Journal: mBio

Article Title: Effective treatment of advanced Oropouche virus, Rift Valley fever virus, and Dabie bandavirus infections with 4'-fluorouridine

doi: 10.1128/mbio.01467-25

Figure Lengend Snippet: Effect of 4′-FlU on survival outcome and body weights of mice treated prophylactically and challenged with RVFV, DBV, or OROV. Animals in each group were treated p.o., QD with the indicated dose of 4′-FlU, placebo, or positive control drug ( n = 10, unless otherwise indicated) initiated within 2 h of each infection. ( A ) BALB/c mice challenged with RVFV, ( B ) Ifnar -/- mice challenged with DBV, and ( C ) Ifnar -/- mice challenged with OROV. The weight data are represented as the group mean and standard error of the percent change in weight of surviving animals relative to their starting weights on the day of virus challenge. Solid symbols in the single-day RVFV weight loss graph represent the same animals in . Sham-infected (MEM only) normal control animals ( n = 4) are shown for comparison. Blue-shaded areas denote the treatment durations. **** P < 0.0001, *** P < 0.001, ** P < 0.01, * P < 0.05 compared with animals that received the placebo.

Article Snippet: Varying concentrations of 4′-FlU (Emory Institute for Drug Development), ribavirin (ICN Pharmaceuticals, Inc.), or favipiravir (TargetMol) were added to quadruplicate test wells containing 70%–80% confluent Vero 76 (RVFV) or Vero E6 (DBV and OROV) cells just prior to infection at a multiplicity of infection (MOI) of approximately 0.002.

Techniques: Positive Control, Infection, Virus, Control, Comparison

Journal: mBio

Article Title: Effective treatment of advanced Oropouche virus, Rift Valley fever virus, and Dabie bandavirus infections with 4'-fluorouridine

doi: 10.1128/mbio.01467-25

Figure Lengend Snippet: Analysis of day 4 viremia and tissue viral titers in virus-infected mice treated with 4′-FlU. Mice were treated prophylactically with 4′-FlU then challenged with ( A ) RVFV, ( B ) DBV, or ( C ) OROV. Subsets of animals in each group ( n = 4-5) were designated for sacrifice on day 4 p.i. to assess infectious virus titers in the serum, liver, and spleen tissues. Unique symbols in each treatment group represent values for the same animal across all parameters. Horizontal lines represent the mean for each group. The dotted lines represent the assays’ lower limits of detection. **** P < 0.0001, *** P < 0.001, ** P < 0.01, * P < 0.05 compared with animals that received the placebo.

Article Snippet: Varying concentrations of 4′-FlU (Emory Institute for Drug Development), ribavirin (ICN Pharmaceuticals, Inc.), or favipiravir (TargetMol) were added to quadruplicate test wells containing 70%–80% confluent Vero 76 (RVFV) or Vero E6 (DBV and OROV) cells just prior to infection at a multiplicity of infection (MOI) of approximately 0.002.

Techniques: Virus, Infection

Journal: mBio

Article Title: Effective treatment of advanced Oropouche virus, Rift Valley fever virus, and Dabie bandavirus infections with 4'-fluorouridine

doi: 10.1128/mbio.01467-25

Figure Lengend Snippet: Effect of delayed 4′-FlU treatment on survival outcome and daily weights of mice challenged with RVFV, DBV, or OROV. Animals in each group ( n = 10, unless otherwise indicated) were treated p.o., QD with the indicated dose of 4′-FlU, placebo, or positive control drug. ( A ) BALB/c mice challenged with RVFV. ( B ) Ifnar -/- mice challenged with DBV. ( C ) Ifnar -/- mice challenged with OROV. The weight data are represented as the group mean and standard error of the percent change in weight of surviving animals relative to their starting weights on the day of virus challenge. Sham-infected (MEM only) normal control animals are shown for comparison. Blue-shaded areas define the treatment (Tx) range, and brackets indicate specific group Tx durations. **** P < 0.0001, *** P < 0.001, ** P < 0.01, * P < 0.05 compared with animals that received the placebo.

Article Snippet: Varying concentrations of 4′-FlU (Emory Institute for Drug Development), ribavirin (ICN Pharmaceuticals, Inc.), or favipiravir (TargetMol) were added to quadruplicate test wells containing 70%–80% confluent Vero 76 (RVFV) or Vero E6 (DBV and OROV) cells just prior to infection at a multiplicity of infection (MOI) of approximately 0.002.

Techniques: Positive Control, Virus, Infection, Control, Comparison

Journal: mBio

Article Title: Effective treatment of advanced Oropouche virus, Rift Valley fever virus, and Dabie bandavirus infections with 4'-fluorouridine

doi: 10.1128/mbio.01467-25

Figure Lengend Snippet: Analysis of viremia and tissue viral titers in virus-challenged mice treated post-exposure with 4′-FlU. Mice were challenged with ( A ) RVFV, ( B ) DBV, or ( C ) OROV, then treated with 4′-FlU beginning on the indicated day p.i. Subsets of animals in each group ( n = 4) were designated for sacrifice on day 3 or 4 p.i. to assess infectious virus titers in the serum, liver, and spleen tissues. Unique symbols in each treatment group represent values for the same animal across all parameters. Horizontal lines represent the mean for each group. The dotted lines represent the assays’ lower limits of detection. **** P < 0.0001, *** P < 0.001, ** P < 0.01, * P < 0.05 compared with animals that received the placebo.

