V1V2 deletion impairs virus infectivity and is reflected by a high stoichiometry of entry.

<p>(A) Comparison of infectivity of pseudoviruses expressing wt and V1V2-deleted envs upon infection of TZM-bl cells. Data points depict mean values of luciferase reporter activity per µl virus stock measured in 3 independent experiments. The p-value was calculated by a paired t-test. (B and C) Relative infectivity of mixed trimer infection experiments of 10 wt envs and their V1V2 deleted variants using the R508S/R511S (B) and the V513E (C) dominant-negative mutations are shown. Infectivity of pseudotyped virus stocks expressing the indicated ratios of dominant-negative mutant envs was measured on TZM-bl cells. Infectivity of virus stocks containing solely functional envelope were set as 100%. Data depict mean and SD from 2 to 4 independent experiments. (D) Estimates of T for the wt and V1V2-deleted envs derived from mixed trimer experiments. Data points are the mean of the individual estimates of T obtained with the R508S/R511S and V513E dominant-negative mutations. The p-value was calculated by a paired t-test.