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G Stanway

Publications and source records attributed to G Stanway.

At least 55 records · Page 3Linked to original sources

The nucleotide sequence of coxsackievirus A9; implications for receptor binding and enterovirus classification.

The complete nucleotide sequence of the genome of coxsackievirus A9 (CAV-9) has been determined from cDNA cloned in Escherichia coli. Excluding the 3' poly(A) stretch, the RNA genome is 7452 nucleotides long and encodes a single polyprotein of 2201 amino acids. Comparison of the nucleotide and predicted amino acid sequences with those of the coxsackieviruses B1, B3 and B4 reveals a surprising degree of homology, with overall amino acid homologies of 86.9%, 86.2% and 87.0%, respectively. In contrast, there is much less homology to another coxsackie A virus, CAV-21, 60.4% overall amino acid homology. This demonstrates the high degree of diversity within the CAV group and indicates that the current classification does not directly correlate with molecular genetic properties. One major feature of CAV-9 is an insertion, relative to all other enteroviruses sequenced to date, which is located at the C terminus of VP1, and includes an arginine-glycine-aspartic acid tripeptide. Such sequences in a number of other proteins are known to have activity in promoting attachment to cell receptors and the implications for CAV-9 receptor binding are discussed.

Amino Acid Sequence↗

The nucleotide sequence of human rhinovirus 1B: molecular relationships within the rhinovirus genus.

We have determined the complete nucleotide sequence of human rhinovirus 1B and made comparisons with other rhinoviruses. Extensive homology was found with serotypes 2 and 89 but the similarity to serotype 14 was considerably less. Rhinovirus-specific characteristics have been noted, in particular the length of the 5' non-coding region and the pattern of codon usage, and these may be sufficient to define the rhinoviruses as a distinct genus rather than being considered as members of the enteroviruses as has been suggested previously.

Amino Acid Sequence↗

Nucleic acid sequence relationships between enterovirus serotypes.

Forty-eight different enterovirus serotypes were analysed by a nucleic-acid hybridization test using probes derived from the 3' end of coxsackievirus A21 (CA21) and B3 (CB3), poliovirus 3 (P3) and enterovirus 70 (E70). More than 90% of the serotypes could be detected with this collection of reagents. The CB3 probe reacted with all the coxsackie B viruses, with all three poliovirus serotypes, and with almost all of the 30 ECHO virus types tested. In addition some of the coxsackie A viruses and the BrDr 73 strain of enterovirus 71 gave a positive signal with this probe. The P3 probe detected all the poliovirus strains and also some coxsackievirus A isolates but no coxsackie B or ECHO viruses. A similar hybridization pattern as with the P3 probe was obtained when the CA 21 probe was used. The E70 probe appeared to be strain-specific. The results indicate that nucleic-acid hybridization is a useful method for rapid detection and subgrouping of enteroviruses during virus isolation, and that the test could be further developed for typing of the strains.

Animals↗

Detection of human rhinoviruses and their molecular relationship using cDNA probes.

We describe here a cDNA:RNA hybridization system for the study of human rhinoviruses. We have constructed an M13 probe from the 5' end of the genome of rhinovirus 14 (HRV-14) and used this to detect directly viral RNA. Of the 56 human rhinoviruses so far investigated 54 or 96.4% gave clearly positive hybridization signals. However, the strength of this signal depended very much on the molecular relationship of these viruses. Thus, HRV-3, 4, 17, 72, and, to a slightly lesser extent, HRV-2, 6, 9, 13, 19, 31, 42, 49, 64, and 69 appear to be closely related to HRV-14 whereas HRV-5, 7, 8, 16, 32, 40, 45, 55, 56, 63, 80, 82, and 85 appear to be relatively divergent. Further, evidence is provided in this study that indicates that it would be feasible to use cDNA probes to detect human rhinoviruses in nasal washings. However, the sensitivity of detection was clearly affected by both the inclusion of inhibitors of endogenous RNase activity in the RNA extraction mixture and also in the method of extracting the viral RNA. From reconstruction experiments in nasal washings and under optimal conditions, we can detect virus at 10(2.8) TCID50/ml.

Common Cold↗

The nucleotide sequence of a type 3 poliovirus isolated during a recent outbreak of poliomyelitis in Finland.

