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Biomedical subjects

I H Holmes

Publications and source records attributed to I H Holmes.

At least 37 records · Page 2Linked to original sources
PubMed1991

VP4 relationships between porcine and other rotavirus serotypes.

VP4 relationship of Australian porcine rotaviruses were identified using genetic reassortants and MAbs. All porcine virus isolates except BEN-144 appeared to share VP4 antigenicity with OSU virus. VP4 and BEN-144 virus (Gottfried-like virus) showed some antigenic relationships with the human neonatal viruses ST-3 and RV-3. In addition, VP4 of porcine CRW-8 showed antigenic relationships with simian SA-11. RRV and also canine K9 viruses, while that of porcine TFR-41 showed at least one way VP4 antigenic relatedness with UK bovine rotavirus. Furthermore, BMI-1 virus which is antigenically similar to an American virus SB1-A (a naturally occurring reassortant) may have arisen similarly by gene reassortment in nature in Australia.

Animals↗
PubMed1990

A porcine rotavirus strain with dual VP7 serotype specificity.

Porcine rotavirus MDR-13, which on original isolation showed a two-way antigenic relationship with human rotavirus RV-3, shows VP7 relationships with serotype G5 as well as G3 viruses upon gene reassortment. Analysis of porcine MDR-13 and the MD-UK reassortant revealed marked nucleotide and amino acid similarity of VP7 genes of these viruses with those of both serotype G3 and G5 viruses. Evolution of such a strain, possibly by sequential mutations in the VP7 gene, is discussed.

Amino Acid Sequence↗
PubMed1990

Serotyping of human group A rotavirus with oligonucleotide probes.

Rotaviruses (RV) in stools of children with diarrhea in Thailand were serotyped by monoclonal enzyme immunoassay (MEIA), and RNA extracted from these specimens were tested for hybridization with oligonucleotides constructed from the nucleotide sequences of VP7 of human serotypes 1, 2, 3, and 4. Of 178 specimens that contained RV as identified with a monoclonal antibody to group A RV, 84% (149/178) hybridized with serotype-specific oligonucleotides, and 42% (74/178) were serotyped by MEIA (P less than .001). Of the 74 specimens that were serotyped by MEIA, 92% (35/38) of type 1, 97% (34/35) of type 2, and the one type 4 RV hybridized with the HuG1Ac, HuG2Ac, and HuG4Ac oligonucleotides, respectively. RV strains identified in children in Thailand in 1987 and 1988 to which a serotype could be assigned by either method were either type 1, type 2, or, less often, type 4. Testing RV for hybridization with oligonucleotides for genes encoding VP7 is an alternate method of determining RV serotypes.

Antibodies, Monoclonal↗
PubMed1989

Comparative sequence analysis of VP7 genes from five Australian porcine rotaviruses.

The genes coding for the rotavirus major neutralizing protein, VP7, from 5 Australian porcine rotaviruses representing glycoprotein (i.e. VP7 or G) serotypes 3, 4, and 5, were sequenced. The genes were each 1,062 nucleotides long with two long open reading frames for proteins of either 326 or 297 amino acids and containing only one potential glycosylation site at amino acid position 69. When compared to the corresponding genes of human viruses, the porcine genes showed very high nucleotide and deduced amino acid homology. Sequence comparison also revealed that Australian porcine rotaviruses of G serotype 4 and 5 were similar to the corresponding porcine strains found in the U.S.A. and U.K., while G serotype 3 and 4 porcine rotaviruses were closely related to human G serotype 3 strain, RV-3 and serotype 4 strain, ST-3, respectively. These Australian rotavirus VP7 sequences were found to correlate with serological data we reported previously.

Amino Acid Sequence↗
PubMed1989

The VP7 gene of a new G serotype of human rotavirus (B37) is similar to G3 proteins in the antigenic c region.

The human rotavirus isolate B37 has a characteristic "super-short" RNA electropherotype and has been shown to represent a new VP7 serotype (M. J. Albert, L. E. Unicomb, and R. F. Bishop, 1987, J. Clin. Microbiol. 25, 183-185). The VP7 gene was cloned, and its nucleotide and predicted amino acid sequences were compared to other published VP7 gene sequences. Consistent with the serological evidence, two major antigenic regions of the B37 VP7 (i.e., regions A and B) differ in sequence from those of other G serotypes. Unexpectedly, the C antigenic region shows close similarity to G3 rotaviruses, but we were unable to detect a serological relationship using serotype 3 monoclonal antibodies.

Amino Acid Sequence↗
PubMed1989

Sequences of VP9 genes from short and supershort rotavirus strains.

