scholarly journals In Vitro Antiviral Activity and Single-Dose Pharmacokinetics in Humans of a Novel, Orally Bioavailable Inhibitor of Human Rhinovirus 3C Protease

2005 ◽  
Vol 49 (6) ◽  
pp. 2267-2275 ◽  
Author(s):  
Amy K. Patick ◽  
Mary A. Brothers ◽  
Fausto Maldonado ◽  
Susan Binford ◽  
Oscar Maldonado ◽  
...  
Keyword(s):  
Single Dose ◽  
Antiviral Activity ◽  
Human Rhinovirus ◽  
Dependent Manner ◽  
Irreversible Inhibitor ◽  
3C Protease ◽  
Infected Cells ◽  
Orally Bioavailable ◽  
Nm Range

ABSTRACT (E)-(S)-4-((S)-2-{3-[(5-methyl-isoxazole-3-carbonyl)-amino]-2-oxo-2H-pyridin-1-yl}-pent-4-ynoylamino)-5-((S)-2-oxo-pyrrolidin-3-yl)-pent-2-enoic acid ethyl ester (Compound 1) is a novel, irreversible inhibitor of human rhinovirus (HRV) 3C protease {inactivation rate constant (Kobs/[I]) of 223,000 M−1s−1}. In cell-based assays, Compound 1 was active against all HRV serotypes (35 of 35), HRV clinical isolates (5 of 5), and related picornaviruses (8 of 8) tested with mean 50% effective concentration (EC5 0) values of 50 nM (range, 14 to 122 nM), 77 nM (range, 72 to 89 nM), and 75 nM (range, 7 to 249 nM), respectively. Compound 1 inhibited HRV 3C-mediated polyprotein processing in infected cells in a concentration-dependent manner, providing direct confirmation that the cell-based antiviral activity is due to inhibition of 3C protease. In vitro and in vivo nonclinical safety studies showed Compound 1 to be without adverse effects at maximum achievable doses. Single oral doses of Compound 1 up to 2,000 mg in healthy volunteers were found to be safe and well tolerated in a phase I-ascending, single-dose study. Compound 1 estimated free observed maximum concentration in plasma (C ma x) for 500-, 1,000-, and 2,000-mg doses were higher than the protein binding-corrected EC50 required to inhibit 80% of the HRV serotypes tested. Treatment of HRV 52-infected cells with one to five 2-h pulses of 150 nM Compound 1 (corresponding to the C max at the 500-mg dose) was sufficient to effect a significant reduction in viral replication. These experiments highlight Compound 1 as a potent, orally bioavailable, irreversible inhibitor of HRV 3C protease and provide data that suggest that C max rather than the C min might be the key variable predicting clinical efficacy.

scholarly journals In Vitro Antiviral Activity of AG7088, a Potent Inhibitor of Human Rhinovirus 3C Protease

1999 ◽  
Vol 43 (10) ◽  
pp. 2444-2450 ◽  
Author(s):  
A. K. Patick ◽  
S. L. Binford ◽  
M. A. Brothers ◽  
R. L. Jackson ◽  
C. E. Ford ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Human Rhinovirus ◽  
Cell Protection ◽  
Irreversible Inhibitor ◽  
Structure Based Drug Design ◽  
Viral Attachment ◽  
3C Protease

