FIG 1.

BM1 shuttled between the cytoplasm and nucleus of 293T cells during infection. 293T cells were incubated with or without influenza B virus diluted in DMEM (1 μg of TPCK-trypsin/ml) at an MOI of ∼1. After a 1-h absorption at 37°C, the culture medium was replaced with DMEM (2% FBS), and the cells were further incubated at 37°C with 5% CO₂. The cells were then fixed with PBS (4% paraformaldehyde) at the indicated time points postinfection. Intracellular localization of BM1 and staining with anti-BM1 polyclonal antibody were performed, followed by imaging with a confocal laser scanning fluorescence microscope (Olympus LSCMFV500).