scholarly journals Identification of cell asymmetry and orientation by light scattering.

1977 ◽  
Vol 25 (7) ◽  
pp. 790-795 ◽  
Author(s):  
M R Loken ◽  
D R Parks ◽  
L A Herzenberg
Keyword(s):  
Light Scattering ◽  
Cell Surface ◽  
Blood Cells ◽  
Incident Beam ◽  
Model System ◽  
Forward Angle ◽  
Cell Orientation ◽  
Cell Asymmetry ◽  
Scatter System ◽  
Selection Of

Light scattering from chicken red blood cells has been used as a model system to identify the asymmetry of cells. The histogram for forward angle light scattering for these cells is bimodal, the signal size being dependent on the cell orientation. A dual orthogonal scatter system is used to conclusively demonstrate this orientational variation in signal. A third scattering system, using a single incident beam with two orthogonal detectors, is used to further characterize the orientational variation of the scatter signal. In this third system it is shown that the signal in a detector set 90 degrees from the incident beam collects light reflected from the cell surface. The optical selection of cells in specific orientations using these systems may circumvent the need to physically orient cell in flow systems.

Perfluorocarbon attenuates response of concanavalin A-stimulated mononuclear blood cells without altering ligand-receptor interaction

2004 ◽  
Vol 287 (1) ◽  
pp. L210-L216 ◽  
Author(s):  
Dirk Haufe ◽  
Thomas Luther ◽  
Matthias Kotzsch ◽  
Lilla Knels ◽  
Thea Koch
Keyword(s):  
Cell Surface ◽  
Concanavalin A ◽  
Blood Cells ◽  
Cell Activation ◽  
Receptor Interaction ◽  
Surface Binding ◽  
Cellular Activation ◽  
Flow Cytofluorometry ◽  
Anti Inflammatory ◽  
Mononuclear Blood Cells

Intrapulmonary application of perfluorocarbons (PFC) in acute lung injury is associated with anti-inflammatory effects. A direct impact on leukocytic function may be involved. To further elucidate PFC effects on cellular activation, we compared in an in vitro model the response of concanavalin A (ConA)-stimulated lymphocytes and monocytes exposed to perfluorohexane. We hypothesized that perfluorohexane attenuates the action of the lectin ConA by altering stimulant-receptor interaction on the cell surface. Mononuclear blood cells were stimulated by incubation with ConA in the presence of different amounts of perfluorohexane. The response of lymphocytes and monocytes was determined by means of IL-2 secretion and tissue factor (TF) expression, respectively. The influence of perfluorohexane on cell-surface binding of fluorescence-labeled ConA was studied using flow cytofluorometry and fluorescence microscopy. Perfluorohexane itself did not induce a cellular activation but significantly inhibited both monocytic TF expression and, to a far greater extent, IL-2 secretion of ConA-stimulated mononuclear blood cells. The effect of perfluorohexane was due neither to an alteration of cell viability nor to a binding of the stimulant. The amount of cell surface-bound ConA was not altered by perfluorohexane, and the overall pattern of ConA receptor rearrangement did not differ between controls and treated cells. In the present study, we provide further evidence for an anti-inflammatory effect of PFC that might be beneficial in states of pulmonary hyperinflammation. A PFC-induced alteration of stimulant-receptor interaction on the surface membrane does not seem to be the cause of attenuated cell activation.

Spike-shaped oscillations in the absence of measurable changes in cyclic AMP concentration in a mutant of Dictyostelium discoideum

1987 ◽  
Vol 87 (5) ◽  
pp. 723-730
Author(s):  
B. Wurster ◽  
R. Mohn
Keyword(s):  
Light Scattering ◽  
Cyclic Amp ◽  
Cell Surface ◽  
Dictyostelium Discoideum ◽  
Cyclic Gmp ◽  
Parent Strain ◽  
Reaction System ◽  
Cell Suspensions ◽  
Deficient Mutant ◽  
Cyclic Amp Synthesis

