PubMed Health⌕ Search

Biomedical subjects

C R Pringle

Publications and source records attributed to C R Pringle.

At least 73 records · Page 4Linked to original sources
PubMed1990

Heptad repeat sequences are located adjacent to hydrophobic regions in several types of virus fusion glycoproteins.

Extensive regions of heptad repeat units consistent with an alpha-helical coiled coil conformation are located adjacent to hydrophobic, potentially fusion-related regions in the amino acid sequences of paramyxovirus fusion and retrovirus envelope glycoproteins. Similar arrangements of hydrophobic peptides and heptad repeat units exist in coronavirus peplomer proteins and influenza virus haemagglutinins. This suggests that there may be similarities in the structures of these proteins and in the functions of the hydrophobic fusion-related regions during virus entry.

Amino Acid Sequence↗
PubMed1990

Molecular cloning of pneumonia virus of mice.

cDNA clones representing nine genes of pneumonia virus of mice (PVM) have been generated. The sizes of the corresponding mRNAs and a provisional transcriptional map of the virus genome have been determined. The apparent gene order is very similar to that of respiratory syncytial virus. The sequences adjacent to the 3' termini of the PVM genes were determined and are very similar to those of respiratory syncytial virus. Several PVM gene polypeptide products have been assigned.

Animals↗
PubMed1989

Polypeptides of pneumonia virus of mice. I. Immunological cross-reactions and post-translational modifications.

A murine polyclonal antiserum and monoclonal antibodies have been employed to identify pneumonia virus of mice (PVM) polypeptides in infected cells and to study post-translational modifications. Immunoprecipitation experiments using a murine polyclonal antiserum and a monoclonal antibody directed against a 39K protein have established an antigenic relationship between two PVM proteins and the N and P proteins of human respiratory syncytial virus. Although 20 virus-specific polypeptides have been identified in lysates of infected cells, evidence is presented that some of these are related and that the number of unique polypeptides probably does not exceed 11 or 12. The phosphoproteins of PVM have a pattern of mobilities more like that of the recently described pneumovirus causing rhinotracheitis in turkeys than that of human or bovine respiratory syncytial virus.

Animals↗
PubMed1989

Polypeptides of pneumonia virus of mice. II. Characterization of the glycoproteins.

The kinetics of synthesis and the nature of the oligosaccharides of the glycoproteins of pneumonia virus of mice (PVM) were studied. Tryptic peptide mapping showed that the two major glycosylated polypeptides G1 and G2 were different forms of the same protein. G2 was derived from G1 which in turn appeared to be derived from an unidentified precursor. The G1/G2 protein of PVM is probably a haemagglutinin since a monoclonal antibody directed against it has a high haemagglutination inhibition titre. On the basis of experiments with inhibitors and glycosidases it was deduced that G1 and G2 have both N-linked and O-linked oligosaccharides. The putative fusion protein-equivalent of PVM was shown to possess N-linked oligosaccharides. In the presence of tunicamycin a high mobility form (F1t) appeared to be derived from a precursor (F0t) with the same mobility as the fully glycosylated protein. If by analogy with other paramyxoviruses this represents a cleavage event, the difference in mobility of the precursor and product suggests that the putative F2 product is smaller than the corresponding F2 protein of other paramyxoviruses. However, no F2 candidate protein was detected and evidence for an F1,2 dimer was inconclusive. The glycoproteins of PVM resemble those of respiratory syncytial virus in terms of their pattern of glycosylation, but differ in their processing.

Animals↗
PubMed1988

Turkey rhinotracheitis virus: in vivo and in vitro polypeptide synthesis.

Turkey rhinotracheitis (TRT) virus is a paramyxovirus associated with recent outbreaks of acute respiratory disease in turkeys. On morphological criteria it resembles the pneumoviruses more than the other members of the paramyxovirus family. In this communication we report the identification of five virus-induced polypeptides in TRT virus-infected BS-C-1 cells. The Mr of these polypeptides were estimated as 38K, 35K, 30K, 19K and 15K from their electrophoretic mobility in SDS-polyacrylamide 6 to 15% gradient gels. The virus specificity of four (the 38K, 35K, 30K and 19K Mr polypeptides) of these five was confirmed by their predominance as products of in vitro translation of mRNA from TRT virus-infected BS-C-1 cells. An additional virus-specific polypeptide with an estimated Mr of 22K was revealed by in vitro translation and may be either a non-structural polypeptide or a minor structural protein. All six polypeptides were immunoprecipitated by a murine antiserum. Three other polypeptides (129K, 57K and 45K) were also immunoprecipitated. The 57K, 45K and 15K Mr polypeptides were glycosylated, and the 57K glycopolypeptide may be a disulphide-bonded dimer of the 45K and 15K glycopolypeptides. Another major glycopolypeptide of 83K Mr was observed but its virus-specificity could not be confirmed. Taken together our results tentatively identify eight or nine TRT virus-specified polypeptides and are consistent with the classification of TRT virus as a new member of the genus Pneumovirus.

