HPIV3 IBs inhibit HPIV3-induced SG formation.

(A-C) HeLa cells were transfected with an empty plasmid or plasmid encoding N or P for 24 h, then infected with HPIV3 (MOI = 1) for another 24 h. (A) Cells were immunostained for HPIV3 (purple), G3BP (green), and Myc/HA tag (viral protein, red). Nuclei were stained with DAPI (blue). “+” indicates the cells containing IBs. The white scale bar corresponds to 10 μm. (B and C) The percentage of cells containing IBs or SGs was quantified in three independent experiments. (D-F) HeLa cells were transfected with an empty plasmid or co-transfected with plasmids encoding GFP-P and N-Myc or the mutant N_L478A-Myc for 24h, then infected with HPIV3 (MOI = 1) for another 24 h. (D) Cells were immunostained for TIA-1 (purple) and Myc (red). Nuclei were stained with DAPI (blue). The white scale bar corresponds to 10μm. (E and F) The percentage of cells containing IBs or SGs was quantified in three independent experiments. (G-I) HeLa cells were either mock-infected or infected with HPIV3^HA-P (MOI = 10). At the indicated time points post-infection, (G) cells were immunostained for HPIV3 (purple), HA tag (green), and G3BP (red). Nuclei were stained with DAPI (blue). The white scale bar corresponds to 10 μm. (H and I) The percentage of cells containing IBs or SGs was quantified in three independent experiments. Data are represented as means ±SD. Student’s t test: * P<0.05, ** P<0.01, *** P<0.001, ns = not significant.