- Volume 67, Issue 6, 1986
Volume 67, Issue 6, 1986
- Animal
-
-
-
Persistence of Virulent Semliki Forest Virus in Mouse Brain Following Co-inoculation with Defective Interfering Particles
More LessSummarySemliki Forest virus (SFV) normally causes an acute lethal encephalitis in mice following intranasal inoculation. However, animals co-administered with 10 LD50 SFV and defective interfering (DI) SFV survive the infection without clinical signs of disease. In this report we demonstrate the isolation of infectious virus from the brains of 12/169 protected mice up to 6.5 months post-infection. Although, with one exception, mice were clinically normal, five of 12 of the SFV isolates were identical to the original virus as judged by plaque morphology, maximum temperature for growth, virulence in mice and pathology. Others were less virulent (although not any were plaque or temperature-sensitive mutants) and on re-inoculation into fresh mice caused a demyelinating pathology which was not an attribute of the original inoculum. How the virulent virus can persist in brain, sometimes in amounts in excess of 100 LD50, without causing disease remains to be determined.
-
-
-
-
Very Rapid Generation/Amplification of Defective Interfering Particles by Vesicular Stomatitis Virus Variants Isolated from Persistent Infection
More LessSummaryMultiply cloned variants of vesicular stomatitis virus (VSV) were found to generate/amplify defective interfering (DI) particles at a rate greatly exceeding the rates normally observed for wild-type VSV (or for other mutants of VSV). A single undiluted passage of the first clonal pool of this variant virus produced concentrated visible bands of DI particles on sucrose gradients whereas wild-type and other mutant strains of VSV required from three to six or more serial undiluted passages. Since DI particle amplication by wild-type VSV at each undiluted passage can exceed 10000-fold enrichment, these variant virus clones were generating/amplifying DI particles many millions of times more rapidly than were wild-type and other mutant strains of VSV. This rate of generation/amplification is so high that it was not feasible to obtain accurate estimates of the rates of generation (or amplification) of these DI particles.
-
-
-
Anomalous Behaviour of Newcastle Disease Virus Haemagglutinin-Neuraminidase Protein in Western Blotting Analysis of Monoclonal Antibody Binding Sites
More LessSummaryPrevious studies with a particular monoclonal antibody (MAb 445) raised against the Ulster strain of Newcastle disease virus (NDV) have shown that this MAb immune-precipitates only the 74000 mol. wt. (74K) haemagglutinin-neuraminidase protein (HN) of both Ulster and Beaudette C strains of NDV. Using the technique of Western blotting, it is shown that under certain denaturing conditions virion proteins comigrating in SDS-polyacrylamide gels with the faster migrating 67K fusion protein and 53K nucleocapsid/nucleocapsid-associated protein, as well as the 74K HN, all reacted strongly with MAb 445 and with MAb 14 which is also directed against the HN protein. Analysis of this anomalous behaviour using SDS-polyacrylamide diagonal gel electrophoresis has led to the unexpected conclusion that the 74K HN can electrophorese as three immunoreactive species of apparent mol. wt. 74K, 67K and 53K. If the Western blotting technique is to be applied to proteins which have not been sufficiently denatured (in an attempt to preserve epitope integrity) it is important to establish that no additional proteins remain associated with the protein bands that react with the MAb.
-
-
-
Binding of Murine 125I-labelled Natural Interferon-γ to Murine Cell Receptors
More LessSummaryNatural murine interferon-γ (naMuIFN-γ) produced by T-lymphoma cells (L12-R4) stimulated with phorbol myristic acetate was purified by use of an anti-MuIFN-γ immunoadsorbent and was labelled with 125I to study its binding to murine cell receptors. All the cell lines examined bound naMuIFN-γ, although the binding affinity varied considerably. By adding increasing concentrations of unlabelled naMuIFN-γ in competition binding assays we determined dissociation constants (K D) of 8.2 × 10−10 and 7.4 × 10−10 m for L1210 and TS/A cells, respectively, and of 6.5 × 10−9 m for L-929 cells. The numbers of receptors present per cell of these lines were 3000, 1000 and 2000 respectively. Highly purified naMuIFN-γ as well as recombinant MuIFN-γ competed for binding sites with 125I-labelled IFN-γ on L1210 cells, although the latter displayed a K D greater than the former (5.8 × 10−9 m compared to 8.2 × 10−10 m). Moreover, protease, but not endoglycosidase, treatment of target cells prevented the subsequent binding of 125I-labelled IFN-γ, suggesting that a protein moiety is involved in the binding of the ligand. These studies demonstrate that naMuIFN-γ binds in a specific manner and with high affinity to murine cell receptors.
