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Updated: Oct 5, 2025
A Murine Model of Dengue Virus-induced Acute Viral Encephalitis-like Disease
Published on: April 28, 2019
Humoral immune response induced with dengue virus-like particles serotypes 1 and 4 produced in silkworm
Doddy Irawan Setyo Utomo1, Sabar Pambudi2, Enoch Y Park3,4
1Laboratory of Biotechnology, Department of Bioscience, Graduate School of Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan.
Abstract:
Dengue is an arboviral disease, which threatens almost half the global population, and has emerged as the most significant of current global public health challenges. In this study, we prepared dengue virus-like particles (DENV-LPs) consisting of Capsid-premembrane-envelope (CprME) and premembrane-envelope (prME) polypeptides from serotype 1 and 4, which were expressed in the silkworms using Bombyx mori nucleopolyhedrovirus (BmNPV) bacmid. 1CprME, 1prME, 4CprME, and 4prME expressed proteins in hemolymph, and the molecular weight of the purified proteins was 55 kDa, respectively. The purified polypeptides formed spherical Dengue virus-like particles (DENV-LPs) with ~ 30-55 nm in diameter. The immunoelectron microscopy (IEM) images revealed antigens to the surface of a lipid bilayer of DENV-LPs. The heparin-binding assay shows a positive relationship between absorbance and E protein domain III (EDIII) quantity, which is supported by the isothermal titration calorimetry assay. This indicates a moderate binding affinity between heparin and DENV-LP. The high correlation between patient sera and DENV-LP reactivities revealed that these DENV-LPs shared similar epitopes with the natural dengue virus. IgG elicitation studies in mice have demonstrated that DENV-LPs/CPrMEs elicit a stronger immune response than DENV-LP/prMEs, which lends credence to this claim.
Insights
Researchers developed dengue virus-like particles (DENV-LPs) using silkworms. These DENV-LPs mimic the natural virus, showing potential for dengue vaccine development.
Area of Science:
- Virology
- Immunology
- Biotechnology
Background:
- Dengue fever is a major global arboviral disease with significant public health impact.
- Developing effective vaccines and diagnostics for dengue remains a critical challenge.
Purpose of the Study:
- To produce dengue virus-like particles (DENV-LPs) from serotypes 1 and 4 using a silkworm expression system.
- To characterize the physical, biochemical, and immunological properties of the produced DENV-LPs.
- To evaluate the immunogenicity of DENV-LPs in a mouse model.
Main Methods:
- Dengue virus serotype 1 and 4 Capsid-premembrane-envelope (CprME) and premembrane-envelope (prME) polypeptides were expressed in silkworms using Bombyx mori nucleopolyhedrovirus (BmNPV).
- Proteins were purified from hemolymph, and DENV-LPs were characterized by size, morphology, and antigenicity using immunoelectron microscopy (IEM).
- Heparin-binding assays, isothermal titration calorimetry, and reactivity with patient sera were performed. Immunogenicity was assessed in mice.
Main Results:
- Spherical DENV-LPs (~30-55 nm) were successfully produced and purified, displaying viral antigens on their surface.
- DENV-LPs exhibited moderate binding affinity to heparin, correlated with E protein domain III (EDIII) quantity.
- DENV-LPs showed high reactivity with patient sera, indicating shared epitopes with the natural dengue virus.
- DENV-LPs/CPrMEs elicited a stronger IgG immune response in mice compared to DENV-LP/prMEs.
Conclusions:
- Silkworm expression is a viable method for producing functional DENV-LPs.
- The produced DENV-LPs possess key characteristics of the natural virus, including antigenic properties and moderate heparin binding.
- DENV-LPs, particularly those derived from CprME, demonstrate promising immunogenicity, supporting their potential as vaccine candidates against dengue.
