PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “NEWCASTLE DISEASE”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 883 records · Page 49Linked to original sources

Effect of thimerosal concentration on the efficacy of inactivated Newcastle disease oil-emulsion vaccines.

Different quantities of the preservative thimerosal in inactivated Newcastle disease oil-emulsion vaccines were tested to determine the influence on the hemagglutination-inhibition (HI) response of broilers. The effect of thimerosal was measured in vaccines that had been stored for 1, 21, and 52 weeks; HI serology was conducted at 2, 4, and 6 weeks after vaccination. Mean HI titers 4 weeks after vaccination decreased at a significant rate (P less than or equal to 0.001) with increasing concentrations of thimerosal. HI titers 4 weeks after vaccination with 1-week-old vaccine were significantly (P less than or equal to 0.05) higher than those after vaccination with 52-week-old vaccine at all thimerosal concentrations tested. Titers were also significantly higher (P less than or equal to 0.05) after vaccination with 1-week-old vaccine than after vaccination with 21-week-old vaccine at all thimerosal concentrations below about 8.25 mg/ml of antigen. Thimerosal at the levels recommended in commercial vaccines does not significantly decrease vaccine efficacy.

Animals↗

The 36K polypeptide synthesized in Newcastle disease virus-infected cells possesses properties predicted for the hypothesized 'V' protein.

Newcastle disease virus (NDV) virions possess two proteins which react strongly with monoclonal antibody 688 following separation by high resolution two-dimensional (isoelectric focusing/SDS) PAGE and detection by Western blotting. One is the phosphorylated nucleocapsid-associated 53K [P (NAP)] protein, the other comigrates with the 36K protein detected by radiolabelling NDV-infected chick embryo fibroblasts. [35S]Cysteine/[3H]leucine dual-labelling experiments show that the 36K protein is very rich in cysteine compared to the P (NAP) protein. In the Beaudette C strain it comigrates on one-dimensional SDS-polyacrylamide gels with the matrix protein (M); however, it is resolved from the slower migrating M protein from the Ulster strain of NDV. The size, strain-specific isoelectric point, high cysteine content and antigenic relatedness to the P (NAP) protein suggest that the 36K protein is the 'V' protein of NDV, the counterpart of which is found in other Paramyxoviridae.

Amino Acid Sequence↗

Separation and sugar component analysis of the oligosaccharides in the surface glycoproteins of Newcastle disease virus.

The precursor glycoproteins HN0 and F0 in the surface spikes of Newcastle Disease Virus strain Ulster as produced by MDBK cells, were found to contain 10.4 and 11.9 weight per cent, respectively, of the sugars typical for N-glycosidically linked glycoprotein glycans. A molar ratio of D-mannose:D-galactose: L-fucose:N-acetyl-D-glucosamine approaching 1.0:1.1:0.5:1.0 was found for HN0, and of 1.0:0.7:0.3:0.6 for F0. By a sequence of degradation (with pronase, with endo-beta-N-acetylglucosaminidase H [endo H], and by hydrazinolysis) and separation procedures (Concanavalin A-affinity and Biogel P-4 chromatography), the radiolabelled carbohydrate moieties of NDV HN0 and F0 (as oligosaccharitols) were separated into (at least) ten and eight fractions, respectively. Separate in vivo labelling with tritiated derivatives of the four sugars showed that both glycoproteins contain oligosaccharides of the oligomannosidic ("high mannose"), of the N-acetyllactosaminic ("complex"), as well as of the "mixed" type. The majority of the oligosaccharides in F0, but not of those in HN0, was found to be endo H-sensitive.

Carbohydrates↗

An electron microscopic study of MDBK cells persistently infected with Newcastle disease virus.

