Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| coronavirus reverse genetics and development of vectors for gene expression. | knowledge of coronavirus replication, transcription, and virus-host interaction has been recently improved by engineering of coronavirus infectious cdnas. with the transmissible gastroenteritis virus (tgev) genome the efficient (>40 microg per 106 cells) and stable (>20 passages) expression of the foreign genes has been shown. knowledge of the transcription mechanism in coronaviruses has been significantly increased, making possible the fine regulation of foreign gene expression. a new family of ... | 2005 | 15609512 |
| coronavirus genome structure and replication. | in addition to the sars coronavirus (treated separately elsewhere in this volume), the complete genome sequences of six species in the coronavirus genus of the coronavirus family [avian infectious bronchitis virus-beaudette strain (ibv-beaudette), bovine coronavirus-ent strain (bcov-ent), human coronavirus-229e strain (hcov-229e), murine hepatitis virus-a59 strain (mhv-a59), porcine transmissible gastroenteritis-purdue 115 strain (tgev-purdue 115), and porcine epidemic diarrhea virus-cv777 strai ... | 2005 | 15609507 |
| an elisa optimized for porcine epidemic diarrhoea virus detection in faeces. | monoclonal antibodies to porcine epidemic diarrhoea virus (pedv) membrane protein m were prepared and used for the comparative assessment of three blocking elisa variants to detect pedv. the competitive blocking elisa (cb-elisa) format showed the highest sensitivity, allowing detection of 10(2.5) plaque-forming units of pedv/ml in culture medium. its specificity was verified by inclusion of control samples containing transmissible gastroenteritis virus (tgev) and rotavirus a in each analysis. ei ... | 2004 | 15607079 |
| the nucleoprotein is required for efficient coronavirus genome replication. | the construction of a set of transmissible gastroenteritis coronavirus (tgev)-derived replicons as bacterial artificial chromosomes is reported. these replicons were generated by sequential deletion of nonessential genes for virus replication, using a modified tgev full-length cdna clone containing unique restriction sites between each pair of consecutive genes. efficient activity of tgev replicons was associated with the presence of the nucleoprotein provided either in cis or in trans. tgev rep ... | 2004 | 15507657 |
| development of a novel real-time rt-pcr assay with lux primer for the detection of swine transmissible gastroenteritis virus. | real-time rt-pcr assay, based on light upon extension (lux) fluorogenic primer and lightcycle technology, was developed for rapid detection of transmissible gastroenteritis virus (tgev). viral rna from different tgev isolates and clinical specimens was detected. to evaluate the sensitivity of the assay, a gel-based rt-pcr method targeted at the same 101 bp sequence was also developed. serial 10-fold dilutions of tgev rna were detected by the two methods. although the real time method used only 2 ... | 2004 | 15488621 |
| testing the hypothesis of a recombinant origin of the sars-associated coronavirus. | the origin of severe acute respiratory syndrome-associated corona-virus (sars-cov) is still a matter of speculation, although more than one year has passed since the onset of the sars outbreak. in this study, we implemented a 3-step strategy to test the intriguing hypothesis that sars-cov might have been derived from a recombinant virus. first, we blasted the whole sars-cov genome against a virus database to search viruses of interest. second, we employed 7 recombination detection techniques wel ... | 2005 | 15480857 |
| a novel sorting signal for intracellular localization is present in the s protein of a porcine coronavirus but absent from severe acute respiratory syndrome-associated coronavirus. | coronaviruses (cov) mature by a budding process at intracellular membranes. here we showed that the major surface protein s of a porcine cov (transmissible gastroenteritis virus) is not transported to the cell surface but is retained intracellularly. site-directed mutagenesis indicated that a tyrosine-dependent signal (yxxi) in the cytoplasmic tail is essential for intracellular localization of the s protein. surface expression of mutant proteins was evident by immunofluorescence analysis and su ... | 2004 | 15304515 |
| sequence comparison of the orf 7 region of transmissible gastroenteritis viruses isolated in japan. | the 3' end region nucleotide sequence, including orf7, of nine japanese and two u.s.a. isolates of transmissible gastroenteritis virus (tgev) were determined and compared. nine japanese tgev strains have been isolated over the past 40 years (1956-1997). from the comparison of determined nucleotide sequences, we could divide the tgev japanese isolates into two groups and distinguish them from tgev u.s.a. isolates. | 2004 | 15240950 |
| verification of sensitivity and specificity of group a rotavirus detection in piglets faeces with monoclonal blocking elisa methods. | monoclonal antibodies to group a rotavirus vp6 protein were prepared and used for verification of three blocking enzyme-linked immunosorbent assay (elisa) modifications to detect rotavirus a. selected competitive blocking elisa (cb-elisa) and electron microscopy (em) were used for examination of 194 field faecal samples of piglets affected with diarrhoea. rotavirus was detected in 43 samples (22.2%) by cb-elisa method, whereas in 26 (13.4%) samples by em examination. however, of 26 samples posit ... | 2004 | 15228549 |
| molecular dynamics simulations of various coronavirus main proteinases. | in this study, two homology models (denoted as mprost and mprosh) of main proteinase (mpro) from the novel coronavirus associated with severe acute respiratory syndrome (sars-cov) were constructed based on the crystal structures of mpro from transmissible gastroenteritis coronavirus (tgev) (mprot) and human coronavirus hcov-229e (mproh), respectively. both mprost and mprosh exhibit similar folds as their respective template proteins. these homology models reveal three distinct functional domains ... | 2004 | 15214807 |
| a corn-based delivery system for animal vaccines: an oral transmissible gastroenteritis virus vaccine boosts lactogenic immunity in swine. | recombinant plant expression systems offer a means to produce large quantities of selected antigens for subunit vaccines. cereals are particularly well-suited expression vehicles since the expressed proteins can be stored at relatively high concentrations for extended periods of time without degradation and dry seed can be formulated into oral vaccines suitable for commercial applications. a subunit vaccine candidate directed against porcine transmissible gastroenteritis virus and expressed in c ... | 2004 | 15193404 |
| immunopurification applied to the study of virus protein composition and encapsidation. | a protocol for obtaining small amounts of highly pure virus preparations starting from reduced volumes (<5 ml) of infected tissue culture supernatants is described. this procedure was adapted to the study of transmissible gastroenteritis coronavirus (tgev) protein composition and rna encapsidation. this protocol relies on virion capture by monoclonal antibodies specific for a virion membrane protein. these antibodies were bound to protein a-coated elisa wells armed with rabbit anti-mouse igg ant ... | 2004 | 15158585 |
