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)

Bone marrow cells of a patient with Letterer-Siwe disease were cultured for three weeks in long-term bone marrow culture (LTBMC) conditions and examined at one-week intervals with a large panel of monoclonal antibodies by immunohistochemistry and by the immunogold transmission electron microscopy (immunoTEM) technique. Although at diagnosis the bone marrow showed a slight increase of monocytes with a normal phenotype, a rapid expansion of cells expressing CD1a and CD1c was observed already after 1 week of culture. A progressive increase in CD4, CD11b and CD11c expression was also observed. ImmunoTEM of cultured cells demonstrated that CD1a+ cells had macrophage-like morphology, and did not contain Birbeck granules. These findings indicate that bone marrow monocytes acquire some phenotypical features of Langerhans cells in LTBMC and support the hypothesis that these cells may derive directly from a bone marrow monocytic precursor.
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PMID:Bone marrow monocytes in histiocytosis X acquire some phenotypic features of Langerhans cells in long term bone marrow cultures. 247 66

Normal human oral (check) mucosa was studied to discover whether the oral cavity resembles the Mucosal Immune System (MIS) or the Skin Immune System (SIS). Immunophenotypes of lymphocyte subsets and Langerhans cells (LC) with their exact locations in the epithelium and papillary layer of the normal buccal mucosa were determined and compared with data of normal human skin. In a double staining procedure, the distribution of T-lymphocytes in relation to blood and lymph vessels was determined. Immunophenotyping of LC was done with a CD1a monoclonal antibody. In contrast to the skin, T-lymphocytes in buccal mucosa are not primarily perivascular in location. They are more or less randomly distributed on both sides of the basement membrane. The epithelium of the buccal mucosa contains about 37 times as many T-lymphocytes as the epidermis of normal skin. T-cell numbers in the papillary layer are more or less comparable. The CD4/CD8 ratios of about 1/2 in the epithelium of buccal mucosa and 1/4 in the skin indicates preferential presence of the CD8 subset in both sites, but the helper/inducer T-lymphocytes play a much greater role in the epithelium of the buccal mucosa when compared with skin. B-lymphocytes were not found in the epithelium and papillary layer of the buccal mucosa. Thus, immune response associated cells in buccal mucosa do not show the MIS pattern since B cells are absent. It has more in common with SIS but differences are also apparent. In the epithelium of the buccal mucosa the density of LC does not differ significantly from that of the skin, but the papillary layer of the buccal mucosa contains significantly fewer LC than the skin. As in the skin most of the LC of the buccal mucosa are found in the epithelium.
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PMID:Quantification and distribution of lymphocyte subsets and Langerhans cells in normal human oral mucosa and skin. 257 Jan 42

The distribution and immunophenotype of macrophages and interdigitating reticulum cells were investigated on frozen sections of seven normal thymuses and 10 thymomas. In normal thymus, macrophages were mainly located in the cortex, were markedly PAM-1+/MAC+, weakly Leu-M3+ (CD14), T4+ (CD4), T9+ and OKM-1+ (CD11b). Interdigitating reticulum cells were mainly located in the medulla and were pan-Leu+ (CD45), T4+(CD4+), HLA-DR+; furthermore, they were also often TAC+ (CD25) and T9+. Thymomas were composed of cytokeratin-containing epithelial cells admixed with variable proportions of T6+ (CD1a) lymphocytes. As defined by the histological features two thymomas were lymphocyte-rich, five were mixed type and three were epithelial-rich; eight thymomas were mainly composed of cortical epithelial cells and two were composed of spindle epithelial cells suggesting a medullary origin. In all cases, thymoma-associated macrophages were markedly PAM-1+/MAC+; they were numerous, and regularly distributed throughout the tumour. The density of macrophages per unit area was similar to that of the normal thymus, and was not influenced by the histological type or by the lymphocyte content of the tumour. Interdigitating reticulum cells were few and were confined to the areas of medullary differentiation.
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PMID:Macrophages and interdigitating reticulum cells in normal thymus and in thymoma: an immunohistochemical study. 292 78

