scholarly journals Splicing of influenza virus matrix protein mRNA expressed from a simian virus 40 recombinant

1993 ◽  
Vol 74 (7) ◽  
pp. 1317-1326 ◽  
Author(s):  
J. Valcarcel ◽  
P. Fortes ◽  
J. Ortin
Keyword(s):  
Influenza Virus ◽  
Matrix Protein ◽  
Simian Virus 40 ◽  
Simian Virus

Effect of 5-azacytidine on gene expression in marrow stromal cells

1989 ◽  
Vol 9 (6) ◽  
pp. 2748-2751
Author(s):  
D F Andrews ◽  
J Nemunaitis ◽  
C Tompkins ◽  
J W Singer
Keyword(s):  
Stromal Cells ◽  
Time Course ◽  
Matrix Protein ◽  
Interleukin 1 ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
Marrow Stromal Cells ◽  
Necrosis Factor Alpha ◽  
Factor Alpha

When exposed to 5-azacytidine, marrow stromal cells from active long-term marrow cultures and cell lines derived from simian virus 40-transformed stromal cells rapidly upregulated c-abl and interleukin-6 transcripts while downregulating the expression of collagen I, a major matrix protein. Similar effects occurred with interleukin-1 alpha and tumor necrosis factor alpha, although the time course was considerably prolonged.

scholarly journals Role for Influenza Virus Envelope Cholesterol in Virus Entry and Infection

2003 ◽  
Vol 77 (23) ◽  
pp. 12543-12551 ◽  
Author(s):  
Xiangjie Sun ◽  
Gary R. Whittaker
Keyword(s):  
Influenza Virus ◽  
Simian Virus 40 ◽  
Critical Factor ◽  
Simian Virus ◽  
Host Cells ◽  
Cholesterol Depletion ◽  
Virus Infectivity ◽  
Dependent Manner ◽  
Virus Envelope ◽  
Nonenveloped Virus

ABSTRACT Enveloped viruses are highly dependent on their lipid envelopes for entry into and infection of host cells. Here, we have examined the role of cholesterol in the virus envelope, using methyl-β-cyclodextrin depletion. Pretreatment of virions with methyl-β-cyclodextrin efficiently depleted envelope cholesterol from influenza virus and significantly reduced virus infectivity in a dose-dependent manner. A nonenveloped virus, simian virus 40, was not affected by methyl-β-cyclodextrin treatment. In the case of influenza virus, infectivity could be partially rescued by the addition of exogenous cholesterol. Influenza virus morphology, binding, and internalization were not affected by methyl-β-cyclodextrin depletion, whereas envelope cholesterol depletion markedly affected influenza virus fusion, as measured by a specific reduction in the infectivity of viruses induced to fuse at the cell surface and by fluorescence-dequenching assays. These data suggest that envelope cholesterol is a critical factor in the fusion process of influenza virus.

scholarly journals Glycosylation and surface expression of the influenza virus neuraminidase requires the N-terminal hydrophobic region.

1984 ◽  
Vol 4 (1) ◽  
pp. 8-16 ◽  
Author(s):  
L Markoff ◽  
B C Lin ◽  
M M Sveda ◽  
C J Lai
Keyword(s):  
Influenza Virus ◽  
Dna Sequences ◽  
Sodium Dodecyl ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
Wild Type ◽  
Hydrophobic Region ◽  
Infected Cells ◽  
Late Region ◽  
Na Gene

