FIG 6.

Effects of F412A on SERINC5-mediated restriction of various HIV-1 envelopes. (A) Infectivity values of HIV-1 NL43_ΔEnvΔNef pseudotyped with various HIV-1 envelopes produced in the presence of WT or F412A mutant of SERINC5-HA in JTAg-SERINC^−/− cells. The single-round infectivity was measured as β-galactosidase activity in TZM-bl target cells, and the background levels of luminescence (cells only) were deducted as relative light units. The restriction activity is shown as fold difference in infectivity in the absence and presence of WT or mutant SERINC5. (B) HIV-1 NL43_ΔEnvΔNef pseudotyped with Env_JRFL was produced in JTAg-SERINC^−/− cells in the presence of empty vector or genes encoding WT or F412A of SERINC5-HA. The pseudoviruses were preincubated with increasing concentrations of the indicated neutralizing antibodies for 1 h at 37°C, and then TZM-bl indicator cells were exposed to them. Neutralization activity was calculated as the percentage reduction in infectivity relative to infectivity in the absence of antibody. Data are means and SD from 3 independent experiments.