aim of cancer vaccines is induction of tumor-specific cytotoxic T lymphocytes (CTLs that can reduce the tumor mass. Dendritic cells (DCs are potent antigen-presenting cells and play a central role in the initiation and regulation of primary immune responses. Thus, DCs-based vaccination represents a potentially powerful strategy for induction of antigen-specific CTLs. Fusions of DCs and whole tumor cells represent an alternative approach to deliver, process, and subsequently present a broad spectrum of antigens, including those known and unidentified, in the context of costimulatory molecules. Once DCs/tumor fusions have been infused back into patient, they migrate to secondary lymphoid organs, where the generation of antigen-specific polyclonal CTL responses occurs. We will discuss perspectives for future development of DCs/tumor fusions for CTL induction.

Ursolic acid isolated from Uncaria rhynchophylla activates human dendritic cells via TLR2 and/or TLR4 and induces the production of IFN-gamma by CD4+ naïve T cells.

Science.gov (United States)

Jung, Tae-Young; Pham, Thanh Nhan Nguyen; Umeyama, Akemi; Shoji, Noboru; Hashimoto, Toshihiro; Lee, Je-Jung; Takei, Masao

2010-09-25

Ursolic acid is triterpene isolated from Uncaria rhynchophylla and is a pharmacologically active substance. The induction of dendritic cell maturation is critical for the induction of Ag-specific T-lymphocyte response and may be essential for the development of human vaccine relying on T cell immunity. In this study, we investigated that the effect of Ursolic acid on the phenotypic and functional maturation of human monocyte-derived dendritic cells in vitro. Dendritic cells harvested on day 8 were examined using functional assay. The expression levels of CD1a, CD80, CD83, CD86, HLA-DR and CCR7 on Ursolic acid-primed dendritic cells was slightly enhanced. Ursolic acid dose-dependently enhanced the T cell stimulatory capacity in an allogeneic mixed lymphocyte reaction, as measured by T cell proliferation. The production of IL-12p70 induced by Ursolic acid-primed dendritic cells was inhibited by the anti-Toll-like receptor-2 (TLR2) mAb and anti-TLR4 mAb. Moreover, Ursolic acid-primed dendritic cells expressed levels of mRNA coding for both TLR2 and TLR4. The majority of cells produced considerable interferon-gamma (IFN-gamma), but also small amounts of interleukin (IL-4)-4. Ursolic acid-primed dendritic cells have an intermediate migratory capacity towards CCL19 and CCL21. These results suggest that Ursolic acid modulates human dendritic cells function in a fashion that favors Th1 polarization via the activation of IL-12p70 dependent on TLR2 and/or TLR4, and may be used on dendritic cells-based vaccines for cancer immunotherapy. 2010 Elsevier B.V. All rights reserved.

Dendritic cell neoplasms: an overview.

Science.gov (United States)

Kairouz, Sebastien; Hashash, Jana; Kabbara, Wadih; McHayleh, Wassim; Tabbara, Imad A

2007-10-01

Dendritic cell neoplasms are rare tumors that are being recognized with increasing frequency. They were previously classified as lymphomas, sarcomas, or histiocytic neoplasms. The World Health Organization (WHO) classifies dendritic cell neoplasms into five groups: Langerhans' cell histiocytosis, Langerhans' cell sarcoma, Interdigitating dendritic cell sarcoma/tumor, Follicular dendritic cell sarcoma/tumor, and Dendritic cell sarcoma, not specified otherwise (Jaffe, World Health Organization classification of tumors 2001; 273-289). Recently, Pileri et al. provided a comprehensive immunohistochemical classification of histiocytic and dendritic cell tumors (Pileri et al., Histopathology 2002;59:161-167). In this article, a concise overview regarding the pathological, clinical, and therapeutic aspects of follicular dendritic, interdigitating dendritic, and Langerhans' cell tumors is presented.

Dynamic visualization of dendritic cell-antigen interactions in the skin following transcutaneous immunization.

Directory of Open Access Journals (Sweden)

Teerawan Rattanapak

Full Text Available Delivery of vaccines into the skin provides many advantages over traditional parenteral vaccination and is a promising approach due to the abundance of antigen presenting cells (APC residing in the skin including Langerhans cells (LC and dermal dendritic cells (DDC. However, the main obstacle for transcutaneous immunization (TCI is the effective delivery of the vaccine through the stratum corneum (SC barrier to the APC in the deeper skin layers. This study therefore utilized microneedles (MN and a lipid-based colloidal delivery system (cubosomes as a synergistic approach for the delivery of vaccines to APC in the skin. The process of vaccine uptake and recruitment by specific types of skin APC was investigated in real-time over 4 hours in B6.Cg-Tg (Itgax-EYFP 1 Mnz/J mice by two-photon microscopy. Incorporation of the vaccine into a particulate delivery system and the use of MN preferentially increased vaccine antigen uptake by a highly motile subpopulation of skin APC known as CD207⁺ DC. No uptake of antigen or any response to immunisation by LC could be detected.

Mechanism of ad5 vaccine immunity and toxicity: fiber shaft targeting of dendritic cells.

Directory of Open Access Journals (Sweden)

Cheng Cheng

2007-02-01

Full Text Available Recombinant adenoviral (rAd vectors elicit potent cellular and humoral immune responses and show promise as vaccines for HIV-1, Ebola virus, tuberculosis, malaria, and other infections. These vectors are now widely used and have been generally well tolerated in vaccine and gene therapy clinical trials, with many thousands of people exposed. At the same time, dose-limiting adverse responses have been observed, including transient low-grade fevers and a prior human gene therapy fatality, after systemic high-dose recombinant adenovirus serotype 5 (rAd5 vector administration in a human gene therapy trial. The mechanism responsible for these effects is poorly understood. Here, we define the mechanism by which Ad5 targets immune cells that stimulate adaptive immunity. rAd5 tropism for dendritic cells (DCs was independent of the coxsackievirus and adenovirus receptor (CAR, its primary receptor or the secondary integrin RGD receptor, and was mediated instead by a heparin-sensitive receptor recognized by a distinct segment of the Ad5 fiber, the shaft. rAd vectors with CAR and RGD mutations did not infect a variety of epithelial and fibroblast cell types but retained their ability to transfect several DC types and stimulated adaptive immune responses in mice. Notably, the pyrogenic response to the administration of rAd5 also localized to the shaft region, suggesting that this interaction elicits both protective immunity and vector-induced fevers. The ability of replication-defective rAd5 viruses to elicit potent immune responses is mediated by a heparin-sensitive receptor that interacts with the Ad5 fiber shaft. Mutant CAR and RGD rAd vectors target several DC and mononuclear subsets and induce both adaptive immunity and toxicity. Understanding of these interactions facilitates the development of vectors that target DCs through alternative receptors that can improve safety while retaining the immunogenicity of rAd vaccines.

Human antibodies to dendritic cells : generation, analysis and use in vaccination

NARCIS (Netherlands)

Lekkerkerker, A.N.

2002-01-01

Dendritic cells (DCs) are widely recognized as professional antigen presenting cells (APCs) that play a pivotal role in directing the immune response. DCs are a heterogeneous cell population that continuously derive from bone marrow cells and reside as sentinels in an immature stage in the

Increase of circulating CD4+CD25highFoxp3+ regulatory T cells in patients with metastatic renal cell carcinoma during treatment with dendritic cell vaccination and low-dose interleukin-2

DEFF Research Database (Denmark)

Berntsen, Annika; Brimnes, Marie Klinge; thor Straten, Per

2010-01-01

Regulatory T cells (Treg) play an important role in the maintenance of immune tolerance and may be one of the obstacles of successful tumor immunotherapy. In this study, we analyzed the impact of administration of dendritic cell (DC) vaccination in combination with low-dose interleukin (IL)-2...... in patients with metastatic renal cell carcinoma on the frequency of CD4+CD25highFoxp3+ Treg cells in peripheral blood. We found that the treatment increased the frequency of Treg cells more than 7-fold compared with pretreatment levels (P...

Dendritic cell mediated delivery of plasmid DNA encoding LAMP/HIV-1 Gag fusion immunogen enhances T cell epitope responses in HLA DR4 transgenic mice.

Directory of Open Access Journals (Sweden)

Gregory G Simon

2010-01-01

Full Text Available This report describes the identification and bioinformatics analysis of HLA-DR4-restricted HIV-1 Gag epitope peptides, and the application of dendritic cell mediated immunization of DNA plasmid constructs. BALB/c (H-2d and HLA-DR4 (DRA1*0101, DRB1*0401 transgenic mice were immunized with immature dendritic cells transfected by a recombinant DNA plasmid encoding the lysosome-associated membrane protein-1/HIV-1 Gag (pLAMP/gag chimera antigen. Three immunization protocols were compared: 1 primary subcutaneous immunization with 1x10(5 immature dendritic cells transfected by electroporation with the pLAMP/gag DNA plasmid, and a second subcutaneous immunization with the naked pLAMP/gag DNA plasmid; 2 primary immunization as above, and a second subcutaneous immunization with a pool of overlapping peptides spanning the HIV-1 Gag sequence; and 3 immunization twice by subcutaneous injection of the pLAMP/gag DNA plasmid. Primary immunization with pLAMP/gag-transfected dendritic cells elicited the greatest number of peptide specific T-cell responses, as measured by ex vivo IFN-gamma ELISpot assay, both in BALB/c and HLA-DR4 transgenic mice. The pLAMP/gag-transfected dendritic cells prime and naked DNA boost immunization protocol also resulted in an increased apparent avidity of peptide in the ELISpot assay. Strikingly, 20 of 25 peptide-specific T-cell responses in the HLA-DR4 transgenic mice contained sequences that corresponded, entirely or partially to 18 of the 19 human HLA-DR4 epitopes listed in the HIV molecular immunology database. Selection of the most conserved epitope peptides as vaccine targets was facilitated by analysis of their representation and variability in all reported sequences. These data provide a model system that demonstrates a the superiority of immunization with dendritic cells transfected with LAMP/gag plasmid DNA, as compared to naked DNA, b the value of HLA transgenic mice as a model system for the identification and evaluation

Immunogenicity of DNA vaccines encoding simian immunodeficiency virus antigen targeted to dendritic cells in rhesus macaques.

Directory of Open Access Journals (Sweden)

Matthias Tenbusch

Full Text Available BACKGROUND: Targeting antigens encoded by DNA vaccines to dendritic cells (DCs in the presence of adjuvants enhances their immunogenicity and efficacy in mice. METHODOLOGY/PRINCIPAL FINDINGS: To explore the immunogenicity of this approach in non-human primates, we generated a single chain antibody to the antigen uptake receptor DEC-205 expressed on rhesus macaque DCs. DNA vaccines encoding this single chain antibody fused to the SIV capsid protein were delivered to six monkeys each by either intramuscular electroporation or conventional intramuscular injection co-injected or not with poly ICLC, a stabilized poly I: C analogue, as adjuvant. Antibodies to capsid were induced by the DC-targeting and non-targeting control DNA delivered by electroporation while conventional DNA immunization at a 10-fold higher dose of DNA failed to induce detectable humoral immune responses. Substantial cellular immune responses were also observed after DNA electroporation of both DNAs, but stronger responses were induced by the non-targeting vaccine. Conventional immunization with the DC-targeting DNA at a 10-fold higher dose did not give rise to substantial cellular immune responses, neither when co-injected with poly ICLC. CONCLUSIONS/SIGNIFICANCE: The study confirms the potent immunogenicity of DNA vaccines delivered by electroporation. Targeting the DNA via a single chain antibody to DEC-205 expressed by DCs, however, does not improve the immunogenicity of the antigens in non-human primates.

Dendritic cells during Epstein Barr virus infection

Directory of Open Access Journals (Sweden)

Christian eMunz

2014-06-01

Full Text Available Epstein Barr virus (EBV causes persistent infection in more than 90% of the human adult population and is associated with 2% of all tumors in humans. This -herpesvirus infects primarily human B and epithelial cells, but has been reported to be sensed by dendritic cells (DCs during primary infection. These activated DCs are thought to contribute to innate restriction of EBV infection and initiate EBV specific adaptive immune responses via cross-priming. The respective evidence and their potential importance for EBV specific vaccine development will be discussed in this review.

Dendritic Cell-Based Immunotherapies to Fight HIV: How Far from a Success Story? A Systematic Review and Meta-Analysis

Directory of Open Access Journals (Sweden)

Antonio Victor Campos Coelho

2016-11-01

Full Text Available The scientific community still faces the challenge of developing strategies to cure HIV-1. One of these pursued strategies is the development of immunotherapeutic vaccines based on dendritic cells (DCs, pulsed with the virus, that aim to boost HIV-1 specific immune response. We aimed to review DCs-based therapeutic vaccines reports and critically assess evidence to gain insights for the improvement of these strategies. We performed a systematic review, followed by meta-analysis and meta-regression, of clinical trial reports. Twelve studies were selected for meta-analysis. The experimental vaccines had low efficiency, with an overall success rate around 38% (95% confidence interval = 26.7%–51.3%. Protocols differed according to antigen choice, DC culture method, and doses, although multivariate analysis did not show an influence of any of them on overall success rate. The DC-based vaccines elicited at least some immunogenicity, that was sometimes associated with plasmatic viral load transient control. The protocols included both naïve and antiretroviral therapy (ART-experienced individuals, and used different criteria for assessing vaccine efficacy. Although the vaccines did not work as expected, they are proof of concept that immune responses can be boosted against HIV-1. Protocol standardization and use of auxiliary approaches, such as latent HIV-1 reservoir activation and patient genomics are paramount for fine-tuning future HIV-1 cure strategies.

A Herpes Simplex Virus Type 2 Deleted for Glycoprotein D Enables Dendritic Cells to Activate CD4+ and CD8+ T Cells

Science.gov (United States)

Retamal-Díaz, Angello R.; Kalergis, Alexis M.; Bueno, Susan M.; González, Pablo A.

2017-01-01

Herpes simplex virus type 2 (HSV-2) is highly prevalent in the human population producing significant morbidity, mainly because of the generation of genital ulcers and neonatal encephalitis. Additionally, HSV-2 infection significantly increases the susceptibility of the host to acquire HIV and promotes the shedding of the latter in the coinfected. Despite numerous efforts to create a vaccine against HSV-2, no licensed vaccines are currently available. A long-standing strategy, based on few viral glycoproteins combined with adjuvants, recently displayed poor results in a Phase III clinical study fueling exploration on the development of mutant HSV viruses that are attenuated in vivo and elicit protective adaptive immune components, such as antiviral antibodies and T cells. Importantly, such specialized antiviral immune components are likely induced and modulated by dendritic cells, professional antigen presenting cells that process viral antigens and present them to T cells. However, HSV interferes with several functions of DCs and ultimately induces their death. Here, we propose that for an attenuated mutant virus to confer protective immunity against HSV in vivo based on adaptive immune components, such virus should also be attenuated in dendritic cells to promote a robust and effective antiviral response. We provide a background framework for this idea, considerations, as well as the means to assess this hypothesis. Addressing this hypothesis may provide valuable insights for the development of novel, safe, and effective vaccines against herpes simplex viruses. PMID:28848543

A Herpes Simplex Virus Type 2 Deleted for Glycoprotein D Enables Dendritic Cells to Activate CD4+ and CD8+ T Cells

Directory of Open Access Journals (Sweden)

Angello R. Retamal-Díaz

2017-08-01

Full Text Available Herpes simplex virus type 2 (HSV-2 is highly prevalent in the human population producing significant morbidity, mainly because of the generation of genital ulcers and neonatal encephalitis. Additionally, HSV-2 infection significantly increases the susceptibility of the host to acquire HIV and promotes the shedding of the latter in the coinfected. Despite numerous efforts to create a vaccine against HSV-2, no licensed vaccines are currently available. A long-standing strategy, based on few viral glycoproteins combined with adjuvants, recently displayed poor results in a Phase III clinical study fueling exploration on the development of mutant HSV viruses that are attenuated in vivo and elicit protective adaptive immune components, such as antiviral antibodies and T cells. Importantly, such specialized antiviral immune components are likely induced and modulated by dendritic cells, professional antigen presenting cells that process viral antigens and present them to T cells. However, HSV interferes with several functions of DCs and ultimately induces their death. Here, we propose that for an attenuated mutant virus to confer protective immunity against HSV in vivo based on adaptive immune components, such virus should also be attenuated in dendritic cells to promote a robust and effective antiviral response. We provide a background framework for this idea, considerations, as well as the means to assess this hypothesis. Addressing this hypothesis may provide valuable insights for the development of novel, safe, and effective vaccines against herpes simplex viruses.

A Lipid Based Antigen Delivery System Efficiently Facilitates MHC Class-I Antigen Presentation in Dendritic Cells to Stimulate CD8+ T Cells

Science.gov (United States)

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.

Poly-I:C Decreases Dendritic Cell Viability Independent of PKR Activation

DEFF Research Database (Denmark)

Larsen, Hjalte List; Pedersen, Anders Elm

2012-01-01

Vaccination with tumor-antigen pulsed, monocyte-derived dendritic cells (DCs) has emerged as a promising strategy in cancer immunotherapy. The standard DC maturation cocktail consists of a combination of tumor necrosis factor-α (TNF-α)/interleukin (IL)-1β/IL-6 and prostaglandin E2 (PGE2...

Enhancement of the priming efficacy of DNA vaccines encoding dendritic cell-targeted antigens by synergistic toll-like receptor ligands

Directory of Open Access Journals (Sweden)

Kornbluth Richard S

2009-08-01

Full Text Available Abstract Background Targeting of protein antigens to dendritic cells (DC via the DEC205 receptor enhances presentation of antigen-derived peptides on MHC-I and MHC-II molecules and, in the presence of costimulatory signals, antigen-specific immune responses. The immunogenicity and efficacy of DNA vaccination can also be enhanced by fusing the encoded antigen to single chain antibodies directed against DEC205. To further improve this strategy, we evaluated different toll-like receptor ligands (TLR and CD40 ligands (CD40L as adjuvants for DNA vaccines encoding a DEC205-single-chain antibody fused to the ovalbumin model antigen or HIV-1 Gag and assessed the priming efficacy of DNA in a DNA prime adenoviral vector boost immunization regimen. Results Mice were primed with the adjuvanted DEC-205 targeted DNA vaccines and boosted with adenoviral vectors encoding the same antigens. CD8+ T cell responses were determined after the adenoviral booster immunization, to determine how well the different DNA immunization regimens prime for the adenoviral boost. In the absence of adjuvants, targeting of DNA-encoded ovalbumin to DCs suppressed CD8+ T-cell responses after the adenoviral booster immunization. CD8+ T-cell responses to the DEC205 targeted DNA vaccines increased only slightly by adding either the TLR-9 ligand CpG, the TLR-3 ligand Poly I:C, or CD40 ligand expression plasmids. However, the combination of both TLR-ligands led to a strong enhancement of CD8+ T-cell responses compared to a non-targeted DNA vaccine. This finding was confirmed using HIV Gag as antigen. Conclusion Although DNA prime adenoviral vector boost immunizations belong to the strongest inducers of cytotoxic T cell responses in different animal models and humans, the CD8+ T cell responses can be further improved by targeting the DNA encoded antigen to DEC205 in the presence of synergistic TLR ligands CpG and Poly I:C.

Induction of anti-HBs in HB vaccine nonresponders in vivo by hepatitis B surface antigen-pulsed blood dendritic cells.

Science.gov (United States)

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.

High hydrostatic pressure affects antigenic pool in tumor cells: Implication for dendritic cell-based cancer immunotherapy.

Science.gov (United States)

Urbanova, Linda; Hradilova, Nada; Moserova, Irena; Vosahlikova, Sarka; Sadilkova, Lenka; Hensler, Michal; Spisek, Radek; Adkins, Irena

2017-07-01

High hydrostatic pressure (HHP) can be used to generate dendritic cell (DC)-based active immunotherapy for prostate, lung and ovarian cancer. We showed here that HHP treatment of selected human cancer cell lines leads to a degradation of tumor antigens which depends on the magnitude of HHP applied and on the cancer cell line origin. Whereas prostate or ovarian cell lines displayed little protein antigen degradation with HHP treatment up to 300MPa after 2h, tumor antigens are hardly detected in lung cancer cell line after treatment with HHP 250MPa at the same time. On the other hand, quick reduction of tumor antigen-coding mRNA was observed at HHP 200MPa immediately after treatment in all cell lines tested. To optimize the DC-based active cellular therapy protocol for HHP-sensitive cell lines the immunogenicity of HHP-treated lung cancer cells at 150, 200 and 250MPa was compared. Lung cancer cells treated with HHP 150MPa display characteristics of immunogenic cell death, however cells are not efficiently phagocytosed by DC. Despite induction of the highest number of antigen-specific CD8 + T cells, 150 MPa-treated lung cancer cells survive in high numbers. This excludes their use in DC vaccine manufacturing. HHP of 200MPa treatment of lung cancer cells ensures the optimal ratio of efficient immunogenic killing and delivery of protein antigens in DC. These results represent an important pre-clinical data for generation of immunogenic killed lung cancer cells in ongoing NSCLC Phase I/II clinical trial using DC-based active cellular immunotherapy (DCVAC/LuCa). Copyright © 2017 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

Dectin-1 Positive Dendritic Cells Expand after Infection with Leishmania major Parasites and Represent Promising Targets for Vaccine Development

Science.gov (United States)

Zimara, Nicole; Chanyalew, Menberework; Aseffa, Abraham; van Zandbergen, Ger; Lepenies, Bernd; Schmid, Maximilian; Weiss, Richard; Rascle, Anne; Wege, Anja Kathrin; Jantsch, Jonathan; Schatz, Valentin; Brown, Gordon D.; Ritter, Uwe

2018-01-01

Resistant mouse strains mount a protective T cell-mediated immune response upon infection with Leishmania (L.) parasites. Healing correlates with a T helper (Th) cell-type 1 response characterized by a pronounced IFN-γ production, while susceptibility is associated with an IL-4-dependent Th2-type response. It has been shown that dermal dendritic cells are crucial for inducing protective Th1-mediated immunity. Additionally, there is growing evidence that C-type lectin receptor (CLR)-mediated signaling is involved in directing adaptive immunity against pathogens. However, little is known about the function of the CLR Dectin-1 in modulating Th1- or Th2-type immune responses by DC subsets in leishmaniasis. We characterized the expression of Dectin-1 on CD11c+ DCs in peripheral blood, at the site of infection, and skin-draining lymph nodes of L. major-infected C57BL/6 and BALB/c mice and in peripheral blood of patients suffering from cutaneous leishmaniasis (CL). Both mouse strains responded with an expansion of Dectin-1+ DCs within the analyzed tissues. In accordance with the experimental model, Dectin-1+ DCs expanded as well in the peripheral blood of CL patients. To study the role of Dectin-1+ DCs in adaptive immunity against L. major, we analyzed the T cell stimulating potential of bone marrow-derived dendritic cells (BMDCs) in the presence of the Dectin-1 agonist Curdlan. These experiments revealed that Curdlan induces the maturation of BMDCs and the expansion of Leishmania-specific CD4+ T cells. Based on these findings, we evaluated the impact of Curdlan/Dectin-1 interactions in experimental leishmaniasis and were able to demonstrate that the presence of Curdlan at the site of infection modulates the course of disease in BALB/c mice: wild-type BALB/c mice treated intradermally with Curdlan developed a protective immune response against L. major whereas Dectin-1−/− BALB/c mice still developed the fatal course of disease after Curdlan treatment. Furthermore

Consolidative dendritic cell-based immunotherapy elicits cytotoxicity against malignant mesothelioma.

NARCIS (Netherlands)

Hegmans, J.P.; Veltman, J.D.; Lambers, M.E.; Vries, I.J.M. de; Figdor, C.G.; Hendriks, R.W.; Hoogsteden, H.C.; Lambrecht, B.N.; Aerts, J.G.

2010-01-01

RATIONALE: We previously demonstrated that dendritic cell-based immunotherapy induced protective antitumor immunity with a prolonged survival rate in mice. However, the clinical relevance is still in question. To examine this, we designed a clinical trial using chemotherapy followed by

HPV16-associated tumours: Therapy of surgical minimal residual disease with dendritic cell-based vaccines

Czech Academy of Sciences Publication Activity Database

Reiniš, Milan; Indrová, Marie; Mendoza, Luis; Mikyšková, Romana; Bieblová, Jana; Bubeník, Jan; Šímová, Jana

2004-01-01

Roč. 25, č. 4 (2004), s. 1165-1170 ISSN 1019-6439 R&D Projects: GA MZd NC7148; GA ČR GA301/04/0492; GA ČR GA301/01/0985; GA AV ČR IAA5052203 Institutional research plan: CEZ:AV0Z5052915 Keywords : HPV16 * minimal residual tumour disease * dendritic cells Subject RIV: EC - Immunology Impact factor: 3.056, year: 2004

Neutrophils, dendritic cells and Toxoplasma.

Science.gov (United States)

Denkers, Eric Y; Butcher, Barbara A; Del Rio, Laura; Bennouna, Soumaya

2004-03-09

Toxoplasma gondii rapidly elicits strong Type 1 cytokine-based immunity. The necessity for this response is well illustrated by the example of IFN-gamma and IL-12 gene knockout mice that rapidly succumb to the effects of acute infection. The parasite itself is skilled at sparking complex interactions in the innate immune system that lead to protective immunity. Neutrophils are one of the first cell types to arrive at the site of infection, and the cells release several proinflammatory cytokines and chemokines in response to Toxoplasma. Dendritic cells are an important source of IL-12 during infection with T. gondii and other microbial pathogens, and they are also specialized for high-level antigen presentation to T lymphocytes. Tachyzoites express at least two types of molecules that trigger innate immune cell cytokine production. One of these involves Toll-like receptor/MyD88 pathways common to many microbial pathogens. The second pathway is less conventional and involves molecular mimicry between a parasite cyclophilin and host CC chemokine receptor 5-binding ligands. Neutrophils, dendritic cells and Toxoplasma work together to elicit the immune response required for host survival. Cytokine and chemokine cross-talk between parasite-triggered neutrophils and dendritic cells results in recruitment, maturation and activation of the latter. Neutrophil-empowered dendritic cells possess properties expected of highly potent antigen presenting cells that drive T helper 1 generation.

Autocrine CCL19 blocks dendritic cell migration toward weak gradients of CCL21

DEFF Research Database (Denmark)

Hansen, Morten; Met, Özcan; Larsen, Niels Bent

2016-01-01

Background aims. Maturation of dendritic cells (DCs) induces their homing from peripheral to lymphatic tissues guided by CCL21. However, in vitro matured human monocyte-derived DC cancer vaccines injected intradermally migrate poorly to lymph nodes (LNs). In vitro maturation protocols generate DCs...

Toll-like receptor activation enhances cell-mediated immunity induced by an antibody vaccine targeting human dendritic cells

Directory of Open Access Journals (Sweden)

Berger Marc A

2007-01-01

Full Text Available Abstract Previously, we have successfully targeted the mannose receptor (MR expressed on monocyte-derived dendritic cells (DCs using a fully human MR-specific antibody, B11, as a vehicle to deliver whole protein tumor antigens such as the human chorionic gonadotropin hormone (hCGβ. Since MRs play a role in bridging innate immunity with adaptive immunity we have explored several toll-like receptor (TLR-specific ligands that may synergize with MR targeting and be applicable as adjuvants in the clinic. We demonstrate that antigen-specific helper and cytolytic T cells from both healthy donors and cancer patients were effectively primed with B11-hCGβ-treated autologous DCs when a combination of one or several TLR ligands is used. Specifically, concomitant signaling of DCs via TLR3 with dsRNA (poly I:C and DC TLR 7/8 with Resiquimod (R-848, respectively, elicited efficient antigen presentation-mediated by MR-targeting. We demonstrate that MR and TLRs contribute towards maturation and activation of DCs by a mechanism that may be driven by a combination of adjuvant and antibody vaccines that specifically deliver antigenic targets to DCs.

RNA-Based Vaccines in Cancer Immunotherapy

Directory of Open Access Journals (Sweden)

Megan A. McNamara

2015-01-01

Full Text Available RNA vaccines traditionally consist of messenger RNA synthesized by in vitro transcription using a bacteriophage RNA polymerase and template DNA that encodes the antigen(s of interest. Once administered and internalized by host cells, the mRNA transcripts are translated directly in the cytoplasm and then the resulting antigens are presented to antigen presenting cells to stimulate an immune response. Alternatively, dendritic cells can be loaded with either tumor associated antigen mRNA or total tumor RNA and delivered to the host to elicit a specific immune response. In this review, we will explain why RNA vaccines represent an attractive platform for cancer immunotherapy, discuss modifications to RNA structure that have been developed to optimize mRNA vaccine stability and translational efficiency, and describe strategies for nonviral delivery of mRNA vaccines, highlighting key preclinical and clinical data related to cancer immunotherapy.

Indoleamine 2,3-dioxygenase-expressing leukemic dendritic cells impair a leukemia-specific immune response by inducing potent T regulatory cells.

Science.gov (United States)

Curti, Antonio; Trabanelli, Sara; Onofri, Chiara; Aluigi, Michela; Salvestrini, Valentina; Ocadlikova, Darina; Evangelisti, Cecilia; Rutella, Sergio; De Cristofaro, Raimondo; Ottaviani, Emanuela; Baccarani, Michele; Lemoli, Roberto M

2010-12-01

The immunoregulatory enzyme indoleamine 2,3-dioxygenase, which catalyzes the conversion of tryptophan into kynurenine, is expressed in a significant subset of patients with acute myeloid leukemia, resulting in the inhibition of T-cell proliferation and the induction of regulatory T cells. Acute myeloid leukemia cells can be differentiated into dendritic cells, which have increased immunogenicity and have been proposed as vaccines against leukemia. Leukemic dendritic cells were generated from acute myeloid leukemia cells and used as stimulators in functional assays, including the induction of regulatory T cells. Indoleamine 2,3-dioxygenase expression in leukemic dendritic cells was evaluated at molecular, protein and enzymatic levels. We demonstrate that, after differentiation into dendritic cells, both indoleamine 2,3-dioxygenase-negative and indoleamine 2,3-dioxygenase-positive acute myeloid leukemia samples show induction and up-regulation of indoleamine 2,3-dioxygenase gene and protein, respectively. Indoleamine 2,3-dioxygenase-positive acute myeloid leukemia dendritic cells catabolize tryptophan into kynurenine metabolite and inhibit T-cell proliferation through an indoleamine 2,3-dioxygenase-dependent mechanism. Moreover, indoleamine 2,3-dioxygenase-positive leukemic dendritic cells increase the number of allogeneic and autologous CD4(+)CD25(+) Foxp3(+) T cells and this effect is completely abrogated by the indoleamine 2,3-dioxygenase-inhibitor, 1-methyl tryptophan. Purified CD4(+)CD25(+) T cells obtained from co-culture with indoleamine 2,3-dioxygenase-positive leukemic dendritic cells act as regulatory T cells as they inhibit naive T-cell proliferation and impair the complete maturation of normal dendritic cells. Importantly, leukemic dendritic cell-induced regulatory T cells are capable of in vitro suppression of a leukemia-specific T cell-mediated immune response, directed against the leukemia-associated antigen, Wilms' tumor protein. These data identify

Controlling T-Cell Activation with Synthetic Dendritic Cells Using the Multivalency Effect

NARCIS (Netherlands)

Hammink, R.; Mandal, S.; Eggermont, L.J.; Nooteboom, M.; Willems, P.H.G.M.; Tel, J.; Rowan, A.E.; Figdor, C.G.; Blank, K.G.

2017-01-01

Artificial antigen-presenting cells (aAPCs) have recently gained a lot of attention. They efficiently activate T cells and serve as powerful replacements for dendritic cells in cancer immunotherapy. Focusing on a specific class of polymer-based aAPCs, so-called synthetic dendritic cells (sDCs), we

Improved overall survival in dendritic cell vaccination-induced immunoreactive subgroup of advanced melanoma patients

Directory of Open Access Journals (Sweden)

Ballardini Michela

2006-08-01

Full Text Available Abstract Background We present our experience of therapeutic vaccination using dendritic cells (DC pulsed with autologous tumor antigens in patients with advanced melanoma. Methods Twenty-one pretreated advanced melanoma patients were vaccinated with autologous DC pulsed with 100 μg/ml of autologous-tumor-lysate (ATL or – homogenate (ATH and 50 μg/ml of keyhole limpet hemocyanin (KLH. The first 8 patients were treated subcutaneously or intradermally with immature-DC (iDC (range 4.5 – 82 × 106 and the remaining 13 intradermally with in vitro matured DC (mDC (range 1.2–26 × 106. Subcutaneous interleukin-2 (3 × 106 IU was administered from days 3 to 7 of each treatment cycle. Results Three of the 8 iDC patients obtained stabilizations (SD, each of 6 months' duration. The 13 mDC patients showed 1 complete response (8 months, 1 partial response (3 months, 2 mixed responses (6 and 12 months and 3 SD (9, 7+, and 3+ months. Overall responses (OR were observed in 4/21 (19% patients, or 4/13 (30.7% considering mDC treatment only. 10/21 (47.6% patients showed non progressive disease (NPD, with 7/13 (53.8% cases of NPD for mDC-treated patients. No major toxicities were observed. The positive delayed-type hypersensitivity (DTH test to ATL/ATH and/or KLH correlated with increased overall survival (OS. Median OS was 24 months (range 3 – 45 for the 10 DTH-positive (1 iDC and 9 mDC and 5 months (range 3–14 for the 11 DTH-negative patients (P in vitro evaluation of gamma IFN-secreting T-cells in 10 patients showed good correlation with both DTH (75% and clinical outcome (70%. Conclusion Vaccination using DC pulsed with ATL/ATH and KLH in advanced melanoma patients is well tolerated and can induce a clinical response, especially when mDC are used. Successful immunization, verified by positive DTH, leads to longer survival.

Improved overall survival in dendritic cell vaccination-induced immunoreactive subgroup of advanced melanoma patients.

Science.gov (United States)

Ridolfi, Ruggero; Petrini, Massimiliano; Fiammenghi, Laura; Stefanelli, Monica; Ridolfi, Laura; Ballardini, Michela; Migliori, Giuseppe; Riccobon, Angela

2006-08-16

We present our experience of therapeutic vaccination using dendritic cells (DC) pulsed with autologous tumor antigens in patients with advanced melanoma. Twenty-one pretreated advanced melanoma patients were vaccinated with autologous DC pulsed with 100 microg/ml of autologous-tumor-lysate (ATL) or -homogenate (ATH) and 50 microg/ml of keyhole limpet hemocyanin (KLH). The first 8 patients were treated subcutaneously or intradermally with immature-DC (iDC) (range 4.5-82 x 10(6)) and the remaining 13 intradermally with in vitro matured DC (mDC) (range 1.2-26 x 10(6)). Subcutaneous interleukin-2 (3 x 10(6) IU) was administered from days 3 to 7 of each treatment cycle. Three of the 8 iDC patients obtained stabilizations (SD), each of 6 months' duration. The 13 mDC patients showed 1 complete response (8 months), 1 partial response (3 months), 2 mixed responses (6 and 12 months) and 3 SD (9, 7+, and 3+ months). Overall responses (OR) were observed in 4/21 (19%) patients, or 4/13 (30.7%) considering mDC treatment only. 10/21 (47.6%) patients showed non progressive disease (NPD), with 7/13 (53.8%) cases of NPD for mDC-treated patients. No major toxicities were observed. The positive delayed-type hypersensitivity (DTH) test to ATL/ATH and/or KLH correlated with increased overall survival (OS). Median OS was 24 months (range 3-45) for the 10 DTH-positive (1 iDC and 9 mDC) and 5 months (range 3-14) for the 11 DTH-negative patients (P < 0.001). The in vitro evaluation of gamma IFN-secreting T-cells in 10 patients showed good correlation with both DTH (75%) and clinical outcome (70%). Vaccination using DC pulsed with ATL/ATH and KLH in advanced melanoma patients is well tolerated and can induce a clinical response, especially when mDC are used. Successful immunization, verified by positive DTH, leads to longer survival.