A full-length double-stranded DNA copy of an influenza A virus N2 neuraminidase (NA) gene was cloned into the late region of pSV2330, a hybrid expression vector that includes pBR322 plasmid DNA sequences and the simian virus 40 early region and simian virus 40 late region promoters, splice sequences, and transcription termination sites. The protein encoded by the cloned wild-type NA gene was shown to be present in the cytoplasm of fixed cells and at the surface of "live" or unfixed cells by indirect immunofluorescence with N2 monoclonal antibodies. Immunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis of [35S]methionine-labeled proteins from wild-type vector-infected cells with heterospecific N2 antibody showed that the product of the cloned NA DNA comigrated with glycosylated NA from influenza virus-infected cells, remained associated with internal membranes of cells fractionated into membrane and cytoplasmic fractions, and could form an immunoprecipitable dimer. NA enzymatic activity was detectable after simian virus 40 lysis of vector-infected cells. These properties of the product of the cloned wild-type gene were compared with those of the polypeptides produced by three deletion mutant NA DNAs that were also cloned into the late region of the pSV2330 vector. These mutants lacked 7 (dlk), 21 (dlI), or all 23 amino acids (dlZ) of the amino (N)-terminal variable hydrophobic region that anchors the mature wild-type NA tetrameric structure in the infected cell or influenza viral membrane. Comparison of the phenotypes of these mutants showed that this region in the NA molecule also includes sequences that control translocation of the nascent polypeptide into membrane organelles for glycosylation.

Glycosylation and surface expression of the influenza virus neuraminidase requires the N-terminal hydrophobic region

1984 ◽  
Vol 4 (1) ◽  
pp. 8-16
Author(s):  
L Markoff ◽  
B C Lin ◽  
M M Sveda ◽  
C J Lai
Keyword(s):  
Influenza Virus ◽  
Dna Sequences ◽  
Sodium Dodecyl ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
Wild Type ◽  
Hydrophobic Region ◽  
Infected Cells ◽  
Late Region ◽  
Na Gene

A full-length double-stranded DNA copy of an influenza A virus N2 neuraminidase (NA) gene was cloned into the late region of pSV2330, a hybrid expression vector that includes pBR322 plasmid DNA sequences and the simian virus 40 early region and simian virus 40 late region promoters, splice sequences, and transcription termination sites. The protein encoded by the cloned wild-type NA gene was shown to be present in the cytoplasm of fixed cells and at the surface of "live" or unfixed cells by indirect immunofluorescence with N2 monoclonal antibodies. Immunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis of [35S]methionine-labeled proteins from wild-type vector-infected cells with heterospecific N2 antibody showed that the product of the cloned NA DNA comigrated with glycosylated NA from influenza virus-infected cells, remained associated with internal membranes of cells fractionated into membrane and cytoplasmic fractions, and could form an immunoprecipitable dimer. NA enzymatic activity was detectable after simian virus 40 lysis of vector-infected cells. These properties of the product of the cloned wild-type gene were compared with those of the polypeptides produced by three deletion mutant NA DNAs that were also cloned into the late region of the pSV2330 vector. These mutants lacked 7 (dlk), 21 (dlI), or all 23 amino acids (dlZ) of the amino (N)-terminal variable hydrophobic region that anchors the mature wild-type NA tetrameric structure in the infected cell or influenza viral membrane. Comparison of the phenotypes of these mutants showed that this region in the NA molecule also includes sequences that control translocation of the nascent polypeptide into membrane organelles for glycosylation.

scholarly journals Effect of 5-azacytidine on gene expression in marrow stromal cells.

1989 ◽  
Vol 9 (6) ◽  
pp. 2748-2751 ◽  
Author(s):  
D F Andrews ◽  
J Nemunaitis ◽  
C Tompkins ◽  
J W Singer
Keyword(s):  
Stromal Cells ◽  
Time Course ◽  
Matrix Protein ◽  
Interleukin 1 ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
Marrow Stromal Cells ◽  
Necrosis Factor Alpha ◽  
Factor Alpha

When exposed to 5-azacytidine, marrow stromal cells from active long-term marrow cultures and cell lines derived from simian virus 40-transformed stromal cells rapidly upregulated c-abl and interleukin-6 transcripts while downregulating the expression of collagen I, a major matrix protein. Similar effects occurred with interleukin-1 alpha and tumor necrosis factor alpha, although the time course was considerably prolonged.

scholarly journals An efficient method for introducing macromolecules into living cells.