ABSTRACT AG7088 is a potent, irreversible inhibitor of human rhinovirus (HRV) 3C protease {inactivation rate constant (k obs/[I]} = 1,470,000 ± 440,000 M−1 s−1 for HRV 14) that was discovered by protein structure-based drug design methodologies. In H1-HeLa and MRC-5 cell protection assays, AG7088 inhibited the replication of all HRV serotypes (48 of 48) tested with a mean 50% effective concentration (EC50) of 0.023 μM (range, 0.003 to 0.081 μM) and a mean EC90 of 0.082 μM (range, 0.018 to 0.261 μM) as well as that of related picornaviruses including coxsackieviruses A21 and B3, enterovirus 70, and echovirus 11. No significant reductions in the antiviral activity of AG7088 were observed when assays were performed in the presence of α1-acid glycoprotein or mucin, proteins present in nasal secretions. The 50% cytotoxic concentration of AG7088 was >1,000 μM, yielding a therapeutic index of >12,346 to >333,333. In a single-cycle, time-of-addition assay, AG7088 demonstrated antiviral activity when added up to 6 h after infection. In contrast, a compound targeting viral attachment and/or uncoating was effective only when added at the initiation of virus infection. Direct inhibition of 3C proteolytic activity in infected cells treated with AG7088 was demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of radiolabeled proteins, which showed a dose-dependent accumulation of viral precursor polyproteins and reduction of processed protein products. The broad spectrum of antiviral activity of AG7088, combined with its efficacy even when added late in the virus life cycle, highlights the advantages of 3C protease as a target and suggests that AG7088 will be a promising clinical candidate.

scholarly journals In Vitro Resistance Study of Rupintrivir, a Novel Inhibitor of Human Rhinovirus 3C Protease

2007 ◽  
Vol 51 (12) ◽  
pp. 4366-4373 ◽  
Author(s):  
S. L. Binford ◽  
P. T. Weady ◽  
F. Maldonado ◽  
M. A. Brothers ◽  
D. A. Matthews ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Serial Passage ◽  
Human Rhinovirus ◽  
Amino Acid Substitutions ◽  
In Vitro Activity ◽  
Irreversible Inhibitor ◽  
Common Features ◽  
3C Protease ◽  
Multiple Amino Acid

ABSTRACT Rupintrivir (formerly AG7088) is an irreversible inhibitor of the human rhinovirus (HRV) 3C protease that has been demonstrated to have in vitro activity against all HRVs tested, consistent with its interaction with a strictly conserved subset of amino acids in the 3C protease. The potential for resistance was studied following in vitro serial passage of HRV serotypes 14, 2, 39, and Hanks in the presence of increasing rupintrivir concentrations. HRV variants with reduced susceptibilities to rupintrivir (sevenfold for HRV 14) or with no significant reductions in susceptibility but genotypic changes (HRV 2, 39, and Hanks) were initially isolated following 14 to 40 cumulative days in culture (three to six passages). Sequence analysis of the 3C protease identified one to three substitutions in diverse patterns but with common features (T129T/A, T131T/A, and T143P/S in HRV 14; N165T in HRV 2; N130N/K and L136L/F in HRV 39; T130A in HRV Hanks). Notably, three of the four HRV variants contained a substitution at residue 130 (residue 129 in HRV 14). Continued selection in the presence of escalating concentrations of rupintrivir (40 to 72 days) resulted in the accumulation of additional mutations (A121A/V and Y139Y/H in HRV 14, E3E/G and A103A/V in HRV 2, S105T in HRV 39), with only minimal further reductions in susceptibility (up to fivefold). The ability of specific substitutions to confer resistance was examined by susceptibility testing of HRV 14 variants constructed to contain 3C protease mutations. In summary, the slow accumulation of multiple amino acid substitutions with only minimal to moderate reductions in susceptibility highlight the advantages of 3C protease as an antiviral target.

scholarly journals Conservation of Amino Acids in Human Rhinovirus 3C Protease Correlates with Broad-Spectrum Antiviral Activity of Rupintrivir, a Novel Human Rhinovirus 3C Protease Inhibitor

2005 ◽  
Vol 49 (2) ◽  
pp. 619-626 ◽  
Author(s):  
S. L. Binford ◽  
F. Maldonado ◽  
M. A. Brothers ◽  
P. T. Weady ◽  
L. S. Zalman ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Antiviral Activity ◽  
Broad Spectrum ◽  
Amino Acid Sequences ◽  
Human Rhinovirus ◽  
Clinical Isolates ◽  
Sequence Analyses ◽  
3C Protease