Vaccine adjuvant MF59 promotes the intranodal differentiation of antigen-loaded and activated monocyte-derived dendritic cells.

Directory of Open Access Journals (Sweden)

Rossella Cioncada

Full Text Available MF59 is an oil-in-water emulsion adjuvant approved for human influenza vaccination in European Union. The mode of action of MF59 is not fully elucidated yet, but results from several years of investigation indicate that MF59 establishes an immunocompetent environment at injection site which promotes recruitment of immune cells, including antigen presenting cells (APCs, that are facilitated to engulf antigen and transport it to draining lymph node (dLN where the antigen is accumulated. In vitro studies showed that MF59 promotes the differentiation of monocytes to dendritic cells (Mo-DCs. Since after immunization with MF59, monocytes are rapidly recruited both at the injection site and in dLN and appear to have a morphological change toward a DC-like phenotype, we asked whether MF59 could play a role in inducing differentiation of Mo-DC in vivo. To address this question we immunized mice with the auto-fluorescent protein Phycoerythrin (PE as model antigen, in presence or absence of MF59. We measured the APC phenotype and their antigen uptake within dLNs, the antigen distribution within the dLN compartments and the humoral response to PE. In addition, using Ovalbumin as model antigen, we measured the capacity of dLN APCs to induce antigen-specific CD4 T cell proliferation. Here, we show, for the first time, that MF59 promotes differentiation of Mo-DCs within dLNs from intranodal recruited monocytes and we suggest that this differentiation could take place in the medullary compartment of the LN. In addition we show that the Mo-DC subset represents the major source of antigen-loaded and activated APCs within the dLN when immunizing with MF59. Interestingly, this finding correlates with the enhanced triggering of antigen-specific CD4 T cell response induced by LN APCs. This study therefore demonstrates that MF59 is able to promote an immunocompetent environment also directly within the dLN, offering a novel insight on the mechanism of action of

Targeted delivery of TLR ligands to human and mouse dendritic cells strongly enhances adjuvanticity.

Science.gov (United States)

Tacken, Paul J; Zeelenberg, Ingrid S; Cruz, Luis J; van Hout-Kuijer, Maaike A; van de Glind, Gerline; Fokkink, Remco G; Lambeck, Annechien J A; Figdor, Carl G

2011-12-22

Effective vaccines consist of 2 components: immunodominant antigens and effective adjuvants. Whereas it has been demonstrated that targeted delivery of antigens to dendritic cells (DCs) improves vaccine efficacy, we report here that co-targeting of TLR ligands (TLRLs) to DCs strongly enhances adjuvanticity and immunity. We encapsulated ligands for intracellular TLRs within biodegradable nanoparticles coated with Abs recognizing DC-specific receptors. Targeted delivery of TLRLs to human DCs enhanced the maturation and production of immune stimulatory cytokines and the Ag-specific activation of naive CD8(+) T cells. In vivo studies demonstrated that nanoparticles carrying Ag induced cytotoxic T-lymphocyte responses at 100-fold lower adjuvant dose when TLRLs were co-encapsulated instead of administered in soluble form. Moreover, the efficacy of these targeted TLRLs reduced the serum cytokine storm and related toxicity that is associated with administration of soluble TLRLs. We conclude that the targeted delivery of adjuvants may improve the efficacy and safety of DC-based vaccines.

Immune Response Generated With the Administration of Autologous Dendritic Cells Pulsed With an Allogenic Tumoral Cell-Lines Lysate in Patients With Newly Diagnosed Diffuse Intrinsic Pontine Glioma

Directory of Open Access Journals (Sweden)

Daniel Benitez-Ribas

2018-04-01

Full Text Available Background and objectiveDiffuse intrinsic pontine glioma (DIPG is a lethal brainstem tumor in children. Dendritic cells (DCs have T-cell stimulatory capacity and, therefore, potential antitumor activity for disease control. DCs vaccines have been shown to reactivate tumor-specific T cells in both clinical and preclinical settings. We designed a phase Ib immunotherapy (IT clinical trial with the use of autologous dendritic cells (ADCs pulsed with an allogeneic tumors cell-lines lysate in patients with newly diagnosed DIPG after irradiation (radiation therapy.MethodsNine patients with newly diagnosed DIPG met enrollment criteria. Autologous dendritic cell vaccines (ADCV were prepared from monocytes obtained by leukapheresis. Five ADCV doses were administered intradermally during induction phase. In the absence of tumor progression, patients received three boosts of tumor lysate every 3 months during the maintenance phase.ResultsVaccine fabrication was feasible in all patients included in the study. Non-specific KLH (9/9 patients and specific (8/9 patients antitumor response was identified by immunologic studies in peripheral blood mononuclear cells (PBMC. Immunological responses were also confirmed in the T lymphocytes isolated from the cerebrospinal fluid (CSF of two patients. Vaccine administration resulted safe in all patients treated with this schema.ConclusionThese preliminary results demonstrate that ADCV preparation is feasible, safe, and generate a DIPG-specific immune response detected in PBMC and CSF. This strategy shows a promising backbone for future schemas of combination IT.

Tumour cell lysate-loaded dendritic cell vaccine induces biochemical and memory immune response in castration-resistant prostate cancer patients.

Science.gov (United States)

Reyes, D; Salazar, L; Espinoza, E; Pereda, C; Castellón, E; Valdevenito, R; Huidobro, C; Inés Becker, M; Lladser, A; López, M N; Salazar-Onfray, F

2013-09-17

Recently, we produced a tumour antigen-presenting cells (TAPCells) vaccine using a melanoma cell lysate, called TRIMEL, as an antigen source and an activation factor. Tumour antigen-presenting cells induced immunological responses and increased melanoma patient survival. Herein, we investigated the effect of TAPCells loaded with prostate cancer cell lysates (PCCL) as an antigen source, and TRIMEL as a dendritic cell (DC) activation factor; which were co-injected with the Concholepas concholepas haemocyanin (CCH) as an adjuvant on castration-resistant prostate cancer (CRPC) patients. The lysate mix capacity, for inducing T-cell activation, was analysed by flow cytometry and Elispot. Delayed-type hypersensitivity (DTH) reaction against PCCL, frequency of CD8(+) memory T cells (Tm) in blood and prostate-specific antigen (PSA) levels in serum were measured in treated patients. The lysate mix induced functional mature DCs that were capable of activating PCCL-specific T cells. No relevant adverse reactions were observed. Six out of 14 patients showed a significant decrease in levels of PSA. DTH(+) patients showed a prolonged PSA doubling-time after treatment. Expansion of functional central and effector CD8(+) Tm were detected. Treatment of CRPC patients with lysate-loaded TAPCells and CCH as an adjuvant is safe: generating biochemical and memory immune responses. However, the limited number of cases requires confirmation in a phase II clinical trial.

Solid lipid nanoparticles mediate non-viral delivery of plasmid DNA to dendritic cells

Science.gov (United States)

Penumarthi, Alekhya; Parashar, Deepti; Abraham, Amanda N.; Dekiwadia, Chaitali; Macreadie, Ian; Shukla, Ravi; Smooker, Peter M.

2017-06-01

There is an increasing demand for novel DNA vaccine delivery systems, mainly for the non-viral type as they are considered relatively safe. Therefore, solid lipid nanoparticles (SLNs) were investigated for their suitability as a non-viral DNA vaccine delivery system. SLNs were synthesised by a modified solvent-emulsification method in order to study their potential to conjugate with plasmid DNA and deliver them in vitro to dendritic cells using eGFP as the reporter plasmid. The DNA-SLN complexes were characterised by electron microscopy, gel retardation assays and dynamic light scattering. The cytotoxicity assay data supported their biocompatibility and was used to estimate safe threshold concentration resulting in high transfection rate. The transfection efficiency of these complexes in a dendritic cell line was shown to increase significantly compared to plasmid alone, and was comparable to that mediated by lipofectamine. Transmission electron microscopy studies delineated the pathway of cellular uptake. Endosomal escape was observed supporting the mechanism of transfection.

Mannan-MUC1-pulsed dendritic cell immunotherapy: a phase I trial in patients with adenocarcinoma.

Science.gov (United States)

Loveland, Bruce E; Zhao, Anne; White, Shane; Gan, Hui; Hamilton, Kate; Xing, Pei-Xiang; Pietersz, Geoffrey A; Apostolopoulos, Vasso; Vaughan, Hilary; Karanikas, Vaios; Kyriakou, Peter; McKenzie, Ian F C; Mitchell, Paul L R

2006-02-01

Tumor antigen-loaded dendritic cells show promise for cancer immunotherapy. This phase I study evaluated immunization with autologous dendritic cells pulsed with mannan-MUC1 fusion protein (MFP) to treat patients with advanced malignancy. Eligible patients had adenocarcinoma expressing MUC1, were of performance status 0 to 1, with no autoimmune disease. Patients underwent leukapheresis to generate dendritic cells by culture ex vivo with granulocyte macrophage colony-stimulating factor and interleukin 4 for 5 days. Dendritic cells were then pulsed overnight with MFP and harvested for reinjection. Patients underwent three cycles of leukapheresis and reinjection at monthly intervals. Patients with clinical benefit were able to continue with dendritic cell-MFP immunotherapy. Ten patients with a range of tumor types were enrolled, with median age of 60 years (range, 33-70 years); eight patients were of performance status 0 and two of performance status 1. Dendritic cell-MFP therapy led to strong T-cell IFNgamma Elispot responses to the vaccine and delayed-type hypersensitivity responses at injection sites in nine patients who completed treatments. Immune responses were sustained at 1 year in monitored patients. Antibody responses were seen in three patients only and were of low titer. Side effects were grade 1 only. Two patients with clearly progressive disease (ovarian and renal carcinoma) at entry were stable after initial therapy and went on to further leukapheresis and dendritic cell-MFP immunotherapy. These two patients have now each completed over 3 years of treatment. Immunization produced T-cell responses in all patients with evidence of tumor stabilization in 2 of the 10 advanced cancer patients treated. These data support further clinical evaluation of this dendritic cell-MFP immunotherapy.

Dendritic cell targeted liposomes–protamine–DNA complexes mediated by synthetic mannosylated cholestrol as a potential carrier for DNA vaccine

International Nuclear Information System (INIS)

Li Pan; Chen Simu; Jiang Yuhong; Jiang Jiayu; Zhang Zhirong; Sun Xun

2013-01-01

To construct mannosylated liposomes/protamine/DNA (LPD) carriers for DNA vaccine targeting to dendritic cells (DCs), a mannosylated cholesterol derivative (Man-C6-Chol) was synthesized via simple ester linkage and amide bonds. Then, the Man-C6-Chol was applied to LPD formulation as a synthetic ligand. The physicochemical properties of mannosylated LPD (Man-LPD) were first evaluated, including the size and zeta potential, morphology and the ability to protect DNA against DNase I degradation. Man-LPD showed a small size with a stable viral-like structure. In comparison to non-mannose liposomes/LPD (Man-free liposomes/LPD), mannosylated liposomes/LPD (Man-liposomes/Man-LPD) exhibited higher efficiency in both intracellular uptake (2.3-fold) and transfection (4.5-fold) in vitro. Subsequent MTT assays indicated that the LPD carriers had low toxicity on the tested cells. Afterwards, the investigation into the maturation activation on primary bone marrow-derived DCs (BMDCs) showed that both Man-LPD and Man-free LPD induced remarkable up-regulation of CD80, CD86 and CD40 on BMDCs. Inspired by these studies, we can conclude that the synthetic mannosylated LPD targeting to DCs was a potential carrier for DNA vaccine. (paper)

Vaccination of B-CLL patients with autologous dendritic cells can change the frequency of leukemia antigen-specific CD8+ T cells as well as CD4+CD25+FoxP3+ regulatory T cells toward an antileukemia response.

Science.gov (United States)

Hus, I; Schmitt, M; Tabarkiewicz, J; Radej, S; Wojas, K; Bojarska-Junak, A; Schmitt, A; Giannopoulos, K; Dmoszyńska, A; Roliński, J

2008-05-01

Recently, we described that vaccination with allogeneic dendritic cells (DCs) pulsed with tumor cell lysate generated specific CD8+ T cell response in patients with B-cell chronic lymphocytic leukemia (B-CLL). In the present study, the potential of autologous DCs pulsed ex vivo with tumor cell lysates to stimulate antitumor immunity in patients with B-CLL in early stages was evaluated. Twelve patients at clinical stage 0-2 as per Rai were vaccinated intradermally up to eight times with a mean number of 7.4 x 10(6) DCs pulsed with B-CLL cell lysate. We observed a decrease of peripheral blood leukocytes and CD19+/CD5+ leukemic cells in five patients, three patients showed a stable disease and four patients progressed despite DC vaccination. A significant increase of specific cytotoxic CD8+ T lymphocytes against the leukemia-associated antigens RHAMM or fibromodulin was detected in four patients after DC vaccination. In patients with a clinical response, an increase of interleukin 12 (IL-12) serum levels and a decrease of the frequency of CD4+CD25(+)FOXP3+ T regulatory cells were observed. Taken together, the study demonstrated that vaccination with autologous DC in CLL patients is feasible and safe. Immunological and to some extend hematological responses could be noted, justifying further investigation on this immunotherapeutical approach.

Dendritic cell-based immunotherapy induces transient clinical response in advanced rat fibrosarcoma - comparison with preventive anti-tumour vaccination

Czech Academy of Sciences Publication Activity Database

Kučera, A.; Pýcha, K.; Pajer, Petr; Špíšek, R.; Škába, R.

2009-01-01

Roč. 55, č. 4 (2009), s. 119-125 ISSN 0015-5500 Institutional research plan: CEZ:AV0Z50520514 Keywords : dendritic cells * immunotherapy * cancer immunotherapy * chemotherapy Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.924, year: 2009

Plasmacytoid dendritic cells: Development, functions, and role in atherosclerotic inflammation

Directory of Open Access Journals (Sweden)

Dimitry A Chistiakov

2014-07-01

Full Text Available Plasmacytoid dendritic cells (pDCs are a specialized subset of DCs that links innate and adaptive immunity. They sense viral and bacterial pathogens and release high levels of Type I interferons (IFN-I in response to infection. pDCs were shown to contribute to inflammatory responses in the steady state and in pathology. In atherosclerosis, pDCs are involved in priming vascular inflammation and atherogenesis through production of IFN-I and chemokines that attract inflammatory cells to inflamed sites. pDCs also contribute to the proinflammatory activation of effector T cells, cytotoxic T cells, and conventional DCs. However, tolerogenic populations of pDCs are found that suppress atherosclerosis-associated inflammation through down-regulation of function and proliferation of proinflammatory T cell subsets and induction of regulatory T cells with potent immunomodulatory properties. Notably, atheroprotective tolerogenic DCs could be induced by certain self-antigens or bacterial antigens that suggests for great therapeutic potential of these DCs for development of DC-based anti-atherogenic vaccines.

Particle size and surface charge affect particle uptake by human dendritic cells in an in vitro model

DEFF Research Database (Denmark)

Foged, Camilla; Brodin, Birger; Frøkjær, Sven

2005-01-01

Current vaccine development includes optimization of antigen delivery to antigen presenting cells, such as dendritic cells (DC). Particulate systems have attracted increasing attention in the development of vaccine delivery systems. In the present study, we investigated DC uptake of model...... fluorescent polystyrene particles with a broad size range and variable surface properties. Localization of particles was investigated using confocal laser scanning microscopy and uptake was quantified by flow cytometry. Immature DC were generated from mononuclear cells isolated from human blood...

Increase of Circulating CD4(+)CD25(high)Foxp3(+) Regulatory T Cells in Patients With Metastatic Renal Cell Carcinoma During Treatment With Dendritic Cell Vaccination and Low-Dose Interleukin-2

DEFF Research Database (Denmark)

Berntsen, Annika; Brimnes, M.K.; Straten, P.T.

2010-01-01

Regulatory T cells (Treg) play an important role in the maintenance of immune tolerance and may be one of the obstacles of successful tumor immunotherapy. In this study, we analyzed the impact of administration of dendritic cell (DC) vaccination in combination with low-dose interleukin (IL)-2...... in patients with metastatic renal cell carcinoma on the frequency of CD4(+) CD25(high)Foxp3(+) Treg cells in peripheral blood. We found that the treatment increased the frequency of Treg cells more than 7-fold compared with pretreatment levels (P cells decreased when patients...... had been off IL-2 treatment for only 8 days, but remained higher than pretreatment levels. A functional assay showed that isolated Treg cells were capable of inhibiting proliferation of responder cells. Also, in vitro studies showed that coculture of mature DCs, autologous T cells and IL-2 leads...

Langerin+ dermal dendritic cells are critical for CD8+ T cell activation and IgH γ-1 class switching in response to gene gun vaccines.

Science.gov (United States)

Stoecklinger, Angelika; Eticha, Tekalign D; Mesdaghi, Mehrnaz; Kissenpfennig, Adrien; Malissen, Bernard; Thalhamer, Josef; Hammerl, Peter

2011-02-01

The C-type lectin langerin/CD207 was originally discovered as a specific marker for epidermal Langerhans cells (LC). Recently, additional and distinct subsets of langerin(+) dendritic cells (DC) have been identified in lymph nodes and peripheral tissues of mice. Although the role of LC for immune activation or modulation is now being discussed controversially, other langerin(+) DC appear crucial for protective immunity in a growing set of infection and vaccination models. In knock-in mice that express the human diphtheria toxin receptor under control of the langerin promoter, injection of diphtheria toxin ablates LC for several weeks whereas other langerin(+) DC subsets are replenished within just a few days. Thus, by careful timing of diphtheria toxin injections selective states of deficiency in either LC only or all langerin(+) cells can be established. Taking advantage of this system, we found that, unlike selective LC deficiency, ablation of all langerin(+) DC abrogated the activation of IFN-γ-producing and cytolytic CD8(+) T cells after gene gun vaccination. Moreover, we identified migratory langerin(+) dermal DC as the subset that directly activated CD8(+) T cells in lymph nodes. Langerin(+) DC were also critical for IgG1 but not IgG2a Ab induction, suggesting differential polarization of CD4(+) T helper cells by langerin(+) or langerin-negative DC, respectively. In contrast, protein vaccines administered with various adjuvants induced IgG1 independently of langerin(+) DC. Taken together, these findings reflect a highly specialized division of labor between different DC subsets both with respect to Ag encounter as well as downstream processes of immune activation.

Divergent Effects of Dendritic Cells on Pancreatitis

Science.gov (United States)

2015-09-01

role of dendritic cells in pancreatitis. Dendritic cells are professional antigen presenting cells which initiate innate and adaptive immune... Lymphoid -tissue-specific homing of bone- marrow-derived dendritic cells . Blood. 113:6638–6647. http://dx.doi .org/10.1182/blood-2009-02-204321 Dapito...Award Number: W81XWH-12-1-0313 TITLE: Divergent Effects of Dendritic Cells on Pancreatitis PRINCIPAL INVESTIGATOR: Dr. George Miller

Yellow fever vaccine YF-17D activates multiple dendritic cell subsets via TLR2, 7, 8, and 9 to stimulate polyvalent immunity.

Science.gov (United States)

Querec, Troy; Bennouna, Soumaya; Alkan, Sefik; Laouar, Yasmina; Gorden, Keith; Flavell, Richard; Akira, Shizuo; Ahmed, Rafi; Pulendran, Bali

2006-02-20

The live attenuated yellow fever vaccine 17D (YF-17D) is one of the most effective vaccines available, with a 65-yr history of use in >400 million people globally. Despite this efficacy, there is presently no information about the immunological mechanisms by which YF-17D acts. Here, we present data that suggest that YF-17D activates multiple Toll-like receptors (TLRs) on dendritic cells (DCs) to elicit a broad spectrum of innate and adaptive immune responses. Specifically, YF-17D activates multiple DC subsets via TLRs 2, 7, 8, and 9 to elicit the proinflammatory cytokines interleukin (IL)-12p40, IL-6, and interferon-alpha. Interestingly, the resulting adaptive immune responses are characterized by a mixed T helper cell (Th)1/Th2 cytokine profile and antigen-specific CD8+ T cells. Furthermore, distinct TLRs appear to differentially control the Th1/Th2 balance; thus, whilst MyD88-deficient mice show a profound impairment of Th1 cytokines, TLR2-deficient mice show greatly enhanced Th1 and Tc1 responses to YF-17D. Together, these data enhance our understanding of the molecular mechanism of action of YF-17D, and highlight the potential of vaccination strategies that use combinations of different TLR ligands to stimulate polyvalent immune responses.

Commensal oral bacteria antigens prime human dendritic cells to induce Th1, Th2 or Treg differentiation.

Science.gov (United States)

Kopitar, A N; Ihan Hren, N; Ihan, A

2006-02-01

In various immunopathologic conditions, bacterial flora induce an immune response which results in inflammatory manifestations, e.g. periapical granuloma. Dendritic cells provide the main orchestration of specific immune responses. The aim of our study was to test the capacity of distinct oral bacterial antigens (prepared from Streptococcus mitis, Propionibacterium acnes, and Bacteroides spp.) to prime human dendritic cells for stimulation of the T-lymphocyte response. To assess the T-lymphocyte response, the expression of CD25, CD69, intracellular interferon gamma (cIFN-gamma), and intracellular interleukin 4 (cIL-4) was determined. Dendritic cells were prepared from leukocyte buffy coat from healthy blood donors. Monocytes were stimulated with IL-4 and GM-CSF and dendritic cells activated with bacterial lysates. Cell suspensions contained up to 90% dendritic cells, which represented 2-12% of the initial number of mononuclear cells. Lymphocyte subsets that developed in lymphocyte cultures after 1 week of stimulation were analyzed by flow cytometry. Dendritic cells, primed with antigens of Bacteroides fragilis have shown significantly higher activation and expression of intercellular IFN-gamma by T lymphocytes compared to negative controls. The dendritic cells primed with antigens of P. acnes had no effect on T-lymphocyte activation or cytokine production; instead they induced differentiation of T lymphocytes into CD25bright cells (regulatory T cells) with a potentially inhibitory effect on immune response. Dendritic cells primed with antigens of S. mitis induced increased expression of cIL-4. We conclude that commensal oral bacteria antigens prepared from B. fragilis, S. mitis, and P. acnes prime human dendritic cells to induce Th1, Th2, and T(reg) differentiation, respectively. This may advance our understanding of immunopathologic manifestations in the oral cavity and offer new possibilities for redirecting immune responses in mucosal vaccination.

Indoleamine 2,3-dioxygenase-expressing leukemic dendritic cells impair a leukemia-specific immune response by inducing potent T regulatory cells

OpenAIRE

Curti, A; Trabanelli, S; Onofri, C; Aluigi, M; Salvestrini, V; Ocadlikova, D; Evangelisti, C; Rutella, S; De Cristofaro, R; Ottaviani, E; Baccarani, M; Lemoli, RM

2010-01-01

Background: The immunoregulatory enzyme indoleamine 2,3-dioxygenase, which catalyzes the conversion of tryptophan into kynurenine, is expressed in a significant subset of patients with acute myeloid leukemia, resulting in the inhibition of T-cell proliferation and the induction of regulatory T cells. Acute myeloid leukemia cells can be differentiated into dendritic cells, which have increased immunogenicity and have been proposed as vaccines against leukemia.\\ud Design and Methods: Leukemic d...

IL-27p28 Production by XCR1+ Dendritic Cells and Monocytes Effectively Predicts Adjuvant-Elicited CD8+ T Cell Responses.

Science.gov (United States)

Kilgore, Augustus M; Welsh, Seth; Cheney, Elizabeth E; Chitrakar, Alisha; Blain, Trevor J; Kedl, Benjamin J; Hunter, Chris A; Pennock, Nathan D; Kedl, Ross M

2018-01-01

It is well accepted that the innate response is a necessary prerequisite to the formation of the adaptive response. This is true for T cell responses against infections or adjuvanted subunit vaccination. However, specific innate parameters with predictive value for the magnitude of an adjuvant-elicited T cell response have yet to be identified. We previously reported how T cell responses induced by subunit vaccination were dependent on the cytokine IL-27. These findings were unexpected, given that T cell responses to an infection typically increase in the absence of IL-27. Using a novel IL-27p28-eGFP reporter mouse, we now show that the degree to which an adjuvant induces IL-27p28 production from dendritic cells and monocytes directly predicts the magnitude of the T cell response elicited. To our knowledge, these data are the first to identify a concrete innate correlate of vaccine-elicited cellular immunity, and they have significant practical and mechanistic implications for subunit vaccine biology.

Signaling network of dendritic cells in response to pathogens: a community-input supported knowledgebase.

Science.gov (United States)

Patil, Sonali; Pincas, Hanna; Seto, Jeremy; Nudelman, German; Nudelman, Irina; Sealfon, Stuart C

2010-10-07

Dendritic cells are antigen-presenting cells that play an essential role in linking the innate and adaptive immune systems. Much research has focused on the signaling pathways triggered upon infection of dendritic cells by various pathogens. The high level of activity in the field makes it desirable to have a pathway-based resource to access the information in the literature. Current pathway diagrams lack either comprehensiveness, or an open-access editorial interface. Hence, there is a need for a dependable, expertly curated knowledgebase that integrates this information into a map of signaling networks. We have built a detailed diagram of the dendritic cell signaling network, with the goal of providing researchers with a valuable resource and a facile method for community input. Network construction has relied on comprehensive review of the literature and regular updates. The diagram includes detailed depictions of pathways activated downstream of different pathogen recognition receptors such as Toll-like receptors, retinoic acid-inducible gene-I-like receptors, C-type lectin receptors and nucleotide-binding oligomerization domain-like receptors. Initially assembled using CellDesigner software, it provides an annotated graphical representation of interactions stored in Systems Biology Mark-up Language. The network, which comprises 249 nodes and 213 edges, has been web-published through the Biological Pathway Publisher software suite. Nodes are annotated with PubMed references and gene-related information, and linked to a public wiki, providing a discussion forum for updates and corrections. To gain more insight into regulatory patterns of dendritic cell signaling, we analyzed the network using graph-theory methods: bifan, feedforward and multi-input convergence motifs were enriched. This emphasis on activating control mechanisms is consonant with a network that subserves persistent and coordinated responses to pathogen detection. This map represents a navigable

Dendritic cell based PSMA immunotherapy for prostate cancer using a CD40-targeted adenovirus vector.

Directory of Open Access Journals (Sweden)

Briana Jill Williams

Full Text Available Human prostate tumor vaccine and gene therapy trials using ex vivo methods to prime dendritic cells (DCs with prostate specific membrane antigen (PSMA have been somewhat successful, but to date the lengthy ex vivo manipulation of DCs has limited the widespread clinical utility of this approach. Our goal was to improve upon cancer vaccination with tumor antigens by delivering PSMA via a CD40-targeted adenovirus vector directly to DCs as an efficient means for activation and antigen presentation to T-cells. To test this approach, we developed a mouse model of prostate cancer by generating clonal derivatives of the mouse RM-1 prostate cancer cell line expressing human PSMA (RM-1-PSMA cells. To maximize antigen presentation in target cells, both MHC class I and TAP protein expression was induced in RM-1 cells by transduction with an Ad vector expressing interferon-gamma (Ad5-IFNγ. Administering DCs infected ex vivo with CD40-targeted Ad5-huPSMA, as well as direct intraperitoneal injection of the vector, resulted in high levels of tumor-specific CTL responses against RM-1-PSMA cells pretreated with Ad5-IFNγ as target cells. CD40 targeting significantly improved the therapeutic antitumor efficacy of Ad5-huPSMA encoding PSMA when combined with Ad5-IFNγ in the RM-1-PSMA model. These results suggest that a CD-targeted adenovirus delivering PSMA may be effective clinically for prostate cancer immunotherapy.

Vaccination of carp against SVCV with an oral DNA vaccine or an insect cells-based subunit vaccine.

Science.gov (United States)

Embregts, C W E; Rigaudeau, D; Tacchi, L; Pijlman, G P; Kampers, L; Veselý, T; Pokorová, D; Boudinot, P; Wiegertjes, G F; Forlenza, M

2018-03-19

We recently reported on a successful vaccine for carp against SVCV based on the intramuscular injection of a DNA plasmid encoding the SVCV glycoprotein (SVCV-G). This shows that the intramuscular (i.m.) route of vaccination is suitable to trigger protective responses against SVCV, and that the SVCV G-protein is a suitable vaccine antigen. Yet, despite the general success of DNA vaccines, especially against fish rhabdoviruses, their practical implementation still faces legislative as well as consumer's acceptance concerns. Furthermore, the i.m. route of plasmid administration is not easily combined with most of the current vaccination regimes largely based on intraperitoneal or immersion vaccination. For this reason, in the current study we evaluated possible alternatives to a DNA-based i.m. injectable vaccine using the SVCV-G protein as the vaccine antigen. To this end, we tested two parallel approaches: the first based on the optimization of an alginate encapsulation method for oral delivery of DNA and protein antigens; the second based on the baculovirus recombinant expression of transmembrane SVCV-G protein in insect cells, administered as whole-cell subunit vaccine through the oral and injection route. In addition, in the case of the oral DNA vaccine, we also investigated the potential benefits of the mucosal adjuvants Escherichia coli lymphotoxin subunit B (LTB). Despite the use of various vaccine types, doses, regimes, and administration routes, no protection was observed, contrary to the full protection obtained with our reference i.m. DNA vaccine. The limited protection observed under the various conditions used in this study, the nature of the host, of the pathogen, the type of vaccine and encapsulation method, will therefore be discussed in details to provide an outlook for future vaccination strategies against SVCV. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Evaluation of Immune Responses Mediated by Listeria-Stimulated Human Dendritic Cells: Implications for Cancer Vaccine Therapy

Science.gov (United States)

2013-07-01

transfected with RNA. NatBiotech. 1998;16:364-369. 20. Heiser A, Dahm P, Yancey DR, et al. Human dendritic cells transfected with RNA encoding prostate...specific antigen stimulate prostate-specific CTL responses in vitro. J Immunol. 2000;164(10):5508-5514. 21. Heiser A, Maurice MA, Yancey DR...primary and metastatic tumors. Cancer Res. 2001;61(8):3388-3393. 22. Heiser A, Coleman D, Dannull J, et al. Autologous dendritic cells transfected

Dendritic cells recognize tumor-specific glycosylation of carcinoembryonic antigen on colorectal cancer cells through dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin

NARCIS (Netherlands)

van Gisbergen, Klaas P. J. M.; Aarnoudse, Corlien A.; Meijer, Gerrit A.; Geijtenbeek, Teunis B. H.; van Kooyk, Yvette

2005-01-01

Dendritic cells play a pivotal role in the induction of antitumor immune responses. Immature dendritic cells are located intratumorally within colorectal cancer and intimately interact with tumor cells, whereas mature dendritic cells are present peripheral to the tumor. The majority of colorectal

Optimization of dendritic cell loading with tumor cell lysates for cancer immunotherapy.

Science.gov (United States)

Hatfield, Paul; Merrick, Alison E; West, Emma; O'Donnell, Dearbhaile; Selby, Peter; Vile, Richard; Melcher, Alan A

2008-09-01

The immune response to cancer is critically determined by the way in which tumor cells die. As necrotic, stress-associated death can be associated with activation of antitumor immunity, whole tumor cell antigen loading strategies for dendritic cell (DC)-based vaccination have commonly used freeze-thaw "necrotic" lysates as an immunogenic source of tumor-associated antigens. In this study, the effect of such lysates on the ability of DCs to mature in response to well-established maturation stimuli was examined, and methods to enhance lysate-induced DC activation explored. Freeze-thaw lysates were prepared from murine tumor cell lines and their effects on bone marrow-derived DC maturation and function examined. Unmodified freeze-thaw tumor cell lysates inhibited the toll-like receptor-induced maturation and function of bone marrow-derived DCs, preventing up-regulation of CD40, CD86, and major histocompatibility complex class II, and reducing secretion of inflammatory cytokines [interleukin (IL)-12 p70, tumor necrosis factor-alpha, and IL-6]. Although IL-10 secretion was increased by lysate-pulsed DCs, this was not responsible for the observed suppression of IL-12. Although activation of the nuclear factor-kappaB pathway remained intact, the kinase activity of phosphorylated p38 mitogen-activated protein kinase was inhibited in lysate-pulsed DCs. Lysate-induced DC suppression was partially reversed in vitro by induction of tumor cell stress before lysis, and only DCs loaded with stressed lysates afforded protection against tumor challenge in vivo. These data suggest that ex vivo freeze-thaw of tumor cells does not effectively mimic in vivo immunogenic necrosis, and advocates careful characterization and optimization of tumor cell-derived vaccine sources for cancer immunotherapy.

Effects of Portulaca oleracea L. Polysaccharides on Phenotypic and Functional Maturation of Murine Bone Marrow Derived Dendritic Cells.

Science.gov (United States)

Zhao, Rui; Zhang, Tao; Zhao, Hui; Cai, Yaping

2015-01-01

Portulaca oleracea L. is an annual plant widely distributed from the temperate to the tropical zones. POL-P3b, a polysaccharide fraction purified from Portulaca oleracea L., is able to enhance immunity and inhibit tumor formation. Induction of antitumor immunity by dendritic-tumor fusion cells can be modulated by their activation status. Mature dendritic cells are significantly better than immature dendritic cells at cytotoxic T-lymphocyte induction. In this study, we analyzed the effects of POL-P3b on the maturation and function of murine bone-marrow-derived dendritic cells (DCs) and relevant mechanisms. The phenotypic maturation of DCs was confirmed by flow cytometry. We found that POL-P3b upregulated the expression of CD80, CD86, CD83, and major histocompatibility complex class II molecules on DCs, stimulated production of more interleukin (IL)-12, tumor necrosis factor-α, and less IL-10. Also, DCs pulsed POL-P3b and freeze-thaw antigen increased DCs-driven T cells' proliferation and promoted U14 cells' apoptosis. Furthermore, the expression of TLR-4 was significantly increased on DCs treated by POL-P3b. These results suggested that POL-P3b may induce DCs maturation through TLR-4. Taken together, our results may have important implications for the molecular mechanisms of immunopotentiation of POL-P3b, and provide direct evidence to suggest that POL-P3b should be considered as a potent adjuvant nutrient supplement for DC-based vaccines.

