Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:3.6.1.3 (ATPase)
65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The lck gene encodes a membrane-associated protein tyrosine kinase that is expressed specifically in lymphoid cells, especially thymocytes. Structural analysis of the murine and human lck genes previously identified conserved 5' flanking sequences that were proposed to represent transcriptional regulatory elements. Here we demonstrate that a murine lck promoter construct containing these sequences directs the expression of the SV40 T-antigen gene in lymphoid cells. Remarkably, expression of SV40 T-antigen in transgenic animals dramatically disturbs thymic development, resulting in preferential loss of CD4+CD8+ thymocytes. In contrast, immature cells lacking both CD4 and CD8 markers are present in near-normal numbers. Thus SV40 T-antigen expression appears partially to arrest thymopoiesis. Mice bearing the lck-SV40 transgene develop readily explantable thymic tumors at 12-18 weeks of age. Fluorocytometric analyses of lck-SV40 tumor cells reveal that immature thymocytes are frequently immortalized. The lck-SV40 mouse may therefore provide materials for the in vitro investigation of thymocyte differentiation.
...
PMID:Disruption of thymocyte development and lymphomagenesis induced by SV40 T-antigen. 196 44

Cells with dendritic shape, the so-called dendritic cells (DCs), have been described in many tissues. In order to characterize one DCs population, normal human thymus specimens were obtained from children undergoing cardiovascular surgery. These specimens were either put in culture or fixed for in situ ultrastructural, immunocytochemical and cytochemical studies. In culture, DCs could be differentiated from other non-lymphoid cell populations. They presented long, fine processes and an irregular nucleus. Like interdigitating cells (IDCs) in situ, their cytoplasm contained many free ribosomes and mitochondria, and a well-developed endoplasmic reticulum and Golgi complex. They showed a variable number of tubulovesicular structures and membrane-bound dark homogeneous granules. They never displayed phagolysosomes, tonofilaments or desmosomes. They were Ia+, ATPase+, S-100 protein+, vimentin+, esterase-, lysozyme-, and cytokeratin- cells. Macrophages were easily identified by their numerous lysosomes and large phagolysosomes. They were esterase+, lysozyme+, vimentin+, ATPase +/-, S-100 protein- and cytokeratin-. Although they were Ia+, membrane labelling was not as important as on DC's membrane. In situ, S-100 protein-positive cells had a dendritic shape and were located mainly in medullary regions and at the cortico-medullary border. The staining was diffused both in the nucleus and in the cytoplasm. Lysozyme-positive cells were randomly distributed in the cortex, the medulla and the connective septa. They were round cells and the staining was intracytoplasmic. These observations demonstrate that DCs can be isolated in human thymic cultures, and they suggest that these cells correspond to IDCs in situ. They also provide evidence to suggest that DCs and macrophages are two distinct cellular populations.
...
PMID:Characterization of human thymic dendritic cells in culture. 242 46

A combined histologic, immunohistologic, enzyme histochemical, and immunologic study has been carried out in a 7-year-old girl with recurring extramediastinal monocentric giant lymph node hyperplasia of hyaline-vascular type. A large panel of monoclonal and polyclonal antibodies to lymphoid and nonlymphoid cell markers were tested on frozen and paraffin-embedded lymph node tissue as well as on cell suspension and peripheral blood. Tissue enzyme histochemical study, including a conventional hematologic panel, was performed on frozen and plastic-embedded sections. The pattern was dominated by nodular aggregates of round BA-1+ Leu-14+ HLA-DR+ ATPase+ lymphocytes with polyclonal sIgD and sIgM positivity and lacking cIg and BA-2 staining. Leu-1+/Leu-4+, OKT6+, OKT10+, Leu-7+, and CALLA+ cells were few or absent in the nodules, whereas DRC-1+ BA-2+ HLA-DR+ 5'-Nuc+ cells formed a dendritic network in the outer portion of the nodules. No immunoreactivity for lymphoid and nonlymphoid cell markers, including cytokeratin and keratin, was detected in centrinodular histiocytic-like cells. Particularly, the Hassall's-like structures contained a target-like positivity for laminin, and consisted of flattened acid phosphatase (AP), alpha-naphthyl acetate esterase (ANAE), 5'-nucleotidase (5'-Nuc), and adenosine triphosphatase (ATPase) positive cells, whose enzyme profile overlapped with that of the histiocytic-like cells. The extranodular areas were mainly composed of Leu-1+/Leu-4+ lymphocytes with Leu-3a+/OKT4+ phenotype and, to a lesser extent, of OKT6+ OKT10+ lymphoid cells and scattered cells with markers of histiocytic lineage. The abundant vascular component was generally identified by laminin positivity and, in smaller proportion, it was positive for Factor VIII-related antigen. Most of the medium-sized vessels with high endothelium had marked AP, ANAE, and ATPase activities. The process observed resulted from vascularized nodular aggregates of nontransformed B-cells with the phenotype of primary follicle lymphocytes, associated to centrinodular histiocytic-like cells with a distinct enzyme profile.
...
PMID:Immunohistochemical, enzyme histochemical, and immunologic features of giant lymph node hyperplasia of the hyaline-vascular type. 242 88

