title: Multifarious roles of sialic acids in immunity.
abstract: Sialic acids are a diverse family of monosaccharides widely expressed on all cell surfaces of vertebrates and so-called "higher" invertebrates, and on certain bacteria that interact with vertebrates. This overview surveys examples of biological roles of sialic acids in immunity, with emphasis on an evolutionary perspective. Given the breadth of the subject, the treatment of individual topics is brief. Subjects discussed include biophysical effects regulation of factor H; modulation of leukocyte trafficking via selectins; Siglecs in immune cell activation; sialic acids as ligands for microbes; impact of microbial and endogenous sialidases on immune cell responses; pathogen molecular mimicry of host sialic acids; Siglec recognition of sialylated pathogens; bacteriophage recognition of microbial sialic acids; polysialic acid modulation of immune cells; sialic acids as pathogen decoys or biological masks; modulation of immunity by sialic acid O-acetylation; sialic acids as antigens and xeno-autoantigens; antisialoglycan antibodies in reproductive incompatibility; and sialic-acid-based blood groups.
authors.affiliation: Glycobiology Research and Training Center, Department of Medicine, University of California at San Diego, La Jolla, 92093-0687, USA. a1varki@ucsd.edu
authors.forename: Ajit
authors.initials: A
authors.lastname: Varki
authors.forename: Pascal
authors.initials: P
authors.lastname: Gagneux
mesh_terms: D000818:Animals; D055592:Biophysical Phenomena; D054884:Host-Pathogen Interactions / Q000276:immunology; D006801:Humans; D007113:Immunity, Innate; D037102:Lectins / Q000276:immunology; D007962:Leukocytes / Q000276:immunology; D008024:Ligands; D008827:Microbiological Phenomena; D018448:Models, Immunological; D018716:Molecular Mimicry / Q000276:immunology; D009439:Neuraminidase / Q000276:immunology; D019087:Selectins / Q000737:chemistry / Q000276:immunology; D063265:Sialic Acid Binding Immunoglobulin-like Lectins; D012794:Sialic Acids / Q000737:chemistry / Q000276:immunology*
chemical_list: D037102:Lectins; D008024:Ligands; D019087:Selectins; D063265:Sialic Acid Binding Immunoglobulin-like Lectins; D012794:Sialic Acids; D009439:Neuraminidase