- Volume 27, Issue 2, 1975
Volume 27, Issue 2, 1975
- Articles
-
-
-
Royal Society Discussion Meeting
To be held on Wednesday and Thursday 18th and 19th June 1975 at 6 Carlton House Terrace, London SW1Y 5AG.
Anyone interested is welcome to attend but should first apply to the Executive Secretary at the above address for further details, quoting reference: 92/PMR. Telephone enquiries to (01)839-5561, extension 278.
-
-
-
-
Host Components in Hepatitis B Antigen
More LessSUMMARYPurified [125I]-labelled 20 to 25 nm hepatitis B antigen particles were found to give low affinity immunoprecipitation reactions with antisera to several normal serum components, which were immunologically distinct from the reaction due to the classical hepatitis B antigen surface determinant. These additional antigenic determinants were acid-stable and tightly bound to the particles; they could not be released by treatment with Tween 80 or ether, but were removed by protease digestion with the preservation of particle integrity. It was not possible to distinguish whether they were due to the presence of trace amounts of partly denatured serum components, or to a weak cross-reaction with antigens present in normal serum. The implications of this finding for hepatitis B antigen and antibody detection in sensitive assays are discussed. No evidence was found for native antigenic material, present in normal serum or normal liver cells, being integral to the structure of these particles.
-
-
-
Transformation by a Temperature Sensitive Mutant of Rous Sarcoma Virus in the Absence of Serum
More LessSUMMARYCultures of chicken embryo fibroblasts infected with the temperature-sensitive transformation mutant of Rous sarcoma virus, tsLA24PR-A, were arrested between mitosis and S phase by exposure to serum-free medium at the non-permissive temperature (41 °C) for 2 days. On shifting to the permissive temperature (35 °C) the cells assumed a transformed morphology and increased uptake of [2-3H]-deoxy-glucose. There was a concomitant increase in acid insoluble [3H]-thymidine uptake and the percentage of nuclei autoradiographically labelled with [3H]-thymidine. This suggests that the virus transforming function can cause stationary cells to enter their growth cycle.
The level of release of infectious virus was shown to decrease on cell cycle arrest in serum-free medium and not to recover on a shift to 35 °C, when cellular DNA synthesis and transformation was induced. Cultures rendered stationary in medium containing serum depleted of multiplication stimulating factor did not show this reduction in virus production.
-
-
-
A Classification of Virus Groups Based on the Size of the Particle in Relation to Genome Size
More LessSUMMARYFor 59 different viruses, when the amount of nucleic acid in the particle is related either to the dry weight of the particle or to the particle volume, two classes of virus groups emerge – those with enveloped or those with geometrical particles.
The enveloped viruses have particles with the following properties: (i) about 40 × 106 daltons of anhydrous weight per 106 daltons of nucleic acid; (ii) a particle volume of about 2 × 105 nm3 per 106 daltons of nucleic acid; (iii) a limiting lipoprotein membrane. These properties are qualitatively and quantitatively close to those of prokaryotic cells.
The geometric viruses have particles with roughly one-tenth the anhydrous mass per unit of nucleic acid and one twenty-fifth the particle volume per unit of nucleic acid. They do not possess a limiting lipoprotein membrane.
-
-
-
Evidence for a Host Cell Surface Antigen on the Envelope of Avian Tumour Viruses
More LessSUMMARYAvian sarcoma viruses of the A, B, C, D and E subgroups are inactivated about 100-fold by the serum of rabbits immunized against chick embryo (CE) cells, in the presence, but not in the absence, of complement. The inactivation is not due to the action of the antiserum and complement on the CE cell cultures used for virus assay, nor to anti-Forssman antibodies, but it is presumably due to antibodies to some antigen(s) common to the surface of CE cells and to the virus envelope. This host cell surface antigen (HSCA) is also present on the surface of the helper viruses RAV1 and RAV2 of Bryan strain Rous sarcoma virus. However, it cannot be said whether it is identical for viruses of all subgroups. A parallel electron microscopical study has revealed a characteristic swelling and loss of opacity to electrons of virus particles treated with the antiserum and complement, which appears to precede virolysis.