Article Snippet: Varying concentrations of 4′-FlU (Emory Institute for Drug Development), ribavirin (ICN Pharmaceuticals, Inc.), or favipiravir (TargetMol) were added to quadruplicate test wells containing 70%–80% confluent Vero 76 (RVFV) or Vero E6 (DBV and OROV) cells just prior to infection at a multiplicity of infection (MOI) of approximately 0.002.

Techniques: Virus

Journal: mBio

Article Title: Effective treatment of advanced Oropouche virus, Rift Valley fever virus, and Dabie bandavirus infections with 4'-fluorouridine

doi: 10.1128/mbio.01467-25

Figure Lengend Snippet: Impact of 4′-FlU dose sparing on DBV-infected Ifnar -/- mice when treatment is started 4 days p.i. Animals in each group ( n = 10/treatment group; n = 4 sham-infected normal controls) were treated p.o., QD with 10 mg/kg 4′-FlU starting on day 4 p.i., for the indicated number of days to assess ( A ) survival outcome and ( B ) daily body weights. The weight data are represented as the group mean and standard error of the percent change in weight of surviving animals relative to their starting weights on the day of virus challenge. ( C ) Day 5 weight change from all animals. ( D ) viremia, ( E ) liver, and ( F ) spleen tissue viral titers from pre-selected mice in the 7-day treatment and placebo groups sacrificed on day 5 p.i. Samples could not be obtained from 3 mice in the placebo group. Solid symbols shown in panel C represent the same animals sacrificed for viral titer analyses. Horizontal lines represent the mean for each group. The dotted lines represent the assays’ lower limits of detection. **** P < 0.0001, *** P < 0.001, ** P < 0.01, * P < 0.05 compared with animals that received the vehicle placebo.

Article Snippet: Varying concentrations of 4′-FlU (Emory Institute for Drug Development), ribavirin (ICN Pharmaceuticals, Inc.), or favipiravir (TargetMol) were added to quadruplicate test wells containing 70%–80% confluent Vero 76 (RVFV) or Vero E6 (DBV and OROV) cells just prior to infection at a multiplicity of infection (MOI) of approximately 0.002.

Techniques: Infection, Virus

Journal: mBio

Article Title: Effective treatment of advanced Oropouche virus, Rift Valley fever virus, and Dabie bandavirus infections with 4'-fluorouridine

doi: 10.1128/mbio.01467-25

Figure Lengend Snippet: Effect of 4′-FlU treatment administered QOD on Ifnar -/- mice challenged with OROV. Animals in each group ( n = 10/treatment group unless otherwise indicated; n = 4 sham-infected normal controls) were treated p.o., QOD with the indicated dose of 4′-FlU, initiated on day 2 p.i., for 9 days in duration. ( A ) Survival and ( B ) body weights were assessed daily. The weight data are represented as the group mean and standard error of the percent change in weight of surviving animals relative to their starting weights on the day of virus challenge. Sham-infected animals are shown for comparison. ( C ) Day 5 weight change of all animals. Subsets of animals in each group ( n = 3-4) were predesignated for sacrifice on day 4 p.i. to assess ( D ) serum, ( E ) liver, and ( F ) spleen virus titers. They did not receive the second dose of 4′-FlU. Samples could not be collected from a single mouse in the placebo group, which succumbed before it could be euthanized on day 4. Unique symbols in each treatment group represent values for the same animal across all parameters. Horizontal lines represent the mean for each group. The dotted lines represent the assays’ lower limits of detection. **** P < 0.0001, *** P < 0.001, ** P < 0.01, * P < 0.05 compared with animals that received the placebo.

Article Snippet: Varying concentrations of 4′-FlU (Emory Institute for Drug Development), ribavirin (ICN Pharmaceuticals, Inc.), or favipiravir (TargetMol) were added to quadruplicate test wells containing 70%–80% confluent Vero 76 (RVFV) or Vero E6 (DBV and OROV) cells just prior to infection at a multiplicity of infection (MOI) of approximately 0.002.

Techniques: Infection, Virus, Comparison

Journal: mBio

Article Title: Effective treatment of advanced Oropouche virus, Rift Valley fever virus, and Dabie bandavirus infections with 4'-fluorouridine

doi: 10.1128/mbio.01467-25

Figure Lengend Snippet: In vitro and in vivo comparison of the prototypic BeAn 19991 and 240023 reassortant strains of OROV. ( A ) Growth kinetics of both OROV strains in Vero E6 cells infected at an MOI of 0.001. Cell culture supernatants were collected every 24 h for 6 days, and infectious virus concentrations were determined by endpoint titration in Vero E6 cells. **** P < 0.0001, *** P < 0.001, * P < 0.05. ( B ) Survival and ( C ) body weights were assessed daily in Ifnar -/- mice ( n = 10/treatment group; n = 4 sham-infected normal controls) challenged s.c. with 50 CCID 50 of the indicated strain of OROV and treated p.o., QD with 3 mg/kg 4′-FlU or the vehicle placebo, initiated on day 2 p.i., for 8 days. The body weight data are represented as the group mean and standard error of the percent change in weight of surviving animals relative to their starting weights on the day of virus challenge. Normal control animals ( n = 4) are shown for comparison. **** P < 0.0001 compared with respective placebo-treated animals challenged with the same strain.

Article Snippet: Varying concentrations of 4′-FlU (Emory Institute for Drug Development), ribavirin (ICN Pharmaceuticals, Inc.), or favipiravir (TargetMol) were added to quadruplicate test wells containing 70%–80% confluent Vero 76 (RVFV) or Vero E6 (DBV and OROV) cells just prior to infection at a multiplicity of infection (MOI) of approximately 0.002.

Techniques: In Vitro, In Vivo, Comparison, Infection, Cell Culture, Virus, Titration, Control