scholarly journals Identification and phylogenetic analysis of two canine coronavirus strains

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Junji Gan ◽  
Ye Tang ◽  
Haifeng Lv ◽  
Wenbin Xiong ◽  
Xiaoyan Tian
Keyword(s):  
Phylogenetic Analysis ◽  
Culture Media ◽  
Rna Virus ◽  
Pcr Analysis ◽  
Cell Culture Media ◽  
N Protein ◽  
Cytopathic Effects ◽  
Canine Coronavirus ◽  
Infected Cells ◽  
Reference Strains

AbstractCanine coronavirus (CCoV), a member of the genus Alphacoronavirus, is an enveloped, single-stranded positive-sense RNA virus that responsible for gastroenteritis in dogs. In this study, two CCoV isolates were successfully propagated from 53 CCoV-positive clinical specimens by serial passaging in A-72 cells. These two strains, CCoV JS1706 and CCoV JS1712, caused cytopathic effects in A-72 cells. The sizes of virus plaque formed by them differed in early passages. Electron microscopy revealed a large quantity of typical coronavirus particles with 80–120 nm in diameter in cell culture media and cytoplasm of infected cells, in which they appeared as inclusion bodies. RT-PCR analysis of S gene indicated that these two isolates were belonged to CCoV IIa subtype. Homology of RdRp, S, M and N proteins between the two strains were 100, 99.6, 99.2 and 100.0%, respectively, whereas they were 99.4–100%, 83.1–95.2%, 88.5–99.2% and 91.9–99.7% identity compared to CCoV II reference strains. Phylogenetic analysis of RdRp, S, M and N protein showed that they were closely related to CCoV II strains. These two subtype IIa isolates will be useful for evaluating the pathogenesis and evolution of CCoV and for developing diagnostic reagents and vaccines.

scholarly journals Phosphorylation of the Porcine Reproductive and Respiratory Syndrome Virus Nucleocapsid Protein

2002 ◽  
Vol 76 (20) ◽  
pp. 10569-10576 ◽  
Author(s):  
Sarah K. Wootton ◽  
Raymond R. R. Rowland ◽  
Dongwan Yoo
Keyword(s):  
Nucleocapsid Protein ◽  
Time Course ◽  
Rna Virus ◽  
Respiratory Syndrome Virus ◽  
N Protein ◽  
Two Dimensional Electrophoresis ◽  
Cytoplasmic Rna ◽  
Infected Cells ◽  
Phosphoamino Acid Analysis ◽  
Dimensional Electrophoresis

ABSTRACT Porcine reproductive and respiratory syndrome virus (PRRSV) is a cytoplasmic RNA virus with the unique or unusual feature of having a nucleocapsid (N) protein that is specifically transported to the nucleolus of virus-infected cells. In this communication, we show that the N protein is a phosphoprotein. Phosphoamino acid analysis of authentic and recombinant N proteins demonstrated that serine residues were exclusively phosphorylated. The pattern of phosphorylated N protein cellular distribution in comparison with that of [35S]methionine-labeled N protein suggested that phosphorylation does not influence subcellular localization of the protein. Time course studies showed that phosphorylation occurred during, or shortly after, synthesis of the N protein and that the protein remained stably phosphorylated throughout the life cycle of the virus to the extent that phosphorylated N protein was found in the mature virion. Two-dimensional electrophoresis and acid-urea gel electrophoresis showed that one species of the N protein is predominant in virus-infected cells, suggesting that multiple phosphorylated isoforms of N do not exist.

scholarly journals Induction of Caspase-Dependent Apoptosis in Cultured Cells by the Avian Coronavirus Infectious Bronchitis Virus

2001 ◽  
Vol 75 (14) ◽  
pp. 6402-6409 ◽  
Author(s):  
C. Liu ◽  
H. Y. Xu ◽  
D. X. Liu
Keyword(s):  
Infectious Bronchitis Virus ◽  
Cultured Cells ◽  
Culture Media ◽  
Vero Cells ◽  
Infectious Bronchitis ◽  
Cytopathic Effects ◽  
General Caspase Inhibitor ◽  
Infected Cells ◽  
Chromosomal Condensation ◽  
Underlying Mechanisms

ABSTRACT Avian coronavirus infectious bronchitis virus (IBV) is the causative agent of chicken infectious bronchitis, an acute, highly contagious viral respiratory disease. Replication of IBV in Vero cells causes extensive cytopathic effects (CPE), leading to destruction of the entire monolayer and the death of infected cells. In this study, we investigated the cell death processes during acute IBV infection and the underlying mechanisms. The results show that both necrosis and apoptosis may contribute to the death of infected cells in lytic IBV infection. Caspase-dependent apoptosis, as characterized by chromosomal condensation, DNA fragmentation, caspase-3 activation, and poly(ADP-ribose) polymerase degradation, was detected in IBV-infected Vero cells. Addition of the general caspase inhibitor z-VAD-FMK to the culture media showed inhibition of the hallmarks of apoptosis and increase of the release of virus to the culture media at 16 h postinfection. However, neither the necrotic process nor the productive replication of IBV in Vero cells was severely affected by the inhibition of apoptosis. Screening of 11 IBV-encoded proteins suggested that a 58-kDa mature cleavage product could induce apoptotic changes in cells transiently expressing the protein. This study adds one more example to the growing list of animal viruses that induce apoptosis during their replication cycles.