Ultrastructural examination of a line of MDBK cells persistently infected with Newcastle disease virus (MDBKpi cells) revealed the presence of cytoplasmic aggregates of both smooth and granular nucleocapsids. Only granular nucleocapsids aligned under modified areas of plasma membrane and were incorporated into virus particles. On the grounds of morphogenesis, there was no apparent explanation for the persistent, not-cytocidal nature of the infection. Both nuclear and cytoplasmic aggregates of smooth nucleocapsids were present in MDBKpi cells which had been held without subculture for between 40 and 130 days (aged MDBKpi cells). Modified areas of plasma membrane with associated alignment of nucleocapsids were not present in aged MDBKpi cells, and neither budding nor released virus particles were observed, indicating a block in virus maturation. It is suggested that the granular material coating granular nucleocapsids allows them to interact with modified areas of plasma membrane, thereby inducing virus budding. A deficiency of this material, as apparently occurs in aged MDBKpi cells, would therefore cause a block in virus maturation. The nature of this granular material is discussed, and we suggest that it consists of M protein.

Animals↗

The matrix protein of Newcastle disease virus localizes to the nucleus via a bipartite nuclear localization signal.

The Newcastle disease virus matrix (M) protein expressed from a cDNA clone is observed in the nucleus of transfected cells, displaying a localization pattern identical to that observed in virus-infected cells. To identify the nuclear localization signal (NLS) in the M protein, M gene mutants encoding deletion and amino acid substitution proteins were constructed and expressed transiently in COS-1 cells. Protein products were examined for intracellular localization using indirect immunofluorescence. Two basic amino acid clusters in the M protein were found to be required for nuclear localization since deletion of these basic clusters or substitution with random amino acids resulted in cytoplasmic localization. Substitution of pairs of basic amino acids with non-basic residues revealed that components from both basic regions are required for nuclear localization. This interdependence between two basic clusters suggests that the NLS in the M protein belongs to the newly described class of "bipartite" NLSs. Unlike most NLSs, M protein sequences containing the critical basic amino acid clusters fused to two different cytoplasmic reporter proteins failed to transport these proteins to the nucleus.

Amino Acid Sequence↗

Mutations in the cytoplasmic domain of the fusion glycoprotein of Newcastle disease virus depress syncytia formation.

The role of the cytoplasmic domain of the Newcastle disease virus fusion protein in syncytia formation was explored by characterizing the intracellular processing and activities of proteins with deletions and point mutations in this region. Deletion of the entire domain (amino acids 523 to 553) resulted in a protein which was minimally proteolytically cleaved and had no syncytia forming activity. Deletion of the carboxy terminal half of the domain (amino acids 540 to 553) resulted in a protein that was normally processed but had no syncytia forming activity. Deletion of amino acids 547 to 553 resulted in a protein with approximately 30% wild-type levels of activity while deletion of amino acids 550 to 553 yielded a protein with wild-type activity. The results suggested that amino acids 540 to 550 are important for syncytia formation and this conclusion was supported by two internal deletions as well as point mutations in this region. Mutation of two cysteine residues in and adjacent to the transmembrane domain, which are potential sites for fatty acid acylation, had no effect on syncytia formation either singly or in combination.

Amino Acid Sequence↗

Isolation and characterization of heat-resistant (HR) mutants of Newcastle disease virus.

Heat-resistant (HR) mutants (MR 70 and HR 74) of Newcastle disease virus (NDV) which exhibited significantly higher thermostability in their infectivity than wild-type virus were isolated and characterized. They differ from each other in their plaque morphology; HR 70 produces small turbid plaques, whereas those of HR 74 are large and clear. Cytopathogenicity of these mutants is much lower than that of the wild-type virus in cultured cells such as CEF, LLCMK2 and HeLa cells. Moreover, these HR mutants exhibited extended mean embryo survival times. Synthesis of cellular RNA's and proteins in cells infected with HR mutants was not significantly reduced under conditions in which synthesis of these macromolecules was strongly reduced in cells infected with wild-type virus. No significant differences were observed between HR mutants and wild-type virus in their other phenotypic characteristics such as the capacity for interferon production, growth characteristics at a low multiplicity of infection, and cleavage of viral glycoproteins in infected cells. From these findings, it was suggested that the inhibitory effect of virus infection on cellular macromolecular synthesis is a possible determinant of cytopathogenicity of NDV.

Animals↗

Inhibition of the assembly of Newcastle disease virus by monensin.

