FIG. 6.

Native virally expressed gp46 competes with SU-Fc for binding to T cells. Jurkat cells were incubated with 1 ml of unconditioned fresh medium (Control) or 1 ml of concentrated MolT 4 conditioned medium supernatants lacking Vgp46 (No Env) or with 1 or 0.5 ml of concentrated MT-2 medium supernatants containing 0.4 μg of viral gp46 (Vgp46) per ml. Cells were also incubated with 1 ml of concentrated MT-2 medium supernatants from which the Vgp46 had been depleted by passage over an anti-gp46 affinity column (Depl.) or with 1 ml of fresh medium containing 1 μg of recombinant gp120 (gp120) per ml or 1 μg of purified irrelevant human IgG (IgG) per ml. Subsequently, 0.5 μg of SU-Fc was added to each sample, and bound SU-Fc was detected by flow cytometry. The basal mean fluorescence of control cells incubated in the absence of SU-Fc was subtracted from the data presented. Assays were performed in triplicate, and the mean fluorescence and standard deviation are shown.