Definition

A liposomal formulation of alpha galactosylceramide, a synthetic glycolipid isolated from the Okinawan marine sponge (Agelas mauritianus) with potential immunosuppressing activity. Upon administration, alpha galactosylceramide serves as a ligand for CD1d which is expressed on various antigen-presenting cells (APCs) including dendritic cells (DCs), macrophages, and B-cells. This induces the activation of the immunoregulatory invariant natural killer T cells (iNKTs), which induces the expansion of tolerogenic regulatory DCs and, in turn, regulatory T cells (Tregs). Tregs may specifically suppress T-cell responses against host alloantigens, thereby reducing graft rejection while maintaining normal immune cell function. CD1d is a non-polymorphic, major histocompatibility complex (MHC) class I-like antigen-presenting molecule with an antigen-binding groove adapted for the presentation of lipid antigens.