Cutting edge: inflammasome activation by alum and alum's adjuvant effect are mediated by NLRP3.
Alum is the only adjuvant approved for routine use in humans, although the basis for its adjuvanticity remains poorly understood. We have recently shown that alum activates caspase-1 and induces secretion of mature IL-1beta and IL-18. In this study we show that, in human and mouse macrophages, alum-induced secretion of IL-1beta, IL-18, and IL-33 is mediated by the NLR (nucleotide-binding domain leucine-rich repeat-containing) protein NLRP3 and its adaptor ASC, but not by NLRC4. Other particulate adjuvants, such as QuilA and chitosan, induce inflammasome activation in a NLRP3-dependent fashion, suggesting that activation of the NLRP3-inflammasome may be a common mechanism of action of particulate adjuvants. Importantly, we demonstrate that Ag-specific Ab production elicited by vaccines that contain alum is significantly impaired in NLRP3-deficient mice. Our results demonstrate for the first time a role for the NLRP3-inflammasome during development of the immune response elicited by alum-enhanced vaccination and suggest that therapeutic intervention aimed at NLRP3 may improve adjuvant efficacy.
Li
Hanfen
H
Department Molecular Sciences, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
Willingham
Stephen B
SB
Ting
Jenny P-Y
JP
Re
Fabio
F
D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D017607:Aluminum Compounds / Q000494:pharmacology*; D000536:Aluminum Hydroxide / Q000494:pharmacology*; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D002460:Cell Line; D002478:Cells, Cultured; D006801:Humans; D007107:Immune System / Q000187:drug effects / Q000276:immunology; D007249:Inflammation / Q000276:immunology; D051379:Mice; D018345:Mice, Knockout; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein; D010710:Phosphates / Q000494:pharmacology*; D034622:RNA Interference
D000276:Adjuvants, Immunologic; D017607:Aluminum Compounds; D002352:Carrier Proteins; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein; C492716:Nlrp3 protein, mouse; D010710:Phosphates; D000536:Aluminum Hydroxide; C012714:aluminum phosphate