Figure 6.

Representative histologic sections of inguinal lymph node collected from patient 2 by excisional biopsy 4 days after the second infusion of neo-modified HIV-specific CTL. Serial sections were analyzed for sites of localization of neo-modified CD8⁺ CTL (PCR-ISH) (a), cells expressing granzyme-B (anti-GrB mAb) (b), cells expressing HIV tat fusion transcripts (RT-PCR-ISH) (c), cells expressing the CC-chemokine MIP-1β (anti-human MIP-1β mAb) (d), and cells showing DNA fragmentation (TUNEL “apoptosis” assay) (e). Dual stains were used to identify the proportion of CD4⁺ (anti-CD4 mAb + TUNEL) (f; inset shows higher magnification of dual-stained cells [arrows]) and CD8⁺ (anti-CD8 mAb + TUNEL) (g) T lymphocytes demonstrating apoptosis. The HIV-specific CTL expressed the cell surface receptors CD8 and CCR5 and could be stimulated to express granzyme-B before their infusion (h: anti-CD8 mAb (left), anti-CCR5 mAb (middle), anti-GrB mAb (right). Antibody labels were detected by immunoperoxidase staining with DAB as the chromogen and apoptotic cells detected by TUNEL, followed by anti-DIG mAb, and developed with BCIP/NBT. f, follicular germinal centers. Bar, 100 μm.