Cancer vaccine development: Designing tumor cells for greater immunogenicity

Science.gov (United States)

Bozeman, Erica N.; Shashidharamurthy, Rangaiah; Paulos, Simon A.; Palaniappan, Ravi; D’Souza, Martin; Selvaraj, Periasamy

2014-01-01

Cancer vaccine development is one of the most hopeful and exhilarating areas in cancer research. For this reason, there has been a growing interest in the development and application of novel immunotherapies for the treatment of cancer with the focus being on stimulating the immune system to target tumor cells specifically while leaving normal cells unharmed. From such research has emerged a host of promising immunotherapies such as dendritic cell-based vaccines, cytokine therapies and gene transfer technology. These therapies seek to counteract the poor immunogenicity of tumors by augmenting the host’s immune system with a variety of immunostimulatory proteins such as cytokines and costimulatory molecules. While such therapies have proven effective in the induction of anti-tumor immunity in animal models, they are less than optimal and pose a high risk of clinical infeasibility. Herein, we further discuss these immunotherapies as well as a feasible and efficient alternative that, in pre-clinical animal models, allows for the expression of specific immunostimulatory molecules on the surface of tumor cells by a novel protein transfer technology. PMID:20036822

A pan-inhibitor of DASH family enzymes induces immune-mediated regression of murine sarcoma and is a potent adjuvant to dendritic cell vaccination and adoptive T-cell therapy.

Science.gov (United States)

Duncan, Brynn B; Highfill, Steven L; Qin, Haiying; Bouchkouj, Najat; Larabee, Shannon; Zhao, Peng; Woznica, Iwona; Liu, Yuxin; Li, Youhua; Wu, Wengen; Lai, Jack H; Jones, Barry; Mackall, Crystal L; Bachovchin, William W; Fry, Terry J

2013-10-01

Multimodality therapy consisting of surgery, chemotherapy, and radiation will fail in approximately 40% of patients with pediatric sarcomas and result in substantial long-term morbidity in those who are cured. Immunotherapeutic regimens for the treatment of solid tumors typically generate antigen-specific responses too weak to overcome considerable tumor burden and tumor suppressive mechanisms and are in need of adjuvant assistance. Previous work suggests that inhibitors of DASH (dipeptidyl peptidase IV activity and/or structural homologs) enzymes can mediate tumor regression by immune-mediated mechanisms. Herein, we demonstrate that the DASH inhibitor, ARI-4175, can induce regression and eradication of well-established solid tumors, both as a single agent and as an adjuvant to a dendritic cell (DC) vaccine and adoptive cell therapy (ACT) in mice implanted with the M3-9-M rhabdomyosarcoma cell line. Treatment with effective doses of ARI-4175 correlated with recruitment of myeloid (CD11b) cells, particularly myeloid DCs, to secondary lymphoid tissues and with reduced frequency of intratumoral monocytic (CD11bLy6-CLy6-G) myeloid-derived suppressor cells. In immunocompetent mice, combining ARI-4175 with a DC vaccine or ACT with tumor-primed T cells produced significant improvements in tumor responses against well-established M3-9-M tumors. In M3-9-M-bearing immunodeficient (Rag1) mice, ACT combined with ARI-4175 produced greater tumor responses and significantly improved survival compared with either treatment alone. These studies warrant the clinical investigation of ARI-4175 for treatment of sarcomas and other malignancies, particularly as an adjuvant to tumor vaccines and ACT.

Orchestration of transplantation tolerance by regulatory dendritic cell therapy or in-situ targeting of dendritic cells.

Science.gov (United States)

Morelli, Adrian E; Thomson, Angus W

2014-08-01

Extensive research in murine transplant models over the past two decades has convincingly demonstrated the ability of regulatory dendritic cells (DCregs) to promote long-term allograft survival. We review important considerations regarding the source of therapeutic DCregs (donor or recipient) and their mode of action, in-situ targeting of DCregs, and optimal therapeutic regimens to promote DCreg function. Recent studies have defined protocols and mechanisms whereby ex-vivo-generated DCregs of donor or recipient origin subvert allogeneic T-cell responses and promote long-term organ transplant survival. Particular interest has focused on how donor antigen is acquired, processed and presented by autologous dendritic cells, on the stability of DCregs, and on in-situ targeting of dendritic cells to promote their tolerogenic function. New evidence of the therapeutic efficacy of DCregs in a clinically relevant nonhuman primate organ transplant model and production of clinical grade DCregs support early evaluation of DCreg therapy in human graft recipients. We discuss strategies currently used to promote dendritic cell tolerogenicity, including DCreg therapy and in-situ targeting of dendritic cells, with a view to improved understanding of underlying mechanisms and identification of the most promising strategies for therapeutic application.

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.

Science.gov (United States)

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.

GM-CSF Controls Nonlymphoid Tissue Dendritic Cell Homeostasis but Is Dispensable for the Differentiation of Inflammatory Dendritic Cells

Science.gov (United States)

Greter, Melanie; Helft, Julie; Chow, Andrew; Hashimoto, Daigo; Mortha, Arthur; Agudo-Cantero, Judith; Bogunovic, Milena; Gautier, Emmanuel L.; Miller, Jennifer; Leboeuf, Marylene; Lu, Geming; Aloman, Costica; Brown, Brian D.; Pollard, Jeffrey W.; Xiong, Huabao; Randolph, Gwendalyn J.; Chipuk, Jerry E.; Frenette, Paul S.; Merad, Miriam

2012-01-01

SUMMARY GM-CSF (Csf-2) is a critical cytokine for the in vitro generation of dendritic cells (DCs) and is thought to control the development of inflammatory DCs and resident CD103+ DCs in some tissues. Here we showed that in contrast to the current understanding, Csf-2 receptor acts in the steady state to promote the survival and homeostasis of nonlymphoid tissue-resident CD103+ and CD11b+ DCs. Absence of Csf-2 receptor on lung DCs abrogated the induction of CD8+ T cell immunity after immunization with particulate antigens. In contrast, Csf-2 receptor was dispensable for the differentiation and innate function of inflammatory DCs during acute injuries. Instead, inflammatory DCs required Csf-1 receptor for their development. Thus, Csf-2 is important in vaccine-induced CD8+ T cell immunity through the regulation of nonlymphoid tissue DC homeostasis rather than control of inflammatory DCs in vivo. PMID:22749353

Advanced manufacturing of microdisk vaccines for uniform control of material properties and immune cell function.

Science.gov (United States)

Zeng, Qin; Zhang, Peipei; Zeng, Xiangbin; Tostanoski, Lisa H; Jewell, Christopher M

2017-12-19

The continued challenges facing vaccines in infectious disease and cancer highlight a need for better control over the features of vaccines and the responses they generate. Biomaterials offer unique advantages to achieve this goal through features such as controlled release and co-delivery of antigens and adjuvants. However, many synthesis strategies lead to particles with heterogeneity in diameter, shape, loading level, or other properties. In contrast, advanced manufacturing techniques allow precision control of material properties at the micro- and nano-scale. These capabilities in vaccines and immunotherapies could allow more rational design to speed efficient design and clinical translation. Here we employed soft lithography to generate polymer microdisk vaccines with uniform structures and tunable compositions of vaccine antigens and toll like receptor agonists (TLRas) that serve as molecular adjuvants. Compared to conventional PLGA particles formed by emulsion, microdisks provided a dramatic improvement in the consistency of properties such as diameter. During culture with primary dendritic cells (DCs) from mice, microdisks were internalized by the cells without toxicity, while promoting co-delivery of antigen and TLRa to the same cell. Analysis of DC surface activation markers by flow cytometry revealed microdisk vaccines activated dendritic cells in a manner that depended on the level of TLRa, while antigen processing and presentation depended on the amount of antigen in the microdisks. Together, this work demonstrates the use of advanced manufacturing techniques to produce uniform vaccines that direct DC function depending on the composition in the disks.

A biophysical approach to the optimisation of dendritic-tumour cell electrofusion

International Nuclear Information System (INIS)

Sukhorukov, Vladimir L.; Reuss, Randolph; Endter, Joerg M.; Fehrmann, Steffen; Katsen-Globa, Alisa; Gessner, Petra; Steinbach, Andrea; Mueller, Kilian J.; Karpas, Abraham; Zimmermann, Ulrich; Zimmermann, Heiko

2006-01-01

Electrofusion of tumour and dendritic cells (DCs) is a promising approach for production of DC-based anti-tumour vaccines. Although human DCs are well characterised immunologically, little is known about their biophysical properties, including dielectric and osmotic parameters, both of which are essential for the development of efficient electrofusion protocols. In the present study, human DCs from the peripheral blood along with a tumour cell line used as a model fusion partner were examined by means of time-resolved cell volumetry and electrorotation. Based on the biophysical cell data, the electrofusion protocol could be rapidly optimised with respect to the sugar composition of the fusion medium, duration of hypotonic treatment, frequency range for stable cell alignment, and field strengths of breakdown pulses triggering membrane fusion. The hypotonic electrofusion consistently gave a tumour-DC hybrid rate of up to 19%, as determined by counting dually labelled fluorescent hybrids in a microscope. This fusion rate is nearly twice as high as that usually reported in the literature for isotonic media. The experimental findings and biophysical approach presented here are generally useful for the development of efficient electrofusion protocols, especially for rare and valuable human cells

FRET microscopy autologous tumor lysate processing in mature dendritic cell vaccine therapy

Directory of Open Access Journals (Sweden)

Ridolfi Ruggero

2010-06-01

Full Text Available Abstract Background Antigen processing by dendritic cells (DC exposed to specific stimuli has been well characterized in biological studies. Nonetheless, the question of whether autologous whole tumor lysates (as used in clinical trials are similarly processed by these cells has not yet been resolved. Methods In this study, we examined the transfer of peptides from whole tumor lysates to major histocompatibility complex class II molecules (MHC II in mature dendritic cells (mDC from a patient with advanced melanoma. Tumor antigenic peptides-MHC II proximity was revealed by Förster Resonance Energy Transfer (FRET measurements, which effectively extends the application of fluorescence microscopy to the molecular level ( Results We detected significant energy transfer between donor and acceptor-labelled antibodies against HLA-DR at the membrane surface of mDC. FRET data indicated that fluorescent peptide-loaded MHC II molecules start to accumulate on mDC membranes at 16 hr from the maturation stimulus, steeply increasing at 22 hr with sustained higher FRET detected up to 46 hr. Conclusions The results obtained imply that the patient mDC correctly processed the tumor specific antigens and their display on the mDC surface may be effective for several days. These observations support the rationale for immunogenic efficacy of autologous tumor lysates.

Signaling network of dendritic cells in response to pathogens: a community-input supported knowledgebase

Directory of Open Access Journals (Sweden)

Nudelman Irina

2010-10-01

Full Text Available Abstract Background Dendritic cells are antigen-presenting cells that play an essential role in linking the innate and adaptive immune systems. Much research has focused on the signaling pathways triggered upon infection of dendritic cells by various pathogens. The high level of activity in the field makes it desirable to have a pathway-based resource to access the information in the literature. Current pathway diagrams lack either comprehensiveness, or an open-access editorial interface. Hence, there is a need for a dependable, expertly curated knowledgebase that integrates this information into a map of signaling networks. Description We have built a detailed diagram of the dendritic cell signaling network, with the goal of providing researchers with a valuable resource and a facile method for community input. Network construction has relied on comprehensive review of the literature and regular updates. The diagram includes detailed depictions of pathways activated downstream of different pathogen recognition receptors such as Toll-like receptors, retinoic acid-inducible gene-I-like receptors, C-type lectin receptors and nucleotide-binding oligomerization domain-like receptors. Initially assembled using CellDesigner software, it provides an annotated graphical representation of interactions stored in Systems Biology Mark-up Language. The network, which comprises 249 nodes and 213 edges, has been web-published through the Biological Pathway Publisher software suite. Nodes are annotated with PubMed references and gene-related information, and linked to a public wiki, providing a discussion forum for updates and corrections. To gain more insight into regulatory patterns of dendritic cell signaling, we analyzed the network using graph-theory methods: bifan, feedforward and multi-input convergence motifs were enriched. This emphasis on activating control mechanisms is consonant with a network that subserves persistent and coordinated responses to

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

Science.gov (United States)

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

Trivalent MDCK cell culture-derived influenza vaccine Optaflu (Novartis Vaccines).

Science.gov (United States)

Doroshenko, Alexander; Halperin, Scott A

2009-06-01

Annual influenza epidemics continue to have a considerable impact in both developed and developing countries. Vaccination remains the principal measure to prevent seasonal influenza and reduce associated morbidity and mortality. The WHO recommends using established mammalian cell culture lines as an alternative to egg-based substrates in the manufacture of influenza vaccine. In June 2007, the EMEA approved Optaflu, a Madin Darby canine kidney cell culture-derived influenza vaccine manufactured by Novartis Vaccines. This review examines the advantages and disadvantages of cell culture-based technology for influenza vaccine production, compares immunogenicity and safety data for Optaflu with that of currently marketed conventional egg-based influenza vaccines, and considers the prospects for wider use of cell culture-based influenza vaccines.

Neisseria meningitidis expressing lgtB lipopolysaccharide targets DC-SIGN and modulates dendritic cell function.

Science.gov (United States)

Steeghs, Liana; van Vliet, Sandra J; Uronen-Hansson, Heli; van Mourik, Andries; Engering, Anneke; Sanchez-Hernandez, Martha; Klein, Nigel; Callard, Robin; van Putten, Jos P M; van der Ley, Peter; van Kooyk, Yvette; van de Winkel, Jan G J

2006-02-01

Neisseria meningitidis lipopolysaccharide (LPS) has been identified as a major determinant of dendritic cell (DC) function. Here we report that one of a series of meningococcal mutants with defined truncations in the lacto-N-neotetraose outer core of the LPS exhibited unique strong adhesion and internalization properties towards DC. These properties were mediated by interaction of the GlcNAc(beta1-3)-Gal(beta1-4)-Glc-R oligosaccharide outer core of lgtB LPS with the dendritic-cell-specific ICAM-3 grabbing non-integrin (DC-SIGN) lectin receptor. Activation of DC-SIGN with this novel oligosaccharide ligand skewed T-cell responses driven by DC towards T helper type 1 activity. Thus, the use of lgtB LPS may provide a powerful instrument to selectively induce the desired arm of the immune response and potentially increase vaccine efficacy.

A novel dendritic cell-based direct ex vivo assay for detection and enumeration of circulating antigen-specific human T cells.

Science.gov (United States)

Carrio, Roberto; Zhang, Ge; Drake, Donald R; Schanen, Brian C

2018-05-07

Although a variety of assays have been used to examine T cell responses in vitro, standardized ex vivo detection of antigen-specific CD4 + T cells from human circulatory PBMCs remains constrained by low-dimensional characterization outputs and the need for polyclonal, mitogen-induced expansion methods to generate detectable response signals. To overcome these limitations, we developed a novel methodology utilizing antigen-pulsed autologous human dendritic target cells in a rapid and sensitive assay to accurately enumerate antigen-specific CD4 + T cell precursor frequency by multiparametric flow cytometry. With this approach, we demonstrate the ability to reproducibly quantitate poly-functional T cell responses following both primary and recall antigenic stimulation. Furthermore, this approach enables more comprehensive phenotypic profiling of circulating antigen-specific CD4 + T cells, providing valuable insights into the pre-existing polarization of antigen-specific T cells in humans. Combined, this approach permits sensitive and detailed ex vivo detection of antigen-specific CD4 + T cells delivering an important tool for advancing vaccine, immune-oncology and other therapeutic studies.

Synergistic effects of dendritic cell targeting and laser-microporation on enhancing epicutaneous skin vaccination efficacy.

Science.gov (United States)

Machado, Yoan; Duinkerken, Sanne; Hoepflinger, Veronika; Mayr, Melissa; Korotchenko, Evgeniia; Kurtaj, Almedina; Pablos, Isabel; Steiner, Markus; Stoecklinger, Angelika; Lübbers, Joyce; Schmid, Maximillian; Ritter, Uwe; Scheiblhofer, Sandra; Ablinger, Michael; Wally, Verena; Hochmann, Sarah; Raninger, Anna M; Strunk, Dirk; van Kooyk, Yvette; Thalhamer, Josef; Weiss, Richard

2017-11-28

Due to its unique immunological properties, the skin is an attractive target tissue for allergen-specific immunotherapy. In our current work, we combined a dendritic cell targeting approach with epicutaneous immunization using an ablative fractional laser to generate defined micropores in the upper layers of the skin. By coupling the major birch pollen allergen Bet v 1 to mannan from S. cerevisiae via mild periodate oxidation we generated hypoallergenic Bet-mannan neoglycoconjugates, which efficiently targeted CD14 + dendritic cells and Langerhans cells in human skin explants. Mannan conjugation resulted in sustained release from the skin and retention in secondary lymphoid organs, whereas unconjugated antigen showed fast renal clearance. In a mouse model, Bet-mannan neoglycoconjugates applied via laser-microporated skin synergistically elicited potent humoral and cellular immune responses, superior to intradermal injection. The induced antibody responses displayed IgE-blocking capacity, highlighting the therapeutic potential of the approach. Moreover, application via micropores, but not by intradermal injection, resulted in a mixed TH1/TH17-biased immune response. Our data clearly show that applying mannan-neoglycoconjugates to an organ rich in dendritic cells using laser-microporation is superior to intradermal injection. Due to their low IgE binding capacity and biodegradability, mannan neoglycoconjugates therefore represent an attractive formulation for allergen-specific epicutaneous immunotherapy. Copyright © 2017 Elsevier B.V. All rights reserved.

Chemokines: a new dendritic cell signal for T cell activation

Directory of Open Access Journals (Sweden)

Christoph A Thaiss

2011-08-01

Full Text Available Dendritic cells (DCs are the main inducers and regulators of cytotoxic T lymphocyte (CTL responses against viruses and tumors. One checkpoint to avoid misguided CTL activation, which might damage healthy cells of the body, is the necessity for multiple activation signals, involving both antigenic as well as additional signals that reflect the presence of pathogens. DCs provide both signals when activated by ligands of pattern recognition receptors and licensed by helper lymphocytes. Recently, it has been established that such T cell licensing can be facilitated by CD4+ T helper cells (classical licensing or by NKT cells (alternative licensing. Licensing regulates the DC/CTL cross-talk at multiple layers. Direct recruitment of CTLs through chemokines released by licensed DCs has recently emerged as a common theme and has a crucial impact on the efficiency of CTL responses. Here, we discuss recent advances in our understanding of DC licensing for cross-priming and implications for the temporal and spatial regulation underlying this process. Future vaccination strategies will benefit from a deeper insight into the mechanisms that govern CTL activation.

Phenotype of dendritic cells generated in the presence of non-small cell lung cancer antigens - preliminary report.

Directory of Open Access Journals (Sweden)

Dariusz Sagan

2009-01-01

Full Text Available 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

Dendritic excitability modulates dendritic information processing in a purkinje cell model.

Science.gov (United States)

Coop, Allan D; Cornelis, Hugo; Santamaria, Fidel

2010-01-01

Using an electrophysiological compartmental model of a Purkinje cell we quantified the contribution of individual active dendritic currents to processing of synaptic activity from granule cells. We used mutual information as a measure to quantify the information from the total excitatory input current (I(Glu)) encoded in each dendritic current. In this context, each active current was considered an information channel. Our analyses showed that most of the information was encoded by the calcium (I(CaP)) and calcium activated potassium (I(Kc)) currents. Mutual information between I(Glu) and I(CaP) and I(Kc) was sensitive to different levels of excitatory and inhibitory synaptic activity that, at the same time, resulted in the same firing rate at the soma. Since dendritic excitability could be a mechanism to regulate information processing in neurons we quantified the changes in mutual information between I(Glu) and all Purkinje cell currents as a function of the density of dendritic Ca (g(CaP)) and Kca (g(Kc)) conductances. We extended our analysis to determine the window of temporal integration of I(Glu) by I(CaP) and I(Kc) as a function of channel density and synaptic activity. The window of information integration has a stronger dependence on increasing values of g(Kc) than on g(CaP), but at high levels of synaptic stimulation information integration is reduced to a few milliseconds. Overall, our results show that different dendritic conductances differentially encode synaptic activity and that dendritic excitability and the level of synaptic activity regulate the flow of information in dendrites.

Dendritic cells in Barrett's esophagus and esophageal adenocarcinoma.

Science.gov (United States)

Bobryshev, Yuri V; Tran, Dinh; Killingsworth, Murray C; Buckland, Michael; Lord, Reginald V N

2009-01-01

Like other premalignant conditions that develop in the presence of chronic inflammation, the development and progression of Barrett's esophagus is associated with the development of an immune response, but how this immune response is regulated is poorly understood. A comprehensive literature search failed to find any report of the presence of dendritic cells in Barrett's intestinal metaplasia and esophageal adenocarcinoma and this prompted our study. We used immunohistochemical staining and electron microscopy to examine whether dendritic cells are present in Barrett's esophagus and esophageal adenocarcinoma. Immunohistochemical staining with CD83, a specific marker for dendritic cells, was performed on paraffin-embedded sections of Barrett's intestinal metaplasia (IM, n = 12), dysplasia (n = 11) and adenocarcinoma (n = 14). CD83+ cells were identified in the lamina propria surrounding intestinal type glands in Barrett's IM, dysplasia, and cancer tissues. Computerized quantitative analysis showed that the numbers of dendritic cells were significantly higher in cancer tissues. Double immunostaining with CD83, CD20, and CD3, and electron microscopy demonstrated that dendritic cells are present in Barrett's esophagus and form clusters with T cells and B cells directly within the lamina propria. These findings demonstrate that dendritic cells are present in Barrett's tissues, with a significant increase in density in adenocarcinoma compared to benign Barrett's esophagus. Dendritic cells may have a role in the pathogenesis and immunotherapy treatment of Barrett's esophagus and adenocarcinoma.

Endothelial cell-derived microparticles induce plasmacytoid dendritic cell maturation: potential implications in inflammatory diseases.

Science.gov (United States)

Angelot, Fanny; Seillès, Estelle; Biichlé, Sabeha; Berda, Yael; Gaugler, Béatrice; Plumas, Joel; Chaperot, Laurence; Dignat-George, Françoise; Tiberghien, Pierre; Saas, Philippe; Garnache-Ottou, Francine

2009-11-01

Increased circulating endothelial microparticles, resulting from vascular endothelium dysfunction, and plasmacytoid dendritic cell activation are both encountered in common inflammatory disorders. The aim of our study was to determine whether interactions between endothelial microparticles and plasmacytoid dendritic cells could contribute to such pathologies. Microparticles generated from endothelial cell lines, platelets or activated T cells were incubated with human plasmacytoid dendritic cells sorted from healthy donor blood or with monocyte-derived dendritic cells. Dendritic cell maturation was evaluated by flow cytometry, cytokine secretion as well as naive T-cell activation and polarization. Labeled microparticles were also used to study cellular interactions. Endothelial microparticles induced plasmacytoid dendritic cell maturation. In contrast, conventional dendritic cells were resistant to endothelial microparticle-induced maturation. In addition to upregulation of co-stimulatory molecules, endothelial microparticle-matured plasmacytoid dendritic cells secreted inflammatory cytokines (interleukins 6 and 8, but no interferon-alpha) and also induced allogeneic naive CD4(+) T cells to proliferate and to produce type 1 cytokines such as interferon-gamma and tumor necrosis factor-alpha. Endothelial microparticle endocytosis by plasmacytoid dendritic cells appeared to be required for plasmacytoid dendritic cell maturation. Importantly, the ability of endothelial microparticles to induce plasmacytoid dendritic cells to mature was specific as microparticles derived from activated T cells or platelets (the major source of circulating microparticules in healthy subjects) did not induce such plasmacytoid dendritic cell maturation. Our data show that endothelial microparticles specifically induce plasmacytoid dendritic cell maturation and production of inflammatory cytokines. This novel activation pathway may be implicated in various inflammatory disorders and

Immunological Characterization of Whole Tumour Lysate-Loaded Dendritic Cells for Cancer Immunotherapy

Science.gov (United States)

Ottobrini, Luisa; Biasin, Mara; Borelli, Manuela; Lucignani, Giovanni; Trabattoni, Daria; Clerici, Mario

2016-01-01

Introduction Dendritic cells play a key role as initiators of T-cell responses, and even if tumour antigen-loaded dendritic cells can induce anti-tumour responses, their efficacy has been questioned, suggesting a need to enhance immunization strategies. Matherials & Methods We focused on the characterization of bone marrow-derived dendritic cells pulsed with whole tumour lysate (TAA-DC), as a source of known and unknown antigens, in a mouse model of breast cancer (MMTV-Ras). Dendritic cells were evaluated for antigen uptake and for the expression of MHC class I/II and costimulatory molecules and markers associated with maturation. Results Results showed that antigen-loaded dendritic cells are characterized by a phenotypically semi-mature/mature profile and by the upregulation of genes involved in antigen presentation and T-cell priming. Activated dendritic cells stimulated T-cell proliferation and induced the production of high concentrations of IL-12p70 and IFN-γ but only low levels of IL-10, indicating their ability to elicit a TH1-immune response. Furthermore, administration of Antigen loaded-Dendritic Cells in MMTV-Ras mice evoked a strong anti-tumour response in vivo as demonstrated by a general activation of immunocompetent cells and the release of TH1 cytokines. Conclusion Data herein could be useful in the design of antitumoral DC-based therapies, showing a specific activation of immune system against breast cancer. PMID:26795765

A Poly(Lactic-co-Glycolic) Acid Nanovaccine Based on Chimeric Peptides from Different Leishmania infantum Proteins Induces Dendritic Cells Maturation and Promotes Peptide-Specific IFNγ-Producing CD8+ T Cells Essential for the Protection against Experimental Visceral Leishmaniasis.

Science.gov (United States)

Athanasiou, Evita; Agallou, Maria; Tastsoglou, Spyros; Kammona, Olga; Hatzigeorgiou, Artemis; Kiparissides, Costas; Karagouni, Evdokia

2017-01-01

Visceral leishmaniasis, caused by Leishmania ( L .) donovani and L. infantum protozoan parasites, can provoke overwhelming and protracted epidemics, with high case-fatality rates. An effective vaccine against the disease must rely on the generation of a strong and long-lasting T cell immunity, mediated by CD4 + T H1 and CD8 + T cells. Multi-epitope peptide-based vaccine development is manifesting as the new era of vaccination strategies against Leishmania infection. In this study, we designed chimeric peptides containing HLA-restricted epitopes from three immunogenic L. infantum proteins (cysteine peptidase A, histone H1, and kinetoplastid membrane protein 11), in order to be encapsulated in poly(lactic- co -glycolic) acid nanoparticles with or without the adjuvant monophosphoryl lipid A (MPLA) or surface modification with an octapeptide targeting the tumor necrosis factor receptor II. We aimed to construct differentially functionalized peptide-based nanovaccine candidates and investigate their capacity to stimulate the immunomodulatory properties of dendritic cells (DCs), which are critical regulators of adaptive immunity generated upon vaccination. According to our results, DCs stimulation with the peptide-based nanovaccine candidates with MPLA incorporation or surface modification induced an enhanced maturation profile with prominent IL-12 production, promoting allogeneic T cell proliferation and intracellular production of IFNγ by CD4 + and CD8 + T cell subsets. In addition, DCs stimulated with the peptide-based nanovaccine candidate with MPLA incorporation exhibited a robust transcriptional activation, characterized by upregulated genes indicative of vaccine-driven DCs differentiation toward type 1 phenotype. Immunization of HLA A2.1 transgenic mice with this peptide-based nanovaccine candidate induced peptide-specific IFNγ-producing CD8 + T cells and conferred significant protection against L. infantum infection. Concluding, our findings supported that

Functional Identification of Dendritic Cells in the Teleost Model, Rainbow Trout (Oncorhynchus mykiss)

Science.gov (United States)

Bassity, Elizabeth; Clark, Theodore G.

2012-01-01

Dendritic cells are specialized antigen presenting cells that bridge innate and adaptive immunity in mammals. This link between the ancient innate immune system and the more evolutionarily recent adaptive immune system is of particular interest in fish, the oldest vertebrates to have both innate and adaptive immunity. It is unknown whether dendritic cells co-evolved with the adaptive response, or if the connection between innate and adaptive immunity relied on a fundamentally different cell type early in evolution. We approached this question using the teleost model organism, rainbow trout (Oncorhynchus mykiss), with the aim of identifying dendritic cells based on their ability to stimulate naïve T cells. Adapting mammalian protocols for the generation of dendritic cells, we established a method of culturing highly motile, non-adherent cells from trout hematopoietic tissue that had irregular membrane processes and expressed surface MHCII. When side-by-side mixed leukocyte reactions were performed, these cells stimulated greater proliferation than B cells or macrophages, demonstrating their specialized ability to present antigen and therefore their functional homology to mammalian dendritic cells. Trout dendritic cells were then further analyzed to determine if they exhibited other features of mammalian dendritic cells. Trout dendritic cells were found to have many of the hallmarks of mammalian DCs including tree-like morphology, the expression of dendritic cell markers, the ability to phagocytose small particles, activation by toll-like receptor-ligands, and the ability to migrate in vivo. As in mammals, trout dendritic cells could be isolated directly from the spleen, or larger numbers could be derived from hematopoietic tissue and peripheral blood mononuclear cells in vitro. PMID:22427987

Effective clinical-scale production of dendritic cell vaccines by monocyte elutriation directly in medium, subsequent culture in bags and final antigen loading using peptides or RNA transfection.

Science.gov (United States)

Erdmann, Michael; Dörrie, Jan; Schaft, Niels; Strasser, Erwin; Hendelmeier, Martin; Kämpgen, Eckhart; Schuler, Gerold; Schuler-Thurner, Beatrice

2007-09-01

Dendritic cell (DC) vaccination approaches are advancing fast into the clinic. The major obstacle for further improvement is the current lack of a simple functionally "closed" system to generate standardized monocyte-derived (mo) DC vaccines. Here, we significantly optimized the use of the Elutra counterflow elutriation system to enrich monocytic DC precursors by (1) developing an algorithm to avoid red blood cell debulking and associated monocyte loss before elutriation, and (2) by elutriation directly in culture medium rather than phosphate-buffered saline. Upon elutriation the bags containing the collected monocytes are simply transferred into the incubator to generate DC progeny as the final "open" washing step is no longer required. Elutriation resulted in significantly more (> or = 2-fold) and purer DC than the standard gradient centrifugation/adherence-based monocyte enrichment, whereas morphology, maturation markers, viability, migratory capacity, and T cell stimulatory capacity were identical. Subsequently, we compared RNA transfection, as this is an increasingly used approach to load DC with antigen. Elutra-derived and adherence-derived DC could be electroporated with similar, high efficiency (on average >85% green fluorescence protein positive), and appeared also equal in antigen expression kinetics. Both Elutra-derived and adherence-derived DC, when loaded with the MelanA peptide or electroporated with MelanA RNA, showed a high T cell stimulation capacity, that is, priming of MelanA-specific CD8+ T cells. Our optimized Elutra-based procedure is straightforward, clearly superior to the standard gradient centrifugation/plastic adherence protocol, and now allows the generation of large numbers of peptide-loaded or RNA-transfected DC in a functionally closed system.

An Optimized Method for Manufacturing a Clinical Scale Dendritic Cell-Based Vaccine for the Treatment of Glioblastoma

Science.gov (United States)

Pogliani, Simona; Pellegatta, Serena; Antozzi, Carlo; Baggi, Fulvio; Gellera, Cinzia; Pollo, Bianca; Parati, Eugenio A.; Finocchiaro, Gaetano; Frigerio, Simona

2012-01-01

Immune-based treatments represent a promising new class of therapy designed to boost the immune system to specifically eradicate malignant cells. Immunotherapy may generate specific anti-tumor immune responses, and dendritic cells (DC), professional antigen-presenting cells, are widely used in experimental cancer immunotherapy. Several reports describe methods for the generation of mature, antigen-pulsed DC for clinical use. Improved quality and standardization are desirable to obtain GMP-compliant protocols. In this study we describe the generation of DC from 31 Glioblastoma (GB) patients starting from their monocytes isolated by immunomagnetic CD14 selection using the CliniMACS® device. Upon differentiation of CD14+ with IL-4 and GM-CSF, DC were induced to maturation with TNF-α, PGE2, IL-1β, and IL-6. Whole tumor lysate was obtained, for the first time, in a closed system using the semi-automated dissociator GentleMACS®. The yield of proteins improved by 130% compared to the manual dissociation method. Interestingly the Mean Fluorescence Intensity for CD83 increased significantly in DC pulsed with “new method” lysate compared to DC pulsed with “classical method” lysate. Our results indicate that immunomagnetic isolation of CD14+ monocytes using the CliniMACS® device and their pulsing with whole tumor lysate proteins is a suitable method for clinical-scale generation of high quality, functional DC under GMP-grade conditions. PMID:23284979

An endogenous immune adjuvant released by necrotic cells for enhancement of DNA vaccine potency.

Science.gov (United States)

Dorostkar, Rohollah; Bamdad, Taravat; Parsania, Masoud; Pouriayevali, Hassan

2012-12-01

Improving vaccine potency in the induction of a strong cell-mediated cytotoxicity can enhance the efficacy of vaccines. Necrotic cells and the supernatant of necrotic tumor cells are attractive adjuvants, on account of their ability to recruit antigen-presenting cells to the site of antigen synthesis as well as its ability to stimulate the maturation of dendritic cells. To evaluate the utility of supernatant of necrotic tumor cells as a DNA vaccine adjuvant in a murine model. The supernatant of EL4 necrotic cells was co-administered with a DNA vaccine expressing the glycoprotein B of Herpes simplex virus-1 as an antigen model under the control of Cytomegalovirus promoter. C57BL/6 mice were vaccinated three times at two weeks intervals with glycoprotein B DNA vaccine and supernatant of necrotic EL4 cells. Five days after the last immunization, cell cytotoxicity, IFN-γ and IL-4 were evaluated. The obtained data showed that the production of IFN-γ from the splenocytes after antigenic stimulation in the presence of the supernatant of necrotic EL4 cells was significantly higher than the other groups (pEL4 cells in the mice immunized with DNA vaccine and supernatant of necrotic EL4 cells comparing to the other groups (p<0.001). The supernatant of necrotic cells contains adjuvant properties that can be considered as a candidate for tumor vaccination.

Transduction of skin-migrating dendritic cells by human adenovirus 5 occurs via an actin-dependent phagocytic pathway.

