Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0019158 (hepatitis)
 30,205 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Coronaviruses have a marked tropism for epithelial cells. Entry and release of the porcine transmissible gastroenteritis virus (TGEV) is restricted to apical surfaces of polarized epithelial cells, as we have recently shown (J. W. A. Rossen, C. P. J. Bekker, W. F. Voorhout, G. J. A. M. Strous, A. van der Ende, and P. J. M. Rottier, 1994, J. Virol. 68, 7966-7973). In this paper we analyze the interactions of mouse hepatitis coronavirus A59 (MHV-A59) with polarized murine kidney cells (mTAL) grown on permeable supports. After inoculation from the apical or basolateral side, virus entry was found to take place only through the apical membrane. The virus utilized a protein of the carcinoembryonic antigen family as its receptor. In contrast to TGEV, MHV-A59 was released preferentially from the basolateral plasma membrane domain, as evidenced by the accumulation of viral proteins and infectivity in the basolateral culture fluid as well as by electron microscopical observations. In the mouse, MHV initially replicates in the nasal epithelium before being disseminated throughout the body; the basolateral release of MHV from epithelial cells into the animal's circulation may be the first step in the establishment of a systemic infection.
 ...
PMID:MHV-A59 enters polarized murine epithelial cells through the apical surface but is released basolaterally. 779 80

The entire nucleotide sequence of cloned cDNAs containing the 5'-untranslated region and gene 1 of Purdue-115 strain of transmissible gastroenteritis virus (TGEV) was determined. This completes the sequence of the TGEV genome, which is 28,579 nucleotides long. The gene 1 is composed of two large open reading frames, ORF1a and ORF1b, which contain 4017 and 2698 codons, respectively (stop excluded). A brief, three-codon-long ORF is present upstream of ORF1a. ORF1b overlaps ORF1a by 43 bases in the (-1) reading frame. In vitro experiments indicated that translation of the ORF1a/b polyprotein involves an efficient ribosomal frameshifting activity, as previously shown for other coronaviruses. Analysis of the predicted ORF1a and ORF1b translation products revealed that the putative functional domains identified in infectious bronchitis virus (IBV), mouse hepatitis virus (MHV) and human coronavirus 229E (HCV 229E) are all present in TGEV. The amino-terminal half of the ORF1a product exhibits greater divergence than the carboxyl-terminal half, including within the TGEV/HCV229E pair. The ORF1b protein is overall highly conserved among the above four coronaviruses, except a divergent region situated near the carboxy terminus.
 ...
PMID:Complete sequence (20 kilobases) of the polyprotein-encoding gene 1 of transmissible gastroenteritis virus. 785 95

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

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-PK1 cells occurred preferentially from the apical plasma membrane domain, as evidenced by the accumulation of viral proteins and infectivity in the apical culture fluid. In contrast, MHV was released preferentially from the basolateral membrane of mTAL cells. The apical release of TGEV and the basolateral release of MHV may explain the in vivo establishment of a local and systemic infection, respectively.
 ...
PMID:Coronaviruses in polarized epithelial cells. 883 Apr 69

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

On the basis of biochemical, phenotypic, and 16S rRNA analysis, a novel gram-negative bacterium, isolated from normal and diarrheic dogs as well as humans with gastroenteritis, has been recently named Helicobacter canis. A 2-month-old female crossbred puppy was submitted to necropsy with a history of weakness and vomiting for several hours prior to death. The liver had multiple and slightly irregular yellowish foci up to 1.5 cm in diameter. Histologically, the liver parenchyma contained randomly distributed, occasionally coalescing hepatocellular necrosis, often accompanied by large numbers of mononuclear cells and neutrophils. Sections of liver stained by the Warthin-Starry silver impregnation technique revealed spiral- to curve-shaped bacteria predominantly located in bile canaliculi and occasionally in bile ducts. Aerobic culture of liver was negative, whereas small colonies were noted on Campylobacter selective media after 5 days of microaerobic incubation. The bacteria were gram negative and oxidase positive but catalase, urease, and indoxyl acetate negative; nitrate was not reduced to nitrite, and the organism did not hydrolyze hippurate. The bacteria were also resistant to 1.5% bile. Electron microscopy revealed spiral-shaped bacteria with bipolar sheathed flagella. By 16S rRNA analysis, the organism was determined to be H. canis. This is the first observation of H. canis in active hepatitis in a dog and correlates with recent findings of Helicobacter hepaticus- and Helicobacter bilis-related hepatic disease in mice. Further studies are clearly warranted to ascertain whether H. canis-associated hepatitis is more widespread in canines as well as a cause of previously classified idiopathic liver disease in humans.
 ...
PMID:Helicobacter canis isolated from a dog liver with multifocal necrotizing hepatitis. 888 May 4

