The effects of the human innate pattern recognition receptor L-ficolin and its variants against Hepatitis C virus infection

Enveloped virus infections have major impacts to global health and economy. For example, Hepatitis C virus is a leading cause of chronic hepatic disease, and the 2013 Ebola virus outbreak highlighted the need for broadly-active treatments. The immune factors behind successful control of these infect...

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Main Author: Mason, Christopher Paul
Format: Thesis (University of Nottingham only)
Language:English
Published: 2019
Subjects:
Online Access:https://eprints.nottingham.ac.uk/56745/
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author Mason, Christopher Paul
author_facet Mason, Christopher Paul
author_sort Mason, Christopher Paul
building Nottingham Research Data Repository
collection Online Access
description Enveloped virus infections have major impacts to global health and economy. For example, Hepatitis C virus is a leading cause of chronic hepatic disease, and the 2013 Ebola virus outbreak highlighted the need for broadly-active treatments. The immune factors behind successful control of these infections are poorly understood. A potential common target for intervention is the glycosylation patterns that decorate the surface proteins of enveloped virions. L-ficolin is a liver-expressed lectin that binds several diverse enveloped viruses via their glycosylated surface envelope proteins, and contributes to the innate immune response through blocking of viral entry and complement activation. Two mutations, Thr236Met and Ala258Ser, in L-ficolin are maintained in human populations at high frequencies and influence ligand binding, serum L-ficolin concentration, and response to microbial infection. In this study, expression of recombinant His6-tagged L-ficolin was optimised. It was hypothesised that L-ficolin mutants described above have superior ligand binding and antiviral properties. The T236M mutation conferred increased binding of acetylated BSA. In an associated study, L-ficolin was used as an oligomeric scaffold for presenting anti-HCV nanobodies. This novel chimaeric molecule, named ficobody, exhibited superior ligand- and HCV glycoprotein-binding activity when compared to L-ficolin. This is the first instance in which lectins have been used as a scaffold for protein presentation. Furthermore, correlations between serum L-ficolin concentrations and HCV infection outcome and ethnicity were investigated, finding that chronic HCV patients had significantly lower L-ficolin concentrations. Finally, mutant viruses were used to explore if specific glycosylation sites on the HCV glycoproteins are essential for L-ficolin interaction, producing data that supported previous findings on the roles of specific glycosylation sites in HCV entry. Understanding the antiviral significance of L-ficolin variants could inform the use of L-ficolin and ficobody in the prognosis, prophylaxis and treatment of a wide variety of enveloped virus infections.
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spelling nottingham-567452025-02-28T14:31:40Z https://eprints.nottingham.ac.uk/56745/ The effects of the human innate pattern recognition receptor L-ficolin and its variants against Hepatitis C virus infection Mason, Christopher Paul Enveloped virus infections have major impacts to global health and economy. For example, Hepatitis C virus is a leading cause of chronic hepatic disease, and the 2013 Ebola virus outbreak highlighted the need for broadly-active treatments. The immune factors behind successful control of these infections are poorly understood. A potential common target for intervention is the glycosylation patterns that decorate the surface proteins of enveloped virions. L-ficolin is a liver-expressed lectin that binds several diverse enveloped viruses via their glycosylated surface envelope proteins, and contributes to the innate immune response through blocking of viral entry and complement activation. Two mutations, Thr236Met and Ala258Ser, in L-ficolin are maintained in human populations at high frequencies and influence ligand binding, serum L-ficolin concentration, and response to microbial infection. In this study, expression of recombinant His6-tagged L-ficolin was optimised. It was hypothesised that L-ficolin mutants described above have superior ligand binding and antiviral properties. The T236M mutation conferred increased binding of acetylated BSA. In an associated study, L-ficolin was used as an oligomeric scaffold for presenting anti-HCV nanobodies. This novel chimaeric molecule, named ficobody, exhibited superior ligand- and HCV glycoprotein-binding activity when compared to L-ficolin. This is the first instance in which lectins have been used as a scaffold for protein presentation. Furthermore, correlations between serum L-ficolin concentrations and HCV infection outcome and ethnicity were investigated, finding that chronic HCV patients had significantly lower L-ficolin concentrations. Finally, mutant viruses were used to explore if specific glycosylation sites on the HCV glycoproteins are essential for L-ficolin interaction, producing data that supported previous findings on the roles of specific glycosylation sites in HCV entry. Understanding the antiviral significance of L-ficolin variants could inform the use of L-ficolin and ficobody in the prognosis, prophylaxis and treatment of a wide variety of enveloped virus infections. 2019-07-19 Thesis (University of Nottingham only) NonPeerReviewed application/pdf en arr https://eprints.nottingham.ac.uk/56745/1/4219249%20-%20Christopher%20Mason%20-%20PhD%20Thesis.pdf Mason, Christopher Paul (2019) The effects of the human innate pattern recognition receptor L-ficolin and its variants against Hepatitis C virus infection. PhD thesis, University of Nottingham. Microbiology; Immunology; Virology; L-Ficolin; Virus; Innate Immune System; Hepatitis C Virus; Ebola Virus
spellingShingle Microbiology; Immunology; Virology; L-Ficolin; Virus; Innate Immune System; Hepatitis C Virus; Ebola Virus
Mason, Christopher Paul
The effects of the human innate pattern recognition receptor L-ficolin and its variants against Hepatitis C virus infection
title The effects of the human innate pattern recognition receptor L-ficolin and its variants against Hepatitis C virus infection
title_full The effects of the human innate pattern recognition receptor L-ficolin and its variants against Hepatitis C virus infection
title_fullStr The effects of the human innate pattern recognition receptor L-ficolin and its variants against Hepatitis C virus infection
title_full_unstemmed The effects of the human innate pattern recognition receptor L-ficolin and its variants against Hepatitis C virus infection
title_short The effects of the human innate pattern recognition receptor L-ficolin and its variants against Hepatitis C virus infection
title_sort effects of the human innate pattern recognition receptor l-ficolin and its variants against hepatitis c virus infection
topic Microbiology; Immunology; Virology; L-Ficolin; Virus; Innate Immune System; Hepatitis C Virus; Ebola Virus
url https://eprints.nottingham.ac.uk/56745/