Figure 5.

Effect of variants on the susceptibility of tetherin to antagonism by SIVtan Env. (A) FACS analysis of 293T cells transfected with vectors expressing the indicated tetherin variants and SIVtan or HIV-1 M NL4-3 Env. Shown are results obtained with the antibody from eBioscience. (B) Cell surface expression levels of all tetherin variants. Shown are average values ± SD (n = 3) of the mean fluorescence intensities (MFIs) measured in the presence of SIVtan Env relative to those obtained in the presence of HIV-1 M NL4-3 Env which served as negative control (100%). (C) Virus release from 293T cells following transfection with the vpu-deficient proviral HIV-1 NL4-3 construct, an expression vector for HIV-1 M or SIVtan Env and varying amounts of tetherin expression plasmids. Infectious virus release was determined as described in the legend of Figure  3. Shown are average values ± SD derived from one experiment, performed in triplicate.