scholarly journals An inhibitor of animal cell growth increases cell-to-cell adhesion.

1981 ◽  
Vol 91 (3) ◽  
pp. 855-859 ◽  
Author(s):  
R J Mannino ◽  
K Ballmer ◽  
D Zeltner ◽  
M M Burger
Keyword(s):  
Cell Adhesion ◽  
Cell Growth ◽  
Cell Surface ◽  
Concanavalin A ◽  
Animal Cell ◽  
Cell Movement ◽  
Transformed Cells ◽  
Con A ◽  
Cell Densities ◽  
Cell To Cell Adhesion

The interactions of both normal and transformed cells with their environment is mediated to a large extent by the cell surface. Succinylated concanavalin A (succinyl-Con A) is a nontoxic and nonagglutinating derivative of the jack-bean lectin concanavalin A. Succinyl-Con A, presumably through an interaction with the cell surface, reversibly inhibits the growth of normal cells and restores a normal growth phenotype to transformed cells. Whereas at high cell densities migration was inhibited, it turned out that at low cell densities where cells are not in contact with each other, cell movement was not affected by succinyl-Con A. Together with some additional observations, this suggests that this lectin derivative increases cell-to-cell adhesion in culture and thereby may influence cell migration. An increase in cell-to-cell adhesion by this lectin derivative may not be brought about simply by physically linking cells together. It occurs after a lag time, possibly by inducing surface changes. The relationship between cell adhesion in culture, cell movement, and cell growth is discussed.

Regulation of epithelial and lymphocyte cell adhesion by adenosine deaminase–CD26 interaction

2002 ◽  
Vol 361 (2) ◽  
pp. 203-209 ◽  
Author(s):  
Silvia GINÉS ◽  
Marta MARIÑO ◽  
Josefa MALLOL ◽  
Enric I. CANELA ◽  
Chikao MORIMOTO ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Adhesion ◽  
T Cell ◽  
B Cells ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cell Surface ◽  
Adenosine Deaminase ◽  
Cell To Cell Adhesion ◽  
Lymphocyte Cell

The extra-enzymic function of cell-surface adenosine deaminase (ADA), an enzyme mainly localized in the cytosol but also found on the cell surface of monocytes, B cells and T cells, has lately been the subject of numerous studies. Cell-surface ADA is able to transduce co-stimulatory signals in T cells via its interaction with CD26, an integral membrane protein that acts as ADA-binding protein. The aim of the present study was to explore whether ADA—CD26 interaction plays a role in the adhesion of lymphocyte cells to human epithelial cells. To meet this aim, different lymphocyte cell lines (Jurkat and CEM T) expressing endogenous, or overexpressing human, CD26 protein were tested in adhesion assays to monolayers of colon adenocarcinoma human epithelial cells, Caco-2, which express high levels of cell-surface ADA. Interestingly, the adhesion of Jurkat and CEM T cells to a monolayer of Caco-2 cells was greatly dependent on CD26. An increase by 50% in the cell-to-cell adhesion was found in cells containing higher levels of CD26. Incubation with an anti-CD26 antibody raised against the ADA-binding site or with exogenous ADA resulted in a significant reduction (50–70%) of T-cell adhesion to monolayers of epithelial cells. The role of ADA—CD26 interaction in the lymphocyte—epithelial cell adhesion appears to be mediated by CD26 molecules that are not interacting with endogenous ADA (ADA-free CD26), since SKW6.4 (B cells) that express more cell-surface ADA showed lower adhesion than T cells. Adhesion stimulated by CD26 and ADA is mediated by T cell lymphocyte function-associated antigen. A role for ADA—CD26 interaction in cell-to-cell adhesion was confirmed further in integrin activation assays. FACS analysis revealed a higher expression of activated integrins on T cell lines in the presence of increasing amounts of exogenous ADA. Taken together, these results suggest that the ADA—CD26 interaction on the cell surface has a role in lymphocyte—epithelial cell adhesion.

Adhesion of Phytophthora palmivora zoospores: detection and ultrastructural visualization of concanavalin A-receptor sites appearing during encystment

1975 ◽  
Vol 19 (1) ◽  
pp. 11-20
Author(s):  
V.O. Sing ◽  
S. Bartnicki-Garcia
Keyword(s):  
Electron Microscopy ◽  
Cell Surface ◽  
Concanavalin A ◽  
Solid Surfaces ◽  
Trypsin Digestion ◽  
Phytophthora Palmivora ◽  
Con A ◽  
Binding Material ◽  
Ultraviolet Microscopy ◽  
Receptor Sites

The binding of concanavalin A (Con A) to the cell surface of zoospores and cysts of Phytophthora palmivora was studied by radiometry (125I-Con A), ultraviolet microscopy (fluorescein-Con A) and electron microscopy peroxidase-diaminobenzidine technique). Zoospores were found to secrete during the early stages of encystment a Con A-binding material susceptible to trypsin digestion. This glycoprotein is contained in the so-called peripheral vesicles and is probably responsible for the adhesion of the encysting zoospores to solid surfaces.

scholarly journals Distribution of concanavalin A binding sites on the surface of dissociated rat submandibular gland acinar cells.

