- Volume 55, Issue 2, 1981
Volume 55, Issue 2, 1981
-
-
Temperate Coliphage HK022: Virions, DNA, One-step Growth, Attachment Site, and the Prophage Genetic Map
More LessSUMMARYTemperate coliphage HK022 has 45 × 51 nm heads, 106 nm long, flexible tails, and linear DNA of 26.4 × 106 mol. wt. The prophage attachment site (atthtt ) is co-transducible with pyrD and is located between pyrD and pyrC.
-
- Bacterial
-
-
-
Purification, Fine Structure and Characterization of Temperate Phages from Drug-resistant Staphylococcus aureus
More LessSUMMARYThree kinds of temperate Staphylococcus aureus phages were differentiated by serological, sedimentation and electron microscopic studies. Phage S1 had a long hexagonal head and a long tail, a density in Cs2SO4 of 1.365 g/ml and belonged to serological group A; phage S2 had a short hexagonal head and a short tail, a density of 1.385 to 1.392 g/ml and belonged to serological group B; phage S3 had a shape similar to phage S2 except for some minor differences, but had a density of 1.416 g/ml and belonged to serological group F. S. aureus MS27 was found to be singly lysogenic for S2. However, S. aureus MS3878 was a doubly lysogenic strain carrying S1 and S2 and S. aureus E169 was a triply lysogenic strain carrying S1, S2 and S3. All these temperate phages showed similarity in shape to typing phages belonging to the same serological group. The temperate S. aureus phages revealed the presence of a hexagonal baseplate with spikes. The burst sizes of phages S1, S2 and S3 were about 50, 110 and 120 respectively. The DNA from S1, S2 and S3 ranged from 29.4 to 30 megadaltons in size.
-
-
-
-
Temperate Coliphage HK022: Virions, DNA, One-step Growth, Attachment Site, and the Prophage Genetic Map
More LessSummaryTemperate coliphage HK022 has 45 × 51 nm heads, 106 nm long, flexible tails, and linear DNA of 26.4 × 106 mol. wt. The prophage attachment site (atthtt ) is co-transducible with pyrD and is located between pyrD and pyrC.
-
- Animal
-
-
-
RNA Degradation Defect in Central Nervous System Isolates of Vesicular Stomatitis Virus
More LessSUMMARYSix temperature-sensitive (ts) mutants of vesicular stomatitis virus (VSV) isolated from the central nervous system (CNS) following injection with ts G31 (III) all possessed a post-transcriptional defect, not found in the initial virus, that affects the stability of viral RNA transcripts. Examination of viral RNA metabolism in mouse neuroblastoma (N-18) cells revealed that RNA synthesis of the CNS isolates was decreased considerably at elevated temperatures (up to 80 or 90% at 39 °C). In addition, analysis of the RNA transcripts suggested that little if any normal-sized transcripts were made in cells infected with these CNS isolates at either 37 °C or 39 °C. The RNA deficiencies did not appear to be the result of a temperature-sensitive lability of virion transcriptase as examined by in vitro transcriptase assays. However, when N-18 cells infected with one of the CNS isolates, ts G31 BP, were first preincubated at the permissive temperature of 31 °C for 3 h and then shifted to 39 °C, RNA synthesis proceeded at a rate comparable to that of 31 °C. The viral mRNA species synthesized following the temperature shift also contained normalsized tracts of poly(A) RNA, suggesting that neither the viral transcriptase nor its polyadenylate synthetase was thermally labile. However, for any of the six CNS isolates, all species of viral RNA synthesized in cells that were first preincubated at 31 °C degraded rapidly when the cells were shifted to 39 °C. In contrast little or no RNA degradation of either 42S progeny RNA or mRNA species was detected in the wild-type VSV, ts G31 or three other VSV mutants that are defective in some aspect of viral RNA metabolism: [ts G11 (I), ts G22 (II), ts G41 (IV)]. The apparent phenotype alteration in the stability of viral RNA in all of these CNS isolates is discussed in terms of the possible genotypic changes that may have occurred as well as the unique CNS disease that accompanies infection by these viruses.
