Copy-back viral genomes induce a cellular stress response that interferes with viral protein expression without affecting antiviral immunity
Fig 3
RNA granules formed during RSV cbVG-high infection are canonical SGs.
(A) G3BP1 (red) and TIAR (green) staining for SGs in cells treated with SA (0.5 mM) for 1 h or infected with RSV cbVG-high (RSV NP, white) at MOI 1.5 TCID50/cell 23 hpi and treated with DMSO or CHX (10 μg/mL) for 1 h. (B) Quantification of SG-positive cells after drug treatment in SA or RSV cbVG-high infected cells. Approximately 150 cells were counted for each condition. Fold change relative to DMSO-treated cells is shown from three independent experiments. (C) RNA granule detection (G3BP1, red; TIAR, green) in A549 control and RNAseL KO cells transfected with poly I:C 10 μg/mL or infected with RSV cbVG-high (RSV NP, white) 24 hpi at MOI 1.5 TCID50/cell. (D) RNA granule detection (G3BP1, red; and TIAR, green) A549 cells transfected with poly I:C or RSV and SeV cbVG derived oligonucleotides RSV 238 and SeV 268. All widefield images were acquired with the Apotome 2.0 at 63× or 40× magnification. Scale bar = 50 μm. Numerical values plotted can be found in the Supporting information: S1 Data. cbVG, copy-back viral genome; CHX, cycloheximide; G3BP1, GTPase-activating protein-binding protein 1; hpi, hours postinfection; KO, knockout; MOI, multiplicity of infection; NP, nucleoprotein; RSV, respiratory syncytial virus; SA, sodium arsenite; SeV, Sendai virus; SG, stress granule; TIAR, TIA-1-related.