scholarly journals Production of a monoclonal antibody against cell-surface glycoprotein of guinea pig adrenocortical cells.

1993 ◽  
Vol 41 (2) ◽  
pp. 235-243 ◽  
Author(s):  
Y Kameda ◽  
C Hirota
Keyword(s):  
Monoclonal Antibody ◽  
Sialic Acid ◽  
Cell Surface ◽  
Guinea Pig ◽  
Plasma Membranes ◽  
Surface Glycoprotein ◽  
Zona Fasciculata ◽  
Cell Surface Antigens ◽  
Adrenocortical Cells ◽  
Cell Surface Glycoprotein

A monoclonal antibody (MAb) that reacted with the cell-surface antigens of adrenocortical cells was generated against cell suspensions from guinea pig adrenal glands. Cell-surface membranes of the adrenocortical cells in all zones, i.e., zona glomerulosa, zona fasciculata, and zona reticularis, were labeled with the antibody. Adrenal medulla remained unlabeled. Immunoelectron microscopy showed that entire plasma membranes, i.e., plasma membranes between adjacent cells and free cell-surface membranes, including sinusoidal microvilli, were immunoreactive to the antibody. Immunoblot analysis demonstrated that the antibody bound to two prominent bands at molecular weights of approximately 62,000 and 110,000. Two bands were stained with lectin-digoxigenin conjugates. The 110 KD band reacted with Datura stramonium (DSA) and Maackia amurensis (MAA) agglutinins, indicating the presence of N-acetyl-glucosamine and sialic acid-linked alpha (2-3) to galactose; the 62 KD band reacted with SNA, indicating the presence of sialic acid-linked alpha (2-6) to galactose. In adrenocortical cells, the reaction pattern of Sambucus nigra (SNA) agglutinin was similar to that of the (MAb), whereas reaction patterns of DSA and MAA were different. Both neuraminidase digestion and prior absorption of the antibody with N-acetyl-neuraminic acid completely prevented the immunolabeling of adrenocortical cells. These results indicate that the MAb mainly recognizes the 2-6 sialylated cell-surface antigen of adrenocortical cells.

A new brain cell surface glycoprotein identified by monoclonal antibody

Neuroscience ◽  
1982 ◽  
Vol 7 (1) ◽  
pp. 239-250 ◽  
Author(s):  
M. Hirn ◽  
M. Pierres ◽  
H. Deagostini-Bazin ◽  
M.R. Hirsch ◽  
C. Goridis ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Cell Surface ◽  
Brain Cell ◽  
Surface Glycoprotein ◽  
Cell Surface Glycoprotein

scholarly journals CD47: A Cell Surface Glycoprotein Which Regulates Multiple Functions of Hematopoietic Cells in Health and Disease

2013 ◽  
Vol 2013 ◽  
pp. 1-19 ◽  
Author(s):  
Per-Arne Oldenborg
Keyword(s):  
Cell Surface ◽  
Intracellular Signaling ◽  
Plasma Membranes ◽  
Cell Activation ◽  
Regulatory Protein ◽  
Hematopoietic Cells ◽  
Surface Glycoprotein ◽  
Proper Function ◽  
Cell Surface Glycoprotein ◽  
Extracellular Milieu

Interactions between cells and their surroundings are important for proper function and homeostasis in a multicellular organism. These interactions can either be established between the cells and molecules in their extracellular milieu, but also involve interactions between cells. In all these situations, proteins in the plasma membranes are critically involved to relay information obtained from the exterior of the cell. The cell surface glycoprotein CD47 (integrin-associated protein (IAP)) was first identified as an important regulator of integrin function, but later also was shown to function in ways that do not necessarily involve integrins. Ligation of CD47 can induce intracellular signaling resulting in cell activation or cell death depending on the exact context. By binding to another cell surface glycoprotein, signal regulatory protein alpha (SIRPα), CD47 can regulate the function of cells in the monocyte/macrophage lineage. In this spotlight paper, several functions of CD47 will be reviewed, although some functions may be more briefly mentioned. Focus will be on the ways CD47 regulates hematopoietic cells and functions such as CD47 signaling, induction of apoptosis, and regulation of phagocytosis or cell-cell fusion.

scholarly journals Monoclonal antibody YB5.B8 identifies the human c-kit protein product

Blood ◽  
1991 ◽  
Vol 77 (9) ◽  
pp. 1876-1883 ◽  
Author(s):  
NB Lerner ◽  
KH Nocka ◽  
SR Cole ◽  
FH Qiu ◽  
A Strife ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Mast Cells ◽  
Cell Surface ◽  
Bone Marrow Cells ◽  
Protein Product ◽  
Surface Glycoprotein ◽  
Leukemic Cells ◽  
Acute Myelocytic Leukemia ◽  
Erythroid Progenitors ◽  
Cell Surface Glycoprotein