-
-
-
-
Modification and Exploitation of a Poliovirus-induced Membrane Complex by Superinfecting ME Virus
More LessSUMMARYThe replication of Mouse Elberfeld (ME) virus was accelerated when HEp-2 cells were mixedly infected with poliovirus in the presence of guanidine. The latent period of the replication of ME virus was shortened by 3 h when cells were preinfected for at least 2 h with poliovirus and inhibited by guanidine. Simultaneous infection with poliovirus and ME virus resulted in a shortening by 1 h of the latent period of ME virus replication. The accelerated replication of ME virus was shown to be due to modification and exploitation of a membrane complex induced by poliovirus in the presence of guanidine; on superinfection ME virus successively modified this poliovirus-induced complex of 470S (‘light’ complex) into a ‘heavy’ complex of 700S specific for ME virus.
-
-
-
Effect of Enzymes on the Attachment of Influenza and Encephalomyocarditis Viruses to Erythrocytes
More LessSUMMARYEncephalomyocarditis (EMC) and influenza viruses attach to human erythrocytes causing haemagglutination of the cells. Sialoglycoproteins, containing predominantly glycophorin A, from these cells behave as soluble virus receptors and inhibit haemagglutination by both viruses. Removal of 43% of the sialic acid from erythrocytes with neuraminidase prevented their haemagglutination by EMC virus while loss of 40% of glycophorin sialic acid destroyed its inhibitory properties against this virus. However, about 80% of the sialic acid had to be removed from erythrocytes or from glycophorin to achieve the same results for influenza virus. Trypsin treatment of erythrocytes of glycophorin had little effect on haemagglutination or inhibition involving either virus, although the glycopeptides released contain up to 70% of the total sialic acid, and despite the fact that glycophorin was drastically reduced in size as shown by SDS-polyacrylamide gel electrophoresis. It is concluded that not all of the sialic acid present in erythrocyte sialoglycoprotein receptors is involved in attachment of EMC or influenza viruses and that the attachment sites on erythrocytes for these viruses are not identical.
-
-
-
Suppressive Effects of Interferon on Cell Fusion by Sendai Virus
More LessSUMMARYSuppressive effects of human IFN-α, IFN-β and mouse-IFN on syncytium formation in human and mouse transformed cells have been studied using u.v.-irradiated Sendai virus (UV-Sendai virus). After treatment of human RSa cells with 500 units/ml human IFN-α for 16 h, the syncytium formation induced by UV-Sendai virus was reduced to less than 10% of controls. The suppressive effect was dependent on the amount of interferon added, and it was blocked by the addition of cycloheximide. Suppression of syncytium formation was also observed on human IFr cells, which are partially resistant to the anticellular effect of interferon but are sensitive to the antiviral effect of interferon. Human IFN-β also had a suppressive effect on syncytium formation in human transformed cells, and human IFN-α, IFN-β and mouse IFN showed species specificity in their effect on fusion. This anti-cell fusion activity was developed in IFr cells from about 5 h after addition of IFN-α and when the cells were treated with IFN-α for 16 h, the resistant state of cells continued for over 20 h after removal of IFN-α.
-
-
-
Renal Metabolism of Rabbit Serum Interferon
More LessSUMMARYThree different approaches have been used to evaluate the catabolism of rabbit serum interferon (IFN) by the kidneys. Firstly, in normal rabbits the disappearance of exogenous IFN from plasma was very rapid, whereas it was significantly slower after bilateral nephrectomy. Secondly, the IFN level in arterial blood was always higher than in renal venous blood: the mean renal extraction rate of IFN in the rabbit, with a renal plasma flow of 9 ml/min, was about 1 ml/min. Thirdly, a selective and reversible tubular damage induced by maleate before intravenous administration of IFN significantly inhibited luminal uptake of IFN and markedly increases the interferonuria. All of these results support the view that the kidneys have a preponderant role in IFN filtration, catabolism and excretion.
-
-
-
Conversion of Herpetic Lesions to Malignancy by Ultraviolet Exposure and Promoter Application
More LessSUMMARYMany lines of evidence exist associating herpes simplex virus (HSV) with the development of carcinoma, but much of this evidence is anecdotal or associative in nature and does not prove a cause and effect. The purpose of this research was to investigate the oncogenic potential of HSV type 2 (HSV-2) in vivo. A mouse model for lip carcinogenesis was designed to combine HSV-2 infection, u.v. exposure and tetradecanoyl-phorbol-acetate (TPA) application. HSV-2 inoculation on to abraded mouse lips was capable of causing vesicular ulcerative lesions which healed completely after 10 to 14 days. Ultraviolet irradiation of the HSV lesion site daily for 6 min at 42 ergs/mm2/s on days 3 to 6 post-infection caused hyperkeratosis, acanthosis and dysplasia to develop in several lips; while the same u.v. exposure by itself failed to alter the histologic appearance. The addition of repeated TPA application to the HSV + u.v. regimen promoted tumour emergence. Thirty-two of 156 Balb/c mice developed tumours. Although the majority were papillomas, six were squamous cell carcinomas. These tumour-bearing mice had increased HSV-specific antibody titres. HSV antigens were shown to be present in outgrowths from explanted tumours as well as in tumour biopsies by immunoperoxidase staining with HSV-specific antisera. It is suggested that the in vivo u.v.-irradiated HSV acted as the inducer and TPA as the promoter, analogous to the classical two-stage carcinogenesis model.
