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)

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.
 ...
PMID:Macrophages and interdigitating reticulum cells in normal thymus and in thymoma: an immunohistochemical study. 292 78

The immunophenotypes of the HLA-DR-positive leucocyte populations in normal human skin were studied using an extensive panel of monoclonal antibodies, which included antibodies from the Third International Leucocyte Differentiation Antigen Workshop (3rd LDAW). Langerhans' cells (LC) in the epidermis stained with antibodies from CD15c, Groups 10, 12a, 12b and 15, of the myeloid panel and from CD39 of the B-cell panel. However, LC did not react with CD14 antibodies or 63D3, which are frequently used to stain tissue macrophages. In addition to epidermal LC (26 cells/linear mm) a significant population of CD1a-positive cells was identified in the papillary dermis (7 cells/linear mm of overlying epidermis). The dermal HLA-DR-positive leucocytes consisted of three cell populations. The most numerous cell type stained with antibodies to monocytes/macrophages. There were fewer, though substantial, numbers of T lymphocytes (mainly CD7-negative) and the least numerous was the population of CD1a-positive cells. The CD1a-positive cells and the population of dermal cells that stain with monocyte/macrophage markers are both potential antigen-presenting cells for the skin-associated immune system.
 ...
PMID:HLA-DR-positive leucocyte subpopulations in human skin include dendritic cells, macrophages, and CD7-negative T cells. 306 20

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.
 ...
PMID:Letterer-Siwe disease: immunohistochemical evidence for a proliferative disorder involving immature cells of Langerhans lineage. 313 61

Peptides of melanosomal proteins have recently been shown to be recognized in an HLA-restricted mode by specific cytolytic T lymphocytes in melanoma patients. Dendritic antigen-presenting cells (DC) are considered to be the most effective stimulators of T cell responses, and the use of these cells has therefore been proposed to generate therapeutic responses to tumor antigens in cancer patients. We, therefore, generated DC from peripheral blood of normal donors in the presence of granulocyte/macrophage colony-stimulating factor and interleukin-4. Flow cytometric analysis of the cells during a 2-week culture revealed a loss of CD14 and CD34 expression, a concomittent increase of CD1a, CD11a,b and c, CD44, CD45, CD54, HLA-class I and II, and intermediate levels of CD26, CD80 and CD86. Cultured DC stimulated proliferation of allogeneic T cells and induced a marked, up to 20-fold, stimulation of T cell proliferation after pulsing with tetanus toxoid. To achieve independence of already-identified antigenic peptides presented in HLA class I-restricted fashion, which limits the general applicability of such peptides for vaccination of melanoma patients, we tested whether DC are transfectable with eukaryotic expression plasmids. DC transfected with two reporter genes (CAT, beta-galactosidase) using a liposome-based transfection technique, exhibited only low levels of enzymatically active proteins, but were able to degrade rapidly intracellular proteins and to process peptides efficiently. Chloramphenicol acetyltransferase as well as tyrosinase mRNA were detectable after transfection by reverse-transcriptase-polymerase chain reaction, and enzyme activities became measurable. Furthermore, DC transfected with the tyrosinase gene were able to induce specific T cell activation in vitro, indicating appropriate peptide processing and presentation in DC after transfection. These data suggest new approaches to future tumor vaccination strategies.
 ...
PMID:Dendritic cells generated from peripheral blood transfected with human tyrosinase induce specific T cell activation. 748 49

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.
 ...
PMID:Intra-epithelial lymphocytes. Evidence for regional specialization and extrathymic T cell maturation in the human gut epithelium. 749 55

The relative contribution of dermal-derived immunocompetent cells to the overall immunologic response in skin has been hampered by the lack of appropriate isolation techniques. In this report, we provide a purification schema that reliably yields highly purified populations of dermal dendritic cells (DDC). These cells are motile, express high levels of class II MHC antigens that decorate their cytoplasmic dendritic processes, and lack numerous B cell, T cell, and natural killer cell antigens. Using a broad panel of 45 different antibodies, an extensive phenotypic analysis was completed, revealing distinctive profiles for subsets of DDC. Despite homogeneous light scatter profile and cytologic appearance, three subsets of DDC could be distinguished by phenotypic and functional criteria. All DDC, but not epidermal Langerhans cells, express factor XIIIa. By triple color cell staining the relative distribution of factor XIIIa positive DDC is as follows: subset 1, 65% to 70% of total DDC express neither CD1a nor CD14; subset 2, 15% to 20% of total DDC express CD1a but not CD14; and subset 3, 10% to 15% of total DDC express CD14 but not CD1a. The CD14-negative subset of DDC were shown to be as potent stimulators of allogeneic mixed lymphocyte reactions as Langerhans cells or blood-derived dendritic cells. However, DDC subsets differed in their ability to support autologous T cell proliferation in response to the mitogenic lectin PHA or bacterial-derived superantigen. In these assays, subsets 1 and 2 were significantly more potent as antigen-presenting cells compared with subset 3. Thus, normal skin contains at least three separate populations of DDC, which have distinctive phenotypic markers and immunologic capabilities.
 ...
PMID:Characterization of dermal dendritic cells obtained from normal human skin reveals phenotypic and functionally distinctive subsets. 750 23