| effect of temperature on the detection of porcine epidemic diarrhea virus and transmissible gastroenteritis virus in fecal samples by reverse transcription-polymerase chain reaction. | the effect of storage temperature was determined for the detection of porcine epidemic diarrhea virus (pedv) and transmissible gastroenteritis virus (tgev) in fecal samples from experimentally and naturally infected pigs by multiplex reverse transcription-polymerase chain reaction (rt-pcr). to examine the effect of storage temperature on the ability to detect pedv and tgev rna by multiplex rt-pcr, fecal samples were stored for different temperatures (4, 21, 36, and 45 c) before extracting viral ... | 2004 | 15152841 |
| reverse genetic analysis of the transcription regulatory sequence of the coronavirus transmissible gastroenteritis virus. | coronavirus discontinuous transcription uses a highly conserved sequence (cs) in the joining of leader and body rnas. using a full-length infectious construct of transmissable gastroenteritis virus, the present study demonstrates that subgenomic transcription is heavily influenced by upstream flanking sequences and supports a mechanism of transcription attenuation that is regulated in part by a larger domain composed of primarily upstream flanking sequences which select appropriately positioned ... | 2004 | 15141005 |
| respiratory and fecal shedding of porcine respiratory coronavirus (prcv) in sentinel weaned pigs and sequence of the partial s-gene of the prcv isolates. | porcine respiratory coronavirus (prcv), a spike (s) gene deletion mutant of transmissible gastroenteritis virus (tgev), causes mild or subclinical respiratory infections in pigs. the shedding of prcv/tgev was studied at different days post-arrival in fecal and nasal swabs from prcv/tgev seronegative sentinel pigs introduced into a prcv seropositive herd with questionable tgev serology and diarrhea. nasal shedding of prcv was detected in 57% and 63% of samples by nested-rt-pcr and cell culture im ... | 2004 | 15098110 |
| effects of infection with transmissible gastroenteritis virus on concomitant immune responses to dietary and injected antigens. | normal piglets weaned onto soy- or egg-based diets generated antibody responses to fed protein. concurrent infection with transmissible gastroenteritis virus (tgev) did not affect the responses to dietary antigens at weaning, nor did it affect the subsequent development of tolerance. however, tgev infection did enhance the primary immunoglobulin m (igm) and igg1, but not igg2, antibody responses to injected soy in comparison to those of uninfected animals. paradoxically, tgev-infected animals sh ... | 2004 | 15013985 |
| sequence motifs involved in the regulation of discontinuous coronavirus subgenomic rna synthesis. | coronavirus transcription leads to the synthesis of a nested set of mrnas with a leader sequence derived from the 5' end of the genome. the mrnas are produced by a discontinuous transcription in which the leader is linked to the mrna coding sequences. this process is regulated by transcription-regulating sequences (trss) preceding each mrna, including a highly conserved core sequence (cs) with high identity to sequences present in the virus genome and at the 3' end of the leader (trs-l). the rol ... | 2004 | 14694129 |
| identification of a putative cellular receptor 150 kda polypeptide for porcine epidemic diarrhea virus in porcine enterocytes. | porcine epidemic diarrhea virus (pedv) causes an acute enteritis in pigs of all ages, often fatality for neonates. pedv occupies an intermediate position between two well characterized members of the coronavirus group i, human coronavirus (hcov-229e)and transmissible gastroenteritis virus (tgev) which uses aminopeptidase n (apn), a 150 kda protein, as their receptors. however, the receptor of the pedv has not been identified yet. a virus overlay protein binding assay (vopba) was used to identify ... | 2003 | 14685034 |
| a reverse transcriptase-polymerase chain reaction assay for the diagnosis of turkey coronavirus infection. | this study reports on the development of a reverse transcriptase-polymerase chain reaction (rt-pcr) for the specific detection of turkey coronavirus (tcov). of the several sets of primers tested, 1 set of primers derived from the p gene and 2 sets derived from the n gene of tcov could amplify the tcov genome in the infected samples. the rt-pcr was sensitive and specific for tcov and did not amplify other avian rna and dna viruses tested except the infectious bronchitis virus (ibv). to overcome t ... | 2003 | 14667027 |
| neutralization of enteric coronaviruses with escherichia coli cells expressing single-chain fv-autotransporter fusions. | we report here that fusions of single-chain antibodies (scfvs) to the autotransporter beta domain of the iga protease of neisseria gonorrhoeae are instrumental in locating virus-neutralizing activity on the cell surface of escherichia coli. e. coli cells displaying scfvs against the transmissible gastroenteritis coronavirus on their surface blocked in vivo the access of the infectious agent to cultured epithelial cells. this result raises prospects for antiviral strategies aimed at hindering the ... | 2003 | 14645594 |
| identifying inhibitors of the sars coronavirus proteinase. | the severe acute respiratory syndrome (sars) is a serious respiratory illness that has recently been reported in parts of asia and canada. in this study, we use molecular dynamics (md) simulations and docking techniques to screen 29 approved and experimental drugs against the theoretical model of the sars cov proteinase as well as the experimental structure of the transmissible gastroenteritis virus (tgev) proteinase. our predictions indicate that existing hiv-1 protease inhibitors, l-700,417 fo ... | 2003 | 14592491 |
| binding of transmissible gastroenteritis coronavirus to brush border membrane sialoglycoproteins. | transmissible gastroenteritis coronavirus (tgev) is a porcine pathogen causing enteric infections that are lethal for suckling piglets. the enterotropism of tgev is connected with the sialic acid binding activity of the viral surface protein s. here we show that, among porcine intestinal brush border membrane proteins, tgev recognizes a mucin-type glycoprotein designated mgp in a sialic acid-dependent fashion. virus binding assays with cryosections of the small intestine from a suckling piglet r ... | 2003 | 14557669 |
| relationship of sars-cov to other pathogenic rna viruses explored by tetranucleotide usage profiling. | the exact origin of the cause of the severe acute respiratory syndrome (sars) is still an open question. the genomic sequence relationship of sars-cov with 30 different single-stranded rna (ssrna) viruses of various families was studied using two non-standard approaches. both approaches began with the vectorial profiling of the tetra-nucleotide usage pattern v for each virus. in approach one, a distance measure of a vector v, based on correlation coefficient was devised to construct a relationsh ... | 2003 | 14499005 |
