Search Results - (Author, Cooperation:M. K. Estes)

2014-11-15

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Animals ; Diarrhea/immunology/therapy/virology ; Disease Models, Animal ; Feces/virology ; Flagellin/*administration & dosage/immunology ; Homeodomain Proteins/genetics ; *Immunity, Innate ; Interleukin-18/administration & dosage/genetics/*immunology ; Interleukins/administration & dosage/genetics/*immunology ; Mice ; Mice, Inbred C57BL ; Mice, Mutant Strains ; Mutation ; Rotavirus Infections/immunology/*prevention & control/therapy ; Toll-Like Receptor 5/genetics/*physiology ; Virus Shedding

2012-04-17

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

ABO Blood-Group System/chemistry/genetics/immunology/*metabolism ; Amino Acid Sequence ; Animals ; CHO Cells ; Cricetinae ; Crystallography, X-Ray ; Erythrocytes/metabolism/virology ; Host Specificity/*physiology ; Humans ; Models, Molecular ; Molecular Sequence Data ; N-Acetylneuraminic Acid/antagonists & inhibitors/chemistry/immunology/metabolism ; RNA-Binding Proteins/chemistry/*metabolism ; Receptors, Virus/chemistry/genetics/*metabolism ; *Rotavirus/chemistry/classification/metabolism/pathogenicity ; Viral Nonstructural Proteins/chemistry/*metabolism

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] Genome transcription in rotavirus occurs within double-layered particles (DLPs) following the removal of the outer capsid protein layer at cell entry11. The structural integrity of the DLP, which is composed of the viral proteins VP1, VP2, VPS and VP6, is essential for transcription. Although the ...

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] Cryo-electron micrographs of native double-shelled virions embedded in vitreous ice (Fig. la) show the characteristic smooth outer margin of the virions and the spikes emanating from them4. Cryo-electron micrographs of virions complexed with anti-VP4 IgGs (Fig. Ib) show additional density at ...

Electronic Resource

1432-8798

Springer Online Journal Archives 1860-2000

Medicine

Summary Rotaviruses are a major cause of gastroenteritis in children worldwide. Rotaviruses are antigenically complex, with multiple serotypes (G types). The first longitudinal study of group A rotavirus serotype (G type) distribution in Hungary is reported. Neutralizing monoclonal antibodies specific for G1, G2, G3, and G4 were used in an enzyme immunoassay to determine the antigenic variation of group A rotaviruses in two collections of stool specimens assembled from 1984–1992 in Baranya County, southwest Hungary, and from 1988–1992 at the Central Hospital for Infectious Diseases in Budapest. Ninety-two percent of the 1215 virus-positive samples were typed as follows: G1 (81%), G2 (4%), G3 (1%), G4 (5%), or mixed type (1%). G1 was the predominant type during the entire study period with the exception of the 1988/1989 rotavirus season in Baranya County when G4 predominated. Among G1 strains, different electropherotypes were detected with a shift of the predominant G1 electropherotype(s) each 2 to 3 years. G typing from two longitudinal collections established regional differences within Hungary in the prevalence of rotavirus antigenic types among children with rotavirus-associated diarrhea. These are the first longitudinal rotavirus typing results for Hungary and Central Europe.

