Imagerie PI2

@article{mairhofer_impaired_2015,

title = {Impaired gp100-Specific CD8(+) Ŧ-Cell Responses in the Presence of Myeloid-Derived Suppressor Cells in a Spontaneous Mouse Melanoma Model},

author = {David G Mairhofer and Daniela Ortner and Christoph H Tripp and Sandra Schaffenrath and Viktor Fleming and Lukas Heger and Kerstin Komenda and Daniela Reider and Diana Dudziak and Suzie Chen and Jürgen C Becker and Vincent Flacher and Patrizia Stoitzner},

doi = {10.1038/jid.2015.241},

issn = {1523-1747},

year  = {2015},

date = {2015-11-01},

journal = {The Journal of Investigative Dermatology},

volume = {135},

number = {11},

pages = {2785--2793},

abstract = {Murine tumor models that closely reflect human diseases are important tools to investigate carcinogenesis and tumor immunity. The transgenic (tg) mouse strain tg(Grm1)EPv develops spontaneous melanoma due to ectopic overexpression of the metabotropic glutamate receptor 1 (Grm1) in melanocytes. In the present study, we characterized the immune status and functional properties of immune cells in tumor-bearing mice. Melanoma development was accompanied by a reduction in the percentages of CD4(+) T cells including regulatory T cells (Tregs) in CD45(+) leukocytes present in tumor tissue and draining lymph nodes (LNs). In contrast, the percentages of CD8(+) T cells were unchanged, and these cells showed an activated phenotype in tumor mice. Endogenous melanoma-associated antigen glycoprotein 100 (gp100)-specific CD8(+) T cells were not deleted during tumor development, as revealed by pentamer staining in the skin and draining LNs. They, however, were unresponsive to ex vivo gp100-peptide stimulation in late-stage tumor mice. Interestingly, immunosuppressive myeloid-derived suppressor cells (MDSCs) were recruited to tumor tissue with a preferential accumulation of granulocytic MDSC (grMDSCs) over monocytic MDSC (moMDSCs). Both subsets produced Arginase-1, inducible nitric oxide synthase (iNOS), and transforming growth factor-β and suppressed T-cell proliferation in vitro. In this work, we describe the immune status of a spontaneous melanoma mouse model that provides an interesting tool to develop future immunotherapeutical strategies.},

keywords = {Analysis of Variance, Animal, Animals, Antigen, cancer, CARCINOGENESIS, CD8-Positive T-Lymphocytes, Cell Proliferation, Cultured, DERMATOLOGY, development, disease, Disease Models, Experimental, GLYCOPROTEIN, gp100 Melanoma Antigen, Growth, Human, Humans, Immunity, Immunologic, IN VITRO, Inbred C57BL, iNOS, Leukocytes, LYMPH, LYMPH NODE, Lymph Nodes, Lymphocyte Activation, MELANOCYTES, Melanoma, Mice, mouse, murine, NITRIC OXIDE, nitric oxide synthase, Phenotype, Proliferation, Random Allocation, Receptor, Regulatory, RESPONSES, Skin, SUBSETS, Suppressor Factors, T CELLS, T-CELLS, T-Lymphocytes, Team-Mueller, Transforming Growth Factor beta, transgenic, tumor, Tumor Cells, tumor immunity},

pubstate = {published},

tppubtype = {article}

}

@article{flacher_murine_2014,

title = {Murine Langerin+ dermal dendritic cells prime CD8+ Ŧ cells while Langerhans cells induce cross-tolerance},

author = {Vincent Flacher and Christoph H Tripp and David G Mairhofer and Ralph M Steinman and Patrizia Stoitzner and Juliana Idoyaga and Nikolaus Romani},

doi = {10.15252/emmm.201303283},

issn = {1757-4684},

year  = {2014},

date = {2014-09-01},

journal = {EMBO molecular medicine},

volume = {6},

number = {9},

pages = {1191--1204},

abstract = {Skin dendritic cells (DCs) control the immunogenicity of cutaneously administered vaccines. Antigens targeted to DCs via the C-type lectin Langerin/CD207 are cross-presented to CD8(+) T cells in vivo. We investigated the relative roles of Langerhans cells (LCs) and Langerin(+) dermal DCs (dDCs) in different vaccination settings. Poly(I:C) and anti-CD40 agonist antibody promoted cytotoxic responses upon intradermal immunization with ovalbumin (OVA)-coupled anti-Langerin antibodies (Langerin/OVA). This correlated with CD70 upregulation in Langerin(+) dDCs, but not LCs. In chimeric mice where Langerin targeting was restricted to dDCs, CD8(+) T-cell memory was enhanced. Conversely, providing Langerin/OVA exclusively to LCs failed to prime cytotoxicity, despite initial antigen cross-presentation to CD8(+) T cells. Langerin/OVA combined with imiquimod could not prime CD8(+) T cells and resulted in poor cytotoxicity in subsequent responses. This tolerance induction required targeting and maturation of LCs. Altogether, Langerin(+) dDCs prime long-lasting cytotoxic responses, while cross-presentation by LCs negatively influences CD8(+) T-cell priming. Moreover, this highlights that DCs exposed to TLR agonists can still induce tolerance and supports the existence of qualitatively different DC maturation programs.},

