Giant Plasma Membrane Vesicles as Cellular‐Mimics for Probing SARS‐CoV‐2 Binding at Single Particle Level.

Membrane receptors, attachment factors and various other membrane factors play a critical role in the specific attachment of virus particles to a cell surface. Researchers have been employing a range of model systems starting from receptor‐reconstituted lipid membranes to live cells for quantitative evaluation of virus‐receptor/attachment factor interactions. In this work, we show that giant plasma membrane vesicles (GPMVs) derived from adherent cells are a suitable cell‐mimicking model system to examine the binding of SARS‐CoV‐2 to cellular receptors. We evaluated the binding of cell‐cultured SARS‐CoV‐2 to GPMVs by imaging single virus particles with the wide‐field fluorescence microscopy technique. The GPMVs were derived from three different cell lines, i. e., Vero, HEK293T and A549. We compared the number of bound virus particles per cell, cell‐attached GPMV, and cell‐free GPMV of three different cell lines. We explain the observed trend in the data from the expression level of endogenous ACE2 protein and also, conclude that the protein is functional in GPMVs for virus and antibody binding. [ABSTRACT FROM AUTHOR]