The morphological, ultrastructural and immunophenotypic properties of Histiocytosis-X (H-X) cells were investigated in a lymph node involved by Letterer-Siwe (L-S) disease. H-X cells were T6+ (CD1a), S-100+, T4+ (CD4) and HLA-DR+; in addition they were consistently T11+ (CD2) and were stained by antibodies directed against receptors for transferrin (T9), C3bi (OKM-1/CD11b), IgG-Fc (Leu-11/CD16) and Interleukin-2 (IL-2R/CD25). On immunostained cytosmears, T6+ cells were highly polymorphic and a prominent fraction (45%) showed immature morphology, characterized by lymphoid appearance. Cells expressing macrophage markers (ANAE, AACT, Leu-M3/CD14, PAM-1) were 10-fold fewer than T6+ cells and did not show a lymphoid morphology. At TEM level, H-X cells were characterized by poor content of LC granules and by the presence of myelin-like laminated bodies and of lysosome-like dense bodies. The immunophenotypic properties of H-X cells were compared to those of epidermal Langerhans cells (LCs) and of LCs present in lymph nodes of three cases of dermatophatic lymphadenitis. Epidermal LCs were T6+/HLA-DR+, and sometimes faintly T4+. Lymph node LCs were T6+, S-100+, T4+, HLA-DR+, and showed the same variety of surface receptors detected in H-X cells; furthermore, in a case with massive infiltration of the paracortex by T6+ cells, lymph node LCs were faintly T11+ and some of the T6+ cells had lymphoid aspect. Our findings suggest that the H-X cell population of L-S disease is not homogeneous, but is composed of discrete cell subsets with distinctive antigenic and morphological traits closely resembling those of cells of LC lineage at different maturational stages.
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PMID:Letterer-Siwe disease: immunohistochemical evidence for a proliferative disorder involving immature cells of Langerhans lineage. 313 61

The simultaneous demonstration of three surface antigens of Langerhans cells (LC) within LC-enriched fresh epidermal cell suspensions from normal human skin was achieved, by means of a triple immunogold (IG) staining, using commercially available monoclonal antibodies (moAb) and immunoreagents, in a simple pre-embedding immunoelectronmicroscopy (IEM) procedure. As a result, suspended LC were triple-stained as follows: gold particles of 40 nm revealed the CD1 a antigen; gold particles of 20 nm revealed the HLA-DR antigen; and gold particles of 5 nm revealed the CD4 antigen. All the observed epidermal Birbeck granule-bearing LC were triple IG stained, thus simultaneously expressing the three surface differentiation antigens, which are therefore different from but coexisting with each other. The present investigation assesses the constant simultaneous expression by Birbeck granules bearing LC of not only CD1a and HLA-DR antigens, but also CD4 antigen. The occurrence is therefore excluded of both CD1a-positive HLA-DR-negative LC subpopulation and CD4-negative LC subpopulation, presumably due to the different sensitivity of the various procedures performed. The hypothetical occurrence of CD4-positive, CD1a-, and/or HLA-DR-negative LC subpopulations is ruled out. This study reaffirms indeed the high specificity and sensitivity of the IG-IEM method for a precise detection of the cell surface antigens of LC, and states the suitability of the IG labeling even for accurate multiple IEM stainings of LC.
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PMID:Simultaneous colloidal gold immunoelectronmicroscopy labeling of CD1a, HLA-DR, and CD4 surface antigens of human epidermal Langerhans cells. 326 98

