Periodic Reporting for period 2 - MAD-CoV 2 (Modern approaches for developing antivirals against SARS-CoV 2)
Période du rapport: 2021-08-01 au 2022-07-31
The general objectives has been, i) to establish state-of-the-art infection model system; ii) to verify the antiviral activity of recombinant soluble human Angiotensin-converting enzyme 2 (srhACE-2), iii) to identify and characterize new essential host cell factors for SARS-CoV-2 and other Corona viruses with pandemic potential, iv) to develop novel antiviral therapies to target novel host factor essential for SARS-CoV-2 infections, v) to exploit project outputs and disseminate the results to the scientific community, public health bodies, NGOs, outbreak management teams.
The general concept of the project has been to address the objectives by two different approaches;
1.The fast track: Demonstrating that GMP clinical grade soluble recombinant human ACE2 (srhACE2) ameliorates SARS-CoV-2 infections, (ACE2 being the receptor of SARS-CoV-2)
2.The innovative track: Identifying and exploiting novel therapeutic targets using unique high-throughput mutagenesis screens.
In period 2 the PMT continued the scientific and financial monitoring of the project. The first face-to-face consortium meeting in Barcelona in March 2022, one face-to-face ExCom meeting and two online ExCom meetings were organized. The PMT also coordinated the preparation for the mid-term review and the implementation of the action plan following the reviewers’ recommendations. Finally, the PMT pursued interaction with the other IMI funded projects to seek opportunities for collaboration.
Within WP2 we have verified the antiviral activity of recombinant soluble human Angiotensin-converting enzyme 2 (srhACE-2) against all Variants of Concorn (VOC). In addition, we demonstrated the antiviral activity of srhACE-2 in Vivo. In period 2, we also investigated the role of ACE2 in molecular pathogenesis of COVID-19 in diabetic condition, using 3D-organoids.
Within WP3, after establishing cell lines amenable to forward genetic resistance screens with the SARS-CoV-2 virus, such screens were extensively performed in the second working period. One host cell factor required for infection could be identified and is currently tested in validation systems. Additonal screens with varying setups will identify more relevant host cell factors.
In addition, a Spike-protein interaction screen with the mouse lectin library was successfully conducted in the first reporting period. During the second period, the human lection library was cloned, expressed, and purified. It will be used for Spike interaction screens in an extended third period.
Within WP4, partner JLU has continued the work on the host cell factor SPEN/SHARP that had started in the previous period. SPEN/SHARP is a transcription repressor that was published to be an important SARS-CoV-2 host cell factor (Daniloski et al., Cell 2021, DOI: 10.1016/j.cell.2020.10.030). To pursue this further, JLU equipped wt and SPEN/SHARP CrispR/Cas9 KO Hela cells with ACE2 to make them permissible for SARS-CoV-2. Subsequent infection experiments however, did not reveal a particular dependency of SARS-CoV-2 replication on SPEN/SHARP, indicating it is not an essential host factor. This subproject was therefore discontinued.
Partner JLU also investigated the sensitivity of different SARS-CoV-2 variants to the antiviral type I interferons (IFNs), and found that the now dominant variant of concern Omicron (BA.1) has evolved towards an increased IFN resistance (Shalamova et al., PNAS Nexus 2022, DOI: 10.1101/2022.02.17.480904).
In addition, partner JLU used results from a previous genome-wide screen and discovered the membrane-anchored cell protein LRP1 as an important cofactor of infection by a series of RNA viruses including SARS-CoV-2 (collaboration with partner 1 SVA and partner 3 IMBA). In fact, SARS-CoV-2 and its predecessor SARS-CoV-1 were among the most LRP1-dependent RNA viruses we studied. The results were published as preprint (Devignot et al., bioRxiv 2022, DOI: 10.1101/2022.02.17.480904) and reviewer experiments are currently ongoing.
Within WP5, IT has prepared the project website, and the project communication pack in period 1. Furthermore, partner IBEC has been in charge to supervise MAD-CoV 2 Virtual Reality video and mobile app. Both dissemination tools were delivered by the expected time (31/07/2021). MAD-CoV 2 activity has been disseminated by the partners to the scientific community and the general public in various conferences, courses and workshops.