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)

Feline leukemia viruses (FeLVs) belonging to the C subgroup induce aplastic anemia in domestic cats and have the ability, unique among FeLV strains, to proliferate in guinea pig fibroblasts in tissue culture. Previous studies have shown that the pathogenic and host range specificity of a prototype molecular clone of FeLV-C [FeLV-Sarma-C (FSC)] colocalize to a region encoding the 3' 73 amino acids of the pol gene product and the N-terminal 241 amino acids of the envelope surface glycoprotein named SU. Here, we amplified, via PCR, cloned, and sequenced the SU coding sequence from three additional anemia-inducing subgroup C FeLV isolates. Chimeric viruses were constructed by replacement of fragments of FeLV-C envelope genes into the FeLV-A prototype virus 61E. Using a modified vesicular stomatitis virus-FeLV pseudotype assay, we demonstrated that the subgroup C receptor specificity for each virus was determined by changes within the N-terminal 87-92 amino acids of SU, in which most changes occurred within the 15- to 20-amino-acid first variable region (V1). Determinants for growth in guinea pig cells colocalized to this region. Despite the consistent localization of biological determinants, the only consistent features that distinguished the deduced FeLV-A and FeLV-C proteins was one lysine-to-arginine change and a structural prediction of an alpha-helix in FeLV-A proteins versus random coil in FeLV-C proteins within V1. However, arginine in equilibrium with lysine substitutions were not sufficient to convert the subgroup A virus to the subgroup C phenotype or vice versa. Thus, certain distinct structural changes within the N-terminal region of FeLV SU can result in convergent viral phenotypes.
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PMID:Feline leukemia virus subgroup C phenotype evolves through distinct alterations near the N terminus of the envelope surface glycoprotein. 132 57

The cDNA encoding interferon-induced human double-stranded RNA-activated p68 kinase was expressed in murine NIH 3T3 cells by using the pcDNA1/neo vector. Several stable clones were selected which expressed either the wild-type kinase or an inactive mutant possessing a single amino acid substitution in the invariant lysine 296 in the catalytic domain II. The transfected wild-type kinase showed properties similar to those of the natural kinase, such as subcellular ribosomal localization and dependence on double-stranded RNA for autophosphorylation. Upon infection with encephalomyocarditis virus (EMCV), wild-type- but not mutant-expressing clones were found to partially resist virus growth. Such natural antiviral activity was virus specific, since no inhibition was observed in the case of vesicular stomatitis virus infection. In accord with EMCV inhibition, the wild-type p68 kinase was found to be highly phosphorylated during infection. Furthermore, its natural substrate, the small subunit of protein synthesis initiation factor eIF2, was phosphorylated. These results demonstrate that p68 kinase is activated during EMCV infection, leading to reduced virus production.
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PMID:Constitutive expression of human double-stranded RNA-activated p68 kinase in murine cells mediates phosphorylation of eukaryotic initiation factor 2 and partial resistance to encephalomyocarditis virus growth. 138 42

Several trinitrophenyl (TNP)-specific mouse cytotoxic T cell (CTL) clones recognize TNP-conjugated peptides in association with class I MHC molecules ('hapten-peptide determinants'). However, cell modification with trinitrobenzene sulfonic acid (TNBS) also leads to the formation of TNP determinants covalently attached to MHC molecules ('altered self'). To determine the importance of 'peptide' versus 'altered self' determinants, we used the mutant cell line RMA-S which expresses peptide-free ('empty') Kb and Db molecules at 26 degrees C. Additionally, we stabilized Kb molecules on RMA-S cells at 37 degrees C using the Kb binding heptapeptide N53-59 derived from the vesicular stomatitis virus nucleoprotein. Lacking lysine, this peptide remains unmodified by TNBS and, therefore, only allows the formation of 'altered self' TNP determinants on occupied Kb molecules. RMA-S targets, pretreated or untreated with N53-59, upon TNBS modification were only lysed poorly or not at all by four different TNP-specific CTL. In contrast, all of these clones efficiently lysed TNBS-treated, unmutated RMA cells, and three of them strongly reacted with RMA or RMA-S cells in the presence of tryptic TNP-BSA peptides. Moreover, the clone unreactive for TNP-BSA peptides also recognized TNP self-peptides extracted from TNBS-treated syngeneic spleen cells. Taken together, these data clearly show that TNP residues linked to MHC via associated peptides but not by covalent bondage represent the dominant antigenic epitopes for class I MHC-restricted, hapten-specific T cells.
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PMID:Peptide-conjugated hapten groups are the major antigenic determinants for trinitrophenyl-specific cytotoxic T cells. 138 86

