scholarly journals The adherence of human neutrophils and eosinophils to schistosomula: evidence for membrane fusion between cells and parasites.

1980 ◽  
Vol 86 (1) ◽  
pp. 46-63 ◽  
Author(s):  
J P Caulfield ◽  
G Korman ◽  
A E Butterworth ◽  
M Hogan ◽  
J R David
Keyword(s):  
Plasma Membrane ◽  
Outer Membrane ◽  
Mammalian Cells ◽  
Surface Membrane ◽  
Freeze Fracture ◽  
Spatial Relationship ◽  
Hybrid Membrane ◽  
Human Neutrophils ◽  
Inner Membrane ◽  
Edge Zone

Human neutrophils and eosinophils adhere to the surface of schistosomula of Schistosoma mansoni that have been preincubated with antischistosomular sera with or without complement. Neutrophils are seen to form small (< 0.5 micrometer), heptalaminar and large (5-8 micrometer), pentalaminar fusions with the normal pentalaminar parasite surface membrane. By freeze-fracture techniques, attachment areas 5-8 micrometer in diameter are seen to form between neutrophils and schistosomula. These areas have three zones--an edge and two centrally located areas, one of which is rich and one of which is poor in intramembrane particles (IMPs). The edge zone is continuous around the attachment areas and is usually composed of a skip-fracture that passes out of the schistosomular outer membrane into the inner membrane. In some cases, the edge zone is made up of a string of IMPs. The IMP-rich central areas have an IMP concentration similar to that of unattached neutrophil membranes, are raised off of the surface of the schistosomulum, and have two normal schistosomular membranes underneath indicating that they are indeed unattached. the IMP-poor central areas are composed of a fused or hybrid membrane that is continuous with the neutrophil plasma membrane but that bears the same spatial relationship to the schistosomular inner membrane that the normal outer membrane does. Similar changes are seen in samples prepared with glycerination. Eosinophils generally do not fuse with the schistosomular outer membrane but, instead, discharge their granular contents onto the surface of the schistosomula and appear to adhere to the parasite through this discharged material. It is suggested that schistosomula have a capability to fuse with mammalian cells and that this fusion proceeds from a fusion of the outer leaflets to a fusion of the bilayers, as appears also to be the case in other systems.

Freeze-fracture studies of frog atrial fibres

1976 ◽  
Vol 22 (2) ◽  
pp. 427-434
Author(s):  
F. Mazet ◽  
J. Cartaud
Keyword(s):  
Gap Junctions ◽  
Gap Junction ◽  
Outer Membrane ◽  
Electrical Coupling ◽  
Freeze Fracture ◽  
Present Knowledge ◽  
Inner Membrane ◽  
Freeze Fracturing ◽  
Morphological Variant ◽  
Characteristic Features

The freeze-fracturing technique was used to characterize the junctional devices involved in the electrical coupling of frog atrial fibres. These fibres are connected by a type of junction which can be interpreted as a morphological variant of the “gap junction” or “nexus”. The most characteristic features are rows of 9-nm junctional particles forming single or anastomosed circular profiles on the inner membrane face, and corresponding pits on the outer membrane face. Very seldom aggregates consisting of few geometrically disposed 9-nm particles are found. The significance of the junctional structures in the atrial fibres is discussed, with respect to present knowledge about junctional features of gap junctions in various tissues, including embryonic ones.

scholarly journals Surface membrane vesicles from mononuclear cells stimulate erythroid stem cells to proliferate in culture

Blood ◽  
1982 ◽  
Vol 60 (3) ◽  
pp. 583-594 ◽  
Author(s):  
N Dainiak ◽  
CM Cohen
Keyword(s):  
Plasma Membrane ◽  
Plasma Membranes ◽  
Mononuclear Cells ◽  
Surface Membrane ◽  
Freeze Fracture ◽  
Membrane Vesicles ◽  
Cell Types ◽  
Target Cells ◽  
Freeze Fracture Electron Microscopy

