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)

In this study, we have investigated the characteristics of secreted IgA and other classes of Ig induced after vaccination of sows with transmissible gastroenteritis virus (TGEV) or the antigenically related porcine respiratory coronavirus (PRCV). Both viruses induced the secretion of neutralizing antibodies of different classes in the sows' milk, but these protected suckling piglets against TGEV to different degrees. Quantitative differences in the induction of IgA by both viruses were found among the different viral antigenic sites and subsites of glycoprotein S. In TGEV-vaccinated sows, antigenic subsite A was the best inducer of IgA, followed by antigenic site D. After vaccination with PRCV, lower levels of IgA were detected on colostrum and milk, antigenic site D and subsite Ab being the immunodominant sites. This quantitative difference in epitope recognition could explain the differences in newborn piglet protection found using Ig classes purified from the milk of sows immunized with both viruses. Apparently only IgA recognizing at least antigenic sites A and D confers good protection in vivo, whereas any Ig class recognizing only one antigenic site may neutralize the virus in cell culture. These results indicate that the formulation of a subunit vaccine against TGEV has to consider the inclusion of more than one antigenic site involved in virus neutralization.
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PMID:Characterization of the IgA and subclass IgG responses to neutralizing epitopes after infection of pregnant sows with the transmissible gastroenteritis virus or the antigenically related porcine respiratory coronavirus. 752 77

The spike glycoprotein (S) of coronavirus, the major target for virus-neutralizing antibodies, is assumed to mediate the attachment of virions to the host cell. A 26-kilodalton fragment proteolytically cleaved from transmissible gastroenteritis virus (TGEV) S protein was previously shown to bear two adjacent antigenic sites, A and B, both defined by high-titer neutralizing antibodies. Recombinant baculoviruses expressing C-terminal truncations of the 26-kilodalton region were used to localize functionally important determinants in the S protein primary structure. Two overlapping 223- and 150-amino-acid-long products with serine 506 as a common N terminus expressed all of the site A and B epitopes and induced virus-binding antibodies. Coexpression of one of these truncated protein S derivatives with aminopeptidase N (APN), a cell surface molecule acting as a receptor for TGEV, led to the formation of a complex which could be immunoprecipitated by anti-S antibodies. These data provide evidence that major neutralization-mediating and receptor-binding determinants reside together within a domain of the S protein which behaves like an independent module. In spite of their ability to prevent S-APN interaction, the neutralizing antibodies appeared to recognize a preformed complex, thus indicating that antibody- and receptor-binding determinants should be essentially distinct. Together these findings bring new insight into the molecular mechanism of TGEV neutralization.
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PMID:Major receptor-binding and neutralization determinants are located within the same domain of the transmissible gastroenteritis virus (coronavirus) spike protein. 752 85

The S glycoprotein of feline infectious peritonitis virus (FIPV) has been shown to contain the antigenic sites responsible for eliciting both neutralization and antibody-dependent enhancement. To determine the region of S responsible, overlapping DNA fragments spanning the entire S gene were cloned and expressed as fusion proteins by in vitro transcription and translation. Fusion proteins containing relevant epitopes were identified by radioimmunoprecipitation with neutralizing and enhancing FIPV-specific monoclonal antibodies (MAbs). A region spanning residues 509 to 673 reacted with most MAbs tested. Translation in the presence of microsomal membranes did not enhance reactivity, suggesting that glycosylation is not essential for recognition by the MAbs. To localize the antigenic sites further, several MAb-resistant (mar) mutants of FIPV were cloned and sequenced. Amino acid residues that contribute to the neutralizing and enhancing epitopes were localized to two regions, designated A1 and A2, which show partial overlap with the homologous antigenic site A of transmissible gastroenteritis virus. Site A1 contains residues 568 and 591 and is homologous with part of subsite Aa of transmissible gastroenteritis virus. Site A2 contains residues 643, 649, and 656. Double mutations in sites A1 and A2 were found in mar mutants derived from neutralizing and enhancing MAbs 23F4.5 and 18A7.4, while a single mutation in site A2 was found in a mar mutant derived from MAb 24H5.4, which is neutralizing but not enhancing. The data suggest that site A2, which includes residues 643 to 656, is a dominant neutralizing site of FIPV and that sites A1 and A2 may act in concert to induce antibody-dependent enhancement.
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PMID:Localization of antigenic sites of the S glycoprotein of feline infectious peritonitis virus involved in neutralization and antibody-dependent enhancement. 770 8

