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

The population of CD1a+ cells and the quantity of Birbeck granules were evaluated in comparison with the population of T lymphocytes in a variety of clinical lesions of mycosis fungoides. Anti-CD1a and Lag antibodies that specifically react with Birbeck granules and related structures of human Langerhans cells were used immunohistochemically. CD1a+ cells in the dermis of lesions of mycosis fungoides significantly increased in plaques of the plaque stage and in plaques of the tumor stage. They were most frequent in lesions with CD4+ cells ranging in number from 100 to 150/mm2. These lesions were suspected to be progressing from the plaque to the tumor stage. During the course of the disease, most of the dermal CD1a+ cells had few Lag antigens. These results suggest that dermal CD1a+Lag- cells may promote the progression of mycosis fungoides from the plaque to the tumor stage.
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PMID:A subpopulation of Langerhans cells (CD1a+Lag-) increased in the dermis of plaque lesions of mycosis fungoides. 171 24

Keratinocytes express the macrophage/monocyte antigen CD36 in a variety of inflammatory cutaneous diseases characterised by a T lymphocyte rich infiltrate. Since cell-mediated immune mechanisms also play a role in host responses to skin tumours, we investigated the presence of CD36 antigen on keratinocytes in a range of epidermal cell-derived benign and malignant tumours characterised by a peritumoural, dermal lymphocytic infiltrate. Frozen tissue sections of lesional tissue from a range of epidermally derived tumours were labelled with antibodies to CD1a, CD11b, CD36, and HLA-DR antigens. Benign and malignant squamoproliferative tumour cells exhibited a spectrum of CD36 expression, whereas those of basal cell origin were consistently CD36-. Suprabasal expression of CD36 was present in the normal perilesional epidermis of all tumours studied including basal cell carcinoma. Keratinocyte CD11b expression was not observed. The widespread presence of keratinocyte CD36 positivity in squamoproliferative, but not basal epidermal, tumours suggests its expression may be linked to the degree of keratinocyte differentiation. The stimulus for expression is unknown, but the fact that suprabasal perilesional epidermis expressed CD36 strongly in the absence of infiltrate suggests it may represent a non-specific response by keratinocytes to various stimuli.
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PMID:Keratinocyte expression of CD36 antigen in benign and malignant epidermal cell-derived tumours. 171 27

The human CD1 locus encodes three nonpolymorphic MHC class I-like cell surface glycoproteins, CD1a-c, which are expressed primarily by immature thymocytes. A mAb and antipeptide antiserum were utilized to determine the tissue distribution of a fourth CD1 molecule, CD1d. Within the lymphoid lineage, CD1d was expressed on B cells but not on thymocytes. Immunoperoxidase staining of fresh frozen intestinal tissues demonstrated that the majority of intestinal epithelial cells, with the exception of cells at the base of some crypts, expressed CD1d. The CD1d staining was observed in the cytoplasm and along the basolateral membranes of the epithelial cells. The intestinal epithelial cell expression of CD1d was confirmed by immunoblotting with a CD1d antipeptide antiserum. Further immunoperoxidase studies indicated that CD1d, unlike murine CD1, was also expressed by nonlymphoid tissues outside of the gastrointestinal tract. The expression of CD1d outside the lymphoid and myeloid lineages clearly distinguishes this molecule from CD1a-c and suggests that it may serve a distinct function. The prominent expression of CD1d by intestinal epithelial cells suggests that this molecule may be an important ligand for T lymphocytes within the gut-associated lymphoid tissue.
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PMID:Expression of a nonpolymorphic MHC class I-like molecule, CD1D, by human intestinal epithelial cells. 171 64

We studied whether abnormalities in epidermal APC could be responsible for intracutaneous T cell activation in atopic dermatitis (AD). In the absence of added Ag, patients' peripheral blood T cells demonstrated significantly increased proliferation to their autologous lesional epidermal cells (mean +/- SEM = 19,726 +/- 9,754 cpm [3H]TdR uptake) relative to epidermal cells from uninvolved AD skin (2179 +/- 697 cpm) (n = 10) (p = 0.0001, log transformed data). AD T cell proliferative responses to autologous epidermal cells were dependent upon cells expressing HLA-DR, CD1a, and CD36, and not upon keratinocytes or their cytokines. Ultrastructurally, these cells ranged from typical Langerhans cells to indeterminate cells with irregular nuclear contours. Enriched populations of lesional AD Langerhans cells were highly stimulatory for autologous T cells, whereas equal numbers of Langerhans cells from non atopic epidermis were poor stimulators, even at high concentrations. The dermal perivascular dendritic cell markers CD36 and CD1b, not usually present on normal epidermal APC, were expressed by 40 and 60% of lesional AD CD1a+ epidermal Langerhans cells, respectively. Addition of anti-CD1b to cocultures of AD epidermal cells and autologous T lymphocytes augmented T cell activation, suggesting that the expression of CD1b by AD Langerhans cells may represent over expression of a molecule functionally linked to the enhanced T cell stimulatory capacity of these cells. Thus, stimulatory signals for T cells contained within AD epidermis are carried by cells in an abnormal differentiation state as indicated by expression of phenotypic characteristics of both epidermal and dermal antigen presenting cells (HLA-DR+, CD1a+, CD1b+, CD36+). We propose that activation of autologous T cells by an altered cutaneous APC population may represent a mechanism for the hyperactive and disordered cell-mediated immune response that characterizes the dermatitic lesions of AD.
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PMID:Hyperstimulatory CD1a+CD1b+CD36+ Langerhans cells are responsible for increased autologous T lymphocyte reactivity to lesional epidermal cells of patients with atopic dermatitis. 171 88