The human gut epithelium is a unique immunological compartment, containing substantial amounts of intra-epithelial lymphocytes (IEL) with unknown functions. In this study we show that distinct and unusual subpopulations of IEL are present at different levels of human intestine. IEL phenotypes in normal jejunum, ileum and colon were compared using immunoflow cytometry and immunohistochemistry. The expression of mRNA for recombination-activating gene-1 (RAG-1) in IEL from all three levels was compared using reverse-transcription polymerase chain reaction, and the morphology of IEL in situ was determined using immunoelectron microscopy. Surface marker profiles of isolated intestinal epithelial cells at all three levels were also investigated. On average the proportion of TCR gamma delta IEL was comparable in jejunum than ileum and colon and varied in phenotype with gut level. CD4-CD8-TCR alpha beta IEL dominated in colon but were absent in jejunum. CD8+ TCR alpha beta IEL were present at all levels but only in jejunum did they constitute the majority of all IEL. CD4+ TCR alpha beta IEL were present in similar frequencies at all levels of the gut. In general, the majority of IEL had an activated phenotype (CD45RO+, alpha E beta 7+). Furthermore, IEL exhibited phenotypes which are rare in peripheral blood. The thymocyte markers CD1a and CD1c as well as the NK cell marker CD56 were expressed on a fraction of TCR alpha beta and TCR gamma delta IEL. A small population of 'null' cells (CD45+ TCR/CD#-CD20-CD14-CD15- cells) was also present at equal proportions along the gut. Jejunal but not colonic IEL expressed RAG-1 mRNA suggesting that extrathymic T cell maturation occurs in the epithelium of small intestine. RAG-1 was expressed in CD2+TCR/CD3- and CD3+/TCR-IEL. Ultrastructurally, IEL often formed small clusters and intimate contacts with epithelial cells, suggesting cell cooperation within the epithelium. Some IEL had pseudopodium-like extensions penetrating the epithelial basement membrane suggesting transmigration. Epithelial cells in small intestine but not colon expressed heat shock protein 60 and HLA-DR. CD1a, CD1b and CD1c were not expressed on intestinal epithelial cells at any level. The distinct surface marker profiles of IEL and epithelial cells along small and large intestine suggest functional regional specialization and are compatible with the hypothesis that TCR alpha beta IEL participate in immune reactions to lumenal antigens while TCR gamma delta IEL perform surveillance of the epithelium.
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PMID:Intra-epithelial lymphocytes. Evidence for regional specialization and extrathymic T cell maturation in the human gut epithelium. 749 55

The expression of immune associated surface antigens of keratinocytes was studied in human papillomavirus (HPV) derived lesions in order to determine whether HPV types have a regulatory role in the pathogenesis of papillomas. A series of cutaneous and mucosal lesions were immunolabeled with monoclonal antibodies to the major histocompatibility complex class 1 (beta 2-microglobulin) and 2 (HLA-DR antigens), intercellular adhesion molecule (ICAM-1) and glycoprotein CD36 (OKM5) as well as CD1a (Langerhans cells), CD4, CD8 (T cells) and CD11a (LFA1 antigen). Testing for the presence of HPV was carried out by in situ hybridization with biotinylated probes for viral DNA detection and typing. We observed a drastic reduction or a loss of beta 2-microglobulin by keratinocytes from cutaneous lesions in correlation with the disappearance of Langerhans cells. Only mild alterations were observed in mucosal lesions. HLA-DR expressed by keratinocytes was only detected in condylomas and laryngeal papillomas and was usually associated with a dense inflammatory reaction. This HLA-DR expression may be correlated with an up-regulation of ICAM-1 and the presence of LFA1 positive leukocytes, mainly of CD8 phenotype, in the epithelium. CD36 was detected on differentiated keratinocytes of all lesions; its expression seems related to the proliferation state of the lesions and probably does not represent an immune marker. The different reactivity patterns observed in cutaneous and mucosal lesions may reflect: 1. different roles for mucosal and cutaneous HPV types in the induction of immunoregulatory surface antigens of keratinocytes, or 2. the changing nature of the cytokines released by mononuclear cells and infected keratinocytes in these lesions.
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PMID:Expression of immune associated surface antigens of keratinocytes in human papillomavirus-derived lesions. 750 44

