FIG 8.

Relationship between changes in V1/V2 loop length, Env incorporation, and fusion to MDDCs and CD4 T cells. (A) Correlation between V1/V2 length and envelope incorporation. The ratio between the intensity of the Env and p24^Gag signal was measured for the entire set of WT and mutant genotypes. This quantification was performed twice using two sets of viral production. The change in envelope incorporation (Mut/WT) was calculated for each set, averaged, and plotted versus the changes in length (WT − Mut). (B) Link between envelope incorporation (Mut/WT) and fusion to resting or activated CD4 T cells and MDDCs (Mut/WT). (C) Effect of Env titration on fusion to MDDCs and CD4 T cells. Proviral DNA of the 109F4 WT envelope was cotransfected into 293T cells with NL4-3 ΔEnv at the indicated ratio and with BlaM-Vpr. After normalization by the use of the p24^Gag signal, MDDCs and CD4 T cells were infected with the equivalent of 500 ng of p24^Gag for 2 h. The level of fusion was reported relative to the level of fusion obtained with 100% WT 109F4. Envelope incorporation was measured by Western blotting with the b13 antibody, and p24^Gag was used to control for the amount of input virions.