Animals↗
PubMed1987

Molecular cloning and sequencing of the F and 22K membrane protein genes of the RSS-2 strain of respiratory syncytial virus.

The nucleotide sequences of the adjacent genes coding for the F protein and 22K protein of the RSS-2 strain of human respiratory syncytial (RS) virus were determined from cDNA clones of genomic RNA. Comparison of these sequences and the inferred amino acid sequences of the F and 22K proteins with the corresponding published sequences of another subgroup A virus, the A2 strain of RS virus, reveals extensive overall homology (greater than 95%) at both the nucleotide and amino acid levels, even though these two viruses were isolated 15 years apart in different continents. The intergenic region and the hydrophobic amino-terminal signal sequence of the F proteins of the two viruses, however, are much less conserved.

Amino Acid Sequence↗
PubMed1987

Effect of melittin on transcription by vesiculovirus mutant and wild-type viruses.

The bee venom peptide melittin activated the virion transcriptase activity of three vesiculoviruses with preservation of virion structure. The kinetics of RNA synthesis were similar to those observed with purified transcribing nucleoprotein (TNP) preparations. Six temperature-sensitive host range (tdCE) mutants of Chandipura virus displayed 1.7- to 5.5-fold greater efficiencies of transcription at 39 degrees with melittin-permeabilized virions in comparison with TNP preparations. Comparative study of other host range mutants (tdCE3) and tsB1) of vesicular stomatitis virus (VSV) New Jersey and a thermosensitive polymerase mutant (tsG114) of VSV Indiana suggested that the enhanced transcription at 39 degrees associated with melittin-activated tdCE mutants was due to the retention of host factors in the virions.

Bee Venoms↗
PubMed1987

Progress towards control of the acute respiratory viral diseases of childhood.

Many of the common respiratory illnesses of infancy and childhood are caused by viruses of the Paramyxoviridae family, in particular measles virus, respiratory syncytial (RS) virus and parainfluenzavirus type 3 (PI3). Effective measles vaccine was developed by classical methods, but these same methods have failed to provide vaccines to control RS and PI3 virus infections. The WHO Programme for Vaccine Development was initiated in 1983 to encourage the application of the new biotechnologies to continuing problems, such as the acute virus-induced respiratory diseases of childhood. At a meeting of research workers held in July 1986 under the auspices of this programme, renewed optimism was expressed concerning the prospects for immunoprophylaxis of RS virus-induced disease. Animal models are now available for evaluation of the immunogenic potential of candidate vaccines. Vaccinia/RS recombinant viruses have been produced which have allowed the immunogenic properties of individual RS virus proteins to be defined. Complete protection without the exacerbation of disease, which earlier had accompanied the use of formalin-inactivated vaccines, has been achieved in animals immunized with vaccinia virus recombinants expressing the F protein; partial protection was obtained using G protein gene vectors. PI3 appears to be an inherently stable virus and evidence from animal experiments suggests that bovine PI3 might be suitable for use as a live vaccine in man.

Acute Disease↗
PubMed1986

Role of glycosylation in transport of vesicular stomatitis virus envelope glycoprotein. A new class of mutant defective in glycosylation and transport of G protein.

A temperature-sensitive mutant (ts gamma 1) of the Cocal serotype of vesicular stomatitis virus synthesizes at the permissive temperature (32 degrees C) a glycoprotein G whose size is smaller (Mr 68,000) than the wild-type (Mr 71,000) and that renders the virion thermolabile. At the nonpermissive temperature (39 degrees C), reduced amounts of noninfectious virus-like particles deficient in G protein were produced. The size of the intracellular G protein was further decreased (Mr 64,000) at the nonpermissive temperature. Biochemical studies including sugar labeling, tryptic peptide analysis, and NH2-terminal sequence analysis of the various glycoproteins suggest that at 32 degrees C a G protein containing a single glycosidic moiety is synthesized. The G protein containing only 1 oligosaccharide residue is transported to the cell surface and is incorporated in infectious virus particles. In contrast, the G protein synthesized at 39 degrees C is nonglycosylated and fails to reach the cell surface. These results suggest that glycosylation of G protein is essential for its transport to the cell surface, and the presence of a single carbohydrate chain is sufficient for this purpose.

