FIG. 2.

Dose-response curves for C3bc (a) and TCC (b) formation induced by whole BCG bacilli or M. tuberculosis sonicate (Mtson) or culture fluid (Mtcf). Dilutions of each agent in PBS were incubated with 75% pooled normal human plasma in heparin (HP) or EDTA (EP) (n = 5) for 1 h at 37°C under agitation and centrifuged, and C3bc and TCC levels were measured in the supernatants by ELISA. For experiments with BCG the concentrations 1, 10, and 100 μg/ml were instead 1.5, 15.0, and 150.0 μg of BCG/ml, respectively. The mean values for PBS controls in heparin- or EDTA-plasma were 37.6 or 10.1 AU of C3bc/ml and 6.8 or 1.4 AU of TCC/ml, respectively. Each data point represents the mean of triplicate experiments.