FIG. 5.

Single-round infection assays with PM1-M87-selected viruses on TZM-bl cells and PM1 cells expressing M87 and M87o. TZM-bl, TZM-M87, and TZM-M87o were challenged with (A) different viruses carrying T-20-resistant (DTV, DIM, and GIA) and T-20-insensitive (X10, X23, and R14) and M87-resistant envelope proteins (NL/sel and BaL/sel) or (B) pseudotyped particles carrying envelope proteins with the point mutations indicated. In addition, PM1, PM1-M87, and PM1-M87o cells were challenged with pseudotyped particles carrying envelope proteins with the point mutations indicated (C). Forty-eight hours postinfection the cells were lysed and firefly luciferase activity (for A and B) and Renilla activity (for C) was determined. Luciferase activity obtained from TZM-bl and PM1 cells not expressing a membrane-anchored fusion inhibitor was set to 100%. Shown are the mean values of triplicate infections of a representative experiment.