Tyrosine protein kinases (TPKs) have been implicated in mitotic signalling in a wide range of cells including lymphocytes. We describe here the partial characterization of a heat stable TPK inhibitor from both normal and malignant human lymphoid cells. Inhibitory activity was not attributable to contaminating ATPase, protease or phosphatase activities or to the Ca2+-binding protein S100. Preparations of the TPK inhibitor did not reduce the activity of cAMP-dependent protein kinase. While the inhibitor decreased the activity of TPKs towards an exogenous peptide substrate, it did not affect the autophosphorylation of microsomal TPKs. These results raise the possibility that the activity of TPKs in lymphoid cells may be regulated by an inhibitor protein.
...
PMID:An endogenous inhibitor of the protein tyrosine kinase activity of normal and malignant human lymphoid cells. 252 67

Bone marrow-derived leukocytes of murine epidermis can express two phenotypes: typical Langerhans cells, which are Ia+ and Thy-1-, and a recently discovered second population that is Thy-1+ and Ia-. To verify that these phenotypes are expressed by two different cell types, and to help understand their lineage and function, we have studied morphology and reactivity with a large panel of antibodies. Dual antibody immunofluorescence combined with electron microscopy showed that Thy-1+ and Ia+ cells were each distributed in a regular fashion and formed adjacent dendritic systems in or close to the basal layer. Double-labeling studies with anti-Ia and a second monoclonal antibody revealed that all Langerhans cells expressed F4/80 (macrophage), Mac-1 (C3bi receptor), and 2.4G2 (Fc receptor), as well as the thymus leukemia (TL) and heat-stable (M1.69/16) antigens. A large fraction expressed S100 and all exhibited membrane ATPase and nonspecific esterase. In contrast, Thy-1+ cells lacked all these features of Langerhans cells, except that a minority were strongly reactive with 2.4G2. Thy-1+ cells also lacked differentiation antigens of most other types of leukocytes, except they were rich in asialo GM1. By electron microscopy, Thy-1+ cells had cytoplasmic granules that were similar in structure and in their aryl sulfatase content to those previously described in natural killer cells. The granules were enlarged in beige mice, suggesting a lysosomal origin, and were present in mast cell-deficient W/Wv mice, indicating no relation to mast cells. We conclude that Thy-1+ epidermal cells are thoroughly distinct from Langerhans cells. On the basis of morphology and phenotype, they may represent a type of tissue natural killer cell. Thy-1+ natural killer cells are now being identified in several nonlymphoid sites, such as gut epithelium and the livers of mice given adjuvants. If Thy-1+ epidermal cells prove to be natural killer cells, it is noteworthy that they represent a resident population regularly distributed in the basal layer of all mouse strains. The notion that Thy-1+ epidermal cells are immature natural killer cells is intriguing in light of recent evidence that Ia+ Langerhans cells are also immature with respect to accessory cell function. The epidermis may not have the functional capacities of a lymphoid organ, but it could contribute immature cells important for both natural and acquired resistance.
...
PMID:The Thy-1-bearing cell of murine epidermis. A distinctive leukocyte perhaps related to natural killer cells. 286 Dec 45

Ectoenzyme activities were determined in peripheral blood cells from patients with acute leukemias, from normal controls, and in cells of hematopoietic cell lines. In common acute lymphoblastic leukemia, cell membrane-associated 5'-nucleotidase (5'-N) activity was significantly higher than in acute T and unclassified lymphoblastic leukemias. In acute myeloblastic and myelomonocytic leukemias, cells contained significantly higher gamma-glutamyl transpeptidase (gamma-GT) activity than in lymphoblastic leukemias. Normal B lymphocytes differed from T cells and monocytes mainly in their 5'-N activity, whereas in monocytes, gamma-GT activity was more pronounced than in other normal blood cells. Hematopoietic cell lines showed some distinct patterns of ectoenzyme activity. Most B cell lines had high 5'-N and (Na-K-Mg) adenosine triphosphatase activities. In lines of myeloid origin, elevated gamma-GT values were found. In lymphoid stem cells and in T lymphoblast lines, most ectoenzyme activities were lower than in the other cell lines. In some cell lines, characteristic high-activity marker enzymes were detected.
...
PMID:Determination of ectoenzyme activities in leukemic cells and in established hematopoietic cell lines. 286 54