Amino Acid Sequence↗
PubMed1986

Nucleotide sequence of the Bunyamwera virus M RNA segment: conservation of structural features in the Bunyavirus glycoprotein gene product.

The complete nucleotide sequence of the Bunyamwera virus M RNA segment was determined from four overlapping cDNA clones and by primer extension. The RNA segment is 4458 bases in length, and encodes a single gene product in the viral complementary RNA. The predicted protein is 1433 amino acids long (mol wt 162,065), contains four potential glycosylation sites, and is relatively cysteine rich. It is presumed that the three proteins G1, G2, and NSM which have been mapped to the M RNA segment are synthesized as a precursor polyprotein which is subsequently proteolytically cleaved. A putative hydrophobic signal sequence at the amino terminus and a hydrophobic anchor sequence at the carboxy terminus of the predicted protein have been identified, in addition to internal regions of hydrophobicity of unknown function. The nucleotide and amino acid sequences of the Bunyamwera virus M segment have been compared with those of the snowshoe hare virus M segment (Y. Eshita and D. H. L. Bishop, Virology 137, 227-240, 1984). Common features include the overall architecture of the RNAs, single cysteine-rich primary gene products, and conservation of hydrophobic domains in the gene products. When aligned the amino acid sequences are 43% homologous, and 66 of 70 cysteine residues can be matched. The evolutionary significance of these findings is discussed.

Amino Acid Sequence↗
PubMed1986

In vitro transcriptase deficiency of temperature-dependent host range mutants of Chandipura virus.

Ten of 12 Chandipura virus tdCE mutants, which exhibit temperature-dependent restriction of growth in chick embryo (CE) cells but not in BS-C-1 cells, showed deficient transcriptase activity in vitro at 39 degrees C relative to wild-type virus. A gradation in transcriptional activity at 39 degrees C in vitro was observed. Reversion of the tdCE phenotype to unrestricted growth in CE cells at 39 degrees C was accompanied by partial restoration of normal transcriptase activity at 39 degrees C, suggesting that reversion was mediated by either extragenic or intragenic suppression. Viral protein synthesis was reduced or absent in CE cells at 39 degrees C indicating that transcription was also defective in vivo under these conditions. Induction of heat-shock proteins in CE cells at 39 degrees C occurred normally in tdCE mutant-infected cells and RNA methylation in vitro was unaffected.

Animals↗
PubMed1986

Murine pneumonia virus: seroepidemiological evidence of widespread human infection.

More than 75% of a random sample of adult human sera exhibited moderate to high murine pneumonia virus (PVM)-neutralizing activity. There was no correlation between PVM-neutralizing activity and respiratory syncytial virus or parainfluenza type 3 virus-neutralizing activities of the same sera. In children the proportion of sera with moderate to high titres increased with age, indicating early exposure to infection. Seroconversion (i.e. greater than fourfold increase in titre) was observed in four of 108 paired samples of previously undiagnosed respiratory infections. These observations suggest that the human population is frequently exposed to infection with PVM or an antigenically related virus. The sera of patients suffering from Paget's disease of bone tended to exhibit higher than normal PVM-neutralizing titres in comparison with the sera of patients with other bone diseases. Thus, PVM (or an antigenically related virus) resembles some other parainfluenza viruses in being circumstantially associated with Paget's disease of bone.

Age Factors↗
PubMed1985

A survey of respiratory syncytial virus and parainfluenza virus type 3 neutralising and immunoprecipitating antibodies in relation to Paget disease.

