Adding SE or SE-P directly to target cells results in reduced metabolic activity and HIV infection rates. (A) Schematic outline of the experiment. TZM-bl cells were incubated with different dilutions of SE or SE-P and subsequently infected with HIV-1. (B) Infection rates and (C) metabolic activities were determined after 1 (upper panel) or 3 days (lower panel). (D) Correlation between Tat-driven reporter activities ("infection") and the metabolic activities of the target cells. Values were derived from the experiments shown in panels B and C, and are shown relative to those obtained in the absence of SE or SE-P (100%).