scholarly journals IN VITRO INTERACTION OF MOUSE HEPATITIS VIRUS AND MACROPHAGES FROM GENETICALLY RESISTANT MICE

1970 ◽  
Vol 131 (4) ◽  
pp. 851-862 ◽  
Author(s):  
Ilan Shif ◽  
Frederik B. Bang
Keyword(s):  
Hepatitis Virus ◽  
High Titer ◽  
Mouse Hepatitis Virus ◽  
Peritoneal Macrophages ◽  
Wild Type Virus ◽  
New Host ◽  
New Variant ◽  
Variant Virus ◽  
C3h Mice

A variant mouse hepatitis virus MHV(C3H) to which cultured peritoneal macrophages from both PRI and C3H mice were susceptible was isolated from stocks of the MHV(PRI) strain of mouse hepatitis virus. It was cloned on C3H macrophage monolayers and killed both adult PRI and C3H mice when injected intraperitoneally. This new variant was antigenically indistinguishable from the wild type virus. While the emergence of the variant virus was delayed in the course of infecting C3H macrophages with large inocula of MHV(PRI), the second passage grew to a high titer in both cell types without delay. Thus, adaptation to the new host was immediate. Interference, apparently not interferon-mediated, between the two variant viruses may have been the cause for the delay in the emergence of the variant virus. The delayed destruction of C3H-cultured macrophages by large inocula of MHV(PRI) uniformly resulted in the emergence of MHV(C3H). Whether the new variant emerged as a result of a selection of a pre-existing stable mutant or was conditioned by "growth" in the resistant host was not determined.

scholarly journals IN VITRO INTERACTION OF MOUSE HEPATITIS VIRUS AND MACROPHAGES FROM GENETICALLY RESISTANT MICE

1970 ◽  
Vol 131 (4) ◽  
pp. 843-850 ◽  
Author(s):  
Ilan Shif ◽  
Frederik B. Bang
Keyword(s):  
Virus Replication ◽  
Hepatitis Virus ◽  
Mouse Hepatitis Virus ◽  
Peritoneal Macrophages ◽  
Slow Inactivation ◽  
Virus Particles ◽  
C3h Mice ◽  
The Difference ◽  
In Vitro Interaction

Peritoneal macrophages from genetically resistant C3H mice and genetically susceptible Princeton (PRI) mice adsorbed the MHV (PRI) strain of mouse hepatitis virus equally well. The difference between the permissive cells and the nonpermissive ones seems to reside in the ability of the former to "eclipse" the virus and, subsequently, support virus replication. C3H cells exposed to low multiplicities of the virus remained intact with no demonstrable viral replication. Virus, taken up by the resistant cells, was protected from heat and underwent slow inactivation while few or no virus particles were released into the medium.

scholarly journals ONTOGENY OF MACROPHAGE RESISTANCE TO MOUSE HEPATITIS IN VIVO AND IN VITRO

1967 ◽  
Vol 125 (4) ◽  
pp. 537-548 ◽  
Author(s):  
Ruth Gallily ◽  
Anne Warwick ◽  
Frederik B. Bang
Keyword(s):  
Hepatitis Virus ◽  
Mouse Hepatitis Virus ◽  
Susceptible Strain ◽  
Time Of Death ◽  
Complete Resistance ◽  
Different Ages ◽  
C3h Mice ◽  
Resistant Cells

Adult or weanling C3H mice were found to be genetically resistant to a strain of mouse hepatitis virus. Infant C3H mice, however, developed infection and died from mouse hepatitis virus when minimal infectious doses of virus were given to them. There was a delay in the time of death compared to that of the genetically susceptible strain, and the virus recovered from these mice had increased pathogenicity for C3H mice. The ontogeny of resistance to hepatitis in the C3H mice thus progresses from delayed susceptibility to complete resistance as the age of the host increases. It is reflected in increased resistance of macrophages derived in vitro from liver cultures of infant mice of different ages. This increase in resistance with age was reduced by maintaining the cultures for a longer period of time before inoculation, or by increasing the number of explants in a given culture. Resistant cells were uniformly furnished by mice age 16 days, or more. It is concluded that a process of maturation of resistance of the cells takes place after the mice are born, but that this does not continue under in vitro conditions, and that it may be modified by the environment of the cells.

scholarly journals Macrophages genetically resistant to mouse hepatitis virus converted in vitro to susceptible macrophages.

