Fig. 1: CasRx-mediated CTSL knockdown inhibits pseudotyped coronaviruses and authentic SARS-CoV-2 Delta variant (B.1.617.2) infection in cells.
From: Cas13d knockdown of lung protease Ctsl prevents and treats SARS-CoV-2 infection
a, Schematic depiction of the SARS-CoV-1 (SARS-1), SARS-CoV-2 (SARS-2) or B.1.617.2 Delta variant entry pathway, with CTSL cleavage sites on their respective spike proteins and mutation sites on the B.1.617.2 Delta variant spike protein shown. b,c, Relative infection of pseudotyped virus in Vero-ACE2-TMPRSS2 (b) and Caco-2 (c) cells. Cells were pretreated with CasRx-pre-gControl or CasRx-pre-gCTSL for 24 h or 25 μM E-64d for 1 h, followed by incubation with infectivity-normalized pseudovirus SARS-2 (b and c), SARS-1 (c) or VSV (c). n = 12 biologically independent replicates each group except n = 6 in the background (Bg) group for b; n = 12 (SARS-2, SARS-1) or 9 (VSV) biologically independent replicates each group except n = 5 in all E-64d groups for c. d,e, CasRx-pre-gCTSL treatment reduces live B.1.617.2 Delta variant infection in Vero-ACE2-TMPRSS2 cells. d, Viral N gene transcript level as normalized to 18S ribosomal RNA. e, Virus infectivity as determined by TCID50. n = 3 biologically independent replicates for d and e. Background cells were not challenged with virus and used as a negative control. Data are presented as mean ± s.e.m. P values were calculated by two-tailed Student’s t-tests. NS, not significant; **P < 0.01; ****P < 0.001.