1975 ◽  
Vol 23 (8) ◽  
pp. 607-617 ◽  
Author(s):  
T Amakawa ◽  
T Barka
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Surface ◽  
Concanavalin A ◽  
Binding Sites ◽  
Lectin Binding ◽  
Single Cells ◽  
Apical Cell ◽  
Acinar Cells ◽  
Con A ◽  
Dissociated Cells

The submandibular glands of 4-week-old rats were dissociated by a procedure involving digestions with collagenase and hyaluronidase, chelation of divalent cations and mechanical force. A suspension of single cells was obtained in low yield by centrifugation in a Ficoll-containing medium. Immediately after dissociation and after a culture period of 16-18 hr the dissociated cells were tested for agglutinability by concanavalin A (Con A). Using ferritin (tfer)-conjugated Con A the lectin binding by the isolated acinar cells was also studied. The dissociated cells were agglutinated by low concentrations of Con A and bound Fer-Con A molecules on their entire surface without any indication of polarization of the cell membrane. There was a considerable cell to cell variation in the amount of Fer-Con A binding which was, in general, sparse and patchy. The contact surfaces between agglutinated cells revealed a dense binding of Fer-Con A molecules irrespective of the types of cells participating in the agglutination reaction. Cells cultured for 16-18 hr were no longer agglutinated by Con A. As compared to the freshly dissociated cells the cultured acinar cells revealed a more uniform and denser binding of Fer-Con A molecules. Furthermore, there were more lectin molecules bound to the cell surface corresponding to the basal part of the cell, where the nucleus and most of the rough surface endoplasmic reticulum were located, than to the apical cell surface. It is suggested that the higher density of lectin-binding sites on the cell surface in the vicinity of the cisternae of the rough endoplasmic reticulum indicates insertion sites of newly synthesized membrane glycoproteins.

scholarly journals Studies on cell adhesion and recognition. II. The kinetics of cell adhesion and cell spreading on surfaces coated with carbohydrate-reactive proteins (glycosidases and lectins) and fibronectin.

1981 ◽  
Vol 88 (1) ◽  
pp. 138-148 ◽  
Author(s):  
W G Carter ◽  
H Rauvala ◽  
S I Hakomori
Keyword(s):  
Cell Adhesion ◽  
Cell Surface ◽  
Cell Attachment ◽  
Cell Spreading ◽  
Galactose Oxidase ◽  
Cross Linking ◽  
Con A ◽  
Coated Surfaces ◽  
Plastic Surfaces ◽  
Kinetics Of

The kinetics of cell attachment and cell spreading on the coated surfaces of two classes of carbohydrate-reactive proteins, enzymes and lectins, have been compared with those on fibronectin-coated surfaces with the following results: (a) A remarkable similarity between the kinetics of cell attachment to fibronectin-coated and glycosidase-coated surfaces was found. In contrast, cell attachment kinetics induced by lectin- and galactose oxidase-coated surfaces, in general, were strikingly different from those on fibronectin and glycosidase surfaces. The distinction between fibronectin- or glycosidase- and lectin- or galactose oxidase (an enzyme with lectin-type characteristics)-coated surfaces was further supported by the finding that cytochalasin B and EDTA inhibited cell attachment to fibronectin- and glycosidase-coated surfaces but not lectin-coated surfaces. (b) Fibronectin, if labeled and added to a cell suspension, showed only low or negligible interaction with the cell surface. However, fibronectin absorbed on plastic surfaces showed a high cell-attaching activity. It is assumed that fibronectin coated on plastic surfaces may form polyvalent attachment sites in contrast to its lower valency in aqueous solution. (c) Various inhibitors of cell attachment to both fibronectin-, galactose oxidase-, and lectin-coated surfaces were effective only during the first few minutes of the adhesion assay, after which time the attached cells became insensitive to the inhibitors. It is suggested that the initial specific recognition on either lectin-type or fibronectin-type surfaces is followed by an active cell-dependent attachment process. The primary role of the adhesion surface is to stimulate the cell-dependent attachment response. (d) Cells attached on tetravalent concanavalin A (Con A) spread very rapidly and quantitatively, whereas divalent succinyl Con A and monovalent Con A were effective stimulators of cell attachment but not cell spreading. Cross-linking of succinyl Con A restored the cell spreading activity. Tetravalent Con A surfaces specifically bind soluble glycoproteins, whereas succinyl Con A has a greatly reduced ability to bind the same glycoproteins. These results suggest that cross-linking of cell surface glycoproteins by the multivalent adhesive surface may trigger the cellular reaction leading to cell spreading.

