QS-21 是一种免疫刺激型皂甙，可作为有效的疫苗佐剂。QS-21 通过作用于抗原呈递细胞 (APC) 和 T 细胞，刺激 Th2 体液和 Th1 细胞介导的免疫反应。QS-21 可以激活 NLRP3 炎性小体，释放 caspase-1 依赖性细胞因子 IL-1β 和 IL-18。 应用： 在体外，QS-21（2.5, 5, 25μM）处理HUVEC、PBMC细胞24 h，显著降低了细胞存活率，这种细胞毒性作用在HUVEC细胞中更为明显。QS-21（0-50μM）处理两种人胃癌细胞系（SNU 1和KATO III）和人正常细胞系（GES-1）24h，以剂量依赖性方式对KATO III和SNU 1细胞产生毒性作用，IC50 值分别为67µM和13.6µM，但是对GES-1细胞几乎没有细胞毒性。 在体内，使用QS-21佐剂配制的Aβ42对小鼠进行免疫加强，产生的抗体效价最高，随后是CFA/IFA >明矾> TMG。 QS-21, an immunostimulatory saponin, could be used as a potent vaccine adjuvant. QS-21 stimulates Th2 humoral and Th1 cell-mediated immune responses through action on antigen presenting cells (APCs) and T cells. QS-21 can activate the NLRP3 inflammasome with subsequent release of caspase-1 dependent cytokines, IL-1β and IL-18. Application： In vitro, QS-21 (2.5, 5, 25 μM) treatment of HUVEC and PBMC cells for 24 hours significantly reduced cell viability, with this cytotoxic effect being more pronounced in HUVEC cells[4]. QS-21 (0-50 μM) treatment of two human gastric cancer cell lines (SNU 1 and KATO III) and a normal human cell line (GES-1) for 24 hours resulted in dose-dependent toxicity in KATO III and SNU 1 cells, with IC50 values of 67μM and 13.6μM, respectively, but showed almost no cytotoxicity to GES-1 cells. In vivo, immunization of mice with Aβ42 formulated with QS-21 adjuvant produced the highest antibody titers, followed by CFA/IFA > alum > TMG.