Effects of loop deletions with or without the CT deletion on JRFL gp160 cell surface display, virus assembly, and subsequent virus entry.

Cell surface displayed Env proteins were measured by flow cytometry. Mean values are shown and cell surface displayed Env proteins relative to the WT are calculated as a percentage. The amount of assembled pseudovirus in culture supernatant was measured by capture ELISA. Three-fold serially diluted culture supernatants with a starting volume of 50 µl were tested in luciferase assay. Relative pseudovirus entry was defined as a percentage of luminescence reading (response units, RU) of each mutant virus relative to the WT when same amount of assembled pseudovirus was used. In this case, the same amount of pseudovirus gave OD405nm of 0.95 in the capture ELISA (Fig. 2C). NT: not tested.