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)

Helical instability induced by gly residues in the transmembrane domain (TMD) of G protein, the fusion protein of vesicular stomatitis virus (VSV), was speculated to aid in the later steps of the fusion process, because G protein with ala's substituted for the two TMD gly's was inactive (Cleverley, D. Z., and Lenard, J. (1998) Proc. Natl. Acad. Sci. U. S. A. 95, 3425-30). Here we examine the conformations of synthetic peptides corresponding to fusion-active (GGpep) and inactive (AApep; G's replaced by A's) TMDs by CD spectroscopy, and then their effects on the kinetics of poly (ethyleneglycol) (PEG)-mediated fusion of small unilamellar vesicles. GGpep and AApep both assumed history-dependent, non-interconvertible ordered structures. Both peptides were largely helical under all conditions if derived from trifluoroethanol solutions, and aggregated in a beta-sheet form if derived from acetonitrile solutions. In solvent, detergents or lipid bilayers, GGpep showed a greater range of secondary structural features than did AApep. The two peptides had large but different effects on PEG-mediated fusion. Both enhanced the rate but not the extent of lipid mixing. AApep significantly inhibited the extent of fusion pore formation while GGpep had no effect. The initial rate of fusion was enhanced 6-fold by GGpep and less than 2-fold by AApep. Addition of 5 mol % hexadecane overrode all peptide-induced effects. We suggest that both GGpep and hexadecane promote pore formation by stabilizing the nonlamellar structures in fusion intermediates or initial small pores. AApep, which had fewer nonhelical features in its CD spectrum than GGpep, actually inhibited fusion pore formation.
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PMID:VSV transmembrane domain (TMD) peptide promotes PEG-mediated fusion of liposomes in a conformationally sensitive fashion. 1247 41

The vesicular stomatitis virus cytopathic effect reduction assay is suitable to quantify polyethylene glycol-alpha interferon 2a (PEG-IFN-alpha 2a) and PEG-IFN-alpha 2b. Human serum and ribavirin did not interfere with the assay. This bioassay was successfully used for assaying PEG-IFN-alpha 2a and PEG-IFN-alpha 2b in serum samples from patients undergoing combination therapy.
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PMID:Convenient biological assay for polyethylene glycol-interferons in patients with hepatitis C. 1532 40

The development of pegylated interferons (PEG-IFN) has significantly improved the eradication rates in patients with chronic hepatitis C. Two forms of PEG-IFN have been developed, based on two pegylation chemistries: the 12-kDa linear PEG-IFN-alpha2b and the 40-kDa branched PEG-IFN-alpha2a. We compared the in vitro antiviral activity of linear and branched PEG-IFN using the vesicular stomatitis virus (VSV) cytopathic effect (CPE) reduction assay. The specific antiviral activity of branched PEG-IFN was 7% of that of linear PEG-IFN. A given quantity of linear and of branched PEG-IFN does not represent the same biologic activity. A bioassay could give new insights to compare the pharmacokinetic profile of linear PEG-IFN and of branched PEG-IFN.
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PMID:Pegylation of IFN-alpha and antiviral activity. 1723 27

Type I interferons (IFNs) inhibit viral replication and cell growth and enhance the immune response, and therefore have many clinical applications. IFN-alpha2b ranks third in world market use for a biopharmaceutical, behind only insulin and erythropoietin. The average annual cost of IFN-alpha2b for the treatment of hepatitis C infection is $26,000, and is therefore unavailable to the majority of patients in developing countries. Therefore, we expressed IFN-alpha2b in tobacco chloroplasts, and transgenic lines were grown in the field after obtaining United States Department of Agriculture Animal and Plant Health Inspection Service (USDA-APHIS) approval. Stable, site-specific integration of transgenes into chloroplast genomes and homoplasmy through several generations were confirmed. IFN-alpha2b levels reached up to 20% of total soluble protein, or 3 mg per gram of leaf (fresh weight). Transgenic IFN-alpha2b had similar in vitro biological activity to commercially produced PEG-Introntrade mark when tested for its ability to protect cells against cytopathic viral replication in the vesicular stomatitis virus cytopathic effect (VSV CPE) assay and to inhibit early-stage human immunodeficiency virus (HIV) infection. The antitumour and immunomodulating properties of IFN-alpha2b were also seen in vivo. Chloroplast-derived IFN-alpha2b increased the expression of major histocompatibility complex class I (MHC I) on splenocytes and the total number of natural killer (NK) cells. Finally, IFN-alpha2b purified from chloroplast transgenic lines (cpIFN-alpha2b) protected mice from a highly metastatic tumour line. This demonstration of high levels of expression of IFN-alpha2b, transgene containment and biological activity akin to that of commercial preparations of IFN-alpha2b facilitated the first field production of a plant-derived human blood protein, a critical step towards human clinical trials and commercialization.
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PMID:Field production and functional evaluation of chloroplast-derived interferon-alpha2b. 1749 Apr 49

As with standard plasmid vectors, it is possible to transfect lentivectors in plasmid form into cells with low-to-medium efficiency to obtain transient expression of effectors. Packaging lentiviral expression constructs into pseudoviral particles, however, enables up to 100% transduction, even with difficult-to-transfect cells, such as primary, stem, and differentiated cells. Moreover, the lentiviral delivery does not produce the specific cellular responses typically associated with chemical transfections, such as cell death resulting from toxicity of the transfection reagent. When transduced into target cells, the lentiviral construct integrates into genomic DNA and provides stable expression of the small hairpin RNA (shRNA), cDNA, microRNA or reporter gene. Target cells stably expressing the effector molecule can be isolated using a selectable marker contained in the expression vector construct such as puromycin or GFP. After pseudoviral particles infect target cells, they cannot replicate within target cells because the viral structural genes are absent and the long terminal repeats (LTRs) are designed to be self-inactivating upon transduction. There are three main components necessary for efficient lentiviral packaging. 1. The lentiviral expression vector that contains some of the genetic elements required for packaging, stable integration of the viral expression construct into genomic DNA, and expression of the effector or reporter. 2. The lentiviral packaging plasmids that provide the proteins essential for transcription and packaging of an RNA copy of the expression construct into recombinant pseudoviral particles. This protocol uses the pPACK plasmids (SBI) that encode for gag, pol, and rev from the HIV or FIV genome and Vesicular Stomatitis Virus g protein (VSV-G) for the viral coat protein. 3. 293TN producer cells (derived from HEK293 cells) that express the SV40 large T antigen, which is required for high-titer lentiviral production and a neomycin resistance gene, useful for reselecting the cells for maintenance. An overview of the viral production protocol can be seen in Figure 1. Viral production starts by co-transfecting 293TN producer cells with the lentiviral expression vector and the packaging plasmids. Viral particles are secreted into the media. After 48-72 hours the cell culture media is harvested. Cellular debris is removed from the cell culture media, and the viral particles are precipitated by centrifugation with PEG-it for concentration. Produced lentiviral particles are then titered and can be used to transduce target cells. Details of viral titering are not included in this protocol, but can be found at: http://www.systembio.com/downloads/global_titer_kit_web_090710.pdf. This protocol has been optimized using the specific products indicated. Other reagents may be substituted, but the same results cannot be guaranteed.
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PMID:Packaging HIV- or FIV-based lentivector expression constructs and transduction of VSV-G pseudotyped viral particles. 2250 77