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R Vigne

Publications and source records attributed to R Vigne.

At least 55 records · Page 3Linked to original sources
PubMed1987

Characteristics of a novel lentivirus derived from South African sheep with pulmonary adenocarcinoma (jaagsiekte).

A novel lentivirus was isolated from South African sheep with experimentally transmitted lung adenocarcinoma. Similar to visna virus and caprine arthritis encephalitis virus, this new strain induced cytopathic effects on ovine plexus choroid cultures. In contrast to a recent Israeli isolate from sheep with adenocarcinoma, the South African lentivirus could not transform fibroblast cultures. The antigenic relatedness between the new isolate and visna virus was assessed by immunoprecipitation of radiolabeled viral proteins, using monospecific antisera against visna virus proteins. The results indicate that the new virus contains four major structural proteins of sizes similar to those of visna virus (i.e., gp135, p30, p16, and p14) and have some common antigenic determinants (about 90% in the major core antigen p30). However, the nucleotidic sequences of the novel lentivirus were found to be only 16.5 to 27.4% homologous to visna virus and 8.3 to 15% homologous to caprine arthritis encephalitis virus, by means of liquid hybridization under stringent conditions. The genetic divergence indicated by this last result was confirmed by the dissimilar restriction endonuclease cleavage map of the new virus in comparison to those of visna virus and three caprine arthritis encephalitis virus strains. The demonstration of a third type of ovine lentivirus supports the concept of an important genetic variation among the lentiviruses infecting one animal species.

Animals↗
PubMed1986

Isolation and identification of a South African lentivirus from jaagsiekte lungs.

In the course of attempts to grow the jaagsiekte retrovirus in cell culture, a typical lentivirus was isolated for the first time in South Africa from adenomatous lungs. Morphologically the virus could not be distinguished from other lentiviruses, but serologically it was shown to be more closely related to visna virus than to caprine arthritis-encephalitis virus. However, a preliminary restriction enzyme analysis of the linear proviral DNA of this new lentivirus (SA-DMVV) revealed that it is significantly district from visna virus and CAEV and therefore may represent a third type of lentivirus. Antibodies to the virus were demonstrated in a number of sheep in various parts of the country, but a direct link to a disease condition was not found. Attempts to produce lung lesions by intratracheal injection of the virus have been unsuccessful to date but a transient arthritis was produced by intraarticular inoculation. Viral replication seems to be enhanced in jaagsiekte lungs.

Animals↗
PubMed1984

Highly lytic and persistent lentiviruses naturally present in sheep with progressive pneumonia are genetically distinct.

Ovine and caprine lentiviruses share the capacity to induce slowly progressive and inflammatory diseases of the central nervous system (leukoencephalitis or visna), lungs (progressive pneumonia or maedi), and joints (arthritis) in their natural hosts. Studies on their replication indicated that ovine lentiviruses and caprine arthritis-encephalitis virus (CAEV) recently isolated in the United States establish persistent infection in ovine and caprine fibroblasts, whereas older prototype ovine lentiviruses such as Icelandic visna virus or American progressive pneumonia virus irreversibly lyse fibroblast cultures. Since all of the recent isolates were found to be persistent, Narayan et al. (J. Gen. Virol. 59:345-356, 1982) concluded that the highly lytic viruses were only tissue-culture-adapted strains. In the present report, we isolated new ovine lentiviruses from French sheep with naturally occurring progressive pneumonia which are either highly lytic (five isolates), as are the Icelandic strains of visna virus, or persistent (one isolate), as are CAEV or American persistent ovine lentiviruses. Protein and nucleic acid content analyses of these new highly lytic (type I) and persistent (type II) isolates indicated that type I and type II ovine lentiviruses were genetically distinct, type I and type II viruses being closely related to the Icelandic strains of visna virus and to CAEV, respectively. We conclude that (i) highly lytic ovine lentiviruses, such as the Icelandic prototype strains of visna virus and persistent lentiviruses more related to CAEV, are naturally present in the ovine species, and (ii) irreversible cell lysis induced by highly lytic viruses does not result from a tissue culture adaptation of field isolates that were originally persistent but is instead the consequence of a genetic content distinct from that of persistent viruses.