Monensin inhibits the intracellular transport of the glycoproteins of Newcastle disease virus between cis and trans Golgi stacks of infected BHK cells, as evidenced by its effect upon their post-translational modifications such as fatty acid acylation, glycosylation and proteolytic cleavage. Thus the drug has markedly altered the subcellular distribution of the glycoproteins so that they accumulate in the internal smooth membranes but are virtually absent in the plasma membrane. These glycoproteins that accumulated in intracellular membranes have a cytoplasmic domain susceptible to protease digestion and thus are transmembranous. Under such conditions, the behavior of M protein, which plays a crucial role in virus assembly (Y. Nagai et al., 1976, Virology 69, 523-538), has been analyzed. It has been found that the M protein can neither associate with the internal membranes nor bind to the plasma membrane. Thus no virus budding has been observed, either at the plasma membranes or at internal membranes. These results substantiate the view that the interaction between M and glycoproteins is of great importance for virus assembly and suggest further that this interaction is possibly only when the glycoproteins have been incorporated into the plasma membrane.

Animals↗

Molecular changes of the fusion protein gene of chicken embryo fibroblast-adapted velogenic Newcastle disease virus: effect on its pathogenicity.

Molecular changes of cell culture-adapted Newcastle disease virus (NDV) were studied by adapting a velogenic NDV isolated from commercial layer chicken-to-chicken embryo fibroblast (CEF) cells. The isolate was passaged 50 times in CEF cells. At every 10th passage the virus was characterized conventionally by mean death time analysis, intracerebral pathogenicity index, and virus titration. As the passage level increased, a gradual reduction in the virulence of the virus was observed. Molecular characterization of the virus included cloning and sequencing of a portion of the fusion gene (1349 bp) encompassing the fusion protein cleavage site (FPCS), which was previously amplified by reverse transcription-polymerase chain reaction. Sequence analysis revealed a total of 134 nucleotide substitutions, which resulted in the change of 41 amino acids between the parent and the 50th passage virus. Pathogenicity studies conducted in 20-wk-old seronegative chickens revealed gross and histopathologic changes in the chickens injected with the parent virus and absence of the lesions in chickens injected with the adapted virus. The 50th passage cell culture virus was back-passaged five times in susceptible chickens and was subjected to virulence attribute analysis and sequence analysis of the FPCS region, with minor differences between them.

Adaptation, Biological↗

Acidic pH enhancement of the fusion of Newcastle disease virus with cultured cells.

Fusion of the lentogenic strain "Clone 30" of Newcastle disease virus (NDV) with the cell line COS-7 has been studied. Fusion was monitored using the octadecylrhodamine B chloride dequenching assay [Hoekstra, D., de Boer, T., Klappe, K. and Wilschut, J. (1984). Biochemistry 23, 5675-5681]. In the present work, fusion of NDV with COS-7 cells was found to occur in a time- and temperature-dependent fashion. Significant dequenching of the probe occurred at temperatures higher than 28 degrees C. A 20-fold excess of unlabeled virus inhibited fusion by about 53% compared with the control, whereas 62% inhibition of fusion was obtained after digestion of viral glycoproteins with trypsin. The data are discussed in terms of the nonfusion transfer of the probe. In addition, preincubation of cells with 50 mM ammonium chloride or 0.1% sodium azide prevented NDV from fusing with COS-7 cells by about 30% in comparison with the control. The cytopathic effect of NDV infection in cell culture in the presence of ammonium chloride was reduced compared with control. Moreover, viral preincubation at pH 5 yielded a mild inhibition of fusogenic activity. Our results suggest that NDV may use the endocytic pathway as a complementary way of entering cells by direct fusion with the plasma membrane.

Ammonium Chloride↗

Crystallization of Newcastle disease virus hemagglutinin-neuraminidase glycoprotein.