Segment 10 genes from a short (RV-5, serotype G2) and a supershort (B37, a new G serotype) strain were cloned and their sequences compared to the (corresponding) segment 11 sequences of Wa, SA11, and UK rotaviruses. The determined nucleotide sequences were 817 (RV-5) and 947 (B37) bases in length and showed extensively conserved 5' noncoding and protein coding regions. The major open reading frame codes for a protein of 200 (RV-5) or 198 (B37) amino acids, and the newly proposed second open reading frame can code for a protein of 92 amino acids. Compared to long strain gene segments, the base sequences of the short and supershort strains were found to contain extended, AT-rich 3' noncoding regions which were not significantly homologous to each other, to other parts of the VP9 gene, or to other rotavirus genes that have been sequenced. The function(s) of these 3' regions is not apparent.

Amino Acid Sequence↗
PubMed1989

Neutralizing monoclonal antibodies against three serotypes of porcine rotavirus.

Using three serotypes (four strains) of cultivable porcine rotavirus as immunizing antigens, 10 neutralizing monoclonal antibodies were characterized. One VP4-specific monoclonal antibody directed against porcine rotavirus BEN-144 (serotype G4) neutralized human rotavirus strain ST-3 in addition to the homologous porcine virus. All nine VP7-specific monoclonal antibodies were highly specific for viruses of the same serotype as the immunizing rotavirus strain. One exception was the VP7-specific monoclonal antibody C3/1, which neutralized both serotype G3 and G5 rotaviruses. However, this monoclonal antibody did not neutralize the porcine rotavirus AT/76, also of serotype G3, nor mutants of SA-11 virus (serotype G3) which were selected with monoclonal antibody A10/N3 and are known to have mutations affecting the C antigenic region.

Animals↗
PubMed1988

Atypical rotaviruses in Australian pigs.

Atypical rotaviruses of two different electropherotypes were identified by PAGE in 16 out of 237 (5.3%) diarrhoeic faecal samples from piglets. A cDNA probe derived from a group B rotavirus hybridized strongly to two samples (of 3 tested) with electropherotypes suggestive of groups B or E, identifying them as group B. The electropherotype(s) of seven samples were typical of group C. By immunofluorescence, antibodies to group B, C, and E rotaviruses have been detected in sera from Australian sows, so it appears that atypical rotaviruses belonging to three different groups occur in pigs in this country.

Animals↗
PubMed1988

Nucleotide sequence of UK bovine rotavirus segment 4: possible host restriction of VP3 genes.

The bovine UK and simian SA11 rotaviruses are commonly used VP7-type reference strains. Since the surface protein VP3 is a significant neutralization antigen, it is important to fully characterize the VP3 types associated with current reference strains. Here we present the complete nucleotide and predicted amino acid sequence of VP3 from UK rotavirus (VP7 type 6) and compare it to the published sequences of SA114fm and RV-5. We also compare the deduced amino acid sequence covering the trypsin cleavage region of UK VP3 to 25 other available sequences. The UK protein is clearly different from that of bovine NCDV (another commonly used VP7 type 6 strain) and represents a second VP3 type associated with bovine rotaviruses. Our SA11 sequence differs from that determined by Lopez et al. [1985, Virology 144, 11-19; later referred to as SA114fM by Lopez et al. (1986, Virology 154, 224-227], their sequence being very similar to the published sequence of NCDV VP3. The significance of these results with regard to virus serotypes is discussed. Finally, in analyzing the nucleotide sequence surrounding the initiation codon, a potential hairpin-loop structure was identified which may be involved in translational regulation.

Amino Acid Sequence↗
PubMed1988

New porcine rotavirus serotype antigenically related to human rotavirus serotype 3.

Serotyping of porcine rotaviruses isolated in MA104 cells from Australian piglets with diarrhea showed that two strains belonged to serotype 3 and one strain was antigenically similar to the OSU strain of porcine rotavirus (serotype 5). In addition, neutralizing antibodies to human rotavirus serotype 4 (ST-3 strain) were detected in serum samples from sows in one area, and so it seems probable that porcine rotaviruses of at least three serotypes occur in Australia.

Animals↗
PubMed1988

Serotypic analysis of VP3 and VP7 neutralization escape mutants of rhesus rotavirus.

Neutralization escape mutants of simian rotaviruses (rhesus rotavirus and SA11) were tested in hemagglutination inhibition and neutralization assays against hyperimmune and infection sera to determine if mutation in an immunodominant epitope could enable neutralization escape. An SA11 mutant with a new glycosylation site at amino acid 211 of VP7 was shown to escape neutralization by hyperimmune but not infection sera.

Animals↗
PubMed1987

Marked sequence variation between segment 4 genes of human RV-5 and simian SA 11 rotaviruses.

