Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0017160 (gastroenteritis)
11,398 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

During a search for established cell lines to produce large quantities of porcine transmissible gastroenteritis virus (TGEV), we observed bright immunofluorescent staining 6- 12h after infection of pig kidney derived LLC-PK1 line. Infectious virus yield was, however, 2 log10 lower than that from secondary adult pig thyroid (APT/2) cell cultures, although small plaques were visible by three days in cultures maintained under agarose, suggesting limited replication. Attempts to adapt TGEV to the LLC-PK1 cell line by 10 serial 20h passes were unsuccessful. Procedures to purify virions from infected LLC-PK1 cells produced less than 1% of the particles isolated from parallel APT/2 cultures. Examination of intracellular viral RNA in actinomycin-D treated cells revealed similar amounts of genomic RNA and the 4 major subgenomic species in both cell types, suggesting that there was no defect in viral RNA replication. In vitro translation of polyadenylated RNA from infected APT/2 and LLC-PK1 cells, followed by immune precipitation of the products, showed similar profiles of precursors to structural polypeptides, confirming the functional integrity of the viral messengers in the restrictive cell. Comparison of the viral polypeptides synthesised following infection of the two cell types showed that similar species were synthesised in both, corresponding to a group of 28-30,000 mol. wt. envelope glycopolypeptides, a 47,000 mol. wt. nucleoprotein and peplomer glycopolypeptides of about 200,000 mol. wt. The rate of viral polypeptide synthesis in LLC-PK1 cells was reproducibly higher than in APT/2, resulting in the earlier detection of bands and greater incorporation of isotope. Tunicamycin at 1 microgram/ml had a similar effect in both cells, preventing glycosylation of the 26,000 mol. wt. precursor of the envelope glycopolypeptides and synthesis of the 200,000 peplomer glycoprotein. Degradation of the nucleoprotein from 47,000 to 42,000 mol. wt. although detectable in both cells was more marked in the LLC-PK1 cultures. Phosphorylation of these proteins was readily demonstrated in both cells, although phosphorylation of host proteins and, to some extent, viral envelope proteins was considerably greater in the LLC-PK1. The significance of this finding with respect to virus maturation is being investigated.
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PMID:Defective replication of porcine transmissible gastroenteritis virus in a continuous cell line. 633 Nov 29

The caliciviruses, as a proposed family Caliciviridae, have a distinct virion morphology with cup-shaped depressions on a spherical capsid surface. The viruses have single-stranded RNA, which has a molecular weight about 2.6 x 10(6) and is infectious. The RNA is covalently linked to a small protein. A single major polypeptide is found in the capsid. A subgenomic RNA, molecular weight about 1 x 10(6), coding for the capsid polypeptide is found in infected cells. Caliciviruses infecting swine, pinnipeds and cats have been characterized. Viruses which are morphologically identical to the known caliciviruses have been identified in human feces; these viruses have been shown to be associated with gastroenteritis, but they have not yet been propagated in the laboratory.
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PMID:Caliciviridae. 720 66

The pathogenicity of neutralization-resistant mutants of the enteric coronavirus transmissible gastroenteritis virus (TGEV) was examined in the newborn piglet. The parental virus (Purdue-115 strain), as well as several mutants selected using monoclonal antibodies (MAbs) directed to antigenic sites A and B, caused an acute enteritis with 100% mortality. By contrast, most of the site D (MAb 40.1) mutants exhibited a strongly reduced enteropathogenicity, leading to the survival of animals inoculated with up to 1000-fold the 100% lethal dose of parental virus. Such a phenotypical change was correlated with point mutations or a small deletion, all located within the S gene sequence coding for the Pro-145 to Cys-155 segment of the mature polypeptide. These observations suggest that an N-terminal subregion of the S molecule is an essential determinant for pathogenesis in TGEV infection.
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PMID:Site-specific alteration of transmissible gastroenteritis virus spike protein results in markedly reduced pathogenicity. 756 60

Previous studies in our laboratory demonstrated that 2 attenuated strains of transmissible gastroenteritis virus (TGEV) contain deletions affecting messenger (m) RNAs 2, 3, or 4. In this report, we have compared mRNAs of four modified-live virus vaccines for TGEV with the virulent Miller PP3 isolate to determine whether any transcriptional patterns are shared among attenuated strains. Using northern blot analysis, all vaccine viruses expressed mRNAs indistinguishable in size from those of Miller PP3. However, using S1 nuclease protection experiments, alterations in the regions of the genome from which mRNAs 2 and 3 are transcribed were detected in 2 of the vaccine strains. When genomic cDNA fragments derived from the coding region for mRNA 2 were sequenced, a 6-nucleotide deletion, also found in the attenuated strain Purdue-115, was discovered. The product of mRNA 2, a spike glycoprotein, was visualized by western blotting for each vaccine strain, and no profound differences in mobility were detected relative to Miller PP3. Alterations in the region of the genome from which mRNA 3 is transcribed appear to be identical or very similar to sequence alterations already described in this region for Purdue-115, one of which is likely to alter the polypeptide product of mRNA 3. Insertions or deletions in mRNAs 2 or 3 may contribute to attenuation but are not a prerequisite for this phenotype. The S1 nuclease protection analysis is a sensitive tool for differentiating particular strains of TGEV.
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PMID:Molecular characterization of attenuated vaccine strains of transmissible gastroenteritis virus. 801 75