Abstract In order to examine the contribution of cell surface materials to erythroid burst-promoting activity (BPA), we separated media conditioned by a variety of human cell types into pellets and supernatants by centrifugation. When added to serum-restricted cultures of nonadherent human marrow cells, pellets contained about half of the total stimulatory activity. Freeze-fracture electron microscopy of the pellets revealed the presence of unilamellar membrane vesicles ranging from 0.10 to 0.40 microM in diameter. The amount of BPA in culture increased with added vesicle concentration in a saturable fashion. Preparation of leukocyte conditioned medium (LCM) from 125I-wheat germ agglutinin labeled cells and studies comparing the glycoprotein composition of vesicles with that of leukocyte plasma membranes suggest that LCM-derived vesicles are of plasma membrane origin. Moreover, partially purified leukocyte plasma membrane preparations also contained BPA. While disruption of vesicles by freezing/thawing and hypotonic lysis did not alter BPA, heat, trypsin, or pronase treatment removed greater than 65% of BPA, implying that vesicle surface rather than intravesicular molecules express BPA. Results of BPA assays performed in two-layer clots indicated that proximity to target cells is required for vesicle BPA expression. We conclude that membrane vesicles spontaneously shed from cell surfaces may be important regulators of erythroid burst proliferation in vitro.

Rectilinear particle arrays in freeze-fracture replicas of the surface membrane of Paramecium tetraurelia

1986 ◽  
Vol 83 (1) ◽  
pp. 269-291
Author(s):  
R.R. Preston ◽  
T.M. Newman
Keyword(s):  
Plasma Membrane ◽  
Cell Surface ◽  
Surface Membrane ◽  
Freeze Fracture ◽  
Dorsal Surface ◽  
Surface Coat ◽  
Paramecium Tetraurelia ◽  
Intramembranous Particle ◽  
Logarithmic Growth Phase ◽  
Culture Cycle

Freeze-fracture replicas of the plasma membrane of unfixed, uncryoprotected Paramecium tetraurelia bear large rectilinear arrays of 11 nm particles arranged in 7–11 parallel rows. The arrays are of sufficient size to leave impressions in replicas of the underlying outer alveolar membrane, and are apparent as parallel ridges in replicas of the surface coat of deep-etched cells. By noting the location of arrays in replicas of identified portions of the cortex of P. tetraurelia, it has been possible to map the distribution of arrays over the cell surface. The arrays are found primarily over the anterior surfaces of the cell, covering an area that extends from the preoral suture over the left adoral field and a large portion of the anterior dorsal surface. Freeze-fracture analyses of cells taken from a number of different stages of a culture cycle suggest that the particle arrays are not replicated as an integral part of the cortex during cell division, but are assembled and oriented in the membrane as the cells mature. The appearance of small intramembranous particle complexes in the plasma membrane of cells in logarithmic growth phase supports this hypothesis, possibly representing an assembly stage in the formation of the larger particle arrays. The facts that the particle arrays are apparent in replicas of the surface coat of cells, are found primarily at the anterior of the cell body, and have a highly specific orientation with respect to the cell surface, strongly suggest that they function as chemoreceptors in P. tetraurelia.

scholarly journals Evidence for small intracellular vesicles in human blood phagocytes containing cytochrome b558 and the adhesion molecule CD11b/CD18

Blood ◽  
1993 ◽  
Vol 81 (11) ◽  
pp. 3122-3129 ◽  
Author(s):  
J Calafat ◽  
TW Kuijpers ◽  
H Janssen ◽  
N Borregaard ◽  
AJ Verhoeven ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Density Gradient ◽  
Whole Blood ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Surface Membrane ◽  
Ultrastructural Level ◽  
Human Neutrophils ◽  
Cytochrome B558 ◽  
Intracellular Vesicles