| electron microscopy and ether sensitivity of transmissible gastroenteritis virus of swine. | 1965 | 14316771 | |
| propagation of transmissible gastroenteritis virus in tissue culture. | 1956 | 13395256 | |
| the effect of octin on baby pigs infected with transmissible gastroenteritis virus. | 1956 | 13362775 | |
| monoclonal antibody-based immunohistochemical detection of porcine epidemic diarrhea virus antigen in formalin-fixed, paraffin-embedded intestinal tissues. | an immunohistochemistry technique was developed for the diagnosis of porcine epidemic diarrhea virus (pedv). the technique was tested on formalin-fixed, paraffin-embedded intestinal tissues from piglets naturally infected with pedv. five different monoclonal antibodies (mabs) were tested in this study. pedv antigen was consistently detected in the plp (4% paraformaldehyde, 100 mm l-lysine dihydrochloride, 10 mm sodium m-periodate in phosphate-buffered saline)-fixed pedv-infected vero cells or fo ... | 1999 | 12968761 |
| bovine viral diarrhea virus isolated from fetal calf serum enhances pathogenicity of attenuated transmissible gastroenteritis virus in neonatal pigs. | a bovine viral diarrhea virus (bvdv-c) was isolated from swine tissue culture cells used to attenuate the transmissible gastroenteritis virus (tgev) after 68 passes. piglets given a pure culture of bvdv-c developed clinical signs similar to those of a mild tgev infection and recovered by 10 days postexposure. villous blunting and fusion was observed in the small intestine, and a lymphocyte depletion was observed in peyer's patches in the ileum. piglets given a combination of bvdv-c and attenuate ... | 1999 | 12968752 |
| increased litter survival rates, reduced clinical illness and better lactogenic immunity against tgev in gilts that were primed as neonates with porcine respiratory coronavirus (prcv). | establishing immunological memory in female piglets at a young age with prcv was effective in inducing a secondary immune response to a limiting dose of virulent tgev given orally 13-18 days prior to farrowing. subsequently, because of passive antibody transfer, the offspring of these primed gilts were more efficient in surviving a lethal tgev challenge. an average survival rate of 89% occurred in 6 litters of piglets from primed gilts that were boosted with 2.8 x 10(6) plaque forming units (pfu ... | 2003 | 12935745 |
| exogenous porcine viruses. | porcine organs, cells and tissues provide a viable source of transplants in humans, though there is some concern of public health risk from adaptation of swine infectious agents in humans. limited information is available on the public health risk of many exogenous swine viruses, and reliable and rapid diagnostic tests are available for only a few of these. the ability of several porcine viruses to cause transplacental fetal infection (parvoviruses, circoviruses, and arteriviruses), emergence or ... | 2003 | 12934944 |
| detection of porcine circovirus type 2 in feces of pigs with or without enteric disease by polymerase chain reaction. | to establish the sensitive polymerase chain reaction(pcr) method and detect porcine circovirus type 2 (pcv2) from intestines and feces of commercial swine herds with or without enteric disease, intestinal samples from 68 pigs and 29 fecal samples from commercial swine farms were collected. a primer set, forward primer 5'-gaagaatggaagaagcgg-3' and reverse primer 5'-ctcacagcagtagacaggt-3', could detect the virus at a concentration as low as 2 infectious virions per milliliter under controlled cond ... | 2003 | 12918820 |
| construction, characterization, and immunogenicity of an attenuated salmonella enterica serovar typhimurium pgte vaccine expressing fimbriae with integrated viral epitopes from the spic promoter. | transmissible gastroenteritis virus (tgev) is a porcine coronavirus that causes diarrhea, leading to near 100% mortality in neonatal piglets with corresponding devastating economic consequences. for the protection of neonatal and older animals, oral live vaccines present the attractive property of inducing desired mucosal immune responses, including colostral antibodies in sows--an effective means to passively protect suckling piglets. newly attenuated salmonella vaccine constructs expressing tg ... | 2003 | 12874347 |
| transmissible gastroenteritis coronavirus packaging signal is located at the 5' end of the virus genome. | to locate the transmissible gastroenteritis coronavirus (tgev) packaging signal, the incorporation of tgev subgenomic mrnas (sgmrnas) into virions was first addressed. tgev virions were purified by three different techniques, including an immunopurification using an m protein-specific monoclonal antibody. detection of sgmrnas in virions by specific reverse transcription-pcrs (rt-pcrs) was related to the purity of virus preparations. interestingly, virus mrnas were detected in partially purified ... | 2003 | 12829829 |
| partial sequence of the spike glycoprotein gene of transmissible gastroenteritis viruses isolated in korea. | the spike (s) glycoprotein of transmissible gastroenteritis virus (tgev) is the predominant inducer of neutralizing antibodies and has been implicated in virulence and host cell tropism. in this study, the nucleotide and deduced amino acid sequences of the amino terminal half of the s glycoprotein gene of one korean field tgev strain (133) isolated in 1997 and three korean field tgev strains (kt2, kt3 and kt4) isolated in 2000 and hkt2 strain, kt2 passaged 104 times in st cells, were determined. ... | 2003 | 12814887 |
| a 3d model of sars_cov 3cl proteinase and its inhibitors design by virtual screening. | to constructed a three-dimensional (3d) model for the 3c like (3cl) proteinase of sars coronavirus (sars-cov), and to design inhibitors of the 3cl proteinase based on the 3d model. | 2003 | 12791174 |
| coronavirus main proteinase (3clpro) structure: basis for design of anti-sars drugs. | a novel coronavirus has been identified as the causative agent of severe acute respiratory syndrome (sars). the viral main proteinase (mpro, also called 3clpro), which controls the activities of the coronavirus replication complex, is an attractive target for therapy. we determined crystal structures for human coronavirus (strain 229e) mpro and for an inhibitor complex of porcine coronavirus [transmissible gastroenteritis virus (tgev)] mpro, and we constructed a homology model for sars coronavir ... | 2003 | 12746549 |
| transmissible gastroenteritis coronavirus gene 7 is not essential but influences in vivo virus replication and virulence. | transmissible gastroenteritis coronavirus (tgev) contains eight overlapping genes that are expressed from a 3'-coterminal nested set of leader-containing mrnas. to facilitate the genetic manipulation of the viral genome, genes were separated by duplication of transcription regulating sequences (trss) and introduction of unique restriction endonuclease sites at the 5' end of each gene using an infectious cdna clone. the recombinant tgev (rtgev) replicated in cell culture with similar efficiency t ... | 2003 | 12706086 |
