Mature activated DCs serve as a link between the innate and adaptive arms of the immune system, and this process can be facilitated by several bacterial components (9, 10). Of these bacterial products, killed Bordetella pertussis is a potent adjuvant ), and its components including B. pertussis toxin (PT) and B. pertussis endotoxin (LPS) have been shown to block or reverse carrier-mediated hapten suppression (12, 13). Specifically, PT stimulates DCs toup-regulate MHC class II and costimulatory molecules [cluster ofdifferentiation (CD)80, CD86, CD40, and dendritic and epithelial cell (DEC)205]to produce IL-12 and TNF-α and to up-regulate phosphorylation of ERK (14). Thisoverall DC activation by PT elicits a Th1 response by promoting T cells toproduce IFN-γ. Bacterial DNA containing unmethy[1]lated CpG-dinucleotide isalso a strong adjuvant for Th1 re[1]sponseand cytotoxic T-cell responses. Similar to PT, the effect of CpG inpromoting Th1-like immune responses (17, 18) is a result of DC maturationleading to up-regulation of MHC class II, B7, and CD40 molecules on the DCsurface and pro[1]ductionof IL-12, IL-6, and TNF-α (19). Therefore, the mecha[1]nism of action for bothadjuvants is attributed to potent acti[1]vationof DCs.

NE similarly enhances innate immunity byrecruiting DCs to the site of injection and by promoting cytokine production(20, 21).

细菌鞭毛蛋白是吸入式疫苗很好的佐剂，因为针对鞭毛蛋白的受体在上呼吸道多。所以要考虑佐剂对应什么受体，什么细胞有这些受体，还要考虑哪些器官组织分布拥有这些受体的细胞。