Animals↗
PubMed1984

Lentiviruses are naturally resident in a latent form in long-term ovine fibroblast cultures.

Long-term ovine fibroblast cultures contain replicative-competent lentiviruses in a latent form. This in vitro phenomenon, never described previously for lentiviruses, was clearly demonstrated by activating the expression of latent viruses with various inducing cell treatments, some of which were efficient in inducing endogenous retroviruses or latent herpesviruses. Activated lentiviruses were highly lytic in ovine fibroblasts (type I), or they established persistent infections (type II) as described previously for field isolates from sheep with progressive pneumonia (Quérat et al., J. Virol. 52:671-678, 1984).

Animals↗
PubMed1982

[An ELISA test for detection of maedi-visna antibodies. Comparative study with gel immunodiffusion and complement-fixation test].

An indirect microELISA test was performed for detection of maedi-visna antibodies in ovine and caprine species. The antigen consisted in viral particles, highly purified by successive ultracentrifugations. By comparative testing of 934 sera in ELISA and gel immunodiffusion, we found a good correlation between these two tests, and moreover, ELISA revealed another 11.3% of positive samples. The precocity of this ELISA was shown by experimental infection of sheep with different strains of maedi-visna: positive sera were detected 7 weeks post-infection, instead 4-5 months with gel immunodiffusion. The complement fixation test was compared with gel immunodiffusion and was found the less sensitive. This ELISA test appeared to be satisfactory, and may be used for early diagnosis of maedi-visna infection.

Animals↗
PubMed1982

Precursor polypeptides to structural proteins of visna virus.

Visna virus is a retrovirus which replicates in fibroblast-like cells of the sheep choroid plexus through a lytic cycle. Visna virions contain three major low-molecular-weight proteins (p30, p16, and p14) which, together with the genomic RNA and several molecules of reverse transcriptase, constitute the core structure of the virions. The core is surrounded by an envelope containing a major glycoprotein (gp135). By analogy with the oncoviruses, these three groups of structural proteins (i.e., the internal proteins, the envelope glycoprotein, and the reverse transcriptase) are probably encoded by the gag, env, and pol genes, respectively. To elucidate the genetic organization of the visna virus genome and its expression, we studied the synthesis of viral proteins in infected sheep choroid plexus cells. Intracellular viral proteins were detected by immunoprecipitation of pulse-labeled cell extracts with monospecific sera raised against p30, p16, and gp135 and resolution of the proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Immunoprecipitation with anti-p30 and anti-p16 sera allowed the characterization of the 55,000-dalton polypeptide precursor to internal virion proteins p30, p16, and p14 (Pr55(gag)). Tryptic peptide mapping confirmed the precursor-product relationship between Pr55(gag) and the three internal proteins. In addition, a gag-related polypeptide of 150,000 daltons was also detected. This polypeptide, which was less abundant than Pr55(gag), is a likely precursor to the viral reverse transcriptase (Pr150(gag-pol)). Pr55(gag) and Pr150(gag-pol) are not glycosylated. The precursor related to major envelope protein gp135 is a glycosylated polypeptide with an average molecular weight of 150,000 (gPr150(env)). Pulse-chase experiments indicated that gPr150(env) matures into glycoprotein gp135 intracellularly; however, gp135 was never preponderant in cell extracts. The non-glycosylated from of gPr150(env), which accumulated in the presence of 2-deoxy-d-glucose, appeared as a polypeptide of about 100,000 daltons. These results indicated that visna virus codes for the largest non-glycosylated env-related precursor among all of the retroviruses and therefore probably contains the largest env gene.

Animals↗
PubMed1982

Intracellular ribonucleoprotein complexes of visna virus are infectious.

