Anti-CD4/CXCR4 bead pre-stimulation abolishes genistein inhibition of HIV infection of resting CD4 T cells. (A and B) Purified resting CD4 T cells were cultured in medium overnight (A) or pre-stimulated with anti-CD4/CXCR4 magnetic beads (2 beads per cell) overnight (B), and then treated with genistein (10 μM) for 1 hour. Cells were infected with HIV-1NL4-3 for 2 hours, washed, incubated for 5 days in the absence of genistein, and then activated by anti-CD3/CD28 magnetic beads (2 beads per cell). Viral replication was measured by p24 release into the supernatant. (C) Viral replication measured at day 8 post infection. (D) The full viral replication course in cells pre-stimulated with anti-CD4/CXCR4 beads. (E and F) A repeat of the experiment in another donor. Viral replication at day 10 and 11 is shown.