Siglecs as positive and negative regulators of the immune system.
Siglecs (sialic acid-binding Ig-like lectins) are mainly expressed in the immune system. Sn (sialoadhesin) (siglec-1), CD22 (siglec-2) and siglec-15 are well conserved, whereas the CD33-related siglecs are undergoing rapid evolution, as reflected in large differences in repertoires among the different mammals studied so far. In the present paper, we review recent findings on the signalling properties of the CD33-related siglecs and discuss the emergence of both inhibitory and activating forms of this family. We also discuss how Sn may function as a positive regulator of adaptive immune responses and its emerging role as an induced macrophage pattern-recognition molecule for sialylated pathogens, especially enveloped viruses.
Crocker
Paul R
PR
Division of Cell Biology and Immunology, Wellcome Trust Biocentre, University of Dundee, Dundee, UK. p.r.crocker@dundee.ac.uk
Redelinghuys
Pierre
P
D000818:Animals; D015703:Antigens, CD / Q000276:immunology; D015214:Antigens, Differentiation, Myelomonocytic / Q000276:immunology; D004705:Endocytosis; D006801:Humans; D007107:Immune System / Q000276:immunology*; D007155:Immunologic Factors / Q000276:immunology; D037102:Lectins / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000276:immunology; D011971:Receptors, Immunologic / Q000737:chemistry / Q000276:immunology; D063267:Sialic Acid Binding Ig-like Lectin 1; D063268:Sialic Acid Binding Ig-like Lectin 3; D063265:Sialic Acid Binding Immunoglobulin-like Lectins
D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; C571163:CD33 protein, human; D007155:Immunologic Factors; D037102:Lectins; D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic; C571166:SIGLEC1 protein, human; D063267:Sialic Acid Binding Ig-like Lectin 1; D063268:Sialic Acid Binding Ig-like Lectin 3; D063265:Sialic Acid Binding Immunoglobulin-like Lectins