High-pressure freezing of cells in suspension for low-voltage scanning electron microscopy (LVSEM)

1991 ◽  
Vol 49 ◽  
pp. 64-65
Author(s):  
Marek Malecki ◽  
James Pawley ◽  
Hans Ris
Keyword(s):  
Electron Microscopy ◽  
High Pressure ◽  
Low Voltage ◽  
Culture Media ◽  
Cell Structure ◽  
Freeze Substitution ◽  
Ice Crystal ◽  
High Pressure Freezing ◽  
Cell Culture Media ◽  
Voltage Scanning

The ultrastructure of cells suspended in physiological fluids or cell culture media can only be studied if the living processes are stopped while the cells remain in suspension. Attachment of living cells to carrier surfaces to facilitate further processing for electron microscopy produces a rapid reorganization of cell structure eradicating most traces of the structures present when the cells were in suspension. The structure of cells in suspension can be immobilized by either chemical fixation or, much faster, by rapid freezing (cryo-immobilization). The fixation speed is particularly important in studies of cell surface reorganization over time. High pressure freezing provides conditions where specimens up to 500μm thick can be frozen in milliseconds without ice crystal damage. This volume is sufficient for cells to remain in suspension until frozen. However, special procedures are needed to assure that the unattached cells are not lost during subsequent processing for LVSEM or HVEM using freeze-substitution or freeze drying. We recently developed such a procedure.

Cell culture media: NMR approaches to evaluating quality and nutrient consumption

Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
KB Killday ◽  
AS Freund ◽  
C Fischer ◽  
KL Colson
Keyword(s):  
Cell Culture ◽  
Culture Media ◽  
Cell Culture Media ◽  
Nutrient Consumption

The Influence of Glycosylation on the Catalytic and Fibrinolytic Properties of Pro-Urokinase

1992 ◽  
Vol 68 (05) ◽  
pp. 539-544 ◽  
Author(s):  
Catherine Lenich ◽  
Ralph Pannell ◽  
Jack Henkin ◽  
Victor Gurewich
Keyword(s):  
Escherichia Coli ◽  
Mammalian Cell ◽  
Human Gene ◽  
Culture Media ◽  
Mammalian Cell Culture ◽  
Glycosylation Site ◽  
Clot Lysis ◽  
Cell Culture Media ◽  
E Coli ◽  
The Uk

SummaryWe previously found that human pro-UK expressed in Escherichia coli is more active in fibrinolysis than recombinant human pro-UK obtained from mammalian cell culture media. To determine whether this difference is related to the lack of glycosylation of the E. coli product, we compared the activity of E. coli-derived pro-UK [(-)pro-UK] with that of a glycosylated pro-UK [(+)pro-UK] and of a mutant of pro-UK missing the glycosylation site at Asn-302 [(-) (302) pro-UK]. The latter two pro-UKs were obtained by expression of the human gene in a mammalian cell. The nonglycosylated pro-UKs were activated by plasmin more efficiently (≈2-fold) and were more active in clot lysis (1.5-fold) than the (+)pro-UK. Similarly, the nonglycosylated two-chain derivatives (UKs) were more active against plasminogen and were more rapidly inactivated by plasma inhibitors than the (+)UK.These findings indicate that glycosylation at Asn-302 influences the activity of pro-UK/UK and could be the major factor responsible for the enhanced activity of E. coli-derived pro-UK.

scholarly journals Immunomagnetic sequential ultrafiltration (iSUF) platform for enrichment and purification of extracellular vesicles from biofluids

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jingjing Zhang ◽  
Luong T. H. Nguyen ◽  
Richard Hickey ◽  
Nicole Walters ◽  
Xinyu Wang ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Culture Media ◽  
Metastatic Breast ◽  
Clinical Samples ◽  
Clinical Use ◽  
Immunomagnetic Beads ◽  
Liquid Biopsies ◽  
Cell Culture Media ◽  
Non Invasive ◽  
Healthy Donors

AbstractExtracellular vesicles (EVs) derived from tumor cells have the potential to provide a much-needed source of non-invasive molecular biomarkers for liquid biopsies. However, current methods for EV isolation have limited specificity towards tumor-derived EVs that limit their clinical use. Here, we present an approach called immunomagnetic sequential ultrafiltration (iSUF) that consists of sequential stages of purification and enrichment of EVs in approximately 2 h. In iSUF, EVs present in different volumes of biofluids (0.5–100 mL) can be significantly enriched (up to 1000 times), with up to 99% removal of contaminating proteins (e.g., albumin). The EV recovery rate by iSUF for cell culture media (CCM), serum, and urine corresponded to 98.0% ± 3.6%, 96.0% ± 2.0% and 94.0% ± 1.9%, respectively (p > 0.05). The final step of iSUF enables the separation of tumor-specific EVs by incorporating immunomagnetic beads to target EV subpopulations. Serum from a cohort of clinical samples from metastatic breast cancer (BC) patients and healthy donors were processed by the iSUF platform and the isolated EVs from patients showed significantly higher expression levels of BC biomarkers (i.e., HER2, CD24, and miR21).

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