Science.gov (United States)

Guzman, Efrain; Taylor, Geraldine; Hope, Jayne; Herbert, Rebecca; Cubillos-Zapata, Carolina; Charleston, Bryan

2016-10-01

Dendritic cells (DC) are central to the initiation of immune responses, and various approaches have been used to target vaccines to DC in order to improve immunogenicity. Cannulation of lymphatic vessels allows for the collection of DC that migrate from the skin. These migrating DC are involved in antigen uptake and presentation following vaccination. Human replication-deficient adenovirus (AdV) 5 is a promising vaccine vector for delivery of recombinant antigens. Although the mechanism of AdV attachment and penetration has been extensively studied in permissive cell lines, few studies have addressed the interaction of AdV with DC. In this study, we investigated the interaction of bovine skin-migrating DC and replication-deficient AdV-based vaccine vectors. We found that, despite lack of expression of Coxsackie B-Adenovirus Receptor and other known adenovirus receptors, AdV readily enters skin-draining DC via an actin-dependent endocytosis. Virus exit from endosomes was pH independent, and neutralizing antibodies did not prevent virus entry but did prevent virus translocation to the nucleus. We also show that combining adenovirus with adjuvant increases the absolute number of intracellular virus particles per DC but not the number of DC containing intracellular virus. This results in increased trans-gene expression and antigen presentation. We propose that, in the absence of Coxsackie B-Adenovirus Receptor and other known receptors, AdV5-based vectors enter skin-migrating DC using actin-dependent endocytosis which occurs in skin-migrating DC, and its relevance to vaccination strategies and vaccine vector targeting is discussed.

Dendritic thickness: a morphometric parameter to classify mouse retinal ganglion cells

Directory of Open Access Journals (Sweden)

L.D. Loopuijt

2007-10-01

Full Text Available To study the dendritic morphology of retinal ganglion cells in wild-type mice we intracellularly injected these cells with Lucifer yellow in an in vitro preparation of the retina. Subsequently, quantified values of dendritic thickness, number of branching points and level of stratification of 73 Lucifer yellow-filled ganglion cells were analyzed by statistical methods, resulting in a classification into 9 groups. The variables dendritic thickness, number of branching points per cell and level of stratification were independent of each other. Number of branching points and level of stratification were independent of eccentricity, whereas dendritic thickness was positively dependent (r = 0.37 on it. The frequency distribution of dendritic thickness tended to be multimodal, indicating the presence of at least two cell populations composed of neurons with dendritic diameters either smaller or larger than 1.8 µm ("thin" or "thick" dendrites, respectively. Three cells (4.5% were bistratified, having thick dendrites, and the others (95.5% were monostratified. Using k-means cluster analysis, monostratified cells with either thin or thick dendrites were further subdivided according to level of stratification and number of branching points: cells with thin dendrites were divided into 2 groups with outer stratification (0-40% and 2 groups with inner (50-100% stratification, whereas cells with thick dendrites were divided into one group with outer and 3 groups with inner stratification. We postulate, that one group of cells with thin dendrites resembles cat ß-cells, whereas one group of cells with thick dendrites includes cells that resemble cat a-cells.

iPSC-Derived Regulatory Dendritic Cells Inhibit Allograft Rejection by Generating Alloantigen-Specific Regulatory T Cells

Directory of Open Access Journals (Sweden)

Songjie Cai

2017-05-01

Full Text Available Regulatory dendritic cell (DCregs-based immunotherapy is a potential therapeutic tool for transplant rejection. We generated DCregs from murine induced pluripotent stem cells (iPSCs, which could remain in a “stable immature stage” even under strong stimulation. Harnessing this characteristic, we hypothesized that iPS-DCregs worked as a negative vaccine to generate regulatory T cells (Tregs, and induced donor-specific allograft acceptance. We immunized naive CBA (H-2Kk mice with B6 (H-2Kb iPS-DCregs and found that Tregs (CD4+CD25+FOXP3+ significantly increased in CBA splenocytes. Moreover, immunized CBA recipients permanently accepted B6 cardiac grafts in a donor-specific pattern. We demonstrated mechanistically that donor-type iPS-DCregs triggered transforming growth factor β1 secretion, under which the donor-antigen peptides directed naive CD4+ T cells to differentiate into donor-specific FOXP3+ Tregs instead of into effector T cells in vivo. These findings highlight the potential of iPS-DCregs as a key cell therapy resource in clinical transplantation.

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

Science.gov (United States)

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.

Vitamin E Succinate as an Adjuvant for Dendritic Cell Based Vaccines

National Research Council Canada - National Science Library

Ramanathapuram, Lalitha

2004-01-01

.... In this study we have employed Vitamin E succinate also known as alpha-tocopheryl succinate (alpha-TOS), a non-toxic esterified analogue of Vitamin E, as an adjuvant to enhance the effectiveness of DC vaccines in treating established murine mammary...

Systemic RNA delivery to dendritic cells exploits antiviral defence for cancer immunotherapy

Science.gov (United States)

Kranz, Lena M.; Diken, Mustafa; Haas, Heinrich; Kreiter, Sebastian; Loquai, Carmen; Reuter, Kerstin C.; Meng, Martin; Fritz, Daniel; Vascotto, Fulvia; Hefesha, Hossam; Grunwitz, Christian; Vormehr, Mathias; Hüsemann, Yves; Selmi, Abderraouf; Kuhn, Andreas N.; Buck, Janina; Derhovanessian, Evelyna; Rae, Richard; Attig, Sebastian; Diekmann, Jan; Jabulowsky, Robert A.; Heesch, Sandra; Hassel, Jessica; Langguth, Peter; Grabbe, Stephan; Huber, Christoph; Türeci, Özlem; Sahin, Ugur

2016-06-01

Lymphoid organs, in which antigen presenting cells (APCs) are in close proximity to T cells, are the ideal microenvironment for efficient priming and amplification of T-cell responses. However, the systemic delivery of vaccine antigens into dendritic cells (DCs) is hampered by various technical challenges. Here we show that DCs can be targeted precisely and effectively in vivo using intravenously administered RNA-lipoplexes (RNA-LPX) based on well-known lipid carriers by optimally adjusting net charge, without the need for functionalization of particles with molecular ligands. The LPX protects RNA from extracellular ribonucleases and mediates its efficient uptake and expression of the encoded antigen by DC populations and macrophages in various lymphoid compartments. RNA-LPX triggers interferon-α (IFNα) release by plasmacytoid DCs and macrophages. Consequently, DC maturation in situ and inflammatory immune mechanisms reminiscent of those in the early systemic phase of viral infection are activated. We show that RNA-LPX encoding viral or mutant neo-antigens or endogenous self-antigens induce strong effector and memory T-cell responses, and mediate potent IFNα-dependent rejection of progressive tumours. A phase I dose-escalation trial testing RNA-LPX that encode shared tumour antigens is ongoing. In the first three melanoma patients treated at a low-dose level, IFNα and strong antigen-specific T-cell responses were induced, supporting the identified mode of action and potency. As any polypeptide-based antigen can be encoded as RNA, RNA-LPX represent a universally applicable vaccine class for systemic DC targeting and synchronized induction of both highly potent adaptive as well as type-I-IFN-mediated innate immune mechanisms for cancer immunotherapy.

Bortezomib as a new therapeutic approach for blastic plasmacytoid dendritic cell neoplasm.

Science.gov (United States)

Philippe, Laure; Ceroi, Adam; Bôle-Richard, Elodie; Jenvrin, Alizée; Biichle, Sabeha; Perrin, Sophie; Limat, Samuel; Bonnefoy, Francis; Deconinck, Eric; Saas, Philippe; Garnache-Ottou, Francine; Angelot-Delettre, Fanny

2017-11-01

Blastic plasmacytoid dendritic cell neoplasm is an aggressive hematologic malignancy with a poor prognosis. No consensus regarding optimal treatment modalities is currently available. Targeting the nuclear factor-kappa B pathway is considered a promising approach since blastic plasmacytoid dendritic cell neoplasm has been reported to exhibit constitutive activation of this pathway. Moreover, nuclear factor-kappa B inhibition in blastic plasmacytoid dendritic cell neoplasm cell lines, achieved using either an experimental specific inhibitor JSH23 or the clinical drug bortezomib, interferes in vitro with leukemic cell proliferation and survival. Here we extended these data by showing that primary blastic plasmacytoid dendritic cell neoplasm cells from seven patients were sensitive to bortezomib-induced cell death. We confirmed that bortezomib efficiently inhibits the phosphorylation of the RelA nuclear factor-kappa B subunit in blastic plasmacytoid dendritic cell neoplasm cell lines and primary cells from patients in vitro and in vivo in a mouse model. We then demonstrated that bortezomib can be associated with other drugs used in different chemotherapy regimens to improve its impact on leukemic cell death. Indeed, when primary blastic plasmacytoid dendritic cell neoplasm cells from a patient were grafted into mice, bortezomib treatment significantly increased the animals' survival, and was associated with a significant decrease of circulating leukemic cells and RelA nuclear factor-kappa B subunit expression. Overall, our results provide a rationale for the use of bortezomib in combination with other chemotherapy for the treatment of patients with blastic plasmacytoid dendritic cell neoplasm. Based on our data, a prospective clinical trial combining proteasome inhibitor with classical drugs could be envisaged. Copyright© Ferrata Storti Foundation.

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

Science.gov (United States)

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

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

Science.gov (United States)

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.

Immunogenicity of dendritic cell-based HPV16 E6/E7 peptide vaccines: CTL activation and protective effects

Czech Academy of Sciences Publication Activity Database

Indrová, Marie; Reiniš, Milan; Bubeník, Jan; Jandlová, Táňa; Bieblová, Jana; Vonka, V.; Velek, Jiří

2004-01-01

Roč. 50, č. 6 (2004), s. 184-193 ISSN 0015-5500 R&D Projects: GA MZd NC7148; GA MZd NR7807; GA ČR GA301/01/0985; GA ČR GA301/04/0492; GA AV ČR KSK5011112 Grant - others:Fogarty International Center(US) D43 TW000233 Institutional research plan: CEZ:AV0Z5052915 Keywords : HPV16 E6/E7 peptides * dendritic cell s * cytotoxic lymphocytes Subject RIV: EC - Immunology Impact factor: 0.507, year: 2004

Design of a potent CD1d-binding NKT cell ligand as a vaccine adjuvant.

Science.gov (United States)

Li, Xiangming; Fujio, Masakazu; Imamura, Masakazu; Wu, Douglass; Vasan, Sandhya; Wong, Chi-Huey; Ho, David D; Tsuji, Moriya

2010-07-20

The glycolipid alpha-galactosylceramide (alpha-GalCer) has been shown to bind CD1d molecules to activate invariant natural killer T (iNKT) cells, and subsequently induce activation of various immune-competent cells, including dendritic cells, thereby providing a significant adjuvant effect for various vaccines. However, in phase I clinical trials, alpha-GalCer was shown to display only marginal biological activity. In our search for a glycolipid that can exert more potent stimulatory activity against iNKT cells and dendritic cells and produce an adjuvant effect superior to alpha-GalCer, we performed step-wise screening assays on a focused library of 25 alpha-GalCer analogues. Assays included quantification of the magnitude of stimulatory activity against human iNKT cells in vitro, binding affinity to human and murine CD1d molecules, and binding affinity to the invariant t cell receptor of human iNKT cells. Through this rigorous and iterative screening process, we have identified a lead candidate glycolipid, 7DW8-5, that exhibits a superior adjuvant effect than alpha-GalCer on HIV and malaria vaccines in mice.

Mast-Cell-Derived TNF Amplifies CD8+ Dendritic Cell Functionality and CD8+ T Cell Priming

Directory of Open Access Journals (Sweden)

Jan Dudeck

2015-10-01

Full Text Available Mast cells are critical promoters of adaptive immunity in the contact hypersensitivity model, but the mechanism of allergen sensitization is poorly understood. Using Mcpt5-CreTNFFL/FL mice, we show here that the absence of TNF exclusively in mast cells impaired the expansion of CD8+ T cells upon sensitization and the T-cell-driven adaptive immune response to elicitation. T cells primed in the absence of mast cell TNF exhibited a diminished efficiency to transfer sensitization to naive recipients. Specifically, mast cell TNF promotes CD8+ dendritic cell (DC maturation and migration to draining lymph nodes. The peripherally released mast cell TNF further critically boosts the CD8+ T-cell-priming efficiency of CD8+ DCs, thereby linking mast cell effects on T cells to DC modulation. Collectively, our findings identify the distinct potential of mast cell TNF to amplify CD8+ DC functionality and CD8+ T-cell-dominated adaptive immunity, which may be of great importance for immunotherapy and vaccination approaches.

Denervation-induced homeostatic dendritic plasticity in morphological granule cell models

Directory of Open Access Journals (Sweden)

Hermann Cuntz

2014-03-01

Full Text Available Neuronal death and subsequent denervation of target areas are major consequences of several neurological conditions such asischemia or neurodegeneration (Alzheimer's disease. The denervation-induced axonal loss results in reorganization of the dendritic tree of denervated neurons. The dendritic reorganization has been previously studied using entorhinal cortex lesion (ECL. ECL leads to shortening and loss of dendritic segments in the denervated outer molecular layer of the dentate gyrus. However, the functional importance of these long-term dendritic alterations is not yet understood and their impact on neuronal electrical properties remains unclear. Here we analyzed what happens to the electrotonic structure and excitability of dentate granule cells after lesion-induced alterations of their dendritic morphology, assuming all other parameters remain equal. We performed comparative electrotonic analysis in anatomically and biophysically realistic compartmental models of 3D-reconstructed healthy and denervated granule cells. Using the method of morphological modeling based on optimization principles minimizing the amount of wiring and maximizing synaptic democracy, we built artificial granule cells which replicate morphological features of their real counterparts. Our results show that somatofugal and somatopetal voltage attenuation in the passive cable model are strongly reduced in denervated granule cells. In line with these predictions, the attenuation both of simulated backpropagating action potentials and forward propagating EPSPs was significantly reduced in dendrites of denervated neurons. Intriguingly, the enhancement of action potential backpropagation occurred specifically in the denervated dendritic layers. Furthermore, simulations of synaptic f-I curves revealed a homeostatic increase of excitability in denervated granule cells. In summary, our morphological and compartmental modeling indicates that unless modified by changes of

A Rapid Culture Technique Produces Functional Dendritic-Like Cells from Human Acute Myeloid Leukemia Cell Lines

Directory of Open Access Journals (Sweden)

Jian Ning

2011-01-01

Full Text Available Most anti-cancer immunotherapeutic strategies involving dendritic cells (DC as vaccines rely upon the adoptive transfer of DC loaded with exogenous tumour-peptides. This study utilized human acute myeloid leukemia (AML cells as progenitors from which functional dendritic-like antigen presenting cells (DLC were generated, that constitutively express tumour antigens for recognition by CD8+ T cells. DLC were generated from AML cell lines KG-1 and MUTZ-3 using rapid culture techniques and appropriate cytokines. DLC were evaluated for their cell-surface phenotype, antigen uptake and ability to stimulate allogeneic responder cell proliferation, and production of IFN-γ; compared with DC derived from normal human PBMC donors. KG-1 and MUTZ-3 DLC increased expression of CD80, CD83, CD86, and HLA-DR, and MUTZ-3 DLC downregulated CD14 and expressed CD1a. Importantly, both KG-1 and MUTZ-3-derived DLC promoted proliferation of allogeneic responder cells more efficiently than unmodified cells; neither cells incorporated FITC-labeled dextran, but both stimulated IFN-γ production from responding allogeneic CD8+ T cells. Control DC produced from PBMC using the FastDC culture also expressed high levels of critical cell surface ligands and demonstrated good APC function. This paper indicates that functional DLC can be cultured from the AML cell lines KG-1 and MUTZ-3, and FastDC culture generates functional KG-1 DLC.

Dendritic Cell-Based Immunotherapy of Breast Cancer: Modulation by CpG

National Research Council Canada - National Science Library

Baar, Joseph

2004-01-01

... in the United States in 2004. Thus, patients with MBC who fail conventional therapies are candidates for clinical trials using novel therapeutic approaches, including immunotherapy. Dendritic cells (DC...

Equine dendritic cells generated with horse serum have enhanced functionality in comparison to dendritic cells generated with fetal bovine serum.

Science.gov (United States)

Ziegler, Anja; Everett, Helen; Hamza, Eman; Garbani, Mattia; Gerber, Vinzenz; Marti, Eliane; Steinbach, Falko

2016-11-15

Dendritic cells are professional antigen-presenting cells that play an essential role in the initiation and modulation of T cell responses. They have been studied widely for their potential clinical applications, but for clinical use to be successful, alternatives to xenogeneic substances like fetal bovine serum (FBS) in cell culture need to be found. Protocols for the generation of dendritic cells ex vivo from monocytes are well established for several species, including horses. Currently, the gold standard protocol for generating dendritic cells from monocytes across various species relies upon a combination of GM-CSF and IL-4 added to cell culture medium which is supplemented with FBS. The aim of this study was to substitute FBS with heterologous horse serum. For this purpose, equine monocyte-derived dendritic cells (eqMoDC) were generated in the presence of horse serum or FBS and analysed for the effect on morphology, phenotype and immunological properties. Changes in the expression of phenotypic markers (CD14, CD86, CD206) were assessed during dendritic cell maturation by flow cytometry. To obtain a more complete picture of the eqMoDC differentiation and assess possible differences between FBS- and horse serum-driven cultures, a transcriptomic microarray analysis was performed. Lastly, immature eqMoDC were primed with a primary antigen (ovalbumin) or a recall antigen (tetanus toxoid) and, after maturation, were co-cultured with freshly isolated autologous CD5 + T lymphocytes to assess their T cell stimulatory capacity. The microarray analysis demonstrated that eqMoDC generated with horse serum were indistinguishable from those generated with FBS. However, eqMoDC incubated with horse serum-supplemented medium exhibited a more characteristic dendritic cell morphology during differentiation from monocytes. A significant increase in cell viability was also observed in eqMoDC cultured with horse serum. Furthermore, eqMoDC generated in the presence of horse serum

Dendritic Kv3.3 potassium channels in cerebellar purkinje cells regulate generation and spatial dynamics of dendritic Ca2+ spikes.

Science.gov (United States)

Zagha, Edward; Manita, Satoshi; Ross, William N; Rudy, Bernardo

2010-06-01

Purkinje cell dendrites are excitable structures with intrinsic and synaptic conductances contributing to the generation and propagation of electrical activity. Voltage-gated potassium channel subunit Kv3.3 is expressed in the distal dendrites of Purkinje cells. However, the functional relevance of this dendritic distribution is not understood. Moreover, mutations in Kv3.3 cause movement disorders in mice and cerebellar atrophy and ataxia in humans, emphasizing the importance of understanding the role of these channels. In this study, we explore functional implications of this dendritic channel expression and compare Purkinje cell dendritic excitability in wild-type and Kv3.3 knockout mice. We demonstrate enhanced excitability of Purkinje cell dendrites in Kv3.3 knockout mice, despite normal resting membrane properties. Combined data from local application pharmacology, voltage clamp analysis of ionic currents, and assessment of dendritic Ca(2+) spike threshold in Purkinje cells suggest a role for Kv3.3 channels in opposing Ca(2+) spike initiation. To study the physiological relevance of altered dendritic excitability, we measured [Ca(2+)](i) changes throughout the dendritic tree in response to climbing fiber activation. Ca(2+) signals were specifically enhanced in distal dendrites of Kv3.3 knockout Purkinje cells, suggesting a role for dendritic Kv3.3 channels in regulating propagation of electrical activity and Ca(2+) influx in distal dendrites. These findings characterize unique roles of Kv3.3 channels in dendrites, with implications for synaptic integration, plasticity, and human disease.

A full scale comparative study of methods for generation of functional Dendritic cells for use as cancer vaccines

Directory of Open Access Journals (Sweden)

Kvalheim Gunnar

2007-07-01

Full Text Available Background Dendritic cells (DCs are professional antigen-presenting cells with the ability to induce primary T-cell responses and are commonly produced by culturing monocytes in the presence of IL-4 and GM-CSF for 5–7 days (Standard DC. Recently, Dauer and co-workers presented a modified protocol for differentiation of human monocytes into mature DCs within 48 hours (Fast DC. Here we report a functional comparison of the two strategies for generation of DCs from human monocytes with adaptions for large-scale clinical use. Methods The Elutra Cell Selection System was used to isolate monocytes after collection of leukapheresis product. The enriched monocytes were cultured in gas permeable Teflon bags with IL-4 and GM-CSF for 24 hours (Fast DC or 5 days (Standard DC to obtain immature DCs. The cells were then transfected with mRNA from the leukemia cell line Jurkat E6 by electroporation and incubated for additional 24 h or 2 days in the presence of pro-inflammatory cytokines (TNFα, IL-1β, IL-6 and PGE2 to obtain mature DCs. Results Mature Fast DC and Standard DC displayed comparable levels of many markers expressed on DC, including HLA-DR, CD83, CD86, CD208 and CCR7. However, compared to Standard DC, mature Fast DC was CD14high CD209low. Fast DC and Standard DC transfected with Jurkat E6-cell mRNA were equally able to elicit T cell specifically recognizing transfected DCs in vitro. IFNγ-secreting T cells were observed in both the CD4+ and CD8+ subsets. Conclusion Our results indicate that mature Fast DC are functional antigen presenting cells (APCs capable of inducing primary T-cell responses, and suggest that these cells may be valuable for generation of anti-tumor vaccines.

A full scale comparative study of methods for generation of functional Dendritic cells for use as cancer vaccines.

Science.gov (United States)

Jarnjak-Jankovic, Silvija; Hammerstad, Hege; Saebøe-Larssen, Stein; Kvalheim, Gunnar; Gaudernack, Gustav

2007-07-03

Dendritic cells (DCs) are professional antigen-presenting cells with the ability to induce primary T-cell responses and are commonly produced by culturing monocytes in the presence of IL-4 and GM-CSF for 5-7 days (Standard DC). Recently, Dauer and co-workers presented a modified protocol for differentiation of human monocytes into mature DCs within 48 hours (Fast DC). Here we report a functional comparison of the two strategies for generation of DCs from human monocytes with adaptions for large-scale clinical use. The Elutra Cell Selection System was used to isolate monocytes after collection of leukapheresis product. The enriched monocytes were cultured in gas permeable Teflon bags with IL-4 and GM-CSF for 24 hours (Fast DC) or 5 days (Standard DC) to obtain immature DCs. The cells were then transfected with mRNA from the leukemia cell line Jurkat E6 by electroporation and incubated for additional 24 h or 2 days in the presence of pro-inflammatory cytokines (TNFalpha, IL-1beta, IL-6 and PGE2) to obtain mature DCs. Mature Fast DC and Standard DC displayed comparable levels of many markers expressed on DC, including HLA-DR, CD83, CD86, CD208 and CCR7. However, compared to Standard DC, mature Fast DC was CD14high CD209low. Fast DC and Standard DC transfected with Jurkat E6-cell mRNA were equally able to elicit T cell specifically recognizing transfected DCs in vitro. IFNgamma-secreting T cells were observed in both the CD4+ and CD8+ subsets. Our results indicate that mature Fast DC are functional antigen presenting cells (APCs) capable of inducing primary T-cell responses, and suggest that these cells may be valuable for generation of anti-tumor vaccines.

Retrospective Comparative Study of the Effects of Dendritic Cell Vaccine and Cytokine-Induced Killer Cell Immunotherapy with that of Chemotherapy Alone and in Combination for Colorectal Cancer

Directory of Open Access Journals (Sweden)

Jingxiu Niu

2014-01-01

Full Text Available Purpose. This retrospective study determined the delayed-type hypersensitivity (DTH skin test and safety of dendritic cell (DC vaccine and cytokine-induced killer (CIK cell immunotherapy and the survival compared to chemotherapy in 239 colorectal cancer (CRC patients. Methods. DTH and safety of the immunotherapy were recorded. The overall survival (OS and disease free survival curves were compared according to the immunotherapy and/or chemotherapy received with Kaplan-Meier estimates. Results. Of the 70 patients who received immunotherapy, 62.86% had a positive DTH skin test, 38.57% developed fever, 47.14% developed insomnia, 38.57% developed anorexia, 4.29% developed joint soreness, and 11.43% developed skin rash. For 204 resectable CRC patients, median survival time (MST (198.00 days was significantly longer in patients with immunotherapy plus chemotherapy than with chemotherapy alone (106.00 days (P=0.02. For 35 patients with unresectable or postsurgery relapsed CRC and who were confirmed to be dead, no statistical difference was observed in the MST between the patients treated with immunotherapy and with chemotherapy (P=0.41. MST in the patients treated with chemotherapy plus immunotherapy was 154 days longer than that of patients treated with chemotherapy alone (P=0.41. Conclusions. DC vaccination and CIK immunotherapy did not cause severe adverse effects, induce immune response against CRC, and prolong OS.

Antibody-antigen-adjuvant conjugates enable co-delivery of antigen and adjuvant to dendritic cells in cis but only have partial targeting specificity

NARCIS (Netherlands)

Kreutz, M.; Giquel, B.; Hu, Q.; Abuknesha, R.; Uematsu, S.; Akira, S.; Nestle, F.O.; Diebold, S.S.

2012-01-01

Antibody-antigen conjugates, which promote antigen-presentation by dendritic cells (DC) by means of targeted delivery of antigen to particular DC subsets, represent a powerful vaccination approach. To ensure immunity rather than tolerance induction the co-administration of a suitable adjuvant is

Triple co-culture cell model as an in vitro model for oral particulate vaccine systems

DEFF Research Database (Denmark)

Nielsen, Line Hagner; De Rossi, C.; Lehr, C.-M.

the immunostimulatory ability of particulate vaccine formulations designed for oral delivery. Levels of cytokine production in response to vaccine administration were measured following particulate vaccine administration, as an indication of dendritic cell and macrophage activation. Precursors of cubosomes containing......; this was not observed with ovalbumin and blank solution. An example of the results is shown in Figure 2 for IL-17A. An established co-culture of Caco-2, THP-1 and MUTZ-3 cells showed promise as an in vitro model for testing of oral vaccine formulations. Mobility of co-culture immune cells as well as cytokine production...... with particle formulations. This was not the case when incubating with ovalbumin solution or blank. The ELISA screening assay showed production of a wide range of cytokines following culture incubation with cubosomes (with and without ovalbumin) and LPS solutions, indicative of a stimulatory effect...

CD163 positive subsets of blood dendritic cells

DEFF Research Database (Denmark)

Maniecki, Maciej Bogdan; Møller, Holger Jon; Moestrup, Søren Kragh

2006-01-01

CD163 and CD91 are scavenging receptors with highly increased expression during the differentiation of monocytes into the anti-inflammatory macrophage phenotype. In addition, CD91 is expressed in monocyte-derived dendritic cells (MoDCs), where the receptor is suggested to be important...... for internalization of CD91-targeted antigens to be presented on the dendritic cell surface for T-cell stimulation. Despite their overlap in functionality, the expression of CD91 and CD163 has never been compared and the expression of CD163 in the monocyte-dendritic cell lineage is not yet characterized. CD163...... expression in dendritic cells (DCs) was investigated using multicolor flow cytometry in peripheral blood from 31 healthy donors and 15 HIV-1 patients in addition to umbilical cord blood from 5 newborn infants. Total RNA was isolated from MACS purified DCs and CD163 mRNA was determined with real-time reverse...

Dendritic Cell Targeted Chitosan Nanoparticles for Nasal DNA Immunization against SARS CoV Nucleocapsid Protein

OpenAIRE

Raghuwanshi, Dharmendra; Mishra, Vivek; Das, Dipankar; Kaur, Kamaljit; Suresh, Mavanur R.

2012-01-01

This work investigates the formulation and in vivo efficacy of dendritic cell (DC) targeted plasmid DNA loaded biotinylated chitosan nanoparticles for nasal immunization against nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus (SARS-CoV) as antigen. The induction of antigen-specific mucosal and systemic immune response at the site of virus entry is a major challenge for vaccine design. Here, we designed a strategy for non-invasive receptor mediated gene delivery to na...

A Model of Dendritic Cell Therapy for Melanoma

Directory of Open Access Journals (Sweden)

Ami eRadunskaya

2013-03-01

Full Text Available Dendritic cells are a promising immunotherapy tool for boosting an individual's antigen specific immune response to cancer. We develop a mathematical model using differential and delay-differential equations to describe the interactions between dendritic cells, effector-immune cells and tumor cells. We account for the trafficking of immune cells between lymph, blood, and tumor compartments. Our model reflects experimental results both for dendritic-cell trafficking and for immune suppression of tumor growth in mice. In addition, in silico experiments suggest more effective immunotherapy treatment protocols can be achieved by modifying dose location and schedule. A sensitivity analysis of the model reveals which patient-specific parameters have the greatest impact on treatment efficacy.

The effect of a therapeutic dendritic cell-based cancer vaccination depends on the blockage of CTLA-4 signaling

DEFF Research Database (Denmark)

Met, Ozcan; Wang, Mingjun; Pedersen, Anders E

2006-01-01

tumor cells, and later on these mice even rejected wild-type EL-4 tumor cells indicating that tumor epitope spreading takes place during the process of vaccination-induced E.G7-OVA rejection. In agreement with these observations, mice having rejected E.G7-OVA tumors showed long lasting CTL memory...... in spleen and bone marrow towards both the SIINFEKL-peptide and other EL-4-derived tumor rejecting epitopes....

Efficient elutriation of monocytes within a closed system (Elutra) for clinical-scale generation of dendritic cells.

Science.gov (United States)

Berger, Thomas G; Strasser, Erwin; Smith, Richard; Carste, Curt; Schuler-Thurner, Beatrice; Kaempgen, Eckhart; Schuler, Gerold

2005-03-01

Dendritic cells (DC) are promising tools for the immunotherapy of cancer. The induction of tumor-specific T cells and clinical regressions have already been observed in early phase I/II vaccination trials. As DC vaccination is now facing trials with larger patient collectives it becomes increasingly important to obtain large numbers of cells suitable for therapeutic applications under labor- and cost-effective conditions. We describe here a procedure that uses a novel cell separator (Elutra, Gambro BCT) to enrich monocytes from an entire apheresis product within one hour. Cells are separated on the basis of size and to a lesser extent density, by elutriation in a 40-ml conical chamber. The total monocyte recovery following elutriation (n = 6) was 98.53% (+/-8.07%), the recovery in the monocyte-rich fraction 75.45% (+/-11.31%), and the mean purity 82.95% (+/-6.01%). These monocytes can be cultured either in conventional culture dishes or in closed cell culture bags and differentiated, by using GM-CSF+IL-4 followed by a maturation cocktail composed of IL-1beta+IL-6+TNF-alpha+PGE2, into fully mature DC. The Elutra separator allows for fast and easy enrichment of monocytes within a closed system. Subsequently, elutriated monocytes can be successfully cultured into phenotypically and functionally mature DC for immunotherapeutic approaches. The method neither requires a density gradient step to enrich PBMC from leucapheresis products nor does it apply (xenogeneic) antibodies to target monocytes. Isolation of monocytes with Elutra may greatly facilitate future DC-based vaccination approaches.

The role of natural killer T cells in dendritic cell licensing, cross-priming and memory CD8+ T cell generation

Directory of Open Access Journals (Sweden)

Catherine eGottschalk

2015-07-01

Full Text Available New vaccination strategies focus on achieving CD8+ T cell (CTL immunity rather than on induction of protective antibody responses. While the requirement of CD4+ T (Th cell help in dendritic cell (DC activation and licensing, and in CTL memory induction has been described in several disease models, CTL responses may occur in a Th cell help independent manner. Natural Killer T cells (NKT cells can substitute for Th cell help and license DC as well. NKT cells produce a broad spectrum of Th1 and Th2 cytokines, thereby inducing a similar set of costimulatory molecules and cytokines in DC. This form of licensing differs from Th cell help by inducing other chemokines: while Th cell licensed DC produce CCR5 ligands, NKT cell-licensed DC produce CCL17 which attracts CCR4+ CD8+ T cells for subsequent activation. It has recently been shown that iNKT cells do not only enhance immune responses against bacterial pathogens or parasites, but also play a role in viral infections. The inclusion of NKT cell ligands in Influenza virus vaccines enhanced memory CTL generation and protective immunity in a mouse model. This review will focus on the role of iNKT cells in the cross-talk with cross-priming DC and memory CD8+ T cell formation.

RAB-10 Regulates Dendritic Branching by Balancing Dendritic Transport

Science.gov (United States)

Taylor, Caitlin A.; Yan, Jing; Howell, Audrey S.; Dong, Xintong; Shen, Kang

2015-01-01

The construction of a large dendritic arbor requires robust growth and the precise delivery of membrane and protein cargoes to specific subcellular regions of the developing dendrite. How the microtubule-based vesicular trafficking and sorting systems are regulated to distribute these dendritic development factors throughout the dendrite is not well understood. Here we identify the small GTPase RAB-10 and the exocyst complex as critical regulators of dendrite morphogenesis and patterning in the C. elegans sensory neuron PVD. In rab-10 mutants, PVD dendritic branches are reduced in the posterior region of the cell but are excessive in the distal anterior region of the cell. We also demonstrate that the dendritic branch distribution within PVD depends on the balance between the molecular motors kinesin-1/UNC-116 and dynein, and we propose that RAB-10 regulates dendrite morphology by balancing the activity of these motors to appropriately distribute branching factors, including the transmembrane receptor DMA-1. PMID:26633194

Tumour tissue microenvironment can inhibit dendritic cell maturation in colorectal cancer.

LENUS (Irish Health Repository)

Michielsen, Adriana J

2011-01-01

Inflammatory mediators in the tumour microenvironment promote tumour growth, vascular development and enable evasion of anti-tumour immune responses, by disabling infiltrating dendritic cells. However, the constituents of the tumour microenvironment that directly influence dendritic cell maturation and function are not well characterised. Our aim was to identify tumour-associated inflammatory mediators which influence the function of dendritic cells. Tumour conditioned media obtained from cultured colorectal tumour explant tissue contained high levels of the chemokines CCL2, CXCL1, CXCL5 in addition to VEGF. Pre-treatment of monocyte derived dendritic cells with this tumour conditioned media inhibited the up-regulation of CD86, CD83, CD54 and HLA-DR in response to LPS, enhancing IL-10 while reducing IL-12p70 secretion. We examined if specific individual components of the tumour conditioned media (CCL2, CXCL1, CXCL5) could modulate dendritic cell maturation or cytokine secretion in response to LPS. VEGF was also assessed as it has a suppressive effect on dendritic cell maturation. Pre-treatment of immature dendritic cells with VEGF inhibited LPS induced upregulation of CD80 and CD54, while CXCL1 inhibited HLA-DR. Interestingly, treatment of dendritic cells with CCL2, CXCL1, CXCL5 or VEGF significantly suppressed their ability to secrete IL-12p70 in response to LPS. In addition, dendritic cells treated with a combination of CXCL1 and VEGF secreted less IL-12p70 in response to LPS compared to pre-treatment with either cytokine alone. In conclusion, tumour conditioned media strongly influences dendritic cell maturation and function.

Equine dendritic cells generated with horse serum have enhanced functionality in comparison to dendritic cells generated with fetal bovine serum

OpenAIRE

Ziegler, Anja; Everett, Helen; Hamza, Eman; Garbani, Mattia; Gerber, Vinzenz; Marti, Eliane; Steinbach, Falko

2016-01-01

BACKGROUND: Dendritic cells are professional antigen-presenting cells that play an essential role in the initiation and modulation of T cell responses. They have been studied widely for their potential clinical applications, but for clinical use to be successful, alternatives to xenogeneic substances like fetal bovine serum (FBS) in cell culture need to be found. Protocols for the generation of dendritic cells ex vivo from monocytes are well established for several species, including hor...

