Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P06126 (CD1a)
 2,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Actinic prurigo is an inflammatory disease of the skin that appears to be mediated by an abnormal immune response. Cell adhesion molecules play a key role in the induction of the immune response as well as in the pathogenesis of inflammation. We investigated the expression of cell adhesion and activation molecules, as well as the density of Langerhans cells in skin from patients with actinic prurigo. Skin biopsies from ultraviolet light-induced lesions, and non-irradiated areas from 10 actinic prurigo patients were studied; in addition, several spontaneous skin lesions were studied. Skin biopsies from normal individuals were used as controls. The expression of ICAM-1, ICAM-3, LFA-3, CD2, LFA-1, VLA-4, CD1a, VCAM-1, CD69, and activated b1 integrins were assessed by immunostaining. An increased expression of LFA-1, LFA-2, ICAM-3, VLA-4, and activated b1 integrins was observed in the cell infiltrate of actinic prurigo lesions and an up-regulated expression of ICAM-1 was detected in keratinocytes from these specimens. Interestingly, the number of Langerhans cells (CD1a + ) in actinic prurigo skin was not significantly affected by ultraviolet irradiation, a phenomenon that was not observed in normal controls. The increased expression of adhesion molecules in the cell infiltrate of actinic prurigo, indicates that these cells are activated and suggests that they are involved in the skin damage seen in these patients. The resistance of Langerhans cells from patients with actinic prurigo to ultraviolet light may have an important role in the pathogenesis of this condition. The involvement of keratinocytes in the pathogenesis of actinic prurigo is suggested by the expression of ICAM-1 on these cells.
Eur J Dermatol
PMID:An immunohistochemical study of UV-induced skin lesions in actinic prurigo. Resistance of langerhans cells to UV light. 964 10

Langerhans cell histiocytosis is most common in children and is unusual in the elderly. We describe 3 cases of langerhans cell histiocytosis limited to the skin in elderly patients. Biopsy specimens showed a dermal infiltrate abutting the epidermis composed of atypical langerhans cells with abundant eosinophilic cytoplasm and a "kidney-shaped" nucleus. Immunoperoxidase stain CD1a was positive in all 3 cases and S-100 stain was positive in 2. Electron microscopy revealed Birbeck granules in the cytoplasm of the atypical langerhans cells in 2 cases. Langerhans cell histiocytosis with skin involvement has a chronic course with an overall good prognosis. However, cutaneous manifestations may precede systemic involvement by many years.
J Am Acad Dermatol 1998 Aug
PMID:Langerhans cell histiocytosis in the elderly: a report of three cases. 970 58

Granulocyte macrophage-colony stimulating factor (GM-CSF) is a multipotent cytokine produced by many cutaneous cell types including keratinocytes. Langerhans cells (LC) represent the major antigen-presenting cells in skin, and in vitro studies demonstrate that GM-CSF is of pivotal importance in LC. Healthy volunteers (n = 3 non-atopic, n = 3 with atopy) received recombinant human GM-CSF (0. 05 microg/mL) by intradermal injection for 3 days to the same site. Diluent was injected in a similar manner as control. Biopsies were taken 24 h after the final injection and examined immunohistochemically for LC and inflammatory cell markers. Compared with control sites, intradermal GM-CSF resulted in shortening of dendritic cell processes and redistribution of LC in the epidermis; numbers of CD1a + cells in the epidermis were significantly decreased (P < 0.005), while those in the dermis were significantly increased (P < 0.05) following intradermal GM-CSF when compared with controls. Double labelling studies on epidermal CD1a + cells indicated de novo expression of intercellular adhesion molecule (ICAM)-1 and increased expression of HLA-DR following GM-CSF (P < 0. 005, P < 0.005, respectively). Additional findings included a marked mixed inflammatory cell infiltrate in the dermis and increased expression of the endothelial cell adhesion molecules E-selectin and ICAM-1. These data indicate that in normal human skin, GM-CSF induces changes in the phenotype and distribution of CD1a + cells consistent with LC functional maturation and exit from the epidermis to the dermis. As these events are central to the initiation of cutaneous inflammation, GM-CSF may potentially play a critical role in the pathogenesis of inflammatory dermatoses.
Br J Dermatol 1998 Aug
PMID:Effect of granulocyte macrophage-colony stimulating factor on Langerhans cells in normal and healthy atopic subjects. 976 37