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 virus (FIPV) and feline enteric coronavirus (FeCV), we cloned the cDNA encoding feline APN (fAPN) by PCR from cDNA isolated from a feline cell line and stably expressed it in FIPV- and FeCV-resistant mouse and hamster cells. The predicted amino acid sequence of fAPN shows 78 and 77% identity with human and porcine APN, respectively. When inoculated with either of two biologically different strains of FIPV or with FeCV, fAPN-transfected mouse and hamster cells became infected and viral antigens developed in the cytoplasm. Infectious FIPV was released from hamster cells stably transfected with fAPN. The fAPN-transfected mouse and hamster cells were challenged with other coronaviruses in serogroup I including canine coronavirus, porcine coronavirus TGEV, and human coronavirus HCV-229E. In addition to serving as a receptor for the feline coronaviruses, fAPN also served as a functional receptor for each of these serogroup I coronaviruses as shown by development of viral antigens in the cytoplasm of infected mouse or hamster cells stably transfected with fAPN. In contrast, fAPN did not serve as a functional receptor for mouse hepatitis virus (MHV-A59), which is in serogroup II and utilizes mouse biliary glycoprotein receptors unrelated to APN. Thus, fAPN serves as a receptor for a much broader range of group I coronaviruses than human and porcine APNs. The human, porcine, and canine coronaviruses in serogroup I that are able to use fAPN as a receptor have previously been shown to infect cats without causing disease. Therefore, host factors in addition to receptor specificity apparently affect the virulence and transmissibility of nonfeline serogroup I coronaviruses in the cat.
 ...
PMID:Feline aminopeptidase N serves as a receptor for feline, canine, porcine, and human coronaviruses in serogroup I. 897 Sep 93

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

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 sorting candidate, in the directionality of virus release. Three independent approaches were taken. (i) The inhibition of N glycosylation by tunicamycin resulted in the synthesis of spikeless virions. The absence of spikes, however, did not influence the polarity in the release of virions. Thus, murine hepatitis virus strain A59 (MHV-A59) was still secreted from the basolateral membranes of mTAL and LMR cells and from the apical sides of MDCK(MHVR) cells, whereas transmissible gastroenteritis virus (TGEV) was still released from the apical surfaces of LMR cells. (ii) Spikeless virions were also studied by using the MHV-A59 temperature-sensitive mutant Albany 18. When these virions were produced in infected LMR and MDCK(MHVR) cells at the nonpermissive temperature, they were again preferentially released from basolateral and apical membranes, respectively. (iii) We recently demonstrated that coronavirus-like particles resembling normal virions were assembled and released when the envelope proteins M and E were coexpressed in cells (H. Vennema, G.-J. Godeke, J. W. A. Rossen, W. F. Voorhout, M. C. Horzinek, D.-J. E. Opstelten, and P. J. M. Rottier, EMBO J. 15:2020-2028, 1996). The spikeless particles produced in mTAL cells by using recombinant Semliki Forest viruses to express these two genes of MHV-A59 were specifically released from basolateral membranes, i.e., with the same polarity as that of wild-type MHV-A59. Our results thus consistently demonstrate that the spike protein is not involved in the directional sorting of coronaviruses in epithelial cells. In addition, our observations with tunicamycin show that contrary to the results with some secretory proteins, the N-linked oligosaccharides present on the viral M proteins of coronaviruses such as TGEV also play no role in viral sorting. The implications of these conclusions are discussed.
 ...
PMID:The viral spike protein is not involved in the polarized sorting of coronaviruses in epithelial cells. 942 Feb 51

Twenty-six unclassified Campylobacter-like strains previously isolated from 15 chicken carcasses and caecal contents, together with two more strains isolated from chicken faeces on a different occasion, were identified as Helicobacter pullorum using various phenotypic identification methods. API Campy identification kits and a 16-test identification scheme developed for campylobacters failed to identify these bacteria, or identified them as Campylobacter spp. Eighteen strains (including the two isolated on a different occasion) were chosen for examination using a more comprehensive probabilistic identification scheme. Using this method, 14 of the 18 strains were identified as H. pullorum with ID scores > 95%; two strains were also identified as H. pullorum with lower ID scores. Of the remaining two strains, one was not identified with this scheme and the other was misidentified to the H. acinonyx pylori complex. Whole cell protein profiling by SDS-PAGE confirmed the identity of these isolates as H. pullorum, affirming the value of a polyphasic approach for accurately identifying campylobacteria. The comparatively high prevalence of H. pullorum in poultry determined in this study (60%) suggests that routine isolation and identification methods should be amended to enable a thorough evaluation of its role in human gastroenteritis and avian hepatitis. Some phenotypic characters useful in identifying poultry campylobacteria are presented which could be utilized, along with other technique(s), for improved differentiation of the campylobacteria that are found in poultry.
 ...
PMID:Identification of unusual Campylobacter-like isolates from poultry products as Helicobacter pullorum. 971 86


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>