Immune modulation by dendritic-cell-based cancer vaccines

Indian Academy of Sciences (India)

The interplay between host immunity and tumour cells has opened the possibility of targeting tumour cells bymodulation of the human immune system. Cancer immunotherapy involves the treatment of a tumour by utilizing therecombinant human immune system components to target the pro-tumour microenvironment or by ...

Progress on the development of human in vitro dendritic cell based assays for assessment of the sensitizing potential of a compound

International Nuclear Information System (INIS)

Galvao dos Santos, G.; Reinders, J.; Ouwehand, K.; Rustemeyer, T.; Scheper, R.J.; Gibbs, S.

2009-01-01

Allergic contact dermatitis is the result of an adaptive immune response of the skin to direct exposure to an allergen. Since many chemicals are also allergens, European regulations require strict screening of all ingredients in consumer products. Until recently, identifying a potential allergen has completely relied on animal testing (e.g.: Local Lymph Node Assay). In addition to the ethical problems, both the 7th Amendment to the Cosmetics Directive and REACH have stimulated the development of alternative tests for the assessment of potential sensitizers. This review is aimed at summarising the progress on cell based assays, in particular dendritic cell based assays, being developed as animal alternatives. Primary cells (CD34 + derived dendritic cells, monocyte derived dendritic cells) as well as dendritic cell-like cell lines (THP-1, U-937, MUTZ-3, KG-1, HL-60, and K562) are extensively described along with biomarkers such as cell surface markers, cytokines, chemokines and kinases. From this review, it can be concluded that no single cell based assay nor single marker is yet able to distinguish all sensitizers from non-sensitizers in a test panel of chemicals, nor is it possible to rank the sensitizing potential of the test chemicals. This suggests that sensitivity and specificity may be increased by a tiered assay approach. Only a limited number of genomic and proteomic studies have been completed until now. Such studies have the potential to identify novel biomarkers for inclusion in future assay development. Although progress is promising, this review suggests that it may be difficult to meet the up and coming European regulatory deadlines.

Strategies to Genetically Modulate Dendritic Cells to Potentiate Anti-Tumor Responses in Hematologic Malignancies

Directory of Open Access Journals (Sweden)

Annelisa M. Cornel

2018-05-01

Full Text Available Dendritic cell (DC vaccination has been investigated as a potential strategy to target hematologic malignancies, while generating sustained immunological responses to control potential future relapse. Nonetheless, few clinical trials have shown robust long-term efficacy. It has been suggested that a combination of surmountable shortcomings, such as selection of utilized DC subsets, DC loading and maturation strategies, as well as tumor-induced immunosuppression may be targeted to maximize anti-tumor responses of DC vaccines. Generation of DC from CD34+ hematopoietic stem and progenitor cells (HSPCs may provide potential in patients undergoing allogeneic HSPC transplantations for hematologic malignancies. CD34+ HSPC from the graft can be genetically modified to optimize antigen presentation and to provide sufficient T cell stimulatory signals. We here describe beneficial (gene-modifications that can be implemented in various processes in T cell activation by DC, among which major histocompatibility complex (MHC class I and MHC class II presentation, DC maturation and migration, cross-presentation, co-stimulation, and immunosuppression to improve anti-tumor responses.

Prevention and Treatment of Spontaneous Mammary Carcinoma with Dendritic Tumor Fusion Cell Vaccine

National Research Council Canada - National Science Library

Gong, Jianlin

2002-01-01

In the present study, the prevention of cancer development by vaccination with fusion cells was evaluated In a genetically engineered murine model which develops spontaneous mammary carcinomas. The mice (MMT...

The cancer-immunity cycle as rational design for synthetic cancer drugs: Novel DC vaccines and CAR T-cells.

Science.gov (United States)

Ramachandran, Mohanraj; Dimberg, Anna; Essand, Magnus

2017-08-01

Cell therapy is an advanced form of cancer immunotherapy that has had remarkable clinical progress in the past decade in the search for cure of cancer. Most success has been achieved for chimeric antigen receptor (CAR) T-cells where CAR T-cells targeting CD19 show very high complete response rates for patients with refractory acute B-cell acute lymphoblastic leukemia (ALL) and are close to approval for this indication. CD19 CAR T-cells are also effective against B-cell chronic lymphoblastic leukemia (CLL) and B-cell lymphomas. Although encouraging, CAR T-cells have not yet proven clinically effective for solid tumors. This is mainly due to the lack of specific and homogenously expressed targets to direct the T-cells against and a hostile immunosuppressive tumor microenvironment in solid tumors. Cancer vaccines based on dendritic cells (DC) are also making progress although clinical efficacy is still lacking. The likelihood of success is however increasing now when individual tumors can be sequences and patient-specific neoepitopes identified. Neoepitopes and/or neoantigens can then be included in patient-based DC vaccines. This review discusses recent advancements of DC vaccines and CAR T-cells with emphasis on the cancer-immunity cycle, and current efforts to design novel cell therapies. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Well-defined block copolymers for gene delivery to dendritic cells: probing the effect of polycation chain-length.

Science.gov (United States)

Tang, Rupei; Palumbo, R Noelle; Nagarajan, Lakshmi; Krogstad, Emily; Wang, Chun

2010-03-03

The development of safe and efficient polymer carriers for DNA vaccine delivery requires mechanistic understanding of structure-function relationship of the polymer carriers and their interaction with antigen-presenting cells. Here we have synthesized a series of diblock copolymers with well-defined chain-length using atom transfer radical polymerization and characterized the influence of polycation chain-length on the physico-chemical properties of the polymer/DNA complexes as well as the interaction with dendritic cells. The copolymers consist of a hydrophilic poly(ethylene glycol) block and a cationic poly(aminoethyl methacrylate) (PAEM) block. The average degree of polymerization (DP) of the PAEM block was varied among 19, 39, and 75, with nearly uniform distribution. With increasing PAEM chain-length, polyplexes formed by the diblock copolymers and plasmid DNA had smaller average particle size and showed higher stability against electrostatic destabilization by salt and heparin. The polymers were not toxic to mouse dendritic cells (DCs) and only displayed chain-length-dependent toxicity at a high concentration (1mg/mL). In vitro gene transfection efficiency and polyplex uptake in DCs were also found to correlate with chain-length of the PAEM block with the longer polymer chain favoring transfection and cellular uptake. The polyplexes induced a modest up-regulation of surface markers for DC maturation that was not significantly dependent on PAEM chain-length. Finally, the polyplex prepared from the longest PAEM block (DP of 75) achieved an average of 20% enhancement over non-condensed anionic dextran in terms of uptake by DCs in the draining lymph nodes 24h after subcutaneous injection into mice. Insights gained from studying such structurally well-defined polymer carriers and their interaction with dendritic cells may contribute to improved design of practically useful DNA vaccine delivery systems. Copyright 2009 Elsevier B.V. All rights reserved.

Delivery of antigen to nasal-associated lymphoid tissue microfold cells through secretory IgA targeting local dendritic cells confers protective immunity.

Science.gov (United States)

Rochereau, Nicolas; Pavot, Vincent; Verrier, Bernard; Jospin, Fabienne; Ensinas, Agathe; Genin, Christian; Corthésy, Blaise; Paul, Stéphane

2016-01-01

Transmission of mucosal pathogens relies on their ability to bind to the surfaces of epithelial cells, to cross this thin barrier, and to gain access to target cells and tissues, leading to systemic infection. This implies that pathogen-specific immunity at mucosal sites is critical for the control of infectious agents using these routes to enter the body. Although mucosal delivery would ensure the best onset of protective immunity, most of the candidate vaccines are administered through the parenteral route. The present study evaluates the feasibility of delivering the chemically bound p24gag (referred to as p24 in the text) HIV antigen through secretory IgA (SIgA) in nasal mucosae in mice. We show that SIgA interacts specifically with mucosal microfold cells present in the nasal-associated lymphoid tissue. p24-SIgA complexes are quickly taken up in the nasal cavity and selectively engulfed by mucosal dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin-positive dendritic cells. Nasal immunization with p24-SIgA elicits both a strong humoral and cellular immune response against p24 at the systemic and mucosal levels. This ensures effective protection against intranasal challenge with recombinant vaccinia virus encoding p24. This study represents the first example that underscores the remarkable potential of SIgA to serve as a carrier for a protein antigen in a mucosal vaccine approach targeting the nasal environment. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Immunotherapy of HPV-16-associated tumours with tumour cell line/dendritic cell line (TC-1/DC2.4) hybrid vaccines

Czech Academy of Sciences Publication Activity Database

Šímová, Jana; Bieblová, Jana; Jandlová, Táňa; Bubeník, Jan

2003-01-01

Roč. 2003, č. 49 (2003), s. 203-206 ISSN 0015-5500 Institutional research plan: CEZ:AV0Z5052915 Keywords : HPV16 * dendritic cells * fusion Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.527, year: 2003

Triple co-culture cell model as an in vitro model for oral particulate vaccine systems

DEFF Research Database (Denmark)

Nielsen, Line Hagner; De Rossi, C.; Lehr, C-M.

; this was not observed with ovalbumin and blank solution. An example of the results is shown in Figure 2 for IL-17A. An established co-culture of Caco-2, THP-1 and MUTZ-3 cells showed promise as an in vitro model for testing of oral vaccine formulations. Mobility of co-culture immune cells as well as cytokine production......A triple co-culture cell model of Caco-2 cells, dendritic cells and macrophages (Figure 1) has previously been developed for studying intestinal permeability in a state of inflammation [1],[2]. The aim of this study was to investigate the applicability of this cell model for testing...... the model antigen ovalbumin was spray dried to obtain a particulate vaccine model system for testing in the cell model. The precursors were shown to form cubosomes when dispersed in aqueous medium, and was therefore used as the vaccine formulation for testing on the co-cultures. After 11 days, the TEER...

Highly efficient gene delivery by mRNA electroporation in human hematopoietic cells: superiority to lipofection and passive pulsing of mRNA and to electroporation of plasmid cDNA for tumor antigen loading of dendritic cells.

Science.gov (United States)

Van Tendeloo, V F; Ponsaerts, P; Lardon, F; Nijs, G; Lenjou, M; Van Broeckhoven, C; Van Bockstaele, D R; Berneman, Z N

2001-07-01

Designing effective strategies to load human dendritic cells (DCs) with tumor antigens is a challenging approach for DC-based tumor vaccines. Here, a cytoplasmic expression system based on mRNA electroporation to efficiently introduce tumor antigens into DCs is described. Preliminary experiments in K562 cells using an enhanced green fluorescent protein (EGFP) reporter gene revealed that mRNA electroporation as compared with plasmid DNA electroporation showed a markedly improved transfection efficiency (89% versus 40% EGFP(+) cells, respectively) and induced a strikingly lower cell toxicity (15% death rate with mRNA versus 51% with plasmid DNA). Next, mRNA electroporation was applied for nonviral transfection of different types of human DCs, including monocyte-derived DCs (Mo-DCs), CD34(+) progenitor-derived DCs (34-DCs) and Langerhans cells (34-LCs). High-level transgene expression by mRNA electroporation was obtained in more than 50% of all DC types. mRNA-electroporated DCs retained their phenotype and maturational potential. Importantly, DCs electroporated with mRNA-encoding Melan-A strongly activated a Melan-A-specific cytotoxic T lymphocyte (CTL) clone in an HLA-restricted manner and were superior to mRNA-lipofected or -pulsed DCs. Optimal stimulation of the CTL occurred when Mo-DCs underwent maturation following mRNA transfection. Strikingly, a nonspecific stimulation of CTL was observed when DCs were transfected with plasmid DNA. The data clearly demonstrate that Mo-DCs electroporated with mRNA efficiently present functional antigenic peptides to cytotoxic T cells. Therefore, electroporation of mRNA-encoding tumor antigens is a powerful technique to charge human dendritic cells with tumor antigens and could serve applications in future DC-based tumor vaccines.

Human intestinal dendritic cells as controllers of mucosal immunity

Directory of Open Access Journals (Sweden)

David Bernardo

2013-06-01

Full Text Available Dendritic cells are the most potent, professional antigen-presenting cells in the body; following antigen presentation they control the type (proinflammatory/regulatory of immune response that will take place, as well as its location. Given their high plasticity and maturation ability in response to local danger signals derived from innate immunity, dendritic cells are key actors in the connection between innate immunity and adaptive immunity responses. In the gut dendritic cells control immune tolerance mechanisms against food and/or commensal flora antigens, and are also capable of initiating an active immune response in the presence of invading pathogens. Dendritic cells are thus highly efficient in controlling the delicate balance between tolerance and immunity in an environment so rich in antigens as the gut, and any factor involving these cells may impact their function, ultimately leading to the development of bowel conditions such as celiac disease or inflammatory bowel disease. In this review we shall summarize our understanding of human intestinal dendritic cells, their ability to express and induce migration markers, the various environmental factors modulating their properties, their subsets in the gut, and the problems entailed by their study, including identification strategies, differences between humans and murine models, and phenotypical variations along the gastrointestinal tract.

Targeting Radiation Therapy for Developing Dendritic Cell Based Immunotherapy of Metastatic Prostate Cancer

National Research Council Canada - National Science Library

Chakravarty, Prabir K

2006-01-01

.... The hypothesis was tested using a murine prostate cancer model, RM-1. The study showed that irradiation induces apoptosis and the irradiated tumor cells were able to activate dendritic cells and stimulate tumor specific immune response in vitro...

Uncarinic Acid C Isolated from Uncaria rhynchophylla Induces Differentiation of Th1-Promoting Dendritic Cells Through TLR4 Signaling

OpenAIRE

Kim, Kyu Sik; Pham, Thanh Nhan Nguyen; Jin, Chun-Ji; Umeyama, Akemi; Shoji, Noboru; Hashimoto, Toshihiro; Lee, Je-Jung; Takei, Masao

2011-01-01

Uncarinic acid C (URC) is triterpene isolated from Uncaria rhynchophylla and is a pharmacologically active substance. The induction of dendritic cells (DC) is critical for the induction of Ag-specific T lymphocyte responses and may be essential for the development of human vaccines relying on T cell immunity. DC might be a potential target for URC. We demonstrate that URC activates human DC as documented by phenotypic and functional maturation, and altered cytokine production. The expression ...

Allergen recognition by innate immune cells: critical role of dendritic and epithelial cells

Directory of Open Access Journals (Sweden)

Fabian eSalazar

2013-11-01

Full Text Available Allergy is an exacerbated response of the immune system against non-self-proteins called allergens and is typically characterized by biased type-2 T helper cell and deleterious IgE mediated immune responses. The allergic cascade starts with the recognition of allergens by antigen presenting cells, mainly dendritic cells, culminating in mast cell sensitization and triggering. Dendritic cells have been demonstrated to play a crucial role in orchestrating allergic diseases. Using different C-type lectin receptors dendritic cells are able to recognize and internalize a number of allergens from diverse sources leading to sensitization. Furthermore, there is increasing evidence highlighting the role of epithelial cells in triggering and modulating immune responses to allergens. As well as providing a physical barrier, epithelial cells can interact with allergens and influence dendritic cells behaviour through the release of a number of Th2 promoting cytokines. In this review we will summarise current understanding of how allergens are recognised by dendritic cells and epithelial cells and what are the consequences of such interaction in the context of allergic sensitisation and downstream events leading to allergic inflammation. Better understanding of the molecular mechanisms of allergen recognition and associated signalling pathways could enable developing more effective therapeutic strategies that target the initial steps of allergic sensitisation hence hindering development or progression of allergic diseases.

Cigarette smoke promotes dendritic cell accumulation in COPD; a Lung Tissue Research Consortium study

Directory of Open Access Journals (Sweden)

Yi Eunhee S

2010-04-01

Full Text Available Abstract Background Abnormal immune responses are believed to be highly relevant in the pathogenesis of chronic obstructive pulmonary disease (COPD. Dendritic cells provide a critical checkpoint for immunity by their capacity to both induce and suppress immunity. Although evident that cigarette smoke, the primary cause of COPD, significantly influences dendritic cell functions, little is known about the roles of dendritic cells in the pathogenesis of COPD. Methods The extent of dendritic cell infiltration in COPD tissue specimens was determined using immunohistochemical localization of CD83+ cells (marker of matured myeloid dendritic cells, and CD1a+ cells (Langerhans cells. The extent of tissue infiltration with Langerhans cells was also determined by the relative expression of the CD207 gene in COPD versus control tissues. To determine mechanisms by which dendritic cells accumulate in COPD, complimentary studies were conducted using monocyte-derived human dendritic cells exposed to cigarette smoke extract (CSE, and dendritic cells extracted from mice chronically exposed to cigarette smoke. Results In human COPD lung tissue, we detected a significant increase in the total number of CD83+ cells, and significantly higher amounts of CD207 mRNA when compared with control tissue. Human monocyte-derived dendritic cells exposed to CSE (0.1-2% exhibited enhanced survival in vitro when compared with control dendritic cells. Murine dendritic cells extracted from mice exposed to cigarette smoke for 4 weeks, also demonstrated enhanced survival compared to dendritic cells extracted from control mice. Acute exposure of human dendritic cells to CSE induced the cellular pro-survival proteins heme-oxygenase-1 (HO-1, and B cell lymphoma leukemia-x(L (Bcl-xL, predominantly through oxidative stress. Although activated human dendritic cells conditioned with CSE expressed diminished migratory CCR7 expression, their migration towards the CCR7 ligand CCL21 was not

Mouse dendritic cells pulsed with capsular polysaccharide induce resistance to lethal pneumococcal challenge: roles of T cells and B cells.

Directory of Open Access Journals (Sweden)

Noam Cohen

Full Text Available Mice are exceedingly sensitive to intra-peritoneal (IP challenge with some virulent pneumococci (LD50 = 1 bacterium. To investigate how peripheral contact with bacterial capsular polysaccharide (PS antigen can induce resistance, we pulsed bone marrow dendritic cells (BMDC of C57BL/6 mice with type 4 or type 3 PS, injected the BMDC intra-foot pad (IFP and challenged the mice IP with supra-lethal doses of pneumococci. We examined the responses of T cells and B cells in the draining popliteal lymph node and measured the effects on the bacteria in the peritoneum and blood. We now report that: 1 The PS co-localized with MHC molecules on the BMDC surface; 2 PS-specific T and B cell proliferation and IFNγ secretion was detected in the draining popliteal lymph nodes on day 4; 3 Type-specific resistance to lethal IP challenge was manifested only after day 5; 4 Type-specific IgM and IgG antibodies were detected in the sera of only some of the mice, but B cells were essential for resistance; 5 Control mice vaccinated with a single injection of soluble PS did not develop a response in the draining popliteal lymph node and were not protected; 6 Mice injected with unpulsed BMDC also did not resist challenge: In unprotected mice, pneumococci entered the blood shortly after IP inoculation and multiplied exponentially in both blood and peritoneum killing the mice within 20 hours. Mice vaccinated with PS-pulsed BMDC trapped the bacteria in the peritoneum. The trapped bacteria proliferated exponentially IP, but died suddenly at 18-20 hours. Thus, a single injection of PS antigen associated with intact BMDC is a more effective vaccine than the soluble PS alone. This model system provides a platform for studying novel aspects of PS-targeted vaccination.

Promiscuous survivin peptide induces robust CD4+ T-cell responses in the majority of vaccinated cancer patients.

Science.gov (United States)

Widenmeyer, Melanie; Griesemann, Heinrich; Stevanović, Stefan; Feyerabend, Susan; Klein, Reinhild; Attig, Sebastian; Hennenlotter, Jörg; Wernet, Dorothee; Kuprash, Dmitri V; Sazykin, Alexei Y; Pascolo, Steve; Stenzl, Arnulf; Gouttefangeas, Cécile; Rammensee, Hans-Georg

2012-07-01

CD4(+) T cells have been shown to be crucial for the induction and maintenance of cytotoxic T cell responses and to be also capable of mediating direct tumor rejection. Therefore, the anticancer therapeutic efficacy of peptide-based vaccines may be improved by addition of HLA class II epitopes to stimulate T helper cells. Survivin is an apoptosis inhibiting protein frequently overexpressed in tumors. Here we describe the first immunological evaluation of a survivin-derived CD4(+) T cell epitope in a multipeptide immunotherapy trial for prostate carcinoma patients. The survivin peptide is promiscuously presented by several human HLA-DRB1 molecules and, most importantly, is naturally processed by dendritic cells. In vaccinated patients, it was able to induce frequent, robust and multifunctional CD4(+) T cell responses, as monitored by IFN-γ ELISPOT and intracellular cytokine staining. Thus, this HLA-DR restricted epitope is broadly immunogenic and should be valuable for stimulating T helper cells in patients suffering from a wide range of tumors. Copyright © 2011 UICC.

MicroRNA-22 impairs anti-tumor ability of dendritic cells by targeting p38.

Directory of Open Access Journals (Sweden)

Xue Liang

Full Text Available Dendritic cells (DCs play a critical role in triggering anti-tumor immune responses. Their intracellular p38 signaling is of great importance in controlling DC activity. In this study, we identified microRNA-22 (miR-22 as a microRNA inhibiting p38 protein expression by directly binding to the 3' untranslated region (3'UTR of its mRNA. The p38 down-regulation further interfered with the synthesis of DC-derived IL-6 and the differentiation of DC-driven Th17 cells. Moreover, overexpression of miR-22 in DCs impaired their tumor-suppressing ability while miR-22 inhibitor could reverse this phenomenon and improve the curative effect of DC-based immunotherapy. Thus, our results highlight a suppressive role for miR-22 in the process of DC-invoked anti-tumor immunity and that blocking this microRNA provides a new strategy for generating potent DC vaccines for patients with cancer.

Radiation and Anti-Cancer Vaccines: A Winning Combination.

Science.gov (United States)

Cadena, Alexandra; Cushman, Taylor R; Anderson, Clark; Barsoumian, Hampartsoum B; Welsh, James W; Cortez, Maria Angelica

2018-01-30

The emerging combination of radiation therapy with vaccines is a promising new treatment plan in the fight against cancer. While many cancer vaccines such as MUC1, p53 CpG oligodeoxynucleotide, and SOX2 may be great candidates for antitumor vaccination, there still remain many investigations to be done into possible vaccine combinations. One fruitful partnership that has emerged are anti-tumor vaccines in combination with radiation. Radiation therapy was previously thought to be only a tool for directly or indirectly damaging DNA and therefore causing cancer cell death. Now, with much preclinical and clinical data, radiation has taken on the role of an in situ vaccine. With both cancer vaccines and radiation at our disposal, more and more studies are looking to combining vaccine types such as toll-like receptors, viral components, dendritic-cell-based, and subunit vaccines with radiation. While the outcomes of these combinatory efforts are promising, there is still much work to be covered. This review sheds light on the current state of affairs in cancer vaccines and how radiation will bring its story into the future.

Effects of dendritic cell vaccine activated with protein components of toxoplasma gondii on tumor specific CD8+ T-cells

Directory of Open Access Journals (Sweden)

Amari A

2009-12-01

Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Dendritic Cell (DC is an important antigen-presenting cell that present tumor antigen to CD8+ and CD4+ T- Lymphocytes and induce specific anti-tumor immunity. In order to induce effective anti-tumor response, an option is increasing the efficiency of antigen presentation of dendritic cells and T cell activation capacity. The aim of the present study was to investigate the effect of dendritic cell maturation with protein components of toxoplasma gondii on cytotoxic T lymphocyte activity and their infiltration in to the tumor."n"nMethods: For DC generation, bone marrow cells were cultured in the presence of GM-CSF and IL-4 for five days. After that, LPS, protein components and whole extract of toxoplasma gondii were added to the culture media and incubated for another two days for DC maturation. To generate tumor, mices were injected subcutaneously with WEHI-164 cell line. For immunotherapy 106 DCs matured with different compounds were injected around the tumor site. Infiltration of CD8+ T cells were determined by flow cytometry and cytotoxic activity was measured by LDH detection kit."n"nResults: Immunotherapy with DCs treated with protein components of toxoplasma gondii led to a significant increase in the

Maturational steps of bone marrow-derived dendritic murine epidermal cells. Phenotypic and functional studies on Langerhans cells and Thy-1+ dendritic epidermal cells in the perinatal period.

Science.gov (United States)

Elbe, A; Tschachler, E; Steiner, G; Binder, A; Wolff, K; Stingl, G

1989-10-15

The adult murine epidermis harbors two separate CD45+ bone marrow (BM)-derived dendritic cell systems, i.e., Ia+, ADPase+, Thy-1-, CD3- Langerhans cells (LC) and Ia-, ADPase-, Thy-1+, CD3+ dendritic epidermal T cells (DETC). To clarify whether the maturation of these cells from their ill-defined precursors is already accomplished before their entry into the epidermis or, alternatively, whether a specific epidermal milieu is required for the expression of their antigenic determinants, we studied the ontogeny of CD45+ epidermal cells (EC). In the fetal life, there exists a considerable number of CD45+, Ia-, ADPase+ dendritic epidermal cells. When cultured, these cells become Ia+ and, in parallel, acquire the potential of stimulating allogeneic T cell proliferation. These results imply that CD45+, Ia-, ADPase+ fetal dendritic epidermal cells are immature LC precursors and suggest that the epidermis plays a decisive role in LC maturation. The day 17 fetal epidermis also contains a small population of CD45+, Thy-1+, ADPase-, CD3- round cells. Over the course of 2 to 3 wk, they are slowly replaced by an ever increasing number of round and, finally, dendritic CD45+, Thy-1+, CD3+ EC. Thus, CD45+, Thy-1+, ADPase-, CD3- fetal EC may either be DETC precursors or, alternatively, may represent a distinctive cell system of unknown maturation potential. According to this latter theory, these cells would be eventually outnumbered by newly immigrating CD45+, Thy-1+, CD3+ T cells--the actual DETC.

Shikonin enhances efficacy of a gene-based cancer vaccine via induction of RANTES

Directory of Open Access Journals (Sweden)

Chen Hui-Ming

2012-04-01

Full Text Available Abstract Background Shikonin, a phytochemical purified from Lithospermum erythrorhizon, has been shown to confer diverse pharmacological activities, including accelerating granuloma formation, wound healing, anti-inflammation and others, and is explored for immune-modifier activities for vaccination in this study. Transdermal gene-based vaccine is an attractive approach for delivery of DNA transgenes encoding specific tumor antigens to host skin tissues. Skin dendritic cells (DCs, a potent antigen-presenting cell type, is known to play a critical role in transmitting and orchestrating tumor antigen-specific immunities against cancers. The present study hence employs these various components for experimentation. Method The mRNA and protein expression of RANTES were detected by RT-PCR and ELISA, respectively. The regional expression of RANTES and tissue damage in test skin were evaluated via immunohistochemistry assay. Fluorescein isothiocyanate sensitization assay was performed to trace the trafficking of DCs from the skin vaccination site to draining lymph nodes. Adjuvantic effect of shikonin on gene gun-delivered human gp100 (hgp100 DNA cancer vaccine was studied in a human gp100-transfected B16 (B16/hgp100 tumor model. Results Among various phytochemicals tested, shikonin induced the highest level of expression of RANTES in normal skin tissues. In comparison, mouse RANTES cDNA gene transfection induced a higher level of mRANTES expression for a longer period, but caused more extensive skin damage. Topical application of shikonin onto the immunization site before gene gun-mediated vaccination augmented the population of skin DCs migrating into the draining lymph nodes. A hgp100 cDNA gene vaccination regimen with shikonin pretreatment as an adjuvant in a B16/hgp100 tumor model increased cytotoxic T lymphocyte activities in splenocytes and lymph node cells on target tumor cells. Conclusion Together, our findings suggest that shikonin can

Multiple dendritic cell populations activate CD4+ T cells after viral stimulation.

Directory of Open Access Journals (Sweden)

Adele M Mount

2008-02-01

Full Text Available Dendritic cells (DC are a heterogeneous cell population that bridge the innate and adaptive immune systems. CD8alpha DC play a prominent, and sometimes exclusive, role in driving amplification of CD8(+ T cells during a viral infection. Whether this reliance on a single subset of DC also applies for CD4(+ T cell activation is unknown. We used a direct ex vivo antigen presentation assay to probe the capacity of flow cytometrically purified DC populations to drive amplification of CD4(+ and CD8(+ T cells following infection with influenza virus by different routes. This study examined the contributions of non-CD8alpha DC populations in the amplification of CD8(+ and CD4(+ T cells in cutaneous and systemic influenza viral infections. We confirmed that in vivo, effective immune responses for CD8(+ T cells are dominated by presentation of antigen by CD8alpha DC but can involve non-CD8alpha DC. In contrast, CD4(+ T cell responses relied more heavily on the contributions of dermal DC migrating from peripheral lymphoid tissues following cutaneous infection, and CD4 DC in the spleen after systemic infection. CD4(+ T cell priming by DC subsets that is dependent upon the route of administration raises the possibility that vaccination approaches could be tailored to prime helper T cell immunity.

Design of a potent CD1d-binding NKT cell ligand as a vaccine adjuvant

OpenAIRE

Li, Xiangming; Fujio, Masakazu; Imamura, Masakazu; Wu, Douglass; Vasan, Sandhya; Wong, Chi-Huey; Ho, David D.; Tsuji, Moriya

2010-01-01

The glycolipid α-galactosylceramide (α-GalCer) has been shown to bind CD1d molecules to activate invariant natural killer T (iNKT) cells, and subsequently induce activation of various immune-competent cells, including dendritic cells, thereby providing a significant adjuvant effect for various vaccines. However, in phase I clinical trials, α-GalCer was shown to display only marginal biological activity. In our search for a glycolipid that can exert more potent stimulatory activity against iNK...

Dendritic nonlinearities are tuned for efficient spike-based computations in cortical circuits.

Science.gov (United States)

Ujfalussy, Balázs B; Makara, Judit K; Branco, Tiago; Lengyel, Máté

2015-12-24

Cortical neurons integrate thousands of synaptic inputs in their dendrites in highly nonlinear ways. It is unknown how these dendritic nonlinearities in individual cells contribute to computations at the level of neural circuits. Here, we show that dendritic nonlinearities are critical for the efficient integration of synaptic inputs in circuits performing analog computations with spiking neurons. We developed a theory that formalizes how a neuron's dendritic nonlinearity that is optimal for integrating synaptic inputs depends on the statistics of its presynaptic activity patterns. Based on their in vivo preynaptic population statistics (firing rates, membrane potential fluctuations, and correlations due to ensemble dynamics), our theory accurately predicted the responses of two different types of cortical pyramidal cells to patterned stimulation by two-photon glutamate uncaging. These results reveal a new computational principle underlying dendritic integration in cortical neurons by suggesting a functional link between cellular and systems--level properties of cortical circuits.

Colocalization of a CD1d-Binding Glycolipid with a Radiation-Attenuated Sporozoite Vaccine in Lymph Node-Resident Dendritic Cells for a Robust Adjuvant Effect.

Science.gov (United States)

Li, Xiangming; Kawamura, Akira; Andrews, Chasity D; Miller, Jessica L; Wu, Douglass; Tsao, Tiffany; Zhang, Min; Oren, Deena; Padte, Neal N; Porcelli, Steven A; Wong, Chi-Huey; Kappe, Stefan H I; Ho, David D; Tsuji, Moriya

2015-09-15

A CD1d-binding glycolipid, α-Galactosylceramide (αGalCer), activates invariant NK T cells and acts as an adjuvant. We previously identified a fluorinated phenyl ring-modified αGalCer analog, 7DW8-5, displaying nearly 100-fold stronger CD1d binding affinity. In the current study, 7DW8-5 was found to exert a more potent adjuvant effect than αGalCer for a vaccine based on radiation-attenuated sporozoites of a rodent malaria parasite, Plasmodium yoelii, also referred to as irradiated P. yoelii sporozoites (IrPySpz). 7DW8-5 had a superb adjuvant effect only when the glycolipid and IrPySpz were conjointly administered i.m. Therefore, we evaluated the effect of distinctly different biodistribution patterns of αGalCer and 7DW8-5 on their respective adjuvant activities. Although both glycolipids induce a similar cytokine response in sera of mice injected i.v., after i.m. injection, αGalCer induces a systemic cytokine response, whereas 7DW8-5 is locally trapped by CD1d expressed by dendritic cells (DCs) in draining lymph nodes (dLNs). Moreover, the i.m. coadministration of 7DW8-5 with IrPySpz results in the recruitment of DCs to dLNs and the activation and maturation of DCs. These events cause the potent adjuvant effect of 7DW8-5, resulting in the enhancement of the CD8(+) T cell response induced by IrPySpz and, ultimately, improved protection against malaria. Our study is the first to show that the colocalization of a CD1d-binding invariant NK T cell-stimulatory glycolipid and a vaccine, like radiation-attenuated sporozoites, in dLN-resident DCs upon i.m. conjoint administration governs the potency of the adjuvant effect of the glycolipid. Copyright © 2015 by The American Association of Immunologists, Inc.

Dengue-2 and yellow fever 17DD viruses infect human dendritic cells, resulting in an induction of activation markers, cytokines and chemokines and secretion of different TNF-α and IFN-α profiles

Directory of Open Access Journals (Sweden)

Mariana Gandini

2011-08-01

Full Text Available Flaviviruses cause severe acute febrile and haemorrhagic infections, including dengue and yellow fever and the pathogenesis of these infections is caused by an exacerbated immune response. Dendritic cells (DCs are targets for dengue virus (DENV and yellow fever virus (YF replication and are the first cell population to interact with these viruses during a natural infection, which leads to an induction of protective immunity in humans. We studied the infectivity of DENV2 (strain 16681, a YF vaccine (YF17DD and a chimeric YF17D/DENV2 vaccine in monocyte-derived DCs in vitro with regard to cell maturation, activation and cytokine production. Higher viral antigen positive cell frequencies were observed for DENV2 when compared with both vaccine viruses. Flavivirus-infected cultures exhibited dendritic cell activation and maturation molecules. CD38 expression on DCs was enhanced for both DENV2 and YF17DD, whereas OX40L expression was decreased as compared to mock-stimulated cells, suggesting that a T helper 1 profile is favoured. Tumor necrosis factor (TNF-α production in cell cultures was significantly higher in DENV2-infected cultures than in cultures infected with YF17DD or YF17D/DENV. In contrast, the vaccines induced higher IFN-α levels than DENV2. The differential cytokine production indicates that DENV2 results in TNF induction, which discriminates it from vaccine viruses that preferentially stimulate interferon expression. These differential response profiles may influence the pathogenic infection outcome.

Immunity and Tolerance Induced by Intestinal Mucosal Dendritic Cells

Directory of Open Access Journals (Sweden)

Julio Aliberti

2016-01-01

Full Text Available Dendritic cells present in the digestive tract are constantly exposed to environmental antigens, commensal flora, and invading pathogens. Under steady-state conditions, these cells have high tolerogenic potential, triggering differentiation of regulatory T cells to protect the host from unwanted proinflammatory immune responses to innocuous antigens or commensals. On the other hand, these cells must discriminate between commensal flora and invading pathogens and mount powerful immune response against pathogens. A potential result of unbalanced tolerogenic versus proinflammatory responses mediated by dendritic cells is associated with chronic inflammatory conditions, such as Crohn’s disease, ulcerative colitis, food allergies, and celiac disease. Herein, we review the dendritic cell population involved in mediating tolerance and immunity in mucosal surfaces, the progress in unveiling their development in vivo, and factors that can influence their functions.

