| sequence analysis of ccv and its relationship to fipv, tgev and prcv. | | 1993 | 8209747 |
| n-acetylneuraminic acid plays a critical role for the haemagglutinating activity of avian infectious bronchitis virus and porcine transmissible gastroenteritis virus. | porcine transmissible gastroenteritis virus (tgev) was found to resemble avian infectious bronchitis virus (ibv) in its interaction with erythrocytes. inactivation of the receptors on erythrocytes by neuraminidase treatment and restoration of receptors by reattaching n-acetylneuraminic acid (neu5ac) to cell surface components indicated that alpha 2,3-linked neu5ac serves as a receptor determinant for tgev as has been reported recently for ibv. similar to ibv, the haemagglutinating activity of tg ... | 1993 | 8209748 |
| evolution and tropism of transmissible gastroenteritis coronavirus. | 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 t ... | 1993 | 8209753 |
| transmissible gastroenteritis virus and porcine respiratory coronavirus: molecular characterization of the s gene using cdna probes and nucleotide sequence analysis. | 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 2 ... | 1993 | 8209764 |
| an overview of successful tgev vaccination strategies and discussion on the interrelationship between tgev and prcv. | porcine respiratory coronavirus (prcv) is a new variant of tge with an altered pathogenesis. prcv multiplies mainly in tonsilar tissues and the respiratory tract. there are no enteric symptoms and in experimentally infected pigs, even the respiratory tract infection is usually asymptomatic. prcv is spread aerogenically through herds and the significance of prcv as a pathogen in swine has yet to be determined. despite the differences in pathogenesis and tissue tropism, the behavior of tgev and pr ... | 1993 | 8209768 |
| genome organization of porcine epidemic diarrhoea virus. | in order to study the organization of the genome of porcine epidemic diarrhoea virus (pedv), we constructed a cdna library in a phage expression vector by using poly(a) rna from pedv-infected vero cells. an anti-pedv hyperimmune serum was used to probe the library. the first isolated clone mapped within the n gene and was subsequently used for rescreening the library. the selected clones allowed us to establish the sequence of the 3'-most 7.4 kb of the pedv genome. analysis of the cdna sequences ... | 1993 | 8209771 |
| control of tgev mrna transcription. | coronavirus proteins are translated from a nested set of subgenomic mrnas which have common 3' termini with unique 5' extensions. evidence suggests that coronavirus mrnas are generated by a mechanism of leader primed transcription. leader rna binds to consensus sequences upstream of each gene on full length negative strand viral rna and transcription proceeds to the 5' end of the negative strand to produce the nested set of mrnas. even though this gives rise to polycistronic mrna species only th ... | 1993 | 8209778 |
| age-related increase of porcine natural interferon alpha producing cell frequency and of interferon yield per cell. | porcine blood mononuclear cells (pbmc) were shown to secrete interferon alpha (ifn-alpha) after induction by a coronavirus, the transmissible gastroenteritis virus (tgev). ifn-alpha producing cells, referred to as natural interferon alpha producing (nip) cells, were detected by an elispot assay using anti-porcine ifn-alpha monoclonal antibodies. the frequency of nip cells among blood cells is low, at most 40-110 per 10(5) pbmc and each nip cell was found to produce several units of ifn. we have ... | 1993 | 8236791 |
| epithelioid and fibroblastic cell lines derived from the ileum of an adult histocompatible miniature boar (d/d haplotype) and immortalized by sv40 plasmid. | intestinal explants were maintained for weeks in a growth medium containing collagenase for progressive digestion to derive finite cell lines from the ileum (64 lines) or from the colon (8 lines) of a boar. two ileal cell lines retaining either a fibroblastic or an epithelioid morphology have been used to derive heteroploid cell lines (ipi-1 and ipi-2) immortalized by transfection with an sv40 plasmid (psv3-neo). the ipi-1 cells were found of fibroblastic lineage. the ipi-2 cell line gave rise t ... | 1993 | 8269973 |
| antigenic and biological diversity among transmissible gastroenteritis virus isolates of swine. | twenty-four field isolates of transmissible gastroenteritis virus (tgev) were isolated and examined for antigenic and biological characteristics. most tgev isolates produced a typical cytopathic effect (cpe) in swine testis (st) cell culture, which included a ballooning or lifting away of the infected cells from the cell monolayer with heavy granulation evident. minor variations in cpe were observed with one isolate, ia-145. protein profiles of the tgev isolates as determined by sds-page were es ... | 1993 | 8273277 |
| dot-blot hybridization using digoxigenin-labeled cdna probe complementary to the s1 gene of avian infectious bronchitis virus permits discrimination between virus strains. | digoxigenin-dutp-labeled dna probe was prepared from a cdna clone complementary to the gene encoding s1 region of the spike protein of infectious bronchitis coronavirus (ibv) strain m41. the probe exclusively reacted with four strains at 56 degrees c which were grouped to the same serotype as the strain used for the probe. in contrast, at 68 degrees c, the probe reacted only with the homologous strain and did not react even with the strains belonging to the same serotype. the dot-blot hybridizat ... | 1993 | 8286524 |
| sequence analysis of the porcine epidemic diarrhea virus genome between the nucleocapsid and spike protein genes reveals a polymorphic orf. | in order to investigate the genome organization of the porcine epidemic diarrhea virus (pedv) further, cdna clones covering the region between the nucleocapsid and the spike (s) protein genes were independently constructed and sequenced for the two virulent isolates br1/87 and cv777. of the three major orfs identified, two were found to encode the major and minor coronavirus membrane proteins m and sm. a potentially single orf, designated orf3 according to the pattern of the viral subgenomic mrn ... | 1994 | 8291230 |
| [the isolation and in-vitro cultivation of a virulent strain of the porcine transmissible gastroenteritis virus]. | | 1993 | 8303889 |
| competition elisa, using monoclonal antibodies to the transmissible gastroenteritis virus (tgev) s protein, for serologic differentiation of pigs infected with tgev or porcine respiratory coronavirus. | monoclonal antibodies (mab) to subsite a (25c9) and subsite d (44c11) of the s protein of transmissible gastroenteritis virus (tgev) were used in a blocking elisa on fixed tgev-infected swine testis cells to differentiate sera from pigs experimentally inoculated with either tgev or porcine respiratory coronavirus (prcv). serum samples were obtained from pigs at various intervals from postinoculation day (pid) 0 through at least pid 22 to 40. eleven-day-old pigs, seronegative for tgev-neutralizin ... | 1993 | 8381626 |
