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

Epithelial cells are important target cells for coronavirus infection. Earlier we have shown that transmissible gastroenteritis coronavirus (TGEV) and mouse hepatitis coronavirus (MHV) are released from different sides of porcine and murine epithelial cells, respectively. To study the release of these viruses from the same cells, we constructed a porcine LLC-PK1 cell line stably expressing the recombinant MHV receptor cDNA (LMR cells). The MHV and TGEV receptor glycoproteins were shown by immunofluorescence to appear at the surface of the cells and to be functional so that the cells were susceptible to both MHV and TGEV infection. Both coronaviruses entered polarized LMR cells only through the apical surface. Remarkably, while the cells remained susceptible to TGEV for long periods, infectability by MHV decreased with time after plating of the cells onto filters. This was not due to a lack of expression of the MHV receptor, since this glycoprotein was still abundant on the apical surface of these cells. TGEV and MHV appeared to exit LMR cells from opposite sides. Whereas TGEV was released preferentially at the apical membrane, MHV was released preferentially at the basolateral surface. These results show that vesicles containing the two coronaviruses are targeted differently in LMR cells. We propose that the viruses are sorted at the Golgi complex into different transport vesicles that carry information directing them to one of the two surface domains. The apical release of TGEV and the basolateral release of MHV might be factors contributing to the difference in virus spread found between TGEV and MHV in their respective natural hosts, the former causing mainly a localized enteric infection, the latter spreading through the body to other organs.
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PMID:A murine and a porcine coronavirus are released from opposite surfaces of the same epithelial cells. 886 33

Coronaviruses infect humans and animals through epithelial cells of the gastrointestinal and respiratory tracts that serve as their primary target. When studying infections in cultured polarized epithelial cells, we found previously that coronaviruses are released from specific plasma-membrane domains; thus, mouse hepatitis virus (strain A59; MHV-A59) leaves murine epithelial kidney cells from the basolateral surface, whereas release of transmissible gastroenteritis virus from porcine epithelial kidney cells is confined to the apical membrane. This observation begged the question whether a particular coronavirus is consistently shed through the same membrane, irrespective of the nature of the epithelial cell. We therefore extended our studies with MHV-A59 to Madin-Darby canine kidney (MDCK) strain I and human colon carcinoma (Caco-2) cells, both of which are naturally refractory to MHV-A59 but were made susceptible to infection by transfection with recombinant MHV receptor cDNA. The release of MHV-A59 from Caco(MHVR) cells occurred preferentially from the basolateral side, consistent with our previous observations. In contrast, release from MDCK(MHVR) cells occurred almost exclusively from the apical surface. Because of this difference, we studied MHV-A59 infection of MDCK(MHVR) cells in more detail. The virus entered the cells preferentially from the apical side, a situation similar to that in murine epithelial cells, where the highest density of MHV receptor glycoprotein was found. The results from this and previous studies show that targeting of vesicles containing MHV-A59 to a specific side of epithelial cells may vary in different epithelial cell types.
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PMID:Mouse hepatitis virus strain A59 is released from opposite sides of different epithelial cell types. 901 Feb 86

Rotaviruses, members of the Reoviridae family, are major etiologic agents of acute nonbacterial gastroenteritis of the young in a wide variety of mammalian and avian species, including humans. The need for effective immunoprophylaxis against rotaviral gastroenteritis has stimulated interest in the biochemical, molecular, genetic, and clinical aspects of these agents with the aim of developing safe and effective vaccines. Because neutralizing antibodies appear to play an important role in protection against many viral diseases, rotavirus antigens that induce neutralizing antibodies have played a central role in research and development of a rotavirus vaccine. The VP7 glycoprotein and VP4 spike protein that constitute the outer capsid of a complete rotavirus particle have been shown to be independent neutralization antigens. Since type specificity of the outer capsid proteins of a rotavirus appears to play an important role in protection against disease in experimental animal models, continued efforts have been made for classification and typing of neutralization specificities on the VP7 or VP4 capsid protein. Based on a criterion of > 20-fold differences between the homologous and heterologous reciprocal neutralizing antibody titers, fourteen VP7 (G) serotypes have been established. Studies are underway to characterize and classify the VP4 (P) serotypes among the strains that exhibit the fourteen different G serotypes. Attempts to classify the VP4 serotypes based on the same criterion (i.e., > 20-fold antibody differences) that is applied to classification of VP7 serotypes are in progress. This standard of > 20-fold antibody differences can be applied with hyperimmune serum raised to a reassortant possessing the VP4 encoding gene (and an unrelated VP7 encoding gene). Genotypes can provide leads towards classification but the serotype of a strain should be based on neutralization.
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PMID:Classification of rotavirus VP4 and VP7 serotypes. 901 7

