Differential Expression of Interleukin-2 and Gamma Interferon in Human Immunodeficiency Virus Disease

Differential production of IL-2 and IFN-γ in CD69⁺ cells. Whole blood was incubated with SEB (Sigma) (5 μg/ml) for 2 h before Golgi-stop reagent (BD Pharmingen) containing brefeldin A was added. Cells were incubated for an additional 3 h, at which time the cells were treated with Facs lyse solution (Becton Dickinson) and frozen at −86°C overnight. Frozen cells were thawed and treated with Facs permeabilizing solution (Becton Dickinson) and then stained with anti-CD69 phycoerythrin-conjugated antibody, anti-CD4 peridinin chlorophyll protein-conjugated antibody, and either anti-IL-2 or anti-IFN-γ fluorescein isothiocyanate-conjugated antibody (Becton Dickinson). Cells stained with isotype control antibodies were used to establish quadrants. Unstimulated cells in this case were exposed to anti-CD28 antibody (1 μg/ml) to control for additional experiments in which cells were stimulated with SEB plus anti-CD28 antibody (data not shown). The numbers shown indicate the percentages of CD69⁺ cells that were IL-2 positive following SEB stimulation.