High-throughput proteomic analysis of the dengue virus secretome and the identification of plasma biomarkers of disease severity

  • Viravarn Luvira

Student thesis: Doctoral ThesisDoctor of Philosophy (PhD)

Abstract

Dengue virus (DENV) causes the most important arthropod-borne viral disease of humans. Dengue (DEN) pathogenesis is not well understood and there are neither fully protective vaccines nor antiviral drugs to prevent DEN. A diagnostic test to predict disease severity is also lacking. A greater understanding of the cellular changes that occur in response to DENV infection will increase our understanding of pathogenesis and potentially lead to the development of new treatment options. In this study, quantitative mass spectrometry (MS) was therefore used to systematically analyse the host response to DENV infection both in vitro and in vivo.

Initially, the proteome and secretome of DENV infected HEK293T cells and HEK293T cells expressing a DENV replicon were compared. Bioinformatic analysis of the results showed that the replicon system was good surrogate for viral replication studies.

The combined proteomic/secretomic analysis was then extended to DENV infected Huh-7 liver cells. Bioinformatic analysis of the results showed that the predominant effect of infection was a significant decrease in the levels of proteins, both in the proteome and secretome, that were involved in “complement and coagulation cascades” and “lipid metabolic” processes.
Proteomic analysis of serum from patients with different grades of DEN identified proteins that were significantly altered in response to DENV infection and two proteins, C-reactive protein and apolipoprotein CII, that could be used to discriminate disease states.

The results of the proteomic analyses using cell-based models and patient serum were then compared, which revealed that Huh-7 cells provide a good model for studying the role of complement, coagulation and acute phase proteins (APPs) in DEN.

The results of the proteomic analyses were validated for selected APPs. The levels of APPs in DENV infected Huh-7 cells could be rescued by treatment with MG132, suggesting liver APPs are degraded by the proteasome in DENV infection.
Date of Award23 Jan 2020
Original languageEnglish
Awarding Institution
  • The University of Bristol
SupervisorDavid J Morgan (Supervisor) & Andrew D Davidson (Supervisor)

Keywords

  • Dengue
  • Proteomics
  • acute phase proteins
  • fibrinogens

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