We have cloned, sequenced and expressed the spike (S) gene of canine coronavirus (CCV; strain K378). Its deduced amino acid sequence has revealed features in common with other coronavirus S proteins: a stretch of hydrophobic amino acids at the amino terminus (the putative signal sequence), another hydrophobic region at the carboxy terminus (the membrane anchor), heptad repeats preceding the anchor, and a cysteine-rich region located just downstream from it. Like other representatives of the same antigenic cluster (CCV-Insavc-1 strain, feline infectious peritonitis and enteric coronaviruses, porcine transmissible gastroenteritis and respiratory coronaviruses, and the human coronavirus HCV 229E), the CCV S polypeptide lacks a proteolytic cleavage site present in many other coronavirus S proteins. Pairwise comparisons of the S amino acid sequences within the antigenic cluster demonstrated that the two CCV strains (K378 and Insavc-1) are 93.3% identical, about as similar to each other as they are to the two feline coronaviruses. The porcine sequences are clearly more divergent mainly due to the large differences in the amino-terminal (residues 1 to 300) domains of the proteins; when only the carboxy-terminal parts (residues 301 and on) are considered the homologies between the canine, feline and porcine S polypeptides are generally quite high, with identities ranging from 90.8% to 96.8% . The human coronavirus is less related to the other members of the antigenic group. A phylogenetic tree constructed on the basis of the S sequences showed that the two CCVs are evolutionarily more related to the feline than to the porcine viruses. Expression of the CCV S gene using the vaccinia virus T7 RNA polymerase system yielded a protein of the expected M(r) (approximately 200K) which could be immunoprecipitated with an anti-feline infectious peritonitis virus polyclonal serum and which was indistinguishable from the S protein synthesized in CCV-infected cells.
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PMID:Nucleotide sequence and expression of the spike (S) gene of canine coronavirus and comparison with the S proteins of feline and porcine coronaviruses. 802 9

The complete sequence of the spike (S) gene of the Br1/87 isolate of porcine epidemic diarrhoea virus (PEDV) was determined from cDNA clones. The predicted polypeptide was 1383 amino acids long, contained 29 potential N-linked glycosylation sites and showed structural features similar to those of the coronavirus spike protein. The PEDV S protein, like that of the members of the transmissible gastroenteritis virus (TGEV)-related subset, lacks a proteolytic site to yield cleaved amino and carboxy subunits S1 and S2. Viral polypeptide species of the expected M(r), i.e. 170K/190K, were observed in PEDV-infected cells. Sequence comparison confirmed that, within the subset, PEDV was most closely related to the human respiratory coronavirus HCV 229E. However, PEDV S protein has an additional 250 residue N-terminal domain which is absent from HCV 229E and porcine respiratory coronavirus, the respiratory variant of TGEV. Alignment of the S1 regions revealed a second domain of about 90 residues with increased sequence divergence which might possibly express virus-specific determinants.
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PMID:Sequence of the spike protein of the porcine epidemic diarrhoea virus. 817 82

In previous studies we have demonstrated molecular mimicry between the S peplomer protein of Mouse Hepatitis Virus (MHV) and Fc gamma Receptor (Fc gamma R) of IgG. Rabbit IgG, but not its F(ab')2 fragments, monoclonal rat and mouse IgG and the rat 2.4G2 anti-mouse Fc gamma R monoclonal antibody (mab) immunoprecipitated natural and recombinant MHV S protein. On the basis of a number of criteria, MHV S peplomer protein exhibits Fc IgG binding ability. We report here a molecular mimicry between the S peplomer protein of Bovine Coronavirus (BCV) and Fc gamma R. BCV S peplomer protein which belongs to the same antigenic subgroup as MHV also binds Fc portion of rabbit IgG and is immunoprecipitated by the 2.4G2 anti-Fc gamma R mab. In contrast, Transmissible Gastroenteritis Coronavirus (TGEV) and Infectious Bronchitis Virus (IBV) S peplomer proteins which represent two distinct antigenic subgroups of Coronaviridae do not bind rabbit IgG and do not react with anti-Fc gamma R mab. However, homologous swine IgG, but not its F(ab')2 fragments, immunoprecipitated from TGEV-infected cells a polypeptide chain with molecular mass of 195 kDa, identical to that immunoprecipitated by the T36 mab anti-TGEV S peplomer protein.
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PMID:Molecular mimicry between S peplomer proteins of coronaviruses (MHV, BCV, TGEV and IBV) and Fc receptor. 820 28

