CD22 mediated BCR regulation

Stable Identifier
R-HSA-5690714
Type
Pathway
Species
Homo sapiens
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BCR activation is highly regulated and coreceptors like CD22 (SIGLEC2) set a signalling threshold to prevent aberrant immune response and autoimmune disease (Cyster et al. 1997, Han et al. 2005). CD22 is a glycoprotein found on the surface of B cells during restricted stages of development. CD22 is a member of the receptors of the sialic acid-binding Ig-like lectin (Siglec) family which binds specifically to the terminal sequence N-acetylneuraminic acid alpha(2-6) galactose (NeuAc-alpha(2-6)-Gal) present on many B-cell glycoproteins (Powell et al. 1993, Sgroi et al. 1993). CD22 has seven immunoglobulin (Ig)-like extracellular domains and a cytoplasmic tail containing six tyrosines, three of which belong to the inhibitory immunoreceptor tyrosine-based inhibition motifs (ITIMs) sequences. Upon BCR cross-linking CD22 is rapidly tyrosine phosphorylated by the tyrosine kinase Lyn, thereby recruiting and activating tyrosine phosphatase, SHP-1 and inhibiting calcium signalling.

Literature References
PubMed ID Title Journal Year
22566885 Regulation of B cell functions by the sialic acid-binding receptors siglec-G and CD22

Jellusova, J, Nitschke, L

Front Immunol 2011
15378059 CD22 regulates B lymphocyte function in vivo through both ligand-dependent and ligand-independent mechanisms

Poe, JC, Fujimoto, Y, Hasegawa, M, Haas, KM, Miller, AS, Sanford, IG, Bock, CB, Fujimoto, M, Tedder, TF

Nat. Immunol. 2004
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