Figure 3.

Costimulatory effect of immobilized Tat on CD4⁺ T cell proliferation (A) and Tat peptides on IL-2 production and cell proliferation (B and C). Primary CD4⁺ T cells were seeded in wells coated with dilution buffer (BSA), anti-CD3, anti-CD3/CD28, anti-CD3/CD28 + Tat, or anti-CD3/CD28 + Tat peptides (Pept. 1–5). In A and C, [³H]thymidine incorporation was measured by liquid scintillation, and results are expressed as arithmetic mean cpm of triplicate cultures. The results represent the means ± SD of 4–6 separate experiments, performed in duplicate. In B, the amount of IL-2 was evaluated after 16 h in the culture supernatant of cultures seeded on wells coated as indicated. Data are expressed as means ± SD of five separate experiments performed in triplicate.