Fig. 1.

CD59 proteins associated with IBV particles. (a, b and c) IBV virions were twice purified from the supernatant of IBV-infected Vero, H1299 and DF1 cells by 10–50 % sucrose gradient centrifugation. Aliquots of the fractions from top (T) to bottom (B) were analysed by Western blotting for detection of viral N proteins, CD59 and beta-actins. The supernatant from mock-infected cells was set as the control. (d) Immunocapture of IBV virions by anti-CD59 mAbs from the cell-free supernatant of IBV-infected cells and the purified IBV particles (fraction 10 after 10–50 % sucrose gradient centrifugation). Viral genomic RNA capture rates were quantified by sqRT-PCR. The purified viruses captured by mouse immunoglobulin G (IgG) were tested in parallel. All experiments were independently conducted in triplicate.