Electronic Resource

1432-8798

Springer Online Journal Archives 1860-2000

Medicine

Summary A dot blot hybridization assay was developed for detection of human calicivirus/Sapporo/82/J (HuCV/Sa/82) or strains closely related to HuCV/Sa/82 in stool specimens. The cDNA derived from the RNA-dependent RNA polymerase (RDRP) region of HuCV/Sa/82 was used as a positive probe and the pBR 322 DNA as a negative control probe. Both probes were labeled with digoxigenin and the products of hybridization reaction were detected with an anti-digoxigenin antibody-alkaline phosphatase conjugate. This assay was specific for HuCV/Sa/82 and for HuCV antigenically related to HuCV/Sa/82. The lower limit of sensitivity of this assay was estimated to be about 105 physical particles or 10 pg of cDNA, similar to that of the previously developed ELISA for HuCV. In 1 273 stool specimens obtained from children with acute gastroenteritis in Sapporo, Japan, 110 (8.6%) contained small round structured viruses by EM and 23 (1.8%) were positive for HuCV antigenically related to HuCV/Sa/82 by either the hybridization assay or ELISA. A higher positive rate was obtained with the dot blot assay (21%) than by ELISA (10%), suggesting that the dot blot assay either detects HuCV more broadly than the ELISA or detects HuCV covered with fecal antibodies which interrupt antigen-antibody reactions in the ELISA. Negative results for detection of Norwalk virus (NV) cDNA and feline calicivirus (FCV) RNA by both this assay and the ELISA indicated that the HuCV/Sa/82 strain is distinct antigenically and genetically from NV and FCV.

Electronic Resource

1432-8798

Springer Online Journal Archives 1860-2000

Medicine

Summary We report biochemical (RNA and protein patterns and gene-coding assignments) and serologic (serotype and subgroup) properties of three strains of rabbit rotaviruses — Ala, C11 and R2. The RNA electropherotypes were a standard “short” pattern for R2, an unusual “short” pattern for Ala, and an unusual “long” pattern for C11. Serologic studies indicated that these viruses were all group A serotype 3 rotaviruses. In addition, the Ala and C11 viruses were found to possess subgroup I specificity, whereas the R2 virus possessed subgroup II specificity. In contrast to their distinctive RNA patterns, the polypeptide patterns of the rabbit viruses were similar to those of SA11. To identify cognate genes and determine gene-coding assignments for the rabbit rotaviruses, cDNA probes of individual SA11 genes were hybridized to rabbit rotaviral genomic RNA segments that had been separated by polyacrylamide gel electrophoresis and transferred to filters (Northern blots). The order of genome segments 7–11 for each of the rabbit rotaviruses was unique and differed from that of SA11 genes. These differences were possibly due to rearrangements of the RNA sequences within these individual genome segments. Sequence analysis of the individual RNA segments will confirm whether genome rearrangements are the molecular basis for these novel migration patterns.

Electronic Resource

1432-8798

Springer Online Journal Archives 1860-2000

Medicine

Summary Stool samples from 451 patients involved in volunteer studies, 26 outbreaks and ∼175 sporadic cases of acute gastroenteritis from different geographical locations in the world were tested for Norwalk virus (NV) using a newly developed antigen ELISA and RT-PCR. NV was detected in most outbreaks previously characterized as being of NV origin. Overall, a low number of positives for NV was obtained using either RT-PCR with primers that amplified a unique region of the genome, or an ELISA with hyperimmune antisera made to the baculovirus-expressed recombinant NV capsid. However, a significant number of positives was obtained when these samples were tested by RT-PCR using primers that amplified the more highly conserved regions of the genome. Sequence analysis of the amplified viral cDNAs indicated that small round structured viruses (SRSVs) with a wide range of variable genomic sequences (44–87% nucleotide and 31–99% amino acid similarity to the 8Flla NV genome sequence) were responsible for these outbreaks. Several recent outbreaks from the US, Japan and the UK were related to the Snow Mountain Agent (SMA) by sequence analyses. Continued accumulation of sequence information will facilitate the design of new primers for virus detection and increase our understanding of the relationships and epidemiology of these viruses from different sources.

