Triggering of innate immune responses by schistosome egg glycolipids and their carbohydrate epitope

To investigate the interactions of glycoconjugates with the innate immune system, peripheral blood mononuclear cells were stimulated with glycolipids derived from Schistosoma mansoni eggs and worms and with biochemically synthesized neoglycoconjugates. Egg glycolipids stimu-lated the production of interleukin (IL) – 10, IL-6, and tumor necrosis factor–a in monocytes, whereas worm glycolipids failed to do so. When monoclonal antibodies that specifically recognize defined carbohydrate epitopes were used, the binding of a GalNAcb1-4(Fuca1-2Fuca1-3)GlcNAc (LDN-DF) reactive antibody was pronounced on egg glycolipids but was absent on worm glyco-lipids. The binding of antibodies that recognize Galb1-4(Fuca1-3)GlcNAc (LewisX), GalNAcb1-4GlcNAc (LDN), and GalNAcb1-4(Fuca1-3)GlcNAc (LDN-F) was comparable for both prepara-tions. Cytokine production in response to neoglycoconjugates containing enzymatically synthesized glycans also was measured. The LDN-DF neoglycoconjugate was the most potent cytokine inducer, which indicates that this difucosylated glycan can act at the host-parasite interface and can trigger in-nate immune responses. The development of an immune response to a pathogen re-quires that the cells of the immune system recognize the invader