title: C-type lectins: their network and roles in pathogen recognition and immunity.
abstract: C-type lectins (CTLs) represent the most complex family of animal/human lectins that comprises 17 different groups. During evolution, CTLs have developed by diversification to cover a broad range of glycan ligands. However, ligand binding by CTLs is not necessarily restricted to glycans as some CTLs also bind to proteins, lipids, inorganic molecules, or ice crystals. CTLs share a common fold that harbors a Ca2+for contact to the sugar and about 18 invariant residues in a phylogenetically conserved pattern. In vertebrates, CTLs have numerous functions, including serum glycoprotein homeostasis, pathogen sensing, and the initiation of immune responses. Myeloid CTLs in innate immunity are mainly expressed by antigen-presenting cells and play a prominent role in the recognition of a variety of pathogens such as fungi, bacteria, viruses, and parasites. However, myeloid CTLs such as the macrophage inducible CTL (Mincle) or Clec-9a may also bind to self-antigens and thus contribute to immune homeostasis. While some CTLs induce pro-inflammatory responses and thereby lead to activation of adaptive immune responses, other CTLs act as inhibitory receptors and dampen cellular functions. Since CTLs are key players in pathogen recognition and innate immunity, targeting CTLs may be a promising strategy for cell-specific delivery of drugs or vaccine antigens and to modulate immune responses.
authors.affiliation: Immunology Unit and Research Center for Emerging Infections and Zoonoses, University of Veterinary Medicine, Bünteweg 17, 30559, Hannover, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Mayer
authors.affiliation: Immunology Unit and Research Center for Emerging Infections and Zoonoses, University of Veterinary Medicine, Bünteweg 17, 30559, Hannover, Germany.|Institute for Parasitology, Center for Infection Medicine, University of Veterinary Medicine, Hannover, Germany.
authors.forename: Marie-Kristin
authors.initials: MK
authors.lastname: Raulf
authors.affiliation: Immunology Unit and Research Center for Emerging Infections and Zoonoses, University of Veterinary Medicine, Bünteweg 17, 30559, Hannover, Germany. bernd.lepenies@tiho-hannover.de.
authors.forename: Bernd
authors.initials: B
authors.lastname: Lepenies
mesh_terms: D000818:Animals; D006706:Homeostasis; D054884:Host-Pathogen Interactions / Q000276:immunology*; D006801:Humans; D007113:Immunity, Innate; D037181:Lectins, C-Type / Q000737:chemistry / Q000276:immunology*; D011134:Polysaccharides / Q000737:chemistry
chemical_list: D037181:Lectins, C-Type; D011134:Polysaccharides
keywords: Antigen-presenting cell; C-type lectins; Carbohydrates; ITAM; ITIM; Innate immunity; Targeting