Electronic Resource

1432-8798

Springer Online Journal Archives 1860-2000

Medicine

Summary.  Previous sequence analyses of the rotavirus nonstructural NSP4 from human and some animal rotavirus strains revealed the presence of three distinct NSP4 alleles or genetic groups. To examine the species of origin relatedness and diversity of NSP4, the nucleotide and deduced amino acid sequences of the gene encoding the NSP4 from 15 animal rotavirus strains of porcine, equine, bovine, lapine and canine origin were determined and compared to human and other animal strains sequenced previously. Lapine and equine strains were shown to belong to the NSP4 genotype A. Murine NSP4 sequences formed a previously unrecognized fourth distinct NSP4 genotype (genotype D) that was more divergent compared to NSP4 genotype A, B, and C than the latter three are among each other. Within NSP4 genotypes, strains isolated from rabbits, horses, cows (genotype A) and pigs (genotype B) clustered according to species of origin, suggesting a conserved pattern of evolution within species. NSP4 sequence comparison among one wildtype and two tissue culture-adapted lapine strains, known to cause disease in neonatal rabbits, failed to identify amino acid changes within the variable region spanning amino acids 130 to 141, suggesting that disease in rabbits is the result of the lapine virus infection and replication, including production of the NSP4 enterotoxin.

Electronic Resource

1432-8798

Springer Online Journal Archives 1860-2000

Medicine

Summary.  The genes encoding the outer capsid VP4 proteins of four lapine rotavirus strains, three isolated in the US (ALA, C-11 and BAP-2) and one isolated in Japan (R-2) were sequenced, and the predicted amino acid (aa) sequence was compared to all known rotavirus genotypes. A high degree of aa identity (96.8–98.9%) was found among the American lapine strains, while the Japanese rotavirus strain R-2 shared less aa identity (89.5–90.0%) with the American strains. The four lapine rotaviruses shared the closest aa identity (90.6–94.9%) with the P[14] genotype, consisting of viruses isolated from humans in Italy, Finland and Thailand. These results indicate that the VP4 protein of the four lapine strains are genotype P14, and that among lapine strains there are possibly two subtypes, one represented by the American lapine strains and the other by the Japanese R-2 strain.

Electronic Resource

1432-8798

Springer Online Journal Archives 1860-2000

Medicine

Summary Numerous outbreaks of gastroenteritis have been associated with Norwalk virus and Small Round Structured Viruses (SRSVs). These single-stranded RNA viruses, recently classified in the Caliciviridae, have been divided into three genogroups. Antigenic relationships also have been established among the different strains. As both an in vitro culture system and an animal model are lacking for these viruses, virus detection depends primarily on electron microscopy, immunological assays or molecular detection. In this study we first analyzed the genetic homology of the RNA polymerase region for 40 SRSV strains. From a consensus sequence for these strains, we designed a degenerate oligonucleotide to prime cDNA synthesis from viral RNA. We evaluated the degenerate primer in combination with three previously described primers in PCR reactions. A panel of 15 stools containing SRSVs, typed when possible by solid phase immune electron microscopy (SPIEM), were selected to represent all three genogroups and four different SPIEM antigenic types. Serial dilutions of the purified viral nucleic acids were amplified using the three different primer sets. Virus-specific probes were used to characterize the amplicons obtained. Virus-specific amplicons were obtained with at least one primer pair for each strain, but apparent viral RNA titers differed as much as 1 000-fold between primer sets. Amplicons from all but one of the 15 strains were confirmed as virus-specific using a panel of 10 different probes. Correlations between the most sensitive primer pair and SPIEM type were seen. This study showed that a single degenerate primer could be used in cDNA synthesis for a variety of SRSVs but that the sensitivity of the RT-PCR assay depended upon the second primer and virus-specific probes used.

Electronic Resource

1432-8798

Springer Online Journal Archives 1860-2000

Medicine

Summary We have used a reverse transcription-polymerase chain reaction with nested sets of primers to determine the nucleotide sequences of a 166 base pair segment of the RNA polymerase region of seven strains of small round structured viruses (SRSVs) from the United Kingdom. These SRSV strains were previously classified by solid-phase immune electron microscopy into three antigenic types — UK2, UK3 and UK4, which are comparable to the prototype strains Norwalk virus, Hawaii agent, and Snow Mountain agents, respectively. Based on their sequences, the seven strains from the United Kingdom could be divided into two groups. The first group included two strains of the UK2 type along with Norwalk virus and Southampton virus and the second group included three strains of UK3 and two strains of UK4 types. Viruses in the first group showed 75.3%–77.1% nucleotide and 89.1%–94.6% amino acid identity with Norwalk virus while those of the second group showed 60.8%–63.3% nucleotide and 67.3%–69.1% amino acid identity. Nucleotide and amino acid identity within the second group ranged between 91.6%–99.4% and 96.4%–100%, respectively. These results suggest that the SRSVs antigenically related with Norwalk virus, Hawaii agent, and Snow Mountain agent, can be classified into two genotypes on the basis of their sequences in the RNA polymerase region.

