Journal: bioRxiv

Article Title: Combination of Antiviral Drugs to Inhibit SARS-CoV-2 Polymerase and Exonuclease as Potential COVID-19 Therapeutics

doi: 10.1101/2021.07.21.453274

Figure Lengend Snippet: Structures of the prodrugs Sofosbuvir (a), Remdesivir (b), Favipiravir (c), Tenofovir disoproxil (d), Molnupiravir (e) and AT-527 (f) (top) and their respective active triphosphate forms Sofosbuvir-5’-triphosphate, Remdesivir-5’-triphosphate, Favipiravir-ribofuranosyl-5’-triphosphate (Favipiravir-RTP), Tenofovir diphosphate, N 4 -hydroxycytidine-5’-triphosphate (NHC-TP) and 2’-fluoro-2’-methyl guanosine-5’-triphosphate (AT-9010, G fm -TP) (bottom).

Article Snippet: Remdesivir triphosphate (RDV-TP) and NHC triphosphate were purchased from MedChemExpress (Monmouth Junction, NJ), Sofosbuvir triphosphate (SOF-TP) was purchased from Sierra Bioresearch (Tucson, AZ), Tenofovir diphosphate (Tfv-DP) was purchased from Alfa Chemistry (Ronkonkoma, NY), and Favipiravir triphosphate and AT-9010 were purchased from NuBlocks LLC (Oceanside, CA).

Techniques:

Journal: bioRxiv

Article Title: Combination of Antiviral Drugs to Inhibit SARS-CoV-2 Polymerase and Exonuclease as Potential COVID-19 Therapeutics

doi: 10.1101/2021.07.21.453274

Figure Lengend Snippet: A mixture of 400 nM RNAs (sequences shown at the top of the figure) and 50 nM SARS-CoV-2 pre-assembled exonuclease complex (nsp14/nsp10) were incubated in buffer solution at 37 °C for 15 min in the absence (b, e) and presence of 20 μM Pibrentasvir (c, f). The intact RNAs (a, d) and the products of the exonuclease reactions (b, c, e, f) were analyzed by MALDI-TOF MS. The signal intensity was normalized to the highest peak. The peak at 9776 Da corresponds to the intact RNA (9773 Da expected) and the peak at 9812 Da corresponds to the intact Remdesivir delayed RNA termination product (9797 Da expected). The small peak at 10158 Da corresponds to mismatched incorporation of an additional G; this is likely due to the low fidelity of SARS-CoV-2 RdRp . In the absence of Pibrentasvir, exonuclease activity caused nucleotide cleavage from the 3’-end of the RNA as shown by the lower molecular weight fragments corresponding to cleavage of 1–11 nucleotides (b, e). When 20 μM Pibrentasvir was added, exonuclease activity was reduced as shown by the reduced intensities of the fragmentation peaks and increased intact RNA peaks (c, f).

Article Snippet: Remdesivir triphosphate (RDV-TP) and NHC triphosphate were purchased from MedChemExpress (Monmouth Junction, NJ), Sofosbuvir triphosphate (SOF-TP) was purchased from Sierra Bioresearch (Tucson, AZ), Tenofovir diphosphate (Tfv-DP) was purchased from Alfa Chemistry (Ronkonkoma, NY), and Favipiravir triphosphate and AT-9010 were purchased from NuBlocks LLC (Oceanside, CA).

Techniques: Incubation, Activity Assay, Molecular Weight

Journal: bioRxiv

Article Title: Combination of Antiviral Drugs to Inhibit SARS-CoV-2 Polymerase and Exonuclease as Potential COVID-19 Therapeutics

doi: 10.1101/2021.07.21.453274

Figure Lengend Snippet: In vitro pharmacological parameters of potency and efficacy of combinations of RdRp and HCV NS5A inhibitors on SARS-CoV-2 replication in Calu-3 cells

Article Snippet: Remdesivir triphosphate (RDV-TP) and NHC triphosphate were purchased from MedChemExpress (Monmouth Junction, NJ), Sofosbuvir triphosphate (SOF-TP) was purchased from Sierra Bioresearch (Tucson, AZ), Tenofovir diphosphate (Tfv-DP) was purchased from Alfa Chemistry (Ronkonkoma, NY), and Favipiravir triphosphate and AT-9010 were purchased from NuBlocks LLC (Oceanside, CA).

Techniques: In Vitro

Journal: bioRxiv

Article Title: Combination of Antiviral Drugs to Inhibit SARS-CoV-2 Polymerase and Exonuclease as Potential COVID-19 Therapeutics

doi: 10.1101/2021.07.21.453274

Figure Lengend Snippet: Calu-3 cells, at a density of 5 × 10 5 cells/well in 48-well plates, were infected with SARS-CoV-2 at a MOI of 0.1, for 1 h at 37 °C. An inoculum was removed and cells were washed and incubated with fresh DMEM containing 2% FBS and the indicated concentration of Remdesivir (RDV) (A), Sofosbuvir (B), Tenofovir (C), and Favipiravir (D), alone and in combination with the HCV NS5A inhibitors. Supernatants were assessed after 48–72 h. Viral replication in the culture supernatant was measured as PFU/mL by titering in VeroE6 cells. Results are displayed as virus titers. The data represent means ± SEM of three independent experiments.

Article Snippet: Remdesivir triphosphate (RDV-TP) and NHC triphosphate were purchased from MedChemExpress (Monmouth Junction, NJ), Sofosbuvir triphosphate (SOF-TP) was purchased from Sierra Bioresearch (Tucson, AZ), Tenofovir diphosphate (Tfv-DP) was purchased from Alfa Chemistry (Ronkonkoma, NY), and Favipiravir triphosphate and AT-9010 were purchased from NuBlocks LLC (Oceanside, CA).

Techniques: Infection, Incubation, Concentration Assay, Virus

Journal: Heliyon

Article Title: Rescue and characterization of the first West African Marburg virus 2021 from Guinea

doi: 10.1016/j.heliyon.2023.e19613

Figure Lengend Snippet: (A) HuH7 cells were infected with recMARV Guinea and recMARV Musoke. Cells were incubated for 48 h in 3% DMEM ++ (untreated control), or in 3% DMEM ++ containing either DMSO, 1 μM, or 0.1 μM remdesivir. Viral titers from supernatants were calculated as TCID 50 /ml. Three independent experiments were performed, SD is indicated by error bars. LLOD, lower limit of detection, stars indicate statistical significance (* p-value ≤0.05; ** p-value ≤0.01). (B) Cytopathic effect (CPE) was monitored 48 hpi.

Article Snippet: After removal of the virus-containing inoculum, cells were incubated for 48 h at 37 °C in 3% DMEM ++ containing either 0.1 μM, or 1 μM remdesivir (GS-5734, Biomol)/DMSO or DMSO (0.1%) as control, as well as an untreated control.

Techniques: Infection, Incubation, Control