0000000000180074

AUTHOR

Thomas Tüting

Transcriptional targeting of dendritic cells for gene therapy using the promoter of the cytoskeletal protein fascin.

Strong cell-type-specific promoters are basic tools in gene therapy allowing for novel applications and focused strategies by transcriptionally targeting gene expression to selected cells. In immunotherapy, dendritic cells (DC) are of central importance, since they represent the principal inducers of immune responses. Here we describe isolation and use of the promoter of the murine actin-bundling protein fascin to target transcriptionally gene expression to cutaneous DC. Using the reporter gene enhanced green fluorescent protein (EGFP), we demonstrate that the fascin promoter mediates a strong antigen expression that is restricted to mature DC. DNA vaccination with antigen-encoding expressi…

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Altered intracellular sorting signals do not influence the efficacy of genetic melanoma vaccines incorporating helper determinants in mice.

Background A genetic melanoma vaccine consisting of cDNA encoding the model self-antigen tyrosinase-related protein 2 (TRP2) fused in-frame to the immunogenic enhanced green fluorescent protein (EGFP) was able to break immune tolerance and stimulate CD8+ T cells in vivo. In the present study we investigated whether alteration of the intracellular antigen localization as a result of the linkage with immune-enhancing helper proteins affects the resulting immune response. Methods Expression plasmids and recombinant adenoviruses were constructed encoding various fusion proteins with different intracellular sorting signals which direct the antigen to the cytosol, the endoplasmic reticulum or the…

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Efficacy of recombinant adenovirus as vector for allergen gene therapy in a mouse model of type I allergy

DNA-based immunization represents an attractive alternative approach to the current treatment of allergic diseases by specific immunotherapy with allergen extracts. In this study, we used a replication-deficient adenovirus vector (AdCMV), to examine the in vivo efficacy of preventive and therapeutic genetic immunization in a mouse model of type I allergy. Primary immunization with a recombinant adenovirus expressing the model antigen beta-galactosidase (AdCMV-(beta)gal) induced a Th1 immune response (predominance of IgG2a antibodies, high frequency of IFN-gamma producing T cells) and large numbers of cytotoxic T lymphocytes. Prophylactic vaccination with AdCMV-(beta)gal abolished the produc…

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Primary plasmacytoma of the skin.

Primary plasmacytoma of the skin without evidence of bone marrow plasmacytosis is a rare disorder belonging to the heterogenous spectrum of plasma cell neoplasms. With immunohistochemical techniques, differentiation from benign plasma cell aggregates can be accomplished by demonstrating the monoclonality of tumor cells. We describe a patient in whom a solitary primary cutaneous plasmacytoma developed on the left thigh. Immunohistochemically, plasma cells showed restriction of immunoglobulin lambda-chain expression. Underlying multiple myeloma was excluded by serum protein and immunoglobulin electrophoresis, roentgenographic skeletal survey, and bone marrow biopsy. The tumor responded well t…

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Interleukin-10-treated dendritic cells modulate immune responses of naive and sensitized T cells in vivo.

Interleukin-10 is a pleiotropic cytokine known to have inhibitory effects on the accessory functions of dendritic cells. In vitro, interleukin-10 converts immature dendritic cells into tolerizing antigen- presenting cells. To assess whether interleukin-10-treated dendritic cells exert tolerizing effects in vivo, CD4+ T cells from DO11.10 ovalbumin-T cell receptor transgenic mice were transferred to syngeneic BALB/c recipients. Recipient animals were treated with ovalbumin-pulsed/unpulsed, interleukin-10-treated/untreated CD11c+ dendritic cells thereafter and ovalbumin-specific proliferation of lymph node cells was assessed by restimulation with the peptide in vitro. In prophylactic experime…

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Particle-Mediated Gene Transfer into Dendritic Cells: A Novel Strategy for the Induction of Immune Responses against Tumor Antigens

The expression of a foreign protein in the skin following direct in vivo gene transfer results in the induction of potent cellular and humoral immune responses. This strategy, now known as genetic or DNA immunization, was first described by Johnston et al. in 1992. They reported that bombardment of murine skin with an expression plasmid encoding human growth hormone coated onto microscopic gold particles using a gene gun resulted not only in the systemic delivery of the molecule, but also in the induction of antigenspecific antibody responses (1). It is now well established that DNA immunization by particle-mediated gene transfer promotes broad-based and long-lasting antigen-specific immune…

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Cannabinoid 1 Receptors in Keratinocytes Modulate Proinflammatory Chemokine Secretion and Attenuate Contact Allergic Inflammation

Abstract Epidermal keratinocytes (KCs) and cannabinoid (CB) receptors both participate in the regulation of inflammatory responses in a mouse model for allergic contact dermatitis, the contact hypersensitivity (CHS) response to the obligate sensitizer 2,4-dinitrofluorobenzene. In this study, we investigated the cellular and molecular mechanisms how CB1 receptors attenuate CHS responses to 2,4-dinitrofluorobenzene. We used a conditional gene-targeting approach to identify the relative contribution of CB1 receptors on epidermal KCs for the control of CHS responses. To determine the underlying cellular and molecular mechanisms that regulate inflammatory responses in the effector phase of CHS, …

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Melanomas resist T-cell therapy through inflammation-induced reversible dedifferentiation.

