Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038362 (stomatitis)
8,852 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Persistent influenza C virus infection was readily initiated in Madin-Darby canine kidney (MDCK) cells at low m.o.i. and has been maintained for over 1 year. The persistently infected (p.i.) cultures were characterized by the following properties: virus infection was limited to a minority of cells, small amounts of infectious virus were produced together with low levels of interferon (IFN) and the cultures were resistant to superinfection by homologous virus and vesicular stomatitis virus, but not by influenza A and B viruses. These properties fluctuated cyclically with passage of the p.i. culture. When p.i. cultures were cured by cultivation in the presence of antiserum, the cultures lost their IFN-producing activity and became as susceptible to homologous virus as normal MDCK cell culture. The results suggest that persistent influenza C virus infection may be regulated by endogenously produced IFN. Under the condition of high m.o.i. a persistent influenza C virus infection could not be initiated in MDCK cells due to the development of cytopathic effects.
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PMID:Persistent infection of MDCK cells by influenza C virus: initiation and characterization. 248 13

A procedure is described to select mutants of Chinese hamster ovary cells that are conditionally defective for the cell-surface expression of integral membrane glycoproteins, including the hemagglutinin (HA) of influenza virus. Using a combination of cell sorting and biochemical screening, seven cell lines were obtained that express more cell-surface HA at 32 degrees C than at 39 degrees C. The production of infectious vesicular stomatitis virus, whose growth requires insertion of an integral membrane protein into the plasma membrane, was also temperature conditional in the majority of these mutant cell lines. Five of the lines synthesized apparently normally core-glycosylated HA at the elevated temperature but the protein was neither displayed on the cell surface nor accumulated intracellularly. In these cell lines, little or no terminally glycosylated HA molecules were observed after synthesis at 39 degrees C. By contrast, the core glycosylation of HA and several other integral membrane proteins was abnormal in the remaining two cell lines at both permissive and restrictive temperatures, due to a lesion in a cellular gene(s) that affects the formation of and/or the addition of mannose-rich oligosaccharide chains to newly synthesized polypeptides. Although HA was transported to the plasma membrane at both 32 and 39 degrees C, it did not accumulate on the cell surface at the higher temperature, apparently because of an increased rate of degradation.
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PMID:Isolation of Chinese hamster ovary cell lines temperature conditional for the cell-surface expression of integral membrane glycoproteins. 253 14

The interferon-inducible gene (IFI-78K gene) that codes for a human protein, p78, of 78,000 Mr is the equivalent of the mouse Mx gene encoding Mx protein. The IFI-78K gene is located on chromosome 21 together with the alpha/beta interferon (IFN-alpha/beta) receptor. The p78 protein is important since it may be involved in resistance to influenza viruses. The regulation of the IFI-78K gene was studied in human diploid cells by using a cDNA probe to p78 mRNA and specific monoclonal antibodies to p78 protein. The IFI-78K gene, a normally quiescent gene, is transcriptionally regulated by IFN-alpha, and its induction does not require protein synthesis. The rate of transcription measured in a run-on assay increased rapidly but transiently. The level of p78 mRNA increased up to 8 h, declining slowly afterwards. The p78 protein, undetectable in untreated cells, accumulated up to 16 h, and its amount remained stable for at least 36 h after the addition of IFN-alpha. Cytokines such as tumor necrosis factor, interleukin-1 alpha, and interleukin-1 beta activated the IFI-78K gene at concentrations comparable to that of IFN-alpha. However, gene activation by these cytokines required protein synthesis. Poly(rI)-poly(rC) induced the IFI-78K gene directly at the transcriptional level without requirement for protein synthesis. Newcastle disease virus, influenza virus, and to a lesser extent vesicular stomatitis virus also induced the IFI-78K gene in the absence of any protein synthesis. Induction of transcription by viruses was markedly enhanced by pretreatment of cells with IFN-gamma (which by itself is a poor inducer of the IFI-78K gene), resulting in accumulation of p78 protein during the course of infection; this suggests that IFN-gamma programs cells to full antiviral activity upon virus infection.
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PMID:Regulation of the interferon-inducible IFI-78K gene, the human equivalent of the murine Mx gene, by interferons, double-stranded RNA, certain cytokines, and viruses. 254 74

