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 cellular and molecular events taking place during epidermal antigen exposure in sensitized individuals are principally well understood. Epidermal Langerhans cells (LC) are supposed to take up, process, and express a given foreign substance on their cell surface. The antigen is then recognized by T cells bearing the appropriate T-cell receptor (TCR). Because LC do not bear variable antigen (Ag)-specific binding sites, one could postulate that the epidermal exposure of any substance should activate LC and other cells of the skin immune system. To test this hypothesis, we analyzed immunophenotypically the cellular trafficking events in positive (n = 5) and negative epicutaneous patch-test reactions (n = 10), using a panel of monoclonal antibodies against CD1a, CD11c (Ki-M1, LeuM5), CD68 (Ki-M6), Ki-M8, and CD3 (Leu4). We can demonstrate that irrespective of whether or not an antigen will be responded to by the immune system (i.e., positive or negative test reaction), epidermal antigen exposure causes a decrease of LC density in the epidermis and simultaneously causes an increase of LC in the dermis. Moreover, monocytes and T cells immigrate into the dermis both in positive and negative patch-test reactions. As is to be expected, the degree of this cellular traffic is more pronounced in positive test reactions, which may be due to amplification mechanisms caused by antigen recognition of sensitized T cells. This finding demonstrates that human skin contains cell migration programs that ensure that any foreign substance will be accessible to the skin immune and phagocytic system.
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PMID:Cell trafficking in positive and negative patch-test reactions: demonstration of a stereotypic migration pathway. 167 41

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

The immunophenotypic properties of the abnormal cells in routine specimens from 16 cases of Langerhans cell histiocytosis (LCH) were examined. In five cases, cryostat sections were also available. The abnormal cells expressed a similar phenotype and were positive for HLA-DR, S-100 protein, peanut agglutinin (PNA), CD1a, CD4 and several macrophage-associated markers, including CD11c, CDw32 and CD68 (the latter detectable in routine sections with antibody KP1). Staining with CD14, CD35 (C3b receptor), and CD11b (C3bi receptor) was negative with the exception of one of the cases in which a proportion of the cells showed faint positivity with CD11b. Staining for pan-T-cell (CD2, CD3, CD5) and pan-B-cell (CD19, CD22) antigens was negative in all lesions. It is concluded that LCH expresses a characteristic phenotype with some heterogeneity with regard to macrophage markers and that immunohistochemical methods in cryostat sections and routine specimens form a useful supplement to other techniques for the diagnosis of this condition.
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PMID:Immunohistochemical study of the abnormal cells in Langerhans cell histiocytosis (histiocytosis x). 210 27

A 71-year-old Japanese woman had two dome-shaped tumors on her right buttock with several surrounding papules. Histological examination revealed that large anaplastic cells and atypical lymphoid cells densely infiltrated the entire dermis. On immunohistochemical examination, Ki-1, HLA-DR, CD25 (IL-2 receptor alpha), CD122 (IL-2 receptor beta), CD4, CD11c and CD68 were all positive in the tumor cells, whereas CD1a, CD3, CD5, CD8 and CD19 were negative. Neither rearrangement of the T-cell receptor beta, T-cell receptor gamma nor the immunoglobulin heavy-chain was seen. Ultrastructurally, most of the tumor cells contained thick bundles of intermediate filaments in the perinuclear cytoplasm. Thus, this patient was diagnosed as having Ki-1-positive lymphoma of non-T, non-B origin. No recurrence or metastasis of the tumor has been observed in the last 2 years, although surgical resection was required 3 times before control was achieved.
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PMID:Primary cutaneous CD30(Ki-1)-positive lymphoma of non-T, non-B origin. 759 89

The immunophenotype and proliferation fraction have been investigated in 26 cases of Langerhans' cell histiocytosis (LCH). In all cases LCH cells were positive for S-100 protein, CD1a, or both. In most cases LCH cells expressed the macrophage-associated marker CD68 and in two cases they contained lysozyme. Expression of both cytoplasmic CD2 and CD3 was observed in cryostat sections. An unexpected finding was the presence of placental alkaline phosphatase in LCH cells. Langerhans' cells in normal skin were negative for both CD2 and CD3, but a proportion contained placental alkaline phosphatase. In four cases of Rosai-Dorfman disease the histiocytic cells, which share certain immunophenotypic properties with Langerhans' cells, also were positive for placental alkaline phosphatase. A significant proportion of LCH cells stained positively with the antibody to proliferating cell nuclear antigen and also with the proliferation marker Ki-S1. A good correlation between the percentage of Ki-67-positive and proliferating cell nuclear antigen- and Ki-S1-positive cells, respectively, was observed. Thus, in comparison with their putative precursors, LCH cells have an aberrant phenotype and are proliferating locally. This might suggest that LCH is a neoplastic rather than a reactive process.
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PMID:Langerhans' cell histiocytosis (histiocytosis X): immunophenotype and growth fraction. 769 Jul 35