| intestinal protection against challenge with transmissible gastroenteritis virus of pigs immune after infection with the porcine respiratory coronavirus. | an infection of pigs with the porcine respiratory coronavirus (prcv) induces antibodies which neutralize the enteropathogenic transmissible gastroenteritis virus (tgev) and prcv to the same titre. in the present study, 10-week-old seronegative pigs (n = 8), pigs immune following tgev inoculation (n = 4) or pigs immune following aerosol (n = 8) or intragastric inoculation (n = 4) with prcv were challenged with tgev. whereas tgev-immune pigs were completely protected against challenge, all prcv-im ... | 1993 | 8382421 |
| transmissible gastroenteritis in pigs in south east spain: prevalence and factors associated with infection. | in the murcia region of south east spain, epidemics of transmissible gastroenteritis-like disease have occurred in pigs every three years since 1980. in 1987 a sero-epidemiological survey was conducted to estimate the prevalence and spread of transmissible gastroenteritis virus (tgev) infection among breeding pigs and farms, and to determine any association between the infection and herd size and geographical zone. the murcia region was divided into four geographical zones and the farms were cla ... | 1993 | 8384735 |
| the application of immunogold silver staining (igss) for the detection of transmissible gastroenteritis virus in fixed tissues. | protein a-gold (pag) and a primary porcine antiserum were used in immunogold silver staining (igss) for the detection of transmissible gastroenteritis virus (tgev) in formalin-fixed paraffin-embedded tissue sections of small intestine originating from infected pigs. immunogold electron microscopy was used to evaluate the reactivity of the prepared pag marker with the specific porcine tgev antiserum. gold particles were closely associated with single virions and immune aggregates of tgev. when ig ... | 1993 | 8385499 |
| comparison of a monoclonal antibody capture elisa (macelisa) to indirect elisa and virus neutralization test for the serodiagnosis of transmissible gastroenteritis virus. | an enzyme-linked immunosorbent assay (elisa) in which the antigen is captured to the plate by monoclonal antibodies (macelisa) was developed for the detection of antibodies to transmissible gastroenteritis virus (tgev). the viral antigen was semipurified from tgev-infected cells by simple ultracentrifugation. macelisa results with 258 field sera were compared with those of a standard indirect elisa and with the virus neutralization test (vnt). sensitivity, specificity, and kappa values of maceli ... | 1993 | 8385500 |
| isotype-specific antibody-secreting cells to transmissible gastroenteritis virus and porcine respiratory coronavirus in gut- and bronchus-associated lymphoid tissues of suckling pigs. | antibody-secreting cells (asc) were enumerated in gut- and bronchus-associated lymphoid tissues of pigs exposed to three antigenically related coronaviruses: virulent transmissible gastroenteritis virus (tgev), attenuated tgev, and porcine respiratory coronavirus (prcv). exposure of 11-day-old pigs to virulent tgev resulted in severe gastroenteritis and virus shedding mainly in feces but also to a limited extent in nasal secretions. prcv and attenuated tgev exposure produced no clinical signs an ... | 1993 | 8386204 |
| a sero-epizootiological study of porcine respiratory coronavirus in belgian swine. | a porcine respiratory coronavirus (prcv), antigenically closely related to transmissible gastroenteritis virus (tgev), appeared in the european swine population in 1984. the present serological study was performed to obtain insight into the epizootiology of prcv and of tgev. prcv-induced neutralizing antibodies were found in 90.6 per cent of the 160 sera collected from sows at slaughter, demonstrating the enzootic appearance of prcv in the belgian swine population. a serological study of fatteni ... | 1993 | 8388592 |
| enrichment of coronavirus-induced interferon-producing blood leukocytes increases the interferon yield per cell: a study with pig leukocytes. | porcine peripheral blood mononuclear cells, which secrete ifn alpha in response to a coronavirus, transmissible gastroenteritis virus, were detected by a filter immunoplaque assay (elispot). ifn alpha-producing cells (ipc), which are present at a low frequency in the blood, could be enriched up to 100-fold by sequential depletion of plastic-adherent cells and cell fractionation on metrizamide density gradients. ipc were present in the non-adherent low-density cell subpopulation. cell selection e ... | 1993 | 8390709 |
| comparative study of different immunoserological techniques for the detection of antibodies against transmissible gastroenteritis (tge) coronavirus. | in order to carry out a sero-epidemiological survey of transmissible gastroenteritis (tge) infection in a high-density pig-breeding area the murcia region, spain), the sensitivity and the specificity of 5 different techniques were compared. twenty-four sera from non-infected and infected pigs were analyzed by the following tests: in vitro neutralization, indirect elisa with concentrated virus, indirect elisa with purified virus, immunocapture elisa and velcia (virus-enzyme linked cell immunoassa ... | 1993 | 8391366 |
| experience with a planned exposure program for the control of enzootic transmissible gastroenteritis in swine. | oral inoculation of pregnant sows and gilts with a homogenate of pig intestines containing live, virulent transmissible gastroenteritis (tge) virus was associated with significant (p < 0.01) reduction of mortality in nursery pigs in a herd affected with enzootic tge. the mortality of weaned pigs from april through june 1981, when sows were not vaccinated or inoculated, was 9.3%. mortality of weanling pigs from july through december 1981 was 5.7% (p < 0.01), and stayed consistently between 2.6 an ... | 1993 | 8391524 |
| porcine respiratory coronavirus: molecular features and virus-host interactions. | since 1984, a previously unrecognized respiratory coronavirus, causing a mostly unapparent infection, has rapidly and massively spread within the swine population in europe, and few years later, a virus with similar characteristics has been identified in the usa. the agent, designated prcv, appears to be derived from the porcine enteric coronavirus tgev. the aim of the present article is to review comprehensively the state of the knowledge about this new virus and its infection. the review inclu ... | 1993 | 8393722 |
| a spike protein-dependent cellular factor other than the viral receptor is required for mouse hepatitis virus entry. | previous studies have shown that some mouse strains are resistant to mouse hepatitis virus (mhv) infection despite the presence of functional viral receptors (k. yokomori and m. m. c. lai, j. virol. 66, 6931-6938, 1992). to determine the molecular requirement for mhv infection, several cell lines derived from both susceptible and resistant mouse strains were tested for their ability to support infection by two different mhv strains, jhm and a59. most of the cell lines tested, including ones from ... | 1993 | 8395126 |
