Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “VIRAL INTERFERENCE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 973 records · Page 54Linked to original sources
PubMed1969

Interaction between cytomegalovirus and Newcastle disease virus as mediated by intrinsic interference.

Cytomegalovirus (CMV) was demonstrated to induce intrinsic interference to Newcastle disease virus (NDV) in human fibroblast cells under noncytopathic conditions. This interference is unique in that (i) cytomegalovirus is the first DNA virus demonstrated to have this property and (ii) the state of interference was transient and progressively lost as the condition of the cells changed with the development of cytopathic effect. These observations are consistent with the view that the newly formed protein responsible for interference with NDV has a limited half-life and is no longer made when cytopathic conditions are produced by CMV.

Cell Line↗
PubMedDate not supplied

Identification of field isolates of infectious bronchitis virus by interference with the La Sota of strain of Newcastle disease virus.

The interference phenomenon of infectious bronchitis virus (IBV) with growth of Newcastle disease virus (NDV) in embryonating chicken eggs (ECE) was used as a diagnostic method. Fifteen field isolates obtained from presumptively infectious-bronchitis-affected chickens were analyzed by the IBV-NDV interference test. Eight isolates were capable of interfering with the growth of the La Sota strain of NDV, as measured by hemagglutination (HA) activity when IBV was inoculated 10 hr before NDV into ECE. The interference was considered specific for IBV, because it could be eliminated by adding homologous anti-IBV serum. The sensibility of this method could be demonstrated, because in some cases low-passage levels of IBV isolates showing HA interference ability were not capable of producing lesions in ECE. Furthermore, serologically negative IBV samples did not interfere with NDV growth. From these results, the IBV-NDV interference test appears to be a potential diagnostic alternative for identifying IBV field isolates.

Animals↗
PubMed1985

[Characteristics of virion formation during mixed infection with influenza viruses A and B].

Simultaneous infection of MDCK cells with influenza A and B viruses at an equal multiplicity of infection leads to the synthesis of the proteins of both viruses. In the population of virions the hemagglutinin of influenza B virus prevails, whereas NP proteins of both viruses are present in similar quantities. Trypsin treatment of the double-infected cells resulting in the cleavage of the hemagglutinin molecules at the cell surface allows revealing the predominance of influenza B hemagglutinin on cell surface, although both hemagglutinins are accumulated in the cells. An impairment of the hemagglutinin transport to the cell surface as a possible additional mechanism of heterotypic interference and its possible effect on the polypeptide content of the phenotypically mixed virions are discussed.

Animals↗
PubMed1976

Interference stimulated by tick-borne encephalitis virus: influence of divalent cations.

The effects of divalent cations (barium, cobalt, calcium, copper, magnesium, zinc and iron) on the interference of tick-borne encephalitis (TE) virus with vaccinia virus in Detroit-6 cell cultures were investigated. An increase in interference was shown in the presence of cobalt, zinc, copper, and magnesium. Barium and iron displayed a marked inhibitory action. But an increase in interference was not parallel with an increased production of interferon.

Barium↗
PubMed2003

The effect of bovine lactoferrin and lactoferricin B on the ability of feline calicivirus (a norovirus surrogate) and poliovirus to infect cell cultures.

AIMS: To characterize the effect of bovine lactoferrin and lactoferricin B against feline calicivirus (FCV), a norovirus surrogate and poliovirus (PV), as models for enteric viruses. METHODS AND RESULTS: Crandell-Reese feline kidney (CRFK) cells were used for the propagation of FCV and monkey embryo kidney (MEK) cells for PV. The assays included visual assessment of cell lines for cytopathic effects and determination of the percentage cell death using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium] dye reduction assay. Incubation of bovine lactoferrin with CRFK cells either prior to or together with FCV inoculation substantially reduced FCV infection. In contrast, the interference of lactoferrin with the infection of cells with PV was demonstrated only when lactoferrin was present with cell lines and virus for the entire assay period. Using indirect immunofluorescence, lactoferrin was detected on the surface of both CRFK and MEK cells, suggesting that the interference of viral infection may be attributed to lactoferrin binding to the surfaces of susceptible cells, thereby preventing the attachment of the virus particles. Lactoferricin B, a cationic antimicrobial peptide derived from the N-terminal domain of bovine lactoferrin, reduced FCV but not PV infection. CONCLUSION: Lactoferrin was shown to interfere with the infection of cells for both FCV and PV. However, lactoferricin B showed no interference of infection with PV and interference with infection for FCV required the presence of lactoferricin B together with the cell line and virus. SIGNIFICANCE AND IMPACT OF THE STUDY: An in vitro basis is provided for the effects of bovine lactoferrin and lactoferricin B in moderating food-borne infections of enteric viruses.

Animals↗
PubMedDate not supplied

[Mechanism of postvaccinal immunity in Marek's disease].