When synthesized in polarized epithelial cells, the envelope glycoproteins hemagglutinin of influenza and G of vesicular stomatitis virus are targeted to the apical and basolateral plasma membranes, respectively. To determine which portions of these transmembrane proteins contain information necessary for their sorting, the behavior of two different G-hemagglutinin chimeric polypeptides, consisting of all or nearly all the luminal portion of the vesicular stomatitis virus G protein linked to C-terminal segments of influenza hemagglutinin that included its transmembrane and cytoplasmic domains, was studied in MDCK cells transformed with the corresponding cDNAs. Both chimeras were transported from the endoplasmic reticulum to the Golgi apparatus and from there to the cell surface with the same rapid kinetics as the intact G protein. By using a cell surface immunoprecipitation assay with monolayers cultured on permeable filters that allows the recovery of labeled protein molecules present in each cell surface domain, it was found that both chimeric proteins as well as the intact G protein were delivered almost exclusively to the basolateral surface. This polarized distribution of the polypeptides did not change during a subsequent 90-min chase period, although during this time a large fraction of the glycoprotein molecules underwent degradation. In addition, a small fraction of the cell surface-associated glycoprotein molecules shed their ectoplasmic segments into the basolateral compartment, apparently as a result of a proteolytic cleavage. Immunofluorescence on transverse frozen sections and immunoelectron microscopy revealed a prominent accumulation of the chimeric polypeptides in the lateral cell membranes, with lesser amounts on the basal and apical surfaces. These results indicate that information specifying the basolateral transport of the G glycoprotein is located within the first 426 N-terminal amino acids of its ectoplasmic portion.
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PMID:A sorting signal for the basolateral delivery of the vesicular stomatitis virus (VSV) G protein lies in its luminal domain: analysis of the targeting of VSV G-influenza hemagglutinin chimeras. 254 64

The cDNA derived from the Newcastle disease virus (NDV) hemagglutinin-neuraminidase (HN) gene was inserted into a replication-competent Schmidt-Ruppin Rous sarcoma virus-derived vector. Chick embryo cells transfected with this vector expressed HN-sized protein which could be precipitated with anti-HN antibody. These cells adsorbed avian red blood cells and the cell surfaces exhibited neuraminidase activity while cells transfected with an antisense version of the gene were negative for hemadsorption and neuraminidase. The cells transfected with the retroviral vector containing the HN gene were resistant to infection by NDV and influenza virus, viruses which bind to sialic acid containing receptors, but sensitive to vesicular stomatitis virus (VSV). Cells transfected with the antisense version of the HN gene were sensitive to NDV, influenza virus, and VSV infection. Thus the HN protein-expressing cells are likely resistant to NDV and influenza virus due to the destruction of the cellular receptors by the neuraminidase of the HN protein. The expression of the influenza virus HA protein using the same retrovirus vector has been reported previously (L. A. Hunt, D. W. Brown, H. L. Robinson, C. W. Naeve, and R. G. Webster, 1988, J. Virol. 62, 3014-3019). Cells infected with this vector were sensitive to infection with influenza virus, NDV, and VSV. Thus expression of a viral surface protein does not necessarily confer resistance of the cell to the homologous virus.
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PMID:Avian cells expressing the Newcastle disease virus hemagglutinin-neuraminidase protein are resistant to Newcastle disease virus infection. 254 25

