@article {Blanchard2020.04.24.060418, author = {Emmeline L. Blanchard and Daryll Vanover and Swapnil Subhash Bawage and Pooja Munnilal Tiwari and Laura Rotolo and Jared Beyersdorf and Hannah E. Peck and Nicholas C Bruno and Robert Hincapie and M.G. Finn and Frank Michel and Eric R. Lafontaine and Robert J. Hogan and Chiara Zurla and Philip J. Santangelo}, title = {Treating Influenza and SARS-CoV-2 via mRNA-encoded Cas13a}, elocation-id = {2020.04.24.060418}, year = {2020}, doi = {10.1101/2020.04.24.060418}, publisher = {Cold Spring Harbor Laboratory}, abstract = {Here, Cas13a has been used to target and mitigate influenza virus A (IAV) and SARS-CoV-2 using a synthetic mRNA-based platform. CRISPR RNAs (crRNA) against PB1 and highly conserved regions of PB2 were screened in conjunction with mRNA-encoded Cas13a. Screens were designed such that only guides that decreased influenza RNA levels in a Cas13-mediated fashion, were valid. Cas13a mRNA and validated guides, delivered post-infection, simulating treatment, were tested in combination and across multiplicities of infection. Their function was also characterized over time. Similar screens were performed for guides against SARS-CoV-2, yielding multiple guides that significantly impacted cytopathic effect. Last, the approach was utilized in vivo, demonstrating the ability to degrade influenza RNA in a mouse model of infection, using polymer-formulated, nebulizer-based mRNA delivery. Our findings demonstrate the applicability of Cas13a in mitigating respiratory infections both in vitro and in a mouse model, paving the way for future therapeutic use.Competing Interest StatementThe authors have declared no competing interest.}, URL = {https://www.biorxiv.org/content/early/2020/04/24/2020.04.24.060418}, eprint = {https://www.biorxiv.org/content/early/2020/04/24/2020.04.24.060418.full.pdf}, journal = {bioRxiv} }