Viral Infection at High Magnification: 3D Electron Microscopy Methods to Analyze the Architecture of Infected Cells

Abstract

As obligate intracellular parasites, viruses need to hijack their cellular hosts and reprogram their machineries in order to replicate their genomes and produce new virions. For the direct visualization of the different steps of a viral life cycle (attachment, entry, replication, assembly and egress) electron microscopy (EM) methods are extremely helpful. While conventional EM has given important information about virus-host cell interactions, the development of three-dimensional EM (3D-EM) approaches provides unprecedented insights into how viruses remodel the intracellular architecture of the host cell. During the last years several 3D-EM methods have been developed. Here we will provide a description of the main approaches and examples of innovative applications.

Cytoarchitecture of Zika virus infection in human neuroblastoma and Aedes albopictus cell lines

“…Both cell types exhibited the hallmark membrane proliferation and rearrangements seen with many positive-strand RNA viruses (20). The 60–100 nm spherical virus-induced replication compartments were abundant and a clear apposition to the ER lamella was evident.…”

Rumen Virus Populations: Technological Advances Enhancing Current Understanding

“…The combination of electron microscopy and specialized staining techniques, enables the visualization of virus particle structures at nanometer scale, which could not otherwise be distinguished using conventional light microscopy. Several different electron microscopy technologies exist including scanning electron microscopy (SEM), transmission electron microscopy (TEM), high voltage electron microscopy, immunoelectron microscopy (IEM) and cryoelectron microscopy (cryoEM) with or without shadowing and three dimensional image reconstruction (reviewed by Ackermann, 2012;Romero-Brey and Bartenschlager, 2015). Of these technologies, TEM is the most widely used technique for the visualization of all types of viruses (Ackermann and Prangishvili, 2012;Popov et al, 2019).…”

The sleeping beauty kissed awake: new methods in electron microscopy to study cellular membranes

“…Three-dimensional EM has contributed considerably to the understanding of membrane rearrangements induced by viruses. As an example, ET showed how ( positive-strand) RNA viruses modify intracellular membranes utilized for the replicative cycle [70,71]. Flaviviruses such as dengue virus create invaginations of the endoplasmic reticulum, which probably facilitate genome replication while leaving a small opening through which replicated RNA can travel to the cytoplasm.…”