Ultraviolet (UV) irradiation of the skin induces complex local and systemic immunomodulatory reactions. The biological effects of UV irradiation on human skin derived afferent lymph however are unknown. The aim of this study was to examine the effects of a single combined UV-A and UV-B irradiation with 1 minimal erythema dose (MED) on human skin derived lymph in vivo. After cannulation of a superficial lymph vessel on the lower leg, lymph flow and cell output per hour were determined before and for 6 days after UV irradiation of the lymph draining skin area in 5 volunteers. Furthermore, expression of CD1a, CD4, CD8, CD28, CD54, CD80, CD86 and HLA-DR on migrating lymph cells and cytokine levels (IL-1alpha, IL-1beta, IL-2, IL-6, IL-8, IL-10, IL-13, TNF-alpha and IFN-gamma) in the afferent lymph were analyzed by cytofluorometry and ELISA. After UV irradiation a small initial enhancement in the daily lymph flow per hour was noticed in correlation with the slight erythematous skin reaction. Following resolution of the skin reaction, a delayed increase in cell output in correlation with an additional peak in the lymph flow was found between the 4th and 6th day after UV irradiation. However, no changes in the expression of CD1a, CD4, CD8, CD28, CD54, CD80, CD86 and HLA-DR on migrating lymph cells were detectable. Interestingly, in parallel to the increased lymph flow and cell output, only elevated IL-8 protein levels were reproducibly detected in the afferent lymph after UV irradiation. Furthermore, using immunohistochemistry positive staining for IL-8 was found on migrating mononuclear lymph cells. In conclusion, our data demonstrate that a single UV irradiation of the skin with 1 minimal erythema dose leads to a delayed enhancement of lymph flow, number of migrating lymph cells and cytokine levels of IL-8. Moreover, we provide evidence that migrating lymph cells, besides resident epidermal and dermal cells, may contribute to the detected levels of IL-8 in the afferent lymph.
Exp Dermatol 1998 Dec
PMID:Effects of UV irradiation with one minimal erythema dose on human afferent skin lymph in vivo. 985 39

Linear IgA bullous dermatosis (LAD) is an acquired, heterogeneous, subepidermal blistering disease characterized by linear IgA deposits at the dermoepidermal basement membrane zone (BMZ), often with circulating IgA antibodies to the BMZ. The pathogenetic mechanism, possibly related to the immunophenotype of infiltrating cells, as well as the potential role of cytokines in determining bullous lesions, have not yet been elucidated. An immunohistochemical study was performed with a large panel of monoclonal antibodies [to CD3, CD4, CD8, CD25, CD1a, CD30, CD54, CD50, endothelial leucocyte adhesion molecule-1, vascular cell adhesion molecule-1, myeloperoxidase (MPO), eosinophil cationic protein EG1 and EG2, tryptase, HLA-DR, human interleukin (IL)-3, human IL-5, human IL-8, human IL-4, tumour necrosis factor (TNF)-alpha, interferon (IFN)-gamma and granulocyte/macrophage colony-stimulating factor] using the alkaline phosphatase-antialkaline phosphatase procedure on lesional and perilesional skin of nine patients (one male, eight female; age range 8 months-80 years) with clinical, histological and immunofluorescent proven LAD. The predominant infiltrating cells, distributed mostly inside and below the bullae, were neutrophils and eosinophils which showed intense activation (MPO +, EG1 +, EG2 +). The lymphocytic infiltrate, consisting principally of CD4 +, HLA-DR + and CD30 + T cells, had a predominantly perivascular distribution. Proinflammatory cytokines, such as TNF-alpha and IFN-gamma, showed a moderate focal expression on the dermal perivascular sites; IL-8 was found to have a particularly intense staining on all the epidermal cell layers and at perivascular and vascular sites. Other cytokines, such as IL-4 and IL-5, showed a prevalent intracytoplasmic staining on some cells of the dermal infiltrate (probably mastocytes and lymphocytes), and at the dermal-epidermal separation sites there was also an intense scattered distribution of IL-5. The specific tissue lesions of LAD may be the consequence of the IgA deposits at the BMZ and also of the release of these cytokines together with tissue damage enzymes derived from neutrophils or eosinophils.
Br J Dermatol 1999 Jun
PMID:The role of lymphocytes, granulocytes, mast cells and their related cytokines in lesional skin of linear IgA bullous dermatosis. 1035 73

The role of tumour necrosis factor (TNF)-alpha in the mobilization and migration of human epidermal Langerhans cells (LC) has been investigated. Intradermal injection of normal human volunteers with homologous recombinant TNF-alpha was found to cause a dose-dependent reduction in the frequency of LC within epidermal sheets 2 h later. Equivalent results were obtained when epidermal LC were identified on the basis of either CD1a or HLA-DR expression. At the dose of TNF-alpha used routinely (500 U), treatment resulted in an average reduction in LC density of approximately 24%. Treatment with TNF-alpha was associated with a perivascular polymorphonuclear infiltration at 2 h, but the epidermis appeared normal with neither fibrinoid necrosis nor vasculitis, and LC morphology was not affected significantly. These results demonstrate that TNF-alpha provides an important signal for LC migration in humans and is likely therefore to play a crucial part in the induction of cutaneous immune responses.
Br J Dermatol 1999 Aug
PMID:Tumour necrosis factor-alpha induces Langerhans cell migration in humans. 1046 87