The apathogenic variant No. 38 of Marek's disease virus, Kekava strain (MDV-Kekava), at the level of the 16th and 45th passages in vitro made chickens resistant to Marek's disease when inoculated 14 days before the infection of the chickens with the pathogenic variant No. 55 of MDV-Kekava. A simultaneous administration of both variants did not protect the animals against the disease. The occurrence in variants of MDV-Kekava of genetic markets manifest upon virus passages in chick embryo fibroblast (CEF) cultures provided an opportunity to study the interactions between them in chickens, using the CEF culture for virus isolation. The results of virus isolation from the blood cells of vaccinated chickens showed interference to occur in chickens between the virus variants as the rate of isolation of the pathogenic variant was 3 times as low as that of apathogenic MDV-Kekava, and both virus variants persisted in different cells. When chickens were inoculated simultaneously with both virus variants, the recovery rate of both pathogenic and apathogenic variants from the blood cells was similar. In such cases, persistence of two virus variants in one cell is also possible. The experimental results suggest that in the mechanism of resistance of vaccinated chickens to Marek's disease a significant role may be played by interference between the viruses in which the "occupation" of target cells by vaccine virus protects them from pathogenic MDV.

Animals↗
PubMed1993

In vivo infection of sheep by bovine leukemia virus mutants.

Direct inoculation of a cloned bovine leukemia virus (BLV) provirus into sheep has allowed study of the viral infectivity of genetic mutants in vivo. Three BLV variants cloned from BLV-induced tumors and 12 in vitro-modified proviruses were isolated and analyzed for viral expression in cell culture. The proviruses were then inoculated into sheep in order to assess viral infectivity in vivo. Of three variants cloned from BLV-induced tumors (344, 395, and 1345), one (344) was found infectious in vivo. This particular provirus was used to engineer 12 BLV mutants. A hybrid between the 5' region of the complete but noninfectious provirus 395 and the 3' end of mutant 344 was infectious in vivo, suggesting that the tax/rex sequences were altered in virus 395. As expected, several regions of the BLV genome appeared to be essential for viral infection: the protease, pol, and env genes. Even discrete modifications in the fusion peptide located at the NH2 end of the transmembrane gp30 glycoprotein destroyed the infectious potential. In contrast, mutations and deletions in the X3 region present between the env gene and the 3' tax/rex region did not interfere with viral infection in vivo. This region of unknown function could thus be used to introduce foreign sequences. A BLV recombinant carrying a ribozyme directed against the tax/rex sequences was still infectious in vivo. Cotransfection of two noninfectious mutants carrying deletions led to infection in two of four independent injections, the infectious virus being then a recombinant between the two deletants. The experimental approach described here should help to gain insight into essential mechanisms such as in vivo viral replication, cooperation between deletants for viral infectivity, and viral superinfections. The gene products in the X3 and X4 region which are dispensable for in vivo infection could be involved in leukemogenesis, and thus proviruses deleted in these sequences could constitute the basis for a live attenuated vaccine.

Animals↗
PubMed1982

The effect of defective-interfering Semliki Forest virus on the histopathology of infection with virulent Semliki Forest virus in mice.

The majority of mice inoculated with a mixture of a lethal dose of virulent Semliki Forest virus (SFV) strain ts+ and defective-interfering (DI) SFV remained completely health, with virus infectivity levels in brain tissue reduced by 99.9%. The results of previous studies had suggested that these effects were primarily the result of the intrinsic interfering capacity of DI virus rather than of host defense responses. Because SFV strain ts+ and an avirulent strain of SFV have clearly distinguishable histopathologic effects in brain tissue, the capability of DI virus to change the virulent into the avirulent form of the disease was examined. Modulation of strain ts+ virus infection by DI virus was accompanied by a complete absence of histopathologic changes despite significant levels of infectious virus and thus differed qualitatively from infection with avirulent SFV. These results provide further evidence that the interference is not mediated through stimulation of an immune cell infiltration.

Animals↗
PubMed1976

Enhanced resistance of mice to infection with Langat (TP21) virus following pre-treatment with Sindbis or Semliki forest virus.

Significant protection to heterologous i.c. challenge with the flavovirus Langat occurred after a single i.c. injection of avirulent strains of the alpha viruses Semliki Forest or Sindbis given 1 day to 5 weeks before challenge. Some protection also occurred after an i.p. infection with these viruses. We consider that the protection afforded by the alpha viruses is due to interference with the multiplication of Langat virus and is related to the maximum level of brain infectivity reached in the alpha virus infection.

Animals↗
PubMed1965

Hemadsorption-negative plaque test: new assay for rubella virus revealing a unique interference.

A simple and rapid plaque procedure has been developed for detecting and accurately assaying rubella virus in a noncytopathic virus-cell relationship. Plaque-formation is based on the development, in individual cells infected with rubella virus, of a unique type of intrinsic interference to infection with Newcastle disease virus. Rubella virus-infected cells challenged with Newcastle disease virus and tested for hemadsorption 15 hours later stand out as hemadsorption-negative areas. Individual living cells infected with rubella virus can be resolved under conditions allowing standard cloning procedures. In principle, the hemadsorption-negative plaque test can be used to search for a new class of noncytopathic, non-hemadsorbing viruses-those that induce an intrinsic interference to infection by any hemadsorbing virus.

Animals↗
PubMed1976

Comparison of vesicular stomatitis virus defective interfering particle synthesis in chick embryo and L cells.