The complete nucleotide sequence of dsRNA gene segment 4 of a human serotype 2 rotavirus, RV-5, was determined by sequencing overlapping cloned DNA copies of the gene. Segment 4 is 2359 base pairs in length and contains a single long open reading frame of 2325 bases capable of coding for a protein of 775 amino acids, with 5' and 3' non coding regions of 9 and 25 nucleotides respectively. Comparison with SA 11 segment 4 sequence reveals a moderately conserved trypsin cut site and an overall amino acid homology of 69.8 percent. One localized region of 126 amino acids is only 37.8 percent homologous. Localized frame shifts account for some of this variation, but at the nucleotide level the segment 4 sequences show more variability than other rotavirus genes that have been studied so far.

Amino Acid Sequence↗
PubMed1987

Glycosylation, an important modifier of rotavirus antigenicity.

Mutants of a non-glycosylated strain of SA 11 rotavirus (clone 28), were selected using a monoclonal antibody directed against the VP 7 protein. These mutants possessed an amino acid substitution at residue 238 of VP 7, whereas mutants of wild type SA 11 selected with the same antibody have previously been shown to contain a substitution at residue 211 (i.e., in the antigenic C region). In both cases the mutations produce new potential glycosylation sites, and these were found to be utilized. The mutations also lead to gross antigenic changes, and these were found to be reversible upon removal of the attached carbohydrate. The results suggest an important role for carbohydrate in influencing the exposure of antigenic determinants of the rotavirus serotype-specific protein, VP 7.

Amino Acid Sequence↗
PubMed1986

Intracellular localization of rotaviral proteins.

The differential distribution of two SA 11 rotaviral capsid antigens in thin sections of infected cells was examined using antibody-coated colloidal gold electron-dense particles as specific post-embedding immunocyto-chemical labels. The treatment of thin sections of conventionally fixed and embedded tissue specimens with sodium metaperiodate allowed specific localization of the antigens in tunicamycin-treated, infected CV-1 cells. Both protein antigens were investigated with specific anti-rotavirus hyper-immune sera and with specific monoclonal antibodies. These studies showed that the major outer capsid glycoprotein, gp34, of SA11 rotavirus particles was mainly located within the cisternae and along the membranes of the rough endoplasmic reticulum. The antigen of the major inner capsid protein, p42, was identified attached to enveloped virus particles, and even more obviously, on laminar crystalline structures in the nucleus and cytoplasm of the infected cells.

Animals↗
PubMed1986

Location of the major antigenic sites involved in rotavirus serotype-specific neutralization.

Antigenic sites on the rotavirus major outershell glycoprotein were identified by using mutant viruses selected for resistance to neutralizing (serotype-specific) monoclonal antibodies. The glycoprotein genes from these mutants were sequenced to determine the position and nature of the resultant amino acid substitutions in the protein. Three regions (A, B, and C) were identified (amino acids 87-96, 145-150, and 211-223, respectively), of which region C appears to be the most important. A mutation in region C caused a 10-fold increase in resistance to neutralization by polyclonal antiviral antiserum. The results of this study, together with other data, indicate that the three-dimensional folding of the native protein is such that regions A and C are in close proximity.

Amino Acid Sequence↗
PubMed1985

Demonstration of an immunodominant neutralization site by analysis of antigenic variants of SA11 rotavirus.

Serotype-specific monoclonal antibodies were used to select mutants of SA11 rotavirus that were resistant to neutralization. The antigenic characteristics of these mutants were studied with with a panel of monoclonal antibodies. We isolated one type of mutant which showed a dramatic increase (greater than 10-fold) in resistance to neutralization by hyperimmune antiserum, and this together with other data indicates the presence on the rotavirus major outer shell glycoprotein of an immunodominant antigenic site involved in virus neutralization. The mutants were also useful in classifying neutralizing monoclonal antibodies.

Antibodies, Monoclonal↗
PubMed1984

Sequence homology between human and animal rotavirus serotype-specific glycoproteins.

The dsRNA gene segment coding for the major outer shell glycoprotein of a human rotavirus (Hu/Australia/5/77, serotype 2) was converted into DNA and cloned into the PstI site of the plasmid pBR322. The cloned gene was sequenced and found to be 1062 bp long with one long open reading frame capable of coding for a protein 326 amino-acids. When this gene sequence was compared to the published sequences of the corresponding genes of two animal rotaviruses, SA11 (simian) and UK (bovine), all three were found to be closely related (74-78%). The predicted amino-acid sequences of the three genes were also highly conserved (75-86%), despite the fact that the three viruses belong to different serotypes.

Animals↗