Human neutrophils contain a rapidly mobilizable pool of so-called secretory vesicles distinct from the azurophil granules and specific granules. Using human albumin as a marker for these intracellular vesicles in immuno-electron microscopy, we found that part of the cytochrome b558 in non-purified whole blood neutrophils colocalized in these vesicles. This was detected with monoclonal antibody (MoAb) CLB- 48, binding to the high molecular weight subunit of cytochrome b558. Approximately 65% of the albumin-containing vesicles showed MoAb CLB-48 labeling. This was also found in eosinophilic granulocytes and in monocytes. Cytofluorimetric determination of cytochrome b558 expression on the plasma membrane of intact, nonpurified granulocytes (and monocytes) with MoAb 7D5, which is directed against an extracellular epitope of cytochrome b558, did not show any binding. However, granulocytes (and monocytes) significantly bound 7D5 after density centrifugation. The positive binding of 7D5 to purified neutrophilic granulocytes correlated with a strongly reduced labeling of cytochrome b558 in the albumin-positive vesicles. Binding of CD11b MoAb CLB-B2.12 to the alpha subunit of the complement receptor type 3 (CR3) on the surface of intact, nonpurified neutrophils was detected to a limited extent in whole blood samples, but was strongly increased upon density gradient centrifugation of the cells, as we have described before. Investigation at the ultrastructural level showed that the CD11b antigen codistributed with albumin in vesicular structures in nonpurified phagocytes, especially in neutrophils and eosinophils. Together, these data substantiate the idea of an intracellular store that can be easily mobilized (even under the simple stress condition of density gradient centrifugation). Such mobilization may result in the expression of cytochrome b558 on the plasma membrane, as was indicated in this study. Apart from cytochrome b558, several other surface membrane molecules, as we show here for the integrin CD11b/CD18 (CR3), are probably also located in these rapidly mobilizable intracellular vesicles.

scholarly journals Evidence for small intracellular vesicles in human blood phagocytes containing cytochrome b558 and the adhesion molecule CD11b/CD18

Blood ◽  
1993 ◽  
Vol 81 (11) ◽  
pp. 3122-3129 ◽  
Author(s):  
J Calafat ◽  
TW Kuijpers ◽  
H Janssen ◽  
N Borregaard ◽  
AJ Verhoeven ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Density Gradient ◽  
Whole Blood ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Surface Membrane ◽  
Ultrastructural Level ◽  
Human Neutrophils ◽  
Cytochrome B558 ◽  
Intracellular Vesicles

Abstract Human neutrophils contain a rapidly mobilizable pool of so-called secretory vesicles distinct from the azurophil granules and specific granules. Using human albumin as a marker for these intracellular vesicles in immuno-electron microscopy, we found that part of the cytochrome b558 in non-purified whole blood neutrophils colocalized in these vesicles. This was detected with monoclonal antibody (MoAb) CLB- 48, binding to the high molecular weight subunit of cytochrome b558. Approximately 65% of the albumin-containing vesicles showed MoAb CLB-48 labeling. This was also found in eosinophilic granulocytes and in monocytes. Cytofluorimetric determination of cytochrome b558 expression on the plasma membrane of intact, nonpurified granulocytes (and monocytes) with MoAb 7D5, which is directed against an extracellular epitope of cytochrome b558, did not show any binding. However, granulocytes (and monocytes) significantly bound 7D5 after density centrifugation. The positive binding of 7D5 to purified neutrophilic granulocytes correlated with a strongly reduced labeling of cytochrome b558 in the albumin-positive vesicles. Binding of CD11b MoAb CLB-B2.12 to the alpha subunit of the complement receptor type 3 (CR3) on the surface of intact, nonpurified neutrophils was detected to a limited extent in whole blood samples, but was strongly increased upon density gradient centrifugation of the cells, as we have described before. Investigation at the ultrastructural level showed that the CD11b antigen codistributed with albumin in vesicular structures in nonpurified phagocytes, especially in neutrophils and eosinophils. Together, these data substantiate the idea of an intracellular store that can be easily mobilized (even under the simple stress condition of density gradient centrifugation). Such mobilization may result in the expression of cytochrome b558 on the plasma membrane, as was indicated in this study. Apart from cytochrome b558, several other surface membrane molecules, as we show here for the integrin CD11b/CD18 (CR3), are probably also located in these rapidly mobilizable intracellular vesicles.

