Structural changes in dengue virus when exposed to a temperature of 37°C

Area of Science:

• Virology
• Structural Biology
• Cryo-Electron Microscopy

Background:

• Antibody binding studies suggested temperature-induced structural changes in insect cell-derived dengue virus.
• Previous observations indicated a transition from smooth to rough viral surfaces upon incubation at 37°C.

Purpose of the Study:

• To present the cryo-electron microscopy (cryo-EM) structures of dengue virus incubated at 37°C.
• To elucidate the structural alterations in dengue virus at an elevated temperature.

Main Methods:

• Cryo-electron microscopy was used to image dengue virus particles incubated at 37°C.
• Image analysis identified distinct particle classes, and 3D reconstruction was performed on a major class.

Main Results:

• Four classes of dengue virus particles were observed at 37°C.
• A predominant class (50% of particles) exhibited an expanded E protein shell with a hole at the 3-fold vertices.
• Analysis suggests weakened interdimeric and some intradimeric E protein interactions.

Conclusions:

• Dengue virus undergoes significant structural changes at 37°C, characterized by E protein shell expansion and pore formation.
• These temperature-induced structural modifications likely alter the accessibility of viral epitopes.
• The findings provide insights into dengue virus dynamics and potential antibody interactions.