A case study of sinus histiocytosis of Rosai-Dorfman (SH) clinically limited to the skin is presented with immunohistochemical study of the infiltrate, in both paraffin and cryostat sections. Factor XIIIa, a dendrocyte marker, was demonstrated in the cytoplasm of histiocytes. This feature had not been previously reported in this disease. In addition, the cells expressed S100 protein, CD4, CD1a, CD68, and CD11c. This immunophenotyping study suggests that SH could affect the antigen-presenting activity of Factor XIIIa cells, i.e., the skin dermal dendrocyte.
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PMID:Sinus histiocytosis (Rosai-Dorfman disease) clinically limited to the skin. An immunohistochemical and ultrastructural study. 769 80

Macrophages play important roles in immunity and inflammation, and in allergic, granulomatous and neoplastic diseases. Here, we present the indepth results of an ongoing study of macrophage differentiation pathways in cutaneous macrophage disorders and in vitro. Up to now, a total of 40 cases of cutaneous macrophage disorders (histiocytoses and granulomas) and related diseases were examined using a panel of monoclonal and polyclonal antibodies to macrophage differentiation antigens (mAb MS-1, mAb alpha CD1a, mAb alpha CD34, mAb RM 3/1, mAb alpha CD11c, mAb alpha CD36, mAb MAC 387, mAb 27E10, polyclonal antibodies alpha MRP-8 and -14, mAb alpha CD68, mAb 25F9, mAb DRC1-R4/23, and mAb 1F10). Of these, MS-1 high molecular weight protein, synthesized by non-continuous sinusoidal endothelial cells and highly dendritic perivascular macrophages in normal human organs, is the most specific macrophage differentiation marker. MS-1 high molecular weight protein is selectively expressed by cutaneous non-Langerhans cell histocytoses, and proves to be a valuable diagnostic tool for these diseases. MS-1 high molecular weight protein is not found in Langerhans cell histiocytosis cells, epithelioid cells in sarcoidosis, and palisading histiocytes in granuloma annulare. MS-1+ macrophages may be found intermingled in cellular type dermatofibroma and in foreign body granulomas; they differ from MS-1+ non-Langerhans cell histiocytosis cells by their highly dendritic morphology, and thus rather resemble the MS-1+ macrophages in normal skin. RM 3/1 antigen shows a similar, but broader expression pattern including non-Langerhans cell histiocytoses, xanthelasmata palpebrarum, foreign body granulomas, granuloma annulare, and cellular type dermatofibroma. Moreover, xanthelasmata palpebrarum paradigmatically represent a class of macrophage lesions with strong RM 3/1, but little MS-1 antigen expression. In sarcoidosis, RM 3/1+ macrophages are only found at the very periphery of epithelioid cell granulomas. In contrast, 25F9 antigen is strongly and consistently expressed in epithelioid cells of sarcoidosis, and in foreign body granulomas. In cultured human monocytes/macrophages, RM 3/1 antigen is expressed early on, while MS-1 high molecular weight protein and 25F9 antigen are late and very late macrophage differentiation antigens, respectively. Expression of RM 3/1 antigen and MS-1 high molecular weight protein is inducible by glucocorticoid and interleukin-4, and less so by interleukin-13 and interleukin-10, and combinations thereof, while 25F9 antigen seems to be less influenced by these agents. Interferon-gamma (and less so tumor necrosis factor-alpha) inhibit expression of all three antigens in cultured human monocytes/macrophages.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Dissection of macrophage differentiation pathways in cutaneous macrophage disorders and in vitro. 774 70