CS31A fibrillae are thin, flexible, heteropolymeric proteinaceous appendages exposed as a capsule-like material around the cell surface of certain Escherichia coli strains. Two antigenic peptides of the S spike glycoprotein (TGEV-S) amino acids (aa) 363-371 and 521-531 of the transmissible gastroenteritis virus (TGEV) were tandemly introduced in the loop-structured, variable region aa 202-218 of the major ClpG subunit protein composing the bulk of CS31A. The resulting hybrid fibrillae with a 25 aa heterologous peptide were produced at the cell surface. Using a monoclonal antibody (Mab) specific for the TGEV epitopes, purified hybrid fibrillae were analysed in Western blotting under native conditions, which showed that the two viral epitopes were recognized immunologically as an integral part of the hybrid fibrillae, and therefore that they were antigenically active. The immunogenicity of the fusion construct was evaluated with live recombinant bacteria, purified hybrid ClpG monomers, and purified chimeric CS31A polymers. Whatever the form of hybrid used as antigen, intraperitoneally immunized outbred mice elicited serum anti-TGEV peptides antibodies (Abs) with significant titres and capable of recognizing native TGEV particles, indicating that the epitopes are exposed in an immunogenic conformation in all cases. However, virus neutralization titres were only obtained after immunization with either purified polymers or monomers. Furthermore, 4 months after an ultimate immunization with 20 micrograms of hybrid fibrillae mice developed a strong anamnestic Ab response against the two TGEV peptides following booster inoculation with virions. We conclude that CS31A fibrillae carrying a combination of TGEV epitopes as insert can induce an immunological memory in outbred animals infected with TGEV, and therefore that hybrid CS31A fibrillae may prove efficient as components of a subunit vaccine.
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PMID:An Escherichia coli CS31A fibrillum chimera capable of inducing memory antibodies in outbred mice following booster immunization with the entero-pathogenic coronavirus transmissible gastroenteritis virus. 906 25

Rotaviruses are major pathogens causing life-threatening dehydrating gastroenteritis in children and animals. One of the nonstructural proteins, NSP4 (encoded by gene 10), is a transmembrane, endoplasmic reticulum-specific glycoprotein. Recently, our laboratory has shown that NSP4 causes diarrhea in 6- to 10-day-old mice by functioning as an enterotoxin. To confirm the role of NSP4 in rotavirus pathogenesis, we sequenced gene 10 from two pairs of virulent and attenuated porcine rotaviruses, the OSU and Gottfried strains. Comparisons of the NSP4 sequences from these two pairs of rotaviruses suggested that structural changes between amino acids (aa) 131 and 140 are important in pathogenesis. We next expressed the cloned gene 10 from the OSU virulent (OSU-v) and OSU attenuated (OSU-a) viruses by using the baculovirus expression system and compared the biological activities of the purified proteins. NSP4 from OSU-v virus increased intracellular calcium levels over 10-fold in intestinal cells when added exogenously and 6-fold in insect cells when expressed endogenously, whereas NSP4 from OSU-a virus had little effect. NSP4 from OSU-v caused diarrhea in 13 of 23 neonatal mice, while NSP4 from OSU-a caused disease in only 4 of 25 mice (P < 0.01). These results suggest that avirulence is associated with mutations in NSP4. Results from site-directed mutational analyses showed that mutated OSU-v NSP4 with deletion or substitutions in the region of aa 131 to 140 lost its ability to increase intracellular calcium levels and to induce diarrhea in neonatal mice, confirming the importance of amino acid changes from OSU-v NSP4 to OSU-a NSP4 in the alteration of virus virulence.
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PMID:Mutations in rotavirus nonstructural glycoprotein NSP4 are associated with altered virus virulence. 955 47

The diversity in selected regions of the transmissible gastroenteritis virus (TGEV) and porcine respiratory coronavirus (PRCV) genomes was analyzed among known TGEV and PRCV strains and field isolates. The N-terminal half of the spike (S) glycoprotein gene and open reading frames (ORF) 3, 3-1 and 4 were amplified by reverse transcriptase reaction and polymerase chain reaction (RT/PCR), and analyzed using restriction fragment length polymorphism (RFLP) patterns of the amplified DNA. Reference TGEV strains (Miller and Purdue) and a PRCV strain (ISU-1), and TGEV and PRCV field isolates were analyzed. Based on the size of the ORF 3, 3-1 and 4 RT/PCR products, TGEV and PRCV strains could be quickly and easily differentiated into three groups designated TGEV Miller, Purdue types and PRCV. By RFLP analysis of the N-terminal region of the S glycoprotein gene and ORFs 3, 3-1 and 4, TGEV and PRCV strains were differentiated into five groups using the restriction enzyme Sau3AI. Sequence analysis of a PCR product in the ORFs 3, 3-1 and 4 from virulent and attenuated Miller strains demonstrated additional differences in that region which have been correlated with a change in virulence of TGEV isolates.
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PMID:Field isolates of transmissible gastroenteritis virus differ at the molecular level from the Miller and Purdue virulent and attenuated strains and from porcine respiratory coronaviruses. 963 93

