Electron Tomography as a Tool to Study SARS-CoV-2 Morphology.

Area of Science:

• Virology
• Microscopy
• Structural Biology

Background:

• Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes COVID-19, leading to global disruption.
• Emerging SARS-CoV-2 variants pose challenges to existing treatments and vaccines.
• Understanding viral replication at the ultrastructural level is crucial for developing new therapies.

Purpose of the Study:

• To review the application of electron microscopy (EM) for visualizing SARS-CoV-2 ultrastructure.
• To demonstrate how EM techniques can reveal distinct SARS-CoV-2 particle types and maturation stages.
• To highlight EM's potential in evaluating antiviral strategies against evolving viral variants.

Main Methods:

• Utilized transmission electron microscopy (TEM) to obtain high-resolution images of SARS-CoV-2.
• Employed electron tomography (ET) to reconstruct three-dimensional ultrastructural details of virions.
• Analyzed morphological changes during intracellular SARS-CoV-2 replication and virion formation.

Main Results:

• TEM and ET successfully visualized morphologically distinct types of SARS-CoV-2 particles.
• These methods provided insights into the maturation status of SARS-CoV-2 within infected cells.
• The study demonstrated the value of EM in understanding viral particle heterogeneity.

Conclusions:

• Electron microscopy (TEM and ET) is a powerful tool for studying SARS-CoV-2 ultrastructure and maturation.
• Visualizing viral particle morphology aids in understanding virus-host interactions.
• EM analysis offers a promising approach for developing antivirals effective against new SARS-CoV-2 variants and evaluating engineered RNA viruses.