FIG. 3.

Effects of mutations in the stem of the V3 loop on tropism of 89.6P Env. (A) Buoyant density sedimentation analysis of indicated V3 mutants in lentiviral vector particles, performed as described in Materials and Methods. (B) Effects of V3 mutations in strain 89.6P Env on infection of a CXCR4-tropic cell line, MT-2 (left), and a CCR-5-tropic indicator cell line, MAGI-CCR5 (right), using a luciferase reporter gene. The positions of the indicated V3 mutations in strain 89.6P Env are the same as those shown for the HXB2/BaL chimera (Fig. 2A). Both codon-modified and wild-type (wt) 89.6P Envs were used as positive controls.