Fig. 1.
(a) Bacille Calmette–Guérin (BCG) dose-dependent interferon (IFN)-γ production by human peripheral blood mononuclear cells (PBMCs). PBMCs were incubated with medium or five different doses of BCG ranging from 2·5 × 103 to 2·5 × 106 colony-forming units (CFU)/ml for 3 days and then assayed for IFN-γ production in the conditioned media. (b) The roles of endogenous T helper 1 (Th1) and Th2 cytokines in BCG-induced IFN-γ production by human PBMCs. PBMCs were incubated with 2·5 × 105 CFU/ml of BCG in the presence or absence of indicated cytokine-neutralizing antibodies (3 µg/ml) for 3 days and then assayed for IFN-γ production in the conditioned media. Species and isotype-matched control antibodies had no effect on IFN-γ production (data not shown). *Significantly decreased.