FIG 6.

The enhanced capacity of T1L/T3DM2 to infect and bind cells is lost upon ISVP formation. (A and B) Virions (2 × 10¹⁰ particles) of the indicated virus strains were resolved on SDS-PAGE and immunoblotted using μ1- and σ1-specific antibodies and appropriate secondary antibodies. (A) A representative immunoblot is shown. (B) The results are plotted as ratios of σ1 and μ1 band intensities from three independent virus preparations. Error bars indicate SD. (C) T1L or T1L/T3DM2 virions from a representative virus preparation serially diluted in PBS and mixed with human erythrocytes were incubated overnight. Results are expressed as HA titer, the lowest dilution of virus that was capable of showing a shield of hemagglutination. (D) L929 cells were adsorbed with 0.02 PFU per cell of ISVPs of the indicated viruses. After incubation at 37°C for 18 h, reovirus-positive cells were identified using reovirus-specific rabbit polyclonal antiserum and a secondary antibody. Results are expressed as mean percent reovirus-positive cells for three independent samples. Error bars indicate SD. (E) L929 cells were adsorbed with 5 × 10⁴ ISVPs per cell of the indicated virus strains. Attached virus was detected using reovirus-specific rabbit polyclonal antisera and secondary antibody. Cells were counterstained with a DNA stain. Viral attachment was quantified using an infrared scanner. Results are expressed as binding index (ratio of fluorescence of attached virus to that of cellular DNA) for three independent samples. Error bars indicate SD.