Sheep choroid plexus cells infected with visna virus produce intracytoplasmic viral ribonucleoprotein complexes with sedimentation values of 120S to 200S and buoyant densities of 1.29 to 1.32 g/cm3. These ribonucleoprotein complexes display an endogenous RNA-directed DNA polymerase activity and contain all of the species of RNA associated with polysomes. An analysis of the polypeptides present in the ribonucleoproteins allowed us to identify the mature internal virion core proteins and their precursor, Pr55gag, as well as the glycosylated envelope precursor gPr150env and small amounts of mature glycoprotein gp135. Ultracentrifugation-purified ribonucleoproteins could infect sheep choroid plexus cells and led to a normal lytic cycle with virus production. Our results suggest that visna virus can propagate by means of intracellular infectious particles.

Animals↗
PubMed1980

Growth-related alterations induced in chick embryo fibroblasts by src-gene deletion mutants of the Schmidt-Ruppin strain of Rous sarcoma virus.

Certain tdSRD viruses induce multilayered cell foci, agar colony formation, and increased density of cellular populations in line-15 chick embryo fibroblasts. These alterations in cellular growth properties are distinct from oncogenic transformation. Available evidence favors the idea that transformation-defective focus formation is caused by one or more of the replicative viral genes, but which of the three-gag, pol, or env-is involved, remains to be determined.

Animals↗
PubMed1980

Genetic variation and host markers in the src gene of recovered avian sarcoma viruses.

The src genes of three recovered avian sarcoma viruses were compared by RNase T1 oligonucleotide fingerprinting and tryptic peptide analysis. In all three recovered avian sarcoma viruses the oligonucleotide composition of src was different and also distinct from that of the parental Schmidt-Ruppin strain of Rous sarcoma virus. This evidence for genetic variation src was strengthened by two dimensional peptide maps of the src gene products pp60src, translated in a reticulocyte lysate system in vitro. Numerous differences between the peptide patterns of the pp60src proteins produced by the parental and the recovered viruses were detected. No two src proteins were identical, while the tryptic peptide maps of the internal gag proteins synthesized by these viruses were indistinguishable. The src proteins of recovered avian sarcoma viruses also contained peptides that were absent from the src protein of parental Schmidt-Ruppin D virus but were found in the endogenous src protein of normal cells. We conclude that there is considerable genetic variation in the src gene of recovered avian sarcoma viruses and that these recovered src genes contain host cell-derived markers.

Animals↗
PubMed1979

Antigenic variation in visna virus.

Two antigenic variants of visna virus were isolated sequentially from a single sheep inoculated with a plaque-purified strain of virus designated 1514. The genetically stable variants, LV1-1 and LV1-4, are of two classes: LV1-1 is partially neutralized by antibody to the inoculum strain 1514, while LV1-4 is not neutralized by antibody to 1514. The genetic mechanism responsible for generating the antigenic variants was investigated by comparing the chymotryptic and tryptic maps of the envelope glycoprotein gp135 and core polypeptides (p30, p16, p14), and by comparing the pattern of large oligonucleotides produced by digestion of the RNAs by T1 ribonuclease. We show that only the peptide maps of gp135 differ among strains, that the number of peptide fragments altered is small and that gp135 is the polypeptide that elicits neutralizing antibody. The maps of the RNAs are identical. We conclude that mutation in the glycoprotein gene rather than recombination is more probably responsible for antigenic variation, and speculate on the special aspects of visna virus replication relevant to this phenomenon.

Amino Acid Sequence↗
PubMed1979

Characterization of visna virus mRNA.

Visna virus is a retrovirus responsible for a classical slow infection of the central nervous system of sheep. In the present work we focused our attention on the viral mRNA's. We found that, during the acute infection in vitro, (i) viral mRNA's amount to only 0.1% of the total cytoplasmic RNA, (ii) 20% of the total cytoplasmic viral RNA is found in polyribosomes, and (iii) three viral mRNA's can be identified by sucrose gradient sedimentation or polyacrylamide gel electrophoresis. Their sedimentation coefficients are 36S, 27S, and 21S.