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

Recognition of a host cell receptor by a virus is the first and perhaps the most crucial step in initiating the disease process. This study was undertaken to identify the cellular receptor(s) for bovine herpesvirus 1 (BHV-1). Previously, we reported the development and characterization of bovine anti-idiotypic antibodies (anti-ids) that induce neutralizing antibodies to BHV-1. These anti-ids inhibit BHV-1 penetration of permissive cells. We have used these anti-ids, which mimic an epitope on the virus glycoprotein IV (gIV), and gradient-purified virus in immunoprecipitation (IP) as well as photoaffinity labelling (PAL) assays. In the IP assays, both bovine anti-ids and BHV-1 virions coupled to Sepharose precipitated a 60K protein from 125I-labelled BHV-1 permissive cell membrane extracts. Normal bovine IgG or an irrelevant virus, transmissible gastroenteritis virus (TGEV), used as negative controls failed to precipitate this protein. Similarly, in the PAL assays, the 60K cell surface protein was identified on cells permissive for BHV-1 infection, but not on non-permissive cells when 125I-labelled ligands, the anti-ids or BHV-1 were used as probes. The iodinated ligands failed to identify the 60K protein if they had been pretreated with the antibody 1. Pretreatment of the iodinated ligands with an isotype-matched control antibody had no effect on the identification of the 60K protein present on cells permissive for BHV-1 infection. The negative controls, i.e. normal bovine IgG and TGEV, failed to identify this 60K protein on permissive or non-permissive cells. These results suggest that the 60K protein is a cellular receptor recognized by BHV-1 during the infection process.
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PMID:Identification of a putative cellular receptor for bovine herpesvirus 1. 807 28

Rotaviruses cause gastroenteritis in neonates of many animal species including cattle, swine, horses, dogs, cats, chickens and turkeys. Rotavirions are nonenveloped, are about 75 nm in diameter, have a double capsid, and contain 11 double-stranded RNA segments as their genome. Several antigenically distinct groups of rotaviruses have been identified and have been alphabetically designated as A through G. Group A rotaviruses were the first group of rotaviruses isolated and are the most commonly detected rotaviruses in diarrheic animals. Group A rotaviruses have two surface proteins, VP4 and VP7, both of which are important in serotype determination and in inducing neutralizing antibodies and protective immunity. Multiple serotypes of group A rotavirus based on glycoprotein VP7 (designated as G types) and based on VP4 (P types) have been identified. The immune response to rotaviruses is essentially serotype specific, however, cross-reactive or heterotypic epitopes have also been identified. Currently acceptable methods for immunogen quantitation include the induction of neutralizing antibody in host or laboratory animals. The in vivo efficacy of vaccines against rotavirus-associated gastroenteritis remains the standard method against which in vitro methods must be compared. Several animal models have been developed which could potentially be used in evaluating the efficacy of candidate vaccines. Monoclonal antibodies to rotavirus immunogens are also currently available and serve as valuable reagents for in vitro quantitation of rotaviral immunogens.
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PMID:Immunogens of rotaviruses. 811 88

Coronaviruses (CV) infect a variety of livestock, poultry and companion animals. They belong to at least five antigenic groups. CV cause localized infections of the respiratory and/or intestinal tracts, with the exception of feline infectious peritonitis virus (FIPV) and hemagglutinating encephalomyelitis (HEV) which cause systemic infections. The enteropathogenic CV infect the villous enterocytes resulting in villous atrophy leading to malabsorptive diarrhea. Several CV (bovine CV-BCV, porcine respiratory CV-PRCV, infectious bronchitis virus-IBV) cause respiratory disease. Current evidence indicates that protection against enteric and respiratory CV infections is mediated by passive or active immunity at the primary site of CV replication. Maternal vaccination approaches to induce passive immunity include the use of inactivated and modified live viral vaccines. Modified live viruses and a Ts mutant CV (FIPV) are also used as oral or intranasal vaccines to induce active mucosal immunity. The success of these vaccines in the field is often compromised by a number of potential problems. Coronaviruses are spherical, enveloped viruses, ranging from 80-160 nm in diameter and containing a positive-stranded RNA genome. They possess prominent surface spikes and some species display a fringe of smaller surface projections believed to be the hemagglutinin (HE). Coronaviruses possess 3 to 4 structural proteins: the spike (S) glycoprotein (150-200 kDa), the integral membrane glycoprotein (M; 20-30 kDa) and the nucleocapsid phosphoprotein (N; 43-50 kDa). A subset of CV (BCV, HEV, turkey CV) possess a third glycoprotein on the virion surface, the HE (60-65 kDa). These proteins can be quantitated using pooled monoclonal antibodies (mAb) to distinct epitopes of each protein in ELISA. Most research has focused on the S protein as a candidate antigen for CV vaccines since it induces virus neutralizing (VN) antibodies. However the HE protein stimulates the production of VN and HE inhibiting antibodies and the M protein induces antibodies that neutralize virus in the presence of complement. Attempts to correlate in vitro VN antibody activity with in vivo protection have shown that the passive transfer of VN mAb to the S or HE protein conferred passive protection against CV challenge in some studies, but not others. Additional research has implicated a possible role for other CV proteins in immunity. Studies of mAb to the M protein of transmissible gastroenteritis (TGEV) have provided evidence for a direct role of the M protein in the induction of alpha IFN by porcine blood leukocytes. The potential significance of this phenomenon to immunity to TGEV is unclear.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Coronavirus immunogens. 811 87