We have cloned and sequenced the complete genome of a strain of poliovirus type 3 (23127) isolated during an outbreak of poliomyelitis in Finland. The genome is 7435 nucleotides long excluding the 3' poly(A) stretch and is 95.5% homologous at the amino acid level to the previously sequenced type 3 strain, P3/Leon/37. The most striking feature of the presented sequence is the extent of amino acid substitutions relative to P3/Leon/37 and other type 3 strains in areas of known antigenic importance. The major antigenic determinant for virus neutralization (site 1), located at residues 89 to 100 of VP1, has three amino acid substitutions and there are six substitutions in site 3, a composite site made up of sequences from VP1 and VP3. The variation in these regions probably accounts for the observed unusual antigenicity and may explain why the virus was able to spread in a well-vaccinated community. Sequence comparisons imply that the virus is not derived from the currently used live attenuated vaccine.

Amino Acid Sequence↗

Construction of poliovirus intertypic recombinants by use of cDNA.

We investigated the use of infectious cDNA for the production of poliovirus type 1-type 3 recombinants. One such recombinant virus was produced, but a second construct involving the transfer of part of the capsid protein region was not infectious. Our results suggest that the approach may prove valuable but that not all cDNA constructs will give rise to viable viruses.

Base Sequence↗

Reversion to neurovirulence of the live-attenuated Sabin type 3 oral poliovirus vaccine.

The complete nucleotide sequence has been determined of a strain of poliovirus type 3, P3/119, isolated from the central nervous system of a victim of fatal vaccine-associated poliomyelitis. Comparison of this sequence with those obtained previously for the Sabin type 3 vaccine, P3/Leon 12a1b and its neurovirulent progenitor, P3/Leon/37, reveals that these three strains are on a direct geneaological lineage and therefore that P3/119 is a bona fide revertant of the vaccine. P3/119 differs in sequence from its attenuated vaccine parent at just seven positions. Only one of these differences, a mutation from U to C at position 472 in the presumed noncoding region of the genome, is a back mutation to the wild type sequence. Of the six other differences, three give rise to coding changes in virus structural proteins, two are silent changes in the major open reading frame of the genome and one affects the 3'-terminus just prior to the poly A tract. These differences indicate that there are three possible types of molecular change which could, singly or collectively, result in attenuation and reversion to neurovirulence of the Sabin type 3 vaccine.

Amino Acid Sequence↗

The complete nucleotide sequence of a common cold virus: human rhinovirus 14.

The complete nucleotide sequence of the single-stranded RNA genome of human rhinovirus 14, one of the causative agents of the common cold, has been determined from cDNA cloned in E. coli. The genome is typical of the picornaviridae family, comprising a 5' non-coding region of 624 nucleotides, a long open reading frame of 6537 nucleotides (90.8% of the genome) and a 3' non-coding region of 47 nucleotides. Comparison of the nucleotide sequence and the predicted amino acid sequence with those of the polioviruses reveals a surprising degree of homology which may allow recognition of regions of antigenic importance and prediction of the virus polyprotein cleavage sites. The results presented here imply a closer genetic relationship between the rhinovirus and enterovirus genera than previously suspected.

Amino Acid Sequence↗

Molecular cloning of the genomes of poliovirus type 3 strains by the cDNA: RNA hybrid method.

The genomes of two neurovirulent strains of poliovirus type 3, wild type P3/Leon/37 and a vaccine revertant P3/119/70, have been cloned in E. coli. The cDNA: RNA hybrid method used was efficient and may have wide applicability for cDNA cloning. Overlapping clones spanning the entire genome were obtained for each strain. These have been used to produce full-length DNA copies of the two genomes each within a single plasmid.

Base Sequence↗

New poliovirus vaccines: a molecular approach.

This article summarizes recent work on the determinants of antigenicity in poliovirus type 3 and reports on experiments in progress aimed at understanding the molecular basis of attenuation in Sabin's type 3 vaccines. Ways in which this new information might be used to produce alternative, safe, inexpensive, multivalent vaccines against polio and other enteroviruses are discussed.

Amino Acid Sequence↗

Comparison of the complete nucleotide sequences of the genomes of the neurovirulent poliovirus P3/Leon/37 and its attenuated Sabin vaccine derivative P3/Leon 12a1b.

