FIG. 8.
MAb binding to H9 cells infected with HIV-1MN and HIV-1HxB2 as measured by flow cytometry. (A) H9 cells infected with HIV-1MN were probed with IgG 4E10 (100 μg/ml), Fab Z13 (200 μg/ml), IgG 2F5 (100 μg/ml), IgG b12 (50 μg/ml), IgG 50–69 (10 μg/ml), and Fab ELZ510 (200 μg/ml). (B) H9 cells infected with HIV-1HxB2 were probed with IgG 4E10, IgG 2F5, IgG b12, and IgG KZ52 (100 μg/ml each) or IgG 50–69 (20 μg/ml). Infected cells were incubated in the presence or absence of 25 μg of sCD4 per ml for 1 h at 37°C prior to the addition of MAbs. Uninfected H9 cells were also probed by each MAb at the same concentration and always yielded background signals that were lower than that observed for the negative control MAbs on infected cells.