A comparison of the ability of vesicular stomatitis virus (VSV) to generate and replicate defective interfering (DI) particles in primary chick embryo (CE) and mouse L cells was investigated as a means of analyzing host control over DI-particle synthesis and interfering capacity. Serial undiluted passage of VSV in CE and L cells indicate that VSV-DI particles are generated and (or) replicate with greater efficiency in CE than in L cells. When DI particles accumulate in L cells, they are able to interfere with infectious particle replication. The DI particles from CE cells interfered to the same extent with infectious particle replication in both CE and L cells. L cells, therefore, are not considered 'low-interference' hosts in which DI particles are produced and do not interfere with infectious virus replication, but rather hosts which restrict the production of DI particles.

Animals↗
PubMed1988

Randomised trial of alternative formulations of oral poliovaccine in Brazil.

In February to July, 1986, an outbreak of type 3 poliomyelitis occurred in north-east Brazil that was linked to type-specific failure of trivalent oral polio vaccine (TOPV). To see if alternative vaccines would improve seroconversion to type 3, 441 children less than 5 years of age who had previously received no or up to four doses of TOPV were randomly assigned to receive one dose of standard TOPV (1,000,000, 100,000, and 300,000 median tissue culture infection doses [TCID50] of types 1, 2, and 3, respectively); a new formulation of TOPV containing twice the dosage of type 3 (600,000 TCID50); or a monovalent vaccine containing 300,000 TCID50 of type 3. While rates of seroconversion to types 1 or 2 were equivalent following vaccination with either formulation of TOPV, children who received the new formulation were 2.7 times more likely to seroconvert to type 3. Similar differences for type 3 were observed when monovalent vaccine was compared with standard TOPV, though both groups had received the same dose of type 3 antigen. The low rate of seroconversion to type 3 in the standard TOPV group was associated with a higher rate of reinfection with type 2, which also appeared to interfere to some extent with seroconversion to type 1. These findings extend earlier observations that interference from Sabin type 2 virus may be an important contributory cause of type-specific TOPV failure, and suggest that interference can be overcome with alterations in the formulation.

Antibodies, Viral↗
PubMed2002

Long-distance movement, virulence, and RNA silencing suppression controlled by a single protein in hordei- and potyviruses: complementary functions between virus families.

RNA silencing is a natural defense mechanism against genetic stress factors, including viruses. A mutant hordeivirus (Barley stripe mosaic virus [BSMV]) lacking the gammab gene was confined to inoculated leaves in Nicotiana benthamiana, but systemic infection was observed in transgenic N. benthamiana expressing the potyviral silencing suppressor protein HCpro, suggesting that the gammab protein may be a long-distance movement factor and have antisilencing activity. This was shown for gammab proteins of both BSMV and Poa semilatent virus (PSLV), a related hordeivirus. Besides the functions in RNA silencing suppression, gammab and HCpro had analogous effects on symptoms induced by the hordeiviruses. Severe BSMV-induced symptoms were correlated with high HCpro concentrations in the HCpro-transgenic plants, and substitution of the gammab cistron of BSMV with that of PSLV led to greatly increased symptom severity and an altered pattern of viral gene expression. The efficient systemic infection with the chimera was followed by the development of dark green islands (localized recovery from infection) in leaves and exemption of new developing leaves from infection. Recovery and the accumulation of short RNAs diagnostic of RNA silencing in the recovered tissues in wild-type N. benthamiana were suppressed in HCpro-transgenic plants. These results provide evidence that potyviral HCpro and hordeivirus gammab proteins contribute to systemic viral infection, symptom severity, and RNA silencing suppression. HCpro's ability to suppress the recovery of plants from viral infection emphasizes recovery as a manifestation of RNA silencing.

Cysteine Endopeptidases↗
PubMed1981

Effects of monoparacoumarylputrescinium chloride on the hypersensitive reaction of Gomphrena globosa leaves to tomato bushy stunt virus.

Monoparacoumarylputrescinium chloride (pCPH), supplied to detached leaves of Gomphrena globosa via the petiole, induced interference with tomato bushy stunt virus infection by reducing the number and size of the necrotic local lesions. The phenolic compound neither inactivated directly the virus in vitro, nor induced interference when supplied just after virus inoculation, all this indicating an effect on cell metabolism. The interference was positively correlated to both pCPH concentration and time of induction (viz., the intervals between pCPH supply and inoculation). Coumaric acid did not, whereas putrescine, but not spermidine or spermine, did induce interference. Disc electrophoresis in polyacrylamide gels revealed no changes in the soluble protein constitution between pCPH-treated and control leaves.

Coumaric Acids↗
PubMed1978

Classification of the New Jersey serotype of vesicular stomatitis virus into two subtypes.

We propose a reclassification of five strains of the New Jersey serotype of vesicular stomatitis virus into two subtypes designated Concan and Hazelhurst. This subclassification into two subtypes is based on reciprocal differences in antibody neutralization of virion infectivity, nucleotide base sequence homology, oligonucleotide maps of virion RNA, and interference by defective-interfering particles.

Base Sequence↗