Skip to main content

Table 2 Proposed mechanisms of adjuvant activity of major adjuvant components

From: Immune mechanisms of protection: can adjuvants rise to the challenge?

Adjuvant Composition Adjuvant activity Mechanism of adjuvant action References
Aluminum salts AlOH or AlPO4 non-crystalline gels Antibody and TH2 cells ↑ Chemokine/cytokine production; ↑ recruitment of monocytes and differentiation to DC; ↑ antigen uptake by DC [31, 34, 46, 106, 107]
MF59 Oil (squalene)-in-water emulsion ↑ Ab titre; ↑ Ab cross-reactivity; drives TH2 cells ↑ Chemokine/cytokine production; recruitment of myeloid DCs to injection site; ↑ antigen uptake by DCs [34, 108110]
TLR ligands MPL, GpG, imiquimod, resiquimod (both imidazoquinolinamines) or poly(I:C) Drives TH1 and CTL cells; ↑ T cell memory TLR signaling in DCs promotes antigen presentation on MHC I and MHC II, enhanced migration of DCs to lymph nodes and DCs cytokine production; may have direct impacts on lymphocytes [111]
QS21 Purified fraction of Quil A that has lower toxicity and retains adjuvant effects Antibody, TH1 and CTL responses Enhances protective responses through poorly understood mechanisms; has lytic capacity and local reactogenicity [97]
  1. Abbreviations: Ab, antibody; CTL, cytotoxic T lymphocyte; MPL, monophosphoryl lipid A; poly(I:C), a synthetic analog of double-stranded RNA; Th, T helper cell; TLR, Toll-like receptor.