FIG. 2.

Nef-induced apoptosis as a function of time. (A) Jurkat cell cultures were either untreated (▪) or exposed to soluble HIV-1 Nef (□) for various times. Cells were then harvested, assayed for apoptosis by TUNEL, and analyzed by fluorescence microscopy. Data from two experiments performed in triplicate with six individually treated cell sets were pooled to generate average values and were used to determine standard errors. (B) Jurkat cell cultures were exposed to 100 ng of Nef/ml of medium for 12, 24, and 36 h and subsequently harvested and assayed by TUNEL. Images were taken via fluorescence microscopy and arranged via Adobe Photoshop software (version 5.0.2; Adobe Systems). Subpanels A, C, and E represent untreated Jurkat cell cultures at 12, 24, and 36 h, respectively, after initial medium replenishment. Subpanels B, D, and F depict Jurkat cell cultures after 12, 24, and 36 h exposure to soluble Nef protein (100 ng/ml). Magnification, ×280. The image was formatted using Adobe Photoshop 5.0.2 software.