RT Journal Article
SR Electronic
T1 A spatial multi-scale fluorescence microscopy toolbox discloses entry checkpoints of SARS-CoV-2 variants in Vero E6 cells
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.03.31.437907
DO 10.1101/2021.03.31.437907
A1 Barbara Storti
A1 Paola Quaranta
A1 Cristina Di Primio
A1 Nicola Clementi
A1 Nicasio Mancini
A1 Elena Criscuolo
A1 Pietro Giorgio Spezia
A1 Vittoria Carnicelli
A1 Giulia Lottini
A1 Emanuele Paolini
A1 Giulia Freer
A1 Michele Lai
A1 Mario Costa
A1 Fabio Beltram
A1 Alberto Diaspro
A1 Mauro Pistello
A1 Riccardo Zucchi
A1 Paolo Bianchini
A1 Giovanni Signore
A1 Ranieri Bizzarri
YR 2021
UL http://biorxiv.org/content/early/2021/06/28/2021.03.31.437907.abstract
AB We exploited a multi-scale microscopy imaging toolbox to address some major issues related to SARS-CoV-2 interactions with host cells. Our approach harnesses both conventional and super-resolution fluorescence microscopy and easily matches the spatial scale of single-virus/cell checkpoints. We deployed this toolbox to characterize subtle issues related to the entry phase of SARS-CoV-2 variants in Vero E6 cells. Our results suggest that in these cells the variant of concern B.1.1.7, (aka Alpha variant), became the predominant circulating variant in several countries by a clear transmission advantage. In fact, in these cells B.1.1.7 outcompetes its ancestor B.1.177 in terms of a much faster kinetics of entry. Given the cell-entry scenario dominated by the endosomal “late pathway”, the faster internalization of B.1.1.7 could be directly related to the N501Y mutation in the S protein, which is known to strengthen the binding of Spike receptor binding domain with ACE2. Remarkably, we also directly observed the main role of clathrin as mediator of late-entry endocytosis, reconciling it with the membrane localization of the ACE2 receptor previously attributed to caveolin-enriched rafts. Overall, we believe that our fluorescence microscopy-based approach represents a fertile strategy to investigate the molecular features of SARS-CoV-2 interactions with cells.Competing Interest StatementThe authors have declared no competing interest.