QS-21 structure/function studies: effect of acylation on adjuvant activity

QS-21 is a natural saponin adjuvant derived from the tree Quillaia saponaria Molina. Previous studies over a limited dose range suggested the acylation is critical to adjuvant activity. In this study, we prepared DS-1 (deacylated QS-21) and RDS-1 (reacylated DS-1 with dodecylamine at a different site than QS-21) to determine the effect on a dose-response curve over a wider range in mice. DS-1 and RDS-1 induced IgG1 responses at higher doses compared to that induced by QS-21. DS-1 was inactive for inducing IgG2a or CTL responses at any doses. RDS-1 showed moderate IgG2a response at 240 mug, but did not show CTL response at any dose evaluated. (C) 2002 Elsevier Science Ltd. All rights reserved.