Dose-effect of TNF-α and IL-7 on the kinetics of apoptosis and viral production in SP CD4+ thymocytes.
Cells were isolated as described in “Materials and methods,” infected with a primary isolate HIV-1B-LAIp, and maintained in culture in the presence of IL-1 (10 ng/mL), IL-6 (10 ng/mL), IL-7, and TNF-α. In panels A and B, cells were exposed to 2 different concentrations of TNF-α (0.1 or 1 ng/mL) in the presence of a constant concentration of IL-7 (5 ng/mL) (left panels), or they were exposed to 2 different concentrations of IL-7 (0.5 and 5 ng/mL) in the presence of a constant concentration of TNF-α (1 ng/mL) (right panels). Percentage of apoptotic cells was determined by the Yopro dye technique (A), and viral production was evaluated by p24 titration (B). The experiment presented here is representative of independent experiments carried out with thymuses from 3 different donors.
