Microscopic detection of adventitious viruses in cell cultures

1972 ◽  
Vol 18 (3) ◽  
pp. 299-304 ◽  
Author(s):  
Nan Anderson ◽  
Frances W. Doane
Keyword(s):  
Electron Microscopy ◽  
Foamy Virus ◽  
Light And Electron Microscopy ◽  
Monkey Kidney ◽  
Contamination Rate ◽  
Kidney Cells ◽  
African Green Monkey Kidney ◽  
Thin Sections ◽  
Tumor Viruses ◽  
Viral Contaminants

Sixty-five batches of three types of monkey kidney cells were examined by light and electron microscopy for the presence of simian viruses. Cynomolgus cells showed the highest contamination rate (67%), followed by rhesus (18%). Foamy virus was the most common contaminant, being detected in 13 batches, twice in concert with a paramyxovirus. Six batches contained a paramyxovirus; one batch contained a papovavirus. Of the 22 batches of African green monkey kidney cells examined, none showed evidence of virus. "Healthy" established cell lines from three laboratories were also checked by electron microscopy, and several contaminating viruses were found. These were apparently either accidentally introduced during handling, as in the case of SV5, reovirus, and parvovirus, or were latent viruses (hamster and mouse) derived from the host tissue. While negative staining provided the simplest technique for detection of the viral contaminants, thin sectioning was required to locate foamy virus and the latent "tumor" viruses. A rapid method for the preparation of thin sections is described.

Surface expression of influenza virus neuraminidase, an amino-terminally anchored viral membrane glycoprotein, in polarized epithelial cells

1985 ◽  
Vol 5 (9) ◽  
pp. 2181-2189
Author(s):  
L V Jones ◽  
R W Compans ◽  
A R Davis ◽  
T J Bos ◽  
D P Nayak
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Surface Expression ◽  
African Green Monkey ◽  
Monkey Kidney ◽  
Kidney Cells ◽  
African Green Monkey Kidney ◽  
Amino Terminal ◽  
Green Monkey ◽  
Na Gene

We have investigated the site of surface expression of the neuraminidase (NA) glycoprotein of influenza A virus, which, in contrast to the hemagglutinin, is bound to membranes by hydrophobic residues near the NH2-terminus. Madin-Darby canine kidney or primary African green monkey kidney cells infected with influenza A/WSN/33 virus and subsequently labeled with monoclonal antibody to the NA and then with a colloidal gold- or ferritin-conjugated second antibody exhibited specific labeling of apical surfaces. Using simian virus 40 late expression vectors, we also studied the surface expression of the complete NA gene (SNC) and a truncated NA gene (SN10) in either primary or a polarized continuous line (MA104) of African green monkey kidney cells. The polypeptides encoded by the cloned NA cDNAs were expressed on the surface of both cell types. Analysis of [3H]mannose-labeled polypeptides from recombinant virus-infected MA104 cells showed that the products of cloned NA cDNA comigrated with glycosylated NA from influenza virus-infected cells. Both the complete and the truncated glycoproteins were found to be preferentially expressed on apical plasma membranes, as detected by immunogold labeling. These results indicate that the NA polypeptide contains structural features capable of directing the transport of the protein to apical cell surfaces and the first 10 amino-terminal residues of the NA polypeptide are not involved in this process.

Replication factories and nuclear bodies: the ultrastructural characterization of replication sites during the cell cycle

1994 ◽  
Vol 107 (8) ◽  
pp. 2191-2202 ◽  
Author(s):  
P. Hozak ◽  
D.A. Jackson ◽  
P.R. Cook
Keyword(s):  
Electron Microscopy ◽  
Light And Electron Microscopy ◽  
S Phase ◽  
Nuclear Bodies ◽  
Nuclear Antigen ◽  
Thin Sections ◽  
Permeabilized Cells ◽  
Ultrastructural Characterization ◽  
Replication Sites ◽  
Proliferating Cell

