원문정보
초록
영어
Through binding to free glycans or glycoconjugates, animal cell surface lectins are involved in a wide range of biological processes. It has been known that most animal lectins, including selectins, siglecs (sialic acid-binding immunoglobulin-type lectins), mannose receptors, mannose-6-phosphate receptors, asialoglycoprotein receptors and C-type lectins, act as signal transducers after binding to glycans although intracellular signaling events induced by lectins depend on the nature of glycans, cell type and/or species. In particular, cell-surface lectins in the immune system bind to glycans displayed on the exterior of pathogens and this recognition event stimulates the immune response. For example, mouse SIGN-R1 (SIGN-related 1), a homolog of human DC-SIGN (dendritic cell-specific ICAM-3-grabbing nonintegrin), is highly expressed on macrophages in the splenic marginal zone and the medullar lymph nodes. This lectin binds predominantly to mannose-rich or fucosylated glycans in a Ca2+-dependent manner. Once glycans on bacterial cells or viruses interact with SIGN-R1, glycan antigens elicit SIGN-R1 mediated immune activation. To investigate immune activation by lectin mediated endocytosis, we conducted a traditional cell assay to probe six glycan-bovine serum albumin (BSA) conjugates (BSA-Man, BSA-Fuc, BSA-GlcNAc, BSA-Gal, BSA-Mana1,2Man and BSA-Lex) and S. cerevisiae mannan for their abilities to stimulate ROS generation. The results show that incubation with mannan and all of the glycoconjugates except BSA-Gal leads to increases in the intensities of fluorescence signals from cells compared to the untreated control.