Harnessing naturally occurring tumor immunity: a clinical vaccine trial in prostate cancer.

Directory of Open Access Journals (Sweden)

Mayu O Frank

2010-09-01

Full Text Available Studies of patients with paraneoplastic neurologic disorders (PND have revealed that apoptotic tumor serves as a potential potent trigger for the initiation of naturally occurring tumor immunity. The purpose of this study was to assess the feasibility, safety, and immunogenicity of an apoptotic tumor-autologous dendritic cell (DC vaccine.We have modeled PND tumor immunity in a clinical trial in which apoptotic allogeneic prostate tumor cells were used to generate an apoptotic tumor-autologous dendritic cell vaccine. Twenty-four prostate cancer patients were immunized in a Phase I, randomized, single-blind, placebo-controlled study to assess the safety and immunogenicity of this vaccine. Vaccinations were safe and well tolerated. Importantly, we also found that the vaccine was immunogenic, inducing delayed type hypersensitivity (DTH responses and CD4+ and CD8+ T cell proliferation, with no effect on FoxP3+ regulatory T cells. A statistically significant increase in T cell proliferation responses to prostate tumor cells in vitro (p = 0.002, decrease in prostate specific antigen (PSA slope (p = 0.016, and a two-fold increase in PSA doubling time (p = 0.003 were identified when we compared data before and after vaccination.An apoptotic cancer cell vaccine modeled on naturally occurring tumor immune responses in PND patients provides a safe and immunogenic tumor vaccine.ClinicalTrials.gov NCT00289341.

File list: Unc.Bld.50.AllAg.Dendritic_Cells [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available Unc.Bld.50.AllAg.Dendritic_Cells hg19 Unclassified Blood Dendritic Cells SRX818200,...203,SRX818202,SRX818182,SRX818195,SRX818196,SRX818181 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Unc.Bld.50.AllAg.Dendritic_Cells.bed ...

File list: Unc.Bld.20.AllAg.Dendritic_Cells [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available Unc.Bld.20.AllAg.Dendritic_Cells hg19 Unclassified Blood Dendritic Cells SRX818200,...189,SRX818202,SRX818182,SRX818195,SRX818196,SRX818181 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Unc.Bld.20.AllAg.Dendritic_Cells.bed ...

Induction and maintenance of protective CD8+ T cells against malaria liver stages: implications for vaccine development

Directory of Open Access Journals (Sweden)

Sze-Wah Tse

2011-08-01

Full Text Available CD8+ T cells against malaria liver stages represent a major protective immune mechanism against infection. Following induction in the peripheral lymph nodes by dendritic cells (DCs, these CD8+ T cells migrate to the liver and eliminate parasite infected hepatocytes. The processing and presentation of sporozoite antigen requires TAP mediated transport of major histocompatibility complex class I epitopes to the endoplasmic reticulum. Importantly, in DCs this process is also dependent on endosome-mediated cross presentation while this mechanism is not required for epitope presentation on hepatocytes. Protective CD8+ T cell responses are strongly dependent on the presence of CD4+ T cells and the capacity of sporozoite antigen to persist for a prolonged period of time. While human trials with subunit vaccines capable of inducing antibodies and CD4+ T cell responses have yielded encouraging results, an effective anti-malaria vaccine will likely require vaccine constructs designed to induce protective CD8+ T cells against malaria liver stages.

Caspase-2-dependent dendritic cell death, maturation, and priming of T cells in response to Brucella abortus infection.

Directory of Open Access Journals (Sweden)

Xinna Li

Full Text Available Smooth virulent Brucella abortus strain 2308 (S2308 causes zoonotic brucellosis in cattle and humans. Rough B. abortus strain RB51, derived from S2308, is a live attenuated cattle vaccine strain licensed in the USA and many other countries. Our previous report indicated that RB51, but not S2308, induces a caspase-2-dependent apoptotic and necrotic macrophage cell death. Dendritic cells (DCs are professional antigen presenting cells critical for bridging innate and adaptive immune responses. In contrast to Brucella-infected macrophages, here we report that S2308 induced higher levels of apoptotic and necrotic cell death in wild type bone marrow-derived DCs (WT BMDCs than RB51. The RB51 and S2308-induced BMDC cell death was regulated by caspase-2, indicated by the minimal cell death in RB51 and S2308-infected BMDCs isolated from caspase-2 knockout mice (Casp2KO BMDCs. More S2308 bacteria were taken up by Casp2KO BMDCs than wild type BMDCs. Higher levels of S2308 and RB51 cells were found in infected Casp2KO BMDCs compared to infected WT BMDCs at different time points. RB51-infected wild type BMDCs were mature and activated as shown by significantly up-regulated expression of CD40, CD80, CD86, MHC-I, and MHC-II. RB51 induced the production of cytokines TNF-α, IL-6, IFN-γ and IL12/IL23p40 in infected BMDCs. RB51-infected WT BMDCs also stimulated the proliferation of CD4(+ and CD8(+ T cells compared to uninfected WT BMDCs. However, the maturation, activation, and cytokine secretion are significantly impaired in Casp2KO BMDCs infected with RB51 or Salmonella (control. S2308-infected WT and Casp2KO BMDCs were not activated and could not induce cytokine production. These results demonstrated that virulent smooth strain S2308 induced more apoptotic and necrotic dendritic cell death than live attenuated rough vaccine strain RB51; however, RB51, but not its parent strain S2308, induced caspase-2-mediated DC maturation, cytokine production, antigen

The administration route is decisive for the ability of the vaccine adjuvant CAF09 to induce antigen-specific CD8(+) T-cell responses

DEFF Research Database (Denmark)

Schmidt, Signe Tandrup; Khadke, Swapnil; Korsholm, Karen Smith

2016-01-01

A prerequisite for vaccine-mediated induction of CD8(+) T-cell responses is the targeting of dendritic cell (DC) subsets specifically capable of cross-presenting antigen epitopes to CD8(+) T cells. Administration of a number of cationic adjuvants via the intraperitoneal (i.p.) route has been show...

Effective Respiratory CD8 T-Cell Immunity to Influenza Virus Induced by Intranasal Carbomer-Lecithin-Adjuvanted Non-replicating Vaccines

Science.gov (United States)

Gasper, David J.; Neldner, Brandon; Plisch, Erin H.; Rustom, Hani; Imai, Hirotaka; Kawaoka, Yoshihiro; Suresh, M.

2016-01-01

CD8+ cytotoxic T lymphocytes (CTLs) are critical for clearing many viral infections, and protective CTL memory can be induced by vaccination with attenuated viruses and vectors. Non-replicating vaccines are typically potentiated by the addition of adjuvants that enhance humoral responses, however few are capable of generating CTL responses. Adjuplex is a carbomer-lecithin-based adjuvant demonstrated to elicit robust humoral immunity to non-replicating antigens. We report that mice immunized with non-replicating Adjuplex-adjuvanted vaccines generated robust antigen-specific CTL responses. Vaccination by the subcutaneous or the intranasal route stimulated systemic and mucosal CTL memory respectively. However, only CTL memory induced by intranasal vaccination was protective against influenza viral challenge, and correlated with an enhancement of memory CTLs in the airways and CD103+ CD69+ CXCR3+ resident memory-like CTLs in the lungs. Mechanistically, Myd88-deficient mice mounted primary CTL responses to Adjuplex vaccines that were similar in magnitude to wild-type mice, but exhibited altered differentiation of effector cell subsets. Immune potentiating effects of Adjuplex entailed alterations in the frequency of antigen-presenting-cell subsets in vaccine draining lymph nodes, and in the lungs and airways following intranasal vaccination. Further, Adjuplex enhanced the ability of dendritic cells to promote antigen-induced proliferation of naïve CD8 T cells by modulating antigen uptake, its intracellular localization, and rate of processing. Taken together, we have identified an adjuvant that elicits both systemic and mucosal CTL memory to non-replicating antigens, and engenders protective CTL-based heterosubtypic immunity to influenza A virus in the respiratory tract. Further, findings presented in this manuscript have provided key insights into the mechanisms and factors that govern the induction and programming of systemic and protective memory CTLs in the

Macrophage galactose-type C-type lectin receptor for DC targeting of antitumor glycopeptide vaccines

DEFF Research Database (Denmark)

Nuti, M; Zizzari, I; Napoletano, C

2011-01-01

e13528 Background: Dendritic cells (DCs) are the most potent antigen presenting cells and are employed in cancer vaccination. Several receptors are being studied in order to identif strategies to increase DCs activating capacity. The C-type lectin macrophage galactose type C-type lectin (MGL...... of IFNg and IL-2 secretion by both CD8 and CD4 T cells. CONCLUSIONS: These results demonstrate that MGL engagement profoundly affects DC plasticity inducing and directing a Th1 immune response. Moreover, MGL receptor expressed on human DC can be targeted by glycopeptide based vaccines with adjuvant...

Sensitivity of Dendritic Cells to Microenvironment Signals

Directory of Open Access Journals (Sweden)

Juliana Maria Motta

2016-01-01

Full Text Available Dendritic cells are antigen-presenting cells capable of either activating the immune response or inducing and maintaining immune tolerance. They do this by integrating stimuli from the environment and changing their functional status as a result of plasticity. The modifications suffered by these cells have consequences in the way the organism may respond. In the present work two opposing situations known to affect dendritic cells are analyzed: tumor growth, leading to a microenvironment that favors the induction of a tolerogenic profile, and organ transplantation, which leads to a proinflammatory profile. Lessons learned from these situations may help to understand the mechanisms of modulation resulting not only from the above circumstances, but also from other pathologies.

Full restoration of Brucella-infected dendritic cell functionality through Vγ9Vδ2 T helper type 1 crosstalk.

Directory of Open Access Journals (Sweden)

Ming Ni

Full Text Available Vγ9Vδ2 T cells play an important role in the immune response to infectious agents but the mechanisms contributing to this immune process remain to be better characterized. Following their activation, Vγ9Vδ2 T cells develop cytotoxic activity against infected cells, secrete large amounts of cytokines and influence the function of other effectors of immunity, notably cells playing a key role in the initiation of the adaptive immune response such as dendritic cells. Brucella infection dramatically impairs dendritic cell maturation and their capacity to present antigens to T cells. Herein, we investigated whether V T cells have the ability to restore the full functional capacities of Brucella-infected dendritic cells. Using an in vitro multicellular infection model, we showed that: 1/Brucella-infected dendritic cells activate Vγ9Vδ2 T cells through contact-dependent mechanisms, 2/activated Vγ9Vδ2 T cells induce full differentiation into IL-12 producing cells of Brucella-infected dendritic cells with functional antigen presentation activity. Furthermore, phosphoantigen-activated Vγ9Vδ2 T cells also play a role in triggering the maturation process of dendritic cells already infected for 24 h. This suggests that activated Vγ9Vδ2 T cells could be used to modulate the outcome of infectious diseases by promoting an adjuvant effect in dendritic cell-based cellular therapies.

Role of Dendritic Cells in Immune Dysfunction

Science.gov (United States)

Savary, Cherylyn A.

1997-01-01

Specific aims include: (1) Application of the bioreactor to enhance cytokine-regulated proliferation and maturation of dendritic cells (DC); (2) Based on clues from spaceflight: compare the frequency and function of DC in normal donors and immunocompromised cancer patients; and (3) Initiate studies on the efficiency of cytokine therapy and DC-assisted immunotherapy (using bioreactor-expanded DC) in animal models of experimental fungal infections.

Antitumour responses induced by a cell-based Reovirus vaccine in murine lung and melanoma models

International Nuclear Information System (INIS)

Campion, Ciorsdan A.; Soden, Declan; Forde, Patrick F.

2016-01-01

The ever increasing knowledge in the areas of cell biology, the immune system and the mechanisms of cancer are allowing a new phase of immunotherapy to develop. The aim of cancer vaccination is to activate the host immune system and some success has been observed particularly in the use of the BCG vaccine for bladder cancer as an immunostimulant. Reovirus, an orphan virus, has proven itself as an oncolytic virus in vitro and in vivo. Over 80 % of tumour cell lines have been found to be susceptible to Reovirus infection and it is currently in phase III clinical trials. It has been shown to induce immune responses to tumours with very low toxicities. In this study, Reovirus was examined in two main approaches in vivo, in mice, using the melanoma B16F10 and Lewis Lung Carcinoma (LLC) models. Initially, mice were treated intratumourally (IT) with Reovirus and the immune responses determined by cytokine analysis. Mice were also vaccinated using a cell-based Reovirus vaccine and subsequently exposed to a tumourigenic dose of cells (B16F10 or LLC). Using the same cell-based Reovirus vaccine, established tumours were treated and subsequent immune responses and virus retrieval investigated. Upregulation of several cytokines was observed following treatment and replication-competent virus was also retrieved from treated tumours. Varying levels of cytokine upregulation were observed and no replication-competent virus was retrieved in vaccine-treated mice. Prolongation of survival and delayed tumour growth were observed in all models and an immune response to Reovirus, either using Reovirus alone or a cell-based vaccine was also observed in all mice. This study provides evidence of immune response to tumours using a cell-based Reovirus vaccine in both tumour models investigated, B16F10 and LLC, cytokine induction was observed with prolongation of survival in almost all cases which may suggest a new method for using Reovirus in the clinic

Chemoresistance of human monocyte-derived dendritic cells is regulated by IL-17A.

Directory of Open Access Journals (Sweden)

Selma Olsson Åkefeldt

Full Text Available Dendritic cells initiate adaptive immune responses, leading either to control cancer by effector T cells or to exacerbate cancer by regulatory T cells that inhibit IFN-γ-mediated Th1-type response. Dendritic cells can also induce Th17-type immunity, mediated by IL-17A. However, the controversial role of this cytokine in cancer requires further investigations. We generated dendritic cells from peripheral blood monocytes to investigate lifespan, phenotype and chemoresistance of dendritic cells, treated with IL-17A with or without IFN-γ. Studying the expression of Bcl-2 family members, we demonstrated that dendritic cells constitutively express one pro-survival Bcl-2 member: MCL1. Immature dendritic cells were CD40(lowHLADR(low CD1a(+ MCL1(+, did not express CD14, CD68 or BCL2A1, and displayed a short 2-day lifespan. IL-17A-treated DC exhibited a semi-mature (CD40(high HLADR(low pre-M2 (CCL22(+ CD206(+ CD163(+ IL1RN(+ IL-10(- CXCL10(- IL-12(- mixed (CD1a(+ CD14+ CD68(+ macrophage-dendritic cell phenotype. They efficiently exerted mannose receptor-mediated endocytosis and did not produce superoxide anions, in the absence of TLR engagement. Interestingly, IL-17A promoted a long-term survival of dendritic cells, beyond 12 days, that correlated to BCL2A1 induction, a pro-survival Bcl-2 family member. BCL2A1 transcription was activated by NF-κB, downstream of IL-17A transduction. Thus, immature dendritic cells only express MCL1, whereas IL-17A-treated dendritic cells concomitantly expressed two pro-survival Bcl-2 family members: MCL1 and BCL2A1. These latter developed chemoresistance to 11 of the 17 chemotherapy agents tested. However, high doses of either vinblastine or cytarabine decreased MCL1 expression and induced dendritic cell death. When IL-17A is produced in vivo, administration of anti-IL-17A biotherapy may impair dendritic cell survival by targeting BCL2A1 expression. Consequently, depending on the effector or regulatory role of dendritic

Dendritic branching of olfactory bulb mitral and tufted cells: regulation by TrkB.

Directory of Open Access Journals (Sweden)

Fumiaki Imamura

2009-08-01

Full Text Available Projection neurons of mammalian olfactory bulb (OB, mitral and tufted cells, have dendrites whose morphologies are specifically differentiated for efficient odor information processing. The apical dendrite extends radially and arborizes in single glomerulus where it receives primary input from olfactory sensory neurons that express the same odor receptor. The lateral dendrites extend horizontally in the external plexiform layer and make reciprocal dendrodendritic synapses with granule cells, which moderate mitral/tufted cell activity. The molecular mechanisms regulating dendritic development of mitral/tufted cells is one of the unsolved important problems in the olfactory system. Here, we focused on TrkB receptors to test the hypothesis that neurotrophin-mediate mechanisms contributed to dendritic differentiation of OB mitral/tufted cells.With immunohistochemical analysis, we found that the TrkB neurotrophin receptor is expressed by both apical and lateral dendrites of mitral/tufted cells and that expression is evident during the early postnatal days when these dendrites exhibit their most robust growth and differentiation. To examine the effect of TrkB activation on mitral/tufted cell dendritic development, we cultured OB neurons. When BDNF or NT4 were introduced into the cultures, there was a significant increase in the number of primary neurites and branching points among the mitral/tufted cells. Moreover, BDNF facilitated filopodial extension along the neurites of mitral/tufted cells.In this report, we show for the first time that TrkB activation stimulates the dendritic branching of mitral/tufted cells in developing OB. This suggests that arborization of the apical dendrite in a glomerulus is under the tight regulation of TrkB activation.

Clinical development of a novel CD1d-binding NKT cell ligand as a vaccine adjuvant.

Science.gov (United States)

Padte, Neal N; Li, Xiangming; Tsuji, Moriya; Vasan, Sandhya

2011-08-01

Natural killer T (NKT) cells are known to play a role against certain microbial infections, including malaria and HIV, two major global infectious diseases. Strategies that can harness and amplify the immunotherapeutic potential of NKT cells can serve as powerful tools in the fight against such diseases. 7DW8-5, a novel glycolipid, may be one such tool. The interaction of 7DW8-5 with CD1d molecules induces activation of NKT cells, thereby activating various immune-competent cells including dendritic cells (DCs) to provide a significant adjuvant effect for several vaccines. This review discusses the discovery and characterization of 7DW8-5 and the practical considerations of its preclinical and clinical development as a potential glycolipid adjuvant for candidate malaria and HIV vaccines. Copyright © 2010. Published by Elsevier Inc.

Dendritic cells modified by vitamin D

DEFF Research Database (Denmark)

Pedersen, Ayako Wakatsuki; Claesson, Mogens Helweg; Zocca, Mai-Britt

2011-01-01

Dendritic cells (DCs), the most potent antigen-presenting cells of the immune system, express nuclear receptors for 1,25-dihydroxyvitamin D(3) (VD3) and they are one of its main targets. In the presence of VD3, DCs differentiate into a phenotype that resembles semimature DCs, with reduced T cell ...

Modified vaccinia virus Ankara triggers type I IFN production in murine conventional dendritic cells via a cGAS/STING-mediated cytosolic DNA-sensing pathway.

Directory of Open Access Journals (Sweden)

Peihong Dai

2014-04-01

Full Text Available Modified vaccinia virus Ankara (MVA is an attenuated poxvirus that has been engineered as a vaccine against infectious agents and cancers. Our goal is to understand how MVA modulates innate immunity in dendritic cells (DCs, which can provide insights to vaccine design. In this study, using murine bone marrow-derived dendritic cells, we assessed type I interferon (IFN gene induction and protein secretion in response to MVA infection. We report that MVA infection elicits the production of type I IFN in murine conventional dendritic cells (cDCs, but not in plasmacytoid dendritic cells (pDCs. Transcription factors IRF3 (IFN regulatory factor 3 and IRF7, and the positive feedback loop mediated by IFNAR1 (IFN alpha/beta receptor 1, are required for the induction. MVA induction of type I IFN is fully dependent on STING (stimulator of IFN genes and the newly discovered cytosolic DNA sensor cGAS (cyclic guanosine monophosphate-adenosine monophosphate synthase. MVA infection of cDCs triggers phosphorylation of TBK1 (Tank-binding kinase 1 and IRF3, which is abolished in the absence of cGAS and STING. Furthermore, intravenous delivery of MVA induces type I IFN in wild-type mice, but not in mice lacking STING or IRF3. Treatment of cDCs with inhibitors of endosomal and lysosomal acidification or the lysosomal enzyme Cathepsin B attenuated MVA-induced type I IFN production, indicating that lysosomal enzymatic processing of virions is important for MVA sensing. Taken together, our results demonstrate a critical role of the cGAS/STING-mediated cytosolic DNA-sensing pathway for type I IFN induction in cDCs by MVA. We present evidence that vaccinia virulence factors E3 and N1 inhibit the activation of IRF3 and the induction of IFNB gene in MVA-infected cDCs.

Dendritic cells: biology of the skin

NARCIS (Netherlands)

Toebak, M.J.; Gibbs, S.; Bruynzeel, D.P.; Scheper, R.J.; Rustemeyer, T.

2009-01-01

Allergic contact dermatitis results from a T-cell-mediated, delayed-type hypersensitivity immune response induced by allergens. Skin dendritic cells (DCs) play a central role in the initiation of allergic skin responses. Following encounter with an allergen, DCs become activated and undergo

File list: InP.Bld.10.AllAg.Dendritic_Cells [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available InP.Bld.10.AllAg.Dendritic_Cells hg19 Input control Blood Dendritic Cells SRX627429...,SRX627427 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/InP.Bld.10.AllAg.Dendritic_Cells.bed ...

Dendritic cell activation and maturation induced by recombinant calreticulin fragment 39-272.

Science.gov (United States)

Li, Yue; Zeng, Xiaoli; He, Lijuan; Yuan, Hui

2015-01-01

Dendritic cells (DC) are the most potent antigen-presenting cells for initiating immune responses. DC maturation can be induced by exposing of immature DC to pathogen products or pro-inflammatory factor, which dramatically enhances the ability of DC to activate Ag-specific T cells. In this study, a recombinant calreticulin fragment 39-272 (rCRT/39-272) covering the lectin-like N domain and partial P domain of murine CRT has been expressed and purified in Escherichia coli. Functional analysis studies revealed that rCRT/39-272 has potent immunostimulatory activities in both activating human monocytes and B cells to secrete cytokines. rCRT/39-272 can drive the activation of bone marrow derived DC in TLR4/CD14 dependent way, as indicated by secretion of cytokines IL-12/IL-23 (p40) and IL-1β. Exposure of DC to rCRT/39-272 induces P-Akt, suggesting that rCRT/39-272 induces maturation of DC through PI3K/Akt signaling pathway. The results suggest that soluble rCRT/39-272 is a potent stimulatory agent to DC maturation in TLR4/CD14 and PI3K/Akt dependent pathway. It may play important roles in initiating cellular immunity in vivo and the T cell response in vitro. Thus it could be used for study of DC-based tumor vaccines.

Xenopus laevis Retinal Ganglion Cell Dendritic Arbors Develop Independently of Visual Stimulation

Directory of Open Access Journals (Sweden)

Barbara Lom

2004-01-01

Full Text Available Newly formed neurons must locate their appropriate target cells and then form synaptic connections with these targets in order to establish a functional nervous system. In the vertebrate retina, retinal ganglion cell (RGC dendrites extend from the cell body and form synapses with nearby amacrine and bipolar cells. RGC axons, however, exit the retina and synapse with the dendrites of midbrain neurons in the optic tectum. We examined how visual stimulation influenced Xenopus RGC dendritic arborization. Neuronal activity is known to be an important factor in shaping dendritic and axonal arborization. Thus, we reared tadpoles in dark and light environments then used rhodamine dextran retrograde labeling to identify RGCs in the retina. When we compared RGC dendritic arbors from tadpoles reared in dark and light environments, we found no morphological differences, suggesting that physiological visual activity did not contribute to the morphological development of Xenopus RGC dendritic arbors.

Antigen dynamics of follicular dendritic cells

NARCIS (Netherlands)

Heesters, B.A.

2015-01-01

Stromal-derived follicular dendritic cells (FDCs) are a major depot for antigen that are essential for formation of germinal centers, the site where memory and effector B cells differentiate and high-affinity antibody production takes place. Historically, FDCs have been characterized as ‘accessory’

Recombinant allergy vaccines based on allergen-derived B cell epitopes.

Science.gov (United States)

Valenta, Rudolf; Campana, Raffaela; Niederberger, Verena

2017-09-01

Immunoglobulin E (IgE)-associated allergy is the most common immunologically-mediated hypersensitivity disease. It affects more than 25% of the population. In IgE-sensitized subjects, allergen encounter can causes a variety of symptoms ranging from hayfever (allergic rhinoconjunctivitis) to asthma, skin inflammation, food allergy and severe life-threatening anaphylactic shock. Allergen-specific immunotherapy (AIT) is based on vaccination with the disease-causing allergens. AIT is an extremely effective, causative and disease-modifying treatment. However, administration of natural allergens can cause severe side effects and the quality of natural allergen extracts limits its application. Research in the field of molecular allergen characterization has allowed deciphering the molecular structures of the disease-causing allergens and it has become possible to engineer novel molecular allergy vaccines which precisely target the mechanisms of the allergic immune response and even appear suitable for prophylactic allergy vaccination. Here we discuss recombinant allergy vaccines which are based on allergen-derived B cell epitopes regarding their molecular and immunological properties and review the results obtained in clinical studies with this new type of allergy vaccines. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

File list: InP.Bld.05.AllAg.Dendritic_Cells [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available InP.Bld.05.AllAg.Dendritic_Cells mm9 Input control Blood Dendritic Cells SRX885956,...76,SRX122481,SRX667880,SRX667874,SRX667878 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Bld.05.AllAg.Dendritic_Cells.bed ...

Vaccination with Necroptotic Cancer Cells Induces Efficient Anti-tumor Immunity

Directory of Open Access Journals (Sweden)

Tania Løve Aaes

2016-04-01

Full Text Available Successful immunogenic apoptosis in experimental cancer therapy depends on the induction of strong host anti-tumor responses. Given that tumors are often resistant to apoptosis, it is important to identify alternative molecular mechanisms that elicit immunogenic cell death. We have developed a genetic model in which direct dimerization of FADD combined with inducible expression of RIPK3 promotes necroptosis. We report that necroptotic cancer cells release damage-associated molecular patterns and promote maturation of dendritic cells, the cross-priming of cytotoxic T cells, and the production of IFN-γ in response to tumor antigen stimulation. Using both FADD-dependent and FADD-independent RIPK3 induction systems, we demonstrate the efficient vaccination potential of immunogenic necroptotic cells. Our study broadens the current concept of immunogenic cell death and opens doors for the development of new strategies in cancer therapy.

Magnetic Enrichment of Dendritic Cell Vaccine in Lymph Node with Fluorescent-Magnetic Nanoparticles Enhanced Cancer Immunotherapy

Science.gov (United States)

Jin, Honglin; Qian, Yuan; Dai, Yanfeng; Qiao, Sha; Huang, Chuan; Lu, Lisen; Luo, Qingming; Chen, Jing; Zhang, Zhihong

2016-01-01

Dendritic cell (DC) migration to the lymph node is a key component of DC-based immunotherapy. However, the DC homing rate to the lymphoid tissues is poor, thus hindering the DC-mediated activation of antigen-specific T cells. Here, we developed a system using fluorescent magnetic nanoparticles (α-AP-fmNPs; loaded with antigen peptide, iron oxide nanoparticles, and indocyanine green) in combination with magnetic pull force (MPF) to successfully manipulate DC migration in vitro and in vivo. α-AP-fmNPs endowed DCs with MPF-responsiveness, antigen presentation, and simultaneous optical and magnetic resonance imaging detectability. We showed for the first time that α-AP-fmNP-loaded DCs were sensitive to MPF, and their migration efficiency could be dramatically improved both in vitro and in vivo through MPF treatment. Due to the enhanced migration of DCs, MPF treatment significantly augmented antitumor efficacy of the nanoparticle-loaded DCs. Therefore, we have developed a biocompatible approach with which to improve the homing efficiency of DCs and subsequent anti-tumor efficacy, and track their migration by multi-modality imaging, with great potential applications for DC-based cancer immunotherapy. PMID:27698936

Phenotype and Function of CD209+ Bovine Blood Dendritic Cells, Monocyte-Derived-Dendritic Cells and Monocyte-Derived Macrophages.

Directory of Open Access Journals (Sweden)

Kun Taek Park

Full Text Available Phylogenic comparisons of the mononuclear phagocyte system (MPS of humans and mice demonstrate phenotypic divergence of dendritic cell (DC subsets that play similar roles in innate and adaptive immunity. Although differing in phenotype, DC can be classified into four groups according to ontogeny and function: conventional DC (cDC1 and cDC2, plasmacytoid DC (pDC, and monocyte derived DC (MoDC. DC of Artiodactyla (pigs and ruminants can also be sub-classified using this system, allowing direct functional and phenotypic comparison of MoDC and other DC subsets trafficking in blood (bDC. Because of the high volume of blood collections required to study DC, cattle offer the best opportunity to further our understanding of bDC and MoDC function in an outbred large animal species. As reported here, phenotyping DC using a monoclonal antibody (mAb to CD209 revealed CD209 is expressed on the major myeloid population of DC present in blood and MoDC, providing a phenotypic link between these two subsets. Additionally, the present study demonstrates that CD209 is also expressed on monocyte derived macrophages (MoΦ. Functional analysis revealed each of these populations can take up and process antigens (Ags, present them to CD4 and CD8 T cells, and elicit a T-cell recall response. Thus, bDC, MoDC, and MoΦ pulsed with pathogens or candidate vaccine antigens can be used to study factors that modulate DC-driven T-cell priming and differentiation ex vivo.

Induction of multi-functional T cells in a phase I clinical trial of dendritic cell immunotherapy in hepatitis C virus infected individuals.

Directory of Open Access Journals (Sweden)

Shuo Li

Full Text Available We have previously reported a world-first phase I clinical trial to treat HCV patients using monocyte-derived dendritic cells (Mo-DC loaded with HCV-specific lipopeptides. While the brief treatment proved to be safe, it failed to reduce the viral load and induced only transient cell-mediated immune responses, measured by IFNγ ELIspot. Here we reanalysed the PBMC samples from this trial to further elucidate the immunological events associated with the Mo-DC therapy. We found that HCV-specific single- and multi-cytokine secreting T cells were induced by the Mo-DC immunotherapy in some patients, although at irregular intervals and not consistently directed to the same HCV antigen. Despite the vaccination, the responses were generally poor in quality and comprised of primarily single-cytokine secreting cells. The frequency of FOXP3(+ regulatory T cells (Treg fluctuated following DC infusion and eventually dropped to below baseline by week 12, an interesting trend suggesting that the vaccination may have resulted in a more subtle outcome than was initially apparent. Our data suggested that Mo-DC therapy induced complex immune responses in vivo that may or may not lead to clinical benefit.

Helminth antigens enable CpG-activated dendritic cells to inhibit the symptoms of collagen-induced arthritis through Foxp3+ regulatory T cells.

Directory of Open Access Journals (Sweden)

Franco Carranza

Full Text Available Dendritic cells (DC have the potential to control the outcome of autoimmunity by modulating the immune response. In this study, we tested the ability of Fasciola hepatica total extract (TE to induce tolerogenic properties in CpG-ODN (CpG maturated DC, to then evaluate the therapeutic potential of these cells to diminish the inflammatory response in collagen induced arthritis (CIA. DBA/1J mice were injected with TE plus CpG treated DC (T/C-DC pulsed with bovine collagen II (CII between two immunizations with CII and clinical scores CIA were determined. The levels of CII-specific IgG2 and IgG1 in sera, the histological analyses in the joints, the cytokine profile in the draining lymph node (DLN cells and in the joints, and the number, and functionality of CD4+CD25+Foxp3+ T cells (Treg were evaluated. Vaccination of mice with CII pulsed T/C-DC diminished the severity and incidence of CIA symptoms and the production of the inflammatory cytokine, while induced the production of anti-inflammatory cytokines. The therapeutic effect was mediated by Treg cells, since the adoptive transfer of CD4+CD25+ T cells, inhibited the inflammatory symptoms in CIA. The in vitro blockage of TGF-β in cultures of DLN cells plus CII pulsed T/C-DC inhibited the expansion of Treg cells. Vaccination with CII pulsed T/C-DC seems to be a very efficient approach to diminish exacerbated immune response in CIA, by inducing the development of Treg cells, and it is therefore an interesting candidate for a cell-based therapy for rheumatoid arthritis (RA.

Taming dendritic cells with TIM-3: Another immunosuppressive strategy by tumors

Science.gov (United States)

Patel, Jaina; Bozeman, Erica N.; Selvaraj, Periasamy

2013-01-01

The identification of TIM-3 expression on tumor associated dendritic cells (TADCs) provides insight into another aspect of tumor-mediated immunosuppression. The role of TIM-3 has been well characterized on tumor-infiltrating T cells, however its role on TADCs was not previously known. The current paper demonstrated that TIM-3 was predominantly expressed by TADCs and its interaction with the nuclear protein HMGB1 suppressed nucleic acid mediated activation of an effective antitumor immune response. The authors were able to show that TIM-3 interaction with HMGB1 prevented the localization of nucleic acids into endosomal vesicles. Furthermore, chemotherapy was found to be more effective in anti-TIM-3 mAb treated mice or mice depleted of all DCs which indicated that significant role played by TADCs inhibiting tumor regression. Taken together, these findings identify TIM-3 as a potential target for inducing antitumor immunity in conjunction with DNA vaccines and/or immunogenic chemotherapy in clinical settings. PMID:23240746

p16 expression in follicular dendritic cell sarcoma: a potential mimicker of human papillomavirus-related oropharyngeal squamous cell carcinoma.

Science.gov (United States)

Zhang, Lingxin; Yang, Chen; Lewis, James S; El-Mofty, Samir K; Chernock, Rebecca D

2017-08-01

Follicular dendritic cell sarcoma is a rare mesenchymal neoplasm that most commonly occurs in cervical lymph nodes. It has histologic and clinical overlap with the much more common p16-positive human papillomavirus (HPV)-related squamous cell carcinoma of the oropharynx, which characteristically has nonkeratinizing morphology and often presents as an isolated neck mass. Not surprisingly, follicular dendritic cell sarcomas are commonly misdiagnosed as squamous cell carcinoma. Immunohistochemistry is helpful in separating the 2 entities. Follicular dendritic cell sarcoma expresses dendritic markers such as CD21 and CD23 and is almost always cytokeratin negative. However, in many cases of HPV-related oropharyngeal carcinoma, only p16 immunohistochemistry as a prognostic and surrogate marker for HPV is performed. p16 expression in follicular dendritic cell sarcoma has not been characterized. Here, we investigate the expression of p16 in follicular dendritic cell sarcoma and correlate it with retinoblastoma protein expression. A pilot study of dendritic marker expression in HPV-related oropharyngeal squamous cell carcinoma was also performed. We found that 4 of 8 sarcomas expressed p16 with strong and diffuse staining in 2 cases. In 2 of the 4 cases, p16 expression corresponded to loss of retinoblastoma protein expression. Dendritic marker expression (CD21 and CD23) was not found in HPV-related oropharyngeal squamous cell carcinomas. As such, positive p16 immunohistochemistry cannot be used as supportive evidence for the diagnosis of squamous cell carcinoma as strong and diffuse p16 expression may also occur in follicular dendritic cell sarcoma. Cytokeratins and dendritic markers are critical in separating the two tumor types. Copyright © 2017 Elsevier Inc. All rights reserved.

