Cell hybridization and cell agglutination. I. Enhancement of cell hybridization by lectins

1985 ◽  
Vol 78 (1) ◽  
pp. 263-271
Author(s):  
Y. Matsuya ◽  
I. Yamane
Keyword(s):  
Polyethylene Glycol ◽  
Cell Fusion ◽  
Wheat Germ ◽  
Great Increase ◽  
Cell Hybridization ◽  
Cell Agglutination ◽  
Plant Lectins ◽  
Peg Treatment ◽  
A Cell ◽  
Conventional Cell

A great increase in hybridization frequency of cultured rodent cells was obtained when conventional cell fusion using 50% polyethylene glycol (PEG) was combined with a cell agglutination produced by plant lectins. The rate of appearance of hybrid colonies was found to be correlated with the extent of cell agglutination by lectin, as well as with cell fusion induced by subsequent PEG treatment. Phytohemagglutinin (PHA), wheat germ agglutinin, Wistaria floribunda agglutinin and concanavalin A were all active; the most effective was PHA. When parental cells in a monolayer were treated with PHA followed by PEG, the resulting hybridization frequency was very low because of markedly decreased viability, whereas the same cells in suspension yielded hybrid colonies at a higher rate. These results suggest that the enhancement of hybridization by PHA/PEG treatment was brought about by the ability of lectin to agglutinate cells.

scholarly journals Cell hybridization and cell agglutination. II. Enhancement of cell hybridization by polycations

1985 ◽  
Vol 78 (1) ◽  
pp. 273-282
Author(s):  
Y. Matsuya ◽  
I. Yamane
Keyword(s):  
Polyethylene Glycol ◽  
Cell Fusion ◽  
Mammalian Cells ◽  
Polyvinyl Pyrrolidone ◽  
Efficient Technique ◽  
Cell Hybridization ◽  
Cell Agglutination ◽  
Peg Treatment

An efficient technique for hybridization of mammalian cells was developed by combining agglutination by pretreatment with polycations, such as polyarginine, and conventional polyethylene glycol(PEG)-mediated cell fusion. Polyarginine and subsequent PEG treatment resulted in markedly decreased viability in the treated cells, but addition of polyvinyl pyrrolidone or glycerol to the polyarginine prevented this cytotoxicity. Polyarginine was much more effective than polylysine or polyornithine in inducing hybridization. Other polycations, including polybrene and protamine but not DEAE-dextran, were also active in inducing hybridization. The condition of the cells at the time of polycation treatment was an important factor in the enhancement of hybridization. The condition of the cells at the time of polycation treatment was an important factor in the enhancement of hybridization. The enhancement of hybridization of cells in monolayer incubated for 2 h was much higher than that of cells incubated for 24 h. These findings suggest that polycations do not necessarily operate by agglutinating cells. The mechanism of polycation-enhanced cell hybridization is discussed.

Studies of membrane fusion. III. Fusion of erythrocytes with polyethylene glycol

1979 ◽  
Vol 36 (1) ◽  
pp. 61-72
Author(s):  
S. Knutton
Keyword(s):  
Polyethylene Glycol ◽  
Cell Fusion ◽  
Close Contact ◽  
Freeze Fracture ◽  
Cell Swelling ◽  
Adjacent Cell ◽  
Cell Contact ◽  
Cell Agglutination ◽  
High Concentrations ◽  
Freeze Fracture Electron Microscopy

Freeze-fracture electron microscopy has been used to investigate the mechanism of polyethylene glycol-induced cell fusion. Interaction of cells with the high concentrations of polyethylene glycol required for cell fusion results in cell agglutination with large planar areas of very close contact between adjacent cell membranes. An aggregation of intramembrane particles into large patches at the sites of cell-cell contact accompanies cell agglutination. Fusion occurs following the removal of most of the PEG when cells only remain in close contact at small (approximately 0.1 micrometer diameter) plaques of smooth membrane resulting in cells connected by one (or more) small cytoplasmic connexions. Expansion to form spherical fused cells occurs by a process of cell swelling.