| binding of porcine transmissible gastroenteritis virus by enterocytes from newborn and weaned piglets. | enterocytes were harvested by chelation in a series of seven fractions from the tips of the villi to the crypts of the jejunum of newborn or weaned piglets. binding of the low cell culture passaged miller-6 strain of transmissible gastroenteritis virus (tgev) to villous enterocytes from newborn piglets was at a high level, similar to that observed to cultured swine testis (st) cells. binding of the virus to cryptal enterocytes from newborn piglets or to villous or cryptal enterocytes from weaned ... | 1993 | 8395743 |
| sequence determination of the nucleocapsid protein gene of the porcine epidemic diarrhoea virus confirms that this virus is a coronavirus related to human coronavirus 229e and porcine transmissible gastroenteritis virus. | the nucleotide sequence of 1.7 kbp cdna, comprising the region nearest the 3' end of the genome of the porcine epidemic diarrhoea virus (pedv), has been independently determined for two european isolates of pedv. almost identical results were obtained for the two isolates, which were derived from cases of pedv infection in belgium and britain in 1977 and 1987, respectively. the sequences contained a 1323 nucleotide (nt) open reading frame (orf), which showed moderate identity to the nucleocapsid ... | 1993 | 8397280 |
| inhibition of appearance of ph-dependent virus-cell fusion by neutralizing monoclonal antibodies to transmissible gastroenteritis virus. | five mabs, which showed neutralizing (nt) activity and recognized s (previously designated e2) glycoprotein of tge virus to-163, inhibited cell fusion by tge virus in ib-rs-2 cells. other s-specific mabs with no nt activity did not inhibit the cell fusion. the results indicate that a neutralization epitope is same or very close to a fusion active site. the kinetics of membrane fusion following a reduction in ph were also investigated. the cell fusion appeared between 2 and 6 hr after the bindin ... | 1993 | 8399749 |
| transmissible gastroenteritis coronavirus: the development and applications of the fixed-cell immunoperoxidase technique. | since the first demonstration in 1971 that solid-phase enzyme-linked immunosorbent assays (elisas) could be used for the quantitative determination of antigens and antibodies, this method has been widely applied in serodiagnosis of parasitic and infectious diseases. in addition to the classic elisa variants using antigen or antibody to coat the plastic plates, there has recently been growing interest in the application of fixed-cell elisa to research and diagnostic work on viral diseases. the au ... | 1993 | 8400392 |
| cellular immune responses of pigs after primary inoculation with porcine respiratory coronavirus or transmissible gastroenteritis virus and challenge with transmissible gastroenteritis virus. | the contribution of cell-mediated immunity to protective immunity against virulent transmissible gastroenteritis virus (tgev) infection conferred by primary porcine respiratory coronavirus (prcv) or tgev exposure was assessed in pigs that were challenged with tgev 24 days after a primary oronasal inoculation with prcv or tgev when 11 days old. prcv exposure induced partial protection against tgev challenge in suckling pigs based upon a decreased number of diarrhea cases (42% vs. 90% in age-match ... | 1995 | 8533315 |
| cloning and sequencing of a 8.4-kb region from the 3'-end of a taiwanese virulent isolate of the coronavirus transmissible gastroenteritis virus. | the nucleotide sequence (8396 nucleotides) was determined, from the 3'-end of the putative polymerase gene to the poly(a) tail, for a taiwanese virulent isolate, tfi, of transmissible gastroenteritis virus (tgev). the tfi nucleotide sequence had very high identity to the british virulent field isolate fs772/70 (98.3%), the attenuated purdue 115 (96.7%) and from the s gene to orf-4 gene region, to the low passaged virulent miller (98.3%) strains of tgev. comparison of the tfi s protein sequence w ... | 1995 | 8546012 |
| immunohistological demonstration of feline infectious peritonitis virus antigen in paraffin-embedded tissues using feline ascites or murine monoclonal antibodies. | feline infectious peritonitis (fip) virus antigen was demonstrated after methanol, ethanol or formalin fixation in paraffin-embedded tissues by means of monoclonal and polyclonal antibodies. the monoclonal antibody was induced by immunization with transmissible gastroenteritis virus. polyclonal antibodies were obtained by purification on protein a-sepharose of ascites fluid from a cat with fip. almost all cats diagnosed as suffering from fip by postmortem and histological examination exhibited f ... | 1995 | 8588340 |
| cloning, sequencing and expression of the s protein gene from two geographically distinct strains of canine coronavirus. | the gene encoding the spike (s) protein from two geographically distinct strains (american and british) of canine coronavirus (ccv) was cloned and sequenced. the nucleotide sequence revealed open reading frames of 1443 or 1453 amino acids, respectively. structural features include an n-terminal hydrophobic signal sequence, a hydrophilic cysteine-rich cluster near the c-terminus, two heptad repeats and 29 or 33 potential n-glycosylation sites. pairwise comparisons of s amino acid sequences from t ... | 1995 | 8607285 |
| molecular characterization of transmissible gastroenteritis coronavirus defective interfering genomes: packaging and heterogeneity. | three transmissible gastroenteritis virus (tgev) defective rnas were selected by serial undiluted passage of the pur46 strain in st cells. these rnas of 22, 10.6, and 9.7 kb (di-a, di-b, and di-c, respectively) were detected at passage 30, remained stable upon further passage in cell culture, and significantly interfered with helper mrna synthesis. rna analysis from purified virions showed that the three defective rnas were efficiently packaged. virions of different densities containing either f ... | 1996 | 8610441 |
| tandem placement of a coronavirus promoter results in enhanced mrna synthesis from the downstream-most initiation site. | insertion of the 17-nucleotide promoter region for the bovine coronavirus n gene as part of a 27-nucleotide cassette into the open reading frame of a cloned synthetic defective-interfering (di) rna resulted in synthesis of subdi rna transcripts from the replicating di rna genome. duplicating and triplicating the promoter sequence in tandem caused a progressive increase in the efficiency of subgenomic mrna synthesis despite a concurrent decrease in the rate of di rna accumulation that was not spe ... | 1996 | 8610468 |
| induction of protective immunity against transmissible gastroenteritis virus after exposure of neonatal pigs to porcine respiratory coronavirus. | to test the ability of porcine respiratory coronavirus (prcv) to induce protective immunity to antigenically related transmissible gastroenteritis virus (tgev) in neonatal pigs. | 1996 | 8633800 |
| tropism of human adenovirus type 5-based vectors in swine and their ability to protect against transmissible gastroenteritis coronavirus. | the infection of epithelia] swine testicle and intestinal porcine epithelial (ipec-1) cell lines by adenovirus type 5 (ad5) has been studied in vitro by using an ad5-luciferase recombinant containing the firefly luciferase gene as a reporter. porcine cell lines supported ad5 replication, showing virus titers, kinetics of virus production, and luciferase expression levels similar to those obtained in human 293 cells, which constitutively express the 5'-end 11% of the ad5 genome. the tropism of ad ... | 1996 | 8648712 |