The hemagglutinin-neuraminidase (HN) glycoprotein of Newcastle disease virus was isolated by cleaving HN (cHN) from reconstituted virosome with chymotrypsin. N-terminal sequence analysis of the purified cHN showed that chymotrypsin cleavage had occurred at amino acid 123, freeing the C-terminal 454 amino acids. The purified cHN retained its neuraminidase and receptor binding activities and reacted with specific monoclonal antibodies, showing that the isolated cHN was biologically and antigenically functional. The crystals of the cHN were obtained in acetate buffer (pH 4.6) containing polyethylene glycol 3350 and ammonium sulfate and belong to the orthorhombic space group P2(1)2(1)2(1) with unit cell dimension of approximately a = 72 A, b = 78 A, and c = 198 A. Crystals of cHN grown in the presence of sialic acid (Neu5Ac) were grown in HEPES buffer (pH 6.2) containing polyethylene glycol 3350 and belong to the hexagonal space groups P6(1) or P6(5) with unit cell dimensions of a = b = 137.5 A and c = 116.6A. The orthorhombic crystals produced in this study diffract X rays to at least 2.0-A resolution, thereby setting the stage for the solution of the three-dimensional structure of the HN glycoprotein of a paramyxovirus.

Amino Acid Sequence↗

Genome replication of Newcastle disease virus: involvement of the rule-of-six.

We examined replication of Newcastle disease virus (NDV) by using minigenomes consisting of the 3' leader and 5' trailer regions of NDV flanking a reporter gene encoding secreted placental alkaline phosphatase (SEAP). Negative-sense minigenome RNA was generated from transfected plasmid DNA by means of in vivo transcription. Subsequent replication of minigenome RNA was determined either after infection with NDV helpervirus or after contransfection with helperplasmids that expressed the essential viral replication proteins NP, P, and L. In both systems, efficient replication of minigenome RNA was observed only if the genome size was a multiple of six nucleotides. Hence, in these systems, replication of NDV minigenome RNA's is strictly dependent on the rule-of-six. When the supernatant from helpervirus-infected, transfected cells was used to infect fresh monolayers, efficient transfer of SEAP activity by virus-like particles was observed only if the size of the minigenome RNA obeyed the rule-of-six. However, after several serial passages, we also observed efficient transfer of SEAP activity by virus-like particles derived from minigenome RNA's that did not obey the rule-of-six. Evidence was obtained which indicated that successful replication of these minigenomes was not due to a change in genome size.

3' Untranslated Regions↗

Insensitivity of a ricin-resistant mutant of Chinese hamster ovary cells to fusion induced by Newcastle disease virus.

The role of membrane components in the interaction of cells with Newcastle disease virus (NDV) was studied using a ricin-resistant mutant of Chinese hamster ovary cells (CHO-15B), in which there is a deficiency in distal saccharides at the plasma membrane. Compared to the parental wild type, the mutant was shown to be 4- to 10-fold less sensitive to either fusion from without or fusion from within induced by NDV. The mutant and wild type were nearly indistinguishable with respect to other interactions with NDV. Viral attachment was investigated with 125I-labeled NDV and found to be comparable in both lines. Functionally equivalent amounts of hemagglutinin were produced, as measured by the fraction of cells positive for hemadsorption, or by the number of erythrocytes adsorbed per cell. No significant differences in the morphogenesis or yield of progeny virus were seen. The ability of the mutant to produce a fusion factor was measured by transfer of infected cells to uninfected monolayers. Infected CHO-15B cells were capable of inducing fusion normally in the indicator wild-type monolayers, but were incapable of inducing fusion in mutant monolayers. These results suggest that the insensitivity of the CHO-15B mutants to fusion may be due to inhibition of an early virus-cell interaction subsequent to viral attachment, whereas other events in infection appear to be unaffected by the cell surface mutation.

Adsorption↗

Nucleotide sequence analysis of the haemagglutinin-neuraminidase gene of Newcastle disease virus.