Some infants infected with human immunodeficiency virus type 1 (HIV-1) rapidly develop a fatal disease characterized by a severe lymphopenia. To explain the immune dysfunction, we proposed a mechanism by which a nongeneration of CD4+ T cells is caused by HIV-1 infection of thymic cells. To examine this hypothesis, we infected primary triple-negative (TN; phenotypically CD3- CD4- CD8-), CD1a- TN, or CD1a+ TN thymic cell subsets. Our data indicate that by flow cytometry, TN, CD1a- TN, and CD1a+ TN cells remain CD4 negative throughout the culture period. We demonstrated that TN and CD1a+ TN thymic cell subsets are susceptible to HIV-1 as is the entire thymic cell population, whereas CD1a- TN cells are not. A limited number of infected TN cells are expressing HIV-1 but the level of transcription is very high in permissive cells, as detected by in situ hybridization. We then performed blocking experiments on TN cells to examine the mechanism of HIV-1 entry into these cells. CD4 (OKT4a) monoclonal antibody blocks their infection. Finally, infection experiments on two subpopulations of TN cells (CD2+ CD7+ and CD2- CD7-) indicate that infected TN cells may correspond to both immature thymocytes and thymic dendritic cells. These data are of particular interest since infection of thymic stromal cells might result in an impairment of T-cell differentiation, which may explain a nongeneration of functional CD4+ T-cell population in the thymus. This phenomenon may play a role in AIDS pathogenesis, in particular in infants born from seropositive mothers.
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PMID:Two subpopulations of human triple-negative thymic cells are susceptible to infection by human immunodeficiency virus type 1 in vitro. 751 58

The present study compared the T-cell progenitor content of CD34+ lineage (Lin)- cells isolated from normal adult bone marrow (ABM) and mobilized peripheral blood (MPB). Both cell populations were found to differentiate into T cells when injected into human fetal thymi implanted into severe combined immunodeficient mice. Cytokine-MPB cells were less efficient than ABM cells in engrafting in the fetal human thymus, although both gave rise to thymocytes with identical phenotypes based on the analysis of CD1a, CD3, CD4, and CD8 expression. Thymocytes derived from adult CD34+ Lin- cells were capable of fully differentiating into mature CD3+ T cells expressing either the T-cell receptor (TCR) gamma delta or the TCR alpha beta (the later associated with CD4 or CD8), showing that the T-cell progenies of adult CD34+ cells were polyclonal and functional. Our data indicate that human MPB CD34+ cells are qualitatively identical to their BM counterparts, and demonstrate the existence of T-lymphoid progenitor cell activity in MPB.
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PMID:Generation of T cells from cytokine-mobilized peripheral blood and adult bone marrow CD34+ cells. 751 4

The epidermal Langerhans' cells are dendritic cells of the skin capable of triggering cutaneous immune responses. They possess the membrane antigens required to this effect: class II histocompatibility antigen, CD1a and CD4; the latter acts as receptor for the human immunodeficiency virus. The skin is the organ primarily affected by Kaposi's sarcoma (KS). In epidemic KS, the local immunologic conditions of the skin are little known. We therefore studied 12 patients with AIDS-associated KS, evaluating the density and phenotypic expression in KS-affected and unaffected skin of the following antigens: CD1a, HLA-DR, CD4 in dendritic epidermal cells and dermis, and CD3, CD4 and CD8 in cells of the inflammatory infiltrate, using monoclonal antibodies applied to frozen sections with the avidin-biotin-peroxidase technique. Langerhans' cells in the AIDS-KS skin lesions were found to be decreased in number. This decrease was even more pronounced in the case of cells expressing HLA-DR antigen. A number of them were also revealed with CD4. The tumour lymphocytic infiltrate was almost exclusively composed of CD3+ CD8+ phenotype lymphocytes. The dermis also revealed CD4+ dendritic cells. The basal keratinocytes focally expressed HLA-DR. These phenotypical alterations of the Langerhans' cells and the local immunological imbalance observed may contribute to the growth and continuity of the KS lesions.
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PMID:Langerhans' cells and lymphocytic infiltrate in AIDS-associated Kaposi's sarcoma. An immunohistochemical study. 752 Nov 2


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