| the transmissible gastroenteritis coronavirus contains a spherical core shell consisting of m and n proteins. | coronaviruses are enveloped rna viruses involved in a variety of pathologies that affect animals and humans. existing structural models of these viruses propose a helical nucleocapsid under the virion envelope as the unique internal structure. in the present work, we have analyzed the structure of the transmissible gastroenteritis coronavirus. the definition of its organization supports a new structural model for coronaviruses, since a spherical, probably icosahedral, internal core has been char ... | 1996 | 8676505 |
| classical transmissible gastroenteritis returns. | | 1996 | 8677610 |
| elimination of transmissible gastroenteritis virus from a pig farm by culling and serological surveillance. | the first and only outbreak of transmissible gastroenteritis in pigs in ireland occurred in 1984 in a 650-sow unit which was one of three such units owned by one enterprise which supplied pigs to a 12,000 head fattening unit in the same ownership. the depopulation of the clinically infected unit and extensive serological monitoring of pigs in the other units and in pig farms throughout the country has proved successful in the elimination of transmissible gastroenteritis infections from pigs in i ... | 1996 | 8686150 |
| characterization of transmissible gastroenteritis coronavirus s protein expression products in avirulent s. typhimurium delta cya delta crp: persistence, stability and immune response in swine. | the spike protein from transmissible gastroenteritis virus (tgev) was expressed in attenuated s. typhimurium delta cya delta crp delta asd chi 3987. three partially overlapping fragments of tgev s gene, encoding the amino-terminal, intermediate, and carboxy-terminal end of the protein, as well as the full length gene were inserted into the asd+ plasmid pya292 to generate recombinant plasmids pyats-1, pyats-2, pyats-3, and pyats-4, respectively, which were transformed into s. typhimurium chi 3987 ... | 1996 | 8701580 |
| [identification and characterization of new and unknown coronaviruses using rt-pcr and degenerate primers]. | a modified method of the reverse transcription followed by polymerase chain reaction (rt-pcr) was developed in order to examine the genome of a recently discovered virus, the porcine epidemic diarrhoea virus (pedv), which resembled morphologically the coronaviruses. the published sequences of the genomes of various coronaviruses were compared. on the level of the amino acid sequence, conserved regions, common to all coronaviruses, were found in the gene encoding the nonstructural protein 1b as w ... | 1996 | 8720732 |
| contribution of passive immunity to porcine respiratory coronavirus to protection against transmissible gastroenteritis virus challenge exposure in suckling pigs. | to determine the ability of porcine respiratory coronavirus (prcv) infections to induce passive immunity in suckling pigs to transmissible gastroenteritis virus (tgev) challenge exposure. design and animals: 4 tgev seronegative sows and their litters (group a) served as controls, whereas 2 other groups (b and c) of sows (also tgev seronegative) were oronasally inoculated with live prcv during 1 or 2 subsequent pregnancies, respectively. | 1996 | 8723879 |
| a continuous epitope from transmissible gastroenteritis virus s protein fused to e. coli heat-labile toxin b subunit expressed by attenuated salmonella induces serum and secretory immunity. | antigenic site d from the spike protein of transmissible gastroenteritis virus (tgev), which is a continuous epitope critical in neutralization, has been expressed as a fusion protein with e. coli heat-labile toxin b subunit (lt-b) in attenuated s. typhimurium. synthetic peptides containing the sequence of site d induced tgev neutralizing antibodies when inoculated subcutaneously in both rabbits and swine. a synthetic oligonucleotide encoding residues 373-398 of tgev s protein, including antigen ... | 1996 | 8725098 |
| isolation of porcine respiratory coronavirus from pigs affected with porcine reproductive and respiratory syndrome. | four cytopathogenic viruses were isolated in cpk cells derived from porcine kidneys from tonsils and lungs of 3 of 15 pigs affected with porcine reproductive and respiratory syndrome virus. physicochemically and morphologically, the isolates were similar to a coronavirus. the isolates were not distinguished from transmissible gastroenteritis virus (tgev) by a neutralization test using polyclonal antibodies, but differentiated from tgev by monoclonal antibodies capable of discriminating between t ... | 1996 | 8741277 |
| immunohistochemistry of transmissible gastroenteritis virus antigens in fixed paraffin-embedded tissues. | an immunohistochemistry technique was developed using fixed tissues to study the presence and location of transmissible gastroenteritis virus (tgev) antigens in situ. experimentally infected gnotobiotic and conventional pigs as well as pigs with natural tgev infection were examined. the staining technique was based on detection of the major structural protein of tgev, the nucleocapsid, by using a pool of 3 monoclonal antibodies. formalin and periodate-lysine-paraformaldehyde (plp)-fixed intestin ... | 1996 | 8744736 |
| use of nonradioactive cdna probes to differentiate porcine respiratory coronavirus and transmissible gastroenteritis virus isolates. | | 1996 | 8744748 |
| transmissible gastroenteritis coronavirus, but not the related porcine respiratory coronavirus, has a sialic acid (n-glycolylneuraminic acid) binding activity. | the hemagglutinating activity of transmissible gastroenteritis virus (tgev), an enteric porcine coronavirus, was analyzed and found to be dependent on the presence of alpha-2,3-linked sialic acid on the erythrocyte surface. n-glycolylneuraminic acid was recognized more efficiently by tgev than was n-acetylneuraminic acid. for an efficient hemagglutination reaction the virions had to be treated with sialidase. this result suggests that the sialic acid binding site is blocked by virus-associated c ... | 1996 | 8764078 |
| coronaviruses in polarized epithelial cells. | coronaviruses have a marked tropism for epithelial cells. in this paper the interactions of the porcine transmissible gastroenteritis virus (tgev) and mouse hepatitis virus (mhv-a59) with epithelial cells are compared. porcine (llc-pk1) and murine (mtal) epithelial cells were grown on permeable supports. by inoculation from the apical or basolateral side both tgev and mhv-a59 were found to enter the polarized cells only through the apical membrane. the release of newly synthesized tgev from llc- ... | 1995 | 8830469 |
| the use of arms pcr and rflp analysis in identifying genetic profiles of virulent, attenuated or vaccine strains of tgev and prcv. | the use of arms (amplification refractory mutation system) pcr coupled with rflp (restriction fragment length polymorphism) analysis has been used to identify a unique genetic marker on the ambico oral vaccine strain. this method was also used to characterize the genetic profiles of a number of other tgev strains. this procedure takes advantage of the nucleotide differences between the ambico strain, and the miller and purdue strains. within the s gene there are three nucleotide differences betw ... | 1995 | 8830487 |
