qs 21

QS-21, an immunostimulatory saponin, is a powerful vaccine adjuvant that stimulates both Th2 humoral and Th1 cell-mediated immune responses by interacting with antigen presenting cells (APCs) and T cells. Additionally, QS-21 activates the NLRP3 inflammasome, leading to the release of cytokines IL-1β and IL-18, which are dependent on caspase-1.