Electronic Resource

1432-8798

Springer Online Journal Archives 1860-2000

Medicine

Summary.  The rabbit model of rotavirus infection has been used to examine the immune response to rotavirus infection and to evaluate strategies for rotavirus vaccine development. To determine the 50% infectious does (ID50) of tissue culture adapted ALA virus, rabbits were orally inoculated with 101–103 PFU of ALA rotavirus. The ID50 of ALA virus was determined to be 1.7×102 PFU. The immune response induced in rabbits infected at low virus doses (102–103 PFU) was of similar magnitude to the immune responses induced with a high dose (106 PFU) inoculum, indicating that the immune response to ALA rotavirus in rabbits is not dose dependent. To determine if a single rotavirus inoculation would induce a long lasting immune response, four rabbits were inoculated once with ALA virus (3.5 × 105 PFU) and their serologic and mucosal antirotavirus titers were monitored at intervals for 1.5–2 years. The infected rabbits maintained serologic and mucosal rotavirus antibody titers until the final time point more than 700 days post inoculation. These data are important because they indicate that the antigenic load achieved following a single oral inoculation is sufficient to achieve long lasting immunity, the goal of any potential vaccine.

Electronic Resource

1432-8798

Springer Online Journal Archives 1860-2000

Medicine

Summary.  The Snow Mountain agent (SMA) is the prototype genogroup II and serotype 3 human calicivirus responsible for epidemic outbreaks of acute gastroenteritis. We have cloned the region of the SMA genome that encodes the single capsid protein. The predicted amino acid sequence of the capsid protein is distinct from other calicivirus strains that have been termed SMA-like based on sequence similarity between the RNA polymerase regions and IEM reactivity. In a previous report, a high sequence similarity in a small region of the RNA polymerase between SMA and another strain, OTH-25, suggested that the capsid proteins of OTH-25 and SMA would be very similar. In this report, we show that the capsid proteins of OTH-25 and SMA are more distinct than was predicted by homology in the RNA polymerase. In addition, phylogenetic analysis of a region of the RNA polymerase and of the N-terminal conserved domain of the capsid of 12 human caliciviruses resulted in trees with different topologies, suggesting that recombination has occurred within this group of viruses. Molecular characterization of the prototype calicivirus strains is important in determining the relationships between capsid similarity at the amino acid level, genetic grouping by sequence comparison, and antigenic reactivity.

Electronic Resource

1432-8798

Springer Online Journal Archives 1860-2000

Medicine

Summary. Human calicivirus Sapporo (SV) has typical calicivirus morphology and causes acute gastroenteritis in children. The nucleotide sequence of 3.2 kb of the 3′ end of SV was determined from a cloned cDNA. The 3′ end of the SV genome is predicted to encode the RNA-dependent RNA polymerase region, the capsid protein and two small open reading frames. The nonstructural and capsid protein coding sequences in the SV genome are fused in a single open reading frame. The organization of these proteins in the SV sequence is similar to that of rabbit hemorrhagic disease virus and the recently described Manchester virus, and distinct from the genome organization of the prototype human calicivirus, Norwalk virus, that lacks typical calicivirus morphology and has been described as a small round structured virus (SRSV). Sequence analysis of the predicted capsid region showed that the SV capsid is longer by ∼30 amino acids than the capsid of any of the SRSVs, and multiple sequence alignments showed that these additional amino acids are located in the variable region of the capsid protein. Expression of the capsid protein of SV in insect cells resulted in the self-assembly of virus-like particles that have a morphology similar to that of the native virus. This result shows that calicivirus morphology is determined by the primary sequence of the capsid protein.

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