The importance of electrostatic interactions in the early phases of vesicular stomatitis virus (VSV) infection has been investigated in susceptible cells of different origin, human (HeLa) and avian (CER), by using some polyanions (heparin, polygalacturonic acid and mucin) and polycations (polymyxin B sulphate, poly-L-lysine, protamine, histone and polybrene). In HeLa cells, the attachment of VSV was enhanced by polymers having a positive charge and inhibited by those having a negative charge. In CER cells, all the polyanions tested reduced virus infection. Among the polycations, histone, polymyxin B sulphate and poly-L-lysine enhanced virus plaque formation while protamine and polybrene reduced virus attachment. The effect of polyions on VSV particles and on cell membrane receptors has also been investigated. The analysis of the results obtained suggest that, although electrostatic interactions play an essential role in the binding of VSV to the cell membrane, more specific structural features appear to be required for viral attachment to occur.
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PMID:Electrostatic interactions in the early events of VSV infection. 164 50

2'-5'-oligoadenylate synthetases constitute a multimember family of interferon-inducible enzymes which need double-stranded RNA as an obligatory cofactor. We have isolated cDNA clones for two new murine synthetases. These two clones, 9-2 and 3-9, encoded proteins of 414 and 363 amino acid residues, respectively, out of which the amino terminal 346 residues were almost identical. They were also very similar to the corresponding regions of human synthetases E16 and E18. On the other hand, the carboxyl-terminal 68 residues of clone 9-2 had no homology with the carboxyl-terminal residues of E18. These murine clones had only 67% amino acid identity with the previously isolated murine synthetase clone L3. 9-2 and 3-9 proteins were expressed efficiently by in vitro transcription and translation of cDNA clones containing the synthetase coding regions preceded by the 5'-untranslated region of the vesicular stomatitis virus NS gene. These in vitro synthetized proteins bound to double-stranded RNA and catalyzed the synthesis of 2'-5' oligoadenylates. A nested set of deletion mutants of the 9-2 clone was produced by restriction digestion and polymerase chain reaction. Functional testing of the corresponding truncated proteins revealed that a region between amino acid residues 104 and 158 was necessary for binding to double-stranded RNA and a region between residues 320 and 344 was necessary for enzyme activity. Moreover substitution of the lysine residue at position 333 by arginine did not affect the enzyme activity.
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PMID:Cloning, sequencing, and expression of two murine 2'-5'-oligoadenylate synthetases. Structure-function relationships. 165 24

We have previously shown that antisense oligomers linked to poly(L-lysine) (PLL) exhibit antiviral properties against vesicular stomatitis virus (VSV) at concentrations lower than 1 microM. The conjugation to PLL provides an interesting alternative to natural or neutral oligomers to increase the biological effects of antisense oligomers. The internalization pathway of oligomer-PLL conjugates as compared to unconjugated oligomers has been studied in L929 cells. In parallel to their enhanced antiviral activity, PLL increases greatly the uptake of fluorescently tagged oligomers. This internalization follows a classical endocytic pathway and the oligomer has to be cleaved from PLL in the cell to exhibit an antiviral effect.
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PMID:Biological activity of oligonucleotide-poly(L-lysine) conjugates: mechanism of cell uptake. 196 25

Murine bone-marrow-culture-derived-macrophages can be differentially activated to lyse either vesicular stomatitis virus infected BALB/c3T3 cells or the tumor target P815. Macrophages were activated in a manner so that they could lyse both targets. The ability of this activated population to lyse either target type was differentially inhibited by varying the assay conditions. The lysis of P815 targets was more sensitive to inhibition by the proteinase inhibitor N-p-tosyl-L-lysine chloromethyl ketone than was the lysis of virally infected cells. On the other hand, reduction of the concentration of glucose in the assay medium, which inhibits the production of oxygen metabolites by the hexose monophosphate shunt, or the addition of anti-tumor necrosis factor (anti-TNF) serum were able to decrease the lysis of virally infected targets but not P815 targets. Thus, the observed differences in the lysis of these two targets were due to both the activation state of the macrophages and the differential susceptibility of the targets to different effector mechanisms.
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PMID:Activated macrophages use different cytolytic mechanisms to lyse a virally infected or a tumor target. 216 99

