FIG. 1.

Ability of HIV-1 LAI Env mutants to complement virus entry. Virus entry in MT4 cells (A) or HeLa P4 (CD4⁺) cells (B) was measured by quantification of luciferase activity. Cells were inoculated in triplicate with luciferase reporter viruses pseudotyped with HIV-1 LAI wild-type (W) or mutant Env. The inoculum consisted of supernatants obtained after cotransfection of 293T cells with wild-type and mutant env expression vectors and the env-defective pNL-Luc-E⁻R⁺ vector (100 ng of p24 per infection). The background was measured by inoculating cells with supernatants obtained after transfection of 293T cells with the pNL-Luc-E⁻R⁺ vector alone. The values indicated were those obtained after background subtraction. rlu, relative light units.