| identification of proteins specified by porcine epidemic diarrhoea virus. | up to now, little was known about the proteins of porcine epidemic diarrhoea virus (pedv). using (i) metabolic labelling, (ii) antisera directed against synthetic peptides and monoclonal antibodies, and (iii) eukaryotic and prokaryotic expression systems, we have started to identify and characterize these proteins. the nucleocapsid protein (n) of pedv was identified as a phosphoprotein with a relative mobility (m(r)) of 57 k. no additional phosphoproteins were detected. at least three glycoprote ... | 1995 | 8830494 |
| functional domains in the spike protein of transmissible gastroenteritis virus. | the coronavirus spike protein s is assumed to mediate essential biological functions, including recognition of target cells. earlier studies from our and other groups identified two regions of the tgev s (220k) protein possibly implicated in such functions. the first of these corresponds to the 224 amino acid n-terminal region which is deleted in prcv, the respiratory variant of tgev. we have examined the pathogenicity for the newborn piglet of a series of neutralization escape mutants encoding ... | 1995 | 8830497 |
| recombinant expression of the tgev membrane glycoprotein m. | we have previously shown that the membrane protein m of tgev is involved in efficient induction of alpha interferon (ifn alpha) synthesis by non-immune peripheral blood mononuclear cells incubated with fixed, tgev-infected cells or inactivated virions. in order to determine whether m protein is able to induce interferon in the absence of other viral factors, we expressed the protein either stably in the porcine st cells or transiently in the simian cos7 cells. although showing no obvious differe ... | 1995 | 8830498 |
| cellular receptors for transmissible gastroenteritis virus on porcine enterocytes. | the activity of aminopeptidase-n (apn), reported to be a major receptor for porcine transmissible gastroenteritis virus (tgev), in enterocyte fractions harvested from the jejunal villi and crypts of newborn and weaned piglets, did not correspond with the levels of saturable virus binding previously demonstrated for the same fractions. plasma membranes prepared from enterocytes harvested from the jejunal villi of a newborn piglet were used in the preparation of a monoclonal antibody (mab) which b ... | 1995 | 8830502 |
| multiple receptor-dependent steps determine the species specificity of hcv-229e infection. | human coronavirus (hcv)-229e causes disease only in humans and grows in human cells and in cells of other species that express recombinant human aminopeptidase n (hapn), the receptor for hcv-229e. we compared the species specificity of hcv-229e infection with the species specificity of virus binding using immunofluorescence, assay of virus yields, fluorescence activated cell sorting and a monoclonal antibody directed against hapn that blocks infection. we found that hcv-229e binds to intestinal ... | 1995 | 8830504 |
| molecular differentiation of transmissible gastroenteritis virus and porcine respiratory coronavirus strains. correlation with antigenicity and pathogenicity. | transmissible gastroenteritis virus (tgev) causes an economically important enteric disease of swine. differences in the pathogenicity, antigenicity and tissue tropism have been observed among porcine coronaviruses. although porcine respiratory coronavirus (prcv) is antigenically similar but not identical to tgev isolates, these respiratory coronaviruses differ markedly in pathogenicity and tissue tropism compared to tgev isolates. using a reverse transcriptase/polymerase chain reaction-restrict ... | 1995 | 8830506 |
| analysis of the sialic acid-binding activity of the transmissible gastroenteritis virus. | porcine transmissible gastroenteritis virus (tgev) has been shown to agglutinate erythrocytes using alpha 2,3-linked sialic acid on the cell surface as binding site. the hemagglutinating activity requires the pretreatment of virus with neuraminidase. we obtained evidence that tgev recognizes not only n-acetylneuraminic acid but also n-glycoloylneuraminic acid, a sialic acid present on many porcine cells. | 1995 | 8830509 |
| overexpression of tgev cell receptor impairs the production of virus particles. | the porcine aminopeptidase-n (papn) is the cellular receptor for the transmissible gastroenteritis virus (tgev) due to the specific binding of the spike protein s to apn. in the present study, we performed both biological and biochemical experiments to analyze how the level of expression of a virus receptor can influence the viral protein biosynthesis and the virus production. we generated two swine testis cell clones overexpressing papn (st-apn clones). these clones produced 10(4) less infectio ... | 1995 | 8830512 |
| complete genomic sequence of the transmissible gastroenteritis virus. | | 1995 | 8830524 |
| evidence for a pseudoknot in the 3' untranslated region of the bovine coronavirus genome. | a potential pseudoknot was found in the 3' untranslated region of the bovine coronavirus genome beginning 63 nt downstream from the stop codon of the n gene. mutation analysis of the pseudoknot in a cloned defective interfering rna indicated that this structural element is necessary for defective interfering rna replication. | 1995 | 8830533 |
| characterization of the transmissible gastroenteritis virus (tgev) transcription initiation sequence. characterization of tgev tis. | the ability of the tgev transcription initiation sequence (tis) to produce subgenomic rnas was investigated by placing a reporter gene, chloramphenicol acetyltransferase (cat) under the control of either the mrna 6 or the mrna 7 tiss. both constructs only produced cat in tgev infected cells and the amount of cat produced from the mrna 7 tis was less than from the mrna 6 tis. mutations were made within and around the tiss and the effect on cat production assayed. the results showed that the tgev ... | 1995 | 8830536 |
| pedv leader sequence and junction sites. | | 1995 | 8830538 |
| molecular bases of tropism in the pur46 cluster of transmissible gastroenteritis coronaviruses. | transmissible gastroenteritis coronavirus (tgev) infects both, the enteric and the respiratory tract of swine. s protein, that is recognized by the cellular receptor, has been proposed that plays an essential role in controlling the dominant tropism. the genetic relationship of s gene from different enteric strains and non-enteropathogenic porcine respiratory coronaviruses (prcvs) was determined. a correlation between tropism and the genetic structure of the s gene was established. prcvs, derive ... | 1995 | 8830541 |
| structure and encapsidation of transmissible gastroenteritis coronavirus (tgev) defective interfering genomes. | serial undiluted passages were performed with the pur46 strain of tgev in swine testis (st) cells. total cellular rna was analyzed at different passages after orthophosphate metabolic labeling. three new defective rna species of 24, 10.5, and 9.5 kb (di-a, di-b, and di-c respectively) were detected at passage 30, which were highly stable and significantly interfered with helper mrna synthesis in subsequent passages. by northern hybridization dis a, b, and c were detected in purified virions at a ... | 1995 | 8830546 |