ABSTRACT The picornavirus 3C protease is required for the majority of proteolytic cleavages that occur during the viral life cycle. Comparisons of published amino acid sequences from 6 human rhinoviruses (HRV) and 20 human enteroviruses (HEV) show considerable variability in the 3C protease-coding region but strict conservation of the catalytic triad residues. Rupintrivir (formerly AG7088) is an irreversible inhibitor of HRV 3C protease with potent in vitro activity against all HRV serotypes (48 of 48), HEV strains (4 of 4), and untyped HRV field isolates (46 of 46) tested. To better understand the relationship between in vitro antiviral activity and 3C protease-rupintrivir binding interactions, we performed nucleotide sequence analyses on an additional 21 HRV serotypes and 11 HRV clinical isolates. Antiviral activity was also determined for 23 HRV clinical isolates and four additional HEV strains. Sequence comparison of 3C proteases (n = 58) show that 13 and 11 of the 14 amino acids that are involved in side chain interactions with rupintrivir are strictly conserved among HRV and HEV, respectively. These sequence analyses are consistent with the comparable in vitro antiviral potencies of rupintrivir against all HRV serotypes, HRV isolates, and HEV strains tested (50% effective concentration range, 3 to 183 nM; n = 125). In summary, the conservation of critical amino acid residues in 3C protease and the observation of potent, broad-spectrum antipicornavirus activity of rupintrivir highlight the advantages of 3C protease as an antiviral target.

scholarly journals Comparison of Antiviral Activity of Gemcitabine with 2′-Fluoro-2′-Deoxycytidine and Combination Therapy with Remdesivir against SARS-CoV-2

2021 ◽  
Vol 22 (4) ◽  
pp. 1581
Author(s):  
Yejin Jang ◽  
Jin Soo Shin ◽  
Myoung Kyu Lee ◽  
Eunhye Jung ◽  
Timothy An ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Human Lung ◽  
Lung Epithelial Cells ◽  
Dependent Manner ◽  
Fluorescent Image ◽  
Lung Epithelial ◽  
Infected Cells ◽  
Polymerase Chain ◽  
Dose Dependent

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the coronavirus disease 2019 (COVID-19) pandemic. The virus still spreads globally through human-to-human transmission. Nevertheless, there are no specific treatments clinically approved. This study aimed to compare antiviral activity of gemcitabine and its analogue 2′-fluoro-2′-deoxycytidine (2FdC) against SARS-CoV-2 as well as cytotoxicity in vitro. Fluorescent image-based antiviral assays revealed that gemcitabine was highly potent, with a 50% effective concentration (EC50) of 1.2 μM, more active than the well-known nucleoside monophosphate remdesivir (EC50 = 35.4 μM). In contrast, 2FdC was marginally active (EC50 = 175.2 μM). For all three compounds, the 50% cytotoxic concentration (CC50) values were over 300 μM toward Vero CCL-81 cells. Western blot and quantitative reverse-transcription polymerase chain reaction analyses verified that gemcitabine blocked viral protein expression in virus-infected cells, not only Vero CCL-81 cells but also Calu-3 human lung epithelial cells in a dose-dependent manner. It was found that gemcitabine has a synergistic effect when combined with remdesivir. This report suggests that the difluoro group of gemcitabine is critical for the antiviral activity and that its combination with other evaluated antiviral drugs, such as remdesivir, could be a desirable option to treat SARS-CoV-2 infection.

scholarly journals Inhibition of Human Rhinovirus-Induced Cytokine Production by AG7088, a Human Rhinovirus 3C Protease Inhibitor

2000 ◽  
Vol 44 (5) ◽  
pp. 1236-1241 ◽  
Author(s):  
L. S. Zalman ◽  
M. A. Brothers ◽  
P. S. Dragovich ◽  
R. Zhou ◽  
T. J. Prins ◽  
...  
Keyword(s):  
Infectious Virus ◽  
Respiratory Illness ◽  
Bronchial Epithelial Cell ◽  
Human Rhinovirus ◽  
Epithelial Cell Line ◽  
Irreversible Inhibitor ◽  
Bronchial Epithelial ◽  
3C Protease ◽  
Infected Cells ◽  
Dose Dependent

