Fig. 4.

ASOs targeting SL1 renders the SARS-CoV-2 5′ UTR susceptible to Nsp1-mediated shutdown. (A) Schematic of SL1 region and various ASOs (which are all LNA mixmers unless otherwise noted). Complementary sequences between ASOs and SL1 are matched by color. (B) Initial screen of ASO activity. Each ASO was transfected at 50 nM with CoV-2 reporter along with either MBP-alone or MBP-Nsp1. Bar on far right indicates cotransfection with a reporter lacking SL1 as a control. (C) Images of HeLa cells transfected with 50 nM ASO4, -7, -6, or a control ASO along with CoV-2 or ΔSL1 reporter and either MBP or MBP-Nsp1. Intensity values are false-colored according to a scale (Right). (D) Quantification of C. (E) Dose–response assay of each ASO. Cells were transfected with CoV-2 reporter and MBP or MBP-Nsp1 as above. ASOs were transfected at either 25, 50, or 100 nM. (Scale bars 10 μm.) *P < 0.05, **P < 0.01, and ***P < 0.001, Student t test.