FIG. 6.
Neutralization and escape of cell-bound HIV. (A) Kinetics of escape of magnetically adsorbed HIV-1IIIBnls.β-gal from neutralization by MAb b12. (B) Neutralization kinetics of cell-bound HIV-1IIIBnls.β-gal. Virus was magnetically adsorbed at 37°C to HeLa-CD4 cells cultured in medium containing 5 μg/ml MAb b12. At different times postadsorption, cells were washed twice with culture medium containing no Ab and further incubated for 4 days. Data are presented as percentages of the mean infectivity measured in cultures incubated with IVIG control Ab. Neutralization kinetics of cell-free HIV-1IIIB by 5 μg/ml MAb b12 are plotted for comparison. (C) Kinetics of escape of cell-bound HIV from protease-mediated inactivation and MAb b12-mediated neutralization. Data points represent means ± SEMs for three or four replicate samples. β-Gal+, β-galactosidase positive.