An entropic safety catch controls Hepatitis C virus entry and antibody resistance

  1. Lenka Stejskal
  2. Mphatso D Kalemera
  3. Charlotte B Lewis
  4. Machaela Palor
  5. Lucas Walker
  6. Tina Daviter
  7. William D Lees
  8. David S Moss
  9. Myrto Kremyda-Vlachou
  10. Zisis Zisis Kozlakidis
  11. Giulia Gallo
  12. Dalan Bailey
  13. William Rosenberg
  14. Christopher JR Illingworth
  15. Adrian J Shepherd
  16. Joe Grove  Is a corresponding author
  1. University College London, United Kingdom
  2. University of Glasgow, United Kingdom
  3. Birkbeck, University of London, United Kingdom
  4. World Health Organization, France
  5. The Pirbright Institute, United Kingdom
  6. University of Cambridge, United Kingdom

Abstract

E1 and E2 (E1E2), the fusion proteins of Hepatitis C Virus (HCV), are unlike that of any other virus yet described, and the detailed molecular mechanisms of HCV entry/fusion remain unknown. Hypervariable region-1 (HVR-1) of E2 is a putative intrinsically disordered protein tail. Here, we demonstrate that HVR-1 has an autoinhibitory function that suppresses the activity of E1E2 on free virions; this is dependent on its conformational entropy. Thus, HVR-1 is akin to a safety catch that prevents premature triggering of E1E2 activity. Crucially, this mechanism is turned off by host receptor interactions at the cell surface to allow entry. Mutations that reduce conformational entropy in HVR-1, or genetic deletion of HVR-1, turn off the safety catch to generate hyper-reactive HCV that exhibits enhanced virus entry but is thermally unstable and acutely sensitive to neutralising antibodies. Therefore, the HVR-1 safety catch controls the efficiency of virus entry and maintains resistance to neutralising antibodies. This discovery provides an explanation for the ability of HCV to persist in the face of continual immune assault and represents a novel regulatory mechanism that is likely to be found in other viral fusion machinery.

Data availability

The underlying data for this manuscript are provided as a Source Data file. Full molecular dynamic simulation trajectories are available here: https://zenodo.org/record/4309544

Article and author information

Author details

  1. Lenka Stejskal

    Institute of Immunity and Transplantation, University College London, London, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.
  2. Mphatso D Kalemera

    Institute of Immunity and Transplantation, University College London, London, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-9461-1117
  3. Charlotte B Lewis

    University of Glasgow, Glasgow, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.
  4. Machaela Palor

    Institute of Immunity and Transplantation, University College London, London, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.
  5. Lucas Walker

    Institute of Immunity and Transplantation, University College London, London, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.
  6. Tina Daviter

    Institute of Structural and Molecular Biology, Birkbeck, University of London, London, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.
  7. William D Lees

    Institute of Structural and Molecular Biology, Birkbeck, University of London, London, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.
  8. David S Moss

    Institute of Structural and Molecular Biology, Birkbeck, University of London, London, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.
  9. Myrto Kremyda-Vlachou

    Division of Infection and Immunity, University College London, London, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.
  10. Zisis Zisis Kozlakidis

    International Agency for Research on Cancer, World Health Organization, Lyon, France
    Competing interests
    The authors declare that no competing interests exist.
  11. Giulia Gallo

    The Pirbright Institute, Pirbright, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.
  12. Dalan Bailey

    Virus Programme, The Pirbright Institute, Guildford, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-5640-2266
  13. William Rosenberg

    Institute for Liver and Digestive Health, University College London, London, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-2732-2304
  14. Christopher JR Illingworth

    Department of Genetics, University of Cambridge, Cambridge, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-0030-2784
  15. Adrian J Shepherd

    Biological Sciences, Birkbeck, University of London, London, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-0194-8613
  16. Joe Grove

    University of Glasgow, Glasgow, United Kingdom
    For correspondence
    Joe.Grove@glasgow.ac.uk
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-5390-7579

Funding

Wellcome Trust (107653/Z/15/Z)

  • Joe Grove

Medical Research Council (MC_UU_12014)

  • Joe Grove

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Ethics

Human subjects: Fully consented blood samples (for IgG isolation) were collected from HCV+ patients under ethical approval: "Characterising and modifying immune responses in chronic viral hepatitis"; IRAS Number 43993; REC number 11/LO/0421.

