A J774A.1 macrophages were treated with an increasing concentration of FK506 and stimulated with AF SC (MOI = 1), zymosan (50 μg/ml) or LPS (25 ng/ml) overnight. TNF-α was measured in the culture supernatant by ELISA. FK506 significantly reduced TNF-α levels at 5 and 10 ng/ml for AF. A significant reduction in TNF-α was also seen for zymosan, but not LPS. 