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

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

Extracellular nucleotide degradation was studied in intact human B and T lymphocyte subpopulations and in lymphoblastoid cell lines. Cells of B lymphocyte lineage showed high nucleotide degrading activity, whereas T lymphocytes were unable to degrade extracellular nucleotides. The external surface of B cells contained active sites of ecto-triphosphonucleotidase (ecto-ATPase), ecto-diphosphonucleotidase (ecto-ADPase), and ecto-monophosphonucleotidase (ecto-AMPase). The expression of all three ectoenzyme activities seemed closely associated with B cell development. ATPase and ADPase activities increase continuously during B cell maturation, ecto-AMPase activity, on the other hand, reaches maximal activity in late pre-B cells. These results combined with our previous studies of intracellular ATP catabolism (Barankiewicz, J., and Cohen, A. (1984) J. Biol. Chem. 259, 15178-15181) provide evidence that extracellular ATP catabolism may represent exclusive source for adenosine in lymphocytes. It is suggested that adenosine may serve as a means of communication between B and T cells in lymphoid organs, B lymphocytes being the sole producers of adenosine and T lymphocytes being the recipients of this signal.
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PMID:Extracellular nucleotide catabolism in human B and T lymphocytes. The source of adenosine production. 325 29

Murine epidermal Langerhans cells (LC) have been studied in tissue culture and compared to spleen dendritic cells (DC). LC comprised 3% of the starting cell suspensions and were distinguished from keratinocytes by cytology and reactivity with anti-Ia and anti-Mac-1 monoclonal antibodies. The LC were nonadherent, had a low buoyant density, did not proliferate, and could be enriched to 10-50% purity. LC continued to exhibit Ia and Mac-1 antigens for 4 d in culture. However, LC rapidly lost Birbeck granules, Fc receptors, F4/80 antigen, and cytochemical reactivity for nonspecific esterase and membrane ATPase. As a result, the ultrastructure and phenotype of cultured LC became remarkably similar to lymphoid DC. Stimulatory capacity for T cell proliferative responses (oxidative mitogenesis and the mixed leukocyte reaction) was monitored daily. Initially, stimulatory capacity was very weak, even though LC expressed substantial levels of Ia antigens. After 2-3 d in culture, LC had become 3-10 times more potent than spleen DC. 30 LC could induce significant responses in cultures of 3 X 10(5) responding T cells. Removal of Ia+ LC at the start of culture ablated the development of stimulatory activity, but exposure to 1,500 rad of ionizing irradiation did not. Mixing experiments showed that contaminating Ia- epidermal cells did not alter the function of Ia+ stimulators. Therefore, LC seem to be immunologically immature, but acquire many of the features of spleen DC during culture. We suggest that functioning lymphoid DC may, in general, be derived from less mature precursors located in nonlymphoid tissues.
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PMID:Murine epidermal Langerhans cells mature into potent immunostimulatory dendritic cells in vitro. 387 37

Previous evidence has established the similarity between (Na+ + K+)-ATPase (ATP phosphohydrolase, EC.3.6.1.3) and the antigen recognized by the rat antimouse monoclonal antibody anti-BSP-3. This antibody has been used for investigation of the surface expression and biochemical analysis of the enzyme in different mouse lymphoid populations. The BSP-3 determinant is found on almost all thymocytes and concanavalin A-induced thymocytes, to a lesser extent on bone marrow cells and also on a minor population of spleen cells. Spleen cells from athymic mice are negative. The (Na+ + K+)-ATPase purified from mouse thymus by affinity chromatography migrates in SDS-polyacrylamide gels in the form of two polypeptide chains of 105 000 and 51 000 daltons. Chains of the same molecular weight, fractionated on SDS-PAGE from microsomes of mouse thymuses, are shown to react with subunit-specific polyclonal antisera against ATPase in immunoblotting experiments. Immunoprecipitation with anti-BSP-3 from surface iodinated thymocytes yields only the small subunit. Comparison of the chains isolated from thymus and brain shows molecular weight differences in both subunits. These results, and variations in the reactivity pattern of the anti-BSP-3 antibody on several cell types, may indicate a possible heterogeneity of the (Na+ + K+)-ATPase expressed by various tissues and cells.
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PMID:Recognition of sodium- and potassium-dependent adenosine triphosphatase on mouse lymphoid cells by means of a monoclonal antibody. 609 1

