Fig. 5

Transient Env accumulation at sites of cell–cell contact. Time-lapse live confocal fluorescence images of Env-isfGFP-∆V1V2 expressing cells were acquired at 10-min intervals from 5 h post transfection for 30 h. a A target cell contacting an Env-expressing donor cell at t = 0 min. At 0 min, no Env accumulation was observed at contact area (empty arrow). At t = 10 min, there was some accumulation of Env and at t = 50 min, a visible accumulation of Env was noted. An arrow in each panel highlights the same contact site. Bar = 5 μm. b Transient Env accumulation observed in some of the 45 prolonged contact events between infected and uninfected cells. Different colors show different localization of Env during cell contacts. The interval between the initiation of cell and Env accumulation occur is shown as a green line. c When Env accumulation was observed (green line in b), the cells were counted according to the duration of the contact time before env accumulation. d When Env accumulation was observed, cells were counted according to the duration of visible Env accumulation