Avian sarcoma viruses are not inactivated, in the presence or absence of complement, by antiserum to BHK21 hamster cells transformed by RSV and carrying virus-induced surface antigen (VISA). Therefore, the virus particles do not carry any surface antigen common to transformed non-permissive and permissive cells.
-
-
-
Genetic Control of Resistance of Chick Embryo Cultures to RSV(RAV 50)
More LessSUMMARYThe genetic control of resistance of chick embryo cultures to RSV(RAV 50) was studied in crosses between the highly inbred Reaseheath lines, I, C and W and in the test-cross between WC(F1) and RPRL line 7. Embryo cultures resistant to RSV(RAV 2) were also resistant to RSV(RAV 50). Genetic analysis of the segregation results of resistance and susceptibility in the F2, back-crosses, and test-cross populations suggests that the tvb genes pleiotropically control the resistance of the embryo cultures to RSV (RAV 50).
-
-
-
Type C Virus Production by a Continuous Line of Pig Oviduct Cells (PFT)
More LessSUMMARYLate passages of the PFT porcine oviduct cell line spontaneously release a typical type C virus antigenically related to the type C virus released from the PK(15) porcine kidney cell line. The PFT virus was non-infective for a large variety of cell lines. Type C virus can also be induced by BrdU treatment from earlier passages of the PFT cell line.
-
-
-
The Formation of Virus Polyribosomes in L Cells Infected with Vaccinia Virus
More LessSUMMARYThe fate of early virus messenger RNA in the cytoplasm of vaccinia-infected L cells has been studied during the first hour after infection. The RNA is made in the virus core structure from which it is rapidly released. It accumulates in the polyribosome fraction, where at least 75% is bound to ribosomes through an EDTA-sensitive link. Three distinct structures have been identified as possible intermediates in virus polyribosome formation. The first is a ribonucleoprotein complex (RNP) in which virus RNA is associated with cellular proteins. A complex having apparently similar properties, is formed when virus RNA is added to a cytoplasmic extract in vitro. The other two structures may consist of an RNP moiety associated with the small ribosomal subunit, or with a single ribosome. At least part of the RNA isolated as RNP appears to be a precursor of the virus messenger found in polyribosomes.
-
-
-
The Effect of Interferon on the Formation of Virus Polyribosomes in L Cells Infected with Vaccinia Virus
More LessSUMMARYThe effect of interferon treatment of mouse L cells on the fate of virus messenger RNA following infection with vaccinia virus has been studied. The polyribosomes of interferon-treated, infected cells are found to be disaggregated and it is proposed that this results from inhibition of the initiation of virus polypeptide synthesis. Evidence is presented that inhibition of polypeptide chain elongation also occurs. The block in initiation appears to be due to the failure of the small ribosome subunit to attach to the virus messenger ribonucleoprotein complex. The translation of the different vaccinia messenger species is inhibited to a comparable extent.
-
-
-
Biophysical and Biochemical Properties of Two Viruses Isolated from Aspergillus foetidus
K. W. Buck and G. RattiSUMMARYAspergillus foetidus virus S (AfV-S) and A. foetidus virus F (AfV-F) have been shown to be serogically unrelated. Amino acid compositions of the two virus capsids are compared and their capsid polypeptides have been examined by SDS-polyacrylamide gel electrophoresis. AfV-F contained one major (Ø3) and two minor (Ø1 and Ø2) polypeptides with mol. wt. 87000, 125000 and 100000, while AfV-S contained one major (σ1) and one minor (σ2) polypeptide with mol. wt. 83000 and 78000 respectively. Evidence is presented that σ2 may be derived from σ1 polypeptide by proteolytic degradation in vitro. The mol. wt. of AfV-F4 and AfV-S1a particles were found from sedimentation and diffusion coefficients to be 13.1 × 106 and 12.4 × 106 respectively. AfV-F capsid was estimated to contain 120 molecules of polypeptide Ø3 and one molecule each of polypeptides Ø1 and Ø2, while AfV-S capsid was estimated to contain 120 molecules of polypeptide Ø1.