| engineering the transmissible gastroenteritis virus genome as an expression vector inducing lactogenic immunity. | the genome of the coronavirus transmissible gastroenteritis virus (tgev) has been engineered as an expression vector with an infectious cdna. the vector led to the efficient (>40 micro g/10(6) cells) and stable (>20 passages) expression of a heterologous gene (green fluorescent protein [gfp]), driven by the transcription-regulating sequences (trs) of open reading frame (orf) 3a inserted in the site previously occupied by the nonessential orfs 3a and 3b. expression levels driven by this trs were ... | 2003 | 12634392 |
| differentiation between porcine epidemic diarrhea virus and transmissible gastroenteritis virus in formalin-fixed paraffin-embedded tissues by multiplex rt-nested pcr and comparison with in situ hybridization. | porcine epidemic diarrhea virus (pedv) and transmissible gastroenteritis virus (tgev) were detected and differentiated in formalin-fixed, paraffin-embedded tissues from experimentally and naturally infected pigs by multiplex reverse transcription-nested polymerase chain reaction (rt-npcr). the results of this new method were compared with in situ hybridization. a method based on xylene deparaffinization followed by proteinase k digestion yielded rna of a suitable quality for reliable and consist ... | 2003 | 12565152 |
| establishment and characterization of two new pig cell lines for use in virological diagnostic laboratories. | two pig cell lines derived from kidney and trachea tissues and referred to as newborn swine kidney (nsk) and newborn pig trachea (nptr) were established following serial culture of primary cells. they were characterized by an epithelial-like morphology, high capacity to replicate and stability of the cell monolayer for several days after seeding. their modal chromosome number was modified in comparison to that of primary swine cells and they both displayed a transforming potential in vitro and d ... | 2003 | 12505635 |
| delivery of subunit vaccines in maize seed. | the use of recombinant gene technologies by the vaccine industry has revolutionized the way antigens are generated, and has provided safer, more effective means of protecting animals and humans against bacterial and viral pathogens. viral and bacterial antigens for recombinant subunit vaccines have been produced in a variety of organisms. transgenic plants are now recognized as legitimate sources for these proteins, especially in the developing area of oral vaccines, because antigens have been s ... | 2002 | 12480322 |
| identification of the epitope region capable of inducing neutralizing antibodies against the porcine epidemic diarrhea virus. | in order to identify the neutralizing epitope of the porcine epidemic diarrhea virus (pedv), the spike protein region that is presumed to contain the virus-neutralizing epitope was determined. this was based on the sequence information for the neutralizing epitope of the transmissible gastroenteritis virus (tgev). a recombinant protein that corresponds to the spike region of tgev was produced, and polyclonal antisera were generated using the recombinant protein. it was discovered that polyclonal ... | 2002 | 12442904 |
| coronaviruses from pheasants (phasianus colchicus) are genetically closely related to coronaviruses of domestic fowl (infectious bronchitis virus) and turkeys. | reverse-transcriptase polymerase chain reactions (rt-pcrs) were used to examine rna extracted from mouth/nasal swabs from pheasants exhibiting signs of respiratory disease. the oligonucleotides used were based on sequences of infectious bronchitis virus (ibv), the coronavirus of domestic fowl. a rt-pcr for the highly conserved region ii of the 3' untranslated region of the ibv genome detected a coronavirus in swabs from 18/21 estates. sequence identity with the corresponding region of ibvs and c ... | 2002 | 12425795 |
| case-control study on the association of porcine circovirus type 2 and other swine viral pathogens with postweaning multisystemic wasting syndrome. | a field-based case-control study was conducted to assess the strength of association of porcine circovirus type 2 (pcv2) and some major swine viruses with postweaning multisystemic wasting syndrome (pmws). cases were defined as individual pigs with a clinical history of progressive weight loss and histopathological lesions characteristic of pmws. controls were pigs without clinical signs and histopathological lesions typical of pmws. a total of 31 cases and 56 controls was identified from diagno ... | 2002 | 12423025 |
| generation of a replication-competent, propagation-deficient virus vector based on the transmissible gastroenteritis coronavirus genome. | replication-competent propagation-deficient virus vectors based on the transmissible gastroenteritis coronavirus (tgev) genome that are deficient in the essential e gene have been developed by complementation within e(+) packaging cell lines. cell lines expressing the tgev e protein were established using the noncytopathic sindbis virus replicon psinrep21. in addition, cell lines stably expressing the e gene under the cmv promoter have been developed. the sindbis replicon vector and the ectopic ... | 2002 | 12388713 |
| a survey of agents associated with neonatal diarrhea in iowa swine including clostridium difficile and porcine reproductive and respiratory syndrome virus. | this survey was undertaken to determine the relative frequency of agents that are currently associated with neonatal diarrhea in swine, including clostridium difficile and porcine reproductive and respiratory syndrome virus (prrsv). the subjects for this study were the first 100 live 1-7-day-old piglets submitted to the iowa state university veterinary diagnostic laboratory with a clinical signalment of diarrhea, beginning on january 1, 2000. the evaluation of each pig included bacterial culture ... | 2002 | 12152806 |
| structure of coronavirus main proteinase reveals combination of a chymotrypsin fold with an extra alpha-helical domain. | the key enzyme in coronavirus polyprotein processing is the viral main proteinase, m(pro), a protein with extremely low sequence similarity to other viral and cellular proteinases. here, the crystal structure of the 33.1 kda transmissible gastroenteritis (corona)virus m(pro) is reported. the structure was refined to 1.96 a resolution and revealed three dimers in the asymmetric unit. the mutual arrangement of the protomers in each of the dimers suggests that m(pro) self-processing occurs in trans ... | 2002 | 12093723 |
| antigenic relationship of turkey coronavirus isolates from different geographic locations in the united states. | the purpose of the present study was to examine the antigenicity of turkey coronavirus (tcv) isolates from various geographic areas with antibodies to different viruses. seventeen isolates of tcv were recovered from intestinal samples submitted to animal disease diagnostic laboratory, purdue university, from turkey farms located in different geographic areas. the prototype tcv minnesota isolate (tcv-atcc) was obtained from the american type culture collection. intestinal sections were prepared f ... | 2002 | 12061660 |
