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)

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

Recently we reported that the high-affinity receptor for IgE, Fc epsilon RI, is constitutively expressed on normal epidermal Langerhans cells (LC) and on certain cells within the dermis. To study the nature of these cells we performed immunofluorescence double-labeling experiments using an anti-Fc epsilon RI reagent (MoAb 15-1) as well as monoclonal antibodies (MoAb) against leukocyte differentiation antigens expressed on LC, interdigitating cells and macrophages. Avidin-fluorescein isothiocyanate was used to distinguish mast cells. We found that dermal Fc epsilon RI+ cells are bone marrow derived (CD45+). Further, we found that a subset of 15-1+ dermal cells coexpresses antigens present on certain members of the LC/DC family: the majority of Fc epsilon RI+ cells reacted with MoAb anti-HLA-DR and RFD1, the latter recognizes an antigenic moiety on interdigitating cells, and a small subpopulation coexpressed CD1a. In reverse fashion, virtually all CD1a+ cells and most RFD1+ cells reacted with the anti-Fc epsilon RI reagent. Approximately one third of 15-1+ cells represented avidin-FITC+ mast cells whereas Fc epsilon RI expression was not detected on FXIIIa+ dermal dendrocytes or CD3+ lymphocytes. By immunoelectronmicroscopy, we found that perivascularly located 15-1-reactive cells exhibited pronounced dendrites, an indented nucleus, numerous mitochondria, and abundant endo-/lysosomal structures. However, Birbeck granules or granules specific for basophils or eosinophils were never detected in these cells. Collectively, our data suggest that the pool of dermal Fc epsilon RI+ cells consists mainly of cells of the LC (CD1a+)/DC(RFD1+) lineage and mast cells but does not include FXIIIa+ dermal macrophages.
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PMID:Immunomorphologic characterization of Fc epsilon RI-bearing cells within the human dermis. 812 Apr 15

By means of microsurgical lymph cannulation human skin lymph derived from the late phase of an elicitation reaction to diphenylcyclopropenone was sampled. Cells were isolated by centrifugation and then treated with mouse anti-CD1a monoclonal antibodies and sheep antimouse antibody-coated Dynabeads. Ultrastructural and immunocytochemical analyses revealed anti-CD1a/Dynabead-rosetted CD1a- and protein S-100-positive cells which did not express monocyte surface markers, but surface antigens such as HLA-DR, ICAM-1 and, in part, LFA-3. In comparison to freshly prepared human epidermal Langerhans cells (LC), a large fraction of these cells contained no or markedly fewer Birbeck granules and exhibited extensive ruffling of the surface. These data suggest that the phenotype of LC in skin lymph derived from the elicitation phase of allergic contact dermatitis is similar to LC cultured in vitro. In the functional concept of LC of our time, these cells correspond to the dendritic cells designated as "veiled".
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PMID:Phenotype of Langerhans cells in human afferent skin lymph derived from allergic contact dermatitis. 816 48

Langerhans cell histiocytosis (LCH), formerly histiocytosis X, is a rare disorder of unknown aetiology and pathogenesis which is characterized by clinical heterogeneity and an unpredictable course. LCH is considered to be a reactive, proliferative disease. The pathognomonic cell in the lesion has been shown to be identical or very similar to the Langerhans cell. Immunophenotyping studies have shown the cell to be CD1a (OKT-6), S-100 protein, HLA-DR, and CD4 positive; ultrastructurally, the presence of intracytoplasmic Birbeck granules is the hallmark of the entity. The lesions may be localized or generalized. Due to the lack of an accepted classification system for the stage of the disease and its rarity, very few comparative therapy studies have been carried out. Recently, the Histiocyte Society has suggested diagnostic criteria for LCH, and established a program of initial evaluation of the patient in order to start controlled treatment trials. Traditionally, chemotherapy has been preferred with a trend over time towards a more conservative approach. The rate of sequelae is high and connected to a chronic course of recurrent multiosseous disease. Case fatality is strongly associated to development of organ dysfunction seen in disseminated disease, which is especially seen at low age (< 2 years) of onset.
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PMID:[Langerhans-cell histiocytosis (histiocytosis X) in children]. 831 26

