Lactosylceramide (CDw17) (LacCer)

Lactosylceramide (LacCer), also designated as CDw17 or CD17, is a bioactive glycosphingolipid that functions as a critical pattern recognition receptor (PRR) on the plasma membrane of human cells, particularly neutrophils and endothelial cells [2, 11]. It is composed of a ceramide backbone linked to a lactose moiety and serves as a central intermediate in the biosynthesis of complex glycosphingolipids like gangliosides [3, 16]. LacCer is uniquely organized into specialized membrane microdomains, or lipid rafts, where it physically associates with signaling proteins such as the Src-family tyrosine kinase Lyn and inhibitory G-protein alpha subunits (Gai) [10, 15]. Upon binding to pathogen-associated molecular patterns (PAMPs), such as fungal beta-glucans or bacterial components, LacCer initiates an outside-in signaling cascade that activates NADPH oxidase, leading to the generation of reactive oxygen species (ROS) and the induction of inflammatory responses, chemotaxis, and phagocytosis [11, 15]. Beyond its role in innate immunity, LacCer is a potent signaling molecule involved in cell proliferation, angiogenesis, and apoptosis [6, 9]. Dysregulation of LacCer metabolism and signaling is strongly linked to the progression of atherosclerosis, cancer metastasis, and neuroinflammatory conditions, making its metabolic pathways and signaling platforms significant targets for therapeutic intervention [1, 4, 7].

Other names

CD17CDw17Cytolipin HGalactosylglucosylceramideGal-Glc-CerLactosyl-beta-1,1-ceramide

Lactosylceramide functions as a pattern recognition receptor (PRR) that binds pathogen-associated molecular patterns (PAMPs) like beta-glucans. Upon ligand binding, it clusters into lipid rafts and activates the Src-family kinase Lyn, which triggers a signaling cascade involving PI3K, p38 MAPK, and PKC, ultimately leading to NADPH oxidase activation and reactive oxygen species (ROS) generation [11, 15].