In order to investigate the genome organization of the porcine epidemic diarrhea virus (PEDV) further, cDNA clones covering the region between the nucleocapsid and the spike (S) protein genes were independently constructed and sequenced for the two virulent isolates Br1/87 and CV777. Of the three major ORFs identified, two were found to encode the major and minor coronavirus membrane proteins M and sM. A potentially single ORF, designated ORF3 according to the pattern of the viral subgenomic mRNAs, could be identified between the S and sM genes. A striking variability, essentially generated by short deletions clustered in a few loci, was observed in the ORF3 of both isolates. The largest predicted polypeptide of 223 amino acids showed homology with polypeptides potentially encoded by other members of the same genetic subset, including two shorter polypeptides of human respiratory virus HCV 229E and one of transmissible gastroenteritis virus TGEV. This homology suggests that the two HCV ORFs may have originated from a single precursor. The function of these polypeptides is not known, but the predicted products of the PEDV ORF3 and related ORFs share features suggestive of a membrane-associated protein.
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PMID:Sequence analysis of the porcine epidemic diarrhea virus genome between the nucleocapsid and spike protein genes reveals a polymorphic ORF. 829 Dec 30

Adult diarrheal rotavirus (ADRV) is a currently noncultivatable group B human rotavirus responsible for epidemic outbreaks of gastroenteritis in China. Gene segment 5 of ADRV encodes the major inner capsid protein, VP6. ADRV gene 5 was inserted into a recombinant baculovirus by homologous recombination between baculovirus shuttle plasmid pACYM1-AD5 and AcNPV genomic DNA. Baculovirus recombinants were selected visually and plaque purified and VP6 expression was detected by Coomassie staining of PAGE-separated proteins. The baculovirus-expressed gene 5 polypeptide is 44 kDa, the same as for the major inner capsid protein present on EDTA-treated ADRV virions and in vitro-expressed VP6 protein. The expressed protein is oligomeric and in the absence of reducing agents multimerizes to apparent trimer, hexamer, and greater molecular mass as assayed by SDS-PAGE. The VP6 protein is immunoprecipitable by hyperimmune serum to ADRV, human ADRV convalescent serum, by a group B-specific monoclonal antibody and by porcine group B rotavirus infection serum. The baculovirus-expressed protein is immunogenic and antibodies to the expressed protein recognize ADRV virions. The ADRV VP6 protein should be useful for developing diagnostic assays for serum antibodies to group B rotavirus as well as for generating hyperimmune serum and monoclonal antibodies for detecting viral antigen from ADRV and other group B rotaviruses.
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PMID:Baculovirus expression of the ADRV gene 5 encoded protein produces an oligomerized, antigenic, and immunogenic VP6 protein. 838 12

The amino acid sequence of the adenovirus type 31 (subgenus A) fibre polypeptide was deduced from the nucleotide sequence of the fibre gene. The analysed peptide sequence showed an organization consistent with the structural domains described for other adenoviruses: an amino-terminal tail region, an intervening shaft region and a carboxy-terminal knob. The AV31 fibre shaft displayed 20 repeats of the 15-amino-acid segments in the shaft domain, which agreed with the reported length of the fibre. The predicted AV31 fibre polypeptide sequence was compared to fibre polypeptides of serotypes representing subgenera A to F. As expected, AV31 and AV12, both belonging to subgenus A, showed the highest overall homology (75.4%). When comparing the AV31 fibre to the fibre polypeptides of subgenera B to F, AV31 and AV41 (subgenus F) shared the highest overall homology (35.3%), followed by AV40 (34.8%). The lowest overall homology (20.3%) was found for the AV31 and Av3 fibres (subgenus B). From the data presented, it could be suggested that AV31 is more closely related to the enteric viruses of subgenus F than to the other adenoviruses analysed. Comparing the fibre polypeptides of 14 adenovirus serotypes, 10 conserved amino acid sequences were detected, 5 of which were in the knob region. Since the fibre knob interacts with the host cell during infection, these conserved amino acids might be important for virus attachment. The gastroenteritis-causing adenoviruses AV40 and AV41 shared 3 additional conserved amino acid residues with AV31 and AV12 in the knob region.
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PMID:Sequence characterization of the adenovirus 31 fibre and comparison with serotypes of subgenera A to F. 857 8


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