-
-
-
Nucleotide Sequences of the Joint between the L and S Segments of Herpes Simplex Virus Types 1 and 2
More LessSUMMARYThe a sequence of herpes simplex virus (HSV) is present as a direct repeat at the genomic termini and also in inverted orientation at the joint between the L and S segments. DNA sequences have been determined for the joint regions of the genomes of HSV-1 and HSV-2, and relative to these sequences the genomic termini are in both cases located close to a short direct repeat of 17 to 21 base pairs (bp) at the b-a and a-c junctions. The HSV-1 joint region contains three separate tandem direct reiterations of short sequences, (12, 16 and 17 bp in strain 17) and we conclude that size heterogeneity in the a and c sequences is due to variable copy numbers of these repeated units. It is likely that a considerable part of the HSV-1 joint region does not code for polypeptide.
-
-
-
Epstein—Barr Virus-induced Proteins. IV. Characterization of an EBV-associated Phosphopolypeptide
More LessSUMMARYCells of the Epstein—Barr virus (EBV) non-producing lines NC37 and Raji were induced by the tumour promoter TPA and were labelled with 32P. The analysis by immunoprecipitation with human VCA+EA+ sera revealed that a major phospho-polypeptide with a mol. wt. of 58000 was specifically precipitated. In addition, a phosphopolypeptide of the same size was the dominant phosphopolypeptide detected in EBV-producing B95-8 and P3HR-1 cells as well as in P3HR-1-superinfected NC37 cells. This phosphopolypeptide seemed to be EBV-specific, because it was not detectable in TPA-treated, but EBV genome-negative, Ramos and BJAB cells. Synthesis of this phosphopolypeptide was inhibited in TPA-treated NC37 cells by treatment with Ara-C. VCA+EA+ sera were found to be more immunoreactive with this phosphopolypeptide than VCA+EA− or EBNA+ sera. Based on these results this phosphopolypeptide may have some immunological relatedness to the EBV-specific early antigen (EA) complex defined by immunofluorescence.
-
-
-
Cytopathic Effects in Mouse Neuroblastoma Cells during a Non-permissive Infection with a Mutant of Vesicular Stomatitis Virus
More LessSUMMARYMorphological changes were extensive following infection of murine neuroblastoma N-18 cells with a temperature-sensitive (ts) mutant of vesicular stomatitis virus (VSV), G31 (complementation group III), and incubation at 39 °C, a non-permissive condition for virion maturation. Incubation for 24 h after infection resulted in extensive morphological degeneration of mitochondria with over 80% of the mitochondria having degenerated. Mitochondrial function, as determined by Janus green B supravital staining, was reduced by 81% from that in uninfected cells. Cellular ATP levels were reduced by 50% 12 h after infection. Mitochondrial degeneration still occurred in infected cells after the inactivation of lysosomes with chloroquine. Extensive cell fusion and cytoplasmic vacuole formation also occurred during the non-permissive infection with ts G31. Loss of plasma membrane integrity was not the cause of vacuole formation since 90% of the cells were able to exclude trypan blue 24 h after infection, nor were the vacuoles the result of inactivation of the mitochondria since cyanide-poisoned cells did not form vacuoles. The cytopathic alterations observed in N-18 cells during the non-permissive infection of N-18 cells with ts G31 did not occur during the non-permissive infection of N-18 cells with ts G11 (I), ts G41 (IV), or u.v.-inactivated ts G31. However, the non-permissive infection with ts O45(V) led to mitochondrial degeneration and cytoplasmic vacuole formation, but no cell fusion occurred. These results are discussed in light of the ultrastructural features previously observed in the central nervous system of mice infected with ts G31 and cells in culture infected with wild-type VSV.