scholarly journals Inhibition of cell movement and associated changes by hexachlorocyclohexanes due to unregulated intracellular calcium increases

Blood ◽  
1988 ◽  
Vol 71 (3) ◽  
pp. 677-683 ◽  
Author(s):  
SS Kaplan ◽  
UE Zdziarski ◽  
DB Kuhns ◽  
RE Basford
Keyword(s):  
Intracellular Calcium ◽  
Concanavalin A ◽  
Oxidative Metabolism ◽  
Polymorphonuclear Leukocyte ◽  
Cell Function ◽  
Cell Movement ◽  
Con A ◽  
Physiologic Responses

Abstract Hexachlorocyclohexanes (HCCHs) are potent stimulators of polymorphonuclear leukocyte (PMN) oxidative metabolism and of mobilization of calcium from intracellular stores. It was of interest, therefore, to evaluate the effect of HCCHs on PMN orientation and chemotaxis and to determine their effectiveness as chemotaxins. Chemotaxis was evaluated using micro-Boyden chambers, f-actin was quantitated by nitrobenzoxadiazole (NBD)-phallacidin fluorescence, and microtubules were quantitated by observing the concanavalin A (Con A) capping phenomenon. We also evaluated changes in intracellular calcium [Ca2+]i using quin 2 fluorescence. We found that the HCCH isomers were not chemotaxins and that the HCCH isomers that stimulated O2- formation (delta and gamma HCCH) inhibited chemotaxis. This effect was associated with inhibition of orientation. In addition, we found extensive inhibition of both f-actin and Con A cap formation. These effects of HCCH on cell function were associated with marked increases of [Ca2+]i. This work suggests that non-receptor-mediated increases of [Ca2+]i associated with HCCH have divergent effects on cell function and suggests that physiologic responses of PMNs requiring cytoskeletal alterations, such as chemotaxis, depend on the controlled responses of receptor-mediated stimulation.

Cell Agglutination Mediated by Concanavalin A and the Dynamic State of the Cell Surface

1974 ◽  
Vol 14 (1) ◽  
pp. 197-202
Author(s):  
M. INOUE
Keyword(s):  
Cell Surface ◽  
Concanavalin A ◽  
Binding Sites ◽  
Dynamic Condition ◽  
Dynamic State ◽  
Con A ◽  
Cell Agglutination ◽  
Surface Receptors ◽  
Topographical Distribution ◽  
Ehrlich Ascites Tumour

The binding of 131I-labelled concanavalin A (131I-Con A) to the cell surface has been studied in Ehrlich ascites tumour cells (EATC) and beef erythrocytes under various conditions. The binding of concanavalin A (Con A) to the cell surface was very specific and the available binding sites were saturated within a few minutes. The amount of 131I-Con A bound to EATC was 4.14 x 107 molecules/cell at 37 °C and 2.12 x 107 molecules/cell at 0 °C. Under these conditions, cell agglutination was observed only at 37 °C and not at 0 °C. However, the binding sites measured at 0 °C were also effective for agglutination at 37 °C. Beef erythrocytes were agglutinated by Con A only after treatment of cells with papain. The number of binding sites for Con A on the cell surface was decreased by this treatment to about half the number present on untreated cells. Various reagents such as colchicine, monoiodoacetic acid, dinitrophenol, rotenone, sodium azide and carboxyl cyanide-m-fluorophenylhydrazone (FCCP) had no effect on Con A-mediated cell agglutination. In contrast, periodate treatment produced a remarkable decrease in the agglutinability of cells. From these data, it is concluded that the cell agglutination induced by Con A was due to the topographical distribution of the surface receptors for the lectin, and not the result of energy-dependent or microtubule-dependent reaction processes. The number and the state of Con A receptors on the cell surface were in a dynamic condition, their conformation, orientation, and/or topographical distribution changing under different conditions.