The nucleotide sequence of the haemagglutinin-neuraminidase (HN) gene of Newcastle disease virus (NDV) has been determined. The HN gene is 2031 nucleotides long, approximately 13.5% of the viral genome. The nucleotide sequence contains a single long open reading frame which would encode a protein of 577 amino acids, with a mol. wt. of 63,149. This is in good agreement with estimates of the molecular weight of the unglycosylated HN protein. Analysis of the amino acid sequence reveals six potential glycosylation sites and shows the major hydrophobic region to be close to the N terminus. This provides evidence for the N-terminal attachment of HN to the viral membrane. The hydrophilic nature of the extreme N-terminal amino acids suggests the absence of a cleaved signal sequence. Analysis of the long non-coding region at the 3' end of the mRNA encoded by the HN gene of NDV suggests a possible explanation for the origin of HN0 in extremely avirulent strains of NDV. There are regions of high homology between the deduced amino acid sequence of the NDV HN glycoprotein and the HN glycoproteins of two other paramyxoviruses, Sendai virus and simian virus 5 (SV5). An alignment of the HN amino acid sequences of these viruses shows 32% of amino acid residues are conserved between NDV and SV5, and 23% between NDV and Sendai virus. In contrast, only very limited homology is found between NDV HN and the influenza virus glycoproteins.

Amino Acid Sequence↗

Serum protease inhibitor abrogation of Newcastle disease virus enhancement of cytolysis by recombinant tumor necrosis factors alpha and beta.

Newcastle disease virus (NDV) has been used to induce regression of tumors in human cancer patients. We recently demonstrated that human malignant melanoma cells resistant to the lytic effects of tumor necrosis factor-alpha (TNF-alpha) become susceptible after treatment with NDV. We examined the effects of a serine protease inhibitor, N-1-tosylamide-2-phenyl-ethyl-chloromethyl ketone (TPCK), on viral enhancement of TNF cytotoxicity. Virulent NDV (but neither heat- nor UV-inactivated NDV) induced a 100-fold increase in the sensitivity of murine fibroblast L929 cells to recombinant human TNF-alpha (rHuTNF-alpha), rHuTNF-beta, and recombinant murine TNF-alpha (rMuTNF-alpha). TPCK, which is an inhibitor of chymotrypsin-like proteases, blocked between 42% and 93% of the cytolytic activity of rMuTNF-alpha, rHuTNF-alpha, and rHuTNF-beta toward NDV-treated L929 cells. Similarly, TPCK abrogated 62% of the cytotoxicity of rMuTNF-alpha toward dactinomycin-treated L929 cells. In contrast, TPCK had no effect on WEHI 164 clone 13 cells, a murine fibrosarcoma cell line that is much more sensitive to the lytic effects of TNF and does not show enhanced sensitivity to TNF after treatment with either NDV or dactinomycin. These results suggest a role for a cellular protease in the mechanism by which some viruses sensitize tumor cells to the cytolytic activity of TNF.

Amino Acid Chloromethyl Ketones↗

A survey of Newcastle disease in Swiss laying-hen flocks using serological testing and simulation modelling.

Newcastle disease (ND) is a highly contagious viral disease of birds particularly domestic poultry. Switzerland is currently declared free from ND; since vaccination is prohibited, the detection of antibodies against ND virus (NDV) results in the destruction of the respective flock (stamping-out policy). However, in 1995 and 1996, antibody-positive flocks were detected and sporadic ND outbreaks even occurred in Switzerland. Therefore, a serosurvey was done to look for evidence of NDV infections in Swiss laying-hen flocks. The survey was designed to provide 95% confidence of detecting at least one seropositive flock if the flock prevalence were 1%. Thirty blood samples from each of 260 commercial laying-hen flocks were collected during 1996 in a central poultry slaughterhouse. Sera were screened for NDV antibodies with a commercial blocking enzyme-linked immunosorbent assay (ELISA). Samples with a questionable or positive test result were retested with the same ELISA. A stochastic computer model was applied to define a cut-off number of test-positive samples to help to differentiate between true- and false-positive flocks and to estimate the true flock prevalence of infection. Four flocks were identified as NDV-seropositive and the NDV true seroprevalence among commercial laying-hen flocks in Switzerland was most likely between 1.35 and 1.55%. This indicates that Swiss laying-hen and parental flocks with more than 150 animals have been in contact with strains of NDV that cause subclinical infection in chicken, because no clinical symptoms have been observed. In this context, computer simulation was a useful technique to interpret survey results.

Animals↗