| binding of transmissible gastroenteritis coronavirus to cell surface sialoglycoproteins. | the surface glycoprotein s of transmissible gastroenteritis virus (tgev) has two binding activities. (i) binding to porcine aminopeptidase n (papn) is essential for the initiation of infection. (ii) binding to sialic acid residues on glycoproteins is dispensable for the infection of cultured cells but is required for enteropathogenicity. by comparing parental tgev with mutant viruses deficient in the sialic acid binding activity, we determined the contributions of both binding activities to the ... | 2002 | 12021336 |
| field validation of a commercial blocking elisa to differentiate antibody to transmissible gastroenteritis virus (tgev) and porcine respiratory coronavirus and to identify tgev-infected swine herds. | a commercially available blocking elisa was analyzed for its ability to identify antibodies to porcine coronaviruses (transmissible gastroenteritis virus [tgev] or porcine respiratory coronavirus [prcv]), to differentiate antibodies to tgev and prcv, and to identify tgev-infected herds. nine sera from uninfected pigs, 34 sera from 16 pigs experimentally infected with tgev, and sera from 10 pigs experimentally infected with prcv were evaluated using both the tgev/prcv blocking elisa and a virus n ... | 2002 | 11939346 |
| stabilization of a full-length infectious cdna clone of transmissible gastroenteritis coronavirus by insertion of an intron. | the stable propagation of a full-length transmissible gastroenteritis coronavirus (tgev) cdna in escherichia coli cells as a bacterial artificial chromosome has been considerably improved by the insertion of an intron to disrupt a toxic region identified in the viral genome. the viral rna was expressed in the cell nucleus under the control of the cytomegalovirus promoter and the intron was efficiently removed during translocation of this rna to the cytoplasm. the insertion in two different posit ... | 2002 | 11932433 |
| conservation of substrate specificities among coronavirus main proteases. | the key enzyme in coronavirus replicase polyprotein processing is the coronavirus main protease, 3cl(pro). the substrate specificities of five coronavirus main proteases, including the prototypic enzymes from the coronavirus groups i, ii and iii, were characterized. recombinant main proteases of human coronavirus (hcov), transmissible gastroenteritis virus (tgev), feline infectious peritonitis virus, avian infectious bronchitis virus and mouse hepatitis virus (mhv) were tested in peptide-based t ... | 2002 | 11842254 |
| in vitro and in vivo expression of foreign genes by transmissible gastroenteritis coronavirus-derived minigenomes. | a helper-dependent expression system based on transmissible gastroenteritis coronavirus (tgev) has been developed using a minigenome of 3.9 kb (m39). expression of the reporter gene beta-glucuronidase (gus) (2-8 microg per 10(6) cells) and the porcine respiratory and reproductive syndrome virus (prrsv) orf5 (1-2 microg per 10(6) cells) has been shown using a tgev-derived minigenome. gus expression levels increased about eightfold with the m.o.i. and were maintained for more than eight passages i ... | 2002 | 11842252 |
| experimental infection of piglets with transmissible gastroenteritis virus: a comparison of three strains (korean, purdue and miller). | eighty-four colostrum-deprived piglets aged 1 day were inoculated with either a korean strain of transmissible gastroenteritis virus (tgev) or one of two american strains (purdue and miller). the purpose was to compare, by morphometric analysis and in-situ hybridization, the korean strain with the two american strains in respect of pathogenicity and viral distribution over a period of 72 h. the progression of infection in pigs infected with the korean strain was much slower than that in pigs inf ... | 2002 | 11814319 |
| antigenic and genomic relatedness of turkey-origin coronaviruses, bovine coronaviruses, and infectious bronchitis virus of chickens. | in earlier studies in our laboratory, we found that bovine coronavirus (bcv) was pathogenic for 1-day-old turkey poults. this finding prompted us to study the antigenic and genomic relatedness of turkey origin coronaviruses (tocvs) to bcv. a one-step reverse transcription (rt)-polymerase chain reaction (pcr) targeting a 730-base pair fragment of the nucleocapsid (n) gene of bcv and a nested pcr targeting a 407-base pair fragment of the n gene were used in an attempt to detect tocv from north car ... | 2001 | 11785902 |
| the membrane m protein of the transmissible gastroenteritis coronavirus binds to the internal core through the carboxy-terminus. | 2001 | 11774530 | |
| cloning of a transmissible gastroenteritis coronavirus full-length cdna. | 2001 | 11774519 | |
| a simple strategy to assemble infectious rna and dna clones. | 2001 | 11774510 | |
| expression of transcriptional units using transmissible gastroenteritis coronavirus derived minigenomes and full-length cdna clones. | 2001 | 11774506 | |
| a strategy for the generation of an infectious transmissible gastroenteritis coronavirus from cloned cdna. | 2001 | 11774479 | |
| are intestinal mucins involved in the pathogenicity of transmissible gastroenteritis coronavirus? | 2001 | 11774472 | |
| heterologous gene expression from transmissible gastroenteritis virus replicon particles. | we have recently isolated a transmissible gastroenteritis virus (tgev) infectious construct designated tgev 1000 (b. yount, k. m. curtis, and r. s. baric, j. virol. 74:10600-10611, 2000). using this construct, a recombinant tgev was constructed that replaced open reading frame (orf) 3a with a heterologous gene encoding green fluorescent protein (gfp). following transfection of baby hamster kidney (bhk) cells, a recombinant tgev (tgev-gfp2) was isolated that replicated efficiently and expressed g ... | 2002 | 11773416 |
| transcription regulatory sequences and mrna expression levels in the coronavirus transmissible gastroenteritis virus. | the transcription regulatory sequences (trss) of the coronavirus transmissible gastroenteritis virus (tgev) have been characterized by using a helper virus-dependent expression system based on coronavirus-derived minigenomes to study the synthesis of subgenomic mrnas. the trss are located at the 5' end of tgev genes and include a highly conserved core sequence (cs), 5'-cuaaac-3', that is essential for mediating a 100- to 1,000-fold increase in mrna synthesis when it is located in the appropriate ... | 2002 | 11773405 |
| a serodiagnostic elisa using recombinant antigen of swine transmissible gastroenteritis virus nucleoprotein. | a serodiagnostic elisa utilizing the recombinant nucleoprotein (rn protein) of transmissible gastroenteritis virus (tgev) was developed, and evaluated by examining a panel of 141 virus neutralization (vn) positive and 101 negative sera. the rn protein-based elisa (rnelisa) appeared to be highly sensitive and specific (98.6% and 98.0%, respectively) when it was compared to the vn test. the result was similar to that of an elisa based on purified viral antigens with showing good correlation (r=0.8 ... | 2001 | 11767065 |