| comparison of the amino acid sequence and phylogenetic analysis of the peplomer, integral membrane and nucleocapsid proteins of feline, canine and porcine coronaviruses. | complete nucleotide sequences were determined by cdna cloning of peplomer (s), integral membrane (m) and nucleocapsid (n) genes of feline infectious peritonitis virus (fipv) type i strain ku-2, ucd1 and black, and feline enteric coronavirus (fecv) type ii strain 79-1683. only m and n genes were analyzed in strain ku-2 and strain 79-1683 which still had unknown nucleotide sequences. deduced amino acid sequences of s, m and n proteins were compared in a total of 7 strains of coronaviruses, which i ... | 1996 | 8839428 |
| a murine and a porcine coronavirus are released from opposite surfaces of the same epithelial cells. | 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 immuno ... | 1996 | 8862433 |
| in situ hybridization technique for the detection of swine enteric and respiratory coronaviruses, transmissible gastroenteritis virus (tgev) and porcine respiratory coronavirus (prcv), in formalin-fixed paraffin-embedded tissues. | the in situ hybridization (ish) technique was developed to detect the swine coronaviruses, transmissible gastroenteritis virus (tgev) and porcine respiratory coronavirus (prcv), in cell culture and tissue sections from tgev-or prcv-infected pigs. the 35s-labeled rna probes were generated from two plasmids ppsp.fp1 and ppsp.fp2 containing part of the s gene of tgev. the procedure was first standardized in cell cultures. the radiolabeled ppsp.fp2 probe detected both tgev and prcv in virus-inoculat ... | 1996 | 8882645 |
| characterization of functional domains in the human coronavirus hcv 229e receptor. | human aminopeptidase n (hapn or cd13) and porcine aminopeptidase n (papn) are functional receptors for human coronavirus (hcv) 229e and porcine transmissible gastroenteritis virus (tgev), respectively. however, hapn cannot function as a receptor for tgev and papn cannot function as a receptor for hcv 229e. in this study, we constructed a series of chimeric hapn/papn genes and expressed the corresponding proteins in transfected cells. subsequently, we identified the chimeric proteins that can fun ... | 1996 | 8887485 |
| feline aminopeptidase n serves as a receptor for feline, canine, porcine, and human coronaviruses in serogroup i. | two members of coronavirus serogroup i, human respiratory coronavirus hcv-229e and porcine transmissible gastroenteritis virus (tgev), use aminopeptidase n (apn) as their cellular receptors. these viruses show marked species specificity in receptor utilization, as hcv-229e can utilize human but not porcine apn, while tgev can utilize porcine but not human apn. to determine whether feline apn could serve as a receptor for two feline coronaviruses in serogroup i, feline infectious peritonitis viru ... | 1996 | 8970993 |
| the major subunit clpg of escherichia coli cs31a fibrillae as an expression vector for different combinations of two tgev coronavirus epitopes. | previously, two b-cell epitopes from the entero-pathogenic transmissible gastroenteritis virus (tgev), namely the c epitope (tgev-c) amino acids (aa) 363-371 and the a epitope (tgev-a) aa 522-531 of the spike s protein (tgev-s), have been separately expressed on the cs31a fibrillae at the surface of escherichia coli following insertion into a same region of clpg. however, the resulting chimeras induced a marginal tgev-neutralizing antibody (ab) response in mice. here, with the view to improving ... | 1996 | 8972902 |
| interspecies aminopeptidase-n chimeras reveal species-specific receptor recognition by canine coronavirus, feline infectious peritonitis virus, and transmissible gastroenteritis virus. | we report that cells refractory to canine coronavirus (ccv) and feline infectious peritonitis virus (fipv) became susceptible when transfected with a chimeric aminopeptidase-n (apn) cdna containing a canine domain between residues 643 and 841. this finding shows that apn recognition by these viruses is species related and associated with this c-terminal domain. the human/canine apn chimera was also able to confer susceptibility to the porcine transmissible gastroenteritis virus (tgev), whereas i ... | 1997 | 8985407 |
| mucosal immunity: an overview and studies of enteric and respiratory coronavirus infections in a swine model of enteric disease. | based on the tenet of a common mucosal immune system, antigenic stimulation at one mucosal site results in the distribution of antigen-specific iga precursor cells to distant mucosal sites. however, recent studies suggest that functional compartmentalization and limited reciprocity may exist within some components of the common mucosal immune system. although oral immunization is often very effective in inducing immunity to respiratory pathogens, the converse (respiratory immunization to prevent ... | 1996 | 8988861 |
| mouse hepatitis virus strain a59 is released from opposite sides of different epithelial cell types. | 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 ... | 1997 | 9010286 |
| two amino acid changes at the n-terminus of transmissible gastroenteritis coronavirus spike protein result in the loss of enteric tropism. | to study the molecular basis of tgev tropism, a collection of recombinants between the pur46-mad strain of transmissible gastroenteritis coronavirus (tgev) infecting the enteric and respiratory tracts and the ptv strain, which only infects the respiratory tract, was generated. the recombinant isolation frequency was about 10(-9) recombinants per nucleotide and was 3.7-fold higher at the 5'-end of the s gene than in other areas of the genome. thirty recombinants were plaque purified and character ... | 1997 | 9018137 |
| cooperation between transmissible gastroenteritis coronavirus (tgev) structural proteins in the in vitro induction of virus-specific antibodies. | following infection of haplotype defined nih-miniswine with virulent transmissible gastroenteritis coronavirus (tgev), isolated mesenteric lymph node cd4+ t-cells mounted a specific proliferative response against infectious or inactivated purified virus in secondary in vitro stimulation. a specific, dose-dependent response to the three major recombinant viral proteins: spike (s), membrane (m), and nucleoprotein (n), purified by affinity chromatography, was characterized. induction of in vitro an ... | 1996 | 9029784 |
| development of a nested pcr assay for detection of feline infectious peritonitis virus in clinical specimens. | a diagnostic test for feline infectious peritonitis virus (fipv) infection based on a nested pcr (npcr) assay was developed and tested with fipv, feline enteric coronavirus (fecv), canine coronavirus (ccv), and transmissible gastroenteritis virus (tgev) and clinical fluid samples from cats with effusive feline infectious peritonitis (fip). the target sequence for the assay is in the s1 region of the peplomer protein e2 gene. a vaccine strain of fipv and two wild-type fipv strains tested positive ... | 1997 | 9041410 |
