Ribavirin inhibits the replication of infectious bursal disease virus predominantly through depletion of cellular guanosine pool

Towseef Akram; Irfan Gul; Mahrukh Parveez Zia; Amreena Hassan; Amina Khatun; Riaz Ahmad Shah; Syed Mudasir Ahmad; Nazir Ahmad Ganai; Naveed Anjum Chikan; Won-Il Kim; Nadeem Shabir

doi:10.3389/fvets.2023.1192583

Ribavirin inhibits the replication of infectious bursal disease virus predominantly through depletion of cellular guanosine pool

Front Vet Sci. 2023 Jul 31:10:1192583. doi: 10.3389/fvets.2023.1192583. eCollection 2023.

Authors

Towseef Akram¹, Irfan Gul^{1

2}, Mahrukh Parveez Zia^{1

3}, Amreena Hassan^{1

2}, Amina Khatun⁴, Riaz Ahmad Shah¹, Syed Mudasir Ahmad¹, Nazir Ahmad Ganai¹, Naveed Anjum Chikan⁵, Won-Il Kim⁶, Nadeem Shabir¹

Affiliations

¹ Division of Animal Biotechnology, Faculty of Veterinary Sciences and Animal Husbandry, Sher-e- Kashmir University of Agricultural Sciences and Technology of Kashmir, Srinagar, India.
² Department of Biotechnology, University of Kashmir, Srinagar, India.
³ Department of Biotechnology, School of Engineering and Technology, Sharda University, Greater Noida, UP, India.
⁴ Faculty of Animal Science and Veterinary Medicine, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh.
⁵ Division of Computational Biology, Daskdan Innovations Pvt. Ltd., Srinagar, India.
⁶ College of Veterinary Medicine, Jeonbuk National University, Iksan, Republic of Korea.

Abstract

Introduction: The antiviral activity of different mutagens against single-stranded RNA viruses is well documented; however, their activity on the replication of double-stranded RNA viruses remains unexplored. This study aims to investigate the effect of different antivirals on the replication of a chicken embryo fibroblast-adapted Infectious Bursal Disease virus, FVSKG2. This study further explores the antiviral mechanism utilized by the most effective anti-IBDV agent.

Methods: The cytotoxicity and anti-FVSKG2 activity of different antiviral agents (ribavirin, 5-fluorouracil, 5-azacytidine, and amiloride) were evaluated. The virus was serially passaged in chicken embryo fibroblasts 11 times at sub-cytotoxic concentrations of ribavirin, 5-fluorouracil or amiloride. Further, the possible mutagenic and non-mutagenic mechanisms utilized by the most effective anti-FVSKG2 agent were explored.

Results and discussion: Ribavirin was the least cytotoxic on chicken embryo fibroblasts, followed by 5-fluorouracil, amiloride and 5-azacytidine. Ribavirin inhibited the replication of FVSKG2 in chicken embryo fibroblasts significantly at concentrations as low as 0.05 mM. The extinction of FVSKG2 was achieved during serial passage of the virus in chicken embryo fibroblasts at ≥0.05 mM ribavirin; however, the emergence of a mutagen-resistant virus was not observed until the eleventh passage. Further, no mutation was observed in 1,898 nucleotides of the FVSKG2 following its five passages in chicken embryo fibroblasts in the presence of 0.025 mM ribavirin. Ribavarin inhibited the FVSKG2 replication in chicken embryo fibroblasts primarily through IMPDH-mediated depletion of the Guanosine Triphosphate pool of cells. However, other mechanisms like ribavirin-mediated cytokine induction or possible inhibition of viral RNA-dependent RNA polymerase through its interaction with the enzyme's active sites enhance the anti-IBDV effect. Ribavirin inhibits ds- RNA viruses, likely through IMPDH inhibition and not mutagenesis. The inhibitory effect may, however, be augmented by other non-mutagenic mechanisms, like induction of antiviral cytokines in chicken embryo fibroblasts or interaction of ribavirin with the active sites of RNA-dependent RNA polymerase of the virus.

Keywords: antiviral; dsRNA; infectious bursal disease virus; mutagen; ribavirin.