Bolesatine is a glycoprotein purified to homogeneity from Boletus satanas Lenz, a toxic mushroom which causes serious gastroenteritis. This lectin possesses a mitogenic activity on human lymphocytes at very low concentrations, whereas higher concentrations inhibit protein synthesis in vitro in several systems. The mitogenic activity on peripheral blood T lymphocytes in vitro has been shown to be at least 200-fold higher than the activity of the well studied phytohemagglutinin (PHA). In order to verify this property in vivo, the effect of bolesatine has been studied in thymus of rats given orally bolesatine. Two groups of bolesatine-treated animals were used in addition to the control group. One group was given every 48 h, 28 micrograms of bolesatine/kg body weight seven times and 150 micrograms/kg body weight 48 h before the sacrifice. The other group was given 55 micrograms of bolesatine/kg body weight according to the same protocol and 150 micrograms/kg body weight 48 h before the sacrifice. In these conditions, the ratio thymus weight/body weight is increased by 10% and 28%, respectively, in groups 1 and 2. Similarly, the DNA synthesis is increased by more than 50%, indicating that (i) bolesatine probably possesses a mitogenic effect on thymocytes in vivo (ii) that the increase of the ratio thymus weight/body weight is not due to swelling by water retention, but rather to a multiplication of thymocytes. These results are confirmed in a second run of experiments in which bolesatine given orally to rats in lower doses of 3-12 micrograms/kg induces an increase of both thymus weight by 47% to 54% and an increase of total proteins by 52% to 56%, respectively, whereas the ratio total protein/g of thymus does not change. Thus bolesatine, known to be mitogenic to human lymphocytes in vitro is also mitogenic to rat thymocytes in vivo.
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PMID:Effect of bolesatine, a glycoprotein from Boletus satanas, on rat thymus in vivo. 819 88

Transmissible gastroenteritis coronavirus (TGEV) is an enteropathogenic coronavirus isolated for the first time in 1946. Nonenteropathogenic porcine respiratory coronaviruses (PRCVs) have been derived from TGEV. The genetic relationship among six European PRCVs and five coronaviruses of the TGEV antigenic cluster has been determined based on their RNA sequences. The S proteins of six European PRCVs have an identical deletion of 224 amino acids starting at position 21. The deleted area includes the antigenic sites C and B of TGEV S glycoprotein. Interestingly, two viruses (NEB72 and TOY56) with respiratory tropism have the S protein with a similar size to the enteric viruses. NEB72 and TOY56 viruses have 2 and 15 specific amino acid differences with the enteric viruses, respectively. Four of the residues changed are located within the deletion present in the PRCVs and may influence the enteric tropism of TGEV in vivo. A receptor binding site (RBS) used by the virus to infect ST and other cell types might be located between sites A and D of the S glycoprotein, since monoclonal antibodies (MAbs) specific for these sites inhibit the binding of the virus to ST cells. An evolutionary tree relating 13 enteric and respiratory isolates has been proposed. According to this tree, a main virus lineage evolved from a recent progenitor which was circulating around 1941. From this, secondary lineages originated PUR46, NEB72, TOY56, MIL65, BRI70, and the PRCVs, in this order. Least squares estimation of the origin of TGEV-related coronaviruses showed a significant constancy in the mutation fixation rate.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Evolution and tropism of transmissible gastroenteritis coronavirus. 820 53

Two transmissible gastroenteritis virus (TGEV, Miller strain) cDNA clones were identified and their nucleotide sequences determined. The clones were non-overlapping and were located in the 5' region of the S glycoprotein gene. The TGEV clone pE21 contained 381 bp of the S glycoprotein gene and had > 98% nucleotide and amino acid sequence homology with the Purdue (P115) strain of TGEV and over 87% sequence homology with feline infectious peritonitis virus (FIPV). The TGEV clone, pD24, contained 267 bp of the S glycoprotein gene. It had > 98% nucleotide and amino acid sequence homology with P115 but only a 49% nucleotide sequence homology and a 24% amino acid sequence homology with FIPV. Using dot blot hybridization, a probe prepared from pD24 could differentiate TGEV from the antigenically related coronaviruses, FIPV, feline enteric coronavirus and canine coronavirus. This probe could also differentiate TGEV from porcine respiratory coronavirus (PRCV). Using polymerase chain reaction amplified regions of PRCV isolates and nucleotide sequencing, a 681 bp deletion in the 5' region of the S gene from PRCV isolate ISU-1 was identified. This deletion was located in the area of the S glycoprotein gene identified by the pD24 probe.
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PMID:Transmissible gastroenteritis virus and porcine respiratory coronavirus: molecular characterization of the S gene using cDNA probes and nucleotide sequence analysis. 820 64


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