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M R Macnaughton

Publications and source records attributed to M R Macnaughton.

32 records · Page 2Linked to original sources
PubMed1980

Two particle types of avian infectious bronchitis virus.

Two distinct types of avian infectious bronchitis virus (IBV) particles were isolated on sucrose density gradients. The higher density particles banded at 1.18 g/ml, had typical coronavirus morphology and contained all the structural polypeptides and a complete genome. The less dense particles of density 1.13 g/ml appeared to have typical coronavirus morphology, although they were much more flattened than the more dense particles. Furthermore, these particles lacked the ribonucleoprotein polypeptide and the genome, although all the other polypeptides were present in the same amounts as in the denser particles.

Centrifugation, Density Gradient↗
PubMed1980

Enzyme-linked immunosorbent assay for coronaviruses HCV 229E and MHV 3.

The antigenic relationship between human cornonavirus strain 229E (HCV 229E) and mouse hepatitis virus strain 3 (MHV 3) was studied by means of the indirect form of enzyme-linked immunosorbent assay (ELISA). A cross-reaction was found with hyprimmune rabbit sera between HCV 229E and MHV 3 which may be due to the adherence of bovine serum componeants from tissue culture media, which were present on virus particles even after extensive purification. No cross-reaction was observed with immune sera absorbed with bovine serum, or with HCV 229E grown in tissue culture without serum. This indirect ELISA with HCV 229E may prove to be useful for studies with human sera.

Animals↗
PubMed1980

Infectivity of human coronavirus strain 229E.

The replication of human coronavirus strain 229E was observed by using indirect immunofluorescence in infected monolayers of MRC continuous cells. By 8 h after infection, bright cytoplasmic fluorescence was detected in cells infected with human coronavirus 229E. Discrete foci of infection were observed from 8 to 16 h after infection in cells infected with high dilutions of human coronavirus 229E; each fluorescent focus corresponded to a single virus infection. A fluorescent focus assay is described, using indirect immunofluorescence, which is more sensitive than the established techniques of tube titration and plaque assay. Particle/infectivity ratios for unpurified and purified virus preparations revealed a considerable drop in infectivity on purification.

Cell Line↗
PubMed1980

Enzyme-linked immunosorbent assay for detection of antibody in volunteers experimentally infected with human coronavirus strain 229 E.

An enzyme-linked immunosorbent assay was developed for detecting antibody rises to human coronavirus strain 229E and related strains in paired sera from infected volunteers. There was a close correlation between development of colds infected volunteers. There was a close correlation between development of colds and significant antibody rises detected by the enzyme-linked immunosorbent assay. Furthermore, the assay was more sensitive than a neutralization assay. This enzyme-linked immunosorbent assay is an easy, accurate, and sensitive assay for measuring significant antibody rises to human coronavirus strain 229E group viruses, and it could be useful in the clinical diagnosis of these infections.

Antibodies, Viral↗
PubMed1979

Comparison of the morphology of three coronaviruses.

The morphology of three coronaviruses, avian infectious bronchitis virus strain Connecticut (IBV Conn), human coronavirus strain 229E (HCV 229E) and mouse hepatitis virus strain 3 (MHV3), were examined by negative staining. Significant differences were found in the sizes of the three coronaviruses. Furthermore, three types of surface projection of the same lengths, but varying widths and morphology, were observed. Both IBV Conn and HCV 229E had bulbous projections characteristic of coronaviruses, although the projections of HCV 229E were somewhat thinner than those of IBV Conn. On the other hand, MHV3 particles had thin, cone-shaped surface projections, that were completely unlike typical coronavirus projections. The significance of these results is discussed.

Coronaviridae↗
PubMed1978

The genome of human coronavirus strain 229E.

The genomic RNA of human coronavirus strain 229E (HCV 229E) migrated on polyacrylamide gels as a single peak with a mol. wt. of 5.8 X 10(6). Denaturation of the genome with formaldehyde did not alter its electrophoretic mobility, which suggests that the HCV 229E genome is a single-stranded molecule. At least 30% of the genomic RNA was shown to contain covalently attached polyadenylic acid [poly(A)]sequences by binding the RNA to an oligo(dT)-cellulose column. These poly(A) tracts were shown to be about 70 nucleotides in length by measuring the resistance to digestion of HCV 229E RNA with pancreatic and T1 RNases. Finally, the genomic RNA was shown to terminate at or near the 3'-terminus on the basis of its susceptibility to polynucleotide phosphorylase.

Base Sequence↗
PubMed1977

The polypeptide composition of avain infectious bronchitis virus particles.

Egg grown avian infectious bronchitis virus (IBV) centrifuged on sucrose density gradients was found to consist of a major virus peak of density 1.17 to 1.18 g/cm(3). Three different IBV strains were examined and no morphological differences were detected between virus particles of different densities or from different strains. The polypeptides of the different density virus particles from the three IBV strains were analysed on polyacrylamide gels. In all cases 7 polypeptides were observed, although there were differences in the proportions of these polypeptides in particles of different densities and those from the different strains. The polypeptides have been called VP1 (molecular weight 130,000), VP2 (105,000), VP3 (97,000), VP4 (81,000), VP5 (74,000), VP6 (51,000) and VP7 (33,000). Additional polypeptides were produced if slightly harsher treatments were used.

Animals↗
PubMed1977

Polypeptides of the surface projections and the ribonucleoprotein of avian infectious bronchitis virus.

Purified avian infectious bronchitis virus was digested with bromelain (0.7 mg/ml), and the surface projections were removed. Polyacrylamide gel electrophoresis of the polypeptides from these bromelain-treated particles showed that VP1, VP2, and VP5 were missing from the seven polypeptides. VP1 to VP7, that were present in untreated virus preparations. Milder bromelain treatment (0.07 mg/ml) left visible surface projections and polypeptides comprising VP1 and VP2 intact, but removed VP5. Thus, there are apparently two types of surface projections on the virus particle. The ribonucleoprotein complex was released from virus particles disrupted with 1% Nonidet P-40. The proportion of VP6 in such preparations was greatly reduced, implying that VP6 is the structural polypeptide of the ribonucleoprotein. Polypeptides VP1, VP2, VP4, and VP5 are glycosylated, but none of the polypeptides contains lipid.

Bromelains↗
PubMed1976

Different patterns of polyadenylation of rhinovirus: specified RNA during multiplication in human aneuploid and diploid cells.

The polyadenylation of rhinovirus-specified RNA in aneuploid HeLa cells and diploid human embryo lung (HEL) cells has been investigated. Polyadenylation occurs at a faster rate and more extensively to virus-specified RNA in infected HEL cells compared with HeLa cells. Poly(A) is added post-transcriptively in both cell types. Furthermore the addition of adenosine or poly(A) during virus multiplication increases the polyadenylation of virus single-stranded RNAs in both cell types, but to a greater extent in HeLa cells.

Adenosine↗
PubMed1976

Rhinovirus multistranded RNA: dependence of the replicative form on the presence of actinomycin D.

The multistranded and double-stranded RNAs synthesized in HeLa cells infected with rhinovirus in the presence and in the absence of actinomycin D have been characterized by polyacrylamide gel electrophoresis and hybridization studies. The replicative form is only found in infected cells treated with actinomycin D, whereas the replicative intermediate is found in both the presence and the absence of the drug. The significance of these results is discussed.

Dactinomycin↗