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)

Interferons (IFNs) act by inducing several intracellular antiviral proteins. We report here that IFNs also induce an extracellular soluble protein that inhibits vesicular stomatitis virus (VSV) infection. This protein accounts for 25%-50% of the total antiviral activity elicited by IFN. The antiviral protein was purified to homogeneity from culture supernatants of IFN-treated cells by several chromatographic steps, to give a single 28-kDa active polypeptide. Upon sequencing, this novel protein corresponded to the N-terminal ligand-binding domain of the human 160-kDa low-density lipoprotein receptor (LDLR). In addition, we find that IFN induces the cell surface LDLR and this phenomenon may explain previous reports on reduction of serum cholesterol in IFN-treated patients. Viruses produce soluble cytokine receptors that inhibit their respective cytokines, thereby assisting virus infection. It appears now that host cells employ similar molecules for the opposite role of controlling virus infections.
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PMID:Isolation and characterization of a soluble form of the LDL receptor, an interferon-induced antiviral protein. 751 46

We have previously reported the generation of pseudotype virus from chimeric gene constructs encoding the ectodomain of the E1 or E2 glycoprotein of hepatitis C virus (HCV) genotype 1a appended to the trans membrane domain and cytoplasmic tail of the vesicular stomatitis virus (VSV) G protein. Sera derived from chimpanzees immunized with homologous HCV glycoproteins neutralized pseudotype virus infectivity (L. M. Lagging et al., J. Virol. 72, 3539-3546, 1998). We have now extended this study to further understand the role of HCV glycoproteins in pseudotype virus entry. Although a number of mammalian epithelial cells were susceptible to VSV/HCV pseudotype virus infection, plaquing efficiency was different among host cell lines. Pseudotype virus adsorption at low temperature decreased plaque numbers. Treatment of E1 or E2 pseudotype virus in media between pH 5 and 8 before adsorption on cells did not significantly reduce plaque numbers. On the other hand, treatment of cells with lysosomotropic agents or inhibitors of vacuolar H(+) ATPases had an inhibitory role on virus entry. Concanavalin A, a plant lectin, exhibited neutralization of both HCV E1 and E2 pseudotype virus infectivity. However, mannose binding protein, a C-type mammalian lectin, did not neutralize virus in the absence or presence of serum complement. Pseudotype virus infectivity was only partially inhibited by heparin, a highly sulfated glycosaminoglycan, in a saturable manner. Additional studies suggested that low-density lipoprotein receptor related molecules partially inhibit E1 pseudotype virus infectivity, while CD81 related molecules interfere with E2 pseudotype virus infectivity. A further understanding of HCV entry and strategies appropriate for mimicking cell surface molecules may help in the development of new therapeutic modalities against HCV infection.
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PMID:Functional features of hepatitis C virus glycoproteins for pseudotype virus entry into mammalian cells. 1102 9

In mammalian cells and yeasts, amino acid motifs in the cytoplasmic tails of transmembrane proteins play a prominent role in protein targeting in the early secretory pathway by mediating localization to or rapid export from the endoplasmic reticulum (ER). However, early sorting events are poorly characterized in protozoan parasites. Here, we show that a C-terminal QKTT sequence mediates the ER localization of chimeric reporter constructs consisting of bacterial alkaline phosphatase (BAP) fused to the transmembrane domain (TMD) and truncated cytoplasmic tail of the human low-density lipoprotein receptor (LDL) receptor or of murine lysosome-associated membrane protein (lamp-1) in Toxoplasma gondii. The cytoplasmic tail of human TGN46 also determines ER localization of BAP chimeras in the parasite, but this can be overcome by the addition at the C-terminus of the tail of an acidic patch, which functions as an ER export signal in conjunction with an upstream tyrosine motif. These results suggest that COPI-dependent ER retrieval and COPII-dependent export mechanisms mediated by KKXX and DXE motifs of mammalian cells are generally conserved in T. gondii. In contrast, the failure of the QKTT motif and TGN46 cytoplasmic tail to induce steady-state ER localization of vesicular stomatitis virus glycoprotein (VSVG) chimeras in HeLa and NRK cells indicates that significant differences in early secretory trafficking also exist.
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PMID:Cytoplasmic tail motifs mediate endoplasmic reticulum localization and export of transmembrane reporters in the protozoan parasite Toxoplasma gondii. 1120 9

We have developed an ex vivo gene transfer technique to rabbit arterial wall using autologous smooth muscle cells (SMCs). SMCs were harvested from rabbit ear artery, transduced in vitro with vesicular stomatitis virus G-glycoprotein pseudotyped retrovirus or feline immunodeficiency virus (FIV) and returned to the adventitial surface of the carotid artery using a periadventitial silicone collar or collagen sheet placed around the artery. Beta-galactosidase (lacZ) and human apolipoprotein E3 (apoE3) cDNAs were used as transgenes. After retrovirus-mediated gene transfer of lacZ the selected cells implanted with high efficiency and expressed lacZ marker gene at a very high level 7 and 14 days after the operation. The level of lacZ expression decreased thereafter but was still detectable 12 weeks after the gene transfer, and was exclusively localized to the site of cell implantation inside the collar. Utilizing FIV vector expressing apoE3, low levels of apoE were measured from serum collected from a low-density lipoprotein receptor deficient Watanabe heritable hyperlipidemic rabbits 1 month after the gene transfer. The physiological effect of apoE expression was detected as transiently elevated serum cholesterol levels. The results indicate that the model can be used for high efficiency local gene transfer in arteries, e.g. during vascular surgery. The model is also valuable for studying expression, stability and safety of new gene transfer vectors and their expression products in vivo.
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PMID:Feline immunodeficiency virus and retrovirus-mediated adventitial ex vivo gene transfer to rabbit carotid artery using autologous vascular smooth muscle cells. 1501 Feb 68