Immunohistochemical techniques have been used to localize clotting factor XIII subunit A in human reactive lymphoid follicles. The follicular dendritic reticulum cells (DRCs) were identified by the monoclonal antibodies R4/23 and OKB-7 as well as by their 5'-nucleotidase positivity. Follicular histiocytic reticulum cells (HRCs) were demonstrated by their acid phosphatase and non-specific esterase reactions. Capillaries were selectively visualized by adenosine triphosphatase. The immunohistochemical demonstration of F-XIIIa was preferably carried out in combination with one or two of the above marker techniques, on the same cryostat section. The subunit A of factor XIII is present in follicular DRCs. Their selective immunohistochemical demonstration with antibody against F-XIIIa requires formaldehyde fixation of cryostat sections. Similar fixation, however, is inappropriate for the demonstration of F-XIIIa reactivity of DRCs in paraffin sections. For this purpose, acetic acid-formalin fixation is useful. Follicular HRCs are consistently negative for F-XIIIa, contrary to the F-XIIIa positivity of sinusoidal and interfollicular HRCs. Developmental and functional implications of F-XIIIa reactivity in DRCs and HRCs are suggested.
...
PMID:Selective visualization of human dendritic reticulum cells in reactive lymphoid follicles by the immunohistochemical demonstration of the subunit A of factor XIII (F-XIIIa). 288 67

The relationship between T nodules and adjacent B-lymphoid follicles was investigated in 37 reactive lymph nodes by light microscopy and combined enzyme immunohistochemistry. In 16 cases (43%), T nodules and adjacent B-lymphoid follicles were unified in an ovoid, distinct nodular structure termed a "composite nodule." The composite nodule comprises two separate domains. The peripheral, subcapsular B domain contains all stationary and migratory elements of the B-lymphoid follicle, ie, B1+ B-cells, OKT4+, Leu 3a+ helper/inducer T cells, HLA-DR+ dendritic reticulum cells, and ANAE+, AcPhase+ tangible body macrophages and is surrounded by a B1+, HLA-DR+ lymphocytic corona displaying focal adenosine triphosphatase (ATPase) and alkaline phosphatase (AlkPhase) activity. The deep, paracortical T-domain contains all elements of the T nodule, ie, OKT4+, Leu3a+ helper/inducer T cells, high endothelial venules and HLA-DR+, ATPase+ interdigitating reticulum cells. The composite nodule is surrounded by a rim of ATPase+, AlkPhase+ high endothelial venules. Both domains are subject to changes in volume; thus, in follicular hyperplasia, the B domain enlarges at the cost of the T domain, and the reverse may occur in T-zone hyperplasia. Based on the striking resemblance between the composite nodule and the white pulp of the spleen, it is suggested that the composite nodule plays a major role in the triggering, helper-T-cell-dependent stimulation and subsequent maturation of antigen-responsive B cells into antibody-secreting plasma cells.
...
PMID:The composite nodule. A structural and functional unit of the reactive human lymph node. 293 88

To establish if epidermal Langerhans cells (LC) are related to spleen dendritic cells, we have considered the morphology, phenotype, and function of the 2 cell types in culture. Cultured LC could be partially enriched (up to 50%) on the basis of 2 simple physical properties: nonadherence to plastic, and low buoyant density in dense albumin columns. The morphology of cultured LC and spleen dendritic cells were similar. In particular both cell types had many cell processes and/or veils, and cultured LC lost their distinguishing Birbeck granules. Freshly isolated LC exhibited nonspecific esterase and ATPase, as well as the F4/80 (alpha-macrophage) and 2.4G2 (alpha-Fc receptor) antigens. However all these traits were lost in culture, while Ia and Mac-1 antigens persisted. As a result, the cytochemical and antigenic phenotype of LC became similar to spleen dendritic cells. The one exception was that LC lacked the 33D1 dendritic cell antigen. The function of LC at first differed from spleen dendritic cells in that fresh LC were weak stimulators of T cell proliferation in the mixed leukocyte reaction and in sodium periodate-induced mitogenesis. However, stimulatory activity per cell increased at least 30 fold in culture so that by 2-3 days, LC were 3-10 times more potent than dendritic cells. Maturation of LC function was radioresistant and was accompanied by a small increase in cell surface Ia antigens. Although LC have been likened both to lymphoid dendritic cells and to macrophages, our data suggest a different conclusion. LC seem to be dendritic cell precursors and are immunologically immature. Possibly, lymphoid dendritic cells are in general derived from substantial pools of precursors in nonlymphoid tissues, such as epidermal LC.
...
PMID:A comparison of murine epidermal Langerhans cells with spleen dendritic cells. 315 9

Ultrastructural, enzyme histochemical (acide phosphatase, adenosine triphosphatase, neutral 5'-nucleotidase) and immunohistochemical (cytokeratins with monoclonal antibodies BH11 and BC3) features of the thymus cortical epithelial cells of leukemic DBA/2 inbred mice have been studied. In the leukemic mice epithelial cells appeared possessing some ultrastructural and histochemical features of cell activation. Lympho-epithelial complexes, composed mainly of BH11 and BC3 immunoreactive cells and of lymphoid cells were subcapsulary and subseptally found. It is discussed on the eventual involvement of the lympho-epithelial complexes in the intrathymic leukemogenesis during lymphoid leukemia.
...
PMID:Structural and histochemical features of cortical thymic epithelial cells in mice with chemically-induced lymphoid leukemia. 324 59


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

---