-
-
-
Kinetics of Inhibition of Papovavirus DNA Synthesis by Superinfection with Adenovirus 2 and Non-defective Adenovirus 2-Simian Virus 40 Hybrid Viruses
More LessSUMMARYSimian Virus 40 (SV40) DNA synthesis is inhibited in monkey cells by superinfection with adenovirus 2 (Ad2) and various non-defective Ad2-SV40 hybrid viruses. Similarly, BKV (a human papovavirus) DNA synthesis is inhibited in human cells by superinfection with Ad2. Kinetic studies indicate that inhibition begins during the early phase of the Ad2 lytic cycle. Superinfection with Ad2 does not significantly alter the formation of SV40 T antigen. Superinfection with Ad2 late in the SV40 lytic cycle is less efficient in the inhibition of SV40 DNA synthesis, and the onset of Ad2 DNA synthesis is delayed, compared to superinfection early in the SV40 lytic cycle. These findings suggest that the Ad2 and SV40 genomes may compete to bind an early Ad2 protein which is essential for Ad2 replication, but which blocks SV40 replication.
-
-
-
Comparison of T Antigen-associated Host Phosphoproteins from SV40-infected and -transformed Cells of Different Species
More LessSUMMARYSimian virus 40 (SV40)-infected and -transformed cells contain, in addition to the virus-coded tumour antigens, one or more 48K to 56K host tumour antigens. At least part of this class of host proteins exists as a fast-sedimenting complex with the SV40 large T antigen. The host proteins associated with the large T antigen in SV40-transformed monkey, mouse and human cells and SV40-infected monkey cells were compared by two-dimensional gel electrophoresis and V8 partial proteolysis peptide mapping. Although these proteins differed slightly in apparent mol. wt. and peptide pattern, they migrated identically in isoelectric focusing gels. These results suggest that the cellular proteins associated with large T antigen in different hosts are very closely related to each other. Despite their similarities, the 55K proteins from different host cells form complexes of different stabilities with large T antigen, as judged by spontaneous dissociation of the complexes during storage, and the fractions of the 55K cellular protein and large T antigen found free and in the complexed form in each different host cell.
-
-
-
Properties of the Avian Viral Protein p12
More LessSUMMARYThe avian RNA tumour virus structural protein p12 was purified from avian myeloblastosis virus (AMV) by nucleic acid affinity chromatography to apparent homogeneity as judged from SDS-polyacrylamide gel electrophoresis. A filter-binding assay was used for the identification of p12. High concentrations of p12 precipitated nucleic acids out of solution in the absence of MgCl2. Binding of p12 to single-stranded nucleic acids protected them from digestion with nucleases and resulted in a hyperchromic effect. These phenomena were reversible in the presence of salt. The affinity of p12 to nucleic acids was determined by competing for the binding of p12 to denatured radioactive DNA by various other nucleic acids. It was found that p12 bound preferentially to single-stranded nucleic acids and showed a higher affinity to poly(rI) than to poly(rC) and poly(rA). Purified RNA-dependent DNA polymerase activity from AMV was stimulated up to sixfold by p12, depending on the template. Solubilization of RNA in RNA-DNA hybrids by RNase H was inhibited in the presence of p12.
-
-
-
Terminal Structure of Reovirus RNAs
More LessSUMMARYS1 nuclease analysis and 3′ terminal sequencing of the reovirus genome double-stranded RNAs and in vitro produced viral mRNAs has been used to establish that the viral mRNA is a full length copy of the genome template. Sequence determination at the 3′ end of the genome minus strand has by transposition allowed determination of the 5′ terminal sequences of the viral mRNAs. In all but one case an AUG codon which could function in initiation of protein synthesis has been found within the determined sequence. The 3′ ends of the plus strands from all genome segments were found to have a common sequence. The implications of these results on the mechanism of virus replication are discussed.
-
-
-
Isolation from Chickens of a Rotavirus Lacking the Rotavirus Group Antigen
More LessSUMMARYA virus, designated 132 virus, was isolated from the faeces of chickens in chick embryo liver cell cultures. The morphology and morphogenesis of 132 virus were indistinguishable from that of rotaviruses. The nucleic acid of 132 virus had the nuclease resistance of double-stranded RNA, and was separated by polyacrylamide gel electrophoresis into 11 segments with mol. wt. ranging from 2.07 × 106 to 0.20 × 106. SPF chickens were susceptible to oral infection with 132 virus, which replicated in the villous epithelial cells of the small intestine. 132 virus was therefore a rotavirus by morphological, biochemical and biological criteria. However, by immunofluorescence it was not possible to demonstrate an antigenic relationship between 132 virus and known avian and mammalian rotaviruses, indicating that 132 virus does not possess the group antigen shared by all previously characterized rotaviruses. This finding has implications for the diagnosis of rotavirus infections by serological tests.