Employing a discontinuous Percoll gradient following Ficoll-Hypaque separation of peripheral blood mononuclear cells from normal subjects (n = 14) and patients with HIV-1 infection (n = 50), we separated a population of low-density cells consisting of monocytoid cells, lymphocytes, and some granulocytes. In cytospin preparations, less than 5% of the monocytoid cells were positive for nonspecific esterase and CD14. However, CD1a was positive in 5-20% of these cells. Ultrastructurally, CD1a-labeled immunogold particles were demonstrated on the monocytoid cells which bore some features of dendritic cells. Flow cytometry of the low-density cells identified a subset of buoyant, large cell population, which excluded lymphocytes. This large low-density cell (LLDC) population was significantly expanded in patients with HIV infection and comprised 32.3 +/- 21.3% of low-density cells compared to 7.0 +/- 2.8% in normal subjects (P < 0.0001). Of the LLDC population 45.2 +/- 23.4% were CD1a+ in patients compared to 17.5 +/- 13.3% in normal subjects (P < or = 0.0001). HLA-DR and HLA-DQ were coexpressed in approximately 70 and 50% of these CD1a+ LLDC, respectively. A simple nonculture assay method employed by us facilitates rapid screening of infected blood specimens for the CD1a+ large low-density cells with dendritic cell features, which could be an additional parameter to monitor HIV disease progression.
 ...
PMID:The number of CD1a+ large low-density cells with dendritic cell features is increased in the peripheral blood of HIV+ patients. 750 34

Dendritic antigen-presenting cells are considered to be the most effective stimulators of T cell immunity. The use of dendritic cells has been proposed to generate therapeutic T cell responses to tumor antigens in cancer patients. One limitation is that the number of dendritic cells in peripheral blood is exceedingly low. Dendritic cells originate from CD34+ hematopoietic progenitor cells (HPC) which are present in the bone marrow and in small numbers in peripheral blood. CD34+ HPC can be mobilized into the peripheral blood by in vivo administration of granulocyte-colony-stimulating factor. The aim of the current study was to determine whether functional dendritic cells could be elicited and grown in vitro from CD34+ HPC derived from bone marrow or granulocyte-colony-stimulating factor-mobilized peripheral blood. Culture of CD34+ HPC with granulocyte-macrophage-colony-stimulating factor and tumor necrosis factor alpha yielded a heterogeneous cell population containing cells with typical dendritic morphology. Phenotypic studies demonstrated a loss of the CD34 molecule over 1 week and an increase in cells expressing surface markers associated with dendritic cells, CD1a, CD80 (B7/BB1), CD4, CD14, HLA-DR, and CD64 (Fc gamma RI). Function was validated in experiments showing that cultured cells could stimulate proliferation of allogeneic CD4+ and CD8+ T lymphocytes. Antigen-presenting capacity was further confirmed in experiments showing that cultured cells could effectively stimulate tetanus toxoid-specific responses and HER-2/neu peptide-specific responses. The derivation and expansion of dendritic cells from cultured bone marrow or granulocyte-colony-stimulating factor-mobilized CD34+ HPC may provide adequate numbers for testing of dendritic cells in clinical studies, such as vaccine and T cell therapy trials.
 ...
PMID:Generation of immunostimulatory dendritic cells from human CD34+ hematopoietic progenitor cells of the bone marrow and peripheral blood. 753 43