Discrimination of Two Fusogenic Properties of Aqueous Polyethylene Glycol Solutions

1981 ◽  
Vol 36 (7-8) ◽  
pp. 593-596 ◽  
Author(s):  
Hermann Krähling
Keyword(s):  
Polyethylene Glycol ◽  
Cell Line ◽  
Cell Fusion ◽  
Mammalian Cell ◽  
Dose Response ◽  
Cell Contact ◽  
Cell Shrinkage ◽  
Mammalian Cell Lines ◽  
A Cell ◽  
Free Membrane

Abstract Investigations on the dose response of cell fusion, induced by ionfree aqueous polyethylene glycol (PEG) solutions, reveal distinct lowest fusogenic PEG concentrations for different permanently growing mammalian cell lines. Part of the requisite PEG can be replaced by carbo­ hydrates, preserving the fusogenity of the solutions. This discriminates two effects of PEG solutions causing cell fusion: a) cell shrinkage, the required hyperosmolality of the solutions may be provided by PEG or by carbohydrates, is supposed to cause intracellular processes necessary for consolidating polycaryons; b) membrane alterations, which can not be induced by carbo­ hydrates, enable intimate cell-cell contact via particle-free membrane areas. Depending on cell line salts can not only raise the osmolality of PEG solutions but are able to co-operate with PEG in generating membrane alterations.

Membrane alterations and other morphological features associated with polyethylene glycol-induced cell fusion

1979 ◽  
Vol 40 (1) ◽  
pp. 63-75
Author(s):  
J.M. Robinson ◽  
D.S. Roos ◽  
R.L. Davidson ◽  
M.J. Karnovsky
Keyword(s):  
Polyethylene Glycol ◽  
Cell Surface ◽  
Membrane Fusion ◽  
Cell Fusion ◽  
Deleterious Effect ◽  
Freeze Fracture ◽  
Neighbouring Cell ◽  
Monolayer Cultures ◽  
Peg Treatment ◽  
Entire Cell

Polyethylene glycol (PEG) induces rapid fusion of LM cells. Membrane fusion, as detected by formation of pentalaminar membrane arrays, occurs as early as 1 min after PEG treatment. The entire cell surface arrears to be capable of fusion since fusion occurs in regions where pseudopodia make contact with each other or with a neighbouring cell body and also in areas where cells are in contact along their entire periphery. Cytoskeletal components showed no apparent deleterious effect from PEG treatment or subsequent cell fusion as determined by thin-section EM. Freeze-fracture of monolayer cultures reveals a thermotropic rearrangement of intramembranous particles following PEG treatment.

Polyethylene glycol-induced mammalian cell hybridization: Effect of polyethylene glycol molecular weight and concentration

1976 ◽  
Vol 2 (3) ◽  
pp. 271-280 ◽  
Author(s):  
Richard L. Davidson ◽  
Kathleen A. O'Malley ◽  
Thomas B. Wheeler
Keyword(s):  
Molecular Weight ◽  
Polyethylene Glycol ◽  
Mammalian Cell ◽  
Cell Hybridization ◽  
Hybridization Effect

Quantitative cell fusion: the fusion sensitivity (FS) potential

1981 ◽  
Vol 49 (1) ◽  
pp. 87-97
Author(s):  
D. Rohme
Keyword(s):  
Cell Line ◽  
Cell Fusion ◽  
Cell Lines ◽  
Dose Response ◽  
Sendai Virus ◽  
Biological Significance ◽  
Diploid Cell ◽  
Mammalian Cell Lines ◽  
Virus Dose ◽  
A Cell

The dose response of Sendai virus-induced cell fusion was studied in 10 mammalian cell lines, comprising 5 continuous and 5 diploid cell lines originating from 5 species. The extent of fusion was calculated using a parameter directly proportional to the number of fusion events (t-parameter). At lower levels of fusion the dose response was found to be based on the same simple kinetic rules in all cell lines and was defined by the formula: t = FS. FAU/(I + FS. FAU), where FS (fusion sensitivity) is a cell-specific constant of the fusion rate and FAU (fusion activity units) is the virus dose. The FS potential of a cell line was determined as the linear regression coefficient of the fusion index (t/(I - t)) on the virus dose. At higher levels of fusion, when the fusion extent reached cell-line-specific maximal levels, the dose response was not as uniform. In general, and particularly in the cases of the diploid cell lines, these maximal levels were directly proportional to the FS potentials. Thus, it was concluded that the FS potential is the basic quantitative feature, which expresses the cellular fusion efficiency. The fact that FS varied extensively between cell lines, but at the same time apparently followed certain patterns (being higher in continuous compared to diploid cell lines and being related to the species of origin of the cells), emphasizes it biological significance as well as its possible usefulness in studies of the efficiency of various molecular interactions in the cell membrane/cytoskeleton system.