Abstract The c-kit proto-oncogene encodes a 145- to 160-Kd transmembrane tyrosine kinase, which is a member of the platelet-derived growth factor receptor family and is allelic with the murine white spotting locus (W). W mutations affect several aspects of hematopoiesis, most notably erythroid progenitors and mast cells. A monoclonal antibody, YB5.B8, had been raised against the leukemic blasts of a patient with M1-type acute myelocytic leukemia (AML) and it precipitates a 150-Kd cell surface glycoprotein from leukemic cells. The YB5.B8 epitope is expressed on mast cells, on up to 3% of normal mononuclear bone marrow cells, and it identifies a sub-group of AML patients with a poor prognosis. In view of similarities noted between the cell surface antigen identified by YB5.B8 and the c-kit protein product, we performed experiments to determine whether they are identical. c-kit RNA expression in the cell lines HEL (human erythroleukemia) and A172 (glioblastoma) was shown to parallel the expression of the YB5.B8 epitope in these lines as measured by flow cytometry. Immunoprecipitation analysis with anti-kit serum and YB5.B8 antibody indicated that the two antibodies identified proteins of identical size in HEL (155 Kd) and A172 (145 Kd) cells, and sequential immunoprecipitations with the kit and the YB5.B8 antibodies demonstrated that the two antibodies recognize the same molecule. The proteins identified by both the anti-kit and YB5.B8 antibodies displayed in vitro autophosphorylation activity in immune complex kinase assays. In addition, YB5.B8 was able to inhibit the binding of the kit ligand to HEL cells. These studies provide evidence that the YB5.B8 antigen and the c-kit protein product are identical and raise certain hypotheses regarding the role of c-kit in AML.

scholarly journals Rat Parotid Gland Acinar Cell Proliferation: Signal Transduction at the Plasma Membrane

1993 ◽  
Vol 4 (3) ◽  
pp. 537-543 ◽  
Author(s):  
K.R. Purushotham ◽  
Y. Nakagawa ◽  
M.G. Humphreys-Beher ◽  
N. Maeda ◽  
C.A. Schneyer
Keyword(s):  
Signal Transduction ◽  
Cell Proliferation ◽  
Cell Surface ◽  
Acinar Cell ◽  
Intracellular Signaling ◽  
Plasma Membranes ◽  
Surface Glycoprotein ◽  
Dependent Manner ◽  
Intact Cells ◽  
Cell Surface Glycoprotein

Galactosyltransferase (Gal Tase) is involved in a "receptor-ligand-type" interaction at the cell surface that mediates signal transduction following isoproterenol (ISO) treatment leading to acinar cell proliferation. Evidence is presented herein for the identification of the cell-surface glycoprotein signaling component. Using intact cells or isolated plasma membranes, the EGF-receptor (EGF-R) was specifically radiolabeled with [14C]-Galactose following ISO treatment. Injection of a polyclonal antibody monospecific for rat EGF-R also inhibited proliferation in a dose-dependent manner. The immunoaffinity purified receptor demonstrated altered lectin binding and increased in vitro Gal Tase substrate capacity following β-agonist treatment when compared with EGF-R isolated from control animals. When acinar cells were incubated in the presence of EGF, plasma membranes from control and ISO-treated animals showed autophosphorylation of EGF-R tyrosine moieties, transient increases in membrane associated phospholipase Cy, and increased cellular levels of cAMP. These properties of the tyrosine phosphate signaling pathway could be duplicated by the exogenous addition of bovine Gal Tase to ISO-treated cells but not control cells. The results suggest that cell surface Gal Tase interacts with a form of the EGF-R, having altered carbohydrate moieties to promote intracellular signaling for acinar cell proliferation.

scholarly journals High-efficiency expression gene cloning by flow cytometry.

1996 ◽  
Vol 44 (6) ◽  
pp. 629-640 ◽  
Author(s):  
R Dell'Arciprete ◽  
M Stella ◽  
M Fornaro ◽  
R Ciccocioppo ◽  
M G Capri ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Cell Surface ◽  
Gene Cloning ◽  
High Efficiency ◽  
Fluorescent Protein ◽  
Cesium Chloride ◽  
Surface Glycoprotein ◽  
Cell Surface Antigens ◽  
Cell Surface Glycoprotein ◽  
Co Precipitation

Our goal was to develop a convenient and widely applicable procedure for gene cloning based on flow cytometry. To this purpose, we have developed an efficient protocol for DNA transfection and selection of rare transfectants. Transfection by calcium phosphate co-precipitation was extensively investigated. The use of specific batches of calcium chloride, of carrier DNA purified in guanidinium thiocyanate, and of plasmid DNA banded in cesium chloride proved crucial for high efficiency of transfection. Several tissue culture parameters were also found critical. With the optimized procedure we can transfect almost 100% of the COS-7 cells with cDNA encoding cell surface antigens or green fluorescent protein. Moreover, we routinely obtain high average levels of expression. Efficient cell sorting in flow cytometry was achieved by subtracting the cell autofluorescence background, by displacing stained cells in the red dimension, and by combining fluorescein-conjugated primary and secondary antibodies. Efficient recovery of the transfected DNA constructs was obtained from 2500-3000 cells directly sorted in Hirt lysis buffer. Using the above protocol we have cloned by expression the gene encoding Trop-2, a cell surface glycoprotein expressed by human carcinomas.

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