Adoptive cell transfer therapies (ACTs) with cytotoxic T cells that target melanocytic antigens can achieve remissions in patients with metastatic melanomas, but tumours frequently relapse. Hypotheses explaining the acquired resistance to ACTs include the selection of antigen-deficient tumour cell variants and the induction of T-cell tolerance. However, the lack of appropriate experimental melanoma models has so far impeded clear insights into the underlying mechanisms. Here we establish an effective ACT protocol in a genetically engineered mouse melanoma model that recapitulates tumour regression, remission and relapse as seen in patients. We report the unexpected observation that melanoma…

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CXCR3-ligand-mediated skin inflammation in cutaneous lichenoid graft-versus-host disease.

Background Lichenoid graft-versus-host disease (liGVHD) histologically shares several common features with other lichenoid dermatoses, such as cutaneous lupus erythematosus and lichen planus (LP), which collectively show a junctional infiltrate of cytotoxic lymphocytes with liquefaction of the basal layer ("interface dermatitis"). Because recent studies have shown a role for type I interferon (IFN)–associated inflammation, including lymphocyte recruitment via CXCR3 ligand interaction in cutaneous lupus erythematosus and LP, we hypothesized that similar mechanisms might also be involved in liGVHD. Methods Ten representative lesional skin biopsies taken from patients with different subsets of…

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Immunogenicity of enhanced green fluorescent protein (EGFP) in BALB/c mice: identification of an H2-Kd-restricted CTL epitope

Enhanced green fluorescent protein (EGFP) is a novel marker gene product, which is readily detectable using techniques of fluorescence microscopy, flow cytometry, or macroscopic imaging. In the present studies, we have examined the immunogenicity of EGFP in murine models. A stable transfectant of the transplantable CMS4 sarcoma of BALB/c origin expressing EGFP, CMS4-EGFP-Zeo, was generated. Splenocytes harvested from mice immunized with a recombinant adenovirus expressing EGFP (Ad-EGFP) were restimulated in vitro with CMS4-EGFP-Zeo. Effector lymphocytes displayed strong cytotoxicity against CMS4-EGFP-Zeo, but not against mock-transfected CMS4-Zeo tumor cells. A number of candidate H2-Kd-bin…

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Induction of dendritic cell maturation and modulation of dendritic cell-induced immune responses by prostaglandins

Dendritic cells (DC) are the most potent antigen-presenting cells of the immune system. In this study we investigated the effects of various prostaglandins (PG) on the stimulatory capacity of DC. DC were generated from peripheral progenitor cells in the presence of IL-4 and GM-CSF and stimulated with IL-1, IL-6 and TNF-alpha on day 7. Simultaneously, PG (PGD(2), PGE(1), PGE(2), PGF(2 alpha), PGI(2)) were added at various concentrations (10(-5) to 10(-9) M) on day 7. In all experiments, PGE(2) had the most potent influence on the maturation of the DC, followed by other PG in the order PGE(1) > PGD(2) > PGF(2 alpha) > PGI(2). In addition, the expression of the surface molecules CD40, CD54, CD…

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Cancer cell–autonomous contribution of type I interferon signaling to the efficacy of chemotherapy

International audience; The immune system is routinely confronted with cell death resulting from the physiological turnover of renewable tissues, as well as from pathological insults of several types. We hypothesize the existence of a mechanism that allows the immune system to discriminate between physiological and pathological instances of cell death, but the factors that determine whether cellular demise is perceived as a neutral, tolerogenic or immunogenic event remain unclear 1. Infectious insults are accompanied by so-called microbe-associated molecular patterns (MAMPs), i.e., viral or bacterial products that activate immune cells through a panel of pattern-recognition receptors (PRRs)…

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A comparison of two types of dendritic cell as adjuvants for the induction of melanoma-specific T-cell responses in humans following intranodal injection

Dendritic cells (DCs) elicit potent anti-tumoral T-cell responses in vitro and in vivo. However, different types of DC have yet to be compared for their capacity to induce anti-tumor responses in vivo at different developmental stages. Herein, we correlated the efficiencies of different types of monocyte-derived DC as vaccines on the resulting anti-tumor immune responses in vivo. Immature and mature DCs were separately pulsed with a peptide derived from tyrosinase, MelanA/MART-1 or MAGE-1 and a recall antigen. Both DC populations were injected every 2 weeks in different lymph nodes of the same patient. Immune responses were monitored before, during and after vaccination. Mature DCs induced …

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Proteasome-inhibited dendritic cells demonstrate improved presentation of exogenous synthetic and natural HLA-class I peptide epitopes.

The design and successful clinical implementation of cancer vaccines targeting the induction of T-cell mediated immunity is a rapidly evolving field that is hampered by an empirical selection of antigen and adjuvant. In particular, vaccines using defined tumor-associated peptide epitopes elicit only a restricted T-cell repertoire in a minority of patients. In this regard, vaccines comprising the whole spectrum of antigens presented by individual autologous tumors would be advantageous. In an in vitro model, we evaluated the capacity of naturally processed Epstein-Barr virus-transformed B-lymphoblastoid-cell line (LCL)-derived peptides to activate virus-specific CD8+ T cells of seropositive …

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Evaluation of genetic melanoma vaccines in cdk4-mutant mice provides evidence for immunological tolerance against authochthonous melanomas in the skin

We evaluated the efficacy of a candidate melanoma vaccine approach in mice genetically prone to develop melanoma due to the introduction of an oncogenic mutation (R24C) in the germline sequence of the cyclin-dependent kinase 4 (cdk4), a protein critically involved in cell cycle regulation. Melanomas were induced in cdk4-mutant mice by chemical carcinogenesis and UVB irradiation. A genetic prime-boost strategy targeting the clinically relevant differentiation antigen tyrosinase-related protein 2 (TRP2) was performed which was able to stimulate a melanocyte-specific cellular immune response associated with localized autoimmune vitiligo-like depigmentation. However, significant destruction of …

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