I2CT

@article{flacher_skin_2012,

title = {Skin langerin+ dendritic cells transport intradermally injected anti-DEC-205 antibodies but are not essential for subsequent cytotoxic CD8+ Ŧ cell responses},

author = {V Flacher and C H Tripp and B Haid and A Kissenpfennig and B Malissen and P Stoitzner and J Idoyaga and N Romani},

year  = {2012},

date = {2012-03-01},

journal = {Journal of Immunology},

volume = {188},

number = {1550-6606 (Electronic)},

pages = {2146--2155},

abstract = {Incorporation of Ags by dendritic cells (DCs) increases when Ags are targeted to endocytic receptors by mAbs. We have previously demonstrated in the mouse that mAbs against C-type lectins administered intradermally are taken up by epidermal Langerhans cells (LCs), dermal Langerin(neg) DCs, and dermal Langerin(+) DCs in situ. However, the relative contribution of these skin DC subsets to the induction of immune responses after Ag targeting has not been addressed in vivo. We show in this study that murine epidermal LCs and dermal DCs transport intradermally injected mAbs against the lectin receptor DEC-205/CD205 in vivo. Skin DCs targeted in situ with mAbs migrated through lymphatic vessels in steady state and inflammation. In the skin-draining lymph nodes, targeting mAbs were found in resident CD8alpha(+) DCs and in migrating skin DCs. More than 70% of targeted DCs expressed Langerin, including dermal Langerin(+) DCs and LCs. Numbers of targeted skin DCs in the nodes increased 2-3-fold when skin was topically inflamed by the TLR7 agonist imiquimod. Complete removal of the site where OVA-coupled anti-DEC-205 had been injected decreased endogenous cytotoxic responses against OVA peptide-loaded target cells by 40-50%. Surprisingly, selective ablation of all Langerin(+) skin DCs in Langerin-DTR knock-in mice did not affect such responses independently of the adjuvant chosen. Thus, in cutaneous immunization strategies where Ag is targeted to DCs, Langerin(+) skin DCs play a major role in transport of anti-DEC-205 mAb, although Langerin(neg) dermal DCs and CD8alpha(+) DCs are sufficient to subsequent CD8(+) T cell responses},

keywords = {administration & dosage, Animals, Antibodies, antibody, Antigen, Antigens, Biosynthesis, C-Type, C-type lectin, CD, Cell Surface, Comparative Study, Cytotoxic, Dendritic Cells, DERMATOLOGY, Gene Knock-In Techniques, Genetics, imiquimod, immune response, IMMUNE-RESPONSES, Immunization, Immunology, in situ, In vivo, Inbred BALB C, Inbred C57BL, INDUCTION, inflammation, Inflammation Mediators, Injections, Intradermal, knock-in, Langerhans Cells, LECTIN, Lectins, LYMPH, LYMPH NODE, Lymph Nodes, LYMPHATIC VESSEL, Lymphatic Vessels, mAb, Mannose-Binding Lectins, MEDIATOR, metabolism, Mice, Minor Histocompatibility Antigens, mouse, murine, Organ Culture Techniques, Ovum, pathology, physiology, Protein, Protein Transport, Rats, Receptor, Receptors, RESPONSES, Skin, SUBSETS, Surface, T-Lymphocytes, target, Team-Mueller, TLR7, transgenic},

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}

}