1985 ◽  
Vol 101 (1) ◽  
pp. 19-27 ◽  
Author(s):  
S J Doxsey ◽  
J Sambrook ◽  
A Helenius ◽  
J White
Keyword(s):  
Influenza Virus ◽  
Cell Surface ◽  
Simian Virus 40 ◽  
Surface Expression ◽  
Simian Virus ◽  
Cell Surface Expression ◽  
Erythrocyte Membranes ◽  
Target Cells ◽  
Fusion Activity ◽  
Culture Cells

The hemagglutinin (HA) of influenza virus was used to obtain efficient and rapid bulk delivery of antibodies and horseradish peroxidase (HRP) into the cytoplasm of living tissue culture cells. By exploiting HA's efficient cell surface expression, its high affinity for erythrocytes, and its acid-dependent membrane fusion activity, a novel delivery method was developed. The approach is unique in that the mediator of both binding and fusion (the HA) is present on the surfaces of the target cells. A recently developed 3T3 cell line which permanently expresses HA, Madin-Darby canine kidney cells infected with influenza virus, and CV-1 cells infected with a simian virus 40 vector carrying the HA gene were used as recipient cells. Protein-loaded erythrocytes were bound to the HA on the cell surface and a brief drop in pH to 5.0 was used to trigger HA's fusion activity and hence delivery. About 3 to 8 erythrocytes fused per 3T3 and CV-1 cell, respectively, and 75-95% of the cells received IgG or HRP. Quantitative analysis showed that 1.8 X 10(8) molecules of HRP and 1.4 X 10(7) IgG molecules were delivered per CV-1 cell and 6.2 X 10(7) HRP molecules per 3T3 cell. Cell viability, as judged by methionine incorporation into protein and cell growth and division, was not impaired. Electron and fluorescence microscopy showed that the fused erythrocyte membranes remained as discrete domains in the cell's plasma membrane. The method is simple, reliable, and nonlytic. The ability to simultaneously and rapidly deliver impermeable substances into large numbers of cells will permit biochemical analysis of the fate and effect of a variety of delivered molecules.

scholarly journals Induction of adaptive immune responses against antigens incorporated within the capsid of simian virus 40

2020 ◽  
Vol 101 (8) ◽  
pp. 853-862
Author(s):  
Kikue Saika ◽  
Masahiko Kato ◽  
Hideaki Sanada ◽  
Sho Matsushita ◽  
Masanori Matsui ◽  
...  
Keyword(s):  
Immune Responses ◽  
Influenza A ◽  
Matrix Protein ◽  
Insect Cells ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
Vaccine Platform ◽  
Adaptive Immune Responses ◽  
Adaptive Immune ◽  
Ctl Epitope

Simian virus 40 (SV40) is a monkey polyomavirus. The capsid structure is icosahedral and comprises VP1 units that measure 45 nm in diameter. Five SV40 VP1 molecules form one pentamer subunit, and a single icosahedral subunit comprises 72 pentamers; a single SV40 VP1 capsid comprises 360 SV40 VP1 molecules. In a previous study, we showed that an influenza A virus matrix protein 1 (M1) CTL epitope inserted within SV40 virus-like particles (VLPs) induced cytotoxic T lymphocytes (CTLs) without the need for an adjuvant. Here, to address whether SV40 VLPs induce adaptive immune responses against VLP-incorporated antigens, we prepared SV40 VLPs containing M1 or chicken ovalbumin (OVA). This was done by fusing M1 or OVA with the carboxyl terminus of SV40 VP2 and co-expressing them with SV40 VP1 in insect cells using a baculovirus vector. Intraperitoneal (i.p.) or intranasal administration of SV40 VLPs incorporating M1 induced the production of CTLs specific for the M1 epitope without the requirement for adjuvant. The production of antibodies against SV40 VLPs was also induced by i.p. administration of SV40 VLPs in the absence of adjuvant. Finally, the administration of SV40 VLPs incorporating OVA induced anti-OVA antibodies in the absence of adjuvant; in addition, the level of antibody production was comparable with that after i.p. administration of OVA plus alum adjuvant. These results suggest that the SV40 capsid incorporating foreign antigens can be used as a vaccine platform to induce adaptive immune responses without the need for adjuvant.

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