Synthetic oligonucleotides (oligomers) complementary to vesicular stomatitis virus (VSV) N protein mRNA have specific antiviral properties at concentrations lower than 1 microM when they are covalently linked to poly(L-lysine) (PLL). Since it is generally postulated that antisense oligomers act at the translational level, oligomers with potential targets on VSV viral mRNA and/or genomic RNA have been tested here. In vitro translation experiments in reticulocyte lysates, in vitro transcription experiments with permeabilized viruses, measurement of viral RNA transcription and accumulation in VSV infected cells, and antiviral experiments demonstrate in our model that antisense oligomers probably also act at other levels. Difficulties in the choice of the most effective antisense oligomer targets are also discussed.
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PMID:Antiviral activity and possible mechanisms of action of oligonucleotides-poly(L-lysine) conjugates targeted to vesicular stomatitis virus mRNA and genomic RNA. 247 15

The matrix (M) protein of vesicular stomatitis virus (VSV) has a major antigenic determinant (epitope 1) that maps to a region extending from amino acids 19 through 43 and transcription-inhibition activity that maps to the first 43 N-terminal amino acids (J.R. Ogden, R. Pal, and R. R. Wagner, J. Virol. 58:860-868, 1986). The M protein of temperature-sensitive mutant tsO23(III) is devoid of epitope 1 and transcription-inhibition activity and substitutes glutamic acid for glycine at amino acid 21 as well as having amino acid substitutions at positions 111 and 227 (K. Morita, R. Vanderoef, and J. Lenard, J. Virol. 61:256-263, 1987). We undertook to map more precisely epitope 1 and the transcription-inhibition region of VSV M protein by means of synthetic oligopeptides generated by an automated solid-phase protein synthesizer. A pentadecapeptide designated PI(wt, Gly21), corresponding to amino acids 17 to 31 of wild-type (wt) M protein, strongly bound monoclonal antibody MAb2 (directed to epitope 1); however, an analogous pentadecapeptide with glutamic acid substituted for glycine at position 21, designated PII(tsO23, Glu21), completely failed to recognize MAb2. Polyclonal antibody raised in rabbits immunized with PI(wt, Gly21) reacted strongly with wt M protein, the homologous pentadecapeptide, and, to a lesser extent, PII(tsO23, Glu21). Anti-PII(tsO23, Glu21) failed to recognize PI(wt, Gly21) or wt M protein. Anti-PI(wt, Gly21) competed efficiently for binding of MAb2 to wt M protein and was as effective as MAb2 in reversing inhibition of VSV transcription by wt M protein. Neither PI(wt, Gly21) nor PII(tsO23, Glu21) exhibited any ability to inhibit VSV transcription. However, a lysine-rich oligopeptide, PII(Met1-Leu20), corresponding to the first 20 N-terminal amino acids of wt M protein, and polylysine itself did inhibit VSV transcription, albeit much less efficiently than native wt M protein. Monospecific polyclonal antibody directed to the 20-mer oligopeptide PIII(Met1-Leu20) reversed transcription inhibition by M protein in a dose-dependent manner almost identical to that of anti-PI(wt, Gly21) and epitope 1-specific MAb2. Examination by circular dichroism spectropolarimetry revealed significant differences in the conformation of the two pentadecapeptides attributable to the Gly in equilibrium Glu amino acid substitution at position 21.
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PMID:Antigenicity, function, and conformation of synthetic oligopeptides corresponding to amino-terminal sequences of wild-type and mutant matrix proteins of vesicular stomatitis virus. 283 87

Short (14 to 20-mer range) synthetic oligodeoxyribonucleotides (oligos) allow to modulate specifically viral or cellular gene expression at various stages thus providing a versatile tool for fundamental studies and a rational approach to antiviral chemotherapy. Several problems, such as metabolic stability and efficient cell internalization of oligos, still limit this approach appreciably, as briefly discussed here. We demonstrate here that the conjugation of 15-mer (beta)-anomeric oligos to poly(L-lysine) allows a specific protection of various cell lines against vesicular stomatitis virus infection at concentrations lower than 1 microM. This can be achieved with oligos complementary to the viral N-protein mRNA initiation site or to viral intergenic sequences, i.e., to untranscribed regions. No antiviral activity can be obtained with (alpha)-anomeric oligos directed against the same targets, although such analogues are much more resistant to nuclease degradation and form stable hybrids, at least in cell-free experiments.
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PMID:Antiviral activity of conjugates between poly(L-lysine) and synthetic oligodeoxyribonucleotides. 285 89


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