-
-
-
Enhancement by Carprofen or Indomethacin of Interferon Induction by 10-Carboxymethyl-9-Acridanone in Murine Cell Cultures
More LessSummaryNon-steroidal anti-inflammatory drugs such as carprofen or indomethacin enhanced interferon (IFN) production induced by suboptimal concentrations of 10-carboxy-methyl-9-acridanone (CMA) in murine cell cultures. This effect was observed in fibroblasts and in different populations of leukocytes as in peritoneal exudate and spleen cells, and was most pronounced in bone marrow-derived macrophages. Carprofen was the most effective compound causing an up to 500-fold increase of CMA-induced IFN production in pure bone marrow-derived macrophages. In these macrophage cultures the potentiating effect on CMA-induced IFN production by carprofen and indomethacin did not depend on inhibition of cyclooxygenase.
-
- Plant
-
-
-
Kinetics of Accumulation of the Three Non-structural Proteins of Alfalfa Mosaic Virus in Tobacco Plants
More LessSummaryAntisera to synthetic peptides corresponding to the C-termini of two non-structural proteins (NSP) of alfalfa mosaic virus (AIMV), P1 (126K) and P3 (32K), were prepared and characterized. These antisera, together with one which had previously been made against the C-terminus of P2 (90K), enabled us to detect the three NSPs in a crude membrane fraction from AlMV-infected tobacco leaves. The accumulation of these proteins at 25 °C and at 10 °C was followed as a function of time after inoculation, and their amounts were compared with viral replicase activity. All three proteins accumulated at the beginning of the infection period and then disappeared, P3 more rapidly than the other two. There was a good correlation between replicase activity and the amounts of P1 and P2, but not the amount of P3. These results are consistent with the notion that P1 and P2 are part of the replication complex. Although much less coat protein was made in inoculated leaves at 10 °C than at 25 °C, the maximum amounts of the three NSPs and the maximum replicase activity were at least as high at 10 °C as at 25 °C. Thus, 10 °C is not a restrictive temperature for the assembly of a functional replication complex.
-
-
-
-
Translation of Cymbidium Ringspot Virus RNA in Cowpea Protoplasts and Rabbit Reticulocyte Lysates
More LessSummaryRNA from cymbidium ringspot virus (CyRSV), a tombusvirus, was translated in rabbit reticulocyte lysates and in vitro translation products were compared with virus-specific proteins in extracts of cowpea protoplasts inoculated with virus particles. Four major polypeptides were produced in vitro, with molecular weights of 43000 (43K), 40K, 34K and 22K, and three were produced in vivo, with molecular weights of 45K, 43K and 22K. The 43K and probably also the 22K product were the same in vitro and in vivo; the former was definitely identified as the virus coat protein. The 45K protein was a modified coat protein found only in extracts of infected protoplasts that had been frozen. Translation experiments with size-fractionated RNA indicated that the translation strategy of CyRSV RNA involved, as templates, both genome-size RNA (40K product) and subgenomic species (43K, 34K and 22K products). The presence of at least three coding regions on the virus genome was suggested by comparative peptide mapping of the four major translation products. No infection-specific polypeptides or translation products were detected as specific to satellite RNA, either in inocula for protoplasts or in RNA added to reticulocyte lysates.
-
-
-
Virus Protein Association with Cylindrical Inclusions of Two Viruses that Infect Wheat
More LessSummaryImmunoelectron microscopy with gold-labelled antibodies showed that homologous capsid proteins or virions are associated with cylindrical inclusions of wheat streak mosaic virus and of wheat spindle streak mosaic virus in vivo. Capsid proteins did not bind to any other structure in the cell. The specific association of capsid proteins with cylindrical inclusions is discussed in relation to cell-to-cell spread of virions through plasmodesmata.
