scholarly journals Development of a Novel Marker Gene Based Assay System for Detection and Evaluation of Antiviral Agents with Activity against Papillomaviruses

1991 ◽  
Vol 2 (6) ◽  
pp. 363-370 ◽  
Author(s):  
K. May ◽  
D. N. Planterose ◽  
M. J. Browne ◽  
R. M. Perkins
Keyword(s):  
Retinoic Acid ◽  
Human Papillomavirus ◽  
Marker Gene ◽  
Antiviral Agents ◽  
Assay System ◽  
Cell Phenotype ◽  
Bovine Papillomavirus ◽  
Tissue Plasminogen

A novel assay system has been developed in which expression of a human tissue-plasminogen activator (t-PA) gene, carried on a recombinant papillomavirus vector, is used as a marker for the presence of bovine papillomavirus type 1 (BPV-1) within transformed mouse C127 cells. This provides a relatively quick and simple means of identifying and evaluating agents with anti-papillomavirus activity. Using this system the antiviral activity and cytotoxicity of interferon and retinoic acid, have been investigated. After seven subcultures in the presence of 200 Units ml−1 mouse α and β interferon, t-PA expression was completely inhibited, with a concurrent alteration in cellular morphology, and restoration of contact inhibition. In accordance with the problems encountered with interferon therapy of human papillomavirus infections, these effects were dependent on the continued presence of interferon, its removal leading to a rapid return of t-PA expression, and reversion of cells to the transformed phenotype. In comparison, 2.0 μg ml−1 retinoic acid partially reduced t-PA expression (this effect was largely maintained even after removal of the inhibiting compound) but did not affect the transformed cell phenotype. These results are discussed in relation to other in vitro studies and also to the clinical treatment of human papillomavirus (HPV) disease.

scholarly journals Bovine papillomavirus type 1 oncoprotein E5 inhibits equine MHC class I and interacts with equine MHC I heavy chain

2009 ◽  
Vol 90 (12) ◽  
pp. 2865-2870 ◽  
Author(s):  
Barbara Marchetti ◽  
Elisabeth A. Gault ◽  
Marc S. Cortese ◽  
ZhengQiang Yuan ◽  
Shirley A. Ellis ◽  
...  
Keyword(s):  
Heavy Chain ◽  
Class I ◽  
Bovine Papillomavirus ◽  
Class I Mhc ◽  
Mhc I ◽  
Reading Frame ◽  
Histocompatibility Complex ◽  
Human Telomerase

Bovine papillomavirus type 1 is one of the aetiological agents of equine sarcoids. The viral major oncoprotein E5 is expressed in virtually all sarcoids, sarcoid cell lines and in vitro-transformed equine fibroblasts. To ascertain whether E5 behaves in equine cells as it does in bovine cells, we introduced the E5 open reading frame into fetal equine fibroblasts (EqPalF). As observed in primary bovine fibroblasts (BoPalF), E5 by itself could not immortalize EqPalF and an immortalizing gene, such as human telomerase (hTERT/hT), was required for the cells to survive selection. The EqPalF-hT-1E5 cells were morphologically transformed, elongated with many pseudopodia and capable of forming foci. Equine major histocompatibility complex class I (MHC I) was inhibited in these cells at least at two levels: transcription of MHC I heavy chain was inhibited and the MHC I complex was retained in the Golgi apparatus and prevented from reaching the cell surface. We conclude that, as in bovine cells and tumours, E5 is a player in the transformation of equine cells and the induction of sarcoids, and a potential major cause of MHC I downregulation and hence poor immune clearance of tumour cells.

scholarly journals Novel bis-Tetrahydrofuranylurethane-Containing Nonpeptidic Protease Inhibitor (PI) UIC-94017 (TMC114) with Potent Activity against Multi-PI-Resistant Human Immunodeficiency Virus In Vitro

2003 ◽  
Vol 47 (10) ◽  
pp. 3123-3129 ◽  
Author(s):  
Yasuhiro Koh ◽  
Hirotomo Nakata ◽  
Kenji Maeda ◽  
Hiromi Ogata ◽  
Geoffrey Bilcer ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Protease Inhibitor ◽  
Therapeutic Agent ◽  
Close Contact ◽  
Wide Spectrum ◽  
Antiviral Agents ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT We designed, synthesized, and identified UIC-94017 (TMC114), a novel nonpeptidic human immunodeficiency virus type 1 (HIV-1) protease inhibitor (PI) containing a 3(R),3a(S),6a(R)-bis-tetrahydrofuranylurethane (bis-THF) and a sulfonamide isostere which is extremely potent against laboratory HIV-1 strains and primary clinical isolates (50% inhibitory concentration [IC50], ∼0.003 μM; IC90, ∼0.009 μM) with minimal cytotoxicity (50% cytotoxic concentration for CD4+ MT-2 cells, 74 μM). UIC-94017 blocked the infectivity and replication of each of HIV-1NL4-3 variants exposed to and selected for resistance to saquinavir, indinavir, nelfinavir, or ritonavir at concentrations up to 5 μM (IC50s, 0.003 to 0.029 μM), although it was less active against HIV-1NL4-3 variants selected for resistance to amprenavir (IC50, 0.22 μM). UIC-94017 was also potent against multi-PI-resistant clinical HIV-1 variants isolated from patients who had no response to existing antiviral regimens after having received a variety of antiviral agents. Structural analyses revealed that the close contact of UIC-94017 with the main chains of the protease active-site amino acids (Asp-29 and Asp-30) is important for its potency and wide spectrum of activity against multi-PI-resistant HIV-1 variants. Considering the favorable pharmacokinetics of UIC-94017 when administered with ritonavir, the present data warrant that UIC-94017 be further developed as a potential therapeutic agent for the treatment of primary and multi-PI-resistant HIV-1 infections.

