Analysis of SARS-CoV-2-controlled autophagy reveals spermidine, MK-2206, and niclosamide as putative antiviral therapeutics

Nils C. Gassen; Jan Papies; Thomas Bajaj; Frederik Dethloff; Jackson Emanuel; Katja Weckmann; Daniel E. Heinz; Nicolas Heinemann; Martina Lennarz; Anja Richter; Daniela Niemeyer; Victor M. Corman; Patrick Giavalisco; Christian Drosten; Marcel A. Müller

We aimed to characterize the effect of SARS-CoV-2 infection on autophagy by applying previously 66 established assays (10) and additionally including detailed analyses of upstream autophagy regulators 67 according to expert-curated guidelines for detecting autophagy (11). First, we explored whether SARS- The copyright holder for this preprint (which was not peer-reviewed) is . https://doi.org/10.1101/2020.04.15.997254 doi: bioRxiv preprint fusion of APs with lysosomes to autophagy-active autophagolysosomes (AL) (11). Based on our 74 previous experience (10), we chose a low MOI of 0.0005 and time points 8, 24, and 48 hours post 75 infection to monitor autophagy during the exponential growth of SARS-CoV-2 reaching maximum titers 76 of 10 7 genome equivalents per ml (GE/ml; NCI-H1299) and 10 10 GE/ml (VeroFM) at 48 hours post 77 infection ( Figure S1a) . We found that 100 nM of BafA1 was sufficient to induce maximal LC3B lipidation 78 levels in both cell cultures (Figure S1b-d) . Immunoblotting of LC3B-II/I in the presence of 100 nM BafA1 79 indicated that mock-infected compared to SARS-CoV-2-infected cells showed a significant increase of 80 LC3B-II over LC3B-I due to the BafA1-induced inhibition of autophagic flux (Figures 1a-b) . 142 the author/funder. All rights reserved. No reuse allowed without permission.