scholarly journals Surface membrane vesicles from mononuclear cells stimulate erythroid stem cells to proliferate in culture

Blood ◽  
1982 ◽  
Vol 60 (3) ◽  
pp. 583-594
Author(s):  
N Dainiak ◽  
CM Cohen
Keyword(s):  
Plasma Membrane ◽  
Plasma Membranes ◽  
Mononuclear Cells ◽  
Surface Membrane ◽  
Freeze Fracture ◽  
Membrane Vesicles ◽  
Cell Types ◽  
Target Cells ◽  
Freeze Fracture Electron Microscopy

In order to examine the contribution of cell surface materials to erythroid burst-promoting activity (BPA), we separated media conditioned by a variety of human cell types into pellets and supernatants by centrifugation. When added to serum-restricted cultures of nonadherent human marrow cells, pellets contained about half of the total stimulatory activity. Freeze-fracture electron microscopy of the pellets revealed the presence of unilamellar membrane vesicles ranging from 0.10 to 0.40 microM in diameter. The amount of BPA in culture increased with added vesicle concentration in a saturable fashion. Preparation of leukocyte conditioned medium (LCM) from 125I-wheat germ agglutinin labeled cells and studies comparing the glycoprotein composition of vesicles with that of leukocyte plasma membranes suggest that LCM-derived vesicles are of plasma membrane origin. Moreover, partially purified leukocyte plasma membrane preparations also contained BPA. While disruption of vesicles by freezing/thawing and hypotonic lysis did not alter BPA, heat, trypsin, or pronase treatment removed greater than 65% of BPA, implying that vesicle surface rather than intravesicular molecules express BPA. Results of BPA assays performed in two-layer clots indicated that proximity to target cells is required for vesicle BPA expression. We conclude that membrane vesicles spontaneously shed from cell surfaces may be important regulators of erythroid burst proliferation in vitro.

scholarly journals Similarity of junctions between plasma membranes and endoplasmic reticulum in muscle and neurons.

1976 ◽  
Vol 70 (2) ◽  
pp. 338-347 ◽  
Author(s):  
M Henkart ◽  
D M Landis ◽  
T S Reese
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Plasma Membranes ◽  
Surface Membrane ◽  
Freeze Fracture ◽  
Cerebellar Neurons ◽  
Membrane Specialization ◽  
Large Particles ◽  
Subsurface Cisterns ◽  
Particle Aggregates

The structure of membranes at junctions between the plasma membrane and underlying cisterns of endoplasmic reticulum in amphioxus muscle and mouse cerebellar neurons was studied using the freeze-fracture technique. In amphioxus muscle, subsurface cisterns of sarcoplasmic reticulum form junctions with the surface membrane at the level of the sarcomere I bands. On the protoplasmic leaflet of the sarcolemma overlying these junctions were aggregates of large particles. On the protoplasmic leaflet of the membranes of cerebellar basket, stellate and Purkinie cells there were similar aggregates of large particles. In both tissues, the corresponding external membrane halves had arrays of pits apparently complementary to the aggregates of large particles. Cross fractures through junctions showed that the particle aggregates in neuronal and muscle membranes were consistently located over intracellular cisterns closely applied to the plasma membrane. Thus, a similar plasma membrane specialization is found at subsurface cisterns in mammalian neurons and amphioxus muscle. This similarity supports the hypothesis that subsurface cisterns in neurons, like those in muscle, couple some intracellular activity to the electrical activity of the plasma membrane.

scholarly journals Freeze-fracture of membrane fusions during exocytosis in pancreatic B-cells.