1976 ◽  
Vol 143 (3) ◽  
pp. 690-695 ◽  
Author(s):  
W Weiser ◽  
F B Bang
Keyword(s):  
Hepatitis Virus ◽  
Mouse Hepatitis Virus ◽  
Genetic Resistance ◽  
Fold Increase ◽  
C3h Mice ◽  
Resistant Cells

Genetic resistance to mouse hepatitis, which resides largely in the macrophages of resistant C3H mice, may be altered by exposing the cells in vitro to fluid from allogeneic mixed lymphocytes. A 1,000-fold increase in susceptibility was produced in these genetically resistant cells by exposure to this fluid. This presumed lymphokine was effective without producing any change in host adaption of the virus.

scholarly journals A proline insertion-deletion in the spike glycoprotein fusion peptide of mouse hepatitis virus strongly alters neuropathology

2019 ◽  
Vol 294 (20) ◽  
pp. 8064-8087 ◽  
Author(s):  
Manmeet Singh ◽  
Abhinoy Kishore ◽  
Dibyajyoti Maity ◽  
Punnepalli Sunanda ◽  
Bankala Krishnarjuna ◽  
...  
Keyword(s):  
Hepatitis Virus ◽  
Mouse Hepatitis Virus ◽  
Brain Parenchyma ◽  
Fusion Peptides ◽  
Spike Glycoprotein ◽  
Fusion Event ◽  
Viral Spread ◽  
Secondary Amino ◽  
The Brain

Fusion peptides (FPs) in spike proteins are key players mediating early events in cell-to-cell fusion, vital for intercellular viral spread. A proline residue located at the central FP region has often been suggested to have a distinctive role in this fusion event. The spike glycoprotein from strain RSA59 (PP) of mouse hepatitis virus (MHV) contains two central, consecutive prolines in the FP. Here, we report that deletion of one of these proline residues, resulting in RSA59 (P), significantly affected neural cell syncytia formation and viral titers postinfection in vitro. Transcranial inoculation of C57Bl/6 mice with RSA59 (PP) or RSA59 (P) yielded similar degrees of necrotizing hepatitis and meningitis, but only RSA59 (PP) produced widespread encephalitis that extended deeply into the brain parenchyma. By day 6 postinfection, both virus variants were mostly cleared from the brain. Interestingly, inoculation with the RSA59 (P)–carrying MHV significantly reduced demyelination at the chronic stage. We also found that the presence of two consecutive prolines in FP promotes a more ordered, compact, and rigid structure in the spike protein. These effects on FP structure were due to proline's unique stereochemical properties intrinsic to its secondary amino acid structure, revealed by molecular dynamics and NMR experiments. We therefore propose that the differences in the severity of encephalitis and demyelination between RSA59 (PP) and RSA59 (P) arise from the presence or absence, respectively, of the two consecutive prolines in FP. Our studies define a structural determinant of MHV entry in the brain parenchyma important for altered neuropathogenesis.

scholarly journals Enhanced Virulence Mediated by the Murine Coronavirus, Mouse Hepatitis Virus Strain JHM, Is Associated with a Glycine at Residue 310 of the Spike Glycoprotein

2003 ◽  
Vol 77 (19) ◽  
pp. 10260-10269 ◽  
Author(s):  
Evelena Ontiveros ◽  
Taeg S. Kim ◽  
Thomas M. Gallagher ◽  
Stanley Perlman
Keyword(s):  
Virus Strain ◽  
Hepatitis Virus ◽  
Neurological Diseases ◽  
Mouse Hepatitis Virus ◽  
Neutralizing Antibody ◽  
Lateral Spread ◽  
S Protein ◽  
Acute Encephalitis ◽  
The Central Nervous System

ABSTRACT The coronavirus, mouse hepatitis virus strain JHM, causes acute and chronic neurological diseases in rodents. Here we demonstrate that two closely related virus variants, both of which cause acute encephalitis in susceptible strains of mice, cause markedly different diseases if mice are protected with a suboptimal amount of an anti-JHM neutralizing antibody. One strain, JHM.SD, caused acute encephalitis, while infection with JHM.IA resulted in no acute disease. Using recombinant virus technology, we found that the differences between the two viruses mapped to the spike (S) glycoprotein and that the two S proteins differed at four amino acids. By engineering viruses that differed by only one amino acid, we identified a serine-to-glycine change at position 310 of the S protein (S310G) that recapitulated the more neurovirulent phenotype. The increased neurovirulence mediated by the virus encoding glycine at position S310 was not associated with a different tropism within the central nervous system (CNS) but was associated with increased lateral spread in the CNS, leading to significantly higher brain viral titers. In vitro studies revealed that S310G was associated with decreased S1-S2 stability and with enhanced ability to mediate infection of cells lacking the primary receptor for JHM (“receptor-independent spread”). These enhanced fusogenic properties of viruses encoding a glycine at position 310 of the S protein may contribute to spread within the CNS, a tissue in which expression of conventional JHM receptors is low.