Interdigitating cells (IDCs) have been found in the peritumoral infiltrate of 18 patients with squamous cell carcinoma of the larynx. These cells have a dendritic shape and are characterized by the expression of S-100 protein and CD1a antigens. By electron microscopy, these cells are seen to establish intimate contacts with the apposed lymphocytes, which sometimes show signs of functional activation and proliferation. These findings indicate that IDCs may play a role in setting up a T-cell immune reaction against neoplastic cells, which may influence the biological behaviour and/or local growth of the tumour. Moreover, monocytes and cells with intermediate features between monocytes and IDCs are also found in the peritumoral infiltrate, thus suggesting that IDCs differentiate in situ from monocytic precursors, possibly under the influence of either tumour-derived factors or the local lymphoid microenvironment.
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PMID:Interdigitating cells in the peritumoral infiltrate of laryngeal carcinomas: an immunocytochemical and ultrastructural study. 172 94

Histiocytic cells infiltrating the lesions in eosinophilic granuloma of bone as well as in cutaneous histiocytosis X were studied using a murine monoclonal antibody (MA) produced with proliferating cells from an eosinophilic granuloma of bone. This MA reacts with Langerhans cells (LC) of normal human skin or mucous membranes and with proliferating cells of eosinophilic granuloma of bone and skin lesions of Letter-Siwe disease, as shown by immunohistochemistry and immunogold labelling. As other murine MA's obtained after immunization with human cortical thymocytes, this MA immunoprecipitates the 49-kDa CD1a antigen found on human LC and thymic-cell surfaces but not its breakdown product after treatment with trypsin, as demonstrated by analysis of immunoelectron labelling, cytofluorometry and gel electrophoresis. This first production of a CD1a MA from an eosinophilic granuloma supports the concept of Langerhans-cell histiocytosis.
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PMID:Eosinophilic granuloma of bone and biochemical demonstration of 49-kDa CD1a molecule expression by Langerhans-cell histiocytosis. 172 15

Human epidermal Langerhans cells play an important role in the immunoregulation of the skin. We measured the numbers of CD(3+)-, CD(8+)-, CD1a(+)-, HLADR(+)-, IL2R(+)-, CD(4+)- and CD68 positive cells in the skin of 8 asymptomatic HIV-infected Persons, 3 Patients with AIDS and 11 healthy volunteers by suction blister technique. Our results indicate increased numbers of CD1a+ cells and increased numbers of CD4+ cells in the epidermis in asymptomatic HIV-infection. At the same time CD68+ cells are decreased already in an early stage of HIV-Infection. The number of CD1a/CD4+ cells is related to the degree of immunodeficiency. This fact might be caused by the activation of MPS.
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PMID:[Lymphocytes, Langerhans cells and CD68-positive monocytes/macrophages in the skin of HIV-infected patients and normal controls]. 172 11

A 54-year-old man was admitted because of right supraclavicular lymphadenopathy of some weeks duration. Computed axial tomography revealed a large multinodular lesion in a supraclavicular lymph node. The patient then had a supraclavicular lymph node biopsy. Light microscopy showed a tumor whose structure was suggestive of an interdigitating cell sarcoma. Enzyme and immunohistochemical analysis showed that the tumor cells possessed membranous adenosine triphosphatase activity, intracytoplasmic S100 protein, surface CD1a and CD4 antigens, and HLA-DR antigen. Ultrastructural examination showed that the cells exhibited many interdigitating cytoplasmic extensions, but no Birbeck granules. DNA content analysis of the tumor cells proved that the cells were malignant. These data are consistent with derivation from a lymph node interdigitating cell.
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PMID:Lymph node interdigitating cell sarcoma. A case report. 172 55

Three different strategies for isolating RNA from epidermal cells were compared. Starting with dermatome sections frozen or disaggregated epidermal cells purified by fluorescence activated cell sorting (FACS), RNA was isolated with a guanidinium thiocyanate technique. Specific mRNA were detected by Northern blot analysis (involucrin, keratin 5, actin), or by reverse transcription and amplification with the polymerase chain reaction (PCR), using primers specific for keratinocyte products (keratins 1 and 14) and Langerhans cells (CD1a). Messenger RNA's characteristic of Langerhans cells and of keratinocytes at different stages of differentiation were detected in dermatome and epidermal sheet preparations as well as in FACS-separated cells. The use of snap-frozen dermatome sections allows the isolation of RNA from epidermis that has undergone minimal trauma and is very close to its in vivo state, but that includes RNA from some dermal cells. Extraction of RNA from Dispase-separated sheets involves slightly more manipulation of the epidermis but provides a sample free from dermal contaminants. PCR analysis of sorted epidermal cells is both sensitive and specific, but involves still greater manipulation. This final technique, however, allows the investigation of mRNA produced by small groups of epidermal cells that are still much closer to their in vivo state than if they had been cultured. By combining these techniques it is possible to determine the baseline production of specific mRNA in the skin in vivo and to assign their production to specific groups of cells with a sensitivity and specificity greater than any approach previously described.
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PMID:Isolation, detection, and amplification of intact mRNA from dermatome strips, epidermal sheets, and sorted epidermal cells. 174 22

The cytomorphology of 13 cases of Langerhans cell histiocytosis is described. The most striking features were the presence of intranuclear clefts, pale nuclei and inconspicuous nucleoli, together with ample pale cytoplasm, only slight cellular pleomorphism, and an admixture of varying numbers of eosinophils, macrophages and degenerated cells. In 13 of 16 cases investigated ultrastructurally, characteristic Birbeck granules were detected. Out of six cases tested, four exhibited positivity for S-100, and of three cases tested, all were positive for CD1a (leu 6) and HLA-DR. In one case malignant transformation occurred, terminating in monocytic leukaemia.
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PMID:The cytology of Langerhans cell histiocytosis (histiocytosis X). 193 78


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