| completion of the porcine epidemic diarrhoea coronavirus (pedv) genome sequence. | the sequence of the replicase gene of porcine epidemic diarrhoea virus (pedv) has been determined. this completes the sequence of the entire genome of strain cv777, which was found to be 28,033 nucleotides (nt) in length (excluding the poly a-tail). a cloning strategy, which involves primers based on conserved regions in the predicted orf1 products from other coronaviruses whose genome sequence has been determined, was used to amplify the equivalent, but as yet unknown, sequence of pedv. primary ... | 2001 | 11724265 |
| differential detection of transmissible gastroenteritis virus and porcine epidemic diarrhea virus by duplex rt-pcr. | transmissible gastroenteritis (tge) and porcine epidemic diarrhea (ped) are highly contagious enteric diseases of piglets. the clinical signs of these diseases are very similar and include watery, yellowish diarrhea. thus, the effective differential detection of tge virus and ped virus is required. in the present study, a duplex reverse transcription-polymerase chain reaction (rt-pcr) was established for the differential detection of tge and ped viruses. the primers were designed for the s gene ... | 2001 | 11724144 |
| organization of two transmissible gastroenteritis coronavirus membrane protein topologies within the virion and core. | the difference in membrane (m) protein compositions between the transmissible gastroenteritis coronavirus (tgev) virion and the core has been studied. the tgev m protein adopts two topologies in the virus envelope, a nexo-cendo topology (with the amino terminus exposed to the virus surface and the carboxy terminus inside the virus particle) and a nexo-cexo topology (with both the amino and carboxy termini exposed to the virion surface). the existence of a population of m molecules adopting a nex ... | 2001 | 11711614 |
| micro-indirect immunofluorescent antibody test for the detection of antibody to transmissible gastroenteritis virus. | 2001 | 11702938 | |
| dna mediated immunization with encoding the nucleoprotein gene of porcine transmissible gastroenteritis virus. | the immune response to a naked plasmid dna encoding the nucleoprotein (n protein) of porcine transmissible gastroenteritis virus (tgev) was investigated in this study. a complementary dna of the entire n gene was amplified by rt-pcr, and inserted into a mammalian expression vector (pcdna3.1) to construct a recombinant plasmid (pcdna/n). to evaluate the immunogenicity of the construct, balb/c mice were intramuscularly immunized with different doses (50, 100 and 200 microg/mouse) of pcdna/n twice ... | 2001 | 11597750 |
| molecular determinants of species specificity in the coronavirus receptor aminopeptidase n (cd13): influence of n-linked glycosylation. | aminopeptidase n (apn), a 150-kda metalloprotease also called cd13, serves as a receptor for serologically related coronaviruses of humans (human coronavirus 229e [hcov-229e]), pigs, and cats. these virus-receptor interactions can be highly species specific; for example, the human coronavirus can use human apn (hapn) but not porcine apn (papn) as its cellular receptor, and porcine coronaviruses can use papn but not hapn. substitution of papn amino acids 283 to 290 into hapn for the corresponding ... | 2001 | 11559807 |
| complete genome sequence of transmissible gastroenteritis coronavirus pur46-mad clone and evolution of the purdue virus cluster. | the complete sequence (28580 nt) of the pur46-mad clone of the purdue cluster of transmissible gastroenteritis coronavirus (tgev) has been determined and compared with members of this cluster and other coronaviruses. the computing distances among their s gene sequences resulted in the grouping of these coronaviruses into four clusters, one of them exclusively formed by the purdue viruses. three new potential sequence motifs with homology to the alpha-subunit of the polymerase-associated nucleoca ... | 2001 | 11556396 |
| localization to the nucleolus is a common feature of coronavirus nucleoproteins, and the protein may disrupt host cell division. | the subcellular localization of transmissible gastroenteritis virus (tgev) and mouse hepatitis virus (mhv) (group i and group ii coronaviruses, respectively) nucleoproteins (n proteins) were examined by confocal microscopy. the proteins were shown to localize either to the cytoplasm alone or to the cytoplasm and a structure in the nucleus. this feature was confirmed to be the nucleolus by using specific antibodies to nucleolin, a major component of the nucleolus, and by confocal microscopy to im ... | 2001 | 11533198 |
| partial passive protection with two monoclonal antibodies and frequency of feeding of hyperimmune anti-transmissible gastroenteritis virus (tgev) serum for protection of three-day-old piglets from a tgev challenge infection. | passive protection experiments were conducted to determine the frequency and amounts of hyperimmune antiserum needed to block a transmissible gastroenteritis virus (tgev) challenge infection and to identify monoclonal antibodies that are partially protective against tgev. hyperimmune antiserum or monoclonal antibodies were added to milk at each feeding or at selected feedings when the amount of antiserum was reduced. three-day-old piglets were challenged with virulent virus that had been preincu ... | 2001 | 11478599 |
| feline and canine coronaviruses are released from the basolateral side of polarized epithelial llc-pk1 cells expressing the recombinant feline aminopeptidase-n cdna. | in this study feline (fecv and fipv) and canine (ccov) coronavirus entry into and release from polarized porcine epithelial llc-pk1 cells, stably expressing the recombinant feline aminopeptidase-n cdna, were investigated. virus entry appeared to occur preferentially through the apical membrane, similar to the entry of the related porcine coronavirus transmissible gastroenteritis virus (tgev) into these cells. however, whereas tgev is released apically, feline and canine coronaviruses were found ... | 2001 | 11402864 |
| comparison of the sialic acid binding activity of transmissible gastroenteritis coronavirus and e. coli k99. | transmissible gastroenteritis coronavirus (tgev) and escherichia coli k99 are both enteropathogenic for pigs with infections being most severe in neonate animals. for both microorganisms, a sialic acid binding activity has been shown to be an essential pathogenicity factor. here we demonstrate with haemagglutination and haemagglutination-inhibition assays that tgev and e. coli k99 differ in their sialic acid binding activities with respect to the type and amount of sialic acid residues required ... | 2001 | 11311429 |
| enhanced immune responses to viral epitopes by combining macrophage-inducible expression with multimeric display on a salmonella vector. | in this study, the immunogenicity of chimeric 987p fimbriae on a salmonella vaccine strain was improved by optimizing fimbrial expression. the constitutive teta promoter and the in vivo activated nirb and pagc promoters were evaluated for their use to express two epitopes of the transmissible gastroenteritis virus (tgev) spike protein carried by fimbriae which were displayed on a salmonella vaccine strain. constructs with the pagc promoter were shown to drive increased expression of chimeric 987 ... | 2001 | 11282213 |
