Poster Presentation 12th Australasian Virology Society Meeting 2024

Fitness landscape and evolutionary models for combating Hepatitis C virus (#232)

Ahmed Abdul Quadeer 1 2 , Hang Zhang 3 , Raymond Louie 4 5 , Rowena Bull 5 6 , Matthew McKay 1 2
  1. Electrical and Electronic Engineering, University of Melbourne, Parkville, VIC, Australia
  2. Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Parkville, VIC, Australia
  3. Electronic and Computer Engineering, Hong Kong University of Science and Technology, Hong Kong SAR, China
  4. Computer Science and Engineering, University of New South Wales, Sydney, NSW, Australia
  5. The Kirby Institute for Infection and Immunity, University of New South Wales, Sydney, NSW, Australia
  6. School of Biomedical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia

Hepatitis C virus (HCV) poses a significant threat to public health, particularly due to its high mutation rate, enabling immune evasion and drug resistance. Our research defines innovative fitness landscape and evolutionary models, rooted in biophysics and population genetics, to analyze complex and diverse sequence data for understanding viral evolution and accelerating HCV vaccine development and therapeutic strategies.

Our models identified regions of the E2 glycoprotein that are difficult for the virus to mutate without compromising fitness, making them attractive targets for broadly neutralizing antibodies (bNabs) [1]. We also revealed that differences in evolutionary constraints between HCV subtypes 1a and 1b may explain the higher chronicity rate and disease severity associated with subtype 1b, while also identifying bNabs resilient to both subtypes [2]. Extending our analysis to the E1-E2 heterodimer, we discovered that fitness-compensating E1 mutations could accelerate escape from E2-targeting antibodies, highlighting the importance of considering both proteins in vaccine design. Our approach also identified bNabs predicted to be resilient against escape mutations in both E1 and E2 [3]. In the space of antiviral therapy, our models revealed the significant role of epistasis in the evolution of drug resistance mutations (DRMs) targeting the non-structural 3 (NS3) protein. We identified specific DRMs associated with strong epistatic interactions, which appear to facilitate viral escape from drug-induced selection pressures [4].

Our developed computational models provide valuable insights for rational vaccine design and the development of more effective antiviral therapies, potentially leading to improved strategies for combating HCV infection.

  1. Quadeer, A. A., Louie, R. H. Y. & McKay, M. R. Identifying immunologically-vulnerable regions of the HCV E2 glycoprotein and broadly neutralizing antibodies that target them. Nat Commun 10, 2073 (2019).
  2. Zhang, H., Quadeer, A. A. & McKay, M. R. Evolutionary modeling reveals enhanced mutational flexibility of HCV subtype 1b compared with 1a. iScience 25, (2022).
  3. Zhang, H., Bull, R. A., Quadeer, A. A. & McKay, M. R. HCV E1 influences the fitness landscape of E2 and may enhance escape from E2-specific antibodies. Virus Evolution 9, vead068 (2023).
  4. Zhang, H., Quadeer, A. A. & McKay, M. R. Direct-acting antiviral resistance of Hepatitis C virus is promoted by epistasis. Nat Commun 14, 7457 (2023).