Fig. 6: Examples of applying expansion microscopy to study virus biology.
From: Visualising viral interactions and mechanisms at the nanoscale with expansion microscopy
Representative examples of expansion microscopy in the study of virus biology. a Localisation of the hepatitis C virus (HCV) pS225-NS5A protein (phosphorylated proteoform of the viral NS5A protein) with respect to the total amount of NS5A in Huh7 cells79. Post-expansion confocal images show NS5A and pS225-NS5A (left, scale bar in magnified views: 1 µm) as well as three-dimensional reconstructions of NS5A puncta (right). NS5A is a multifunctional phosphoprotein essential for HCV genome replication and assembly, and expansion microscopy enables nanoscale analysis of its spatial organisation. b Expansion microscopy of HIV-1 assembly sites in HeLa cells84. Maximum intensity projections before (pre-expansion, left) and after expansion (post-expansion, right) reveal nanoscale co-clustering of the viral structural protein Gag with host transmembrane proteins such as PSGL-1, regulated by local enrichment of the acidic phospholipid PIP₂. c Confocal imaging of SARS-CoV-2–infected A549-ACE2 cells at 24 h post-infection. Pre-expansion images (left) show viral nucleocapsid protein (N), spike protein (S), and host stress granule marker G3BP1, while post-expansion images (right) resolve nanoscale co-localisation of N with G3BP1 and S, highlighting the interplay between viral components and host cell structures during infection91. In all post-expansion images, the scale bars correspond to pre-expansion scales. Images are taken from the cited articles under CC BY 4.0 international licenses.
