Cryo-electron tomography of viral infection — from applications to biosafety

• Published in: Current opinion in virology Vol. 61; p. 101338
• Main Authors: Zimmermann, Liv, Chlanda, Petr
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.08.2023
• Subjects: Containment of Biohazards; COVID-19; Cryoelectron Microscopy - methods; Electron Microscope Tomography - methods; Humans; Virus Diseases
• ISSN: 1879-6257; 1879-6265
• DOI: 10.1016/j.coviro.2023.101338

Cellular cryo-electron tomography (cryo-ET) offers 3D snapshots at molecular resolution capturing pivotal steps during viral infection. However, tomogram quality depends on the vitrification level of the sample and its thickness. In addition, mandatory inactivation protocols to assure biosafety when handling highly pathogenic viruses during cryo-ET can compromise sample preservation. Here, we focus on different strategies applied in cryo-ET and discuss their advantages and limitations with reference to severe acute respiratory syndrome coronavirus 2 studies. We highlight the importance of virus-like particle (VLP) and replicon systems to study virus assembly and replication in a cellular context without inactivation protocols. We discuss the application of chemical fixation and different irradiation methods in cryo-ET sample preparation and acquisition workflows. •Whole-cell and on-lamellae cryo-ET for structural studies of viral infection.•Inactivation protocols for improved structural preservation and biosafety.•VLP and replicon model systems for structural biology of highly pathogenic viruses.