ABSTRACT Symptom severity in patients with human rhinovirus (HRV)-induced respiratory illness is associated with elevated levels of the inflammatory cytokines interleukin-6 (IL-6) and IL-8. AG7088 is a novel, irreversible inhibitor of the HRV 3C protease. In this study, AG7088 was tested for its antiviral activity and ability to inhibit the production of IL-6 and IL-8 in a human bronchial epithelial cell line, BEAS-2B. Infection of BEAS-2B cells with HRV 14 resulted in the production of both infectious virus and the cytokines IL-6 and IL-8. Treatment of HRV 14-infected cells with AG7088 resulted in a statistically significant (P, <0.05) dose-dependent reduction in the levels of infectious virus as well as IL-6 and IL-8 released into the cell supernatant compared to the results obtained for compound-free infected cells. AG7088 was also able to inhibit the replication of HRV 2 and 16 in BEAS-2B cells. In time-of-addition studies, AG7088 could be added as late as 14 to 26 h after HRV 14 infection of BEAS-2B cells and still result in a statistically significant (P, <0.05) reduction in the levels of infectious virus, IL-6, and IL-8 compared to the results obtained for compound-free infected cells. These findings have implications for the development of an antirhinovirus agent that may not only block virus replication but also diminish symptoms.

scholarly journals Antiviral Activity of the G-Quadruplex Ligand TMPyP4 against Herpes Simplex Virus-1

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 196
Author(s):  
Sara Artusi ◽  
Emanuela Ruggiero ◽  
Matteo Nadai ◽  
Beatrice Tosoni ◽  
Rosalba Perrone ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Dna Replication ◽  
Herpes Simplex ◽  
Antiviral Activity ◽  
Herpes Simplex Virus 1 ◽  
Tem Analysis ◽  
Infected Cells ◽  
Simplex Virus ◽  
Hsv 1

The herpes simplex virus 1 (HSV-1) genome is extremely rich in guanine tracts that fold into G-quadruplexes (G4s), nucleic acid secondary structures implicated in key biological functions. Viral G4s were visualized in HSV-1 infected cells, with massive virus cycle-dependent G4-formation peaking during viral DNA replication. Small molecules that specifically interact with G4s have been shown to inhibit HSV-1 DNA replication. We here investigated the antiviral activity of TMPyP4, a porphyrin known to interact with G4s. The analogue TMPyP2, with lower G4 affinity, was used as control. We showed by biophysical analysis that TMPyP4 interacts with HSV-1 G4s, and inhibits polymerase progression in vitro; in infected cells, it displayed good antiviral activity which, however, was independent of inhibition of virus DNA replication or entry. At low TMPyP4 concentration, the virus released by the cells was almost null, while inside the cell virus amounts were at control levels. TEM analysis showed that virus particles were trapped inside cytoplasmatic vesicles, which could not be ascribed to autophagy, as proven by RT-qPCR, western blot, and immunofluorescence analysis. Our data indicate a unique mechanism of action of TMPyP4 against HSV-1, and suggest the unprecedented involvement of currently unknown G4s in viral or antiviral cellular defense pathways.

scholarly journals Antiviral Activity of Benzoic Acid Derivative NC-5 Against Influenza A Virus and Its Neuraminidase Inhibition

2019 ◽  
Vol 20 (24) ◽  
pp. 6261
Author(s):  
Min Guo ◽  
Jiawei Ni ◽  
Jie Yu ◽  
Jing Jin ◽  
Lingman Ma ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Benzoic Acid ◽  
Influenza A Virus ◽  
Influenza A ◽  
Matrix Protein ◽  
Influenza Viruses ◽  
Drug Candidate ◽  
Dependent Manner ◽  
Drug Resistant