-
-
-
Neutralization of Foot-and-Mouth Disease Virus. I. Sensitization of the 140S Virion by Antibody Also Reactive with the 12S Protein Subunit
More LessSUMMARYThe in vitro interaction of foot-and-mouth disease virus (FMDV) with an immune serum resulted in a fraction of virus which failed to be neutralized. This inability of antibody to neutralize the entire population of a virus preparation was studied with emphasis on the antigenic specificity of the antibody-virus reaction. Antibody to FMDV recognized multiple antigenic determinants. Immunoadsorbent fractionation of the serum into 12S subunit cross-reactive and 140S virion-specific antibody revealed that these multiple antigenic determinants are factors in determining the neutralizing ability of the antibody. Antibody specific to the infective 140S virion neutralized virus effectively, whereas antibody reactive with both the 140S virion and 12S non-infective component did so ineffectively. Neutralization was independent of viral aggregation, strain, or type heterogeneity, dissociation of the immune complex, heterogeneity of antibody class, or incubation time. The non-neutralized fraction of virus was not due to insufficient antibody in the system, was demonstrated to be complexed with antibody (‘sensitized’) and could be neutralized with anti-globulin serum. The findings demonstrate the heterogeneity of antibody specificity to FMDV in serum preparations and relate the importance of antibody specificity to the neutralization of virus in vitro.
-
-
-
Cell-free Translation of Cricket Paralysis Virus RNA: Analysis of the Synthesis and Processing of Virus-specified Proteins
More LessSUMMARYTranslation of cricket paralysis virus (CrPV) RNA in a rabbit reticulocyte lysate yielded proteins which co-migrate on polyacrylamide gels with the structural proteins VP1 and VP3. These proteins were identified by partial proteolysis and a number of high mol. wt. proteins were shown to be precursors of the structural proteins. The third structural protein VP2 was not identified in vitro but was shown to be formed in vivo from the minor ‘structural’ protein VP0. The profile of high mol. wt. proteins in vitro differed from those found in infected cells, but processing was similar with precursors being cleaved sequentially to give a group of proteins with mol. wt. of 50000 to 63000. Processing proceeded in vitro to give VP1 and VP3 but synthesis of VP2 and its immediate precursor VP0 was not apparent. This is consistent with an inhibition of synthesis of VP0 found in infected cells treated with iodoacetamide and suggests that CrPV utilizes a different mechanism for the synthesis of VP0 and VP2 than it does for VP1 and VP3. A tentative model for the processing of CrPV-specified proteins is proposed.
-
-
-
Proteolytic Cleavage of VP1 in ‘A’ Particles of Coxsackievirus B3 Does Not Appear to Mediate Virus Uncoating by HeLa Cells
More LessSUMMARY‘A’ particles of Coxsackievirus B3 were generated from native virus by heating and purified by sucrose gradient centrifugation. These particles were found to be similar to ‘A’ particles formed by elution from cellular receptors of HeLa cells. Electrophoretic analysis of [35S]methionine-labelled ‘A’ particles revealed that treatment of the particles with chymotrypsin resulted in the cleavage of VP1 and the formation of a cleavage product which migrated between VP2 and VP3. Analysis of the protease-treated material on sucrose gradients revealed a ribonuclease-sensitive particle which sedimented more slowly than an ‘A’ particle. This particle apparently degraded to release the viral RNA, thereby providing an in vitro model for protease-mediated uncoating of ‘A’ particles. The subviral particles of Coxsackievirus B3 were found to be immunoprecipitable with heterotypic Coxsackievirus group B antisera, thereby providing a method for the recovery of products produced in the cell early in infection. Infected cells which had been treated to remove unreacted virus were disrupted, and the lysates were reacted with heterotypic antisera. Analysis of the precipitated material revealed that no cleavage products were formed and no polypeptides were lost. Therefore, it appears that proteolysis is not involved in the uncoating of Coxsackievirus B3 in infected cells.
-
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)