| active and passive immune responses to transmissible gastroenteritis virus (tgev) in swine inoculated with recombinant baculovirus-expressed tgev spike glycoprotein vaccines. | baculovirus-expressed transmissible gastroenteritis virus (tgev) spike (s) glycoprotein vaccines were inoculated parenterally in swine to determine whether such vaccines could induce serum and whey virus-neutralizing (vn) antibodies and protective lactogenic immunity for tgev-challenge-exposed pigs. animals and procedures: 3 recombinant baculoviruses that expressed full or partial length tgev miller strain s glycoproteins were inoculated sc in 17 conventionally raised 11-day-old tgev-seronegativ ... | 1997 | 9055968 |
| point mutations in the s protein connect the sialic acid binding activity with the enteropathogenicity of transmissible gastroenteritis coronavirus. | enteropathogenic transmissible gastroenteritis virus (tgev), a porcine coronavirus, is able to agglutinate erythrocytes because of sialic acid binding activity. competitive inhibitors that may mask the sialic acid binding activity can be inactivated by sialidase treatment of virions. here, we show that tgev virions with efficient hemagglutinating activity were also obtained when cells were treated with sialidase prior to infection. this method was used to analyze tgev mutants for hemagglutinatin ... | 1997 | 9060696 |
| 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. | 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 ... | 1997 | 9066025 |
| rapid diagnosis of porcine epidemic diarrhea virus infection by polymerase chain reaction. | the diagnosis of porcine epidemic diarrhea virus (pedv) infection in the laboratory is rather fastidious because of difficulties in virus propagation. the feasibility of virus propagation in vivo is also limited by the handling of a number of samples at the same time. in this study, the detection of pedv by reverse transcription polymerase chain reaction (rt-pcr) is described. the rt-pcr could detect up to 10(4) tcid50/ml of pedv and did not show any cross reaction with transmissible gastroenter ... | 1997 | 9101487 |
| reconstituted coronavirus tgev virosomes lose the virus ability to induce porcine interferon-alpha production. | the transmissible gastroenteritis virus (tgev) is a coronavirus which induces a strong interferon-alpha (ifn-alpha) production in vivo and in vitro. previous studies have shown that the tgev external protein m plays a major role in ifn-alpha induction by a non-infectious virus, whereas protein s is not involved. the present study extended these results by showing that monoclonal antibodies (mabs) directed at the external viral protein sm could not block ifn-alpha induction, which argues against ... | 1997 | 9112732 |
| detection of porcine respiratory coronavirus and transmissible gastroenteritis virus by an enzyme-linked immunosorbent assay. | an enzyme-linked immunosorbent assay (elisa) for the detection of transmissible gastroenteritis virus (tgev) and porcine respiratory coronavirus (prcv) was developed. a bovine tgev-specific polyclonal antibody was purified by affinity chromatography with the trio bioprocessing system and was used as the capture antibody, at a concentration of 1.5 micrograms/well. the f5.39 monoclonal antibody was obtained by the fusion of spleen lymphocytes from tgev immunized mice with ns-1 myeloma cells. this ... | 1994 | 9133060 |
| reconstituted coronavirus tgev virosomes lose the virus ability to induce porcine interferon-alpha production. | the transmissible gastroenteritis virus (tgev) is a coronavirus which induces a strong interferon-alpha (ifn-alpha) production in vivo and in vitro. previous studies have shown that the tgev external protein m plays a major role in ifn-alpha induction by a non-infectious virus, whereas protein s is not involved. the present study extended these results by showing that monoclonal antibodies (mabs) directed at the external viral protein sm could not block ifn-alpha induction, which argues against ... | 1997 | 9172843 |
| interference of coronavirus infection by expression of immunoglobulin g (igg) or iga virus-neutralizing antibodies. | immunoglobulin gene fragments encoding the variable modules of the heavy and light chains of a transmissible gastroenteritis coronavirus (tgev)-neutralizing monoclonal antibody (mab) have been cloned and sequenced. the selected mab recognizes a highly conserved viral epitope and does not lead to the selection of neutralization escape mutants. the sequences of mab 6a.c3 kappa and gamma 1 modules were identified as subgroup v and subgroup iiic, respectively. the chimeric immunoglobulin genes encod ... | 1997 | 9188593 |
| an overview of immunological and genetic methods for detecting swine coronaviruses, transmissible gastroenteritis virus, and porcine respiratory coronavirus in tissues. | transmissible gastroenteritis (tge) is an enteric disease of swine caused by a coronavirus, designated as transmissible gastroenteritis virus (tgev). commonly used methods for tgev detection include viral isolation and detection of the viral antigen by indirect immunofluorescence (ifa), immunoperoxidase, and immunogold silver staining. each of these techniques has some advantages and disadvantages. in general ifa and immunohistochemistry are preferred over viral isolation as tgev isolation is no ... | 1997 | 9191988 |
| pathogenicity and sequence analysis studies suggest potential role of gene 3 in virulence of swine enteric and respiratory coronaviruses. | coronaviruses have been commonly associated with enteric and respiratory diseases. two of the swine coronaviruses, namely transmissible gastroenteritis virus (tgev) and porcine respiratory coronavirus (prcv), have been extensively studied. tgev replicates in both the enteric and respiratory tracts and causes enteric disease, whereas, prcv replicates in the respiratory tract with limited to no replication in the enteric tract. we have isolated prcv from swine herds with respiratory disease and ha ... | 1997 | 9192036 |
| development of pcr-based techniques to identify porcine transmissible gastroenteritis coronavirus isolates. | sixteen isolates of transmissible gastroenteritis virus and one isolate of porcine respiratory coronavirus were characterized using rt-pcr amplification of 4 antigenic subsites in the site a epitope on the tgev spike gene. the pcr products were digested with restriction enzymes sau3ai and sspi and the sizes of the fragments were determined. three different digestion patterns were observed with each enzyme. the recognition site for sau3ai was missing in 1 isolate, was present in 13 isolates and 3 ... | 1997 | 9242995 |
| detection of transmissible gastroenteritis virus by rt-pcr and differentiation from porcine respiratory coronavirus. | an rt-pcr method was developed that amplified genetic material from the 5' end of the s protein gene of both transmissible gastroenteritis virus (tgev) and porcine respiratory coronavirus (prcv), but discriminated between the two by the size of the product generated. a number of restriction endonuclease enzymes were assessed for recognition of the amplicons so produced. the assay was shown to detect viral rna from all of the 26 different tgev and prcv isolates examined, covering a period from 19 ... | 1997 | 9255741 |