Studies of membrane fusion. I. Paramyxovirus-induced cell fusion, a scanning electron-microscope study

1977 ◽  
Vol 28 (1) ◽  
pp. 179-188
Author(s):  
S. Knutton ◽  
D. Jackson ◽  
M. Ford
Keyword(s):  
Cell Surface ◽  
Cell Fusion ◽  
Hela Cells ◽  
Cell Swelling ◽  
Cell Contact ◽  
Cell Agglutination ◽  
Scanning Electron Microscope Study ◽  
Virus Particles ◽  
Scanning Electron ◽  
Cell Cell

Fusion of erythrocytes and HeLa cells with Sendai and Newcastle disease viruses has been studied by scanning electron microscopy. Most virus particles are spherical but vary in diameter from approximately 200 to approximately 600 nm. At 4 degrees C virus particles bind randomly to the cell surface and at high cell densities cross-linking of adjacent cells by virus particles results in cell agglutination. Cell-cell fusion takes place when the agglutinated cell suspension is warmed to 37 degrees C. Fusion is initiated at sites of cell-cell contact and is accompanied in all cases by cell swelling. In the case of suspension HeLa cells, virally mediated cell swelling involves an ‘unfolding’ of cell surface microvilli and results in the formation of smooth-surfaced single or fused cells. With erythrocytes, swelling results in haemolysis. There is a dramatic reduction in the numbers of virus particles bound to cells following fusion.

scholarly journals An analysis of lectin-initiated cell agglutination in a series of CHO subclones which respond morphologically to growth in dibutyryl cyclic AMP.

1976 ◽  
Vol 70 (1) ◽  
pp. 204-216 ◽  
Author(s):  
J van Veen ◽  
R M Roberts ◽  
K D Noonan
Keyword(s):  
Surface Membrane ◽  
Con A ◽  
Cell Agglutination ◽  
Lectin Receptors ◽  
Lectin Receptor ◽  
Free Mobility ◽  
Receptor Sites ◽  
Protein And Rna Synthesis ◽  
A Cell ◽  
Membrane Components

We have investigated the molecular basis of the agglutinability of CHO subclones which respond differentially in terms of morphology and surface architecture in the presence of dB-cAMP in the medium. We have demonstrated that the agglutinability of these subclones with both wheat germ agglutinin (WGA) and concanavalin A (Con A) probably depends on the free lateral mobility of the lectin receptor sites in the plane of the membrane. The nonagglutinable surface architecture seems to depend on the presence in the membrane of a protease-labile peptide(s), which appears to be distinct from the lectin receptors, as well as on continuous protein and RNA synthesis. This dependence on continuous transcription and translation may be related to the maintenance of the protease-labile peptide(s) in such a state as to restrict mobility of the lectin receptors. The surface architecture defined as nonagglutinable also depends on the state of polymerization of the intracellular microtubules and microfilaments. It is suggested that these microskeletal elements serve to anchor the lectin receptors in such a manner as to restrict their mobility and thereby reduce the relative agglutinability of a cell line. We suggest that control of the free mobility of both the Con A and WGA receptor sites is dependent on two constraints, one applied by protease-labile ("surface") membrane components and the other by components of the intracellular microskeletal system.

Estimation of the number of monoclonal hybridomas in a cell fusion experiment. Effect of post-fusion cell dilution on hybridoma survival

1981 ◽  
Vol 45 (2) ◽  
pp. 109-115 ◽  
Author(s):  
Angel L. De Blas ◽  
Makarand V. Ratnaparkhi ◽  
James E. Mosimann
Keyword(s):  
Cell Fusion ◽  
A Cell ◽  
Fusion Cell
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