Infection with vesicular stomatitis virus (VSV) results in the rapid inhibition of cellular macromolecular synthesis, including transcription, translation, and maturation of the U1 and U2 snRNPs. Unlike infection with VSV, influenza virus infection did not result in the inhibition of either the processing of U1 and U2 snRNAs or the assembly of the RNPs. Although influenza virus relies on the cellular splicing apparatus to generate viral mRNAs, the maturation of snRNPs was inhibited during double infections with VSV. However, this inhibition of snRNP maturation had no effect on the splicing of a cellular pre mRNA in extracts prepared from VSV-infected HeLa cells. Thus, the effects of VSV on the processing and assembly of snRNPs appear to involve virus-specific functions and unique cellular targets. Coinfection with VSV and influenza virus resulted in the dramatic inhibition of influenza virus transcription; polyadenylated mRNAs corresponding to the influenza virus NP and NS1 proteins could not be detected by Northern blot analysis. However, reduced levels of the influenza virus replicative templates were still synthesized during double infection. Coinfection with VSV also resulted in the inhibition of influenza viral mRNA translation, even when superinfection with VSV was delayed until 3 or 6 hr after influenza virus infection. VSV required at least 2 hr to affect the inhibition of translation; this corresponded to the time after VSV infection when inhibition of cellular protein synthesis was evident. These results demonstrate that, in contrast to adenovirus, the VSV-mediated inhibition of cellular macromolecular synthesis may be effective against influenza virus.
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PMID:Inhibitory effects of vesicular stomatitis virus on cellular and influenza viral RNA metabolism and protein synthesis. 254 15

Although there are notable infectious conditions that are capable of producing clinical disease in the NWC, overall, these species are quite healthy. Of the bacterial diseases, enterotoxemia caused by Clostridium perfringens types C and D would be deemed the most significant in North America, while type A also would be regarded as important in South America. Other important bacterial infections of potential concern are tuberculosis, Johne's disease, anthrax, malignant edema, actinomycosis, tetanus, and the South American condition referred to as alpaca fever, which, to date, has not been observed in North America. Fungal infections include classical ringworm, principally caused by Trichophyton spp., and the cases of coccidioidomycosis that are associated with the arid desert lands of the southwestern United States. Most notable of naturally occurring viral infections in the NWC would be rabies, ecthyma, and a recently described blindness neuropathy that has been associated with the equine herpesvirus I. NWC can be infected experimentally with agents causing hoof-and-mouth disease and vesicular stomatitis, but naturally occurring cases do not seem to occur. Serological evidence of exposure to many viral agents, including blue tongue, parainfluenza 3, bovine respiratory syncytial virus, bovine herpesvirus I, bovine viral diarrhea, influenza A, and rotavirus, has been demonstrated; however, no clinical disease associated with these agents, as yet, is apparent.
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PMID:Infectious diseases of New-World camelids (NWC). 264 31

A novel immunopotentiating agent, 5-amino-3-beta-D-ribofuranosylthiazolo [4,5-d]pyrimidine-2,7(3H,6H)-dione (7-thia-8-oxoguanosine), lacks virus-inhibitory properties in vitro but induces interferon and potentiates immune functions, such as natural killer cell activity. It was evaluated in rodent models to determine the spectrum of antiviral activity and effective treatment regimens. At 50 to 200 mg/kg given as single or divided intraperitoneal (i.p.) doses 1 day before virus inoculation, significant protection was afforded to mice infected i.p. with Semliki Forest, San Angelo, banzi, and encephalomyocarditis viruses. Similarly, suckling rats were protected from an intranasal challenge with rat coronavirus. Against San Angelo virus, treatments could be delayed to 1 day post-virus inoculation and still show a beneficial effect. The compound was moderately effective in mice infected i.p. with herpes simplex virus type 2 or intranasally with vesicular stomatitis virus. No activity was seen against influenza B virus in mice when the analog was administered one time pre-virus inoculation or in multiple doses given before and after the virus inoculation. Nor was there a prophylactic effect against herpetic skin lesions on mice. This immune modulator may have promise for the treatment of a variety of virus infections.
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PMID:Broad-spectrum in vivo antiviral activity of 7-thia-8-oxoguanosine, a novel immunopotentiating agent. 281 49

