FIG. 8.

Pseudotyped virions bearing FS-containing envelopes are more sensitive to neutralization by MAbs. We compared HXB and FS-containing HXB (HxB/FS) virus pseudotypes for their sensitivity to neutralization by anti-gp120 MAbs. U87 cells stably transfected with CD4 and CXCR4 were infected as described in Materials and Methods in the presence of the indicated MAbs at a final concentration of 0.5 μg/ml. The results are combined from three independent experiments done in triplicate; standard errors of the mean are shown. Asterisks indicate statistical significance (P < 0.05). hIg, human immunoglobulins.