We describe the case of a patient with peripheral gamma/delta T-cell lymphoma (T-ML) with hepatosplenomegaly, generalized lymphadenopathy, and bone marrow involvement. A 44-year-old man had lymphoma, which became clinically apparent 2 months after the onset of myositis and insulin-dependent diabetes mellitus. A cervical lymph node biopsy specimen showed diffuse infiltration by large neoplastic cells with vascular proliferation. The neoplastic cells expressed the T-cell receptor (TCR)delta chain detected by TCR delta 1 and delta-TCS1, CD3, CD30, CD45RO, and epithelial membrane antigen, but not the TCR beta chain detected by beta F1, CD1a, CD2, CD4, CD5, CD7, CD8, CD25, HLA-DR, and terminal deoxynucleotidyl transferase. The cells had a clonal rearrangement of TCR gamma chain gene and a germ-line configuration of immunoglobulin heavy chain gene and TCR beta chain gene. Despite chemotherapy, the patient died of refractory lymphoma 4 months after diagnosis. Examination at autopsy revealed that the main hepatic and splenic neoplastic infiltration sites were the portal area and white pulp, respectively. Our patient differed from those with gamma/delta T-ML with hepatosplenic involvement reported previously with respect to the hepatic and splenic neoplastic infiltration patterns and the presence of lymphadenopathy.
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PMID:Gamma/delta T-cell lymphoma with hepatosplenomegaly: report of a case. 836 90

In a pilot study designed to investigate immunopathologic events in the evolution of cutaneous lesions in pemphigus foliaceus, we found that in this condition the epidermis is replete with CD68+ dendritic cells. The present study was designed to investigate the nature of this novel intraepidermal CD68+ cell population. For that purpose lesional skin of five patients with PF and, for comparison, of patients with another acantholytic autoimmune disease, pemphigus vulgaris, were examined using a panel of monoclonal antibodies in a three-step immunoperoxidase technique, in an immunofluorescence double-labeling technique, and by immunoelectron microscopy. We found epidermal CD1a+ Langerhans cells significantly decreased in pemphigus foliaceus compared to pemphigus vulgaris, but pemphigus foliaceus and not pemphigus vulgaris epidermis harbored large amounts of bone marrow-derived (CD45+) cells that expressed CD68, HLA-DR, and beta 2-integrin antigens, the most pronounced expression being observed for CD11c and CD18. These epidermal CD68+ cells were of dendritic shape, were CD1a-, and lacked Birbeck granules (BG); however, a small portion of CD68+ cells was also CD1a+ and exhibited BG as revealed by immunoelectron microscopy. These findings demonstrate that in certain conditions, i.e., in pemphigus foliaceus but not in pemphigus vulgaris, there is a shift from CD1a+/CD68- epidermal Langerhans cells towards CD1a-/CD68+ dendritic epidermal cells. The detection of a small number of CD1a+/CD68+/BG+ dendritic epidermal cells may identify these cells as a link between the CD1a+/CD68+/BG+ Langerhans cells and the CD1a-/CD68+/BG- cell population and suggests that these cells represent a transitional form of myelomonocytic cells during their phenotypic and morphologic transformation into resident epidermal Langerhans cells.
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PMID:CD68 positive epidermal dendritic cells. 837 Sep 61

Two cases of true histiocytic lymphoma of the small intestine occurred in middle-aged patients, manifesting as tumors causing intestinal obstruction. One of the patients died of uncontrollable local and metastatic disease, 16 months after surgery and polychemotherapy, and the other patient is alive 12 months after surgery and chemotherapy. The histologic characteristics of the tumor cells, namely complex nuclear outlines and abundant variably eosinophilic cytoplasm, suggested histiocytic differentiation. Both cases had negative results for B-cell and T-cell markers but stained for the histiocytic markers lysozyme, CD68, and HLA-DR and had positive results for S-100 protein and vimentin. Acetone-fixed frozen sections of one case showed positive results for several histiocytic markers, including CD11c, CD14, CD33, CD68, and BerMac3 (unclustered monoclonal antibody). CD4, a T-cell antigen present in a subset of histiomonocytic cells, had positive results in the cytoplasm. The tumor cells had negative results for CD1a, CD15, and CD30. Immunoglobulin and T-cell receptor gene probes showed germline configuration in one case studied. These results indicate the tumors are true histiocytic lymphomas, which have immunophenotypic features of both ordinary histiocytes and interdigitating reticulum cells.
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PMID:True histiocytic lymphoma of small intestine. Analysis of two S-100 protein-positive cases with features of interdigitating reticulum cell sarcoma. 837 37