| rapid in situ hybridization technique for the detection of ribonucleic acids in tissues using radiolabelled and fluorescein-labelled riboprobes. | in situ hybridization (ish) is a useful diagnostic and research tool, but is also time consuming. this study was conducted to determine if a rate enhancement hybridization (reh) buffer, developed for membrane hybridization, could be used to decrease hybridization time for ish. tissue from swine with an enteric disease produced by a swine coronavirus, transmissible gastroenteritis virus (tgev), was used as a model to standardize hybridization conditions for a rapid ish technique. small intestinal ... | 1997 | 9281413 |
| in vivo study of interferon-alpha-secreting cells in pig foetal lymphohaematopoietic organs following in utero tgev coronavirus injection. | non-infectious uv-inactivated transmissible gastroenteritis virus (tgev) was previously shown to induce interferon alpha (ifn alpha) secretion following in vitro incubation with blood mononuclear cells. in this study, pig foetuses at different stages of gestation were injected in utero with (a) partially uv-inactivated wild tgev or (b) fully uv-inactivated wild or dm49-4 mutant tgev coronavirus. nucleated cells from foetal liver, bone marrow, spleen and blood were isolated 10 or 20 h after injec ... | 1997 | 9300531 |
| coronavirus genomic and subgenomic minus-strand rnas copartition in membrane-protected replication complexes. | the majority of porcine transmissible gastroenteritis coronavirus plus-strand rnas (genome and subgenomic mrnas), at the time of peak rna synthesis (5 h postinfection), were not found in membrane-protected complexes in lysates of cells prepared by dounce homogenization but were found to be susceptible to micrococcal nuclease (85%) or to sediment to a pellet in a cesium chloride gradient (61%). they therefore are probably free molecules in solution or components of easily dissociable complexes. b ... | 1997 | 9311859 |
| in vivo induction of interferon-alpha in pig by non-infectious coronavirus: tissue localization and in situ phenotypic characterization of interferon-alpha-producing cells. | a low frequency peripheral blood mononuclear cell (pbmc) subpopulation, referred to as natural interferon-producing (nip) cells, is described as producing interferon-alpha (ifn-alpha) following contact with non-infectious viral structures, namely viral glycoproteins. these cells are characterized in vitro as non-t, non-b, mhc class ii+ and cd4+ cells. in this study, nip cells were analysed in vivo after an intravenous injection of uv-inactivated transmissible gastroenteritis virus in newborn pig ... | 1997 | 9349468 |
| identification of residues critical for the human coronavirus 229e receptor function of human aminopeptidase n. | aminopeptidase n (apn) is the major cell surface receptor for group 1 coronaviruses. in this study, we have isolated and characterized a feline apn cdna and shown that the transfection of human embryonic kidney cells with this cdna renders them susceptible to infection with the feline coronavirus feline infectious peritonitis virus, the human coronavirus (hcv) 229e and the porcine coronavirus porcine transmissible gastroenteritis virus. by using chimeric apn genes, assembled from porcine and fel ... | 1997 | 9367365 |
| the viral spike protein is not involved in the polarized sorting of coronaviruses in epithelial cells. | coronaviruses are assembled by budding into a pre-golgi compartment from which they are transported along the secretory pathway to leave the cell. in cultured epithelial cells, they are released in a polarized fashion; depending on the virus and cell type, they are sorted preferentially either to the apical domain or to the basolateral plasma membrane domain. in this study, we investigated the role of the coronavirus spike protein, because of its prominent position in the virion the prime sortin ... | 1998 | 9420251 |
| the coronavirus transmissible gastroenteritis virus causes infection after receptor-mediated endocytosis and acid-dependent fusion with an intracellular compartment. | aminopeptidase n is a species-specific receptor for transmissible gastroenteritis virus (tgev), which infects piglets, and for the 229e virus, which infects humans. it is not known whether these coronaviruses are endocytosed before fusion with a membrane of the target cell, causing a productive infection, or whether they fuse directly with the plasma membrane. we have studied the interaction between tgev and a cell line (mdck) stably expressing recombinant pig aminopeptidase n (papn). by electro ... | 1998 | 9420255 |
| direct and rapid detection of porcine epidemic diarrhea virus by rt-pcr. | to establish a practical method for detecting porcine epidemic diarrhea virus (pedv), the use of primers derived from sequences that amplify the m protein genes of pedv in a rt-pcr detection system was investigated. primers were designed to amplify a 854-bp fragment by rt-pcr. this reaction was specific to the pedv rna but not to that of other viral genera tested. in experiments with mixtures of pedv and either small intestine or fecal homogenates, this method could detect efficiently the pedv r ... | 1997 | 9504764 |
| development and evaluation of an elisa to measure antibody responses to both the nucleocapsid and spike proteins of canine coronavirus. | a rapid and reproducible enzyme linked immunosorbent assay (elisa) was developed for detection of canine coronavirus (ccv) specific antibodies directed to both the nucleocapsid (nc) and the spike (s) proteins. the coating antigen, a methanol-treated, s-protein enriched preparation, was produced by subjecting infected cells to triton x-114 detergent followed by phase separation. the sensitivity of this assay was determined by following the course of infection in dogs experimentally infected with ... | 1998 | 9530608 |
| wapping gastroenteritis with transgenic antibodies. | | 1998 | 9555720 |
| engineering passive immunity in transgenic mice secreting virus-neutralizing antibodies in milk. | protection against enteric infections can be provided by the oral administration of pathogen-neutralizing antibodies. to provide passive immunity, 18 lines of transgenic mice secreting a recombinant monoclonal antibody (mab) neutralizing transmissible gastroenteritis coronavirus (tgev) into the milk were generated. the genes encoding a chimeric mab with the variable modules of the murine tgev-specific mab 6a.c3 and the constant modules of a human igg, isotype mab were expressed under the control ... | 1998 | 9555725 |
| transgenic mice secreting coronavirus neutralizing antibodies into the milk. | ten lines of transgenic mice secreting transmissible gastroenteritis coronavirus (tgev) neutralizing recombinant monoclonal antibodies (rmabs) into the milk were generated. the rmab light- and heavy-chain genes were assembled by fusing the genes encoding the variable modules of the murine mab 6a.c3, which binds an interspecies conserved coronavirus epitope essential for virus infectivity, and a constant module from a porcine myeloma with the immunoglobulin a (iga) isotype. the chimeric antibody ... | 1998 | 9557658 |