To date no hematopoietic progenitors of dendritic Langerhans' cells (DLC), which represent an highly efficient class of antigen presenting cells, have been identified or the cytokines they elaborate have been defined. Here we describe an acute leukemia patient whose blasts (90-96% in peripheral blood and bone marrow) had a phenotype consistent with putative progenitors of DLC. The patient was treated with ara-C and VP-16 but did not achieve remission. The blasts had lobulated nuclei, no cytoplasmic vacuolation or Auer rods and were weakly positive for acid phosphatase and non-specific esterase and negative for PAS, granzyme A, dipeptidyl aminopeptidase IV, ATPase/ADPase and lysozyme production. The blasts were positive for CD1a, CD4, CD16, CD35, HLADR, HLADQ, CD11b, CD11c, CD14, CD33, CD34, CD11a, CD71, CD19, CD25, IL-2R beta and negative for CD2, CD7, CD8, CD10, CD22, CD56, CD57, surface or cytoplasmic CD3, TCR delta and TCR beta, HTLV-1p19 and P-glycoprotein. On liquid culture with or without 5 x 10(-9) M 12-O-tetradecanoylphorbol-13-acetate (TPA) for 3 days, the blasts formed aggregates of proliferating and elongating cells on the wall of the flasks with a decline in CD34, numerous dendritic processes appeared on the cells and there was strong positivity for ATPase/ADPase, but no other changes in phenotype. No macrophages were observed, indicating derivation from separate DLCs. Cytogenetic analysis showed chromosomal abnormalities and electron microscopy showed Birbeck granules. Southern blotting of DNA showed rearrangement of one allele for both JH and TCR beta but no HTLV-1 related sequences. Culture supernatants from blasts cultured with or without TPA showed the production of large amounts of IL-8, IL-6, TNF-alpha, MIP-1 alpha, IL-10 and interferon gamma and modest amounts of IL-1 alpha, GM-CSF and stem cell factor. The presence not only of CD1a, HLADR, HLADQ and many other characteristics including Birbeck granules, but also differentiation along the lines of DLC with appearance of dendritic processes on the cells and expression of ATPase/ADPase activity, indicate that the leukemic blasts in our patient represented a leukemic counterpart of normal progenitors of DLC and the leukemia a new entity which could possibly be classified as AML-M8. Lastly, many pro-inflammatory cytokines produced by DLC could contribute to inflammation and IL-10 to immunosuppression.
 ...
PMID:Phenotype, genotype and cytokine production in acute leukemia involving progenitors of dendritic Langerhans' cells. 791 55

In lymphoproliferative diseases of the skin, DC have a key role in T- and B-cell homing. Furthermore, DC alterations may have a pathogenic role in the natural history of specific disorders, either in the neoplastic lymphoid cell progression or in antitumoral lymphocyte reaction. Finally, the morphoantigenic and topographic features of DC may have diagnostic and histogenetic relevance in specific conditions. In CTCL, dermal CD1a+ DC ("indeterminate cells") seem to play a significant role in the neoplastic progression of MF, whereas the possible pathogenetic role of specific alterations of epidermal LC is yet to be proven. Recently, a possible implication of DD (resident, perivascular factor XIIIa+/CD1a- DC) in the pathogenesis of MF has been also suggested. The presence and possible significance of DC in CTCL non-MF are presently poorly studied. At present, DC number, distribution, and phenotype seem possibly useful in the differential diagnosis between CTCL and pseudo-CTCL, but this hypothesis has to be adequately confirmed. CBCL has been recently proposed as a unique type of clinically low-grade lymphoma, namely, skin-associated lymphoid tissue (SALT)-related B-cell lymphoma. Both SALT- and mucosa-associated lymphoid tissue (MALT)-related B-cell lymphoma share with a peculiar nodal lymphoma of follicle mantle origin (parafollicular-monocytoid lymphoma) the nonaggressive clinical behavior and the uniform phenotype (CD5-, CD10-) and genotype (lack of bcl-2 gene rearrangement) of neoplastic B cells, despite the wide variability of cytomorphologic appearances. The putative origin of CBCL is further supported by the typical CD14-, nerve growth factor receptor (NGFr)+ immunophenotype of DRC. Moreover, the immunophenotype and architectural fashion of DRC are interesting clues to the differentiation between neoplastic and true reactive folliclelike nodules and may be of help in the differential diagnosis between CBCL and B-cell pseudolymphoma as well as in the correct interpretation of lesions showing monoclonal proliferations of B cells accompanied by polyclonal follicular reactions.
 ...
PMID:Dendritic cells in T- and B-cell proliferation in the skin. 804 37


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>