Sites of replication in synchronized HeLa cells were visualized by light and electron microscopy; cells were permeabilized and incubated with biotin-16-dUTP, and incorporation sites were immunolabelled. Electron microscopy of thick resinless sections from which approximately 90% chromatin had been removed showed that most DNA synthesis occurs in specific dense structures (replication factories) attached to a diffuse nucleoskeleton. These factories appear at the end of G1-phase and quickly become active; as S-phase progresses, they increase in size and decrease in number like sites of incorporation seen by light microscopy. Electron microscopy of conventional thin sections proved that these factories are a subset of nuclear bodies; they changed in the same characteristic way and contained DNA polymerase alpha and proliferating cell nuclear antigen. As replication factories can be observed and labelled in non-permeabilized cells, they cannot be aggregation artifacts. Some replication occurs outside factories at discrete sites on the diffuse skeleton; it becomes significant by mid S-phase and later becomes concentrated beneath the lamina.

The Effects of Some Metabolic Inhibitors on the Ability of SV 40 Virus in Transformed Cells to be Detected by Cell Fusion

1970 ◽  
Vol 6 (3) ◽  
pp. 721-737
Author(s):  
J. F. WATKINS
Keyword(s):  
Cell Fusion ◽  
Monkey Kidney ◽  
New Method ◽  
Metabolic Inhibitors ◽  
Transformed Cells ◽  
Kidney Cells ◽  
African Green Monkey Kidney ◽  
Green Monkey ◽  
Mouse Cells ◽  
Sv 40 Virus

When mouse fibroblasts transformed by SV 40 virus are fused with African Green Monkey kidney cells about 5% of the heterokaryons produce infective SV 40 virus. If the transformed mouse cells are treated with iododeoxyuridine before fusion, the percentage of heterokaryons producing SV 40 virus is increased to between 50 and 80%; if the transformed cells are treated with 8-azaguanine, the percentage of heterokaryons yielding virus is increased to between 59% and 96%. This shows that whether the SV 40 virus can be detected by cell fusion depends on the state of the transformed cells beforehand. A new method for titrating SV 40 virus is described.

Recombination between irradiated shuttle vector DNA and chromosomal DNA in African green monkey kidney cells

1990 ◽  
Vol 10 (1) ◽  
pp. 37-46
Author(s):  
J S Mudgett ◽  
W D Taylor
Keyword(s):  
Gamma Irradiation ◽  
Uv Light ◽  
Shuttle Vector ◽  
Monkey Kidney ◽  
Host Cells ◽  
Mammalian Host ◽  
Kidney Cells ◽  
African Green Monkey Kidney ◽  
Green Monkey ◽  
Chromosome Recombination

An autonomously replicating shuttle vector was used to investigate enhancement of plasmid-chromosome recombination in mammalian host cells by gamma irradiation and UV light. Sequences homologous to the shuttle vector were stably inserted into the genome of African green monkey kidney cells to act as the target substrate for these recombination events. The shuttle vector molecules were irradiated at various doses before transfection into the mammalian host cells that contained the stable insertions. The homologous transfer of the bacterial ampicillin resistance gene from the inserted sequences to replace a mutant ampicillin sensitivity gene on the shuttle vector was identified by the recovery of ampicillin-resistant plasmids after Hirt extraction and transformation into Escherichia coli host cells. Gamma irradiation increased homologous shuttle vector-chromosome recombination, whereas UV light did not increase the frequency of recombinant plasmids detected. Introducing specific double-strand breaks in the plasmid or prolonging the time of plasmid residence in the mammalian host cells also enhanced plasmid-chromosome recombination. In contrast, plasmid mutagenesis was increased by UV irradiation of the plasmid but did not change with time. The ampicillin-resistant recombinant plasmid molecules analyzed appeared to rise mostly from nonconservative exchanges that involved both homologous and possibly nonhomologous interactions with the host chromosome. The observation that similar recombinant structures were obtained from all the plasmid treatments and host cells used suggests a common mechanism for plasmid-chromosome recombination in these mammalian cells.

Assessment of potential miRNA biomarkers of VERO-cell tumorigenicity in a new line (AGMK1-9T7) of African green monkey kidney cells

Vaccine ◽  
2017 ◽  
Vol 35 (41) ◽  
pp. 5503-5509 ◽  
Author(s):  
Belete Teferedegne ◽  
Daniel M. Rotroff ◽  
Juliete Macauley ◽  
Gideon Foseh ◽  
Gladys Lewis ◽  
...  
Keyword(s):  
Vero Cell ◽  
African Green Monkey ◽  
Monkey Kidney ◽  
Kidney Cells ◽  
African Green Monkey Kidney ◽  
Green Monkey

scholarly journals Surface expression of influenza virus neuraminidase, an amino-terminally anchored viral membrane glycoprotein, in polarized epithelial cells.