Dendritic cells in peripheral tolerance and immunity

DEFF Research Database (Denmark)

Gad, Monika; Claesson, Mogens Helweg; Pedersen, Anders Elm

2003-01-01

Dendritic cells capable of influencing immunity exist as functionally distinct subsets, T cell-tolerizing and T cell-immunizing subsets. The present paper reviews how these subsets of DCs develop, differentiate and function in vivo and in vitro at the cellular and molecular level. In particular...

A full scale comparative study of methods for generation of functional Dendritic cells for use as cancer vaccines

OpenAIRE

Jarnjak-Jankovic, Silvija; Hammerstad, Hege; S?b?e-Larssen, Stein; Kvalheim, Gunnar; Gaudernack, Gustav

2007-01-01

Background Dendritic cells (DCs) are professional antigen-presenting cells with the ability to induce primary T-cell responses and are commonly produced by culturing monocytes in the presence of IL-4 and GM-CSF for 5–7 days (Standard DC). Recently, Dauer and co-workers presented a modified protocol for differentiation of human monocytes into mature DCs within 48 hours (Fast DC). Here we report a functional comparison of the two strategies for generation of DCs from human monocytes with adapt...

DC-SIGN, a C-type lectin on dendritic cells that unveils many aspects of dendritic cell biology

NARCIS (Netherlands)

Geijtenbeek, Teunis B. H.; Engering, Anneke; van Kooyk, Yvette

2002-01-01

Dendritic cells (DC) are present in essentially every tissue where they operate at the interface of innate and acquired immunity by recognizing pathogens and presenting pathogen-derived peptides to T cells. It is becoming clear that not all C-type lectins on DC serve as antigen receptors recognizing

Epstein Barr virus Latent Membrane Protein-1 enhances dendritic cell therapy lymph node migration, activation, and IL-12 secretion.

Directory of Open Access Journals (Sweden)

James M Termini

Full Text Available Dendritic cells (DC are a promising cell type for cancer vaccines due to their high immunostimulatory capacity. However, improper maturation of DC prior to treatment may account for the limited efficacy of DC vaccine clinical trials. Latent Membrane Protein-1 (LMP1 of Epstein-Barr virus was examined for its ability to mature and activate DC as a gene-based molecular adjuvant for DC vaccines. DC were transduced with an adenovirus 5 vector (Ad5 expressing LMP1 under the control of a Tet-inducible promoter. Ad5-LMP1 was found to mature and activate both human and mouse DC. LMP1 enhanced in vitro migration of DC toward CCL19, as well as in vivo migration of DC to the inguinal lymph nodes of mice following intradermal injection. LMP1-transduced DC increased T cell proliferation in a Pmel-1 adoptive transfer model and enhanced survival in B16-F10 melanoma models. LMP1-DC also enhanced protection in a vaccinia-Gag viral challenge assay. LMP1 induced high levels of IL-12p70 secretion in mouse DC when compared to standard maturation protocols. Importantly, LMP1-transduced human DC retained the capacity to secrete IL-12p70 and TNF in response to DC restimulation. In contrast, DC matured with Monocyte Conditioned Media-Mimic cocktail (Mimic were impaired in IL-12p70 secretion following restimulation. Overall, LMP1 matured and activated DC, induced migration to the lymph node, and generated high levels of IL-12p70 in a murine model. We propose LMP1 as a promising molecular adjuvant for DC vaccines.

Ginseng Berry Extract Promotes Maturation of Mouse Dendritic Cells.

Directory of Open Access Journals (Sweden)

Wei Zhang

Full Text Available Ginseng extract has been shown to possess certain anti-virus, anti-tumor and immune-activating effects. However, the immunostimulatory effect of ginseng berry extract (GB has been less well characterized. In this study, we investigated the effect of GB on the activation of mouse dendritic cells (DCs in vitro and in vivo. GB treatment induced up-regulation of co-stimulatory molecules in bone marrow-derived DCs (BMDCs. Interestingly, GB induced a higher degree of co-stimulatory molecule up-regulation than ginseng root extract (GR at the same concentrations. Moreover, in vivo administration of GB promoted up-regulation of CD86, MHC class I and MHC class II and production of IL-6, IL-12 and TNF-α in spleen DCs. GB also promoted the generation of Th1 and Tc1 cells. Furthermore, Toll like receptor 4 (TLR4 and myeloid differentiation primary response 88 (MyD88 signaling pathway were essential for DC activation induced by GB. In addition, GB strongly prompted the proliferation of ovalbumin (OVA-specific CD4 and CD8 T cells. Finally, GB induced DC activation in tumor-bearing mice and the combination of OVA and GB treatment inhibited B16-OVA tumor cell growth in C57BL/6 mice. These results demonstrate that GB is a novel tumor therapeutic vaccine adjuvant by promoting DC and T cell activation.

Synthetic and biogenic magnetite nanoparticles for tracking of stem cells and dendritic cells

International Nuclear Information System (INIS)

Schwarz, Sebastian; Fernandes, Fabiana; Sanroman, Laura; Hodenius, Michael; Lang, Claus; Himmelreich, Uwe; Schmitz-Rode, Thomas; Schueler, Dirk; Hoehn, Mathias

2009-01-01

Accurate delivery of cells to target organs is critical for success of cell-based therapies with stem cells or immune cells such as antigen-presenting dendritic cells (DC). Labeling with contrast agents before implantation provides a powerful means for monitoring cellular migration using magnetic resonance imaging (MRI). In this study, we investigated the uptake of fully synthesized or bacterial magnetic nanoparticles (MNPs) into hematopoietic Flt3 + stem cells and DC from mouse bone marrow. We show that (i) uptake of both synthetic and biogenic nanoparticles into cells endow magnetic activity and (ii) low numbers of MNP-loaded cells are readily detected by MRI.

Cell culture based production of avian influenza vaccines

NARCIS (Netherlands)

Wielink, van R.

2012-01-01

Vaccination of poultry can be used as a tool to control outbreaks of avian influenza, including that of highly pathogenic H5 and H7 strains. Influenza vaccines are traditionally produced in embryonated chicken eggs. Continuous cell lines have been suggested as an alternative substrate to produce

Mycobacterium tuberculosis directs T helper 2 cell differentiation by inducing interleukin-1β production in dendritic cells.

Science.gov (United States)

Dwivedi, Ved Prakash; Bhattacharya, Debapriya; Chatterjee, Samit; Prasad, Durbaka Vijay Raghva; Chattopadhyay, Debprasad; Van Kaer, Luc; Bishai, William R; Das, Gobardhan

2012-09-28

Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), resides and replicates within phagocytes and persists in susceptible hosts by modulating protective innate immune responses. Furthermore, M. tuberculosis promotes T helper 2 (Th2) immune responses by altering the balance of T cell polarizing cytokines in infected cells. However, cytokines that regulate Th2 cell differentiation during TB infection remain unknown. Here we show that IL-1β, produced by phagocytes infected by virulent M. tuberculosis strain H37Rv, directs Th2 cell differentiation. In sharp contrast, the vaccine strain bacille Calmette-Guérin as well as RD-1 and ESAT-6 mutants of H37Rv failed to induce IL-1β and promote Th2 cell differentiation. Furthermore, ESAT-6 induced IL-1β production in dendritic cells (DCs), and CD4(+) T cells co-cultured with infected DCs differentiated into Th2 cells. Taken together, our findings indicate that IL-1β induced by RD-1/ESAT-6 plays an important role in the differentiation of Th2 cells, which in turn facilitates progression of TB by inhibiting host protective Th1 responses.

Dendritic Cells and Programmed Death-1 Blockade: A Joint Venture to Combat Cancer.

Science.gov (United States)

Versteven, Maarten; Van den Bergh, Johan M J; Marcq, Elly; Smits, Evelien L J; Van Tendeloo, Viggo F I; Hobo, Willemijn; Lion, Eva

2018-01-01

Two decades of clinical cancer research with dendritic cell (DC)-based vaccination have proved that this type of personalized medicine is safe and has the capacity to improve survival, but monotherapy is unlikely to cure the cancer. Designed to empower the patient's antitumor immunity, huge research efforts are set to improve the efficacy of next-generation DC vaccines and to find synergistic combinations with existing cancer therapies. Immune checkpoint approaches, aiming to breach immune suppression and evasion to reinforce antitumor immunity, have been a revelation in the immunotherapy field. Early success of therapeutic antibodies blocking the programmed death-1 (PD-1) pathway has sparked the development of novel inhibitors and combination therapies. Hence, merging immunoregulatory tumor-specific DC strategies with PD-1-targeted approaches is a promising path to explore. In this review, we focus on the role of PD-1-signaling in DC-mediated antitumor immunity. In the quest of exploiting the full potential of DC therapy, different strategies to leverage DC immunopotency by impeding PD-1-mediated immune regulation are discussed, including the most advanced research on targeted therapeutic antibodies, lessons learned from chemotherapy-induced immune activation, and more recent developments with soluble molecules and gene-silencing techniques. An overview of DC/PD-1 immunotherapy combinations that are currently under preclinical and clinical investigation substantiates the clinical potential of such combination strategies.

Cord blood mesenchymal stem cells propel human dendritic cells to an intermediate maturation state and boost interleukin-12 production by mature dendritic cells.

NARCIS (Netherlands)

Berk, L.C.J. van den; Roelofs, H.; Huijs, T.; Siebers-Vermeulen, K.G.C.; Raymakers, R.A.P.; Kogler, G.; Figdor, C.G.; Torensma, R.

2009-01-01

Pathogen-derived entities force the tissue-resident dendritic cells (DCs) towards a mature state, followed by migration to the draining lymph node to present antigens to T cells. Bone marrow mesenchymal stem cells (MSCs) modulate the differentiation, maturation and function of DCs. In umbilical cord

Brucella discriminates between mouse dendritic cell subsets upon in vitro infection.

Science.gov (United States)

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.

Towards Future T Cell-Mediated Influenza Vaccines

Directory of Open Access Journals (Sweden)

Thi H. O. Nguyen

2016-04-01

Full Text Available Influenza A virus (IAVs infections impact significantly on global health, being particularly problematic in children, the elderly, pregnant women, indigenous populations and people with co-morbidities. Antibody-based vaccines require annual administration to combat rapidly acquired mutations modifying the surface haemagglutinin (HA and neuraminidase (NA glycoproteins. Conversely, influenza-specific CD8+ T cell responses directed at peptides derived from the more conserved internal virus proteins are known to be protective, suggesting that T cell-based vaccines may provide long-lasting cross-protection. This review outlines the importance of CD8+ T cell immunity to seasonal influenza and pandemic IAVs and summarises current vaccination strategies for inducing durable CD8+ T cell memory. Aspects of future IAV vaccine design and the use of live virus challenge in humans to establish proof of principle are also discussed.

Murine Th9 cells promote the survival of myeloid dendritic cells in cancer immunotherapy.

Science.gov (United States)

Park, Jungsun; Li, Haiyan; Zhang, Mingjun; Lu, Yong; Hong, Bangxing; Zheng, Yuhuan; He, Jin; Yang, Jing; Qian, Jianfei; Yi, Qing

2014-08-01

Dendritic cells (DCs) are professional antigen-presenting cells to initiate immune responses, and DC survival time is important for affecting the strength of T-cell responses. Interleukin (IL)-9-producing T-helper (Th)-9 cells play an important role in anti-tumor immunity. However, it is unclear how Th9 cells communicate with DCs. In this study, we investigated whether murine Th9 cells affected the survival of myeloid DCs. DCs derived from bone marrow of C57BL/6 mice were cocultured with Th9 cells from OT-II mice using transwell, and the survival of DCs was examined. DCs cocultured with Th9 cells had longer survival and fewer apoptotic cells than DCs cultured alone in vitro. In melanoma B16-OVA tumor-bearing mice, DCs conditioned by Th9 cells lived longer and induced stronger anti-tumor response than control DCs did in vivo. Mechanistic studies revealed that IL-3 but not IL-9 secreted by Th9 cells was responsible for the prolonged survival of DCs. IL-3 upregulated the expression of anti-apoptotic protein Bcl-xL and activated p38, ERK and STAT5 signaling pathways in DCs. Taken together, our data provide the first evidence that Th9 cells can promote the survival of DCs through IL-3, and will be helpful for designing Th9 cell immunotherapy and more effective DC vaccine for human cancers.

Autologous Dendritic Cells Pulsed with Allogeneic Tumor Cell Lysate in Mesothelioma: From Mouse to Human.

Science.gov (United States)

Aerts, Joachim G J V; de Goeje, Pauline L; Cornelissen, Robin; Kaijen-Lambers, Margaretha E H; Bezemer, Koen; van der Leest, Cor H; Mahaweni, Niken M; Kunert, André; Eskens, Ferry A L M; Waasdorp, Cynthia; Braakman, Eric; van der Holt, Bronno; Vulto, Arnold G; Hendriks, Rudi W; Hegmans, Joost P J J; Hoogsteden, Henk C

2018-02-15

Purpose: Mesothelioma has been regarded as a nonimmunogenic tumor, which is also shown by the low response rates to treatments targeting the PD-1/PD-L1 axis. Previously, we demonstrated that autologous tumor lysate-pulsed dendritic cell (DC) immunotherapy increased T-cell response toward malignant mesothelioma. However, the use of autologous tumor material hampers implementation in large clinical trials, which might be overcome by using allogeneic tumor cell lines as tumor antigen source. The purpose of this study was to investigate whether allogeneic lysate-pulsed DC immunotherapy is effective in mice and safe in humans. Experimental Design: First, in two murine mesothelioma models, mice were treated with autologous DCs pulsed with either autologous or allogeneic tumor lysate or injected with PBS (negative control). Survival and tumor-directed T-cell responses of these mice were monitored. Results were taken forward in a first-in-human clinical trial, in which 9 patients were treated with 10, 25, or 50 million DCs per vaccination. DC vaccination consisted of autologous monocyte-derived DCs pulsed with tumor lysate from five mesothelioma cell lines. Results: In mice, allogeneic lysate-pulsed DC immunotherapy induced tumor-specific T cells and led to an increased survival, to a similar extent as DC immunotherapy with autologous tumor lysate. In the first-in-human clinical trial, no dose-limiting toxicities were established and radiographic responses were observed. Median PFS was 8.8 months [95% confidence interval (CI), 4.1-20.3] and median OS not reached (median follow-up = 22.8 months). Conclusions: DC immunotherapy with allogeneic tumor lysate is effective in mice and safe and feasible in humans. Clin Cancer Res; 24(4); 766-76. ©2017 AACR . ©2017 American Association for Cancer Research.

Antitumor Responses Stimulated by Dendritic Cells Are Improved by Triiodothyronine Binding to the Thyroid Hormone Receptor β.

Science.gov (United States)

Alamino, Vanina A; Mascanfroni, Iván D; Montesinos, María M; Gigena, Nicolás; Donadio, Ana C; Blidner, Ada G; Milotich, Sonia I; Cheng, Sheue-Yann; Masini-Repiso, Ana M; Rabinovich, Gabriel A; Pellizas, Claudia G

2015-04-01

Bidirectional cross-talk between the neuroendocrine and immune systems orchestrates immune responses in both physiologic and pathologic settings. In this study, we provide in vivo evidence of a critical role for the thyroid hormone triiodothyronine (T3) in controlling the maturation and antitumor functions of dendritic cells (DC). We used a thyroid hormone receptor (TR) β mutant mouse (TRβPV) to establish the relevance of the T3-TRβ system in vivo. In this model, TRβ signaling endowed DCs with the ability to stimulate antigen-specific cytotoxic T-cell responses during tumor development. T3 binding to TRβ increased DC viability and augmented DC migration to lymph nodes. Moreover, T3 stimulated the ability of DCs to cross-present antigens and to stimulate cytotoxic T-cell responses. In a B16-OVA mouse model of melanoma, vaccination with T3-stimulated DCs inhibited tumor growth and prolonged host survival, in part by promoting the generation of IFNγ-producing CD8(+) T cells. Overall, our results establish an adjuvant effect of T3-TRβ signaling in DCs, suggesting an immediately translatable method to empower DC vaccination approaches for cancer immunotherapy. ©2015 American Association for Cancer Research.

Novel Vectors for Dendritic Cell Transduction

National Research Council Canada - National Science Library

Strong, Teresa

2003-01-01

.... Polynucleotide vaccines have several advantages compared to traditional vaccines including the ability to elicit antigen-specific T cells, inherent immunogenicity, ability to modify the encoded...

Monitoring of regulatory T cell frequencies and expression of CTLA-4 on T cells, before and after DC vaccination, can predict survival in GBM patients.

Directory of Open Access Journals (Sweden)

Brendan Fong

Full Text Available PURPOSE: Dendritic cell (DC vaccines have recently emerged as an innovative therapeutic option for glioblastoma patients. To identify novel surrogates of anti-tumor immune responsiveness, we studied the dynamic expression of activation and inhibitory markers on peripheral blood lymphocyte (PBL subsets in glioblastoma patients treated with DC vaccination at UCLA. EXPERIMENTAL DESIGN: Pre-treatment and post-treatment PBL from 24 patients enrolled in two Phase I clinical trials of dendritic cell immunotherapy were stained and analyzed using flow cytometry. A univariate Cox proportional hazards model was utilized to investigate the association between continuous immune monitoring variables and survival. Finally, the immune monitoring variables were dichotomized and a recursive partitioning survival tree was built to obtain cut-off values predictive of survival. RESULTS: The change in regulatory T cell (CD3(+CD4(+CD25(+CD127(low frequency in PBL was significantly associated with survival (p = 0.0228; hazard ratio = 3.623 after DC vaccination. Furthermore, the dynamic expression of the negative co-stimulatory molecule, CTLA-4, was also significantly associated with survival on CD3(+CD4(+ T cells (p = 0.0191; hazard ratio = 2.840 and CD3(+CD8(+ T cells (p = 0.0273; hazard ratio = 2.690, while that of activation markers (CD25, CD69 was not. Finally, a recursive partitioning tree algorithm was utilized to dichotomize the post/pre fold change immune monitoring variables. The resultant cut-off values from these immune monitoring variables could effectively segregate these patients into groups with significantly different overall survival curves. CONCLUSIONS: Our results suggest that monitoring the change in regulatory T cell frequencies and dynamic expression of the negative co-stimulatory molecules on peripheral blood T cells, before and after DC vaccination, may predict survival. The cut-off point generated from these data can be utilized in future

Dendritic Cell-Based Cancer Vaccines

Czech Academy of Sciences Publication Activity Database

Bubeník, Jan

1999-01-01

Roč. 45, č. 3 (1999), s. 71-74 ISSN 0015-5500 R&D Projects: GA MZd NC45011; GA MZd NC5526; GA ČR GA312/98/0826; GA ČR GA312/99/0542 Institutional research plan: CEZ:AV0Z5052915 Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.493, year: 1999

Androgen Ablation Augments Prostate Cancer Vaccine Immunogenicity Only When Applied After Immunization

Science.gov (United States)

Koh, Yi T.; Gray, Andrew; Higgins, Sean A.; Hubby, Bolyn; Kast, W. Martin

2009-01-01

Background Androgen ablation (AA) causes apoptosis of normal and neoplastic prostate cells. It is a standard treatment for advanced prostate cancer. Androgen ablation-mediated immunological effects include bone marrow hyperplasia, thymic regeneration, T and B cell lymphopoeisis and restoration of age-related peripheral T cell dysfunction. Androgens also regulate the transcription of several cytokines. Dendritic cells (DC) are the most potent antigen presenting cells that can activate antigen-specific naïve T cells. Despite myriad clinical trials involving DC-based prostate cancer immunotherapies, the effects of AA on DC function remain largely uncharacterized. Therefore, we investigated the effects of AA on DC and whether it could improve the efficacy of prostate cancer immunotherapy. Methods Cytokine expression changes due to AA were quantified by multiplex ELISA. Flow cytometry was used to assess AA-mediated effects on DC maturation and expression of costimulatory markers. Mixed leukocyte reactions and cell-mediated lysis assays elucidated the role of androgens in DC function. The effect of AA on the efficacy of vaccination against a prostate tumor-associated antigen was tested using Elispot assays. Results Androgen ablation increased dendritic cell maturation and costimulatory marker expression, but had no effect on DC costimulatory function. However, DC isolated from castrated mice increased the expression of key cytokines by antigen-experienced T cells while decreasing their expression in naïve cells. Finally, androgen ablation improved immune responses to vaccination only when applied after immunization. Conclusion Androgen ablation causes differential effects of DC on primary and secondary T cell responses, thus augmenting vaccine immunogenicity only when applied after immunization. PMID:19143030

Resistivity and thickness effects in dendritic web silicon solar cells

Science.gov (United States)

Meier, D. L.; Hwang, J. M.; Greggi, J.; Campbell, R. B.

1987-01-01

The decrease of minority carrier lifetime as resistivity decreases in dendritic-web silicon solar cells is addressed. This variation is shown to be consistent with the presence of defect levels in the bandgap which arise from extended defects in the web material. The extended defects are oxide precipitates (SiOx) and the dislocation cores they decorate. Sensitivity to this background distribution of defect levels increases with doping because the Fermi level moves closer to the majority carrier band edge. For high-resistivity dendritic-web silicon, which has a low concentration of these extended defects, cell efficiencies as high as 16.6 percent (4 sq cm, 40 ohm-cm boron-doped base, AM1.5 global, 100 mW/sq cm, 25 C JPL LAPSS1 measurement) and a corresponding electron lifetime of 38 microsec have been obtained. Thickness effects occur in bifacial cell designs and in designs which use light trapping. In some cases, the dislocation/precipitate defect can be passivated through the full thickness of web cells by hydrogen ion implantation.

[From new vaccine to new target: revisiting influenza vaccination].

Science.gov (United States)

Gérard, M

2011-09-01

Annual vaccination is since many years the corner stone of Influenza control strategy. Because conventional vaccine are needle-based, are less immunogenic in old people and induce only systemic IgG production, intranasal and intradermal vaccines that are recently or will be soon available in Belgium will offer distinct advantages. Intradermal vaccination is on the Belgian market since 2010. A stronger immune response that allows an antigen sparing strategy is elicited because antigens are delivered near the dermal dendritic cells. Local side effects are more pronounced than after intramuscular injection. The needle-free intranasal vaccine that has been approved for use in people less than 18 years old by the EMEA in October 2010 induces also a mucosal IgA response. Improved clinical results than with intramuscular vaccine has been documented in several studies in children. Several conditions are contraindication to nasal vaccination because of patterns of side effects and because the vaccine is an live-attenuated vaccine. Pregnant women has become a top priority for Influenza vaccination in the recommendations of the High Council of Health in Belgium since the 2009 H1N1 pandemic. Several studies has since then documented the increased risk for Influenza-related morbidity in pregnant women especially during the third trimester and independently of the presence of other comorbidities. Reduced incidence of documented Influenza and of Influenza-related hospitalizations are observed in the new born of vaccinated women until 6 months of age. Availability of new vaccines for Influenza and better knowledge of the benefit of vaccination in target populations are important tools to optimize vaccine coverage of the population.

The scavenger receptor MARCO modulates TLR-induced responses in dendritic cells.

Directory of Open Access Journals (Sweden)

Haydn T Kissick

Full Text Available The scavenger receptor MARCO mediates macrophage recognition and clearance of pathogens and their polyanionic ligands. However, recent studies demonstrate MARCO expression and function in dendritic cells, suggesting MARCO might serve to bridge innate and adaptive immunity. To gain additional insight into the role of MARCO in dendritic cell activation and function, we profiled transcriptomes of mouse splenic dendritic cells obtained from MARCO deficient mice and their wild type counterparts under resting and activating conditions. In silico analysis uncovered major alterations in gene expression in MARCO deficient dendritic cells resulting in dramatic alterations in key dendritic cell-specific pathways and functions. Specifically, changes in CD209, FCGR4 and Complement factors can have major consequences on DC-mediated innate responses. Notably, these perturbations were magnified following activation with the TLR-4 agonist lipopolysaccharide. To validate our in silico data, we challenged DC's with various agonists that recognize all mouse TLRs and assessed expression of a set of immune and inflammatory marker genes. This approach identified a differential contribution of MARCO to TLR activation and validated a major role for MARCO in mounting an inflammatory response. Together, our data demonstrate that MARCO differentially affects TLR-induced DC activation and suggest targeting of MARCO could lead to different outcomes that depend on the inflammatory context encountered by DC.

Dendritic-cell-based immunotherapy evokes potent anti-tumor immune responses in CD105+ human renal cancer stem cells.

Science.gov (United States)

Zhang, Xiao-Fei; Weng, De-Sheng; Pan, Ke; Zhou, Zi-Qi; Pan, Qiu-Zhong; Zhao, Jing-Jing; Tang, Yan; Jiang, Shan-Shan; Chen, Chang-Long; Li, Yong-Qiang; Zhang, Hong-Xia; Chang, Alfred E; Wicha, Max S; Zeng, Yi-Xin; Li, Qiao; Xia, Jian-Chuan

2017-11-01

Cancer stem cells (CSCs) are responsible for tumor initiation, progression, and resistance to therapeutic agents; they are usually less sensitive to conventional cancer therapies, and could cause tumor relapse. An ideal therapeutic strategy would therefore be to selectively target and destroy CSCs, thereby preventing tumor relapse. The aim of the present study was to evaluate the effectiveness of dendritic cells (DCs) pulsed with antigen derived from CD105+ human renal cell carcinoma (RCC) CSCs against renal cancer cells in vitro and in vivo. We identified "stem-like" characteristics of CD105+ cells in two human RCC cell lines: A498 and SK-RC-39. Loading with cell lysates did not change the characteristics of the DCs. However, DCs loaded with lysates derived from CD105+ CSCs induced more functionally specific active T cells and specific antibodies against CSCs, and clearly depressed the tumor growth in mice. Our results could form the basis for a novel strategy to improve the efficacy of DC-based immunotherapy for human RCC. © 2017 Wiley Periodicals, Inc.

Cross Talk between inhibitory immunoreceptor Tyrosine-Based Activation Motif-Signaling and Toll-Like Receptor Pathways in Macrophages and Dendritic Cells

Czech Academy of Sciences Publication Activity Database

Hirsch, Ivan; Janovec, Václav; Stranska, R.; Bendriss-Vermare, N.

2017-01-01

Roč. 8, Apr 7 (2017), č. článku 394. ISSN 1664-3224 Institutional support: RVO:61388963 Keywords : plasmacytoid dendritic cell * conventional dendritic cells * macrophage * toll-like receptors * regulatory receptors Subject RIV: EC - Immunology OBOR OECD: Immunology Impact factor: 6.429, year: 2016 http://journal.frontiersin.org/article/10.3389/fimmu.2017.00394/full

Bioreactors for high cell density and continuous multi-stage cultivations: options for process intensification in cell culture-based viral vaccine production.

Science.gov (United States)

Tapia, Felipe; Vázquez-Ramírez, Daniel; Genzel, Yvonne; Reichl, Udo

2016-03-01

With an increasing demand for efficacious, safe, and affordable vaccines for human and animal use, process intensification in cell culture-based viral vaccine production demands advanced process strategies to overcome the limitations of conventional batch cultivations. However, the use of fed-batch, perfusion, or continuous modes to drive processes at high cell density (HCD) and overextended operating times has so far been little explored in large-scale viral vaccine manufacturing. Also, possible reductions in cell-specific virus yields for HCD cultivations have been reported frequently. Taking into account that vaccine production is one of the most heavily regulated industries in the pharmaceutical sector with tough margins to meet, it is understandable that process intensification is being considered by both academia and industry as a next step toward more efficient viral vaccine production processes only recently. Compared to conventional batch processes, fed-batch and perfusion strategies could result in ten to a hundred times higher product yields. Both cultivation strategies can be implemented to achieve cell concentrations exceeding 10(7) cells/mL or even 10(8) cells/mL, while keeping low levels of metabolites that potentially inhibit cell growth and virus replication. The trend towards HCD processes is supported by development of GMP-compliant cultivation platforms, i.e., acoustic settlers, hollow fiber bioreactors, and hollow fiber-based perfusion systems including tangential flow filtration (TFF) or alternating tangential flow (ATF) technologies. In this review, these process modes are discussed in detail and compared with conventional batch processes based on productivity indicators such as space-time yield, cell concentration, and product titers. In addition, options for the production of viral vaccines in continuous multi-stage bioreactors such as two- and three-stage systems are addressed. While such systems have shown similar virus titers compared to

Phenotypic, ultra-structural, and functional characterization of bovine peripheral blood dendritic cell subsets.

Directory of Open Access Journals (Sweden)

Janet J Sei

Full Text Available Dendritic cells (DC are multi-functional cells that bridge the gap between innate and adaptive immune systems. In bovine, significant information is lacking on the precise identity and role of peripheral blood DC subsets. In this study, we identify and characterize bovine peripheral blood DC subsets directly ex vivo, without further in vitro manipulation. Multi-color flow cytometric analysis revealed that three DC subsets could be identified. Bovine plasmacytoid DC were phenotypically identified by a unique pattern of cell surface protein expression including CD4, exhibited an extensive endoplasmic reticulum and Golgi apparatus, efficiently internalized and degraded exogenous antigen, and were the only peripheral blood cells specialized in the production of type I IFN following activation with Toll-like receptor (TLR agonists. Conventional DC were identified by expression of a different pattern of cell surface proteins including CD11c, MHC class II, and CD80, among others, the display of extensive dendritic protrusions on their plasma membrane, expression of very high levels of MHC class II and co-stimulatory molecules, efficient internalization and degradation of exogenous antigen, and ready production of detectable levels of TNF-alpha in response to TLR activation. Our investigations also revealed a third novel DC subset that may be a precursor of conventional DC that were MHC class II+ and CD11c-. These cells exhibited a smooth plasma membrane with a rounded nucleus, produced TNF-alpha in response to TLR-activation (albeit lower than CD11c+ DC, and were the least efficient in internalization/degradation of exogenous antigen. These studies define three bovine blood DC subsets with distinct phenotypic and functional characteristics which can be analyzed during immune responses to pathogens and vaccinations of cattle.

Engineering intranasal mRNA vaccines to enhance lymph node trafficking and immune responses.

Science.gov (United States)

Li, Man; Li, You; Peng, Ke; Wang, Ying; Gong, Tao; Zhang, Zhirong; He, Qin; Sun, Xun

2017-12-01

Intranasal mRNA vaccination provides immediate immune protection against pandemic diseases. Recent studies have shown that diverse forms of polyethyleneimine (PEI) have potent mucosal adjuvant activity, which could significantly facilitate the delivery of intranasal mRNA vaccines. Nevertheless, optimizing the chemical structure of PEI to maximize its adjuvanticity and decrease its toxicity remains a challenge. Here we show that the chemical structure of PEI strongly influences how well nanocomplexes of PEI and mRNA migrate to the lymph nodes and elicit immune responses. Conjugating cyclodextrin (CD) with PEI600 or PEI2k yielded CP (CD-PEI) polymers with different CD/PEI ratios. We analyzed the delivery efficacy of CP600, CP2k, and PEI25k as intranasal mRNA vaccine carriers by evaluating the lymph nodes migration and immune responses. Among these polymers, CP2k/mRNA showed significantly higher in vitro transfection efficiency, stronger abilities to migrate to lymph nodes and stimulate dendritic cells maturation in vivo, which further led to potent humoral and cellular immune responses, and showed lower local and systemic toxicity than PEI25k/mRNA. These results demonstrate the potential of CD-PEI2k/mRNA nanocomplex as a self-adjuvanting vaccine delivery vehicle that traffics to lymph nodes with high efficiency. As we face outbreaks of pandemic diseases such as Zika virus, intranasal mRNA vaccination provides instant massive protection against highly variant viruses. Various polymer-based delivery systems have been successfully applied in intranasal vaccine delivery. However, the influence of molecular structure of the polymeric carriers on the lymph node trafficking and dendritic cell maturation is seldom studied for intranasal vaccination. Therefore, engineering polymer-based vaccine delivery system and elucidating the relationship between molecular structure and the intranasal delivery efficiency are essential for maximizing the immune responses. We hereby

Immune hierarchy among HIV-1 CD8+ T cell epitopes delivered by dendritic cells depends on MHC-I binding irrespective of mode of loading and immunization in HLA-A*0201 mice

DEFF Research Database (Denmark)

Kloverpris, Henrik N; Karlsson, Ingrid; Thorn, Mette

2009-01-01

Recent human immunodeficiency virus type 1 (HIV-1) vaccination strategies aim at targeting a broad range of cytotoxic T lymphocyte (CTL) epitopes from different HIV-1 proteins by immunization with multiple CTL epitopes simultaneously. However, this may establish an immune hierarchical response......, where the immune system responds to only a small number of the epitopes administered. To evaluate the feasibility of such vaccine strategies, we used the human leukocyte antigen (HLA)-A*0201 transgenic (tg) HHD murine in vivo model and immunized with dendritic cells pulsed with seven HIV-1-derived HLA......-gamma)-producing CD8(+) T cells, mainly focused on two of seven administered epitopes. The magnitude of individual T-cell responses induced by immunization with multiple peptides correlated with their individual immunogenicity that depended on major histocompatibility class I binding and was not influenced by mode...

Cyclooxygenase-2 inhibitor enhances the efficacy of a breast cancer vaccine: role of IDO.

Science.gov (United States)

Basu, Gargi D; Tinder, Teresa L; Bradley, Judy M; Tu, Tony; Hattrup, Christine L; Pockaj, Barbara A; Mukherjee, Pinku

2006-08-15

We report that administration of celecoxib, a specific cyclooxygenase-2 (COX-2) inhibitor, in combination with a dendritic cell-based cancer vaccine significantly augments vaccine efficacy in reducing primary tumor burden, preventing metastasis, and increasing survival. This combination treatment was tested in MMTV-PyV MT mice that develop spontaneous mammary gland tumors with metastasis to the lungs and bone marrow. Improved vaccine potency was associated with an increase in tumor-specific CTLs. Enhanced CTL activity was attributed to a significant decrease in levels of tumor-associated IDO, a negative regulator of T cell activity. We present data suggesting that inhibiting COX-2 activity in vivo regulates IDO expression within the tumor microenvironment; this is further corroborated in the MDA-MB-231 human breast cancer cell line. Thus, a novel mechanism of COX-2-induced immunosuppression via regulation of IDO has emerged that may have implications in designing future cancer vaccines.

Memory CD8+ T cells protect dendritic cells from CTL killing

NARCIS (Netherlands)

Watchmaker, Payal B.; Urban, Julie A.; Berk, Erik; Nakamura, Yutaro; Mailliard, Robbie B.; Watkins, Simon C.; van Ham, S. Marieke; Kalinski, Pawel

2008-01-01

CD8(+) T cells have been shown to be capable of either suppressing or promoting immune responses. To reconcile these contrasting regulatory functions, we compared the ability of human effector and memory CD8(+) T cells to regulate survival and functions of dendritic cells (DC). We report that, in

Multifunctional gadolinium-based dendritic macromolecules as liver targeting imaging probes.

