FIG. 3.

Apoptosis exceeds by far the infection level in NL4-3-infected lymphoid cultures ex vivo. CD3⁺ T cells were isolated from human lymphoid cultures ex vivo infected for 7 days with 49-5 (B and E) or NL4-3 (C and F) or from uninfected controls (A and D). (A to C) Viral infection was determined by HIV-1 RNA in situ hybridization. Representative infected cells are indicated by arrows. (D to F) Apoptosis was determined in parallel samples by using the TUNEL assay. Apoptotic cells are characterized by brown staining, and representative apoptotic cells are indicated by arrows.