The vaccine adjuvant alum inhibits IL-12 by promoting PI3 kinase signaling while chitosan does not inhibit IL-12 and enhances Th1 and Th17 responses
European Journal of Immunology, 07/11/2012
Mori A et al. – A combination of chitosan and the TLR9 agonist CpG activated the NLRP3 inflammasome and enhanced secretion of IL–12 and the other key Th1 and Th17–cell polarizing cytokines. When used as an adjuvant, CpG–chitosan induced NLRP3–dependent antigen–specific Th1 and Th17 responses. A combination of alum and CpG also enhanced Th1 and Th17 responses but was less effective than CpG–chitosan. Therefore, chitosan is an attractive alternative to alum in adjuvants for vaccines where potent cell–mediated immunity is required.