As part of a study into the molecular basis of attenuation and reversion to neurovirulence in the Sabin poliovirus vaccines, we have determined the complete nucleotide sequence of a cloned DNA copy of the genome of P3/Leon/37, the neurovirulent progenitor of the type 3 Sabin vaccine strain, P3/Leon 12a1b. Comparison of the sequence with that which we previously obtained for the vaccine strain [Stanway, G., Cann, A. J., Hauptmann, R., Hughes, P., Clarke, L. D., Mountford, R. C., Minor, P. D., Schild, G. C. & Almond, J. W. (1983) Nucleic Acids Res. 11, 5629-5643] indicates that attenuation has been brought about by a maximum of 10 point mutations, at least 5 of which are likely to be of minor significance. Predicted amino acid sequences of all the known virus-encoded proteins show that amino acid substitutions have occurred at only three positions. Two of these are in structural proteins (i.e., Ser----Phe in VP3 and Lys----Arg in VP1), and the third, Thr----Ala, is in the nonstructural protein P2-3b. The distribution and nature of nucleotide and amino acid sequence differences suggest that a single base substitution may be responsible for the attenuated phenotype of the vaccine strain.

Base Sequence↗

Nucleic acid sequence of the region of the genome encoding capsid protein VP1 of neurovirulent and attenuated type 3 polioviruses.

Three closely related strains of poliovirus type 3 have been used to study the molecular basis of attenuation in the currently used Sabin vaccine of this serotype. Plaque-purified derivatives of these strains possess closely similar serological and biochemical properties yet differ markedly in neurovirulence for monkeys. Molecular cloning via an RNA . cDNA method has facilitated comparative nucleotide sequencing. Initial efforts have concentrated on the region of the genome encoding VP1. Only minor structural differences between neurovirulent and attenuated type 3 strains were detected, in contrast to the major differences observed between the vaccine strains of poliovirus type 1 and its virulent precursor P1/Mahoney. These observations suggest that the molecular basis of attenuation of type 3 Sabin vaccine virus does not involve the VP1 polypeptide and, therefore, that mutations conferring the attenuated phenotype probably lie elsewhere in the genome.

Base Sequence↗

The nucleotide sequence of poliovirus type 3 leon 12 a1b: comparison with poliovirus type 1.

The complete nucleotide sequence of the genome of the Sabin vaccine strain of poliovirus type 3 (P3/Leon 12 a1 b) has been determined from cDNA cloned in E. coli. The genome comprises a 5' non-coding region of 742 nucleotides, a large open reading frame of 6618 nucleotides (89% of the sequence) and a 3' non-coding region of 72 nucleotides. There is 77.4% base-sequence homology and 89.6% predicted amino-acid homology between types 1 and 3. Conservation of all glutamine-glycine and tyrosine-glycine cleavage sites suggests a mechanism of polyprotein processing similar to that established for poliovirus type 1.

Amino Acid Sequence↗

Poliovirus type 3: molecular cloning of the genome and nucleotide sequence of the region encoding the protease and polymerase proteins.

Overlapping cDNA clones representing the entire genome of poliovirus type 3 have been prepared in E. coli by two separate methods. Cloning of RNA . cDNA hybrids produced a more comprehensive set of clones with generally larger cDNA inserts than cloning of double - stranded cDNA. A restriction map of the entire genome and the nucleotide sequence of 2003 bases from the 3' terminus, comprising the region encoding the protease and polymerase proteins, are presented.

Amino Acid Sequence↗

Location and primary structure of a major antigenic site for poliovirus neutralization.

We have determined a major antigenic site for virus neutralization on the capsid protein VP1 of poliovirus type 3. Antigenic mutant viruses selected for resistance to individual monoclonal antibodies had point mutations concentrated in a region 277-294 bases downstream from the start of the region of viral RNA coding for VP1. These findings provide the basis for an improved understanding of the molecular basis of virus neutralization.

Amino Acid Sequence↗

Radioimmunolocalization of tumours by external scintigraphy after administration of 131I antibody to human chorionic gonadotrophin: preliminary communication.

(131)Iodine ((131)I) labelled antibody directed against human chorionic gonadatrophin (hCG) was given on 21 occasions to 18 patients with hCG-producing neoplasms. Tumours were localized by external scintigraphy in 13 of 21 investigations. Positive results were obtained reliably when serum hCG exceeded 500 miu/ml and in some cases sensitivity was comparable to that of computerized tomography. A positive result probably implies viability in the tumour and this was of practical value in discriminating between necrotic deposits and living tumour before surgery.

Antibodies↗