Langerhans' cell histiocytosis (LCH) is characterized by the presence of large mononucleated cells, associated with inflammatory cells. The Langerhans' cell (LC) lineage of the mononucleated cells is suggested by the presence of Birbeck granules and the expression of CD1a. We investigated the presence of 14 markers expressed by normal LCs in vitro. Nine skin and one lymph node frozen biopsies of LCH children were analysed by in situ immunohistochemistry. The data were compared with six skin and five lymph node frozen biopsies. LCH cells of the ten samples were positive for all 14 LC markers. We observed three different groups of markers, according to the respective staining of normal LCs and LCH cells. Group 1 included DR, DQ, CD1a, CD1c, and ICAM-3. Markers of group 1 were present on the majority of both normal LCs and LCH cells. Group 2 included CD1b, CD4, LFA-1, LFA-3, CD32, and CD68. Markers of group 2 were detected on the majority of LCH cells, but only on a fraction of normal LCs. Group 3 included CD11b, CD24, and B7/BB1. Markers of this group were detected on LCH cells, but not on normal LCs. This in situ immunohistochemical study confirms that LCH cells belong to the LC lineage. The different clinical LCH syndromes had the same immunohistochemical staining. The expression of some markers of groups 2 and 3 is known to be related to the activation of LCs in vitro. Our study suggests that LCH cells are activated LCs.
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PMID:Langerhans' cell histiocytosis cells are activated Langerhans' cells. 796 9

Human bronchoalveolar lavage (BAL) has been described to contain, besides a large number of alveolar macrophages (AM) (approximately 95%), small numbers of monocyte-like cells (approximately 2%) and dendritic cells (DC) (approximately 0.4%). To separate AM (high autofluorescence) from DC, we used a fluorescence activated cell sorter (FACS) to separate BAL cells into a low autofluorescent (LAF) fraction and a high autofluorescent (HAF) fraction. Immunocytologic and functional properties of these fractions were investigated. The LAF fraction was composed of acid phosphatase (APh)- and RFD9-negative cells, which were strongly positive for HLA-DR, L25, RFD1, and CD68. A portion of these cells expressed CD1a (22%) and My4 (60%). The marker pattern of these cells is reminiscent to that of intraepithelial bronchial DC and to that of blood DC. The majority of the LAF cells had a monocyte-like morphology, but after overnight culture the percentage of LAF cells with long cytoplasmic extensions (DC morphology) was strongly augmented (from 18 to 51%). The HAF fraction contained 100% AM, strongly positive for APh, HLA-DR, CD68, RFD7, and RFD9. In culture, the LAF cells formed clusters with T cells and vigorously stimulated the proliferation of allogeneic T cells and naive (CD45RO-negative) T cells. BAL and LAF cells produced higher responses in nonsmokers than in smokers. In contrast, HAF cells did not form clusters with T cells and did not stimulate allogeneic T cell proliferation. HAF cells even suppressed mitogen-driven T cell proliferation.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Dendritic cells and their precursors isolated from human bronchoalveolar lavage: immunocytologic and functional properties. 808 70

Mononuclear phagocytes and dendritic cells (DC) play an important role in the immune response in the lung. DC act in the afferent phase of the immune response by presenting antigen to T cells, while macrophages play a role in the efferent phase by exerting phagocytic/cytotoxic functions. We investigated the localization and the marker pattern of these cells in the human lung. Macrophages, identified as large, rounded, acid phosphatase-positive cells, were mainly detected in the alveolar spaces, in the lumen of the bronch(iol)us, and in the bronchoalveolar lavage (BAL). They were positive for major histocompatibility complex (MHC) class II antigens (DR, DQ), CD68, RFD7, RFD9, and partly positive for RFD1. Irregularly shaped cells with a marker pattern comparable to that of blood-derived DC (positive for DR, DQ, L25, RFD1, and CD68) were predominantly observed in the epithelium and subepithelial tissue of the bronch(iol)us and in the bronchus-associated lymphoid tissue. In the epithelium, approximately 30% of these cells were positive for CD1a (OKT6). In the subepithelial tissue, these DC formed characteristic small clusters with T cells. The BAL, the alveolar spaces, and the alveolar walls contained only a small number of DC. These immunohistologic data suggest that the bronch(iol)us is well equipped to initiate immune responses. The high number of macrophages in the alveolar compartment, which have been described to suppress T cell proliferation, together with low numbers of DC, makes the alveolar compartment less suited for mounting an immune response.
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PMID:Distribution and immunophenotype of mononuclear phagocytes and dendritic cells in the human lung. 817 11


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