Nanoparticle Vaccines Adopting Virus-like Features for Enhanced Immune Potentiation

Chattopadhyay, Saborni; Chen, Jui-Yi; Chen, Hui-Wen; Hu, Che-Ming Jack

The lipid bilayered structure of liposomes is structurally analogous to enveloped viruses, which are formed from budding of infected cells and are wrapped in pieces of cell's plasma membrane. The inherent semblance to viral particles may help explain the innate adjuvanticity of liposomes upon incorporation with protein and peptide antigens [21] . Numerous antigen targets, ranging from toxoid, viral antigens, and bacterial antigens, have been observed to elicit enhanced humoral responses following liposomal incorporations [22] . Mechanistic studies have shed light on the liposomes' adjuvanticity. For instance, liposomes have been shown to be capable of modulating CD8+ T cell mediated immune responses [23] , reflecting facilitation of antigen processing via the classical MHC I and MHC II pathways. Liposomes have also been reported to promote the development of T cell-independent B cell immune responses [24] and have potential to promote long-term immunity through the development of T-cell memory [25] . In addition to their innate adjuvanticity, liposomes have been incorporated with a plethora of adjuvants ranging from small molecules [26, 27] , glycolipids [28] [29] [30] [31] , oligodeoxynucleotides [32] [33] [34] [35] , to cyclic dinucleotides [6, 36] .