Fimbrial-dependent mating inMicrobotryum violaceuminvolves a mannose–lectin interaction

1996 ◽  
Vol 42 (5) ◽  
pp. 461-466 ◽  
Author(s):  
Alan J. Castle ◽  
Nadia Stocco ◽  
Robert Boulianne
Keyword(s):  
Cell Adhesion ◽  
Concanavalin A ◽  
Smut Fungus ◽  
Mating Types ◽  
Carbohydrate Component ◽  
Microbotryum Violaceum ◽  
Anther Smut ◽  
Cell To Cell Adhesion ◽  
Fimbrial Protein ◽  
Dependent Mechanism

Fimbriae of the anther smut fungus, Microbotryum violaceum are polymers of six 74-kDa glycoprotein isoforms. Digestion of fimbrial monomers with α-mannosidase yielded two polypeptides with masses of 70 and 48 kDa. The 70-kDa polypeptide is probably a product of incomplete digestion and the 48-kDa polypeptide is the aglycone. Thus, most of the carbohydrate component of fimbrial protein is mannose. Previous observations have suggested that fimbriae are necessary for mating in M. violaceum. Further evidence for this role was obtained in the present study by showing that mating is inhibited by an anti-fimbrial protein antiserum, by mannose and related sugars glucose and arabinose, and by the lectin concanavalin A. Since inhibition was not complete, however, two mechanisms for adhesion between compatible cells were proposed, one fimbrial dependent and one independent. Lastly, fimbrial protein from a1but not a2mating types bound to a mannose–agarose column, suggesting a lectin-like capability. The fimbrial dependent mechanism of cell-to-cell adhesion may involve binding of the mannose residues of the fimbriae of a2cells by the fimbriae of a1cells.Key words: mating, Microbotryum violaceum, lectin, fimbriae.

scholarly journals LIGAND-INDUCED MOVEMENT OF LYMPHOCYTE MEMBRANE MACROMOLECULES

1972 ◽  
Vol 136 (4) ◽  
pp. 885-906 ◽  
Author(s):  
Emil R. Unanue ◽  
William D. Perkins ◽  
Morris J. Karnovsky
Keyword(s):  
Cell Surface ◽  
B Lymphocytes ◽  
Surface Antigen ◽  
Concanavalin A ◽  
Con A ◽  
Large Aggregate ◽  
Lymphocyte Membrane ◽  
Cell Surface Carbohydrate ◽  
Ultrastructural Radioautography ◽  
Spleen Lymphocytes

The fate of different complexes on the membrane of thymocytes and spleen lymphocytes was studied with the use of both immunofluorescence and ultrastructural radioautography. The complexes of anti-immunoglobulin (Ig) with the surface Ig of B lymphocytes were present all around the membrane at 4°C; an increase in temperature produced a rapid aggregation of the complex into a cap which was readily interiorized in vesicles. Ultrastructural details of this process were given. The movement of the complexes depended upon the amount of anti-Ig and the temperature. The complexes of anti-lymphocyte antibody with surface antigen(s) did not result in formation of a single large aggregate (or cap) unless an anti-antibody was brought into the reaction. The caps formed by this trilayered complex were not interiorized. Concanavalin A (Con A) bound to cell surface carbohydrate moieties and the complexes of Con A readily formed a cap and were interiorized. Finally, antibodies to H-2 determinants did not form in most instances a single cap aggregate even when anti-antibodies were used. With time the H-2 complexes tended to form several large aggregates with some endocytosis.

Ferritin-Conjugated Plant Agglutinins as Specific Stains for Cell Surface Saccharides

1971 ◽  
Vol 29 ◽  
pp. 536-537
Author(s):  
G. L. Nicolson ◽  
S. J. Singer
Keyword(s):  
Cell Surface ◽  
Concanavalin A ◽  
Room Temperature ◽  
Ultrastructural Localization ◽  
Final Concentration ◽  
Alkaline Ph ◽  
Con A ◽  
Specific Sugar

Plant agglutinins are proteins which bind to specific sugar ligands. For the ultrastructural localization of specific saccharides, we have now conjugated two different plant agglutinins with ferritin (Fer): concanavalin A (Con A), which binds specifically to sugars sterically related to D-glucose and D-mannose, and ricin (Ric), specific for sugars related to D-galactose and L-rhamnose.The conjugates Fer-Con A and Fer-Ric are prepared as follows. To a solution containing 8% Fer and 2.5% purified agglutinin in a buffer (SPB) containing 0.5M NaCl, 0.05M Na phosphate, pH 6.8, is added with stirring freshly distilled glutaraldehyde to a final concentration of 0.05%. Alkaline pH must be avoided to prevent aggregation of the agglutinins. After 45 min. at room temperature the mixture is dialyzed against SPB containing 0.1M NH4Cl. The Fer-agglutinins are centrifuged to remove large aggregates and finally chromatographically purified on Agarose A-1.5m (Fer-ConA) or Biogel P300 (Fer-Ric).

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