Copyright

© 2022, Stejskal et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

Metrics

  • 1,134
    views
  • 241
    downloads
  • 7
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Lenka Stejskal
  2. Mphatso D Kalemera
  3. Charlotte B Lewis
  4. Machaela Palor
  5. Lucas Walker
  6. Tina Daviter
  7. William D Lees
  8. David S Moss
  9. Myrto Kremyda-Vlachou
  10. Zisis Zisis Kozlakidis
  11. Giulia Gallo
  12. Dalan Bailey
  13. William Rosenberg
  14. Christopher JR Illingworth
  15. Adrian J Shepherd
  16. Joe Grove
(2022)
An entropic safety catch controls Hepatitis C virus entry and antibody resistance
eLife 11:e71854.
https://doi.org/10.7554/eLife.71854

Share this article

https://doi.org/10.7554/eLife.71854

Further reading

    1. Evolutionary Biology
    2. Microbiology and Infectious Disease
    Vera Vollenweider, Karoline Rehm ... Rolf Kümmerli
    Research Article

    The global rise of antibiotic resistance calls for new drugs against bacterial pathogens. A common approach is to search for natural compounds deployed by microbes to inhibit competitors. Here, we show that the iron-chelating pyoverdines, siderophores produced by environmental Pseudomonas spp., have strong antibacterial properties by inducing iron starvation and growth arrest in pathogens. A screen of 320 natural Pseudomonas isolates used against 12 human pathogens uncovered several pyoverdines with particularly high antibacterial properties and distinct chemical characteristics. The most potent pyoverdine effectively reduced growth of the pathogens Acinetobacter baumannii, Klebsiella pneumoniae, and Staphylococcus aureus in a concentration- and iron-dependent manner. Pyoverdine increased survival of infected Galleria mellonella host larvae and showed low toxicity for the host, mammalian cell lines, and erythrocytes. Furthermore, experimental evolution of pathogens combined with whole-genome sequencing revealed limited resistance evolution compared to an antibiotic. Thus, pyoverdines from environmental strains have the potential to become a new class of sustainable antibacterials against specific human pathogens.

    1. Microbiology and Infectious Disease
    Dipasree Hajra, Raju S Rajmani ... Dipshikha Chakravortty
    Research Article

    Sirtuins are the major players in host immunometabolic regulation. However, the role of sirtuins in the modulation of the immune metabolism pertaining to salmonellosis is largely unknown. Here, our investigation focussed on the role of two important sirtuins, SIRT1 and SIRT3, shedding light on their impact on intracellular Salmonella’s metabolic switch and pathogenesis establishment. Our study indicated the ability of the live Salmonella Typhimurium to differentially regulate the levels of SIRT1 and SIRT3 for maintaining the high glycolytic metabolism and low fatty acid metabolism in Salmonella. Perturbing SIRT1 or SIRT3 through knockdown or inhibition resulted in a remarkable shift in the host metabolism to low fatty acid oxidation and high glycolysis. This switch led to decreased proliferation of Salmonella in the macrophages. Further, Salmonella-induced higher levels of SIRT1 and SIRT3 led to a skewed polarization state of the macrophages from a pro-inflammatory M1 state toward an immunosuppressive M2, making it more conducive for the intracellular life of Salmonella. Alongside, governing immunological functions by modulating p65 NF-κB acetylation, SIRT1, and SIRT3 also skew Salmonella-induced host metabolic switch by regulating the acetylation status of HIF-1α and PDHA1. Interestingly, though knockdown of SIRT1/3 attenuated Salmonella proliferation in macrophages, in in vivo mice model of infection, inhibition or knockdown of SIRT1/3 led to more dissemination and higher organ burden, which can be attributed to enhanced ROS and IL-6 production. Our study hence reports for the first time that Salmonella modulates SIRT1/3 levels to maintain its own metabolism for successful pathogenesis.