1977 ◽  
Vol 75 (1) ◽  
pp. 23-30 ◽  
Author(s):  
L Orci ◽  
A Perrelet ◽  
D S Friend
Keyword(s):  
Plasma Membrane ◽  
B Cells ◽  
Secretory Granule ◽  
Mammalian Cells ◽  
Freeze Fracture ◽  
Total Clearance ◽  
Close Apposition ◽  
Fracture Appearance ◽  
Pancreatic B Cells ◽  
Glucose Stimulated Insulin Secretion

To examine the freeze-fracture appearance of membrane alterations at sites of exocytosis in mammalian cells, we studied the secretory granule and plasma membrane of rat pancreatic B-cells during glucose-stimulated insulin secretion. Constant features observed were the scarcity of particles in secretory-granule P-fracture faces and the almost total clearance of intramembranous particles in P-and E fracture faces of the plasma membrane in areas of close apposition of these two membranes preceding fusion; also observed was the temporary persistence of particle-cleared regions after the fusion was completed. Our observations thus support the concept that membranes fuse at sites of closely apposed, particle-free regions and that the physiologically created clear areas found in freeze-fracture replicas of the plasma membrane are the hallmarks of incipient or recent membrane fusion.

Heterogeneity of Size and Distribution of Intramembrane Particles in the Plasma Membrane of Yeast

1977 ◽  
Vol 35 ◽  
pp. 596-597
Author(s):  
E. Keyhani
Keyword(s):  
Plasma Membrane ◽  
Candida Utilis ◽  
Synthetic Medium ◽  
Freeze Fracture ◽  
Translational Diffusion ◽  
Yeast Cells ◽  
Distilled Water ◽  
Intramembrane Particles ◽  
The Matrix ◽  
Water Cell

The matrix of biological membranes consists of a lipid bilayer into which proteins or protein aggregates are intercalated. Freeze-fracture techni- ques permit these proteins, perhaps in association with lipids, to be visualized in the hydrophobic regions of the membrane. Thus, numerous intramembrane particles (IMP) have been found on the fracture faces of membranes from a wide variety of cells (1-3). A recognized property of IMP is their tendency to form aggregates in response to changes in experi- mental conditions (4,5), perhaps as a result of translational diffusion through the viscous plane of the membrane. The purpose of this communica- tion is to describe the distribution and size of IMP in the plasma membrane of yeast (Candida utilis).Yeast cells (ATCC 8205) were grown in synthetic medium (6), and then harvested after 16 hours of culture, and washed twice in distilled water. Cell pellets were suspended in growth medium supplemented with 30% glycerol and incubated for 30 minutes at 0°C, centrifuged, and prepared for freeze-fracture, as described earlier (2,3).

Deformation of Yeast Plasma Membrane by Ethidium Bromide

1988 ◽  
Vol 46 ◽  
pp. 254-255
Author(s):  
E. Keyhani
Keyword(s):  
Plasma Membrane ◽  
Thin Section ◽  
Ethidium Bromide ◽  
Freeze Fracture ◽  
Mutagenic Effect ◽  
Yeast Cells ◽  
Hydrophobic Region ◽  
Thin Section Electron Microscopy ◽  
Section Electron ◽  
Deep Pits

The mutagenic effect of ethidium bromide on the mitochondrial DNA is well established. Using thin section electron microscopy, it was shown that when yeast cells were grown in the presence of ethidium bromide, besides alterations in the mitochondria, the plasma membrane also showed alterations consisting of 75 to 110 nm-deep pits. Furthermore, ethidium bromide induced an increase in the length and number of endoplasmic reticulum and in the number of intracytoplasmic vesicles.Freeze-fracture, by splitting the hydrophobic region of the membrane, allows the visualization of the surface view of the membrane, and consequently, any alteration induced by ethidium bromide on the membrane can be better examined by this method than by the thin section method.Yeast cells, Candida utilis. were grown in the presence of 35 μM ethidium bromide. Cells were harvested and freeze-fractured according to the procedure previously described.

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