It has been shown that S1a and S2a particles each contain a molecule of double-stranded RNA with mol. wt. 2.24 × 106 (RNA-224) and 2.76 × 106 (RNA-276) respectively, whereas S1b and S2b particles each contain a molecule of RNA-224 and RNA-276 respectively, together with an additional molecule of double-stranded RNA of mol. wt. 0.1 × 106. Evidence is presented that S4 particles contain two molecules of RNA-224. S3 particles gave only RNA-224 on extraction, but contain the equivalent of 1½ molecules of RNA-224; the nature of these particles and other possible virus replicative intermediates is discussed. Double-stranded RNA of mol. wt. 1.24 × 106 was derived from a newly described particle class, Fo.
-
-
-
Relative Quantitative Assay of the Biological Activity of Interferon Messenger Ribonucleic Acid
More LessSUMMARYRNA extracted from cells previously stimulated to synthesize the antiviral protein, interferon, causes species-specific interferon synthesis when added to heterospecific cell cultures. Our results confirm the report of De Maeyer-Guignard, De Maeyer & Montagnier (1972). We have used this observation to obtain a relative quantitative assay for the interferon messenger RNA activity. At appropriate RNA concentrations, the yield of interferon is proportional to the concentration of RNA adsorbed to recipient cell cultures.
-
-
-
No Evidence for Particles Encapsulating RNA-instructed DNA Polymerase and High Molecular Weight Virus-related RNA in Herpesvirus Induced Tumours of Non-human Primates
R. Laufs and H. SteinkeSUMMARYThe simultaneous detection test gave no evidence for the presence of RNA tumour viruses in herpesvirus induced malignant lymphomas of non-human primates. The 12 tumours tested were obtained from three different monkey species inoculated with Herpesvirus saimiri or Herpesvirus ateles. Particles encapsulating RNA-instructed DNA polymerase and high mol. wt. virus-related RNA were easily demonstrated in tumours of the mouse induced by type-C or type-B oncornaviruses and in human lymphoid cells infected with simian sarcoma virus type 1 which were examined in parallel. Attempts to demonstrate partial expression of an oncornavirus genome in the herpesvirus induced tumours and attempts to detect an interspecies antigen related to monkey oncornaviruses were negative and strengthened the observations made with the simultaneous detection test.
-
-
-
Location and Abundance of Poly (A) Sequences in Sendai Virus Messenger RNA Molecules
More LessSUMMARYAdenine-rich sequences from 18S Sendai virus messenger RNA species were 99 % adenylate, 3’-OH terminal, and were present in at least 50 % of the RNA molecules. Intact virus messenger RNA molecules were resistant to exonucleolytic attack by polynucleotide phosphorylase, suggesting that their 3’-termini are masked.
-
-
-
Non-viral Lesions Formed in Non-inoculated Upper Leaves of Local Lesion Hosts Following Inoculation of the Lower Leaves with Tobacco Mosaic Virus
More LessSUMMARYWhen the lower leaves of Nicotiana glutinosa or Samsun NN tobacco, local lesion hosts for tobacco mosaic virus (TMV), were inoculated with TMV and kept at 20 °C in continuous light, non-viral lesions began to appear on non-inoculated upper leaves about 8 days later. It is postulated that these non-viral lesions might be induced by substances that move through stem tissues from the inoculated leaves bearing local lesions.
-
-
-
The Effect of Dimethyladipimidate on the Stability of Cowpea Chlorotic Mottle and Brome Mosaic Viruses
More LessSUMMARYCross-linking lysyl residues of brome mosaic and cowpea chlorotic mottle viruses with dimethyladipimidate at pH 8.5 in the presence of MgCl2 resulted in particles that were stable under conditions in which the viruses normally came apart. Virus substituted in the absence of MgCl2 was not stabilized nor would it reassociate into normal particles. Substitution of isolated coat protein subunits did not, however, interfere with the assembly of capsids.
-
-
-
Infection of Tobacco Mesophyll Protoplasts by Alfalfa Mosaic Virus
More LessSUMMARYThe best conditions found for infection of tobacco mesophyll protoplasts with alfalfa mosaic virus (AMV) were pH 5.2, 2.5 μg/ml virus and 1 μg/ml poly-l-ornithine. Newly synthesized virus could be detected 15 h after inoculation and the virus concentration reached an estimated 106 to 107 particles per infected protoplast 2 days after inoculation.
-
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)