FIG. 6.

Glycosylation on HA reduces the efficiency of lysis of influenza virus-infected cells. (A) Cell surface expression of modified HA proteins following infection of 143BTK⁻ cells with recombinant influenza viruses. 143BTK⁻ cells were infected with the viruses indicated and were incubated overnight, and then surface HA expression was detected using a polyclonal anti-H3-specific rabbit serum and fluorescent anti-rabbit secondary (2ry) antibody. The mean fluorescence intensity (MFI) of cells stained with the secondary antibody only (white bars) or with both the anti-HA antiserum and secondary antibody (black bars) is shown. (B) Data from a ⁵¹Cr release assay comparing the percent specific lysis of uninfected 143BTK⁻ cells (dashed line, filled squares) to those of cells infected with the A/Victoria/3/75 influenza virus isolate (solid line, filled squares) or recombinant influenza viruses 26/99 HA/NA (dashed line, filled triangles), G1Δ (solid line, open circles), or G2Δ (solid line, open squares) by PBMC effectors at a range of E:T ratios. These results are representative of findings from two independent experiments. Ab, antibody.