The sequence of the region located between the S and M glycoprotein genes of the 79-1146 strain of feline infectious peritonitis virus (FIPV) is presented. The inter-structural gene region encodes 3 open reading frames (ORFs), termed ORFs 3a, 3b and 4, with nucleotide sequences conforming to the minimum conserved transcription signal upstream of each. An additional ORF, 3x, partially overlaps the 3' end of ORF 3a. The FIPV interstructural gene region is identical in length when compared to the Insavc-1 strain of canine coronavirus (CCV) but differs from various strains of transmissible gastroenteritis virus (TGEV) by the presence of deletions and insertions. The sizes of ORF 3a and 4 are conserved in FIPV, TGEV and CCV. However, as with CCV, the FIPV ORF 3b is truncated in comparison with TGEV.
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PMID:Nucleotide sequence of the inter-structural gene region of feline infectious peritonitis virus. 965 87

The use of transgenic plants as vaccine production systems was described recently. We report on the immunological response elicited by two recombinant versions of the glycoprotein S from the swine-transmissible gastroenteritis coronavirus (TGEV) expressed in transgenic plants. Arabidoposis plants were genetically transformed with cDNAs constructs encoding either the N-terminal domain (amino acid residues 1-750) or the full-length glycoprotein S of TGEV, responsible for the neutralizing antibody induction against the virus, under the control of the cauliflower mosaic virus 35S (CaMV 35S) promoter. Genomic DNA and mRNA analyses of leaf extracts from transformed plants demonstrated the incorporation of the foreign cDNA into the arabidopsis genome, as well as their transcription. Expression of recombinant polypeptides were observed in most transgenic plants by ELISA using specific antibodies. Mice immunized with leaf extracts from transgenic plants developed antibodies that reacted specifically with TGEV in ELISA, immunoprecipitated the virus-induced protein, and neutralized the virus infectivity. From these results, we conclude that transgenic plants expressing glycoprotein S polypeptides may possibly be used as a source of recombinant antigen for vaccine production.
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PMID:Expression of immunogenic glycoprotein S polypeptides from transmissible gastroenteritis coronavirus in transgenic plants. 979 Oct 26

The spike (S) glycoprotein of the Miller strain of transmissible gastroenteritis virus (TGEV) was recently cloned and expressed in baculovirus. The recombinant S protein was used as the coating antigen in a competition (blocking) enzyme-linked immunosorbent assay (ELISA) in combination with monoclonal antibodies to the S protein epitope A (conserved on TGEV and porcine respiratory coronavirus [PRCV]) or epitope D (present on TGEV only) to differentiate PRCV- from TGEV-induced antibodies. One set (set A) of 125 serum samples were collected at different times after inoculation of caesarean-derived, colostrum-deprived (n = 52) and conventional young pigs (n = 73) with 1 of the 2 porcine coronaviruses or uninoculated negative controls (TGEV/PRCV/negative = 75/30/20). A second set (set B) of 63 serum samples originated from adult sows inoculated with PRCV and the recombinant TGEV S protein or with mock-protein control and then exposed to virulent TGEV after challenge of their litters. Sera from set A were used to assess the accuracy indicators (sensitivity, specificity, accuracy) of the fixed-cell blocking ELISA, which uses swine testicular cells infected with the M6 strain of TGEV as the antigen source (ELISA 1) and the newly developed ELISA based on the recombinant S protein as antigen (ELISA 2). The sera from set B (adults) were tested for comparison. The plaque reduction virus neutralization test was used as a confirmatory test for the presence of antibodies to TGEV/PRCV in the test sera. The accuracy indicators for both ELISAs suggest that differential diagnosis can be of practical use at least 3 weeks after inoculation by testing the dual (acute/convalescent) samples from each individual in conjunction with another confirmatory (virus neutralization) antibody assay to provide valid and complete differentiation information. Moreover, whereas ELISA 1 had 10-20% false positive results to epitope D for PRCV-infected pigs (set A samples), no false-positive results to epitope D occurred using ELISA 2, indicating its greater specificity. The progression of seroresponses to the TGEV S protein epitopes A or D, as measured by the 2 ELISAs, was similar for both sets (A and B) of samples. Differentiation between TGEV and PRCV antibodies (based on seroresponses to epitope D) was consistently measured after the third week of inoculation.
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PMID:Evaluation of the baculovirus-expressed S glycoprotein of transmissible gastroenteritis virus (TGEV) as antigen in a competition ELISA to differentiate porcine respiratory coronavirus from TGEV antibodies in pigs. 1035 50

Castor beans (Ricinus communis) contain ricin. Ricin is a glycoprotein reported to cause hypotension, gastroenteritis, depression, and death. However, few deaths are reported following castor bean ingestion in animals. From January 1987 to December 1998, the American Society for the Prevention of Cruelty to Animals-National Animal Poison Control Center received 98 incidents of castor bean ingestion in dogs. The most commonly reported clinical signs were vomiting, depression, and diarrhea. Death or euthanasia occurred in 9% of the cases. The severity of clinical signs following castor bean ingestion may depend on whether the beans were chewed or swallowed whole.
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PMID:Evaluation of castor bean toxicosis in dogs: 98 cases. 1082 94


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