Science.gov (United States)

Luo, Kui; Liu, Gang; He, Bin; Wu, Yao; Gong, Qingyong; Song, Bin; Ai, Hua; Gu, Zhongwei

2011-04-01

The quest for highly efficient and safe contrast agents has become the key factor for successful application of magnetic resonance imaging (MRI). The gadolinium (Gd) based dendritic macromolecules, with precise and tunable nanoscopic sizes, are excellent candidates as multivalent MRI probes. In this paper, a novel series of Gd-based multifunctional peptide dendritic probes (generation 2, 3, and 4) possessing highly controlled structures and single molecular weight were designed and prepared as liver MRI probes. These macromolecular Gd-ligand agents exhibited up to 3-fold increase in T(1) relaxivity comparing to Gd-DTPA complexes. No obvious in vitro cytotoxicity was observed from the measured concentrations. These dendritic probes were further functionalized with multiple galactosyl moieties and led to much higher cell uptake in vitro as demonstrated in T(1)-weighted scans. During in vivo animal studies, the probes provided better signal intensity (SI) enhancement in mouse liver, especially at 60 min post-injection, with the most efficient enhancement from the galactosyl moiety decorated third generation dendrimer. The imaging results were verified with analysis of Gd content in liver tissues. The design strategy of multifunctional Gd-ligand peptide dendritic macromolecules in this study may be used for developing other sensitive MRI probes with targeting capability. Copyright © 2011 Elsevier Ltd. All rights reserved.

Vaccines based on the cell surface carbohydrates of pathogenic bacteria

Directory of Open Access Journals (Sweden)

Jones Christopher

2005-01-01

Full Text Available Glycoconjugate vaccines, in which a cell surface carbohydrate from a micro-organism is covalently attached to an appropriate carrier protein are proving to be the most effective means to generate protective immune responses to prevent a wide range of diseases. The technology appears to be generic and applicable to a wide range of pathogens, as long as antibodies against surface carbohydrates help protect against infection. Three such vaccines, against Haemophilus influenzae type b, Neisseria meningitidis Group C and seven serotypes of Streptococcus pneumoniae, have already been licensed and many others are in development. This article discusses the rationale for the development and use of glycoconjugate vaccines, the mechanisms by which they elicit T cell-dependent immune responses and the implications of this for vaccine development, the role of physicochemical methods in the characterisation and quality control of these vaccines, and the novel products which are under development.

Targeted Delivery of Toxoplasma gondii Antigens to Dendritic Cells Promote Immunogenicity and Protective Efficiency against Toxoplasmosis

Directory of Open Access Journals (Sweden)

Zineb Lakhrif

2018-02-01

Full Text Available Toxoplasmosis is a major public health problem and the development of a human vaccine is of high priority. Efficient vaccination against Toxoplasma gondii requires both a mucosal and systemic Th1 immune response. Moreover, dendritic cells play a critical role in orchestrating the innate immune functions and driving specific adaptive immunity to T. gondii. In this study, we explore an original vaccination strategy that combines administration via mucosal and systemic routes of fusion proteins able to target the major T. gondii surface antigen SAG1 to DCs using an antibody fragment single-chain fragment variable (scFv directed against DEC205 endocytic receptor. Our results show that SAG1 targeting to DCs by scFv via intranasal and subcutaneous administration improved protection against chronic T. gondii infection. A marked reduction in brain parasite burden is observed when compared with the intranasal or the subcutaneous route alone. DC targeting improved both local and systemic humoral and cellular immune responses and potentiated more specifically the Th1 response profile by more efficient production of IFN-γ, interleukin-2, IgG2a, and nasal IgA. This study provides evidence of the potential of DC targeting for the development of new vaccines against a range of Apicomplexa parasites.

Spatial distribution of excitatory synapses on the dendrites of ganglion cells in the mouse retina.

Directory of Open Access Journals (Sweden)

Yin-Peng Chen

Full Text Available Excitatory glutamatergic inputs from bipolar cells affect the physiological properties of ganglion cells in the mammalian retina. The spatial distribution of these excitatory synapses on the dendrites of retinal ganglion cells thus may shape their distinct functions. To visualize the spatial pattern of excitatory glutamatergic input into the ganglion cells in the mouse retina, particle-mediated gene transfer of plasmids expressing postsynaptic density 95-green fluorescent fusion protein (PSD95-GFP was used to label the excitatory synapses. Despite wide variation in the size and morphology of the retinal ganglion cells, the expression of PSD95 puncta was found to follow two general rules. Firstly, the PSD95 puncta are regularly spaced, at 1-2 µm intervals, along the dendrites, whereby the presence of an excitatory synapse creates an exclusion zone that rules out the presence of other glutamatergic synaptic inputs. Secondly, the spatial distribution of PSD95 puncta on the dendrites of diverse retinal ganglion cells are similar in that the number of excitatory synapses appears to be less on primary dendrites and to increase to a plateau on higher branch order dendrites. These observations suggest that synaptogenesis is spatially regulated along the dendritic segments and that the number of synaptic contacts is relatively constant beyond the primary dendrites. Interestingly, we also found that the linear puncta density is slightly higher in large cells than in small cells. This may suggest that retinal ganglion cells with a large dendritic field tend to show an increased connectivity of excitatory synapses that makes up for their reduced dendrite density. Mapping the spatial distribution pattern of the excitatory synapses on retinal ganglion cells thus provides explicit structural information that is essential for our understanding of how excitatory glutamatergic inputs shape neuronal responses.

Blastic plasmacytoid dendritic cell neoplasm with absolute monocytosis at presentation

Directory of Open Access Journals (Sweden)

Jaworski JM

2015-02-01

Full Text Available Joseph M Jaworski,1,2 Vanlila K Swami,1 Rebecca C Heintzelman,1 Carrie A Cusack,3 Christina L Chung,3 Jeremy Peck,3 Matthew Fanelli,3 Micheal Styler,4 Sanaa Rizk,4 J Steve Hou1 1Department of Pathology and Laboratory Medicine, Hahnemann University Hospital/Drexel University College of Medicine, Philadelphia, PA, USA; 2Department of Pathology, Mercy Fitzgerald Hospital, Darby, PA, USA; 3Department of Dermatology, Hahnemann University Hospital/Drexel University College of Medicine, Philadelphia, PA, USA; 4Department of Hematology/Oncology, Hahnemann University Hospital/Drexel University College of Medicine, Philadelphia, PA, USA Abstract: Blastic plasmacytoid dendritic cell neoplasm is an uncommon malignancy derived from precursors of plasmacytoid dendritic cells. Nearly all patients present initially with cutaneous manifestations, with many having extracutaneous disease additionally. While response to chemotherapy initially is effective, relapse occurs in most, with a leukemic phase ultimately developing. The prognosis is dismal. While most of the clinical and pathologic features are well described, the association and possible prognostic significance between peripheral blood absolute monocytosis (>1.0 K/µL and blastic plasmacytoid dendritic cell neoplasm have not been reported. We report a case of a 68-year-old man who presented with a rash for 4–5 months. On physical examination, there were multiple, dull-pink, indurated plaques on the trunk and extremities. Complete blood count revealed thrombocytopenia, absolute monocytosis of 1.7 K/µL, and a negative flow cytometry study. Biopsy of an abdominal lesion revealed typical features of blastic plasmacytoid dendritic cell neoplasm. Patients having both hematologic and nonhematologic malignancies have an increased incidence of absolute monocytosis. Recent studies examining Hodgkin and non-Hodgkin lymphoma patients have suggested that this is a negative prognostic factor. The association between

Unsaturated compounds induce up-regulation of CD86 on dendritic cells in the in vitro sensitization assay LCSA.

Science.gov (United States)

Frohwein, Thomas Armin; Sonnenburg, Anna; Zuberbier, Torsten; Stahlmann, Ralf; Schreiner, Maximilian

2016-04-01

Unsaturated compounds are known to cause false-positive reactions in the local lymph node assay (LLNA) but not in the guinea pig maximization test. We have tested a panel of substances (succinic acid, undecylenic acid, 1-octyn-3-ol, fumaric acid, maleic acid, linoleic acid, oleic acid, alpha-linolenic acid, squalene, and arachidonic acid) in the loose-fit coculture-based sensitization assay (LCSA) to evaluate whether unspecific activation of dendritic cells is a confounder for sensitization testing in vitro. Eight out of 10 tested substances caused significant up-regulation of CD86 on dendritic cells cocultured with keratinocytes and would have been classified as sensitizers; only succinic acid was tested negative, and squalene had to be excluded from data analysis due to poor solubility in cell culture medium. Based on human data, only undecylenic acid can be considered a true sensitizer. The true sensitizing potential of 1-octyn-3-ol is uncertain. Fumaric acid and its isomer maleic acid are not known as sensitizers, but their esters are contact allergens. A group of 18- to 20-carbon chain unsaturated fatty acids (linoleic acid, oleic acid, alpha-linolenic acid, and arachidonic acid) elicited the strongest reaction in vitro. This is possibly due to the formation of pro-inflammatory lipid mediators in the cell culture causing nonspecific activation of dendritic cells. In conclusion, both the LLNA and the LCSA seem to provide false-positive results for unsaturated fatty acids. The inclusion of T cells in dendritic cell-based in vitro sensitization assays may help to eliminate false-positive results due to nonspecific dendritic cell activation. This would lead to more accurate prediction of sensitizers, which is paramount for consumer health protection and occupational safety.

Dendritic-cell control of pathogen-driven T-cell polarization

NARCIS (Netherlands)

Kapsenberg, Martien L.

2003-01-01

Dendritic cells (DCs) are central in the orchestration of the various forms of immunity and tolerance. Their immunoregulatory role mainly relies on the ligation of specific receptors that initiate and modulate DC maturation resulting in the development of functionally different effector DC subsets

Dendrite short-circuit and fuse effect on Li/polymer/Li cells

International Nuclear Information System (INIS)

Rosso, Michel; Brissot, Claire; Teyssot, Anna; Dolle, Mickael; Sannier, Lucas; Tarascon, Jean-Marie; Bouchet, Renaud; Lascaud, Stephane

2006-01-01

We report on experimental and theoretical studies of dendritic growth in Li/polymer/Li symmetric cells. Potential evolution with time, impedance and in situ microscopy experiments enable to characterise the onset and evolution of dendrites. In particular we observe that dendrites may burn when a high enough current goes through them, a thermo-fusible effect predicted in a previous paper and confirmed by SEM experiments. We present a calculation that gives a quantitative description of this effect: our results enable to understand a series of experimental data published in the literature concerning impedance variations observed while cycling lithium-polymer cells

Chemokine-mediated distribution of dendritic cell subsets in renal cell carcinoma

Directory of Open Access Journals (Sweden)

Meyer Werner

2010-10-01

Full Text Available Abstract Background Renal cell carcinoma (RCC represents one of the most immunoresponsive cancers. Antigen-specific vaccination with dendritic cells (DCs in patients with metastatic RCC has been shown to induce cytotoxic T-cell responses associated with objective clinical responses. Thus, clinical trials utilizing DCs for immunotherapy of advanced RCCs appear to be promising; however, detailed analyses concerning the distribution and function of DC subsets in RCCs are lacking. Methods We characterized the distribution of the different immature and mature myeloid DC subsets in RCC tumour tissue and the corresponding normal kidney tissues. In further analyses, the expression of various chemokines and chemokine receptors controlling the migration of DC subsets was investigated. Results The highest numbers of immature CD1a+ DCs were found within RCC tumour tissue. In contrast, the accumulation of mature CD83+/DC-LAMP+ DCs were restricted to the invasive margin of the RCCs. The mature DCs formed clusters with proliferating T-cells. Furthermore, a close association was observed between MIP-3α-producing tumour cells and immature CCR6+ DC recruitment to the tumour bed. Conversely, MIP-3β and SLC expression was only detected at the tumour border, where CCR7-expressing T-cells and mature DCs formed clusters. Conclusion Increased numbers of immature DCs were observed within the tumour tissue of RCCs, whereas mature DCs were found in increased numbers at the tumour margin. Our results strongly implicate that the distribution of DC subsets is controlled by local lymphoid chemokine expression. Thus, increased expression of MIP-3α favours recruitment of immature DCs to the tumour bed, whereas de novo local expression of SLC and MIP-3β induces accumulation of mature DCs at the tumour margin forming clusters with proliferating T-cells reflecting a local anti-tumour immune response.

Chemokine-mediated distribution of dendritic cell subsets in renal cell carcinoma

International Nuclear Information System (INIS)

Middel, Peter; Brauneck, Sven; Meyer, Werner; Radzun, Heinz-Joachim

2010-01-01

Renal cell carcinoma (RCC) represents one of the most immunoresponsive cancers. Antigen-specific vaccination with dendritic cells (DCs) in patients with metastatic RCC has been shown to induce cytotoxic T-cell responses associated with objective clinical responses. Thus, clinical trials utilizing DCs for immunotherapy of advanced RCCs appear to be promising; however, detailed analyses concerning the distribution and function of DC subsets in RCCs are lacking. We characterized the distribution of the different immature and mature myeloid DC subsets in RCC tumour tissue and the corresponding normal kidney tissues. In further analyses, the expression of various chemokines and chemokine receptors controlling the migration of DC subsets was investigated. The highest numbers of immature CD1a+ DCs were found within RCC tumour tissue. In contrast, the accumulation of mature CD83+/DC-LAMP+ DCs were restricted to the invasive margin of the RCCs. The mature DCs formed clusters with proliferating T-cells. Furthermore, a close association was observed between MIP-3α-producing tumour cells and immature CCR6+ DC recruitment to the tumour bed. Conversely, MIP-3β and SLC expression was only detected at the tumour border, where CCR7-expressing T-cells and mature DCs formed clusters. Increased numbers of immature DCs were observed within the tumour tissue of RCCs, whereas mature DCs were found in increased numbers at the tumour margin. Our results strongly implicate that the distribution of DC subsets is controlled by local lymphoid chemokine expression. Thus, increased expression of MIP-3α favours recruitment of immature DCs to the tumour bed, whereas de novo local expression of SLC and MIP-3β induces accumulation of mature DCs at the tumour margin forming clusters with proliferating T-cells reflecting a local anti-tumour immune response

Bacterial CpG-DNA activates dendritic cells in vivo: T helper cell-independent cytotoxic T cell responses to soluble proteins.

Science.gov (United States)

Sparwasser, T; Vabulas, R M; Villmow, B; Lipford, G B; Wagner, H

2000-12-01

Receptors for conserved molecular patterns associated with microbial pathogens induce synthesis of co-stimulatory molecules and cytokines in immature dendritic cells (DC), as do antigen-reactive CD4 T helper cells via CD40 signaling. Once activated, antigen-presenting DC may activate CD8 T cell responses in a T helper cell-independent fashion. Using immunostimulatory CpG-oligonucleotides (ODN) mimicking bacterial CpG-DNA, we tested whether CpG-DNA bypasses the need for T helper cells in CTL responses towards proteins by directly activating antigen-presenting DC to transit into professional APC. We describe that immature DC in situ constitutively process soluble proteins and generate CD8 T cell determinants yet CD8 T cell responses remain abortive. Induction of primary antigen-specific CD8 cytotoxic T lymphocyte (CTL)-mediated responses becomes initiated in wild-type as well as T helper cell-deficient mice, provided soluble protein and CpG-ODN are draining into the same lymph node. Specifically we show that CpG-ODN trigger antigen-presenting immature DC within the draining lymph node to acutely up-regulate co-stimulatory molecules and produce IL-12. These results provide new insights for generating in vivo efficient CTL responses to soluble proteins which may influence vaccination strategies.

Oral chronic graft-versus-host disease: analysis of dendritic cells subpopulations*

Science.gov (United States)

Botari, Clara Marino Espricigo; Nunes, Adauto José Ferreira; de Souza, Mair Pedro; Orti-Raduan, Érica Sinara Lenharo; Salvio, Ana Gabriela

2014-01-01

The graft-versus-host disease is the major cause of morbidity and mortality in patients who have undergone hematopoietic stem cell transplantation. Aiming at contributing to the understanding of the role of myeloid and plasmacytoid dendritic cells, and natural killer cells in chronic graft-versus-host disease, we examined biopsies of jugal mucosa of 26 patients with acute myeloid leukemia who had undergone allogenic hematopoietic stem cell transplantation. Half of these patients developed oral chronic graft-versus-host disease. Microscopic sections were immunohistochemically stained for anti-CD1a, anti-CD123 and anti-CD56. We calculated the number of immunostained cells in the corium per square millimeter and applied the Mann-Whitney test. Results showed a statistically significant increase of myeloid dendritic cells (CD1a+; p=0,02) and natural killer cells (CD56; p=0,04) in patients with oral chronic graft-versus-host disease. CD123 immunostaining showed no statistical difference between groups. It was concluded that myeloid dendritic cells and natural killer cells participate in the development of oral chronic graft-versus-host disease. PMID:25054751

Oral chronic graft-versus-host disease: analysis of dendritic cells subpopulations.

Science.gov (United States)

Botari, Clara Marino Espricigo; Nunes, Adauto José Ferreira; Souza, Mair Pedro de; Orti-Raduan, Erica Sinara Lenharo; Salvio, Ana Gabriela

2014-01-01

The graft-versus-host disease is the major cause of morbidity and mortality in patients who have undergone hematopoietic stem cell transplantation. Aiming at contributing to the understanding of the role of myeloid and plasmacytoid dendritic cells, and natural killer cells in chronic graft-versus-host disease, we examined biopsies of jugal mucosa of 26 patients with acute myeloid leukemia who had undergone allogenic hematopoietic stem cell transplantation. Half of these patients developed oral chronic graft-versus-host disease. Microscopic sections were immunohistochemically stained for anti-CD1a, anti-CD123 and anti-CD56. We calculated the number of immunostained cells in the corium per square millimeter and applied the Mann-Whitney test. Results showed a statistically significant increase of myeloid dendritic cells (CD1a+; p=0,02) and natural killer cells (CD56; p=0,04) in patients with oral chronic graft-versus-host disease. CD123 immunostaining showed no statistical difference between groups. It was concluded that myeloid dendritic cells and natural killer cells participate in the development of oral chronic graft-versus-host disease.

Burn injury suppresses human dermal dendritic cell and Langerhans cell function

NARCIS (Netherlands)

van den Berg, Linda M.; de Jong, Marein A. W. P.; Witte, Lot de; Ulrich, Magda M. W.; Geijtenbeek, Teunis B. H.

2011-01-01

Human skin contains epidermal Langerhans cells (LCs) and dermal dendritic cells (DCs) that are key players in induction of adaptive immunity upon infection. After major burn injury, suppressed adaptive immunity has been observed in patients. Here we demonstrate that burn injury affects adaptive

Future of an “Asymptomatic” T-cell Epitope-Based Therapeutic Herpes Simplex Vaccine

Science.gov (United States)

Dervillez, Xavier; Gottimukkala, Chetan; Kabbara, Khaled W.; Nguyen, Chelsea; Badakhshan, Tina; Kim, Sarah M.; Nesburn, Anthony B.; Wechsler, Steven L.; BenMohamed, Lbachir

2012-01-01

Summary Considering the limited success of the recent herpes clinical vaccine trial [1], new vaccine strategies are needed. Infections with herpes simplex virus type 1 and type 2 (HSV-1 & HSV-2) in the majority of men and women are usually asymptomatic and results in lifelong viral latency in neurons of sensory ganglia (SG). However, in a minority of men and women HSV spontaneous reactivation can cause recurrent disease (i.e., symptomatic individuals). Our recent findings show that T cells from symptomatic and asymptomatic men and women (i.e. those with and without recurrences, respectively) recognize different herpes epitopes. This finding breaks new ground and opens new doors to assess a new vaccine strategy: mucosal immunization with HSV-1 & HSV-2 epitopes that induce strong in vitro CD4 and CD8 T cell responses from PBMC derived from asymptomatic men and women (designated here as “asymptomatic” protective epitopes”) could boost local and systemic “natural” protective immunity, induced by wild-type infection. Here we highlight the rationale and the future of our emerging “asymptomatic” T cell epitope-based mucosal vaccine strategy to decrease recurrent herpetic disease. PMID:22701511

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

Science.gov (United States)

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

Dextromethorphan Inhibits Activations and Functions in Dendritic Cells

Directory of Open Access Journals (Sweden)

Der-Yuan Chen

2013-01-01

Full Text Available Dendritic cells (DCs play an important role in connecting innate and adaptive immunity. Thus, DCs have been regarded as a major target for the development of immunomodulators. In this study, we examined the effect of dextromethorphan (DXM, a common cough suppressant with a high safety profile, on the activation and function of DCs. In the presence of DXM, the LPS-induced expression of the costimulatory molecules in murine bone marrow-derived dendritic cells (BMDCs was significantly suppressed. In addition, DXM treatment reduced the production of reactive oxygen species (ROS, proinflammatory cytokines, and chemokines in maturing BMDCs that were activated by LPS. Therefore, DXM abrogated the ability of LPS-stimulated DCs to induce Ag-specific T-cell activation, as determined by their decreased proliferation and IFN-γ secretion in mixed leukocyte cultures. Moreover, the inhibition of LPS-induced MAPK activation and NF-κB translocation may contribute to the suppressive effect of DXM on BMDCs. Remarkably, DXM decreased the LPS-induced surface expression of CD80, CD83, and HLA-DR and the secretion of IL-6 and IL-12 in human monocyte-derived dendritic cells (MDDCs. These findings provide a new insight into the impact of DXM treatment on DCs and suggest that DXM has the potential to be used in treating DC-related acute and chronic diseases.

B cell and T cell immunity in the female genital tract: potential of distinct mucosal routes of vaccination and role of tissue-associated dendritic cells and natural killer cells.

Science.gov (United States)

Anjuère, F; Bekri, S; Bihl, F; Braud, V M; Cuburu, N; Czerkinsky, C; Hervouet, C; Luci, C

2012-10-01

The female genital mucosa constitutes the major port of entry of sexually transmitted infections. Most genital microbial pathogens represent an enormous challenge for developing vaccines that can induce genital immunity that will prevent their transmission. It is now established that long-lasting protective immunity at mucosal surfaces has to involve local B-cell and T-cell effectors as well as local memory cells. Mucosal immunization constitutes an attractive way to generate systemic and genital B-cell and T-cell immune responses that can control early infection by sexually transmitted pathogens. Nevertheless, no mucosal vaccines against sexually transmitted infections are approved for human use. The mucosa-associated immune system is highly compartmentalized and the selection of any particular route or combinations of routes of immunization is critical when defining vaccine strategies against genital infections. Furthermore, mucosal surfaces are complex immunocompetent tissues that comprise antigen-presenting cells and also innate immune effectors and non-immune cells that can act as 'natural adjuvants' or negative immune modulators. The functions of these cells have to be taken into account when designing tissue-specific antigen-delivery systems and adjuvants. Here, we will discuss data that compare different mucosal routes of immunization to generate B-cell and T-cell responses in the genital tract, with a special emphasis on the newly described sublingual route of immunization. We will also summarize data on the understanding of the effector and induction mechanisms of genital immunity that may influence the development of vaccine strategies against genital infections. © 2012 The Authors. Clinical Microbiology and Infection © 2012 European Society of Clinical Microbiology and Infectious Diseases.

Tumor vaccine composed of C-class CpG oligodeoxynucleotides and irradiated tumor cells induces long-term antitumor immunity

Directory of Open Access Journals (Sweden)

Cerkovnik Petra

2010-09-01

Full Text Available Abstract Background An ideal tumor vaccine should activate both effector and memory immune response against tumor-specific antigens. Beside the CD8+ T cells that play a central role in the generation of a protective immune response and of long-term memory, dendritic cells (DCs are important for the induction, coordination and regulation of the adaptive immune response. The DCs can conduct all of the elements of the immune orchestra and are therefore a fundamental target and tool for vaccination. The present study was aimed at assessing the ability of tumor vaccine composed of C-class CpG ODNs and irradiated melanoma tumor cells B16F1 followed by two additional injections of CpG ODNs to induce the generation of a functional long-term memory response in experimental tumor model in mice (i.p. B16F1. Results It has been shown that the functional memory response in vaccinated mice persists for at least 60 days after the last vaccination. Repeated vaccination also improves the survival of experimental animals compared to single vaccination, whereas the proportion of animals totally protected from the development of aggressive i.p. B16F1 tumors after vaccination repeated three times varies between 88.9%-100.0%. Additionally, the long-term immune memory and tumor protection is maintained over a prolonged period of time of at least 8 months. Finally, it has been demonstrated that following the vaccination the tumor-specific memory cells predominantly reside in bone marrow and peritoneal tissue and are in a more active state than their splenic counterparts. Conclusions In this study we demonstrated that tumor vaccine composed of C-class CpG ODNs and irradiated tumor cells followed by two additional injections of CpG ODNs induces a long-term immunity against aggressive B16F1 tumors.

FcεRI γ-Chain Negatively Modulates Dectin-1 Responses in Dendritic Cells

Directory of Open Access Journals (Sweden)

Yi-Gen Pan

2017-10-01

Full Text Available The inhibitory effect of immunoreceptor tyrosine-based activation motif (ITAM-containing adapters DAP12 and FcεRI γ-chain (FcRγ has been found in many immune functions. Herein, we have further explored the role of these adapters in C-type lectin receptors response. We identified that FcRγ, but not DAP12, could negatively regulate the Dectin-1 responses in dendritic cells (DCs. Loss of FcRγ or both DAP12 and FcRγ enhanced the maturation and cytokine production in DCs upon Dectin-1 activation compared to normal cells, whereas DCs lacking only DAP12 showed little changes. In addition, increments of T cell activation and T helper 17 polarization induced by FcRγ-deficient DCs were observed both in vitro and in vivo. Examining the Dectin-1 signaling, we revealed that the activations of several signaling molecules were augmented in FcRγ-deficient DCs stimulated with Dectin-1 ligands. Furthermore, we demonstrated that the association of phosphatases SHP-1 and PTEN with FcRγ may contribute to the negative regulation of FcRγ in Dectin-1 activation in DCs. These results extend the inhibitory effect of ITAM-containing adapters to Dectin-1 response in immune functions, even though Dectin-1 contains an ITAM-like intracellular domain. According to the role of Dectin-1 in responding to microbes and tumor cells, our finding may have applications in the development of vaccine and cancer therapy.

Lactobacilli activate human dendritic cells that skew T cells toward T helper 1 polarization.

Science.gov (United States)

Mohamadzadeh, Mansour; Olson, Scott; Kalina, Warren V; Ruthel, Gordon; Demmin, Gretchen L; Warfield, Kelly L; Bavari, Sina; Klaenhammer, Todd R

2005-02-22

Professional antigen-presenting dendritic cells (DCs) are critical in regulating T cell immune responses at both systemic and mucosal sites. Many Lactobacillus species are normal members of the human gut microflora and most are regarded as safe when administered as probiotics. Because DCs can naturally or therapeutically encounter lactobacilli, we investigated the effects of several well defined strains, representing three species of Lactobacillus on human myeloid DCs (MDCs) and found that they modulated the phenotype and functions of human MDCs. Lactobacillus-exposed MDCs up-regulated HLA-DR, CD83, CD40, CD80, and CD86 and secreted high levels of IL-12 and IL-18, but not IL-10. IL-12 was sustained in MDCs exposed to all three Lactobacillus species in the presence of LPS from Escherichia coli, whereas LPS-induced IL-10 was greatly inhibited. MDCs activated with lactobacilli clearly skewed CD4(+) and CD8(+) T cells to T helper 1 and Tc1 polarization, as evidenced by secretion of IFN-gamma, but not IL-4 or IL-13. These results emphasize a potentially important role for lactobacilli in modulating immunological functions of DCs and suggest that certain strains could be particularly advantageous as vaccine adjuvants, by promoting DCs to regulate T cell responses toward T helper 1 and Tc1 pathways.

Overlapping, Additive and Counterregulatory Effects of Type II and I Interferons on Myeloid Dendritic Cell Functions

Directory of Open Access Journals (Sweden)

Loredana Frasca

2011-01-01

Full Text Available Dendritic cells (DCs are central player in immunity by bridging the innate and adaptive arms of the immune system (IS. Interferons (IFNs are one of the most important factors that regulate both innate and adaptive immunity too. Thus, the understanding of how type II and I IFNs modulate the immune-regulatory properties of DCs is a central issue in immunology. In this paper, we will address this point in the light of the most recent literature, also highlighting the controversial data reported in the field. According to the wide literature available, type II as well as type I IFNs appear, at the same time, to collaborate, to induce additive effects or overlapping functions, as well as to counterregulate each one's effects on DC biology and, in general, the immune response. The knowledge of these effects has important therapeutic implications in the treatment of infectious/autoimmune diseases and cancer and indicates strategies for using IFNs as vaccine adjuvants and in DC-based immune therapeutic approaches.

Suppression of adaptive immunity to heterologous antigens during Plasmodium infection through hemozoin-induced failure of dendritic cell function

Directory of Open Access Journals (Sweden)

Phillips R

2006-04-01

Full Text Available Abstract Background Dendritic cells (DCs are central to the initiation and regulation of the adaptive immune response during infection. Modulation of DC function may therefore allow evasion of the immune system by pathogens. Significant depression of the host's systemic immune response to both concurrent infections and heterologous vaccines has been observed during malaria infection, but the mechanisms underlying this immune hyporesponsiveness are controversial. Results Here, we demonstrate that the blood stages of malaria infection induce a failure of DC function in vitro and in vivo, causing suboptimal activation of T cells involved in heterologous immune responses. This effect on T-cell activation can be transferred to uninfected recipients by DCs isolated from infected mice. Significantly, T cells activated by these DCs subsequently lack effector function, as demonstrated by a failure to migrate to lymphoid-organ follicles, resulting in an absence of B-cell responses to heterologous antigens. Fractionation studies show that hemozoin, rather than infected erythrocyte (red blood cell membranes, reproduces the effect of intact infected red blood cells on DCs. Furthermore, hemozoin-containing DCs could be identified in T-cell areas of the spleen in vivo. Conclusion Plasmodium infection inhibits the induction of adaptive immunity to heterologous antigens by modulating DC function, providing a potential explanation for epidemiological studies linking endemic malaria with secondary infections and reduced vaccine efficacy.

Detection of Avian Antigen-Specific T Cells Induced by Viral Vaccines

DEFF Research Database (Denmark)

Dalgaard, Tina Sørensen; Norup, Liselotte Rothmann; Juul-Madsen, Helle Risdahl

2016-01-01

Live attenuated viral vaccines are widely used in commercial poultry production, but the development of new effective inactivated/subunit vaccines is needed. Studies of avian antigen-specific T cells are primarily based on analyses ex vivo after activating the cells with recall antigen. There is ......Live attenuated viral vaccines are widely used in commercial poultry production, but the development of new effective inactivated/subunit vaccines is needed. Studies of avian antigen-specific T cells are primarily based on analyses ex vivo after activating the cells with recall antigen...

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

Science.gov (United States)

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

Polymorphism in liver-stage malaria vaccine candidate proteins: immune evasion and implications for vaccine design.

Science.gov (United States)

Flanagan, Katie L; Wilson, Kirsty L; Plebanski, Magdalena

2016-01-01

The pre-erythrocytic stage of infection by malaria parasites represents a key target for vaccines that aim to eradicate malaria. Two important broad immune evasion strategies that can interfere with vaccine efficacy include the induction of dendritic cell (DC) dysfunction and regulatory T cells (Tregs) by blood-stage malaria parasites, leading to inefficient priming of T cells targeting liver-stage infections. The parasite also uses 'surgical strike' strategies, whereby polymorphism in pre-erythrocytic antigens can interfere with host immunity. Specifically, we review how even single amino acid changes in T cell epitopes can lead to loss of binding to major histocompatibility complex (MHC), lack of cross-reactivity, or antagonism and immune interference, where simultaneous or sequential stimulation with related variants of the same T cell epitope can cause T cell anergy or the conversion of effector to immunosuppressive T cell phenotypes.

Polyethylenimine-based polyplex delivery of self-replicating RNA vaccines.

Science.gov (United States)

Démoulins, Thomas; Milona, Panagiota; Englezou, Pavlos C; Ebensen, Thomas; Schulze, Kai; Suter, Rolf; Pichon, Chantal; Midoux, Patrick; Guzmán, Carlos A; Ruggli, Nicolas; McCullough, Kenneth C

2016-04-01

Self-amplifying replicon RNA (RepRNA) are large molecules (12-14 kb); their self-replication amplifies mRNA template numbers, affording several rounds of antigen production, effectively increasing vaccine antigen payloads. Their sensitivity to RNase-sensitivity and inefficient uptake by dendritic cells (DCs) - absolute requirements for vaccine design - were tackled by condensing RepRNA into synthetic, nanoparticulate, polyethylenimine (PEI)-polyplex delivery vehicles. Polyplex-delivery formulations for small RNA molecules cannot be transferred to RepRNA due to its greater size and complexity; the N:P charge ratio and impact of RepRNA folding would influence polyplex condensation, post-delivery decompaction and the cytosolic release essential for RepRNA translation. Polyplex-formulations proved successful for delivery of RepRNA encoding influenza virus hemagglutinin and nucleocapsid to DCs. Cytosolic translocation was facilitated, leading to RepRNA translation. This efficacy was confirmed in vivo, inducing both humoral and cellular immune responses. Accordingly, this paper describes the first PEI-polyplexes providing efficient delivery of the complex and large, self-amplifying RepRNA vaccines. The use of self-amplifying replicon RNA (RepRNA) to increase vaccine antigen payloads can potentially be useful in effective vaccine design. Nonetheless, its use is limited by the degradation during the uptake process. Here, the authors attempted to solve this problem by packaging RepRNA using polyethylenimine (PEI)-polyplex delivery vehicles. The efficacy was confirmed in vivo by the appropriate humoral and cellular immune responses. This novel delivery method may prove to be very useful for future vaccine design. Copyright © 2015 Elsevier Inc. All rights reserved.

Geranylgeranyltransferase I is essential for dendritic development of cerebellar Purkinje cells

Directory of Open Access Journals (Sweden)

Wu Kong-Yan

2010-06-01

Full Text Available Abstract Background During cerebellar development, Purkinje cells (PCs form the most elaborate dendritic trees among neurons in the brain, but the mechanism regulating PC arborization remains largely unknown. Geranylgeranyltransferase I (GGT is a prenyltransferase that is responsible for lipid modification of several signaling proteins, such as Rho family small GTPase Rac1, which has been shown to be involved in neuronal morphogenesis. Here we show that GGT plays an important role in dendritic development of PCs. Results We found that GGT was abundantly expressed in the developing rat cerebellum, in particular molecular layer (ML, the region enriched with PC dendrites. Inhibition or down-regulation of GGT using small interference RNA (siRNA inhibited dendritic development of PCs. In contrast, up-regulation of GGT promoted dendritic arborization of PCs. Furthermore, neuronal depolarization induced by high K+ or treatment with brain-derived neurotrophic factor (BDNF promoted membrane association of Rac1 and dendritic development of PCs in cultured cerebellar slices. The effect of BDNF or high K+ was inhibited by inhibition or down-regulation of GGT. Conclusion Our results indicate that GGT plays an important role in Purkinje cell development, and suggest a novel role of GGT in neuronal morphogenesis in vivo.

Large-Scale mRNA Transfection of Dendritic Cells by Electroporation in Continuous Flow Systems

DEFF Research Database (Denmark)

Selmeczi, Dávid; Hansen, Thomas Steen; Met, Özcan