We sought proof of principle that tumor-targeting ligands can be displayed on the surface of vesicular stomatitis virus (VSV) by engineering its glycoprotein. Here, we successfully rescued VSVs displaying tumor vasculature-targeting ligands. By using a rational approach, we investigated various feasible insertion sites on the G protein of VSV (VSV-G) for display of tumor vasculature-targeting ligands, cyclic RGD (cRGD) and echistatin. We found seven sites on VSV-G that tolerated insertion of the 9-residue cRGD peptide, two of which could tolerate insertion of the 49-amino acid echistatin domain. All of the ligand-displaying viruses replicated as well as the parental virus. In vitro studies demonstrated that the VSV-echistatin viruses specifically bound to targeted integrins. Since the low-density lipoprotein receptor (LDLR) was recently identified as a major receptor for VSV, we investigated the entry of ligand-displaying viruses after masking LDLR. The experiment showed that the modified viruses can enter the cell independently of LDLR, whereas entry of unmodified virus is significantly blocked by a specific monoclonal antibody against LDLR. Both parental and ligand-displaying viruses displayed equal oncolytic efficacies in a syngeneic mouse myeloma model. We further demonstrated that single-chain antibody fragments against tumor-specific antigens can be inserted at the N terminus of the G protein and that corresponding replication-competent VSVs can be rescued efficiently. Overall, we demonstrated that functional tumor-targeting ligands can be displayed on replication-competent VSVs without perturbing viral growth and oncolytic efficacy. This study provides a rational foundation for the future development of fully retargeted oncolytic VSVs.
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PMID:Characteristics of oncolytic vesicular stomatitis virus displaying tumor-targeting ligands. 2408 73

Production of a vesicular stomatitis virus spike protein G (VSVG)-pseudotyped lentiviral expression vector in HEK293 cells decreased on overexpression of low-density lipoprotein receptor (LDLR) but not that of ICAM1 or TfR1. Reverse transcription-quantitative PCR (RT-qPCR) revealed a reduction in vector RNA as a function of LDLR expression. Decreased syncytium formation suggested diminished surface expression of VSVG. Intracellular VSVG granules colocalized with LDLR, ER-Golgi intermediate compartment protein 53 (ERGIC53), LAMP2, and vimentin but not with GM130 or calnexin, suggesting that VSVG interacts with LDLR within the ERGIC, resulting in rerouting into the aggresome/autophagosome pathway.
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PMID:Release of Vesicular Stomatitis Virus Spike Protein G-Pseudotyped Lentivirus from the Host Cell Is Impaired upon Low-Density Lipoprotein Receptor Overexpression. 2633 60

Familial hypercholesterolemia (FH) is an autosomal dominant disease most often caused by mutations in the low-density lipoprotein receptor (LDLR) gene, which consists of 18 exons spanning 45 kb and codes for a precursor protein of 860 amino acids. Mutations in the LDLR gene lead to a reduced hepatic clearance of LDL as well as a high risk of coronary artery disease (CAD) and sudden cardiac death (SCD). Recently, LDLR transgenes have generated interest as potential therapeutic agents. However, LDLR packaging using a lentiviral vector (LVV) system pseudotyped with a vesicular stomatitis virus (VSV)-G envelope is not efficient. In this study, we modified the LVV system to improve transduction efficiency and investigated the LDLR regions responsible for transduction inhibition. Transduction efficiency of 293T cells with a 5'-LDLReGFP-3' fusion construct was only 1.55% compared to 42.32% for the eGFP construct. Moreover, co-expression of LDLR affected eGFP packaging. To determine the specific region of the LDLR protein responsible for packaging inhibition, we designed constructs with mutations or sequential deletions at the 3' and 5' ends of LDLR cDNA. All constructs except one without the ligand-binding domain (LBD) (pWoLBD-eGFP) resulted in low transduction efficiency, despite successful packaging of viral RNA in the VSV envelope, as confirmed through RT-PCR. When we evaluated a direct interaction between LDLR and the VSV envelope glycoprotein using MD simulation and protein-protein interactions, we uncovered Val119, Thr120, Thr67, and Thr118 as exposed residues in the LDLR receptor that interact with the VSV protein. Together, our results suggest that the LBD of LDLR interacts with the VSV-G protein during viral packaging, which significantly reduces transduction efficiency.
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PMID:Molecular Dynamics Simulation Reveals Exposed Residues in the Ligand-Binding Domain of the Low-Density Lipoprotein Receptor that Interacts with Vesicular Stomatitis Virus-G Envelope. 3173 79