| plant-based vaccines: unique advantages. | numerous studies have shown that viral epitopes and subunits of bacterial toxins can be expressed and correctly processed in transgenic plants. the recombinant proteins induce immune responses and have several benefits over current vaccine technologies, including increased safety, economy, stability, versatility and efficacy. antigens expressed in corn are particularly advantageous since the seed can be produced in vast quantities and shipped over long distances at ambient temperature, potential ... | 2001 | 11257418 |
| interferon-alpha-producing cells are localized in gut-associated lymphoid tissues in transmissible gastroenteritis virus (tgev) infected piglets. | transmissible gastroenteritis virus (tgev) infection of piglets results in a very rapid and massive release of ifn-alpha in serum and secretions. the objective of this work was to characterize the ifn-alpha-producing cells (ipc) in tissues of tgev-infected piglets. caesarean-derived colostrum-deprived piglets were infected orally with the tgev virulent miller strain and ipc were characterized in situ by immunohistochemistry, using a rabbit anti-pig ifn-alpha antiserum. ipc were almost exclusivel ... | 2001 | 11254179 |
| in situ hybridization for the detection of transmissible gastroenteritis virus in pigs and comparison with other methods. | archived formalin-fixed, paraffin-embedded tissues from 25 pigs naturally infected with transmissible gastroenteritis virus (tgev) were examined by in situ hybridization for tgev nucleic acid using a nonradioactive digoxigenin-labeled cdna probe that targeted the nucleocapsid sequence of tgev strains. the results of in situ hybridization for the detection of tgev were compared with virus isolation (vi), a fluorescent antibody test (fat), and transmission electron microscopy (tem). vi, fat, and t ... | 2001 | 11227192 |
| efficacy of a transmissible gastroenteritis coronavirus with an altered orf-3 gene. | serial passage of virulent transmissible gastroenteritis virus through cell culture reduced its virulence in 3-day-old piglets. intramuscular inoculation of pregnant gilts with 2 doses of this modified-live virus elicited a level of lactogenic immunity that protected their nursing piglets against a lethal dose of challenge virus. sequence analysis of a 637-bp fragment of the spike gene containing most of the aminopeptidase receptor and the 4 major antigenic sites from the original and the serial ... | 2001 | 11227191 |
| an investigation of the etiology of a mild diarrhea observed in a group of grower/finisher pigs. | an investigation into a mild diarrhea in a group of grower/finisher pigs was carried out in order to determine the etiology. a tiamulin injection and a carbadox-medicated ration were given to pens of pigs in a 2 x 2 factorial experimental design. pens of pigs were assessed a score, based on the consistency of the feces in the pen, each week. the clinical investigation looked for the intestinal pathogens brachyspira pilosicoli, b. hyodysenteriae, lawsonia intracellularis, salmonella spp., yersini ... | 2001 | 11195519 |
| the membrane m protein carboxy terminus binds to transmissible gastroenteritis coronavirus core and contributes to core stability. | the architecture of transmissible gastroenteritis coronavirus includes three different structural levels, the envelope, an internal core, and the nucleocapsid that is released when the core is disrupted. starting from purified virions, core structures have been reproducibly isolated as independent entities. the cores were stabilized at basic ph and by the presence of divalent cations, with mg(2+) ions more effectively contributing to core stability. core structures showed high resistance to diff ... | 2001 | 11152504 |
| sialic acid binding activity of transmissible gastroenteritis coronavirus affects sedimentation behavior of virions and solubilized glycoproteins. | the sedimentation behavior of transmissible gastroenteritis coronavirus (tgev) was analyzed. upon sucrose gradient centrifugation, the major virus band was found at a density of 1.20 to 1.22 g/cm(3). this high density was observed only when tgev with a functional sialic acid binding activity was analyzed. mutants of tgev that lacked sialic acid binding activity due to a point mutation in the sialic acid binding site of the s protein were mainly recovered at a lower-density position on the sucros ... | 2001 | 11134297 |
| construction and characterization of recombinant porcine adenovirus serotype 5 expressing the transmissible gastroenteritis virus spike gene. | five recombinant porcine adenoviruses of serotype 5 (padv-5) carrying the full-length or the 5' 2.2 kb half of the transmissible gastroenteritis virus (tgev) spike (s) gene were generated by homologous recombination in e. coli strain bj5183 cells and subsequent transfection of swine testicle cells. the foreign genes were inserted into the e3 region of padv-5. one recombinant virus had no deletion in the e3 region, whereas a 1.2 kb fragment was removed from the e3 region in the remainder of the r ... | 2001 | 11125171 |
| prevalence of porcine epidemic diarrhoea virus and transmissible gastroenteritis virus infection in korean pigs. | 2000 | 11110482 | |
| strategy for systematic assembly of large rna and dna genomes: transmissible gastroenteritis virus model. | a systematic method was developed to assemble functional full-length genomes of large rna and dna viruses. coronaviruses contain the largest single-stranded positive-polarity rna genome in nature. the approximately 30-kb genome, coupled with regions of genomic instability, has hindered the development of a full-length infectious cdna construct. we have assembled a full-length infectious construct of transmissible gastroenteritis virus (tgev), an important pathogen in swine. using a novel approac ... | 2000 | 11044104 |
| comparison of serologic testing and slaughter evaluation for assessing the effects of subclinical infection on growth in pigs. | to compare serologic testing with slaughter evaluation in assessing effects of subclinical infection on average daily weight gain (adg) in pigs. | 2000 | 10997163 |
| seroprevalence of porcine respiratory coronavirus in selected korean pigs. | a total of 446 serum samples from 88 herds in korea were examined for antibody to porcine respiratory coronavirus (prcv) using blocking enzyme-linked immunosorbent assay (elisa). all serum samples were collected from 24- to 26-week-old finishing pigs between december 1998 and june 1999. by elisa, 237 out of 446 sera tested (53.1%) and 54 out of 88 sampled herds (61.3%) were positive against prcv. of 446 sera from 88 herd tested, 185 (41.5%) serum samples from 22 (25%) herds were seronegative aga ... | 2000 | 10960715 |
| molecular characterization and pathogenesis of transmissible gastroenteritis coronavirus (tgev) and porcine respiratory coronavirus (prcv) field isolates co-circulating in a swine herd. | tgev replicates in intestinal enterocytes and causes diarrhea in young pigs. prcv, a spike (s) gene deletion mutant of tgev with an altered respiratory tissue tropism, causes mild or subclinical respiratory infections. comparisons of tgev and prcv strains suggest that tropism and pathogenicity are influenced by the s gene and orf3, respectively. recently, outbreaks of tge of reduced virulence were reported in the field. we investigated a similar suspect tgev outbreak of reduced virulence in nurs ... | 2000 | 10948987 |