Tissue sections of lymph nodes, appendices and tonsils, together with smears of immunologically separated peripheral lymphoid cells from a B-CLL and lymphomatous cells from an immunocytoma were submitted to combined enzyme cytochemical investigations with acid alpha-naphthyl acetate esterase (ANAE), beta-glucuronidase (B-G), acid phosphatase (AcPh), adenosine triphosphatase (ATPase), a,d 5'nucleotidase (5'N). T-cells were Acph+, ATPase- and 5'N-. The vast majority of T- and B-cells displayed ANAE and B-G activities with two distinct staining patterns (T-like and B-like pattern). A high proportion of lymphoid cells in the germinal centre (G.C.) and the vast majority of lymphoid cells in the mantle-zone (M.Z.) were shown to belong to B-cell system because of the expression of ATPase and 5'N in their membranes. Some lymphoid cells positive for ANAE and B-G with a B-like pattern and for AcPh were recognizable in the G.C. In the M.Z. only a few lymphoid cells being ANAE+, with a T-like pattern, and AcPh+ were shown to belong to the T-cell system. In contrast, in this zone a high proportion of small lymphoid cells (64% +/- 10%) showed ANAE activity, mostly with B-like pattern. Therefore, these findings indicate that in the M.Z. a high proportion of B-cells ATPase+ and 5'N+ also display ANAE activity. By comparison of the results obtained from lymphoid tissue sections, B-CLL and immunocytoma cell suspensions and normal circulating lymphocytes we can conclude that B-ANAE-positive cells of the M.Z. do not usually appear in the peripheral blood. They circulate in large numbers only in some pathological conditions (like our reported B-CLL). Therefore, B-ANAE-positive lymphoid cells of the mantle, with a B-like staining pattern, include a wide range of subsets which exclude large lymphoid cells and plasma cells.
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PMID:Histochemical study on human germinal centre, mantle-zone and extra-follicular area lymphoid cell subpopulations. Immunological and cytochemical correlations with lymphomatous cells, peripheral normal and leukemic lymphocytes. 613 70

Normal fetal and postnatal thymuses, as well as thymuses from patients with myasthenia gravis (MG), were investigated by immunohistochemical and enzyme histochemical techniques and their morphology reviewed. Intrathymic B-cells, detected by ATPase activity, were found to be markedly increased in number in MG thymuses. They were scattered in the medulla and accumulated around the junctional and medullary vessels and Hassall's corpuscles (HCs). Large epithelial cells, singly or within HCs, were found to be unevenly distributed in the medulla of all the thymuses examined. The striated muscle-like nature of some of these cells was revealed by the presence of myoglobin in their cytoplasm. In myasthenics these cells and small developing HCs characteristically surrounded lymph follicles and were in direct contact with the expanded cap of the follicle mantle, without interposition of reticulin fibres. The close association of immune reactive foci (lymphoid follicles, junctional and medullary vessels, and HCs) with structures involved in autoimmune responses in the thymus (muscle-like and true myoid cells, HCs) strongly suggests that the autoimmune reactions against AChR (acetylcholine receptor) and other muscular components, which constitute the basic defects in myasthenia gravis, may begin in the thymus.
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PMID:Immunohistochemical and enzyme histochemical contributions to the problem concerning the role of the thymus in the pathogenesis of myasthenia gravis. 613 9

Actin, myosin and actin-binding protein have been identified in lymphoid cell lines of Null, B or T type of normal and malignant origin. The cells were fractionated into cytosol (Fraction 1), high KC1 extract (Fraction 2) and mainly membrane (Fraction 3). The distribution of the three contractile proteins and the ATPase activities of myosin and actomyosin in B lymphoblastoid normal and B-lymphoma malignant cell lines. Actomyosin-ATPase activity in the normal B line was much higher than it was in the Null B or T malignant lines examined. These results agree with the assumption that malignant transformation is accompanied by an impairment of the action of contractile proteins that leads to a decrease in motility.
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PMID:Actin, myosin and actin-binding protein in lymphoid cells from human normal and leukemic cell lines. 621 68

Using monoclonal antibodies on fresh frozen endoscopically obtained oesophageal biopsies the distribution of Langerhans cells, B lymphocytes, and various subpopulations of T lymphocytes was studied in the normal human oesophageal mucosa and in oesophagitis. Identification of the lymphocytes was carried out by an immunoperoxidase technique using OKT3 (antihuman T cell antibody), OKT4 (antihuman helper T cell antibody), OKT8 (antihuman cytotoxic T cell) and OKT10 (antihuman null cell antibody). Identification of the Langerhans cells was carried out using an ATPase stain and OKIa (Ia like antigen) and OKT6 (antihuman thymocyte). In the normal oesophageal epithelium cytotoxic T lymphocytes are found as well as Ia positive Langerhans cells. Helper T lymphocytes and B lymphocytes are present mainly in the lamina propria. In oesophagitis an increase in Langerhans cells and cytotoxic T lymphocytes within the epithelium is found. From these findings it can be concluded that the oesophagus contains a reticuloepithelial system as well as a lymphocytic population which are a part of the gut-associated lymphoid tissue.
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PMID:Lymphocytes and Langerhans cells in the human oesophageal epithelium. 641 48

