Fig. 2.

S. mansoni infection impairs proliferative responses to PPD and concanavalin A. Splenic lymphocytes isolated from S. mansoni infected mice and uninfected controls were cultured in the presence of PPD or concanavalin A. The cultures were pulse labelled with tritiated thymidine at day 3 for con A stimulated cultures and day 5 for PPD stimulated cultures and were harvested 18 h after pulse labelling. The results were expressed as stimulation indices (mean count per minute in stimulated cultures/mean count per minute in unstimulated cultures). In this representative experiment 10 animals were used in each group. (a) show responses to PPD and (b) show responses to ConA *P < 0·05, **P < 0·01. This experiment was repeated twice with consistent results.