We describe the pro-inflammatory and cytotoxic effects of nitric oxide in vivo in human skin. Nitrite and ascorbic acid were mixed on the skin of 12 normal volunteers, three times daily, to release nitric oxide. Exposure to nitric oxide was varied by randomizing the concentration of nitrite and duration of application. Nitric oxide treated skin showed significant increases in cells expressing CD3, CD4, CD8, CD68, neutrophil elastase, ICAM-1, VCAM-1, nitrosotyrosine, p53, and apoptotic cells compared with skin treated with ascorbic acid alone. There was no significant increase in mast cells. Following application of nitric oxide there were significantly fewer CD1a positive Langerhans cells in the epidermis. These appeared to lose dendritic morphology and migrate from the epidermis. There was no significant difference in staining for Ki-67, a marker related to proliferating cell nuclear antigen, between active and control skin but staining was greater after exposure to higher dose nitric oxide than the low dose. Apoptosis, cytotoxicity, and p53 staining were relatively greater after 48 h exposure than after 24 h. These results suggest that nitric oxide is pro-inflammatory and is toxic to DNA, leading to the accumulation of p53 and subsequent apoptosis. High-dose nitric oxide paradoxically led to a smaller increase in macrophages and T cells than low dose suggesting an immunosuppressive effect of higher levels.
J Invest Dermatol 1999 Sep
PMID:The inflammatory and cytotoxic effects of a nitric oxide releasing cream on normal skin. 1046 39

We describe a widespread papular eruption in a 5-year-old girl with rheumatic fever. Histological examination revealed a dense histiocytic infiltration in the dermis. On immunohistochemical studies, the cells were positive for vimentin, CD68, MAC387, alpha1-antichymotrypsin and lysozyme, but negative for CD1a and S-100 protein. Electron microscopic studies showed no Birbeck granules in their cytoplasm. A diagnosis of generalized eruptive histiocytoma of childhood was established. The skin lesions completely disappeared within 8 months.
Eur J Dermatol
PMID:Generalized eruptive histiocytoma of childhood associated with rheumatic fever. 1052 34

The cutaneous lymphocyte-associated antigen (CLA), recognized by the monoclonal antibody HECA-452, is a cell surface glycoprotein that binds specifically to E-selectin. CLA is present on most T cells at sites of cutaneous immune response and has been shown to be important in lymphocyte homing to the skin. It is expressed only by a minor subset of peripheral T cells and is absent on thymocytes. We have analysed (using a FACScan flow cytometer) the expression of CLA on human lymph cells derived from normal skin, from ultraviolet (UV)-irradiated skin and from allergic contact dermatitis. Whereas in the peripheral blood CLA was expressed on < 20% of CD4 +, CD8 + and CD56 + cells (natural killer cells), > 60% of CD4 +, CD8 + and CD56 + cells isolated from skin-derived lymph expressed CLA. Furthermore, > 90% of CD1a + dendritic lymph cells were positive for CLA. UV irradiation of the skin and induction of an allergic contact dermatitis did not change CLA expression on lymph cells, although lymph flow and cell output increased. These results provide further evidence for an important role of CLA in cell homing to the skin.
Br J Dermatol 1999 Sep
PMID:The HECA-452 epitope is highly expressed on lymph cells derived from human skin. 1058 71

Scintigraphy using monoclonal antibodies has been suggested as a possible adjunct to conventional staging techniques for the routine staging and diagnosis of Langerhans cell histiocytosis. In this study we have developed a model for Langerhans cell histiocytosis comprising a CD1a-positive subcutaneous xenograft in the flanks of nude (nu/nu) mice. The anti-CD1a murine monoclonal antibody NA1/34 was investigated for its potential both as an imaging and as a therapeutic targeting agent in this model. Biodistribution with NA1/34 compared with irrelevant isotype-matched monoclonal antibody demonstrated specific accumulation within the xenografts of 10.0%id per g (percentage injected dose per gram) and 3.3%id per g at 48 h postinjection, respectively. NA1/34 displayed no specific accumulation to CD1a-negative xenografts. F(ab')2 fragments of NA1/34 displayed a faster clearance time of 19.6 h compared with the intact antibody, 122.4 h, resulting in a more rapid maximum xenograft uptake time of 5 h compared with 48 h postinjection for the intact antibody. Although the overall xenograft/tissue ratio for the F(ab')2 was at no time greater than that for the intact antibody, the F(ab')2 did display dramatically greater xenograft/blood ratios, reaching 19:1 at 120 h postinjection Xenograft regression using single doses of 350 microCi and 500 microCi 131I-labeled NA1/34 significantly (p < 0.001) delayed xenograft progression compared with control nonirradiated xenografts, with average delays of 3.2 and 5.7 times the control, respectively. This study suggests that the anti-CD1a monoclonal antibody, NA1/34, offers advantages in the prognosis and staging of Langerhans cell histiocytosis, in a human setting. We discuss the advantages of radioimmunoscintigraphy over conventional differential diagnostic techniques. The potential for the future radioimmunotherapy of Langerhans cell histiocytosis is also discussed.
J Invest Dermatol 2000 Jan
PMID:Diagnostic and therapeutic evaluation of an anti-Langerhans cell histiocytosis monoclonal antibody (NA1/34) in a new xenograft model. 1062 Jan 28


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