CD22 and Siglec-G regulate inhibition of B-cell signaling by sialic acid ligand binding and control B-cell tolerance

Language
en
Document Type
Article
Issue Date
2016-09-08
Issue Year
2014
Authors
Nitschke, Lars
Editor
Abstract

CD22 and Siglec-G are two B-cell expressed members of the Siglec (sialic acid-binding immunoglobulin (Ig)-like lectin) family and are potent inhibitors of B-cell signaling. Genetic approaches have provided evidence that this inhibition of B-cell antigen receptor (BCR) signaling by Siglecs is dependent on ligand binding to sialic acids in specific linkages. The cis-ligand-binding activity of CD22 leads to homo-oligomer formation, which are to a large extent found in membrane domains that are distinct from those containing the BCR. In contrast, Siglec-G is recruited via sialic acid binding to the BCR. This interaction of Siglec-G with mIgM leads to an inhibitory function that seems to be specific for B-1 cells. Both CD22 and Siglec-G control B-cell tolerance and loss of these proteins, its ligands or its inhibitory pathways can increase the susceptibility for autoimmune diseases. CD22 is a target protein both in B-cell leukemias and lymphomas, as well as in B-cell mediated autoimmune diseases. Both antibodies and synthetic chemically modified sialic acids are currently tested to target Siglecs on B cells.

Journal Title
Glycobiology
Volume
24
Issue
9
Citation
Glycobiology 24.9 (2014): S. 807-817. <http://glycob.oxfordjournals.org/content/24/9/807.abstract>
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