Antiviral Agents of Plant Origin. Antiherpetic Activity of Acacetin

1993 ◽  
Vol 4 (1) ◽  
pp. 49-53 ◽  
Author(s):  
K. Hayashi ◽  
T. Hayashi ◽  
M. Arisawa ◽  
N. Morita
Keyword(s):  
Antiviral Agents ◽  
Host Cells ◽  
Yield Reduction ◽  
Scoparia Dulcis ◽  
Dependent Inhibition ◽  
Infected Cells ◽  
Dose Dependent Inhibition ◽  
Simplex Virus

The effect of acacetin isolated from Scoparia dulcis and several related flavonoids on herpes simplex virus type 1 (HSV-1) was studied in vitro by the method of plaque yield reduction. Among these compounds, acacetin was shown to be the most potent agent and caused dose-dependent inhibition of virus replication. Acacetin had a weak virucidal activity at higher concentrations. Analysis of early events following infection showed that attachment of the virus to host cells and penetration were unaffected by acacetin. Acacetin was found to exert strong inhibition of protein synthesis in virus-infected cells but not in uninfected cells. The transcription of immediate-early genes and translation of their transcripts were in particular almost stopped by acacetin even at a lower concentration. These selective effects can be attributed mainly to the antiviral activity of acacetin.

scholarly journals Establishment of an antiviral assay system and identification of severe fever with thrombocytopenia syndrome virus inhibitors

2017 ◽  
Vol 25 (3) ◽  
pp. 83-89 ◽  
Author(s):  
Masanori Baba ◽  
Masaaki Toyama ◽  
Norikazu Sakakibara ◽  
Mika Okamoto ◽  
Naomichi Arima ◽  
...  
Keyword(s):  
Antiviral Agents ◽  
Vero Cells ◽  
Assay System ◽  
Viral Rna ◽  
University Hospital ◽  
Selective Inhibitors ◽  
Reverse Transcription Pcr ◽  
The Family ◽  
Severe Fever

Aims Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne infectious disease. SFTS is epidemic in Asia, and its fatality rate is around 30% in Japan. The causative virus severe fever with thrombocytopenia syndrome virus (SFTSV) is a phlebovirus of the family Phenuiviridae (the order Bunyavirales). Although effective treatments are required, there are no antiviral agents currently approved for clinical use. Ribavirin and favipiravir were examined for their anti-SFTSV activity and found to be selective inhibitors of SFTSV replication in vitro. However, their activity was not sufficient. Therefore, it is mandatory to identify novel compounds active against SFTSV. To this end, we have established a safe and rapid assay system for screening selective inhibitors of SFTSV. Methods The virus was isolated from SFTS patients treated in Kagoshima University Hospital. Vero cells were infected with SFTSV and incubated in the presence of various concentrations of test compounds. After three days, the cells were examined for their intracellular viral RNA levels by real-time reverse transcription-PCR without extracting viral RNA. The cytotoxicity of test compounds was determined by a tetrazolium dye method. Results Among the test compounds, the antimalarial agent amodiaquine was identified as a selective inhibitor of SFTSV replication. Its 50% effective concentration (EC50) and cytotoxic concentration (CC50) were 19.1 ± 5.1 and >100 µM, respectively. The EC50 value of amodiaquine was comparable to those of ribavirin and favipiravir. Conclusion Amodiaquine is considered to be a promising lead of novel anti-SFTSV agents, and evaluating the anti-SFTSV activity of its derivatives is in progress.

scholarly journals Bovine Papillomavirus Type 1 Infection Is Mediated by SNARE Syntaxin 18

2007 ◽  
Vol 81 (14) ◽  
pp. 7435-7448 ◽  
Author(s):  
Valerie Laniosz ◽  
Kha C. Nguyen ◽  
Patricio I. Meneses
Keyword(s):  
Viral Infections ◽  
Major Capsid Protein ◽  
Target Cells ◽  
Bovine Papillomavirus ◽  
Snare Protein ◽  
Golgi Compartment ◽  
L1 And L2

ABSTRACT Events that lead to viral infections include the binding of the virus to the target cells, internalization of the virus into the cells, and the ability of the viral genome to be expressed. These steps are mediated by cellular and viral proteins and are temporally regulated. The papillomavirus capsid consists of two virally encoded capsid proteins, L1 and L2. Much is known about the role of the major capsid protein L1 compared to what is known of the role of the L2 protein. We identified the interaction of the L2 protein with SNARE protein syntaxin 18, which mediates the trafficking of vesicles and their cargo between the endoplasmic reticulum, the cis-Golgi compartment, and possibly the plasma membrane. Mutations of L2 residues 41 to 44 prevented the interaction of L2 protein with syntaxin 18 in cotransfection experiments and resulted in noninfectious pseudovirions. In this paper, we describe that syntaxin 18 colocalizes with infectious bovine papillomavirus type 1 (BPV1) pseudovirions during infection but does not colocalize with the noninfectious BPV1 pseudovirions made with an L2 mutant at residues 41 to 44. We show that an antibody against BPV1 L2 residues 36 to 49 (αL2 36-49) binds to in vitro-generated BPV1 pseudoviral capsids and does not coimmunoprecipitate syntaxin 18- and BPV1 L2-transfected proteins. αL2 36-49 was able to partially or completely neutralize infection of BPV1 pseudovirions and genuine virions. These results support the dependence of syntaxin 18 during BPV1 infection and the ability to interfere with infection by targeting the L2-syntaxin 18 interaction and further define the infectious route of BPV1 mediated by the L2 protein.

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