The aetiology of Paget disease of bone has not been established but certain features have suggested involvement of a parainfluenzalike virus. To seek further evidence of the possible role of paramyxoviruses in Paget disease we have surveyed the presence of neutralising and immunoprecipitating antibodies to both respiratory syncytial virus and parainfluenza virus type 3 in the sera of patients attending a bone disease clinic. These two viruses were implicated by the sporadic observation of viral antigen in individual nuclei of osteoclasts in Paget disease bone lesions. A total of 315 samples were obtained from 177 patients attending the clinic during 1 year. Thirty-six of the patients had confirmed Paget disease and the remainder other conditions. All sera possessed neutralising activity to both viruses. The mean titres for each virus were similar in patients with Paget disease and those with other conditions whether matched or not. In the case of respiratory syncytial virus the neutralising titres were distributed closer to the mean in the Paget group and showed little variation in repeat samples taken over periods of up to 1 year in contrast to the greater variability of the control group. The antigenic specificity of 20 age- and sex-matched sera from each group was examined by immunoprecipitation. No significant differences were observed between Paget and non-Paget patients. These results do not provide confirmation of involvement of either virus in Paget disease, but the serological data suggest that persistent infection with respiratory syncytial virus can occur.

Adolescent↗
PubMed1985

Synthesis of bunyavirus-specific proteins in a continuous cell line (XTC-2) derived from Xenopus laevis.

The XTC-2 cell line, derived from Xenopus laevis, supported the replication of representative viruses from each of the four genera in the family Bunyaviridae. Generally, viral titres were higher in XTC-2 cells than in other susceptible cell lines, and for some viruses plaques were detected earlier in XTC-2 cells. The XTC-2 cell line permitted comparative analyses of bunyavirus-specific protein synthesis. The patterns of synthesis of viral proteins, characteristic of each of the genera, were observed with representative viruses. These studies provided biochemical characterization of two Scottish isolates, which support the inclusion of Clo Mor virus in the Nairovirus genus and St Abb's Head (M349) virus in the Uukuvirus genus.

Animals↗
PubMed1984

Genome subunit reassortment among Bunyaviruses analysed by dot hybridization using molecularly cloned complementary DNA probes.

A simple and rapid procedure for determining the genotypes of viruses has been applied to analysis of genome subunit reassortment in heterologous crosses of Batai virus, Bunyamwera virus, and Maguari virus, three members of the Bunyamwera serogroup of bunyaviruses. The procedure for determining genotype made use of specific molecular probes to identify the parental origin of the L and M RNA subunits. Complementary DNA copies of the three RNA segments of Bunyamwera virus were prepared by reverse transcription using synthetic oligonucleotide primers for first and second strand synthesis. The cDNA transcripts were inserted into a pBR322 vector and gene-specific probes prepared from nick-translated plasmid DNA. L and M gene-specific probes were identified which could unequivocally discriminate Bunyamwera virus genome subunits in a dot-hybridization test using cytoplasmic RNA extracts immobilised on nitrocellulose filters. None of the S gene-specific probes were sufficiently discriminatory for use in this test. Instead the parental origin of the S RNA subunit was inferred from the electrophoretic mobility of the virion N protein. It was observed that reassortment did not occur at random in heterologous crosses of is mutants of the three viruses, and only the M RNA subunit appeared to segregate freely. However, unrestricted reassortment was observed when recombinant viruses with nonhomologous subunit combinations were used as the parental viruses. It was concluded, therefore, that restriction was mediated at the gene product level and that nonrandom reassortment was not due to incompatibility of genome subunits.

Animals↗
PubMed1982

Measurement of surface antigen by specific bacterial adherence and scanning electron microscopy (SABA/SEM) in cells infected by vesiculovirus ts mutants.

Temperature-sensitive (ts) mutants of the rhabdoviruses vesicular stomatitis virus and Chandipura virus have been used to measure the appearance of virus antigen on the surface of infected cells by the technique of surface analysis by bacterial adherence and scanning electron microscopy (SABA/SEM). The number of staphylococci specifically adhering to antiserum-treated infected PTK-2 or BSC-1 cells at permissive (31 degrees C) and restrictive (39 degrees C) temperatures was followed in time-course experiments and a close correspondence was observed between the proportion of staphylococci bound at 39 degrees C and the known phenotypic properties of the ts mutants. Virus surface antigen was undetected in cells infected by transcription- and replication-defective ts mutants with thermolabile L proteins under restrictive conditions up to an input multiplicity of infection of 50, and in cells infected by a replication-defective NS protein mutant. Some surface antigen was detected late in infection in PTK-2 cells infected by a replication-defective N protein mutant. Surface antigen accumulated normally in maturation-defective mutants with lesions in envelope proteins. These results establish the suitability of the SABA/SEM technique for quantitative estimation of virus antigen on the surface of infected cells.

Adhesiveness↗