1985 ◽  
Vol 5 (9) ◽  
pp. 2181-2189 ◽  
Author(s):  
L V Jones ◽  
R W Compans ◽  
A R Davis ◽  
T J Bos ◽  
D P Nayak
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Surface Expression ◽  
African Green Monkey ◽  
Monkey Kidney ◽  
Kidney Cells ◽  
African Green Monkey Kidney ◽  
Amino Terminal ◽  
Green Monkey ◽  
Na Gene

We have investigated the site of surface expression of the neuraminidase (NA) glycoprotein of influenza A virus, which, in contrast to the hemagglutinin, is bound to membranes by hydrophobic residues near the NH2-terminus. Madin-Darby canine kidney or primary African green monkey kidney cells infected with influenza A/WSN/33 virus and subsequently labeled with monoclonal antibody to the NA and then with a colloidal gold- or ferritin-conjugated second antibody exhibited specific labeling of apical surfaces. Using simian virus 40 late expression vectors, we also studied the surface expression of the complete NA gene (SNC) and a truncated NA gene (SN10) in either primary or a polarized continuous line (MA104) of African green monkey kidney cells. The polypeptides encoded by the cloned NA cDNAs were expressed on the surface of both cell types. Analysis of [3H]mannose-labeled polypeptides from recombinant virus-infected MA104 cells showed that the products of cloned NA cDNA comigrated with glycosylated NA from influenza virus-infected cells. Both the complete and the truncated glycoproteins were found to be preferentially expressed on apical plasma membranes, as detected by immunogold labeling. These results indicate that the NA polypeptide contains structural features capable of directing the transport of the protein to apical cell surfaces and the first 10 amino-terminal residues of the NA polypeptide are not involved in this process.

scholarly journals Immunocytochemical localization of actin in epithelial cells of rat small intestine by light and electron microscopy.

1988 ◽  
Vol 36 (7) ◽  
pp. 717-727 ◽  
Author(s):  
S J Hagen ◽  
J S Trier
Keyword(s):  
Electron Microscopy ◽  
Small Intestine ◽  
Epithelial Cells ◽  
Light And Electron Microscopy ◽  
Basal Membrane ◽  
Ground Substance ◽  
Structural Protein ◽  
Thin Sections ◽  
Filament Bundles ◽  
Lowicryl K4m

We used post-embedding immunocytochemical techniques and affinity-purified anti-actin antibody to evaluate localization of actin in epithelial cells of small intestine by fluorescence and electron microscopy. Small intestine was fixed with 2% formaldehyde-0.1% glutaraldehyde and embedded in Lowicryl K4M. One-micron or thin sections were stained with antibody followed by rhodamine- or colloidal gold-labeled goat anti-rabbit IgG, respectively. Label was present overlying microvilli, the apical terminal web, and the cytoplasm directly adjacent to occluding and intermediate junctions. Label was associated with outer mitochondrial membranes of all cells and the supranuclear Golgi region of goblet cells. Lateral cytoplasmic interdigitations between mature cells and subplasmalemmal filaments next to intrusive cells were densely labeled. The cytoplasm adjacent to unplicated domains of lateral membrane was focally labeled. Label was prominent over organized filament bundles within the subplasmalemmal web at the base of mature cells, whereas there was focal labeling of the cytoplasm adjacent to the basal membrane of undifferentiated cells. Basolateral epithelial cell processes were labeled. Label was focally present overlying the cellular ground substance. Our results demonstrate that actin is distributed in a distinctive fashion within intestinal epithelial cells. This distribution suggests that in addition to its function as a structural protein, actin may participate in regulation of epithelial tight junction permeability, in motile processes including migration of cells from the crypt to the villus tip, in accommodation of intrusive intraepithelial cells and in adhesion of cells to one another and to their substratum.

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