FIG. 3.

Confocal microscopy analyses confirm that the most proximal events in the virus replicative cycle are more efficient after insertion of host ICAM-1 into HIV-1. PM1 cells (A) and purified CD4⁺ T lymphocytes (B) were exposed at 37°C for 45 and 90 min, respectively, to the virus preparations studied. Next, the cells were extensively washed, fixed, and labeled as described in Materials and Methods. (Left) Cells were left untreated (Mock) before being infected with HIV-1. (Right) Cells were pretreated with a blocking anti-LFA-1 antibody (MEM30) before being incubated with HIV-1.