Soluble human colon carcinoma extract(s) (SCE) were potent nonspecific inhibitors of lymphoproliferative responses to mitogens. Inhibition was concomitant with induction in about 35% of cells of morphologic alterations for most of them comparable with the ones observed in mitogen-induced blast cells. Nonetheless, these blastlike cells did not proliferate. SCE did not interfere with mitogen binding to cell receptors. Moreover, SCE was unable to induce or activate suppressor cells, and its primary target cell was the unresponsive lymphoid cell itself. The inhibitory effect of SCE was early and irreversible. The differential activity of SCE can be correlated with an early [3H]uridine uptake, which was inhibited 6 hours later, as seen for the other biochemical parameters of cell activation. Also, SCE altered membrane-bound ATPase activities. Na,K-ATPase was strongly inhibited, whereas Ca2+-dependent and Mg2+-dependent ATPases were stimulated. These observations were discussed as an SCE-lymphocyte plasma membrane interaction translated into differential signals to the intracellular metabolic pathways.
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PMID:Nonspecific inhibitory activity of soluble human colon carcinoma extracts: tentative mechanism of action. 645 70

Mesenteric lymphadenectomy in rats is followed by union of peripheral and central lymphatics, allowing the collection of intestine-derived peripheral lymph cells via the thoracic duct for several days. These cells include a proportion of nonlymphoid cells (NLC) that show irregular and heterogeneous surface morphology including long pseudopodia and veils. They stain variably for nonspecific esterase and acid phosphatase and are ATPase-positive. Their nuclei are irregular and some contain cytoplasmic inclusions, some of which show peroxidase activity and/or contain DNA. NLC have a range of densitites generally lower than that of lymphocytes. Freshly collected NLC express the leukocyte-common antigen (defined by monoclonal antibody MRC Ox 1) and Ia antigens (I-A and I-E subregion products defined by monoclonal antibodies) but they show a relative lack of other surface markers normally found on rat B or T lymphocytes (W3/13, W3/25, MRC Ox 12 (sIg), MRC Ox 19) or rat macrophages (FcR, C'R, mannose R, W3/25). In general NLC are only weakly adherent to glass or plastic. Although a subpopulation of NLC appear to have had a phagocytic past, freshly collected NLC fail to phagocytose a variety of test particles in vitro. NLC also appear incapable of pinocytosis in vitro. This heterogeneity may represent distinct subpopulations of NLC or different stages in the development of a single cell lineage. Direct cannulation of mesenteric lacteals shows that the majority of NLC are derived from the small intestine and their precursors appear to be present both in lamina propria and Peyer's patches. Kinetic studies, following irradiation or intravenous tritiated thymidine, show that the majority of NLC turn over rapidly in the intestine with a modal time of 3-5 d. Studies with bone marrow chimeras show that they are derived from a rapidly dividing precursor present in normal bone marrow. NLC occur at very low frequencies in normal thoracic duct lymph at all times following cannulation. The evidence presented suggests that NLC closely resemble mouse lymphoid dendritic cells. This conclusion is supported by evidence already obtained showing that NLC are potent stimulators of the semi-allogeneic rat primary mixed leukocyte reaction. In addition to the ceils resembling dendritic cells rare monocytoid cells are found in thoracic duct lymph of lymphadenectomized specific pathogen-free rats. The proportion of these cells increases greatly when the animals are conventionally housed. It seems probable that the physiological function of NLC is to act as accessory cells in the lymph nodes to which they normally drain. Methods for enriching NLC and thus facilitating analysis of their functions are discussed.
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PMID:Characterization of nonlymphoid cells derived from rat peripheral lymph. 685 8

Plasma membranes were isolated from lymphoid cells of benign thymomas obtained from inbred BUF/Mna rats (21 mo old) and from normal thymocytes obtained from young rats (7 wk old) of the same strain. The isolated plasma membranes were electron microscopically pure, and the specific activities of Na+, K+-ATPase, and 5'-nucleotidase were enhanced. The lipid compositions of the plasma membranes from these two sources were analyzed and compared. The cholesterol and plasmalogen contents of membranes from both sources were similar, but the phospholipid content of the benign thymoma lymphoid cell membranes was slightly lower than that of the normal thymocytes, resulting in a somewhat higher molar ratio of cholesterol to phospholipid. The plasma membranes of the thymoma lymphoid cells also exhibited a slightly higher microviscosity as measured with fluorescence polarization. No significant differences were observed in the phospholipid compositions of the two membrane preparations.
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PMID:Lipid analysis of isolated plasma membranes of lymphoid cells in benign thymomas of Buffalo/Mna rats. 693 30


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