keywords = {agonists, Animals, Antibodies, antibody, Antigen, Antigen Presentation, Antigens, C-Type, C-type lectin, cancer, CD70, CD8-Positive T-Lymphocytes, CD8+ T cells, CD8+ T‐cell responses, Cellular, CROSS-PRESENTATION, Cross-Priming, Cytotoxicity, Dendritic Cells, DERMAL DENDRITIC CELLS, DERMATOLOGY, disease, imiquimod, Immunization, IMMUNOGENICITY, Immunologic Memory, Immunological, Immunology, In vivo, Inbred C57BL, INDUCTION, Intradermal, Langerhans Cells, LECTIN, Lectins, Mannose-Binding Lectins, Maturation, Mice, Models, murine, OVALBUMIN, physiology, priming, RESPONSES, Skin, Surface, T CELLS, T-CELLS, Team-Mueller, tolerance, Vaccination, vaccine, Vaccines},

pubstate = {published},

tppubtype = {article}

}

@article{flacher_targeting_2009,

title = {Targeting of epidermal Langerhans cells with antigenic proteins: attempts to harness their properties for immunotherapy},

author = {Vincent Flacher and Florian Sparber and Christoph H Tripp and Nikolaus Romani and Patrizia Stoitzner},

doi = {10.1007/s00262-008-0563-9},

issn = {1432-0851},

year  = {2009},

date = {2009-07-01},

journal = {Cancer immunology, immunotherapy: CII},

volume = {58},

number = {7},

pages = {1137--1147},

abstract = {Langerhans cells, a subset of skin dendritic cells in the epidermis, survey peripheral tissue for invading pathogens. In recent functional studies it was proven that Langerhans cells can present exogenous antigen not merely on major histocompatibility complexes (MHC)-class II molecules to CD4+ T cells, but also on MHC-class I molecules to CD8+ T cells. Immune responses against topically applied antigen could be measured in skin-draining lymph nodes. Skin barrier disruption or co-application of adjuvants was required for maximal induction of T cell responses. Cytotoxic T cells induced by topically applied antigen inhibited tumor growth in vivo, thus underlining the potential of Langerhans cells for immunotherapy. Here we review recent work and report novel observations relating to the potential use of Langerhans cells for immunotherapy. We investigated the potential of epicutaneous immunization strategies in which resident skin dendritic cells are loaded with tumor antigen in situ. This contrasts with current clinical approaches, where dendritic cells generated from progenitors in blood are loaded with tumor antigen ex vivo before injection into cancer patients. In the current study, we applied either fluorescently labeled protein antigen or targeting antibodies against DEC-205/CD205 and langerin/CD207 topically onto barrier-disrupted skin and examined antigen capture and transport by Langerhans cells. Protein antigen could be detected in Langerhans cells in situ, and they were the main skin dendritic cell subset transporting antigen during emigration from skin explants. Potent in vivo proliferative responses of CD4+ and CD8+ T cells were measured after epicutaneous immunization with low amounts of protein antigen. Targeting antibodies were mainly transported by langerin+ migratory dendritic cells of which the majority represented migratory Langerhans cells and a smaller subset the new langerin+ dermal dendritic cell population located in the upper dermis. The preferential capture of topically applied antigen by Langerhans cells and their ability to induce potent CD4+ and CD8+ T cell responses emphasizes their potential for epicutaneous immunization strategies.},

keywords = {Active, Animals, Antibodies, antibody, Antigen, Antigens, BLOOD, C-Type, cancer, CD, CD4-Positive T-Lymphocytes, CD4+ T cells, CD8-Positive T-Lymphocytes, CD8+ T cells, Dendritic Cells, DERMATOLOGY, DERMIS, Epidermis, Growth, Human, Humans, immune response, IMMUNE-RESPONSES, Immunization, Immunology, Immunotherapy, in situ, In vivo, Inbred BALB C, Inbred C57BL, INDUCTION, Langerhans Cells, LECTIN, Lectins, LYMPH, LYMPH NODE, Lymph Nodes, Major Histocompatibility Complex, Mannose-Binding Lectins, metabolism, methods, MHC class I, MHC class I molecules, Mice, Neoplasm, Neoplasms, OVALBUMIN, Patients, PROGENITORS, Protein, Proteins, RESPONSES, review, Skin, T CELLS, T-CELLS, Team-Mueller, therapy, tumor},

pubstate = {published},

tppubtype = {article}

}

@article{kwan_dendritic_2005,

title = {Dendritic cell precursors are permissive to dengue virus and human immunodeficiency virus infection},

author = {Wing-Hong Kwan and Anna-Marija Helt and Concepción Marañón and Jean-Baptiste Barbaroux and Anne Hosmalin and Eva Harris and Wolf H Fridman and Chris G F Mueller},