Periodic activities of Dictyostelium discoideum cells involve two types of oscillations, spike-shaped and sinusoidal. Spike-shaped oscillations are accompanied by the periodic synthesis and release of cyclic AMP, and cyclic AMP-activated cyclic AMP synthesis is believed to control these oscillations. Experiments described here call into question the importance of cyclic AMP in spike-shaped oscillations. Cell suspensions of strain agip43, an aggregation-deficient mutant of D. discoideum, displayed spike-shaped oscillations in light scattering with period lengths about 1.5 times larger than those of the parent strain. These oscillations were not accompanied by measurable oscillations of cyclic AMP and cyclic GMP. Applied cyclic AMP pulses elicited increases of two- to threefold in the cyclic AMP level and increases of seven- to ninefold in the cyclic GMP concentration. Cyclic AMP additions caused phase shifts in the oscillations of agip43 cells, suggesting that cyclic AMP receptors at the cell surface communicate with the oscillator. We interpret these results in terms of an oscillator not based on cyclic AMP. This oscillator should be coupled to the reaction system involving cyclic AMP synthesis and release. The latter can operate in an oscillatory manner in the parent strain Ax2 but not in mutant agip43.

Detection of islet cell surface antibodies by an indirect rosette assay, using islet cells and protein A-labeled sheep red blood cells

1984 ◽  
Vol 74 (1) ◽  
pp. 173-180 ◽  
Author(s):  
Shoji Maruyama ◽  
Masahiko Sugiura ◽  
Michio Nakazawa ◽  
Hiroko Tomiyama ◽  
Miyuki Shizawa ◽  
...  
Keyword(s):  
Cell Surface ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Islet Cell ◽  
Islet Cells ◽  
Protein A ◽  
Sheep Red Blood Cells ◽  
Islet Cell Surface Antibodies ◽  
Surface Antibodies

scholarly journals Mammalian cell surface display for monoclonal antibody-based FACS selection of viral envelope proteins

mAbs ◽  
2017 ◽  
Vol 9 (7) ◽  
pp. 1052-1064 ◽  
Author(s):  
Tim-Henrik Bruun ◽  
Veronika Grassmann ◽  
Benjamin Zimmer ◽  
Benedikt Asbach ◽  
David Peterhoff ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Cell Surface ◽  
Mammalian Cell ◽  
Surface Display ◽  
Cell Surface Display ◽  
Envelope Proteins ◽  
Viral Envelope ◽  
Selection Of ◽  
Viral Envelope Proteins

Chemotaxis-associated properties of separated prestalk and prespore cells of Dictyostelium discoideum

1986 ◽  
Vol 64 (8) ◽  
pp. 722-732 ◽  
Author(s):  
J. D. Mee ◽  
D. M. Tortolo ◽  
M. B. Coukell
Keyword(s):  
Light Scattering ◽  
Cell Surface ◽  
Dictyostelium Discoideum ◽  
Binding Sites ◽  
Large Fraction ◽  
Cell Types ◽  
The Other ◽  
Deficient Mutant ◽  
Camp Phosphodiesterase ◽  
Intracellular Cgmp

During development, prestalk and prespore cells of Dictyostelium discoideum become organized in multicellular structures. This physical association makes it difficult to characterize the two cell types biochemically and physiologically. In the present study, we have separated prestalk and prespore cells from 16-h slugs by the method of Tsang and Bradbury and have examined a number of chemotaxis-associated properties of these cells. When assayed on phosphate-buffered agar under both gradient and nongradient conditions, isolated prestalk cells responded chemotactically to cAMP and, unexpectedly, to folate and certain folate derivatives. In contrast, separated prespore cells failed to respond appreciably to any of these compounds. Neither prestalk nor prespore cells of strain HC91 exhibited a cAMP-induced increase in intracellular cGMP. However, a cGMP response was observed in both prestalk and prespore cells of strain NP368, a cGMP phosphodiesterase deficient mutant. Both cell types exhibited comparable cAMP-mediated light-scattering changes and possessed similar levels of surface cAMP- and folate-binding sites. On the other hand, prestalk cells had at least fourfold higher cAMP phosphodiesterase and folate deaminase activities than prespore cells, and a large fraction of both activities was on the cell surface. Therefore, the greater chemotactic response of prestalk cells to cAMP and folate on agar might be due, in part, to their increased capacity to generate a chemoattractant gradient. Results obtained in this study demonstrate that prestalk and prespore cells separated by this procedure can be used in certain physiological as well as biochemical experiments.

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