Production of IFN-γ by T cells in the presence of TNF-–activated ECs and IL-15. PBLs were cultured alone (BSA) or on TNF-–activated ECs (TNF-EC) in the presence or absence of IL-15 (25 ng/mL) and/or anti–ICAM-1. After 48 hours of culture the expression of CD69 and intracellular IFN-γ was measured in T cells. A representative experiment out of four is shown.