Preparation of ACE2 293T cell line
ACE2 expressing human embryonic kidney cells (HEK293T) were generated by
lentiviral transduction using pLENTI-hACE2-HygR (a gift from Raffaele De
Francesco; Addgene plasmid#155296) (Notarbartolo et al., 2021). 72h
after transduction the cells were FACS sorted based on the ACE2
expression detected with anti-hACE2 Alexa Fluor 488 conjugated
antibodies (catalog #Fab9332G, clone#535919; R&D Systems). A CRE
reporter was inserted into ACE2 293T cells using pLenti- V6.3
lox-dsRED-stop-lox-eGFP-blas (a gift from Ewa Snaar-Jagalska, Addgene
plasmid #106171) (Heitzer et al., 2019). After selection with the
Blasticidin, these cells were then FACS sorted based on their dsRED
intensity.