Liposomal α-galactosylceramide is taken up by gut-associated lymphoid tissue and stimulates local and systemic immune responses.

α-Galactosylceramide (α-GalCer), a synthetic glycosphingolipid that exhibits potent immunostimulatory effects through activation of natural killer T (NKT) cells, can be used to treat conditions such as atopy, cancer, infection and autoimmunity. Administration of therapeutics through the oral route has advantages such as patient convenience, safety and reduced cost; however, there has been little research to investigate whether oral delivery of α-GalCer is possible. The aim of this study was therefore to determine whether α-GalCer formulated in either DMSO/Tween 80 or in liposomes, could access lymphoid tissue and stimulate immune activation following oral administration. Fluorescently labelled cationic liposomes incorporating α-GalCer were prepared, characterized and administered by oral gavage to fasted mice. Liposomes were detected inside the Peyer's patches (PPs), in the subepithelial dome just under the follicle-associated epithelium. CD11b These results show that oral delivery of a liposomal α-GalCer can stimulate local and systemic immune responses to a different degree compared to the non-liposomal form.