scholarly journals Cleavage between Replicase Proteins p28 and p65 of Mouse Hepatitis Virus Is Not Required for Virus Replication

2004 ◽  
Vol 78 (11) ◽  
pp. 5957-5965 ◽  
Author(s):  
Mark R. Denison ◽  
Boyd Yount ◽  
Sarah M. Brockway ◽  
Rachel L. Graham ◽  
Amy C. Sims ◽  
...  
Keyword(s):  
Rna Synthesis ◽  
Hepatitis Virus ◽  
Mouse Hepatitis Virus ◽  
Wild Type ◽  
Virus Growth ◽  
Amino Terminal ◽  
Normal Expression ◽  
Infected Cells ◽  
Critical Residues

ABSTRACT The p28 and p65 proteins of mouse hepatitis virus (MHV) are the most amino-terminal protein domains of the replicase polyprotein. Cleavage between p28 and p65 has been shown to occur in vitro at cleavage site 1 (CS1), 247Gly↓Val248, in the polyprotein. Although critical residues for CS1 cleavage have been mapped in vitro, the requirements for cleavage have not been studied in infected cells. To define the determinants of CS1 cleavage and the role of processing at this site during MHV replication, mutations and deletions were engineered in the replicase polyprotein at CS1. Mutations predicted to allow cleavage at CS1 yielded viable virus that grew to wild-type MHV titers and showed normal expression and processing of p28 and p65. Mutant viruses containing predicted noncleaving mutations or a CS1 deletion were also viable but demonstrated delayed growth kinetics, reduced peak titers, decreased RNA synthesis, and small plaques compared to wild-type controls. No p28 or p65 was detected in cells infected with predicted noncleaving CS1 mutants or the CS1 deletion mutant; however, a new protein of 93 kDa was detected. All introduced mutations and the deletion were retained during repeated virus passages in culture, and no phenotypic reversion was observed. The results of this study demonstrate that cleavage between p28 and p65 at CS1 is not required for MHV replication. However, proteolytic separation of p28 from p65 is necessary for optimal RNA synthesis and virus growth, suggesting important roles for these proteins in the formation or function of viral replication complexes.

scholarly journals Inhibition of Cellular Proteasome Activities Enhances Hepadnavirus Replication in an HBX-Dependent Manner

2004 ◽  
Vol 78 (9) ◽  
pp. 4566-4572 ◽  
Author(s):  
Zhensheng Zhang ◽  
Ulrike Protzer ◽  
Zongyi Hu ◽  
James Jacob ◽  
T. Jake Liang
Keyword(s):  
Recombinant Adenovirus ◽  
Hepatitis Virus ◽  
Proteasome Inhibitors ◽  
Productive Infection ◽  
Wild Type Virus ◽  
Dependent Manner ◽  
Type Virus ◽  
Wild Type

ABSTRACT The X protein (HBX) of the hepatitis B virus (HBV) is not essential for the HBV life cycle in vitro but is important for productive infection in vivo. Our previous study suggests that interaction of HBX with the proteasome complex may underlie the pleiotropic functions of HBX. With the woodchuck model, we demonstrated that the X-deficient mutants of woodchuck hepatitis virus (WHV) are not completely replication defective, possibly behaving like attenuated viruses. In the present study, we analyzed the effects of the proteasome inhibitors on the replication of wild-type and X-negative HBV and WHV. Recombinant adenoviruses or baculoviruses expressing replicating HBV or WHV genomes have been developed as a robust and convenient system to study viral replication in tissue culture. In cells infected with either the recombinant adenovirus-HBV or baculovirus-WHV, the replication level of the X-negative construct was about 10% of that of the wild-type virus. In the presence of proteasome inhibitors, the replication of the wild-type virus was not affected, while the replication of the X-negative virus of either HBV or WHV was enhanced and restored to the wild-type level. Our data suggest that HBX affects hepadnavirus replication through a proteasome-dependent pathway.

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