Animals↗
PubMed1978

Absence of circularly permuted and largely redundant sequences in the genome of visna virus.

A previous study of the infectivity of visna virus proviral DNA suggested that the genetic information of the virus is distributed over at least two of the RNA subunits. Because the genetic complexity of visna virus corresponds to the size of one subunit, this result may imply that sequence redundancies exist within each subunit. In the present article we have examined this question by constructing a map of the large RNase T1-resistant oligonucleotides of the viral genome. Our principal results are as follows: (i) all 36S RNA subunits have the same genetic content regardless of their polyadenylic acid [poly(A)] content; (ii) the poly(A) tract is present at the 3' end of the molecule; and (iii) the recoveries of 19 large RNase T1-resistant oligonucleotides from poly(A)-tagged RNA fragments of various sizes demonstrate that the oligonucleotides are organized in the same linear order within all subunits. Our results, therefore, exclude the existence of large sequence redundancies in the genome of visna virus.

Base Sequence↗
PubMed1977

Partial enzyme digestion studies on Escherichia coli, Pseudomonas, Chlorella, Drosophila, HeLa and yeast 5S RNAs support a general class of 5S RNA models.

Fox and Woese (1975a) have shown that a model of 5S RNA secondary structure similar to the one originally derived for Chlorella 5S RNA can be generalized with relatively minor variations to all sequenced 5S RNA molecules, i.e. that corresponding base paired regions can be formed at approximately the same positions. We present experimental data in favour of this hypothesis and show that the points at which ribonucleases T1, T2 and pancreatic ribonuclease cleave six different 5S RNA molecules under 'mild' conditions (high ionic strength, low temperature, low RNAase concentration) nearly always fall in the proposed single-stranded regions. We conclude that this model is a good approximation to the conformation of 5S RNA in solution.

Base Sequence↗
PubMed1977

Complexity and polyadenylic acid content of visna virus 60-70S RNA.

The genomic complexity of visna virus was measured by quantitative analysis of 18 RNase T1-resistant oligonucleotides from 60-70S RNA. T1-resistant oligonucleotides were separated by two-dimensional polyacrylamide gel electrophoresis. Visna virus had a genomic complexity of 3.6 X 10(6) daltons, very close to the size of a single 30-40S RNA subunit. It was therefore concluded that the visna virus genome is largely polyploid. Visna virus 60-70S RNA polyadenylic acid segment was purified by T1 RNase digestion followed by oligodeoxythymidylic acid-cellulose column chromatography. It contained over 99% AMP and had a size of about 200 nucleotides. The binding capacities on oligodeoxythymidylic acid-cellulose of native 60-70S RNA and purified 30-40S RNA subunits were examined. It was concluded that two out of three intact subunits contain a polyadenylic acid segment.

Avian Sarcoma Viruses↗
PubMed1977

Visna virus RNA synthesis.

Visna is a classical slow infection in which virus characteristically persists in the face of the host immune response. The agent of this disease belongs to the retravirus group. The persistence of infection and the slow spread of virus are at least in part a consequence of restriction of the expression of virus genetic information in tissues of an infected animal (A. T. Haase et al., Science 195:175-177, 1977), but the point at which the virus life cycle is interrupted in vivo and the mechanism of restriction are unknown. We have embarked on a molecular analysis of restriction, focusing first on transcription. In this paper we have established the levels of viral RNA synthesis under permissive conditions, as a base line for subsequent studies in vivo. We show that (i) uninfected cells do not contain RNA sequences related to the visna virus genome, (ii) parental RNA is rapidly transported to the nucleus of the infected cell, (iii) virus RNA is synthesized in the nucleus and then transported to the cytoplasm (iv) synthesis of RNA proceeds mostly exponentially to reach levels of about 4,000 copies per cell at the end of the growth cycle, (v) nuclear and cytoplasmic RNA sediment in two size classes, 35S and 10-20S, (vi) viral mRNA has the same polarity as genome RNA and also sediments in two size classes of 35S and 10-20S.

Animals↗