Infection of the retina with herpes simplex virus type 1 (HSV-1) causes devastating lesions usually leading to blindness. However, the interactions between individual retinal cell types and this virus have not been well characterized, probably because of limitations posed by the complexity of the intact retina. We have now approached this problem through the use of separate, purified populations of isolated chick embryo retinal neurons and photoreceptor cells, of glial cells, and of pigmented epithelial cells. This manuscript deals with the initial part of these studies, aimed at determining the susceptibility of different retinal types to HSV-1 infection. The different cultures were exposed to HSV-1 for 3-48 hr, and cell infection was evaluated by immunocytochemical detection of viral antigens or by autoradiographic study of viral DNA replication. Practically 100% of the retinal glial cells and pigmented epithelial cells appeared susceptible to HSV-1 infection. On the other hand, as many as 70% of the neurons present in glia-free, pigment epithelium-free cultures, also appeared infected after a 24-hr exposure to the virus. Neuronal susceptibility to HSV-1 was already present in early (2-day) cultures, was time- and concentration-dependent, and led to neuronal degeneration after 24-48 hr. Neuronal infection was also corroborated by the detection of viral particles by transmission electron microscopy. Photoreceptor cells were consistently and selectively resistant to HSV-1 infection at all the concentrations and time points investigated. Both immunocytochemical and autoradiographic studies showed similar results. Photoreceptor resistance to HSV-1 appears to be selective, since they could be readily infected with RNA viruses such as vesicular stomatitis virus and influenza virus. These cell culture preparations offer an attractive system for the investigation of cellular mechanisms involved in the differential susceptibility of retinal cells to viral infection. Moreover, they could also help in the screening of treatments potentially capable of preventing and (or) curing HSV-induced retinal infection.
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PMID:Differential sensitivity of cultured retinal neurons and photoreceptors to herpes simplex infection. 282 Jul 71

We have used monospecific antisera to two lysosomal membrane glycoproteins, lgp120 and a similar protein, lgp110, to compare the biosynthesis and intracellular transport of lysosomal membrane components, plasma membrane proteins, and lysosomal enzymes. In J774 cells and NRK cells, newly synthesized lysosomal membrane and plasma membrane proteins (the IgG1/IgG2b Fc receptor or influenza virus hemagglutinin) were transported through the Golgi apparatus (defined by acquisition of resistance to endo-beta-N-acetylglucosaminidase H) with the same kinetics (t1/2 = 11-14 min). In addition, immunoelectron microscopy of normal rat kidney cells showed that lgp120 and vesicular stomatitis virus G-protein were present in the same Golgi cisternae demonstrating that lysosomal and plasma membrane proteins were not sorted either before or during transport through the Golgi apparatus. To define the site at which sorting occurred, we compared the kinetics of transport of lysosomal and plasma membrane proteins and a lysosomal enzyme to their respective destinations. Newly synthesized proteins were detected in dense lysosomes (lgp's and beta-glucuronidase) or on the cell surface (Fc receptor or hemagglutinin) after the same lag period (20-25 min), and accumulated at their final destinations with similar kinetics (t1/2 = 30-45 min), suggesting that these two lgp's are not transported to the plasma membrane before reaching lysosomes. This was further supported by measurements of the transport of membrane-bound endocytic markers from the cell surface to lysosomes, which exhibited additional lag periods of 5-15 min and half-times of 1.5-2 h. The time required for transport of newly synthesized plasma membrane proteins to the cell surface, and for the transport of plasma membrane markers from the cell surface to lysosomes would appear too long to account for the rapid transport of lgp's from the Golgi apparatus to lysosomes. Thus, the observed kinetics suggest that lysosomal membrane proteins are sorted from plasma membrane proteins at a post-Golgi intracellular site, possibly the trans Golgi network, before their delivery to lysosomes.
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PMID:Kinetics of intracellular transport and sorting of lysosomal membrane and plasma membrane proteins. 282 Oct 12


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