| development of a reverse transcription-nested polymerase chain reaction assay for differential diagnosis of transmissible gastroenteritis virus and porcine respiratory coronavirus from feces and nasal swabs of infected pigs. | transmissible gastroenteritis virus (tgev), a coronavirus, replicates in intestinal enterocytes and causes diarrhea in young pigs. porcine respiratory coronavirus (prcv), a spike (s) gene natural deletion mutant of tgev, has a respiratory tissue tropism and causes mild or subclinical respiratory infections. conventional antigen-based diagnostic tests fail to differentiate tgev and prcv, and a blocking elisa test to serologically differentiate tgev/prcv-infected pigs is conducted on convalescent ... | 2000 | 10907874 |
| transmissible gastroenteritis virus induces apoptosis in swine testicular cell lines but not in intestinal enterocytes. | evidence of apoptosis caused by infection with the purdue strain of transmissible gastroenteritis virus (tgev) was sought in vitro (in infected swine testicular [st] cells) and in vivo (in the intestinal tissues of infected piglets). the methods used were (1) dna electrophoresis for detection of dna fragmentation, and (2) terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-fluorescein nick and labelling (tunel). dna "laddering" was detected in tgev-infected st cells only. nu ... | 2000 | 10906258 |
| detection and differentiation of porcine epidemic diarrhoea virus and transmissible gastroenteritis virus in clinical samples by multiplex rt-pcr. | a multiplex reverse-transcriptase-pcr (rt-pcr) procedure was developed for the simultaneous detection of porcine epidemic diarrhoea virus (pedv) and transmissible gastroenteritis virus (tgev) in preweaning pigs with diarrhoea. the membrane gene of pedv and the nucleocapsid gene of tgev were chosen as targets. the pcr products of pedv and tgev had molecular sizes of 412 and 612 base pairs, respectively. primers from pedv did not react with any tgev tested and vice versa. in addition, the primers ... | 2000 | 10872784 |
| mucosal and systemic immune responses to chimeric fimbriae expressed by salmonella enterica serovar typhimurium vaccine strains. | recombinant live oral vaccines expressing pathogen-derived antigens offer a unique set of attractive properties. among these are the simplicity of administration, the capacity to induce mucosal and systemic immunity, and the advantage of permitting genetic manipulation for optimal antigen presentation. in this study, the benefit of having a heterologous antigen expressed on the surface of a live vector rather than intracellularly was evaluated. accordingly, the immune response of mice immunized ... | 2000 | 10816454 |
| engineering the largest rna virus genome as an infectious bacterial artificial chromosome. | the construction of cdna clones encoding large-size rna molecules of biological interest, like coronavirus genomes, which are among the largest mature rna molecules known to biology, has been hampered by the instability of those cdnas in bacteria. herein, we show that the application of two strategies, cloning of the cdnas into a bacterial artificial chromosome and nuclear expression of rnas that are typically produced within the cytoplasm, is useful for the engineering of large rna molecules. a ... | 2000 | 10805807 |
| the viral nucleocapsid protein of transmissible gastroenteritis coronavirus (tgev) is cleaved by caspase-6 and -7 during tgev-induced apoptosis. | the transmissible gastroenteritis coronavirus (tgev), like many other viruses, exerts much of its cytopathic effect through the induction of apoptosis of its host cell. apoptosis is coordinated by a family of cysteine proteases, called caspases, that are activated during apoptosis and participate in dismantling the cell by cleaving key structural and regulatory proteins. we have explored the caspase activation events that are initiated upon infection of the human rectal tumor cell line hrt18 wit ... | 2000 | 10756009 |
| characterization of the stunting syndrome agent: relatedness to known viruses. | an enteric disease of young turkeys, referred to as stunting syndrome (ss), causes reduced growth and impaired feed efficiency. a recently isolated virus, stunting syndrome agent, (ssa) has been found to be the etiologic agent of ss. the objective of the present study was to determine relatedness of the ssa with other viral agents. serologic (viral neutralization and enzyme-linked immunosorbent assay [elisa]) assays and a reverse transcriptase-polymerase chain reaction (rt-pcr) were used. the an ... | 2000 | 10737643 |
| downstream ribosomal entry for translation of coronavirus tgev gene 3b. | gene 3b (orf 3b) in porcine transmissible gastroenteritis coronavirus (tgev) encodes a putative nonstructural polypeptide of 27.7 kda with unknown function that during translation in vitro is capable of becoming a glycosylated integral membrane protein of 31 kda. in the virulent miller strain of tgev, orf 3b is 5'-terminal on mrna 3-1 and is presumably translated following 5' cap-dependent ribosomal entry. for three other strains of tgev, the virulent british fs772/70 and taiwanese tfi and aviru ... | 2000 | 10725209 |
| immunogenicity of porcine transmissible gastroenteritis virus spike protein expressed in plants. | transgenic plants expressing recombinant proteins from pathogenic microorganisms provide an inexpensive edible vaccine for induction of local immunity. three transgenic plant lines were generated expressing the spike (s) protein of transmissible gastroenteritis virus (tgev), a protein crucial for establishing mucosal immunity. all three of them were driven by a strong plant promoter. one construct contained the 3.7 kb 5' end of the native s gene sequence. in the second construct part of the s ge ... | 2000 | 10706964 |
| interference with virus and bacteria replication by the tissue specific expression of antibodies and interfering molecules. | historically, protection against virus infections has relied on the use of vaccines, but the induction of an immune response requires several days and in certain situations, like in newborn animals that may be infected at birth and die in a few days, there is not sufficient time to elicit a protective immune response. immediate protection in new born could be provided either by vectors that express virus-interfering molecules in a tissue specific form, or by the production of animals expressing ... | 1999 | 10659342 |
| characterization of the sialic acid binding activity of transmissible gastroenteritis coronavirus by analysis of haemagglutination-deficient mutants. | transmissible gastroenteritis coronavirus (tgev) agglutinates erythrocytes of several species by virtue of sialic acid binding activity of the surface protein s. we have isolated and characterized five haemagglutination-defective (had) mutants. in contrast to the parental virus, the mutants were unable to bind to porcine submandibulary mucin, a substrate rich in sialic acid. each of the mutants was found to contain a single point mutation in the s protein (cys155phe, met195val, arg196ser, asp208 ... | 2000 | 10644848 |