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Langerhans Cell Migration (Langerhan + cell_migration)
Selected AbstractsA two-step model for Langerhans cell migration to skin-draining LNEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 11 2008Eduardo J. Villablanca Abstract Although the role of Langerhans cells (LC) in skin immune responses is still a matter of debate, it is known that LC require the chemokine receptor CCR7 for migrating to skin-draining LN. A report in the current issue of the European Journal of Immunology unfolds some of the intricacies of LC migration, showing that LC need CXCR4, but not CCR7, for their migration from the epidermis to the dermis. Thus, LC migration to skin-draining LN occurs in two distinct phases: a first step from the epidermis to the dermis regulated by CXCR4 and a second CCR7-dependent step from the dermis to LN. Here we discuss the potential implications of this new two-step LC migration paradigm. [source] Ultraviolet B radiation suppresses Langerhans cell migration in the dermis by down-regulation of ,4 integrinPHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 3 2006Motoko Hamakawa Background/Purpose: Ultraviolet B (UVB) radiation affects the migration and function of epidermal Langerhans cells (LC) and causes immunosuppression of contact hypersensitivity. It is known that LC leaves the epidermis after exposure to UVB. To know the behavior of LC in the dermis after UVB radiation, we studied the effect of UVB radiation on the expression of integrin families on freshly isolated or cultured murine LC. We also examined whether UVB radiation affects the migration of LC to secondary lymphoid tissue chemokine (SLC/6Ckine). Methods: Integrin expressions of murine LC cultured in epidermal cell suspension were analyzed using flowcytometry. We used murine LC sorted flowcytometrically for binding assay to extracellular matrix and for migration assay to chemokine. Skin explant assay and immnohistochemical staining for ,cords formation' were performed as previously described. Results: Twenty and 40 mJ/cm2 of UVB radiation down-regulated the expression of ,4 integrin on 24 h-cultured LC, but not that of ,6, ,1, or ,4 integrin. The number of cultured LC adhered to fibronectin, a ligand for ,4 integrin, was decreased after UVB irradiation, while that to laminin, a ligand for ,6 integrin, was not influenced. UVB radiation reduced the number of migrating LC to SLC. Furthermore, skin sheet explant experiments showed that UVB radiation inhibited the ,cords' formation in dermal vessels of the 48 h-cultured skin. Conclusions: These data suggest that UVB radiation may suppress the migration of LC from the dermis to lymphatic vessels. UVB radiation may downregulate the adherence of LC to dermal fibronectin and migration to SLC, and consequently suppress the migration of LC from the UVB-irradiated dermis to lymphatics. [source] Epidermal Langerhans cell migration and sensitisation to chemical allergensAPMIS, Issue 7-8 2003MARIE CUMBERBATCH Epidermal Langerhans cells (LC) form part of the wider family of dendritic cells (DC; professional antigen-processing and antigen-presenting cells). LC are considered to serve in the skin as sentinels of the adaptive immune system, surveying the local environment and transporting foreign antigen for presentation to responsive T lymphocytes in regional lymph nodes. As such, LC play pivotal roles in the initiation of cutaneous immune responses, including immune responses to chemical allergens encountered at skin surfaces. Here we explore two aspects of LC function in the context of sensitisation to chemical allergens. The first is consideration of the cytokine and chemokine signals that regulate and counter-regulate the mobilisation and migration of LC from the epidermis to skin-draining lymph nodes following topical sensitisation. The second is examination of the ways in which LC may influence the polarity of induced T lymphocytes, and thereby the quality of immune responses. [source] Prominent Langerhans' cell migration in the arthropod bite reactions simulating Langerhans' cell histiocytosisJOURNAL OF CUTANEOUS PATHOLOGY, Issue 12 2007Se Hoon Kim Background:, Epidermal Langerhans' cells (LCs) play pivotal roles in cutaneous immune responses. An encounter with antigens or other stimuli causes the mobilization and migration of LCs. Therefore, some dermatoses, which originated from antigenic stimuli or trauma, can show LC migration. Recently, we experienced several cases of anthropod bites that showed marked inflammatory infiltrates with eosinophils and CD1a-positive LCs. It was difficult to differentiate these cases from Langerhans' cell histiocytosis (LCH). Methods:, The degree and pattern of LC infiltration in the skin of arthropod bite reaction was evaluated. The characteristics of CD1a immunohistochemical expression in the arthropod bite reactions were compared with those of LCH. Results:, A few arthropod bite cases (approximately 36%) showed extensive CD1a-positive LCs in the dermis, especially in the perivascular area. In addition, the CD1a expression patterns of LCs in the arthropod bite reactions were dendritic, whereas that of tumor cells in LCH were distinctly membranous and cytoplasmic. Conclusion:, Some arthropod bite reactions can show marked CD1a-positive LCs in the dermis, especially in the perivascular area. The dendritic CD1a immunohistochemical staining pattern in arthropod bite reactions is useful in helping to differentiate from LCH. [source] | |||||||||||||||||||