Figure 4. AGO2 slicing activity restricts IAV, EMCV and VSV in mammalian somatic cells.

a,b, Representative plaque assay image of IAV (PR8)-infected (indicated MOIs for 16 h) MEFs from WT mice (black) or mice carrying one (Ago2^D597A/+, grey) or two (Ago2^D597A/D597A, blue) alleles of catalytic-inactive AGO2. Virus titres quantified as plaque-forming units (p.f.u.) per ml for the indicated MOIs are shown. c, Relative influenza HA RNA as quantified by qPCR in WT or Ago2^D597A/D597A MEFs infected with IAV (PR8) or IAV delNS1 mutant. d, Expression of RNAi components, type I IFNs and IFN-stimulated genes (ISGs) in WT (black) or Ago2^D597A/D597A (blue) MEFs following influenza infection. e,f, Virus levels in WT (black), Ago2^D597A/+ (grey) and Ago2^D597A/D597A (blue) MEFs infected with EMCV at indicated MOIs for 16 h as measured by plaque assays of cell supernatants (e) or qPCR of EMCV 2A-2B RNA relative to the housekeeping gene TATA box protein (Tbp) (f). g–i, Virus levels in WT (black), Ago2^D597A/+ (grey) and Ago2^D597A/D597A (blue) MEFs infected with VSV, at the indicated MOIs, for 16 h as measured by plaque assays of cell supernatants (g) or qPCR of VSV-G RNA relative to Tbp (h) or immunoblot of VSV G, N, P and M proteins (i). j–l, Virus levels in WT (black) and Ago2^D597A/D597A (blue) MEFs infected with VSV in the presence of 10 μg ml⁻¹ anti-IFNAR antibody (aIFNAR; MAR1-5A3, dotted lines) as quantified by plaque assays (j,k) or qPCR of VSV-G RNA (l). m, Expression of IFN-stimulated gene 15 (Isg15) relative to Tbp as measured by qPCR-confirmed IFNAR blocking. All data are two separate lines of MEFs performed two to three independent times in triplicate, combined. All error bars are s.e.m. *P < 0.05, **P < 0.01, ***P < 0.001, measured by an unpaired t-test or two-way ANOVA (Prism). N.S., not significant.