FIG. 4.

Kinetics of susceptibility of TCR-stimulated PBMCs to infection with ICAM-1/NEG and ICAM-1/POS HXB-Luc particles. PBMCs that had previously been treated for 72 h with PHA-P were incubated with cross-linked OKT3 antibodies for various times prior to infection with ICAM-1/NEG or ICAM-1/POS HXB-Luc viruses previously treated or not treated with ICAM-1-blocking antibody RR1/1.1.1. Cells were lysed 72 h later, and infection was evaluated by measuring the luciferase activity in the lysates. The results shown are means ± standard deviations of triplicate samples and are representative of two independent experiments. The fold increase over infection with ICAM-1-negative virus particles is indicated for each experimental condition. Luciferase activity in mock-infected PBMCs was less than 21 × 10³ cpm.