Design, characterization and preclinical efficacy of a cationic lipid adjuvant for influenza split vaccine

Cationic cage-like complexes formed by DC-cholesterol, Quil-A, and phospholipid

“…In this sample, vesicular uni-or multilamellar colloidal structures of various size (from about 50 nm up to 1 mm) and shape were observed by TEM (Figure 3). This is in agreement with findings of Guy et al 27 Binary Mixtures DC-CHOL:PC and DC-CHOL:Quil-A…”

“…26 DC-CHOL, however, has been reported to form liposomes by itself without additional colipid. 27 Indeed we observed vesicles of varying size in the pure DC-CHOL sample and in formulations containing only small amounts of Quil-A or PC. As a result, PC becomes redundant during the solubilisation of DC-CHOL into liposomes as potential precursor structure.…”

Selection of Adjuvants for Enhanced Vaccine Potency

“…Cationic lipid vesicles (comprising a cationic cholesterol derivative, DC-Chol) bind strongly split influenza vaccine antigens and induced robust anti-influenza immune responses while neutral cholesterol/DOPC liposomes displayed virtually no stable antigen binding and no adjuvant effect in mice [187]. Replacing the polyalkylamine head group spermine with spermidine (with one less secondary amine) in a polycationic liposome reduced the enhancement of the immune response to a flu vaccine by ~50% in mice [177].…”

Liposome–nucleic acid immunotherapeutics

“…In part, this increased effectiveness is a result of greater interaction of cationic liposomes with DC than occurs when neutral or anionic liposomes are used (79,80). In addition, the composition of the neutral or helper lipid incorporated with the cationic liposome also influences vaccine efficacy (81). Targeting of liposomes to DC, by for example addition of mannose groups to the liposomal membrane, can also improve vaccine efficacy (82).…”