Immunologic Presentation of Liposomal Antigens

Abstract

Based on the observation that phagocytosed liposomal antigen readily escapes from endosomes into the cytoplasm of macrophages, it is proposed that liposomal peptide antigen can enter either the Golgi apparatus or the endoplasmic reticulum and thereby interact with MHC class II or MHC class I molecules. This understanding of the intracellular cytoplasmic trafficking patterns of liposomal antigen validates the concept of using liposomes as vehicles for induction of cytotoxic T lymphocytes (CTLs). The proposed immunologic mechanisms are consistent with observations of experimental induction of CTLs by liposomal antigens in numerous laboratories. It is anticipated that induction of both humoral immunity and CTLs will enhance the usefulness of liposomes as vehicles for synthetic vaccines against both intracellular and extracellular antigens.