Copy-back viral genomes induce a cellular stress response that interferes with viral protein expression without affecting antiviral immunity
Fig 1
SGs form during RSV infection containing high levels of cbVGs.
(A) SG (G3BP1, magenta) and viral protein (RSV NP, yellow) detection 12 and 24 hpi with RSV cbVG-high or cbVG-low virus at MOI of 1.5 TCID50/cell. (B) Percent of SG-positive cells within the infected population 12 and 24 hpi with RSV cbVG-high and cbVG-low infections. Approximately 150 infected cells were counted per condition (average of 3 independent experiments shown). (C) SG (G3BP1, magenta) and viral protein (RSV NP, yellow) detection 24 hpi with RSV cbVG-high or cbVG-low at MOIs 0.1, 1.5, 5, and 10 TCID50/cell. (D) Percent of SG-positive cells within the infected population 24 hpi with RSV cbVG-high and cbVG-low virus at MOIs 0.1, 1.5, 5, and 10 TCID50/cell. Approximately 150 infected cells were counted per condition (average of 3 independent experiments shown). (E) SG detection (TIAR, white) in cells staining via FISH for stVG-high (orange) and cbVG (green) cells 24 hpi with RSV cbVG-high virus at MOI 1.5 TCID50/cell. (F) Percent of SG-positive cells within the stVG-high and cbVG-high cell populations during RSV cbVG-high infection (average of 3 independent experiments shown). All widefield images were acquired with the Apotome 2.0 at 63× magnification and are representative of 3 independent experiments. Scale bar = 50 μm. Statistical analysis: one-way ANOVA (*p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.00001). Numerical data plotted can be found in the Supporting information: S1 Data. cbVG, copy-back viral genome; FISH, fluorescence in situ hybridization; G3BP1, GTPase-activating protein-binding protein 1; hpi, hours postinfection; MOI, multiplicity of infection; NP, nucleoprotein; RSV, respiratory syncytial virus; SG, stress granule; TIAR, TIA-1-related.