The influence of adjuvant on humoral responses to glutathione-S-transferase fusion proteins.

Mice were immunized with one of two Schistosoma mansoni antigens, Sm20 and Sm50, expressed as fusion proteins with Schistosoma japonicum 26,000 Dalton glutathione-S-transferase (GST) or with GST alone. Antibody responses to GST were shown to be critically dependent on the adjuvant used. In Sm20-GST immunized mice, we noted a striking bias to respond either to Sm20 or to GST according to the adjuvant used and responses to both in the same individual were rare. Fusion with Sm50, which is relatively non-immunogenic, appeared to down-regulate responses to GST.