The currently available drugs against influenza A virus primarily target neuraminidase (NA) or the matrix protein 2 (M2) ion channel. The emergence of drug-resistant viruses requires the development of new antiviral chemicals. Our study applied a cell-based approach to evaluate the antiviral activity of a series of newly synthesized benzoic acid derivatives, and 4-(2,2-Bis(hydroxymethyl)-5-oxopyrrolidin-l-yl)-3-(5-cyclohexyl-4H-1,2,4-triazol-3-yl)amino). benzoic acid, termed NC-5, was found to possess antiviral activity. NC-5 inhibited influenza A viruses A/FM/1/47 (H1N1), A/Beijing/32/92 (H3N2) and oseltamivir-resistant mutant A/FM/1/47-H275Y (H1N1-H275Y) in a dose-dependent manner. The 50% effective concentrations (EC50) for H1N1 and H1N1-H275Y were 33.6 μM and 32.8 μM, respectively, which showed that NC-5 had a great advantage over oseltamivir in drug-resistant virus infections. The 50% cytotoxic concentration (CC50) of NC-5 was greater than 640 μM. Orally administered NC-5 protected mice infected with H1N1 and H1N1-H275Y, conferring 80% and 60% survival at 100 mg/kg/d, reducing body weight loss, and alleviating virus-induced lung injury. NC-5 could suppress NP and M1 protein expression levels during the late stages of viral biosynthesis and inhibit NA activity, which may influence virus release. Our study proved that NC-5 has potent anti-influenza activity in vivo and in vitro, meaning that it could be regarded as a promising drug candidate to treat infection with influenza viruses, including oseltamivir-resistant viruses.

scholarly journals Evaluation of Interactions of Human Cytomegalovirus Immediate-Early IE2 Regulatory Protein with Small Ubiquitin-Like Modifiers and Their Conjugation Enzyme Ubc9

2001 ◽  
Vol 75 (8) ◽  
pp. 3859-3872 ◽  
Author(s):  
Jin-Hyun Ahn ◽  
Yixun Xu ◽  
Won-Jong Jang ◽  
Michael J. Matunis ◽  
Gary S. Hayward
Keyword(s):  
Hcmv Infection ◽  
Dependent Manner ◽  
Interacting Proteins ◽  
Binding Assays ◽  
Yeast Two Hybrid ◽  
Vitro Binding ◽  
Lysine Residues ◽  
Infected Cells ◽  
Two Hybrid

ABSTRACT The human cytomegalovirus (HCMV) major immediate-early protein IE2 is a nuclear phosphoprotein that is believed to be a key regulator in both lytic and latent infections. Using yeast two-hybrid screening, small ubiquitin-like modifiers (SUMO-1, SUMO-2, and SUMO-3) and a SUMO-conjugating enzyme (Ubc9) were isolated as IE2-interacting proteins. In vitro binding assays with glutathioneS-transferase (GST) fusion proteins provided evidence for direct protein-protein interaction. Mapping data showed that the C-terminal end of SUMO-1 is critical for interaction with IE2 in both yeast and in vitro binding assays. IE2 was efficiently modified by SUMO-1 or SUMO-2 in cotransfected cells and in cells infected with a recombinant adenovirus expressing HCMV IE2, although the level of modification was much lower in HCMV-infected cells. Two lysine residues at positions 175 and 180 were mapped as major alternative SUMO-1 conjugation sites in both cotransfected cells and an in vitro sumoylation assay and could be conjugated by SUMO-1 simultaneously. Although mutations of these lysine residues did not interfere with the POD (or ND10) targeting of IE2, overexpression of SUMO-1 enhanced IE2-mediated transactivation in a promoter-dependent manner in reporter assays. Interestingly, many other cellular proteins identified as IE2 interaction partners in yeast two-hybrid assays also interact with SUMO-1, suggesting that either directly bound or covalently conjugated SUMO moieties may act as a bridge for interactions between IE2 and other SUMO-1-modified or SUMO-1-interacting proteins. When we investigated the intracellular localization of SUMO-1 in HCMV-infected cells, the pattern changed from nuclear punctate to predominantly nuclear diffuse in an IE1-dependent manner at very early times after infection, but with some SUMO-1 protein now associated with IE2 punctate domains. However, at late times after infection, SUMO-1 was predominantly detected within viral DNA replication compartments containing IE2. Taken together, these results show that HCMV infection causes the redistribution of SUMO-1 and that IE2 both physically binds to and is covalently modified by SUMO moieties, suggesting possible modulation of both the function of SUMO-1 and protein-protein interactions of IE2 during HCMV infection.

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