Identification and validation of key host cellular factors directing SARS-CoV-2 assembly and consequences for neuronal proteostasis
Final Report Abstract
In this one-year project we generated highly potent antibodies against several SARS-CoV2 proteins, proved their specificity and used them to establish a reliable in-cell ELISA, i.e. an immunological assay equivalent to a functional bioassay measuring infectivity and validated against such infectivity assays of all relevant SARS-CoV2 strains, including alpha, beta, delta, and omikron 1. We used this assay to screen a number of novel anti-SARS-CoV2 drugs, namely those that do not target the virus itself but host factors that SARS-CoV2 recruits for its replication and that, if inhibited by those drugs, concurrently inhibit SARS- CoV2. The lead compound #431 was effective at around 100 nM in Calu-3 cells in a doseresponse relationship and, by drug affinity chromatography was demonstrated to interact with a protein complex containing proteins p62/SQSTM1, VCP/p97, 14-3-3, and CAPN2. Yet more chemical analogues were shown to be of variable effectiveness allowing the establishment of a structure-activity-relationship and hence proving specificity of the compound. SARS-CoV2 was shown to increase tau phosphorylation in a neuroblastoma cell line overexpressing mutant tau which was prevented by the presence or absence of virus indicating that the targeted host proteins mediate cellular pathology associated to neurotoxicity. A future continuation of this project will focus on using #431 in an animal trial of SARS-CoV2 infection, and further characterize the significance of the candidate proteins targeted by #431, and possible induced cellular pathology.
Publications
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A pan-respiratory antiviral chemotype targeting a transient host multi-protein complex. Open Biology, 14(6).
Michon, Maya; Müller-Schiffmann, Andreas; Lingappa, Anuradha F.; Yu, Shao Feng; Du, Li; Deiter, Fred; Broce, Sean; Mallesh, Suguna; Crabtree, Jackelyn; Lingappa, Usha F.; Macieik, Amanda; Müller, Lisa; Ostermann, Philipp Niklas; Andrée, Marcel; Adams, Ortwin; Schaal, Heiner; Hogan, Robert J.; Tripp, Ralph A.; Appaiah, Umesh ... & Lingappa, Vishwanath R.