-
-
-
Comparison of the Genome RNA Sequence Homologies between Isolates of Cherry Leaf Roll Virus by Complementary DNA Hybridization Analysis
More LessSummaryThe sequence homologies between the RNA genomes of seven European and one North American isolate of cherry leaf roll virus (CLRV) were compared using cDNA hybridization analysis. A high degree of homology (85 to 95%) was detected between birch and cherry isolates of the virus, but lower levels of homology (46 to 48%) were inferred when these were compared with a rhubarb or a North American dogwood isolate of CLRV.
-
Volumes and issues
-
Volume 105 (2024)
-
Volume 104 (2023)
-
Volume 103 (2022)
-
Volume 102 (2021)
-
Volume 101 (2020)
-
Volume 100 (2019)
-
Volume 99 (2018)
-
Volume 98 (2017)
-
Volume 97 (2016)
-
Volume 96 (2015)
-
Volume 95 (2014)
-
Volume 94 (2013)
-
Volume 93 (2012)
-
Volume 92 (2011)
-
Volume 91 (2010)
-
Volume 90 (2009)
-
Volume 89 (2008)
-
Volume 88 (2007)
-
Volume 87 (2006)
-
Volume 86 (2005)
-
Volume 85 (2004)
-
Volume 84 (2003)
-
Volume 83 (2002)
-
Volume 82 (2001)
-
Volume 81 (2000)
-
Volume 80 (1999)
-
Volume 79 (1998)
-
Volume 78 (1997)
-
Volume 77 (1996)
-
Volume 76 (1995)
-
Volume 75 (1994)
-
Volume 74 (1993)
-
Volume 73 (1992)
-
Volume 72 (1991)
-
Volume 71 (1990)
-
Volume 70 (1989)
-
Volume 69 (1988)
-
Volume 68 (1987)
-
Volume 67 (1986)
-
Volume 66 (1985)
-
Volume 65 (1984)
-
Volume 64 (1983)
-
Volume 63 (1982)
-
Volume 62 (1982)
-
Volume 61 (1982)
-
Volume 60 (1982)
-
Volume 59 (1982)
-
Volume 58 (1982)
-
Volume 57 (1981)
-
Volume 56 (1981)
-
Volume 55 (1981)
-
Volume 54 (1981)
-
Volume 53 (1981)
-
Volume 52 (1981)
-
Volume 51 (1980)
-
Volume 50 (1980)
-
Volume 49 (1980)
-
Volume 48 (1980)
-
Volume 47 (1980)
-
Volume 46 (1980)
-
Volume 45 (1979)
-
Volume 44 (1979)
-
Volume 43 (1979)
-
Volume 42 (1979)
-
Volume 41 (1978)
-
Volume 40 (1978)
-
Volume 39 (1978)
-
Volume 38 (1978)
-
Volume 37 (1977)
-
Volume 36 (1977)
-
Volume 35 (1977)
-
Volume 34 (1977)
-
Volume 33 (1976)
-
Volume 32 (1976)
-
Volume 31 (1976)
-
Volume 30 (1976)
-
Volume 29 (1975)
-
Volume 28 (1975)
-
Volume 27 (1975)
-
Volume 26 (1975)
-
Volume 25 (1974)
-
Volume 24 (1974)
-
Volume 23 (1974)
-
Volume 22 (1974)
-
Volume 21 (1973)
-
Volume 20 (1973)
-
Volume 19 (1973)
-
Volume 18 (1973)
-
Volume 17 (1972)
-
Volume 16 (1972)
-
Volume 15 (1972)
-
Volume 14 (1972)
-
Volume 13 (1971)
-
Volume 12 (1971)
-
Volume 11 (1971)
-
Volume 10 (1971)
-
Volume 9 (1970)
-
Volume 8 (1970)
-
Volume 7 (1970)
-
Volume 6 (1970)
-
Volume 5 (1969)
-
Volume 4 (1969)
-
Volume 3 (1968)
-
Volume 2 (1968)
-
Volume 1 (1967)