In human papillomavirus (HPV) infections, Langerhans cells (LC) are essential in the control of viral infection. The evolution of HPV-derived lesions in the normal population and in graft patients is drastically different, since a high proportion of papillomas progress towards malignancy in transplant recipients. We analyzed the distribution of markers of LC and T lymphocytes, the level of keratinocyte activation and the prevalence of HPV in a series of epithelial lesions obtained from the normal population and from graft patients. The local immune response of warts, condyloma acuminata, Bowen, basal and squamous cell carcinomas (SCC) showed a moderate to intense inflammatory reaction of HLA-DR positive cells, the intensity of the immune reaction being correlated with the degree of malignancy. In the normal population, CD4-positive cells were mainly overexpressed in the dermal infiltrate of condyloma and malignant lesions, whereas in grafted patients such infiltrates were CD4- and CD8-positive without significant predominance of a single T cell subset. The epidermis of most lesions was characterized by a reduced number of CD1a-positive LC with an altered morphology. This was concomitant with the decrease or loss of beta 2-microglobulin by epithelial cells. HLA-DR antigen was sometimes expressed by keratinocytes in genital lesions and SCC from the normal population but has not been detected in immunosuppressed patients. Whereas in the normal population HPV infection was only detected in benign papillomas, both benign and oncogenic HPV DNA may be present in carcinomas from graft patients.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Papilloma viruses, warts, carcinoma and Langerhans cells. 839 34

Little is known regarding the identification, classification, and function of class II MHC+ dendritic cells in the perivasculature of human connective tissues, such as the dermis. We developed a method for preparing papillary dermal cell suspensions from human keratome strips. Among the class II MHC+ populations of the dermis identified using triple color flow cytometry, cells of monocyte/macrophage lineage (CD45+ CD1- CD11b+ CD11clo-mid CD32+ CD36+ or - CD11a-) and mesenchymal cells of non-bone marrow origin (CD45-) were identified and characterized. Another distinct class II MHC+ subset was identified, which expressed a number of features analogous to epidermal Langerhans cells (LC) and other dendritic APC. These were a numerically minor population comprising only 2.7% +/- 1% (n = 7) of dermal cells. Like LC, they express HLA-DR, CD45, CD1a (albeit at a lower level of expression), CD1c, and CD32 and lack constitutive CD11a or ICAM-1. In contrast to LC, this dermal CD1a+CD1c+ subset expresses CD1b, CD11b, a higher level of CD11c, and intracytoplasmic factor XIIIa. Alloantigen presentation by unfractionated dermal cells was reduced by prior removal of this CD1b+ subset to the same degree achieved by removal of the entire DR+ population (20% of dermal cells), indicating that this was the critical DR+ subset. Cocultures of CD4+ T lymphocytes with cells sorted by flow cytometry into CD1c+DR+, CD1c-DR+ and DR- dermal cell subsets positively identified the CD1c+DR+ population as the most potent of potential APC subsets in human dermis. Thus, in distinction to other dermal macrophage and mesenchymal subsets with elongate morphology, the CD1aloCD1b,c+CD11c(hi)CD11b+CD32+DR+ population in human dermis is highly analogous to cells of LC/dendritic APC lineage in its phenotype and in its exclusive ability to potently present Ag to T lymphocytes. These studies identify and characterize the APC subset most potent in inducing activation of T cells initially entering the perivasculature of human dermis to be of LC/dendritic APC, and not tissue macrophage, lineage.
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PMID:Heterogeneous populations of class II MHC+ cells in human dermal cell suspensions. Identification of a small subset responsible for potent dermal antigen-presenting cell activity with features analogous to Langerhans cells. 840 86

Two different subsets of CD4+,CD8+ T lymphocytes have been identified in peripheral blood collected from normal subjects and from patients with different diseases. The subpopulations differed in the degree of CD4 and CD8 antigen expression. Hence, it was possible to distinguish by cytofluorimetric analysis cells with a low (dim) or with a high (bright) fluorescence intensity after the staining with anti-CD4 or anti-CD8 mAbs. CD4+dim,CD8+bright lymphocytes were found in patients with EBV-infectious mononucleosis and were present for less than a month. CD4+bright,CD8+dim T cells were observed in neoplastic patients as well as in healthy subjects and were continuously present in similar percentages over a long period of time (at the moment, about 3 years). Both the subpopulations expressed CD2, CD3, CD5 antigens and had an alpha beta-TCR, but did not express CD1a or CD7. Only CD4+dim,CD8+bright cells expressed HLA-DR antigen and the activation marker CD38, while only CD4+bright,CD8+dim lymphocytes expressed CD56 and CD57 molecules. The hypothesis may be put forward that these two subsets represent an effort of the immune system to cope with different requirements, i.e., of viral or neoplastic origin, while it is not clear the meaning of these cells in healthy subjects.
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PMID:Cytofluorimetric identification of two populations of double positive (CD4+,CD8+) T lymphocytes in human peripheral blood. 846 Oct 16


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