doi = {10.1128/JVI.79.12.7291-7299.2005},

issn = {0022-538X},

year  = {2005},

date = {2005-06-01},

journal = {Journal of Virology},

volume = {79},

number = {12},

pages = {7291--7299},

abstract = {CD14(+) interstitial cells reside beneath the epidermis of skin and mucosal tissue and may therefore play an important role in viral infections and the shaping of an antiviral immune response. However, in contrast to dendritic cells (DC) or blood monocytes, these antigen-presenting cells (APC) have not been well studied. We have previously described long-lived CD14(+) cells generated from CD34(+) hematopoietic progenitors, which may represent model cells for interstitial CD14(+) APC. Here, we show that these cells carry DC-SIGN and differentiate into immature DC in the presence of granulocyte-macrophage colony-stimulating factor. We have compared the CD14(+) cells and the DC derived from these cells with respect to dengue virus and human immunodeficiency virus type 1 (HIV-1) infection. Both cell types are permissive to dengue virus infection, but the CD14(+) cells secrete the anti-inflammatory cytokine interleukin 10 and no tumor necrosis factor alpha. Regarding HIV, the CD14(+) cells are permissive to HIV-1, release higher p24 levels than the derived DC, and more efficiently activate HIV Pol-specific CD8(+) memory T cells. The CD14(+) DC precursors infected with either virus retain their DC differentiation potential. The results suggest that interstitial CD14(+) APC may contribute to HIV-1 and dengue virus infection and the shaping of an antiviral immune response.},

keywords = {ANTIGEN PRESENTING CELLS, Antigen-Presenting Cells, APC, BLOOD, CD8-Positive T-Lymphocytes, Cell Differentiation, Cells, COLONY-STIMULATING FACTOR, Cultured, Dendritic Cells, Dengue virus, Differentiation, Epidermis, Hematopoietic Stem Cells, HIV, HIV-1, Human, Humans, IMMATURE, immunodeficiency, infection, interleukin 10, Interleukin-10, Lipopolysaccharide Receptors, MEMORY T CELLS, monocyte, Monocytes, Necrosis, precursor, PROGENITORS, Skin, T CELLS, Team-Mueller, tumor, Tumor Necrosis Factor, viral Infection, virus},

pubstate = {published},

tppubtype = {article}

}

@article{dumortier_antigen_2005,

title = {Antigen presentation by an immature myeloid dendritic cell line does not cause CTL deletion in vivo, but generates CD8+ central memory-like Ŧ cells that can be rescued for full effector function},

author = {Hélène Dumortier and Geertje J D van Mierlo and Deirdre Egan and Willem van Ewijk and René E M Toes and Rienk Offringa and Cornelis J M Melief},

doi = {10.4049/jimmunol.175.2.855},

issn = {0022-1767},

year  = {2005},

date = {2005-01-01},

journal = {Journal of Immunology (Baltimore, Md.: 1950)},

volume = {175},

number = {2},

pages = {855--863},

abstract = {Immature dendritic cells (DC), in contrast to their mature counterparts, are incapable of mobilizing a CD8+ CTL response, and, instead, have been reported to induce CTL tolerance. We directly addressed the impact of immature vs mature DC on CTL responses by infusing adenovirus peptide-loaded DC (of the D1 cell line) into mice that had received adenovirus-specific naive TCR-transgenic CD8+ T cells. Whereas i.v. injection of mature DC triggered vigorous CTL expansion, immature DC elicited little proliferation involving only a minority of the TCR-transgenic CTL. Even though the latter CTL developed effector functions, including cytolytic activity and proinflammatory cytokine secretion, these cells differed significantly from CTL primed by mature DC in that they did not exhibit down-regulation of CD62L and CCR7, receptors involved in trapping of T cells in the lymphoid organs. Interestingly, adoptive transfer of CTL effector cells harvested after priming by either mature or immature DC into naive recipient mice, followed by exposure to adenovirus, yielded quantitatively and qualitatively indistinguishable CTL memory responses. Therefore, in vivo priming of naive CD8+ T cells by immature DC, although failing to induce a full-blown, systemic CTL response, resulted in the formation of central memory-like T cells that were able to expand and produce IFN-gamma upon secondary antigenic stimulation.},

keywords = {Adenovirus E1A Proteins, Animals, Antigen, Antigen Presentation, CD8-Positive T-Lymphocytes, Cell Differentiation, Cell Line, Cell Movement, Clonal Deletion, Cytotoxic, Cytotoxicity, Dendritic Cells, Down-Regulation, Dumortier, Epitopes, Female, I2CT, Immunologic, Immunologic Memory, Inbred C57BL, Lipopolysaccharides, Lymphocyte Activation, Mice, Myeloid Cells, Receptors, Regulatory, T-Cell, T-Lymphocyte, T-Lymphocytes, Team-Dumortier, transgenic},

pubstate = {published},

tppubtype = {article}

}